Extracellular vesicles (EVs) are a heterogeneous group of natural particles with relevance for the treatment of cardiovascular diseases. The endogenous properties of these vesicles allow them to survive in the extracellular space, bypass biological barriers and deliver their biologically active molecular cargo to recipient cells. Moreover, EVs can be engineered to enhance their stability, bioactivity, presentation and capacity for on target binding at both cell type and tissue levels. The therapeutic potential of native (i.e., EVs that were not modified via donor cell or direct modulation) and engineered (i.e. EVs that were modified either pre-or post-isolation or whose pharmacokinetics/presentation was altered using engineering methodologies EVs is still limitedly explored in the context of cardiovascular diseases. Efforts to tap into the therapeutic potential of EVs will require innovative approaches and a comprehensive integration of knowledge gathered from decades of molecular compound delivery. In this review, we outline the endogenous properties of EVs that make them natural delivery agents as well as those features that can be improved using bioengineering approaches. We also discuss the therapeutic applications of native and engineered EVs for cardiovascular applications and examine the opportunities and challenges that need to be addressed to advance this research area with an emphasis on clinical translation. Key points• EVs secreted from stem/progenitor cells as well as differentiated somatic cells have regenerative properties in the context of myocardial infarction, ischemic limb, chronic wounds and stroke.

Background-The increasing incidence of diabetes mellitus will result in a new epidemic of heart failure unless novel treatments able to halt diabetic cardiomyopathy early in its course are introduced. This study aimed to determine whether the activity of the Akt/Pim-1 signaling pathway is altered at critical stages of diabetic cardiomyopathy and whether supplementation with vitamin B1 analog benfotiamine (BFT) helps to sustain the above prosurvival mechanism, thereby preserving cardiomyocyte viability and function. Methods and Results-Untreated streptozotocin-induced type 1 or leptin-receptor mutant type 2 diabetic mice showed diastolic dysfunction evolving to contractile impairment and cardiac dilatation and failure. BFT (70 mg/kg Ϫ1 /d Ϫ1 ) improved diastolic and systolic function and prevented left ventricular end-diastolic pressure increase and chamber dilatation in both diabetic models. Moreover, BFT improved cardiac perfusion and reduced cardiomyocyte apoptosis and interstitial fibrosis. In hearts of untreated diabetic mice, the expression and activity of Akt/Pim-1 signaling declined along with O-N-acetylglucosamine modification of Akt, inhibition of pentose phosphate pathway, activation of oxidative stress, and accumulation of glycation end products. Furthermore, diabetes reduced pSTAT3 independently of Akt. BFT inhibited these effects of diabetes mellitus, thereby conferring cardiomyocytes with improved resistance to high glucose-induced damage. The phosphoinositide-3-kinase inhibitor LY294002 and dominant-negative Akt inhibited antiapoptotic action of BFT-induced and Pim-1 upregulation in high glucose-challenged cardiomyocytes. Conclusions-These results show that BFT protects from diabetes mellitus-induced cardiac dysfunction through pleiotropic mechanisms, culminating in the activation of prosurvival signaling pathway. Thus, BFT merits attention for application in clinical practice. (Circ Heart Fail. 2010;3:294-305.)Key Words: diabetes mellitus Ⅲ cardiomyopathy Ⅲ diastolic dysfunction Ⅲ benfotiamine Ⅲ apoptosis D iabetes mellitus (DM) is a potent and prevalent risk factor for heart failure independent of coronary artery disease or hypertension. 1 Diabetic cardiomyopathy has an insidious onset and remains, therefore, undiagnosed and untreated in a large number of patients. Furthermore, recent studies have shown evidence of diastolic dysfunction in up to 75% of young, asymptomatic patients with type 1 or type 2 DM. 2 The association of diastolic dysfunction and microangiopathy synergistically increases the risk of heart failure, thus pointing out the urgent need of early mechanistic treatment. 3,4 Clinical Perspective on p 305A variety of molecular alterations have been associated with diabetic cardiomyopathy, including defects in calcium homeostasis 5 and substrate metabolism, 6 accumulation of advanced glycation end products (AGE), 7 activation of the hexosamine pathway, 8 and oxidative stress leading to cardiomyocyte apoptosis. 9 However, early stage mechanisms remain mostly unknown.The pivota...

Neurogenic inflammation is mediated by release of tachykinins from sensory nerves, which stimulate plasma extravasation from postcapillary venules. Because there are conflicting results regarding the importance of neurogenic inflammation in the gastrointestinal tract, we quantified plasma extravasation using Evans blue and identified sites of the leak using Monastral blue in the mouse. Substance P and bradykinin stimulated extravasation from postcapillary venules in the stomach, small and large intestine, pancreas, urinary bladder, trachea, and skin by two- to sevenfold by interacting with NK1 and B2 receptors, respectively. Stimulation of sensory nerves with capsaicin also induced extravasation. Capsaicin- and bradykinin-stimulated extravasation was attenuated by an NK1-receptor antagonist and is thus mediated by release of tachykinins and activation of the NK1 receptor. We conclude that 1) substance P stimulates extravasation in the gastrointestinal tract and pancreas of mice by interacting with the NK1 receptors, and 2) capsaicin and bradykinin induce plasma extravasation by stimulating tachykinin release from sensory nerves. Thus neurogenic mechanisms mediate inflammation in the gastrointestinal tract and pancreas of the mouse.

Fibrosis is a significant global health problem associated with many inflammatory and degenerative diseases affecting multiple organs, individually or simultaneously. Fibrosis develops when extracellular matrix (ECM) remodeling becomes excessive or uncontrolled and is associated with nearly all forms of heart disease. Cardiac fibroblasts and myofibroblasts are the main effectors of ECM deposition and scar formation. The heart is a complex multicellular organ, where the various resident cell types communicate between themselves and with cells of the blood and immune systems. Exosomes, which are small extracellular vesicles, (EVs), contribute to cell-to-cell communication and their pathophysiological relevance and therapeutic potential is emerging. Here, we will critically review the role of endogenous exosomes as possible fibrosis mediators and discuss the possibility of using stem cell-derived and/or engineered exosomes as anti-fibrotic agents.