Wnt Signaling Inhibition Prevents Postnatal Inflammation and Disease Progression in Mouse Congenital Myxomatous Valve Disease

Na Xu; Christina M Alfieri; Yang Yu; Minzhe Guo; Katherine E Yutzey

doi:10.1161/ATVBAHA.123.320388

Wnt Signaling Inhibition Prevents Postnatal Inflammation and Disease Progression in Mouse Congenital Myxomatous Valve Disease

Arterioscler Thromb Vasc Biol. 2024 Apr 25. doi: 10.1161/ATVBAHA.123.320388. Online ahead of print.

Authors

Na Xu^{1

2}, Christina M Alfieri¹, Yang Yu³, Minzhe Guo^{4

2}, Katherine E Yutzey^{1

2}

Affiliations

¹ Division of Molecular Cardiovascular Biology, the Heart Institute, Cincinnati Children's Hospital Medical Center, OH. (N.X., C.M.A., K.E.Y.).
² Department of Pediatrics, University of Cincinnati College of Medicine, OH (N.X., M.G., K.E.Y.).
³ Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, OH. (Y.Y.).
⁴ Division of Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, OH. (M.G.).

PMID: 38660802
DOI: 10.1161/ATVBAHA.123.320388

Abstract

Background: Myxomatous valve disease (MVD) is the most common cause of mitral regurgitation, leading to impaired cardiac function and heart failure. MVD in a mouse model of Marfan syndrome includes valve leaflet thickening and progressive valve degeneration. However, the underlying mechanisms by which the disease progresses remain undefined.

Methods: Mice with Fibrillin 1 gene variant Fbn1^C1039G/+ recapitulate histopathologic features of Marfan syndrome, and Wnt signaling activity was detected in TCF/Lef-lacZ reporter mice. Single-cell RNA sequencing was performed from mitral valves of wild-type and Fbn1^C1039G/+ mice at 1 month of age. Inhibition of Wnt signaling was achieved by conditional induction of the secreted Wnt inhibitor Dkk1 expression in periostin-expressing valve interstitial cells of Periostin-Cre; tetO-Dkk1; R26rtTA; TCF/Lef-lacZ; Fbn1^C1039G/+ mice. Dietary doxycycline was administered for 1 month beginning with MVD initiation (1-month-old) or MVD progression (2-month-old). Histological evaluation and immunofluorescence for ECM (extracellular matrix) and immune cells were performed.

Results: Wnt signaling is activated early in mitral valve disease progression, before immune cell infiltration in Fbn1^C1039G/+ mice. Single-cell transcriptomics revealed similar mitral valve cell heterogeneity between wild-type and Fbn1^C1039G/+ mice at 1 month of age. Wnt pathway genes were predominantly expressed in valve interstitial cells and valve endothelial cells of Fbn1^C1039G/+ mice. Inhibition of Wnt signaling in Fbn1^C1039G/+ mice at 1 month of age prevented the initiation of MVD as indicated by improved ECM remodeling and reduced valve leaflet thickness with decreased infiltrating macrophages. However, later, Wnt inhibition starting at 2 months did not prevent the progression of MVD.

Conclusions: Wnt signaling is involved in the initiation of mitral valve abnormalities and inflammation but is not responsible for later-stage valve disease progression once it has been initiated. Thus, Wnt signaling contributes to MVD progression in a time-dependent manner and provides a promising therapeutic target for the early treatment of congenital MVD in Marfan syndrome.

Keywords: Wnt signaling pathway; endothelial cells; inflammation; mitral valve; periostin.