Xue-zhong Li, K. Zhao, Yuansu Zhuang, Xiaopeng Chen, Yi Liu
{"title":"DJ-1 Activation Raf/ERK Pathways Promotes Autophagy Maturation of PC-12 Cells","authors":"Xue-zhong Li, K. Zhao, Yuansu Zhuang, Xiaopeng Chen, Yi Liu","doi":"10.4236/APD.2021.101001","DOIUrl":null,"url":null,"abstract":"Park 7 gene encodes a conserved protein called DJ-1 protein, which involves autophagy stress, but the mechanism is unclear. Therefore, it is necessary to explore the mechanism of DJ-1 regulation PC-12 autophagical stress. Using CRISPR/Cas9 technique to construct DJ-1 knockout PC-12 cell lines, we culture wild-type and DJ-1 knockout PC-12 cell lines, establish oxidative stress cell model by MPP+, and divide them into wild-type control group (WT), wild-type intervention group (WT + MPP+), DJ-1 knockout control group (KO) and DJ-1 knockout intervention group (KO + MPP+), and explore the role of DJ-1 in regulating neuronal autophagy stress by cell viability assay, immunofluorescence, confocal, western blotting and electron microscopy. The results show that the growth ability of DJ-1 knockout cells is inferior to that of normal cells, and DJ-1 knockout cells are more sensitive to oxidative stress and more vulnerable to damage than wild-type cells. Exposing to MPP+, DJ-1 proteins undergo oxidative responses at Cys-106 sites, while DJ-1 knockout PC-12 cells do not show similar responses. The wild-type PC-12 cells have the confocal in both anti-oxidant DJ-1 antibody and anti-C-Raf phosphorylation antibody. The activated DJ-1 induces the phosphorylation of C-Raf at Ser338 sites to activate directly C-Raf, and subsequently activates ERK1/2 signaling pathways to antagonize MPP+-induced neurotoxicity. Lack of DJ-1, oxidative stress can not promote C-Raf activation. Although the phosphorylation level of cell ERK is also increased, the increase of intranucleus pERK is not obvious. Wild type and DJ-1 knockout PC-12 cells can produce autophagical stress in the face of oxidative stress, but the proportion of autophagolysosomes produced in wild type PC-12 cells is larger than that in DJ-1 knockout cells. PD98059 can reduce autophagy stress in the state of oxidative stress in wild-type PC-12 cells, and the number of autophagolysosomes is similarly reduced, while sorafenib decreased slightly DJ-1 the autophagical stress, and the proportion of autophagolysosomes decreased more. Therefore, we can infer that activated DJ-1 directly phosphorylates C-Raf at Ser-338 sites, then activating C-Raf, subsequent activation of the MEK/ERK pathway. DJ-1 promotes autophagy maturation through the C-Raf/ERK pathway, thereby improving cell survival.","PeriodicalId":7350,"journal":{"name":"Advances in Parkinson's Disease","volume":"29 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2021-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Parkinson's Disease","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4236/APD.2021.101001","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Park 7 gene encodes a conserved protein called DJ-1 protein, which involves autophagy stress, but the mechanism is unclear. Therefore, it is necessary to explore the mechanism of DJ-1 regulation PC-12 autophagical stress. Using CRISPR/Cas9 technique to construct DJ-1 knockout PC-12 cell lines, we culture wild-type and DJ-1 knockout PC-12 cell lines, establish oxidative stress cell model by MPP+, and divide them into wild-type control group (WT), wild-type intervention group (WT + MPP+), DJ-1 knockout control group (KO) and DJ-1 knockout intervention group (KO + MPP+), and explore the role of DJ-1 in regulating neuronal autophagy stress by cell viability assay, immunofluorescence, confocal, western blotting and electron microscopy. The results show that the growth ability of DJ-1 knockout cells is inferior to that of normal cells, and DJ-1 knockout cells are more sensitive to oxidative stress and more vulnerable to damage than wild-type cells. Exposing to MPP+, DJ-1 proteins undergo oxidative responses at Cys-106 sites, while DJ-1 knockout PC-12 cells do not show similar responses. The wild-type PC-12 cells have the confocal in both anti-oxidant DJ-1 antibody and anti-C-Raf phosphorylation antibody. The activated DJ-1 induces the phosphorylation of C-Raf at Ser338 sites to activate directly C-Raf, and subsequently activates ERK1/2 signaling pathways to antagonize MPP+-induced neurotoxicity. Lack of DJ-1, oxidative stress can not promote C-Raf activation. Although the phosphorylation level of cell ERK is also increased, the increase of intranucleus pERK is not obvious. Wild type and DJ-1 knockout PC-12 cells can produce autophagical stress in the face of oxidative stress, but the proportion of autophagolysosomes produced in wild type PC-12 cells is larger than that in DJ-1 knockout cells. PD98059 can reduce autophagy stress in the state of oxidative stress in wild-type PC-12 cells, and the number of autophagolysosomes is similarly reduced, while sorafenib decreased slightly DJ-1 the autophagical stress, and the proportion of autophagolysosomes decreased more. Therefore, we can infer that activated DJ-1 directly phosphorylates C-Raf at Ser-338 sites, then activating C-Raf, subsequent activation of the MEK/ERK pathway. DJ-1 promotes autophagy maturation through the C-Raf/ERK pathway, thereby improving cell survival.