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1.
Artigo em Inglês | MEDLINE | ID: mdl-37644186

RESUMO

Our and other's laboratory microarray-derived transcriptomic studies in human PD substantia nigra pars compacta (SNpc) samples have opened an avenue to concentrate on potential gene intersections or cross-talks along the dopaminergic (DAergic) neurodegenerative cascade in sporadic PD (SPD). One emerging gene candidate identified was SKP1A (p19, S-phase kinase-associated protein 1A), found significantly decreased in the SNpc as confirmed later at the protein level. SKP1 is part of the Skp1, Cullin 1, F-box protein (SCF) complex, the largest known class of sophisticated ubiquitin-proteasome/E3-ligases and was found to directly interact with FBXO7, a gene defective in PARK15-linked PD. This finding has led us to the hypothesis that a targeted site-specific reduction of Skp1 levels in DAergic neuronal cell culture and animal systems may result in a progressive loss of DAergic neurons and hopefully recreate motor disabilities in animals. The second premise considers the possibility that both intrinsic and extrinsic factors (e.g., manipulation of selected genes and mitochondria impairing toxins), alleged to play central roles in DAergic neurodegeneration in PD, may act in concert as modifiers of Skp1 deficiency-induced phenotype alterations ('dual-hit' hypothesis of neurodegeneration). To examine a possible role of Skp1 in DAergic phenotype, we have initially knocked down the expression of SKP1A gene in an embryonic mouse SN-derived cell line (SN4741) with short hairpin RNA (shRNA) lentiviruses (LVs). The deficiency of SKP1A closely recapitulated cardinal features of the DAergic pathology of human PD, such as decreased expression of DAergic phenotypic markers and cell cycle aberrations. Furthermore, the knocked down cells displayed a lethal phenotype when induced to differentiate exhibiting proteinaceous round inclusion structures, which were almost identical in composition to human Lewy bodies, a hallmark of PD. These findings support a role for Skp1 in neuronal phenotype, survival, and differentiation. The identification of Skp1 as a key player in DAergic neuron function suggested that a targeted site-specific reduction of Skp1 levels in mice SNpc may result in a progressive loss of DAergic neurons and terminal projections in the striatum. The injected LV SKP1shRNA to mouse SN resulted in decreased expression of Skp1 protein levels within DAergic neurons and loss of tyrosine hydroxylase immunoreactivity (TH-IR) in both SNpc and striatum that was accompanied by time-dependent motor disabilities. The reduction of the vertical movements, that is rearing, may be reminiscent of the early occurrence of hypokinesia and axial, postural instability in PD. According to the 'dual-hit' hypothesis of neurodegenerative diseases, it is predicted that gene-gene and/or gene-environmental factors would act in concert or sequentially to propagate the pathological process of PD. Our findings are compatible with this conjecture showing that the genetic vulnerability caused by knock down of SKP1A renders DAergic SN4741 cells especially sensitive to genetic reduction of Aldh1 and exposure to the external stressors MPP+ and DA, which have been implicated in PD pathology. Future consideration should be given in manipulation SKP1A expression as therapeutic window, via its induction genetically or pharmacological, to prevent degeneration of the nigra striatal dopamine neurons, since UPS is defective.

2.
J Neural Transm (Vienna) ; 130(5): 627-646, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37062012

RESUMO

Since the description of some peculiar symptoms by James Parkinson in 1817, attempts have been made to define its cause or at least to enlighten the pathology of "Parkinson's disease (PD)." The vast majority of PD subtypes and most cases of sporadic PD share Lewy bodies (LBs) as a characteristic pathological hallmark. However, the processes underlying LBs generation and its causal triggers are still unknown. ɑ-Synuclein (ɑ-syn, encoded by the SNCA gene) is a major component of LBs, and SNCA missense mutations or duplications/triplications are causal for rare hereditary forms of PD. Thus, it is imperative to study ɑ-syn protein and its pathology, including oligomerization, fibril formation, aggregation, and spreading mechanisms. Furthermore, there are synergistic effects in the underlying pathogenic mechanisms of PD, and multiple factors-contributing with different ratios-appear to be causal pathological triggers and progression factors. For example, oxidative stress, reduced antioxidative capacity, mitochondrial dysfunction, and proteasomal disturbances have each been suggested to be causal for ɑ-syn fibril formation and aggregation and to contribute to neuroinflammation and neural cell death. Aging is also a major risk factor for PD. Iron, as well as neuromelanin (NM), show age-dependent increases, and iron is significantly increased in the Parkinsonian substantia nigra (SN). Iron-induced pathological mechanisms include changes of the molecular structure of ɑ-syn. However, more recent PD research demonstrates that (i) LBs are detected not only in dopaminergic neurons and glia but in various neurotransmitter systems, (ii) sympathetic nerve fibres degenerate first, and (iii) at least in "brain-first" cases dopaminergic deficiency is evident before pathology induced by iron and NM. These recent findings support that the ɑ-syn/LBs pathology as well as iron- and NM-induced pathology in "brain-first" cases are important facts of PD pathology and via their interaction potentiate the disease process in the SN. As such, multifactorial toxic processes posted on a personal genetic risk are assumed to be causal for the neurodegenerative processes underlying PD. Differences in ratios of multiple factors and their spatiotemporal development, and the fact that common triggers of PD are hard to identify, imply the existence of several phenotypical subtypes, which is supported by arguments from both the "bottom-up/dual-hit" and "brain-first" models. Therapeutic strategies are necessary to avoid single initiation triggers leading to PD.


