The interplay between active and passive mechanics in the aging bladder

老化膀胱中主动和被动力学之间的相互作用

• 批准号: 10827248
• 负责人: Sarah Calve
• 金额: $ 43.95万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-30 至 2025-09-29
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10827248
• 关键词: 3-Dimensional; Actomyosin; Adult; Affect; Age; Aging; Agreement; Behavior; Biological Assay; Biology; Biomechanics; Bladder; Bladder Dysfunction; Collagen; Computer Models; Contracts; Custom; Data; Development; Diabetes Mellitus; Disease; Elements; Etiology; Extracellular Matrix; Fiber; Finite Element Analysis; Functional disorder; Future; Generations; Human; Image Analysis; Lamina Propria; Light; Low Prevalence; Mass Spectrum Analysis; Measures; Mechanics; Mediating; Methodology; Methods; Modeling; Morphology; Multiple Sclerosis; Mus; Muscarinic Acetylcholine Receptor; Muscle Contraction; Obstruction; Parkinson Disease; Pathologic; Periodicity; Persons; Pharmacological Treatment; Physiological; Property; Proteomics; Protocols documentation; Relaxation; Research; Research Personnel; Residual state; Rest; Scheme; Signal Pathway; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Spinal cord injury; Spottings; Stretching; System; Techniques; Testing; Tissues; Tunica Adventitia; Urethra; Urinary Retention; Urination; Urine; Urothelium; Validation; Work; age effect; age related; aged; cholinergic; detrusor muscle; electric field; gain of function; improved; in vivo; insight; lower urinary tract symptoms; mechanical properties; model development; mouse model; multiphoton imaging; multiphoton microscopy; optogenetics; pressure; prevent; quantitative imaging; recruit; response; restoration; soft tissue

The prevalence of lower urinary tract symptoms (LUTS), such as contractile dysfunction and urinary retention, increases significantly with age and an estimated 2.6 billion people worldwide suffered from at least one LUTS in 2008. The aging human bladder has altered mechanical properties and increased residual urine volume. The detrusor is the smooth muscle that responsible for bladder contraction and is embedded in and surrounded by a wavy, collagen-rich extracellular matrix (ECM). The etiologies of many age-related LUTS in humans are tied to alterations in smooth muscle cell (SMC) contractility and signaling pathways, which has also been shown in mouse models of the aging bladder. However, the physical interactions that occur between SMCs and ECM are unknown and are likely a key factor in understanding the active and passive mechanics of bladder dysfunction with aging. The work described in this proposal will use optogenetics, multiphoton microscopy, and a custom testing system to develop an ex vivo methodology that incorporates concentric contraction into bladder mechanical testing. The proposed studies will be conducted by a team with complementary expertise in proteomics, ECM biology and soft tissue biomechanics (PI Calve), urinary bladder mechanics and mechanical testing (co-I Tuttle), and constitutive model development and finite element (FE) analysis (co-I Roccabianca). In Aim 1, the ability of detrusor contraction to restore the bladder ECM to the native empty organization will be tested. Two methods for inducing SMC contraction will be compared (i.e. optogenetic and cholinergic) to determine how effective light-mediated stimulation is in replicating cholinergic detrusor contraction using SM22- Cretg;ChR2(H134R)-EYFP mice. The morphological and mechanical data will be implemented in an FE model, that will be used to evaluate the importance of ECM organization on the mechanical response. Validation of our approach will increase agreement between in vivo and ex vivo testing conditions and uncover the effect of detrusor contraction on ECM organization. In Aim 2 we will test the hypothesis that remodeling of the ECM in the aging bladder inhibits the ability of the detrusor to adequately contract the tissue to the healthy resting configuration. Bladders from aged SM22-Cretg;ChR2(H134R)-EYFP mice will be tested ex vivo to study how aging affects ECM and SMC organization. Proteomics will be used to quantify how the ECM and muscarinic receptor abundance changes with aging. This data will be used to inform FE modeling to help resolve the effect of aging on tissue composition, ECM organization, and mechanics. Successful completion of this project will increase the fundamental understanding of bladder function gain insight into how this contraction-reorganization behavior is diminished in the aging bladder, which we hypothesize contributes to LUTS development and progression. The experimental methodology developed will be useful in evaluating bladder dysfunction in various diseases and open doors to new research into the functional effects of pharmacological treatments for LUTS.

下尿路症状（LUTS）的患病率，例如收缩功能障碍和尿潴留， 随着年龄的增长而显着增加，估计全球有 26 亿人至少患有一种 LUTS 2008 年。老化的人类膀胱已经改变了机械性能并增加了残余尿量。这 逼尿肌是负责膀胱收缩的平滑肌，嵌入并被膀胱包围。 波浪状、富含胶原蛋白的细胞外基质 (ECM)。人类许多与年龄相关的 LUTS 的病因与 平滑肌细胞 (SMC) 收缩性和信号通路的改变，这也已在 老化膀胱的小鼠模型。然而，SMC 和 ECM 之间发生的物理相互作用是 未知，可能是了解膀胱功能障碍的主动和被动机制的关键因素 随着衰老。本提案中描述的工作将使用光遗传学、多光子显微镜和定制的 测试系统，开发一种将同心收缩纳入膀胱的离体方法 机械测试。拟议的研究将由具有互补专业知识的团队进行 蛋白质组学、ECM 生物学和软组织生物力学 (PI Calve)、膀胱力学和力学 测试 (co-I Tuttle) 以及本构模型开发和有限元 (FE) 分析 (co-I Roccabianca)。 在目标 1 中，逼尿肌收缩将膀胱 ECM 恢复到原生空组织的能力 将受到测试。将比较两种诱导 SMC 收缩的方法（即光遗传学和胆碱能） 使用 SM22- 确定光介导的刺激在复制胆碱能逼尿肌收缩方面的效果如何 Cretg；ChR2(H134R)-EYFP 小鼠。形态和力学数据将在有限元模型中实现， 将用于评估 ECM 组织对机械响应的重要性。验证我们的 方法将增加体内和离体测试条件之间的一致性，并揭示 逼尿肌收缩对 ECM 组织的影响。在目标 2 中，我们将测试以下假设：在 老化的膀胱会抑制逼尿肌充分收缩组织以达到健康休息状态的能力 配置。来自老年 SM22-Cretg;ChR2(H134R)-EYFP 小鼠的膀胱将进行离体测试，以研究如何 衰老影响 ECM 和 SMC 组织。蛋白质组学将用于量化 ECM 和毒蕈碱如何 受体丰度随着年龄的增长而变化。该数据将用于为有限元建模提供信息，以帮助解决该影响 衰老对组织成分、ECM 组织和力学的影响。 该项目的成功完成将增加对膀胱功能的基本了解 深入了解这种收缩重组行为如何在老化的膀胱中减弱，我们 假设有助于 LUTS 的发展和进展。开发的实验方法将 可用于评估各种疾病中的膀胱功能障碍，并为新研究打开大门 药物治疗对 LUTS 的功能影响。