Enzymatic Sialylation of IgA1 O-Glycans Implications for

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非酒精性脂肪性肝病代谢组学研究进展

非酒精性脂肪性肝病代谢组学研究进展

机制尚未完全明确,1998 年Day 等[12]提出“二次打击”学说。 开。同时NAFLD 肝硬化患者与酒精性肝硬化患者也可有效区
随后Tilg 等[13 -14]提出“多重平行打击”理论,包括遗传因素、 分开(AUC =0. 83)。他们认为此方法可作为区分NAFLD 纤维
IR、氧化应激、脂毒性、慢性炎症、纤维化、免疫和肠道菌群等, 化程度及诊断的无创生物标志物,且可以显著减少对肝活检的
黄酯和13 - cisRA 呈正相关。他们在人类组织中首次检测到 验证;单不饱和TAG 的增加可能是NAFLD 和CHB 患者NASH
atRA 的活性代谢物4 - oxo - atRA,表明这种类维生素A 可能 的特异性标志物。
有助于人体类维生素A 的信号传导。肝脏维生素A 的稳态平 2. 3 代谢组学对NAFLD 药物作用与疗效研究的推动作用
录组学、蛋白质组学为代表的系统生物学技术提供了新的技术 展的新学科,代谢组学较为全面的展示了机体的代谢结果,为
与思路。区别于其他组学技术,以内源性小分子代谢物为研究 临床医学提供了新的技术和方法。
对象的代谢组学可以很好的揭示机体变化的最终代谢结果。因 2 非酒精性脂肪性肝病(NAFLD)
收 基 作DO稿 金 者I:日 项 简10期 目 介. 3:::912上 栾研6709)2海究雨/0j.中婷-is医1s(n1药.1-19大090006学1—;修-附)5回,属2女5日第6,.期七主20:人2要210民.2从00医4事-.院01慢42人7-性才1肝7培病养计的划基(础XX与20临19床- 通信作者:顼志兵,xzb6160@ 163. com
和遗传易感密切相关的代谢应激性肝损伤,包括非酒精性单纯 1 代谢组学概述
性肝脂肪变(NAFL)、非酒精性脂肪性肝炎(NASH)、肝硬化和 1. 1 代谢组学含义 代谢组学最初于1999 年由Nicholson

清益宁络方对IgA肾病小鼠氧自由基的影响

清益宁络方对IgA肾病小鼠氧自由基的影响

万方数据
生国医堑垫!!生!旦笠!鱼鲞笠!塑垦!i堕丛!i塑堕:垒!鲤坠垫!!:!!!:!!:盟!:! QYNLD can improve the hematuria and proteinuria,reduce the kidney damage,in— SOD activity and reduce the MDA level in the kidney in IgA nephropathy,which may be related to the function of antioxidant.
changes were
(MDA)in the kidney
tissuewere
after treatment,the numbers of mice with hematuria and proteinuria in TG group,QYNLD low dose group and high dose group were all less than those in model group[hematuria:3,2,3 vs 8,proteinuria:3,2,2 vs 8,all P<
high dose group(P> higher in model group those
[(125±28)kU/L vs(169±17)kU/L,(20.2.4-3.2)¨moL/L vs(14.8±2.4)斗moL/L,P<0.01]than
blank group:the SOD activity was significantly increased and the MDA 1evel was significantly reduced in TG, QYNLD low dose and QYNLD high ose group[(149±30),(148±16),(162±38)kU/L,(16.5±2.7),

《临床肝胆病杂志》推荐使用的规范医学名词术语

《临床肝胆病杂志》推荐使用的规范医学名词术语

临床肝胆病杂志第40卷第3期2024年3月J Clin Hepatol, Vol.40 No.3, Mar.2024[3]XIA SL, LIU ZM, CAI JR, et al. Liver fibrosis therapy based on biomi⁃metic nanoparticles which deplete activated hepatic stellate cells[J]. J Control Release, 2023, 355: 54-67. DOI: 10.1016/j.jconrel.2023.01.052.[4]LIU YW, DONG YT, WU XJ, et al. The assessment of mesenchymalstem cells therapy in acute on chronic liver failure and chronic liver disease: A systematic review and meta-analysis of randomized con⁃trolled clinical trials[J]. Stem Cell Res Ther, 2022, 13(1): 204. DOI:10.1186/s13287-022-02882-4.[5]ZHANG ZL, SHANG J, YANG QY, et al. Exosomes derived from hu⁃man adipose mesenchymal stem cells ameliorate hepatic fibrosis by inhibiting PI3K/Akt/mTOR pathway and remodeling choline me⁃tabolism[J]. J Nanobiotechnology, 2023, 21(1): 29. DOI: 10.1186/ s12951-023-01788-4.[6]ZHAO T, SU ZP, LI YC, et al. Chitinase-3 like-protein-1 function andits role in diseases[J]. Signal Transduct Target Ther, 2020, 5(1): 201. DOI: 10.1038/s41392-020-00303-7.[7]YANG H, ZHAO LL, HAN P, et al. Value of serum chitinase-3-likeprotein 1 in predicting the risk of decompensation events in patients with liver cirrhosis[J]. J Clin Hepatol, 2023, 39(7): 1578-1585. DOI:10.3969/j.issn.1001-5256.2023.07.011.杨航, 赵黎莉, 韩萍, 等. 血清壳多糖酶3样蛋白1(CHI3L1)对肝硬化患者发生失代偿事件风险的预测价值[J]. 临床肝胆病杂志, 2023, 39(7): 1578-1585. DOI: 10.3969/j.issn.1001-5256.2023.07.011.[8]MA L, WEI J, ZENG Y, et al. Mesenchymal stem cell-originated exo⁃somal circDIDO1 suppresses hepatic stellate cell activation by miR-141-3p/PTEN/AKT pathway in human liver fibrosis[J]. Drug Deliv, 2022, 29(1): 440-453. DOI: 10.1080/10717544.2022.2030428. [9]NISHIMURA N, DE BATTISTA D, MCGIVERN DR, et al. Chitinase 3-like 1 is a profibrogenic factor overexpressed in the aging liver and in patients with liver cirrhosis[J]. Proc Natl Acad Sci U S A, 2021, 118(17): e2019633118. DOI: 10.1073/pnas.2019633118.[10]WANG CG, LI SZ, SHI JM, et al. Research progress in differentia⁃tion, identification, and purification methods of human pluripotent stem cells to mesenchymal-like cells in vitro[J]. J Jilin Univ Med Ed, 2023, 49(6): 1655-1661. DOI: 10.13481/j.1671-587X.20230634.王成刚, 李生振, 史嘉敏, 等. 体外人多能干细胞向间充质样细胞分化、鉴定和纯化方法的研究进展[J]. 吉林大学学报(医学版), 2023, 49(6): 1655-1661. DOI: 10.13481/j.1671-587X.20230634.[11]LI TT, WANG ZR, YAO WQ, et al. Stem cell therapies for chronicliver diseases: Progress and challenges[J]. Stem Cells Transl Med, 2022, 11(9): 900-911. DOI: 10.1093/stcltm/szac053.[12]YANG X, LI Q, LIU WT, et al. Mesenchymal stromal cells in hepaticfibrosis/cirrhosis: From pathogenesis to treatment[J]. Cell Mol Im⁃munol, 2023, 20(6): 583-599. DOI: 10.1038/s41423-023-00983-5. [13]ZHAO SX, LIU Y, PU ZH. Bone marrow mesenchymal stem cell-derived exosomes attenuate D-GaIN/LPS-induced hepatocyte apop⁃tosis by activating autophagy in vitro[J]. Drug Des Devel Ther, 2019, 13: 2887-2897. DOI: 10.2147/DDDT.S220190.[14]LEE CG, HARTL D, LEE GR, et al. Role of breast regression protein39 (BRP-39)/chitinase 3-like-1 in Th2 and IL-13-induced tissue re⁃sponses and apoptosis[J]. J Exp Med, 2009, 206(5): 1149-1166.DOI: 10.1084/jem.20081271.[15]HIGASHIYAMA M, TOMITA K, SUGIHARA N, et al. Chitinase 3-like 1deficiency ameliorates liver fibrosis by promoting hepatic macro⁃phage apoptosis[J]. Hepatol Res, 2019, 49(11): 1316-1328. DOI:10.1111/hepr.13396.收稿日期:2023-06-09;录用日期:2023-08-17本文编辑:邢翔宇引证本文:LIU PJ, YAO LC, HU X, et al. Effect of human umbilical cord mesenchymal stem cells in treatment of mice with liver fibrosis and its mechanism[J]. J Clin Hepatol, 2024, 40(3): 527-532.刘平箕, 姚黎超, 胡雪, 等. 人脐带间充质干细胞(hUC-MSC)对肝纤维化小鼠模型的治疗作用及其机制分析[J]. 临床肝胆病杂志, 2024, 40(3): 527-532.读者·作者·编者《临床肝胆病杂志》推荐使用的规范医学名词术语有关名词术语应规范统一,以全国自然科学名词审定委员会公布的各学科名词为准。

虫草提取物对肾小球肾炎的防治作用

虫草提取物对肾小球肾炎的防治作用

华中科技大学硕士学位论文人工蛹虫草提取物对肾小球肾炎的防治作用姓名:李维亮申请学位级别:硕士专业:药理学指导教师:裘军20080501分类号学号2005615140018 学校代码10487密级硕士学位论文人工蛹虫草提取物对肾小球肾炎的防治作用学位申请人:李维亮学科专业:药理学指导教师:裘军副教授答辩日期: 2008年5月A Dissertation Submitted in Partial Fulfillment of the Requirementsfor the Degree of MasterPreventive and Therapeutic Effect of Various Extracts from Cultured Cordyceps Militaris on GlomerularNephritistionCandidate : Li WeiliangMajor : PharmacologySupervisor : Prof.Qiu JunHuazhong University of Science and TechnologyWuhan, Hubei 430074, P. R. ChinaMay, 2008目 录中文摘要---------------------------------------------------- 1 英文摘要---------------------------------------------------- 3 前言-------------------------------------------------------- 6 第一部分人工蛹虫草提取物对培养细胞增殖的影响--------------- 8 §1-1人工蛹虫草提取物对体外培养小鼠淋巴细胞增殖的影响---- 8 §2-1人工蛹虫草提取物对体外培养大鼠肾小球系膜细胞作用的实 验研究-------------------------------------------------- 13 小结---------------------------------------------------- 17 第二部分阳离子化牛血清白蛋白诱导大鼠肾小球肾炎模型的建立----18 小结----------------------------------------------------- 33 第三部分蛹虫草提取物对C-BSA诱导的膜性肾小球肾炎的影响------ 34 §3-1人工蛹虫草提取物对肾炎模型大鼠的实验研究------------ 34 §3-2蛹虫草正丁醇提取物对肾炎模型大鼠的实验研究---------- 45 小结----------------------------------------------------- 50 讨论-------------------------------------------------------- 51 参考文献---------------------------------------------------- 53 综述及参考文献---------------------------------------------- 56 致谢-------------------------------------------------------- 70 附录1(攻读学位期间发表论文目录)---------------------------- 71独创性声明本人郑重声明,本学位论文是本人在导师指导下进行的研究工作及取得的研究成果的总结。

胆囊癌临床诊疗的新进展

胆囊癌临床诊疗的新进展

胆囊癌临床诊疗的新进展中华外科杂志普外空间 2022-08-10 10:00 发表于北京作者:杨自逸,刘诗蕾,蔡晨,吴自友,熊逸晨,李茂岚,吴向嵩,全志伟,龚伟文章来源:中华外科杂志, 2022, 60(8)摘要胆囊癌的恶性程度极高,尚缺乏早期诊断方法和有效治疗手段,亟需高质量研究突破诊疗瓶颈。

本文回顾了2021年国内外发表的胆囊癌研究相关文献,对临床诊疗领域的重要进展进行综述,详细介绍了胆囊癌最新流行病学数据及危险因素、新兴的外周血实验室检查和影像学诊断方法、病理学类型新分类、外科治疗的热点与争议及系统性综合治疗动态。

这些研究结果有助于探索更有效的胆囊癌诊治方法,为改善胆囊癌患者的预后带来希望。

胆囊癌是胆道系统常见的恶性肿瘤,具有症状隐匿、发展迅速、早期转移、预后极差的特点。

我国是胆囊癌的高发地区之一,近年来发病率和病死率呈缓慢上升趋势。

目前仍缺乏特异度和灵敏度均较好的胆囊癌早期诊断手段,临床发现的胆囊癌多为中晚期。

尽管医学科技不断发展,早期诊断和根治性手术切除仍是可能治愈胆囊癌的手段,行之有效的系统性治疗方法依然在不断探索中。

本文展示了2021年胆囊癌临床诊疗领域的研究进展,以探索更好的胆囊癌诊疗方法。

一、流行病学特征(一)发病率与死亡率2020年全球癌症统计数据显示,全球胆囊癌新发115 949例(男性41 062例,女性74 887例),死亡84 695例(男性30 265例,女性54 430例)[1],均居消化系统肿瘤第6位。

