Qiteng Xiaozhuo Granules improve chronic glomerulonephritis through promoting glomerular mesangial cell autophagy via FTO-mediated SLC7A5 m6A modification.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Qiteng Xiaozhuo Granules (QTXZG) has long been utilized as a traditional Chinese medicine (TCM) for treating Chronic Glomerulonephritis (CGN), demonstrating significant therapeutic efficacy. However, the underlying pathogenesis of CGN remains poorly understood, and the pharmacological mechanisms of QTXZG in treating CGN warrant further investigation. AIM OF THE STUDY: This study aims to explore the pathological mechanisms of Fat mass and obesity-associated protein (FTO)-mediated m6A modification in CGN and, based on these findings, to clarify the pharmacological mechanism by which QTXZG treats CGN through FTO-mediated m6A modification. METHODS: An AAV9-FTO overexpression adenovirus was constructed to evaluate the protective effect of FTO overexpression on renal injury in CGN mice. In vitro, MDC staining was employed to assess the impact of FTO overexpression on autophagy in glomerular mesangial cells (GMCs). MeRIP-qPCR was utilized to explore the regulatory role of FTO in SLC7A5 m6A modification. In vivo, animal studies were conducted to investigate the effect of QTXZG on the FTO-mediated SLC7A5 m6A modification signaling axis. FTO inhibitor (FB23-2) and autophagy inhibitor (3-MA) were used to explore the pharmacological mechanism of QTXZG in treating CGN through FTO elevation and autophagy promotion. Active components of QTXZG were identified via UHPLC-Q-Orbitrap HRMS, and molecular dynamics simulations analyzed the binding affinity of these components with the FTO protein. RESULTS: In vivo studies demonstrated that FTO overexpression promotes autophagy in GMCs, enhances renal function in CGN mice, and mitigates renal pathological damage. Mechanistic investigations revealed that FTO overexpression facilitates autophagy in GMCs by downregulating SLC7A5 m6A modification. In vivo experiments further confirmed the pharmacological mechanism by which QTXZG promotes autophagy in GMCs through FTO-mediated SLC7A5 m6A modification to treat CGN. Additionally, molecular docking and dynamics simulations identified several active components in QTXZG that exhibit strong binding affinity to the FTO protein. CONCLUSION: QTXZG ameliorates chronic glomerulonephritis by promoting autophagy in GMCs via FTO-mediated SLC7A5 m6A modification.