Other articles by Maria Summa on PubMed

• Natural Plasmodium Infections in Brazilian Wild Monkeys: Reservoirs for Human Infections? Acta Tropica. Aug, 2008  |   Pubmed ID: 18620330 Four hundred and forty-eight samples of total blood from wild monkeys living in areas where human autochthonous malaria cases have been reported were screened for the presence of Plasmodium using microscopy and PCR analysis. Samples came from the following distinct ecological areas of Brazil: Atlantic forest (N=140), semideciduous Atlantic forest (N=257) and Cerrado (a savannah-like habitat) (N=51). Thick and thin blood smears of each specimen were examined and Plasmodium infection was screened by multiplex polymerase chain reaction (multiplex PCR). The frequency of Plasmodium infections detected by PCR in Alouatta guariba clamitans in the São Paulo Atlantic forest was 11.3% or 8/71 (5.6% for Plasmodium malariae and 5.6% for Plasmodium vivax) and one specimen was positive for Plasmodium falciparum (1.4%); Callithrix sp. (N=30) and Cebus apella (N=39) specimens were negative by PCR tests. Microscopy analysis was negative for all specimens from the Atlantic forest. The positivity rate for Alouatta caraya from semideciduous Atlantic forest was 6.8% (16/235) in the PCR tests (5.5, 0.8 and 0.4% for P. malariae, P. falciparum and P. vivax, respectively), while C. apella specimens were negative. Parasitological examination of the samples using thick smears revealed Plasmodium sp. infections in only seven specimens, which had few parasites (3.0%). Monkeys from the Cerrado (a savannah-like habitat) (42 specimens of A. caraya, 5 of Callithrix jacchus and 4 of C. apella) were negative in both tests. The parasitological prevalence of P. vivax and P. malariae in wild monkeys from Atlantic forest and semideciduous Atlantic forest and the finding of a positive result for P. falciparum in Alouatta from both types of forest support the hypothesis that monkeys belonging to this genus could be a potential reservoir. Furthermore, these findings raise the question of the relationship between simian and autochthonous human malaria in extra-Amazonian regions.
• The HIV-1 Viral Protein Tat Increases Glutamate and Decreases GABA Exocytosis from Human and Mouse Neocortical Nerve Endings Cerebral Cortex (New York, N.Y. : 1991). Aug, 2010  |   Pubmed ID: 20034999 Human immunodeficiency virus-1 (HIV-1)-encoded transactivator of transcription (Tat) potentiated the depolarization-evoked exocytosis of [(3)H]D-aspartate ([(3)H]D-ASP) from human neocortical terminals. The metabotropic glutamate (mGlu) 1 receptor antagonist 7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester (CPCCOEt) prevented this effect, whereas the mGlu5 receptor antagonist 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP) was ineffective. Western blot analysis showed that human neocortex synaptosomes possess mGlu1 and mGlu5 receptors. Tat potentiated the K(+)-evoked release of [(3)H]D-ASP or of endogenous glutamate from mouse neocortical synaptosomes in a CPCCOEt-sensitive and MPEP-insensitive manner. Deletion of mGlu1 receptors (crv4/crv4 mice) or mGlu5 receptors (mGlu5(-/-)mouse) silenced Tat effects. Tat enhanced inositol 1,4,5-trisphosphate production in human and mouse neocortical synaptosomes, consistent with the involvement of group I mGlu receptors. Tat inhibited the K(+)-evoked release of [(3)H]gamma-aminobutyric acid ([(3)H]GABA) from human synaptosomes and that of endogenous GABA or [(3)H]GABA from mouse nerve terminals; the inhibition was insensitive to CPCCOEt or MPEP. Tat-induced effects were retained by Tat(37-72) but not by Tat(48-85). In mouse neocortical slices, Tat facilitated the K(+)- and the veratridine-induced release of [(3)H]D-ASP in a CPCCOEt-sensitive manner and was ineffective in crv4/crv4 mouse slices. These observations are relevant to the comprehension of the pathophysiological effects of Tat in central nervous system and may suggest new potential therapeutic approaches to the cure of HIV-1-associated dementia.