胆囊癌全球发病率存在明显的地域差异,全球年龄标准化发病率平均为2.3/10万人,以东亚、南美最高,西欧、北美则发病率较低[2];且近年来男性和年轻群体的胆囊癌发病率呈升高趋势。

我国国家癌症中心数据显示,国内胆囊癌发病率为3.95/10万人(男性3.70/10万人,女性4.21/10万人),死亡率为2.95/10万人(男性1.9/10万人,女性2.1/10万人)[3]。

CD71与IgA肾病的研究进展-论文

CD71与IgA肾病的研究进展-论文

近年来 , I g A N发病 机制研究 中关于异 常糖基化 的 I g A 1如 生 。第三 , 免疫 复合物 I g A1一I g A或 I g A 1一l g G形成 。形 成含
何在 肾小球 系膜 区沉积有不少新进展 , 其中肾小球 系膜 细胞 的 有低半乳糖化 的 I g A 1的高分子量免疫复合 物避免 了与肝细胞 I g A 1特异性 受体—— C D 成 为研 究热 点 , 本文 就 C D 。 的作 用 表达 的去唾液糖蛋 白受体 ( A S G P~ R) 的接触和识别 , 一直持续 与I g A N的关 系作一综述 。
表 达 还 可 以通 过 细胞 增 殖 的状 态 调 节 , 细 胞 增 殖 时 可 以 通 过 有 丝 分裂 原调 节 多 种蛋 白激 酶 的 活性 , 或 者 通 过 基 因转 录 或 稳 定
2 . 3 C D 与 I g A 1的相 互作用 Mo u r a等 为明 确 I g A N
外 区( 9 O~ 第7 6 0氨基酸残基 ) , 其中细胞 外区包含 了 8 0 k D的 ( F c— a R I : C D 。 ) 主要在髓 系 中包 括单核/ 巨噬细胞 、 中性 粒细
有 高亲和力 的转铁蛋 白( T f ) 结合 位点 。每 个亚基 的胞外 区可 胞 、 嗜酸性粒细胞和树 突细胞表达 ; ( 5 ) C D , 受体 : 在 系膜 细胞 、 结合一 分子 T f , 因此一 分子 c D 7 可结 合两分 子 T f , 可携 带 4个 表 皮 细 胞 、 分 化 的 T和 B 淋 巴 细 胞 上 表 达 。 由 于 在 正 常 或
1 C D . 的结构 、 表达调控及分布
存在于循环 中。第到 。 肾小球 系膜

天冬酰胺合成酶通过促进β-catenin核转位驱动胆管癌转移

天冬酰胺合成酶通过促进β-catenin核转位驱动胆管癌转移

天冬酰胺合成酶通过促进β-catenin 核转位驱动胆管癌转移*褚珍珍1,2, 周栩萱1,2, 刘力豪1, 张鲍欢3△, 姚楠1,2△(1暨南大学基础医学院病理生理学系,广东 广州 510632;2国家中医药管理局病理生理科研实验室,广东 广州510632;3暨南大学基础医学院形态学实验教学中心,广东 广州 510632)[摘要] 目的:检测天冬酰胺合成酶(ASNS )在胆管癌(CCA )中的表达情况,探讨ASNS 在CCA 转移中的作用及其机制。

方法:通过公共数据库分析各肿瘤组织中ASNS 的mRNA 表达;收集CCA 患者病理组织(n =27),构建硫代乙酰胺诱导的大鼠自发CCA 模型和左中位胆管结扎联合二乙基亚硝胺诱导的小鼠自发CCA 模型,通过免疫组化、Western blot 和免疫荧光法检测ASNS 蛋白表达。

采用CCK8、划痕和Transwell 实验检测ASNS 对人CCA 细胞HuCCT1和HCCC -9810增殖、迁移和侵袭的影响。

构建ASNS 稳定敲减的CCA 细胞株HuCCT1shNC 、HuCCT1shASNS 、HCCC -9810shNC 和HCCC -9810shASNS ,通过肝原位种植和尾静脉注射研究ASNS 对CCA 细胞肝内生长和肺转移的影响。

利用公共数据库富集与ASNS 相关的信号通路,并用免疫荧光和Western blot 验证相关分子机制。

结果:无论在人或动物CCA 组织中,ASNS 表达水平均高于癌旁组织(P <0.01)。

ASNS 以酶活性非依赖性方式促进CCA 细胞HuCCT1和HCCC -9810的增殖、迁移与侵袭。

生物信息学分析显示,β-catenin 在ASNS 高表达的CCA 组织中富集,ASNS 通过促进β-catenin 核转位,启动CCA 细胞上皮-间充质转化(EMT )。

β-catenin 抑制剂XAV -939可显著抑制CCA 细胞的侵袭与迁移。

地诺单抗生物类似药的N-糖型优化

地诺单抗生物类似药的N-糖型优化

·药物研发·地诺单抗生物类似药的N-糖型优化殷龙贾艳丽姚月琴张俭 谭小钉(江苏迈威康新药研发有限公司泰州 225300)摘 要 目的:使用糖型调节试剂优化地诺单抗(denosumab)生物类似药的N-糖基化修饰,使其主要糖型G0F和G1F的比例与地诺单抗高度类似。

方法:利用单因素和DOE试验方法,考察不同浓度氯化锰、半乳糖及尿苷对地诺单抗生物类似药糖基化修饰的影响。

结果:经过单因素试验、DOE分析及200 L细胞培养工艺放大,确定糖型调节剂氯化锰和半乳糖的最佳用量分别是150 m mol/L和35.56 mmol/L。

结论:使用糖型调节剂氯化锰和半乳糖能有效调节地诺单抗生物类似药的糖基化修饰比例,可为其他单抗生物类似药生产工艺的优化提供借鉴。

关键词生物类似药 糖基化细胞培养中图分类号:TQ460.62; TQ464.7 文献标志码:A 文章编号:1006-1533(2022)03-0077-05N-glycosylation optimization for biosimilar denosumabYIN Long, JIA Yanli, YAO Yueqin, ZHANG Jian, TAN Xiaoding(Jiangsu Mabwell Health Pharmaceutical R&D Co., Ltd., Taizhou 225300, China)ABSTRACT Objective: To optimize the N-glycosylation of denosumab biosimilar using some glycosylation reagents soas to make the proportion of G0F and G1F be highly similar to denosumab. Methods: The effects of the different concentrationsof manganese chloride、galactose and uridine on the glycosylation of denosumab biosimilar were studied by single factor and DOE assays. Results: A preferred combination including manganese chloride 150 m mol/L, galactose 35.56 mmol/L was obtained by single factor test, DOE analysis and 200 L cell cultivation. Conclusion: The use of manganese chloride and galactose can effectively regulate the glycosylation modification ratio of denosumab biosimilar, which can provide a reference for the optimization of production process of the other mono-cloning antibody biosimilars.KEy wORDS biosimilar; glycosylation; cell culture抗体药物属于生物大分子药物,其生物功能的发挥离不开复杂的翻译后修饰。

依维莫司对大鼠实验性IgA肾病的作用

依维莫司对大鼠实验性IgA肾病的作用

依维莫司对大鼠实验性IgA肾病的作用周敏;唐惠玲【摘要】目的:观察依维莫司对大鼠实验性IgA肾病的作用并初步探讨其机制。

方法:建立实验性IgA肾病大鼠模型,实验共分为正常对照( control )组、模型组( IgA组)和依维莫司给药组;测定给药后各组大鼠尿红细胞、尿蛋白和尿N-乙酰-β-D-氨基葡萄糖苷酶( NAG)的含量;免疫荧光染色检测肾组织中IgA 沉淀情况;Western blot法检测髓样分化因子88(MyD88)、TLR4、NF-κB、IL-4和IL-13的蛋白表达水平;实时荧光定量PCR检测IL-4与IL-13的mRNA 表达水平。

结果:依维莫司能够抑制实验性IgA肾病大鼠尿红细胞、尿蛋白和尿NAG含量的升高,抑制MyD88、TLR4、NF-κB和IL-4和IL-13蛋白表达水平的上调,以及抑制IL-4和IL-13 mRNA表达水平的上调。

结论:依维莫司能降低IgA肾病大鼠尿红细胞、尿蛋白和尿NAG含量,其作用可能与其调节MyD88、TLR4、NF-κB、IL-4与IL-13的表达有关。

%[ ABSTRACT] AIM:To investigate the effects of everolimus on the experimental IgA nephropathy in rats and its possible mechanisms .METHODS:The rat model of experimental IgA nephropathy was established .The rats were ran-domly divided into control group , IgA group and everolimus treatment group .After the corresponding treatments were gi-ven, urinary red blood cells , protein and N-acetyl-β-D-glucosaminidase ( NAG) wereexamined .Immunofluorescence stai-ning was used to analyze the level of IgA precipitation in the renal tissues .Additionally, the protein expression of myeloid differentiation factor 88 (MyD88), TLR4, NF-κB, IL-4 and IL-13 was determined by Western blot.The mRNA levels of IL-4 and IL-13 weredetected by qPCR .RESULTS:Everolimus significantly inhibited the increases in the urinary levels of red blood cells, protein and NAG in experimental IgA nephropathy rats .Furthermore, IgA nephropathy-induced increases in the protein expression of MyD88, TLR4, NF-κB, IL-4 and IL-13 were attenuated after everolimus treatment .Similar re-sults were obtained in the mRNA levels of IL-4 and IL-13 by qPCR detection .CONCLUSION: Everolimus improves the impairments of renal function in experimental IgA nephropathy rats as evidenced by decreasing urinary red blood cells , pro-tein and NAG, which may be related to the inhibition of MyD 88, TLR4, NF-κB, IL-4 and IL-13 expression.【期刊名称】《中国病理生理杂志》【年(卷),期】2016(032)010【总页数】5页(P1887-1891)【关键词】依维莫司;IgA肾病;髓样分化因子88;NF-κB;TLR4;IL-4;IL-13【作者】周敏;唐惠玲【作者单位】江苏食品药品职业技术学院药学院,江苏淮安223003;江苏食品药品职业技术学院药学院,江苏淮安223003【正文语种】中文【中图分类】R363IgA肾病是临床上最常见的一种原发性肾小球肾炎,主要表现在肾小球系膜区有IgA或以IgA为主的免疫球蛋白颗粒样或团块状沉积引起的病理性变化,主要有无症状性血尿、肾病综合征、急性肾炎及肾功能不全等临床症状,以往认为IgA 肾病的预后良好,但仍有约25%~30%的患者发展为终末期肾病[1]。

