Understanding key regulators of normal skeletal function have been facilitated by the study of osteogenesis imperfecta (01) or brittle bone disease. Our genetic studies have shown that humans with loss of function mutations in FKBPIO (which encodes the FKBP65 protein) have progressive deforming 01, which may also be associated with progressive joint contractures. What remains unresolved, but necessary to understand, are the cellular consequences and molecular interactions by which FKBP65 regulates synthesis of type I procollagen and formation of a proper bone extracellular matrix (ECM) leading to normal mineralization.
The Specific Aims are: 1. Determine the consequences of FKBP10 loss on cellular phenotype. Loss of FKBP65 has significant effects on cellular phenotype indicating increased ER stress. We will determine the molecular basis for these observations in human 01 cells. 2. Determine the in vivo role of FKBP65 in mesenchymally derived tissues and determine its interaction with other ER-localized proteins. FkbpIO conditional knockout mice have been generated to determine whether the abnormal human cellular phenotype is recapitulated in the mouse. Based on the human phenotype, we will determine tissue-specific roles for Fkbp65 in the FkbpIO null mice.. 3. Determine the molecular basis for other recessive forms of 01. Using autozygosity mapping we have identified three new loci for recessively inherited forms of 01. We hypothesize that, like most genes associated with 01, these genes will be involved in the processing of type I procollagen and that their identification will reveal additional components essential for bone formation. We will use exome sequencing of genes in the autozygous regions to define these new 01 associated genes. The work proposed will determine the role of FKBP10/FKBP65 in mesenchymal tissues and will define new components necessary for normal bone formation. Overall the data generated will determine the molecules necessary for the synthesis, mineralization and maintenance of a normal type I collagen extracellular matrix.

Public Health Relevance

The results of this project will have an immediate impact by providing improved genetic counseling and diagnostic testing for families with brittle bone disease. Determining the mechanism of disease in these new forms of Ol develop will identify disease-based strategies and specific molecular targets for therapy.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Program Projects (P01)
Project #
5P01HD070394-03
Application #
8508692
Study Section
Special Emphasis Panel (ZHD1-DSR-Y)
Project Start
Project End
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
3
Fiscal Year
2013
Total Cost
$348,928
Indirect Cost
$36,646
Name
Baylor College of Medicine
Department
Type
DUNS #
051113330
City
Houston
State
TX
Country
United States
Zip Code
77030
Machol, Keren; Jain, Mahim; Almannai, Mohammed et al. (2016) Corner fracture type spondylometaphyseal dysplasia: Overlap with type II collagenopathies. Am J Med Genet A :
Grafe, Ingo; Alexander, Stefanie; Yang, Tao et al. (2016) Sclerostin Antibody Treatment Improves the Bone Phenotype of Crtap(-/-) Mice, a Model of Recessive Osteogenesis Imperfecta. J Bone Miner Res 31:1030-40
Rajagopal, Abbhirami; Homan, Erica P; Joeng, Kyu Sang et al. (2016) Restoration of the serum level of SERPINF1 does not correct the bone phenotype in Serpinf1 null mice. Mol Genet Metab 117:378-82
Lindert, Uschi; Cabral, Wayne A; Ausavarat, Surasawadee et al. (2016) MBTPS2 mutations cause defective regulated intramembrane proteolysis in X-linked osteogenesis imperfecta. Nat Commun 7:11920
Hosseininia, S; Weis, M A; Rai, J et al. (2016) Evidence for enhanced collagen type III deposition focally in the territorial matrix of osteoarthritic hip articular cartilage. Osteoarthritis Cartilage 24:1029-35
Heard, Melissa E; Besio, Roberta; Weis, MaryAnn et al. (2016) Sc65-Null Mice Provide Evidence for a Novel Endoplasmic Reticulum Complex Regulating Collagen Lysyl Hydroxylation. PLoS Genet 12:e1006002
Lietman, Caressa D; Marom, Ronit; Munivez, Elda et al. (2015) A transgenic mouse model of OI type V supports a neomorphic mechanism of the IFITM5 mutation. J Bone Miner Res 30:489-98
Patel, R M; Nagamani, S C S; Cuthbertson, D et al. (2015) A cross-sectional multicenter study of osteogenesis imperfecta in North America - results from the linked clinical research centers. Clin Genet 87:133-40
Lu, Linchao; Harutyunyan, Karine; Jin, Weidong et al. (2015) RECQL4 Regulates p53 Function In Vivo During Skeletogenesis. J Bone Miner Res 30:1077-89
Posey, Jennifer E; Burrage, Lindsay C; Campeau, Philippe M et al. (2015) Adult presentation of X-linked Conradi-Hünermann-Happle syndrome. Am J Med Genet A 167:1309-14

Showing the most recent 10 out of 66 publications