Assuntos
Doença de Parkinson , Humanos , Corpos de Lewy/metabolismo , Ferro/metabolismo , alfa-Sinucleína/metabolismo , Inflamação/patologia
3.
J Neural Transm (Vienna) ; 129(5-6): 715-721, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35190910

RESUMO

The first class of site-activated chelators with dual inhibition of acetyl-cholinesterase (AChE) and monoamine oxidase (MAO), rationally designed for simultaneously targeting the multiple pathogenic processes in Alzheimer's disease (AD) without significantly disrupting healthy metal metabolism in the body are discussed. It is demonstrated that the novel prochelator 2 was a selective and potent MAO-A inhibitor in vitro (IC50: 0.0077 ± 0.0007 µM) with moderate inhibition of MAO-B (IC50: 7.90 ± 1.34 µM). In vitro prochelator 2 also selectively inhibited AChE in a time-dependent manner and reach maximum inhibition of AChE after 2 h preincubation (IC50: 0.52 ± 0.07 µM for AChE, versus 44.90 ± 6.10 µM for BuChE). Prochelator 2 showed little affinity for metal (Fe, Cu, and Zn) ions until it bound to and was activated by AChE that is located predominately in the brain, releasing an active iron chelator M30. M30 is an efficient chelator for metal (Fe, Cu, and Zn) ions with the capabilities to suppress oxidative stress, to selectively inhibit MAO-A and B in the brain, and to regulate cerebral biometals dyshomeostasis in vivo; M30 is also a neuroprotective-neurorestorative chelator with a broad spectrum of activities against ß-amyloid (Aß) generation, amyloid plaques and neurofibrillary tangles (NFT) formation, and Aß aggregation induced by metal (Cu and Zn) ions. Both M30 and prochelator 2 were not toxic to Human SH-SY5Y neuroblastoma cells at low concentrations, but prochelator 2 shows limited cytotoxicity, at high concentrations. Together, these data suggest that prochelator 2 is a promise lead for simultaneously modulating multiple targets in AD.


Assuntos
Doença de Alzheimer , Neuroblastoma , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Inibidores da Colinesterase/farmacologia , Humanos , Quelantes de Ferro/farmacologia , Metais , Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/farmacologia
4.
Malar J ; 21(1): 39, 2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35135546

RESUMO

BACKGROUND: In 2012, seasonal malaria chemoprevention (SMC) was recommended as policy for malaria control by the World Health Organization (WHO) in areas of highly seasonal malaria transmission across the Sahel sub-region in Africa along with monitoring of drug resistance. We assessed the long-term impact of SMC on Plasmodium falciparum resistance to sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) over a 3-year period of SMC implementation in the health district of Ouelessebougou, Mali. METHODS: In 8 randomly selected sub-districts of Ouelessebougou, Mali, children aged 0-5 years were randomly selected during cross-sectional surveys at baseline (August 2014) and 1, 2 and 3 years post-SMC, at the beginning and end of the malaria transmission season. Blood smears and blood spots on filter paper were obtained and frequencies of mutation in P. falciparum genes related to resistance to SP and AQ (Pfdhfr, Pfdhps, Pfmdr1, and Pfcrt) were assessed by PCR amplification on individual samples and PCR amplification followed by deep sequencing on pooled (by site and year) samples. RESULTS: At each survey, approximately 50-100 individual samples were analysed by PCR amplification and a total of 1,164 samples were analysed by deep sequencing with an average read depth of 18,018-36,918 after pooling by site and year. Most molecular markers of resistance did not increase in frequency over the period of study (2014-2016). After 3 years of SMC, the frequencies of Pfdhps 540E, Pfdhps 437G and Pfcrt K76T remained similar compared to baseline (4.0 vs 1.4%, p = 0.41; 74.5 vs 64.6%, p = 0.22; 71.3 vs 67.4%, p = 0.69). Nearly all samples tested carried Pfdhfr 59R, and this proportion remained similar 3 years after SMC implementation (98.8 vs 100%, p = 1). The frequency of Pfmdr1 N86Y increased significantly over time from 5.6% at baseline to 18.6% after 3 years of SMC (p = 0.016). Results of pooled analysis using deep sequencing were consistent with those by individual analysis with standard PCR, but also indicated for the first time the presence of mutations at the Pfdhps A581G allele at a frequency of 11.7% after 2 years of SMC, as well as the Pfdhps I431V allele at frequencies of 1.6-9.3% following 1 and 2 years of SMC, respectively. CONCLUSION: Two and 3 years of SMC implementation were associated with increased frequency of the Pfmdr1 N86Y mutation but not Pfdhps 540E, Pfdhps 437G and Pfcrt K76T. The first-time detection of the Pfdhps haplotype bearing the I431V and A581G mutations in Mali, even at low frequency, warrants further long-term surveillance.


