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ABSTRACT: Microglia-mediated inflammation in the central nervous system is a hallmark of the pathogenesis of several neurodegenerative diseases including Alzheimer's disease. Microglial cells activation follows the deposition of amyloid β fibrils and it is generally considered a triggering factor in the early steps of the onset of Alzheimer's disease. Although the initial engagement of microglia seems to play a neuroprotective role, many lines of evidence indicate that a persistent activation with the production of proinflammatory molecules contributes to dismantle neuronal activity and to induce neuronal loss occurring in neurodegenerative diseases. To date, limited proteomic data are available on activated microglial cells in response to extracellular amyloidogenic peptides. In this study, murine microglial cells have been employed to investigate the effects of amyloid β peptides in triggering microglial activation. The response was monitored at the proteome level through a two-dimensional gel electrophoresis-based approach. Results show only a limited number of differentially expressed proteins, among these a more acidic species of the cytosolic actin, and the 14-3-3ε protein, found significantly upregulated in Aβ-activated cells. 14-3-3ε belongs to a regulatory protein family involved in important cellular processes, including those leading to neurodegenerative diseases, and thus its increased expression suggests a role of this protein in tuning microglia activation.
Proteomics 11/2011; 12(1):124-34. · 4.43 Impact Factor
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ABSTRACT: In the nervous system, protease-activated receptors (PARs), which are activated by thrombin and other extracellular proteases, are expressed widely at both neuronal and glial levels and have been shown to be involved in several brain pathologies. As far as the glial receptors are concerned, previous experiments performed in rat hippocampus showed that expression of PAR-1, the prototypic member of the PAR family, increased in astrocytes both in vivo and in vitro following treatment with trimethyltin (TMT). TMT is an organotin compound that induces severe hippocampal neurodegeneration associated with astrocyte and microglia activation. In the present experiments, the authors extended their investigation to microglial cells. In particular, by 7 days following TMT intoxication in vivo, confocal immunofluorescence revealed an evident PAR-1-related specific immunoreactivity in OX-42-positive microglial cells of the CA3 and hilus hippocampal regions. In line with the in vivo results, when primary rat microglial cells were treated in vitro with TMT, a strong upregulation of PAR-1 was observed by immunocytochemistry and Western blot analysis. These data provide further evidence that PAR-1 may be involved in microglial response to brain damage.
Journal of Histochemistry and Cytochemistry 03/2011; 59(3):302-11. · 2.72 Impact Factor
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ABSTRACT: Atherosclerosis is a degenerative disease whose role in the onset and development of cardiovascular pathologies and complications is of importance. Due to its silent but progressive development, and considering the endothelial, immunological and inflammatory processes that are involved in its clinical course, this still relatively unknown pathological condition has been and continues to be a matter of investigation worldwide. Our experience with previous studies on atherosclerosis led us to investigate the possible influence of a low molecular weight heparin (LMWH) - Parnaparin® on the development and clinical course of atherosclerosis in double knock-out laboratory animals (ApoE-/- mice). Our experiments demonstrated a possible role of Parnaparin (PNP) in the control of atherogenic disease. In fact, in treated mice vs. untreated ones, PNP reduced the number and the size of atherosclerotic lesions in the aortic wall, as well as the development of liver steatosis, which was massive in untreated animals and moderate in treated ones. These preliminary observations require further clinical studies, but demonstrate a possible role of Parnaparin in the control of the development and clinical evolution of atherosclerosis and liver steatosis in laboratory animals.
International Journal of Molecular Medicine 01/2011; 27(4):561-5. · 1.98 Impact Factor
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ABSTRACT: Phosphoinositide specific phospholipase C (PI-PLC) enzymes interfere with the metabolism of inositol phospholipids (PI), molecules involved in signal transduction, a complex process depending on various components. Many evidences support the hypothesis that, in the glia, isoforms of PI-PLC family display different expression and/or sub cellular distribution under non-physiological conditions such as the rat astrocytes activation during neurodegeneration, the tumoural progression of some neoplasms and the inflammatory cascade activation after lipopolysaccharide administration, even if their role remains not completely elucidated. Treatment of a cultured established glioma cell line (C6 rat astrocytoma cell line) induces a modification in the pattern of expression and of sub cellular distribution of PI-PLCs compared to untreated cells. Special attention require PI-PLC beta3 and PI-PLC gamma2 isoforms, whose expression and sub cellular localization significantly differ after U-73122 treatment. The meaning of these modifications is unclear, also because the use of this N-aminosteroid compound remains controversial, inasmuch it has further actions which might contribute to the global effect recorded on the treated cells.
