RESUMO
Parasitic diseases, predominantly prevalent in developing countries, are increasingly spreading to high-income nations due to shifting migration patterns. The World Health Organization (WHO) estimates approximately 300 million annual cases of giardiasis. The emergence of drug resistance and associated side effects necessitates urgent research to address this growing health concern. In this study, we evaluated over eleven thousand pharmacological compounds sourced from the FDA database to assess their impact on the TATA-binding protein (TBP) of the early diverging protist Giardia lamblia, which holds medical significance. We identified a selection of potential pharmacological compounds for combating this parasitic disease through in silico analysis, employing molecular modeling techniques such as homology modeling, molecular docking, and molecular dynamics simulations. Notably, our findings highlight compounds DB07352 and DB08399 as promising candidates for inhibiting the TBP of Giardia lamblia. Also, these compounds and DB15584 demonstrated high efficacy against trophozoites in vitro. In summary, this study identifies compounds with the potential to combat giardiasis, offering the prospect of specific therapies and providing a robust foundation for future research.
Assuntos
Antiprotozoários , Giardia lamblia , Giardíase , Simulação de Acoplamento Molecular , United States Food and Drug Administration , Giardíase/tratamento farmacológico , Giardia lamblia/efeitos dos fármacos , Antiprotozoários/farmacologia , Antiprotozoários/química , Estados Unidos , Humanos , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/antagonistas & inibidores , Simulação de Dinâmica MolecularRESUMO
Cancer involves a series of diseases where cellular growth is not controlled. Cancer is a leading cause of death worldwide, and the burden of cancer incidence and mortality is rapidly growing, mainly in developing countries. Many drugs are currently used, from chemotherapeutic agents to immunotherapy, among others, along with organ transplantation. Treatments can cause severe side effects, including remission and progression of the disease with serious consequences. Increased glycolytic activity is characteristic of cancer cells. Triosephosphate isomerase is essential for net ATP production in the glycolytic pathway. Notably, some post-translational events have been described that occur in human triosephosphate isomerase in which functional and structural alterations are provoked. This is considered a window of opportunity, given the differences that may exist between cancer cells and their counterpart in normal cells concerning the glycolytic enzymes. Here, we provide elements that bring out the potential of triosephosphate isomerase, under post-translational modifications, to be considered an efficacious target for treating cancer.
Assuntos
Neoplasias , Triose-Fosfato Isomerase , Humanos , Triose-Fosfato Isomerase/genética , Neoplasias/tratamento farmacológico , Processamento de Proteína Pós-Traducional , Ciclo Celular , Proliferação de CélulasRESUMO
BACKGROUND: Hereditary actin-related protein 2/3 complex subunit 1B deficiency is characterized clinically by ear, skin, and lung infections, bleeding, eczema, food allergy, asthma, skin vasculitis, colitis, arthritis, short stature, and lymphadenopathy. OBJECTIVE: We aimed to describe the clinical, laboratory, and genetic features of six patients from four Mexican families. METHODS: We performed exome sequencing in patients of four families with suspected actinopathy, collected their data from medical records, and reviewed the literature for reports of other patients with actin-related protein 2/3 complex subunit 1B deficiency. RESULTS: Six patients from four families were included. All had recurrent infections, mainly bacterial pneumonia, and cellulitis. A total of 67% had eczema whereas 50% had food allergies, failure to thrive, hepatomegaly, and bleeding. Eosinophilia was found in all; 84% had thrombocytopenia, 67% had abnormal-size platelets and anemia. Serum levels of IgG, IgA, and IgE were highly increased in most; IgM was normal or low. T cells were decreased in 67% of patients, whereas B and NK cells were increased in half of patients. Two of the four probands had compound heterozygous variants. One patient was successfully transplanted. We identified 28 other patients whose most prevalent features were eczema, recurrent infections, failure to thrive, bleeding, diarrhea, allergies, vasculitis, eosinophilia, platelet abnormalities, high IgE/IgA, low T cells, and high B cells. CONCLUSION: Actin-related protein 2/3 complex subunit 1B deficiency has a variable and heterogeneous clinical spectrum, expanded by these cases to include keloid scars and Epstein-Barr virus chronic hepatitis. A novel deletion in exon 8 was shared by three unrelated families and might be the result of a founder effect.
