Brain and kidney Extracellular Vesicle Morphology and Complementary Brain proteomics after Inflammatory Challenge

Abstract

Shape, size variation, and protein composition describe different properties of tissue extracellular vesicle (EV) preparations. We compared brain and kidney EV shape and size using transmission electron microscopy (TEM). We also assessed repeated protein detection and reanalyzed a deposited brain proteomics cohort, with attribution to its original source. The study used intracerebroventricular lipopolysaccharide (LPS) and an intravenous miRNA-associated EV formulation. Each group contained three biological samples, as labelled in the source data. Source morphometry summaries included 385 brain and 101 kidney profiles. Kidney circularity was 0.9225, 0.8977, and 0.9288 in the control, LPS, and treatment groups, respectively. The corresponding values for diameter quartile dispersion, a measure of size variation, were 0.2603, 0.5334, and 0.6018. Thus, near-control outline shape coexisted with persistent size variation. None of the six primary morphology tests remained significant after Holm correction. Independent recalculation confirmed 1,527 eligible rat protein accessions across individual searches. The complete quantitative matrix contained 953 features. The main peptide filter combined unique and razor peptides. A stricter analysis retained 916 features. PTGFRN and LAMB2 remained the only significant treatment-versus-LPS findings. In the main analysis, PTGFRN increased 14.71-fold (q = 0.0365), and LAMB2 increased 6.23-fold (q = 0.00585). Their LPS levels were already close to control values. Exploratory normalization used the geometric mean of four measured EV-associated markers. The resulting treatment-versus-LPS increases were 16.43-fold and 6.96-fold, respectively. These ratios support selective changes in relative protein representation within the recovered mixture. They do not establish protein copies per EV. Analysis of the full protein profile and calibration of the complete selection process did not support an overall return to control. This study compares morphology and composition as separate outcomes. It identifies membrane and matrix associations as priorities for validation. Original TEM measurements were unavailable, sample matching remained unresolved, and kidney proteomics were absent. These limitations prevent causal conclusions and individual-sample comparisons between morphology and protein composition.