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Carnevale D.,I.R.C.C.S Neuromed | Mascio G.,I.R.C.C.S Neuromed | Ajmone-Cat M.A.,Section of Experimental Neurology | D'Andrea I.,Section of Behavioral Neurosciences | And 11 more authors.
Neurobiology of Aging | Year: 2012

Hypertension and sporadic Alzheimer's disease (AD) have been associated but clear pathophysiological links have not yet been demonstrated. Hypertension and AD share inflammation as a pathophysiological trait. Thus, we explored if modulating neuroinflammation could influence hypertension-induced β-amyloid (Aβ) deposition. Possible interactions among hypertension, inflammation and Aβ-deposition were studied in hypertensive mice with transverse aortic coarctation (TAC). Given that brain Aβ deposits are detectable as early as 4 weeks after TAC, brain pathology was analyzed in 3-week TAC mice, before Aβ deposition, and at a later time (8-week TAC mice).Microglial activation and interleukin (IL)-1β upregulation were already found in 3-week TAC mice. At a later time, along with evident Aβ deposition, microglia was still activated. Finally, immune system stimulation (LPS) or inhibition (ibuprofen), strategies described to positively or negatively modulate neuroinflammation, differently affected Aβ deposition. We demonstrate that hypertension per se triggers neuroinflammation before Aβ deposition. The finding that only immune system activation, but not its inhibition, strongly reduced amyloid burden suggests that stimulating inflammation in the appropriate time window may represent a promising strategy to limit vascular-triggered AD-pathology. © 2012 Elsevier Inc.

Zuena A.R.,University of Rome La Sapienza | Giuli C.,University of Rome La Sapienza | Venerosi Pesciolini A.,Section of Neurotoxicology and Neuroendocrinology | Tramutola A.,University of Rome La Sapienza | And 9 more authors.
PLoS ONE | Year: 2013

Maternal-fetal HIV-1 transmission can be prevented by administration of AZT, alone or in combination with other antiretroviral drugs to pregnant HIV-1-infected women and their newborns. In spite of the benefits deriving from this life-saving prophylactic therapy, there is still considerable uncertainty on the potential long-term adverse effects of antiretroviral drugs on exposed children. Clinical and experimental studies have consistently shown the occurrence of mitochondrial dysfunction and increased oxidative stress following prenatal treatment with antiretroviral drugs, and clinical evidence suggests that the developing brain is one of the targets of the toxic action of these compounds possibly resulting in behavioral problems. We intended to verify the effects on brain and behavior of mice exposed during gestation to AZT, the backbone of antiretroviral therapy during human pregnancy. We hypothesized that glutamate, a neurotransmitter involved in excitotoxicity and behavioral plasticity, could be one of the major actors in AZT-induced neurochemical and behavioral alterations. We also assessed the antioxidant and neuroprotective effect of L-acetylcarnitine, a compound that improves mitochondrial function and is successfully used to treat antiretroviral-induced polyneuropathy in HIV-1 patients. We found that transplacental exposure to AZT given per os to pregnant mice from day 10 of pregnancy to delivery impaired in the adult offspring spatial learning and memory, enhanced corticosterone release in response to acute stress, increased brain oxidative stress also at birth and markedly reduced expression of mGluR1 and mGluR5 subtypes and GluR1 subunit of AMPA receptors in the hippocampus. Notably, administration during the entire pregnancy of L-acetylcarnitine was effective in preventing/ameliorating the neurochemical, neuroendocrine and behavioral adverse effects induced by AZT in the offspring. The present preclinical findings provide a mechanistic hypothesis for the neurobehavioral effects of AZT and strongly suggest that preventive administration of L-acetylcarnitine might be effective in reducing the neurological side-effects of antiretroviral therapy in fetus/newborn. © 2013 Zuena et al.

De Simone R.,Section of Experimental Neurology | Niturad C.E.,Section of Experimental Neurology | De Nuccio C.,Section of Experimental Neurology | Ajmone-Cat M.A.,Section of Experimental Neurology | And 2 more authors.
Journal of Neurochemistry | Year: 2010

Nucleotides act as early signals for microglial recruitment to sites of CNS injury. As microglial motility and activation can be influenced by several local factors at the site of the lesion, we investigated the effects of interferon-gamma, lipopolysaccharide (LPS) or transforming growth factor-β (TGF-β) addition to mixed glial cell cultures, on microglial migration in response to ADP, P2Y12 and P2Y1 mRNA expression as well as on the expression of an array of genes associated with the process of microglial activation. First, we demonstrated, by pharmacological inhibition and by using small interfering RNAs, that in addition to P2Y12, P2Y1 is involved in ADP-stimulated microglial migration. The ability of specific agonists to induce Ca2+ mobilization further confirmed the expression of functional P2Y receptors in microglia. Then, we found that migratory capability and expression of both P2Y receptors were abrogated in microglial cells from LPS-stimulated mixed glial cultures, while TGF-β increased ADP-induced migration and the expression of P2Y12 and P2Y1 receptors. Interferongamma did not influence receptor expression or microglial migration. Finally, the patterns of gene expression induced in microglia by LPS or TGF-β treatment of mixed glial cultures were clearly distinct. LPS induced a set of classical proinflammatory genes, whereas TGF-β increased the expression of genes associated with atypical microglial phenotype, namely arginase-1 and TGF-β genes. These results imply that both P2Y1 and P2Y12 may guide microglia toward the lesion. They also suggest that the modulation of microglial purinergic receptors expression by local factors, through direct and/or astrocyte-mediated actions, may represent a novel mechanism affecting neuroinflammatory response. © 2010 International Society for Neurochemistry.

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