Efficiency Of Mesenchymal Stem Cells Transplantation Research Articles

Self-assembling peptide modified with QHREDGS as a novel delivery system for mesenchymal stem cell transplantation after myocardial infarction.

The lower cell survival and retention in the hostile microenvironment after transplantation has been implicated as a major bottleneck in the advancement of stem cell therapy for myocardial infarction (MI). In this study, we designed a novel self-assembling peptide (SAP) by attaching prosurvival peptide QHREDGS derived from angiopoeitin-1 to the known SAP, RADA16-I. The mesenchymal stem cells (MSCs) were harvested from male rats and cytoprotective effect of this designer SAP (DSAP) on cultured MSCs was detected by Hoechst 33342 staining after being exposed to oxygen and glucose deprivation (OGD). The cytoprotective effect of MSCs seeded in DSAP (DSAP-MSCs) on OGD treated cardiomyocytes was examined by TUNEL staining, phosphorylated (p-) protein kinase B (Akt) level, and ELISA. The therapeutic potential of MSC transplantation carried in DSAP was evaluated in a female rat MI model. PBS, MSCs alone, MSCs seeded in SAP (SAP-MSCs), or DSAP-MSCs were transplanted into the border of the infarcted area, respectively. DSAP not only increased the proliferation of MSCs and decreased apoptosis of MSCs after OGD treatment but also promoted the secretion of IGF-1 and HGF in MSCs. Treatment with culture supernatant of DSAP-MSCs markedly reduced the percentage of apoptotic cardiomyocytes and increased the level of p-Akt. Compared with the MSC group and SAP-MSC group, DSAP-MSC injection improved cardiac function and reduced infarct size, collagen content, and cell apoptosis. The number of Y chromosome-positive cells and microvessels in the DSAP-MSC group was higher than those in the MSC group and SAP-MSC group. Moreover, DSAP-MSC transplantation down-regulated the expression of IL-6 and IL-1β and up-regulated the level of VEGF and HGF. Interestingly, miR-21 was enriched in DSAP-MSC-derived exosomes (DSAP-MSC-Exos) and the protection against cardiomyocyte apoptosis by DSAP-MSC-Exos was inhibited when miR-21 was knocked down. Furthermore, miR-21 contributed to the improvement of cardiac function after DSAP-MSC-Exo injection in a rat model of MI. Additionally, the combination of DSAP and cardiotrophin-1 (Ctf1) pretreatment further improved the survival of MSCs and the efficiency of MSC transplantation. We proposed QHREDGS-modified SAP as an effective cell delivery system and demonstrated that MSC transplantation in this DSAP promoted angiogenesis and paracrine, thereby reducing scar size and cell apoptosis as well as improving cardiac function probably via exosome-mediated miR-21 after MI. Furthermore, for the first time, we proposed that DSAP, especially working together with Ctf1 pretreatment, could be a valuable way to improve the survival of MSCs and the efficiency of MSC transplantation after MI.-Cai, H., Wu, F.-Y., Wang, Q.-L., Xu, P., Mou, F.-F., Shao, S.-J., Luo, Z.-R., Zhu, J., Xuan, S.-S., Lu, R., Guo, H.-D. Self-assembling peptide modified with QHREDGS as a novel delivery system for mesenchymal stem cell transplantation after myocardial infarction.

Lipopolysaccharide pretreatment inhibits LPS-induced human umbilical cord mesenchymal stem cell apoptosis via upregulating the expression of cellular FLICE-inhibitory protein.

Mesenchymal stem cell (MSC)-based regenerative therapy is currently regarded as a novel approach with which to repair damaged tissues. However, the efficiency of MSC transplantation is limited due to the low survival rate of engrafted MSCs. Lipopolysaccharide (LPS) production is increased in numerous diseases and serves an essential function in the regulation of apoptosis in a variety of cell types. Previous studies have indicated that low-dose LPS pretreatment contributes to cytoprotection. In the current study, LPS was demonstrated to induce apoptosis in human umbilical cord mesenchymal stem cells (hUCMSCs) via the activation of caspase, in a dose-dependent manner. Low-dose LPS pretreatment may protect hUCMSCs against apoptosis induced by high-dose LPS, by upregulating the expression of cellular FADD-like IL-1β-converting enzyme-inhibitory protein (c-FLIP). The results of the present study indicate that pretreatment with an appropriate concentration of LPS may alleviate high-dose LPS-induced apoptosis.

In vivo bioluminescence imaging of transplanted mesenchymal stem cells as a potential source for pancreatic regeneration.

Stem cell therapy has been studied intensively as a promising therapeutic strategy toward a cure for diabetes. To study the effect of mesenchymal stem cell (MSC) transplantation for pancreatic regeneration, we monitored the localization and distribution of transplanted MSCs by bioluminescence imaging in a mouse model. Bone marrow MSCs were isolated and transfected with a highly sensitive firefly luciferase reporter gene. To assess the efficiency of MSC transplantation, a partially pancreatectomized (PPx) mouse model was used. Transplanted MSCs were monitored by confocal microscopy and in vivo bioluminescence imaging. Daily blood glucose levels and glucose tolerance were measured. Insulin-secreting beta cells were immunostained, and insulin levels were measured via enzyme-linked immunosorbent assay. Bioluminescence signals were clearly detected from the transplanted MSCs in the pancreatic region regardless of injection route. However, locally injected MSCs exhibited more rapid proliferation than ductally injected MSCs. PPx mice harboring transplanted MSCs gradually recovered from impaired glucose tolerance. Although insulin secretion was not observed in MSCs, transplanted MSCs facilitate the injured pancreas to recover its function. In vivo optical imaging of transplanted MSCs using a highly sensitive luciferase reporter enables the assessment of MSC transplantation efficiency in a PPx mouse model.

Mesenchymal stem cells as a treatment for neonatal ischemic brain damage

Mesenchymal stem cell (MSC)-based therapies have been proven effective in experimental models of numerous disorders. Treatment of ischemic brain injury by transplantation of MSCs in neonatal animal models has been shown to be effective in reducing lesion volume and improving functional outcome. The beneficial effect of MSC transplantation to treat neonatal brain injury might be explained by the great plasticity of the neonatal brain. The neonatal brain is still in a developmentally active phase, leading to a better efficiency of MSC transplantation than that observed in experiments using adult models of stroke. Enhanced neurogenesis and axonal remodeling likely underlie the improved functional outcome following MSC treatment after neonatal hypoxic-ischemic (HI) brain injury. With respect to the mechanism of repair by MSCs, MSCs do not survive long term and replace damaged tissue themselves. We propose that MSCs react to the needs of the ischemic cerebral environment by secretion of several growth factors, cytokines, and other bioactive molecules to regulate damage and repair processes. Parenchymal cells react to the secretome of the MSCs and contribute to stimulate repair processes. These intrinsic adaptive properties of MSCs make them excellent candidates for a novel therapy to treat the devastating effects of HI encephalopathy in the human neonate.