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Aim there is evidence of significant clinical sequelae of COVID-19 that may impair both life length and its quality. Aim of this study was to assess the long-term consequences of moderate to severe SARS-CoV-2-related pneumonia in patients requiring high-flow oxygen treatment. Methods This prospective follow-up study included 45 patients with confirmed COVID-19 admitted to a medical ward at the Montichiari Hospital, Brescia, Italy from November 2020 to April 2021 Patients had COVID-19 related pneumonia with respiratory failure and needed at least treatment with an inspired fraction of oxygen of 40% (of them, 59% were treated with Venturi mask and 41% needed non-invasive ventilation). Patients underwent a clinical assessment with standard laboratory testing, chest CT scan, lung function tests with DLCO, and evaluation of vital parameters after a mean of 382 days after hospital discharge. A quality-of-life questionnaire was administered to each willing patient. Results See table for details. While standard laboratory testing showed a substantial normalization, we found persistence of radiological alterations (i.e. ground-glass opacities, irregular linear/reticular opacities) in 61% of patients; mean Tiffenau index (FEV1/FVC) was reduced, although not clearly pathologic (79%) and 38% of patients showed a mild to moderate reduction in CO lung diffusion (DLCO). Interestingly, 54% of subjects showed concomitant presence of radiologic alterations AND persistence of dyspnea OR reduction in CO lung diffusion, while 21% had all three concomitant conditions, compatible with the diagnosis of lung fibrosis. Overall, a total of 75% patients had some degree of functional or structural alteration of respiratory apparatus. We also evaluated quality of life thorough a structured questionnaire: after more than one year 62% of the patients still lamented fatigue, 62% effort dyspnea, 12% anorexia, 29% dysgeusia or anosmia, 31% insomnia and 43% anxiety. Conclusions these data seem to demonstrate that SARS-CoV-2-related pneumonia requiring high flow oxygen has a heavy long-term burden, both in terms of persistence of functional and structural pulmonary damage (which may be progressive and evolve to a more severe degree) and of burden on overall quality daily life.

Introduction COVID-19 pandemic still represents a major clinical problem worldwide. Many studies are actively being carried out to better understand prognostic factors of outcome as well as optimal treatment. Aim ACE-2 receptor is highly expressed on the surface of cardiac and pulmonary cells, and it is used by coronaviruses to enter host cells; this makes the role of ACE-inhibitors and Angiotensin Receptor Blockers (ARBs) drugs controversial. Moreover, it is still unclear whether these drugs may have any impact on sequelae. Methods In this retrospective study, we analysed a group of 244 hypertensive unvaccinated patients (134 on ACE-inhibitors, 110 on ARBs) admitted for moderate to severe COVID-19 pneumonia. As shown in the table, the two groups where homogeneous. Of these patients, 46 (20 treated with ACE-I and 26 treated with ARBs) came to a follow-up visit after a mean of 260 days; they underwent a quality-of-life assessment, laboratory and radiologic tests and spirometry (with DLCO). Results A total of 20 of 110 (18%) patients under treatment with ARBs and 23 of 134 (17%) died during hospitalization (p=0.8, NS). At discharge, biochemical, radiological and respiratory data were not significantly different. We did not find any significant difference in terms of radiologic alterations, lung fibrosis, spirometry data, DLCO, persisting effort dyspnea. Biochemical data were substantially super-imposable in the two groups. Conclusions we could not detect any difference in outcome nor in complications type or number in the two groups undergoing treatment with ACE-inhibitor or ARBs. This result seems to support and to strengthen the idea that ACE-inhibitors and ARBs do not play a significant role in onset, evolution and outcome of moderate to severe COVID-19 pneumoniae. Although the number of follow-up patients is small, we did not find any difference in follow-up sequelae in both groups.

