Klotho overexpression suppresses apoptosis by regulating the Hsp70/Akt/Bad pathway in H9c2(2-1) cells

Abstract

Early reperfusion is the most effective and important treatment for acute myocardial infarction. However, reperfusion therapy often leads to a certain degree of myocardial damage. The aim of the present study was to identify the role of klotho, and the molecular mechanism underlying its effects, in myocardial damage using a model of myocardial hypoxia injury. Hypoxia/reoxygenation (H/R) was used to mimic ischemia/reperfusion (I/R) injury in vitro . The expression and distribution of klotho in H9c2(2-1) cells was observed by fluorogenic scanning, and the apoptotic rate was determined by Annexin V-FITC/propidium iodide dual staining. Cell viability was determined by MTT assay, and caspase-3, cleaved caspase-3, Bcl-2, Bax, heat shock protein (Hsp) 70 and Akt levels were assessed by western blotting. A lactate dehydrogenase test was performed to determine the degree of H9c2(2-1) cell damage. The results revealed that klotho was primarily located in the cytoplasm of H9c2(2-1) cells. Klotho overexpression markedly suppressed H/R-induced H9c2(2-1) cell apoptosis. Furthermore, cell viability increased, and injury decreased in response to klotho. Klotho also suppressed the activation of caspase-3, upregulated Bcl2 and decreased Bax levels following H/R injury, as well as alleviating H/R injury by upregulating the expression of Hsp70 and increasing the levels of phosphorylated (p-)Akt and Bad. In conclusion, these results indicate that klotho suppressed H/R-induced H9c2(2-1) cell apoptosis by regulating the levels of Hsp70, p-Akt and p-Bad, which suggest that klotho could be a novel agent for the treatment of coronary disease.

Effects of klotho protein or klotho knockdown in porcine oocytes at different stages

“…These results suggested that introducing the klotho protein into the cytoplasm of porcine oocytes before IVM inhibited apoptosis and supported embryo development. These results were consistent with the findings that klotho inhibited apoptosis in acute kidney injury models (Sugiura et al, 2010) and myocardial cells (Hu et al, 2021). The results of the present study showed that the klotho protein microinjection at the same concentration 6 h after parthenogenetic activation had no effect on the blastocyst formation rate.…”

Dexmedetomidine prevents cardiomyocytes from hypoxia/reoxygenation injury via modulating tetmethylcytosine dioxygenase 1-mediated DNA demethylation of Sirtuin1

“…Reperfusion therapy is the most vital and effective treatment for AMI, and reperfusion of myocardial blood can be achieved through pharmacological thrombolysis, stenting, or thrombectomy. Nevertheless, the restoration of blood supply usually activates a series of cellular injury mechanisms that may lead to myocardial cell death and an increase in infarct size, i.e., myocardial hypoxia/reoxygenation (H/R) damage [ 2–4 ]. As a result, it is essential to explore effective strategies to mitigate it.…”

Rapamycin treatment increases survival, autophagy biomarkers and expression of the anti‐aging klotho protein in elderly mice

“…Recently, researchers reported that Klotho exhibited a potent ability to suppress potentially pathological apoptotic depletion of cardiac cells. Klotho protein was observed to mediate this effect through induction of the heat shock protein (hsp) 70 gene, with downstream inhibition of caspase‐3 activation, increased expression of the pro‐survival proteins Bcl‐2, phosphorylated (p‐)Akt, and Bad, and concomitantly reduced expression of the pro‐apoptotic protein Bax 26 . Findings of the present investigation with potential relevance to the development of improved strategies for the management of diseases in which autophagic activity plays a role, include an observation of significantly elevated levels of LC3B‐II in adipose tissue and kidney from rapamycin‐treated mice and a reduction in rapamycin treatment in adipose tissue and kidney expression of p62 relative to that in the same tissues of vehicle‐treated control mice.…”