Fig 2: PLIN5 regulated the expression levels of mitochondrial function-related genes and apoptosis rate. (A) mRNA levels of COX2, COX4, and CS in cells transfected with PLIN5 expression vector or control vector. (B) mRNA levels of COX2, COX4, and CS in cells transfected with PLIN5 siRNAs or control siRNAs. (C) mRNA levels of GPX1, GPX2, SOD1, SOD2, TXNRD1, CAT, and PRDX3 in cells transfected with PLIN5 expression vector or control vector. (D) mRNA levels of GPX1, GPX2, SOD1, SOD2, TXNRD1, CAT, and PRDX3 in cells transfected with PLIN5 siRNAs or control siRNAs. (E) Apoptosis rate of cells transfected with PLIN5 expression vector or control vector. (F) Cells transfected with PLIN5 expression vector or control vector were treated with 200 µM H2O2 for 12 h. Then, the apoptosis rate was analyzed. These experiments were performed in triplicate. GAPDH was used as the reference gene. * p < 0.05; and ** p < 0.01.

Fig 3: The expression of PLIN5 was regulated by the JNK-p38-ATF pathway. (A) Protein levels of ATF1, ATF4, p-p38, p38, p-JNK, and JNK were detected by Western Blot. (B) The gray value analysis of A. (C) mRNA levels of ATF1, ATF3, and ATF4 in cells with 200 µM H2O2 treatment were detected by qPCR. (D) The cells were transfected with ATF1 expression vector or pcDNA3.1 vector. The protein levels of ATF1 and PLIN5 were detected through Western Blot. (E) The cells were transfected with ATF4 expression vector or pcDNA3.1 vector. The protein levels of ATF4 and PLIN5 were detected through Western Blot. (F) The effects of ATFs’ expression on PLIN5 transcriptional activity were detected by dual-luciferase reporter assay. (G) Protein levels of p-ASK1, Ask1, p-p38, p38, p-JNK, JNK, and PLIN5 were detected by Western Blot. (H) The gray value analysis of G. GAPDH was used as the reference protein. These experiments were performed in triplicate. * p < 0.05; ** p < 0.01; and n. s., not significant.

Fig 4: Hydrogen peroxide or lipopolysaccharide (LPS) treatment enhanced the expression of PLIN5. Hydrogen peroxide and LPS were used to induce cellular oxidative stress. (A) mRNA level of PLIN5 in cells with H2O2 treatment or control (phosphate buffer saline, PBS). (B) Western Blot analysis of PLIN5 protein levels in cells with H2O2 treatment or control (PBS). (C) mRNA level of PLIN5 in cells with LPS treatment or control (PBS). (D) Western Blot analysis of PLIN5 protein levels in cells with LPS treatment or control (PBS). (E) H2O2 treatment did not change the localization of PLIN5. PLIN5 localization analysis of cells with 400 µM oleic acid medium or H2O2 treatment. Green, PLIN5-EGFP; red, lipid droplets; blue, nucleus. Bar, 10 µm. These experiments were performed in triplicate. * p < 0.05; and ** p < 0.01.

Fig 5: Perilipin 5 (PLIN5) was up-regulated in liver tissues of non-alcoholic fatty liver disease (NAFLD) mice. (A) Six-week-old C57/bl male mice were fed with a high-fat diet (HFD) or chow diet (CD) for 10 weeks. The mRNA levels of PLIN5 in liver tissues of mice fed with chow diet (CD) and HFD were detected by qRT-PCR. (B) The protein levels of PLIN5 in liver tissues of mice fed with chow diet (CD) and HFD were detected by Western Blot. (C) Six-week-old C57/bl male mice were fed with methionine-choline-deficient diet (MCDD) for 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, and 8 weeks, respectively. The mRNA levels of PLIN5 were detected by qRT-PCR. (D) The protein levels of PLIN5 were detected by Western Blot. (E) Immunohistochemistry analysis of liver tissues of mice fed with MCDD (1–8 weeks) and control mice (0 week). Scale bar, 20 µm. These experiments were performed in triplicate. * p < 0.05; and ** p < 0.01.