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Preparation of Acute Hippocampal Slices from Rats and Transgenic Mice for the Study of Synaptic Alterations during Aging and Amyloid Pathology
Published on: March 23, 2011
Apoptotic proteins in the course of aging of central nervous system in the rat
Jolanta Dorszewska1, Zofia Adamczewska-Goncerzewicz, Józef Szczech
1Department of Clinical Neurochemistry, University of Medical Sciences in Poznan, 49 Przybyszewskiego St., PL 60-355 Poznan, Poland. dorszewskaj@yahoo.com
Abstract:
Studies were performed on the level of cells with damaged DNA (TUNEL), the level of protein engaged in DNA repair (PARP) and the level of proteins indicating the extent of apoptosis (Bax:Bcl-2) (Western blot). The studies were performed on cerebral cortex (GM), white matter (WM), medulla oblongata (MO), cerebellum (C) of rats, 3.0-3.5-, 12-, 24-months of age. The highest levels of DNA injury in GM of 1-year-old rats and in MO of 2-year-old rats were accompanied by peak levels of PARP. In the remaining structures (WM, C) levels of DNA injury showed no correspondence with levels of PARP. Levels of Bax proteins exceeded levels of Blc-2 protein in all cerebral structures of young rats. In old animals, Bax protein continued to exceed Blc-2 levels both in GM and in MO, in which most pronounced fragmentation of DNA was observed. The data indicated that in spite of high level of TUNEL positive cells in aged brain PARP and Bcl-2 are probably engaged in protection of the cells against death.
Insights
Aging brains show DNA damage, but DNA repair proteins PARP and Bcl-2 may protect cells from death. This study investigated these protective mechanisms in rat brain aging.
Area of Science:
- Neuroscience
- Molecular Biology
- Aging Research
Background:
- Cellular aging is associated with DNA damage accumulation.
- Apoptosis and DNA repair mechanisms are critical in maintaining brain health.
- Understanding these processes in aging is crucial for neuroprotection.
Purpose of the Study:
- To investigate DNA damage, DNA repair (PARP), and apoptosis markers (Bax:Bcl-2) in different rat brain regions across aging.
- To determine the relationship between DNA damage and repair/apoptosis proteins in aged brain structures.
Main Methods:
- Western blot analysis was used to quantify protein levels.
- TUNEL assay was employed to detect DNA fragmentation.
- Studies were conducted on rat cerebral cortex (GM), white matter (WM), medulla oblongata (MO), and cerebellum (C) at ages 3.0-3.5, 12, and 24 months.
Main Results:
- Peak DNA injury in gray matter (GM) of 1-year-old rats and medulla oblongata (MO) of 2-year-old rats correlated with high PARP levels.
- DNA injury levels did not correlate with PARP in white matter (WM) and cerebellum (C).
- Bax protein consistently exceeded Bcl-2 levels in all brain regions and ages, with higher levels in GM and MO of aged rats exhibiting significant DNA fragmentation.
Conclusions:
- Despite increased DNA damage in aged rat brains, PARP and Bcl-2 likely play protective roles against cell death.
- The interplay between DNA repair and apoptosis regulation varies across brain regions during aging.
- These findings highlight potential molecular targets for mitigating age-related neurodegeneration.
