Modulation of cyst growth in renal tissue from patients with autosomal dominant polycystic kidney disease in a human tissue-based 3D-in-vivo-model

在常染色体显性多囊肾病（ADPKD）中，双侧多个肾囊肿逐渐增大，导致肾功能下降。细胞增殖和液体分泌是囊肿增大的两个基本特征。目前，为了保护ADPKD患者的肾功能，仍需要抑制囊肿生长的治疗方法。我们小组最近的数据表明，三种不同的药物抑制剂可以阻止ADPKD小鼠模型中的囊肿生长，这些药物抑制剂是由TMEM16A （Anoctamin 1）介导的经上皮氯化物分泌。此外，我们已经证明缺氧和随后的缺氧诱导因子HIF-1α的激活促进了我们小鼠模型中的囊肿生长。接下来，我们的目标是将这些发现转化为临床应用和我们的患者。作为一个重要的中间步骤，我们需要测试最有希望的药物在人体组织中的功效。长期以来，我们在人体肿瘤研究领域拥有使用3D体内CAM（绒毛膜-尿囊膜）模型的专业知识，并建立了CAM模型来研究不同治疗方法（化疗、放疗）对肿瘤生长和血管生成的影响。除了肿瘤组织外，我们还成功地培养了人类ADPKD肾脏组织超过一周，并且我们能够在各种条件下监测囊肿的生长。除了动物和细胞培养模型外，该模型应该使我们能够回答以下问题：氯化物分泌抑制剂（如TMEM16A抑制剂，不同浓度）对CAM上人多囊肾组织囊肿生长的影响是什么？是否肾脏的不同部位或个体ADPKD患者对某些药物的反应不同？经批准的脯氨酸羟化酶抑制剂对CAM模型中囊肿生长的影响是什么？囊肿液成分对囊肿增大有影响吗？哪些因素影响液体成分？如何从药理学上改变液体成分？是否有可能在CAM上培养小鼠肾脏切片来研究肾脏（病理）生理学，从而提供多囊肾病以外的大量肾脏相关分析？通过这项工作，我们的目标是深入了解个体ADPKD患者对几种不同剂量药物的反应。在这个过程中，我们希望提高我们对ADPKD的病理机制的理解，并确定新的药理靶点。总之，新方法代表了创新治疗方法开发和测试的重要一步，随后有助于根据3r原则（“减少、替代、改进”）减少动物实验。

In autosomal dominant polycystic kidney disease (ADPKD) multiple bilateral renal cysts gradually enlarge, leading to a decline in renal function. Cell proliferation and fluid secretion are two essential characteristics of cyst enlargement. Currently, there is still a need for therapies that inhibit cyst growth in order to preserve renal function in patients suffering from ADPKD. Recent data from our group has shown that cyst growth in an ADPKD mouse model is prevented by three different pharmacological inhibitors of transepithelial chloride secretion mediated by TMEM16A (Anoctamin 1). Furthermore, we have shown that hypoxia and subsequent activation of the hypoxia-inducible factor HIF-1α promotes cyst growth in our mouse model.Next, we aim to translate these findings into clinical application and our patients. As an important intermediate step, we need to test the most promising drugs with regard to their efficacy in human tissue. We have long-standing expertise using the 3D in vivo CAM (chorioallantoic membrane) model in the area of human tumor research and have established the CAM model to study the effects of different therapies (chemotherapy, radiation therapy) on tumor growth and angiogenesis. In addition to tumor tissue, we were successful in cultivating human ADPKD kidney tissue for more than a week and we were able to monitor cyst growth under various conditions. The model should enable us – in addition to animal- and cell culture models – to answer the following questions:1. What are the effects of inhibitors of chloride secretion (e.g. TMEM16A inhibitors, different concentrations) on cyst growth of human polycystic kidney tissue on the CAM? Do different parts of the kidney or individual ADPKD patients respond differently to certain drugs?2. What are the consequences of approved prolyl-hydroxylase inhibitors on cyst growth in the CAM model?3. Does cyst fluid composition have an impact on cyst enlargement? Which factors influence fluid composition and how can it be changed pharmacologically?4. Is it possible to culture mouse kidney slices on the CAM to study kidney (patho-) physiology which would offer a plethora of kidney-related analyses beyond polycystic kidney disease? With the proposed work, we aim to gain insights into the response of individual ADPKD patients to several drugs with different dosages. During the course of this process we hope to improve our understanding of the pathological mechanisms involved in ADPKD and identify novel pharmacological targets. In summary, the new methodology represents an important step in the development and testing of innovative therapeutic approaches and subsequently contributes to the reduction of animal experiments according to the 3R-principles („reduce, replace, refine“).