Non-mitogenic acidic fibroblast growth factor reduces intestinal dysfunction induced by ischemia and reperfusion injury in rats.

BACKGROUND: Acidic fibroblast growth factor (aFGF) has potentially therapeutic uses in some diseases, but the mitogenic activity of aFGF has been found to contribute to several human pathologies, so the extensive applications of wild-type aFGF have been limited. The purpose of the present study was to explore the effects and mechanisms of wild-type (aFGF) and non-mitogenic aFGF on gut ischemia-reperfusion injury in rats. METHODS: Rat intestinal ischemia-reperfusion injury (I/R) was produced by clamping the superior mesenteric artery (SMA) for 45 min followed by reperfusion. One hundred and fourteen rats were randomly divided into four groups: sham operation (group C, n = 6), intestinal I/R + 0.1 mL saline (group S, n = 36), intestinal I/R + 4 microg/0.1 mL wild-type aFGF (group W, n = 36) and intestinal I/R + 4 microg/0.1 mL modified aFGF (i.e. non-mitogenic aFGF; group M, n = 36). According to different periods after reperfusion, groups S, W and M were further divided into 0.5-, 1-, 2-, 6-, 12- and 24-h subgroups. The contents of D-lactate and nitrite/nitrate were determined, the changes of intestinal histology were analyzed, the protein expressions of caspase-3, extracellular signal-regulated kinase (ERK)1/2, and p38 were detected by western blot, and apoptotic cells were examined by the terminal deoxynucleotidyl transferase (TdT)-mediated dUDP-biotin nick end labeling (TUNEL) assay at 0.5, 1, 2, 6, 12 and 24 h after I/R, respectively. RESULTS: Compared with rats in group S, intestinal histological damage, apoptotic index, d-lactate content and nitrite/nitrate level all decreased significantly in group W and group M rats. However, there was no difference between rats treated with wild-type aFGF and those with non-mitogenic aFGF. The protein expression of caspase-3, ERK1/2, and p38 in saline-treated rats was higher than those in aFGF-treated rats. CONCLUSIONS: Both types of aFGF had protective effects on gut I/R and there was no significant difference between the two aFGF. The protective effects of aFGF may come from the non-mitogenic activity rather than the mitogenic activity of aFGF in tissue repair, indicating a potentially clinical use for the non-mitogenic effects of aFGF in preventing visceral organ injury triggered by I/R injury in the future.

[Cellular phenotype conversion induced by co-culture of human mesenchymal stem cells cocultured with human sweat gland cells].

OBJECTIVE: To investigate the cellular phenotype conversion during human mesenchymal stem cells (hMSCs) cocultured with injured human sweat gland cells (hSGCs) in vitro. METHODS: HMSCs and hSGCs were isolated and cultured and expanded respectively. The antigens expression of hMSCs and hSGCs were detected by two-steps immunocytochemistry. HMSCs were labeled with BrdU. The hSGCs were heat-shocked at 47 degrees C for 40 min when they reached 70% confluency, then cooled for 1-2 h at 37 degrees C and (1 - 2) x 10(5) BrdU-labeled hMSCs were added before incubation for up to 2 weeks. The cocultures were observed by phase contrast microscopy and detected by double-staining immunocytochemistry using CEA and BrdU as primary antibodies. RESULTS: The cultured hMSCs and hSGCs were clonogenic growth. HMSCs were positive for anti-CD44 and anti-CD105 staining and negative for anti-CD34 and anti-CEA staining. HSGCs express CK7, CK18, CK19 and CEA. The positive rate of BrdU labeled-hMSCs was 90%. The majority of hSGCs lost cell-cell contact after heat-shock. 2 weeks after cocultured, some cocultured cells were positive for both anti-CEA and anti-BrdU staining and some cocultures had more than two nuclei which stained with two different colors by double-staining immunocytochemistry. Statistic results showed 1%-5% of the hMSCs added to the coculture system were recovered as double-staining cells expressing BrdU and CEA while only 0.01%-0.05% cells stained with two different colors in nuclei. The multi-nucleated cells were wide and flatten. CONCLUSION: HMSCs could differentiate into hSGCs in vitro under injured microenvironment. The mechanisms of which may be that hMSCs differentiate into hSGCs directly or by cell fusion, even nucleus fusion.