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: 7745700
• 负责人: Eric J Culbertson
• 金额: $ 5.17万
• 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 2011-09-24
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7745700
• 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：7-11%的剖腹手术伤口发生切口疝，这是一项重大的医疗保健负担，每年的费用为25亿美元。我们的实验室发现，当剖腹手术伤口被机械破坏并形成切口疝时，会诱导成纤维细胞伤口愈合缺陷。肌肉和肌腱损伤的模型表明，像腹壁这样的承重组织依赖于机械应变来发出修复信号，据信这是通过激活伤口修复成纤维细胞的机械转导途径发生的。该建议是建立在这样的前提下，即承重组织中的伤口愈合严重依赖于成纤维细胞感知的机械应变。这一新概念挑战了“无张力”技术是最好的手术范例，并询问是否实际上需要负载力来发出腹壁伤口修复的信号。我们的目标是1。测试机械应变是否在体外刺激从破裂的外科剖腹手术伤口和疝分离的成纤维细胞中的伤口愈合活性，和2.以证实当在体外去除应变时，这些成纤维细胞丧失增殖和合成功能。使用已建立的大鼠疝模型，我们将培养来自未受伤对照的成纤维细胞。机械性完整、破裂和疝伤口。为了测试第一个目的，将这些培养的成纤维细胞进行循环和静态拉伸，并评估：机械应变和肌动蛋白应力纤维表达的显微形态学证据;对机械应变的增殖（PCNA）和合成成纤维细胞响应的测量;作为成纤维细胞分化的分子标志物的整合素和α-平滑肌肌动蛋白（aSMA）;以及在MAP激酶阻断后阻断成纤维细胞对应变信号的应答，支持这些体外修复细胞中机械转导途径的激活。第二个目的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。我们预期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，并对预防和修复剖腹手术伤口疝的策略产生影响。公共卫生相关性：在美国，切口疝形成率每年接近400，000例，发生在所有剖腹手术伤口的约11%中，在疝修补术中复发率为24-58%。这是一个巨大的卫生保健负担和患者发病率的重要原因。虽然“无张力”疝修补术的出现，被认为是标准的，降低了复发率，我们假设，一个适当的负载力是需要腹壁成纤维细胞愈合承重伤口，和“无张力”的方法可能会绕过腹壁修复的一个重要机制。