Cytoskeleton Interruption in Human Hepatoma HepG2 Cells Induced by Ketamine Occurs Possibly through Suppression of Calcium Mobilization and Mitochondrial Function

Abstract

ABSTRACT:Ketamine is an intravenous anesthetic agent often used for inducing and maintaining anesthesia. Cytoskeletons contribute to the regulation of hepatocyte activity of drug biotransformation. In this study, we attempted to evaluate the effects of ketamine on F-actin and microtubular cytoskeletons in human hepatoma HepG2 cells and its possible molecular mechanisms. Exposure of HepG2 cells to ketamine at <100 M, which corresponds to clinically relevant concentrations for 1, 6, and 24 h, did not affect cell viability. Meanwhile, administration of therapeutic concentrations of ketamine obviously interrupted F-actin and microtubular cytoskeletons. In parallel, levels of intracellular calcium concentration-and timedependently decreased after ketamine administration. Analysis by confocal microscopy further revealed that ketamine suppressed calcium mobilization from an extracellular buffer into HepG2 cells.Exposure to ketamine decreased cellular ATP levels. The mitochondrial membrane potential and complex I NADH dehydrogenase activity were both reduced after ketamine administration. Ketamine did not change the production of actin or microtubulin mRNA in HepG2 cells. Consequently, ketamine-caused cytoskeletal interruption led to suppression of CYP3A4 expression and its metabolizing activity. Therefore, this study shows that therapeutic concentrations of ketamine can disrupt F-actin and microtubular cytoskeletons possibly through suppression of intracellular calcium mobilization and cellular ATP synthesis due to downregulation of the mitochondrial membrane potential and complex I enzyme activity. Such disruption of the cytoskeleton may lead to reductions in CYP3A4 activity in HepG2 cells.

Mechanistic studies on ketamine-induced mitochondrial toxicity in zebrafish embryos

“…Further work is needed to analyze these distinct functions of ATP synthase in ketamine-treated embryos. In conclusion, the current findings are consistent with reported adverse effects of ketamine on the mitochondria and ATP production in human cells (Baker et al, 2016; Chang et al, 2009; Ito et al, 2015), dysfunctional cardiac function in infant non-human primates (Hotchkiss et al, 2007) and newborn human infants (Saarenmaa et al, 2001), additionally providing mechanistic data that show ALCAR as a protectant against these adverse effects.…”

“…Ketamine led to mitochondrial dysfunction in neurons derived from human induced pluripotent stem cell (Ito et al, 2015) and acute ketamine administration has been shown to impair mitochondrial function in rat brains (Venancio et al, 2015). Ketamine suppresses ATP biosynthesis in HepG2 cells (Chang et al, 2009). However, the molecular mechanism of how ketamine causes mitochondrial dysfunction and suppresses ATP production is not known.…”

Disruption of actin filaments induces mitochondrial Ca2+ release to the cytoplasm and [Ca2+]c changes in Arabidopsis root hairs

“…Some studies have already investigated the relationship between F-actin and Ψ m in yeast and mammalian cells [56,57]. In yeast, a decrease in actin dynamics in certain actin mutants significantly reduced the mitochondrial membrane potential [58].…”

Resveratrol Protects against Oxidized LDL-Induced Breakage of the Blood-Brain Barrier by Lessening Disruption of Tight Junctions and Apoptotic Insults to Mouse Cerebrovascular Endothelial Cells ,

“…For imaging analyses of ZO-1 and occludin tight junctions, these 2 proteins were immunodetected using polyclonal antibodies against rabbit anti-ZO-1 and occludin (Zymed). A confocal laser scanning microscope (Model FV500, Olympus) was utilized to analyze the samples (28).…”