Role of mechanical strain in incisional hernia fibroblast function.

机械应变在切口疝成纤维细胞功能中的作用。

• 批准号: 8015570
• 负责人: Eric J Culbertson
• 金额: $ 4.31万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-25 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8015570
• 关键词: Actins; Cells; Defect; Fibroblasts; Healed; Healthcare; Hernia; In Vitro; Integrins; Laboratory Finding; Laparotomy; Measurement; Measures; Mechanics; Microscopic; Mitogen-Activated Protein Kinases; Modeling; Morbidity - disease rate; Muscle; Operative Surgical Procedures; Outcome; Pathway interactions; Patients; Prevention strategy; Rattus; Recurrence; Role; Signal Transduction; Smooth Muscle Actin Staining Method; Stress Fibers; Stretching; Techniques; Tendon Injuries; Testing; Tissues; Weight-Bearing state; Wound Healing; abdominal wall; care burden; cost; healing; molecular marker; public health relevance; repaired; response; wound

DESCRIPTION (provided by applicant): Description: Incisional hernias occur in 7-11% of laparotomy wounds, a substantial health care burden with an annual cost of $2.5 billion. Our laboratory found that a fibroblast wound .healing defect is induced when laparotomy wounds are mechanically disrupted and form incisional hernias. Models of muscle and tendon injury suggest that load-bearing tissues like the abdominal wall are dependent on mechanical strain to signal repair, believed to occur through mechano-transduction pathways that activate wound repair fibroblasts. This proposal is founded on the premise that wound healing in load-bearing tissues is critically dependent on the mechanical strain sensed by fibroblasts. This new concept challenges the surgical paradigm that "tension-free" techniques are best and asks whether a load-force is in fact required to signal abdominal wall wound repair. We aim 1. to test whether mechanical strain In vitro stimulates wound healing activity in fibroblasts isolated from disrupted surgical laparotomy wounds and hernias, and 2. to confirm that these fibroblasts lose proliferative and synthetic function when strain is removed in vitro. Using an established rat hernia model, we will culture fibroblasts from unwounded controls. Mechanically Intact, Disrupted and Hernia wounds. To test the first aim, these cultured fibroblasts will be subjected to cyclic and static stretch, and assessed for: microscopic morphological evidence of mechanical strain and actin stress fiber expression; measurement of the proliferative (PCNA) and synthetic fibroblast response to mechanical strain; integrin and o-smooth muscle actin (aSMA) as molecular markers for fibroblast differentiation; and blockade of fibroblast response to strain signals following MAP kinase blockade supporting activation of a mechanotransduction pathway in these repair cells in vitro. The second aim will be tested by culturing the above groups under constant strain and measuring the effect of removing this strain signal on the same outcomes. We anticipate our findings will clarify the role of mechanical strain in fibroblast proliferation, with implications for strategies for prevention and repair of laparotomy wound hernias. PUBLIC HEALTH RELEVANCE: The rate of incisional hernia formation in the U.S. approaches 400,000 yearly, occurring in approximately 11 % of all laparotomy wounds, with reoccurrences in 24-58% of hernia repairs. This is a substantial health care burden and a significant cause of patient morbidity. Although the advent of the "tension-free" approach to hernia repair, considered the standard, has reduced recurrence rates, we hypothesize that an appropriate load-force is required for abdominal wall fibroblasts to heal the load-bearing wound, and "tension-free" approaches may circumvent an important mechanism for abdominal wall repair.

描述（由申请人提供）：描述：切口疝发生在剖腹手术伤口的7-11%中，这是一个巨大的医疗负担，每年的成本为25亿美元。我们实验室发现了一个成纤维细胞伤口。当剖腹手术伤口被机械破坏而形成切口疝时，会引起愈合缺陷。肌肉和肌腱损伤模型表明，像腹壁这样的承重组织依赖机械应变来进行信号修复，这被认为是通过激活伤口修复成纤维细胞的机械转导途径发生的。这一建议是建立在伤口愈合的前提下，在承重组织是严重依赖于机械应变感知成纤维细胞。这个新概念挑战了“无张力”技术最好的外科范式，并提出了一个问题，即腹壁伤口修复是否实际上需要负载力。我们的目标是1。1 .体外机械应变是否能刺激剖腹手术伤口和疝分离成纤维细胞的伤口愈合活性；证实这些成纤维细胞在体外培养时失去增殖和合成功能。使用已建立的大鼠疝模型，我们将培养未受伤对照的成纤维细胞。机械完整，断裂和疝伤。为了验证第一个目标，这些培养成纤维细胞将受到循环和静态拉伸，并评估：机械应变和肌动蛋白应力纤维表达的微观形态学证据；测定增殖细胞（PCNA）和合成成纤维细胞对机械应变的反应；整合素和o-平滑肌肌动蛋白（aSMA）作为成纤维细胞分化的分子标记；在这些修复细胞中，MAP激酶阻断支持机械转导通路激活后，成纤维细胞对应变信号的反应被阻断。第二个目标将通过在恒定应变下培养上述组，并测量去除该应变信号对相同结果的影响来测试。我们期望我们的研究结果将阐明机械应变在成纤维细胞增殖中的作用，对预防和修复剖腹切口疝的策略具有指导意义。公共卫生相关性：在美国，切口疝的发生率每年接近40万，约占所有剖腹手术伤口的11%，在疝修复中复发率为24-58%。这是一个巨大的卫生保健负担，也是患者发病的一个重要原因。虽然“无张力”入路的出现被认为是标准的疝气修复方法，降低了复发率，但我们假设腹壁成纤维细胞需要适当的负荷力来愈合负重伤口，“无张力”入路可能绕过了腹壁修复的重要机制。