胰高血糖素样肽-1在帕金森病“肠-脑轴”中的作用研究进展

胰高血糖素样肽-1在帕金森病“肠-脑轴”中的作用研究进展

㊃综述㊃基金项目:2023年广州市科技局市校(院)联合资助项目肠道菌群代谢产物S C F A s 通过N F -κB 信号通路在帕金森病发病中的作用及机制研究(S L 2023A 03J 00590)通信作者:陈江瑛,E m a i l :1447369530@q q.c o m 胰高血糖素样肽-1在帕金森病肠-脑轴 中的作用研究进展周正新,梁秋雄,陈江瑛(暨南大学附属广州红十字会医院神经内科,广东广州510220) 摘 要:帕金森病(P D )是中老年时期常见的神经退行性疾病之一㊂P D 患者出现肠道炎症㊁便秘等胃肠道症状可能早于运动障碍㊂B r a a k 假说假设异常的α-突触核蛋白在肠道中开始积累,并通过迷走神经以类似朊病毒的方式传至大脑,且这一观点得到病理生理学证据的支持㊂P D 中 肠-脑轴 的关联在于代谢㊁免疫和炎症等相关机制,通过探讨其中机制可能成为治疗P D 的新思路㊂胰高血糖素样肽-1(G L P -1)作为研究较多的代谢物质之一,广泛参与在神经退行性病变中㊂本文对G L P -1在P D 肠-脑轴 中的作用进行综述,以期为P D 提供新的诊疗及研究思路㊂关键词:帕金森病;胰高血糖素样肽-1;肠-脑轴中图分类号:R 742.5 文献标志码:A 文章编号:1004-583X (2023)09-0855-04d o i :10.3969/j.i s s n .1004-583X.2023.09.015 帕金森病(P a r k i n s o n s d i s e a s e ,P D )是常见的运动障碍疾病,是一种表现有运动症状(运动迟缓㊁震颤㊁肌强直㊁步态异常)和非运动症状(胃肠功能紊乱㊁认知障碍㊁精神障碍㊁睡眠障碍和感觉障碍)的神经退行性疾病,其病因尚不完全清楚,亦缺乏根治手段㊂近年来, 肠-脑轴 这一概念的提出给包括P D 在内的神经疾病发病机制的探究提供了新思路㊂研究P D 与肠道系统相互联系的途径与其靶点,是丰富P D 研究的重点㊂2型糖尿病(t y pe 2d i a b e t e s m e l l i t u s ,T 2D M )是P D 发病的危险因素,且两者均与淀粉样多肽经过非正常折叠成纤维并随后聚集成淀粉样沉积有关[1]㊂因此,可以假设糖代谢异常可能是P D 的重要机制之一㊂P D 模型研究[2]表明,降糖药物胰高血糖素样肽-1(g l u c a g o n -l i k e p e p t i d e -1,G L P -1)受体激动剂具有神经保护作用㊂其中G L P -1,不只是一种可促进胰岛素信号传导㊁调节血糖水平且抑制食欲的肠促胰岛素激素[3],还是 肠-脑轴 的重要介质之一[4]㊂本文就G L P -1在P D肠-脑轴 中的作用进行综述,进一步探讨G L P -1与P D 的关系,以期为P D 的诊治提供新思路和依据㊂1 P D 的肠-脑轴 在大脑㊁肠道和肠道菌群存在着1种尚未被完全了解的交流系统,即 肠-脑轴 ㊂基于此轴,肠道菌群的改变被证明与一些神经疾病有关,如对P D 来说,肠道菌群的改变就是其突出的特征之一㊂1.1 病理联系 作为P D 黑质中形成的标志性聚集物,α-突触核蛋白(α-s y n u c l e i n ,α-s yn )不只在大脑中表达,且在肠道中也有表达[5];甚至其在肠道中的聚集比在大脑中病理形成更早[6]㊂B r a a k 等[7]提出,P D 是起源于中枢神经系统以外的病理模型㊂在该模型中,α-s yn 的错误折叠起自肠道,并通过迷走神经以朊病毒样的行为方式传至大脑[8]㊂且α-s yn 增加在P D 患者前驱阶段和早期无发病阶段的肠上皮中被发现[9]㊂可见,肠道中出现异常的α-s yn 发生在中枢神经退行性变的临床症状出现前㊂这表明,肠道可能是P D 发生的起源场所㊂虽然B r a a k 的观点备受争议,但中枢神经系统外α-s y n 错误折叠和聚集仍是P D 发病机制的经典假说,同时也是P D 肠-脑轴 的病理基础㊂1.2 肠道中介 细菌及其代谢产物除影响免疫系统外,还影响神经系统㊂F r i e d l a n d 等[10]提出了1个新的术语 m a p r a n o s i s 来描述微生物群相关的蛋白质病和神经炎症的过程( -o s i s )㊂尽管目前还未完全明确影响P D 的肠道菌群,但P D 的肠道状态和健康的肠道状态存在差异㊂临床研究[11]显示,P D 患者肠道出现异常改变,既有肠黏膜通透性增加㊁炎症迹象和受到细菌入侵,同时也有异常肠道菌群组成㊂在过表达α-s yn 小鼠大脑中小胶质细胞的激活和α-s yn 的病理形成及这些小鼠运动缺陷的产生都需肠道菌群参与,说明肠道菌群是P D 的危险因素[12]㊂P D 肠道菌群含有外膜脂多糖(l i p o p o l y s a c c h a r i d e s ,L P S )的细菌之相对丰度增加,而产生短链脂肪酸㊃558㊃‘临床荟萃“ 2023年9月20日第38卷第9期 C l i n i c a l F o c u s ,S e pt e m b e r 20,2023,V o l 38,N o .9(s h o r t-c h a i n f a t t y a c i d s,S C F A)的细菌之相对丰度降低,这是因为含有L P S的细菌与免疫激活和炎症有关,而产生S C F A的细菌与可能存在的抗炎性质有关[13]㊂一方面,L P S等促炎细菌成分激活小胶质细胞引发神经退行性变[14],暴露在L P S的全身效应随肠道屏障缺损(即肠道高渗透性)而增加,这是P D 的1个特征;另一方面,菌群的代谢产物S C F A与神经炎症的减轻㊁神经退行性变的减少和运动功能的改善有一定关系,在P D患者中这些菌群相对丰度往往减少[15]㊂位于肠道里的细菌代谢产物S C F A在P D的 肠-脑轴 假说中也发挥重要作用㊂S C F A的受体既存在于免疫细胞上,也存在于大脑细胞上,这为S C F A介导的 肠-脑轴 提供了物质联系[16]㊂目前,1个探索程度相对较低的机制就是S C F A对神经系统的影响㊂研究[17]发现,S C F A可引起G L P-1分泌,且对P D有神经保护作用㊂以上均提示,肠道菌群及其代谢产物对P D的产生有不可忽视的影响㊂2G L P-1在P D 肠-脑轴 中的作用肠-脑轴 与内分泌激素的产生与释放相关㊂研究[18]表明,T2D M是P D的危险因素,且胰岛素抵抗可能存在于大脑中,是神经退行性疾病的常见特征㊂作为与糖尿病相关的内分泌激素,G L P-1是肠促胰素信号系统成员之一,目前对其研究较为热门,其作用机制的研究最为深入也最为复杂㊂大量研究已证实,G L P-1广泛参与了P D的发生发展㊂可见,G L P-1可能在P D的 肠-脑轴 中发挥了重要作用㊂2.1 G L P-1受体在神经系统的分布 G L P-1作用于外周组织中的G L P-1受体(g l u c a g o n-l i k e p e p t i d e-1r e c e p t o r,G L P-1R)㊂这种受体遍布肠道㊁胃部㊁胰腺㊁心脏㊁肾脏㊁骨骼㊁血管和脂肪细胞[19]㊂G L P-1R 也广泛分布于中枢神经系统中,如与P D相关的黑质,其中也包括表达酪氨酸羟化酶(t y r o s i n e h y d r o x y l a s e,T H)的多巴胺能神经元[20],且神经元周围的小胶质细胞和星形胶质细胞也可表达G L P-1R[21],这些为G L P-1与神经退行性变的关系提供了物质基础㊂2.2肠道菌群对G L P-1的作用内源性G L P-1是由肠道L细胞产生㊂L细胞的数量沿胃肠道的纵轴逐渐增加;结肠腔内有大量肠道菌群,L细胞在其中比例最高,L细胞由于与肠道菌群直接接触而受到刺激㊂由此可见,肠道L细胞分泌的G L P-1受肠道菌群的影响;同时,其也受到细菌产生的S C F A影响㊂S C F A通过与L细胞上的跨膜游离脂肪酸受体(f r e e f a t t y a c i d r e c e p t o r2,F F A R2)结合发挥促分泌作用㊂L细胞中的法尼醇X受体(f a r n e s o i d Xr e c e p t o r, F X R)的激活通过减少F F A R2的表达和信号传导以减少S C F A诱导的G L P-1分泌;相反,S C F A诱导G L P-1分泌在敲除F X R小鼠中增强[17]㊂这提示,肠内分泌系统可能是调节G L P-1水平的主要调节位点,即对F X R的拮抗作用可能增强G L P-1的分泌㊂利用这种方法可增加G L P-1的产生,进而获得治疗益处㊂如前所述,P D肠道的特征是产生S C F A细菌丰度减低[15],这引起了各项研究对P D肠道G L P-1分泌的关注㊂因此,有研究[22]表明,与食用相同餐食的对照组相比,P D组餐后G L P-1水平较低㊂说明P D患者G L P-1分泌可能存在障碍,且这种障碍可能是由于产生S C F A的细菌较少所致㊂可以说,肠道菌群可通过G L P-1来影响大脑功能,即形成了 肠-脑轴 的联系㊂2.3 G L P-1对P D的作用 T2D M是P D的危险因素[1],G L P-1R激动剂能降低T2D M患者血糖[23]㊂这提示,G L P-1的稳态失调可能是P D的潜在机制㊂因此,存在将G L P-1信号的增强用于预防神经退行性病变的可能㊂研究[2]发现,G L P-1R激动剂恢复了合成多巴胺的限速酶T H在黑质的表达,还能进一步降低作为脂质过氧化产物和氧化应激标志物的4-羟基壬烯醛的产生[24],提高了神经营养因子,如神经胶质细胞系来源的神经营养因子和脑源性的神经营养因子的合成[25],并阻止体内T H阳性纹状体和中脑多巴胺能神经元中α-s y n[2,25]的积累㊂目前,已有研究进一步证明G L P-1R信号增强带来有益作用的机制㊂有研究[26]表明,G L P-1通过抑制核因子κB (n u c l e a r f a c t o rk a p p a-B,N F-κB)信号传导以发挥抗炎作用;而所对应的炎症正是在含有L P S的细菌的相对丰度增加和肠道屏障功能障碍下发生的㊂G L P-1R的激活通过调节细胞内线粒体活性氧(r e a c t i v e o x y g e n s p e c i e s,R O S)抑制P D的氧化应激(o x i d a t i v e s t r e s s,O S)㊂G L P-1R的激活增强了丝氨酸/苏氨酸激酶(t h r e o n i n e k i n a s e,A k t)的磷酸化并诱导转录因子环磷酸腺苷(c y c l i c a d e n o s i n e m o n o p h o s p h a t e,c AM P)反应元件结合蛋白[27],增强了抗凋亡B淋巴细胞瘤2(b-c e l l l y m p h o m a2,B c l-2)合成并降低促凋亡B c l-2相关X蛋白(b c l-2a s s o c i a t e d X p r o t e i n,B a x)[25,28]和细胞色素C (c y t o c h r o m eC,C y t C)[28]水平,使降低的B c l-2/B a x 比例正常化同时还降低了具有凋亡效应的天冬氨酸㊃658㊃‘临床荟萃“2023年9月20日第38卷第9期 C l i n i c a l F o c u s,S e p t e m b e r20,2023,V o l38,N o.9特异性半胱氨酸蛋白酶3(c a s p a s e3)水平[25]㊂这些研究为G L P-1对P D的作用提供了机制方面的支持证据㊂最近1项针对T2D M患者基于人群的纵向队列研究[29]结果显示,接受G L P-1R激动剂治疗组与其他降糖药物组比较,P D发病率降低㊂该研究为使用G L P-1R激动剂治疗的T2D M患者预防P D提供了可靠的流行病学证据,证明了G L P-1对P D神经保护和抗炎作用㊂3小结P D是发病率第2的神经退行性疾病,在全球范围内,P D导致的残疾和死亡人数高于其他神经系统疾病㊂目前的治疗方案仍未能满足临床需求,加之发病机制尚未完全明确,给P D患者预后带来极大挑战㊂作为目前研究最多且广泛参与T2D M和神经疾病发病机制中的肠促胰素,G L P-1为从肠道与神经系统角度分析 肠-脑轴 的形成开创了新的研究方向㊂期待未来会有更多关于G L P-1对P D 肠-脑轴 作用的研究,以更好地为防控P D等神经疾患奠定研究基础㊂参考文献:[1] N g u y e nP H,R a m a m o o r t h y A,S a h o o B R,e ta l.A m y l o i do l i g o m e r s:A j o i n t e x p e r i m e n t a l/c o m p u t a t i o n a l p e r s p e c t i v eo na l z h e i m e r'sd i s e a s e,p a r k i n s o n'sd i s e a s e,t y p e i i d i ab e t e s,a n da m y o t r o p h i c l a t e r a ls c l e r o s i s[J].C h e m R e v,2021,121(4):2545-2647.[2] Z h a n g L Y,J i nQ Q,Höl s c h e rC,e t a l.G l u c a g o n-l i k e p e p t i d e-1/g l u c o s e-d e p e n d e n ti n s u l i n o t r o p i c p o l y p e p t i d ed u a lr e c e p t o ra g o n i s tD A-C H5i s s u p e r i o r t o e x e n d i n-4i n p r o t e c t i n g n e u r o n si nt h e6-h y d r o x y d o p a m i n er a t p a r k i n s o n m o d e l[J].N e u r a lR e g e nR e s,2021,16(8):1660-1670.[3] K o p p K O,G l o t f e l t y E J,L iY,e ta l.G l u c a g o n-l i k e p e p t i d e-1(G L P-1)r e c e p t o r a g o n i s t s a n d n e u r o i n f l a mm a t i o n:i m p l i c a t i o n s f o r n e u r o d e g e n e r a t i v e d i s e a s e t r e a t m e n t[J].P h a r m a c o lR e s,2022,186:106550.[4] M a n f r e a d y R A,F o r s y t h C B,V o i g t R M,e ta l.G u t-b r a i nc o mm u n i c a t i o n i n p a r k i n s o n'sd i se a s e:E n t e r o e n d o c r i n er e g u l a t i o nb y G L P-1[J].C u r rN e u r o lN e u r o s c iR e p,2022,22(7):335-342.[5] L i u W,L i m K L,T a n E K.I n t e s t i n e-d e r i v e dα-s y n u c l e i ni n i t i a t e s a n da g g r a v a t e s p a t h o g e n e s i so f p a r k i n s o n'sd i s e a s e i nD r o s o p h i l a[J].T r a n s lN e u r o d e g e n e r,2022,11(1):44.[6] R o d r i g u e s P V,d e G o d o y J V P,B o s q u e B P,e t a l.T r a n s c e l l u l a r p r o p a g a t i o n o f f i b r i l l a rα-s y n u c l e i n f r o me n t e r o e n d o c r i n e t on e u r o n a lc e l l sr e q u i r e sc e l l-t o-c e l lc o n t a c ta n d i sR a b35-d e p e n d e n t[J].S c i R e p,2022,12(1):4168.[7] B r a a k H,Rüb U,G a i W P,e ta l.I d i o p a t h i c p a r k i n s o n'sd i se a s e:p o s s i b l er o u t e sb y w h i c hv u l n e r a b l en e u r o n a lt y p e sm a y b e s u b j e c t t o n e u r o i n v a s i o n b y a n u n k n o w n p a t h o g e n[J].JN e u r a lT r a n s m(V i e n n a),2003,110(5):517-536. [8] B o r g h a mm e r P.H o w d o e s p a r k i n s o n's d i s e a s e b e g i n?p e r s p e c t i v e s o n n e u r o a n a t o m i c a l p a t h w a y s,p r i o n s,a n dh i s t o l o g y[J].M o vD i s o r d,2018,33(1):48-57.[9]S h a n n o n KM,K e s h a v a r z i a n A,M u t l u E,e t a l.A l p h a-s y n u c l e i n i nc o l o n i cs u b m u c o s a i ne a r l y u n t r e a t e dP a r k i n s o n'sd i se a s e[J].M o v e m e n tD i s o r d e r s,2012,27(6):709-715.[10] F r i e d l a n dR P,C h a p m a nM R.T h e r o l e o fm i c r o b i a l a m y l o i d i nn e u r o d e g e n e r a t i o n[J].P L o S P a t h o g,2017,13(12): e1006654.[11] D u m i t r e s c uL,M a r t a D,D췍n췍u A,e ta l.S e r u m a n df e c a lm a r k e r s o f i n t e s t i n a l i n f l a mm a t i o n a n d i n t e s t i n a l b a r r i e r p e r m e a b i l i t y a r ee l e v a t e di n p a r k i n s o n's d i s e a s e[J].F r o n tN e u r o s c i.2021,18(15):689723.[12]S a m p s o n T,D e b e l i u sJ,T h r o n T,e ta l.G u t m i c r o b i o t ar e g u l a t em o t o rd e f i c i t sa n dn e u r o i n f l a mm a t i o ni na m o d e lo f p a r k i n s o n's d i s e a s e[J].C e l l,2016,167(6):1469-1480,e12.[13]J o e r s V,M a s i l a m o n i G,K e m p f D,e t a l.M i c r o g l i a,i n f l a mm a t i o na n d g u t m i c r o b i o t ar e s p o n s e si na p r o g r e s s i v em o n k e y m o d e lo f p a r k i n s o n's d i s e a s e:A c a s es e r i e s[J].N e u r o b i o lD i s,2020,144:105027.[14] A b d e l-H a q R,S c h l a c h e t z k i J C M,G l a s s C K,e t a l.M i c r o b i o m e-m i c r o g l i a c o n n e c t i o n sv i a t h e g u t-b r a i na x i s[J].JE x p M e d,2019,216(1):41-59.[15] N i s h i w a k iH,H a m a g u c h iT,I t o M,e ta l.S h o r t-c h a i nf a t t ya c i d-p r o d u c i n g g u t m i c r ob i o t ai s d ec r e a s ed i n p a r k i n s o n'sd i se a s eb u t n o t i nr a p i d-e y e-m o v e m e n t s l e e p b e h a v i o r d i s o r d e r[J].m S y s t e m s,2020,5(6):e00797-e007920.[16]S i l v aY P,B e r n a r d i A,F r o z z aR L.T h e r o l e o f s h o r t-c h a i n f a t t ya c i d sf r o m g u t m i c r ob i o t ai n g u t-b r a i nc o mm u n i c a t i o n[J].F r o n tE n d o c r i n o l(L a u s a n n e),2020,31(11):25.[17] D u c a s t e lS,T o u c h e V,T r a b e l s i M S,e t a l.T h e n u c l e a rr e c e p t o r F X R i n h i b i t s g l u c a g o n-l i k e p e p t i d e-1s e c r e t i o n i n r e s p o n s e t o m i c r o b i o t a-d e r i v e ds h o r t-c h a i nf a t t y a c i d s[J].S c iR e p,2020,10(1):174.[18] U y a r M,L e z i u s S,B u h m a n n C,e ta l.D i a b e t e s,g l y c a t e dh e m o g l o b i n(h b a1c),a n dn e u r o a x o n a l d a m a g e i n p a r k i n s o n'sd i se a s e(MA R K-P D s t u d y)[J].M o v D i s o r d,2022,37(6):1299-1304.[19] D r u c k e rD J.M e c h a n i s m s o f a c t i o na n d t h e r a p e u t i c a p p l i c a t i o no f g l u c a g o n-l i k e p e p t i d e-1[J].C e l lM e t a b,2018,27(4):740-756.[20] E l a b iO F,D a v i e sJ S,L a n eE L.L-d o p a-d e p e n d e n te f f e c t so fG L P-1R a g o n i s t s o n t h e s u r v i v a l o f d o p a m i n e r g i c c e l l st r a n s p l a n t e d i n t o a r a tm o d e l o f p a r k i n s o n d i s e a s e[J].I n t JM o l S c i,2021,22(22):12346.[21] C u iQ N,S t e i nL M,F o r t i nS M,e t a l.T h e r o l eo f g l i a i nt h ep h y s i o l o g y a n d p h a r m a c o l o g y o f g l u c a g o n-l i k e p e p t i d e-1:I m p l i c a t i o n s f o r o b e s i t y,d i a b e t e s,n e u r o d e g e n e r a t i o n a n dg l a u c o m a[J].B r JP h a r m a c o l,2022,179(4):715-726.㊃758㊃‘临床荟萃“2023年9月20日第38卷第9期 C l i n i c a l F o c u s,S e p t e m b e r20,2023,V o l38,N o.9[22] M a n f r e a d y R A,E n g e nP A,V e r h a g e n M L,e t a l.A t t e n u a t e dp o s t p r a n d i a lG L P-1r e s p o n s e i n p a r k i n s o n'sd i s e a s e[J].F r o n tN e u r o s c i,2021,2(15):660942.[23]郑鑫,朱育刚,王德峰.G L P-1受体激动剂对超重及肥胖2型糖尿病患者胰岛细胞功能影响的系统评价[J].临床荟萃, 2019,34(12):1102-1107.[24] Z h a n g Z Q,Höl s c h e r C.G I P h a sn e u r o p r o t e c t i v ee f f e c t si nA l z h e i m e r a n dP a r k i n s o n's d i s e a s em o d e l s[J].P e p t i d e s,2020,125:170184.[25] L vM,X u eG,C h e n g H,e t a l.T h eG L P-1/G I Pd u a l-r e c e p t o ra g o n i s tD A5-C Hi n h ib i t s t h eN F-κB i n f l a mm a t o r yp a t h w a y i nt h eM P T P m o u s em o d e l o f p a r k i n s o n's d i s e a s em o r e e f f e c t i v e l y t h a n t h e G L P-1s i n g l e-r e c e p t o r a g o n i s t N L Y01[J].B r a i nB e h a v,2021,11(8):e2231.[26] C h e nX,H u a n g Q,F e n g J,e ta l.G L P-1a l l e v i a t e s N L R P3i n f l a mm a s o m e-d e p e n d e n t i n f l a mm a t i o n i n p e r i v a s c u l a r a d i p o s et i s s u e b y i n h i b i t i n g t h e N F-κBs i g n a l l i n gp a t h w a y[J].JI n tM e dR e s,2021,49(2):300060521992981.[27]J a l e w a J,S h a r m aMK,G e n g l e r S,e t a l.An o v e lG L P-1/G I Pd u a l re c e p t o ra g o n i s t p r o t e c t sf r o m6-O H D Al e s i o ni nar a tm o d e l o f p a r k i n s o n's d i s e a s e[J].N e u r o p h a r m a c o l o g y,2017,1(117):238-248.[28] L iT,T u L,G u R,e ta l.N e u r o p r o t e c t i o no f G L P-1/G I Pr e c e p t o ra g o n i s t v i a i n h i b i t i o n㊁o f m i t o c h o n d r i a l s t r e s s b yA K T/J N K p a t h w a y i naP a r k i n s o n'sd i s e a s e m o d e l[J].L i f eS c i,2020,1(256):117824.[29] B r a u e rR,W e i L,M aT,e t a l.D i a b e t e sm e d i c a t i o n s a n d r i s ko f p a r k i n s o n's d i s e a s e:Ac o h o r t s t u d y o f p a t i e n t sw i t h d i a b e t e s[J].B r a i n,2020,143(10):3067-3076.收稿日期:2023-05-31编辑:张婷婷㊃858㊃‘临床荟萃“2023年9月20日第38卷第9期 C l i n i c a l F o c u s,S e p t e m b e r20,2023,V o l38,N o.9。