• Improving Processes for Blood Factor Products: from Blood Bank to Hospital Pharmacy American Journal of Health-system Pharmacy : AJHP : Official Journal of the American Society of Health-System Pharmacists. Feb, 2010  |   Pubmed ID: 20133529
• Pre-synaptic Glycine GlyT1 Transporter--NMDA Receptor Interaction: Relevance to NMDA Autoreceptor Activation in the Presence of Mg2+ Ions Journal of Neurochemistry. May, 2011  |   Pubmed ID: 21348870 Rat hippocampal glutamatergic terminals possess NMDA autoreceptors whose activation by low micromolar NMDA elicits glutamate exocytosis in the presence of physiological Mg(2+) (1.2 mM), the release of glutamate being significantly reduced when compared to that in Mg(2+)-free condition. Both glutamate and glycine were required to evoke glutamate exocytosis in 1.2 mM Mg(2+), while dizocilpine, cis-4-[phosphomethyl]-piperidine-2-carboxylic acid and 7-Cl-kynurenic acid prevented it, indicating that occupation of both agonist sites is needed for receptor activation. D-serine mimicked glycine but also inhibited the NMDA/glycine-induced release of [(3H]D-aspartate, thus behaving as a partial agonist. The NMDA/glycine-induced release in 1.2 mM Mg(2+) strictly depended on glycine uptake through the glycine transporter type 1 (GlyT1), because the GlyT1 blocker N-[3-(4'-fluorophenyl)-3-(4'-phenylphenoxy)propyl])sarcosine hydrochloride, but not the GlyT2 blocker Org 25534, prevented it. Accordingly, [(3)H]glycine was taken up during superfusion, while lowering the external concentration of Na(+), the monovalent cation co-transported with glycine by GlyT1, abrogated the NMDA-induced effect. Western blot analysis of subsynaptic fractions confirms that GlyT1 and NMDA autoreceptors co-localize at the pre-synaptic level, where GluN3A subunits immunoreactivity was also recovered. It is proposed that GlyT1s coexist with NMDA autoreceptors on rat hippocampal glutamatergic terminals and that glycine taken up by GlyT1 may permit physiological activation of NMDA pre-synaptic autoreceptors.
• Hippocampal AMPA Autoreceptors Positively Coupled to NMDA Autoreceptors Traffic in a Constitutive Manner and Undergo Adaptative Changes Following Enriched Environment Training Neuropharmacology. Dec, 2011  |   Pubmed ID: 21820454 α-Amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) autoreceptors exist on glutamate hippocampal terminals. Aimed at investigating whether these autoreceptors traffic constitutively, (S)AMPA-evoked [(3)H]D-ASP release from synaptosomes enriched with peptides that impede the interaction of GluA2 subunits with cytosolic proteins involved in receptor movements [namely Glutamate Receptor-Interacting Protein (GRIP), Protein Interacting with C kinase 1 (PICK1), N-ethyl-maleimide-Sensitive Fusion protein NSF proteins] was monitored. (S)AMPA alone had no effect on the spontaneous release of [(3)H]D-ASP from control synaptosomes, but became efficacious in the presence of cyclothiazide or when preventing GluA2/GRIP/PICK1, but not GluA2/NSF, interaction. Hippocampal glutamatergic terminals also possess NMDA autoreceptors. 10 μM NMDA/1 μM glycine-induced [(3)H]D-ASP release was concentration-dependently increased by (S)AMPA. Cyclothiazide potentiated the 10 μM NMDA/1 μM glycine/50 μM (S)AMPA-induced [(3)H]D-ASP overflow, while NBQX halved and MK-801 abolished it, suggesting NMDA-AMPA autoreceptor cross-talk. Western Blot analysis of sub-synaptic fractions confirmed presynaptic GluN2B-GluA2/3 co-localization. Impeding GluA2/GRIP/PICK1 interaction facilitated the NMDA/glycine/(S)AMPA-induced release of [(3)H]D-ASP, while competing for GluA2/NSF interaction reduced it, indicating that NMDA receptor favours AMPA receptor insertion in synaptosomal plasmamembranes. Finally, rearing mice in enriched environment unveiled the (S)AMPA-induced release of [(3)H]D-ASP, but leaved unmodified that caused by NMDA/glycine. The NBQX-sensitive, 50 μM (S)AMPA-evoked release of [(3)H]D-ASP was insensitive to cyclothiazide and to peptide interfering with GluA2/GRIP/PICK1 interaction but was addictive to that caused by NMDA/glycine. Presynaptic GluA2/3 immunoreactivity in EE hippocampal terminals was increased, while GluN2B was unchanged. We conclude that hippocampal AMPA autoreceptors positively coupled to NMDA autoreceptors traffic in a constitutive manner and undergo functional up-regulation in EE animals.
• Detection of Etiological Agents of Malaria in Howler Monkeys from Atlantic Forests, Rescued in Regions of São Paulo City, Brazil Journal of Medical Primatology. Dec, 2011  |   Pubmed ID: 21933192 In some states of the Brazilian extra-Amazonian region, such as the Atlantic Forest area, autochthonous human cases of malaria were related to simian malarias and vice versa.
