Objective:To investigate the impact of small extracellular vesicles(sEVs) derived from perirenal adipose cells on the biological behavior of renal tubular epithelial cells under diabetic conditions and the underlying molecular mechanisms.Methods:Primary perirenal adipose cells were extracted from db/m and db/db mice for in vitro culture. The culture supernatant was collected and sEVs(NDM-sEVs PRAT-Adipo, DM-sEVs PRAT-Adipo) were extracted by ultracentrifugation. The sEVs were incubated with human renal tubular epithelial cell line(HK-2) to observe changes in their proliferation, apoptosis, autophagy, and epithelial-mesenchymal transition(EMT) levels. The protein composition of sEVs was analyzed using mass spectrometry to explore the molecular mechanisms. Results:CCK8 results showed that the proliferation level of HK-2 cells after DM-sEVs PRAT-Adipo intervention did not change significantly compared with the two control groups(Ctrl group and NDM-sEVs PRAT-Adipo intervention group). Western Blot(WB) results indicated that there were no significant changes in apoptosis levels(Bcl-2, Cleaved-caspase 3, Caspase 3) and autophagy levels(p62, LC3BⅠ, LC3BⅡ) in the DM-sEVs PRAT-Adipo intervention group compared with the two control groups. WB and immunofluorescence results demonstrated that DM-sEVs PRAT-Adipo intervention upregulated the expression levels of mesenchymal cell marker proteins(Vimentin, α-SMA, Snail2) and downregulated the expression level of epithelial cell marker protein ZO-1 in HK-2 cells compared with the two control groups. Mass spectrometry analysis of sEVs revealed that the differential proteins between DM-sEVs PRAT-Adipo and NDM-sEVs PRAT-Adipo were enriched in EMT-related pathways. Among them, the enrichment of thrombospondin(THBS1) in DM-sEVs PRAT-Adipo might be involved in the regulation of EMT in HK-2 cells. Conclusion:Under diabetic conditions, sEVs secreted by PRAT-derived adipocytes promote the upregulation of EMT in renal tubular epithelial cells, a process that may be mediated by the enrichment of THBS1 in sEVs.