The Effects of Chronic Stress on Brown Adipose Tissue Remodeling and Metabolism

AbstractMonocytes are part of the mononuclear phagocytic system. Monocytes play a central role during inflammatory conditions and a better understanding of their dynamics might open therapeutic opportunities. In the present study, we focused on the characterization and impact of monocytes on brown adipose tissue (BAT) functions during tissue remodeling. Single-cell RNA sequencing analysis of BAT immune cells uncovered a large diversity in monocyte and macrophage populations. Fate-mapping experiments demonstrated that the BAT macrophage pool requires constant replenishment from monocytes. Using a genetic model of BAT expansion, we found that brown fat monocyte numbers were selectively increased in this scenario. This observation was confirmed using a CCR2-binding radiotracer and positron emission tomography. Importantly, in line with their tissue recruitment, blood monocyte counts were decreased while bone marrow hematopoiesis was not affected. Monocyte depletion prevented brown adipose tissue expansion and altered its architecture. Podoplanin engagement is strictly required for BAT expansion. Together, these data redefine the diversity of immune cells in the BAT and emphasize the role of monocyte recruitment for tissue remodeling.

Download Full-text

Brown Adipose Tissue Remodeling Precedes Cardiometabolic Abnormalities Independent of Overweight in Fructose-Feed Mice

10.1101/615674 ◽

2019 ◽

Cited By ~ 1

Author(s):

Thaissa Queiroz Machado ◽

Debora Cristina Pereira-Silva ◽

Leidyanne Ferreira Gonçalves ◽

Caroline Fernandes-Santos

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Lipid Droplets ◽

Control Diet ◽

Metabolic Dysfunction ◽

Mice Model ◽

Short Term ◽

Intracellular Lipid ◽

Brown Adipose ◽

Adipose Tissue Remodeling

AbstractObjectivesTo investigate the early cardiometabolic abnormalities along with WAT and BAT remodeling in short-term fructose feeding mice model.MethodsMice (n=10-11/group) were fed for four weeks with control diet (AIN93-M) or experimental diets rich in glucose or fructose. We investigated body weight, body adiposity, blood glucose, lipid and hepatic parameters, and white (WAT) and brown adipose tissue (BAT) histopathology.ResultsFructose feeding promoted neither weight gain nor hypertrophy of visceral and subcutaneous WAT depots, but the fat was redistributed toward visceral depots. Glucose, lipid and hepatic metabolic dysfunction were not yet noticed in fructose-fed mice, with the exception for an elevation in total cholesterol and hepatic weight without steatosis. BAT mass did not increase, and it was proportionally reduced compared with visceral WAT in fructose feed mice. BAT suffered premature adverse morphological remodeling, characterized by increased lipid deposition per tissue area in enlarged intracellular lipid droplets.ConclusionShort-term fructose feeding redistributes body fat, changes the proportion of BAT to visceral fat, and promotes BAT adverse remodeling, characterized by enlarged intracellular lipid droplets.

Download Full-text

Functional characterization of human brown adipose tissue metabolism

Biochemical Journal ◽

10.1042/bcj20190464 ◽

2020 ◽

Vol 477 (7) ◽

pp. 1261-1286 ◽

Cited By ~ 3

Author(s):

Marie Anne Richard ◽

Hannah Pallubinsky ◽

Denis P. Blondin

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Functional Characterization ◽

Human Infants ◽

Positron Emission ◽

Brown Adipose ◽

Treatment Of Obesity ◽

And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

Download Full-text