Melatonin Pretreatment Enhances the Homing of Bone Marrow-derived Mesenchymal Stem Cells Following Transplantation in a Rat Model of Liver Fibrosis.

BACKGROUND: Bone marrow-derived mesenchymal stem cells (BMMSCs) transplantation has been considered as a promising milestone in liver fibrosis treatment. However, low amounts of homing are a major obstacle. We aimed to investigate the role of melatonin pretreatment in BMMSC homing into experimental liver fibrosis. METHODS: BMMSCs were obtained, grown, propagated and preconditioned with 5 µM melatonin and analyzed for multipotency and immunophenotypic features at passage three. The cells were labelled with CM-Dil and infused into the rats received the i.p. injection of carbon tetrachloride (CCl4) for five weeks to induce liver fibrosis. Animals were divided into two groups: One group received BMMSCs, whereas the other group received melatonin-pretreated BMMSCs (MT-BMMSCs). After cell injection at 72 h, animals were sacrificed, and the liver tissues were assessed for further evaluations: fibrosis using Masson's trichrome and hematoxylin and eosin staining and homing using fluorescent microscopy and flow cytometry. RESULTS: BMMSCs and MT-BMMSCs expressed a high level of CD44 but low levels of CD11b, CD45 and CD34 (for all P≤0.05) and were able to differentiate into adipocytes and Schwann cells. CCl4 induction resulted in extensive collagen deposition, tissue disruption and fatty accumulation with no obvious difference between the two groups. There was a significant increase in homing of MT-BMMSCs in both florescent microscopy (P≤0.001) and flow cytometry (P≤0.01) assays, as compared with non-treated BMMSCs. CONCLUSION: This study indicates the improved homing potential of BMMSCs in pretreatment with melatonin. Therefore, this strategy may represent an applied approach for improving the stem cell therapy of liver fibrosis.

Homing of allogeneic nestin-positive hair follicle-associated pluripotent stem cells after maternal transplantation in experimental model of cortical dysplasia.

An embryo has the capability to accept allo- or xeno-geneic cells, which probably makes it an ideal candidate for stem cell transplantation of various cerebral cortex abnormalities, such as cortical dysplasia. The aim of this study was to determine hair follicle-associated pluripotent (HAP) stem cells homing into various organs of mother and fetus. Cells were obtained, analyzed for immunophenotypic features, and then labelled with CM-Dil; nestin(+)HAP stem cells or media phosphate-buffered saline (PBS) were intravenously delivered on day 16 of gestation in BALB/c mice, which intraperitoneally received methylazoxymethanol (MAM) one day in advance, and homing was assessed at 24 h after cell injection. Flow cytometry and immunocytochemistry manifested positive expression of nestin in HAP stem cells. For both mother and fetus, brain, lungs, liver, and spleen were the host organs for cell implants. For the brain, the figure was considerably higher in fetus, 4.05 ± 0.5% (p ≤ 0.05 vs. mother). MAM-injected mice had a downward trend for SDF-1α and CXCR4 (p ≤ 0.05 vs. control), but HAP stem cells group showed an upward trend for CXCR4 (p ≤ 0.05 vs. MAM). We conclude the HAP stem cells show homing potential in experimental cortical dysplasia, which may permit these cells to be a target in future work on prenatal therapy of neural disorders.

Promotion of remyelination by adipose mesenchymal stem cell transplantation in a cuprizone model of multiple sclerosis.

OBJECTIVE: Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system (CNS). Stem cell transplantation is a new therapeutic approach for demyelinating diseases such as MS which may promote remyelination. In this study, we evaluate the remyelinating potential of adipose mesenchymal stem cells (ADSCs) and their effect on neural cell composition in the corpus callosum in an experimental model of MS. MATERIALS AND METHODS: This experimental study used adult male C57BL/6 mice. Cultured ADSCs were confirmed to be CD73(+),CD90(+), CD31(-),CD45(-), and labeled by PKH26. Animals were fed with 0.2% w/w cuprizone added to ground breeder chow ad libitum for six weeks. At day 0 after cuprizone removal, mice were randomly divided into two groups: the ADSCs-transplanted group and the control vehicle group (received medium alone). Some mice of the same age were fed with their normal diet to serve as healthy control group. Homing of ADSCs in demyelinated lesions was examined by fluorescent microscope. At ten days after transplantation, the mice were euthanized and their cells analyzed by luxol fast blue staining (LFB), transmission electron microscopy and flow cytometry. Results were analyzed by one-way analysis of variance (ANOVA). RESULTS: According to fluorescent cell labeling, transplanted ADSCs appeared to survive and exhibited homing specificity. LFB staining and transmission electron microscope evaluation revealed enhanced remyelination in the transplanted group compared to the control vehicle group. Flow cytometry analysis showedan increase in Olig2 and O4 cells and a decrease in GFAP and Iba-1 cells in the transplanted group. CONCLUSION: Our results indicate that ADSCs may provide a feasible, practical way for remyelination in diseases such as MS.

Schwann-like cell differentiation from rat bone marrow stem cells.

INTRODUCTION: The main purpose of this study was differentiation of bone marrow stem cells (BMSCs) into Schwann-like cells and to determine the intensity of apoptosis in BMSCs during the differentiation process. MATERIAL AND METHODS: Bone marrow stem cells were isolated from the femur of adult rats and the identity of the undifferentiated BMSCs was confirmed by the detection of specific cell surface markers. The BMSCs were differentiated by sequential administration of ß-mercaptoethanol and all-trans-retinoic acid as pre-inducer factors and a mixture of forskolin, basic fibroblast growth factor, platelet-derived growth factor-AA and heregulin-b1 as inducer factors. The immunocytochemical properties of differentiated Schwann-like cells were examined at a specified time point. Reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate the gene expression of the undifferentiated and differentiated BMSCs. Cell apoptosis and viability were assessed with annexin V and propidium iodide double staining and dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide (MTT) assay. RESULTS: Immunocytochemistry staining and RT-PCR analysis revealed that the induced BMSCs exhibited Schwann cell-specific markers such as S-100, P75 and glial fibrillary acidic protein (GFAP) at the 14(th) day of differentiation. MTT assay and flow cytometry revealed that of the total BMSCs in the differentiation medium, 40% to 50% of the cells died by apoptosis, but the remaining cell population remained strongly attached to the substrate and differentiated. CONCLUSIONS: These findings indicated that BMSCs could differentiate into Schwann-like cells. As a side effect of differentiation an increased cell death rate was noted and our findings indicate that the principle mode of cell death is by apoptosis.