摘要
目的 观察槲皮素对急性肺损伤大鼠肺泡巨噬细胞胞葬功能的影响,并基于过氧化物酶增殖物激活受体γ(PPARγ)/肝X受体α(LXR-α)信号通路研究其作用机制。方法 将60只雄性SD大鼠随机分为6组,每组10只。槲皮素低、中、高剂量组分别于造模前给予10 mg/kg、50 mg/kg、100 mg/kg的槲皮素灌胃,地塞米松组给予5 mg/kg的地塞米松灌胃,正常组和脂多糖组给予等量生理盐水灌胃,均1次/d。连续灌胃14 d后,除正常组外,其余组均采用鼻滴法给予脂多糖建立急性肺损伤模型。于造模后24 h,检测各组大鼠肺泡巨噬细胞胞葬功能,原位末端转移酶标记法(TUNEL)测定肺组织细胞凋亡率,ELISA法检测血清肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、白细胞介素-10(IL-10)水平,HE染色观察肺组织病理形态,免疫组化法检测肺组织中PPARγ、LXR-α、CD68蛋白阳性表达情况,RT-PCR法检测肺组织中PPARγ、LXR-α、CD68 mRNA表达情况。结果 与正常组比较,脂多糖组大鼠肺泡巨噬细胞胞葬功能明显减弱(P<0.05),肺组织细胞凋亡率和血清TNF-α、IL-1β、IL-6水平均明显增高(P均<0.05),血清IL-10水平明显降低(P<0.05),肺细胞肿胀、变性及大量炎性细胞浸润,肺组织中PPARγ、LXR-α、CD68蛋白阳性表达平均光密度值及mRNA相对表达量均明显降低(P均<0.05);与脂多糖组比较,槲皮素各组及地塞米松组大鼠肺泡巨噬细胞胞葬功能均明显增强(P均<0.05),槲皮素中、高剂量组及地塞米松组肺组织细胞凋亡率和血清TNF-α、IL-1β、IL-6水平均明显降低(P均<0.05),槲皮素各剂量组血清IL-10水平均明显升高(P均<0.05),槲皮素高剂量组肺组织病理损伤明显改善,槲皮素中、高剂量组PPARγ、LXR-α、CD68阳性表达平均光密度值和PPARγ、LXR-α、CD68 mRNA相对表达量均明显高于脂多糖组(P均<0.05),地塞米松组PPARγ和CD68阳性表达平均光密度值、PPARγ和LXR-α mRNA相对表达量均明显高于脂多糖组(P均<0.05)。结论 槲皮素可增强脂多糖诱导急性肺损伤大鼠肺泡巨噬细胞胞葬功能,减轻肺组织病理损伤,其机制可能与激活PPARγ/LXR-α信号通路有关。
Objective It is to observe the effect of quercetin on alveolar macrophage efferocytosis in rats with acute lung injury and investigate its potential mechanism based on the peroxidase proliferator-activated receptor γ(PPARγ)/hepatic X receptor α(LXR-α) signaling pathway.Methods Sixty male SD rats were divided into 6 groups,with 10 rats in each group.The low,medium,and high dose groups of quercetin were respectively given 10 mg/kg,50 mg/kg,and 100 mg/kg of quercetin by gavage,the dexamethasone group was given 5 mg/kg of dexamethasone by gavage,and the normal group and lipopolysaccharide group were given equal amounts of normal saline by gavage,all once daily.After 14 days of continuous gavage,all the groups except for the normal group were given lipopolysaccharide by nasal drip method to establish acute lung injury models.At 24 h after modeling,the alveolar macrophage efferocytosis of rats in each group was detected,the apoptosis rate of lung tissue was detected by TUNEL,the serum levels of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interleukin-6(IL-6),interleukin-10(IL-10) were detected by ELISA,the pathological morphology of lung tissues was observed by HE staining,and the positive expressions of HPARγ,PPARγ,and IL-10 proteins in lung tissue were detected by immunohistochemical method,and the expressions of PPARγ,LXR-α,CD68 mRNA in lung tissues were detected by RT-PCR.Results Compared with the normal group,the efferocytosis of alveolar macrophages of rats in the lipopolysaccharide group was significantly weakened(P<0.05),the proportion of apoptosis in lung tissue and the serum levels of TNF-α,IL-1β and IL-6 were significantly increased(all P<0.05),the serum level of IL-10 was significantly decreased(P<0.05),the lung cells were swollen and degenerated,with much inflammatory cell infiltration,the mean optical density values of positive expressions of PPARγ,LXR-α,and CD68 proteins and the relative expression of their mRNA in lung tissues were significantly decreased(all P<0.05).Compared with the lipopolysaccharide group,the efferocytosis of alveolar macrophages of rats in each quercetin group and dexamethasone group was significantly enhanced(all P<0.05),the proportion of apoptosis in lung tissue and the serum levels of TNF-α,IL-1β and IL-6 were significantly decreased in the medium and high dose groups of quercetin and dexamethasone group(all P<0.05),the serum levels of IL-10 were significantly increased in each quercetin group(all P<0.05),the pathological injury of lung tissues were significantly improved in the high dose group of quercetin,the mean optical density values of positive expressions of PPARγ,LXR-α,and CD68 proteins and the relative expression of their mRNA in lung tissues in the medium and high dose groups of quercetin were significantly higher than those in the lipopolysaccharide group(all P<0.05),the mean optical density values of positive expressions of PPARγ and CD68 proteins and the relative expression of PPARγ,LXR-α mRNA in lung tissues in the dexamethasone group were significantly higher than those in the lipopolysaccharide group(all P<0.05).Conclusion Quercetin can enhance the efferocytosis of alveolar macrophages and alleviate the pathological injury of lung tissue in rats with lipopolysaccharids-induced acute lung injury,and its mechanism may be related to the up-regulation of PPARγ/LXR-α signaling pathway.
作者
杨昊若
樊茂蓉
杨斌
YANG Haoruo;FAN Maorong;YANG Bin(Tianjin University of Chinese Medicine,Tianjin 301617,China;Xiyuan Hospital,China Academy of Chinese Medical Sciences,Beijing 100091,China)
出处
《现代中西医结合杂志》
CAS
2024年第2期147-154,161,共9页
Modern Journal of Integrated Traditional Chinese and Western Medicine
基金
国家自然科学基金资助项目(81774297)
中国中医科学院创新工程(CI2021A00901)。
