GROWTH FACTORS AND GINGIVAL FIBROSIS

描述(申请人提供)：牙龈过度生长的临床情况包括过量的牙龈组织，它会在口腔环境中造成干扰，并造成相关的全身并发症。例如，咀嚼受损和口腔卫生受损可能分别导致营养不良和口腔微生物负荷增加。牙龈过度生长主要有两种类型。药物引起的牙龈过度生长是由某些药物治疗引起的副作用。遗传性牙龈纤维瘤病与药物治疗无关。我们实验室最近的研究表明，苯妥英诱导的牙龈过度生长的病变是纤维化的，含有高水平的结缔组织生长因子(CTGF)，而硝苯地平和环孢菌素A诱导的病变纤维化较轻，CTGF水平较低，而非过度生长的组织中没有检测到CTGF。我们的体外研究表明，CTGF能刺激培养的人牙龈成纤维细胞中不溶性胶原的积聚。纤维化和CTGF水平在其他病理中也有关联。CTGF刺激的促进纤维化的分子和细胞活动尚不清楚。 本建议的目标是(1)利用一系列结构域特异性的CTGF单抗确定CTGF的功能结构域(S)，以刺激不溶性胶原的积累、增殖和凋亡；(2)确定苯妥英在培养的人牙龈成纤维细胞中增加CTGF的机制，重点关注前列腺素和cAMP代谢，以及苯妥英对与转化生长因子-β刺激的CTGF转录相关的信号转导通路的调控；(3)检测药物诱导的牙龈过度生长组织和遗传性人类牙龈过度生长组织中是否存在与体外探索的新的分子机制相关的标记：前列腺素受体、增殖标记和凋亡标记。这一实验方法利用体外培养的人牙龈成纤维细胞和人牙龈过度生长组织样本的生物测定，有望确定CTGF的生物活性区域，以及CTGF促进牙龈纤维化的机制。此外，这些发现可能与其他组织中发生的纤维化病理有关，这些组织中也包含高水平的CTGF。

DESCRIPTION (provided by applicant): The clinical condition of gingival overgrowth consists of excess gingival tissues that creates disturbances in the oral environment and creates related systemic complications. For example, impaired mastication and impaired oral hygiene can result, respectively, in poor nutrition and increased microbial load in the oral cavity. There are two principal classifications of gingival overgrowth. Drug-induced gingival overgrowth is a side effect resulting from therapy with certain pharmacologic agents. Hereditary gingival fibromatosis is unrelated to pharmacological therapies. Recent studies from our laboratory show that phenytoin-induced gingival overgrowth lesions are fibrotic and contain elevated levels of connective tissue growth factor (CTGF), whereas nifedipine- and cyclosporin A-induced lesions are less fibrotic and have low levels of CTGF, and non-overgrowth tissues have no detectable CTGF. Our in vitro studies show that CTGF stimulates insoluble collagen accumulation in cultured human gingival fibroblasts. Fibrosis and CTGF levels have been associated in other pathologies. The molecular and cellular activities stimulated by CTGF that promote fibrosis are not well understood. The goals of the current proposal are (1) to identify functional domain(s) of CTGF that stimulate insoluble collagen accumulation, proliferation and apoptosis by cultured human gingival fibroblasts utilizing a series of domain-specific monoclonal CTGF antibodies; (2) determine mechanisms by which phenytoin increases CTGF itself in cultured human gingival fibroblasts focusing on prostaglandin and CAMP metabolism, and on phenytoin modulation of signal transduction pathways related to TGF-beta stimulated CTGF transcription (3) assay human drug-induced gingival overgrowth tissues and hereditary human gingival overgrowth tissues for the presence of markers related to the novel molecular mechanisms explored in vitro: prostaglandin receptors, proliferation markers, and markers for apoptosis. This experimental approach that utilizes bioassays of human gingival fibroblasts in vitro, and human gingival overgrowth tissues samples is expected to identify biologically active domains of CTGF, and mechanisms by which CTGF promotes gingival fibrosis. In addition, these findings will likely have relevance to fibrotic pathologies that occur in other tissues that also contain elevated levels of CTGF.