Therapeutic Potential of Heat Shock Protein 90 Inhibitor 17-DMAG in Regulating METTL3 for Kidney Fibrosis Treatment

KEY POINTS: Targeting METTL3 with the heat shock protein 90 inhibitor 17-DMAG mitigated kidney fibrosis in CKD. The drug repositioning through differentially expressed gene and enrichment analyses identified 17-dimethylaminoethylamino-17-demethoxygeldanamycin as a potential agent to alleviate kidney fibrosis. The N -terminal heat shock protein 90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin suppressed c-Jun-METTL3 signaling, attenuating N 6-methyladenosine methylation and kidney fibrosis. BACKGROUND: Kidney fibrosis is a major pathological feature of CKD, characterized by excessive deposition of extracellular matrix proteins, leading to progressive loss of kidney function. N 6-methyladenosine (m6A) RNA methylation has emerged as a crucial epigenetic modification implicated in various diseases, including kidney fibrosis. METTL3, an m6A writer, plays a key role in promoting fibrosis by stabilizing profibrotic gene expression. Therefore, targeting METTL3 represents a promising therapeutic strategy for CKD treatment. In this study, we explored the therapeutic potential of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) in regulating METTL3 to mitigate kidney fibrosis. METHODS: Through transcriptome-based drug repositioning, we identified 17-DMAG as a potential inhibitor of METTL3. Differentially expressed gene analysis was performed to assess the enrichment of 17-DMAG in CKD-related gene expression profiles. The antifibrotic effects of 17-DMAG were evaluated in in vitro and in vivo models. The mechanism by which 17-DMAG downregulates METTL3 was also investigated. RESULTS: 17-DMAG significantly reduced METTL3 expression in renal epithelial cells in a dose-dependent and time-dependent manner. In in vivo mouse models of kidney fibrosis, 17-DMAG treatment attenuated METTL3 levels, reduced total m6A modification, and effectively mitigated fibrosis, as evidenced by decreased collagen deposition and profibrotic marker expression. Mechanistically, 17-DMAG, a heat shock protein 90 (HSP90) N -terminal inhibitor, induced a heat shock response that sequentially upregulated HSP70 expression. The elevated HSP70 levels inhibited c-Jun N -terminal kinase activity, thereby suppressing the c-Jun transcription factor and ultimately leading to the downregulation of METTL3 expression. MeRIP-Seq analysis revealed that 17-DMAG reversed unilateral ischemia-reperfusion injury-induced m6A epitranscriptomic changes in fibrosis-related genes, including GSK3B , which is involved in fibrotic pathways. CONCLUSIONS: N -terminal HSP90 inhibition, along with subsequent c-Jun suppression, contributed to the mechanism underlying 17-DMAG-induced METTL3 downregulation. Through this regulatory pathway, 17-DMAG effectively suppressed METTL3 expression and attenuated kidney fibrosis in both in vitro and in vivo models.