@article {2051, title = {Cilia-associated wound repair mediated by IFT88 in retinal pigment epithelium.}, journal = {Sci Rep}, volume = {13}, year = {2023}, month = {2023 May 21}, pages = {8205}, abstract = {

Primary cilia are conserved organelles that integrate extracellular cues into intracellular signals and are critical for diverse processes, including cellular development and repair responses. Deficits in ciliary function cause multisystemic human diseases known as ciliopathies. In the eye, atrophy of the retinal pigment epithelium (RPE) is a common feature of many ciliopathies. However, the roles of RPE cilia in vivo remain poorly understood. In this study, we first found that mouse RPE cells only transiently form primary cilia. We then examined the RPE in the mouse model of Bardet-Biedl Syndrome 4 (BBS4), a ciliopathy associated with retinal degeneration in humans, and found that ciliation in BBS4 mutant RPE cells is disrupted early during development. Next, using a laser-induced injury model in vivo, we found that primary cilia in RPE reassemble in response to laser injury during RPE wound healing and then rapidly disassemble after the repair is completed. Finally, we demonstrated that RPE-specific depletion of primary cilia in a conditional mouse model of cilia loss promoted wound healing and enhanced cell proliferation. In summary, our data suggest that RPE cilia contribute to both retinal development and repair and provide insights into potential therapeutic targets for more common RPE degenerative diseases.

}, keywords = {Animals, Cilia, Ciliopathies, Disease Models, Animal, Humans, Mice, Microtubule-Associated Proteins, Retinal Degeneration, Retinal Pigment Epithelium, Tumor Suppressor Proteins}, issn = {2045-2322}, doi = {10.1038/s41598-023-35099-3}, author = {Ning, Ke and Bhuckory, Mohajeet B and Lo, Chien-Hui and Sendayen, Brent E and Kowal, Tia J and Chen, Ming and Bansal, Ruchi and Chang, Kun-Che and Vollrath, Douglas and Berbari, Nicolas F and Mahajan, Vinit B and Hu, Yang and Sun, Yang} } @article {641, title = {Reprogramming towards anabolism impedes degeneration in a preclinical model of retinitis pigmentosa.}, journal = {Hum Mol Genet}, volume = {25}, year = {2016}, month = {2016 10 01}, pages = {4244-4255}, abstract = {

Retinitis pigmentosa (RP) is an incurable neurodegenerative condition featuring photoreceptor death that leads to blindness. Currently, there is no approved therapeutic for photoreceptor degenerative conditions like RP and atrophic age-related macular degeneration (AMD). Although there are promising results in human gene therapy, RP is a genetically diverse disorder, such that gene-specific therapies would be practical in a small fraction of patients with RP. Here, we explore a non-gene-specific strategy that entails reprogramming photoreceptors towards anabolism by upregulating the mechanistic target of rapamycin (mTOR) pathway. We conditionally ablated the tuberous sclerosis complex 1 (Tsc1) gene, an mTOR inhibitor, in the rods of the Pde6bpreclinical RP mouse model and observed, functionally and morphologically, an improvement in the survival of rods and cones at early and late disease stages. These results elucidate the ability of reprogramming the metabolome to slow photoreceptor degeneration. This strategy may also be applicable to a wider range of neurodegenerative diseases, as enhancement of nutrient uptake is not gene-specific and is implicated in multiple pathologies. Enhancing anabolism promoted neuronal survival and function and could potentially benefit a number of photoreceptor and other degenerative conditions.

}, keywords = {Animals, Cell Death, Cellular Reprogramming, Cone-Rod Dystrophies, Disease Models, Animal, Humans, Macular Degeneration, Metabolism, Mice, Photoreceptor Cells, Retinal Cone Photoreceptor Cells, Retinal Rod Photoreceptor Cells, Retinitis Pigmentosa, TOR Serine-Threonine Kinases, Tumor Suppressor Proteins}, issn = {1460-2083}, doi = {10.1093/hmg/ddw256}, author = {Zhang, Lijuan and Justus, Sally and Xu, Yu and Pluchenik, Tamara and Hsu, Chun-Wei and Yang, Jin and Duong, Jimmy K and Lin, Chyuan-Sheng and Jia, Yading and Bassuk, Alexander G and Mahajan, Vinit B and Tsang, Stephen H} } @article {669, title = {Response to Sandford et~al.: PRICKLE2 Variants in Epilepsy: A Call for Precision Medicine.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Mar 03}, pages = {590-591}, keywords = {Animals, Carrier Proteins, DNA-Binding Proteins, Drosophila Proteins, Female, Humans, Male, Mutation, Nerve Tissue Proteins, Seizures, Tumor Suppressor Proteins, Zebrafish Proteins}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.02.002}, author = {Mahajan, Vinit B and Bassuk, Alexander G} } @article {707, title = {Silencing of tuberin enhances photoreceptor survival and function in a preclinical model of retinitis pigmentosa (an american ophthalmological society thesis).}, journal = {Trans Am Ophthalmol Soc}, volume = {112}, year = {2014}, month = {2014 Jul}, pages = {103-15}, abstract = {

PURPOSE: To assess the functional consequences of silencing of tuberin, an inhibitor of the mTOR signaling pathway, in a preclinical model of retinitis pigmentosa (RP) in order to test the hypothesis that insufficient induction of the protein kinase B (PKB)-regulated tuberin/mTOR self-survival pathway initiates apoptosis.

