The molecular mechanisms of cardiac development and related diseases

The ZBTB family in cardiac development and diseases

ZBTB (zinc finger and BTB domain) proteins are a class of evolutionarily conserved transcriptional factors (TFs) with zinc finger (ZF) and BTB (Broad-complex, Tram-track, and Bric-à-brac) domains. The ZBTB protein family has a wide range of functions in numerous biological processes, including cell cycle regulation, DNA repair, organ development, and haematopoietic stem cell fate determination. The ZBTB proteins regulate gene expression through interactions with transcriptional regulators, influencing processes such as myocardial contractility, inflammation, fibrosis, and cellular metabolism. Given the critical role of the ZBTB family in cardiac biology, the present review endeavours to comprehensively summarize the regulatory roles of seven ZBTB family members (HIC2, BCL6, PLZF, ZBTB17, ZBTB20, ZBTB7a, and ZBTB11) in cardiac development and diseases, along with their potential molecular mechanisms. Elucidating the molecular mechanisms of ZBTB proteins opens avenues for developing targeted therapies for cardiovascular diseases, including hypertrophy, fibrosis, and inflammation. This review provides a comprehensive summary of recent research on the role of ZBTB proteins in regulating cardiac transcription. Particular emphasis is placed on elucidating their functions in both cardiac development and the pathogenesis of cardiac diseases.

Association between physical activity and sedentary behavior with cardiometabolic multimorbidity in the elderly hypertensive population: an observational and Mendelian randomization study

BACKGROUND

The causal relationships between physical activity (PA), sedentary behavior (SB), and the risk of cardiometabolic disease (CMD) in hypertensive populations remain unclear. We conducted a Mendelian randomization (MR) analysis to investigate these associations.

METHODS

We conducted an observational analysis using a sample of 18,963 hypertensive population. For the two-sample Mendelian Randomization (MR) analysis, we used genome-wide association study (GWAS) summary data from population-wide cohorts obtained from the MRC Integrative Epidemiology Unit (MRC-IEU). The observational study was conducted from July 2023 to September 2023. Genetic tools were selected from GWAS at genome-wide significance (P < 5 × 10-8). The summary statistics for CMD include type 2 diabetes (T2D), stroke, and coronary heart disease (CHD). Logistic regression models were employed to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between PA and SB with CMD (T2D, stroke, and CHD) in the hypertensive population.

RESULTS

A total of 17,234 elderly hypertensive population were included, with an average age of 73.0 years. Among them, 9888 (57.4 %) were women, and 9406 (54.5 %) had CMD. Compared to low physical activity (LPA), moderate physical activity (MPA) was associated with a decreased risk of T2D [OR (95 % CI): 0.749 (0.682, 0.823)] and stroke [OR (95 % CI): 0.525 (0.480, 0.575)]. Vigorous physical activity (VPA) was linked to a reduced risk of T2D, stroke, and CHD. In contrast, prolonged SB was associated with an increased risk of T2D, stroke, and CHD. The MR analyses found that genetically predicted MPA was significantly associated with a reduced risk of T2D in the general population, consistent with the observational study results in hypertensive individuals. Similarly, VPA and SB were causally associated with T2D, stroke, and CHD, supporting the inverse relationships observed in the observational study.

CONCLUSIONS

This study suggests that a sedentary lifestyle and moderate to vigorous physical activity may play a significant role in the development of CMD in hypertensive populations.

Thyroid hormone ameliorates ursodeoxycholic acid-induced heart damage in zebrafish embryos

Ursodeoxycholic acid (UDCA) is the most commonly prescribed treatment for intrahepatic cholestasis of pregnancy (ICP) worldwide. Clinical studies show that UDCA helps alleviate maternal pruritus and lowers serum bile acid levels. However, despite treatment, women with ICP still experience unpredictable fetal deaths and other serious pregnancy complications. In this study, we hypothesize that while UDCA improves maternal symptoms, it may have harmful effects on the fetus due to its placental barrier crossing, potentially leading to negative pregnancy outcomes. We found that UDCA concentrations above 150 mg/L can exert toxic effects on zebrafish embryos, including increased mortality, slower heart rates, and pericardial edema. At these concentrations, UDCA also triggered apoptosis and elevated oxidative stress in embryonic cardiomyocytes. Importantly, the thyroid hormone T4 was able to partially mitigate these toxic effects. These findings suggest that adverse pregnancy outcomes in ICP may be related to fetal heart damage caused by UDCA's effects on circulation, providing a possible explanation for fetal death in clinical settings. This also underscores the need to optimize UDCA dosing in clinical practice and explore the use of thyroid hormones as a potential protective therapy for the fetus in ICP cases.

The Role of miRNA Expression in Congenital Heart Disease: Insights into the Mechanisms and Biomarker Potential

Congenital heart diseases (CHDs) are among the most common congenital malformations. Despite significant advancements in understanding the embryonic development of the heart, the etiology of CHDs remains largely unknown. The complexity of the processes involved in heart formation limits our ability to identify all molecular mechanisms underlying CHDs. Recently, microRNAs (miRNAs) have provided new insights into the molecular mechanisms of CHDs. This narrative review evaluates the evidence linking expression to CHDs and discusses the potential of RNA expression regulation as a promising avenue for therapeutic biomarker development. A search of the literature, focusing on the role of miRNAs in CHDs, was carried out to identify pertinent studies published over the last decade. The literature search was performed utilizing the PubMed and Scopus databases. The selection criteria included peer-reviewed original studies, clinical research, meta-analyses, and review articles written in English. Multiple investigations have highlighted the essential role of miRNAs in cardiac development and function, showing that their distinct expression patterns can broadly and specifically influence cellular signaling pathways involved in heart abnormalities. The regulation of mRNA expression emerges as a key factor in the pathogenesis of CHD, paving the way for the identification of novel molecular biomarkers. Alterations in transcriptional profiles could offer innovative and highly specific tools for risk stratification and the clinical monitoring of patients. In conclusion, although further studies are needed to validate the efficacy and clinical applicability of these biomarkers, the mRNA-based approach stands out as a promising perspective for precision medicine in the CHD context.