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 !