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Identifier

000465671

Title

In vitro effects of new synthetic and natural compounds on mouse and human Neural Stem Cells and adult neurogenesis in Alzheimer’s Disease.

Alternative Title

In vitro δράσεις νέων συνθετικών και φυσικών αναλόγων σε Νευρικά Βλαστικά Κύτταρα προερχόμενα από το ποντίκι και τον άνθρωπο και στην Ενήλικη Νευρογένεση στη Νόσο Αλτσχάιμερ.

Author

Χαρού, Δέσποινα

Thesis advisor

Χαραλαμπόπουλος, Ιωάννης

Reviewer

Γραβάνης, Αχιλλέας
Αλεξάκη, Βασιλεία-Ισμήνη

Abstract

Neurogenesis in the adult mammalian brain decreases significantly after birth, but key neurogenic niches persist in the cortex and hippocampus in different mammals, including human. Importantly, impaired adult neurogenesis has been linked to Alzheimer’s Disease (AD) pathology, providing a promising new avenue for therapeutic intervention. However, there are important technical challenges in the use of in-vivo models to conduct screens for novel neurogenic drugs, such as the scarcity of neural stem cells (NSCs) in the adult brain, variability between mouse and human models or ethical considerations. In the present PhD thesis, a combination of complementary mouse and human stem cell models were used for in vitro screening and characterization of novel neurogenic compounds, aiming to overcome some of these limitations. Following up on previous work, this drug testing effort focused on brain-derived neurotrophic factor (BDNF), as a crucial neurotrophin regulating neuronal growth and differentiation via its receptor tyrosine receptor kinase B (TrkB). First, an extensive screen of three small molecule libraries from the EuroNeurotrophin consortium is described, assessing compound ability to prevent cell death and promote proliferation via the BDNF/TrkB pathway. Promising candidates were additionally screened using mouse primary adult hippocampal NSCs and embryonic cortical NSCs, investigating if compounds can counter Amyloid-β (Aβ) induced cell death, in the absence of EGF/FGF and promote proliferation, acting specifically through TrkB activation. Selected candidates were also tested for their ability to increase astrocytic gene markers involved in NSC maintenance, protect hippocampal neurons from Αβ toxicity and prevent synapse loss after Aβ treatment. To provide a translational link to human cells, neural progenitor cells (NPCs) differentiated from three human induced pluripotent stem cell (iPSC) lines from healthy and AD donors were also used for further characterization of two top priority candidates. These experiments supported that compounds ENT-A011 and ENT-A061 successfully induced proliferation and prevented cell death after Aβ toxicity of human NPCs. Finally, focusing on ENT-A011, RNA-seq profiling was used to show that the compound acts through a core gene network shared with BDNF, highlighting key aspects of how compound action is mediated in human NPCs. Overall, this work provides a set of new promising synthetic and natural BDNF mimetics with potential neurogenic and neuroprotective actions in AD, including high priority candidates with demonstrated translational interest for downstream testing. Using dedicated stem cell-based screening, this project strived to promote the reuse, reduction and refinement of animal use, demonstrating the promise of stem cell systems for short-listing competitive therapeutic candidates.

Language

English

Subject

BDNF

Human

IPSCS

TRKB

Ανθρώπινα επαγόμενα πολυδύναμα βλαστοκύτταρα

Issue date

2024-07-26

Collection

School/Department--School of Medicine--Department of Medicine--Doctoral theses