Identification and characterization of genetic variants of TGFB1 in patients with congenital heart disease

Novel Circulating Biomarkers in Aortic Valve Stenosis

The underlying pathophysiology of aortic stenosis and factors affecting its clinical progression remain poorly understood. Apart from B-type natriuretic peptide (BNP), novel and emerging biomarkers have been described in association with aortic stenosis, emphasising the potential for these biomarkers to illuminate on yet unknown mechanisms of its pathogenesis. In this review, we aimed to summarise what is known about aortic stenosis biomarkers, highlight the emerging ones, and provide a roadmap for translating these insights into clinical applications. Among the biomarkers studied, lipoprotein(a) [Lp(a)] has emerged as the most promising for risk stratification. Elevated Lp(a) levels are often associated with more rapid aortic stenosis progression. This detrimental effect is attributed to its role in promoting valve calcification. While other emerging biomarkers such as matrix metalloproteinases, monocytes, and metabolites show promises, their specific roles in aortic stenosis pathophysiology remain less clear. This may be due to their relatively recent discovery. Ongoing research aims to elucidate their mechanisms of action.

Gene-Edited Human-Induced Pluripotent Stem Cell Lines to Elucidate DAND5 Function throughout Cardiac Differentiation

(1) Background: The contribution of gene-specific variants for congenital heart disease, one of the most common congenital disabilities, is still far from our complete understanding. Here, we applied a disease model using human-induced pluripotent stem cells (hiPSCs) to evaluate the function of DAND5 on human cardiomyocyte (CM) differentiation and proliferation. (2) Methods: Taking advantage of our DAND5 patient-derived iPSC line, we used CRISPR-Cas9 gene-editing to generate a set of isogenic hiPSCs (DAND5-corrected and DAND5 full-mutant). The hiPSCs were differentiated into CMs, and RT-qPCR and immunofluorescence profiled the expression of cardiac markers. Cardiomyocyte proliferation was analysed by flow cytometry. Furthermore, we used a multi-electrode array (MEA) to study the functional electrophysiology of DAND5 hiPSC-CMs. (3) Results: The results indicated that hiPSC-CM proliferation is affected by DAND5 levels. Cardiomyocytes derived from a DAND5 full-mutant hiPSC line are more proliferative when compared with gene-corrected hiPSC-CMs. Moreover, parallel cardiac differentiations showed a differential cardiac gene expression profile, with upregulated cardiac progenitor markers in DAND5-KO hiPSC-CMs. Microelectrode array (MEA) measurements demonstrated that DAND5-KO hiPSC-CMs showed prolonged field potential duration and increased spontaneous beating rates. In addition, conduction velocity is reduced in the monolayers of hiPSC-CMs with full-mutant genotype. (4) Conclusions: The absence of DAND5 sustains the proliferation of hiPSC-CMs, which alters their electrophysiological maturation properties. These results using DAND5 hiPSC-CMs consolidate the findings of the in vitro and in vivo mouse models, now in a translational perspective. Altogether, the data will help elucidate the molecular mechanism underlying this human heart disease and potentiates new therapies for treating adult CHD.