Authors: Helen Louise May-Simera, Qin Wan, Balendu Shekhar Jha, Juliet Hartford, Vladimir Khristov, Roba Dejene, Justin Chang, Sarita Patnaik, Quanlong Lu, Poulomi Banerjee, Jason Silver, Christine Insinna-Kettenhofen, Dishita Patel, Mostafa Lotfi, May Malicdan, Nathan Hotaling, Arvydas Maminishkis, Rupa Sridharan, Brian Brooks, Kiyoharu Miyagishima, Meral Gunay-Aygun, Rajarshi Pal, Christopher Westlake, Sheldon Miller, Ruchi Sharma, Kapil Bharti
Summary: Primary cilia are sensory organelles that protrude from the cell membrane. Defects in the primary cilium cause ciliopathy disorders, with retinal degeneration as a prominent phenotype. Here, we demonstrate that the retinal pigment epithelium (RPE), essential for photoreceptor development and function, requires a functional primary cilium for complete maturation and that RPE maturation defects in ciliopathies precede photoreceptor degeneration. Pharmacologically enhanced ciliogenesis in wild-type induced pluripotent stem cells (iPSC)-RPE leads to fully mature and functional cells. In contrast, ciliopathy patient-derived iPSC-RPE and iPSC-RPE with a knockdown of ciliary-trafficking protein remain immature, with defective apical processes, reduced functionality, and reduced adult-specific gene expression. Proteins of the primary cilium regulate RPE maturation by simultaneously suppressing canonical WNT and activating PKCδ pathways. A similar cilium-dependent maturation pathway exists in lung epithelium. Our results provide insights into ciliopathy-induced retinal degeneration, demonstrate a developmental role for primary cilia in epithelial maturation, and provide a method to mature iPSC epithelial cells for clinical applications.
Source:
Cell Reports; 2018, 22 (1): 189