Effects of Sitagliptin on the Coronary Flow Reserve, Circulating Endothelial Progenitor Cells and Stromal Cell-derived Factor-1alpha

DPP4 as a Potential Candidate in Cardiovascular Disease

The rising prevalence of cardiovascular disease has become a global health concern. The occurrence of cardiovascular disease is the result of long-term interaction of many risk factors, one of which is diabetes. As a novel anti-diabetic drug, DPP4 inhibitor has been proven to be cardiovascular safe in five recently completed cardiovascular outcome trials. Accumulating studies suggest that DPP4 inhibitor has potential benefits in a variety of cardiovascular diseases, including hypertension, calcified aortic valve disease, coronary atherosclerosis, and heart failure. On the one hand, in addition to improving blood glucose control, DPP4 inhibitor is involved in controlling cardiovascular risk factors. On the other hand, DPP4 inhibitor directly regulates the occurrence and progression of cardiovascular diseases through a variety of mechanisms. In this review, we summarize the recent advances of DPP4 in cardiovascular disease, aiming to discuss DPP4 inhibitor as a potential option for cardiovascular therapy.

Effects of liraglutide versus sitagliptin on circulating cardiovascular biomarkers, including circulating progenitor cells, in individuals with type 2 diabetes and obesity: Analyses from the LYDIA trial

The mechanisms behind the beneficial cardiovascular effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) compared with dipeptidyl peptidase-4 inhibitors (DPP4is) remain largely unknown, despite both targeting the incretin pathway to improve glycaemic control. In these prespecified secondary analyses of the LYDIA trial, we examined the impact of the GLP-1RA liraglutide (1.8 mg once-daily) and the DPP4i sitagliptin (100 mg once-daily) on circulating cardiovascular biomarkers associated with atherosclerotic risk, including circulating progenitor cells (CPCs). LYDIA was a 26-week, randomized, active-comparator trial in 61 adults with type 2 diabetes and obesity (mean ± SD: age 43.8 ± 6.5 years, body mass index 35.3 ± 6.4 kg/m² , HbA1c 7.5% ± 0.83% [58.5 ± 9.1 mmol/mol]). Vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1-alpha (SDF-1ɑ), both of which are implicated in endothelial function, were higher at 26 weeks with liraglutide therapy compared with sitagliptin (mean between-group difference [95% CI]: 77.03 [18.29, 135.77] pg/mL, p = .010; and 996.25 [818.85, 1173.64] pg/mL, p < .001, respectively). There were no between-group differences in CPCs, nitric oxide, C-reactive protein, interleukin-6, tumour necrosis factor alpha and advanced glycation end-products. These analyses suggest a favourable impact of liraglutide on VEGF and SDF-1ɑ levels compared with sitagliptin. These factors may therefore be implicated in the differential cardiovascular effects observed between these agents in large cardiovascular outcome trials. However, these are secondary analyses from a previous trial and thus hypothesis-generating. Purposive trials are required to examine these findings further.

Association of White Matter Hyperintensities and Cardiovascular Disease

Cardiac and cerebrovascular diseases are currently the leading causes of mortality and disability worldwide. Both the heart and brain display similar vascular anatomy, with large conduit arteries running on the surface of the organ providing tissue perfusion through an intricate network of penetrating small vessels. Both organs rely on fine tuning of local blood flow to match metabolic demand. Blood flow regulation requires adequate functioning of the microcirculation in both organs, with loss of microvascular function, termed small vessel disease (SVD) underlying different potential clinical manifestations. SVD in the heart, known as coronary microvascular dysfunction, can cause chronic or acute myocardial ischemia and may lead to development of heart failure. In the brain, cerebral SVD can cause an acute stroke syndrome known as lacunar stroke or more subtle pathological alterations of the brain parenchyma, which may eventually lead to neurological deficits or cognitive decline in the long term. Coronary microcirculation cannot be visualized in vivo in humans, and functional information can be deduced by measuring the coronary flow reserve. The diagnosis of cerebral SVD is largely based on brain magnetic resonance imaging, with white matter hyperintensities, microbleeds, and brain atrophy reflecting key structural changes. There is evidence that such structural changes reflect underlying cerebral SVD. Here, we review interactions between SVD and cardiovascular risk factors, and we discuss the evidence linking cerebral SVD with large vessel atheroma, atrial fibrillation, heart failure, and heart valve disease.

Endothelial Progenitor Cell-Derived Extracellular Vesicles: A Novel Candidate for Regenerative Medicine and Disease Treatment

Extracellular vesicles (EVs) are a heterogeneous group of membranous structures, which can be secreted by most cell types. As a product of paracrine secretion, EVs are considered to be a regulatory mediator for intercellular communication. There are many bioactive cargos in EVs, such as proteins, lipids, and nucleic acids. As the precursor cell of vascular endothelial cells (ECs), endothelial progenitor cells (EPCs) are first discovered in peripheral blood. With the development of studies about the functions of EPCs, an increasing number of researchers focus on EPC-derived EVs (EPC-EVs). EPC-EVs exert key functions for promoting angiogenesis in regenerative medicine and show significant therapeutic effects on a variety of diseases such as circulatory diseases, kidney diseases, diabetes, bone diseases, and tissue/organ damages. This article reviews the current knowledge on the role of EPC-EVs in regenerative medicine and disease treatment, discussing the main challenges and future directions in this field.

When Good Guys Turn Bad: Bone Marrow's and Hematopoietic Stem Cells' Role in the Pathobiology of Diabetic Complications

Diabetes strongly contributes to the development of cardiovascular disease, the leading cause of mortality and morbidity in these patients. It is widely accepted that hyperglycemia impairs hematopoietic stem/progenitor cell (HSPC) mobilization from the bone marrow (BM) by inducing stem cell niche dysfunction. Moreover, a recent study demonstrated that type 2 diabetic patients are characterized by significant depletion of circulating provascular progenitor cells and increased frequency of inflammatory cells. This unbalance, potentially responsible for the reduction of intrinsic vascular homeostatic capacity and for the establishment of a low-grade inflammatory status, suggests that bone BM-derived HSPCs are not only victims but also active perpetrators in diabetic complications. In this review, we will discuss the most recent literature on the molecular mechanisms underpinning hyperglycemia-mediated BM dysfunction and differentiation abnormality of HSPCs. Moreover, a section will be dedicated to the new glucose-lowering therapies that by specifically targeting the culprits may prevent or treat diabetic complications.