Lancet:IgA肾病布地奈德靶向释放制剂2b期临床试验效果显著

Lancet:IgA肾病布地奈德靶向释放制剂2b期临床试验效果显著

Lancet:IgA肾病布地奈德靶向释放制剂2b期临床试验效果显著全世界范围内,原发性IgA肾病是最常见的慢性肾小球疾病,常起病于年轻患者。

大约20-40%的病人在10-20年内进展为终末期肾病。

IgA肾病进展的相关危险因素包括持续蛋白尿,高血压,以及下降的eGFR。

KDIGO指南推荐肾素紧张素转换酶抑制剂(ACEIs)和肾素紧张素受体拮抗剂(ARBs)可作为一线药物,用于24小时蛋白尿超过1g/d的IgA肾病患者。

在最大推荐剂量范围内可逐渐提高该药物使用剂量直到24小时尿蛋白控制在1g/d以下。

而对于最大剂量RAS阻断剂使用6月后蛋白尿仍高于1g/d的患者,KDIGO建议使用6个月高剂量的全身性糖皮质激素。

但是全身性糖皮质激素使用常导致出现明显的副反应,包括严重感染,高血压,体重增加,糖尿病以及骨质疏松等。

目前已有证据显示粘膜免疫在IgA肾病的发病过程中发挥着重要重要。

在IgA肾病病人中,位于其集合淋巴结中的粘膜B淋巴细胞被广泛激活并产生半乳糖缺陷的IgA1,在循环系统中形成大的免疫复合物,继而沉积于肾小球系膜区,引起系膜细胞增殖,炎症介质释放,最终促进蛋白尿产生,纤维化形成。

该发病机制提示我们抑制局部免疫系统中的粘膜B淋巴细胞激活与增殖可能有助于减少半乳糖缺陷的IgA1产生,从而减轻后续的病理生理学改变。

TRF-budesonide 介绍近来,一种新型,口服的布地奈德靶向释放制剂(TRF-budesonide)被研发出来,该制剂可控制其药物抵达至回肠末端后再释放,因此可在粘膜集合淋巴结形成较高的药物浓度。

由于不到10%的布地奈德进入到血液循环,该制剂副反应要明显轻于全身性糖皮质激素。

在近期的一项2a期临床实验中,16个IgA肾病病人接受TRF-budesonide (8 mg/day) 治疗6个月后蛋白尿水平出现明显下降。

2017年6月,新英格兰医学杂志在线发表了关于TRF-budesonide在IgA肾病中应用的后续试验结果(NEFIGAN)。

可诱生粘膜IgA的新型佐剂--氧化型甘露聚糖

可诱生粘膜IgA的新型佐剂--氧化型甘露聚糖

可诱生粘膜IgA的新型佐剂--氧化型甘露聚糖
佚名
【期刊名称】《国际生物制品学杂志》
【年(卷),期】2003(026)003
【摘要】无
【总页数】2页(P140-141)
【正文语种】中文
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纳豆多糖改善小鼠IgA肾病的作用及其免疫学机制的研究分析

