Knockdown of KLF6 ameliorates myocardial infarction by regulating autophagy via transcriptional regulation of PTTG1.

Krüppel-like factor 6 (KLF6) knockdown provides protection against kidney ischemia/reperfusion injury and ischemic stroke. However, it is unclear whether it plays a role in myocardial infarction (MI). Here, the expression of KLF6 was analyzed using the Gene Expression Omnibus (GEO) database and determined in patients with MI. The impact of KLF6 knockdown was further confirmed in in vivo and in vitro models of MI. The interaction between KLF6 and pituitary tumor-transforming gene 1 (PTTG1) was also evaluated. According to the GEO database, KLF6 expression was found to be upregulated in mouse hearts after MI compared to sham-operated mice. The upregulation of KLF6 in hearts from mice post-MI and in patients with MI was confirmed. KLF6 knockdown was found to alleviate myocardial injury, diminish infarct size, and suppress apoptosis and autophagy in mice with MI. In addition, inactivation of the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling was observed after KLF6 knockdown in mice with MI. In an in vitro model of MI, the knockdown of KLF6 increased cell survival and inhibited autophagy through the AMPK/mTOR pathway. In addition, KLF6 interacted with the promoter of PTTG1 and negatively regulated its expression. Knockdown of PTTG1 abolished the function of KLF6 knockdown in vitro. This study demonstrates the protective effect of KLF6 knockdown against MI, which is attributed to the elevation of PTTG1 expression and inhibition of the AMPK/mTOR pathway. These findings provide a novel insight into MI treatment.NEW & NOTEWORTHY Our study demonstrates for the first time the role of Krüppel-like factor 6 (KLF6)/PTTG1 axis in myocardial infarction (MI). This study demonstrates the protective effect of KLF6 knockdown against MI, which is attributed to the elevation of PTTG1 expression and inhibition of the AMPK/mTOR pathway. These findings provide a novel insight into MI treatment.