[Studies on the fibroblast proliferation and transdifferentiation for myofibroblast from skin lesion of the patients with systemic sclerosis repressed by H2 Relaxin].

AIM: The study was to explore the effects of the fibroblast transdifferentiation for myofibroblast (MFB) in the pathogenesis of systemic sclerosis (SSc) and to research the effect mechanism of H2 Relaxin (H2-RLX) against fibrosis in SSc. METHODS: The fibroblasts derived from the skin lesion of the SSc patients and normal skin tissue were respectively cultured in vitro and demonstrated. The MFB proportion in fibroblast was known by α-smooth muscle actin (α-SMA) in fibroblast culture detected with immunohistochemistry for qualitative study and ELISA for quantitative analysis. The influence on fibroblast proliferation and transdifferentiation for MFB was observed by adding H2-RLX. RESULTS: There were no apparent differences for cell morphology between the fibroblasts from SSc patients and controls. The means of positive α-SMA in SSc group were higher than those in controls (P<0.01). With culture time extended, α-SMA levels of the two groups all increased gradually (P<0.01 all), but there were higher α-SMA levels in SSc group than those in controls separately at H24, H48, H72 in culture (P<0.05 all). Fibroblast proliferation and α-SMA levels were not influenced after adding 1 µg/L of H2-RLX, but 10 µg/L and 100 µg/L of it could completely inhibit the fibroblast proliferation and α-SMA levels (P<0.05 all), with the strongest repressing effect after adding 100 µg/L of it. CONCLUSION: There is a specific property of fibroblasts transdifferentiation for MFB strongly from the skin lesion of the SSc patients. H2-RLX could give play to the antifibrotic effects by repressing the fibroblast proliferation and transdifferentiation for MFB in SSc.

[Transdifferentiation of fibroblasts into myofibroblasts in the skin lesion of systemic sclerosis: role of transforming growth factor ß1 and its signal transduction].

OBJECTIVE: To explore the role of the fibroblast transdifferentiation into myofibroblasts (MFBs) in the pathogenesis of systemic sclerosis (SSc) and investigate the influence of transforming growth factor ß(1) (TGF-ß(1)) and blocking of its signal transduction on fibroblast transdifferentiation. METHODS: Fibroblasts derived from the skin lesions of SSc patients and normal skin tissue were cultured in vitro. The proportion of MFBs in the fibroblast culture was analyzed qualitatively using immunocytochemistry and quantitatively with ELISA for α-smooth muscle actin (α-SMA). The changes in fibroblast transdifferentiation were observed after addition of TGF-ß(1) in the cell culture and after blocking the signal transduction of TGF-ß(1). RESULTS: The fibroblasts isolated from SSc patients and control subjects showed a similar morphology. The mean number of cells positive for α-SMA in SSc group was significantly higher than that in the control group (P<0.01). As culture time extended, α-SMA levels of the two groups both increased gradually (P<0.01), but the increments were significantly greater in SSc group than in the control group at 24, 48, and 72 h (P<0.05 all). Addition of TGF-ß(1) resulted in significantly increased α-SMA levels in both groups (P<0.05), and SSc group showed significantly higher α-SMA levels than the control group at 24, 48, and 72 h (P<0.01). In the presence of TGF-ß(1), blocking of Smads, ERK/MAPK, and p38MAPK pathways, but not JNK/MAPK pathway, caused an obvious decrease in α-SMA levels in the fibroblasts in both groups. CONCLUSION: The fibroblasts in the skin lesion of SSc patients have strong potential of transdifferentiation into MFBs, and TGF-ß(1) can promote this transdifferentiation process possibly involving Smads, and ERK/MAPK, and p38MAPK signalling pathways.