Novel Role of Endothelial CD45 in Regulating Endothelial-to-Mesenchymal Transition in Atherosclerosis

Peng, Q.; Arulsamy, K.; Lu, Y. W.; Wu, H.; Zhu, B.; Singh, B.; Cui, K.; Wylie-Sears, J.; Li, K. S.; Wong, S.; Cowan, D. B.; Aikawa, M.; Chen, K.; Wang, D.-Z.; Bischoff, J.; Chen, H.

doi:10.1101/2024.09.03.610974

bioRxiv · 10.1101/2024.09.03.610974

Novel Role of Endothelial CD45 in Regulating Endothelial-to-Mesenchymal Transition in Atherosclerosis

Peng, Q.·Arulsamy, K.·Lu, Y. W.·Wu, H.·Zhu, B.·Singh, B.·Cui, K.·Wylie-Sears, J.·Li, K. S.·Wong, S.·Cowan, D. B.·Aikawa, M.·Chen, K.·Wang, D.-Z.·Bischoff, J.·Chen, H.

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Abstract

BackgroundThe protein tyrosine phosphatase CD45 is expressed in all nucleated cells of the hematopoietic system and in mitral valve endothelial cells (ECs) undergoing endothelial-to-mesenchymal transition (EndoMT). Our recent work indicated that activation of endogenous CD45 in human endothelial colony-forming cells (ECFCs) induced expression of multiple EndoMT marker genes. We hypothesized that CD45 may contribute to atherosclerosis; however, detailed molecular mechanisms underlying how CD45 may contribute to EndoMT and the impact of therapeutic manipulation of CD45 expression in atherosclerosis are unknown. MethodsWe generated a tamoxifen-inducible EC-specific CD45-deficient mouse strain (EC-iCD45KO) on an ApoE-deficient (WT/ApoE-/-) background and fed them a Western diet (WD) to produce atherosclerosis. We enriched mouse aortic ECs with anti-CD31 beads to perform single-cell RNA sequencing. Cellular, biochemical and molecular approaches were used to investigate the effect of endothelial CD45-specific deletion on EndoMT and lesion development in an ApoE-/- mouse model of atherosclerosis. ResultsEC-iCD45KO mice showed reductions in lesion development, plaque macrophage infiltration, and expression of cell adhesion molecules when compared to WT/ApoE-/- controls. Single-cell RNA sequencing revealed that loss of endothelial CD45 decreases EndoMT marker expression and TGF-{beta} signaling in atherosclerotic mice, which is associated with reduction of lesions. Mechanistically, CD45 loss increases Fibroblast Growth Factor Receptor 2 (FGFR2) expression in mouse aortic ECs and Kruppel-like Factor 2 (KLF2) expression in the aortic root. Endothelial CD45-deficiency also inhibits EndoMT and TGF{beta} signaling in atherosclerosis. ConclusionsOur findings demonstrate that genetic depletion of endothelial CD45 protects against EndoMT-driven atherosclerosis by promoting FGFR2 and KLF2 expression while inhibiting Transforming Growth Factor beta (TGF{beta}) signaling and EndoMT. Consequently, targeting endothelial CD45 may represent a novel therapeutic strategy to reduce EndoMT in atherosclerosis.

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Peng, Q., Arulsamy, K., Lu, Y. W., Wu, H., Zhu, B., Singh, B., Cui, K., Wylie-Sears, J., Li, K. S., Wong, S., Cowan, D. B., Aikawa, M., Chen, K., Wang, D.-Z., Bischoff, J., Chen, H.. 2024-09-03. Novel Role of Endothelial CD45 in Regulating Endothelial-to-Mesenchymal Transition in Atherosclerosis. https://doi.org/10.1101/2024.09.03.610974

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