Protein phosphatase 2A promotes mitophagy to alleviate fructose-induced mitochondrial oxidative damage in M2-type macrophages
10.16016/j.2097-0927.202505052
- VernacularTitle:蛋白磷酸酶2A促进线粒体自噬减轻果糖诱导的M2型巨噬细胞线粒体氧化损伤
- Author:
Xiaoman LI
1
;
Li LAN
;
Yijin LONG
;
Huilian LI
;
Minghong WANG
;
Xinhan WANG
;
Xiyi LI
;
Shen TANG
Author Information
1. 广西医科大学基础医学院免疫学教研室
- Keywords:
fructose;
macrophages;
mitophagy;
oxidative stress;
protein phosphatase 2A
- From:
Journal of Army Medical University
2025;47(18):2186-2196
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of fructose exposure on mitochondrial oxidative damage in M2-type macrophages and elucidate the regulatory role of protein phosphatase 2A(PP2A)in the process using its specific activator ABL127,an inhibitor of protein phosphatase methylesterase-1(PPME-1).Methods ① Immortalized mouse bone marrow-derived macrophages Ana-1 were subjected and grouped into M0(conventional culture),M2(treated with 20 ng/mL IL-4 for 24 h),and M2+Fru groups(IL-4 plus 0.04,0.20,1.00,or 5.00 mmol/L fructose).Cell viability was assessed with CCK-8 assay.Number of mitochondria,total and mitochondrial levels of reactive oxygen species(ROS),and mitochondrial membrane potential(ΔΨM)were measured using fluorescent probes.Total and demethylated PP2Ac protein levels were detected by Western blotting.② Ana-1 cells were also divided into M0,M2,M2+Fru(20 ng/mL IL-4+5.00 mmol/L fructose,24 h),and M2+Fru+ABL127(20 ng/mL IL-4+5.00 mmol/L fructose+1.00 μmol/L ABL127,24 h)to investigate PP2A-mediated mechanisms.Numbers of mitochondria and lysosomes,ROS level,and ΔΨM were detected via fluorescence assays.Expression of mitophagy-related proteins,PTEN induced putative kinase 1(PINK1),P62,microtubule-associated protein light chain 3(LC3),and voltage-dependent anion channel(VDAC)was evaluated by Western blotting,and the mRNA levels of M2 markers,found in inflammatory zone 1(Fizz1),arginase-1(Arg-1),and TGF-β were measured using RT-qPCR.Results ① Compared with the M2 group,fructose treatment at a concentration ranging from 0.04 to 5.00 mmol/L showed no effect on cell viability in M2 macrophages,but increased total ROS level in a dose-dependent manner(P<0.05).Fructose of 5.00 mmol/L resulted in significantly elevated mitochondrial ROS and mitochondrial quantity(P<0.05),reduced ΔΨM(P<0.05),up-regulated demethylated-PP2Ac(P<0.05),and no changed total-PP2Ac protein level.② Compared with the M2+Fru group,the addition of ABL127 led to decreased number of mitochondria but increased number of lysosomes(P<0.01),up-regulation of PINK1,LC3Ⅱ and VDAC proteins,down-regulation of P62(P<0.05),reduced total and mitochondrial ROS levels,and enhanced ΔΨM(P<0.01).The mRNA expression of Fizz1,Arg-1,and TGF-β was notably decreased in the M2+Fru group than the M2 group(P<0.05),and the levels were rescued by ABL127 treatment(P<0.05).Conclusion Fructose induces PP2Ac demethylation and then mitochondrial oxidative damage in M2-type macrophages.PP2A activation promotes mitophagy and reverses fructose-induced damage.
