Identification of axonal growth-relevant genes in the
aged post-stroke brain
Ana – Maria BugaUMF Craiova
Romania
Aging brain and age-related disease• decrease in volume,• cognitive decline, • high risk of neurological disorders- cerebral ischemia and dementia)
Ageing vs Developmental changes
Demography
Ageing-related disease
Stroke, cardiovascular disease, Alzheimer’s, cancer, diabetes, etc
BiochemistryGenetics Cell biology
Regenerative medicine
stem cells
Questions
Genetics?
Are ageing controlled by the genome, and if so what are this changes?
How does changes give rise to ageing-related disease like Stroke and can be this controlled to increase the recovery?
Can we find therapeutically targets to improve the functional recovery and to limit damage ?
Overall Goal and Hypothesis
• Goal:• creating an age-specific databaseusing genome wide analysis of
regeneration associated genes to identify genetic pathways associated with axonal growth/inhibition in response to injuries to the aged central nervous system.
• identification of molecular and cellular mechanisms leading to failure of axonal regeneration after a brain injury in aged animals.
• Our Hypothesis: changes in gene expression level are related with differentiation of tissue involved in development and are associated with functional decline in aging
Mammalian Model for Aging
Young Sprague-Dawley rats
Old Sprague-Dawley rats
Aged-related changes in the transcriptional activity in the brains could be one factor contributing to reduced functional recovery ? If yes can be that changed ?
?
3 days
after stroke
PI CL
14 days
after stroke
PI CL
•Reversible occlusion of the middle cerebral artery (MCAO) with a tungsten hook for 90 min.
Naive young
Naive old
Analysis of genes expression by Gene Profiling
using Affimetrix Arrays and real time PCR
Relative expression values clearly distinguish naive rats from post-stroke groups
Buga et al., PLoS One. 2012, in press
Old vs Young Gene Expression
Old PN 3d vs Young PN 3d
Old PN 14d vs Young PN 14d
Age-specific regulation of gene expression after stroke. Venn diagrams.
Buga et al., PLoS One. 2012, paper in press
Patterns of gene expression after stroke
Buga et al., PLoS One. 2012, paper in press
Major stroke-relevant processes
Buga et al., PLoS One. 2012, paper in press
Identification of therapeutic targets
Conclusion of this part
• (i) to stabilize the infarct size during the early phase of stroke by controlling inflammation and apoptosis
• (ii) to enhance to repair the capacity of the CNS during the rehabilitation phase that starts at the end of the second week post-stroke on a background of stabilized physiology and system homeostasis.
• our findings that stroke impacts a wide range of systems in an age-dependent manner, from CNS physiology to CNS regeneration and plasticity, the failure of therapies aimed at only a single target system is perhaps inevitable. Our results suggest that a multi-stage, multimodal treatment in aged animals may be more likely to produce positive results.
Future directions
• Gene expression analysis in postnatal rats day 3 and 7 (P3 and P7)
• production of siRNA and shRNA (if chronic interference with the gene product is required)
• cell culture transfection to test in vitro the function of specific candidate genes identified in the first part of the project. (Dr Emil Toescu – University of Birmingham, UK)
“One of the oldest person in the world”Jeanne Louise Calment
(Died 1997 at the age of 122 years 164 days)
• Born : February 21, 1875 (Arles-France)• Father died 94, mother died 86• Husband died 1942• Never work throughout her life!• Diet rich in Olive oil + 2 pounds of
chocolate/week• Rode bicycle until the age of 100• At the age of 121, she released 2
documentary CDs of her life & thoughts
“Lived with sense of humor and joy in life”
Thank you for your attention !