The research described herein will investigate patterns of stimulation of phagocytic leukocytes and determine to what extent common pathways are following during various stimulatory conditions. It is our goal to determine the interrelatedness of the various indicators of leukocyte stimulation. We will employ synergistic conditions (i.e., very low levels of stimuli in combination) which may be more reflective of physiological conditions in vivo than the use of saturating levels of stimuli to probe these activation mechanisms. Retinoids, which we have shown to have novel stimulatory properties, will also be used as tools to study leukocyte stimulation mechanisms. Osteocalcin, a major non-collagenous bone protein which is chemotactic for monocytes, will be utilized as a stimulus. We will determine what other features of leukocyte biology are stimulated by osteocalcin and investigate the mechanisms of action of this molecule. We will employ fluorescence video imaging microscopy to monitor stimulus-induced changes in cytoplasmic pH and pCa++ in leukocytes and to follow the intracellular processing of osteocalcin in target cells. These experiments will utilize biochemical, cell biological, and morphological techniques to explore the mechanisms involved in leukocyte stimulation. A synthesis of these approaches, and the use of several stimulatory conditions, should provide a deeper understanding of this complex process. A better understanding of leukocyte function and the mechanisms which control these cells may lead to clinical applications which are important therapeutically.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE008507-03
Application #
3222218
Study Section
(SRC)
Project Start
1987-09-01
Project End
1992-08-31
Budget Start
1989-09-01
Budget End
1990-08-31
Support Year
3
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Harvard University
Department
Type
Schools of Medicine
DUNS #
082359691
City
Boston
State
MA
Country
United States
Zip Code
02115
Daumer, K M; Khan, A U; Steinbeck, M J (2000) Chlorination of pyridinium compounds. Possible role of hypochlorite, N-chloramines, and chlorine in the oxidation of pyridinoline cross-links of articular cartilage collagen type II during acute inflammation. J Biol Chem 275:34681-92
Steinbeck, M J; Kim, J K; Trudeau, M J et al. (1998) Involvement of hydrogen peroxide in the differentiation of clonal HD-11EM cells into osteoclast-like cells. J Cell Physiol 176:574-87
Steinbeck, M J; Appel Jr, W H; Verhoeven, A J et al. (1994) NADPH-oxidase expression and in situ production of superoxide by osteoclasts actively resorbing bone. J Cell Biol 126:765-72
Karnovsky, M J (1994) Robert Feulgen Lecture 1994. Cytochemistry and reactive oxygen species: a retrospective. Histochemistry 102:15-27
Steinbeck, M J; Khan, A U; Karnovsky, M J (1993) Extracellular production of singlet oxygen by stimulated macrophages quantified using 9,10-diphenylanthracene and perylene in a polystyrene film. J Biol Chem 268:15649-54
Steinbeck, M J; Khan, A U; Appel Jr, W H et al. (1993) The DAB-Mn++ cytochemical method revisited: validation of specificity for superoxide. J Histochem Cytochem 41:1659-67
Beaty, T H; Colyer, C R; Chang, Y C et al. (1993) Familial aggregation of periodontal indices. J Dent Res 72:544-51
Steinbeck, M J; Khan, A U; Karnovsky, M J (1992) Intracellular singlet oxygen generation by phagocytosing neutrophils in response to particles coated with a chemical trap. J Biol Chem 267:13425-33
Steinbeck, M J; Hegg, G G; Karnovsky, M J (1991) Arachidonate activation of the neutrophil NADPH-oxidase. Synergistic effects of protein phosphatase inhibitors compared with protein kinase activators. J Biol Chem 266:16336-42
Steinbeck, M J; Robinson, J M; Karnovsky, M J (1991) Activation of the neutrophil NADPH-oxidase by free fatty acids requires the ionized carboxyl group and partitioning into membrane lipid. J Leukoc Biol 49:360-8

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