Diabetes is a metabolic disease that currently affects nearly half a billion people worldwide. β-cells dysfunction is one of the main causes of diabetes. Exposure to endocrine-disrupting chemicals is correlated with increased diabetes incidence. We hypothesized that treatment with bisphenol A (BPA) induces endoplasmic reticulum (ER) stress that activates the unfolded protein response (UPR), leading to impaired function of the β-cells, which over time, can cause diabetes. In this study, we aimed to evaluate UPR pathways activation under BPA treatment in β-cells and possible recovery of ER homeostasis. MIN6 cells (mouse insulinoma cell line) and isolated pancreatic islets from NOR (non-obese diabetes resistant) mice were treated with BPA. We analyzed the impact of BPA on β-cell viability, the architecture of the early secretory pathway, the synthesis and processing of insulin and the activation of UPR sensors and effectors. We found that the addition of the chemical chaperone TUDCA rescues the deleterious effects of BPA, resulting in improved viability, morphology and function of the β-cells. In conclusion, we propose that modulators of UPR can be used as therapeutic interventions targeted towards regaining β-cells homeostasis.

Hypertension-induced left ventricular hypertrophy evolves initially as an adaptive response meant to minimize ventricular wall stress. The mechanisms involved in the preservation of the cardiac function during the "compensatory" phase of the left ventricular hypertrophy are still unclear. Therefore, we aimed at uncovering fine changes that aid the heart to cope with the increased stress in hypertension. Male golden Syrian hamsters were given NG-nitro-L-arginine methyl ester (L-NAME) for 16 weeks, and they became hypertensive (HT), developing left ventricular hypertrophy with no impaired contractility or fibrosis. As compared to age-matched control hamsters, the hypertrophied left ventricles in L-NAME-induced HT hamsters exhibited the following structural and molecular changes: (i) accumulation of lipid droplets (LDs) within cardiomyocytes and relocation of gap junctions to the lateral membrane of cardiomyocytes or close to mitochondria (revealed by electron microscopy); (ii) overexpression of the cluster of differentiation 36 (CD36) fatty acid transporter, protein kinase C (PKC), and matrix metalloproteinase-2 (MMP-2), enhanced activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway, and unchanged expression of the connexin 43 (Cx43) and N-cadherin junctional proteins (assessed by Western blot); (ii) increased protein carbonyl content, assessed with a 2,4-Dinitrophenylhydrazine (DNPH)-based spectrophotometric assay, indicative of an enhanced reactive oxygen species (ROS) production; and (iv) augmented MMP-2 activity (determined by gelatin zymography). These changes may participate in an orchestrated adaptive hypertrophic growth response that helps to maintain cardiac performance, in HT hamsters. Together, these findings could provide support for designing future strategies meant to prevent the transition from compensatory left ventricular hypertrophy to decompensated heart failure.

Calcific aortic valve disease (CAVD) is a progressive inflammatory disorder characterized by extracellular matrix remodeling and valvular interstitial cells (VIC) osteodifferentiation leading to valve leaflets calcification and impairment movement. Runx2, the master transcription factor involved in VIC osteodifferentiation, modulates the expression of other osteogenic molecules. Previously, we have demonstrated that the osteoblastic phenotypic shift of cultured VIC is impeded by Runx2 silencing using fullerene (C60)-polyethyleneimine (PEI)/short hairpin (sh)RNA-Runx2 (shRunx2) polyplexes. Since the use of polyplexes for in vivo delivery is limited by their instability in the plasma and the non-specific tissue interactions, we designed and obtained targeted, lipid-enveloped polyplexes (lipopolyplexes) suitable for (1) systemic administration and (2) targeted delivery of shRunx2 to osteoblast-differentiated VIC (oVIC). Vascular cell adhesion molecule (VCAM)-1 expressed on the surface of oVIC was used as a target, and a peptide with high affinity for VCAM-1 was coupled to the surface of lipopolyplexes encapsulating C60-PEI/shRunx2 (V-LPP/shRunx2). We report here that V-LPP/shRunx2 lipopolyplexes are cyto- and hemo-compatible and specifically taken up by oVIC. These lipopolyplexes are functional as they downregulate the Runx2 gene and protein expression, and their uptake leads to a significant decrease in the expression of osteogenic molecules (OSP, BSP, BMP-2). These results identify V-LPP/shRunx2 as a new, appropriately directed vehicle that could be instrumental in developing novel strategies for blocking the progression of CAVD using a targeted nanomedicine approach.

Extracellular vesicles (EVs) are particles released in the extracellular space from all cell types in physiological and pathological conditions and emerge as a new way of cell-cell communication by transferring their biological contents into target cells. The levels and composition of circulating EVs differ from a normal condition to a pathological one, making them real circulating biomarkers. EVs have a very complex contribution in both health and disease, most likely in relationship between diabetes and cardiovascular disease. The involvement of EVs to the development of cardiovascular complications in diabetes remains an open discussion for therapists. Circulating EVs may offer a continuous access path to circulating information on the disease state and a new perspective in finding a correct diagnosis, in estimating a prognosis and also in applying an effective therapy. Besides their role as biomarkers and targets for therapy, EVs can be exploited as biological tools in influencing the different processes affected in diabetic cardiovascular diseases. This chapter will summarize the current knowledge about EVs as biological vectors modulating diabetic cardiovascular diseases, including atherosclerosis, coronary artery disease, and peripheral arterial disease. Finally, we will point out EVs’ considerable value as clinical biomarkers, therapeutic targets, and potential biomedical tools for the discovery of effective therapy in diabetic cardiovascular diseases.