• RANTES-mediated Control of Excitatory Amino Acid Release in Mouse Spinal Cord Journal of Neurochemistry. May, 2012  |   Pubmed ID: 22385043 The impact of Regulated upon Activation Normal T cells Expressed and Secreted (RANTES) on the release of pre-loaded [³H]D-aspartate ([³H]D-ASP) from mouse spinal cord synaptosomes was investigated. RANTES (0.01-1 nM) failed to affect the spontaneous release, but facilitated the 15 mM K⁺-evoked overflow of [³H]D-ASP. Incubation of synaptosomes with antibodies raised against the chemokine receptor (CCR)1 and CCR5 proteins prevented RANTES-induced facilitation of glutamate exocytosis, whereas anti-CCR3 antibody was inefficacious. Accordingly, BX513 and D-Ala-peptide T-amide (DAPTA) CCR1 and CCR5 antagonists, respectively, prevented RANTES-induced effect, whereas the CCR3 antagonist SB 328437 was inactive. To compare these findings to previous results, we quantified the effects of CCR antagonists on the RANTES-induced modifications of the spontaneous and the K⁺-evoked [³H]D-ASP release in the mouse cortex. Here, CCR1 and CCR5, but not CCR3, antagonists prevented the RANTES-mediated [³H]D-ASP release, whereas RANTES-induced inhibition of the 12 mM K⁺-evoked [³H]D-ASP exocytosis was also antagonized by SB 328437. Facilitation of glutamate exocytosis in spinal cord relied on PLC-dependent mobilization of Ca²⁺ from IP₃-sensitive stores; adenylyl cyclase was not involved. CCR1, CCR3 and CCR5 receptor proteins were present in spinal cord synaptosomal and gliosomal lysates, although RANTES-induced changes to glutamate release could not be observed in gliosomes. Our results confirm the role of RANTES as modulator of glutamate transmission.
• In vitro Exposure to Nicotine Induces Endocytosis of Presynaptic AMPA Receptors Modulating Dopamine Release in Rat Nucleus Accumbens Nerve Terminals Neuropharmacology. Oct, 2012  |   Pubmed ID: 22771975 Here we provide functional and immunocytochemical evidence supporting the presence on Nucleus Accumbens (NAc) dopaminergic terminals of cyclothiazide-sensitive, alfa-amino-3-hydroxy-5-methyl-4-isoxazolone propionate (AMPA) receptors, which activation causes Ca²⁺-dependent [³H]dopamine ([³H]DA) exocytosis. These AMPA receptors cross-talk with co-localized nicotinic receptors (nAChRs), as suggested by the finding that in vitro short-term pre-exposure of synaptosomes to 30 μM nicotine caused a significant reduction of both the 30 μM nicotine and the 100 μM AMPA-evoked [³H]DA overflow. Entrapping pep2-SVKI, a peptide known to compete for the binding of GluA2 subunit to scaffolding proteins involved in AMPA receptor endocytosis, in NAC synaptosomes prevented the nicotine-induced reduction of AMPA-mediated [³H]DA exocytosis, while pep2-SVKE, used as negative control, was inefficacious. Immunocytochemical studies showed that a significant percentage of NAc terminals were dopaminergic and that most of these terminals also posses GluA2 receptor subunits. Western blot analysis of GluA2 immunoreactivity showed that presynaptic GluA2 proteins in NAc terminals were reduced in nicotine-pretreated synaptosomes when compared to the control. The nACh-AMPA receptor-receptor interaction was not limited to dopaminergic terminals since nicotine pre-exposure also affected the presynaptic AMPA receptors controlling hippocampal noradrenaline release, but not the presynaptic AMPA receptors controlling GABA and acetylcholine release. These observations could be relevant to the comprehension of the molecular mechanisms at the basis of nicotine rewarding.
• Anxiety-like Behavior of Prenatally Stressed Rats is Associated with a Selective Reduction of Glutamate Release in the Ventral Hippocampus The Journal of Neuroscience : the Official Journal of the Society for Neuroscience. Nov, 2012  |   Pubmed ID: 23197707 Abnormalities of synaptic transmission and plasticity in the hippocampus represent an integral part of the altered programming triggered by early life stress. Prenatally restraint stressed (PRS) rats develop long-lasting biochemical and behavioral changes, which are the expression of an anxious/depressive-like phenotype. We report here that PRS rats showed a selective impairment of depolarization- or kainate-stimulated glutamate and [(3)H]d-aspartate release in the ventral hippocampus, a region encoding memories related to stress and emotions. GABA release was unaffected in PRS rats. As a consequence of reduced glutamate release, PRS rats were also highly resistant to kainate-induced seizures. Abnormalities of glutamate release were associated with large reductions in the levels of synaptic vesicle-related proteins, such as VAMP (synaptobrevin), syntaxin-1, synaptophysin, synapsin Ia/b and IIa, munc-18, and Rab3A in the ventral hippocampus of PRS rats. Anxiety-like behavior in male PRS (and control) rats was inversely related to the extent of depolarization-evoked glutamate release in the ventral hippocampus. A causal relationship between anxiety-like behavior and reduction in glutamate release was demonstrated using a mixture of the mGlu2/3 receptor antagonist, LY341495, and the GABA(B) receptor antagonist, CGP52432, which was shown to amplify depolarization-evoked [(3)H]d-aspartate release in the ventral hippocampus. Bilateral microinfusion of CGP52432 plus LY341495 in the ventral hippocampus abolished anxiety-like behavior in PRS rats. These findings indicate that an impairment of glutamate release in the ventral hippocampus is a key component of the neuroplastic program induced by PRS, and that strategies aimed at enhancing glutamate release in the ventral hippocampus correct the "anxious phenotype" caused by early life stress.