Assuntos
Antimaláricos , Malária Falciparum , Malária , Amodiaquina/farmacologia , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Quimioprevenção , Criança , Pré-Escolar , Estudos Transversais , Combinação de Medicamentos , Resistência a Medicamentos/genética , Humanos , Lactente , Recém-Nascido , Malária/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/prevenção & controle , Mali , Plasmodium falciparum/genética , Pirimetamina/farmacologia , Estações do Ano , Sulfadoxina/farmacologia
5.
Clin Infect Dis ; 72(9): 1585-1593, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32206773

RESUMO

BACKGROUND: Ivermectin-based onchocerciasis elimination, reported in 2009-2012, for Bakoye and Falémé, Mali, supported policy-shifting from morbidity control to elimination of transmission (EOT). These foci are coendemic with lymphatic filariasis (LF). In 2007-2016 mass ivermectin plus albendazole administration was implemented. We report Ov16 (onchocerciasis) and Wb123 (LF) seroprevalence after 24-25 years of treatment to determine if onchocerciasis EOT and LF elimination as a public health problem (EPHP) have been achieved. METHODS: The SD Bioline Onchocerciasis/LF Ig[immunoglobulin]G4 biplex rapid diagnostic test (RDT) was used in 2186 children aged 3-10 years in 13 villages (plus 2 hamlets) in Bakoye and in 2270 children in 15 villages (plus 1 hamlet) in Falémé. In Bakoye, all-age serosurveys were conducted in 3 historically hyperendemic villages (1867 individuals aged 3 -78 years). RESULTS: In Bakoye, IgG4 seropositivity was 0.27% (95% confidence interval [CI] = .13%-.60%) for both Ov16 and Wb123 antigens. In Falémé, Ov16 and Wb123 seroprevalence was 0.04% (95% CI = .01%-.25%) and 0.09% (95% CI = .02%-.32%), respectively. Ov16-seropositive children were from historically meso/hyperendemic villages. Ov16 positivity was <2% in ≤14 year-olds, and 16% in ≥40 year-olds. Wb123 seropositivity was <2% in ≤39 year-olds, reaching 3% in ≥40 year-olds. CONCLUSIONS: Notwithstanding uncertainty in the biplex RDT sensitivity, Ov16 and Wb123 seroprevalence among children in Bakoye and Falémé is consistent with EOT (onchocerciasis) and EPHP (LF) since stopping treatment in 2016. The few Ov16-seropositive children should be skin-snip polymerase chain reaction tested and followed up.


Assuntos
Filariose Linfática , Oncocercose , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Filariose Linfática/tratamento farmacológico , Filariose Linfática/epidemiologia , Filariose Linfática/prevenção & controle , Humanos , Ivermectina/uso terapêutico , Mali/epidemiologia , Pessoa de Meia-Idade , Oncocercose/tratamento farmacológico , Oncocercose/epidemiologia , Oncocercose/prevenção & controle , Estudos Soroepidemiológicos , Adulto Jovem
6.
J Infect Dis ; 221(1): 138-145, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31584094

RESUMO

BACKGROUND: Seasonal malaria chemoprevention (SMC) is a novel strategy to reduce malaria infections in children. Infection with Plasmodium falciparum results in immune dysfunction characterized by elevated expression of markers associated with exhaustion, such as PD1 and LAG3, and regulatory CD4+FOXP3+ T cells. METHODS: In the current study, the impact of seasonal malaria chemoprevention on malaria-induced immune dysfunction, as measured by markers associated with exhaustion and regulatory T cells, was explored by flow cytometry. RESULTS: Children that received seasonal malaria chemoprevention had fewer malaria episodes and showed significantly lower fold changes in CD4+PD1+ and CD4+PD1+LAG3+ compared to those that did not receive SMC. Seasonal malaria chemoprevention had no observable effect on fold changes in CD8 T cells expressing PD1 or CD160. However, children receiving SMC showed greater increases in CD4+FOXP3+ T regulatory cells compared to children not receiving SMC. CONCLUSIONS: These results provide important insights into the dynamics of malaria-induced changes in the CD4 T-cell compartment of the immune system and suggest that the reduction of infections due to seasonal malaria chemoprevention may also prevent immune dysfunction. CLINICAL TRIALS REGISTRATION: NCT02504918.


Assuntos
Antígenos CD/sangue , Antimaláricos/uso terapêutico , Linfócitos T CD4-Positivos/metabolismo , Malária Falciparum/imunologia , Malária Falciparum/prevenção & controle , Receptor de Morte Celular Programada 1/sangue , Amodiaquina/uso terapêutico , Biomarcadores/sangue , Pré-Escolar , Combinação de Medicamentos , Feminino , Fatores de Transcrição Forkhead/sangue , Humanos , Lactente , Masculino , Pirimetamina/uso terapêutico , Estações do Ano , Sulfadoxina/uso terapêutico , Linfócitos T Reguladores , Proteína do Gene 3 de Ativação de Linfócitos
7.
J Neural Transm (Vienna) ; 127(5): 831-842, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31562557

