Quercetin regulates inflammation, oxidative stress, apoptosis, and mitochondrial structure and function in H9C2 cells by promoting PVT1 expression.

OBJECTIVE

To investigate the effect and potential mechanism of quercetin on inflammation, oxidative stress, apoptosis, and mitochondrial structure and function in H9C2 cells.

MATERIALS AND METHODS

H9C2 cells were obtained from the Shanghai Institutes for Biological Sciences, Chinese Academy of Science, and randomly divided into six groups: control, model, PVT1 overexpression (OV), quercetin, OV + quercetin, and NAC groups. The CCK-8 assay was performed to examine cell proliferation. Flow cytometry was used to examine cell apoptosis, cell membrane potential, and ROS levels. The expression of endothelial nitric oxide synthase (eNOS), malondialdehyde (MDA), and superoxide dismutase (SOD) was measured by ELISA and a Biochemical kit. Western blotting was used to determine the levels of p-DRP1 (s637), MFN2, NF-kB, p-NF-kB, IkB, and p-IkB. IL-6, IL-10, TNF-α, and IL-1β mRNA expression was examined by RT-PCR. Electron microscopy was used to observe the structure of mitochondria in H9C2 cells.

RESULTS

MDA, p-NF-κB, p-IKB, IL-6, IL-1β, and TNF-α expression levels, and the cell apoptosis rate were significantly higher in the model group than in the control group (P < 0.05). In contrast, the cell proliferation rate and IL-10, SOD, eNOS, and ATP levels were significantly lower in the model group (P < 0.05). Moreover, MDA expression was significantly lower in the OV, quercetin, quercetin + OV, and NAC groups than in the model group (P < 0.05), while SOD, eNOS, and ATP levels were higher. The electron microscopy results showed that PVT1 overexpression or quercetin treatment could inhibit inflammation-induced mitochondrial fission and promote mitochondrial fusion.

CONCLUSION

Quercetin promotes the proliferation of H9C2 cells, while inhibiting inflammation, oxidative stress, and cell apoptosis, and alleviating the structural and functional dysfunction of mitochondria. These effects are achieved by promoting PVT1 expression.