Gq-Coupled Receptors Inhibit PI 3-Kinase/Akt Signaling Pathway

Gq 偶联受体抑制 PI 3 激酶/Akt 信号通路

• 批准号: 8274809
• 负责人: RICHARD Z LIN
• 金额: $ 32.7万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8274809
• 关键词: 1-Phosphatidylinositol 3-Kinase; Ablation; Address; Adrenergic Agonists; Adverse effects; Affect; Affinity; Animal Model; Animals; Area; Attenuated; Binding; Biological; Breeding; Cancer Patient; Cell Survival; Clenbuterol; Clinical Treatment; Clinical Trials; Complex; Defect; Development; Disease; Embryo; Enzymes; Family; Fluorescence Spectroscopy; Funding; Gene Deletion; Genes; Goals; Growth; Growth Factor; Health; Hindlimb Suspension; Histology; Hospitalization; Human; Hypertrophy; Insulin; Knock-out; Knockout Mice; Knowledge; Lead; Lesion; Maintenance; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of pancreas; Measures; Medical; Molecular; Monitor; Mouse Strains; Mus; Muscle; Muscle Fibers; Muscular Atrophy; Organ; Pancreas; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Phosphatidylinositols; Phosphotransferases; Physical activity; Physiological; Play; Process; Protein Biosynthesis; Recovery; Research; Risk; Rodent; Role; Running; Scanning; Signal Pathway; Signal Transduction; Skeletal Muscle; Staging; System; Techniques; Testing; Tissues; Up-Regulation; Weight; cell growth; in utero; in vivo; insight; intraepithelial; mTOR protein; muscle form; muscle hypertrophy; pancreatic neoplasm; receptor coupling; research study; response; tumor; tumorigenesis; wasting

The goal of this proposal is to understand the role of class IA phosphatidylinositol 3‐kinase (PI3K) p110alpha and p110beta in regulating pathological and physiological cell growth in the pancreas and skeletal muscle. These two class IA PI3Ks are postulated to control protein synthesis and cell growth and survival. However, it has not been possible to investigate the biological roles of these enzymes using whole‐body gene deletion due to embryonic lethality. To overcome this experimental problem, mouse strains in which the two PI3K genes can be selectively deleted in specific tissues were generated. Using these animals, this proposal addresses four research questions. Aim 1 determines if pancreas‐specific ablation of p110alpha or p110beta blocks the formation of pancreatic tumors induced by constitutively active KrasG12D. Mice with pancreas‐specific expression of KrasG12D develop the full spectrum of malignant intraepithelial lesions commonly found in human pancreatic cancer. In addition, a fluorescence spectroscopy technique is used to measure the binding affinity between activated Kras and PI3K complexes containing p110alpha or p110beta, which might provide mechanistic insight into the phenotypes seen in the two knockout strains. Aim 2 investigates how insulin‐like growth factor‐1 (IGF‐1) activates mammalian target of rapamycin (mTOR) signaling in myotubes prepared from muscle‐specific p110alpha knockout mice. IGF‐1 activation of PI3K and then mTOR is thought to be a central regulatory signal for stimulating muscle growth. These studies pursue the molecular mechanisms that explain the unexpected finding of enhanced mTOR signaling in response to IGF‐1 in p110alpha‐null muscle, even though Akt activation is greatly reduced. Aim 3 investigates if ablation of p110alpha or p110beta affects skeletal muscle atrophy caused by hindlimb unloading or muscle regrowth following reambulation. This animal model mimics the process of muscle unloading and reloading that can occur during hospitalization. The degree of muscle atrophy and subsequent regrowth is monitored by microCT scans of muscle mass in the same animal. Aim 4 also uses microCT scans to determine if clenbuterol, a beta2 adrenergic receptor agonist known to promote muscle growth in humans and rodents, can still stimulate muscle hypertrophy in muscle‐specific p110alpha or p110beta knockout mice. Clenbuterol signaling to mTOR is also investigated in myotubes prepared from knockout mice. Knowledge gained from these experiments is important because drugs that inhibit PI3K are already being tested in clinical trials for the treatment of cancer. The identification of cancer patients who will respond to this targeted signal transduction therapy remains a major challenge. Moreover, systemic inhibition of PI3K runs the risk of adverse side effects if these enzymes play important roles in regulating organ function, including maintenance of muscle mass.

