2017-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/696870細胞外基質(ECM)和相關的蛋白質形成網絡以執行的機械、化學和生物功能,ECM 可與蛋白 分子和其本身有交互作用且與其下游信號，如TGFβ 有相互調控, TGFβs 有潛在型態及作用型態 存在, 與潛在型態有關的包含latent associated protein (LAP)及latent TGFβ binding protein (LTBP)。再者, 於罹患心肌病、糖尿病、腎臟病、癌症、肺纖維化、類風濕性關節炎的病人體內， 已發現 TGFβ 異常增加且與疾病嚴重程度相關; TGFβ 異常時, 將導致ECM 結構缺陷, 而 LTBPs 則是TGFβ 啟動的關鍵。故探索LTBPs 如何影響釋放及活化潛在型態的TGFβ 導致信號發生, 並 了解其對腎臟與心臟纖維化的調節, 是相當重要且有趣的。 本計劃要了解LTBPs 的生物功能與對TGFβ 釋放活化的調節，並探研其對腎纖維化及心臟纖 維化的病理機轉影響; 我們將利用腎纖維細胞及心肌細胞, 製造ltbp基因變異, 以了解LTBP於分 子生物上的調控, 包括對ECM 與TGFβ 傳遞途徑的影響; 再者, LTBP4 屬LTBP 家族, 而LTBP4 基因變異的病人有許多器官的纖維化, 包含肺臟, 腸胃,心血管及泌尿系統;故ltbp4S-/- , ltbp4-/-小 鼠及ltbp4 過多表現的基因小鼠是合適的動物模型, 再加上製造cardiorenal syndrome 或 renocardial syndrome 於小鼠, 並以小鼠超音波將協助了解小鼠心臟收縮, 並施以腎纖維化或心肌 梗塞手術, 及培養小鼠心肌細胞及腎臟纖維細胞, 利用這些動物模型配合所發現的LTBP 調控生 物基轉, 將更了解腎纖維化及心臟纖維化與兩者交相作用的機轉; 徹底從基因至蛋白質對 LTBP4 的研究, 將有助治療或緩解心臟衰竭及腎臟纖維化的疾病病程Extracellular matrix (ECM) and associated proteins form a complex network of numerous macromolecules, which performs abundant mechanical, chemical and biological functions. ECM molecules can interact with cells and with themselves as well as play an important role in the regulation of several processes, including TGFβ signaling pathways. Increased TGFβ levels and abnormal ECM networks have been found in patients with cardiomyopathy, diabetic nephropathy, cancer, lung fibrosis, rheumatoid arthritis and systemic sclerosis, in all cases correlating with disease severity. TGFβ pathway has been proved to be closely related to fibrosis in human tissues. TGFβs are secreted from cells as latent complexes, consisting of mature dimeric growth factor, latent associated protein (LAP) and latent TGFβ binding protein (LTBP). The latent complex needs subsequently to be activated and this complex is secreted in a specific and targeted manner. Dysregulation of TGFβ signaling results in the ECM defects, whereas LTBPs are crucial for activation of TGFβ. Extensive evidences have demonstrated that increased TGFβ is correlated with the progression of renal failure and cardiac failure. It will be interesting to understand the contribution from LTBPs to the release and activation of TGFβ in renal fibrosis and cardiac fibrosis. The major goal for this proposal is to investigate the biological functions of the latent transforming growth factor-beta-binding proteins (LTBPs) and identify their pathophysiological effects in renal fibrosis and cardiac dysfunction. We will start from to understand the role of LTBPs in TGFβ pathway in vitro and understand the functions of LTBPs in knockout and overexpression mice in order to investigate the crosstalk between renal and cardiac dysfunction in vivo. TGFβ is related to development of renal fibrosis and cardiac fibrosis. The cardiac and renal interaction is a crucial entity addressed for years. The interconnetion is an attractive platform to understand the molecular and clinical pathogenetic piplines. Patients with renal impairment have high prevalence of cardiac dysfunction, whereas patients with cardiac failure present renal failure frequently. Therefore, in this proposal, we are going to understand more about cardiorenal syndrome or renocardial syndrome by attempting to elucidate how LTBPs may mediate TGFβ releasing and activation in fibrotic tissues. In vitro, we will use pairwise knockdown experiments to study possible functional overlaps between LTBP family members. Mutant renal fibrosis and cardiomyocytes are used to study the molecular mechanisms of LTBP action in ECM assembly and growth factor signaling and TGFβ receptors. Moreover, in human, LTBP4 deficiency causes multiple systemic manifestation including pulmonary, gastrointestinal, cardiovascular and urinary abnormalities. Thus, ltbp4S-/- , ltbp4-/- and ltbp4 overexpression mice will be our relevant animal models to investigate the significance of LTBP4 in the pathophysiology of cardiac fibrosis and renal fibrosis. Mice with cardiorenal syndrome and renocardial syndrome are another useful tools to help us understand the interaction between heart and kidney in fibrosis models. To study thoroughly about LTBP4 from gene to protein levels will be helpful to develop the therapeutic reagents for several other systemic diseases with public health concerns, such as renal failure and cardiac failure.