Background Patients with severe full-thickness burn injury suffer from their inability to maintain body temperature through perspiration because the complete destructed sweat glands can not be regenerated. Bone marrow-derived mesenchymal stem cells （BM-MSCs） represent an ideal stem-cell source for cell therapy because of their easy purification and multipotency. In this study, we attempted to induce human BM-MSCs to differentiate into sweat gland cells for sweat gland regeneration through ectodysplasin （EDA） gene transfection. Methods The dynamic expression of EDA and EDA receptor （EDAR） were firstly observed in the sweat gland formation during embryological development. After transfection with EDA expression vector, human BM-MSCs were transplanted into the injured areas of burn animal models. The regeneration of sweat glands was identified by perspiration test and immunohistochemical analysis. Results Endogenous expression of EDA and EDAR correlated with sweat gland development in human fetal skin. After EDA transfection, BM-MSC acquired a sweat-gland-cell phenotype, evidenced by their expression of sweat gland markers by flow cytometry analysis. Immunohistochemical staining revealed a markedly contribution of EDA-transfected BM-MSCs to the regeneration of sweat glands in the scalded paws. Positive rate for perspiration test for the paws treated with EDA-transfected BM-MSCs was significantly higher than those treated with BM-MSCs or EDA expression vector （P 〈0.05）. Conclusions Our results confirmed the important role of EDA in the development of sweat gland. BM-MSCs transfected with EDA significantly improved the sweat-gland regeneration. This study suggests the potential application of EDA-modified MSCs for the repair and regeneration of injured skin and its appendages.
CAI SaPAN YuHAN BingSUN Tong-zhuSHENG Zhi-yongFU Xiao-bing
AIM： To detect the effect of acid fibroblast growth factor （aFGF） on P53 and P21WAF-1 expression in rat intestine after ischemia-reperfusion （I-R） injury in order to explore the protective mechanisms of aFGF. METHODS： Hale rats were randomly divided into four groups, namely intestinal ischemia-reperfusion group （R）, aFGF treatment group （A）, intestinal ischemia group （I）, and sham-operated control group （C）. In group I, the animals were killed after 45 min of superior mesenteric artery （SHA） occlusion. In groups R and A, the rats sustained for 45 min of SHA occlusion and were treated with normal saline （0.15 mL） and aFGF （20 μg/kg, 0.15 mL）, then sustained at various times for up to 48 h after reperfusion. In group C, SHA was separated, but without occlusion. Apoptosis in intestinal villi was determined with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling technique （TUNEL）. Intestinal tissue samples were taken not only for RT- PCR to detect P53 and P21WAF-1 gene expression, but also for immunohistochemical analysis to detect P53 and P21WAF-1 protein expression and distribution. RESULTS： In histopathological study, ameliorated intestinal structures were observed at 2, 6, and 12 h after reperfusion in A group compared to R group. The apoptotic rates were （41.17±3.49）%, （42.83±5.23）%, and （53.33±6.92）% at 2, 6, and 12 h after reperfusion, respectively in A group, which were apparently lower than those in R group at their matched time points （50.67±6.95）%, （54.17±7.86）%, and （64.33±6.47）%, respectively, （P〈0.05））. The protein contents of P53 and P21WAF-1 were both significantly decreased in A group compared to R group （P〈0.05） at 2-12 h after reperfusion, while the mRNA levels of P53 and P21VVAF-1 in A group were obviously lower than those in R group at 6-12 h after reperfusion （P〈0.05）. CONCLUSION： P53 and P21WAF-1 protein accumulations are associated with intestinal barrier injury induced