Assuntos
Eczema , Eosinofilia , Infecções por Vírus Epstein-Barr , Vasculite , Humanos , Proteína 2 Relacionada a Actina , Actinas , Insuficiência de Crescimento , Herpesvirus Humano 4 , Imunoglobulina A , Imunoglobulina E , Reinfecção , Proteína 3 Relacionada a Actina/metabolismoRESUMO
Introduction: The transcription factor Nuclear factor of activated T cells 5 (NFAT5), pivotal in immune regulation and function, can be induced by osmotic stress and tonicity-independent signals. Objective: We aimed to investigate and characterize two unrelated patients with Epstein-Barr virus susceptibility and no known genetic etiology. Methods: After informed consent, we reviewed the electronic charts, extracted genomic DNA, performed whole-exome sequencing, filtered, and prioritized their variants, and confirmed through Sanger sequencing, family segregation analysis, and some functional assays, including lymphoproliferation, cytotoxicity, and characterization of natural killer cells. Results: We describe two cases of pediatric Mexican patients with rare heterozygous missense variants in NFAT5 and EBV susceptibility, a school-age girl with chronic-active infection of the liver and bowel, and a teenage boy who died of hemophagocytic lymphohistiocytosis. Discussion: NFAT5 is an important regulator of the immune response. NFAT5 haploinsufficiency has been described as an immunodeficiency syndrome affecting both innate and adaptive immunity. EBV susceptibility might be another manifestation in the spectrum of this disease.
Assuntos
Infecções por Vírus Epstein-Barr , Linfo-Histiocitose Hemofagocítica , Adolescente , Criança , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/genética , Feminino , Haploinsuficiência , Herpesvirus Humano 4 , Humanos , Masculino , Fatores de Transcrição/genéticaRESUMO
Beyond the problem in public health that protist-generated diseases represent, understanding the variety of mechanisms used by these parasites to interact with the human immune system is of biological and medical relevance. Giardia lamblia is an early divergent eukaryotic microorganism showing remarkable pathogenic strategies for evading the immune system of vertebrates. Among various multifunctional proteins in Giardia, arginine deiminase is considered an enzyme that plays multiple regulatory roles during the life cycle of this parasite. One of its most important roles is the crosstalk between the parasite and host. Such a molecular "chat" is mediated in human cells by membrane receptors called Toll-like receptors (TLRs). Here, we studied the importance of the 3D structure of giardial arginine deiminase (GlADI) to immunomodulate the human immune response through TLRs. We demonstrated the direct effect of GlADI on human TLR signaling. We predicted its mode of interaction with TLRs two and four by using the AlphaFold-predicted structure of GlADI and molecular docking. Furthermore, we showed that the immunomodulatory capacity of this virulent factor of Giardia depends on the maintenance of its 3D structure. Finally, we also showed the influence of this enzyme to exert specific responses on infant-like dendritic cells.
Assuntos
Giardia , Giardíase , Animais , Humanos , Hidrolases , Imunidade , Imunomodulação , Simulação de Acoplamento Molecular , Receptores Toll-LikeRESUMO
Human triosephosphate isomerase (HsTIM) is a central glycolytic enzyme and is overexpressed in cancer cells with accelerated glycolysis. Triple-negative breast cancer is highly dependent on glycolysis and is typically treated with a combination of surgery, radiation therapy, and chemotherapy. Deamidated HsTIM was recently proposed as a druggable target. Although thiol-reactive drugs affect cell growth in deamidated HsTIM-complemented cells, the role of this protein as a selective target has not been demonstrated. To delve into the usefulness of deamidated HsTIM as a selective target, we assessed its natural accumulation in breast cancer cells. We found that deamidated HsTIM accumulates in breast cancer cells but not in noncancerous cells. The cancer cells are selectively programmed to undergo cell death with thiol-reactive drugs that induced the production of methylglyoxal (MGO) and advanced glycation-end products (AGEs). In vivo, a thiol-reactive drug effectively inhibits the growth of xenograft tumors with an underlying mechanism involving deamidated HsTIM. Our findings demonstrate the usefulness of deamidated HsTIM as target to develop new therapeutic strategies for the treatment of cancers and other pathologies in which this post translationally modified protein accumulates.
