Citrus aurantium and Rhodiola rosea in combination reduce visceral white adipose tissue and increase hypothalamic norepinephrine in a rat model of diet-induced obesity

Obesity is one of the most prevalent metabolic diseases in the Western world and correlates directly with insulin resistance, which may ultimately culminate in type 2 diabetes (T2D). We sought to ascertain whether the human metalloproteinase A Disintegrin and Metalloproteinase 19 (ADAM19) correlates with parameters of the metabolic syndrome in humans and mice. To determine the potential novel role of ADAM19 in the metabolic syndrome, we first conducted microarray studies on peripheral blood mononuclear cells from a well-characterised human cohort. Secondly, we examined the expression of ADAM19 in liver and gonadal white adipose tissue using an in vivo diet induced obesity mouse model. Finally, we investigated the effect of neutralising ADAM19 on diet induced weight gain, insulin resistance in vivo, and liver TNF-α levels. Significantly, we show that, in humans, ADAM19 strongly correlates with parameters of the metabolic syndrome, particularly BMI, relative fat, HOMA-IR, and triglycerides. Furthermore, we identified that ADAM19 expression was markedly increased in the liver and gonadal white adipose tissue of obese and T2D mice. Excitingly, we demonstrate in our diet induced obesity mouse model that neutralising ADAM19 therapy results in weight loss, improves insulin sensitivity, and reduces liver TNF-α levels. Our novel data suggest that ADAM19 is pro-obesogenic and enhances insulin resistance. Therefore, neutralisation of ADAM19 may be a potential therapeutic approach to treat obesity and T2D.

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L-Theanine Activates the Browning of White Adipose Tissue through the AMPK/α-Ketoglutarate/Prdm16 Axis and Ameliorates Diet-induced Obesity in Mice

10.2337/figshare.14414216 ◽

2021 ◽

Author(s):

Wan-Qiu Peng ◽

Gang Xiao ◽

Bai-Yu Li ◽

Ying-Ying Guo ◽

Liang Guo ◽

...

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

Intraperitoneal Administration ◽

Dna Demethylation ◽

Active Dna Demethylation ◽

Diet Induced Obesity ◽

Elevated Expression ◽

Obesity In Mice

L-Theanine is a nonprotein amino acid with much beneficial efficacy. We found that intraperitoneal treatment of the mice with L-Theanine(100mg/kg/day) enhanced adaptive thermogenesis and induced the browning of inguinal white adipose tissue (iWAT) with elevated expression of Prdm16, Ucp1 and other thermogenic genes. Meanwhile, administration of the mice with L-Theanine increased energy expenditure. In vitro studies indicated that L-Theanine induced the development of brown-like features in adipocytes. The shRNA-mediated depletion of Prdm16 blunted the role of L-Theanine in promoting the brown-like phenotypes in adipocytes and in the iWAT of mice. L-Theanine treatment enhanced AMPKα phosphorylation both in adipocytes and in iWAT. Knockdown of AMPKα ablolished L-Theanine-induced upregulation of Prdm16 and adipocytes browning. L-Theanine increased the α-ketoglutarate (α-KG) level in adipocytes, which may increase the transcription of Prdm16 by inducing active DNA demethylation on its promoter. AMPK activation was required for L-Theanine-induced increase of α-KG and DNA demethylation on Prdm16 promoter. Moreover, intraperitoneal administration with L-Theanine ameliorated obesity, improved glucose tolerance and insulin sensitivity, and reduced plasma triglyceride, total cholesterol and free fatty acid in the high fat diet-fed mice. Our results suggest a potential role of L-Theanine in combating diet-induced obesity in mice, which may involve L-Theanine-induced browning of white adipose tissue.

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