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Data set for thesis submission entitled "Characterization of cardiac defects associated with Vinculin deletion in cardiac neural crest"
Vinculin (Vcl) is an adaptor protein of adherens junctions and focal adhesions. Cardiac
neural crest cell (CNCC) is a key population of progenitor cells regulating the cardiac outflow
tract (OFT) septation and valvulogenesis. Neurocristopathy patients carrying a loss-of-function
mutation in VCL presented various cardiac defects. A mouse model of NCC-specific knockout
of Vcl (Vcl-cKO) nicely phenocopied the cardiac defects as seen in the patients and exhibited
hyperplastic semilunar valves. Here, we aimed to characterize the molecular mechanisms
underlying the NCC-mediated valvulogenesis using Vcl-cKO.
Single cell transcriptomic analysis of CNCC progenies in E13.5 embryonic hearts
revealed that transforming growth factor-b (TGF-b) signaling is severely interrupted in the
mutant cells. More intriguingly, subsequent immunohistochemistry analysis (IHC) further
discovered a novel role of TGF-b signal in mediating the crosstalk between CNCC- and
endothelial- derived valvular interstitial cells (VICs) and their activation during valvulogenesis.
Defective TGF-b signal interrupted the activation of CNCC-derived VICs, leading to retarded
myocardialization and failure in valve remodeling.
While TGF-b signaling disruption was observed at E10.5 interrupting the formation of
endocardial cushion, temporal tracking of TGF-b activation in valvular interstitial cells from
E10.5 to E15.5 further revealed two waves of TGF-b signaling activation in semilunar
valvulogenesis, contributing to separate developmental processes. The disruption of TGF-b
signaling was found with a delayed upregulation from E13.5 to E15.5 in mutant VICs. Together
with cell proliferation and apoptosis assays, it might suggest the hyperplastic SLV observed in
Vcl-cKO mutant was associated with aberrant proliferation of CNCC-VICs through delayed
TGF-b signaling activation.
In summary, it was found that Vcl plays a crucial role in mediating semilunar
valvulogenesis through TGF-b signaling regulation in CNCCs. CNCCs contributed essentially
as a TGF-b signaling hub to EndoMT and VIC activation and differentiation.
