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ASSOCIATE
PROFESSOR OF CLINICAL BIOCHEMISTRY
Biochemistry & Mol. Biology Section, Department
of Chemistry, Faculty of Medicine, University
of Catania.
Viale Andrea Doria, 6. 95125 - Catania- Italy
Degrees:
4/9/1984 Graduation in Medicine, with magna
cum laude, University of Catania (Italy). Thesis:
Modifications of brain lipid metabolism during
aging
7/8/1988 Degree of specialist in Neurology,
with magna cum laude, University of Catania
(Italy). Thesis: Oxidative stress in central
nervous system.
4/8/1996 Assistant Professor in Biochemistry,
Department of Biochenmistry, University of Catania.
Awards:
1987 Post-Doctoral fellow in Neurobiology at
the New York University Medical School, (N.Y.),
Department of Pharmacology:“Neurodegenerative
disorders: the role played by endotoxins and
xenobiotics”
1989 Post-Doctoral fellow in Neuropharmacology
at the Thomas Jefferson University Medical School
(Philadelphia, PA,) Department of Pharmacology:
“Oxidative stress and energy transduction
defects in Neurodegenerative disorders”.
2000-2003:
Visiting Professor University College London,
Department of Neurochemistry, funded by Wellcome
Trust of a Grant on “The role of antioxidants
in L-DOPA induced damage to the Substantia Nigra”.
Visiting Professor Northwick Park Institute
for Medical Research, Department of Surgical
Research, University of London, Research Program
on “The role of heat shock signal and
heme oxygenase on neuroprotection”.
Visiting Professor University of Kentucky, Department
of Chemistry, Research Program on “Nutritional
antioxidants and cellular stress response in
Neuroscience”.
Visiting Professor Blanchette Rockefeller Neuroscience
Institute, West Virginia University (MD), Program
on “Functional Genomic in Aging, Neurodegenerative
Disorders and Longevity”.
Coordinator Mediterranean-Europian Academy of
Antiaging Medicine
Membership of Scientific
Society:
- S.I.B. Italian Society of
Biochemistry.
- S.I.B.S Italian Society of
Experimental Biology.
- SIBIOC Italian Society of
Clinical Biochemistry
- ISN International Society
of Neurochemistry
- ESN European Society of Neurochemistry
- A4M American Academy Antiaging
Medicine
Areas of Interest
- Role of Oxidative Stress
and Mitochondrial dysfunction in Aging, Neurodegenerative
disorders and Longevity
- Nutritional Antioxidants
and Modulation of cellular redox state.
- Heat shock signal pathway
and brain cell stress response
- Alcohol metabolism and alcohol-related
pathology
- Gasobiology of the CNS:
Role of Nitric Oxide (NO), Carbon Monoxide
(CO) and Hydrogen sulfite (H2S) in the regulation
of gene expression
- Carbon monoxide and organ
transplantation
ABSTRACT
REDOX REGULATION
OF CELLULAR STRESS RESPONSE IN
AGING BRAIN AND LONGEVITY: ROLE OF VITAGENES
Oxidative damage plays a crucial
role in the brain aging process and induction
of heat shock protein (HSPs) is critically utilized
by brain cells in the repair process following
various pathogenic insults. This basic information
has been exploited to develop novel strategies
in clinical therapeutics. Perturbation of cellular
oxidant / antioxidant balance has been claimed
to be involved in the neuropathogenesis of several
disease states, including stroke, Parkinson’s
disease, Alzheimer’s disease and physiological
aging1. However, in contrast to the conventional
idea that reactive species mostly serve as a
trigger for oxidative damage of biological structures,
we now know that low physiologically relevant
concentration of reactive oxygen species can
regulate a variety of key molecular mechanisms.
Oxidative stress, in fact, hqas been demonstrated
to modulate the expression and activity of important
antioxidant enzymes as well as to enhance expression
and/or DNA binding of numerous transcription
factors, including fos, SAPK, NFkB and HSF (heat
shock factor)2. HSF is the transcriptional activator
for the synthesis of cytoprotective proteins
called heat shock proteins (HSPs). HSPs induction
is not only a signal for detection of physiological
stress, but is utilized by the cells in the
repair process following a wide range of injuries3.
Cells constitutively overexpressing HSPs are
resistant to a variety of oxidants and to heat
shock, and it has been suggested that the protective
effect against oxidative injury may result from
protection against oxidant-induced DNA damage4.
In addition, an increasing body of evidence
suggests that dysfunction of cell energy metabolism
is an important factor in NO-mediated neurotoxicity
and that the intracellular content of thiols
is crucial in determining the sensitivity of
cells to oxidative and nitrosative stress5.
Recently, the involvement of the heme oxygenase
(HO) pathway in antidegenerative mechanisms
has received considerable attention, as it has
been demonstrated that the expression of HO
is closely related to that of amyloid precursor
protein (APP). HO induction, which occurs togheter
with the induction of other HSPs during various
physiophatological conditions6, by generating
the vasoactive molecule carbon monoxide and
the potent antioxidant bilirubin could represent
a protective system potentially active against
brain oxidative injury7-10.
We have recently focused our recent research
on the role of carnitine system in cellular
stress tolerance and antidegeneration. In the
present study we investigated, in rats 6, 12
and 28 months old, and in rats 28 months old
receiving for 6 months 1g/Kg/die acetylcarnitine
(LAC), the role of heat shock signals on aging-induced
changes in mitochondrial bioenergetics and antioxidant
status. In all brain regions examined mRNA and
protein synthesis of Hsp70 and Hsp60 increased
with age up to 28 months; at this age the maximum
induction was observed in the hippocampus and
substantia nigra followed by cerebellum, cortex,
and striatum. Hsps induction was associated
with significant changes in glutathione (GSH)
redox state and HNE levels. Interestingly, a
significant positive correlation between decrease
in GSH/GSSG ratio and increase in Hsp70 was
observed in all brain regions examined during
aging. Analysis of mitochondrial complexes showed
a progressive decrease in Complex I activity
and protein synthesis in all brain regions examined
and this was associated with up-regulation of
mRNA complex subunit expression. Interestingly,
treatment with LAC resulted in a marked decrease
in HNE and DPNH content associated with increased
protein expression and activity of the heat
shock protein (Hsp 32, HO-1) heme oxygenase-1,
primarily in the hippocampus, cortex and cerebellum.
Our results sustain a role for GSH redox state
in Hsp expression. In particulaR, increase of
heme oxygenase expression promotes the functional
recovery of oxidatively damaged proteins and
protects cells from progressive age-related
cell damage. Conceivably, therapeutic strategies
focussing on acetylcarnitine treatment, by up-regulating
HO signal pathway and thus increasing bilirubin
levels, may represent a crucial mechanism of
defence against free radical-induced damage
occurring in aging brain and in neurodegenerative
disorders.
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