Current Issue : January - March Volume : 2017 Issue Number : 1 Articles : 6 Articles
Background: Proliferation of the vasa vasorum has been implicated in the pathogenesis of atherosclerosis, and\nthe vasa vasorum is closely associated with resident stem cells within the vasculature. C-reactive protein (CRP)\nis positively correlated with cardiovascular disease risk, and our previous study demonstrated that it induces\ninflammatory reactions of perivascular adipose tissue by targeting adipocytes.\nMethods: Here we investigated whether CRP affected the proliferation and proangiogenic paracrine activity\nof adipose-derived stem cells (ADSCs), which may contribute to vasa vasorum angiogenesis.\nResults: We found that CRP did not affect ADSC apoptosis, cell cycle, or proliferation but did increase their\nmigration by activating the PI3K/Akt pathway. Our results demonstrated that CRP can upregulate vascular\nendothelial growth factor-A (VEGF-A) expression by activating hypoxia inducible factor-1�± (HIF-1�±) in ADSCs,\nwhich significantly increased tube formation on Matrigel and functional vessels in the Matrigel plug\nangiogenesis assay. The inhibition of CRP-activated phosphorylation of ERK and Akt can suppress CRPstimulated\nHIF-1�± activation and VEGF-A expression. CRP can also stimulate proteolytic activity of matrix\nmetalloproteinase-2 in ADSCs. Furthermore, CRP binds activating CD64 on ADSCs, rather than CD16/32.\nConclusion: Our findings implicate that CRP might play a role in vasa vasorum growth by activating the\nproangiogenic activity of ADSCs....
Background: Mesenchymal stem cells (MSCs) have been widely proven effective for therapeutic angiogenesis in\nischemia animal models as well as clinical vascular diseases. Because of the invasive method, limited resources,\nand aging problems of adult tissue-derived MSCs, more perinatal tissue-derived MSCs have been isolated and\nstudied as promising substitutable MSCs for cell transplantation. However, fewer studies have comparatively\nstudied the angiogenic efficacy of MSCs derived from different tissues sources. Here, we evaluated whether the\nin-situ environment would affect the angiogenic potential of MSCs.\nMethods: We harvested MSCs from adult bone marrow (BMSCs), adipose tissue (AMSCs), perinatal umbilical cord\n(UMSCs), and placental chorionic villi (PMSCs), and studied their ââ?¬Å?MSC identityââ?¬Â by flow cytometry and in-vitro\ntrilineage differentiation assay. Then we comparatively studied their endothelial differentiation capabilities and\nparacrine actions side by side in vitro.\nResults: Our data showed that UMSCs and PMSCs fitted well with the minimum standard of MSCs as well as\nBMSCs and AMSCs. Interestingly, we found that MSCs regardless of their tissue origins could develop similar\nendothelial-relevant functions in vitro, including producing eNOS and uptaking ac-LDL during endothelial\ndifferentiation in spite of their feeble expression of endothelial-related genes and proteins. Additionally, we\nsurprisingly found that BMSCs and PMSCs could directly form tubular structures in vitro on Matrigel and their\nconditioned medium showed significant proangiogenic bioactivities on endothelial cells in vitro compared\nwith those of AMSCs and UMSCs. Besides, several angiogenic genes were upregulated in BMSCs and PMSCs\nin comparison with AMSCs and UMSCs. Moreover, enzyme-linked immunosorbent assay further confirmed that\nBMSCs secreted much more VEGF, and PMSCs secreted much more HGF and PGE2.\nConclusions: Our study demonstrated the heterogeneous proangiogenic properties of MSCs derived from\ndifferent tissue origins, and the in vivo isolated environment might contribute to these differences. Our study\nsuggested that MSCs derived from bone marrow and placental chorionic villi might be preferred in clinical\napplication for therapeutic angiogenesis....
Background: Mesenchymal stem cells (MSCs) are widely used in cell-based therapy owing to their multilineage\npotential and low immunogenicity. However, low differentiation efficiency and unpredictable immunogenicity\nof allogeneic MSCs in vivo limit their success in therapeutic treatment. Herein, we evaluated the differentiation\npotential and immunogenicity of human placenta-derived MSCs manipulated with osteogenic priming and\ndedifferentiation process.\nMethods: MSCs from human placentas were subjected to osteogenic induction and then cultivated in osteogenic\nfactor-free media; the obtained cell population was termed dedifferentiated mesenchymal stem cells (De-MSCs).\nDe-MSCs were induced into osteo-, chondro- and adipo-differentiation in vitro. Cell proliferation was quantified by\na Cell-Counting Kit-8 or tritiated thymidine ([3H]-TdR) incorporation. Meanwhile, the osteogenesis of De-MSCs in\nvivo was assayed by real-time PCR and histological staining. The expressions of stem cell markers and costimulatory\nmolecules on De-MSCs and lymphocytes from primed BALB/c mouse with De-MSCs were determined\nby flow cytometry.\nResults: De-MSCs exhibited some properties similar to MSCs including multiple differentiation potential and\nhypoimmunogenicity. Upon re-osteogenic induction, De-MSCs exhibited higher differentiation capability than MSCs\nboth in vitro and in vivo. Of note, De-MSCs had upregulated immunogenicity in association with their osteogenesis,\nreflected by the alternated expressions of co-stimulatory molecules on the surface and decreased suppression on\nT cell activation. Functionally, De-MSC-derived osteoblasts could prime lymphocytes of peripheral blood and spleen\nin BALB/c mice in vivo.\nConclusions: These data are of great significance for the potential application of De-MSCs as an alternative\nresource for regenerative medicine and tissue engineering. In order to avoid being rejected by the host during\nallogeneic De-MSC therapy, we suggest that immune intervention should be considered to boost the immune\nacceptance and integration because of the upregulated immunogenicity of De-MSCs with redifferentiation in\nclinical applications....