RESUMO

Monoamine oxidase B (MAO-B) inhibitors have an established role in the treatment of Parkinson's disease as monotherapy or adjuvant to levodopa. Two major recognitions were required for their introduction into this therapeutic field. The first was the elucidation of the novel pharmacological properties of selegiline as a selective MAO-B inhibitor by Knoll and Magyar and the original idea of Riederer and Youdim, supported by Birkmayer, to explore its effect in parkinsonian patients with on-off phases. In the 1960s, MAO inhibitors were mainly studied as potential antidepressants, but Birkmayer found that combined use of levodopa and various MAO inhibitors improved akinesia in Parkinson's disease. However, the serious side effects of the first non-selective MAO inhibitors prevented their further use. Later studies demonstrated that MAO-B, mainly located in glial cells, is important for dopamine metabolism in the brain. Recently, cell and molecular studies revealed interesting properties of selegiline opening new possibilities for neuroprotective mechanisms and a disease-modifying effect of MAO-B inhibitors.


Assuntos
Inibidores da Monoaminoxidase/farmacologia , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , Selegilina/farmacologia , Animais , Humanos
8.
J Neural Transm (Vienna) ; 127(5): 755-762, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32385576

RESUMO

Parkinson's disease (PD) etiology is heterogeneous, genetic, and multi-factorial, resulting in a varied disease from a mild slow progression to a more severe rapid progression. Prognostic information on the nature of the patient's disease at diagnosis aids the physician in counseling patients on treatment options and life planning. In a cohort of PD patients from the PPMI study, the relative gene expression levels of SKP1A, UBE2K, ALDH1A1, PSMC4, HSPA8 and LAMB2 were measured in baseline blood samples by real-time quantitative PCR. At baseline PD patients were up to 2 years from diagnosis, H&Y scale ≤ 2 and PD treatment naïve. PD-Prediction algorithm comprised of ALDH1A1, LAMB2, UBE2K, SKP1A and age was created by logistic regression for predicting progression to ≤ 70% Modified Schwab and England Activities of Daily Living (S&E-ADL). In relation to patients negative for PD-Prediction (n = 180), patients positive (n = 30) for Cutoff-1 (at 82% specificity, 80.0% sensitivity) had positive hazard ratio (HR+) of 10.6 (95% CI, 2.2-50.1), and positive (n = 23) for Cutoff-2 (at 93% specificity, 47% sensitivity) had HR+ of 17.1 (95% CI, 3.2-89.9) to progress to ≤ 70% S&E-ADL within 3 years (P value < 0.0001). Likewise, patients positive for PD-Prediction Cutoff-1 (n = 49) had HR+ 4.3 (95% CI, 1.6-11.6) for faster time to H&Y 3 in relation to patients negative (n = 170) for PD-Prediction (P value = 0.0002). Our findings show an algorithm that seems to predict fast PD progression and may potentially be used as a tool to assist the physician in choosing an optimal treatment plan, improving the patient's quality of life and overall health outcome.


Assuntos
Progressão da Doença , Expressão Gênica/genética , Doença de Parkinson/diagnóstico , Doença de Parkinson/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/sangue , Prognóstico , Sensibilidade e Especificidade
9.
Lett Appl Microbiol ; 70(4): 241-251, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31984518

RESUMO

Food poisoning risk related to the consumption of contaminated food with known foodborne pathogens or antibiotic-resistant bacteria is currently a serious threat for public health. Thus, pathogenic methicillin-resistant Staphylococcus strains are considered as one of the major cause of foodborne diseases in hospitals. The present study aims to determine the prevalence and the antibiotic resistance patterns of Staphylococcus in various types of hospital food samples, work surfaces and its carriage by food handlers. A total of 608 collected samples including 300 food samples, 238 food contact surfaces and 70 nasal and hand samples were tested. The identified Staphylococcus and their antibiotic resistance patterns were analysed using the agar disk-diffusion and PCR method was used for mecA resistance gene amplification. The prevalence of S. aureus and the coagulase-negative staphylococci were 17·33 and 23·33%, respectively. The antibiotic resistance reached 100% towards oxacillin and Penicillin G for both S. aureus and CoNs. The mecA gene was detected in 5·71% (4/70) and 7·69% (4/52) of S. aureus and CoNs strains, respectively. The outcome of this study enlightens isolation of MRSA strains and resistant CoNs from food, food contact surfaces and food handlers. The presence of this resistant species in this critical setting, where products were intended to vulnerable and immunocompromised patients, represents a serious threat to this community. It can be a source of nosocomial infection and more precautions must be taken to prevent staphylococci food contamination mainly in hospitals. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study describing the antibiotic resistance patterns of Staphylococcus aureus and coagulase-negative Staphylococcus isolated from hospital food, food contact surfaces and food handlers samples in a Moroccan hospital kitchen. High levels of multi-resistance were reported. The alarming outcome of this study emphasizes the crucial need of implementing an approach to fight multidrug-resistant staphylococci mainly in healthcare settings, where the community have already compromised health issues.


Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Infecções Estafilocócicas/microbiologia , Staphylococcus/isolamento & purificação , Culinária/instrumentação , Infecção Hospitalar/epidemiologia , Contaminação de Equipamentos/estatística & dados numéricos , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Hospitais/estatística & dados numéricos , Humanos , Testes de Sensibilidade Microbiana , Marrocos , Oxacilina/farmacologia , Penicilina G/farmacologia , Prevalência , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética
10.
Malar J ; 18(1): 128, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30971252

RESUMO

BACKGROUND: Plasmodium falciparum-infected erythrocytes (IE) sequester in deep vascular beds where their adhesion is mediated by an array of endothelial surface receptors. Because parasite adhesion has been associated with disease, antibodies that block this activity may confer protective immunity. Here, levels of plasma anti-adhesion activity and surface reactivity against freshly collected IEs from malaria-infected children were measured in a Malian birth cohort and related to child age and malaria infection history. METHODS: Plasma samples from children enrolled at birth in a longitudinal cohort study of mother-infant pairs in Ouelessebougou, Mali were collected at multiple time points during follow-up visits. Anti-adhesion antibodies (i.e., inhibit IE binding to any of several endothelial receptors) and reactivity with surface IE proteins were measured using a binding inhibition assay and by flow cytometry, respectively. RESULTS: Levels of antibodies that inhibit the binding of children's IE to the receptors ICAM-1, integrin α3ß1 and laminin increased with age. The breadth of antibodies that inhibit ICAM-1 and laminin adhesion (defined as the proportion of IE isolates whose binding was reduced by ≥ 50%) also significantly increased with age. The number of malaria infections prior to plasma collection was associated with levels of plasma reactivity to IE surface proteins, but not levels of anti-adhesion activity. CONCLUSIONS: Age is associated with increased levels of antibodies that reduce adhesion of children's IE to three of the ten endothelial receptors evaluated here. These results suggest that anti-adhesion antibodies to some but not all endothelial receptors are acquired during the first few years of life.


Assuntos
Anticorpos Antiprotozoários/imunologia , Eritrócitos/parasitologia , Integrina alfa3beta1/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Malária Falciparum/fisiopatologia , Plasmodium falciparum/imunologia , Adesão Celular , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Laminina/metabolismo , Estudos Longitudinais , Mali
12.
J Neural Transm (Vienna) ; 125(11): 1719-1733, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30341696

RESUMO

In early 1920s, tyramine oxidase was discovered that metabolized tyramine and in 1933 Blaschko demonstrated that this enzyme also metabolized adrenaline, noradrenaline and dopamine. Zeller gave it the name monoamine oxidase (MAO) to distinguish it from the enzyme that oxidatively deaminated diamines. MAO was recognized as an enzyme of crucial interest to pharmacologists because it catalyzed the major inactivation pathway for the catecholamines (and, later, 5-hydroxytryptamine, as well). Within the few decade, the inhibitors of MAO were discovered and introduced for the treatment of depressive illness which was established clinically. However, the first clinical use exposed serious side effects, pharmacological interest in, and investigation of, MAO continued, resulting in the characterization of two forms, distinct forms, MAO-A and -B, and selective inhibitors for them. Selective inhibitors of MAO-B (selegiline, rasagiline and safinamide) have found a therapeutic role in the treatment of Parkinson's disease and reversible inhibitors of MAO-A offered antidepressant activity without the serious side effects of the earlier nonselective MAO inhibitors. Subsequent molecular pharmacological have also generated the concept of neuroprotection, reflecting the possibility of slowing, halting and maybe reversing, neurodegeneration in Parkinson's or Alzheimer's diseases. Increased levels of oxidative stress through the accumulation of iron in the Parkinsonian and Alzheimer brains has been suggested to be critical for the initiation and progress of neurodegeneration. Selective inhibition of brain MAO could contribute importantly to lowering such stress, preventing the formation of hydrogen peroxide. Interaction of Iron with hydrogen peroxide and lead to Fenton reaction and production of the most reactive radical, namely hydroxyl radical. There are complex interactions between free iron levels in brain and MAO, and cascade of neurotoxic events may have practical outcomes for depressive disorders and neurodegenerative diseases. As consequence recent novel therapeutic drugs for neurodegenerative diseases has led to the development of multi target drugs, that possess selective brain MAO A and B inhibitory moiety, iron chelating and antioxidant activities and the ability to increase brain levels of endogenous neurotrophins, such as BDNF, GDNF VEGF and erythropoietin and induce mitochondrial biogenesis.


Assuntos
Transtorno Depressivo/tratamento farmacológico , Quelantes de Ferro/uso terapêutico , Inibidores da Monoaminoxidase/uso terapêutico , Doenças Neurodegenerativas/tratamento farmacológico , Animais , Humanos
13.
Malar J ; 17(1): 106, 2018 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-29523137

