Short-term intermittent cold induces browning of white adipose tissue and increases glucose clearance

PALOMA BIVORT HAIEK; BARBARA VALENTE; ESTEBAN M. REPETTO; CORA B. CYMERYNG; CAMILA MARTINEZ CALEJMAN

Mar del Plata

Congreso; LXVII Reunión Anual de la Sociedad Argentina de Investigación Clínica; 2022

Sociedad Argentina de Investigación Clínica

Introduction: Adipocytes are typically classified as being white orbrown. White adipocytes (WA), which are the most abundant, storeenergy in a single large lipid droplet. Brown adipocytes (BA) havemultiple lipid droplets, many more mitochondria, and specialize inburning energy to generate heat through non-shivering thermogenesis, which requires the expression of Uncoupling Protein 1 (UCP1).In response to cold environments, the sympathetic nervous systemstimulates thermogenesis to BAT utilize large amounts of glucose,fatty acids, and other nutrients to fuel heat production. Notably,some WA can also adopt the metabolic characteristics of classic BAunder certain conditions in a process called browning. These socalled brown-in-white (brite) adipocytes mainly appear in subcutaneous fat depots express Ucp1, and can also contribute to whole bodyenergy expenditure. The energy expenditure properties of brown orbeige adipocytes is garnering interest in developing strategies toincrease BA number and/or activity to treat obesity and other metabolically related diseases. Aim: To study the effect of a short-termintermittent cold (IC) protocol on the activity of BAT and the browning capacity of WAT of mice. Materials & methods: We subjected 8week-old male C57bl 6 mice to increasing short-term periods (5-15min/5 days a week) at 4ºC for a month IC, and we measured itseffect on BAT and WAT and in serum parameters. Results & Conclusions: Although there were no significant changes in BAT morphology as well as UCP1 expression, WAT histology showed a markedreduction in lipid droplet size and a higher expression of UCP1 inthe IC group. Serum glucose levels were markedly reduced in thefed state (156±2 mg/dL vs 210±12 mg/dL p<0.05) in the IC groupwith no significant effects on TG or cholesterol levels. These resultsindicate that a short period of IC might induce the generation of briteadipose tissue and boost its metabolic capacity promoting serumglucose clearance