本提案的目的是了解IA类磷脂酰肌醇3激酶（PI3K）p110 α和p110 β在调节胰腺和骨骼肌的病理和生理细胞生长中的作用。假设这两种IA类PI3K控制蛋白质合成和细胞生长和存活。然而，由于胚胎致死性，不可能使用全身基因缺失来研究这些酶的生物学作用。为了克服这个实验问题，产生了其中两个PI3K基因可以在特定组织中选择性缺失的小鼠品系。利用这些动物，这项提议解决了四个研究问题。目的1确定胰腺特异性消融p110 α或p110 β是否阻断由组成性活性KrasG12D诱导的胰腺肿瘤的形成。胰腺特异性表达KrasG12D的小鼠发展出人类胰腺癌中常见的全谱恶性上皮内病变。此外，荧光光谱技术被用来测量激活的Kras和PI3K复合物含有p110 α或p110 β，这可能提供机械洞察表型中看到的两个敲除菌株之间的结合亲和力。目的2研究胰岛素样生长因子1（insulinlikegrowthfactor1，IGF 1）如何激活p110 α基因敲除小鼠肌管中的哺乳动物雷帕霉素靶蛋白（mammaliantargetofrapamycin，mTOR）信号通路。IGF 1激活PI3K，然后mTOR被认为是刺激肌肉生长的中心调节信号。这些研究追求的分子机制解释了在p110 α缺失肌肉中响应IGF 1增强mTOR信号传导的意外发现，即使Akt激活大大降低。目的3研究p110 α或p110 β的消融是否影响由后肢卸载或肌肉再生引起的骨骼肌萎缩。该动物模型模拟了住院期间可能发生的肌肉卸载和重新加载的过程。肌肉萎缩的程度和随后的再生长通过同一动物中肌肉质量的microCT扫描来监测。Aim 4还使用microCT扫描来确定克伦特罗（一种已知可促进人类和啮齿动物肌肉生长的β 2肾上腺素能受体激动剂）是否仍能刺激肌肉特异性p110 α或p110 β基因敲除小鼠的肌肉肥大。还在从敲除小鼠制备的肌管中研究了克伦特罗向mTOR的信号传导。从这些实验中获得的知识很重要，因为抑制PI3K的药物已经在临床试验中进行了癌症治疗的测试。识别对这种靶向信号转导治疗有反应的癌症患者仍然是一个重大挑战。此外，如果这些酶在调节器官功能（包括维持肌肉质量）中起重要作用，则对PI3K的全身性抑制有不良副作用的风险。

项目成果

Ablation of PI3K p110-α prevents high-fat diet-induced liver steatosis.

• DOI: 10.2337/db10-0869
• 发表时间: 2011-05
• 期刊: Diabetes
• 影响因子: 7.7
• 作者: Chattopadhyay M;Selinger ES;Ballou LM;Lin RZ
• 通讯作者: Lin RZ

Activation of Gαq in Cardiomyocytes Increases Vps34 Activity and Stimulates Autophagy.

• DOI: 10.1097/fjc.0000000000000461
• 发表时间: 2017-04
• 期刊: Journal of cardiovascular pharmacology
• 影响因子: 3
• 作者: Liu S;Jiang YP;Ballou LM;Zong WX;Lin RZ
• 通讯作者: Lin RZ

Rapamycin and mTOR kinase inhibitors.

• DOI: 10.1007/s12154-008-0003-5
• 发表时间: 2008-11-01
• 期刊: Journal of chemical biology
• 作者: Ballou, Lisa M;Lin, Richard Z
• 通讯作者: Lin, Richard Z

Dose ranging, expanded acute toxicity and safety pharmacology studies for intravenously administered functionalized graphene nanoparticle formulations.

• DOI: 10.1016/j.biomaterials.2014.04.066
• 发表时间: 2014-08
• 期刊: BIOMATERIALS
• 影响因子: 14
• 作者: Kanakia, Shruti;Toussaint, Jimmy D.;Chowdhury, Sayan Mullick;Tembulkar, Tanuf;Lee, Stephen;Jiang, Ya-Ping;Lin, Richard Z.;Shroyer, Kenneth R.;Moore, William;Sitharaman, Balaji
• 通讯作者: Sitharaman, Balaji

PI3Ks maintain the structural integrity of T-tubules in cardiac myocytes.

PI3K 维持心肌细胞中 T 管的结构完整性。

• DOI: 10.1371/journal.pone.0024404
• 发表时间: 2011
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Wu,Chia-YenC;Jia,Zhiheng;Wang,Wei;Ballou,LisaM;Jiang,Ya-Ping;Chen,Biyi;Mathias,RichardT;Cohen,IraS;Song,Long-Sheng;Entcheva,Emilia;Lin,RichardZ
• 通讯作者: Lin,RichardZ