Coronavirus disease 2019 (COVID-19) represents a major health problem in terms of deaths and long-term sequelae. We conducted a retrospective cohort study at Montichiari Hospital (Brescia, Italy) to better understand the determinants of outcome in two different COVID-19 outbreaks. A total of 634 unvaccinated patients admitted from local emergency room to the Internal Medicine ward with a confirmed diagnosis of SARS-CoV-2 infection and a moderate-to-severe COVID-19 were included in the study. A group of 260 consecutive patients during SARS-CoV-2 first wave (from February to May 2020) and 374 consecutive patients during SARS-CoV-2 2nd/3rd wave (from October 2020 to May 2021) were considered. Demographic data were not significantly different between waves, except a lower prevalence of female sex during first wave. Mortality was significantly higher during the 1st wave than in the following periods (24.2% vs. 11%; p p p

The aim of the study was to assess the short-term consequences of SARS-CoV-2-related pneumonia, also in relation to radiologic/laboratory/clinical indices of risk at baseline. This prospective follow-up cohort study included 94 patients with confirmed COVID-19 admitted to a medical ward at the Montichiari Hospital, Brescia, Italy from February 28th to April 30th, 2020. Patients had COVID-19 related pneumonia with respiratory failure. Ninety-four patients out of 193 survivors accepted to be re-evaluated after discharge, on average after 4 months. In ¼ of the patients an evidence of pulmonary fibrosis was detected, as indicated by an altered diffusing capacity of the lung for carbon monoxide (DLCO); in 6–7% of patients the alteration was classified as of moderate/severe degree. We also evaluated quality of life thorough a structured questionnaire: 52% of the patients still lamented fatigue, 36% effort dyspnea, 10% anorexia, 14% dysgeusia or anosmia, 31% insomnia and 21% anxiety. Finally, we evaluated three prognostic indices (the Brixia radiologic score, the Charlson Comorbidity Index and the 4C mortality score) in terms of prediction of the clinical consequences of the disease. All of them significantly predicted the extent of short-term lung involvement. In conclusion, our study demonstrated that SARS-CoV-2-related pneumonia is associated to relevant short-term clinical consequences, both in terms of persistence of symptoms and in terms of impairment of DLCO (indicator of a possible development of pulmonary fibrosis); some severity indices of the disease may predict short-term clinical outcome. Further studies are needed to ascertain whether such manifestations may persist long-term.

Glucagon-like peptide 1-receptor agonists (incretin mimetics) and dipeptidyl peptidase-4 inhibitors (incretin enhancers) have been recently introduced in the treatment of diabetes mellitus. In particular, incretin mimetics seems to have ancillary antioxidant/antinflammatory properties that might be involved in endothelial protection. To investigate the effect of incretin mimetic therapy (liraglutide, exenatide) given to 11 patients with type 2 diabetes mellitus, on circulating endothelial progenitor cells (EPCs) (bone marrow-derived cells possibly participating in neovascularization and endothelial protection and repair) and capillary density. Four diabetic patients were treated with exenatide (5 μg twice daily for 4 weeks and then 10 μg twice daily for 3 weeks) and 7 with liraglutide (0.6 mg per day for 1 week and then 1.2 mg per day for 3 weeks). Peripheral venous blood samples were obtained before treatment (basal) and after 4 week in patients treated with liraglutide, and after 4 and 7 weeks in patients treated with exenatide, since drug titration is usually longer. EPCs were evaluated by flow cytometry as CD34+/KDR+ cells. Capillary density was evaluated by videomicroscopy, before and after venous congestion, in the dorsum of the 4th finger. Patients treated with liraglutide (6 males 1 female, age 54 ± 12 years) showed a decrease in body mass index and blood pressure during treatment, while patients treated with exenatide (3 males 1 female, age 57 ± 6 years) did not show any relevant change. EPCs were significantly increased after treatment with exenatide, but not after treatment with liraglutide. Capillary density was slightly increased only after 4 weeks of treatment with exenatide, however the increase was no longer present at the final evaluation. Treatment with exenatide, but not with liraglutide, was able to increase the number of circulating EPCs, possibly through an antioxidative/antiinflammatory effect.

The use of different natural and/or synthetic preparations ofCannabis sativais associated with therapeutic strategies for many diseases. Indeed, thanks to the widespread diffusion of the cannabinoidergic system in the brain and in the peripheral districts, its stimulation, or inhibition, regulates many pathophysiological phenomena. In particular, central activation of the cannabinoidergic system modulates the limbic and mesolimbic response which leads to food craving. Moreover, cannabinoid agonists are able to reduce inflammatory response. In this review a brief history of cannabinoids and the protagonists of the endocannabinoidergic system, i.e. synthesis and degradation enzymes and main receptors, will be described. Furthermore, the pharmacological effects of cannabinoids will be outlined. An overview of the involvement of the endocannabinoidergic system in neuroinflammatory and metabolic pathologies will be made. Finally, particular attention will also be given to the new pharmacological entities acting on the two main receptors, cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 2 (CB2), with particular focus on the neuroinflammatory and metabolic mechanisms involved.

