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1.
PLoS Pathog ; 19(4): e1010941, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37115795

RESUMO

The encapsulated fungus Cryptococcus neoformans is the most common cause of fungal meningitis, with the highest rate of disease in patients with AIDS or immunosuppression. This microbe enters the human body via inhalation of infectious particles. C. neoformans capsular polysaccharide, in which the major component is glucuronoxylomannan (GXM), extensively accumulates in tissues and compromises host immune responses. C. neoformans travels from the lungs to the bloodstream and crosses to the brain via transcytosis, paracytosis, or inside of phagocytes using a "Trojan horse" mechanism. The fungus causes life-threatening meningoencephalitis with high mortality rates. Hence, we investigated the impact of intranasal exogenous GXM administration on C. neoformans infection in C57BL/6 mice. GXM enhances cryptococcal pulmonary infection and facilitates fungal systemic dissemination and brain invasion. Pre-challenge of GXM results in detection of the polysaccharide in lungs, serum, and surprisingly brain, the latter likely reached through the nasal cavity. GXM significantly alters endothelial cell tight junction protein expression in vivo, suggesting significant implications for the C. neoformans mechanisms of brain invasion. Using a microtiter transwell system, we showed that GXM disrupts the trans-endothelial electrical resistance, weakening human brain endothelial cell monolayers co-cultured with pericytes, supportive cells of blood vessels/capillaries found in the blood-brain barrier (BBB) to promote C. neoformans BBB penetration. Our findings should be considered in the development of therapeutics to combat the devastating complications of cryptococcosis that results in an estimated ~200,000 deaths worldwide each year.


Assuntos
Criptococose , Cryptococcus neoformans , Meningite Criptocócica , Animais , Camundongos , Humanos , Cryptococcus neoformans/metabolismo , Roedores , Camundongos Endogâmicos C57BL , Criptococose/microbiologia , Polissacarídeos/metabolismo , Pulmão/metabolismo
2.
J Infect Dis ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38622836

RESUMO

Cryptococcus neoformans (Cn) is an opportunistic fungus that causes severe central nervous system (CNS) disease in immunocompromised individuals. Brain parenchyma invasion requires fungal traversal of the blood-brain barrier. In this study, we describe that Cn alters the brain endothelium by activating small GTPase RhoA, causing reorganization of the actin cytoskeleton and tight junction modulation to regulate endothelial barrier permeability. We confirm that the main fungal capsule polysaccharide glucuronoxylomannan is responsible for these alterations. We reveal a therapeutic benefit of RhoA inhibition by CCG-1423 in vivo. RhoA inhibition prolonged survival and reduced fungal burden in a murine model of disseminated cryptococcosis, supporting the therapeutic potential targeting RhoA in the context of cryptococcal infection. We examine the complex virulence of Cn in establishing CNS disease, describing cellular components of the brain endothelium that may serve as molecular targets for future antifungal therapies to alleviate the burden of life-threatening cryptococcal CNS infection.

3.
Antimicrob Agents Chemother ; 67(10): e0045923, 2023 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-37750714

RESUMO

Cryptococcus neoformans (Cn) is an encapsulated neurotropic fungal pathogen and the causative agent of cryptococcal meningoencephalitis (CME) in humans. Recommended treatment for CME is Amphotericin B (AmpB) and 5-fluorocytosine (5-FC). Though effective, AmpB has displayed numerous adverse side effects due to its potency and nephrotoxicity, prompting investigation into alternative treatments. Palmitoylethanolamide (PEA) is an immunomodulatory compound capable of promoting neuroprotection and reducing inflammation. To investigate the efficacy of PEA as a therapeutic alternative for CME, we intracerebrally infected mice with Cn and treated them with PEA or AmpB alone or in combination. Our results demonstrate that PEA alone does not significantly prolong survival nor reduce fungal burden, but when combined with AmpB, PEA exerts an additive effect and promotes both survivability and fungal clearance. However, we compared this combination to traditional AmpB and 5-FC treatment in a survivability study and observed lower efficacy. Overall, our study revealed that PEA alone is not effective as an antifungal agent in the treatment of CME. Importantly, we describe the therapeutic capability of PEA in the context of Cn infection and show that its immunomodulatory properties may confer limited protection when combined with an effective fungicidal agent.


