Jayanthi Bellae Papannarao

Patients with ischaemic heart disease (IHD) require frequent monitoring, as the transition from stable disease to acute life-threatening events remains largely unpredictable. MicroRNAs (miRNAs), small non-coding RNAs involved in physiological and pathological processes, are released into circulation and remain stable. In this study, we aimed to determine if the serial measurement of cardiovascular-enriched circulating miRNAs could reflect changes in cardiac function in patients with IHD. Fifty-three new IHD patients participated in a five-year study with regular echocardiography, blood tests and follow-ups at 12-month intervals, with 25 followed up at five years. Serial echocardiography revealed a pattern towards worsening diastolic function over the follow-up period. RT-PCR analysis was conducted on four cardiovascular-enriched circulating miRNAs: miR-1, miR-126, miR-132 and miR-34a. Among these, only miR-1 and miR-126 showed statistically significant down-regulation starting from 24 months onwards. Linear mixed models, adjusted for body mass index and HbA1c changes, indicated significant associations between fold changes in miR-1 and miR-34a with cardiac function changes. Results from this first-ever five-year follow-up study have identified a possible link between cardiovascular-enriched miRNAs, miR-1 and -34a and cardiac function in patients with IHD, providing a foundation for prognostic tests for IHD and laying the foundation for further studies in larger populations. It is noteworthy that a significant dropout of participants may have impacted the statistical power in our study.

Cardiac progenitor cells (CPCs) and adipocyte stem cells (ASCs) are widely tested for their efficacy in repairing the diseased heart with varying results. However, no study has directly compared the functional efficacy of CPCs and ASCs collected from the same patient. CPCs and ASCs were isolated from the right atrial appendage and epicardial adipose tissue of the same patients, using explant culture. The flow cytometry analysis confirmed that both the cell types express common mesenchymal stem cells markers CD90 and CD105. ASCs, in addition, expressed CD29 and CD73. The wound-healing assay demonstrated that CPCs migrate faster to cover the wound area. Both cell types were resistant to hypoxia-induced cell death when exposed to hypoxia and serum deprivation; however, the ASCs showed increased proliferation. Conditioned medium (CM) collected after culturing serum-deprived CPCs and ASCs showed differential secretion patterns, with ASC CM showing an increased IGF-1 level, while CPC CM showed an increased FGF level. Only CPC CM reduced hypoxia-induced apoptosis in AC-16 human ventricular cardiomyocytes, while vascular network formation by endothelial cells was comparable between CPC and ASC CM. In conclusion, ASCs and CPCs exhibit differential characteristics within the same patient, and in vitro studies showed that CPCs have marginally superior functional efficacy.