Aim Oxidative stress is considered one of the main events that lead to aging and neurodegeneration. Antioxidant treatments used to counteract oxidative damage have been associated with a wide variety of side effects or at the utmost to be ineffective. The aim of the present study was to investigate the antioxidant property of a natural mineral, the tribomechanically micronized zeolite (MZ). Main methods Cell death and oxidative stress were assessed in retinoic acid differentiated SH-SY5Y cells, a neuronal-like cell line, after a pro-oxidant stimulus. In vivo evaluation of antioxidant activity and amyloidogenic processing of beta amyloid have been evaluated in a transgenic model of aging related neurodegeneration, the APPswePS1dE9 transgenic mice (tg mice) after a five-month long period of water supplementation with MZ. Key findings The study showed that 24 h of cell pretreatment with MZ (1) protected the cells by radical oxygen species (ROS)-induced cell death and moreover (2) induced a reduction of the mitochondrial ROS production following a pro-oxidant stimulation. Looking for an antioxidant effect of MZ in vivo, we found (3) an increased activity of the endogenous antioxidant enzyme superoxide dismutase (SOD) in the hippocampus of tg mice and (4) a reduction in amyloid levels and plaque load in MZ treated tg mice compared to control tg mice. Significance Our results suggest MZ as a novel potential adjuvant in counteracting oxidative stress and plaque accumulation in the field of neurodegenerative diseases.

Background Neuroblastoma is the most common extracranial solid malignancy in childhood, responsible for 15% of all pediatric cancer deaths. It is an heterogeneous disease that does not always respond to classical therapy; so the identification of new and specific molecular targets to improve existing therapy is needed. We have previously demonstrated the involvement of the Notch pathway in the onset and progression of neuroblastoma. In this study we further investigated the role of Notch signaling and identified Delta-like 1 (DLL1) as a novel molecular target in neuroblastoma cells with a high degree of MYCN amplification, which is a major oncogenic driver in neuroblastoma. The possibility to act on DLL1 expression levels by using microRNAs (miRNAs) was assessed. Methods DLL1 mRNA and protein expression levels were measured in three different neuroblastoma cell lines using quantitative real-time PCR and Western Blot analysis, respectively. Activation of the Notch pathway as a result of increased levels of DLL1 was analyzed by Immunofluorescence and Western Blot methods. In silico tools revealed the possibility to act on DLL1 expression levels with miRNAs, in particular with the miRNA-34 family. Neuroblastoma cells were transfected with miRNA-34 family members, and the effect of miRNAs transfection on DLL1 mRNA expression levels, on cell differentiation, proliferation and apoptosis was measured. Results In this study, the DLL1 ligand was identified as the Notch pathway component highly expressed in neuroblastoma cells with MYCN amplification. In silico analysis demonstrated that DLL1 is one of the targets of miRNA-34 family members that maps on chromosome regions that are frequently deregulated or deleted in neuroblastoma. We studied the possibility to use miRNAs to target DLL1. Among all miRNA-34 family members, miRNA-34b is able to significantly downregulate DLL1 mRNA expression levels, to arrest cell proliferation and to induce neuronal differentiation in malignant neuroblastoma cells. Conclusions Targeted therapies have emerged as new strategies for cancer treatment. This study identified the Notch ligand DLL1 as a novel and attractive molecular target in childhood neuroblastoma and its results could help to devise a targeted therapy using miRNAs. Electronic supplementary material The online version of this article (doi:10.1186/s12885-017-3340-3) contains supplementary material, which is available to authorized users.

A neuropathological characteristic of Alzheimer's disease is the extracellular accumulation of amyloid beta peptide (Abeta) in neuritic plaques. Recent evidences suggested that soluble Abeta oligomers are the predominant neurotoxic species for neurons. Thus, considerable attention has been paid to discriminate the cytotoxic pathways of Abeta pre-fibrillar aggregates and mature fibrils. We showed that the mechanisms by which Abeta oligomers and fibrils generated reactive oxygen species differ in terms of site of production and kinetics, suggesting the involvement of different intra/extracellular pathways.

