Inhibition of autophagy by esketamine attenuates hypoxia/reoxygenation injury in cardiomyocytes via inhibition of Ca²⁺/CaMKKβ/AMPK/mTOR pathway by down-regulation of transient receptor potential vanilloid 1 expression.

This research sought to determine the influence of esketamine (ESK) on hypoxia/reoxygenation (H/R) injury in cardiomyocytes by blocking autophagy via the transient receptor potential vanilloid type 1 (TRPV1)/ Ca²⁺/ calmodulin-dependent protein kinase β (CaMKKβ)/ adenosine monophosphate (AMP)-activated protein kinase (AMPK)/ mammalian target of rapamycin (mTOR) pathway. H9c2 cardiomyocytes were hypoxic for 4 h and reoxygenated for 6 h. H9c2 cells were pretreated with ESK (30 μg/ml) before hypoxia. H9c2 cells were transfected with plasmid vectors that interfered with TRPV1 or CaMKKβ, and the success of the transfections was verified by RT-qPCR. Cell viability was detected by MTT assay; apoptosis was detected by flow cytometry; intracellular Ca²⁺ concentration ([Ca²⁺]i) was assessed using fluorescent dye Fluo-3 AM/Pluronic F127, and LC3-I, LC3-II, Beclin-1, and CaMKKβ/AMPK/mTOR-related proteins were detected by Western blot. In results: ESK treatment inhibited H/R-induced cell injury, cellular autophagy, and [Ca²⁺]i elevation. Induction of autophagy or [Ca²⁺]i elevation attenuated the ameliorative effect of ESK on H/R-induced cell injury. Upregulating TRPV1 attenuated We conclude that ESK-induced protection against H/R injury, as well as reduced the effect on the CaMKKβ/AMPK/mTOR pathway. ESK attenuates H/R cardiomyocyte injury by hindering autophagy through the TRPV1/Ca²⁺/CaMKKβ/AMPK/mTOR pathway.