A dual Ucp1 reporter mouse model for imaging and quantitation of brown and brite fat recruitment
A dual Ucp1 reporter mouse model for imaging and quantitation of brown and brite fat recruitment
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DOI：
10.1016/j.molmet.2018.11.009
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发表时间：
2019-02-01
影响因子：
8.1
通讯作者：
Klingenspor, Martin
中科院分区：
文献类型：
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作者：
Wang, Hui;Willershaeuser, Monja;Klingenspor, Martin
目的：棕色脂肪组织(BAT)通过解偶联蛋白1(UCP1)将营养能量转化为热量。在健康成人中发现功能性BAT，促进了寻找药物干预来招募和激活棕色脂肪作为治疗肥胖症和II型糖尿病的方法。这些努力需要体内模型来比较新化合物在相关生理环境中的疗效。方法：我们建立了一个由内源性Ucp1基因的调控元件驱动的表达萤火虫荧光素酶和近红外红色荧光蛋白(IRFP713)的转基因小鼠。结果：我们的详细鉴定表明，萤火虫荧光素酶活性真实地报告了内源性Ucp1基因的表达。IRFP713荧光信号在冷暴露小鼠肩关节间BAT区以等位基因剂量依赖的方式检测到。利用该报告小鼠模型，我们检测到雌性卵巢周围白色脂肪组织比雄性附属器Wat具有更高的褐变能力，这一点得到了分子和形态特征的进一步证实。原位成像在以前未被重视的股部肌肉旁的脂肪组织库中检测到强烈的荧光素酶活性信号，现在被用作股骨棕色脂肪组织。此外，通过生物发光成像筛选培养的脂肪细胞，发现选择性的盐诱导激酶抑制剂HG-9-91-01可以增加棕色和棕色脂肪细胞的Ucp1基因表达和线粒体呼吸。结论：在我们的小鼠模型中，萤火虫荧光素酶活性是Ucp1动态调节的真实报告。此外，通过iRFP713，我们能够以非侵入性的方式监测Ucp1的表达。(C)爱思唯尔股份有限公司出版的2018年。
Objectives: Brown adipose tissue (BAT) dissipates nutritional energy as heat through uncoupling protein 1 (UCP1). The discovery of functional BAT in healthy adult humans has promoted the search for pharmacological interventions to recruit and activate brown fat as a treatment of obesity and diabetes type II. These efforts require in vivo models to compare the efficacy of novel compounds in a relevant physiological context.Methods: We generated a knock-in mouse line expressing firefly luciferase and near-infrared red florescent protein (iRFP713) driven by the regulatory elements of the endogenous Ucp1 gene.Results: Our detailed characterization revealed that firefly luciferase activity faithfully reports endogenous Ucp1 gene expression in response to physiological and pharmacological stimuli. The iRFP713 fluorescence signal was detected in the interscapular BAT region of cold-exposed reporter mice in an allele-dosage dependent manner. Using this reporter mouse model, we detected a higher browning capacity in female peri-ovarian white adipose tissue compared to male epididymal WAT, which we further corroborated by molecular and morphological features. In situ imaging detected a strong luciferase activity signal in a previously unappreciated adipose tissue depot adjunct to the femoral muscle, now adopted as femoral brown adipose tissue. In addition, screening cultured adipocytes by bioluminescence imaging identified the selective Salt-Inducible Kinase inhibitor, HG-9-91-01, to increase Ucp1 gene expression and mitochondrial respiration in brown and brite adipocytes.Conclusions: In our mouse model, firefly luciferase activity serves as a bona fide reporter for dynamic regulation of Ucp1. In addition, by means of iRFP713 we are able to monitor Ucp1 expression in a non-invasive fashion. (C) 2018 Published by Elsevier GmbH.