The appropriate level of microtubule stability is fundamental in neurons to assure correct polarity, migration, vesicles transport and to prevent axonal degeneration. In the present study, we have identified Notch pathway as an endogenous microtubule stabilizer. Stimulation of Notch receptors by exposure of mouse cortical neurons to the Notch ligand Jagged1 resulted in increased microtubule stability, as measured by using antibodies against post-translationally modified α tubulin, and changes in axonal morphology and branching, with varicosity loss, thicker neurites and enlarged growth cones. Similar effects were found after exposure of the cells to different doses of Taxol. However, contrary to Taxol, Jagged1 induced downregulation of the microtubule severing protein Spastin. We suggest that a fine-tuned manipulation of Notch signaling may represent a novel approach to modulate neuronal cytoskeleton plasticity.

Neurogenesis proceeds throughout adulthood in the brain of most mammalian species, but the molecular mechanisms underlying the regulation of stem/progenitor cell proliferation, survival, maturation, and differentiation have not been completely unraveled. We have studied hippocampal neurogenesis in NF-κB p50-deficient mice. Here we demonstrate that in absence of p50, the net rate of neural precursor proliferation does not change, but some of the steps leading to the final neuron differentiation status are hampered, resulting in ∼50% reduction in the number of newly born neurons in the adult mutant hippocampus. Additionally, in p50−/−mice, we observed a selective defect in short-term spatial memory performance without impairment of hippocampal-dependent spatial long-term memory and learning. Our results highlight the role of NF-κB p50 in hippocampal neurogenesis and in short-term spatial memory.

The study summarizes some recent data from our and other groups underlining the contribution to neurodegeneration of two transcription factors known to be involved in DNA damage sensing and repairing: the tumour suppressor gene p53 and the component of the DNA repair system MSH2. Both proteins participate in the cancer prevention machinery for the body as well as in the neurodegenerative process, suggesting that cancer and neurodegenerative disease may share common genetic risk factors for the development and progression of the disease. Here we show that, in neuronal cells, divergent cellular insults, i.e. the exposure to glutamate, beta-amyloid (Abeta) or H(2)O(2), may converge to a common pathway that initiate with elevation of p53 protein levels. We also found that in SH-SY5Y neuronal cells H(2)O(2) induced the activation of DNA repair system with the nuclear translocation of MSH2, and PCNA. Differently no changes in MSH2 and PCNA cellular distribution were found in undifferentiating SH-SY5Y cells exposed to H(2)O(2). This argues that defects in the repair of, or response to, DNA damage impact significantly on brain function.

Functional and structural plasticity is a fundamental property of the brain involving chemical, electrical, molecular and cellular responses and leading to reorganization of connections within a brain region and/or between brain regions. The Notch pathway has been recognized as one of the main contributors in regulating neural development and has been proposed as a key mediator in neuroplasticity. We supported this concept, demonstrating that Notch plays a role in determining the only possible ‘cell fate' decisions in post-mitotic mature neurons: synaptic remodelling or neurite extension/retraction. We demonstrated that Notch pathway activation causes a decrease in neurite branching and a loss of varicosities, with consequent reduction in the release of neurotransmitters. Furthermore, in dysfunctional neurons that present Notch pathway hyper-activation, neuronal morphology was reverted by Notch-inhibiting agents. Potentially, a better understanding of the molecular events participating in neuroplasticity may provide relevant information for innovative therapeutic approaches in a variety of neurological disorders. Hence, we propose a Notch-signalling fine-tuned manipulation as a novel approach to modulate neuronal cytoskeleton plasticity in order to prevent dysfunctional structural plasticity in neurodegenerative diseases.

This study points out different behaviour between HEK cells overexpressing wild-type or mutant APP when exposed to oxidative insult. Although apparently both APPwt and APPmut overexpression conferred resistance to oxidative insult, some differences in terms of degree of protection was observed in the two clones. We found that the two clones differed, especially, in terms of redox profile. HEK-APPmut cells were characterized by higher levels of oxidative markers in comparison with HEK-APPwt. In addition, SOD activity appeared more efficient in HEK-APPwt than in HEK-APPmut, thus justifying the differences in terms of cell survival in the two clones. We suggest that, according to “hormesis theory”, in HEK-APPwt cells low amount of oxidative stress can exert a beneficial effect that at a higher intensity results harmful. In contrast, HEK-APPmut cells lost this stress resistance probably because the degree of oxidative stress is too high and the antioxidant enzymes are themselves compromised.

