Investigations of murine and human cells bearing loss-of-function mutations in ciliopathy genes and of ciliopathy patient samples to evaluate autophagy and the proteasome as potential targets for a curative therapy of ciliopathies.

初级纤毛是小的细胞质突起，几乎在每个脊椎动物的细胞中都可以检测到。它们在几个信号级联的介导中起着至关重要的作用，从而在胚胎发育和成体组织稳态中发挥重要作用。初级纤毛由三个亚室组成：基体，过渡区（TZ）和轴丝。TZ控制纤毛蛋白质的输入和输出，从而调节纤毛发生和纤毛功能。纤毛功能的破坏导致许多严重的人类疾病，总结为纤毛病。通常，纤毛病是基于TZ蛋白编码基因的突变。由于没有治愈性治疗纤毛病变，巨大的努力，以了解这些疾病的分子机制。最近的研究表明，TZ蛋白RPGRIP 1 L（Retinitis Pigmentosa GTlymphocyte Regulator Interacting Protein 1 Like）在TZ内发挥多种功能，其突变导致人类严重的睫状体病。它调节小鼠的纤毛蛋白酶体，从而积极控制纤毛基部的蛋白酶体活性。此外，它以积极的方式调节小鼠的自噬。如果人类纤毛疾病的症状也是由这些蛋白质降解过程的功能缺陷引起的，那么蛋白酶体活性和自噬活性的激活可能是一种有希望的治疗方法。在这方面，我将检测RPGRIP 1 L突变的人细胞（HEK 293，人iPS）或人组织是否表现出蛋白酶体和/或自噬活性降低。如果是这样的话，我将尝试通过应用蛋白酶体和/或自噬激活药物来挽救这些活动。此外，我将分析其他基因编码TZ蛋白（Nphp 1，Nphp 4，Nphp 6和Tctn 1）的蛋白酶体和自噬活性的突变的影响。如果这些细胞（MEF，NIH 3 T3）显示出降低的蛋白酶体和/或自噬活性，则将用蛋白酶体和/或自噬活化剂处理它们。最后，我的工作将评估是否以及在多大程度上用蛋白酶体和/或自噬激活药物治疗纤毛病是一个有前途的未来策略。因此，我的分析可以为临床试验的设计奠定基础，在临床试验中，患者可以用蛋白酶体和/或自噬激活药物进行治疗。

Primary cilia are small cytoplasmic protrusions detectable at nearly every vertebrates’ cell. They are crucially involved in the mediation of several signaling cascades and thereby play an essential role in embryonic development and adult tissue homeostasis. Primary cilia consist of three sub compartments: the basal body, the transition zone (TZ) and the axoneme. The TZ controls the ciliary import and export of proteins and thereby regulates ciliogenesis and ciliary function. Disruption of ciliary function leads to numerous severe human diseases summarised as ciliopathies. Often, ciliopathies are based on mutations in genes encoding TZ proteins. Since there is no curative treatment of ciliopathies, great efforts are made to understand the molecular mechanisms underlying these diseases. Recent studies have shown that the TZ protein RPGRIP1L (Retinitis Pigmentosa GTPase Regulator Interacting Protein 1 Like), whose mutations lead to severe ciliopathies in human, exerts multiple functions within the TZ. It regulates the ciliary proteasome in mice and thereby positively controls the proteasomal activity at the ciliary base. In addition, it regulates autophagy in mice in a positive manner. If symptoms of ciliopathies in human are also caused by functional defects of these protein degradation processes, an activation of proteasomal activity and autophagic activity might be a promising therapeutic approach. In this regard, I will test if human cells (HEK293, human iPS) or human tissues with a mutation in RPGRIP1L, exhibit a reduced proteasomal and/or autophagic activity. And, if so, I will try to rescue these activities by applying proteasome and/or autophagy activating drugs. In addition, I will analyse the effect of mutations of other genes encoding TZ proteins (Nphp1, Nphp4, Nphp6 and Tctn1) in terms of proteasomal and autophagic activity. If these cells (MEFs, NIH3T3) show a reduced proteasomal and/or autophagic activity they will be treated with proteasome and/or autophagic activators. At the end, my work will evaluate if and in what extent a treatment of ciliopathies with proteasome and/or autophagy activating drugs is a promising future strategy. Thus, my analyses could form a basis for the design of a clinical trial in which patients could be treated with proteasome and/or autophagy activating drugs.