vasoactive-intestinal-peptide and Atherosclerosis

Vasoactive intestinal peptide (VIP) is a neuropeptide that exerts various vascular and cardioprotective functions and regulates immune function and inflammatory response at multiple levels. However, its role in inflammatory cardiovascular disorders is largely unknown. Myocarditis and atherosclerosis are two inflammatory and autoimmune cardiovascular diseases that cause important adverse circulatory events. In this study, we investigate the therapeutic effects of VIP in various well-established preclinical models of experimental autoimmune myocarditis and atherosclerosis. Intraperitoneal injection of VIP during the effector phase of experimental autoimmune myocarditis in susceptible BALB/c mice significantly reduced its prevalence, ameliorated signs of heart hypertrophy and injury, attenuated myocardial inflammatory infiltration, and avoided subsequent profibrotic cardiac remodeling. This effect was accompanied by a reduction of Th17-driven cardiomyogenic responses in peripheral lymphoid organs and in the levels of myocardial autoantibodies. In contrast, acute and chronic atherosclerosis was induced in apolipoprotein E-deficient mice fed a hyperlipidemic diet and subjected to partial carotid ligation. Systemic VIP treatment reduced the number and size of atherosclerotic plaques in carotid, aorta, and sinus in hypercholesterolemic mice. VIP reduced Th1-driven inflammatory responses and increased regulatory T cells in atherosclerotic arteries and their draining lymph nodes. VIP also regulated cholesterol efflux in macrophages and reduced the formation of foam cells and their presence in atherosclerotic plaques. Finally, VIP inhibited proliferation and migration of smooth muscle cells and neointima formation in a mouse model of complete carotid ligation. These findings encourage further studies aimed to assess whether VIP can be used as a pharmaceutical agent to treat heart inflammation and atherosclerosis.

Topics: Animals; Apolipoproteins E; Atherosclerosis; Autoantibodies; Autoimmune Diseases; Autoimmunity; Disease Models, Animal; Female; Inflammation; Lymph Nodes; Macrophages; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Muscle, Smooth; Myocarditis; Myocardium; Neuropeptides; T-Lymphocytes, Regulatory; Th17 Cells; Vasoactive Intestinal Peptide

Vasoactive intestinal peptide (VIP) is a 28-amino acid peptide widely expressed in the body and binding three types of receptors: VPAC(1)-R, VPAC(2)-R and PAC(1)-R. Based on beneficial effects of VIP and VPAC(1)-R agonists in mouse models of several chronic inflammatory disorders, we hypothesized that activation of VIP receptors would prevent atherosclerosis development in apolipoprotein E-deficient mice.. Contrary to our hypothesis, administration of a VPAC(1)-R agonist, (Ala(11,22,28))-VIP aggravated atherosclerotic lesion development in the aortic root of these mice compared to control mice. This was accompanied by a significant increase in the expression of MHC class II protein I-A(b), and suggests enhanced inflammatory activity in the vessel wall. The amount of macrophage-specific CD68 staining as well as serum cholesterol and triglyceride levels did not change as a result of the (Ala(11,22,28))-VIP treatment, i.e. the treatment resulted in significant changes in lipid accumulation in the lesions without changing the number of macrophages or systemic lipid levels. Interestingly, administration of VIP did not alter the course of the disease.. Despite beneficial effects in murine models of several inflammatory disorders, VPAC(1)-R activation aggravates atherosclerotic lesion formation in apolipoprotein E-deficient mice through enhanced inflammatory activity in the vessel wall.

Topics: Animals; Apolipoproteins E; Atherosclerosis; B-Lymphocytes; Cytokines; Disease Models, Animal; Hypercholesterolemia; Inflammation; Mice; Mice, Knockout; Receptors, Vasoactive Intestinal Peptide, Type II; Receptors, Vasoactive Intestinal Polypeptide, Type I; Spleen; T-Lymphocytes; Vasoactive Intestinal Peptide