Lysolecithin reprogramming via LPCAT1 modulation restores endothelial function and prevents diabetes-associated dysmetabolism.

BACKGROUND: Dysregulation of lysophosphatidylcholines (LPCs) and phosphatidylcholines (PCs) is linked to endothelial dysfunction and impaired tissue repair. Nevertheless, the organ-specific modulation of lysolecithin remodeling in T2DM remains unexplored. Here, we investigate the LPC/PC remodeling dynamics in a T2DM model and propose a novel therapeutic approach using an orally bioavailable peptide (SP6) derived from Spirulina platensis.

METHODS: LPC/PC levels were analyzed by UHPLC-HRMS. Membrane fluidity, VEGF/API5, LPCAT1, VE-cadherin, and GLUT1 were evaluated by merocyanine assay, qPCR, immunoblotting, and immunofluorescence. In vivo, T2DM was induced by a high-fat diet and streptozotocin, and SP6 was orally administered. Tissue lipidomics, GLUTs expression, and insulin secretion were assessed, with the latter also spatially characterized in pancreatic tissue by MALDI-MS imaging.

RESULTS: High glucose induced LPC/PC imbalance, enhanced membrane fluidity, impaired VEGF/API5 expression, and hindered wound healing and VE-cadherin localization via LPCAT1 downregulation and subsequent impact on GLUT1 translocation. In vivo analysis of diabetic mice revealed a multi-organ influence of SP6 preserving LPCAT1 mRNA levels in pancreas, liver, skeletal muscle, and adipose tissue and a specific pattern of lysolecithin remodeling, with selective modulation of LPC 16:0, 18:0, and 20:4 in plasma. Finally, its effects in T2DM are mediated by preserving insulin secretion and glycemic control through increased ATP production.

CONCLUSION: These findings reveal tissue-specific lysolecithin reprogramming in T2DM development and identify LPCAT1-mediated lysolecithin remodeling as a mechanism involved in T2DM-related endothelial and metabolic dysfunction. SP6 modulates lipid metabolism, vascular integrity, and glucose regulation at the transcript level, suggesting its potential as a new preventive treatment for T2DM and its complications.