Topical application of metformin accelerates cutaneous wound healing in streptozotocin-induced diabetic rats

Molecular Biology Reports - Diabetic chronic wound, which is one of the diabetic complications caused by hyperglycemia, characterized by prolonged inflammation has become one of the most serious...     

Placenta mesenchymal stem cell accelerates wound healing by enhancing angiogenesis in diabetic Goto-Kakizaki (GK) rats

Multipotent mesenchymal stem cells have recently emerged as an attractive cell type for the treatment of diabetes-associated wounds. The purpose of this study was to examine the potential biological function of human placenta-derived mesenchymal stem cells (PMSCs) in wound healing in diabetic Goto-Kakizaki (GK) rats. PMSCs were isolated from human placenta tissue and characterized by flow cytometry. A full-thickness circular excisional wound was created on the dorsum of each rat. Red fluorescent CM-DiI-labeled PMSCs were injected intradermally around the wound in the treatment group. After complete wound healing, full-thickness skin samples were taken from the wound sites for histological evaluation of the volume and density of vessels. Our data showed that the extent of wound closure was significantly enhanced in the PMSCs group compared with the no-graft controls. Microvessel density in wound bed biopsy sites was significantly higher in the PMSCs group compared with the no-graft controls. Most surprisingly, immunohistochemical studies confirmed that transplanted PMSCs localized to the wound tissue and were incorporated into recipient vasculature with improved angiogenesis. Notably, PMSCs secreted comparable amounts of proangiogenic molecules, such as VEGF, HGF, bFGF, TGF-β and IGF-1 at bioactive levels. This study demonstrated that PMSCs improved the wound healing rate in diabetic rats. It is speculated that this effect can be attributed to the PMSCs engraftment resulting in vascular regeneration via direct de novo differentiation and paracrine mechanisms. Thus, placenta-derived mesenchymal stem cells are implicated as a potential angiogenesis cell therapy for repair-resistant chronic wounds in diabetic patients.     

Role of nuclear factor-kappaB in gastric ulcer healing in rats

We investigated the role of nuclear factor-kappaB (NF-kappaB) in gastric ulcer healing in rats. NF-kappaB was activated in ulcerated tissue but not in normal mucosa, and the level of the activation was decreased with ulcer healing. NF-kappaB activation was observed in fibroblasts, monocytes/macrophages, and neutrophils. Treatment of gastric fibroblasts, isolated from the ulcer base, with interleukin-1beta activated NF-kappaB and the subsequently induced cyclooxygenase-2 and cytokine-induced neutrophil chemoattractant-1 (CINC-1) mRNA expression. Inhibition of activated NF-kappaB action resulted in suppression of both their mRNA expression and increases in PGE(2) and CINC-1 levels induced by interleukin-1beta. Persistent prevention of NF-kappaB activation caused an impairment of ulcer healing in rats. Gene expression of interleukin-1beta, CINC-1, cyclooxygenase-2, and inducible nitric oxide synthase in ulcerated tissue had been inhibited before the delay in ulcer healing became manifest. The increased levels of cyclooxygenase-2 protein and PGE(2) production were also reduced. These results demonstrate that NF-kappaB, activated in ulcerated tissue, might upregulate the expression of healing-promoting factors responsible for gastric ulcer healing in rats.     

A vascular endothelial growth factor mimetic accelerates gastric ulcer healing in an iNOS-dependent manner

Angiogenesis is crucial to all types of wound healing, including gastric ulcer healing. The most potent promoter of angiogenesis is vascular endothelial growth factor (VEGF). We hypothesized that a 15-amino acid peptide designed to mimic the angiogenic action of VEGF would accelerate gastric ulcer healing. Gastric ulcers were induced in mice by serosal application of acetic acid. Treatment with the VEGF mimetic accelerated gastric ulcer healing when administered orally or intraperitoneally, at a dose of 50 ng/kg or greater. Such healing was not observed when the reverse sequence pentadecapeptide or the full-length VEGF protein was administered. Contrary to our hypothesis, the VEGF mimetic did not significantly increase angiogenesis in the ulcerated stomach. The enhancement of ulcer healing by the VEGF mimetic occurred independently of cyclooxygenase-2 (COX-2) activity but was blocked by inhibitors of inducible nitric oxide synthase (iNOS). These results demonstrate that a VEGF mimetic is a potent stimulus for gastric ulcer healing, even when given orally. The effects of the mimetic were independent of stimulatory effects on angiogenesis and COX-2 activity but were dependent on iNOS-derived NO production.     