Journal of Cellular Biochemistry 07/2010; 110(4):1005-12. · 2.87 Impact Factor
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ABSTRACT: Signal transduction pathways, involved in cell cycle and activities, depend on various components including lipid signalling molecules, such as phosphoinositides and related enzymes. Many evidences support the hypothesis that inositol lipid cycle is involved in astrocytes activation during neurodegeneration. Previous studies investigated the pattern of expression of phosphoinositide-specific phospholipase C (PI-PLC) family isoforms in astrocytes, individuating in cultured neonatal rat astrocytes, supposed to be quiescent cells, the absence of some isoforms, accordingly to their well known tissue specificity. The same study was conducted in cultured rat astrocytoma C6 cells and designed a different pattern of expression of PI-PLCs in the neoplastic counterpart, accordingly to literature suggesting a PI signalling involvement in tumour progression. It is not clear the role of PI-PLC isoforms in inflammation; recent data demonstrate they are involved in cytokines production, with special regard to IL-6. PI-PLCs expression in LPS treated neonatal rat astrocytes performed by using RT-PCR, observed at 3, 6, 18 and 24 h intervals, expressed: PI-PLC beta1, beta4 and gamma1 in all intervals analysed; PI-PLC delta1 at 6, 18 and 24 h; PI-PLC delta3 at 6 h after treatment. PI-PLC beta3, delta4 and epsilon, present in untreated astrocytes, were not detected after LPS treatment. Immunocytochemical analysis, performed to visualize the sub-cellular distribution of the expressed isoforms, demonstrated different patterns of localisation at different times of exposure. These observations suggest that PI-PLCs expression and distribution may play a role in ongoing inflammation process of CNS.
Journal of Cellular Biochemistry 04/2010; 109(5):1006-12. · 2.87 Impact Factor
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Alberto Ricci,
Salvatore Mariotta,
Elena Pompili,
Rita Mancini,
Elena Bronzetti,
Claudia De Vitis,
Lara Pisani,
Emanuela Cherubini,
Pierdonato Bruno,
Giorgetta Gencarelli,
Maria R Giovagnoli,
Claudio Terzano,
Gennaro Ciliberto,
Enrico Giarnieri, Lorenzo Fumagalli
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ABSTRACT: Neurotrophins (NTs) expression was assessed in malignant and non-malignant pleural effusions (inflammatory exudates and transudates). Enzyme-linked immunosorbent assay, in malignant exudates from small and non-small cell lung cancer (SCLC and NSCLC), detected nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3), and their levels are higher as compared with inflammatory and transudative effusions. By immunoblots, in cultured cancer cells coming from malignant pleural effusions, NTs and low- and high-affinity NT receptors were detected in a percentage of SCLC and NSCLC. Proliferation assay demonstrated that BDNF significantly increased cancer cell proliferation in vitro, on the contrary, NT-3 reduced cancer cell growth rate and NGF did not modify cell growth. Moreover, NGF protects cells from death during starvation. These effects are reverted by the addition of NT receptor antagonists. Cultured cancer cells injected into the lung of immunodeficient mice generate lung tumors expressing NTs and NT receptors. These findings suggest that NTs may be able to modulate cancer cell behavior and their growth.