RESUMO

BACKGROUND: Maternal malaria is a tropical scourge associated with poor pregnancy outcomes. Women become resistant to Plasmodium falciparum pregnancy malaria as they acquire antibodies to the variant surface antigen VAR2CSA, a leading vaccine candidate. Because malaria infection may increase VAR2CSA antibody levels and thereby confound analyses of immune protection, gravidity-dependent changes in antibody levels during and after infection, and the effect of VAR2CSA antibodies on pregnancy outcomes were evaluated. METHODS: Pregnant women enrolled in a longitudinal cohort study of mother-infant pairs in Ouelessebougou, Mali provided plasma samples at enrollment, gestational week 30-32, and delivery. Antibody levels to VAR2CSA domains were measured using a multiplex bead-based assay. RESULTS: Antibody levels to VAR2CSA were higher in multigravidae than primigravidae. Malaria infection was associated with increased antibody levels to VAR2CSA domains. In primigravidae but not in secundigravidae or multigravidae, antibodies levels sharply declined after an infection. A relationship between any VAR2CSA antibody specificity and protection from adverse pregnancy outcomes was not detected. CONCLUSIONS: During malaria infection, primigravidae acquire short-lived antibodies. The lack of an association between VAR2CSA domain antibody reactivity and improved pregnancy outcomes suggests that the recombinant proteins may not present native epitopes targeted by protective antibodies.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Malária Falciparum/patologia , Parasitemia/patologia , Complicações Infecciosas na Gravidez/patologia , Adolescente , Adulto , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Estudos Longitudinais , Mali , Pessoa de Meia-Idade , Gravidez , Resultado da Gravidez , Adulto Jovem
14.
Purinergic Signal ; 14(3): 271-284, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30019187

RESUMO

Extracellular nucleotides can regulate the production/drainage of the aqueous humor via activation of P2 receptors, thus affecting the intraocular pressure (IOP). We evaluated 5-OMe-UDP(α-B), 1A, a potent P2Y6-receptor agonist, for reducing IOP and treating glaucoma. Cell viability in the presence of 1A was measured using [3-(4, 5-dimethyl-thiazol-2-yl) 2, 5-diphenyl-tetrazolium bromide] (MTT) assay in rabbit NPE ciliary non-pigmented and corneal epithelial cells, human retinoblastoma, and liver Huh7 cells. The effect of 1A on IOP was determined in acute glaucomatous rabbit hyaluronate model and phenol-induced chronic glaucomatous rabbit model. The origin of activity of 1A was investigated by generation of a homology model of hP2Y6-R and docking studies. 1A did not exert cytotoxic effects up to 100 mM vs. trusopt and timolol in MTT assay in ocular and liver cells. In normotensive rabbits, 100 µM 1A vs. xalatan, trusopt, and pilocarpine reduced IOP by 45 vs. 20-30%, respectively. In the phenol animal model, 1A (100 µM) showed reduction of IOP by 40 and 20%, following early and late administration, respectively. Docking results suggest that the high activity and selectivity of 1A is due to intramolecular interaction between Pα-BH3 and C5-OMe which positions 1A in a most favorable site inside the receptor. P2Y6-receptor agonist 1A effectively and safely reduces IOP in normotense, acute, and chronic glaucomatous rabbits, and hence may be suggested as a novel approach for the treatment of glaucoma.


Assuntos
Glaucoma , Pressão Intraocular/efeitos dos fármacos , Agonistas do Receptor Purinérgico P2Y/farmacologia , Receptores Purinérgicos P2/efeitos dos fármacos , Animais , Humanos , Coelhos , Difosfato de Uridina/química , Difosfato de Uridina/farmacologia
15.
Clin Infect Dis ; 65(10): 1729-1735, 2017 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29020221

RESUMO

BACKGROUND: Pregnancy malaria (PM) is associated with a proinflammatory immune response characterized by increased levels of cytokines and chemokines such as tumor necrosis factor-α, interferon-γ, interleukin 10 (IL-10), and CXCL9. These changes are associated with poor outcomes including low birthweight delivery and maternal anemia. However, it is unknown if inflammatory pathways during malaria are related to pregnancy loss and preterm delivery (PTD). METHODS: Cytokine and chemokine levels were measured in maternal peripheral blood at enrollment, gestational week 30-32, and delivery, and in placental blood, of 638 women during a longitudinal cohort study in Ouelessebougou, Mali. Plasmodium falciparum infection was assessed by blood smear microscopy at all visits. RESULTS: PM was associated with increased levels of cytokines and chemokines including IL-10 and CXCL9. In a competing risks model adjusted for known covariates, high CXCL9 levels measured in the peripheral blood during pregnancy were associated with increased risk of pregnancy loss and PTD. At delivery, high IL-10 levels in maternal blood were associated with an increase in pregnancy loss, and increased IL-1ß levels in placental blood were associated with pregnancy loss and PTD. CONCLUSIONS: PM is associated with increased proinflammatory cytokine and chemokine levels in placental and maternal peripheral blood. Systemic inflammatory responses to malaria during pregnancy predict increased risk of pregnancy loss and PTD. CLINICAL TRIALS REGISTRATION: NCT01168271.