• Presynaptic MGlu7 Receptors Control GABA Release in Mouse Hippocampus Neuropharmacology. Mar, 2013  |   Pubmed ID: 22564442 The functional role of presynaptic release-regulating metabotropic glutamate type 7 (mGlu7) receptors in hippocampal GABAergic terminals was investigated. Mouse hippocampal synaptosomes were preloaded with [(3)H]D-γ-aminobutyric acid ([(3)H]GABA) and then exposed in superfusion to 12 mM KCl. The K(+)-evoked [(3)H]GABA release was inhibited by the mGlu7 allosteric agonist N,N'-dibenzyhydryl-ethane-1,2-diamine dihydrochloride (AMN082, 0.001-10 μM), as well as by the group III mGlu receptor agonist l-(+)-2-amino-4-phosphonobutyric acid [(l)-AP4, 0.01-1 mM]. The mGlu8 receptor agonist (S)-3,4-dicarboxyphenylglycine [(S)-3,4-DCPG, 10-100 nM] was ineffective. AMN082 and (l)-AP4-induced effects were recovered by the mGlu7 negative allosteric modulator (NAM) 6-(4-methoxyphenyl)-5-methyl-3-(4-pyridinyl)-isoxazolo[4,5-c]pyridin-4(5H)-one hydrochloride (MMPIP). AMN082 also inhibited in a MMPIP-sensitive manner the K(+)-evoked release of endogenous GABA. AMN082 and the adenylyl cyclase (AC) inhibitor MDL-12,330A reduced [(3)H]GABA exocytosis in a 8-Br-cAMP-sensitive. AMN082-inhibitory effect was additive to that caused by (-)baclofen, but insensitive to the GABA(B) antagonist 3-[[(3,4-Dichlorophenyl)methyl]amino]propyl] diethoxymethyl) phosphinic acid (CGP52432). Conversely, (-)baclofen-induced inhibition of GABA exocytosis was insensitive to MMPIP. Finally, the forskolin-evoked [(3)H]GABA release was reduced by AMN082 or (-)baclofen but abolished when the two agonists were added concomitantly. Mouse hippocampal synaptosomal plasmamembranes posses mGlu7 receptor proteins; confocal microscopy analysis unveiled that mGlu7 proteins colocalize with syntaxin-1A (Stx-1A), with vesicular GABA transporter (VGAT)-proteins and with GABA(B) receptor subunit proteins. We propose that presynaptic inhibitory mGlu7 heteroreceptors, negatively coupled to AC-dependent intraterminal pathway, exist in mouse hippocampal GABA-containing terminals, where they colocalize, but do not functionally cross-talk, with GABA(B) autoreceptors. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
• Compensatory Molecular and Functional Mechanisms in Nervous System of the Grm1(crv4) Mouse Lacking the MGlu1 Receptor: a Model for Motor Coordination Deficits Cerebral Cortex (New York, N.Y. : 1991). Sep, 2013  |   Pubmed ID: 22791805 The metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, the only members of group I mGlu receptors, are implicated in synaptic plasticity and mechanisms of feedback control of glutamate release. They exhibit nearly complementary distributions throughout the central nervous system, well evident in the cerebellum, where mGlu1 receptor is most intensely expressed while mGlu5 receptor is not. Despite their different distribution, they show a similar subcellular localization and use common transducing pathways. We recently described the Grm1(crv4) mouse with motor coordination deficits and renal anomalies caused by a spontaneous mutation inactivating the mGlu1 receptor. To define the neuropathological mechanisms in these mice, we evaluated expression and function of the mGlu5 receptor in cerebral and cerebellar cortices. Western blot and immunofluorescence analyses showed mGlu5 receptor overexpression. Quantitative reverse transcriptase-polymerase chain reaction results indicated that the up-regulation is already evident at RNA level. Functional studies confirmed an enhanced glutamate release from cortical cerebral and cerebellar synaptosomes when compared with wild-type that is abolished by the mGlu5 receptor-specific inhibitor, 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP). Finally, acute MPEP treatment of Grm1(crv4/crv4) mice induced an evident although incomplete improvement of motor coordination, suggesting that mGlu5 receptors enhanced activity worsens, instead of improving, the motor-coordination defects in the Grm1(crv4/crv4) mice.
