Role of the F-Bar Protein CIP4 in Cardiac Hypertrophy

F-Bar 蛋白 CIP4 在心脏肥大中的作用

• 批准号: 9024232
• 负责人: Michael Seth Kapiloff
• 金额: $ 38.38万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9024232
• 关键词: Adrenergic Agents; Adult; Amino Acids; Amyloid beta-Protein; Angiotensin II; Angiotensin II Receptor; Apoptosis; Binding; Binding Proteins; Biosensor; C-terminal; Calcineurin; Calmodulin; Cardiac; Cardiac Myocytes; Catalytic Domain; Catecholamines; Cations; Cessation of life; Chronic; Chronic stress; Complex; Cytoskeletal Proteins; Cytoskeleton; Dependovirus; Development; Diagnosis; Disease; Enzymes; Family; Fibrosis; Fluorescence Resonance Energy Transfer; G-Protein-Coupled Receptors; Gene Expression; Growth; Guanosine Triphosphate Phosphohydrolases; Heart; Heart Hypertrophy; Heart failure; Hypertrophy; In Vitro; Infusion procedures; Ion Channel; Isoenzymes; Knockout Mice; Light; Mediating; Membrane; Membrane Proteins; Modeling; Monomeric GTP-Binding Proteins; Mus; Muscle Cells; Myocardial; N-terminal; Neonatal; Neurosecretory Systems; PPP3CA gene; Pathologic; Peptides; Phenotype; Phospholipids; Phosphoric Monoester Hydrolases; Play; Prevention; Process; Proline-Rich Domain; Protein Isoforms; Protein Serine/Threonine Phosphatase; Proteins; Publications; RHO Effector Domain; Regimen; Regulation; Research; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Specificity; Structure; Substrate Specificity; Syndrome; TRIP10 gene; TRPC3 ion channel; Testing; Therapeutic; Ventricular; amphiphysin; calcineurin phosphatase; cardiogenesis; cdc42 GTP-Binding Protein; cell type; constriction; genetic regulatory protein; in vivo; interstitial; member; mortality; new therapeutic target; novel; polyproline; pressure; prevent; protein protein interaction; public health relevance; receptor; response; rho; scaffold; selective expression

 DESCRIPTION (provided by applicant): The cardiac response to chronic stress involves the activation of a signal transduction network that induces myocyte hypertrophy and that in disease promotes myocardial apoptosis and interstitial fibrosis contributing to the development of heart failure. The phosphatase calcineurin (CaN) plays a central role in these processes. In cardiac myocytes there are two different isoforms of the CaN catalytic subunit, Aα and Aβ, and yet only Aβ is required for myocyte hypertrophy. Because CaN isoforms have similar substrate specificity and share common binding partners, it is unclear why there would be functional differences between the isoenzymes. We recently performed a screen for CaNAβ-specific binding partners. One protein that bound CaNA specifically is CIP4, a member of the F-BAR family of membrane-associated proteins. With the exception of our recent publication showing that CIP4 is required for the hypertrophy of cultured neonatal ventricular myocytes, F-BAR proteins have not been studied in the heart. In this application, we test the hypothesis that by serving as a CaNAβ scaffold, CIP4 contributes to the regulation of cardiac myocyte hypertrophy. We propose that CIP4 binding co-localizes CaNAβ with upstream receptors, ion channels and/or other signaling molecules that specifically confer CaNAβ function in pathologic cardiac remodeling. Specific Aim 1: The Requirement for CIP4 in Cardiac Remodeling In Vivo. In light of our in vitro findings, we propose to characterize the cardiac phenotype of a new conditional, cardiac-specific CIP4 knock-out mouse. The mice will be studied both when unstressed and when subject to chronic transverse aortic constriction, β-adrenergic, and angiotensin II receptor stimulation. We anticipate that the CIP4 knock-out mouse will have relatively normal cardiac function when unstressed and will be protected from the cardiac remodeling induced by pressure overload and neuroendocrine stimulation. Specific Aim 2: Mechanisms underlying CIP4-CaNA signaling in myocytes. Using novel FRET biosensors that will detect Ca2+ and CaN activity at CIP4 complexes, we propose to study the regulation of CIP4-bound CaNAβ in cultured adult and neonatal myocytes. We will study the co-localization of CIP4 and CaNAβ in the myocyte and test whether, as in other cell types, CIP4 localization may be regulated by growth factor and G-protein coupled receptor stimulation and by Rho family GTPases. In addition, we will determine whether gene expression regulated by the CaN effectors NFATc and MEF2 requires CIP4 expression in vivo. Specific Aim 3: Therapeutic Disruption of CaNAβ Anchoring In Vivo. The central hypothesis of this application is that the unique role of CaNAβ in pathological myocyte hypertrophy is due to CaNAβ anchoring by specific scaffolds. We propose to express selectively in the cardiac myocyte anchoring disrupter peptides for CaNAβ in order to test whether disruption of CaNAβ anchoring can prevent pathological remodeling in response to long-term pressure overload and catecholamine infusion.

