Dihydromyricetin Protects Against Gentamicin-Induced Ototoxicity via PGC-1α/SIRT3 Signaling in vitro.

Hezhou Han,Yaodong Dong,Xiulan Ma

doi:10.3389/fcell.2020.00702

Hezhou Han, Yaodong Dong + Show 1 more

Open Access

https://doi.org/10.3389/fcell.2020.00702

Copy DOI

Abstract

Aminoglycoside-induced ototoxicity can have a major impact on patients’ quality of life and social development problems. Oxidative stress affects normal physiologic functions and has been implicated in aminoglycoside-induced inner ear injury. Excessive accumulation of reactive oxygen species (ROS) damages DNA, lipids, and proteins in cells and induces their apoptosis. Dihydromyricetin (DHM) is a natural flavonol with a wide range of health benefits including anti-inflammatory, antitumor, and antioxidant effects; however, its effects and mechanism of action in auditory hair cells are not well understood. The present study investigated the antioxidant mechanism and anti-ototoxic potential of DHM using House Ear Institute-Organ of Corti (HEI-OC)1 auditory cells and cochlear explant cultures prepared from Kunming mice. We used gentamicin to establish aminoglycoside-induced ototoxicity models. Histological and physiological analyses were carried out to determine DHM’s pharmacological effects on gentamicin-induced ototoxicity. Results showed DHM contributes to protecting cells from apoptotic cell death by inhibiting ROS accumulation. Western blotting and quantitative RT-PCR analyses revealed that DHM exerted its otoprotective effects by up-regulating levels of peroxisome proliferator activated receptor γ-coactivator (PGC)-1α and Sirtuin (SIRT)3. And the role of PGC-1α and SIRT3 in the protective effects of DHM was evaluated by pharmacologic inhibition of these factors using SR-18292 and 3-(1H-1,2,3-triazol-4-yl) pyridine, respectively, which indicated DHM’s protective effect was dependent on activation of the PGC-1α/SIRT3 signaling. Our study is the first report to identify DHM as a potential otoprotective drug and provides a basis for the prevention and treatment of hearing loss caused by aminoglycoside antibiotic-induced oxidative damage to auditory hair cells.

Highlights

Oxidative stress results from the perturbation of cellular redox balance (Kandola et al, 2015) caused by excessive levels of reactive oxygen species (ROS) that exceed antioxidant defense mechanisms, leading to the destruction of cellular structures and cell death (Sies, 2015)
There was no obvious improvement in viability at DHM concentrations below 100 μM; treatment with 1,000 μM DHM and 500 μM gentamicin yielded cell numbers that were comparable to the control group (Figure 1B), demonstrating that DHM abrogates the cytotoxic effects of gentamicin in a dose-dependent manner
In explants cultured in normal medium, there was a single row of inner hair cells and three rows of outer hair cells with polarized hair bundles protruding from the apical surface of the cell body (Figure 1C)

Summary

Introduction

Oxidative stress results from the perturbation of cellular redox balance (Kandola et al, 2015) caused by excessive levels of reactive oxygen species (ROS) that exceed antioxidant defense mechanisms, leading to the destruction of cellular structures and cell death (Sies, 2015). DHM Protects Against Ototoxicity (Madamanchi and Runge, 2013); aging (Stefanatos and Sanz, 2018); and neurologic hearing loss (Someya et al, 2010; Chen et al, 2015; Esterberg et al, 2016) caused by aminoglycosideinduced damage (Cheng et al, 2005) and apoptosis of hair cells from the base to the apex of the organ of Corti (Jiang et al, 2016) Aminoglycosides exert this effect by stimulating ROS production in hair cells (Mangiardi et al, 2004; Coffin et al, 2013). PGC-1α can suppress ROS production and protect nerve cells from oxidative stressinduced damage by stimulating mitochondrial biosynthesis, enhancing the activity of the electron transport chain, and inducing the expression of a variety of ROS-detoxifying enzymes (Zhang Y. et al, 2018)

Methods

Results

Conclusion