METHODS: In an unbiased genome-scale approach, kinase peptide substrate arrays were used to analyze self-survival pathways at the onset of photoreceptor degeneration. The mutant Pde6b(H620Q)/Pde6b(H620Q) at P14 and P18 photoreceptor outer segment (OS) lysates were labeled with P-ATP and hybridized to an array of 1,164 different synthetic peptide substrates. At this stage, OS of Pde6b(H620Q)/Pde6b(H620Q) rods are morphologically normal. In vitro kinase assays and immunohistochemistry were used to validate phosphorylation. Short hairpin RNA (shRNA) gene silencing was used to validate tuberin{\textquoteright}s role in regulating survival.

RESULTS: At the onset of degeneration, 162 peptides were differentially phosphorylated. Protein kinases A, G, C (AGC kinases), and B exhibited increased activity in both peptide array and in vitro kinase assays. Immunohistochemical data confirmed altered phosphorylation patterns for phosphoinositide-dependent kinase-1 (PDK1), ribosomal protein S6 (RPS6), and tuberin. Tuberin gene silencing rescued photoreceptors from degeneration.

CONCLUSIONS: Phosphorylation of tuberin and RPS6 is due to the upregulated activity of PKB. PKB/tuberin cell growth/survival signaling is activated before the onset of degeneration. Substrates of the AGC kinases in the PKB/tuberin pathway are phosphorylated to promote cell survival. Knockdown of tuberin, the inhibitor of the mTOR pathway, increased photoreceptor survival and function in a preclinical model of RP.

}, keywords = {Animals, Apoptosis, Disease Models, Animal, Gene Silencing, Mice, Mice, Mutant Strains, Phosphorylation, Phosphotransferases, Proto-Oncogene Proteins c-akt, Retinitis Pigmentosa, Ribosomal Protein S6, Signal Transduction, Tumor Suppressor Proteins}, issn = {1545-6110}, author = {Tsang, Stephen H and Chan, Lawrence and Tsai, Yi-Ting and Wu, Wen-Hsuan and Hsu, Chun-Wei and Yang, Jin and Tosi, Joaquin and Wert, Katherine J and Davis, Richard J and Mahajan, Vinit B} } @article {149, title = {Mutations in prickle orthologs cause seizures in flies, mice, and humans.}, journal = {American journal of human genetics}, volume = {88}, year = {2011}, month = {2011 Feb 11}, pages = {138-49}, abstract = {

Epilepsy is heritable, yet few causative gene mutations have been identified, and thus far no human epilepsy gene mutations have been found to produce seizures in invertebrates. Here we show that mutations in prickle genes are associated with seizures in humans, mice, and flies. We identified human epilepsy patients with heterozygous mutations in either PRICKLE1 or PRICKLE2. In overexpression assays in zebrafish, prickle mutations resulted in aberrant prickle function. A seizure phenotype was present in the Prickle1-null mutant mouse, two Prickle1 point mutant (missense and nonsense) mice, and a Prickle2-null mutant mouse. Drosophila with prickle mutations displayed seizures that were responsive to anti-epileptic medication, and homozygous mutant embryos showed neuronal defects. These results suggest that prickle mutations have caused seizures throughout evolution.

}, keywords = {Animals, Blotting, Western, Brain, Calcium, Carrier Proteins, DNA-Binding Proteins, Drosophila melanogaster, Drosophila Proteins, Embryo, Nonmammalian, Epilepsies, Myoclonic, Female, Heterozygote, Humans, Immunoenzyme Techniques, In Situ Hybridization, Male, Mice, Mice, Knockout, Mutation, Nerve Tissue Proteins, Phenotype, Reverse Transcriptase Polymerase Chain Reaction, RNA, Messenger, Seizures, Tumor Suppressor Proteins, Zebrafish, Zebrafish Proteins}, author = {Tao, Hirotaka and Manak, J Robert and Sowers, Levi and Mei, Xue and Kiyonari, Hiroshi and Abe, Takaya and Dahdaleh, Nader S and Yang, Tian and Wu, Shu and Chen, Shan and Fox, Mark H and Gurnett, Christina and Montine, Thomas and Bird, Thomas and Shaffer, Lisa G and Rosenfeld, Jill A and McConnell, Juliann and Madan-Khetarpal, Suneeta and Berry-Kravis, Elizabeth and Griesbach, Hilary and Saneto, Russell P and Scott, Matthew P and Antic, Dragana and Reed, Jordan and Boland, Riley and Ehaideb, Salleh N and El-Shanti, Hatem and Mahajan, Vinit B and Ferguson, Polly J and Axelrod, Jeffrey D and Lehesjoki, Anna-Elina and Fritzsch, Bernd and Slusarski, Diane C and Wemmie, John and Ueno, Naoto and Bassuk, Alexander G} }