纳豆多糖改善小鼠IgA肾病的作用及其免疫学机制的研究分析

纳豆多糖改善小鼠IgA肾病的作用及其免疫学机制的研究分析佟芳;毛成健【摘要】目的探讨纳豆多糖改善小鼠IgA肾病的作用及其免疫学机制.方法将造模成功的50只IgA肾病小鼠分为模型组,纳豆多糖高、中、低剂量组及阳性组(雷公藤多苷),每组10只.同时选择10只正常小鼠(未经造模)作为对照组.正常组和模型组小鼠按0.2 mL/10g 灌胃生理盐水(NS),阳性组(雷公藤多苷,5mg/kg),纳豆多糖高、中、低剂量组(给药剂量分别为40 、20、10 g/kg),1次/d,至第20周处死,取血及脏器,测定白蛋白、尿素氮、肌酐、血清循环免疫复合物和IgA水平.结果与正常组比较,模型组尿微量白蛋白明显升高(P<0.05);与模型组比较,纳豆多糖高、中剂量组和阳性组尿微量白蛋白明显降低(P<0.05);与正常组比较,模型组尿血清白蛋白明显降低(P<0.05),与模型组比较,纳豆多糖高、中剂量组和阳性组血清白蛋白明显升高(P<0.05);与正常组比较,模型组尿素氮、肌酐、血清循环免疫复合物明显升高(P<0.05),与模型组比较,纳豆多糖高、中剂量组和阳性组尿素氮、肌酐、血清循环免疫复合物明显降低(P<0.05);与正常组比较,模型组肾组织IgA水平明显升高(P<0.05),与模型组比较,纳豆多糖高、中剂量组和阳性组IgA水平明显降低(P<0.05).结论纳豆多糖可明显改善小鼠IgA肾病,还可降低尿蛋白和IgA水平.%Objective To observe the protective effect of natto polysaccharide on IgA nephropathy mice and its immunological mechanism.Methods The IgA model mice were divided into model group, high-, medium-and low-doses of natto polysaccharide groups, and positive group.Each group had 10 mice.10 normal mice were enrolled as normal control group.The mice in normal control and model groups were treated with normal saline, and alldoses of natto polysaccharide groups and positive group were treated with natto polysaccharide (40, 20, 10 g/kg) and positive (5mg/kg) respectively.All mice were treated with drugs or NS for 20 weeks, ig,qd.The levels of albumin in serum and urine, urea nitrogen, creatinine, CIC and IgA were investigated in each group.Results Compared with the normal control group, the levels of albumin in urine in model group were obviously higher (P<0.05).but compared with the model group, the levels of albumin in urine in high-, medium-doses of natto polysaccharide groups and positive group were obviously lower (P<0.05).Compared with the normal control group, the levels of albumin in serum in model group were obviously lower (P<0.05), but compared with the model group, the levels of albumin in serum in high-, medium-doses of natto polysaccharide groups and positive group were obviously higher (P<0.05).Compared with the normal control group, the levels of urea nitrogen, creatinine and CIC in model group were obviously higher (P<0.05), but compared with the model group, the levels of urea nitrogen, creatinine and CIC in high-, medium-doses of natto polysaccharide groups and positive group were obviously lower (P<0.05).Compared with the normal control group, the levels of IgA in model group were obviously higher (P<0.05), but compared with the model group, the levels of IgA in high-, medium-doses of natto polysaccharide groups and positive group were obviously lower (P<0.05).Conclusion Natto polysaccharide has protective effect on IgA nephropathy mice, and can reduce the levels of albumin and IgA.【期刊名称】《标记免疫分析与临床》【年(卷),期】2017(024)006【总页数】4页(P706-708,712)【关键词】纳豆多糖;IgA肾病;免疫学【作者】佟芳;毛成健【作者单位】湖北省宜昌市第二人民医院三峡大学第二人民医院肾内科,湖北宜昌443000;湖北省宜昌市第二人民医院三峡大学第二人民医院肾内科,湖北宜昌443000【正文语种】中文IgA肾病是一种与细胞免疫调节紊乱有关的肾小球系膜区出现IgA免疫复合物沉积的原发性肾小球肾炎。

半乳糖缺乏的IgA1在相关肾脏疾病中的研究进展

半乳糖缺乏的IgA1在相关肾脏疾病中的研究进展

半乳糖缺乏的IgA1在相关肾脏疾病中的研究进展张钰恒(综述);高进(审校)【摘要】近年来IgA肾病及紫癜性肾炎越来越受到关注,其发病机制尚不明确、诊断标准过于单一、病程长及预后不良等均成为临床亟待解决的问题。

IgA肾病和紫癜性肾炎都是与IgA有关的免疫复合物疾病。

研究发现在这两种疾病患者血清中半乳糖缺乏的IgA1都显著升高,其水平可能是诊断IgA肾病及紫癜性肾炎的无创性生物标记之一,并在一定程度上可预示疾病预后、监测疾病发展。

文章综述了半乳糖缺乏的IgA1的发现、结构、产生过程、可能的致病机制及其作用。

%In recent years, IgA nephropathy and Henoch-Schönlein purpura nephritis attract more and more attention on their unclear pathogenesis, single diagnostic criteria, long duration and poor prognosis, etc. Research suggests that IgA nephropathy and purpura nephritis are IgA immune complex related diseases, and serum galactose-deficient is elevated in patients with these two dis-eases, which might become a noninvasive biomarker for the diagnosis, prognosis prediction and disease development monitoring for IgA nephropathy and purpura nephritis. Galactose-deficient IgA1 is reviewed for its discovery, structure, process, the possible patho-genic mechanism and its significance in details in this paper.【期刊名称】《临床儿科杂志》【年(卷),期】2014(000)005【总页数】3页(P489-491)【关键词】IgA肾病;紫癜性肾炎;半乳糖缺乏的IgA1;过敏性紫癜【作者】张钰恒(综述);高进(审校)【作者单位】内蒙古医科大学附属医院内蒙古呼和浩特 010059;内蒙古医科大学附属医院内蒙古呼和浩特 010059【正文语种】中文在研究153个美国白人IgA肾病(IgA nephropathy,IgAN)时首次发现血清中存在高水平的半乳糖缺乏的IgA1(galactosedeficient IgA1,Gd-IgA1)[1]。

IgA肾病残余蛋白尿非免疫抑制剂药物治疗进展

IgA肾病残余蛋白尿非免疫抑制剂药物治疗进展

IgA肾病残余蛋白尿非免疫抑制剂药物治疗进展胡妍琦;李六生【摘要】IgA nephropathy (IgAN) is a common cause of end stage renal disease in the world.Any intervention to reduce proteinuria is helpful to slow the progress of IgAN.At present,sometimes complete remission of IgAN with proteinuria cannot be achieved through the use of renin angiotensin system inhibitor,thus other non-immunosuppressant drugs,including fish oil,active vitamin D,Sulodexide,adrenergic inhibitor,aldosterone receptor blockade,statins and so on are often needed.By analyzing the related literature,this paper reviews the progress of non-immunosuppressant therapy for IgAN with residual proteinuria.%IgA肾病在全球范围内是导致终末期肾病的主要原因,任何能减少蛋白尿干预措施均有利于延缓IgA肾病进展.目前肾素-血管紧张素系统抑制剂的应用有时并不能使IgA肾病蛋白尿完全缓解,往往需要其他非免疫抑制剂药物治疗,包括鱼油、活性维生素D、舒洛地特、肾素抑制剂、醛固酮受体拮抗剂、他汀类药物等.该文结合国内外文献就IgA肾病残余蛋白尿非免疫抑制剂药物治疗进展作一综述.【期刊名称】《中国医药导报》【年(卷),期】2018(015)015【总页数】4页(P34-37)【关键词】IgA肾病;残余蛋白尿;非免疫抑制剂;药物治疗【作者】胡妍琦;李六生【作者单位】三峡大学人民医院肾内科,湖北宜昌443000;三峡大学人民医院肾内科,湖北宜昌443000【正文语种】中文【中图分类】R692.6IgA 肾病(IgA nephropathy,IgAN)发病率高,在全球范围内、尤其亚洲国家是最常见的肾小球肾炎,也是导致尿毒症主要原因。

肾素血管紧张素系统阻滞剂对IgA肾病转化生长因子β1的抑制效应

肾素血管紧张素系统阻滞剂对IgA肾病转化生长因子β1的抑制效应

肾素血管紧张素系统阻滞剂对IgA肾病转化生长因子β1的抑制效应周莹;吕吟秋;黄朝兴【摘要】目的探讨肾素血管紧张素系统(RAS)阻滞剂对IgA肾病(IgAN)患者血和尿转化生长因子β1(TGF-β1)的影响及其意义.方法比较12例长期服用小剂量血管紧张素转化酶抑制剂(ACEI)或血管紧张素Ⅱ受体阻滞剂(ARB)的IgAN患者和11例均未服用上述药物的患者治疗前后血和尿的TGF-β1及临床参数的变化.结果 12例IgAN患者在长期服用RAS阻滞剂后其尿TGF-β1和8h尿蛋白均较治疗前降低,未经上述药物治疗的11例IgAN患者的尿TGF-β1及8h尿蛋白均较治疗前明显上升.结论使用小剂量的RAS阻滞剂可明显降低IgAN尿TGF-β1的水平,但不能将其降至正常范围,且不能完全阻断疾病的进展.【期刊名称】《现代实用医学》【年(卷),期】2012(024)012【总页数】3页(P1327-1329)【关键词】肾小球肾炎,IGA;转化生长因子β1;肾素-血管紧张素系统【作者】周莹;吕吟秋;黄朝兴【作者单位】325000浙江省温州,温州医学院附属第一医院;325000浙江省温州,温州医学院附属第一医院;325000浙江省温州,温州医学院附属第一医院【正文语种】中文【中图分类】R692近年来有关转化生长因子 1(transforming growth factor-1,TGF-1)与肾素血管紧张素(RAS)阻滞剂的研究越来越多。

有研究证实,使用血管紧张素转化酶抑制剂(ACEI)/血管紧张素Ⅱ受体阻滞剂(ARB)可降低肾脏内TGF-1的表达,从而延缓肾损伤[1-2]。

本研究对12例长期服用小剂量ACEI或ARB的IgAN患者进行随访,通过监测其血和尿中TGF-1在使用RAS阻滞剂前后变化,并与11例未服用患者进行比较。

观察RAS阻滞剂干预治疗对IgAN患者血和尿TGF-1的作用,并探讨其对IgAN患者病情进展判断的意义。

黄芪提取物对IgAN患者IgA1异常糖基化的作用及其分子机制研究

黄芪提取物对IgAN患者IgA1异常糖基化的作用及其分子机制研究

黄芪提取物对IgAN患者IgA1异常糖基化的作用及其分子机制研究高植明【摘要】目的:考察黄芪提取物对IgAN患者IgA1异常糖基化的作用及其分子机制研究。

方法:本研究通过分离培养IgA肾病患者和非IgA肾病对照者的外周血淋巴细胞,运用免疫组化结合分子生物学手段,研究黄芪提取物对IgA1异常糖基化的调节作用及其作用机制。

结果:在IgAN患者的外周淋巴细胞上清液内,黄芪提取物组的IgA1异常糖基化程度显著降低(P<0.05),Cosmc mRNA表达水平显著提升(P<0.05)。

结论:黄芪提取物在体外实验中表现出降低IgAN患者IgA1异常糖基化程度的能力,其机制可能与之调节Comsc的基因表达有关。

%Objective: To investigate the effect of Astragalus extract on abnormal glycosylation of IgA1 in IgAN patients and its mechanism. Methods: In this study, peripheral blood lymphocytes in IgAN and non-IgAN patients were isolated and cultured, and we tried to found out whether and how Astragalus extracts could regular abnormal glycosylation of IgA1 by immunohistochemistry and molecular biology. Results: In IgAN patients, the degree of abnormal glycosylation of IgA1 in Astragalus extracts group reduced significantly (P<0.05), while Cosmc mRNA levels rose significantly (P<0.05). Conclusion: In vitro experiments, Astragalus extracts could reduce the degree of abnormal glycosylation of IgA1 in IgAN patients, which might probably have something to do with increasing Comsc gene expression.【期刊名称】《北方药学》【年(卷),期】2016(013)008【总页数】2页(P115-115,116)【关键词】黄芪提取物;IgA肾病;异常糖基化;分子机制【作者】高植明【作者单位】珠海市人民医院药学部珠海 519000【正文语种】中文【中图分类】R965IgA肾病是1968年首次报道的肾病类型,患者血清、扁桃体以及肾脏组织中均可发现IgA1分子链区糖链结构异常,是导致肾脏衰竭的最常见原因之一。