Assuntos
Criptococose , Cryptococcus neoformans , Meningite Criptocócica , Meningoencefalite , Humanos , Camundongos , Animais , Meningite Criptocócica/tratamento farmacológico , Meningite Criptocócica/microbiologia , Antifúngicos/uso terapêutico , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Anfotericina B/uso terapêutico , Flucitosina/uso terapêutico , Meningoencefalite/tratamento farmacológico
4.
Arch Virol ; 167(11): 2109-2121, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35794491

RESUMO

Canine parvovirus type 2 (CPV-2) infection in dogs is associated with severe gastroenteritis, bloody diarrhea, and vomiting, resulting in high rates of death, especially in unvaccinated puppies within the first months of age. There are three variants, called CPV-2a, CPV-2b, and CPV-2c, co-circulating worldwide. Our group previously reported that the only circulating CPV-2 variant in the Guadalajara metropolitan area in western Mexico was type 2c. Now, a five-year study was performed in order to investigate the possible dominance of CPV-2c in our region. Rectal swabs were collected from 146 dogs with clinical gastroenteritis from May 2014 to August 2019 at the Veterinary Hospital of the University of Guadalajara. Of these, 90 dogs tested positive for canine parvovirus by PCR. Most of the infected dogs with CPV-2 had a partial or incomplete vaccination status (n = 88, 97.8%). Approximately 65% (n = 59) of them were mixed-breed dogs, 77.8% (n = 70) were under 6 months of age, and 37.8% (n = 34) of them died from clinical complications. RFLP analysis of amplicons derived from the vp2 gene showed that all 90 DNA samples corresponded to CPV-2c, with no evidence of the presence of CPV-2a or CPV-2b variants. Twenty-nine of the 90 DNA samples were selected for amplification of a portion of the vp2 gene, and sequencing of these amplicons showed that all of them had the sequence GAA at codon 426, encoding the amino acid glutamic acid, which is characteristic of CPV-2c. Phylogenetic analysis showed that the CPV-2c sequences were related to those of viruses from Europe and South America. The present study indicates that CPV-2c is still the only variant circulating in the dog population of the Guadalajara metropolitan area.


Assuntos
Doenças do Cão , Gastroenterite , Infecções por Parvoviridae , Parvovirus Canino , Animais , Códon , Doenças do Cão/epidemiologia , Cães , Gastroenterite/epidemiologia , Gastroenterite/genética , Gastroenterite/veterinária , Ácido Glutâmico/genética , México/epidemiologia , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/veterinária , Parvovirus Canino/genética , Filogenia , Melhoramento Vegetal
5.
Toxicol Mech Methods ; 25(3): 166-75, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25578686

RESUMO

TiO2 nanoparticles used as vectors for the delivery of drugs have shown greater effectiveness. However, TiO2 nanoparticles can cause oxidative stress in liver and kidney, so we analyzed if a previous or simultaneous quercetin treatment could counteract this in rats. Five groups of male Wistar rats (200-250 g) were included: (1) healthy controls, (2) TiO2 group, (3) quercetin group, (4) preventive group: quercetin for 5 days prior to exposure of TiO2, and (5) therapeutic group: TiO2 (5 mg/kg, i.v.) plus quercetin single dose for 5 days (5 mg/kg/day, i.p.). Hepatic and renal function tests were made. Five animals from each group were sacrificed (0, 14 and 28 days), and liver and kidney tissue were obtained. Malondialdehyde (MDA), reduced/oxidized glutathione, and activity of glutathione peroxidase/reductase were measured, as well as the level of gene expression by q-PCR. There were no significant changes in serum ALT and AST activities. More damage was observed at 14 versus 28 days, because TiO2 was excreted in urine. Quercetin indeed showed a renal protective effect by increasing glutathione reductase and peroxidase levels and reducing MDA levels. On the other hand, TiO2 liver damage was less pronounced with quercetin as therapeutic treatment. TiO2 induces significantly the glutathione reductase expression and it can be down-regulated by quercetin. Biochemical tests in serum and urine showed a better effect of quercetin administered in the therapeutic group. Care should be taken with the dose and time of administration of quercetin, because this antioxidant could also have a pro-oxidant effect.


