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.

Bone Marrow-Derived Mesenchymal Stem Cells Combined With Simvastatin Accelerates Burn Wound Healing by Activation of the Akt/mTOR Pathway.

Burn wound healing is one of the most important problems in the field of medical science. Promising results have recently been reported by researchers who used bone marrow mesenchymal stem cells (BMSCs) to treat burn wounds. In this study, we investigated the effects of BMSC therapy in combination with simvastatin (SMV) on angiogenesis as well as on the activity of the Akt/mTOR signaling pathway during burn wound healing in rats. After creating second-degree burn wounds, 40 adult male Wistar rats were randomly divided into four treatment groups: the control, SMV, BMSCs, and the combination therapy group (BMSCs+SMV). Animals were killed 14 days after treatment initiation, and the wounds were removed for histological and molecular analyses. All in all, combination therapy produced better outcomes than individual therapy in terms of the wound closure area, epidermal regeneration level, collagen deposition intensity, and reepithelialization rate. In addition, the elevations of expression levels of Akt and mTOR genes, at both mRNA and protein levels, were more pronounced in the BMSCs+SMV group (P < .05, at least, for both qRT-PCR and western blot assessments). qRT-PCR findings also demonstrated that the wounds treated with the combination of BMSCs and SMV had the highest expression levels of CD31 and VEGF genes (P < .01 for all comparisons). These data suggest that the combined administration of BMSCs transplantation and topical SMV has a great potential in burn wound healing. According to the findings, the beneficial effects of the combination therapy are caused, at least in part, through stimulating Akt/mTOR signaling 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.

Effects of ethanol extract of propolis on histopathological changes and anti-oxidant defense of kidney in a rat model for type 1 diabetes mellitus.

AIMS/INTRODUCTION: Oxidative stress has a key role in the pathogenesis of diabetes. Propolis and its constituents have a wide range of medicinal properties against oxidative stress. In the present study, we evaluated the anti-oxidant effects of ethanolic extracts of propolis on kidneys in diabetes mellitus rats. MATERIALS AND METHODS: A total of 40 male Wistar rats were randomly divided into the following five groups: control, diabetes mellitus, diabetes mellitus with vehicle treatment, diabetes mellitus with propolis treatment (100 mg/kg) and diabetes mellitus with propolis treatment (200 mg/kg). Diabetes mellitus in rats was induced by intraperitoneal injection of streptozotocin (60 mg/kg). Diabetic groups were treated with vehicle or ethanolic extracts of Iranian propolis for 6 weeks. Serum concentration of malondialdehyde, superoxide dismutase and glutathione peroxidase were measured. RESULTS: The results showed that Iranian propolis significantly inhibited bodyweight loss in diabetes mellitus rats. The propolis extracts significantly reduced serum glucose levels and kidney weight in diabetes mellitus rats (P < 0.001). Furthermore, propolis extracts significantly reduced the malondialdehyde content, and increased the activity of superoxide dismutase and glutathione peroxidase (P < 0.001) along with the total anti-oxidant activity in the kidney tissue of diabetes mellitus rats. In the kidneys of the diabetes mellitus and vehicle group, the glomerular basement membrane thickness and glomerular area were significantly increased. Treatment of diabetes mellitus rats with the propolis extract significantly reduced the glomerular basement membrane thickness and glomerular area. CONCLUSIONS: The present study results showed that the Iranian propolis extract could enhance the anti-oxidant levels and histopathological changes in the kidneys of rats. The final results showed that most of the favorable effects of propolis are mediated by a reduction of blood glucose levels in diabetic animals.