deficiency exacerbates podocyte injury and autophagy disorder by targeting in diabetic nephropathy.

Circular RNAs (circRNAs) are special non-coding RNA (ncRNA) molecules that play a significant role in many diseases. However, the biogenesis and regulation of circRNAs in diabetic nephropathy (DN) are largely unknown. Here, we investigated the expression profile of circRNAs in kidney of DN mice through circular RNA sequencing (circRNA-seq). The renal biopsy samples of patients with DN had low expression, which was significantly associated with renal function. Furthermore, loss-of-function and gain-of-function experiments were carried out to prove the role of in DN. Podocyte conditional knockin (cKI) or systemic overexpression of alleviated albuminuria and restored macroautophagy/autophagy in kidney of diabetic mice. However, knockdown exacerbated albuminuria and podocyte injury. Mechanistically, we found directly binds to to perform its function. Silencing of or overexpression of recovered podocyte autophagy both and . To examine the cause of downregulation in DN, bioinformatics prediction found that sequence has a high possibility of containing an m6A methylation site. Additionally, METTL3 was proved to regulate the expression and methylation level of through YTHDF2 (YTH N6-methyladenosine RNA binding protein 2). In conclusion, this study revealed that regulates podocyte autophagy by targeting in DN. Therefore, is a potential biomarker for prevention and cure of DN. CCL2/MCP-1: C-C motif chemokine ligand 2; ceRNA: competing endogenous RNA; circRNA: circular RNA; cKI: conditional knockin; cKO: conditional knockout; CRE: creatinine; DM: diabetes mellitus; DN: diabetic nephropathy; ESRD: end-stage renal disease; HG: high glucose; IF: immunofluorescence; MAP1LC3/LC3B: microtubule-associated protein 1 light chain 3 beta; MPC5: mouse podocyte clone 5; MTECs: mouse tubular epithelial cells; MTOR: mechanistic target of rapamycin kinase; NC: normal control; ncRNA: non-coding RNA; NPHS1: nephrosis 1, nephrin; NPHS2: nephrosis 2, podocin; PAS: periodic acid-Schiff; RELA/p65: v-rel reticuloendotheliosis viral oncogene homolog A (avian); SDs: slit diaphragm proteins; Seq: sequencing; STZ: streptozotocin; SV40: SV40-MES13-cells, mouse mesangial cell line; T1D: type 1 diabetes mellitus; T2D: type 2 diabetes mellitus; TEM: transmission electron microscopy; TNF/TNF-α: tumor necrosis factor; VECs: vascular endothelial cells; WT1: WT1 transcription factor; YTHDF2: YTH N6-methyladenosine RNA binding protein 2.