Growth factors (Chur, Switzerland) 03/2010; 28(4):221-31. · 2.47 Impact Factor
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ABSTRACT: Protease-activated receptors (PARs) are cleaved and activated by thrombin and other extracellular proteases which are released during tissue trauma and inflammation. PAR-1 is the prototypic member of the PAR family and has been shown to be upregulated in several brain pathologies being expressed by neurons and glial cells. The present experiments show that the administration of the PAR-1 activating peptides (TRAP6 and TFLLR) inhibits the production of the pro-inflammatory cytokines TNF-alpha and IL-6 in microglial cells treated with lipopolysaccharide (LPS) while promoting the release of the anti-inflammatory cytokine IL-10. Conversely, the addition of the specific PAR-2 agonist SLIGRL had no effect on the amount of cytokines released following LPS treatment. Consistent with these data PAR-1, but not PAR-2, stimulation upregulates the expression of the suppressor of cytokine signaling-3 (SOCS-3). The present data support the hypothesis that in microglia PAR-1 may be involved in the regulation of inflammatory reactions modulating the balance between pro- and anti-inflammatory cytokines possibly through SOCS induction.
International Journal of Molecular Medicine 10/2009; 24(3):367-71. · 1.98 Impact Factor
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ABSTRACT: The immunohistochemical profile of neurotrophins and their receptors in the human cranial dura mater was studied by examining certain dural zones in specimens harvested from different regions (frontal, temporal, parietal and occipital). Dural specimens were obtained during neurosurgical operations performed in ten patients for surgical treatment of intracranial lesions (meningiomas, traumas, gliomas, vascular malformations). The dural fragments were taken from the area of the craniotomy at least 8 cm from the lesion as well as from the area in which the meningioma had its dural attachment. Immunohistochemical characterization and distribution of neurotrophins, with their receptors, were analyzed. The concrete role played by these neurotrophic factors in general regulation, vascular permeability, algic responsivity and release of locally active substances in the human dura mater is still controversial. Our study revealed a general structural alteration of dural tissue due to the invasivity of meningiomatous lesions, together with an improved expression of brain derived neurotrophic factor (BDNF) in highly proliferating neoplastic cells and an evident production of nerve growth factor (NGF) in inflammatory cells, suggesting that BDNF has a role in supporting the proliferation rate of neoplastic cells, while NGF is involved in the activation of a chronic inflammatory response in neoplastic areas.
Oncology Reports 07/2009; 21(6):1373-80. · 1.84 Impact Factor
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Rita Businaro,
Elisabetta Profumo,
Angela Tagliani,
Brigitta Buttari,
Stefano Leone,
Giulia D'Amati,
Flora Ippoliti,
Martina Leopizzi,
Daniela D'Arcangelo,
Raffaele Capoano, Lorenzo Fumagalli,
Bruno Salvati,
Rachele Riganò
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ABSTRACT: The known role of heat-shock proteins (HSPs) in the pathogenesis of atherosclerosis prompted us to investigate whether HSP90 is a target autoantigen of immune responses in patients with carotid atherosclerosis. METHODS AND RESULTS: The presence of HSP90 on 26 cryostat and 6 paraffin embedded sections of carotid atherosclerotic plaques was determined by immunohistochemistry and immunofluorescence. Plaque-infiltrating T lymphocytes from 9 patients and circulating PBMC from 26 patients and 21 healthy subjects were tested by cell proliferation assay and by flow cytometry and ELISA for cytokine production in response to HSP90. ELISA was used to detect soluble HSP90 and anti-HSP90 antibodies in serum samples. Strong HSP90 immunoreactivity was detected in the muscle and endothelial cell layer and in the inflammatory infiltrate of carotid plaques. Plaque-derived and circulating T lymphocytes from patients proliferated in response to HSP90 whereas cells from healthy subjects did not. HSP90-specific T lymphocytes expressed IFN-gamma and IL-4 suggesting concomitant Th1 and Th2 activation. ELISA detected soluble HSP90 in 42% and anti-HSP90 antibodies in 46% of patients' sera. CONCLUSIONS: These new findings, showing that HSP90 is overexpressed in plaque and serum from patients with atherosclerosis and induces an immune response in these patients, implicate HSP90 as a possible target autoantigen in the pathogenesis of carotid atherosclerosis.