Background Pramipexole exists as two isomers. The S(-) enantiomer is a potent D3/D2 receptor agonist and is extensively used in the management of PD. In contrast, the R(+) enantiomer is virtually devoid of any of the DA agonist effects. Very limited studies are available to characterize the pharmacological spectrum of the R(+) enantiomer of pramipexole. Results Using differentiated SH-SY5Y neuroblastoma cells as an experimental model, here we show that S(-) and R(+) pramipexole are endowed with equipotent efficacy in preventing cell death induced by H2O2 and inhibiting mitochondrial reactive oxygen species generation. Both pramipexole enantiomers prevented mitochondrial ROS generation with a potency about ten times higher then that elicited for neuroprotection. Conclusions These results support the concept of both S(-) and R(+) pramipexole enantiomers as mitochondria-targeted antioxidants and suggest that the antioxidant, neuroprotective activity of these drugs is independent of both the chiral 6-propylamino group in the pramipexole molecule and the DA receptor stimulation.

Notch proteins are definitely recognized as key regulators of the neuronal fate during embryo development, but their function in the adult brain is still largely unknown. We have previously demonstrated that Notch pathway stimulation increases microtubules stability followed by the remodeling of neuronal morphology with neurite varicosities loss, thicker neuritis, and enlarged growth cones. Here we show that the neurite remodeling is a dynamic event, dependent on transcription and translation, and with functional implications. Exposure of differentiated human SH-SY5Y neuroblastoma cells to the Notch ligand Jagged1 induces varicosities loss all along the neurites, accompanied by the redistribution of presynaptic vesicles and the decrease in neurotransmitters release. As evaluated by time lapse digital imaging, dynamic changes in neurite morphology were rapidly reversible and dependent on the activation of the Notch signaling pathway. In fact, it was prevented by the inhibition of the proteolytic gamma-secretase enzyme or the transcription machinery, and was mimicked by the transfection of the intracellular domain of Notch. One hour after treatment with Jagged1, several genes were downregulated. Many of these genes encode proteins that are known to be involved in protein synthesis. These data suggest that in adult neurons, Notch pathway activates a transcriptional program that regulates the equilibrium between varicosities formation and varicosities loss in the neuronal presynaptic compartment involving the expression and redistribution of both structural and functional proteins.

Dopamine agonists have been usually used as adjunctive therapy for the cure of Parkinson's disease. It is generally believed that treatment with these drugs is symptomatic rather than curative and it does not stop or delay the progression of neuronal degeneration. However, several dopamine agonists of the D2-receptor family have recently been shown to possess neuroprotective properties in different in vitro and in vivo experimental Parkinson's disease models. Here we summarize some recent molecular evidences underlining the wide pharmacological spectrum of dopamine agonists currently used for treating Parkinson's disease patients. In particular, the mechanism of action of different dopamine agonists does not always appear to be restricted to the stimulation of selective dopamine receptor subtypes since at least some of these drugs are endowed with antioxidant, antiapoptotic or neurotrophic properties. These neuroprotective activities are molecule-specific and may contribute to the clinical efficacy of these drugs for the treatment of chronic and progressive neurodegenerative diseases in which oxidative injury and/or protein misfolding and aggregation exert a primary role.

Here we show that human embryonic kidney (HEK) cells stably transfected with amyloid precursor protein (HEK-APP), expressed a conformational mutant-like and transcriptionally inactive p53 isoform, and turned out to be less sensitive to the cytotoxin doxorubicin in comparison with untransfected cells. Treatment of HEK-APP cells with gamma- and beta-secretase inhibitors prevented generation of unfolded, mutant-like p53 isoform and made the cells vulnerable to doxorubicin as untransfected cells. Changes in p53 conformational state and reduced sensitivity to doxorubicin were also found in untransfected HEK cells after exposure to nanomolar concentrations of beta-amyloid (Abeta) and these effects were antagonized by vitamin E. The modulator effects of Abeta on p53 conformational state were, at least in part, due to the intracellular peptides as (i) treatment of HEK-APP cells with an antibody that sequestered extracellular Abeta did not modify the capability of the cells to express the mutant-like p53 isoform; (ii) in the presence of 1% serum exogenous Abeta peptide crossed the plasma membrane, as demonstrated by confocal analysis and ELISA, and induced p53 conformational change; and (iii) in the presence of 10% serum Abeta did not enter the cells and consequently did not influence the p53 conformational state.

