Identifying Molecular Ageing signatures of Neural Stem Cells to uncover novel Geroneuroprotectors

There is now a need and an opportunity to improve our understanding of the dynamics and molecular mechanisms of NSC ageing to exploit and control adult human endogenous NSC plasticity to maintain brain function during ageing.

Proposed plan of work:

Objective 1:Uncovering molecular signatures of NSC ageing We have already generated transcriptomic data from hippocampal progenitor cells exposed to young v. old serum. The student will use bioinformatic tools to generate molecular signatures of NSC ageing. Those pathways will be refined to be cognitively relevant with additional transcriptomic data currently being generated looking at old serum from low cognitive performers v. serum from cognitively high performers in adult hippocampal neurogenesis-dependant tasks.

Objective 2:Identifying anti-neuroageing compounds (geroneuroproectors)This objective will initiate clinically feasible strategies to reverse ageing-induced changes identified in Objective 1. For that, drug repurposing is an efficient approach to by-pass lengthy drug development and safety trials. The Thuret lab recently successfully established the first strategy and method to identify drugs to reposition as antidepressants targeting NSC fate and applying connectivity mapping20.Objective 2 will test the hypothesisthat the genome-wide transcriptomic signature of NSC ageing identified in Objective 1 will map the opposite mRNA changes induced by known drugs not previously identified for their anti-ageing potential properties. Connectivity mapping is the use of genome-wide expression data from cultured human cells treated with bioactive small molecules to discover functional associations between drugs, genes and diseases through the feature of shared gene expression changes21. The student will use the ageing stem cell transcriptomic signature identified inObjective 1 to probe the NIH Library of Integrated Network-based Cellular Signatures (LINCS)22to identify compounds among the 20,143 known-drug that elicit opposite changes to mRNA in NSC.

Objective 3:Validating the identifiedgeroneuroproectors Selected identified anti-ageing mimetic drugs in Objective 2 will be validated investigating their efficacy in rescuing (i) cellular ageing phenotypes (Proliferation, stemcellness, cell death, DNA damage, gliogenesis, neurogenesis and neurite outgrowth) as well as (ii) the key ageing molecular pathways in our human hippocampal progenitor cell line. We hypothesizethat the selected geroneuroproectorscan reverse cellular and molecular ageing phenotypes.

Objective 4:Generating a novel in vitro accelerated model of NSC ageing & Cross-validation In order to cross-validate the validated geroneuroproectorsin Objective 3, a novel model of accelerated ageing will be generated. We will create stable and tetracycline inducible Progerin expressing NSCs to induce an age-related phenotype which is characterized by increased mitochondrial reactive oxygen species (mtROS) and increased formation of DNA double strand breaks 23. Validated geroneuroprotectors in Objective 3 will be cross-validated for their potential to reduce or reverse increased mtROS production and DNA Damage.