Tuning Adipocyte Size and Obesity through SWELL1

通过 SWELL1 调节脂肪细胞大小和肥胖

• 批准号: 10649660
• 负责人: Rajan Sah
• 金额: $ 41.26万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10649660
• 关键词: Adipocytes; Adipose tissue; Anions; Biochemical; CRISPR screen; CRISPR/Cas technology; Cell membrane; Complex; Diabetes Mellitus; Diet; Disease; E protein; Endothelium; FRAP1 gene; Funding; GLUT 4 protein; Genes; Glucose Intolerance; Growth; Health; High Fat Diet; Human; Image; In Vitro; Incidence; Insulin; Insulin Resistance; Ion Channel; Knock-in Mouse; Knock-out; Knowledge; Label; Laboratories; Leucine; Leucine-Rich Repeat; Lysosomes; Mass Spectrum Analysis; Measures; Mediating; Metabolic; Metabolic syndrome; Methods; Mission; Modeling; Molecular; Mus; National Institute of Diabetes and Digestive and Kidney Diseases; Non-Insulin-Dependent Diabetes Mellitus; Nutrient; Obese Mice; Obesity; Organ; Overnutrition; PIK3CG gene; Pathway interactions; Patients; Population; Prediabetes syndrome; Proto-Oncogene Proteins c-akt; Publishing; Reagent; Research; Signal Pathway; Signal Transduction; Skeletal Muscle; Societies; Swelling; Testing; Therapeutic; Tissue Expansion; Tissue Sample; Tissues; Visceral; adipocyte biology; arm; defined contribution; detection of nutrient; experimental study; glucose uptake; growth factor receptor-bound protein 2; human tissue; in vivo; inflammatory marker; innovation; insulin secretion; insulin sensitivity; metabolic phenotype; mutant; novel; obesity prevention; obesity treatment; overexpression; patch clamp; protein expression; response; superresolution microscopy

Project Summary Healthy adipose tissue expansion is necessary for maintaining metabolic health in the setting of over-nutrition – a situation that is increasingly relevant in the US, as the incidence of obesity is estimated at 33% of the US population. Therefore, elucidating the fundamental nutrient sensing mechanisms that regulate adipocyte expansion is critical for understanding, and ultimately treating, the negative metabolic consequences of obesity. We previously identified Leucine Rich Repeat Containing 8A (LRRC8a or SWELL1), a newly discovered essential component of the volume-regulated anion channel (VRAC), as a novel volume-sensing regulator of both insulin sensitivity and insulin secretion. We and others find that SWELL1 activity and protein expression is reduced in metabolically unhealthy obese mice and humans – suggesting that reduced multi-organ SWELL1 activity/expression contributes to obesity-induced metabolic syndrome. Our group has biochemical, patch- clamp and imaging evidence that SWELL1 channel complexes are also expressed and functional in lysosomes. Given that lysosomes are signaling hubs that integrate nutrient sensing and AKT-mTOR signaling, we hypothesize that lysosomal SWELL1-LRRC8 channels participate in cellular nutrient sensing by activating in response to increases in intraluminal lysosomal leucine, and that this signaling mechanism is dysregulated in the setting of obesity-induced diabetes and insulin resistance. To test this hypothesis, we combine unique reagents and innovative methods from the Diwan (lysosomal signaling), Xu (lysosomal patch-clamp), and Held (mass spectrometry) laboratories, with our expertise in SWELL1 signaling, and access to human adipose tissue samples from highly phenotyped metabolically healthy and unhealthy humans (Klein laboratory). Our objective is to understand the mechanisms of plasma membrane and lysosomal SWELL1 (Lyso- SWELL1) nutrient sensing and how it is dysregulated in disease states, including obesity-induced glucose intolerance and insulin resistance. The rationale for these studies is that delineating the contribution of SWELL1 to lysosomal nutrient sensing and mTORC1 activation will advance our understanding of a fundamental cellular signaling mechanism and guide innovative therapeutic approaches for patients with prediabetes and diabetes. We propose the following AIMs: · AIM#1: Delineate the mechanisms of plasma membrane versus lysosomal SWELL1 signaling to AKT- AMPK-mTOR signaling in adipocytes · AIM#2: Examine the contribution of SWELL1 signaling in vivo in the setting of obesity in mice and humans The knowledge gained from these studies will delineate a novel lysosomal ion channel signaling pathway that regulates adipocyte growth and systemic dysglycemia in obesity, and inform therapeutic strategies currently underway to modulate SWELL1 signaling for the treatment of obesity-induced metabolic syndrome.

