Anti-UCP1 (aa 232-267) polyclonal antibody

Background: Although polyphenol-rich cranberry extracts reportedly have an antiobesity effect, the exact reason for this remains unclear. Objectives: In light of the reported health benefits of the polyphenolic compounds in cranberry, we investigated the effects and mechanism of a cranberry polyphenolic extract (CPE) in high-fat diet (HFD)-fed obese mice. Methods: The distributions of individual CPE compounds were characterized by HPLC fingerprinting. Male C57BL/6J mice (4 wk old) were fed for 16 wk normal diet (ND, 10% fat energy) or HFD (60% fat energy) with or without 0.75% CPE in drinking water (HFD + CPE). Body and adipose depot weights, indices of glucose metabolism, energy expenditure (EE), and expression of genes related to brown adipose tissue (BAT) thermogenesis, and inguinal/epididymal white adipose tissue (iWAT/eWAT) browning were measured. Results: After 16 wk, the body weight was 22.5% lower in the CPE-treated mice than in the HFD group but remained 17.9% higher than in the ND group. CPE treatment significantly increased EE compared with that of the ND and HFD groups. The elevated EE was linked with BAT thermogenesis, and iWAT/eWAT browning, shown by the induction of thermogenic genes, especially uncoupling protein 1 (Ucp1), and browning-related genes, including Cd137, a member of the tumor necrosis factor receptor superfamily (Tnfrsf9). The mRNA expression and abundance of uncoupling protein 1 in BAT of CPE-fed mice were 5.78 and 1.47 times higher than in the HFD group, and 0.61 and 1.12 times higher than in the ND group, respectively. Cd137 gene expression in iWAT and eWAT of CPE-fed mice were 2.35 and 3.13 times higher than in the HFD group, and 0.84 and 1.39 times higher than in the ND group, respectively. Conclusions: Dietary CPE reduced but did not normalize HFD-induced body weight gain in male C57BL/6J mice, possibly by affecting energy metabolism.

Obesity and type 2 diabetes (T2D) are both complicated endocrine disorders resulting from an interaction between multiple predisposing genes and environmental triggers, while diet and exercise have key influence on metabolic disorders. Previous reports demonstrated that 2-aminoadipic acid (2-AAA), an intermediate metabolite of lysine metabolism, could modulate insulin secretion and predict T2D, suggesting the role of 2-AAA in glycolipid metabolism. Here, we showed that treatment of diet-induced obesity (DIO) mice with 2-AAA significantly reduced body weight, decreased fat accumulation and lowered fasting glucose. Furthermore, Dhtkd1(-/-) mice, in which the substrate of DHTKD1 2-AAA increased to a significant high level, were resistant to DIO and obesity-related insulin resistance. Further study showed that 2-AAA induced higher energy expenditure due to increased adipocyte thermogenesis via upregulating PGC1 alpha and UCP1 mediated by beta 3AR activation, and stimulated lipolysis depending on enhanced expression of hormone-sensitive lipase (HSL) through activating beta 3AR signaling. Moreover, 2-AAA could alleviate the diabetic symptoms of db/db mice. Our data showed that 2-AAA played an important role in regulating glycolipid metabolism independent of diet and exercise, implying that improving the level of 2-MA in vivo could be developed as a strategy in the treatment of obesity or diabetes.