The role of angiogenesis in tumour progression is a major subject in modern oncology and a correlation between angiogenesis and poor outcome has been demonstrated for human neuroblastomas. However, the role of angiogenesis in the maturation phase of neuroblastic tumours has never been considered. Human carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), a potent pro-angiogenic factor and mediator of vascular endothelial growth factor (VEGF)-induced angiogenesis, plays a crucial role during the activation phase of angiogenesis and it has been shown to be expressed in the microvessels of the developing central nervous system as well as in newly formed immature blood vessels in many different tumours and under physiological conditions. The present study has investigated the role of CEACAM1/VEGF-mediated angiogenesis across the whole spectrum of neuroblastic tumours, from undifferentiated to fully differentiated mature ganglioneuromas. CEACAM1 is peculiarly expressed in the microvessels of areas of active tumour maturation among differentiating neuroblastic/ganglion cells, whereas it is completely absent in the vessels of poorly differentiated/undifferentiated as well as in entirely mature Schwannian-rich areas. Interestingly, VEGF expression has been found in differentiating neuroblastic/ganglion cells adjacent to CEACAM1-positive microvessels. In keeping with these observations, VEGF expression was found in human neuroblastoma SH-SY5Y cells during differentiation after retinoic acid treatment. Moreover, conditioned medium from SH-SY5Y cells collected at different stages of differentiation induced progressive in vitro up-regulation of CEACAM1 expression in human umbilical vein endothelial cells (HUVECs) that was abrogated by the specific VEGF receptor-2/KDR inhibitor SU5416. Taken together, these data point to a role for CEACAM1/VEGF cross-talk during the maturation phase of neuroblastic tumours. This may mimic physiological events leading to maturation of the vasculature in the developing normal central nervous system. On the other hand, in poorly differentiated/undifferentiated lesions, VEGF-sustained angiogenesis does not reproduce physiological steps, but rather is associated with tumour aggressiveness and may involve other molecular pathways.

Dopaminergic agonists have been usually used as adjunctive therapy for the cure of Parkinson’s disease (PD). It is generally believed that treatment with these drugs is symptomatic rather then curative and does not stop or delay the progression of neuronal degeneration. However, several DA agonists of the DA D2–receptor family (including D2, D3 and D4-subtypes) have recently been shown to possess neuroprotective properties in different in vitro and in vivo experimental PD models. Here we summarize some recent data from our and other groups underlining the wide pharmacological spectrum of DA agonists currently used for treating PD patients. In particular, the mechanism of action of different DA agonists does not appear to be restricted to the stimulation of selective DA receptor subtypes being these drugs endowed with intrinsic, independent, and peculiar antioxidant effects. This activity may represent an additional pharmacological property contributing to their clinical efficacy in PD.

The mismatch repair system (MMR) is an important member of the DNA checkpoint, that includes a number of protein deputed to control genomic stability through cell cycle arrest, DNA repair, and apoptosis. Here we summarize some recent data from our and other groups underlining the contribution to neurodegeneration of MSH2, perhaps the most relevant component of the MMR system. These data suggest that this protein participates not only in the cancer prevention machinery for the body but also in neurodegenerative processes.

