Melatonin in cryopreservation media improves transplantation efficiency of frozen-thawed spermatogonial stem cells into testes of azoospermic mice.

BACKGROUND: Cryostorage of spermatogonial stem cells (SSCs) is an appropriate procedure for long-term storage of SSCs for fertility preservation. However, it causes damage to cellular structures through overproduction of ROS and oxidative stress. In this study, we examined the protective effect of melatonin as a potent antioxidant in the basic freezing medium to establish an optimal cryopreservation method for SSCs. METHODS: SSCs were obtained from the testes of neonatal male mice aged 3-6 days. Then, 100 µM melatonin was added to the basic freezing medium containing DMSO for cryopreservation of SSCs. Viability, apoptosis-related markers (BAX and BCL2), and intracellular ROS generation level were measured in frozen-thawed SSCs before transplantation using the MTT assay, immunocytochemistry, and flow cytometry, respectively. In addition, Western blotting and immunofluorescence were used to evaluate the expression of proliferation (PLZF and GFRα1) and differentiation (Stra8 and SCP3) proteins in frozen-thawed SSCs after transplantation into recipient testes. RESULTS: The data showed that adding melatonin to the cryopreservation medium markedly increased the viability and reduced intracellular ROS generation and apoptosis (by decreasing BAX and increasing BCL2) in the frozen-thawed SSCs (p < 0.05). The expression levels of proliferation (PLZF and GFRα1) and differentiation (Stra8 and SCP3) proteins and resumption of spermatogenesis from frozen-thawed SSCs followed the same pattern after transplantation. CONCLUSIONS: The results of this study revealed that adding melatonin as an antioxidant to the cryopreservation medium containing DMSO could be a promising strategy for cryopreservation of SSCs to maintain fertility in prepubertal male children who suffer from cancer.

Simvastatin accelerates the healing process of burn wound in Wistar rats through Akt/mTOR signaling pathway.

Statins, apart from cholesterol-lowering properties, have wound healing effects. Hereby, we aimed to assess the impact of Simvastatin (SMV), one of the most commonly used statins, on Akt/mTOR signaling pathway during burn wound healing process. After creating a second-degree burn on the dorsal area of adult male Wistar rats (n = 60), they were randomly divided into the control, SMV, vehicle of Simvastatin (SMV-Veh), Rapamycin (RM), vehicle of Rapamycin (RM-Veh), and combined SMV and RM (SMV + RM) groups. The animals were sacrificed on the 7th and 14th post-burn days and wound tissue samples were collected for histologic, immunohistochemical, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot investigations. Rapamycin (RM) was also used to treat animals as an mTOR inhibitor. Topical administration of SMV resulted in a faster healing rate, elevated collagen deposition, and increased myofibroblast population compared to other experimental groups. Moreover, qRT-PCR findings showed that the wounds treated with SMV alone had the highest expression levels of CD31, VEGF, Akt, mTOR, and p70S6K after 7 and 14 days of burn model (p < 0.001). According to western blot findings, daily topical treatment with SMV further increased protein levels of P-AktThr308, P-mTORSer2448, and P-p70S6 KThr389 compared with other treatments, at both follow-up time points (p < 0.001). In contrast, inhibition of Akt/mTOR signaling pathway by RM reduced SMV-induced wound healing process. Seemingly, SMV promotes burn wound healing, at least in part, through activating Akt/mTOR signaling pathway, suggesting topically applied SMV as an alternative therapeutic approach for managing burn wound healing.

Simvastatin combined with bone marrow mesenchymal stromal cells (BMSCs) improve burn wound healing by ameliorating angiogenesis through SDF-1α/CXCR4 pathway.

OBJECTIVES: Chemokines are wound mediators that promote angiogenesis during wound healing. We hypothesized that Simvastatin in combination with the bone marrow mesenchymal stromal cells (BMSCs) improve burn wound healing by ameliorating angiogenesis via SDF-1α/CXCR4 pathway. MATERIALS AND METHODS: Under general anesthesia, deep partial-thickness burns were created on the inter-scapular area of 48 male rats. Study groups were administrated with petroleum jelly (Simvastatin Vehicle), a single dose of intradermal BMSCs (1×106), topical Simvastatin (0.5 mg/kg) daily and combination of BMSCs and Simvastatin for 14 days. In this study, we used MTT assay, in vivo and in vitro wound closure, H&E and Trichorome staining, immunohistochemistry (IHC), real- time PCR, Western blot and tube formation assay. RESULTS: A significant improvement in wound closure percentage, epithelial thickness, collagen remodeling, and up-regulation of stromal cell-derived factor 1 alpha (SDF1α), C-X-C chemokine receptor type 4 (CXCR4), protein kinase B (AKT), and phosphatidylinositol 3- kinase (PI3K), as well as CD31 and vascular endothelial growth factor (VEGF) expression were observed after treatment with simvastatin, BMSCs and combination of them compared to the vehicle group. However, the co-treatment group revealed considerable superiority in examined factors. BMSCs treated with Simvastatin showed the highest viability in the concentration of 0.5 and 1 Nanomolar (nM). Increment in proliferation and capillary vessels formation of BMSCs was observed in the 0.5 nM and 1 nM concentrations of Simvastatin in vitro. CONCLUSION: Treatment of deep partial-thickness of burns with co-treatment of BMSCs and Simvastatin resulted in improved burn wound healing through up-regulating of SDF-1α/CXCR4 pathway.

