基于GRP78/Caspase-12/CHOP信号通路探讨艾灸预防急性胃黏膜损伤的机制

Exploring the mechanism of moxibustion to prevent acute gastric mucosal lesion based on GRP78/Caspase-12/CHOP signaling pathway

目的基于葡萄糖调节蛋白78(GRP78)/半胱氨酸蛋白水解酶-12(Caspase-12)/CCAAT增强子结合蛋白同源蛋白(CHOP)信号通路探讨艾灸预防急性胃黏膜损伤的机制。方法将52只健康SD大鼠随机分为正常组、模型组、艾灸预处理组、针刺预处理组,每组13只。正常组、模型组大鼠只固定不进行处理;艾灸预处理组大鼠选取足三里穴、中脘穴进行艾灸,每次20 min,1次/d,连续灸7 d;针刺预处理组大鼠选穴和治疗时间同艾灸预处理组。预处理结束后,对模型组、艾灸预处理组、针刺预处理组大鼠进行无水乙醇结合阿司匹林混悬液灌胃7 d建立急性胃黏膜损伤模型。实验结束后,HE染色观察各组大鼠胃组织病理形态,ELISA法检测血清肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)、白细胞介素-10(IL-10)水平,免疫组织化学法检测胃组织中GRP78、Caspase-12、CHOP蛋白表达情况。结果模型组大鼠胃组织上皮细胞结构破坏,炎症细胞浸润,胃黏膜组织损伤明显;艾灸预处理组和针刺预处理组大鼠胃组织病理损伤较轻。与正常组比较,模型组大鼠血清TNF-α、IL-6、IL-1β水平均明显升高(P均<0.05),血清IL-10水平明显降低(P<0.05),胃组织中GRP78、Caspase-12、CHOP呈强阳性表达,可见大量棕黄色颗粒;艾灸预处理组和针刺预处理组大鼠血清TNF-α、IL-6、IL-1β水平均明显低于模型组(P均<0.05),血清IL-10水平均明显高于模型组(P均<0.05),胃组织中GRP78、Caspase-12、CHOP呈弱阳性表达,可见少量棕黄色颗粒,且艾灸预处理组上述各项变化均较针刺预处理组明显。结论艾灸预处理对急性胃黏膜损伤具有保护作用,分析与其调节GRP78/Caspase-12/CHOP信号通路,抑制内质网应激,调节促炎及抑炎因子表达有关。

Objective It is to explore the mechanism of moxibustion to prevent acute gastric mucosal lesion based on glucose regulatory protein 78(GRP78)/cysteine protein hydrolase-12(Caspase-12)/CCAAT enhancer binding protein homologous protein(CHOP)signaling pathway.Methods Fifty-two healthy SD rats were randomly divided into normal group,model group,moxibustion pretreatment group,acupuncture pretreatment group,with 13 rats in each group.The rats in the normal group and model group were fixed without treatment;the rats in the moxibustion pretreatment group were treated with moxibustion at Zusanli acupoint and Zhongwan acupoint,20 min per time,once per day,continuously treated for 7 days;the rats in the acupuncture pretreatment group were treated at the same time as the moxibustion pretreatment group.After pretreatment,the rats in the model group,moxibustion pretreatment group and acupuncture pretreatment group were gavaged with anhydrous ethanol combined with aspirin suspension to establish models of acute gastric mucosal lesion.At the end of the experiment,the pathological morphology of the gastric tissues of rats in each group was observed by HE staining,the levels of serum tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),interleukin-1β(IL-1β),and interleukin-10(IL-10)were detected by ELISA,and the expression of GRP78,Caspase-12,and CHOP proteins in gastric tissues were detected by immunohistochemistry.Results The pathological manifestations of the rats in the model group were severe destruction of the epithelial structure of the gastric mucosa,with obvious congestion and inflammatory cell infiltration;the pathological damage of the gastric tissue was less in the moxibustion pretreatment group and acupuncture pretreatment group.Compared with the normal group,the levels of serum TNF-α,IL-6,and IL-1βwere significantly higher,while the level of serum IL-10 was significantly lower in the rats of the model group(P<0.05),strong positive expression of GRP78,Caspase12 and CHOP and a large number of brownish-yellow granules in gastric mucosa were visible;the levels of serum TNF-α,IL-6,and IL-1βwere significantly lower,while the levels of serum IL-10 were significantly higher in the rats of both moxibustion pretreatment group and acupuncture pretreatment group than those in the model group(all P<0.05),with weakly positive expression of GRP78,Caspase12 and CHOP and a small amount of brownish-yellow granules in gastric mucosa,and the changes of the above mentioned indexes in the moxibustion pretreatment group were more obvious than those in the acupuncture pretreatment group.Conclusion Moxibustion pretreatment has a protective effect on acute gastric mucosal injury,which is possibly related with inhibiting endoplasmic reticulum stress,regulating the expression of pro-and anti-inflammatory factors via the GRP78/Caspase-12/CHOP signaling pathway.