Assuntos
Neoplasias da Mama , Triose-Fosfato Isomerase , Feminino , Glicólise , Humanos , Proteínas/metabolismo , Aldeído Pirúvico/metabolismo , Compostos de Sulfidrila , Triose-Fosfato Isomerase/metabolismoRESUMO
The protease catalytic subunit of the nuclear inclusion protein A from tobacco etch virus (TEVp) is widely used to remove tags and fusion proteins from recombinant proteins. Some intrinsic drawbacks to its recombinant production have been studied for many years, such as low solubility, auto-proteolysis, and instability. Some point mutations have been incorporated in the amino acid protease sequence to improve its production. Here, a comprehensive review of each mutation reported so far has been made to incorporate them into a mutant called TEVp7M with a total of seven changes. This mutant with a His7tag at N-terminus was produced with remarkable purification yields (55 mg/L of culture) from the soluble fraction in a single step affinity purification. The stability of His7-TEVp7M was analyzed and compared with the single mutant TEVp S219V, making evident that His7-TEVp7M shows very constant thermal stability against pH variation, whereas TEVp S219V is highly sensitive to this change. The cleavage reaction was optimized by determining the amount of protease that could cleave a 100-fold excess substrate in the shortest possible time at 30 °C. Under these conditions, His7-TEVp7M was able to cleave His-tag in the buffers commonly used for affinity purification. Finally, a structural analysis of the mutations showed that four of them increased the polarity of the residues involved and, consequently, showed increased solubility of TEVp and fewer hydrophobic regions exposed to the solvent. Taken together, the seven changes studied in this work improved stability, solubility, and activity of TEVp producing enough protease to digest large amounts of tags or fusion proteins. KEY POINTS: ⢠Production of excellent yields of a TEVp (TEVp7M) by incorporation of seven changes. ⢠His-tag removal in an excess substrate in the common buffers used for purification. ⢠Incorporated mutations improve polarity, stability, and activity of TEVp7M.
Assuntos
Endopeptidases , Cromatografia de Afinidade , Endopeptidases/genética , Endopeptidases/metabolismo , Proteólise , Proteínas Recombinantes de Fusão/metabolismoRESUMO
Giardiasis represents a latent problem in public health due to the exceptionally pathogenic strategies of the parasite Giardia lamblia for evading the human immune system. Strains resistant to first-line drugs are also a challenge. Therefore, new antigiardial therapies are urgently needed. Here, we tested giardial arginine deiminase (GlADI) as a target against giardiasis. GlADI belongs to an essential pathway in Giardia for the synthesis of ATP, which is absent in humans. In silico docking with six thiol-reactive compounds was performed; four of which are approved drugs for humans. Recombinant GlADI was used in enzyme inhibition assays, and computational in silico predictions and spectroscopic studies were applied to follow the enzyme's structural disturbance and identify possible effective drugs. Inhibition by modification of cysteines was corroborated using Ellman's method. The efficacy of these drugs on parasite viability was assayed on Giardia trophozoites, along with the inhibition of the endogenous GlADI. The most potent drug against GlADI was assayed on Giardia encystment. The tested drugs inhibited the recombinant GlADI by modifying its cysteines and, potentially, by altering its 3D structure. Only rabeprazole and omeprazole decreased trophozoite survival by inhibiting endogenous GlADI, while rabeprazole also decreased the Giardia encystment rate. These findings demonstrate the potential of GlADI as a target against giardiasis.
