Yulink regulated Serca2 expression through the PPARγ pathway. a Treatment with 50 μM rosiglitazone for 6 h rescued and enhanced Serca2 expression at mRNA and protein levels in Yulink KD cardiomyocytes by qPCR (left panel) and Western blot (right panel). Serca2 mRNA levels normalized to values in cells treated with Ctrl vector. (n = 3, **p < 0.01, Student’s t test). Protein levels normalized to internal control, GAPDH. b Treatment with 50 mM pioglitazone (PPARγ agonist) for 12 h increased Serca2 mRNA expression in Yulink KD cardiomyocytes, as shown by qPCR. Data for cardiomyocytes treated with Ctrl vector and Yulink KD cardiomyocytes are shown in blue and red, respectively. Before pioglitazone treatment, Serca2 expression was decreased in Yulink KD cardiomyocytes (n = 3, **p < 0.01, Student’s t test). Pioglitazone increased relative Serca2 expression in Yulink KD cardiomyocytes from 0.25 to 0.82 (n = 3, **p < 0.01, Student’s t test). In Ctrl vector-treated cardiomyocytes, the expressions of Serca2 before and after pioglitazone were 1 and 0.81, respectively (n = 3). c Gene expression and protein levels in PPARγ-shRNA KD cardiomyocytes and cells treated with Ctrl Vector were quantified by qRT-PCR and Western blot, respectively. The mRNA expressions of PPARγ and Serca2 were significantly lower in PPARγ-shRNA KD cardiomyocytes (0.36 and 0.51, respectively) compared to values of 1 in cells treated with Ctrl vector (n = 3, ** p < 0.01, Student’s t test). Decreased total cellular PPARγ and SERCA2 protein levels were also observed in PPARγ-shRNA KD cardiomyocytes; values normalized to GAPDH. d KD of Yulink resulted in obvious decreases in nuclear levels of PPARα and PPARβ/δ (left panel, n = 3, ** p < 0.01, Student’s t test), but treatment with the PPARα agonist GW7647 (middle panel) or PPAR β/δ agonist GW0742 (right panel) did not statistical increase Serca2 expression in Control vector-treated or Yulink KD cardiomyocytes (n = 3)
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