METTL3 mediated m6A modification of HKDC1 promotes renal injury and inflammation in lead nephropathy via binding to ATPB
Environmental and industrial Pb exposure poses a major public health problem. Acute exposure to high Pb concentrations can result in renal injury. Here, we reveal that N6-methyladenosine (m6A) RNA methylation is significantly upregulated in lead nephropathy and is mainly mediated by the methyltransferase METTL3. Functionally, METTL3 knockout in renal tubular epithelial cells or AAV9 mediated METTL3 silencing alleviated renal injury and inflammatory response induced by lead acetate. METTL3 silencing in HK2 cells reduces m6A RNA methylation and inflammatory responses following lead acetate treatment. We identified hexokinase domain-containing 1 (HKDC1), which is known to function in the glycolytic pathway, as a direct METTL3 target. Moreover, HKDC1 was upregulated at both mRNA and protein levels after lead acetate treatment, promoting kidney injury and inflammation. Mechanistically, HKDC1 binds to ATPB and antagonises the ubiquitinase Murf1, thereby increasing ATPB expression. Therefore, excessive ATP is generated to activate the NF-?B signalling pathway and promote renal inflammation. We further confirmed that STM2457, a novel inhibitor of METTL3, protects against renal injury and inflammation induced by lead acetate. Collectively, our study demonstrates that the METTL3/HKDC1 axis is a potential target for the treatment of lead nephropathy, and STM2457 is expected to be a protective agent against renal injury caused by lead acetate. Overall design: This study was designed to investigate the underlying mechanism impact of m6A RNA modifications in heavy metal lead-induced renal diseases and find effective treatment, we performed m6A-RIP-seq and RNA-seq analyses in  lead acetate-exposed mice with or without METTL3 cKO