辅酶Q10对小鼠矽肺纤维化的作用

Effect of coenzyme Q10 on silicosis fibrosis in mice

[背景]矽肺是危害最严重的职业病,目前无特效治疗方案。研究发现辅酶Q10可缓解氨甲蝶呤诱导的肺纤维化,但能否缓解矽肺纤维化尚无文献报道;此外,羟甲基戊二酸单酰辅酶A还原酶(HMGCR)作为内源性合成辅酶Q10的限速酶是否在该过程中发生变化也无研究报道。[目的]探讨辅酶Q10对小鼠矽肺纤维化的影响及HMGCR在该过程中的变化。[方法]C57BL/6小鼠随机分为3组:对照组(生理盐水组)、模型组(SiO2组)、治疗组(SiO2+辅酶Q10组),每组8只。模型组、治疗组采用气管内一次性滴注0.1 m L SiO2悬液(50 mg/mL)构建小鼠矽肺模型,对照组同法滴注等体积生理盐水。治疗组术后48 h给予辅酶Q10100 mg/(kg·d)灌胃。术后60 d处死各组小鼠,行HE及天狼星红染色,观察肺组织病理改变和胶原纤维沉积情况;碱水解法检测小鼠肺组织羟脯氨酸含量;实时荧光定量PCR法检测α平滑肌肌动蛋白(α-SMA)的mRNA表达,免疫组织化学法、Western blot检测α-SMA及HMGCR蛋白表达。[结果]模型组炎症细胞浸润及纤维化程度较对照组升高,而治疗组炎症细胞浸润及纤维化程度均较模型组减轻。模型组羟脯氨酸含量为(0.65±0.06)μg/mg,较对照组[(0.54±0.05)μg/mg]升高,而治疗组羟脯氨酸含量为(0.55±0.05)μg/mg,较模型组降低,差异均有统计学意义(P<0.05)。对照组、模型组、治疗组α-SMA mRNA的相对表达量分别为24 381.85±3 301.44、31 812.66±8 335.82、21 587.55±9 489.53,模型组α-SMA mRNA表达高于对照组及治疗组(P<0.05)。模型组α-SMA蛋白、HMGCR蛋白表达均较对照组升高,而治疗组较模型组降低,差异均有统计学意义(P<0.05)。[结论]辅酶Q10能够减轻小鼠矽肺纤维化并降低HMGCR表达。

[Background] Silicosis is the most serious occupational disease, and there is no specific treatment plan. It had been found that coenzyme Q10(CoQ10) can relieve methotrexate-induced pulmonary fibrosis, but whether it can alleviate silicosis fibrosis has not been reported;in addition, it has not been reported whether hydroxymethyl glutaryl coenzyme A reductase(HMGCR), as a rate limiting enzyme for endogenous synthesis of CoQ10, has changed in this process.[Objective] This experiment investigates the effect of CoQ10 on silicosis fibrosis in mice and the associated potential change of HMGCR.[Methods] C57 BL/6 mice were randomly divided into three groups: control group(saline group), model group(SiO2 group), and treatment group(SiO2+CoQ10 group), with eight mice in each group. Every mouse in the model group and the treatment group was exposed to 0.1 mL SiO2 suspension(50 mg/mL) by intratracheal instillation to build mouse silicosis model, whilethe control group was instilled with the same volume of normal saline. After 48 h of model establishment, the mice in the treatment group were given 100 mg/(kg·d) CoQ10 by gavage. After 60 d, all mice were sacrificed. The pathological changes and collagen deposition were observed after HE and Sirius red staining. The hydroxyproline(HYP) content in the lung tissues of mice was detected by alkaline hydrolysis. The alpha smooth muscle actin(α-SMA) mRNA expression was detected by real-time quantitative fluorescence PCR. The α-SMA and HMGCR protein expressions were detected by immunohistochemistry and Western blot.[Results] Inflammatory cell infiltration and fibrosis were more prominent in the model group than in the control group, and less severe in the treatment group than in the model group. The HYP content of the model group was(0.65±0.06) μg/mg, which was higher than that of the control group [(0.54±0.05) μg/mg], while the HYP content of the treatment group was(0.55±0.05) μg/mg, which was lower than that of the model group(P<0.05). The relative expression levels of α-SMA mRNA in the control group, the model group, and the treatment group were 24 381.85±3 301.44, 31 812.66±8 335.82, and 21 587.55±9 489.53, respectively;the expression of α-SMA mRNA in the model group was higher than those in the control group and the treatment group(P<0.05). The expression levels of α-SMA and HMGCR proteins were higher in the model group than in the control group, and lower in the treatment group than in the model group(P<0.05).[Conclusion] CoQ10 can attenuate silicosis fibrosis and reduce HMGCR expression in mice.