• Increased Excitability in Tat-transgenic Mice: Role of Tat in HIV-related Neurological Disorders Neurobiology of Disease. Jul, 2013  |   Pubmed ID: 23454193 HIV-1 associated neurocognitive disorders (HAND) are a major complication of HIV-1 infection. The mechanism(s) underlying HAND are not completely understood but, based on in vitro studies, the HIV-1 Tat protein may play an important role. In this study, the effect of prolonged exposure to endogenously produced Tat in the brain was investigated using a tat-transgenic (TT) mouse model constitutively expressing the HIV-1 tat gene. We found that stimulus-evoked glutamate exocytosis in the hippocampus and cortex was significantly increased in TT as compared with wild-type control (CC) mice, while GABA exocytosis was unchanged in the hippocampus and decreased in the cortex. This suggests that Tat generates a latent hyper-excitability state, which favors the detrimental effects of neurotoxic and/or excitotoxic agents. To challenge this idea, TT mice were tested for susceptibility to kainate-induced seizures and neurodegeneration, and found to exhibit significantly greater responses to the convulsant agent than CC mice. These results support the concept that constitutive expression of tat in the brain generates a latent excitatory state, which may increase the negative effects of damaging insults. These events may play a key role in the development of HAND.
• CCL5-glutamate Interaction in Central Nervous System: Early and Acute Presynaptic Defects in EAE Mice Neuropharmacology. Dec, 2013  |   Pubmed ID: 23958452 We investigated the CCL5-glutamate interaction in the cortex and in the spinal cord from mice with Experimental Autoimmune Encephalomyelitis (EAE) at 13 and 21/30 days post immunization (d.p.i.), representing the onset and the peak of the disease, respectively. An early reduction of the KCl-evoked glutamate release was observed in cortical terminals from EAE mice at 13 d.p.i., persisting until 21/30 d.p.i. A concomitant reduction of the depolarization-evoked cyclic adenosine monophosphate (cAMP), but not of the inositol 1,4,5-trisphosphate (IP3) cortical production also occurred at 13 d.p.i, that still was detectable at the acute stage of disease (21 dp.i.). Inasmuch, the CCL5-mediated inhibition of glutamate exocytosis observed in control mice turned to facilitation in EAE mouse cortex at 13 d.p.i., then becoming undetectable at 21/30 d.p.i. Differently, glutamate exocytosis, as well as IP3 and cAMP productions were unaltered in spinal cord synaptosomes from EAE mice at 13 d.p.i., but significantly increased at 21/30 d.p.i., while the presynaptic CCL5-mediated facilitation of glutamate exocytosis observed in control mice remained unchanged. In both CNS regions, the presynaptic defects were parallelled by increased CCL5 availability. Inasmuch, the presynaptic defects so far described in EAE mice were reminiscent of the effects acute CCL5 exerts in control conditions. Based on these observations we propose that increased CCL5 bioavailability could have a role in determining the abovedescribed impaired presynaptic impairments in both CNS regions. These presynaptic defects could be relevant to the onset of early cognitive impairments and acute neuroinflammation and demyelinating processes observed in multiple sclerosis patients.
• A Glycosylated, Labionin-containing Lanthipeptide with Marked Antinociceptive Activity ACS Chemical Biology. Feb, 2014  |   Pubmed ID: 24191663 Among the growing family of ribosomally synthesized, post-translationally modified peptides, particularly intriguing are class III lanthipeptides containing the triamino acid labionin. In the course of a screening program aimed at finding bacterial cell wall inhibitors, we discovered a new lanthipeptide produced by an Actinoplanes sp. The molecule, designated NAI-112, consists of 22 amino acids and contains an N-terminal labionin and a C-terminal methyl-labionin. Unique among lanthipeptides, it carries a 6-deoxyhexose moiety N-linked to a tryptophan residue. Consistently, the corresponding gene cluster encodes, in addition to the LanKC enzyme characteristic of this lanthipeptide class, a glycosyl transferase. Despite possessing weak antibacterial activity, NAI-112 is effective in experimental models of nociceptive pain, reducing pain symptoms in mice in both the formalin and the chronic constriction injury tests. Thus, NAI-112 represents, after the labyrinthopeptins, the second example of a lanthipeptide effective against nociceptive pain.