Atherosclerosis 06/2009; 207(1):74-83. · 3.79 Impact Factor
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ABSTRACT: Periconceptional supplementation with multivitamins containing folic acid reduces the risk of congenital malformations. We have previously investigated the effect on the murine development of a multiple retinoic acid competitive antagonist, Bristol-Myers-Squibb 189453, showing that treated fetuses were affected with heart defects, thymus aplasia or hypoplasia, and severe anomalies of the central nervous system. Hereby, we analyzed the effects of nutritive therapy involving folic acid and methionine on teratogen-induced congenital defects in mice.
A total of 132 outbred CD1 litters were studied. Pregnant mice were divided into four experimental groups, and an oral supplementation of H(2)O or folic acid, or methionine, or folic acid+methionine was administered from 0.5 days postcoitum until the end of pregnancy. At 7.5 days postcoitum, mice from all these groups were administered Bristol-Myers-Squibb 189453 to induce the teratogenic effect. At the end of pregnancy, fetuses were dissected and tissues were analyzed by histology and flow cytometric assays.
Folic acid reduces congenital heart diseases from 81.3% to 64.8%, neural tube defects from 20.3% to 3.7%, and thymus abnormalities from 98.4% to 27.8%, restoring a normal number of differentiated thymus cells. Methionine is less effective in contrasting congenital heart diseases and neural tube defects, and induces thymus cell proliferation but not differentiation. Folic acid+methionine weakly reduce congenital heart diseases and neural tube defects, but consistently reduce the incidence of fetuses affected with thymus pathologies from 98.4% to 67.7%.
Our results suggest that folic acid and methionine periconceptional supplementations may influence the incidence of congenital defects and may probably induce negative selection of embryos presenting developmental anomalies.
Cardiovascular pathology: the official journal of the Society for Cardiovascular Pathology 05/2008; 18(2):100-9. · 1.63 Impact Factor
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ABSTRACT: The effect of ST1942, a 2-aminotetraline derivative with anti-inflammatory properties, was evaluated in ischemia/reperfusion injury in CD1 and C57BL/6 mice. ST1942 or saline were injected intraperitoneally 30 min and 6, 24, 36 h after ischemia. Forty-eight hours after ischemia, ST1942 (25 mg/kg) reduced the infarct volume by 50% in CD1 and 61% in C57BL/6 mice. All subsequent data were obtained from the latter strain. The ischemic lesion was significantly reduced by 30% when the first injection was administered 6 h after ischemia, revealing a broad effective window. Degenerating neurons in striatum, cortex and hippocampus of ischemic mice were markedly decreased by ST1942. Also examined was the effect of ST1942 on general and focal neurological deficits for 4 days after ischemia. Mice receiving the drug twice daily showed constantly reduced deficits. We then investigated the cortical mRNA expression of some inflammatory and apoptotic genes by real-time PCR. Forty-eight hours after ischemia ST1942 treatment significantly counteracted ischemia-induced activation of IL-1beta, TNFalpha, and Bax, and enhanced the expression of the antiapoptotic gene, Bcl-2, showing in vivo anti-inflammatory and antiapoptotic actions. The microglial activation/macrophage recruitment in the ischemic lesion was strongly prevented in mice receiving ST1942. In neuron-microglia cocultures, ST1942 significantly counteracted LPS-induced cytotoxicity. Binding data and experiments on microglial cell cultures indicate that the anti-inflammatory effect of ST1942 may be due to its action on 5-HT2B receptors, thus highlighting the possibility that this 5-HT receptor subtype may represent a novel target for neuroprotective drugs in ischemic injury.