Assuntos
Antioxidantes/uso terapêutico , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Quercetina/uso terapêutico , Titânio/toxicidade , Animais , Antioxidantes/administração & dosagem , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/fisiopatologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Sistemas de Liberação de Medicamentos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glutationa/agonistas , Glutationa/antagonistas & inibidores , Glutationa/química , Glutationa/metabolismo , Glutationa Peroxidase/antagonistas & inibidores , Glutationa Peroxidase/química , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Glutationa Redutase/antagonistas & inibidores , Glutationa Redutase/química , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Injeções Intraperitoneais , Injeções Intravenosas , Rim/metabolismo , Rim/fisiopatologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Fígado/fisiopatologia , Masculino , Nanopartículas Metálicas/administração & dosagem , Oxirredução , Quercetina/administração & dosagem , Distribuição Aleatória , Ratos Wistar , Insuficiência Renal/induzido quimicamente , Insuficiência Renal/tratamento farmacológico , Insuficiência Renal/fisiopatologia , Insuficiência Renal/prevenção & controle , Titânio/administração & dosagem
6.
Invest Clin ; 56(4): 341-55, 2015 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-29938964

RESUMO

The g.37190613 locus on 7p14.2-14.1 in the ELMO1 gene has a G>A polymorphism (SNP rs1345365) that has been associated with diabetic nephropathy in different populations. The genetic-association studies in type 2 diabetes mellitus (DM2) on the Mexican population are limited. The aim of this study was to estimate whether the polymorphism G>A of ELMO1 gene is associated with the development of DM2. We included 148 DM2 individuals, 156 individuals with cardiovascular risk factors without diabetes and 269 healthy proband without DM2. The polymorphism was identified by PCR amplification specific allele (PASA), PAGE and silver staining. The association was established by genetic epidemiological models; the dominant model showed a positive association (p=0.0006) as a protective factor, and the para-dominant model to heterozygous, as risk factor. In conclusion, this study revealed the association of the SNP rs1345365 of the ELMO1 gene in a Mexican population.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Diabetes Mellitus Tipo 2/genética , Adulto , Predisposição Genética para Doença , Humanos , Masculino , México , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Grupos Raciais
7.
Mycologia ; 116(2): 258-266, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38232343

RESUMO

Fusarium spp. has emerged as an opportunistic etiological agent with clinical manifestations varying from localized infections to deep-seated systemic disease. It is also a phytopathogen of economic impact. There are few reports on the species diversity of this genus, and no comprehensive studies on the epidemiology nor the antifungal susceptibility of Fusarium in Mexico. The present multicentric study aims to shed light on the species distribution and antifungal susceptibility patterns of 116 strains of Fusarium isolated from clinical and environmental samples. Isolates were identified by standard phenotypic characteristics and by sequencing of the ITS (internal transcribed spacer), TEF1 (translation elongation factor 1-α), RPB2 (RNA polymerase II core subunit), and/or CAM1 (calmodulin) regions. Susceptibility tests were carried out against 15 antifungals of clinical and agricultural use. Regarding Fusarium distribution, we identified 27 species belonging to eight different species complexes. The most frequently isolated species for both clinical and environmental samples were F. falciforme (34%), F. oxysporum sensu stricto (12%), F. keratoplasticum (8%), and F. solani sensu stricto (8%). All Fusarium isolates showed minimum inhibitory concentrations (MICs) equal to or above the maximum concentration evaluated for fluconazole, 5-fluocytosine, caspofungin, micafungin, and anidulafungin. All isolates had a MIC of ≤16 µg/mL for voriconazole, with a mode of 4 µg/mL. F. verticillioides appeared to be the most susceptible to all antifungals tested.


Assuntos
Antifúngicos , Fusarium , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , México , Testes de Sensibilidade Microbiana
8.
Ann Hepatol ; 12(4): 616-25, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23813140