Assuntos
Giardia lamblia/efeitos dos fármacos , Giardíase/tratamento farmacológico , Hidrolases/metabolismo , Animais , Antiprotozoários/farmacologia , Simulação por Computador , Cisteína/química , Avaliação Pré-Clínica de Medicamentos/métodos , Reposicionamento de Medicamentos/métodos , Giardia lamblia/patogenicidade , Giardíase/imunologia , Tiomalato Sódico de Ouro/farmacologia , Humanos , Hidrolases/efeitos dos fármacos , Hidrolases/ultraestrutura , Omeprazol/farmacologia , Inibidores da Bomba de Prótons/farmacologia , Rabeprazol , Tiamina/análogos & derivados , Tiamina/farmacologia , Trofozoítos/efeitos dos fármacosRESUMO
Delivery methods during childbirth and their related gut microbiota profiles have important impacts on health later in life, they can contribute to the development of diseases such as obesity, whose highest prevalence rate is found among the Mexican child population. Coincidentally, Mexico has one of the highest global average annual rate increase in cesarean births (C-section). Since Mexico leads the world in childhood obesity, studying the relationship between childbirth delivery methods and gut microbiota profiles in this vulnerable population may be used to identify early risk factors for obesity in other developed and developing countries. The objective of this study is to determine the association between child delivery method and gut microbiota profiles in healthy Mexican newborns.Fecal samples of 57 term infants who participated in a randomized clinical trial in 2013 to study the safety of Agave fructans in newborns, were used in this study. DNA samples were extracted and used to characterize the microbiota composition using high-throughput 16S rRNA gene sequencing. The samples were further divided based on childbirth delivery method, as well as early diet. Gut microbiota profiles were determined and analyzed using cluster analysis followed by multiple correspondence analysis.An unusual high abundance of Proteobacteria was found in the gut microbiota of all Mexican infants studied, regardless of delivery method. Feces from infants born by C-section had low levels of Bacteroidetes, high levels of Firmicutes, especially Clostridium and Enterococcus, and a strikingly high ratio of Firmicutes/Bacteroidetes (F:B). Profiles enriched in Bacteroidetes and low F:B ratios, were strongly associated with vaginal delivery.The profile of gut microbiota associated with feces from Mexican infants born by C-section, may be added to the list of boosting factors for the worrying obesity epidemic in Mexico.
Assuntos
Cesárea/estatística & dados numéricos , Microbioma Gastrointestinal , Obesidade/epidemiologia , Cesárea/efeitos adversos , Fezes/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , México/epidemiologia , Fatores de RiscoRESUMO
Therapeutic strategies for the treatment of any severe disease are based on the discovery and validation of druggable targets. The human genome encodes only 600-1500 targets for small-molecule drugs, but posttranslational modifications lead to a considerably larger druggable proteome. The spontaneous conversion of asparagine (Asn) residues to aspartic acid or isoaspartic acid is a frequent modification in proteins as part of the process called deamidation. Triosephosphate isomerase (TIM) is a glycolytic enzyme whose deamidation has been thoroughly studied, but the prospects of exploiting this phenomenon for drug design remain poorly understood. The purpose of this study is to demonstrate the properties of deamidated human TIM (HsTIM) as a selective molecular target. Using in silico prediction, in vitro analyses, and a bacterial model lacking the tim gene, this study analyzed the structural and functional differences between deamidated and nondeamidated HsTIM, which account for the efficacy of this protein as a druggable target. The highly increased permeability and loss of noncovalent interactions of deamidated TIM were found to play a central role in the process of selective enzyme inactivation and methylglyoxal production. This study elucidates the properties of deamidated HsTIM regarding its selective inhibition by thiol-reactive drugs and how these drugs can contribute to the development of cell-specific therapeutic strategies for a variety of diseases, such as COVID-19 and cancer.