Neuropsychopharmacology 07/2007; 32(6):1302-11. · 7.99 Impact Factor
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Rachele Riganò,
Elisabetta Profumo,
Brigitta Buttari,
Angela Tagliani,
Linda Petrone,
Giulia D'Amati,
Flora Ippoliti,
Raffaele Capoano, Lorenzo Fumagalli,
Bruno Salvati,
Rita Businaro
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ABSTRACT: Studies aimed at elucidating the pathogenetic mechanisms underlying the initiation and progression of human atherosclerosis have emphasized the central role of inflammatory and immune cells. Atherosclerotic plaques are infiltrated by activated macrophages, T and B lymphocytes, plasma cells, and mast cells, releasing inflammatory molecules, which amplify the severity of the disease. Endothelial cells subjected to various stress conditions express increased amounts of heat shock proteins (HSPs), some of the most successfully conserved proteins throughout evolution. Many experimental observations reviewed in this article draw attention to several HSPs targeted by a specific cellular and humoral immune response in patients with atherosclerotic disease. The review also reports preliminary data obtained by our group on the possible role of HSP90 as a candidate autoantigen in carotid atherosclerosis. Our study deals with the presence of specific antibodies and T cells directed against HSP90 in patients with carotid atherosclerotic plaques. In 60% of these subjects' sera but in none of the sera from healthy controls immunoblotting (IB) detected the presence of specific antibodies. Moreover, 20% of peripheral blood mononuclear cells (PBMC) samples from patients but none from healthy subjects proliferated in response to human purified HSP90. In vitro experiments showed an upregulation of HSP90 expression in endothelial cells exposed to oxidative stress by treatment with H(2)O(2) and greater release of soluble HSP90 in culture supernatants from H(2)O(2)-treated cells than from untreated cells.
Annals of the New York Academy of Sciences 07/2007; 1107:1-10. · 3.15 Impact Factor
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ABSTRACT: Signal transduction from plasma membrane to cell nucleus is a complex process depending on various components including lipid signaling molecules, in particular phosphoinositides and their related enzymes, which act at cell periphery and/or plasma membrane as well as at nuclear level. As far as the nervous system may concern the inositol lipid cycle has been hypothesized to be involved in numerous neural as well as glial functions. In this context, however, a precise panel of glial PLC isoforms has not been determined yet. In the present experiments we investigated astrocytic PLC isoforms in astrocytes obtained from foetal primary cultures of rat brain and from an established cultured (C6) rat astrocytoma cell line, two well known cell models for experimental studies on glia. Identification of PLC isoforms was achieved by using a combination of RT-PCR and immunocytochemistry experiments. While in both cell models the most represented PI-PLC isoforms were beta4, gamma1, delta4, and epsilon, isoforms PI-PLC beta2 and delta3 were not detected. Moreover, in primary astrocyte cultures PI-PLC delta3 resulted well expressed in C6 cells but was absent in astrocytes. Immunocytochemistry performed with antibodies against specific PLC isoforms substantially confirmed this pattern of expression both in astrocytes and C6 glioma cells. In particular while some isoenzymes (namely isoforms beta3 and beta4) resulted mainly nuclear, others (isoforms delta4 and epsilon) were preferentially localized at cytoplasmic and plasma membrane level.
Journal of Cellular Biochemistry 04/2007; 100(4):952-9. · 2.87 Impact Factor
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Elena Bronzetti,
Marco Artico,
Elena Pompili,
Laura M Felici,
Annarita Stringaro,
Sandro Bosco,
Giuseppe Magliulo,
Marisa Colone,
Giuseppe Arancia,
Marco Vitale, Lorenzo Fumagalli
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ABSTRACT: Lymphoid organs are supplied by many nerve endings associated with different kinds of cells and macrophages. The role of these neuromediators on the release of locally active molecules is still unknown. Here we focused our attention on the expression of some neurotrophins (NTs), their high- and low-affinity receptors and several neurotransmitters in human palatine tonsils. Light and electron microscopy immunohistochemistry showed that human tonsillar samples were positive for all analyzed neurotrophins (NGF, BDNF and NT-3) and their high-affinity receptors (TrkA, TrkB and TrkC, respectively). All of these molecules were strongly expressed in macrophages whereas, in some patients, a weaker specific staining of lymphocytes and blood vessels was also found. The low-affinity receptor for NGF (p75) was always absent in the analysed samples. RT-PCR confirmed the occurrence of specific transcripts for NTs and their high-affinity receptors as well as the absence of mRNA for p75 protein. Also, specific immunoreactivity for neurotransmitters SP, VIP, CGRP, ChAT and nNOS was mainly expressed by macrophagic cells. These results suggest the presence of an extensive network of innervation in the human palatine tonsils which may play a role in the regulation of some immune functions as well as in the modulation of a possible functional scenario of interactions among different immune cellular subtypes.
