Lipotoxicity-Related Hematological Disorders in Obesity.

Lipotoxicity can mediate endothelial dysfunction in obesity. Altered endothelial cell phenotype during the pathobiological course of the lipotoxicity may lead to hemostatic abnormalities, which is a hallmark of several hematological disorders. Impaired hemostasis could also be directly related to numerous metabolic diseases such as hypertension, diabetes, and atherosclerosis. On the other hand, the 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/intracrine hematological system, is located at the crossroads of cellular regulation, molecular interactions, and 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 have 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. This chapter aims to review hematological alterations propagating the pathological influences of lipotoxicity on the vascular endothelium.