Growth Factor Treatment for Aged Vocal Folds

描述(申请人提供)：发音障碍在老年人中很常见，对沟通和生活质量有重大影响。与年龄相关的发音困难被归因于细胞外基质周转的正常平衡的破坏。具体地说，蛋白质的合成和降解过程变得不那么有效，导致老化声带内胶原和弹性蛋白沉积的质和量的变化。我们的初步研究还发现，透明质酸合成酶-1、-2和-3的表达存在缺陷，这些基因编码透明质酸，透明质酸是细胞外基质的重要组成部分，也是调节组织重塑的关键因素。不幸的是，对老年声带的普遍治疗只是暂时的间隙填充，而没有解决细胞外基质基因表达的潜在变化。我们的长期目标是开发针对基因表达介导的老年声带合成和降解的治疗方法。这项R21探索性和发育性研究的目的是探索使用生长因子来恢复老年声带细胞外基质成分之间的微妙平衡。这些生长因子疗法目前正在我们实验室进行重组和提炼，并有可能用于治疗声带细胞外基质的各种疾病。在这个为期两年的R21项目期间，我们将重点研究重组人肝细胞生长因子(RhHGF)，以促进老年声带的周转。我们提供了初步的数据，证明了重组人肝细胞生长因子可以在体内使用特定环境(声带损伤)刺激细胞外基质的合成，根据我们之前的研究，我们知道细胞外透明质酸会减少。然后，我们展示了编码透明质酸和其他细胞外基质的基因在老年声带中表达减少的数据，并为探索利用重组人肝细胞生长因子靶向老年声带的合成和降解提供了基础。我们推测：1)重组人肝细胞生长因子通过诱导透明质酸合成酶编码基因上调老年声带细胞外透明质酸水平。我们进一步假设：2)重组人肝细胞生长因子通过上调基质金属蛋白酶和抑制金属蛋白酶组织抑制因子基因的表达，下调老年声带中的胶原和弹性蛋白的表达。我们将使用前瞻性的假对照动物设计来验证我们的假设，通过实时聚合酶链式反应研究重组人肝细胞生长因子对老年声带基因表达的影响，使用高效液相色谱和酶联免疫吸附分析直接定量组织基质，并使用免疫组织化学证实空间变化。公共卫生相关性发音障碍在老年人中很常见，并对沟通和生活质量产生重大影响。与年龄相关的发音困难被归因于细胞外基质周转的正常平衡的破坏。本研究的目的是探索使用生长因子来恢复老年声带细胞外基质成分之间的微妙平衡。

DESCRIPTION (provided by applicant): Voice disorders are common in the elderly and have a significant impact on communication and quality of life. Age-related dysphonia has been attributed to a disruption in the normal balance of extracellular matrix turnover. Specifically, the process of protein synthesis and degradation becomes less efficient, resulting in both qualitative and quantitative changes in the deposition of collagen and elastin within the aged vocal fold. Our preliminary studies have also revealed deficiencies in the expression of hyaluronan synthase -1, -2, and -3, genes that code for hyaluronan, an important component of the extracellular matrix and key factor in the regulation of tissue remodeling. Unfortunately, prevailing treatments for the aged vocal fold serve as temporary space fillers, without addressing underlying changes in extracellular matrix gene expression. Our long-term goal is to develop treatments that target gene expression mediated synthesis and degradation of the aged vocal fold. The goal of this R21 exploratory and developmental research is to explore the use of growth factors for restoring the delicate balance among extracellular matrix components in the aged vocal fold. These growth factor treatments are currently being reconstituted and refined in our laboratory, and have imminent potential for the treatment of various disorders of the vocal fold extracellular matrix. During this two- year R21 project period, we will focus on recombinant human hepatocyte growth factor (rhHGF) for enhancing turnover of the aged vocal fold. We provide preliminary data demonstrating proof of concept that rhHGF can be used to stimulate synthesis of the extracellular matrix in-vivo using a setting (vocal fold injury), where we know extracellular hyaluronan to be reduced from our previous studies. We then present data showing reduced expression for genes coding hyaluronan and other extracellular matrices in the aged vocal fold, and provide a foundation from which to explore the use of rhHGF to target synthesis and degradation of the aged vocal fold. We hypothesize that: 1) rhHGF upregulates extracellular hyaluronan in the aged vocal fold via induction of genes coding hyaluronan synthase. We further hypothesize that: 2) rhHGF downregulates collagens and elastin in the aged vocal fold through upregulation of matrix metalloproteinase and suppression of tissue inhibitor of metalloproteinase gene expression. We will test our hypotheses using a prospective, sham-controlled animal design to investigate rhHGF treatment of the aged-vocal fold on gene expression using real-time polymerase chain reaction, direct quantification of tissue matrix using high performance liquid chromatography and enzyme-linked immunosorbent assays, and confirmation of spatial changes using immunohistochemistry. PUBLIC HEALTH RELEVANCE Voice disorders are common in the elderly and have a significant impact on communication and quality of life. Age-related dysphonia has been attributed to a disruption in the normal balance of extracellular matrix turnover. The goal of this research is to explore the use of growth factors for restoring the delicate balance among extracellular matrix components in the aged vocal fold.