Assuntos
Infecções por Coronavirus/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Neoplasias/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/farmacologia , Triose-Fosfato Isomerase/antagonistas & inibidores , Amidas/antagonistas & inibidores , Amidas/metabolismo , COVID-19 , Cristalografia por Raios X , Inibidores Enzimáticos/química , Humanos , Modelos Moleculares , Mutação , Pandemias , Proteoma/antagonistas & inibidores , Proteoma/genética , Proteoma/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Bibliotecas de Moléculas Pequenas/química , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/metabolismoRESUMO
Research on Giardia lamblia has accumulated large information about its molecular cell biology and infection biology. However, giardiasis is still one of the commonest parasitic diarrheal diseases affecting humans. Additionally, an alarming increase in cases refractory to conventional treatment has been reported in low prevalence settings. Consequently, efforts directed toward supporting the efficient use of alternative drugs, and the study of their molecular targets appears promising. Repurposing of proton pump inhibitors is effective in vitro against the parasite and the toxic activity is associated with the inhibition of the G. lamblia triosephosphate isomerase (GlTIM) via the formation of covalent adducts with cysteine residue at position 222. Herein, we evaluate the effectiveness of omeprazole in vitro and in situ on GlTIM mutants lacking the most superficial cysteines. We studied the influence on the glycolysis of Giardia trophozoites treated with omeprazole and characterized, for the first time, the morphological effect caused by this drug on the parasite. Our results support the effectiveness of omeprazole against GlTIM despite of the possibility to mutate the druggable amino acid targets as an adaptive response. Also, we further characterized the effect of omeprazole on trophozoites and discuss the possible mechanism involved in its antigiardial effect.
Assuntos
Antiprotozoários/farmacologia , Giardia lamblia/efeitos dos fármacos , Omeprazol/farmacologia , Animais , Inibidores Enzimáticos/farmacologia , Estabilidade Enzimática , Giardia lamblia/ultraestrutura , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Concentração Inibidora 50 , Cinética , Aldeído Pirúvico/metabolismo , Temperatura , Triose-Fosfato Isomerase/antagonistas & inibidores , Triose-Fosfato Isomerase/metabolismoRESUMO
Giardia lamblia is one of the most common protozoan infectious agents in the world and is responsible for diarrheal disease and chronic postinfectious illness. During the host-parasite interaction, proteases are important molecules related to virulence, invasion, and colonization, not only for Giardia but also for other parasites. We aimed to characterize the cysteine protease activity detected in trophozoite lysates. This proteolytic activity showed the ability to cleave NH-terminal sequences with either a recognition sequence for a viral protease or a recognition sequence for thrombin. This cleavage activity was detected in nonencysting trophozoites and increased with the progression of encystation. This activity was also detected in excretion/secretion products of axenic trophozoites and in trophozoites cocultured with differentiated Caco-2 cells. Based on size exclusion chromatography, we obtained a fraction enriched in low- to medium-molecular-weight proteins that was capable of exerting this cleavage activity and aggregating human platelets. Finally, our results suggest that this proteolytic activity is shared with other protozoan parasites.
Assuntos
Cisteína Proteases/metabolismo , Giardia lamblia/enzimologia , Proteínas de Protozoários/metabolismo , Células CACO-2 , Catepsina B/química , Catepsina B/genética , Catepsina B/metabolismo , Cisteína Proteases/química , Cisteína Proteases/genética , Giardia lamblia/química , Giardia lamblia/genética , Giardíase , Humanos , Proteólise , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Especificidade por Substrato , Trofozoítos/química , Trofozoítos/enzimologia , Trofozoítos/genéticaRESUMO
The microsporidia are a large group of intracellular parasites with a broad range of hosts, including humans. Encephalitozoon intestinalis is the second microsporidia species most frequently associated with gastrointestinal disease in humans, especially immunocompromised or immunosuppressed individuals, including children and the elderly. The prevalence reported worldwide in these groups ranges from 0 to 60%. Currently, albendazole is most commonly used to treat microsporidiosis caused by Encephalitozoon species. However, the results of treatment are variable, and relapse can occur. Consequently, efforts are being directed toward identifying more effective drugs for treating microsporidiosis, and the study of new molecular targets appears promising. These parasites lack mitochondria, and oxidative phosphorylation therefore does not occur, which suggests the enzymes involved in glycolysis as potential drug targets. Here, we have for the first time characterized the glycolytic enzyme triosephosphate isomerase of E. intestinalis at the functional and structural levels. Our results demonstrate the mechanisms of inactivation of this enzyme by thiol-reactive compounds. The most striking result of this study is the demonstration that established safe drugs such as omeprazole, rabeprazole and sulbutiamine can effectively inactivate this microsporidial enzyme and might be considered as potential drugs for treating this important disease.
