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目的观察氯化镧(lanthanum chloride,LaCl_3)对大鼠大脑皮质细胞凋亡、葡萄糖调节蛋白(glucose regulated protein,GRP)表达、PKR样内质网激酶(PKR-like endoplasmic reticulum kinase,PERK)和肌醇需求酶1(inositol requiring enzyme 1,IRE1)磷酸化的影响,研究LaCl_3对大脑皮质产生损害效应的机制。方法 32只成年雌性Wistar大鼠随机分为对照组、2.5、5和10 g/L LaCl_3组,2.5、5和10 g/L LaCl_3组妊娠大鼠从受孕起分别饮用2.5、5和10 g/L LaCl_3蒸馏水溶液,对照组妊娠大鼠从受孕起饮用蒸馏水。LaCl_3组子代大鼠断乳前经母鼠胎盘和母乳染镧,断乳后饮用2.5、5和10 g/L LaCl_3蒸馏水溶液1个月。取子代大鼠大脑皮质,以尼氏染色法检测大脑皮质神经细胞尼氏体表达水平,以流式细胞仪法测定大脑皮质神经细胞凋亡率,采用Western blot法检测大脑皮质GRP78、GRP94、PERK、IRE1、磷酸化的PERK(pPERK)和IRE1(pIRE1)及分别受PERK和IRE1调控的生长迟滞和DNA损伤诱导蛋白(growth arrest and DNA damage inducible protein,GADD)153和JUN氨基端激酶(JUN NH2-terminal kinase,JNK)的表达水平。结果各LaCl_3组子代大鼠大脑皮质神经细胞尼氏体表达水平低于对照组(P<0.05),而细胞凋亡率高于对照组(P<0.05),且均具有一定的剂量-效应关系。2.5 g/L LaCl_3组子代大鼠大脑皮质GRP78、GRP94、pPERK、pIRE1、GADD153和pJNK表达水平高于对照组(P<0.05),5 g/L LaCl_3组子代大鼠大脑皮质GRP78、GRP94、pPERK、pIRE1、和GADD153表达水平高于对照和2.5 g/L LaCl_3组(P<0.05),10g/L LaCl_3组子代大鼠大脑皮质GRP78、GRP94、pPERK、pIRE1、GADD153和pJNK表达水平高于对照、2.5 g/L和5 g/L LaCl_3组(P<0.05)。结论 LaCl_3对大鼠大脑皮质的毒性效应机制可能涉及GRP78和GRP94表达上调、PERK和IRE1磷酸化水平升高所致凋亡增多。
Objective To observe the effects of lanthanum chloride (LaCl_3) on the apoptosis of rat cerebral cortex, the expression of glucose regulated protein (GRP), PKR-like endoplasmic reticulum kinase (PERK) (IRE1) phosphorylation, and to study the mechanism of LaCl3 on damaging effects on the cerebral cortex. Methods Thirty-two adult female Wistar rats were randomly divided into control group, 2.5, 5 and 10 g / L LaCl 3 groups. 2.5, 5 and 10 g / L LaCl 3 groups received 2.5, 5 and 10 g / L LaCl_3 distilled water solution, the control group of pregnant rats from conception drinking distilled water. LaCl_3 group offspring rats were pre-weaning lanthanum mother’s placenta and breast milk, weaned after drinking 2.5,5 and 10 g / L LaCl 3 distilled water solution for 1 month. The cerebral cortex of the offspring rats was taken and Nissl staining was used to detect the Nissl body expression of cerebral cortex neurons. Flow cytometry was used to determine the apoptotic rate of cerebral cortical neurons. Western blot was used to detect the expression of GRP78, GRP94, PERK, IRE1, phosphorylated PERK (pPERK) and IRE1 (pIRE1), and growth arrest and DNA damage inducible protein (GADD) 153 and JUN N-terminal kinase NH2-terminal kinase, JNK) expression levels. Results The expression of Nissl in cerebral cortex of LaCl_3 group was lower than that of the control group (P <0.05), and the apoptosis rate was higher in the LaCl_3 group than in the control group (P <0.05), and all had a dose-response relationship. The expression of GRP78, GRP94, pPERK, pIRE1, GADD153 and pJNK in the cerebral cortex of the 2.5 g / L LaCl_3 group was higher than that of the control group (P <0.05). The GRP78, GRP94 , PPERK, pIRE1 and GADD153 were significantly higher than that of the control and 2.5 g / L LaCl 3 groups (P <0.05). The expression of GRP78, GRP94, pPERK, pIRE1, GADD153 and pJNK in the cerebral cortex of the 10 g / In the control, 2.5 g / L and 5 g / L LaCl 3 groups (P <0.05). Conclusion The toxic effect of LaCl_3 on rat cerebral cortex may involve the up-regulation of GRP78 and GRP94, and the increase of phosphorylation of PERK and IRE1.