Perez-Medina, C. | Search bioRxiv

bioRxiv2026

Pathological stiffening by crosslinking glycation of titin

Heterogeneous, non-enzymatic glycation chemistry triggered by sugar-derived metabolites is typical of diseases that also entail pathological stiffening of cells, such as diabetes and age-related disorders. However, the mechanisms responsible for cell stiffening and the role of glycated biomolecules remain largely unexplored. Here, we show that glycation of cardiac titin, a giant intracellular protein scaffolding contractile sarcomeres, is increased in diabetes and leads to rigidification of both the protein and cardiomyocytes. Mechanistically, glycation-induced titin stiffening results from decreased contour length and enhanced folding of otherwise structurally intact protein domains following extensive formation of intramolecular crosslinking advanced glycation end products (AGEs). These stiffening effects outweigh softening contributions by competing, non-crosslinking AGEs. In combination, our work overcomes the intrinsic chemical complexity typical of glycation to uncover crosslinking AGEs as a source of pathological stiffening of cells, which we propose contributes to tissue dysfunction in situations of glycative stress.

biophysics↗

bioRxiv2025

HDL-associated phosphatidylserine blunts myeloid activation and protects from atherosclerosis

Background and aimsLipids play a critical role in atherosclerosis. Low-density lipoprotein (LDL)-cholesterol and certain lipid classes like sphingomyelins are associated with inflammation and poor cardiovascular outcomes. Phosphatidylserine (PS), on the other hand, is a negatively charged anti-inflammatory phospholipid class involved in efferocytosis. In this study, we sought to investigate its anti-atherosclerotic properties through a combination of complementary human lipidomics analyses, in vitro assays and in vivo experiments in Apoe-/- mice. MethodsHuman lipidomics studies were performed on the 300OB cohort comprising 300 obese and overweight individuals at risk of cardiovascular disease. In vitro assays were carried out using human monocytes and macrophages, and in vivo experiments included histopathological, immunophenotyping and single-cell transcriptomic analyses. ResultsIn humans, we identified PS as an anti-inflammatory and atheroprotective biomarker. Hence, we developed a high-density lipoprotein (HDL)-like formulation enriched in PS to exploit its properties in a targeted fashion in mice. In vitro, this formulation potently inhibited inflammatory cytokine production on human myeloid cells. Our in-depth in vivo experiments provided evidence of the formulations potent plaque-stabilizing and anti-inflammatory actions. These effects were mediated by a shift in the monocyte/macrophage compartment toward homeostatic/repairing phenotypes. ConclusionsCollectively, our results demonstrate that HDL-associated PS potently suppresses inflammation and atheroprogression, and holds promise as a viable approach to improve immunomodulatory therapies.

immunology↗