This is an exploratory project with the goal of establishing whether so-called primary cilia on cells and/or proteins needed for their assembly and function are essential for skeletal development and postnatal growth. Work is also proposed to test the hypothesis that primary cilia are required for the normal remodeling response of skeletal tissues to mechanical stimulation. The studies are prompted by recent discoveries that primary cilia and signaling molecules associated with them serve as receptors on many cells, in worms and flies as well as in mice and humans, and that mutations in genes coding for proteins in primary cilia can cause skeletal defects in addition to abnormalities in internal organs. The investigators plan to combine genetic and other experimental studies in mice with biochemical analyses of cultured organs and cells derived from mice with mutations in genes that affect the formation or function of primary cilia. Through the studies, the investigators aim at establishing (1) whether primary cilia are needed for the formation and function of growth plates in long bones, (2) whether they also are needed for development of the normal pattern of bones in limbs, and finally, (3) whether the normal response of skeletal tissues to mechanical stimulation requires the presence of primary cilia on the cells in these tissues. The studies are likely to generate new and exciting insights into mechanisms for bone development and maintenance and the molecular machinery that regulates the response of bones to gravity and exercise. The studies may help define new targets for drugs aimed at reversing the loss of bone substance during aging and in osteoporosis or drugs that may accelerate bone loss in diseases with excess accumulation of bone substance, such as osteopetrosis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AR053143-02
Application #
7140626
Study Section
Skeletal Biology Development and Disease Study Section (SBDD)
Program Officer
Sharrock, William J
Project Start
2005-09-21
Project End
2007-08-31
Budget Start
2006-09-01
Budget End
2007-08-31
Support Year
2
Fiscal Year
2006
Total Cost
$218,482
Indirect Cost
Name
Harvard University
Department
Dentistry
Type
Schools of Dentistry
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115
Hou, Bo; Kolpakova-Hart, Elona; Fukai, Naomi et al. (2009) The polycystic kidney disease 1 (Pkd1) gene is required for the responses of osteochondroprogenitor cells to midpalatal suture expansion in mice. Bone 44:1121-33
Kolpakova-Hart, Elona; Nicolae, Claudia; Zhou, Jing et al. (2008) Col2-Cre recombinase is co-expressed with endogenous type II collagen in embryonic renal epithelium and drives development of polycystic kidney disease following inactivation of ciliary genes. Matrix Biol 27:505-12
Kolpakova-Hart, Elona; McBratney-Owen, Brandeis; Hou, Bo et al. (2008) Growth of cranial synchondroses and sutures requires polycystin-1. Dev Biol 321:407-19
Pfeffer, Christian P; Olsen, Bjorn R; Ganikhanov, Feruz et al. (2008) Multimodal nonlinear optical imaging of collagen arrays. J Struct Biol 164:140-5
Kolpakova-Hart, Elona; Jinnin, Masatoshi; Hou, Bo et al. (2007) Kinesin-2 controls development and patterning of the vertebrate skeleton by Hedgehog- and Gli3-dependent mechanisms. Dev Biol 309:273-84
Hou, Bo; Fukai, Naomi; Olsen, Bjorn R (2007) Mechanical force-induced midpalatal suture remodeling in mice. Bone 40:1483-93
Legare, Francois; Pfeffer, Christian; Olsen, Bjorn R (2007) The role of backscattering in SHG tissue imaging. Biophys J 93:1312-20