2020-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/683168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，亦有證據 fibulin 與LTBP的結合與交互作用可以穩固間質纖維的排列。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, 及對腎心症的影響，是相當重要且有趣的。本計劃要了解LTBPs 的生物功能與對TGFβ釋放活化的調節及相關 fibulin交互作用的機制, 並探研其對腎纖維化及心臟纖維化的病理機轉影響; 我們將利用腎近端小管細胞及心肌細胞, 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/fibrillin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; 故誘導型多功能幹細胞(Induced pluripotent stem cell) 平台是一個很適當了解ltbp4 突變心肌細胞的平台，再加上ltbp4S-/- 小鼠及腎臟特定ltbp4 基因破壞小鼠及心臟特定ltbp4 基因破壞小鼠是合適的動物模型, 進而製造腎心症模型於小鼠, 並以小鼠超音波將協助了解小鼠心臟功能, 藉由施以腎纖維化或心肌梗塞手術, 及了解受傷組織的間質蛋白質訊息傳導的變異, 利用這些動物模型配合所發現的LTBP及其相關的 fibulin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 to be related to fibrosis in human tissues. Dysregulation of TGFβ signaling results in the ECM defects, whereas LTBPs are crucial for activation of TGFβ and associated FBNs have been proved to stabilize the structure of ECM structure. 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 and associated FBNs to the release and activation of TGFβ in cardiorenal and renocardial syndrome. The major goal for this proposal is to investigate the biological functions of the latent transforming growth factor-beta-binding proteins (LTBPs) and FBNs and identify their pathophysiological effects in renal fibrosis and cardiac dysfunction. Our preliminary data suggested up-regulation of renal LTBP4 in CKD patients. We will start from to understand the role of LTBPs in TGFβ pathway in vitro and understand the functions of LTBP4 in knockout mice and conditional knock out mice in order to investigate the crosstalk between renal and cardiac dysfunction in vivo. Human induced pluripotent stem cell-derived cardiomyocytes provide a fantastic platform to understand the impact of LTBP4 on cardiomyocytes. In addition, the interaction between kidney and hear is an attractive entity 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, 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, human proximal tubules will served as a nice a start because of up-regulated LTBP4 expression had been noted in peri-proximal tubule areas. We will create mutant renal proximal tubules and cardiomyocytes to study the molecular mechanisms of LTBP action and associated Fibulins 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-/- mice is the relevant animal model to investigate the significance of LTBP4 in the pathophysiology of cardiac fibrosis and renal fibrosis. Moreover, to avoid the perinatal lethality seen in systemic ltbp4-null mice, cardiac-specific and renal-specific ltbp4 conditional knockout mice will be bred. Mice with cardiorenal syndrome and renocardial syndrome are other useful tools to help us understand the interaction between heart and kidney in fibrosis models.To study thoroughly about LTBP4 and fibulins 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.