• 3-Aminoazetidin-2-one Derivatives As N-acylethanolamine Acid Amidase (NAAA) Inhibitors Suitable for Systemic Administration ChemMedChem. Jul, 2014  |   Pubmed ID: 24828120 N-Acylethanolamine acid amidase (NAAA) is a cysteine hydrolase that catalyzes the hydrolysis of endogenous lipid mediators such as palmitoylethanolamide (PEA). PEA has been shown to exert anti-inflammatory and antinociceptive effects in animals by engaging peroxisome proliferator-activated receptor α (PPAR-α). Thus, preventing PEA degradation by inhibiting NAAA may provide a novel approach for the treatment of pain and inflammatory states. Recently, 3-aminooxetan-2-one compounds were identified as a class of highly potent NAAA inhibitors. The utility of these compounds is limited, however, by their low chemical and plasma stabilities. In the present study, we synthesized and tested a series of N-(2-oxoazetidin-3-yl)amides as a novel class of NAAA inhibitors with good potency and improved physicochemical properties, suitable for systemic administration. Moreover, we elucidated the main structural features of 3-aminoazetidin-2-one derivatives that are critical for NAAA inhibition.
• Benzoxazolone Carboxamides: Potent and Systemically Active Inhibitors of Intracellular Acid Ceramidase Angewandte Chemie (International Ed. in English). Jan, 2015  |   Pubmed ID: 25395373 The ceramides are a family of bioactive lipid-derived messengers involved in the control of cellular senescence, inflammation, and apoptosis. Ceramide hydrolysis by acid ceramidase (AC) stops the biological activity of these substances and influences survival and function of normal and neoplastic cells. Because of its central role in the ceramide metabolism, AC may offer a novel molecular target in disorders with dysfunctional ceramide-mediated signaling. Here, a class of benzoxazolone carboxamides is identified as the first potent and systemically active inhibitors of AC. Prototype members of this class inhibit AC with low nanomolar potency by covalent binding to the catalytic cysteine. Their metabolic stability and high in vivo efficacy suggest that these compounds may be used as probes to investigate the roles of ceramide in health and disease, and that this scaffold may represent a promising starting point for the development of novel therapeutic agents.
• Multitarget Drug Discovery for Alzheimer's Disease: Triazinones As BACE-1 and GSK-3β Inhibitors Angewandte Chemie (International Ed. in English). Jan, 2015  |   Pubmed ID: 25504761 Cumulative evidence strongly supports that the amyloid and tau hypotheses are not mutually exclusive, but concomitantly contribute to neurodegeneration in Alzheimer's disease (AD). Thus, the development of multitarget drugs which are involved in both pathways might represent a promising therapeutic strategy. Accordingly, reported here in is the discovery of 6-amino-4-phenyl-3,4-dihydro-1,3,5-triazin-2(1H)-ones as the first class of molecules able to simultaneously modulate BACE-1 and GSK-3β. Notably, one triazinone showed well-balanced in vitro potencies against the two enzymes (IC50 of (18.03±0.01) μM and (14.67±0.78) μM for BACE-1 and GSK-3β, respectively). In cell-based assays, it displayed effective neuroprotective and neurogenic activities and no neurotoxicity. It also showed good brain permeability in a preliminary pharmacokinetic assessment in mice. Overall, triazinones might represent a promising starting point towards high quality lead compounds with an AD-modifying potential.
• Multitarget Fatty Acid Amide Hydrolase/cyclooxygenase Blockade Suppresses Intestinal Inflammation and Protects Against Nonsteroidal Anti-inflammatory Drug-dependent Gastrointestinal Damage FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology. Jun, 2015  |   Pubmed ID: 25757568 The ability of nonsteroidal anti-inflammatory drugs (NSAIDs) to inhibit cyclooxygenase (Cox)-1 and Cox-2 underlies the therapeutic efficacy of these drugs, as well as their propensity to damage the gastrointestinal (GI) epithelium. This toxic action greatly limits the use of NSAIDs in inflammatory bowel disease (IBD) and other chronic pathologies. Fatty acid amide hydrolase (FAAH) degrades the endocannabinoid anandamide, which attenuates inflammation and promotes GI healing. Here, we describe the first class of systemically active agents that simultaneously inhibit FAAH, Cox-1, and Cox-2 with high potency and selectivity. The class prototype 4: (ARN2508) is potent at inhibiting FAAH, Cox-1, and Cox-2 (median inhibitory concentration: FAAH, 0.031 ± 0.002 µM; Cox-1, 0.012 ± 0.002 µM; and Cox-2, 0.43 ± 0.025 µM) but does not significantly interact with a panel of >100 off targets. After oral administration in mice, ARN2508 engages its intended targets and exerts profound therapeutic effects in models of intestinal inflammation. Unlike NSAIDs, ARN2508 causes no gastric damage and indeed protects the GI from NSAID-induced damage through a mechanism that requires FAAH inhibition. Multitarget FAAH/Cox blockade may provide a transformative approach to IBD and other pathologies in which FAAH and Cox are overactive.