Effects of Hair Follicle Stem Cells on Partial-Thickness Burn Wound Healing and Tensile Strength

Background: The recent improvements in wound healing have led to new strategies in regenerative medicine. Burn wound healing is an important issue in skin regeneration and has multiple indications for stem cell therapy. Hair follicle stem cells (HFSCs) are a highly promising source of stem cells for healing use, as these cells are accessible, active and pluripotent adult stem cells. Methods: HFSCs of the rat whisker were isolated, cultured, and labeled with DiI. Flow cytometry method was used to detect special markers of HFSCs. Deep partial-thickness burn wound was created, and labeled HFSCs were injected around the wound bed. Wound closure was recorded via digital photographs. The inflicted rats were sacrificed at 3, 7, or 14 days post burn and used for subsequent histological and tensiometry analysis. Results: Our results indicated that HFSCs were positive for Nestin and CD34 markers, but negative for Kr15. Morphological and histological photographs revealed that wound closure rate was accelerated in stem cell-treated group compared with other groups. In addition, faster re-epithelialization and collagen deposition were observed. The immunohistochemical analysis suggested that CD31 expression and vascular density enhanced in the stem cell-treated group. Further, tissue tensile strength increased in HFSCs-treated rats in comparison to the control group. Conclusion: The present study demonstrates that HFSC could accelerate burn wound healing as well as tensile strength in rats.

In vitro Differentiation of Hair Follicle Stem Cell into Keratinocyte by Simvastatin

Background: Hair follicle stem cells (HFSCs) located in the bulge area has shown to be highly proliferative and could differentiate into neurons, glia, smooth muscle cell, and melanocytes in vitro. Simvastatin is an HMG-CoA reductase inhibitor that exerts pleiotropic effects beyond simple low-density lipoprotein lowering and has a similar impact on the differentiation of bone marrow stromal cells and peripheral blood mononuclear cells. The present study examined the hypothesis that the application of simvastatin would induce the HFSCs differentiation into keratinocyte. Methods: The bulge of the hair follicle was anatomized, and HFSCs were cultivated. The flow cytometry and immunocytochemical staining for detection of nestin, CD34, and Kr15 biomarkers were performed before differentiation. In order to hasten the HFSCs differentiation to keratinocyte, HFSCs were treated with 1 µM, 2 µM, and 5 µM of simvastatin daily for a week. After differentiation, the flow cytometry and immunocytochemical staining were performed with Kr15 and Kr10 biomarkers, and the MTT assay was carried out as an index of cell viability and cell growth. Results: Our results showed that bulge of HFSCs were nestin and CD34 positive and Kr15 negative. Simvastatin significantly increased the viability of HFSCs (p < 0.05) at the concentration of 5 µM. In addition, the percentages of keratinocyte-differentiated cells treated with 5 µM of simvastatin showed a significant increase compared to all other treated groups (p < 0.05). Conclusion: Our findings demonstrate that 5 µM of simvastatin could induce HFSCs differentiation into keratinocyte.

Rosiglitazone, but not epigallocatechin-3-gallate, attenuates the decrease in PGC-1α protein levels in palmitate-induced insulin-resistant C2C12 cells.

Alteration of lipid metabolism is an important mechanism for the treatment of insulin resistance. PGC-1α, a key regulator of mitochondrial biogenesis and function, plays an important role in the improvement of insulin sensitivity by increasing fatty acids ß-oxidation. In the present study, the effects of epigallocatechin-3-gallate (EGCG), an anti-obesity agent and enhancer of lipid catabolism, on PGC-1α protein expression was examined and compared with anti-diabetic drug rosiglitazone (RGZ). After differentiation of C2C12 myoblasts to myotubes, insulin resistance was induced by palmitate treatment. Then the expression of the PGC-1a gene and glucose uptake were evaluated before and after treatment with RGZ and EGCG. Palmitate treatment significantly decreased PGC-1α protein expression in C2C12 cells (P < 0.05). RGZ could restore the expression of PGC-1α in palmitate treated cells (P > 0.05), while EGCG had no significant effect on the expression of this gene (P < 0.05). RGZ and EGCG significantly improved glucose uptake (by 2- and 1.54-fold, respectively) in myotubes treated with palmitate. These data suggest that RGZ and EGCG both exert their anti-diabetic activity by increasing insulin sensitivity, but with different molecular mechanisms. This effect of RGZ, unlike EGCG, is mediated, at least partly, by increasing PGC-1α protein expression.