Figures & data
Figure 1. Schematic representation of extracellular effectors able to modulate white adipose tissue browning. Stimulatory and inhibitory effects on the browning process, schematized by increased uncoupling protein 1 (UCP1) expression in adipose tissue (AT) are represented respectively in green and red arrows. Yellow cells depict “white” adipocytes and gray cells illustrate beige adipocytes with increased mitochondria content. Blood vessels and other cells present in AT (preadipocytes, fibroblasts, macrophages, lymphocytes) are also shown. BAIBA, β -aminoisobutyric acid; FGF21, fibroblast growth factor 21; IL, interleukin; GDF, growth and differentiation factor; BMP, bone morphogenic protein; T3, trioodothyronine; ANP, atrial natriuretic peptide; GLP1, glucagon-like peptide 1; KLF, kruppel-like factor; PG, prostaglandin; CLA, conjugated trans-10, cis-12 fatty acid; ARG, arginine; CIT, citrulline; TGF, transforming growth factor
Figure 2. Schematic representation of citrulline effects on rat adipocyte metabolism and on browning. Modifications are represented with red arrows. Arrow thickness illustrates the intensity of the effects. In response to citrulline (CIT), lipolysis is activated in explants from rat white adipose tissue, with a rise in the phosphorylation of hormone-sensitive lipaseCitation120 and a drastic decrease in glyceroneogenesis and fatty acid re-esterification, leading to increased fatty acid release. CIT also induces the β-oxidative capacity of the cells together with the uncoupling-protein 1 (UCP1).Citation120,122 The observed up-regulation of mitochondrial transcription factor A gene expression indicates that mitochondriogenesis could occur.Citation122
