02873nas a2200301   4500008004100000245015000041210006900191260001600260300001200276490000700288520183800295100001902133700002202152700002502174700002102199700002002220700002002240700001702260700002102277700002202298700002502320700002102345700002002366700001802386700002102404700002402425856012202449       2011                        eng d00aDifferential Lipid Partitioning Between Adipocytes and Tissue Macrophages Modulates Macrophage Lipotoxicity and M2/M1 Polarization in Obese Mice.0 aDifferential Lipid Partitioning Between Adipocytes and Tissue Ma  c2011 Jan 24  a797-8090 v603 a<p>OBJECTIVE Obesity-associated insulin resistance is characterized by a state of chronic, low-grade inflammation that is associated with the accumulation of M1 proinflammatory macrophages in adipose tissue. Although different evidence explains the mechanisms linking the expansion of adipose tissue and adipose tissue macrophage (ATM) polarization, in the current study we investigated the concept of lipid-induced toxicity as the pathogenic link that could explain the trigger of this response. RESEARCH DESIGN AND METHODS We addressed this question using isolated ATMs and adipocytes from genetic and diet-induced murine models of obesity. Through transcriptomic and lipidomic analysis, we created a model integrating transcript and lipid species networks simultaneously occurring in adipocytes and ATMs and their reversibility by thiazolidinedione treatment. RESULTS We show that polarization of ATMs is associated with lipid accumulation and the consequent formation of foam cell-like cells in adipose tissue. Our study reveals that early stages of adipose tissue expansion are characterized by M2-polarized ATMs and that progressive lipid accumulation within ATMs heralds the M1 polarization, a macrophage phenotype associated with severe obesity and insulin resistance. Furthermore, rosiglitazone treatment, which promotes redistribution of lipids toward adipocytes and extends the M2 ATM polarization state, prevents the lipid alterations associated with M1 ATM polarization. CONCLUSIONS Our data indicate that the M1 ATM polarization in obesity might be a macrophage-specific manifestation of a more general lipotoxic pathogenic mechanism. This indicates that strategies to optimize fat deposition and repartitioning toward adipocytes might improve insulin sensitivity by preventing ATM lipotoxicity and M1 polarization.</p>1 aPrieur, Xavier1 aMok, Crystal, Y L1 aVelagapudi, Vidya, R1 aNúñez, Vanessa1 aFuentes, Lucía1 aMontaner, David1 aIshikawa, Ko1 aCamacho, Alberto1 aBarbarroja, Nuria1 aO’Rahilly, Stephen1 aSethi, Jaswinder1 aDopazo, Joaquin1 aOresic, Matej1 aRicote, Mercedes1 aVidal-Puig, Antonio  uhttp://clinbioinfosspa.es/content/differential-lipid-partitioning-between-adipocytes-and-tissue-macrophages-modulates