局限性硬皮病的抗非半乳糖基免疫球蛋白G抗体

局限性硬皮病的抗非半乳糖基免疫球蛋白G抗体

局限性硬皮病的抗非半乳糖基免疫球蛋白G抗体Mimura Y;Ihn H;王琼【期刊名称】《世界核心医学期刊文摘:皮肤病学分册》【年(卷),期】2006(0)1【摘要】Background: Anti-agalactosyl immunoglobulin G (IgG) antibodies (anti-AG IgG) have been reported to be detected and correlated with disease activity in some collagen diseases. Method: Forty-seven serum samples from patients with localiz ed scleroderma were examined using an enzyme-linked immunosorbent assay. Result s: Anti-AG IgG were positive in 19%of patients with localized scleroderma. The frequency of anti-AG IgG in generalized morphea was much higher than that in l inear scleroderma or that in morphea.There was a significant correlation between anti-AG IgG levels and the number of the sclerotic lesions and between anti-A G IgG levels and the number of involved areas. The levels of anti-AG IgG were s ignificantly higher in patients with antinuclear antibody, antisingle-stranded DNA antibody or rheumatoid factor than in those without. Conclusion: Anti-AG Ig G can be an indicator of the severity of localized scleroderma.【总页数】1页(P53-53)【关键词】局限性硬皮病;免疫球蛋白;糖基;泛发性硬斑病;线状硬皮病;阴性患者;类风湿因子;IgG;疾病活动度【作者】Mimura Y;Ihn H;王琼【作者单位】Department of Dermatology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan,Dr【正文语种】中文【中图分类】R593.25【相关文献】1.009局限性硬皮病患者抗-U1RNP抗体的研究 [J], 辛燕2.在局限性硬皮病中抗核抗体是主要自身抗体 [J],SatoS.;KoderaM.;HasegawaM.;阎小宁3.过敏性疾病患者过敏原特异性免疫球蛋白E抗体和总免疫球蛋白E抗体的检测结果与分析 [J], 尤德宏;张纯林;罗程;高锦伟;高燕敏4.过敏性疾病患者过敏原特异性免疫球蛋白E抗体和总免疫球蛋白E抗体的检测结果与分析 [J], 尤德宏;张纯林;罗程;高锦伟;高燕敏5.106例抗髓鞘少突胶质细胞糖蛋白免疫球蛋白G抗体阳性与抗水通道蛋白4免疫球蛋白G抗体阳性视神经炎患者临床特征比较及预后因素分析 [J], 孔秀云;王佳伟;景筠因版权原因,仅展示原文概要,查看原文内容请购买。

远志总皂苷增强鹅膏蕈氨酸诱导阿尔茨海默病大鼠的突触可塑性研究

远志总皂苷增强鹅膏蕈氨酸诱导阿尔茨海默病大鼠的突触可塑性研究

远志总皂苷增强鹅膏蕈氨酸诱导阿尔茨海默病大鼠的突触可塑性研究陈树沙;李新毅;赵大鹏【期刊名称】《中国神经免疫学和神经病学杂志》【年(卷),期】2012(19)6【摘要】Objective To observe the effects of tenuigenin (TEN) in polygala on synaptic plasticity in Alzheimer disease (AD) rats induced by ibotenic acid and aged by D-gal and to investigate the mechanism underlying the effects of TEN in polygala on synaptic plasticity. Methods Thirty-two male Wistar rats were divided randomly into four groups, the control group, the model group, the high dose TEN group and the low dose TEN group. Magnitude of long-term potentiation (LTP) was determined by comparing the average field exciatatory postsynaptic potential (fEPSP) amplitude over the baseline period with that after high-frequency stimulation (HFS) induction in the CA1 region of hippocampus. Then the immunohischemical changes of N-methyl-D-aspartate receptor 2A subunit (NR2A) in CA1 region of hippocampus were examined. Results After the HFS for 1 minute, 30 minutes and 60 minutes, LTP in the control group respectively reached (203. 17 + 7.47)%, (178.15 + 8.11)% and (164.17 + 7.03)%, while LTP of the model group only respectively reached (168.63+10.809)%, (120. 12 ± 7. 382)% and (102.88 + 2.357)%, was significantly lower than the control group (P<0. 05). LTP in high dose TEN in polygalae group respectivelyreached (192. 00 ± 2. 449)%, (168. 00 ±2.449)% and (141.75 + 9.251)%, which were higher (P<0. 05) than the low dose group' s (177.67 +14.038)%, (141. 83±4. 956)% and (121. 17±4. 792)%. Compared with the model group, both of the high and low dose group' s LTP were obviously improved (P<0. 05). The integral optical density values of the control group, the AD model group, the high dose group and the low dose group were respectively 30. 12±.3. 45, 11. 74 ± 1.69, 25.86 + 2.98 and 20. 78 ±2.66. Compared with the control group (30.12±3.45), the expression of NR2A in the AD model group (11. 74±1. 69) was obivously less (P<0. 05). Compared with the model group, the expression of NR2A was significantly more in both the high dose group (25. 86 ± 2. 98) and the low dose group (20. 78 ± 2. 66) (P<0. 05, respectively). Furthermore, the expression ofNR2A was significantly more in the high dose group than the low dose group ( P < 0. 05). Conclusions TEN in polygala may significantly enhance the LTP and increase the expression of NR2A in AD rats, and improve the synaptic plasticity in AD rats.%目的观察远志提取物远志总皂苷(TEN)对D-半乳糖致衰鹅膏蕈氨酸(IBO)诱导阿尔茨海默病(AD)模型大鼠突触可塑性的影响,并探讨其可能机制.方法将雄性Wistar大鼠随机分为对照组、AD模型组及TEN高、低剂量组,每组8只.通过电生理实验测定各组大鼠长时程增强(LTP)的变化,用免疫组织化学方法测定海马CA1区神经元N-甲基-D-天冬氨酸受体2A亚基(NR2A)积分吸光度(IOD)值,间接观察其表达情况,并进行各组间比较.结果高频刺激(HFS)后1 min、30 min和60 min对照组LTP值为(203.17±7.468)%、(178.15±8.110)%和(164.17±7.026)%,AD模型组LTP值[(168.63±10.809)%、(120.12±7.382)%和(102.88±2.357)%]较对照组显著降低(均P<0.05).TEN低剂量组LTP值为(177.67±14.038)%、(141.83±4.956)%和(121.17±4.792)%,TEN高剂量组LTP 值为(192.00±2.449)%、(168.00±2.449)%和(141.75±9.251)%,均较AD模型组升高(P<0.05).与对照组(30.12±3.45)比较,AD模型组IOD值(11.74±1.69)显著降低(P<0.05);与AD模型组比较,TEN组低剂量组、高剂量组IOD值(分别为20.78±2.66、25.86±2.98)均明显增高(P<0.05),且TEN高剂量组高于TEN低剂量组(P<0.05).结论 TEN可能使海马CA1区LTP升高和NR2A表达增加,从而改善AD大鼠突触可塑性.【总页数】4页(P449-452)【作者】陈树沙;李新毅;赵大鹏【作者单位】030001 山西医科大学附属第一临床医学院神经内科;030006 山西医学科学院神经内科;030001 山西医科大学附属第一临床医学院神经内科【正文语种】中文【中图分类】R743.9【相关文献】1.人参皂苷与远志皂苷配伍治疗大鼠阿尔茨海默病的作用研究 [J], 李卉;张艳2.三七总皂苷对博来霉素诱导的大鼠急性弥漫性肺泡损伤的保护作用研究 [J], 高风英;王星海;金文强;陈国平;刘振威3.远志总皂苷对阿尔茨海默病模型大鼠海马脑源性神经营养因子及酪氨酸蛋白激酶B表达的影响 [J], 陈伟荣;燕毅男;崔红丽;李新毅4.力竭运动对大鼠肾小管凋亡和缺氧诱导因子-1α表达的影响及人参总皂苷干预研究 [J], 王会玲;李燕;田军;胡伟锋;张金元5.远志皂苷对脂多糖诱导的帕金森病模型大鼠的作用及机制研究 [J], 袁惠莉;宫晓丽;范征;梁志刚;王晓民因版权原因,仅展示原文概要,查看原文内容请购买。

