iPSC分化过程中各类因子用途及作用

IBMX：A nonspecific inhibitor of cAMP and cGMP phosphodiesterases that is commonly used to increase the pool of intracellular cAMP [19] and to reduce the effect of tumor necrosis factor α(TNFα). increased cAMP has been shown to drive erythroid proliferation.
TNFa : TNFa is a recognized inhibitor of hematopoietic progenitor development and of erythropoiesis.
Stemregenin 1/SR1: an antagonist of the aryl hydrocarbon receptor (AhR), SR1 can extend the period over which CD34-positive hematopoietic cells emerge. StemRegenin1 (SR1) is an antagonist of the aryl hydrocarbon receptor (AHR). It promotes ex vivo expansion of CD34+ human hematopoietic stem cells and the generation of CD34+ hematopoietic progenitor cells from non-human primate induced pluripotent stem cells. SR1 has been shown to collaborate with UM729 in preventing differentiation of acute myeloid leukemia (AML) cells in culture. SR1 also stimulates the proliferation and differentiation of CD34+ hematopoietic progenitor cells into dendritic cells.
Activin A：A short exposure to Activin A resulting in a low level of NODAL signaling was found to stimulate human mesoderm formation, whereas a longer exposure led to endoderm formation
BMP4 can induce GATA2, RUNX1, CD34, and SCL expression in addition to its ability to induce early mesodermal markers. BMP-4 is a member of the highly conserved transforming growth factor-β (TGF-β) superfamily. BMPs have been shown to be key regulators of embryogenesis and are known to play a role in the growth and differentiation of various cell types, including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), mesenchymal cells, epithelial cells, hematopoietic cells, and neuronal cells.
bFGF: Basic fibroblast growth factor (bFGF) is a prototypic member of the fibroblast growth factor family. Cytokines in the FGF family possess broad mitogenic and cell survival activities and are involved in a variety of biological processes including cell proliferation, differentiation, survival, and apoptosis. bFGF has the β-trefoil structure, binds to the four FGF receptor (FGFR) family members, and activates JAK/STAT, PI3K, ERK1/2, and other receptor tyrosine kinase (RTK) signaling pathways. It supports the maintenance of undifferentiated human embryonic stem cells, stimulates human embryonic stem cells to form neural rosettes, and improves proliferation of human mesenchymal stem cells and enhances chondrogenic differentiation
PD98059：PD98059 is a selective, cell permeable inhibitor of the MEK/ERK pathway that acts by preventing the activation of MEK1 (IC₅₀= 2 - 7 µM) and MEK2 (IC₅₀= 50 µM) by upstream kinases. Blocks the differentiation of mouse ES cells. Enhances adipogenic differentiation and blocks osteogenic differentiation of human mesenchymal stem cells
CHIR99021 is an aminopyrimidine derivative that is an extremely potent inhibitor of GSK3, inhibiting GSK3β (IC₅₀= 6.7 nM) and GSK3α(IC₅₀= 10 nM) and functions as a WNT activator. It is the most selective inhibitor of GSK3 reported so far.
VEGF: Growth factor active in angiogenesis, vasculogenesis and endothelial cell growth. Induces endothelial cell proliferation, promotes cell migration, inhibits apoptosis and induces permeabilization of blood vessels. Binds to the FLT1/VEGFR1 and KDR/VEGFR2 receptors,
heparan sulfate and heparin. NRP1/Neuropilin-1 binds isoforms VEGF-165 and VEGF-145. Isoform VEGF165B binds to KDR but does not activate downstream signaling pathways, does not activate angiogenesis and inhibits tumor growth. Binding to NRP1 receptor initiates a signaling pathway needed for motor neuron axon guidance and cell body migration, including for the caudal migration of facial motor neurons from rhombomere 4 to rhombomere 6 during embryonic development
Thrombopoietin (TPO) is a key regulator of megakaryopoiesis and thrombopoiesis in vitro and in vivo. TPO stimulates the proliferation and maturation of megakaryocytes, and has also been shown to promote the survival, self-renewal and expansion of hematopoietic stem cells and primitive multilineage progenitors.
Erythropoietin (EPO)is a glycoprotein produced primarily by the kidney in response to hypoxia or anemia. It is the principal factor that regulates erythropoiesis by stimulating the proliferation and differentiation of erythroid progenitor cells.
Interleukin 6 (IL-6) is a pleiotropic growth factor with the wide range of biological activities in immune regulation, hematopoiesis, and oncogenesis. IL-6 is produced by a variety of cell types including T cells, B cells, monocytes and macrophages, fibroblasts, hepatocytes, vascular endothelial cells, and various tumor cell lines. On its own or in combination with other factors such as IL-2 and interferon-γ, IL-6 stimulates the proliferation of B cells, T cells, and hybridoma cells. In combination with cytokines such as IL-3, GM-CSF and SCF, IL-6 has been shown to promote hematopoietic progenitor cell proliferation and differentiation in vitro. IL-6 signals through a cell surface type I cytokine receptor complex consisting of the ligand-binding IL-6α (CD126) and the signal-transducing gp130 subunits. The binding of IL-6 to its receptor system includes activation of JAK/STAT signaling pathway
IL-3is a hematopoietic growth factor that promotes the survival, differentiation and proliferation of committed progenitor cells of the megakaryocyte, granulocyte-macrophage, erythroid, eosinophil, basophil and mast cell lineages. Produced by T cells, mast cells and eosinophils, IL-3 enhances thrombopoiesis, phagocytosis, and antibody-mediated cellular cytotoxicity. Its ability to activate monocytes suggests that IL-3 may have additional immunoregulatory roles. Many of the IL-3 activities depend upon co-stimulation with other cytokines. IL-3 is a species-specific, variably glycosylated cytokine.
Interleukin 11 (IL-11) is a pleiotropic cytokine with effects on various tissues including the bone marrow, brain, and intestinal mucosa. It belongs to the IL-6 family of cytokines that share a common signal transducer, gp130. IL-11 induces the proliferation of hematopoietic stem cells (Lemoli et al.) and megakaryocytic progenitor cells (Bruno et al.), the maturation of megakaryocytes (Burstein et al.), and the production of platelets (Neben et al.). IL-11 is produced by a variety of cell types including hematopoietic cells, mesenchymal cells, epithelial cells, and neuronal cells. It was first cloned from a cDNA library of the human bone marrow-derived stromal cell line KM-102 (Kawashima et al.). The binding of IL-11 to its receptor induces heterodimerization with the gp130 subunit and activation of JAK tyrosine kinases. IL-11 was the first pharmacologic agent approved for the treatment of chemotherapy-induced
thrombocytopenia. IL-11 also plays a role in cancer progression by inducing the proliferation of epithelial cancer cells and the survival of metastatic cells at distant organs. Recently, IL-11 has gained interest for its role in the pathogenesis of diseases in dysregulated mucosal homeostasis associated with STAT3 upregulation, including gastrointestinal cancers (Putoczki et al.).
SB431542 (SB) is an established small molecular inhibitor that specifically binds to the ATP binding domains of the activin receptor-like kinase receptors, ALK5, ALK4 and ALK7, and thus specifically inhibits Smad2/3 activation and blocks TGF-β signal transduction.。