Assuntos
Albendazol/uso terapêutico , Proteínas Fúngicas/antagonistas & inibidores , Microsporídios/efeitos dos fármacos , Microsporidiose/tratamento farmacológico , Triose-Fosfato Isomerase/antagonistas & inibidores , Sequência de Aminoácidos , Encephalitozoon/efeitos dos fármacos , Encephalitozoon/enzimologia , Encephalitozoon/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/microbiologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Humanos , Microsporídios/enzimologia , Microsporídios/genética , Microsporidiose/microbiologia , Omeprazol/uso terapêutico , Rabeprazol/uso terapêutico , Homologia de Sequência de Aminoácidos , Tiamina/análogos & derivados , Tiamina/uso terapêutico , Triose-Fosfato Isomerase/genética , Triose-Fosfato Isomerase/metabolismoRESUMO
BACKGROUND: The importance of prebiotics consumption is increasing all over the world due to their beneficial effects on health. Production of better prebiotics from endemic plants raises possibilities to enhance nutritional effects in vulnerable population groups. Fructans derived from Agave Plant have demonstrated their safety and efficacy as prebiotics in animal models. Recently, the safety in humans of two fructans obtained from Agave tequilana (Metlin(®) and Metlos(®)) was demonstrated. METHODS: This study aimed to demonstrate the efficacy as prebiotics of Metlin(®) and Metlos(®) in newborns of a randomized, double blind, controlled trial with a pilot study design. Biological samples were taken at 20 ± 7 days, and three months of age from healthy babies. Outcomes of efficacy include impact on immune response, serum ferritin, C-reactive protein, bone metabolism, and gut bacteria changes. RESULTS: There were differences statistically significant for the groups of infants fed only with infant formula and with formula enriched with Metlin(®) and Metlos(®). CONCLUSIONS: Our results support the efficacy of Metlin(®) and Metlos(®) as prebiotics in humans, and stand the bases to recommend their consumption. TRIAL REGISTRATION: ClinicalTrials.gov, NCT 01251783.
Assuntos
Agave/química , Frutanos/farmacologia , Nível de Saúde , Fórmulas Infantis/química , Extratos Vegetais/farmacologia , Prebióticos , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Proteína C-Reativa/metabolismo , Feminino , Ferritinas/sangue , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Imunidade/efeitos dos fármacos , Recém-Nascido , Masculino , México , Projetos Piloto , Valores de Referência , Resultado do TratamentoRESUMO
Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH) and the aldehyde dehydrogenase (ALDH). We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa) of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2-C6) and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde.
