Effect of local injection of mesenchymal stem cells on healing of sutured gastric perforation in an experimental model

BackgroundMesenchymal stem cells are proposed to facilitate repair of organ injuries. The aim of this study was to investigate whether local injection of mesenchymal stem cells could accelerate healing of sutured gastric perforations. MethodsSutured gastric perforations in rats were treated either with local injection of mesenchymal stem cells (injected MSC group) or by topically spraying with fibrin glue containing mesenchymal stem cells (sprayed MSC group). Controls were treated by local injection of saline or topical spray of fibrin glue without mesenchymal stem cells. Healing of sutured gastric perforations was assessed on days 3, 5 and 7. ResultsLocal injection of mesenchymal stem cells significantly promoted the healing of gastric perforations, with the highest pneumatic bursting pressure (mean(s.e.m.) 1123(302) mmHg on day 5 versus 712(174) mmHg in saline controls; P=0001), minimal wound adhesions, and lowest incidence of wound dehiscence (3, 6, 5 and 1 animal on day 5 in control, fibrin, sprayed MSC and injected MSC groups respectively; n=10 per group) and abdominal abscess (2, 2, 1 and no animals respectively on day 5). Histological examination showed that gastric perforations in the injected MSC group displayed reduced inflammation, and increased granulation and re-epithelialization. Sutured gastric perforations in the injected MSC group showed decreased expression of interleukin 6, and increased expression of transforming growth factor 1 and epithelial proliferating cell nuclear antigen, compared with the other groups. ConclusionLocal injection of mesenchymal stem cells was more effective than topical application, and enhanced the healing of sutured gastric perforations by an anti-inflammatory process, enhanced cellular proliferation and earlier onset of granulation. Abnormal healing of gastric perforation may cause morbidity and increase the risk of death. Adipose tissue-derived mesenchymal stem cells have been found to promote the healing of organ injuries through cellular differentiation and secretion of cytokines that stimulate cellular proliferation and angiogenesis, and suppress inflammation. This study explored the therapeutic potential of such mesenchymal stem cells for promotion of the healing of sutured gastric perforations. Mesenchymal stem cells delivered by local injection significantly enhanced the healing of gastric perforations with reduced severity of wound adhesion, and a decreased incidence of wound dehiscence and abdominal abscess. The increased expression of transforming growth factor 1, proliferating cell nuclear antigen and reduced level of interleukin 6 provide evidence for enhancement of the healing process. Engrafted mesenchymal stem cells expressed -smooth muscle actin as a marker of myofibroblasts. This preclinical study indicates that local injection of allogeneic adipose tissue-derived mesenchymal stem cells may have a potential therapeutic role in enhancing the healing of peptic ulcer disease and prevention of ulcer-related complications. Injected stem cells enhance healing