# Large extracellular vesicles (microvesicles) in diabetic nephropathy: a systematic review of preclinical studies

## TL;DR

This review examines how large extracellular vesicles called microvesicles contribute to kidney damage in diabetes and highlights the need for standardized methods in studying them.

## Contribution

The paper systematically reviews preclinical studies on microvesicles in diabetic nephropathy and identifies gaps in methodology and standardization.

## Key findings

- Microvesicles modulate oxidative stress, inflammation, and fibrosis in diabetic nephropathy.
- Study methods show significant variability in isolation, characterization, and quantification of microvesicles.
- Microvesicles are suggested as potential early biomarkers and therapeutic targets in diabetic nephropathy.

## Abstract

Diabetic nephropathy (DN) is a significant complication of diabetes and is characterized by progressive kidney damage and dysfunction. Several studies have highlighted the role of a subset of large-sized extracellular vesicles (EVs), commonly known as microvesicles (MVs), as crucial mediators of DN pathophysiology. This systematic review critically evaluates the methodological approaches used to study MVs in experimental models of DN, while also synthesizing the experimental endpoints investigated, to identify consistencies, gaps, and opportunities for standardization. A systematic literature search across PubMed, Embase, and Scopus identified preclinical studies investigating the impact of MVs on renal injury, inflammation, and fibrosis in diabetes. Seven preclinical studies published between 2014 and 2022 met the inclusion criteria. Data extracted: MV origin, isolation/characterization/quantification, models/conditions, dosing/exposure, and endpoints. Seven studies (2014–2022) met criteria. Differential centrifugation predominated for isolation; flow cytometry (FCM) (often Annexin V ± lineage markers), nanoparticle tracking analysis (NTA), and electron microscopy (EM) variably supported identity/size; FCM and NTA were commonly used for enumeration along with protein assays. MV sources included platelets, podocytes, urinary fractions, and MSC-derived vesicles. Across studies, MVs modulated oxidative stress (NOX4/ROS), inflammation (e.g., TNF-α, CXCL7), fibrotic signaling (p38 MAPK/CD36), and cell injury; cargo (e.g., miR-451a) linked to cell-cycle regulators (p15/p19) in early DN. Notable heterogeneity in media depletion, dose reporting, and detection thresholds limited cross-study comparison. We conclude that preclinical evidence supports MVs as early biomarkers and mechanistic drivers in DN, but standardization in isolation, characterization, dosing, and endpoint panels—aligned with MISEV 2023—is needed to enable comparability and translation.

Diagram illustrating a summary of the methods and endpoints used in the included seven studies of the systematic review. Source is either mice (blood/urine) or conditioned medium. Isolation of MVs is done using differential centrifugation. Characterization involves flow cytometry, Western blot, nanoparticle tracking analysis, transmission electron microscopy, and qRT-PCR. Quantification includes protein assays, fluorescence-activated cell sorting, flow cytometry, nanoparticle tracking analysis, and indirect ELISA. Endpoints assess levels of extracellular vesicles (EVs), cell viability, oxidative stress indicators, inflammatory markers, and cell morphology.