The proteasome is an intracellular protease that is responsible for a significant amount of proteolysis, including the degradation of oxidized proteins and a large number of established short-lived proteins lacking oxidative modifications. Increasing evidence suggests that inhibition of the proteasome-proteolytic pathway occurs as a part of normal aging, with inhibition of proteasome function likely contributing to numerous age-related alterations in the proteome, including age-related increases in oxidized protein. However, the lack of a rigorous biochemical and proteomic analysis has made such estimations largely hypothetical and theoretical. Dietary restriction (DR) is the only known manipulation to consistently and reliably increase average and maximal lifespan in mammals. Numerous studies have demonstrated that DR can ameliorate age-related increases in oxidized protein, and suppress a variety of age-related alterations to the proteome. Data from our laboratory demonstrates that DR ameliorates age-related impairments in proteasome function, with the preservation of proteasome function possibly contributing to the beneficial effects of DR on the proteome. The focus of this proposal is to utilize rigorous proteomic and biochemical analysis to test the hypothesis that DR ameliorates age-related impairments in proteasome function as the result of its direct effects on the proteasome complex, with the preservation of proteasome activity contributing to DR-induced effects on the proteome (oxidized and non-oxidized proteins) during normal aging.
The specific aims for testing this hypothesis are as follows: (1) To determine the effects of DR on proteasome subunit expression, proteasome biogenesis, proteasome composition, and proteasome oxidation;(2) To determine the effects of DR on the individual peptidase activities and protein degrading capabilities of the proteasome;(3) To determine the cell-type specific effects of impaired proteasome function on the proteome, including protein oxidation, in primary CNS cell cultures in vitro;(4) To determine if proteins which exhibit altered expression or increased oxidation following proteasome inhibition in vitro, exhibit similar changes during aging in vivo;(5) To determine if DR ameliorates alterations in the proteome, including increases in oxidized protein, observed during aging in vivo and following proteasome inhibition in vitro.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG025771-06
Application #
8113229
Study Section
Cellular Mechanisms in Aging and Development Study Section (CMAD)
Program Officer
Velazquez, Jose M
Project Start
2007-08-01
Project End
2013-07-31
Budget Start
2011-08-01
Budget End
2013-07-31
Support Year
6
Fiscal Year
2011
Total Cost
$228,247
Indirect Cost
Name
Lsu Pennington Biomedical Research Center
Department
Type
Organized Research Units
DUNS #
611012324
City
Baton Rouge
State
LA
Country
United States
Zip Code
70808
Dasuri, Kalavathi; Ebenezer, Philip; Fernandez-Kim, Sun Ok et al. (2013) Role of physiological levels of 4-hydroxynonenal on adipocyte biology: implications for obesity and metabolic syndrome. Free Radic Res 47:8-19
Beckett, Tina L; Webb, Robin L; Niedowicz, Dana M et al. (2012) Postmortem Pittsburgh Compound B (PiB) binding increases with Alzheimer's disease progression. J Alzheimers Dis 32:127-38
Dasuri, Kalavathi; Zhang, Le; Ebenezer, Philip et al. (2011) Proteasome alterations during adipose differentiation and aging: links to impaired adipocyte differentiation and development of oxidative stress. Free Radic Biol Med 51:1727-35
Dasuri, Kalavathi; Ebenezer, Philip J; Uranga, Romina M et al. (2011) Amino acid analog toxicity in primary rat neuronal and astrocyte cultures: implications for protein misfolding and TDP-43 regulation. J Neurosci Res 89:1471-7
Dasuri, Kalavathi; Ebenezer, Philip J; Zhang, Le et al. (2010) Selective vulnerability of neurons to acute toxicity after proteasome inhibitor treatment: implications for oxidative stress and insolubility of newly synthesized proteins. Free Radic Biol Med 49:1290-7
Dasuri, Kalavathi; Ebenezer, Philip; Zhang, Le et al. (2010) Increased protein hydrophobicity in response to aging and Alzheimer disease. Free Radic Biol Med 48:1330-7
Zhang, Le; Ebenezer, Philip J; Dasuri, Kalavathi et al. (2010) Activation of PERK kinase in neural cells by proteasome inhibitor treatment. J Neurochem 112:238-45
Uranga, Romina M; Bruce-Keller, Annadora J; Morrison, Christopher D et al. (2010) Intersection between metabolic dysfunction, high fat diet consumption, and brain aging. J Neurochem 114:344-61
Dasuri, Kalavathi; Zhang, Le; Ebenezer, Philip et al. (2009) Aging and dietary restriction alter proteasome biogenesis and composition in the brain and liver. Mech Ageing Dev 130:777-83
Zhang, Le; Ebenezer, Philip J; Dasuri, Kalavathi et al. (2009) Proteasome inhibition modulates kinase activation in neural cells: relevance to ubiquitination, ribosomes, and survival. J Neurosci Res 87:3231-8

Showing the most recent 10 out of 13 publications