In this application, we propose to investigate treatment using animal models of the genetically heterogeneous blinding disorder, Bardet-Biedl Syndrome (BBS). At least seventeen BBS genes have been reported to date. BBS is a pleiotropic disorder with the primary clinical features of pigmentary retinopathy, obesity, polydactyly, learning disabilities, renal abnormalities and hypogenitalism. BBS patients also have an increased incidence of hypertension, diabetes mellitus and congenital heart defects. The retinal degeneration of BBS is early onset and typically leads to blindness in the second decade of life. The blindness component of the BBS phenotype is the most concerning aspect of the disorder to patients and their families, and hence the component of BBS that we will focus on for treatment. Strategies for treating inherited forms of blindness include gene therapy, stem cell therapy, and pharmacological treatments. Gene therapy can theoretically target the primary gene defective in the specific patient, or alternatively target genes that modify the primary gene. Access to a number of different BBS animal models provides us with the opportunity to examine a variety of different approaches to treat the blindness component of BBS. In the proposed studies, we will utilize zebrafish to identify the specific genetic types of BBS that are most likey to be readily treatable with gene replacement therapy, and based on the zebrafish data, we will select at least six BBS mouse models to be treated with gene therapy (specific aim 1).
In specific aim 2, we will pursue the hypothesis that some forms of BBS can be treated by alteration of the expression of modifier genes. Finally, in specific aim 3, we hypothesize that specific molecular pathways modify BBS phenotypes. We will test this hypothesis by using pharmaceuticals to treat BBS mouse models targeting specific cellular pathways including apoptosis;endoplasmic reticulum (ER) stress and the unfolded protein response;chaperones;and PDGFR? signaling. Our studies will lead to a better understanding of cilia-related retinopathies;assist in classifying which of a number of treatments will best work, and provide an initial step in going from treatment of animal models to human treatment.

Public Health Relevance

The successful completion of this project will lead to insights into disease mechanisms causing inherited forms of blindness, as well as insights into common major human disorders including obesity, hypertension and diabetes. The results will potentially provide novel treatment strategies for Bardet-Biedl Syndrome, as well as other ciliopathies that lead to blindness.

Agency
National Institute of Health (NIH)
Type
Research Project (R01)
Project #
5R01EY011298-16
Application #
8666753
Study Section
(BVS)
Program Officer
Shen, Grace L
Project Start
Project End
Budget Start
Budget End
Support Year
16
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Iowa
Department
Pediatrics
Type
Schools of Medicine
DUNS #
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Zhang, Yan; Seo, Seongjin; Bhattarai, Sajag et al. (2014) BBS mutations modify phenotypic expression of CEP290-related ciliopathies. Hum Mol Genet 23:40-51
Zode, Gulab S; Sharma, Arti B; Lin, Xiaolei et al. (2014) Ocular-specific ER stress reduction rescues glaucoma in murine glucocorticoid-induced glaucoma. J Clin Invest 124:1956-65
Heymsfield, Steven B; Avena, Nicole M; Baier, Leslie et al. (2014) Hyperphagia: current concepts and future directions proceedings of the 2nd international conference on hyperphagia. Obesity (Silver Spring) 22 Suppl 1:S1-S17
Mei, Xue; Westfall, Trudi A; Zhang, Qihong et al. (2014) Functional characterization of Prickle2 and BBS7 identify overlapping phenotypes yet distinct mechanisms. Dev Biol 392:245-55
Chamling, Xitiz; Seo, Seongjin; Searby, Charles C et al. (2014) The centriolar satellite protein AZI1 interacts with BBS4 and regulates ciliary trafficking of the BBSome. PLoS Genet 10:e1004083
Agassandian, Khristofor; Patel, Milan; Agassandian, Marianna et al. (2014) Ciliopathy is differentially distributed in the brain of a Bardet-Biedl syndrome mouse model. PLoS One 9:e93484
Guo, Deng-Fu; Beyer, Andreas M; Yang, Baoli et al. (2011) Inactivation of Bardet-Biedl syndrome genes causes kidney defects. Am J Physiol Renal Physiol 300:F574-80
Sheffield, Val C; Stone, Edwin M (2011) Genomics and the eye. N Engl J Med 364:1932-42
Sang, Liyun; Miller, Julie J; Corbit, Kevin C et al. (2011) Mapping the NPHP-JBTS-MKS protein network reveals ciliopathy disease genes and pathways. Cell 145:513-28
Meyer, Kacie J; Davis, Lea K; Schindler, Emily I et al. (2011) Genome-wide analysis of copy number variants in age-related macular degeneration. Hum Genet 129:91-100

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