Monday 04/23 - Geraldine GONTIER : Role of Tet2 in regulating neurogenesis and cognition during aging

23 - Avril - 2018

Presupposed dogma indicates that the old brain is unable to combat the effects of aging due to a lack of inherent plasticity that facilitates permanent age-related functional impairments. The discovery of neural stem cells in the adult brain has incited possibilities for restoring regenerative and cognitive function in the elderly by enhancing adult neurogenesis in the aged brain. To date, we and others, have begun to challenge dogma by demonstrating that systemic manipulations, such as heterochronic parabiosis (in which the circulatory systems of young and old animals are connected), can restore adult neurogenesis and rejuvenate cognitive function in the aged brain1-3. Excitingly, the ability to reverse aging in the brain could have wide ranging implications for maintaining functional brain integrity and counteracting vulnerability to dementia-related neurodegenerative diseases, such as Alzheimer’s disease. However, molecular mechanisms mediating neurogenic rejuvenation remain elusive. We report that the epigenetic regulator ten eleven translocation methylcytosine dioxygenase 2 (Tet2) –which catalyzes the production of 5-hydroxymethylcytosine (5hmC)– rescues age-related decline in adult neurogenesis. Interestingly, we detected a decrease in Tet2 expression and 5hmC levels in the aged hippocampus associated with neurogenesis. Mimicking an aged condition in young adults by abrogating Tet2 expression within the hippocampal neurogenic niche, or in adult neural stem cells, decreased neurogenesis and impaired learning and memory. In a heterochronic parabiosis model of neurogenic rejuvenation hippocampal Tet2 expression was restored. Moreover, overexpressing Tet2 in the hippocampal neurogenic niche of mature adults increased 5hmC associated with neurogenic processes, offset the precipitous age-related decline in neurogenesis, and enhanced learning and memory4. Our data identify Tet2 as a novel epigenetic mechanism of neurogenic rejuvenation.

1 - Villeda SA et al, Nature, 2011

2 - Villeda SA et al, Nat. Med, 2014

3 - Smith LK et al, Nat. Med, 2015

4 - Gontier G et al, Cell Report 2018

Invitée par Martin Holzenberger (

Centre de Recherche (CdR) Saint-Antoine INSERM - UMR S 938

Hôpital St-Antoine


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Saint-Antoine Research Center
The CRSA was renewed jointly by Inserm and UPMC as UMRS_938, for 5 years from January 2014 to December 2018.
Presentation of the Centre

The CRSA regroups a very strong potential for biomedical research oriented towards both fundamental and translational research. Research is performed in association with the clinical and biological departments of the Saint-Antoine-Tenon-Armand Trousseau hospitals belonging to the same General Hospital Group. The CRSA is composed of 13 accredited research teams and one administrative team located mainly on the site of the Saint-Antoine hospital but also of hospital Armand Trousseau.

Scientific activities

Two scientific interacting orientations are identified: Research in Oncology and Haematology; and Research in Metabolism and Inflammation and Tissue Repair. They include several aspects of translational research : Fundamental; Preclinical; Pathophysiological and Aspects more specifically clinical.

Collective facilities and technological platforms

The Research Centre developed collective facilities (such as L2, L3 laboratories) but is also implicated in UPMC networks (for technologies such as Mass spectrometry, lipidomic and proteomic; Cell and tissue imagery and flow cytometry ; Imagery and functional exploration of small animals)