scholarly journals Brown adipose tissue regulates glucose homeostasis and insulin sensitivity

2012 ◽  
Vol 123 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Kristin I. Stanford ◽  
Roeland J.W. Middelbeek ◽  
Kristy L. Townsend ◽  
Ding An ◽  
Eva B. Nygaard ◽  
...  
Diabetes ◽  
2014 ◽  
Vol 63 (12) ◽  
pp. 4089-4099 ◽  
Author(s):  
M. Chondronikola ◽  
E. Volpi ◽  
E. Borsheim ◽  
C. Porter ◽  
P. Annamalai ◽  
...  

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Tao Yuan ◽  
Juan Li ◽  
Wei-Gang Zhao ◽  
Wei Sun ◽  
Shuai-Nan Liu ◽  
...  

Abstract Background To investigate effects of metformin on the regulation of proteins of white adipose tissue (WAT) and brown adipose tissue (BAT) in obesity and explore the underlying mechanisms on energy metabolism. Methods C57BL/6J mice were fed with normal diet (ND, n = 6) or high-fat diet (HFD, n = 12) for 22 weeks. HFD-induced obese mice were treated with metformin (MET, n = 6). After treatment for 8 weeks, oral glucose tolerance test (OGTT) and hyperinsulinemic–euglycemic clamp were performed to evaluate the improvement of glucose tolerance and insulin sensitivity. Protein expressions of WAT and BAT in mice among ND, HFD, and MET group were identified and quantified with isobaric tag for relative and absolute quantification (iTRAQ) coupled with 2D LC–MS/MS. The results were analyzed by MASCOT, Scaffold and IPA. Results The glucose infusion rate in MET group was increased significantly compared with HFD group. We identified 4388 and 3486 proteins in WAT and BAT, respectively. As compared MET to HFD, differential expressed proteins in WAT and BAT were mainly assigned to the pathways of EIF2 signaling and mitochondrial dysfunction, respectively. In the pathways, CPT1a in WAT, CPT1b and CPT2 in BAT were down-regulated by metformin significantly. Conclusions Metformin improved the body weight and insulin sensitivity of obese mice. Meanwhile, metformin might ameliorate endoplasmic reticulum stress in WAT, and affect fatty acid metabolism in WAT and BAT. CPT1 might be a potential target of metformin in WAT and BAT.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Jie Li ◽  
Ran An ◽  
Simin Liu ◽  
Haiyan Xu

Abstract Objectives Sucrose Non-Fermenting Related Kinase (SNRK), a serine/threonine kinase, is a novel member of the AMPK/SNF1 family. We previously reported that adipose specific SNRK deficiency induced systemic inflammation and insulin resistance. In this study, we aimed to dissect the role of SNRK in white versus brown adipose tissue in insulin signaling and glucose homeostasis. Methods The SNRKloxp/loxp mice were mated with adiponectin-Cre (A-Cre) transgenic mice to generate the adipose tissue specific knockout model (SNRK−/−, A-Cre), and with UCP1-Cre (U-Cre) mice to generate the brown adipose tissue (BAT) specific knockout model (SNRK−/−, U-Cre). RNA sequencing and phosphoproteomics analysis were applied to identify the signaling pathways affected by SNRK deficiency and the potential substrate of SNRK. Results SNRK deletion exclusively in BAT is sufficient to impair insulin signaling and glucose uptake without inducing local and systemic inflammation. Phosphoproteomic study identified PPP2R5D as the potential substrate of SNRK that regulates insulin signaling through controlling PP2A activity. Dephosphorylated PPP2R5D promotes constitutive assembly of PP2A-Akt complex in SNRK deficient primary brown adipocytes and BAT, therefore reduces insulin stimulated Akt phosphorylation and subsequent glucose uptake. RNA sequencing data provided further evidence to show that the PI3K/AKT signaling pathway is suppressed by SNRK deletion in primary brown adipocytes. Conclusions Insulin resistance in BAT alone is not sufficient to impact whole body glucose homeostasis, indicating that the role of SNRK in WAT and inflammation might be critical for observed systemic insulin resistance in SNRK−/−, A-Cre mice. Funding Sources National Institute of Diabetes and Digestive and Kidney Diseases (R01 DK103699).


Endocrinology ◽  
2014 ◽  
Vol 155 (8) ◽  
pp. 2881-2891 ◽  
Author(s):  
Mariana Nigro ◽  
Anderson T. Santos ◽  
Clarissa S. Barthem ◽  
Ruy A. N. Louzada ◽  
Rodrigo S. Fortunato ◽  
...  

Menopause is associated with increased visceral adiposity and disrupted glucose homeostasis, but the underlying molecular mechanisms related to these metabolic changes are still elusive. Brown adipose tissue (BAT) plays a key role in energy expenditure that may be regulated by sexual steroids, and alterations in glucose homeostasis could precede increased weight gain after ovariectomy. Thus, the aim of this work was to evaluate the metabolic pathways in both the BAT and the liver that may be disrupted early after ovariectomy. Ovariectomized (OVX) rats had increased food efficiency as early as 12 days after ovariectomy, which could not be explained by differences in feces content. Analysis of isolated BAT mitochondria function revealed no differences in citrate synthase activity, uncoupling protein 1 expression, oxygen consumption, ATP synthesis, or heat production in OVX rats. The addition of GDP and BSA to inhibit uncoupling protein 1 decreased oxygen consumption in BAT mitochondria equally in both groups. Liver analysis revealed increased triglyceride content accompanied by decreased levels of phosphorylated AMP-activated protein kinase and phosphorylated acetyl-CoA carboxylase in OVX animals. The elevated expression of gluconeogenic enzymes in OVX and OVX + estradiol rats was not associated with alterations in glucose tolerance test or in serum insulin but was coincident with higher glucose disposal during the pyruvate tolerance test. Although estradiol treatment prevented the ovariectomy-induced increase in body weight and hepatic triglyceride and cholesterol accumulation, it was not able to prevent increased gluconeogenesis. In conclusion, the disrupted liver glucose homeostasis after ovariectomy is neither caused by estradiol deficiency nor is related to increased body mass.


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