MYOZ2 Promoted Adipogenic Differentiation of C3H10T1 / 2 Cells by Negatively Regulating the Expression of TCAP / 中国生物化学与分子生物学报

ABSTRACT

The objective of this study was to investigate the expression profile of the myozenin2 (MYOZ2) gene and elucidate its effect on adipogenic differentiation of C3H10T1 / 2 cells and its possible mechanism∙ The longissimus dorsi‚ subcutaneous fat and liver tissue was collected from 180-day-old Mashen pigs‚ 60-day-old ICR mice‚ 35-day-old Ross broiler and 12-month-old Small tail han sheep‚ and the expression profile of the MYOZ2 gene mRNA was detected∙ The results showed that the MYOZ2 gene has similar patterns of tissue expression in examined species‚ with the highest expression level in longissimus dorsi‚ and a small amount of expression in the subcutaneous fat and liver tissue∙ After the MYOZ2 gene was silenced in C3H10T1 / 2 cells‚ qRT-PCR results showed that the expression levels of key adipogenic genes PPARγ and FABP4 were significantly down-regulated compared with the control group (P < 0∙ 01) ; Western Blotting results showed that the PPARγ protein content was significantly decreased (P < 0∙ 05) ; Oil red O staining showed that the number of lipid droplets and the content of triglyceride were significantly decreased after silencing MYOZ2 (P < 0∙ 05) ∙ The expression of fatty acid metabolism related genes SCD‚ FASN‚ SREBP1‚ NR1H3‚ DGAT1‚ PNPLA2‚ HSL‚ CES1‚ CPT1 after MYOZ2 silencing were detected by qRT-PCR∙ The results showed that SCD‚ FASN‚ SREBP1‚ PNPLA2 and HSL were significantly down-regulated (P < 0∙ 01) ‚ NR1H3 was significantly reduced (P < 0∙ 05) ‚ DGAT1 expression was down-regulated but the difference was not significant‚ CES1 and CPT1 were significantly up-regulated (P < 0∙ 05) ∙ The STRING database was used to construct a MYOZ2-related protein interaction network map‚ and it was found that MYOZ2 may affect the adipogenic differentiation through the interaction of titin-cap (TCAP) and PPARγ∙ After silencing TCAP‚ qRT-PCR results showed that compared with the control group‚ the expression of key adipogenic genes PPARγ and FABP4 were significantly up-regulated (P < 0∙ 01) ; Western Blotting results showed that PPARγ protein was significantly increased (P< 0∙ 05) ; Oil red O staining showed that the number of lipid droplets and the content of triglyceride were significantly increased after TCAP silencing (P < 0∙ 05) ∙ qRT-PCR was used to detect the expression of TCAP after silencing MYOZ2‚ and the results showed that the expression of TCAP was significantly increased (P<0∙ 01) ∙ In summary‚ MYOZ2 was highly expressed in longissimus dorsi and lower expressed in subcutaneous fat and liver tissues∙ In addition‚ MYOZ2 may regulate the expression of key adipogenic genes PPARγ and FABP4 through the interaction of MYOZ2-TCAP -PPARγ‚ and to further regulate the expression of fatty acid metabolism related genes SCD‚ FASN‚ SREBP1‚ NR1H3‚ DGAT1‚ PNPLA2‚ HSL‚ CES1 and CPT1‚ thus playing an important role in the process of adipogenic differentiation∙