International Journal of Molecular Medicine 08/2006; 18(1):49-58. · 1.98 Impact Factor
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ABSTRACT: We have previously shown that various protease-activated receptor (PAR) isoforms, mainly PAR-1, are upregulated in reactive astrocytes of rat hippocampus following i.p. administration of trimethyltin (TMT), a neurotoxicant which is known to cause neuronal death and reactive gliosis. In the present paper, we demonstrate that this PAR-1 upregulation was also mimicked in primary cultures of neonatal rat cortex astrocytes after exposure (24 and 48 h) to TMT (10-100 microM). This result suggests that the PAR-1 increase we have observed in vivo may represent a direct effect of TMT on astrocytes rather than a consequence of a complex astrocytic reaction following neuronal death. Furthermore, an evident upregulation of PAR-1 in cultured primary astrocytes also occurred following exposure to lipopolysaccharide (LPS) (a well-known inductor of glial cell activation) whereas other neurotoxic agents (such as staurosporine, hydrogen peroxide and sodium azide), which are known to induce cell death, were unable to determine any PAR-1 variation. Similarly to astrocytes, both TMT and LPS induced an upregulation of PAR-1 in the rat astrocytoma cell line, C6, thus indicating that this phenomenon was independent from microglial cells eventually contaminating astrocyte primary cultures. Furthermore, after exposure to TMT and LPS, the levels of tumor necrosis factor-alpha and interleukin-1beta were also increased in astrocyte cultures, suggesting that the PAR-1 upregulation we have detected may be involved in glial inflammatory response rather than in cell death.
International Journal of Molecular Medicine 08/2006; 18(1):33-9. · 1.98 Impact Factor
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ABSTRACT: Myosins constitute a large family of molecular motors, hydrolyzing ATP and producing cellular movement. To date, a large number of novel isoforms have been found in muscle and non-muscle cells. Among non-muscle myosins, non-muscle myosin heavy chain (NMHC) II-A and II-B have been well characterized. An additional member of NMHC II-B, with a molecular weight of 220 kDa, was recently identified in bovine skeletal muscle. NMHC II-B proteins, in particular, have been suggested to be a useful early molecular marker for the detection of pathological conditions during acute or chronic organ rejection in which fibrotic changes occur. Since it is known that treatment with cyclosporine A (CsA), an immunosuppressive drug successfully used for preventing organ rejection and autoimmune diseases, is often associated with several side effects (hypertension and nephrotoxicity), the aims of this study were: (1) to demonstrate the homology of the new NMHC protein (220 kDa) in other mammalian species, such as Wistar rats; (2) to evaluate, by morphological and immunohistochemical studies, the possible changes induced by CsA treatment in NMHC protein (220 kDa) cellular localization and/or in its expression levels in myocardial tissue. First of all, our results showed a greater homology of the new NMHC within the same isoforms across species and between isoforms in the same specie; moreover, we observed that this protein increased following CsA treatment. This could be explained as a tentative of cardiac tissue to maintain the structural integrity of intercalated disks and so the contraction/relaxation process.
International Immunopharmacology 07/2006; 6(6):962-7. · 2.38 Impact Factor
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ABSTRACT: Altered glutamate transport and aberrant EAAT1 expression were shown in Alzheimer's disease (AD) brains. It is presently unknown whether these modifications are a consequence of neurodegeneration or play a pathogenetic role. However, recent findings of decreased glutamate uptake, EAAT1 protein and mRNA in AD platelets suggest that glutamate transporter modifications may be systemic and might explain the decreased glutamate uptake. We now used primary fibroblast cultures from 10 AD patients to further investigate the specific involvement of glutamate transporters in this disorder and in normal aging. Decreased glutamate uptake (p<0.001), EAAT1 expression (p<0.05) and mRNA (p<0.01) were observed in aged people, compared to younger controls. In AD fibroblasts, compared to age-matched controls, we observed further reductions of glutamate uptake (p<0.0005) and EAAT1 expression (p<0.005), while EAAT1 mRNA increase (p<0.001) was shown. EAAT1 parameters were mutually correlated (p<0.01) and correlations were shown with dementia severity (p<0.05 MMSE-expression, p<0.005 MMSE-mRNA). We suggest fibroblast cultures as possible ex vivo peripheral model to study the glutamate involvement and possible molecular and therapeutic targets in AD.
