Diabetic kidney disease (DKD) is a major microvascular complication of diabetes characterized by combined microcirculatory dysfunction and immune-mediated injury. Intercellular communication in the renal microenvironment can occur via extracellular vesicles (EVs), which carry proteins, lipids, and nucleic acids, including microRNAs (miRNAs). The study addresses whether EV-encapsulated miRNAs participate in crosstalk between endothelial cells (ECs) and monocytes and thereby contribute to DKD pathogenesis.
EVs were isolated from both monocytes and endothelial cells cultured under normal-glucose and high-glucose conditions. After physical and molecular characterization of EV preparations, differentially expressed miRNAs were screened between conditions. The study used RNase/Triton functional assays to determine whether miRNAs were enclosed within EVs rather than being external contaminants. Dual-luciferase reporter assays were performed to validate direct miRNA–target interactions. Functional relevance was tested using gain- and loss-of-function experiments and rescue experiments in cellular systems, and complementary in vivo experiments examined effects on renal injury. The combination of these methods was intended to link specific EV-miRNAs to molecular signaling pathways and cellular phenotypes relevant to DKD.
Under high-glucose conditions, EVs derived from monocytes promoted endothelial cell injury. This effect was associated with upregulation of miR-191-3p within monocyte-derived EVs. Mechanistically, miR-191-3p was shown to target CYLD, a regulator of inflammatory signaling, and this targeting led to activation of the NF-κB pathway in endothelial cells. The chain of evidence reported includes: differential miRNA expression in EVs under high glucose, confirmation that the miRNA cargo was EV-encapsulated, reporter assays supporting CYLD as a miR-191-3p target, and functional experiments showing that modulation of this axis altered endothelial injury phenotypes in vitro.
Conversely, EVs released by endothelial cells in high-glucose conditions influenced monocyte behavior. EC-derived EVs exhibited decreased levels of miR-615-3p, which correlated with increased expression of IFNGR2 in recipient monocytes and activation of the STAT3 signaling pathway. Functionally, these changes enhanced monocyte inflammatory responses and adhesion properties relevant to vascular and renal inflammation. The study links the loss of a specific endothelial miRNA cargo with upregulation of a receptor (IFNGR2) and downstream STAT3-mediated inflammatory signaling in monocytes.
The authors report that targeted interventions against the identified miRNAs and their downstream effectors mitigated cellular injury in vitro and produced partial improvement of renal damage in vivo. Specifically, modulation of the miR-191-3p/CYLD/NF-κB axis and the miR-615-3p/IFNGR2/STAT3 axis altered the pathological interactions between monocytes and endothelial cells induced by high glucose. The abstract indicates that rescue experiments and combined molecular assays were used to support causality. However, quantitative details of the interventions, the magnitude of protective effects in vivo, and the animal models used are not specified in the abstract.
This study supports a model in which EV-mediated exchange of miRNAs between monocytes and endothelial cells contributes to DKD progression by linking microcirculatory dysfunction and immune activation. Two core regulatory axes were established from the reported data: miR-191-3p/CYLD/NF-κB mediating monocyte-to-endothelial injury, and miR-615-3p/IFNGR2/STAT3 mediating endothelial-to-monocyte proinflammatory effects.
The authors highlight that these EV-miRNAs may represent candidate diagnostic biomarkers or therapeutic targets in DKD, but they also note that additional validation is required. The abstract does not provide full experimental parameters, detailed quantitative outcomes, or clinical validation data; therefore, the diagnostic and therapeutic utility of the identified miRNAs remains to be confirmed by further studies.
In summary, the study identifies EV-encapsulated miRNAs as mediators of pathological monocyte–endothelial crosstalk in DKD, delineating the miR-191-3p/CYLD/NF-κB and miR-615-3p/IFNGR2/STAT3 axes. These findings provide mechanistic insight into how microcirculatory dysfunction and immune injury may interact in diabetic renal disease and propose molecular targets for future diagnostic and therapeutic research. Specific experimental details and quantitative outcomes were not reported in the abstract and require consultation of the full text for comprehensive assessment.