Functions of neurotrophins and growth factors in neurogenesis and brain repair

Abstract

The identification and isolation of multipotent neural stem and progenitor cells in the brain, giving rise to neurons, astrocytes, and oligodendrocytes initiated many studies in order to understand basic mechanisms of endogenous neurogenesis and repair mechanisms of the nervous system and to develop novel therapeutic strategies for cellular regeneration therapies in brain disease. A previous review (Trujillo et al., Cytometry A 2009;75:38-53) focused on the importance of extrinsic factors, especially neurotransmitters, for directing migration and neurogenesis in the developing and adult brain. Here, we extend our review discussing the effects of the principal growth and neurotrophic factors as well as their intracellular signal transduction on neurogenesis, fate determination and neuroprotective mechanisms. Many of these mechanisms have been elucidated by in vitro studies for which neural stem cells were isolated, grown as neurospheres, induced to neural differentiation under desired experimental conditions, and analyzed for embryonic, progenitor, and neural marker expression by flow and imaging cytometry techniques. The better understanding of neural stem cells proliferation and differentiation is crucial for any therapeutic intervention aiming at neural stem cell transplantation and recruitment of endogenous repair mechanisms. ' 2012 International Society for Advancement of Cytometry

Bradykinin promotes neuron-generating division of neural progenitor cells through ERK activation

“…Cell proliferation and cell cycle were measured following incubation in culture for 30 min or 2 h with 0.2 mM BrdU (Sigma-Aldrich) (Cappella et al, 2008;Oliveira et al, 2013). Cells were fixed with ice-cold ethanol for at least 4 h, incubated in 1.5 M HCl for 30 min and 0.1 M borate buffer ( pH 8.0) for 5 min.…”

Investigation of Epidermal Growth Factor, Tumor Necrosis Factor-alpha and Thioredoxin System in Rats Exposed to Cerebral Ischemia

“…EGF induces the phosphorylation reactions and alters the morphology of various cell lines derived from the nervous system. EGF plays a role as neurotransmitter or neurotrophic molecule (5,6).…”

Serotonin induces the migration of PC12 cells via the serotonin receptor 6/cAMP/ERK pathway

“…Another possibility is that 5-HT 3 is not sensitive to a 5-HT induction in the experiments of this study. Homma et al (17) suggest a difference of 5-HT sensitivity between differentiated (pretreated with NGF for 3 days) and undifferentiated PC12 cells to enhance neurite outgrowth mediated by 5-HT 3 . In their experiment, 50 µM 5-HT were required to enhance neurite outgrowth of undifferentiated PC12 cells whereas 5 µM of 5-HT were sufficient for differentiated cells.…”

“…Abnormal migration in prenatal and early postnatal brain causes various types of psychiatric diseases, including mental retardation, autism, bipolar disorders and schizophrenia (1,2). Various molecules have been identified as inducers and modulators of the migration including growth/neurotrophic factors and certain types of neurotransmitters (3)(4)(5).…”