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Enzymatic Sialylation of IgA1O-Glycans:Implications for Studies of IgA NephropathyKazuo Takahashi1,4,Milan Raska1,5,Milada Stuchlova Horynova1,5,Stacy D.Hall1,Knud Poulsen6, Mogens Kilian6,Yoshiyuki Hiki7,Yukio Yuzawa4,Zina Moldoveanu1,Bruce A.Julian1,2,Matthew B.Renfrow3*,Jan Novak1*1Department of Microbiology,University of Alabama at Birmingham,Birmingham,Alabama,United States of America,2Department of Medicine,University of Alabama at Birmingham,Birmingham,Alabama,United States of America,3UAB Biomedical FT-ICR MS Laboratory,Department of Biochemistry and Molecular Genetics,University of Alabama at Birmingham,Birmingham,Alabama,United States of America,4Department of Nephrology,Fujita Health University School of Medicine,Toyoake,Japan, 5Faculty of Medicine and Dentistry,Department of Immunology,Palacky University in Olomouc,Olomouc,Czech Republic,6Department of Biomedicine,Aarhus University,Aarhus,Denmark,7Fujita Health University School of Health Sciences,Toyoake,JapanAbstractPatients with IgA nephropathy(IgAN)have elevated circulating levels of IgA1with some O-glycans consisting of galactose (Gal)-deficient N-acetylgalactosamine(GalNAc)with or without N-acetylneuraminic acid(NeuAc).We have analyzed O-glycosylation heterogeneity of naturally asialo-IgA1(Ale)myeloma protein that mimics Gal-deficient IgA1(Gd-IgA1)of patients with IgAN,except that IgA1O-glycans of IgAN patients are frequently sialylated.Specifically,serum IgA1of healthy controls has more a2,3-sialylated O-glycans(NeuAc attached to Gal)than a2,6-sialylated O-glycans(NeuAc attached to GalNAc).As IgA1-producing cells from IgAN patients have an increased activity of a2,6-sialyltransferase(ST6GalNAc),we hypothesize that such activity may promote premature sialylation of GalNAc and,thus,production of Gd-IgA1,as sialylation of GalNAc prevents subsequent Gal attachment.Distribution of NeuAc in IgA1O-glycans may play an important role in the pathogenesis of IgAN.To better understand biological functions of NeuAc in IgA1,we established protocols for enzymatic sialylation leading to a2,3-or a2,6-sialylation of IgA1O-glycans.Sialylation of Gal-deficient asialo-IgA1(Ale)myeloma protein by an ST6GalNAc enzyme generated sialylated IgA1that mimics the Gal-deficient IgA1glycoforms in patients with IgAN,characterized by a2,6-sialylated Gal-deficient GalNAc.In contrast,sialylation of the same myeloma protein by an a2,3-sialyltransferase yielded IgA1typical for healthy controls,characterized by a2,3-sialylated Gal.The GalNAc-specific lectin from Helix aspersa(HAA)is used to measure levels of Gd-IgA1.We assessed HAA binding to IgA1sialylated at Gal or GalNAc.As expected,a2,6-sialylation of IgA1markedly decreased reactivity with HAA.Notably,a2,3-sialylation also decreased reactivity with HAA.Neuraminidase treatment recovered the original HAA reactivity in both instances.These results suggest that binding of a GalNAc-specific lectin is modulated by sialylation of GalNAc as well as Gal in the clustered IgA1O-glycans.Thus,enzymatic sialylation offers a useful model to test the role of NeuAc in reactivities of the clustered O-glycans with lectins.Citation:Takahashi K,Raska M,Stuchlova Horynova M,Hall SD,Poulsen K,et al.(2014)Enzymatic Sialylation of IgA1O-Glycans:Implications for Studies of IgA Nephropathy.PLoS ONE9(6):e99026.doi:10.1371/journal.pone.0099026Editor:Ivan Cruz Moura,Institut national de la sante´et de la recherche me´dicale(INSERM),FranceReceived March13,2014;Accepted April23,2014;Published June11,2014Copyright:ß2014Takahashi et al.This is an open-access article distributed under the terms of the Creative Commons Attribution License,which permits unrestricted use,distribution,and reproduction in any medium,provided the original author and source are credited.Data Availability:The authors confirm that all data underlying the findings are fully available without restriction.All data are included within the manuscript and supplemental information.Funding:This study was supported in part by the NIH grants DK078244,GM098539,and DK082753,and by a gift from the IGA Nephropathy Foundation of America.The funders had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript.Competing Interests:The authors have declared that no competing interests exist.*E-mail:renfrow@(MR);jannovak@(JN)IntroductionGlycosylation is one of the most common post-translational modifications of proteins;about half of mammalian proteins are glycosylated.Notably,immunoglobulins and other glycoproteins may be abnormally glycosylated in patients with autoimmune and chronic inflammatory disorders,infectious diseases,or cancer[1–10].Consequently,biological functions of differentially glycosy-lated glycoproteins in health and disease are of growing interest in biomedical research[11].Some glycoproteins have clustered sites of O-glycosylation in the segments rich in serine(Ser)and threonine(Thr).Mucins,such as membrane-associated MUC1or secreted mucins,are prototypes of heavily O-glycosylated proteins.The initial step in mucin-type O-glycosylation is the transfer of N-acetylgalactosamine(GalNAc) to Ser/Thr residues catalyzed by UDP-GalNAc-polypeptide N-acetylgalactosaminyltransferases(GalNAc-Ts).The attached Gal-NAc,also called Tn antigen,can be extended by core1b1,3-galactosyltransferase(C1GalT1)that adds galactose(Gal)to GalNAc to form the core1structure(GalNAc-Gal disaccharide, called T antigen).An a2,6-sialyltransferase(ST6GalNAc;in human B cells it is exclusively ST6GalNAcII that has similar specificity as the ST6GalNAcI isoform)can produce sialylated GalNAc,called sialyl-Tn antigen,by adding N-acetylneuraminic acid(NeuAc)residue to GalNAc,whereas Gal can be sialylated by a2,3-sialyltransferases(e.g.,ST3Gal1)to form sialyl-T antigen. Sialic acids occupy the terminal positions of many glycan chains ofglycoproteins and contribute to a wide variety of biological functions and disease states[12,13].Abnormalities in mucin O-glycosylation,including terminal sialylation,are common in some types of cancer[10].Increased amounts of sialyl-Tn and sialyl-T antigens have been reported in cancer cells[10,14–19],with sialylated O-glycans being associated with higher growth rates[20] and the metastatic process[21,22]and interactions with cell-surface receptors[23].Human IgA is represented by two structurally and functionally distinct subclasses,IgA1and IgA2[24].Notably,IgA1,but not IgA2,possesses a19-amino-acid hinge region(HR)with9 potential O-glycosylation sites;3to6core1O-glycans are attached per HR[25–31](Figure1A,B).Primary IgA nephropathy (IgAN),the most common type of primary glomerulonephritis worldwide,is an immune-complex-mediated disease characterized by the presence of glomerular IgA-containing immunodeposits [32–36].These deposits may be derived from IgA1-containing circulating immune complexes(CIC),often present at increased levels in patients with IgAN[37–43].IgA1-containing CIC in patients with IgAN are characterized by Gal-deficient HR O-linked glycans of IgA1(Gd-IgA1)[40,41,43].These Gal-deficient O-glycans with terminal or sialylated GalNAc are recognized by anti-glycan antibodies,resulting in production of nephritogenic immune complexes that may deposit in the glomeruli,activate mesangial cells,and induce tissue injury[41,43–45].It has been shown that IgA1-producing cells from IgAN patients are responsible for the production of Gd-IgA1due to the altered expression and activity of specific glycosyltransferases:decreased for C1GalT1and elevated for ST6GalNAcII.Consequently,in IgAN patients the circulating levels of Gd-IgA1with sialylated and terminal GalNAc are elevated.There are two possible mechanisms for the increased amount of sialyl-Tn antigen in IgA1HR O-glycans in IgAN.In the first,augmented addition of NeuAc to GalNAc prevents further a later addition of Gal(premature sialylation);we have shown that greater activity of ST6GalNAcII is critical for the production of Gd-IgA1[46–48].Alternatively,Gal-deficient GalNAc residues may be due only to decreased C1GalT1 activity and the oversialylation of GalNAc residues would thus be a consequence of inefficient galactosylation.Studies of sialylation of the IgA1O-glycans in IgAN reported variable findings,ranging from increased[40,41,47,49–51]to decreased[52–56]sialylation.Several groups have examined the role of sialylated IgA1O-glycans in mesangial deposition;however, results of these studies have been inconclusive.Some studies suggested that oversialylation of IgA1increased the negative charge of the molecule and thus increased the affinity of such IgA1 to bind mesangial cells[49,51,57].In contrast,others reported that the decreased amount of NeuAc and Gal in IgA1-HR O-glycans enhanced affinity to extracellular matrix proteins in the mesan-gium[58–61].Notably,two studies of IgA1eluted from isolated glomeruli have identified less NeuAc in the mesangial IgA1that was enriched for Gd-IgA1[62,63].Furthermore,serum IgA1from healthy controls has more a2,3-sialylated O-glycans than a2,6-sialylated O-glycans[31].Thus,we speculate that distribution and sites of attachment of NeuAc in IgA1O-glycans may play an important role in the pathogenesis of IgAN,as IgA1-HR O-glycans may have both a2,3-and a2,6-linked NeuAc.To better assess the biological importance of NeuAc in the IgA1 HR,we established protocols for enzymatic sialylation leading to a2,6-or a2,3-sialylation of GalNAc and Gal,respectively. Enzymatic sialylation of terminal GalNAc of Gal-deficient asialo-IgA1(Ale)myeloma protein generated sialylated IgA1that mimics the Gal-deficient IgA1glycoforms in patients with IgAN, characterized by a2,6-sialylated GalNAc.We also used the same IgA1myeloma protein,as it has some of the clustered O-glycans with Gal[30],as an acceptor for a2,3-sialylation of Gal residues and generated IgA1with a2,3-sialylated Gal typical for healthy controls.Surprisingly,reactivity with Helix aspersa agglutinin (HAA),which is specific for terminal GalNAc and is used in ELISA to measure levels of Gd-IgA1[40,41,64],markedly decreased not only after a2,6-sialylation of GalNAc but also after a2,3-sialylation of Gal in IgA1HR O-glycans.This finding is,we believe,the first demonstration that binding of GalNAc-specific lectin is modulated by sialylation of Gal-containing glycans in the clustered O-glycans of IgA1with terminal GalNAc.Thus,this experimental approach is useful for testing the effects of NeuAc in clustered IgA1O-glycans on lectin recognition.Materials and MethodsRecombinant GlycosyltransferasesSoluble forms of recombinant human GalNAc-T2and ST6GalNAcI were produced in insect cells Sf9or human HEK 293T cells[65].Recombinant ST3Gal1was purchased from Calbiochem(La Jolla,CA).Acceptors for Enzyme ReactionsA panel of synthetic HR(sHR)(glyco)peptides with no GalNAc, a single GalNAc residue at five different sites,or five GalNAc residues[28]was used as enzyme acceptors for GalNAc-T2.We confirmed that preexisting sites of glycosylation on the sHR glycopeptides did not affect kinetics of the GalNAc-T2reactions (Figure S1).Thus,sHR peptide,corresponding to the amino-acid sequence of the human IgA1HR,was synthesized by and purchased from Bachem(Torrance,CA).The following sHR peptide was used as the acceptor for GalNAc-T2: VPSTPPTPSPSTPPTPSPSCCHPR-OH.The enzyme reaction mixture contained25mM Tris-HCl(pH7.4),5mM MnCl2, 250m M UDP-GalNAc(Sigma,St.Louis,MO),15m M acceptor sHR substrate or sHR glycopeptides,and the purified enzyme in a final volume of25m L.The reaction mixture was incubated at 37u C,samples were collected at different time points,and the reactions were stopped by boiling.Recombinant GalNAc-T2 added3to7GalNAc residues to sHR in15min.The polymeric form of IgA1(Ale)myeloma protein had been previously isolated from plasma of a patient with multiple myeloma[47].Briefly,the plasma sample was precipitated with ammonium sulfate(50% saturation)and dissolved in phosphate buffer,and IgG and IgM were removed by affinity chromatography with protein G and anti-human IgM antibodies,respectively[66].Next,size-exclusion chromatography on a column of Ultrogel AcA22(Amersham Biosciences,Piscataway,NJ)was used to isolate polymeric IgA1. The final purification step included FPLC separation of the polymeric form of IgA1on a column of Sephacryl300.We previously reported that the IgA1(Ale)myeloma protein used in this study was naturally without sialic acid on O-glycans[30]. Sialyltransferase ReactionssHR(15m M)with3to7GalNAc residues or2m g of purified IgA1(Ale)myeloma protein was incubated with2m l of ST3Gal1 or ST6GalNAcI overnight at37u C in a total volume of20m l reaction buffer(50mM MES buffer,pH6.5,2mM CaCl2,2mM MnCl2,10mM MgCl2,5mM CMP-NeuAc).The sialyltransfer-ase reaction with the sHR acceptor with3to7GalNAc residues was terminated by boiling.The enzyme reaction with IgA1 myeloma protein as acceptor was terminated by snap-freezing the samples at280u C[67].SDS-PAGEIgA1(Ale)myeloma protein starting samples and enzymatically sialylated IgA1samples were cleaved with IgA-specific protease from Clostridium ramosum AK183(recombinant enzyme produced in Escherichia coli )and were separated by SDS-PAGE using 4–15%gradient slab gels (Bio-Rad,Hercules,CA)under reducing conditions;the proteins were detected by silver staining.HAA Lectin-ELISAF(ab’)2fragment of goat anti-human IgA (Jackson ImmunoR-esearch,West Grove,PA)at a concentration of 3m g/ml was coated onto the wells of Costar 96-well plates (Corning Inc.,Corning,NY).Plates were blocked overnight at 4u C with 2%BSA (Sigma-Aldrich,St.Louis,MO)in PBS containing 0.05%Tween 20(v/v).Samples of IgA1diluted in the blocking buffer were added to each well and incubated overnight at 4u C.For neuraminidase treatment,the captured IgA was subsequently desialylated by treatment for 3h at 37u C with 10mU/ml neuraminidase from Vibrio cholerae (Roche,Basel,Switzerland)in 10mM sodium acetate buffer,pH 5[40].Samples were analyzed with and without neuraminidase treatment.Samples were then incubated for 3h at 37u C with GalNAc-specific biotinylated HAA lectin (Sigma-Aldrich)diluted 1:500in blocking buffer [45,47,64,66].The bound lectin was detected with avidin-horseradish peroxidase conjugate,and the reaction was developed.HAA binding to IgA1was expressed relative to the standard IgA1(Ale)myeloma protein [45,47].Proteolytic Release of IgA-HR GlycopeptidesIgA1proteins were treated with an IgA-specific protease (from Clostridium ramosum AK183or from Haemophilus influenzae HK50that differ in the cleavage site;see Figure 1A),followed by trypsin cleavage,to release IgA1HR glycopeptides [30,31].The digests were desalted by use of a C18spin column (Pierce,Rockford,IL)before mass spectrometric (MS)analyses.High-resolution MS AnalysisOn-line LC was performed by use of an Eksigent MicroAS autosampler and 2D LC nanopump (Eksigent,Dublin,CA).One-hundred-fifty nanograms of digested IgA1were loaded onto a 100-m m-diameter,11-cm column pulled tip packed with Jupiter 5-m m C18reversed-phase beads (Phenomenex,Torrance,CA).The digests were then eluted with an acetonitrile gradient from 5to 30%in 0.1%formic acid over 50min at 650nL min 21.Linear quadrupole ion trap Orbitrap Velos (Orbitrap)mass spectrometry (Thermo Fisher Scientific,San Jose,CA)parameters were as described previously [30,31].Briefly,Orbitrap parameters were set to normal mass range (MS1,300,m/z ,1800)with a 50,000resolution scan followed by five data-dependent collision-induced dissociation tandem MS scans per cycle in profile mode.Dynamic exclusion was set to exclude ions for 2min after a repeat count of three within a 45-sec duration.All spectra were analyzed by use of Xcalibur Qual Browser 2.1(Thermo Fisher Scientific)software.Identified IgA1HR O -glycopeptides were checked against theoretical values by use of GlycoMod tool ().Known IgA1HR amino-acid sequences produced by the combination of IgA-specific protease +trypsin digestions were inputted with trypsin enzyme and 0missed cleavage sites.Hexose,N -acetylhexosamine (HexNAc)and NeuAc monosaccharide resi-dues were all selected as possible (variable)additions to the IgA HR peptides with a mass tolerance of 10ppm.Figure 1.Structure of IgA1and the hinge-region (HR)amino-acid sequence.