RESUMO

BACKGROUND: Hepatitis C virus (HCV) infection usually results in long-term viremia. Entry of HCV into the hepatocyte requires claudin-1, -6, -9 and occludin. The efficacy of Pegylated interferon-α (PEG-IFN) treatment against HCV infection increased when ribavirin (RBV) was added to the therapeutic scheme. Our aim was to investigate if PEG-IFN plus RBV regulate claudin expression. MATERIAL AND METHODS: HepG2, Huh-7 and Huh-7.5 cells were treated with PEG-IFN-α2a or α2b and/or RBV at different times before obtaining the cytosolic, membrane and cytoskeletal fractions. Claudin-1, 3, 4, 6, and 9, E-cadherin and occludin expression was evaluated by Western blot analysis. Transepithelial electrical resistance (TER) was also determined. RESULTS: Claudin-1, 3, 4, 6, E-cadherin and occludin are constitutively expressed mainly in HepG2 cell membrane. Claudin-1 and E-cadherin cell membrane expression diminished after exposure to PEGIFNα2b (50 ng) + RBV(50 µg); the maximal decrease was observed with 200 ng of PEG-IFNα2b + 200 µg of RBV. The effect was less intense with PEG-IFNα2a. The inhibition of claudin-1 and E-cadherin expression in Huh-7 and Huh-7.5 cells was only observed with 200 ng of PEG-IFNα2b + 200 µg of RBV. TER diminished marginally in the HCV containing hepatoma cells with 200 ng of PEG-IFNα2b + 200 µg of RBV. Claudin-1 mRNA expression level was not affected by the combined treatment. CONCLUSION: The increased therapeutic efficacy of the PEG-IFNα2b plus RBV treatment could be secondary to the inhibition of claudin-1 and E-cadherin cell membrane expression.


Assuntos
Antivirais/farmacologia , Caderinas/metabolismo , Claudina-1/metabolismo , Hepatócitos/efeitos dos fármacos , Interferon-alfa/farmacologia , Polietilenoglicóis/farmacologia , Ribavirina/farmacologia , Antígenos CD , Western Blotting , Caderinas/genética , Regulação para Baixo , Impedância Elétrica , Células Hep G2 , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Interferon alfa-2 , RNA Mensageiro/metabolismo , Proteínas Recombinantes/farmacologia , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Fatores de Tempo
9.
bioRxiv ; 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37090670

RESUMO

Cryptococcus neoformans ( Cn ) is an encapsulated neurotropic fungal pathogen and the causative agent of cryptococcal meningoencephalitis (CME) in humans. Recommended treatment for CME is Amphotericin B (AmpB) and 5-fluorocytosine (5-FC). Though effective, AmpB has displayed numerous adverse side effects due to its potency and nephrotoxicity, prompting investigation into alternative treatments. Palmitoylethanolamide (PEA) is an immunomodulatory compound capable of promoting neuroprotection and reducing inflammation. To investigate the efficacy of PEA as a therapeutic alternative for CME, we intracerebrally infected mice with Cn and treated them with PEA or AmpB alone or in combination. Our results demonstrate that PEA alone does not significantly prolong survival nor reduce fungal burden, but when combined with AmpB, PEA exerts an additive effect and promotes both survivability and fungal clearance. However, we compared this combination to traditional AmpB and 5-FC treatment in a survivability study and observed lower efficacy. Overall, our study revealed that PEA alone is not effective as an antifungal agent in the treatment of CME. Importantly, we describe the therapeutic capability of PEA in the context of Cn infection and show that its immunomodulatory properties may confer limited protection when combined with an effective fungicidal agent.

10.
PLoS Negl Trop Dis ; 17(1): e0011068, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36656900

RESUMO

Infection of the Central Nervous System (CNS) by the encapsulated fungus Cryptococcus neoformans can lead to high mortality meningitis, most commonly in immunocompromised patients. While the mechanisms by which the fungus crosses the blood-brain barrier to initiate infection in the CNS are well recognized, there are still substantial unanswered questions about the disease progression once the fungus is established in the brain. C. neoformans is characterized by a glucuronoxylomannan (GXM)-rich polysaccharide capsule which has been implicated in immune evasion, but its role during the host CNS infection needs further elucidation. Therefore, the present study aims to examine these key questions about the mechanisms underlying cryptococcal meningitis progression and the impact of fungal GXM release by using an intracerebral rodent infection model via stereotaxic surgery. After developing brain infection, we analyzed distinct brain regions and found that while fungal load and brain weight were comparable one-week post-infection, there were region-specific histopathological (with and without brain parenchyma involvement) and disease manifestations. Moreover, we also observed a region-specific correlation between GXM accumulation and glial cell recruitment. Furthermore, mortality was associated with the presence of subarachnoid hemorrhaging and GXM deposition in the meningeal blood vessels and meninges in all regions infected. Our results show that using the present infection model can facilitate clinical and neuropathological observations during the progression of neurocryptococcosis. Importantly, this mouse model can be used to further investigate disease progression as it develops in humans.