Assuntos
Aborto Espontâneo/epidemiologia , Malária Falciparum/epidemiologia , Complicações Parasitárias na Gravidez/epidemiologia , Nascimento Prematuro/epidemiologia , Síndrome de Resposta Inflamatória Sistêmica/epidemiologia , Aborto Espontâneo/etiologia , Adolescente , Adulto , Citocinas/sangue , Feminino , Humanos , Estudos Longitudinais , Malária Falciparum/complicações , Mali/epidemiologia , Pessoa de Meia-Idade , Gravidez , Nascimento Prematuro/etiologia , Síndrome de Resposta Inflamatória Sistêmica/complicações , Adulto Jovem
16.
J Neural Transm (Vienna) ; 129(5-6): 713-714, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35394205
17.
Malar J ; 16(1): 477, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-29162120

RESUMO

BACKGROUND: There is growing concern that malaria vector resistance to pyrethroid insecticides may reduce the effectiveness of long-lasting insecticidal nets (LLINs). Combination LLINs are designed to control susceptible and pyrethroid-resistant mosquito populations through a mixture of pyrethroid with piperonyl butoxide (PBO) synergist. A cluster randomized trial with entomology outcome measures was conducted in Mali to determine the added benefit over mono-treated pyrethroid predecessors. Four LLIN treatments; permethrin + PBO, permethrin, deltamethrin + PBO, and deltamethrin, were randomly allocated to four villages each (16 villages total) and distributed to cover every sleeping place. Entomological monitoring of indoor Anopheles resting densities, host preference, vector longevity, and sporozoite rates were monitored every 2 months over 2 years in 2014 and 2015. RESULTS: Bottle bioassays confirmed permethrin and deltamethrin resistance in Anopheles gambiae sensu lato (s.l.), (the predominant species throughout the study) with pre-exposure to PBO indicating partial involvement of oxidases. Between 2014 and 2015 the mean indoor resting density was greater in the deltamethrin + PBO LLIN arm than the deltamethrin LLIN arm at 3.05 (95% CI 3.00-3.10) An. gambiae s.l. per room per day compared with 1.9 (95% CI 1.87-1.97). There was no significant difference in sporozoite rate at 3.97% (95% CI 2.91-5.02) for the deltamethrin LLIN arm and 3.04% (95% CI 2.21-3.87) for deltamethrin + PBO LLIN arm (P = 0.17). However, when analysed by season there was some evidence that the sporozoite rate was lower in the deltamethrin + PBO LLIN arm than deltamethrin LLIN arm during the rainy/high malaria transmission seasons at 1.95% (95% CI 1.18-2.72) and 3.70% (95% CI 2.56-4.84) respectively (P = 0.01). CONCLUSIONS: While there was some evidence that An. gambiae s.l. sporozoite rates were lower in villages with deltamethrin + PBO LLINs during the high malaria transmission seasons of 2014-2015, there was no reduction in parity rates or indoor resting densities. There was also no evidence that permethrin + PBO LLINs provided any improved control when compared with permethrin LLINs. Combination nets may have a greater impact in areas where mixed function oxidases play a more important role in pyrethroid resistance.


Assuntos
Anopheles , Mosquiteiros Tratados com Inseticida , Inseticidas , Controle de Mosquitos , Mosquitos Vetores , Animais , Anopheles/parasitologia , Anopheles/fisiologia , Análise por Conglomerados , Sinergismo Farmacológico , Longevidade , Mali , Mosquitos Vetores/parasitologia , Mosquitos Vetores/fisiologia , Nitrilas , Permetrina , Butóxido de Piperonila , Piretrinas , População Rural
18.
J Neural Transm (Vienna) ; 123(2): 125-35, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25859841

RESUMO

The mitochondrial theory of ageing proposes that accumulation of damage to mitochondrial function and DNA mutation lead to ageing of humans and animals. It has been suggested that mitochondria play dynamic roles in regulating synaptogenesis and morphological/functional responses of synaptic activity, and thus, deteriorating of mitochondrial function (e.g., deficits of the mitochondrial respiratory enzymes, reduced calcium influx, increased accumulation of mitochondrial DNA defects/apoptotic proteins and impairment of mitochondrial membrane potential) can lead to severe neuronal energy deficit, and in the long run, to modifications in neuronal synapses and neurodegeneration in the ageing brain. Hence, considering the mechanisms by which mitochondrial impairment can lead to neuronal death, the development of neuroprotective molecules that target various mitochondrial pathogenic processes can be effective in the treatment of ageing and age-related neurodegenerative diseases. This review addresses several aspects of the neuroprotective effects of propargylamine derivatives (e.g., the monoamine oxidase-B inhibitors, selegiline and rasagiline and the multifunctional drugs, ladostigil, M30 and VAR10303) in ageing with a special focus on mitochondrial molecular protective mechanisms.


Assuntos
Envelhecimento/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Pargilina/análogos & derivados , Propilaminas/farmacologia , Envelhecimento/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Humanos , Mitocôndrias/metabolismo , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/uso terapêutico , Pargilina/química , Pargilina/farmacologia , Pargilina/uso terapêutico , Propilaminas/química , Propilaminas/uso terapêutico
19.
Malar J ; 14: 327, 2015 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-26296644

