Open Access

Wei Yu, Xueyan Ma, Jinjin Xu, Andreas Heumüller, Zhaoliang Fei, Xue Feng, Xiaodong Wang, Kuo Liu, Jinhui Li, Guizhong Cui, Guangdun Peng, Hongbin Ji, Jinsong Li, Naihe Jing, Hai Song, Zhiqiang Lin, Yun Zhao, Zuoyun Wang, Bin Zhou, Lei Zhang

• Heart valve disease is a major clinical problem worldwide. Cardiac valve development and homeostasis need to be precisely controlled. Hippo signaling is essential for organ development and tissue homeostasis, while its role in valve formation and morphology maintenance remains unknown. VGLL4 is a transcription cofactor in vertebrates and we found it was mainly expressed in valve interstitial cells at the post-EMT stage and was maintained till the adult stage. Tissue specific knockout of VGLL4 in different cell lineages revealed that only loss of VGLL4 in endothelial cell lineage led to valve malformation with expanded expression of YAP targets. We further semi-knockout YAP in VGLL4 ablated hearts, and found hyper proliferation of arterial valve interstitial cells was significantly constrained. These findings suggest that VGLL4 is important for valve development and manipulation of Hippo components would be a potential therapy for preventing the progression of congenital valve disease.