Assuntos
Criptococose , Cryptococcus neoformans , Meningite Criptocócica , Humanos , Animais , Camundongos , Criptococose/microbiologia , Sistema Nervoso Central , Meningite Criptocócica/microbiologia , Polissacarídeos , Modelos Animais de Doenças , Progressão da Doença
11.
Brain Sci ; 13(3)2023 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-36979318

RESUMO

The main histopathological hallmarks of Parkinson's disease (PD) are the degeneration of the dopaminergic neurons of the substantia nigra pars compacta and the loss of neuromelanin as a consequence of decreased dopamine synthesis. The destruction of the striatal dopaminergic pathway and blocking of striatal dopamine receptors cause motor deficits in humans and experimental animal models induced by some environmental agents. In addition, neuropsychiatric symptoms such as mood and anxiety disorders, hallucinations, psychosis, cognitive impairment, and dementia are common in PD. These alterations may precede the appearance of motor symptoms and are correlated with neurochemical and structural changes in the brain. This paper reviews the most crucial pathophysiology of neuropsychiatric alterations in PD. It is worth noting that PD patients have global task learning deficits, and cognitive functions are compromised in a way is associated with hypoactivation within the striatum, anterior cingulate cortex, and inferior frontal sulcus regions. An appropriate and extensive neuropsychological screening battery in PD must accurately assess at least five cognitive domains with some tests for each cognitive domain. This neuropsychological screening should consider the pathophysiological and clinical heterogeneity of cognitive dysfunction in PD.

12.
Am J Physiol Gastrointest Liver Physiol ; 302(11): G1264-73, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22442156

RESUMO

We evaluated the participation of oxidative stress in the negative regulation of hepatitis C virus (HCV)-RNA induced by acetylsalicylic acid (ASA). We used the HCV subgenomic replicon cell system that stably expresses HCV-nonstructural proteins (Huh7 HCV replicon cells) and the parental cell line. Cells were exposed to 4 mM ASA at different times (12-72 h), and pyrrolidine dithiocarbamate (PDTC) was used as an antioxidant control. Reactive oxygen species (ROS) production, oxidized protein levels, cytosolic superoxide dismutase (Cu/Zn-SOD), and glutathione peroxidase (GPx) activity were measured to evaluate oxidative stress. In addition, viral RNA and prostaglandin (PGE(2)) levels were determined. We observed that ASA treatment decreased ROS production and oxidized protein levels in a time-dependent fashion in both parental and HCV replicon cells with a greater extent in the latter. Similar results were found with PDTC exposure. Average GPx activity was decreased, whereas a striking increase was observed in average cytosolic SOD activity at 48 and 72 h in both cells exposed to ASA, compared with untreated cells. HCV replicon cells showed higher levels of Cu/Zn-SOD expression (mRNA and protein) with ASA treatment (48 and 72 h), whereas NS5A protein levels showed decreased expression. In addition, we found that inhibition of SOD1 expression reversed the effect of ASA. Interestingly, PDTC downregulated HCV-RNA expression (55%) and PGE(2) (60%) levels, imitating ASA exposure. These results suggest that ASA treatment could reduce cellular oxidative stress markers and modify Cu/Zn-SOD expression, a phenomenon that may contribute to the mechanisms involved in HCV downregulation.


Assuntos
Antioxidantes/farmacologia , Antivirais/farmacologia , Aspirina/farmacologia , Hepacivirus/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Linhagem Celular , Células Cultivadas , Hepacivirus/metabolismo , Hepatócitos/metabolismo , Hepatócitos/virologia , Humanos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase-1 , Replicação Viral/efeitos dos fármacos
13.
Pathogens ; 11(1)2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35056057

RESUMO

Toxoplasma gondii is the causative agent of toxoplasmosis in humans and animals. The sexual reproductive cycle of Toxoplasma takes place in the small intestine of felines, the definitive hosts. In the final part of the sexual cycle, T. gondii forms oocysts in infected cats. Oocysts transferred via the faeces to the environment are highly infectious to both animals and humans. This study aimed to determine the prevalence and risk factors associated with T. gondii infection in cats from the metropolitan region of Guadalajara in western Mexico. Western blotting and ELISA for anti-Toxoplasma IgG antibodies was performed, and Toxoplasma DNA was identified using polymerase chain reaction. Prevalence of anti-T. gondii antibodies was 14.8% (44/297), and only 2/297 cases were positive for PCR. Cats older than one year were at an increased risk of infection (OR = 3.9, 95% CI 1.844-8.362). Sex, raw meat feeding, hunting habits, vaccination status, and body condition were not associated with positivity. The prevalence of T. gondii infection determined with Western blot in cats in the metropolitan area of Guadalajara, Jalisco, Mexico, was lower than that reported in previous studies.

