姜黄素通过抑制内质网应激介导的凋亡和炎症减轻氟化钠引起的大鼠脾脏损伤

Curcumin attenuates sodium fluoride-induced spleen injury in rat by inhibiting endoplasmic reticulum stress-mediated apoptosis and inflammation

为探究姜黄素对氟化钠(NaF)致大鼠脾脏损伤的保护作用及其可能作用机制,通过饮水方式构建染氟模型,NaF添加量为150 mg/L。将60只雄性健康SD大鼠随机分为对照组和3个处理组(NaF组,Ⅰ组;NaF+50 mg/kg姜黄素组,Ⅱ组;NaF+100 mg/kg姜黄素组,Ⅲ组)。处理3个月后,收集脾脏,通过苏木素伊红染色观察脾脏病理学变化,原位末端转移酶标记(TUNEL)和免疫组化检测细胞凋亡,荧光定量PCR和酶联免疫吸附试验检测炎症因子表达,免疫印迹检测内质网应激相关蛋白表达。结果显示,姜黄素减弱了NaF引起的脾脏损伤;与Ⅰ组相比,Ⅱ、Ⅲ组TUNEL阳性细胞数和活化的胱天蛋白酶3(cleaved caspase-3)水平均明显降低(P<0.05或P<0.01);此外,姜黄素显著降低NaF引起的脾脏白细胞介素6(IL-6)、白细胞介素1β(IL-1β)和肿瘤坏死因子α(TNF-α)水平升高,与Ⅰ组相比有显著差异(P<0.05或P<0.01);与Ⅰ组相比,Ⅱ、Ⅲ组大鼠组脾脏中葡萄糖调控蛋白78(GRP78)、磷酸化蛋白激酶R样内质网激酶(p-PERK)、磷酸化真核生物起始因子2α(p-eIF2α)、C/EBP同源蛋白(CHOP)、激活型胱天蛋白酶12(cleaved caspase-12)和核因子κB(NF-κB)水平明显降低(P<0.05或P<0.01)。结果表明,姜黄素能降低NaF引起的大鼠脾脏损伤,其保护机制可能与抑制内质网应激诱导的凋亡和炎症反应有关。

The purpose of this study was to investigate the protective effects of curcumin on spleen injury induced by sodium fluoride(NaF)and its possible mechanisms.The fluorine exposure model was established by adding 150 mg/L NaF into drinking water.Sixty healthy SD rats were randomly assigned into the control group and three treatment groups,including groupⅠ(NaF),groupⅡ(NaF+50 mg/kg curcumin),and groupⅢ(NaF+100 mg/kg curcumin).After 3 months of the experiment,spleens were collected to measure the pathological changes,apoptosis,expressions of inflammatory,and endoplasmic reticulum stress-related factors by the methods of hematoxylin-eosin staining,in situ terminal transferase labeling,immunohistochemistry,real-time quantitative PCR,enzyme-linked immunosorbent assay,and immunoblotting,respectively.The results showed that curcumin ameliorated the pathological damage induced by NaF.Compared to groupⅠ,those in groupⅡandⅢexhibited reduced TUNEL-positive cells and decreased level of cleaved caspase-3in spleen(P<0.05or P<0.01).In addition,compared with groupⅠ,curcumin could markedly decrease the increased levels of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),and interleukin-1β(IL-1β)in NaF-treated spleen(P<0.05or P<0.01).Compared to group I,the protein expression of 78kDa glucose-regulated protein(GRP78),phosphorylated PRKR like endoplasmic reticulum kinase(p-PERK),phosphorylated eukaryotic translation initiation factor 2subunit 1alpha(p-eIF2α),C/EBP Homology protein(CHOP),cleaved caspase-12and nuclear factor-κB(NF-κB)were decreased in spleen in response to NaF(P<0.05or P<0.01).In conclusion,curcumin can protect spleen against NaF-induced injury in rat by inhibiting endoplasmic reticulum stress-related apoptosis and inflammation.