Diabetes-induced effects on cardiomyocytes in chick embryonic heart micromass and mouse embryonic D3 differentiated stem cells

Maternal Gestational Diabetes Mellitus and Congenital Heart Disease in Offspring: A Meta-Analysis

Maternal diabetes has been related to an increased risk of congenital heart disease (CHD) in offspring. However, inconsistent results were retrieved for studies evaluating the association between gestational diabetes mellitus (GDM) and CHD in offspring. We therefore performed a systematic review and meta-analysis for comprehensive investigation. Observational studies were identified by searching PubMed, Embase, and Web of Science according to the aim of the meta-analysis. A randomized-effects model was used to pool the data by incorporating the influence of potential heterogeneity. Twenty-three observational studies, involving 46953078 mother-child pairs, were available for the meta-analysis. Among them, 2131800 mothers were diagnosed as GDM and 214379 newborns had CHD. Overall, maternal GDM was associated with a higher incidence of CHD in offspring [odds ratio (OR): 1.32, 95% confidence interval (CI): 1.21 to 1.45, p<0.001; I2=62%]. Sensitivity analysis limited to studies with adjustment of maternal age and other potential confounding factors showed similar results (OR: 1.40, 95% CI: 1.30 to 1.51, p<0.001; I2=47%). Subgroup analysis suggested that the association between maternal GDM and CHD in offspring was not significantly affected by methods for diagnosis of GDM, methods for confirmation of CHD, or study quality scores (p for subgroup difference all>0.05). Subsequent analysis according to types of CHD showed that maternal GDM was associated with higher risks of atrial septal defect, ventricular septal defect, and Tetralogy of Fallot. Maternal GDM may be associated with a higher risk of CHD in offspring.

Associations of maternal diabetes mellitus and adiponectin gene polymorphisms with congenital heart disease in offspring: A case-control study

This study aimed at assessing the association of maternal diabetes mellitus (DM), the adiponectin gene (APM1) gene polymorphisms, and their interactions with risk of congenital heart disease (CHD) in offspring.A case-control study of 464 mothers of CHD patients and 504 mothers of healthy children was conducted.After adjusting for potential confounding factors, our study suggested that mothers with gestational DM (GDM) during this pregnancy (adjusted odds ratio [aOR = 2.96]), GDM in previous pregnancy experiences (aOR = 3.16), and pregestational DM in the 3 months before this pregnancy (aOR = 4.52) were at a significantly higher risk of CHD in offspring, when compared with those without any diabetes. The polymorphisms of maternal APM1 gene at rs1501299 (T/T vs G/G: aOR = 3.45; T/G vs G/G: aOR = 1.73) and rs2241766 (G/G vs T/T, aOR = 3.36; G/T vs T/T, aOR = 1.93) were significantly associated with risk of CHD in offspring. In addition, significant interactions between maternal DM and the APM1 genetic variants on the development of CHD were found.Our findings indicate that maternal DM, APM1 gene genetic variants, and their interactions are significantly associated with risk of CHD in offspring. However, more studies in different ethnic populations and with a larger sample and prospective design are required to confirm our findings.

The Cardiac Mineralocorticoid Receptor (MR): A Therapeutic Target Against Ventricular Arrhythmias

Mineralocorticoid antagonists have been shown to be useful in the treatment of severe heart failure and may even save lives in this context. However, the reason for the beneficial action of these drugs, as well as the physiological role played by the cardiac mineralocorticoid receptor (MR), are still poorly understood. While the proinflammatory action of aldosterone on the heart and the resulting fibrosis partly explain the improvement due to the anti-mineralocorticoid therapy, the reduction in sudden death is probably related to a lower occurrence of ventricular arrhythmias. In this review, the author explains the physiological mechanism linking the positive chronotropic response induced by aldosterone observed in vitro with isolated ventricular cardiomyocytes and the increased risk of ventricular arrhythmias reported in vivo in hyperaldosteronism. He describes the molecular steps involved between MR activation and acceleration of spontaneous myocyte contractions, including expression of a specific micro RNA (miR204), down-regulation of a silencing transcription factor (NRSF), and re-expression of a fetal gene encoding a low threshold voltage-gated calcium channel (CaV3.2). Finally, he provides evidence suggesting aldosterone-independent and redox-sensitive mechanisms of MR activation in cardiac myocytes. Taken together, this information suggests that the use of anti-mineralocorticoid therapy could benefit the heart by preventing ventricular arrhythmias, not only in established hyperaldosteronism, but also in various pathological situations such as Cushing's disease, oxidative stress, or even diabetes mellitus.

The current status and future of cardiac stem/progenitor cell therapy for congenital heart defects from diabetic pregnancy

Pregestational maternal diabetes induces congenital heart defects (CHDs). Cardiac dysfunction after palliative surgical procedures contributes to the high mortality of CHD patients. Autologous or allogeneic stem cell therapies are effective for improving cardiac function in animal models and clinical trials. c-kit+ cardiac progenitor cells (CPCs), the most recognized CPCs, have the following basic properties of stem cells: self-renewal, multicellular clone formation, and differentiation into multiple cardiac lineages. However, there is ongoing debate regarding whether c-kit+ CPCs can give rise to sufficient cardiomyocytes. A new hypothesis to address the beneficial effect of c-kit+ CPCs is that these cells stimulate endogenous cardiac cells through a paracrine function in producing a robust secretome and exosomes. The values of other cardiac CPCs, including Sca1+ CPCs and cardiosphere-derived cells, are beginning to be revealed. These cells may be better choices than c-kit+ CPCs for generating cardiomyocytes. Adult mesenchymal stem cells are considered immune-incompetent and effective for improving cardiac function. Autologous CPC therapy may be limited by the observation that maternal diabetes adversely affects the biological function of embryonic stem cells and CPCs. Future studies should focus on determining the mechanistic action of these cells, identifying new CPC markers, selecting highly effective CPCs, and engineering cell-free products.