14.
Curr Trop Med Rep ; 8(1): 6-17, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33500877

RESUMO

Purpose of Review: Infectious diseases represent up to 12% of all deaths in people with diabetes mellitus (DM). The development and progression of DM generate a chronic inflammatory state with unique characteristics that have been exploited by some pathogens; one of them is Rhizopus spp., a fungus considered the causative agent of mucormycosis. This disease has a poor prognosis with high mortality rates, and the apparition of resistant isolates each year has become a worrying concern. DM is an actual and continuing health problem, and for that reason, it is of foremost importance to study the pathogenesis of mucormycosis to generate new prevention and treatment strategies. Recent Findings: The worldwide incidence of mucormycosis has increased in recent years. The pathogenic mechanisms and factors identified in Rhizopus spp. are the cell wall, spore germination, proteins, and enzymes related to iron sequestration, CotH fungal protein, positive regulation of the GRP78 cell receptor, and immune evasion due to survival within phagocytes, among others. The physiopathology of DM offers favorable conditions for the successful replication of Rhizopus spp. Summary: The main reason for increase of incidence of mucormycosis caused by Rhizopus spp. has been associated with the rise of worldwide prevalence of DM. Knowing the fungal pathogenic mechanisms as well as the relationships between Rhizopus with the microenvironment found in the human body will undoubtedly help generate better antifungals to enhance treatment outcomes. Nowadays, some strategies to combat the fungus are based on the knowledge of its proteins, cellular interactions, and iron metabolism.

15.
PeerJ ; 7: e6430, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30834181

RESUMO

BACKGROUND: The protozoan Giardia lamblia is the causal agent of giardiasis, one of the main diarrheal infections worldwide. Drug resistance to common antigiardial agents and incidence of treatment failures have increased in recent years. Therefore, the search for new molecular targets for drugs against Giardia infection is essential. In protozoa, ionic channels have roles in their life cycle, growth, and stress response. Thus, they are promising targets for drug design. The strategy of ligand-protein docking has demonstrated a great potential in the discovery of new targets and structure-based drug design studies. METHODS: In this work, we identify and characterize a new potassium channel, GiK, in the genome of Giardia lamblia. Characterization was performed in silico. Because its crystallographic structure remains unresolved, homology modeling was used to construct the three-dimensional model for the pore domain of GiK. The docking virtual screening approach was employed to determine whether GiK is a good target for potassium channel blockers. RESULTS: The GiK sequence showed 24-50% identity and 50-90% positivity with 21 different types of potassium channels. The quality assessment and validation parameters indicated the reliability of the modeled structure of GiK. We identified 110 potassium channel blockers exhibiting high affinity toward GiK. A total of 39 of these drugs bind in three specific regions. DISCUSSION: The GiK pore signature sequence is related to the small conductance calcium-activated potassium channels (SKCa). The predicted binding of 110 potassium blockers to GiK makes this protein an attractive target for biological testing to evaluate its role in the life cycle of Giardia lamblia and potential candidate for the design of novel antigiardial drugs.

