Deciphering the role of a novel micropeptide in cardiac function and dysfunction

破译新型微肽在心脏功能和功能障碍中的作用

• 批准号: 10331296
• 负责人: RHONDA BASSEL-DUBY
• 金额: $ 54.5万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-16 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10331296
• 关键词: Actomyosin; Affinity; Binding; Ca(2+)-Transporting ATPase; Cardiac; Cardiac Myocytes; Cardiovascular Diseases; Cardiovascular Pathology; Cardiovascular Physiology; Cardiovascular system; Cell membrane; Cell physiology; Cultured Cells; Cytosol; Development; Dilated Cardiomyopathy; Disease; Dwarfism; Endothelium; Epithelial Cells; Family; Fostering; Functional disorder; Funding; Gene Delivery; Gene Transfer Techniques; Goals; Growth; Health; Heart; Heart Diseases; Heart failure; Homeostasis; Maintenance; Mediating; Membrane; Metabolic Diseases; Metabolism; Mission; Modeling; Mus; Muscle Cells; Muscle Contraction; Muscle relaxation phase; Myocardial dysfunction; Myopathy; Names; Open Reading Frames; Pathogenicity; Pathologic; Peptides; Play; Process; Protein Isoforms; Proteins; Public Health; Pump; RNA; RNA Sequences; Relaxation; Research; Role; Sarcomeres; Sarcoplasmic Reticulum; Second Messenger Systems; Signal Transduction; Signal Transduction Pathway; Stress; Striated Muscles; System; Testing; Therapeutic; Tissues; Transmembrane Domain; United States National Institutes of Health; Untranslated RNA; cell type; extracellular; genetic regulatory protein; heart function; in vivo; innovation; insight; loss of function; mouse model; novel; overexpression; phospholamban; prevent; protein protein interaction; response; reuptake; therapeutic target

Project Summary/Abstract Ca2+ controls cardiac function by acting as the primary regulator of the sarcomeric contractile machinery and as a second messenger in the signal transduction pathways that control cardiac growth, metabolism and pathological remodeling. Ca2+ handling in striated muscle is tightly regulated by Ca2+ pumps in the sarcoplasmic reticulum (SR) and plasma membranes that maintain intracellular Ca2+ levels ~10,000-fold lower than extracellular and SR concentrations. Ca2+ release from the SR membrane transiently increases Ca2+ levels in the cytosol, triggering actomyosin cross-bridge formation within the sarcomere to generate contractile force. Reuptake of Ca2+ into the SR by sarcoplasmic reticulum Ca2+-ATPase (SERCA) is necessary for muscle relaxation and restores SR Ca2+ levels for subsequent contraction-relaxation cycles. SERCA thus serves as a central regulator of cardiac function, as well as the pathogenic signaling cascades that drive heart disease. The activity of SERCA in the heart is modulated by phospholamban (PLN), a tiny peptide that interacts with SERCA in the SR membrane and diminishes Ca2+ pump activity. We discovered that a cardiac-specific RNA annotated as a long noncoding RNA actually encodes a previously unrecognized micropeptide, which we named DWORF (Dwarf Open Reading Frame). During the initial funding period we showed that DWORF has a higher binding affinity for SERCA than PLN and that DWORF overexpression mitigates the contractile dysfunction associated with PLN overexpression, substantiating its role as a potent activator of SERCA. Additionally, using a mouse model of dilated cardiomyopathy, we showed that DWORF overexpression restores cardiac function and prevents the pathological remodeling and Ca2+ dysregulation. Our results established DWORF as a potent activator of SERCA within the heart and as an attractive candidate for a heart failure therapeutic. Recently, we discovered two PLN-related micropeptides, referred to as Endoregulin (ELN) and Another-regulin (ALN), which associate with specific SERCA isoforms, suggesting their involvement in SERCA-dependent Ca2+ signaling. Collectively, we refer to this family of inhibitory SERCA micropeptides as Regulins. Our discovery of the DWORF- Regulin micropeptides provides new inroads into our understanding of the mechanisms involved in cardiac contractility and function and points to unexplored roles of micropeptides in the control of cardiovascular physiology and pathology. Our hypothesis is that DWORF-Regulin micropeptides are critical for cellular homeostasis and stress adaptation in disease, such that these micropeptides can serve as therapeutic targets for cardiovascular and metabolic diseases. The overall goals of this proposal are to define the functions and regulatory protein-protein interactions of DWORF and Regulins in the cardiovascular system and evaluate their therapeutic significance.

项目摘要/摘要 CA2+通过充当肌肉收缩机械的主要调节器来控制心脏功能 信号转导途径中的第二个使者控制心脏增长，代谢和 病理重塑。肌浆中的Ca2+泵紧紧地调节了条纹肌肉中的Ca2+处理 网状膜（SR）和质膜，维持细胞内Ca2+水平比低约10,000倍 细胞外和SR浓度。从SR膜释放的Ca2+瞬时增加了Ca2+水平 细胞质，触发肌动肌球蛋白在肉皮中产生收缩力。 肌质网Ca2+ -ATPase（SERCA）将Ca2+重新摄取是肌肉的必要 放松并恢复SR Ca2+水平，以进行随后的收缩 - 释放周期。 Serca因此充当 心脏功能的中央调节剂，以及驱动心脏病的致病信号传导级联反应。这 SERCA在心脏中的活性由磷团（PLN）调节，这是一种与SERCA相互作用的微小肽 在SR膜中，减少Ca2+泵活性。我们发现心脏特异性的RNA注释了 作为长的非编码RNA实际上编码了先前未识别的菌根，我们将其命名为Dworf （矮人开放阅读框）。在最初的资金期间，我们表明Dworf具有较高的结合 对SERCA的亲和力比PLN的亲和力，Dworf过表达减轻了收缩功能障碍 使用PLN过表达，证实了其作为SERCA有效激活剂的作用。另外，使用鼠标 扩张心肌病模型，我们表明Dworf过表达恢复了心脏功能和 防止病理重塑和CA2+失调。我们的结果确立了Dworf的强大 SERCA的激活剂在心脏内，并作为心力衰竭治疗的有吸引力的候选者。最近，我们 发现了两个与PLN相关的微肽，称为Endoregulin（ELN）和另一个常规蛋白（ALN），它们 与特定的SERCA同工型相关联，表明它们参与了SERCA依赖性Ca2+信号传导。 总的来说，我们将这个抑制性SERCA菌根家族称为调节蛋白。我们发现了Dworf- 调节蛋白菌根肽为我们对涉及心脏机制的理解提供了新的侵害 收缩力和功能，并指出少量肽在控制心血管中的作用 生理和病理学。我们的假设是Dworf-Regulin微肽对于细胞至关重要 疾病中的稳态和压力适应，使这些微肽可以用作治疗靶标 用于心血管和代谢疾病。该提案的总体目标是定义功能和 Dworf和调节蛋白在心血管系统中的调节蛋白 - 蛋白质相互作用并评估其 治疗意义。