Endothelial nitric oxide synthase modulates gastric ulcer healing in rats

Nitric oxide has been shown to be beneficial for gastric ulcer healing. We determined the relative effects of endothelial and inducible nitric oxide synthases on gastric ulcer healing in rats. Ulcers were induced by serosal application of acetic acid. Ulcer severity, angiogenesis, and nitric oxide synthase expression were assessed 3-10 days later. The effects of inhibitors of nitric oxide synthase were also examined. Inducible nitric oxide synthase mRNA was only detected in ulcerated tissue (maximal at day 3), whereas the endothelial isoform mRNA was detected in normal tissue and increased during ulcer healing. Inducible nitric oxide synthase was expressed in inflammatory cells in the ulcer bed, whereas endothelial nitric oxide synthase was found in the vascular endothelium and in some mucosal cells in both normal and ulcerated tissues. Angiogenesis changed in parallel with endothelial nitric oxide synthase expression. N(6)-(iminoethyl)-L-lysine did not affect angiogenesis or ulcer healing, while N(G)-nitro-L-arginine methyl ester significantly reduced both. In conclusion, endothelial nitric oxide synthase, but not the inducible isoform, plays a significant role in gastric ulcer healing.     

间充质干细胞在造血干细胞移植中的应用

间充质干细胞(MSCs)是一种具有自我更新和多向分化潜能的成体干细胞,存在于骨髓、脂肪组织、脐血及多种胎儿组织.它可分泌多种细胞因子及生长因子,促进造血干细胞(HSC)的增殖与分化.MSCs还具有免疫调节、抗炎和组织修复作用,可减轻移植物抗宿主病(GVHD)及其他移植相关并发症.     

Regulated genes in mesenchymal stem cells and gastric cancer

AIM: To investigate the genes regulated in mesenchymal stem cells(MSCs) and diffuse-type gastric cancer(GC),gene expression was analyzed. METHODS: Gene expression of MSCs and diffuse-type GC cells were analyzed by microarray. Genes related to stem cells, cancer and the epithelial-mesenchymal transition(EMT) were extracted from human gene lists using Gene Ontology and reference information. Gene panels were generated, and messenger RNA gene expression in MSCs and diffuse-type GC cells was analyzed. Cluster analysis was performed using the NCSS software.RESULTS: The gene expression of regulator of G-protein signaling 1(RGS1) was up-regulated in diffuse-type GC cells compared with MSCs. A panel of stem-cell related genes and genes involved in cancer or the EMT were examined. Stem-cell related genes, such as growth arrest-specific 6, musashi RNA-binding protein 2 and hairy and enhancer of split 1(Drosophila), NOTCH family genes and Notch ligands, such as delta-like 1(Drosophila) and Jagged 2, were regulated.CONCLUSION: Expression of RGS1 is up-regulated, and genes related to stem cells and NOTCH signaling are altered in diffuse-type GC compared with MSCs.     

Secretome from hypoxia-conditioned adipose-derived mesenchymal stem cells promotes the healing of gastric mucosal injury in a rodent model

Studies have indicated that the definitive engraftment and transdifferentiation potential of stem cells do not seem crucial for its property of tissue repair. Our previous study showed that transplantation of adipose-derived mesenchymal stem cells (ADMSCs) enhanced the healing of sutured gastric perforation. This study aimed to investigate the paracrine role of ADMSCs in the experimental gastric mucosal injury. Normoxia-conditioned medium (Nor CM) and hypoxia (HPO) CM were obtained after culturing ADMSCs in 20% O₂ and 5% O₂ for 48 h. Cell migration, proliferation, viability, and angiogenesis in vitro were significantly enhanced upon incubation with CM, especially the HPO CM. Experiments in vivo using a rodent model of gastric ulcer demonstrated that HPO CM treatment significantly accelerated wound healing by suppressing inflammation and promoting neovascularization and re-epithelization. Meanwhile, the infusion of HPO CM activated the COX₂-PGE₂ axis both in vitro and in vivo. And the upregulation of COX₂ was further dependent on the activation of ErK1/2-MAPK pathway. In addition, vascular endothelial growth factor, tissue inhibitors of metalloproteinases-1, and chemokine (C-C motif) ligand 20 (CCL-20) were analyzed as being highly abundant factors secreted by ADMSCs under hypoxic condition. Notably, the blockade of CCL-20 abrogated the HPO CM-induced COX₂ signaling in the primary gastric mucosal epithelial cells, while incubation with recombinant CCL-20 increased the expression of COX₂. In conclusion, the secretome from hypoxia-conditioned ADMSCs facilitates the repair of gastric mucosal injury through the enhancement of angiogenesis and re-epithelization, as well as the activation of COX₂-PGE₂ axis with a paracrine activity involving CCL-20 factor.     

