Obesity and Lipotoxicity

Ibrahim Celalettin Haznedaroglu, Umit Yavuz Malkan, Haznedaroglu, Ibrahim Celalettin, Malkan, Umit Yavuz

Ayse Basak Engin, Atilla Engin

Lipotoxicity can mediate endothelial dysfunction in obesity. Altered endothelial cell phenotype during the pathobiological course of the lipotoxicity may lead to the hemostatic abnormalities, which is a hallmark of several hematological disorders. Impaired hemostasis could also be directly related to the numerous metabolic diseases such as hypertension, diabetes and atherosclerosis. On the other hand, local hematopoietic bone marrow (BM) renin-angiotensin system (RAS) contributes to the development of atherosclerosis via acting on the lipotoxicity processes. Local BM RAS, principally an autocrine/ paracrine/ intracrinehematological system, is located at the crossroads of cellular regulation, molecular interactions and the lipotoxicity-mediated vascular endothelial dysfunction. The positive regulatory role of plasma LDL on AT1 receptor-mediated hematopoietic stem cell (HSC) differentiation and the production of pro-atherogenic monocytes had been described. LDL-regulated HSC function may explain in part hypercholesterolemia-induced inflammation as well as the anti-inflammatory and anti-atherosclerotic effects of AT1 receptor blockers. The role of local adipose tissue RAS is directly related to the pathogenesis of metabolic derangements in obesity. There may be a crosstalk between local BM RAS and local adipose tissue RAS at the genomics and transcriptomics levels. The aim of this chapter is to review hematological alterations propagating the pathological influences of lipotoxicity on the vascular endothelium.