Neurobiology of Aging 06/2005; 26(6):825-32. · 6.19 Impact Factor
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Barbara Begni,
Laura Brighina,
Elena Sirtori, Lorenzo Fumagalli,
Simona Andreoni,
Simone Beretta,
Thierry Oster,
Catherine Malaplate-Armand,
Valeria Isella,
Ildebrando Appollonio,
Carlo Ferrarese
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ABSTRACT: Oxidative stress has been demonstrated in Alzheimer's disease (AD) brain and may affect glutamate transport (GT), thereby leading to excitotoxic neuronal death. Since oxidative stress markers have been shown also in peripheral tissues, we investigated possible GT alterations in fibroblast cultures obtained from 18 patients with AD and 15 control patients and analyzed the effects of the lipoperoxidation product 4-hydroxynonenal (4-HNE) and antioxidants. Basal GT was decreased by 60% in fibroblasts from patients with AD versus control patients. Exposure to HNE did not affect GT in control patients, but it reduced GT by 50% in patients with AD, without any concomitant change in cell viability; conversely, HNE exposure induced a larger increase in ROS intracellular levels in AD than in control fibroblasts. Glutathione and N-acetylcysteine completely blocked 4-HNE effects and also increased basal uptake in AD cells. Moreover, inhibition of glutathione synthesis in control fibroblasts by pretreatment with buthionine sulfoximine resulted in GT reduction (40%) and an increase in ROS levels after exposure to 4-HNE. Nevertheless, since there are no differences between GSH basal level in controls and patients with AD, the alteration of other antioxidant systems cannot be excluded. Our study supports the hypothesis of a systemic impairment of GT in AD, possibly linked to oxidative stress and to reduced antioxidant defenses, which may be partially reversed by antioxidant treatment. Therefore, we suggest fibroblast cultures as a tool for exploring pathogenetic mechanisms and possible therapeutic strategies in patients with AD.
Free Radical Biology and Medicine 10/2004; 37(6):892-901. · 5.42 Impact Factor
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ABSTRACT: Thrombin, its main inhibitor (protease nexin-1) and its related receptors (protease-activated receptors, PAR-1,-2, -3, -4) were studied in rat hippocampus following administration of trimethyltin (TMT), a neurotoxin inducing neuronal degeneration and reactive gliosis. Reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry revealed that while expression of prothrombin and protease nexin-1 did not change significantly in TMT-treated hippocampi, PARs (in particular PAR-1 and to a lesser extent PAR-2 and PAR-3) were upregulated in reactive astrocytes, suggesting their involvement in neurodegeneration and in the consequent response of the nervous tissue.
Molecular Brain Research 04/2004; 122(1):93-8. · 2.00 Impact Factor
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ABSTRACT: Overexpression of APP and SOD induces beta-amyloid deposition and oxidative stress in Down syndrome (DS) patients. Both phenomena may impair glutamate transport and decreased glutamate uptake sites have been demonstrated in patient brains at autopsy. Since alterations of APP metabolism and oxidative damage are systemic, we investigated glutamate uptake in platelets and fibroblasts from DS patients to explore whether abnormalities in this process are inherent properties of DS cells and not secondary to neurodegeneration. Glutamate uptake was significantly decreased in platelets (P<0.005 vs. control) and fibroblasts (P<0.001 vs. control) from DS patients, particularly in those with free trisomy and with mitochondrial point mutations. Systemic impairment of glutamate uptake in DS is suggested, probably related to APP overexpression and mitochondrial dysfunction. Such mechanisms may contribute to neurodegeneration and dementia development in these patients.
Neuroscience Letters 07/2003; 343(2):73-6. · 2.11 Impact Factor
