Impaired Glycolysis Leads to Defective Efferocytosis and Impaired Plaque Resolution in Tet2 Clonal Hematopoiesis

Methods

To assess the effects of TET2 CH on plaque resolution, we prepared control or chimeric Tet2+/- CH mice with conditional deletion of Tet2 in hematopoietic stem cells during LDL lowering induced plaque remodeling. After establishing atherosclerosis by Western diet feeding for 12 weeks in Ldlr-/- mice, Tet2 was deleted by tamoxifen injection, and hypercholesterolemia was either normalized to simulate clinical lipid management or mice were continued on the Western diet.

Results: Unlike control mice, Tet2+/- CH mice failed to significantly reduce necrotic core area, increase fibrous cap thickness and showed impaired macrophage efferocytosis during LDL lowering. Single-cell RNA sequencing and gene set enrichment analysis of aortic cell populations revealed that Tet2 deficient monocyte/macrophage populations were defective in glycolysis, phagocytosis, actin polymerization and endocytic vesicle trafficking.

Tet2-deficient bone marrow derived macrophages (BMDMs) and Tet2+/- iPSC-derived human macrophages showed defective ability to sustain continual rounds of efferocytosis. BMDMs displayed reduced AC-binding and internalization and impaired activity of Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) complex mediated actin polymerization; these glycolysis related defects were rescued by lactate supplementation or by treatment with the HIF-1α activator molidustat.

Molidustat treatment reversed the defects in necrotic core and fibrous cap formation during LDL lowering induced plaque remodeling in Tet2+/- CH mice. Conclusions: Our data identify impaired efferocytosis and glycolysis-actin polymerization pathways in advanced atherosclerosis as potential therapeutic targets to induce pro-resolving restructuring of the plaque immune cells and to promote beneficial atherosclerosis remodeling in TET2 CH subjects.