FETAL WOUND HEALING

胎儿伤口愈合

• 批准号: 3326646
• 负责人: MICHAEL R HARRISON
• 金额: $ 21.13万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-12-01 至 1992-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3326646
• 关键词: amniotic fluid; carbohydrate metabolism; electron microscopy; embryo /fetus; extracellular matrix; fluorescent dye /probe; gel electrophoresis; gestational age; homologous transplantation; hyaluronate; immunocytochemistry; inflammation; keloid skin disorder; mature animal; microscopy; model design /development; radioimmunoassay; scars; sheep; skin; urinalysis; wound healing

The fetus responds to injury in a fashion fundamentally different from the adult: the process of mesenchymal regeneration proceeds in the absence of inflammation and scarring. We postulate that differences in the extracellular matrix, specifically the early appearance and prolonged maintenance of an environment rich in hyaluronic acid (HA), facilitates cell mobility, cell proliferation, and regeneration in fetal wounds. We propose to characterize the process of healing linear and open wounds in adult sheep and fetal lambs at various gestational ages. The fetal lamb is large enough to compare 1 cm linear incisions, 9 mm open wounds, and adjacent unwounded tissue, and to document the sequential appearance and disappearance of the cellular and extracellular components of repair using the following techniques: a) light microscopy including special stains, b) immunolocalization using fluorescent antibodies to identify cell markers and extracellular matrix components, c) electron microscopy, and d) localization of hyaluronic acid using a newly developed HA-binding protein stain. This model allows us to determine the effect of gestational age by comparing the healing process in adults and fetuses at 60, 100, and 130 days' gestation (term = 145 days). The fetal lamb model can be surgically manipulated to elucidate the effect of the fetal environment on healing: we will compare the process of healing skin and visceral wounds exposed to amniotic fluid to those excluded from amniotic fluid. We will also compare wounds made in adult (maternal) skin allografted onto the fetus at 60 days' gestation (the fetus is tolerant of skin grafts until 70 days) to wounds made on adjacent autografted fetal skin. Recent evidence suggests that prolonged maintenance of HA is central to fetal wound healing. We will compare HA deposition and metabolism in adult wounds and fetal wounds at various gestational ages. After documenting the morphology of HA deposition in our model, we will examine the biochemistry of HA deposition and metabolism by analyzing wound fluid (aspirated from wire mesh cylinders) as well as serum, urine and amniotic fluid using newly developed assays for HA synthesis, hyaluronidase activity, hyaluronidase inhibitors, and newly discovered HA stimulating and inhibiting factors. The devastating clinical problems associated with inflammation and scar formation may be alleviated by modulating the extracellular matrix components to provide a more fetal-like environment for adult tissue repair.

胎儿对损伤的反应方式与正常人完全不同。 成人：间充质再生的过程中进行的缺乏， 炎症和疤痕。 我们假设， 细胞外基质，特别是早期出现和延长 保持富含透明质酸（HA）的环境， 胎儿伤口中的细胞移动性、细胞增殖和再生。 我们建议描述线性和开放性伤口愈合的过程， 不同胎龄的成年绵羊和胎羊。 胎儿羔羊是 足以比较1 cm线性切口、9 mm开放性伤口和 邻近未受伤的组织，并记录连续的外观， 修复的细胞和细胞外成分消失， 以下技术：a）光学显微镜检查，包括特殊染色，B） 使用荧光抗体的免疫定位以鉴定细胞标记物 和细胞外基质成分，c）电子显微镜，和d） 利用新开发的HA结合蛋白定位透明质酸 污点 该模型允许我们通过以下方式确定胎龄的影响： 比较成人和胎儿在60、100和130岁时的愈合过程， 妊娠145天（足月）。 胎羊模型可以通过手术进行 操作以阐明胎儿环境对愈合的影响： 我们将比较暴露于 羊水与排除羊水者。 我们还将比较 将成人（母体）皮肤同种异体移植到60天时的胎儿上 妊娠（胎儿耐受皮肤移植直至70天）至伤口 在邻近的自体移植的胎儿皮肤上制作的。 最近的证据表明，HA的长期维持是 胎儿伤口愈合 我们将比较成人HA沉积和代谢 伤口和胎儿伤口。 在记录了 在我们的模型中HA沉积的形态，我们将检查生物化学 HA沉积和代谢，通过分析伤口液（从 以及血清、尿液和羊水， 开发了HA合成、透明质酸酶活性、透明质酸酶 抑制剂和新发现的HA刺激和抑制因子。 与炎症和瘢痕相关的毁灭性临床问题 可以通过调节细胞外基质 为成人组织提供更像胎儿的环境 修复.