(A)Monomeric IgA1and its HR with nine possible sites of O -glycan attachment and the Fc portion of heavy chain with two N -glycans.Underlined serine (S)and threonine (T)residues in HR are frequently glycosylated [26,30,31].Arrows show cleavage sites of trypsin and two IgA-specific proteases (from Clostridium ramosum AK183and Haemophilus influenzae HK50).(B)O -glycan variants of circulatory IgA1:1,Tn antigen;2,sialyl-Tn antigen;3,T antigen;4,a 3-sialyl-T antigen;5,a 6-sialyl-T antigen;6,disialyl-T antigen.Abbreviations:GalNAc,N -acetylgalactosamine;Gal,galactose;NeuAc,N -acetylneuraminic acid.doi:10.1371/journal.pone.0099026.g001ResultsEnzymatic a2,6Sialylation of Synthetic HR(sHR)with GalNAc ResiduesWe successfully produced a recombinant soluble form of enzymatically active ST6GalNAcI.This enzyme can sialylate GalNAc of glycoproteins,similarly as does the ST6GalNAcII isoform expressed in human IgA1-producing cells.sHR glycopep-tide with3to7GalNAc residues,generated from sHR in GalNAc-T2reaction for15min,was used as an acceptor substrate for ST6GalNAcI(Figure2A).ST6GalNAcI added three to six NeuAc residues to sHR peptides with three to seven GalNAc residues, with at least one GalNAc remaining without NeuAc(Figure2B). Enzymatic a2,3Sialylation of Native IgA1ProteinST3Gal1adds sialic acid to the Gal residue of T antigen (GalNAc-Gal).To determine whether recombinant ST3Gal1adds NeuAc residues to clustered O-glycans of IgA1,we used naturally sialic-acid-deficient IgA1(Ale)myeloma protein,with three to six O-glycans with up to five T antigens,as an acceptor substrate (Figure3A).Our analysis showed that ST3Gal1added NeuAc residues to all five T antigens in the clustered HR O-glycans (Figure3B).IgA-specific protease from Haemophilus influenzae HK50 and trypsin produced N-terminal24-mer glycopeptides(His208-Pro231)and C-terminal14-mer glycopeptides(Ser232-Arg245) (Figure1A).To determine whether ST3Gal1added NeuAc residue to only Gal residues,Ser232-Arg245HR glycopeptide with GalNAc1Gal1NeuAc1was subjected to online liquid chromatog-raphy(LC)collision-induced dissociation(CID)tandem mass spectrometry(MS/MS)(Figure4A,B).Primary absence of NeuAc in the precursor ion indicated that NeuAc was attached to Gal to form a linear trisaccharide(GalNAc-Gal-NeuAc)(Figure4B). Additionally,the presence of a Gal-NeuAc oxonium ion further confirmed that the addition was the linear trisaccharide.We have previously analyzed IgA1-HR O-glycoforms of normal human serum IgA1and found that most T antigens was a2,3-sialylated [31].Thus,such an enzymatically a2,3-sialylated IgA1mimics IgA1from normal human serum.Model of Distinct a2,3/a2,6-sialylated IgA1HR O-glycoformsTo establish protocols for enzymatic sialylation of either Gal or GalNAc in IgA1-HR clustered O-glycans,asialo-IgA1(Ale) myeloma protein was sialylated using ST3Gal1or ST6GalNAcI, respectively.Significant changes in SDS-PAGE mobility after sialyltransferase reactions of IgA1Fc fragment produced by IgA-specific protease from Clostridium ramosum AK183indicated that both ST3Gal1and ST6GalNAcI added NeuAc to IgA1HR O-glycans(Figure5).Enzymatic sialylation of Gal-deficient asialo-IgA1(Ale)myeloma protein thus generated sialylated IgA1that mimics the Gal-deficient IgA1glycoforms in patients with IgAN, characterized by a2,6-sialylated GalNAc,or the IgA1typical for healthy controls,characterized by a2,3-sialylated Gal.Lectin Binding to Sialylated IgA1A GalNAc-specific lectin,HAA,is used in ELISA to measure levels of Gd-IgA1.Notably,a2,6-as well as a2,3-sialylation of IgA1HR O-glycans markedly decreased reactivity with HAA (Figure6).Neuraminidase treatment recovered the original HAA reactivity.These results thus suggest that binding of GalNAc-specific lectin is affected not only by sialylation of GalNAc but also by sialylation of Gal in the clustered O-glycans of Gal-deficient IgA1.DiscussionPatients with IgAN have elevated circulating levels of IgA1with some O-glycans consisting of terminal or sialylated GalNAc.We Figure 2.MS analysis of sialylation of GalNAcosylated synthetic HR glycopeptides(sHR)by ST6GalNAcI.(A)Acceptor sHR glycopeptides for ST6GalNAcI with3to7GalNAc residues were generated by recombinant GalNAc-T2after a15-min reaction.(B)sHR glycopeptides produced after over-night reaction with ST6GalNAcI.Symbols:GalNAc,square;NeuAc,diamond.Red symbols:glycopeptides ionized as4+ions;Blue symbols:glycopeptides ionized as3+ions.doi:10.1371/journal.pone.0099026.g002have previously analyzed O -glycosylation of naturally sialic-acid-deficient IgA1(Ale)myeloma protein that mimics the aberrant (i.e.,Gal-deficient)IgA1in patients with IgAN,although HR O -glycans of circulatory IgA1are frequently sialylated.It has been suggested that the anionic nature of IgA1may promote mesangial IgA1deposition [68,69]and the anionic character of IgA1is in agreement with less NeuAc in IgA1HR O -glycans [47,49–51].However,IgA1eluted from isolated glomeruli has decreased level of NeuAc compared to IgA1in the circulation of the correspond-ing IgAN patients [62,63].These observations of altered sialylation of IgA1O -glycans have become a significant area of interest in the pathogenesis of IgAN.We have reported that IgA1-producing cells from IgAN patients have increased expression of ST6GalNAcII,an isoform closely related to ST6GalNAcI,and that IgA1secreted by IgA1-producing cells from IgAN patients contained terminal and sialylated GalNAc [47].Furthermore,our high-resolution MS analysis showed that IgA1from healthy controls had more a 2,3-sialylated O -glycans than a 2,6-sialylated O -glycans [31].We speculate that distribution of NeuAc in IgA1O -glycans may play an important role in the pathogenesis of IgAN,as IgA1-HR O -glycans have a 2,3-as well as a 2,6-linked NeuAc.To study the effect of NeuAc in the IgA1HR on lectin binding,we established protocols for enzymatic sialylation leading to a 2,3-or a 2,6-sialylation of Gal and GalNAc,respectively.These protocols allow linkage-specific sialylation to assess the effect of the respective type of sialylation on IgA1lectin recognition.Biological roles of NeuAc in clustered O -glycans of IgA1are not fully understood.NeuAc residues in IgA1HR O -glycansinfluenceFigure 3.MS analysis of sialylation by ST3Gal1of IgA1myeloma protein that is naturally sialic-acid-deficient.(A)HR O -glycan profile of IgA1(Ale)myeloma protein.The number of O -glycans was assigned based on the masses of the amino-acid sequence,GalNAc (empty squares),Gal (full circles),and NeuAc (full diamonds).The O -glycans of the protein are minimally sialylated.All HR O -glycoforms are ionized as triply charged ions.(B)HR O -glycan profile of IgA1(Ale)myeloma protein after over-night sialylation reaction with ST3Gal1.The enzyme added NeuAc residues to the O -glycans of Ale myeloma protein.All HR O -glycoforms are ionized as quadruply charged ions.doi:10.1371/journal.pone.0099026.g003the affinity of IgA1to some receptors.For example,binding of IgA1to asialoglycoprotein receptor (ASGP-R)is reduced by sialylation of IgA1[70–75].It also has been suggested thatenhanced sialylation of IgA1extended its half-life in the circulation due to reduced clearance [1,49,51].The association of recurrent macroscopic hematuria with upper-respiratory-tract infections in IgAN patients led to the suggestion that the production of pathogenic IgA1may berelatedFigure 4.LC-CID fragmentation of IgA1Ser 232-Arg 245(HR)with GalNAc 1Gal 1NeuAc 1.(A)Ser 232-Arg 245HR O -glycan profile of IgA1(Ale)myeloma protein enzymatically sialylated with ST3Gal1.(B)LC-CID tandem MS spectrum of Ser 232-Arg 245with GalNAc 1Gal 1NeuAc 1.Absence of sialylated GalNAc (shown in blue parenthesis)indicates that NeuAc is attached to Gal (by an a 2,3-linkage)in the precursor ion.Additionally,the presence of the Gal-NeuAc oxonium ion confirms the attachment of the NeuAc to Gal.doi:10.1371/journal.pone.0099026.g004Figure 5.SDS-PAGE of IgA1(Ale)myeloma protein.IgA1proteins were separated by SDS-PAGE under reducing conditions and the protein bands were silver stained.IgA1was untreated or sialylated with ST3Gal1(ST3)or ST6GalNAcI (ST6)sialyltransferases and the Fc and Fd fragments of the heavy chains were generated using IgA-specific protease from Clostridium ramosum AK183(see Fig.1).Mobility change of Fc fragments after sialyltransferase reactions confirmed sialylation of HR O -glycans.doi:10.1371/journal.pone.0099026.g005Figure 6.HAA reactivity of IgA1(Ale)myeloma protein with (N +)or without (N-)neuraminidase treatment.HAA lectin binding to Gal-deficient IgA1(Ale)in ELISA is reduced by sialylation of GalNAc as well as of Gal by specific sialyltransferases.HAA binding to an untreated IgA1protein is set to 100%.doi:10.1371/journal.pone.0099026.g006to abnormal handling of mucosal antigens.Gd-IgA1in the patients with IgAN is found almost exclusively in CIC bound to IgG or IgA1antiglycan antibodies[37–41].We recently have shown that these IgG antibodies recognize GalNAc-containing epitopes on the Gal-deficient HR O-glycans of IgA1[43].As to the origin of these antibodies,it has been suggested that they may primarily recognize GalNAc-containing epitopes on viruses(e.g., Epstein-Barr virus)or bacteria(streptococci)and that they happen to cross-react with glycans on Gd-IgA1[76].As surfaces of microbes can be sialylated[77],NeuAc in IgA1-HR O-glycans may play an important role in the recognition by specific antibodies against the HR of Gd-IgA1.Our enzymatic sialylation protocol in conjunction with MS/MS analyses of the resultant products will be useful for the molecular studies of the glycoprotein or glycopeptide structures that may exhibit strong affinity to glycan-specific antibodies recognizing Gd-IgA1.IgA-specific proteases are proteolytic enzymes that cleave specific peptide bonds in the human IgA HR[78].Several species of pathogenic bacteria secrete IgA-specific proteases at mucosal sites of infection that neutralize effector functions of human IgA1 and thereby eliminate an important aspect of host defense.Thus, IgA-specific proteases are considered virulence factors,as they prevent effective IgA-mediated immune defense that requires intact IgA[78–80].Importantly,some of these bacteria(e.g., Streptococcus pneumoniae)also secrete neuraminidase[80–84]that removes sialic acid in the first step of the breakdown of soluble mucins as well as cell-surface glycoconjugates[13].It is thus conceivable that structural changes by desialylation of IgA1may facilitate the recognition of Gd-IgA1HR O-glycans by antiglycan IgG.This hypothesis may explain the association of macroscopic hematuria with upper-respiratory-tract infections.In this setting, the amount of circulating antiglycan autoantibodies presumably increases due to the infection.The antibodies bind to Gd-IgA1, resulting in formation of IgA1-IgG complexes,with subsequent renal deposition,mesangial cell activation,and glomerular injury (for review,see[36]).We have developed a new model for sugar-specific sialylation of IgA1O-glycans and showed that GalNAc recognition by HAA lectin is modulated by sialylation of not only GalNAc but also of Gal in the clustered IgA1O-glycans.We envision that our enzymatic sialylation protocol will be useful for the study the biological roles of sialic acid in IgA1-HR O-glycans.Moreover, characterizing IgA1-HR glycoforms,including sialylation,is important for understanding the pathogenesis of IgAN and developing disease-specific biomarkers[85].Supporting InformationFigure S1The amount of GalNAc residues attached to HR acceptor substrates in the time-course study with GalNAc-T2.The amount of GalNAc attached to acceptor substrates was calculated based on the relative abundance of each glycoform.The following HR glycopeptides with a single GalNAc residue at different sites were used as enzyme acceptors:4-HP: VPST(GalNAc)PPTPSPSTPPTPSPS,7-HP:VPSTPPT(Gal-NAc)PSPSTPPTPSPS,9-HP:VPSTPPTPS(Gal-NAc)PSTPPTPSPS,11-HP:VPSTPPTPSPS(Gal-NAc)TPPTPSPS,15-HP:VPSTPPTPSPSTPPT(GalNAc)PSPS.A synthetic HR peptide and HR glycopeptide with five GalNAc residues attached were also used:HP: VPSTPPTPSPSTPPTPSPS;All-HP:VPST(GalNAc)PPT(Gal-NAc)PS(GalNAc)PS(GalNAc)TPPT(GalNAc)PSPS.(TIF)AcknowledgmentsWe appreciate the 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