目的 观察椒苯酮胺(piperphentonamine hydrochloride,PPTA)对脑缺血再灌注大鼠认知障碍的影响并探索其机制.方法 随机将大鼠分为假手术组、模型组、PPTA组(2.5、5、10 mg/kg)和阳性对照依达拉奉组(6 mg/kg).采用大鼠大脑中动脉闭塞2 h再灌注模型,缺血1h后给药.脑缺血再灌注24 h后进行避暗实验.行为学测试后24 h,断头取脑,分离右侧缺血脑区,用RT-PCR方法检测IL-1β、TNF-α、Caspase-3及HSP-70的mRNA表达.结果 避暗实验中,与假手术组相比,模型组动物认知能力显著性降低,而PPTA剂量依赖性地逆转了这一效应；伴随认知能力的下降,模型组动物炎症因子(IL-1β和TNF-α),凋亡因子Caspase-3及HSP-70 mRNA水平均显著性增高；与模型组比较,PPTA显著性降低了IL-1βmRNA,TNF-α mRNA,Caspase-3 mRNA及HSP-70 mRNA水平,而阳性对照药依达拉奉组未见对炎症因子产生显著影响.结论 PPTA可能通过改善脑缺血再灌注损伤后引起的炎症及凋亡反应,增加脑组织对缺血再灌注损伤应激的耐受性,从而发挥神经保护作用,可能是PPTA改善认知障碍的机制之一.%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 β1 (TGF-β1) 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-β1 in the cell culture and after blocking the signal transduction of TGF-β1. 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-β1 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-β1, 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 TQF-β1 can promote this transdifferentiation process possibly involving Smads, and ERK/MAPK, and p38MAPK signalling pathways.
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