Project description:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity, but the molecular mechanisms that drive BAT cell remodeling remain largely unexplored. Using a multilayered approach, we comprehensively mapped a reorganization in BAT cells. We uncovered a subset of macrophages as lipid-associated macrophages (LAMs), which were massively increased in genetic and dietary model of BAT expansion. LAMs participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically stressed brown adipocytes. CD36 scavenger receptor drove LAM phenotype, and CD36-deficient LAMs were able to increase brown fat genes in adipocytes. LAMs released transforming growth factor β1 (TGF-β1), which promoted the loss of brown adipocyte identity through aldehyde dehydrogenase 1 family member A1 (Aldh1a1) induction. These findings unfold cell dynamic changes in BAT during obesity and identify LAMs as key responders to tissue metabolic stress and drivers of loss of brown adipocyte identity.
Project description:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity in mice and human, but the molecular mechanisms that drive BAT cell remodeling remain largely. Using a multilayered approach, we comprehensively map a deep reorganization in the BAT cells. We uncovered a subset of macrophages as the lipid-associated macrophages (LAM), which were massively increased in genetic and dietary model of BAT expansion. LAM participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically-stressed brown adipocytes. CD36 scavenger receptor drives LAM phenotype and through * in vitro* and *in vivo* models, we demonstrated that CD36-deficient LAM increased brown fat genes. LAM release Tgfb1 that reduces brown adipocytes identity through Aldh1a1 induction. This study provides the first description of cell dynamics in BAT of obese models identifying LAM as responder to tissue-level metabolic stress and key driver to loss of BAT cell identity.
Project description:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity in mice and human, but the molecular mechanisms that drive BAT cell remodeling remain largely. Using a multilayered approach, we comprehensively map a deep reorganization in the BAT cells. We uncovered a subset of macrophages as the lipid-associated macrophages (LAM), which were massively increased in genetic and dietary model of BAT expansion. LAM participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically-stressed brown adipocytes. CD36 scavenger receptor drives LAM phenotype and through * in vitro* and *in vivo* models, we demonstrated that CD36-deficient LAM increased brown fat genes. LAM release Tgfb1 that reduces brown adipocytes identity through Aldh1a1 induction. This study provides the first description of cell dynamics in BAT of obese models identifying LAM as responder to tissue-level metabolic stress and key driver to loss of BAT cell identity.
Project description:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity in mice and human, but the molecular mechanisms that drive BAT cell remodeling remain largely. Using a multilayered approach, we comprehensively map a deep reorganization in the BAT cells. We uncovered a subset of macrophages as the lipid-associated macrophages (LAM), which were massively increased in genetic and dietary model of BAT expansion. LAM participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically-stressed brown adipocytes. CD36 scavenger receptor drives LAM phenotype and through * in vitro* and *in vivo* models, we demonstrated that CD36-deficient LAM increased brown fat genes. LAM release Tgfb1 that reduces brown adipocytes identity through Aldh1a1 induction. This study provides the first description of cell dynamics in BAT of obese models identifying LAM as responder to tissue-level metabolic stress and key driver to loss of BAT cell identity.
Project description:Obesity and type 2 diabetes cause a loss in brown adipose tissue (BAT) activity in mice and human, but the molecular mechanisms that drive BAT cell remodeling remain largely. Using a multilayered approach, we comprehensively map a deep reorganization in the BAT cells. We uncovered a subset of macrophages as the lipid-associated macrophages (LAM), which were massively increased in genetic and dietary model of BAT expansion. LAM participate in this scenario by capturing extracellular vesicles carrying damaged lipids and mitochondria released from metabolically-stressed brown adipocytes. CD36 scavenger receptor drives LAM phenotype and through * in vitro* and *in vivo* models, we demonstrated that CD36-deficient LAM increased brown fat genes. LAM release Tgfb1 that reduces brown adipocytes identity through Aldh1a1 induction. This study provides the first description of cell dynamics in BAT of obese models identifying LAM as responder to tissue-level metabolic stress and key driver to loss of BAT cell identity.