Activity of mesenchymal stem cells in therapies for chronic skin wound healing

Chronic or non-healing skin wounds present an ongoing challenge in advanced wound care, particularly as the number of patients increases while technology aimed at stimulating wound healing in these cases remains inefficient. Mesenchymal stem cells (MSCs) have proved to be an attractive cell type for various cell therapies due to their ability to differentiate into various cell lineages, multiple donor tissue types, and relative resilience in ex-vivo expansion, as well as immunomodulatory effects during transplants. More recently, these cells have been targeted for use in strategies to improve chronic wound healing in patients with diabetic ulcers or other stasis wounds. Here, we outline several mechanisms by which MSCs can improve healing outcomes in these cases, including reducing tissue inflammation, inducing angiogenesis in the wound bed, and reducing scarring following the repair process. Approaches to extend MSC life span in implant sites are also examined.     

移植胎鼠间充质干细胞的抗衰老作用

本文旨在研究BALB/c小鼠胎鼠源干细胞同种异体移植的抗衰老作用。采用无菌剖宫产取胎鼠,密度梯度离心法分离干细胞,贴壁培养法纯化扩增间充质干细胞,连续3次尾静脉注射P1代细胞植入15月龄雌性BALB/c小鼠体内。超声检查小鼠心脏,检查血清总超氧化物歧化酶活力、丙二醛含量、谷胱甘肽过氧化物酶活力,各器官做解剖学检查以及组织学衰老程度比较、评分。结果显示,Y染色体原位杂交实验检测到移植后干细胞长期存活,移植后移植组小鼠存活日期明显长于对照组,移植3个月后评价心功能的各指标,心脏质量指数、脾脏质量指数,心脏、肾脏、肺脏、皮肤、结肠等器官组织学衰老程度评分结果以及血液生化指标,皆优于对照组(均P0.05)。以上结果提示,移植小鼠胎鼠源干细胞能有效地延缓小鼠衰老进程。     

Adult bone-marrow-derived mesenchymal stem cells contribute to wound healing of skin appendages

Adult bone-marrow-derived mesenchymal stem cells (MSCs) are well-established as having the capacity to differentiate into cells with mesodermal, ectodermal, and endodermal characteristics and can leave their niche to home toward and engraft within foreign tissues. To investigate whether adult MSCs contribute to the repair of skin appendages after injury, BrdU-labeled MSCs were co-cultured with heat-shocked confluent sweat gland cells (SGCs) in vitro and later intravenously injected into full-thickness skin wounds in rats. When adult MSCs were co-cultured with heat-shocked SGCs, a subset of adult MSCs differentiated into SGCs, the percentage of differentiation being enhanced by epidermal growth factor and the injured microenviroment, but weakened by PD98059. The ERK (extracellular signal-regulated kinase) pathway, especially pERK, was involved in the phenotype conversion of human MSCs into human SGC. Labeled MSCs were noted in hair follicles, sebaceous glands, blood vessels, and dermis in full-thickness wounds, and the incorporated cells in hair follicles and sebaceous glands were also positive for pan-cytokeratin. After wound healing, some labeled MSCs returned to the bone marrow, whereas other were retained in the dermis. We conclude that adult MSCs have the capacity to dock at specific sites, to contribute to wound healing of skin appendages, and to home toward marrow, and that engraftment of bone-marrow-derived cells is a functional event.This work was supported in part by the National Basic Science and Development Program (973 Program and 2005CB522603) and the National Natural Science Foundation of China (30230370 and 30500194).     

Role of capsaicin sensory nerves and EGF in the healing of gastric ulcer in rats

Accumulating evidence indicates that capsaicin sensitive afferent fibers play a pivotal role not only in gastroprotection but also in ulcer healing. Denervation of capsaicin sensitive afferent fibers exerts an adverse action on these effects. However, whether such an action is mediated through a depression on epidermal growth factor (EGF) is undefined. In this study, the effects of denervation of sensory neurons with capsaicin (100 mg/kg, s.c.) on acetic acid-induced chronic gastric ulcers and their relationship with the EGF expression in salivary glands, serum and gastric mucosa were investigated. Capsaicin significantly increased ulcer size, decreased gastric mucosal cell proliferation at the ulcer margin, angiogenesis in the granulation tissue and also gastric mucus content. Ulcer induction by itself dramatically elevated EGF levels in salivary glands and serum on day 1 and 4, and also in the gastric mucosa on day 4. However, capsaicin completely abolished these effects. It is concluded that stimulation of EGF expression in salivary glands and serum may be one of the mechanisms by which capsaicin sensitive nerves contribute to the gastroprotective and ulcer healing actions in the stomach.     

Therapeutic efficacy of human umbilical cord mesenchymal stem cells transplantation against renal ischemia/reperfusion injury in rats

Background

Acute kidney injury (AKI) is a common clinical problem raising the urgent needs to develop new strategies for treatment. The present study investigated the therapeutic potential of human umbilical cord – mesenchymal stem cells (HUC-MSCs) transplantation against renal ischemia/reperfusion injury (IRI) in rats.

