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

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

doi:10.3389/fmolb.2023.1285790

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

Front Mol Biosci. 2023 Dec 12:10:1285790. doi: 10.3389/fmolb.2023.1285790. eCollection 2023.

Authors

Affiliations

¹ Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland.
² Department of Histology and Embryology, Poznan University of Medical Sciences, Poznan, Poland.
³ Department of Cell Biology, Poznan University of Medical Sciences, Poznan, Poland.
⁴ Department of Ophthalmology, Poznan University of Medical Sciences, Poznan, Poland.
⁵ Department of Nephrology, Kidney Transplantation, and Hypertension, The Children's Memorial Health Institute, Warsaw, Poland.
⁶ Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands.
⁷ Department of Human Genetics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands.

^# Contributed equally.

Abstract

Background: 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: WDR35, IFT122, IFT140, IFT144, IFT52, and IFT43. Objective: 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. Methods: Genetic analysis by WDR35 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. Results: WDR35 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. Conclusion: 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 WDR35. This study points out the added value of hURECs in functional testing for ciliopathies.

Keywords: CED; WDR35; ciliopathy; cranioectodermal dysplasia; hURECs; second-stage renal disease.

Grants and funding

The authors declare financial support was received for the research, authorship, and/or publication of this article. JW-S acknowledges funding from the Polish National Science Center (Grant no. DEC-2021/05/X/NZ2/00897).