Perrault, I. | bioRxiv Science

bioRxiv2026

Pharmacological rescue of cilia trafficking defects in IFT140 retinal organoid and RPE models of retinal dystrophy

Pathogenic variants in IFT140 are associated with a spectrum of syndromic and non-syndromic ciliopathies, with retinal degeneration as a common feature. Despite advances in understanding IFT140 function across various tissues, human retina-specific models are lacking. Here, we show that knock-in mice homozygous for the IFT140 patient variant c.932A>G (p.Y311C) did not develop retinal degeneration, while mice with the homozygous variant c.1451C>T (p.T484M), associated with non-syndromic retinal dystrophy, were embryonic lethal. Therefore, to understand the effect of these variants on retinal homeostasis, we generated novel human in vitro models of IFT140-associated retinal dystrophy, including CRISPR/Cas9 IFT140 knock-out (IFT140KO) induced pluripotent stem cells (iPSC) and patient-derived iPSC retinal pigment epithelium (iPSC-RPE) and retinal organoids (iPSC-ROs). IFT140KO iPSC-RPE cells display stubby cilia compared to isogenic controls, while IFT140T484M/T484Mpatient-derived iPSC-RPE cells exhibit slightly shorter cilia and cilia tip protein accumulation. Both IFT140KO and IFT140T484M/T484M iPSC-ROs show accumulation of cilia proteins at the connecting cilium and outer segment of photoreceptors, and mislocalization of rhodopsin to the inner segments and outer nuclear layer. Pharmacological screening of compounds previously reported to improve cilia structure identified the flavonoid eupatilin as the most effective molecule. Treatment with eupatilin improved cilium length and IFT traffic in iPSC-RPE, and IFT traffic and rhodopsin localization in iPSC-ROs. These findings emphasize the importance of human stem cell derived models to investigate tissue specific disease mechanisms and highlight the therapeutic potential of eupatilin to ameliorate cilia defects in retinal tissue.

neuroscience↗

bioRxiv2023

Pharmacological cAMP stimulation via prostaglandin receptors rescues ciliary defects in CEP290-deficient patient and mouse models

The retinas sensitivity to light depends on the primary cilium of photoreceptors, known as the outer segment (OS). OS defects are a primary cause of inherited retinal dystrophies (IRDs) and can also indicate wider ciliary dysfunctions. One such IRD is Leber congenital amaurosis type 10 (LCA10), which occurs as a monosymptomatic retinal disease or the presenting symptom of syndromic ciliopathies within the Senior-Loken-Joubert-Meckel spectrum. LCA10 patients are born blind but retain dormant photoreceptors for decades, offering the potential for reactivation. AAV-based gene therapies for IRDs cannot accommodate the large CEP290 gene, prompting the search for innovative treatments. LCA10 is caused by mutations in CEP290, which plays a vital role in ciliation, similar to cAMP signaling. Utilizing fibroblasts displaying variable CEP290 mutations and associated ciliary defects, we show that exposure to Taprenepag, a specific PGE2 receptor agonist, substantially stimulated cAMP synthesis and consistently improved cilia formation and elongation. We also found that intraperitoneal injection of Taprenepag in mice reached the retina and slowed retinal degeneration, promoting OS formation, and improving light sensitivity in a Cep290 mutant mouse. These findings demonstrate the potential of Taprenepag to treat the CEP290-related visual dysfunction and suggest evaluation for other CEP290-related organ issues and ciliopathies.

genetics↗