移植途径对大鼠骨髓间充质干细胞归巢及肝功能恢复的影响

目的 探讨移植途径对骨髓间充质干细胞（MSCs）归巢及促进肝切除大鼠肝再生的影响.方法 建立肝切除大鼠模型,随机分为3 组,即肝切除对照组、尾静脉移植组和门静脉移植组.移植组分别经尾静脉和门静脉注射DAPI 标记的MSCs 约1.5×106/ 只,分别于第3 天和第9 天后采血清检测肝功能,第9 天处死大鼠取肝脏标本,并通过荧光显微镜观察两种移植途径对MSCs 向肝脏迁移的影响.结果 门静脉移植组（18.1 ± 3.4）个细胞/100 倍视野到肝脏归巢及定植的 MSCs 多于尾静脉移植组（7.6 ± 2.0）个细胞/100 倍视野,差异有统计学意义（P 〈 0.01）.术后第9 天各组大鼠肝功能均有好转,丙氨酸氨基转移酶（ALT）及天冬氨酸氨基转移酶（AST）3 组之间对比差异无统计学意义（F = 2.822,1.046,P = 0.057,0.365,P 〉 0.05）;但两移植组与单纯肝切除组比较血浆白蛋白（ALB）均有明显升高,差异具有统计学意义（F = 6.259,P = 0.006）;尾静脉移植组与门静脉移植组两移植组之间相比,差异无统计学意义（P 〉 0.05）.结论 移植途径对 MSCs 归巢、定植到肝脏有一定影响,门静脉途径优于外周静脉,MSCs 移植对肝大部切除大鼠肝功能恢复具有促进作用.     

Endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) in bone healing

Fracture healing is a complex physiological process. Local vascularity at the site of the fracture has been established as one of the most important factors influencing the healing process, and lack of vascularity has been implicated in atrophic non unions. Existing research has primarily involved utilising Mesenchymal Stem Cells (MSCs) to augment bone healing but there remains much scope to explore the role of stem cells in the vascularisation process. Endothelial Progenitor Cells (EPCs) and other Endothelial Cellular populations (ECs) could constitute a valid alternative to MSCs. This systematic review is examining the importance of co-implantation of MSCs and EPCs/ECs for bone healing. A literature search was performed using the Cochrane Library, OVID Medline, OVID EMBASE and Google Scholar, searching for combinations of the terms EPCs, Endothelial progenitor cells, angiogenesis, fracture, bone and healing. Finally 18 articles that fulfilled our criteria were included in this review. ECs could be of value for the treatment of critical size bone defects as they are known to be capable of forming ectopic, vascularised bone. The co-implantation of ECs with MSCs is more intriguing when we take into account the vast array of complex reciprocal interactions between ECs and MSCs.     

Cell origin of human mesenchymal stem cells determines a different healing performance in cardiac regeneration

The possible different therapeutic efficacy of human mesenchymal stem cells (hMSC) derived from umbilical cord blood (CB), adipose tissue (AT) or bone marrow (BM) for the treatment of myocardial infarction (MI) remains unexplored. This study was to assess the regenerative potential of hMSC from different origins and to evaluate the role of CD105 in cardiac regeneration. Male SCID mice underwent LAD-ligation and received the respective cell type (400.000/per animal) intramyocardially. Six weeks post infarction, cardiac catheterization showed significant preservation of left ventricular functions in BM and CD105(+)-CB treated groups compared to CB and nontreated MI group (MI-C). Cell survival analyzed by quantitative real time PCR for human GAPDH and capillary density measured by immunostaining showed consistent results. Furthermore, cardiac remodeling can be significantly attenuated by BM-hMSC compared to MI-C. Under hypoxic conditions in vitro, remarkably increased extracellular acidification and apoptosis has been detected from CB-hMSC compared to BM and CD105 purified CB-derived hMSC. Our findings suggests that hMSC originating from different sources showed a different healing performance in cardiac regeneration and CD105(+) hMSC exhibited a favorable survival pattern in infarcted hearts, which translates into a more robust preservation of cardiac function.     

Porcine mesenchymal stem cells

The potential of mesenchymal stem and progenitor cells (MSC) to replicate undifferentiated and to mature into distinct mesenchymal tissues suggests these cells as an attractive source for tissue engineering. The objective was to establish a protocol for the isolation of porcine MSC from bone marrow and to demonstrate their ex vivo differentiation into various mesenchymal tissue cells. MSC from passage 2 were selected for differentiation analysis. Differentiation along the osteogenic lineage was documented by deposition of calcium, visualization of alkaline phosphatase activity, and by analysis of osteogenic marker genes. Adipocytes were identified morphologically and by gene-expression analysis. Deposition of type II collagen and histological staining of proteoglycan indicated chondrogenic differentiation. Therefore, porcine MSC may be introduced as a valuable model system with which to study the mesenchymal lineages for basic research and tissue engineering.