Direct effects of estrogens on cholinergic primary neurons from the human fetal nucleus basalis of Meynert

Epidemiological studies have indicated that Alzheimer’s disease (AD) is more common in females and that post-menopausal women are at increased risk than their male counterpart, thus suggesting that estrogens could play a protective role to counteract neurodegenerative processes (1). However, the mechanisms underlying this association remain to be clarified. Since the nucleus basalis of Meynert (nbM) is the major source of cholinergic innervation selectively vulnerable to degeneration in AD, our study is aimed at investigating the effects of estrogens on human cholinergic primary neurons (hfCNs) isolated from the nbM of 12-week old fetuses. The primary culture obtained was immunophenotyped with flow cytometry and resulted almost totally positive (97±2 %) for the neuronal marker MAP2 and for the choline acetyltransferase (ChAT). We demonstrated that hfCNs express receptors for hormones of the reproductive axis (ERs, LHR, GnRHR). In particular, besides to classical estrogen receptors (ERa and ERb), hfCNs express the transmembrane receptor GPR30, which is known to mediate rapid non-genomic estrogen actions. Increasing concentrations of 17-β estradiol (E2, 0.1-100 nM) determined a dose-dependent significant increase in cell number after 24h exposure, which was antagonized by tamoxifen treatment. In addition, E2 exposure determined a significant increase in ChAT expression, thus indicating a direct positive effect of E2 on cholinergic phenotype. Given that substantial evidence now indicates that estrogens exert an anti-inflammatory activity even in the central nervous system (2), we exposed hfCN cells to the proinflammatory cytokine TNFα. E2 treatment (1nM) was able to significantly counteract the TNFα-induced nuclear NF-kB p65 translocation. Interestingly, this effect was mimicked by G1, a GPR30 agonist, and abolished by pretreating cells with the GPR30 antagonist G15, but not by tamoxifen, which usually antagonizes classical ERs. Overall, our results indicate that estrogens exert direct neuroprotective mechanisms on hfCNs through the activation of either classical (trophic) and non-classical (anti-inflammatory) receptors

Dance to enhance the cognitive and physical abilities in elderly individuals

for measures preserving the independence and maintaining the quality of life in elderly individuals. Numerous researches have shown that regular and structured physical activity is associated with successful aging (Vogel et al., 2009). Physical activity appropriated for older adults should include a multicomponent exercise program of moderate aerobic activities, strength training, balance and flexibility exercises. In particular, the physical activity should be personalized and adapted to the specific needs of each subject. Structured specific program of Adapted Physical Activity can prevent and/or reduce the functional decline correlated with aging. Among the various physical activities, recent studies suggest that dancing is a type of physical activity that may allow elderly adults to improve their physical function, health and well-being, and to maintain cognitive function (Hui et al., 2009; Kattenstroth et al., 2010). We investigated the potential cognitive and physical benefits deriving from practice of Dance respect to Adapted Physical Activity participation and not practice of physical activity in leisure time, in 150 healthy elderly subjects (80 women and 70 men; mean age 68,4 ± 0,25). All participants were assessed with a battery of cognitive tests using Attention and Concentration Software by Erickson and underwent fitness tests as Tinetti test and sit and reach. Moreover, subjects filled out the SF-12 questionnaire to assess their quality of life and structured questionnaire to evaluate the participation in leisure cognitive activities (reading books or newspapers, doing crossword puzzles, etc.). Our results demonstrated that subjects practicing Dance or Adapted Physical Activity are statistically better in all proposed tests than the sedentary individuals. In particular, subjects who practice dance, show results significantly better in cognitive tests compared with Adapted Physical Activity. Dance, given its peculiar characteristics, results an effective physical activity in maintaining the cognitive and physical functions and an alternatively training feasible in elderly subjects. Increased self-esteem, social contact and psychophysical wellness significantly ameliorate the quality of life during aging

Primary cell culture from human striatal primordium. Contribution to research on neuronal plasticity

Throughout fetal life, striatal neurons originated in the ganglionic eminence from a population of dividing stem cells. Little is known about the molecular mechanisms that regulate the activation, self-renewal and differentiation of striatal neuronal precursors. In order to identify the regulatory mechanisms controlling striatal cell neurogenesis and differentiation, we have recently isolated and propagated in vitro primary cell cultures from the human fetal striatal primordium (1). These cells express both neuronal and striatal properties, and are responsive to BDNF and FGF2. In this study, we found that human striatal precursor (HSP) cells are a mixed population mainly constituted of neuronal-restricted progenitors and striatal neurons (DARPP32-, GAD1-expressing cells) and neural/stem cells, which under specific in vitro differentiating conditions not only generate neurons, astrocytes and oligodendrocytes, but also possess the ability of osteogenic differentiation. We also observed that BDNF and FGF2 exert different effects on HSP depending on the differentiation state of these cells. In fact, both neurotrophins promote cell proliferation, migration and the expression of neural stem/progenitor markers in undifferentiated HSP cells, while they stimulate neuritogenesis in the neuronal differentiated component as demonstrated after specific neuronal induction. We have previously reported that striatal primordium from human fetus was able to grow into the brain of Huntington’s disease (HD) patients and that this process was associated with metabolic change and some clinical benefit (2,3). Our results add new insight into the developmental processes of human fetal striatal grafts in HD and, in addition, have implications for cell based transplantation approaches in the CNS

FGF2 and ET1 promote human fetal striatal neuroblasts survival in hypoxic conditions

Fetal striatal transplantation emerged as a new strategy to promote reparative responses in Huntington’s disease (HD) patients1. Mechanisms that support neuroblasts survival and replenishment of damaged cells within the HD brain in hypoxia remain to be elucidated. This study investigated how human fetal striatal neuroblasts (HSP cells) respond to hypoxia, using the hypoxia-mimetic agent cobalt chloride (CoCl2)2. We analyzed CoCl2 effect on hypoxia-related proteins, such as HIF-1α and VEGF, and on a neuroprotective factor, such as Seladin-1. Moreover, we evaluated FGF2 (50 ng/ml) and ET1 (100 nM) proliferative/survival effects in HSP cells in normoxic and hypoxic conditions. These growth factors could be important mediators under pathological conditions for striatal neuroblasts function and response to hypoxia. Dose-response experiments with increasing concentration of CoCl2 (50-750 um) showed an increase of HSP cell proliferation at 24-48h, with maximal effects observed at 400 um, while cell survival was impaired at 72h. Hypoxia increased protein expressions of HIF-1α and VEGF, whereas decreased Seladin-1 levels. FGF2 and ET1 significantly stimulated HSP cells proliferation both in normoxic and hypoxic condition, counteracting the apoptotic CoCl2 effect at 72h. FGF2 and ET1 neuroprotective effect was abolished by the selective inhibition of their receptors (FGFR1, ETA and ETB). In particular, ET1 stimulated HSP cells survival through ETA receptor in normoxic condition and through ETB receptor during hypoxia. Our results support the idea that FGF2 and ET1 promote neurogenesis and survival of HSP cells, through receptor-mediated mechanisms, when grafted into the hypoxic HD brain