PIWI-interacting RNAs and PIWI proteins in diabetes and cardiovascular disease: Molecular pathogenesis and role as biomarkers

•The abnormal expression of piRNA and PIWI protein in diabetes and cardiovascular disease is associated with disease progression.•Serum extracellular vesicles-related piRNA has been detected in a surprisingly stable form and defined as a potential disease biomarker and a novel therapeutic target in CVD.•piRNA promotes the occurrence and development of CVD mainly through piRNA/LINE-1/AKT, AKT and AMPK signal pathways. Cardiovascular disease (CVD) is still one of the most significant diseases and is a considerable threat to human health globally. PIWI-interacting RNAs (piRNAs) are novel small noncoding RNAs (ncRNAs) traditionally considered to be specifically expressed in the germline of many animal species and involved in the maintenance of germline stem cells and spermatogenesis. Although little is known about the origin and action of piRNAs and PIWI proteins in somatic cells, these molecules are emerging as readily available biomarkers for the diagnosis and treatment of cardiac injury and multiform CVD. Accumulating evidence reveals that piRNAs and PIWI proteins are associated with some molecular and cellular pathways in CVD. Here, we summarize recent evidence and evaluate the molecular mechanism of the involvement of piRNAs and PIWI proteins in CVD.