 描述（由申请方提供）：心脏对慢性应激的反应涉及信号转导网络的激活，该网络诱导肌细胞肥大，并在疾病中促进心肌细胞凋亡和间质纤维化，从而导致心力衰竭的发生。磷酸酶钙调神经磷酸酶（CaN）在这些过程中起着核心作用。在心肌细胞中，有两种不同的CaN催化亚基亚型，Aα和Aβ，但只有Aβ是心肌细胞肥大所必需的。由于CaN同工酶具有相似的底物特异性和共同的结合伴侣，因此尚不清楚为什么同工酶之间存在功能差异。我们最近进行了CaNAβ特异性结合伴侣的筛选。一种特异性结合CaNA的蛋白质是CIP 4，它是膜相关蛋白的F-BAR家族的成员。除了我们最近的出版物显示CIP 4是培养的新生儿心室肌细胞肥大所必需的外，尚未在心脏中研究F-BAR蛋白。在本申请中，我们测试了CIP 4作为CaNAβ支架有助于调节心肌细胞肥大的假设。我们提出CIP 4结合使CaNAβ与上游受体、离子通道和/或在病理性心脏重塑中特异性赋予CaNAβ功能的其他信号分子共定位。具体目标1：体内心脏重塑对CIP 4的需求。根据我们的体外研究结果，我们建议表征一种新的条件性心脏特异性CIP 4基因敲除小鼠的心脏表型。将在未应激时以及在经受慢性横向主动脉收缩、β-肾上腺素能和血管紧张素II受体刺激时研究小鼠。我们预期，CIP 4基因敲除小鼠在无应激时将具有相对正常的心脏功能，并且将免受压力超负荷和神经内分泌刺激诱导的心脏重构。具体目标2：肌细胞中CIP 4-CaNA信号传导的潜在机制。利用新型FRET生物传感器检测CIP 4复合物中Ca 2+和CaN活性，我们建议研究培养的成人和新生儿心肌细胞中CIP 4结合的CaNAβ的调节。我们将研究CIP 4和CaNAβ在肌细胞中的共定位，并测试CIP 4定位是否与在其他细胞类型中一样可能受到生长因子和G蛋白偶联受体刺激以及Rho家族GTP酶的调节。此外，我们将确定由CaN效应物NFATc和MEF 2调节的基因表达是否需要CIP 4在体内表达。具体目标3：体内CaNAβ转运的治疗性破坏。该应用的中心假设是CaNAβ在病理性肌细胞肥大中的独特作用是由于CaNAβ通过特定支架锚定。我们建议在心肌细胞中选择性地表达CaNAβ锚定破坏肽，以测试CaNAβ锚定的破坏是否可以防止响应于长期压力超负荷和儿茶酚胺输注的病理性重构。