RESUMO

BACKGROUND: The impact of indoor residual spraying (IRS) and long-lasting insecticide nets (LLINs), key components of the national malaria control strategy of Mali, is threatened by vector insecticide resistance. The objective of this study was to assess the level of insecticide resistance in Anopheles gambiae sensu lato populations from Mali against four classes of insecticide recommended for IRS: organochlorines (OCs), pyrethroids (PYs), carbamates (CAs) and organophosphates (OPs). Characterization of resistance was done in 13 sites across southern Mali and assessed presence and distribution of physiological mechanisms that included target-site modifications: knockdown resistance (kdr) and altered acetycholinesterase (AChE), and/or metabolic mechanisms: elevated esterases, glutathione S-transferases (GSTs), and monooxygenases. METHODS: The World Health Organization (WHO) tube test was used to determine phenotypic resistance of An. gambiae s.l. to: dichlorodiphenyltrichloroethane (DDT) (OC), deltamethrin (PY), lambda-cyhalothrin (PY), bendiocarb (CA), and fenitrothion (OP). Identification of sibling species and presence of the ace-1 (R) and Leu-Phe kdr, resistance-associated mutations, were determined using polymerase chain reaction (PCR) technology. Biochemical assays were conducted to detect increased activity of GSTs, oxidases and esterases. RESULTS: Populations tested showed high levels of resistance to DDT in all 13 sites, as well as increased resistance to deltamethrin and lambda-cyhalothrin in 12 out of 13 sites. Resistance to fenitrothion and bendiocarb was detected in 1 and 4 out of 13 sites, respectively. Anopheles coluzzii, An. gambiae sensu stricto and Anopheles arabiensis were identified with high allelic frequencies of kdr in all sites where each of the species were found (13, 12 and 10 sites, respectively). Relatively low allelic frequencies of ace-1 (R) were detected in four sites where this assessment was conducted. Evidence of elevated insecticide metabolism, based on oxidase, GSTs and esterase detoxification, was also documented. CONCLUSION: Multiple insecticide-resistance mechanisms have evolved in An. coluzzii, An. gambiae s.s. and An. arabiensis in Mali. These include at least two target site modifications: kdr, and ace-1 (R) , as well as elevated metabolic detoxification systems (monooxygenases and esterases). The selection pressure for resistance could have risen from the use of these insecticides in agriculture, as well as in public health. Resistance management strategies, based on routine resistance monitoring to inform insecticide-based malaria vector control in Mali, are recommended.


Assuntos
Anopheles/efeitos dos fármacos , Insetos Vetores/efeitos dos fármacos , Resistência a Inseticidas , Inseticidas/farmacologia , Animais , Anopheles/enzimologia , Anopheles/genética , Bioensaio , Carbamatos/farmacologia , DDT/farmacologia , Feminino , Genótipo , Hidrocarbonetos Clorados/farmacologia , Insetos Vetores/enzimologia , Insetos Vetores/genética , Resistência a Inseticidas/genética , Resistência a Inseticidas/fisiologia , Mali , Mutação , Organofosfatos/farmacologia , Vigilância em Saúde Pública , Piretrinas/farmacologia
20.
J Biol Chem ; 288(51): 36717-32, 2013 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-24235151

RESUMO

Calpains are a family of calcium-dependent cysteine proteases that are ubiquitously expressed in mammals and play critical roles in neuronal death by catalyzing substrate proteolysis. Here, we developed two-dimensional gel electrophoresis-based protease proteomics to identify putative calpain substrates. To accomplish this, cellular lysates from neuronal cells were first separated by pI, and the immobilized sample on a gel strip was incubated with a recombinant calpain and separated by molecular weight. Among 25 altered protein spots that were differentially expressed by at least 2-fold, we confirmed that arsenical pump-driving ATPase, optineurin, and peripherin were cleaved by calpain using in vitro and in vivo cleavage assays. Furthermore, we found that all of these substrates were cleaved in MN9D cells treated with either ionomycin or 1-methyl-4-phenylpyridinium, both of which cause a calcium-mediated calpain activation. Their cleavage was blocked by calcium chelator or calpain inhibitors. In addition, calpain-mediated cleavage of these substrates and its inhibition by calpeptin were confirmed in a middle cerebral artery occlusion model of cerebral ischemia, as well as a stereotaxic brain injection model of Parkinson disease. Transient overexpression of each protein was shown to attenuate 1-methyl-4-phenylpyridinium-induced cell death, indicating that these substrates may confer protection of varying magnitudes against dopaminergic injury. Taken together, the data indicate that our protease proteomic method has the potential to be applicable for identifying proteolytic substrates affected by diverse proteases. Moreover, the results described here will help us decipher the molecular mechanisms underlying the progression of neurodegenerative disorders where protease activation is critically involved.


Assuntos
Calpaína/metabolismo , Neurônios Dopaminérgicos/metabolismo , Proteoma/metabolismo , 1-Metil-4-fenilpiridínio/farmacologia , Animais , ATPases Transportadoras de Arsenito/genética , ATPases Transportadoras de Arsenito/metabolismo , Calpaína/antagonistas & inibidores , Morte Celular , Linhagem Celular , Dipeptídeos/farmacologia , Dipeptídeos/uso terapêutico , Neurônios Dopaminérgicos/efeitos dos fármacos , Eletroforese em Gel Bidimensional/métodos , Glicina/análogos & derivados , Glicina/farmacologia , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/metabolismo , Ionomicina/farmacologia , Periferinas/genética , Periferinas/metabolismo , Proteômica/métodos , Ratos , Ratos Sprague-Dawley
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