Delineating cell type, mechanism, consequences and targeting of TGF-β2 expression in biliary liver disease

慢性肝病(CLD)是一个主要的健康问题，因为纤维化恶化进展为肝硬变和肝癌，这是全球第二致命的癌症类型。原发性硬化性胆管炎(PSC)是一种罕见的慢性自身免疫性肝病，可导致胆道系统的破坏。从持续性胆汁淤积对肝脏的损害开始，慢性门脉炎症和肝内外胆管附近的纤维化导致肝硬变重排，损害肝功能。这些PSC患者有10-15%的终生风险发展为胆管癌(CCA)。由于肝移植是迄今为止唯一的根治治疗机会，因此需要新的治疗方案来管理PSC。我们最近发现转化生长因子-β-2是PSC和CCA的特异性生物标志物和新的潜在治疗靶点。在这个项目中，我们的目标是更详细地描述转化生长因子-β2对前列腺癌慢性阻塞性肺疾病进展的影响，以证明未来在患者中进行临床试验的合理性。具体地说，我们将在ABCB4KO小鼠模型和人PSC标本中，以空间和细胞类型特异性的方式分析转化生长因子-β-2在肝脏中的表达调控和转化生长因子-β-2介导的信号转导。此外，我们将在疾病的早期、中期和晚期用转化生长因子-β2注射对野生型和ABCB4KO小鼠进行急慢性治疗，并描述转化生长因子-β2对实质和非实质细胞类型、对肝脏(病理)形态，特别是纤维化和炎症的影响。因此，我们将以最高分辨率深入了解转化生长因子-β-2在胆汁性肝损伤和疾病进展中的作用，包括区分转化生长因子-β-2和转化生长因子-β-1的作用。最后，我们将使用已建立的反义寡核苷酸在CCA患者衍生的器官组织中靶向转化生长因子-β-2的表达，作为初步测试，通过评估肿瘤生长、增殖活性、间质成分和化疗耐药性，对肿瘤进展产生潜在的有利影响。该项目的结果将提供对转化生长因子-β2生物学的基础的洞察，特别是在肝细胞以及胆汁淤积性肝病和PSC的背景下。数据还将有助于在PSC患者中建立转化生长因子-β-2指导的临床试验的决策。最后，我们希望看到靶向转化生长因子-β-2是治疗CCA患者的一种有前途的新方法的证据。

Chronic liver diseases (CLD) are a major health concern since fibrotic deteriorations progress to cirrhosis and liver cancer, the second deadliest cancer type worldwide. Primary sclerosing cholangitis (PSC) belongs to rare chronic autoimmune liver diseases that lead to the destruction of the biliary system. Starting with liver damage from persistent cholestasis, chronic portal inflammation and fibrosis in proximity of intrahepatic and extrahepatic bile ducts lead to cirrhotic rearrangements that compromise liver function. These PSC patients exhibit a 10–15% lifetime risk to develop cholangiocarcinoma (CCA).As liver transplantation is the only curative treatment opportunity so far, new therapeutic options are needed for the management of PSC. We recently identified TGF-β2 as specific biomarker and new potential treatment target for PSC, and possibly also for CCA. In this project, we aim to delineate in much detail the impact of TGF-β2 on CLD progression in PSC to justify a future clinical trial in patients. Specifically, we will analyse TGF-β2 expression regulation and TGF-β2 mediated signal transduction in the liver in a spatial and cell type specific manner during cholestatic disease progression in the ABCB4KO mouse model and in human PSC specimen. Furthermore, we will perform acute and chronic treatment of wildtype and ABCB4KO mice with TGF-β2 injection, at early intermediate and late disease stages, and depict the impact of TGF-β2 on parenchymal and non-parenchymal cell types, on liver (patho)morphology, and in particular fibrogenesis and inflammation. Thus, we will get insights on the role of TGF-β2 in the pathogenesis of biliary liver damage and disease progression in highest resolution, including a discrimination between TGF-β2 and TGF-β1 effects. Finally, we will target TGF-β2 expression using an established antisense oligonucleotide in CCA patient-derived organoids, as a preliminary test for a potential beneficial impact on tumor progression by estimating tumor growth, proliferative activity, stroma composition and chemoresistance. The project results will provide insight in the basics of TGF-β2 biology, specifically in liver cells and in the context of cholestatic liver disease and PSC. Data will also facilitate decision making in setting up a TGF-β2 directed clinical trial in PSC patients. Finally, we hope to see evidence that targeting TGF-β2 is a promising new treatment approach for patients with CCA.