The role of HTRA2 in neurotoxin-induced mitochondrial unfolded protein response
10.3969/j.issn.1002-0152.2025.07.005
- VernacularTitle:高温需求因子A2在神经毒素诱导的线粒体未折叠蛋白反应中的作用
- Author:
Zhiting CHEN
1
;
Qingxian FU
1
;
Lina CHEN
1
;
Qinyong YE
1
Author Information
1. 福建医科大学附属协和医院神经内科(福州 350001)
- Publication Type:Journal Article
- Keywords:
High-temperature requirement A serine peptidase 2(HTRA2);
Mitochondrial unfolded protein re-sponse;
Parkinson disease;
1-methyl-4-phenylpyridinium(MPP+);
Gene knockdown techniques
- From:
Chinese Journal of Nervous and Mental Diseases
2025;51(7):413-419
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the role of high-temperature requirement factor A2(HTRA2)in the mitochondrial unfolded protein response(mtUPR)model induced by the neurotoxin 1-methyl-4-phenylpyridinium(MPP+)and the compensatory effects of other proteases.Methods The mtUPR cell model was established by treating SH-SY5Y cells with MPP+.Cell viability was assessed using the Cell Counting Kit-8(CCK-8)assay,and mitochondrial morphological changes and intracellular reactive oxygen species(ROS)levels were examined under transmission electron microscopy and fluorescence microscope,respectively.Western blot(WB)was used to detect the expression levels of C/EBP Homologous Protein(CHOP),Heat shock protein family E member 1(HSPE1),YME1-like 1 ATPase(YME1L1),Caseinolytic mitochondrial matrix peptidase proteolytic subunit(CLPP),and Lon peptidase 1,mitochondrial(LONP1).Lentivirus-mediated knockdown(KD)of the HTRA2 gene in SH-SY5Y cells was performed.The mRNA and protein expression levels of HTRA2 were detected by quantitative real-time polymerase chain reaction and WB,respectively.After induction of mtUPR in HTRA2-KD SH-SY5Y cells with 400 μmol/L MPP?,cell viability and protein expression levels of HTRA2,YME1L1,CLPP,and LONP were evaluated using the CCK-8 assay and WB,respectively.Results mtUPR cell model was successfully established following treatment of SH-SY5Y cells with 400 μmol/L MPP+for 24 hours.Compared to the control group,there was no significant change in cell viability.Under electron microscopy,there were no remarkable alterations in the mitochondrial cristae and size in the mtUPR group.The average fluorescence intensity of ROS in the mtUPR group was 1.25±0.08 fold that of the PBS group,and the difference was statistically significant(P=0.001).The expression levels of CHOP,HSPE1,HTRA2,CLPP,and LONP were significantly higher in the mtUPR group than in the control group,which were 2.68±0.94、2.83±0.89、1.67±0.20,1.65±0.28,and 1.66±0.13 times that of control group,respectively(all P<0.05).The expression level of YME1L1 in the mtUPR group was 1.28±0.27 times that of the control group,with no statistical significance(P>0.05).After knockdown of the HTRA2 gene in SH-SY5Y cells,the expression levels of CLPP,YME1L1,and LONP1 increased to 1.46±0.79,1.41±0.12,and 1.32±0.25 times that of the empty virus group,respectively(all P<0.05).Following treatment with 400 μmol/L MPP+for 24 hours in HTRA2-KD SH-SY5Y cells,cell viability in HTRA2-KD group decreased to 88.4%±6.1%of the empty virus group(P<0.05).In the HTRA2 group,there were no significant changes in the expression levels of YME1L1 and LONP1 compared to the empty virus group(all P>0.05),while the expression level of CLPP increased to(1.88±0.62)times that of the empty virus group(P=0.033).Conclusion HTRA2 is an important mitochondrial protease in the MPP+-induced mtUPR response,and other mitochondrial proteases partially compensate for the function of HTRA2.
