학술논문

镉暴露激活PI3K/Akt信号通路诱导椎间盘纤维环细胞衰老 / Cadmium promotes senescence of annulus fibrosus cells via activation of PI3K/Akt signaling pathway
Document Type
Academic Journal
Source
中国组织工程研究 / Chinese Journal of Tissue Engineering Research. 28(8):1217-1222
Subject

纤维环细胞
椎间盘退变
衰老
PI3K/Akt
信号通路
cadmium
annulus fibrosus cell
intervertebral disc degeneration
senescence
signaling pathway
Language
Chinese
ISSN
2095-4344
Abstract
背景:镉是一种常见的环境污染物,可对肾脏、骨骼等多种器官和组织产生损害,但目前镉对纤维环细胞的影响知之甚少. 目的:探讨氯化镉对椎间盘纤维环细胞衰老的影响及PI3K/Akt信号通路在其中的作用. 方法:获取SD大鼠椎间盘纤维环细胞,以不同浓度(0,1,5,10,20 μmol/L)的氯化镉干预第3代纤维环细胞,CCK-8法检测细胞活力及增殖情况.对加入或不加入氯化镉的纤维环细胞进行转录组测序及京都基因与基因组百科全书生物信息学分析.将第3代纤维环细胞分为对照组、氯化镉组及PI3K/Akt通路抑制剂LY294002组,通过EdU法检测细胞增殖率,衰老相关β-半乳糖苷酶染色检测阳性细胞率,Western blot、RT-PCR及免疫荧光检测衰老相关蛋白(p16、p21及p53)及p-Akt的蛋白和mRNA表达水平. 结果与结论:①5 μmol/L氯化镉可以抑制纤维环细胞增殖.②京都基因与基因组百科全书功能富集结果显示,主要参与的信号转导途径有PI3K/Akt信号通路、cell cycle信号通路、p53信号通路等,与细胞增殖及衰老相关.选取差异表达明显的PI3K/Akt信号通路进行验证.③与对照组比较,氯化镉组的EdU染色阳性率下降(P<0.05),β-半乳糖苷酶染色阳性率、衰老相关蛋白(p16、p21及p53)及p-Akt表达增加(P<0.05).与氯化镉组比较,LY294002组的EdU染色阳性率下降(P<0.05),β-半乳糖苷酶染色阳性率、衰老相关蛋白(p16、p21及p53)表达增加(P<0.05),p-Akt表达下降(P<0.05).④结果表明,氯化镉可以通过激活PI3K/Akt信号通路导致纤维环细胞衰老,进而诱发椎间盘退变的发生和发展.
BACKGROUND:Cadmium is a common environmental pollutant,which can damage multiple organs and tissues,such as the kidney and bone,but its effect on annulus fibrosus cells in the intervertebral disc has been less reported. OBJECTIVE:To investigate the effect of cadmium chloride on the senescence of annulus fibrosus cells and the role of PI3K/Akt signaling pathway. METHODS:Annulus fibrosus cells from Sprague-Dawley rat intervertebral discs were harvested and passage 3 cells were intervened with different concentrations of cadmium chloride(0,1,5,10,20 μmol/L).Cell viability and proliferation were detected by cell counting kit-8 assay.Transcriptome sequencing and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis were performed on annulus fibrosus cells with or without cadmium chloride addition.Passage 3 annulus fibrosus cells were divided into control group,cadmium chloride group and LY294002 group.Cell proliferation rate was detected by EdU method,positive cell rate was detected by senescence-associated β-galactosidase staining,and expressions of senescence-associated proteins(p16,p21 and p53)and p-Akt at protein and mRNA levels were measured by western blot,RT-PCR and immunofluorescence. RESULTS AND CONCLUSION:5 μmol/L cadmium chloride could inhibit the proliferation of annulus fibrosus cells.Results from the Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis showed that the main signal transduction pathways included PI3K/Akt,cell cycle and p53 signaling pathways,which were related to cell senescence and proliferation.PI3K/Akt signaling pathways with significant differential expression were selected for validation.Compared with the control group,the EdU-positive rate was significantly decreased in the cadmium chloride group(P<0.05),while the β-galactosidase-positive rate,the expression of senescence-associated proteins(p16,p21 and p53)and p-Akt significantly increased(P<0.05).Compared with the cadmium chloride group,the EdU-positive rate and p-Akt expression were significantly decreased in the LY294002 group(P<0.05),while the β-galactosidase-positive rate and the expression of senescence-associated proteins(p16,p21 and p53)significantly increased(P<0.05).To conclude,cadmium chloride can regulate the senescence of annulus fibrosus cells by activating the PI3K/Akt signaling pathway,thereby inducing the occurrence and progression of intervertebral disc degeneration.