Fig. 5: PNPLA7 enhances Parkin mitochondrial recruitment and E3 ligase activity.
a–c Representative Immunoblot results and densitometry analysis of the indicated proteins in differentiated mature inguinal adipocytes (a), total lysate (b), mitochondrial and cytosolic fraction (c) of iWAT isolated from control and Pnpla7Tg mice (n = 3 biological replicates). Data are presented as mean ± SEM. (Two-tailed Student’s t test for 2-group comparisons). d, e Colocalization of Parkin with mitochondria (d) and quantification of the mitochondrial EGFP-Parkin positive cells (e) in differentiated adipocytes with or without PNPLA7 overexpression. Mitochondria were stained with Mito-tracker (red). EGFP-Parkin translocation to mitochondria was analyzed using confocal microscopy. (n = 3 biological replicates, scale bar = 20 μm). Data are presented as mean ± SEM. (Two-tailed Student’s t-test for 2-group comparisons). f, g Representative Immunoblot results of the indicated proteins in differentiated mature adipocytes obtained from control and Pnpla7Tg (f) as well as control and PNPLA7 knockout (g) male mice. (n = 3 biological replicates). h Illustration of the Adeno-Associated Virus (AAV)-mediated knocking down strategy of Parkin in iWAT of Pnpla7Tg mice and littermate control. 4-week-old control (+/+) and Pnpla7Tg (Tg) mice were injected with recombinant adeno-associated virus of AAV-Adipo-shscramble or AAV-Adipo-shParkin into the iWAT. After 28 days injection, the mice were exposed to 6 °C for additional 7 days. These mice were fed with normal chow diet. The mouse picture was created in BioRender. Ji, X. (2025) https://BioRender.com/v1sk48t. i, j The iWAT weight ratio (i) and relative mtDNA content (j) of control (+/+) and Pnpla7Tg (Tg) mice with or without Parkin knockdown as described in (h). (shScramble: +/+ group: n = 6; Pnpla7Tg group: n = 5; shParkin: n = 6/group). Data are presented as mean ± SEM. (Two-tailed Student’s t test for 2-group comparisons; ns indicates no statistical significance). k Representative H&E, UCP1, and TOM20 immunohistochemical staining images of iWAT sections from control (+/+) and Pnpla7Tg (Tg) mice with or without Parkin knockdown as described in (h). (n = 3/group). Scale bar = 100 μm. l Representative Immunoblot results and densitometry analysis of the indicated proteins in iWAT control (+/+) and Pnpla7Tg (Tg) mice with or without Parkin knockdown as described in (h). (n = 3/group). Data are presented as mean ± SEM. (Two-tailed Student’s t test for 2-group comparisons; ns indicates no statistical significance). Source data are provided as a Source Data file.
