Behavioral, cognitive, and motor disorders are clinical manifestations of AIDs Dementia Complex (ADC). ADC is likely mediated, at least in part, by the cytokines tumor necrosis factor alpha (TNF-alpha) and lymphotoxin (LT). TNF and LT are pleiotropic cytokines secreted by macrophages and lymphocytes. TNF and LT possess a broad range of hormonal and cytotoxic actions, but the mechanism of action of TNF and LT is unknown. Our laboratory has made the recent discovery that TNF and LT can form ion-permeable channels in planar lipid membranes, and we have proposed that channel formation may explain some physiologic effects of TNF such as the killing of tumor cells and the depolarization of muscle cells. Several lines of evidence implicate TNF in the pathophysiology of AIDS including the facts that TNF levels are elevated in AIDS patients, TNF can cause cachexia, TNF can increase HIV replication, and TNF can kill HIV-infected lymphocytes. TNF can increase HIV replication, and TNF can kill HIV-infected lymphocytes. TNF has also been found in the CSF of AIDS patients and its ability to depolarize cells and demyelinate nerve fibers may contribute to the dementia complex of AIDS (ADC). The broad goal of this research is to understand the role of these channels in the pathophysiology of AIDS and to search for ways to modify the destructive actions of TNF and LT in AIDS. TNF and LT channels will be characterized using electrophysiologic techniques in lipid bilayer and whole cells (patch clamp).

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Scientist Development Award - Research (K02)
Project #
5K02MH001174-02
Application #
2240653
Study Section
Psychobiological, Biological, and Neurosciences Subcommittee (MHAI)
Project Start
1994-01-01
Project End
1998-12-31
Budget Start
1995-01-01
Budget End
1995-12-31
Support Year
2
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Type
Other Domestic Higher Education
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Kagan, Bruce L; Hirakura, Yutaka; Azimov, Rustam et al. (2002) The channel hypothesis of Alzheimer's disease: current status. Peptides 23:1311-5
Hirakura, Yutaka; Carreras, Isabel; Sipe, Jean D et al. (2002) Channel formation by serum amyloid A: a potential mechanism for amyloid pathogenesis and host defense. Amyloid 9:13-23
Hirakura, Y; Kagan, B L (2001) Pore formation by beta-2-microglobulin: a mechanism for the pathogenesis of dialysis associated amyloidosis. Amyloid 8:94-100
Kagan, B L; Hirakura, Y; Azimov, R et al. (2001) The channel hypothesis of Huntington's disease. Brain Res Bull 56:281-4
Hirakura, Y; Azimov, R; Azimova, R et al. (2000) Polyglutamine-induced ion channels: a possible mechanism for the neurotoxicity of Huntington and other CAG repeat diseases. J Neurosci Res 60:490-4
Hirakura, Y; Yiu, W W; Yamamoto, A et al. (2000) Amyloid peptide channels: blockade by zinc and inhibition by Congo red (amyloid channel block). Amyloid 7:194-9
Chen, Q S; Kagan, B L; Hirakura, Y et al. (2000) Impairment of hippocampal long-term potentiation by Alzheimer amyloid beta-peptides. J Neurosci Res 60:65-72
Schendel, S L; Azimov, R; Pawlowski, K et al. (1999) Ion channel activity of the BH3 only Bcl-2 family member, BID. J Biol Chem 274:21932-6
Mirzabekov, T A; Silberstein, A Y; Kagan, B L (1999) Use of planar lipid bilayer membranes for rapid screening of membrane active compounds. Methods Enzymol 294:661-74
Koo, S P; Bayer, A S; Kagan, B L et al. (1999) Membrane permeabilization by thrombin-induced platelet microbicidal protein 1 is modulated by transmembrane voltage polarity and magnitude. Infect Immun 67:2475-81

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