Akirin2 promotes slow myosin heavy chain expression by CaN/NFATc1 signaling in porcine skeletal muscle satellite cells

Figures

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  Figure 1. Expression of endogenous Akirin2 gene Western blot was used to analyze the Akirin2 protein expression in pig slow oxidative Psoas major (PM) muscle and fast glycolytic tibialis anterior (TA) muscle. Data were presented as means ± SE (n=3). *P < 0.05.

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  Figure 2. Akirin2 regulates the expression of MyHC I in porcine skeletal muscle satellite cells Porcine skeletal muscle satellite cells were transfected with negative control siRNA (NC), Akirin2 siRNA, pcDNA3.1(+) or pcDNA3.1(+)-pAkirin2 when cells reached about 80% confluence and induced to differentiate for 6 days before analysis. Western blot analysis was used to analyzed the Akirin2 A-B. and MyHC I C-D. protein expression in porcine skeletal muscle satellite cells. Data were presented as means ± SE (n=3). *P < 0.05 and **P < 0.01 as compared with control.

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  Figure 3. Effects of Akirin2 on the NFATc1 expression and CaN activity Porcine skeletal muscle satellite cells were cultured, transfected and induced to differentiate as described in Figure 2. Real-time quantitative PCR was used to analyze the MCIP1.4 A-B. mRNA expression in porcine skeletal muscle satellite cells. Western blot was used to analyze to the protein expression of NFATc1 C-D. in porcine skeletal muscle satellite cells. Calcineurin activity was analyzed by Calcineurin Cellular Activity Assay Kit E-F. Data were presented as means ± SE (n=3). *P < 0.05 and ***P < 0.001 as compared with control.

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  Figure 4. Akirin2 regulates the expression of MyHC I via CaN/NFATc1 signaling in porcine skeletal muscle satellite cells Cells were cultured, transfected and induced to differentiate as described in Figure 2. Real-time quantitative PCR was used to analyze the NFATc1 mRNA expression in porcine skeletal muscle satellite cells. Western blot was used to analyze to the protein expression of NFATc1 and MyHC I in porcine skeletal muscle satellite cells. Real-time quantitative PCR analysis indicated that the siRNA induced a 45% downregulation of NFATc1 mRNA expression A. Western blot analysis indicated that the protein expression level of NFATc1 was also significantly decreased B. Silencing of NFATc1 by siRNA inhibited Akirin2 overexpression-induced upregulation of MyHC I C. Inhibition of CaN by CsA abolished Akirin2 overexpression-induced upregulation of MyHC I and NFATc1 protein expressions D. and increase in the CaN activity E. Data were presented as means ± SE (n=3). ***P < 0.001. Value with different letters indicates significantly difference (P < 0.05).