• Activity-Based Probe for N-Acylethanolamine Acid Amidase ACS Chemical Biology. Sep, 2015  |   Pubmed ID: 26102511 N-Acylethanolamine acid amidase (NAAA) is a lysosomal cysteine hydrolase involved in the degradation of saturated and monounsaturated fatty acid ethanolamides (FAEs), a family of endogenous lipid signaling molecules that includes oleoylethanolamide (OEA) and palmitoylethanolamide (PEA). Among the reported NAAA inhibitors, α-amino-β-lactone (3-aminooxetan-2-one) derivatives have been shown to prevent FAE hydrolysis in innate-immune and neural cells and to reduce reactions to inflammatory stimuli. Recently, we disclosed two potent and selective NAAA inhibitors, the compounds ARN077 (5-phenylpentyl-N-[(2S,3R)-2-methyl-4-oxo-oxetan-3-yl]carbamate) and ARN726 (4-cyclohexylbutyl-N-[(S)-2-oxoazetidin-3-yl]carbamate). The former is active in vivo by topical administration in rodent models of hyperalgesia and allodynia, while the latter exerts systemic anti-inflammatory effects in mouse models of lung inflammation. In the present study, we designed and validated a derivative of ARN726 as the first activity-based protein profiling (ABPP) probe for the in vivo detection of NAAA. The newly synthesized molecule 1 is an effective in vitro and in vivo click-chemistry activity based probe (ABP), which is able to capture the catalytically active form of NAAA in Human Embryonic Kidney 293 (HEK293) cells overexpressing human NAAA as well as in rat lung tissue. Competitive ABPP with 1 confirmed that ARN726 and ARN077 inhibit NAAA in vitro and in vivo. Compound 1 is a useful new tool to identify activated NAAA both in vitro and in vivo and to investigate the physiological and pathological roles of this enzyme.
• 3,4-Dihydro-1,3,5-triazin-2(1H)-ones As the First Dual BACE-1/GSK-3β Fragment Hits Against Alzheimer's Disease ACS Chemical Neuroscience. Oct, 2015  |   Pubmed ID: 26171616 One of the main obstacles toward the discovery of effective anti-Alzheimer drugs is the multifactorial nature of its etiopathology. Therefore, the use of multitarget-directed ligands has emerged as particularly suitable. Such ligands, able to modulate different neurodegenerative pathways, for example, amyloid and tau cascades, as well as cognitive and neurogenic functions, are fostered to come. In this respect, we report herein on the first class of BACE-1/GSK-3β dual inhibitors based on a 3,4-dihydro-1,3,5-triazin-2(1H)-one skeleton, whose hit compound 1 showed interesting properties in a preliminary investigation. Notably, compound 2, endowed with well-balanced potencies against the two isolated enzymes (IC50 of 16 and 7 μM against BACE-1 and GSK-3β, respectively), displayed effective neuroprotective and neurogenic activities and no neurotoxicity in cell-based assays. It also showed good brain permeability in a pharmacokinetic assessment in mice. Overall, triazinone derivatives, thanks to the simultaneous modulation of multiple points of the diseased network, might emerge as suitable candidates to be tested in in vivo Alzheimer's disease models.
• Controlled Antiseptic/eosin Release from Chitosan-based Hydrogel Modified Fibrous Substrates Carbohydrate Polymers. Oct, 2015  |   Pubmed ID: 26256189 Fibers of cellulose networks were stably coated with N-methacrylate glycol chitosan (MGC) shells using subsequent steps of dip coating and photo-curing. The photo-crosslinked MGC-coated cellulose networks preserved their fibrous structure. A model hydrophilic antiseptic solution containing eosin, chloroxylenol and propylene glycol was incorporated into the shells to study the drug release dynamics. Detailed drug release mechanism into phosphate buffered saline (PBS) solutions from coated and pristine fibers loaded with the antiseptic was investigated. The results show that the MGC-coated cellulose fibers enable the controlled gradual release of the drug for four days, as opposed to fast, instantaneous release from eosin coated pristine fibers. This release behavior was found to affect the antibacterial efficiency of the fibrous cellulose sheets significantly against Staphylococcus aureus and Candida albicans. In the case of the MGC-eosin functionalized system the antibacterial efficiency was as high as 85% and 90%, respectively, while for the eosin coated pristine cellulose system the efficiency was negative, indicating bacterial proliferation. Furthermore, the MGC-eosin system was shown to be efficacious in a model of wound healing in mice, reducing the levels of various pro-inflammatory cytokines that modulate early inflammatory phase responses. The results demonstrate good potential of these coated fibers for wound dressing and healing applications. Due to its easy application on common passive commercial fibrous dressings such as gauzes and cotton fibers, the method can render them active dressings in a cost effective way.
