Introduction:
Renal ciliopathies are a heterogeneous class of disorders caused by dysfunctions of the primary cilia. They are often multisystem disorders characterized by extensive genetic heterogeneity and clinical variability with high levels of lethality and there is marked phenotypic overlap among distinct ciliopathy syndromes. Nephronophthisis (NPHP) is a typical renal ciliopathy phenotype that causes kidney failure often within early childhood, for which there are no curative treatments beyond dialysis and transplantation.
Methods:
To identify novel therapeutics for NPHP, we designed a high-throughput ciliary phenotype-driven screening strategy to interrogate the TOCRIS library of 1120 biologically active compounds, making use of the Operetta high-content imaging system with Harmony/Columbus software. Initially, 33 compounds were identified that restored ciliary phenotype in renal epithelial cells derived from Cep290 mutant mice. These compounds were subjected to a secondary screen using NPHP patient fibroblasts (P-BB), carrying compound heterozygous CEP290 mutations, including an allele that we had previously shown to be amenable to Anti-sense Oligonucleotide (ASO) mediated exon skipping. In this screen, 12 compounds either restored ciliogenesis or corrected cilia length defects.
Results:
A tertiary phenotypic screen of the 12 TOCRIS compounds was then carried out in human urine-derived renal epithelial cells (hURECs) from a NPHP patient (P-HB) carrying CEP290 mutation (p. (Thr832Asnfs*12) and p.(Gly1890*)) along with control hURECs from an unaffected sibling. The initial hUREC phenotypic screen of P-HB cells displayed a ciliogenesis defect with elongated cilia typically found in CEP290 patients, compared to the unaffected sibling who had normal cilia. Two of the TOCRIS chemical compounds rescued the ciliary phenotype in patient (P-HB).
Conclusions:
We have employed RNAseq to identify the underlying molecular pathways using the TOCRIS compounds which revealed that the correction of abnormal ciliogenesis occurs through the convergent effect of multiple pathways highlighting novel insights into the mechanisms underlying NPHP secondary to CEP290 mutations and potential new targets for therapeutic intervention. This abstract was also submitted for Cilia2024 conference held in Dublin, Ireland.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.