Women Have More Potential to Induce Browning of the Perirenal Fat Depot Than Men

Program: Abstracts - Orals, Poster Preview Presentations, and Posters
Session: SUN 0875-0890-Adipocyte Biology-Clinical studies
Sunday, June 22, 2014: 1:00 PM-3:00 PM
Hall F (McCormick Place West Building)

Poster Board SUN-0886
Johanna C. van den Beukel, MD1, Aldo Grefhorst, PhD1, Jacobie Steenbergen1, Frank J.M.F. Dor, MD, PhD2, Martin J. Hoogduijn, PhD2 and Axel P.N. Themmen, PhD1
1Erasmus MC, Rotterdam, Netherlands, 2Erasmus MC
In mammals, white adipose tissue (WAT) stores energy in the form of triglycerides, whereas brown adipose tissue (BAT) can oxidize triglyceride-derived fatty acids to generate heat, a process mediated by brown-adipocyte-specific uncoupling protein 1 (UCP1). Depending on its location and presence or absence of specific triggers, WAT depots can gain BAT-like properties such as presence of brown-like adipocytes with UCP1 expression. Studies suggest that human perirenal adipose tissue is a WAT depot with BAT-like properties, but it is not known which factors determine this browning. We performed a detailed investigation of human perirenal adipose tissue.

Perirenal and subcutaneous adipose tissue was obtained from 19 male and 23 female healthy live kidney donors, aged 27-81. Browning of the adipose tissue was studied by RNA analysis and immunohistochemistry. Mesenchymal stem cells (MSCs) were isolated from these depots to study the browning potential in vitro.

None of the collected subcutaneous adipose tissues showed presence of brown adipocytes or UCP1 gene expression. When the average outside temperature a week before harvesting was lower than 10 °C, brown adipocytes, i.e. cells with multiple small lipid droplets and positive for UCP1 staining, were present in perirenal adipose tissue of all women but in only 1 out of 10 men. UCP1 gene expression, in contrast, did not differ between men and women partly due to very high expression in 1 man (p=0.43). Subcutaneous-derived MSCs that were differentiated towards adipocytes did not express UCP1. Perirenal-derived MSCs differentiated towards adipocytes expressed significantly more UCP1 when they were from female origin compared to male origin (p=0.009).

Female perirenal adipose tissue has a higher potency to gain BAT-like properties than male perirenal adipose tissue. Thus, perirenal adipose tissue is a genuine beige adipose tissue depot, but its degree of browning depends on sex and environmental triggers such as temperature.

Nothing to Disclose: JCV, AG, JS, FJMFD, MJH, APNT

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