中华猕猴桃果仁非饱和脂肪酸通过下调CTGF抑制胶原蛋白合成抗大鼠肺纤维化

Unsaturated fatty acid of Actinidia chinesis planch seed oil protects against pulmonary fibrosis by inhibiting collagen synthesis via down-regulating connective tissue growth factor(CTGF)expression in rats

目的观察结缔组织生长因子(CTGF)及胶原蛋白合成在果王素(中华猕猴桃果仁非饱和脂肪酸)抗大鼠肺纤维化(PF)中的作用。方法雄性SD大鼠,随机分为对照组、模型组、(60、120、240)mg/kg果王素处理组和5 mg/kg醋酸泼尼松组,每组10只。对照组大鼠以9 g/L氯化钠溶液气管内注射,后5组大鼠则气管内注射博莱霉素A5构建PF模型,建模后次日,后4组大鼠分别以(60、120、240)mg/kg果王素和5 mg/kg醋酸泼尼松灌胃,而前2组予9 g/L氯化钠溶液灌胃,均每天1次。处理后第28天,处死大鼠取肺组织,HE和Masson染色评价PF病变程度,测定羟脯氨酸(HYP)含量,实时荧光定量PCR检测CTGF、α平滑肌肌动蛋白(α-SMA)mRNA表达,Western blot法测定CTGF、α-SMA、1型胶原蛋白(Col1)、Col3的蛋白水平,免疫组织化学染色分析CTGF表达情况。结果与模型组相比,(60、120、240)mg/kg果王素处理组和5 mg/kg醋酸泼尼松组肺泡炎及PF程度显著减轻,肺组织HYP含量减少,CTGF、α-SMA mRNA与蛋白表达下调,Col1、Col3蛋白水平降低。上述指标的改变在(60、120、240)mg/kg果王素处理组之间有剂量依赖性。此外,(60、120)mg/kg果王素处理组上述指标较5 mg/kg醋酸泼尼松组升高,而240 mg/kg果王素处理组与后者相比差异不明显。结论果王素下调肺组织CTGF表达,降低α-SMA水平,进而减少Col1、Col3合成,发挥抗PF作用。

Objective To observe the role of connective tissue growth factor(CTGF) and collagen synthesis in anti-pulmonary fibrosis(PF) by Kiwi fruit essence(unsaturated fatty acid of actinidia chinesis planch seed oil)in rats. MethodsSixty male SD rats were randomly divided into control group, model group, Kiwi fruit essence(60, 120, 240 mg/kg) treatment groups, and 5 mg/kg prednisone acetate group, with 10 animals in each group. Rats in control group were intratracheally administered with 9 g/L sodium chloride solution, and animals in other groups were intratracheally administered with bleomycin A5 to establish PF model. From the second day on, rats in the latter 4 groups were intragastrically treated with Kiwi fruit essence of 60, 120 and 240 mg/kg and prednisone acetate of 5 mg/kg, respectively. Rats in control and model groups were treated with 9 g/L sodium chloride solution once a day. All rats were sacrificed on day 28, and then pulmonary tissues were removed. The extent of PF lesions were evaluated using HE and Masson staining. The contents of hydroxyproline(HYP) were measured by a commercial kit. The mRNA expressions of CTGF and α-smooth muscle actin(α-SMA) inpulmonary tissues was detected by quantitative real-time PCR. The protein expressions of CTGF, α-SMA, collagen type 1(Col1) and Col3 were measured by Western blotting. The protein levels of CTGF were analyzed using immunohistochemical staining. Results Compared with the model group, the alveolitis and PF extent in 60, 120, 240 mg/kg Kiwi fruit essence treatment groups as well as 5 mg/kg prednisone acetate group were significantly alleviated, and the content of HYP and the expression of CTGF, α-SMA, Col1 and Col3 decreased. The changes of above indicators were dose-dependent among the(60, 120, 240) mg/kg Kiwi fruit essence treatment groups. Moreover, the above indicators were found higher in(60, 120) mg/kg Kiwi fruit essence treatment groups than those in 5 mg/kg prednisone acetate group, which, however, showed no significantly difference between 240 mg/kg Kiwi fruit essence treatment group and 5 mg/kg prednisone acetate group. Conclusion Kiwi fruit essence down-regulates CTGF expression and decreases the levels of α-SMA, leading to inhibition of Col1 and Col3 synthesis and alleviation of PF.