16.
Exp Ther Med ; 18(4): 3125-3138, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31572553

RESUMO

Aminoguanidine (AG) inhibits advanced glycation end products (AGEs) and advanced oxidation protein products (AOPP) accumulated as a result of excessive oxidative stress in diabetes. However, the molecular mechanism by which AG reduces AGE-associated damage in diabetes is not well understood. Thus, we investigated whether AG supplementation mitigates oxidative-associated cardiac fibrosis in rats with type 2 diabetes mellitus (T2DM). Forty-five male Wistar rats were divided into three groups: Control, T2DM and T2DM+AG. Rats were fed with a high-fat, high-carbohydrate diet (HFCD) for 2 weeks and rendered diabetic using low-dose streptozotocin (STZ) (20 mg/kg), and one group was treated with AG (20 mg/kg) up to 25 weeks. In vitro experiments were performed in primary rat myofibroblasts to confirm the antioxidant and antifibrotic effects of AG and to determine if blocking the receptor for AGEs (RAGE) prevents the fibrogenic response in myofibroblasts. Diabetic rats exhibited an increase in cardiac fibrosis resulting from HFCD and STZ injections. By contrast, AG treatment significantly reduced cardiac fibrosis, α-smooth muscle actin (αSMA) and oxidative-associated Nox4 and Nos2 mRNA expression. In vitro challenge of myofibroblasts with AG under T2DM conditions reduced intra- and extracellular collagen type I expression and Pdgfb, Tgfß1 and Col1a1 mRNAs, albeit with similar expression of Tnfα and Il6 mRNAs. This was accompanied by reduced phosphorylation of ERK1/2 and SMAD2/3 but not of AKT1/2/3 and STAT pathways. RAGE blockade further attenuated collagen type I expression in AG-treated myofibroblasts. Thus, AG reduces oxidative stress-associated cardiac fibrosis by reducing pERK1/2, pSMAD2/3 and collagen type I expression via AGE/RAGE signaling in T2DM.

17.
Viral Immunol ; 31(3): 223-232, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29099687

RESUMO

Bilirubin (BR), a metabolite with increased concentrations in plasma during viral hepatitis, has been recognized as a potential immune-modulator. We recently reported that conjugated BR (CB) augments regulatory T cell (Treg) suppressor activity during acute hepatitis A virus (HAV) infection. However, the mechanisms related to the effects of CB on Treg function in the course of hepatotropic viral diseases have not been elucidated. T cell immunoglobulin domain and mucin domain 3 (TIM-3), via its interactions with galectin-9 (GAL-9), is a receptor associated with enhanced Treg function. Thus, TIM-3 expression may be related to the crosstalk between CB and Tregs during HAV infection. Herein, in vitro treatment with high concentrations of CB upregulated TIM-3 expression on Tregs from healthy donors. CB treatment in vitro did not induce de novo Treg generation, and in vitro stimulation with TGF-ß, which shows increased secretion during HAV infection, resulted in a trend toward increased TIM-3 expression on Tregs and CD4+ T lymphocytes (TLs) from healthy donors. Interestingly, an upregulation of TIM-3 expression on CD4+CD25+ T cells and an increase in the proportion of CD4+ TLs expressing GAL-9 were found in HAV-infected patients with abnormal CB values relative to healthy controls. In addition, a statistically significantly reduction in IL-17F production was observed after treatment of CD4+ TLs from healthy donors with high doses of CB in vitro. In summary, our results suggest that CB might regulate Treg activity via a TIM-3-mediated mechanism, ultimately leading to an anti-inflammatory hepatoprotective effect.


Assuntos
Bilirrubina/metabolismo , Receptor Celular 2 do Vírus da Hepatite A/biossíntese , Hepatite A/patologia , Fatores Imunológicos/metabolismo , Linfócitos T Reguladores/efeitos dos fármacos , Regulação para Cima , Adolescente , Antígenos CD4/análise , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Interleucina-17/análise , Subunidade alfa de Receptor de Interleucina-2/análise , Masculino , Linfócitos T Reguladores/química
18.
J Pharm Pharmacol ; 70(3): 426-433, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29411390

RESUMO

OBJECTIVES: This study was undertaken to investigate the amoebicidal potential of curcumin on Entamoeba histolytica, as well as its synergistic effect with metronidazole. METHODS: Entamoeba histolytica trophozoites were exposed to 100, 200 and 300 µm of curcumin, for 6, 12 and 24 h. Consequently, the viability of cells was determined by trypan blue exclusion test. All specimens were further analysed by scanning electron microscopy. For drug combination experiment, the Chou-Talalay method was used. KEY FINDINGS: Curcumin affected the growth and cell viability in a time- and dose-dependent manner. The higher inhibitory effects were observed with 300 µm at 24 h; 65.5% of growth inhibition and only 28.8% of trophozoites were viable. Additionally, curcumin also altered adhesion and the morphology of the trophozoites. Scanning electron microscopy revealed treated trophozoites with damages on the membrane, size alterations and parasites with loss of cellular integrity. In addition, the combination of curcumin + metronidazole exhibited a synergistic effect; the activity of both drugs was improved. CONCLUSIONS: This is the first report evaluating the effectiveness of curcumin against E. histolytica. Our results suggest that CUR could be considered for evaluation in future pharmacological studies as a promising amoebicidal agent or as complementary therapy.


