[PDF][PDF] Metabolic dysfunction drives a mechanistically distinct proinflammatory phenotype in adipose tissue macrophages

M Kratz, BR Coats, KB Hisert, D Hagman, V Mutskov… - Cell metabolism, 2014 - cell.com
M Kratz, BR Coats, KB Hisert, D Hagman, V Mutskov, E Peris, KQ Schoenfelt, JN Kuzma…
Cell metabolism, 2014cell.com
Adipose tissue macrophage (ATM)-driven inflammation plays a key role in insulin
resistance; however, factors activating ATMs are poorly understood. Using a proteomics
approach, we show that markers of classical activation are absent on ATMs from obese
humans but are readily detectable on airway macrophages of patients with cystic fibrosis, a
disease associated with chronic bacterial infection. Moreover, treating macrophages with
glucose, insulin, and palmitate—conditions characteristic of the metabolic syndrome …
Summary
Adipose tissue macrophage (ATM)-driven inflammation plays a key role in insulin resistance; however, factors activating ATMs are poorly understood. Using a proteomics approach, we show that markers of classical activation are absent on ATMs from obese humans but are readily detectable on airway macrophages of patients with cystic fibrosis, a disease associated with chronic bacterial infection. Moreover, treating macrophages with glucose, insulin, and palmitate—conditions characteristic of the metabolic syndrome—produces a "metabolically activated" phenotype distinct from classical activation. Markers of metabolic activation are expressed by proinflammatory ATMs in obese humans/mice and are positively correlated with adiposity. Metabolic activation is driven by independent proinflammatory and anti-inflammatory pathways, which regulate balance between cytokine production and lipid metabolism. We identify PPARγ and p62/SQSTM1 as two key proteins that promote lipid metabolism and limit inflammation in metabolically activated macrophages. Collectively, our data provide important mechanistic insights into pathways that drive the metabolic-disease-specific phenotype of macrophages.
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