AUTHOR=Walczak-Sztulpa Joanna , Wawrocka Anna , Kuszel Łukasz , Pietras Paulina , Leśniczak-Staszak Marta , Andrusiewicz Mirosław , Krawczyński Maciej R. , Latos-Bieleńska Anna , Pawlak Marta , Grenda Ryszard , Materna-Kiryluk Anna , Oud Machteld M. , Szaflarski Witold 

TITLE=Ciliary phenotyping in renal epithelial cells in a cranioectodermal dysplasia patient with WDR35 variants

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2023.1285790

DOI=10.3389/fmolb.2023.1285790

ISSN=2296-889X

ABSTRACT=<p><bold>Background:</bold> Cranioectodermal dysplasia (CED) is a skeletal autosomal recessive ciliopathy. The characteristic clinical features of CED are facial dysmorphisms, short limbs, narrow thorax, brachydactyly, ectodermal abnormalities, and renal insufficiency. Thus far, variants in six genes are known to be associated with this disorder: <italic>WDR35</italic>, <italic>IFT122</italic>, <italic>IFT140</italic>, <italic>IFT144</italic>, <italic>IFT52</italic>, and <italic>IFT43</italic>.</p><p><bold>Objective:</bold> The goal of this study was to perform cilium phenotyping in human urine-derived renal epithelial cells (hURECs) from a CED patient diagnosed with second-stage chronic kidney disease (CKD) and three unrelated and unaffected pediatric controls.</p><p><bold>Methods:</bold> Genetic analysis by <italic>WDR35</italic> screening was performed in the affected individual. Cilium frequency and morphology, including cilium length, height, and width, were evaluated by immunofluorescence (IF) experiments in hURECs using two markers visualizing the ciliary axoneme (Acet-Tub and ARL13B) and the base of the cilium (PCNT). The IF results were analyzed using a confocal microscope and IMARIS software.</p><p><bold>Results:</bold><italic>WDR35</italic> analysis revealed the presence of a known nonsense p. (Leu641*) variant and a novel missense variant p. (Ala1027Thr). Moreover, comparative genomic hybridization analysis showed that the patient carries a microdeletion on chromosome 7q31.1. Ciliary phenotyping performed on hURECs showed morphological differences in the patient’s cilia as compared to the three controls. The cilia of the CED patient were significantly wider and longer.</p><p><bold>Conclusion:</bold> The obtained results suggest that CED-related second-stage CKD might be associated with cilia abnormalities, as identified in renal epithelial cells from a CED patient harboring variants in <italic>WDR35</italic>. This study points out the added value of hURECs in functional testing for ciliopathies.</p>