Mitochondrial depolarization after acute ethanol treatment drives mitophagy in living mice

被引：45

作者：

Samuvel, Devadoss J. ^{[1
,2
]}

Li, Li ^{[1
,2
]}

Krishnasamy, Yasodha ^{[1
,2
]}

Gooz, Monika ^{[1
,2
]}

Takemoto, Kenji ^{[1
,2
]}

Woster, Patrick M. ^{[1
,2
]}

Lemasters, John J. ^{[1
,2
,3
]}

Zhong, Zhi ^{[1
,2
]}

机构：

[1] Med Univ South Carolina, Dept Drug Discovery, Charleston, SC 29425 USA

[2] Med Univ South Carolina, Dept Biomed Sci, Charleston, SC 29425 USA

[3] Med Univ South Carolina, Dept Biochem & Mol Biol, Charleston, SC 29425 USA

来源：

AUTOPHAGY | 2022年 / 18卷 / 11期

基金：

美国国家卫生研究院;

关键词：

Acetaldehyde; alcoholic liver disease; Alda-1; mitochondrial depolarization; mitophagy; tacrolimus; ALCOHOLIC LIVER-DISEASE; PERMEABILITY TRANSITION; OXIDATIVE STRESS; ISCHEMIC DAMAGE; RAT HEPATOCYTES; AUTOPHAGY; DNA; DEGRADATION; ACTIVATION; STEATOSIS;

D O I：

10.1080/15548627.2022.2046457

中图分类号：

Q2 [细胞生物学];

学科分类号：

071009 ; 090102 ;

摘要：

Ethanol increases hepatic mitophagy driven by unknown mechanisms. Type 1 mitophagy sequesters polarized mitochondria for nutrient recovery and cytoplasmic remodeling. In Type 2, mitochondrial depolarization (mtDepo) initiates mitophagy to remove the damaged organelles. Previously, we showed that acute ethanol administration produces reversible hepatic mtDepo. Here, we tested the hypothesis that ethanol-induced mtDepo initiates Type 2 mitophagy. GFP-LC3 transgenic mice were gavaged with ethanol (2-6 g/kg) with and without pre-treatment with agents that decrease or increase mtDepo-Alda-1, tacrolimus, or disulfiram. Without ethanol, virtually all hepatocytes contained polarized mitochondria with infrequent autophagic GFP-LC3 puncta visualized by intravital microscopy. At similar to 4 h after ethanol treatment, mtDepo occurred in an all-or-none fashion within individual hepatocytes, which increased dose dependently. GFP-LC3 puncta increased in parallel, predominantly in hepatocytes with mtDepo. Mitochondrial PINK1 and PRKN/parkin also increased. After covalent labeling of mitochondria with MitoTracker Red (MTR), GFP-LC3 puncta encircled MTR-labeled mitochondria after ethanol treatment, directly demonstrating mitophagy. GFP-LC3 puncta did not associate with fat droplets visualized with BODIPY558/568, indicating that increased autophagy was not due to lipophagy. Before ethanol administration, rhodamine-dextran (RhDex)-labeled lysosomes showed little association with GFP-LC3. After ethanol treatment, TFEB (transcription factor EB) translocated to nuclei, and lysosomal mass increased. Many GFP-LC3 puncta merged with RhDex-labeled lysosomes, showing autophagosomal processing into lysosomes. After ethanol treatment, disulfiram increased, whereas Alda-1 and tacrolimus decreased mtDepo, and mitophagy changed proportionately. In conclusion, mtDepo after acute ethanol treatment induces mitophagic sequestration and subsequent lysosomal processing.

引用

页码：2671 / 2685

页数：15

共 82 条

[1] Hepatocyte mitochondria-derived danger signals directly activate hepatic stellate cells and drive progression of liver fibrosis [J].