• Hit Optimization of 5-Substituted-N-(piperidin-4-ylmethyl)-1H-indazole-3-carboxamides: Potent Glycogen Synthase Kinase-3 (GSK-3) Inhibitors with in Vivo Activity in Model of Mood Disorders Journal of Medicinal Chemistry. Nov, 2015  |   Pubmed ID: 26486317 Novel treatments for bipolar disorder with improved efficacy and broader spectrum of activity are urgently needed. Glycogen synthase kinase 3β (GSK-3β) has been suggested to be a key player in the pathophysiology of bipolar disorder. A series of novel GSK-3β inhibitors having the common N-[(1-alkylpiperidin-4-yl)methyl]-1H-indazole-3-carboxamide scaffold were prepared taking advantage of an X-ray cocrystal structure of compound 5 with GSK-3β. We probed different substitutions at the indazole 5-position and at the piperidine-nitrogen to obtain potent ATP-competitive GSK-3β inhibitors with good cell activity. Among the compounds assessed in the in vivo PK experiments, 14i showed, after i.p. dosing, encouraging plasma PK profile and brain exposure, as well as efficacy in a mouse model of mania. Compound 14i was selected for further in vitro/in vivo pharmacological evaluation, in order to elucidate the use of ATP-competitive GSK-3β inhibitors as new tools in the development of new treatments for mood disorders.
• Relationship Between Vitamin D and Body Fat Distribution Evaluated by DXA in Postmenopausal Women Nutrition (Burbank, Los Angeles County, Calif.). Jun, 2016  |   Pubmed ID: 26856648 The aim of this study was to explore the relationship between 25-hydroxyvitamin D (25[OH]D) serum concentrations and body fat distribution in a sample of postmenopausal women.
• Second-Generation Non-Covalent NAAA Inhibitors Are Protective in a Model of Multiple Sclerosis Angewandte Chemie (International Ed. in English). Sep, 2016  |   Pubmed ID: 27404798 Palmitoylethanolamide (PEA) and oleoylethanolamide (OEA) are endogenous lipid mediators that suppress inflammation. Their actions are terminated by the intracellular cysteine amidase, N-acylethanolamine acid amidase (NAAA). Even though NAAA may offer a new target for anti-inflammatory therapy, the lipid-like structures and reactive warheads of current NAAA inhibitors limit the use of these agents as oral drugs. A series of novel benzothiazole-piperazine derivatives that inhibit NAAA in a potent and selective manner by a non-covalent mechanism are described. A prototype member of this class (8) displays high oral bioavailability, access to the central nervous system (CNS), and strong activity in a mouse model of multiple sclerosis (MS). This compound exemplifies a second generation of non-covalent NAAA inhibitors that may be useful in the treatment of MS and other chronic CNS disorders.
• Endogenous N-acyl Taurines Regulate Skin Wound Healing Proceedings of the National Academy of Sciences of the United States of America. Jul, 2016  |   Pubmed ID: 27412859 The intracellular serine amidase, fatty acid amide hydrolase (FAAH), degrades a heterogeneous family of lipid-derived bioactive molecules that include amides of long-chain fatty acids with taurine [N-acyl-taurines (NATs)]. The physiological functions of the NATs are unknown. Here we show that genetic or pharmacological disruption of FAAH activity accelerates skin wound healing in mice and stimulates motogenesis of human keratinocytes and differentiation of human fibroblasts in primary cultures. Using untargeted and targeted lipidomics strategies, we identify two long-chain saturated NATs-N-tetracosanoyl-taurine [NAT(24:0)] and N-eicosanoyl-taurine [NAT(20:0)]-as primary substrates for FAAH in mouse skin, and show that the levels of these substances sharply decrease at the margins of a freshly inflicted wound to increase again as healing begins. Additionally, we demonstrate that local administration of synthetic NATs accelerates wound closure in mice and stimulates repair-associated responses in primary cultures of human keratinocytes and fibroblasts, through a mechanism that involves tyrosine phosphorylation of the epidermal growth factor receptor and an increase in intracellular calcium levels, under the permissive control of transient receptor potential vanilloid-1 receptors. The results point to FAAH-regulated NAT signaling as an unprecedented lipid-based mechanism of wound-healing control in mammalian skin, which might be targeted for chronic wound therapy.
• First New World Primate Papillomavirus Identification in the Atlantic Forest, Brazil: Alouatta Guariba Papillomavirus 1 Genome Announcements. Aug, 2016  |   Pubmed ID: 27540053 We report here the complete genome sequence of the first papillomavirus detected in a New World primate, howler monkey, Alouatta guariba clamitans papillomavirus 1 (AgPV1), from the Atlantic Forest in São Paulo State, Brazil.