This application represents a continuation of our studies of a role and function of a to/co/cf-related transcription factor PITX2 during human development, particularly in respect to the formation of ocular structures. Mutations in the PITX2 gene cause Axenfeld-Rieger syndrome (ARS) associated with glaucoma in humans and arrest in eye development in Pitx2-/- knockout mice. In our previous studies we characterized Pitx2 transcripts and genomic sequences in several species. Human PITX2 sequences were screened for mutations in patients with Axenfeld-Rieger syndrome and other similar conditions and multiple mutations have been identified. We also initiated generation of a knock-in mouse carrying dominant-negative mutation in Pitx2 gene identical to the mutation found in a patient with a severe form of ARS. These studies form basis for our further investigation of PITX2 role(s) in development that are specifically aimed at: 1) To elucidate molecular mechanisms underlying Pitx2 regulation during ocular development. Under this aim, regions involved in regulation of Pitx2 and factors interacting with these sequences will be identified;2) To explore pathological effects of PITX2 inactivation by characterization of mutant mice and human cell lines carrying K88E dominant-negative mutation in the PITX2 gene. Creation of ARS animal model associated with Pitx2 mutations will facilitate studies of mechanisms of Pitx2's action in development, identification of modifiers and evaluation of therapeutic agents. Because of the fact that Pitx2 knockout mice generally do not demonstrate Axenfeld-Rieger features while homozygous -/- animals die before birth due to multiple defects, comprehensive studies of Axenfeld-Rieger anomalies and glaucoma are not possible in these animals. We anticipate that Pitx2(K88E) mice carrying dominant-negative mutation in Pitx2 gene will result in a better model to study A-R syndrome. Identification of downstream targets of PITX2 will be performed by analysis of the differential gene expression in cells/ tissues expressing wild type and mutant forms of PITX2 and microarrays. Mutation analysis in human patients will be performed to identify factors playing the most critical role in the human eye. We contend that these studies will advance our knowledge of the mechanisms of normal eye development and understanding of glaucoma at the molecular level.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
3R01EY015518-04S1
Application #
7848621
Study Section
Special Emphasis Panel (ZRG1-AED (01))
Program Officer
Agarwal, Neeraj
Project Start
2004-12-01
Project End
2010-05-31
Budget Start
2009-06-01
Budget End
2010-05-31
Support Year
4
Fiscal Year
2009
Total Cost
$11,005
Indirect Cost
Name
Medical College of Wisconsin
Department
Pediatrics
Type
Schools of Medicine
DUNS #
937639060
City
Milwaukee
State
WI
Country
United States
Zip Code
53226
Hendee, Kathryn E; Sorokina, Elena A; Muheisen, Sanaa S et al. (2018) PITX2 deficiency and associated human disease: insights from the zebrafish model. Hum Mol Genet 27:1675-1695
Protas, Meredith E; Weh, Eric; Footz, Tim et al. (2017) Mutations of conserved non-coding elements of PITX2 in patients with ocular dysgenesis and developmental glaucoma. Hum Mol Genet 26:3630-3638
Weh, Eric; Takeuchi, Hideyuki; Muheisen, Sanaa et al. (2017) Functional characterization of zebrafish orthologs of the human Beta 3-Glucosyltransferase B3GLCT gene mutated in Peters Plus Syndrome. PLoS One 12:e0184903
Hendee, Kathryn; Wang, Lauren Weiping; Reis, Linda M et al. (2017) Identification and functional analysis of an ADAMTSL1 variant associated with a complex phenotype including congenital glaucoma, craniofacial, and other systemic features in a three-generation human pedigree. Hum Mutat 38:1485-1490
Happ, Hannah; Weh, Eric; Costakos, Deborah et al. (2016) Case report of homozygous deletion involving the first coding exons of GCNT2 isoforms A and B and part of the upstream region of TFAP2A in congenital cataract. BMC Med Genet 17:64
Reis, L M; Tyler, R C; Weh, E et al. (2016) Whole exome sequencing identifies multiple diagnoses in congenital glaucoma with systemic anomalies. Clin Genet 90:378-82
Reis, Linda M; Tyler, Rebecca C; Weh, Eric et al. (2016) Analysis of CYP1B1 in pediatric and adult glaucoma and other ocular phenotypes. Mol Vis 22:1229-1238
Happ, Hannah; Schilter, Kala F; Weh, Eric et al. (2016) 8q21.11 microdeletion in two patients with syndromic peters anomaly. Am J Med Genet A 170:2471-5
Deml, Brett; Reis, Linda M; Lemyre, Emmanuelle et al. (2016) Novel mutations in PAX6, OTX2 and NDP in anophthalmia, microphthalmia and coloboma. Eur J Hum Genet 24:535-41
Reis, Linda M; Semina, Elena V (2015) Conserved genetic pathways associated with microphthalmia, anophthalmia, and coloboma. Birth Defects Res C Embryo Today 105:96-113

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