RESUMO
Endotoxin-induced acute kidney injury (AKI) is commonly observed in clinical practice. Renal tubular epithelial cell (RTEC) pyroptosis is one of the main factors leading to the development of endotoxin-induced AKI. Mitochondrial dysfunction can lead to pyroptosis. However, the biological pathways involved in the potential lipopolysaccharide (LPS)-induced pyroptosis of RTECs, notably those associated with mitochondrial dysfunction, are poorly understood. Previous studies have demonstrated that heme oxygenase (HO)-1 confers cell protection via the induction of PTEN-induced putative kinase 1 (PINK1) expression through PTEN to regulate mitochondrial fusion/fission during endotoxin-induced AKI in vivo. Therefore, the present study investigated the role of HO-1/PINK1 in maintaining mitochondrial function and inhibiting the pyroptosis of RTECs exposed to LPS. Primary cultures of RTECs were obtained from wild-type (WT) and PINK1-knockout (PINK1KO) rats. An in vitro model of endotoxin-associated RTEC injury was established following treatment of the cells with LPS. The WT RTECs were divided into the control, LPS, Znpp + LPS and Hemin + LPS groups, and the PINK1KO RTECs were divided into the control, LPS and Hemin + LPS groups. RTECs were exposed to LPS for 6 h to assess cell viability, inflammation, pyroptosis and mitochondrial function. In the LPS-treated RTECs, the mRNA and protein expression levels of HO-1 and PINK1 were upregulated. Cell viability, adenosine triphosphate (ATP) levels and the mitochondrial oxygen consumption rate were decreased, whereas the inflammatory response, pyroptosis and mitochondrial reactive oxygen species (ROS) levels were increased. The cell inflammatory response and the induction of pyroptosis were inhibited, whereas the levels of mitochondrial ROS were decreased. In addition, the cell viability and ATP levels were increased in the WT RTECs following the upregulation of HO-1 expression. These effects were reversed by the downregulation of HO-1 expression. However, no statistically significant differences were noted between the LPS and the Hemin + LPS groups in the PINK1KO RTECs. Collectively, the findings of the present study indicate that HO-1 inhibits inflammation and regulates mitochondrial function by inhibiting the pyroptosis of LPS-exposed RTECs via PINK1.
RESUMO
Metabolism-mediated drug adverse effects (e.g., drug-drug interaction, bioactivation, etc.) strongly limit the utilization of clinical drugs. The present study aims to predict the metabolic capability of cytochrome P450 (CYP) 3A4 toward pazopanib which is an excellent drug exhibiting therapeutic role toward various cancers especially for ovarian cancer. Pazopanib can be well docked into the activity cavity of CYP3A4, and the interaction structure in pazopanib was methyl group located besides nitrogen in the five-membered ring. The distance between the hydrogen atom in methyl group and active center is 3.64 Å. The interaction amino acid is Glu374. Furthermore, both pazopanib and ketoconazole were docked into the activity cavity of CYP3A4 to compare their binding potential. The distance between ketoconazole and activity center (2.10 Å) is closer than the distance between pazopanib and activity center of CYP3A4, indicating the easy influence of CYP3A4 inhibitor toward the metabolism of pazopanib. All these data were helpful for the clinical application of pazopanib, and R&D of other tinib drug candidates as new anti-tumor drugs.