Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5508333 | Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids | 2017 | 50 Pages |
Abstract
During cold-exposure 'beige' adipocytes with increased mitochondrial content are activated in white adipose tissue (WAT). These cells, similarly to brown adipose tissue (BAT), dissipate stored chemical energy in the form of heat with the help of uncoupling protein 1 (UCP1). We investigated the effect of tissue transglutaminase (TG2) ablation on the function of ATs in mice. Although TG2+/+ and TG2â/â mice had the same amount of WAT and BAT, we found that TG2+/+ animals could tolerate acute cold exposure for 4Â h, whereas TG2â/â mice only for 3Â h. Both TG2â/â and TG2+/+ animals used up half of the triacylglycerol content of subcutaneous WAT (SCAT) after 3Â h treatment; however, TG2â/â mice still possessed markedly whiter and higher amount of gonadal WAT (GONAT) as reflected in the larger size of adipocytes and lower free fatty acid levels in serum. Furthermore, lower expression of 'beige' marker genes such as UCP1, TBX1 and TNFRFS9 was observed after cold exposure in GONAT of TG2â/â mice, paralleled with a lower level of UCP1 protein and a decreased mitochondrial content. The detected changes in gene expression of Resistin and Adiponectin did not provoke glucose intolerance in the investigated TG2â/â mice, and TG2 deletion did not influence adrenaline, noradrenaline, glucagon and insulin production. Our data suggest that TG2 has a tissue-specific role in GONAT function and browning, which becomes apparent under acute cold exposure.
Keywords
FABP4Tbx1PPARGTG2cell death-inducing DFFA-like effector atype II iodothyronine deiodinaseGLUT4TOM20DIO2ADIPOQLPLPRDM16BATRODZIC1FFAHSLTMEM26Ucp1Beige adipocytesadiponectinscATFree fatty acidAdipose tissuesubcutaneous white adipose tissueGonadal white adipose tissueWAT, White adipose tissuebrown adipose tissueBrowningTissue transglutaminaserelative optical densityfold changeDifferentiationUncoupling protein-1glucose transporter 4PR domain containing 16Cold exposurehormone sensitive lipaseLipoprotein lipasefatty acid binding protein 4uncoupling protein 1transmembrane protein 26WATCideaPeroxisome proliferator-activated receptor gamma
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Authors
András Mádi, Ixchelt Cuaranta-Monroy, Kinga Lénárt, Attila Pap, Zoltán András Mezei, Endre Kristóf, Anna Oláh, György Vámosi, Zsolt Bacsó, Péter Bai, László Fésüs,