Novel insights into the role of NF-κB p50 in astrocyte-mediated fate specification of adult neural progenitor cells

Within the CNS nuclear factor-kappa B（NF-κB） transcription factors are involved in a wide range of functions both in homeostasis and in pathology.Over the years,our and other groups produced a vast array of information on the complex involvement of NF-κB proteins in different aspects of postnatal neurogenesis In particular,several extracellular signals and membrane receptors have been identified as being able to affect neural progenitor cells（NPC） and their progeny via NF-κB activation.A crucial role in the regulation of neuronal fate specification in adult hippocampal NPC is played by the NF-κB p50 subunit.NF-κB p50 KO mice display a remarkable reduction in adult hippocampal neurogenesis which correlates with a selective defect in hippocampal-dependent short-term memory.Moreover absence of NF-κB p50 can profoundly affect the in vitro proneurogenic response of adult hippocampal NPC（ahN PC） to several endogenous signals and drugs.Herein we briefly review the current knowledge on the pivotal role of NF-κB p50 in the regulation of adult hippocampal neurogenesis.In addition we discuss more recent data that further extend the relevance of NF-κB p50 to novel astroglia-derived signals which can influence neuronal specification of ahN PC and to astrocyte-NPC cross-talk.

Not only a bad guy:potential proneurogenic role of the RAGE/NF-κB axis in Alzheimer's disease brain

The receptor for advanced glycation endproducts（RAGE）is a receptor of the immunoglobulin superfamily of cell surface molecules which plays important contributions under both physiological and pathological conditions.Over the years extensive research work supported the detrimental role of RAGE in Alzheimer’s disease（AD）pathophysiology,ranging from its involvement in beta amyloid（Aβ）brain influx and clearance,

β_(2) and α_(2) adrenergic receptors mediate the proneurogenic in vitro effects of norquetiapine

Positive modulation of adult hippocampal neurogenesis may contribute to the therapeutic effects of clinically relevant antidepressant drugs,including atypical antipsychotics.Quetiapine,an antipsychotic which represents a therapeutic option in patients who are resistant to classical antidepressants,promotes adult hippocampal neurogenesis in preclinical studies.Norquetiapine,the key active metabolite of quetiapine in humans,has a distinctive receptor profile than the parent compound.The drug is indeed a high affinity norepinephrine transporter inhibitor and such activity has been proposed to contribute to its antidepressant effect.At present,no information is available on the effects of norquetiapine on adult neurogenesis.We extensively investigated the activity of quetiapine and norquetiapine on adult murine neural stem/progenitor cells and their progeny.Additionally,selective antagonists for β_(2)/α_(2) adrenergic receptors allowed us to evaluate if these receptors could mediate quetiapine and norquetiapine effects.We demonstrated that both drugs elicit in vitro proneurogenic effects but also that norquetiapine had distinctive properties which may depend on its ability to inhibit norepinephrine transporter and involve β_(2)/α_(2) adrenergic receptors.Animal care and experimental procedures were approved by the Institutional Animal Care and Use Committees(IACUC)at University of Piemonte Orientale,Italy(approval No.1033/2015PR)on September 29,2015.

Activation of β2 adrenergic receptors promotes adult hippocampal neurogenesis

The subgranular zone (SGZ) of the hippocampal dentate gyrus is one of the few central nervous system regions where generation of adult born neurons occurs physiologically.This process,referred to as adult hippocampal neurogenesis (ahN),relies on the presence of neural progenitor cells (NPC) in the SGZ neurogenic niche.