项目摘要 健康的脂肪组织扩张对于在过度营养的情况下保持代谢健康是必要的 在美国，这种情况越来越重要，因为肥胖事件估计为美国的33％ 人口。因此，阐明调节脂肪细胞的基本营养感应机制 扩张对于理解肥胖症的负面代谢后果至关重要。 我们先前鉴定出含有8a（lrrc8a或swell1）的亮氨酸富含量重复，这是一个新发现的 体积调节的阴离子通道（VRAC）的必需组成部分，是一种新型的体积感应调节剂 胰岛素敏感性和胰岛素分泌。我们和其他人发现Swell1活性和蛋白质表达是 在代谢不健康的肥胖小鼠和人类中减少了 - 表明多器官swell1减少了 活性/表达有助于肥胖引起的代谢综合征。我们的小组有生化，补丁 - 夹具和成像证据表明Swell1通道复合物也表达并在 溶酶体。鉴于溶酶体是整合营养感和Akt-MTOR信号传导的信号集线器， 我们假设通过 响应于腔内溶酶体亮氨酸的增加而激活，并且该信号传导机制 在肥胖诱导的糖尿病和胰岛素抵抗的情况下，失调。为了检验这一假设， 我们结合了Diwan（溶酶体信号传导）的独特试剂和创新方法（溶酶体） 贴片钳）和（质谱）实验室，具有我们在Swell1信号传导方面的专业知识，并访问 来自高度表型的代谢健康和不健康的人（klein）的人脂肪组织样品 实验室）。我们的目的是了解质膜和溶酶体Swell1的机制（lyso- Swell1）营养敏感性及其在疾病状态中的失调，包括肥胖诱导的葡萄糖 肠和胰岛素抵抗。这些研究的理由是描述了Swell1的贡献 溶酶体营养感和MTORC1激活将提高我们对基本细胞的理解 糖尿病前和糖尿病患者的信号传导机制和指导创新的治疗方法。 我们提出以下目标： ·目标＃1：描述质膜与溶酶体swell1信号传导的机制 脂肪细胞中的AMPK-MTOR信号传导 目标＃2：检查体内swell1信号传导在小鼠肥胖和 人类 从这些研究中获得的知识将描绘出一种新型的溶酶体离子通道信号传导途径 调节肥胖症中脂肪细胞的生长和全身性血糖症，并为治疗策略提供信息 正在调节Swell1信号传导以治疗肥胖诱导的代谢综合征。

项目成果

Isolation and Patch-Clamp of Primary Adipocytes.

原代脂肪细胞的分离和膜片钳。

• DOI: 10.1007/978-1-4939-6820-6_14
• 发表时间: 2017
• 期刊: Methods in molecular biology (Clifton, N.J.)
• 作者: Zhang,Yanhui;Tong,Dan;Mishra,Anil;Xie,Litao;Samuel,Isaac;Smith,JessicaK;Sah,Rajan
• 通讯作者: Sah,Rajan

SWELL signalling in adipocytes: can fat 'feel' fat?

• DOI: 10.1080/21623945.2019.1612223
• 发表时间: 2019-01-02
• 期刊: ADIPOCYTE
• 影响因子: 3.3
• 作者: Gunasekar, Susheel K.;Xie, Litao;Sah, Rajan
• 通讯作者: Sah, Rajan

The volume-regulated anion channel (LRRC8) in nodose neurons is sensitive to acidic pH.

• DOI: 10.1172/jci.insight.90632
• 发表时间: 2017-03
• 期刊: JCI insight
• 影响因子: 8
• 作者: Runping Wang;Yongjun Lu;Susheel K. Gunasekar;Yanhui Zhang;C. Benson;M. Chapleau;R. Sah;F. Abboud