Hypoxic Preconditioning Improved Neuroprotective Effect of Bone Marrow-Mesenchymal Stem Cells Transplantation in Acute Glaucoma Models

This study explored the novel strategy of hypoxic preconditioning of Bone Marrow Mesenchymal Stem Cells (BM-MSCs) before intra vitreal transplantation to improve neuroprotective effects of Retinal Ganglion Cells (RGCs) in Acute Glaucoma Models. The methods of this research were isolated mesenchymal stem cells from the bone marrow of adult wild-type Sprague-Dawley (SD) rats. BM-MSCs were cultured under normoxic or hypoxic (1% oxygen for 24 hours) conditions. Normoxic or hypoxic BM-MSCs were transplanted intravitreally 1 week after ocular hypertension induction by acutely increasing IOP to 100 - 120 mmHg for 60 minutes. Rats were killed 4 weeks after transplanted. Apoptosis was examined by tunnel assay and expression Brn3b (Brn3b = RGCs marker) by immunohistochemical analysis of the retina. Results showed that transplantation of hypoxic preconditioning BM-MSCs in acute glaucoma models resulted in a significant apoptosis decreasing (p < 0.05) and an significant increasing in RGCs (p < 0.05), as well as enhanced mor-phologic and functional benefits of stem cell therapy versus normoxic BM-MSCs transplantation. Conclusions: Hypoxic preconditioning enhances the capacity of BM-MSCs transplantation to improve neuroprotective effects of RGCs in Acute Glaucoma Models.

Mesenchymal Stromal Cells Derived from Human Embryonic Stem Cells, Fetal Limb and Bone Marrow Share a Common Phenotype but Are Transcriptionally and Biologically Different

Mesenchymal stromal cells (MSCs) can be obtained from several sources and the significant differences in their properties make it crucial to investigate the differentiation potential of MSCs from different sources to determine the optimal source of MSCs. We investigated if this biological heterogeneity in MSCs from different sources results in different mechanisms for their differentiation. In this study, we compared the gene expression patterns of phenotypically defined MSCs derived from three ontogenically different sources: Embryonic stem cells (hES-MSCs), Fetal limb (Flb-MSCs) and Bone Marrow (BM-MSCs). Differentially expressed genes between differentiated cells and undifferentiated controls were compared across the three MSC sources. We found minimal overlap (5% - 16%) in differentially expressed gene sets among the three sources. Flb-MSCs were similar to BM-MSCs based on differential gene expression patterns. Pathway analysis of the differentially expressed genes using Ingenuity Pathway Analysis (IPA) revealed a large variation in the canonical pathways leading to MSC differentiation. The similar canonical pathways among the three sources were lineage specific. The Flb-MSCs showed maximum overlap of canonical pathways with the BM-MSCs, indicating that the Flb-MSCs are an intermediate source between the less specialised hES-MSC source and the more specialised BM-MSC source. The source specific pathways prove that MSCs from the three ontogenically different sources use different biological pathways to obtain similar differentiation outcomes. Thus our study advocates the understanding of biological pathways to obtain optimal sources of MSCs for various clinical applications.

Preliminary Study on the Mechanism of Acupoint Injection of Bone Marrow Mesenchymal Stem Cells in Improving Blood Flow in the Rat of Hind Limb Ischemia

Objective:To explore the mechanism of acupoint injection of bone marrow mesenchymal stem cells(BM-MSCs) in improving blood flow in the rat with hind limb ischemia.Methods:Twenty-four SD rats were randomly divided into 4 groups:normal control group(n=6),model group(n=6),BM-MSCs acupoint injection group(AI group,n=6) and BM-MSC intramuscular injection group(MI group,n=6).Sanyinjiao(SP 6),Housanli(ST 36),Zhaohai(KI 6),Huantiao(GB 30) and Yanglingquan(GB 34) were selected for the AI group,and five non-acupoints were selected on gastrocnemius and adductor of ischemic hind limbs in the MI group.BM-MSCs were injected to the latter two groups.The rat hind limb ischemia model was established with the method of blocking the femoral artery and its branches.Three weeks after injection of BM-MSCs,in each group,hindlimb adductor and gastrocnemius were taken from the ischemic side.Expressions of vascular endothelial growth factor(VEGF) and transfer growth factor-β1(TGF-β1) in the skeletal muscle were determined with immunohistochemical method,and the small arteries in the skeletal muscle were labeled with α-SMA immunohistochemical staining method,the density of small arteries(number of arterioles /number of muscle fibers) and the number of the blood vessel with VEGF positive expression were calculated.The serum levels of VEGF and nitric oxide(NO) were detected.Results:Compared with the model group,the expression of VEGF and TGF-β1,and the density of small arteries and the number of VEGF-positive blood vessels in the AI group and the MI group significantly increased(both P<0.01).Compared with the MI group,the density of small arteries and the number of VEGF-positive blood vessels in the AI group significantly increased(both P<0.01);Compared with the model group and the normal control group,the serum expression quantity of NO and VEGF in the AI group and the MI group were significantly increased(P<0.01).Conclusions:Acuppoint injection of BM-MSCs secrets more VEGF,TGF-β1 and NO to increase angiogenesis and arteriogenesis,so as to improve blood flow of the rats of hind limb ischemic.