Assuntos
Curcumina/farmacologia , Entamoeba histolytica/efeitos dos fármacos , Entamoeba histolytica/crescimento & desenvolvimento , Trofozoítos/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Metronidazol/farmacologia , Testes de Sensibilidade Parasitária , Trofozoítos/crescimento & desenvolvimento , Trofozoítos/ultraestrutura
19.
Nutr Hosp ; 35(6): 1394-1400, 2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30525855

RESUMO

BACKGROUND: patients with cervical cancer (CC) receiving chemotherapy and radiotherapy have several gastrointestinal adverse effects. OBJECTIVE: to evaluate the effect of dietary symbiotic supplementation on fecal calprotectin (FCP), bacterial DNA levels, and gastrointestinal adverse effects in patients with CC. METHODS: clinical, controlled, randomized, double-blind trial. Patients consumed symbiotics or placebo three times a day for seven weeks. FCP was assessed by Elisa method. DNA from probiotic and pathogenic bacteria were determined by quantitative real-time polymerase chain reaction. Diarrheal evacuations were evaluated with the Bristol stool form scale and nausea and vomiting were measured using the scale of the National Institute of Cancerology of the United States. RESULTS: after a seven-week treatment, FCP concentration was lower in the symbiotic group compared to the control group (p < 0.001). Stool consistency in the placebo and symbiotic groups was similar at baseline. A significant improvement in stool consistency was obtained in both groups at the end of the intervention (p < 0.001). The concentrations and total proportions of the probiotic and pathogenic bacteria were similar in both groups. Nausea significantly diminished in both groups (p < 0.001) at the end of the trial. Furthermore, the symbiotic group had a statistically significant decrease in the frequency and intensity of vomiting when compared to the control group (p < 0.001). CONCLUSIONS: the symbiotic treatment decreases significantly the FCP levels and the frequency and intensity of vomiting in patients with CC.


Assuntos
Fezes/química , Fezes/microbiologia , Complexo Antígeno L1 Leucocitário/análise , Prebióticos/administração & dosagem , Probióticos/administração & dosagem , Neoplasias do Colo do Útero/terapia , Adulto , Antineoplásicos/efeitos adversos , Bifidobacterium/genética , DNA Bacteriano/análise , Suplementos Nutricionais , Método Duplo-Cego , Escherichia coli/genética , Feminino , Gastroenteropatias/etiologia , Gastroenteropatias/prevenção & controle , Humanos , Inflamação/etiologia , Inflamação/prevenção & controle , Lactobacillales/genética , Pessoa de Meia-Idade , Placebos , Radioterapia/efeitos adversos , Salmonella/genética , Neoplasias do Colo do Útero/complicações
20.
Hepatol Res ; 37(5): 311-6, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17441802

RESUMO

AIMS: The prevalence of hepatitis C virus (HCV) infection, risk factors and HCV genotypes in 140 HIV-1 infected individuals from northern Mexico was determined. METHODS: Hepatitis C infection was confirmed by the detection of anti-HCV antibodies and HCV-RNA in sera, and genotyping was performed by the InnoLiPA-HCV genotype assay. RESULTS: Seventeen (12.1%) out of 140 HIV-infected individuals were found to be HCV-positive. Coinfected individuals were more likely to be male (87%). The most frequent genotype was 1a (41%), followed by 1b (29.4%), 2a/c (17.6%), 2b (5.9%) and 3 (5.9%). Serum transaminase concentrations (AST and ALT) were higher in coinfected patients. Among the risk factors for coinfection: sexual transmission was the most frequently observed (men who have sex with men (MSM); 64.7% and bisexual behavior; 64.7%) followed by intravenous drug users (IVDU) (53%). There was no association of the HCV genotypes with the age and risk factors for HIV-1 and HCV infection observed in the studied patients. CONCLUSION: The results suggest that the prevalence of HIV-1/HCV coinfection in Mexico is lower than in other American countries.

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