Early onset generalized dystonia is a severe form of primary dystonia linked to a mutation of the DYT1(TOR1A) gene on chromosome 9q34. DYT1 gene codifies for human torsinA, an AAA+ ATPase associated with the membranes of endoplasmic reticulum (ER) and the synaptic vesicles and proposed to be involved in trafficking of tubular–vesicular membrane through neuronal processes. In this study, the presence and the intracellular distribution of torsinA protein in SH-SY5Y neuroblastoma cells were evaluated by immunofluorescence and Western blot analysis following differentiation with retinoic acid and BDNF. Protein expression was then inhibited by transient antisense transfection and the possible effect on neurite outgrowth was observed. In SH-SY5Y cells torsinA, with an apparent MW of 38 kDa, is endogenously present and distributed, with a punctate pattern, in the cytosol and along the neurites. The protein showed high intensity of immunoreactivity in the neurite varicosities and was partially co-localized with vesicles markers. Terminally differentiated cells showed an increase of protein expression. Oligonucleotide antisense treatment induced a significant response to differentiating stimuli, lead to sprouting of longer neurites and increase in growth cone areas. A relationship between torsinA and tau protein, which is involved in axon elongation and establishment of neuronal polarity, was demonstrated by co-immunoprecipitation experiments. These findings suggest that torsinA, throughout the interaction with microtubule associated proteins, may contribute to control neurite outgrowth and could be involved in maintaining cell polarity.

An association has recently been suggested between several of the genes and proteins that play a central role in early neuronal development, particularly in neuronal migration and axon elongation, and Alzheimer's disease (AD). This paper reviews the work of several investigators who have hypothesised the involvement of three pathways known to be active participants in neuronal maturation (those involving Notch, Reelin, and Wnt intracellular signalling) and also in the neurodegenerative events underlying AD. The choice of these intracellular pathways is based on the observation that there exist several points of convergence among these systems and amyloid precursor protein processing and neurofibrillary tangle formation. Pharmacological manipulation of the Notch/Wnt/Reelin intracellular signalling pathways may thus represent a novel approach to the regulation of neurodegenerative processes in AD.

Early-onset primary dystonia is an inherited disorder characterized by involuntary twisting, repetitive movements and abnormal postures. It has recently been demonstrated that the DYT1 gene is the most relevant gene associated with primary generalized dystonia. The DYT1 gene product is a 332-aminoacid long protein, termed TorsinA, whose function is still not clear. Based on the results obtained in other species, we proposed that TorsinA, similarly to OOC-5 in nematodes, directs and/or stabilizes the subcellular localization of specific kinases, which may in turn phosphorylate microtubule associated proteins, such as tau. In this way, TorsinA may contribute to maintaining the appropriate site-directed polarization and control neurite outgrowth.

DNA repair is one of the most essential systems for maintaining the inherited nucleotide sequence of genomic DNA over time. Repair of DNA damage would be particularly important in neurons, because these cells are among the longest-living cells in the body. MSH2 is one of the proteins which are involved in the recognition and repair of a specific type of DNA damage that is characterized by pair mismatches. We studied the distribution of MSH2 in rat brain by immunohistochemical analysis. We found the level of MSH2 expression in rat brain to be clearly heterogeneous. The highest intensity of staining was found in the pyramidal neurons of the hippocampus and in the entorhinal and frontoparietal cortices. Positive cells were observed in the substantia nigra pars compacta, in cerebellar granular and Purkinjie cells, and in the motor neurons of the spinal cord. We investigated the possible modulation of MSH2 expression after injection of kainate. Systemic administration of kainate induces various behavioural alterations and a typical pattern of neuropathology, with cell death in the hippocampal pyramidal neurons of the CA3/CA4 fields. Kainate injection also resulted in a marked, dose-dependent increase of MSH2 immunoreactivity in the hippocampal neurons of the CA3/CA4 fields. The effect was specific, since no changes in immunoreactivity were detected in the dentate gyrus nor in other brain areas. In summary, our data suggest that a mismatch DNA repair system, of which MSH2 protein is a representative component, is heterogeneously expressed in the rat brain and specifically induced by an experimental paradigm of excitotoxicity.

Notch proteins are involved in cell fate specification during development in tissues including brain. Little is known about their function in adulthood. Recently, Notch receptors have been hypothesized to play a role in neurodegeneration and in particular in Alzheimer's disease (Notch1) and CADASIL (Notch3). Here we show that another family member (Notch2) is constitutively expressed in adult mouse hippocampus in DG and not in CA1 and CA3 neurons. Treatment with kainic acid resulted in marked Notch2 induction in pyramidal neurons of CA1 and in a subpopulation of CA3 neurons surviving the lesion and protein expression was still detectable 6 weeks after drug treatment. These results suggest Notch2 involvement in the response of postmitotic neurons to excitotoxic stimuli.