Induced pluripotent stem (iPS) cells have been generated fromhuman somatic cells by ectopic expression of four Yamanaka factors.\nHere, we report that Survivin, an apoptosis inhibitor, can enhance iPS cells generation from human neural progenitor cells (NPCs)\ntogether with one factor OCT4 (1F-OCT4-Survivin). Compared with 1F-OCT4, Survivin accelerates the process of reprogramming\nfrom human NPCs. The neurocyte-originated induced pluripotent stem (NiPS) cells generated from 1F-OCT4-Survivin resemble\nhuman embryonic stem (hES) cells inmorphology, surface markers, global gene expression profiling, and epigenetic status. Survivin\nkeeps high expression in both iPS and ES cells. During the process of NiPS cell to neural cell differentiation, the expression of\nSurvivin is rapidly decreased in protein level. The mechanism of Survivin promotion of reprogramming efficiency from NPCs\nmay be associated with stabilization of ...
The human induced pluripotent stem cell (hiPSC) provides a breakthrough approach that helps overcoming ethical and allergenic\nchallenges posed in application of neural stem cells (NSCs) in targeted cancer gene therapy. However, the tumor-tropic capacity of\nhiPSC-derived NSCs (hiPS-NSCs) still hasmuch roomto improve.Here we attempted to promote the tumor tropismof hiPS-NSCs\nby manipulating the activity of endogenous miR-199a/214 cluster that is involved in regulation of hypoxia-stimulated cell migration.\nWe first developed a baculovirus-delivered CRISPR interference (CRISPRi) system that sterically blocked the E-box element in the\npromoter of the miR-199a/214 cluster with an RNA-guided catalytically dead Cas9 (dCas9).We then applied this CRISPRi system\nto hiPS-NSCs and successfully suppressed the expression of miR-199a-5p, miR-199a-3p, and miR-214 in the microRNA gene cluster.\nMeanwhile, the expression levels of their targets related to regulation of hypoxia-stimulated cell migration, such as HIF1A, MET,\nand MAPK1, were upregulated. Further migration assays demonstrated that the targeted inhibition of the miR-199a/214 cluster\nsignificantly enhanced the tumor tropism of hiPS-NSCs both in vitro and in vivo. These findings suggest a novel application of\nCRISPRi in NSC-based tumor-targeted gene therapy....
Background: The Activin A and bone morphogenetic protein (BMP) pathways are critical regulators of the immune\nsystem and of bone formation. Inappropriate activation of these pathways, as in conditions of congenital heterotopic\nossification, are thought to activate an osteogenic program in endothelial cells. However, if and how this occurs in\nhuman endothelial cells remains unclear.\nMethods: We used a new directed differentiation protocol to create human induced pluripotent stem cell (hiPSC)-\nderived endothelial cells (iECs) from patients with fibrodysplasia ossificans progressiva (FOP), a congenital disease of\nheterotopic ossification caused by an activating R206H mutation in the Activin A type I receptor (ACVR1). This strategy\nallowed the direct assay of the cell-autonomous effects of ACVR1 R206H in the endogenous locus without the use of\ntransgenic expression. These cells were challenged with BMP or Activin A ligand, and tested for their ability to activate\nosteogenesis, extracellular matrix production, and differential downstream signaling in the BMP/Activin A pathways.\nResults: We found that FOP iECs could form in conditions with low or absent BMP4. These conditions are not normally\npermissive in control cells. FOP iECs cultured in mineralization media showed increased alkaline phosphatase staining,\nsuggesting formation of immature osteoblasts, but failed to show mature osteoblastic features. However, FOP iECs\nexpressed more fibroblastic genes and Collagen 1/2 compared to control iECs, suggesting a mechanism for the tissue\nfibrosis seen in early heterotopic lesions. Finally, FOP iECs showed increased SMAD1/5/8 signaling upon BMP4\nstimulation. Contrary to FOP hiPSCs, FOP iECs did not show a significant increase in SMAD1/5/8 phosphorylation upon\nActivin A stimulation, suggesting that the ACVR1 R206H mutation has a cell type-specific effect. In addition, we found\nthat the expression of ACVR1 and type II receptors were different in hiPSCs and iECs, which could explain the cell typespecific\nSMAD signaling.Conclusions: Our results suggest that the ACVR1 R206H mutation may not directly increase the formation of\nmature chondrogenic or osteogenic cells by FOP iECs. Our results also show that BMP can induce endothelial cell\ndysfunction, increase expression of fibrogenic matrix proteins, and cause differential downstream signaling of the\nACVR1 R206H mutation. This iPSC model provides new insight into how human endothelial cells may contribute\nto the pathogenesis of heterotopic ossification....
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