The long-term goal of this laboratory is to understand the function osteoclasts in the process of bone resorption. the purpose of this application is to elucidate the regulation of H+ generation by osteoclasts. H+ generation will be detected by measuring levels of acridine orange fluorescence in osteoclasts isolated from the endosteum of tibia and other long bones. Three sources of osteoclasts will be used: 3-week-old chicks on a normal calcium diet, 3-week chicks on low calcium intake, and day-old rabbits. This will allow comparison of avian and mammalian models. Specifically, the signal transducers (e.g., G-proteins) and effectors (e.g., adenylate cyclase, phospholipase C, Ca2+ channels) for parathyroid hormone (PTH), calcitonin and prostaglandin E2 will be investigated. Osteoblast-osteoclast interactions will be studied, particularly with regard to PTH effects. Estrogen and androgen effects on H+ generation by osteoclasts will be examined. Finally, specifically bound PTH and calcitonin to osteoclasts will be studied by biotin-strepavidin-gold labeling in order to characterize receptor-mediated endocytosis of these two important regulators of osteoclasts. Understanding the mechanism of action of osteoclasts has relevance to disease with an involvement of bone loss, such as periodontitis, osteoporosis, osteoarthritis and end stage renal disease. Osteoclasts are also important in normal bone turnover and in tooth eruption and movement.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE004345-19
Application #
2128963
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Project Start
1976-04-01
Project End
1996-09-29
Budget Start
1994-09-30
Budget End
1995-09-29
Support Year
19
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Pennsylvania State University
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
City
University Park
State
PA
Country
United States
Zip Code
16802
Brubaker, K D; Mao, F; Gay, C V (1999) Localization of carbonic anhydrase in living osteoclasts with bodipy 558/568-modified acetazolamide, a thiadiazole carbonic anhydrase inhibitor. J Histochem Cytochem 47:545-50
Brubaker, K D; Gay, C V (1999) Evidence for plasma membrane-mediated effects of estrogen. Calcif Tissue Int 64:459-62
Brubaker, K D; Gay, C V (1999) Depolarization of osteoclast plasma membrane potential by 17beta-estradiol. J Bone Miner Res 14:1861-6
Brubaker, K D; Gay, C V (1999) Estrogen stimulates protein tyrosine phosphorylation and Src kinase activity in avian osteoclasts. J Cell Biochem 76:206-16
Hunter, S J; Gay, C V; Osdoby, P A et al. (1998) Spectrin localization in osteoclasts: immunocytochemistry, cloning, and partial sequencing. J Cell Biochem 71:204-15
May, L G; Gay, C V (1997) Multiple G-protein involvement in parathyroid hormone regulation of acid production by osteoclasts. J Cell Biochem 64:161-70
May, L G; Gay, C V (1997) Parathyroid hormone uses both adenylate cyclase and protein kinase C to regulate acid production in osteoclasts. J Cell Biochem 65:565-73
Gay, C V (1996) Role of microscopy in elucidating the mechanism and regulation of the osteoclast resorptive apparatus. Microsc Res Tech 33:165-70
May, L G; Gay, C V (1996) Development of a new method for obtaining osteoclasts from endosteal surfaces. In Vitro Cell Dev Biol Anim 32:269-78
Brubaker, K D; Gay, C V (1994) Specific binding of estrogen to osteoclast surfaces. Biochem Biophys Res Commun 200:899-907

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