Tet2-driven clonal hematopoiesis drives aortic aneurysm via macrophage-to-osteoclast–like differentiation

• Text
• PDF

Abstract

Aortic aneurysms are age-linked aortic dilations that progress silently and carry high mortality rates following rupture. Immune cells are recognized drivers of aneurysm pathogenesis. Clonal hematopoiesis is an age-related expansion of somatically mutated hematopoietic stem cells that reshapes immune function and contributes to diverse age-associated diseases. However, its contribution to aneurysm pathogenesis remains unclear. In this study, targeted ultradeep sequencing of patient specimens revealed a high prevalence of clonal hematopoiesis–associated mutations that correlated with faster aneurysm expansion. Thus, we modeled clonal hematopoiesis by competitively transplanting ten-eleven translocation 2–deficient (Tet2-deficient) bone marrow into apoliprotein E–KO (Apoe-KO) mice and induced aneurysms with angiotensin II. Mice with Tet2 clonal hematopoiesis developed significantly greater aortic dilation than did controls. Interestingly, Tet2-deficient macrophages adopted an acid phosphatase 5, tartrate resistant (ACP5+), osteoclast-like state and produced more matrix metalloproteinase 9 (MMP9). Both genetic and pharmacological inhibition of osteoclast-like differentiation suppressed the Tet2-mediated aneurysmal growth in vivo. Thus, Tet2-driven clonal hematopoiesis accelerated aortic aneurysm progression through MMP9-producing, osteoclast-like macrophages and therefore represents a tractable therapeutic axis.

Authors

Jun Yonekawa, Yoshimitsu Yura, Junmiao Luo, Katsuhiro Kato, Shuta Ikeda, Yohei Kawai, Tomoki Hattori, Ryotaro Okamoto, Mari Kizuki, Emiri Miura-Yura, Keita Horitani, Kyung-Duk Min, Takuo Emoto, Hiroshi Banno, Mikito Takefuji, Kenneth Walsh, Toyoaki Murohara