Assuntos
Álcool Desidrogenase/metabolismo , Etanol/metabolismo , Gluconacetobacter/enzimologia , Acetatos/análise , Álcool Desidrogenase/química , Álcool Desidrogenase/isolamento & purificação , Aldeídos/análise , Sequência de Aminoácidos , Biocatálise , Radioisótopos de Carbono/química , Cromatografia Gasosa-Espectrometria de Massas , Marcação por Isótopo , Cinética , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Oxirredução , Desnaturação Proteica , TemperaturaRESUMO
La deficiencia de Glucosa-6-fosfato deshidrogenasa (G6PD) es la enzimopatíamás frecuente, con una prevalencia global del 4,9% y con alrededor de 330 a 400 millones de personas afectadas en el mundo. La G6PD desempeña un papel fundamental en el equilibrio redox intracelular, especialmente en los eritrocitos; en condiciones de estrés oxidativo inducido (por ejemplo,por exposición a agentes externos como fármacos, alimentos o infecciones),los hematíes portadores de la variante enzimática y con deficiencia de la actividad enzimática, sufren daños irreversibles que condicionan su destrucción acelerada. La hemólisis explica el espectro de manifestaciones clínicas de esta enfermedad, que incluyen ictericia neonatal, episodios de hemólisis aguda inducida por agentes externos o anemia hemolítica crónica. El presente trabajo hace una reseña de los aspectos epidemiológicos y clínicos de esta enfermedad y revisa los aspectos fisiopatológicos a nivel bioquímico-molecular, con particular énfasis en la caracterización genética,estructural y funcional de las variantes asociadas a la deficiencia de G6PD.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most frequent enzymopathy in humans with a global prevalence of 4.9 % and around 330 to 400 million patients affected worldwide. G6PD plays a fundamental role in the intracellular redox equilibrium, especially in red blood cells (RBC). Under oxidative stress (induced by exposure to external agents like drugs, infections or diet) RBC carrying the deficient variant suffer irreversible damage resulting in their accelerated destruction. This hemolysis explains the clinical manifestations of the disease that include neonatal jaundice, inducedacute hemolysis or chronic hemolytic anemia. This work summarizes the epidemiologic and clinical features of G6PD deficiency, and reviews the molecular pathophysiology of this disease with special emphasis on the genetical, structural and functional characterization of variants causing this pathology.
A deficiência da Glicose-6-FosFato desidrogenase (G6PD) é a enzimopatia mais Frequente, com uma prevalência global do 4,9%, e com aproximadamente 330 a 400 milhões de pessoas afetadas no mundo. A G6PD tem um importante papel no equilíbrio celular redox intracelular, especialmente nos eritrócitos; em condições de estresse oxidativo induzido, (por exemplo, pela exposição a agentes externos como Fármacos, alimentos, ou infecções) as hemácias portadoras da variante enzimática e com defciência da atividade enzimática, sofrem danos irreversíveis que condicionam a sua destruição acelerada. A hemólise explica o espectro de manifestações clínicas desta doença, que incluem icterícia neonatal, episódios de hemólise aguda induzida por agentes externos ou anemia hemolítica crônica. Este trabalho faz uma resenha dos aspectos epidemiológicos e clínicos desta doença, e revisa os aspectos fsiopatológicos no nível bioquímico-molecular, com ênfase especial na caracterização genética, estrutural e funcional das variantes associadas à defciência de G6PD.
Assuntos
Humanos , Glucosefosfato Desidrogenase , Deficiência de Glucosefosfato Desidrogenase , Anemia Hemolítica Congênita , Erros Inatos do MetabolismoRESUMO
La deficiencia de Glucosa-6-fosfato deshidrogenasa (G6PD) es la enzimopatía más frecuente, con una prevalencia global del 4,9% y con alrededor de 330 a 400 millones de personas afectadas en el mundo. La G6PD desempeña un papel fundamental en el equilibrio redox intracelular, especialmente en los eritrocitos; en condiciones de estrés oxidativo inducido (por ejemplo, por exposición a agentes externos como fármacos, alimentos o infecciones), los hematíes portadores de la variante enzimática y con deficiencia de la actividad enzimática, sufren daños irreversibles que condicionan su destrucción acelerada. La hemólisis explica el espectro de manifestaciones clínicas de esta enfermedad, que incluyen ictericia neonatal, episodios de hemólisis aguda inducida por agentes externos o anemia hemolítica crónica. El presente trabajo hace una reseña de los aspectos epidemiológicos y clínicos de esta enfermedad y revisa los aspectos fisiopatológicos a nivel bioquímico-molecular, con particular énfasis en la caracterización genética, estructural y funcional de las variantes asociadas a la deficiencia de G6PD.(AU)
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most frequent enzymopathy in humans with a global prevalence of 4.9 % and around 330 to 400 million patients affected worldwide. G6PD plays a fundamental role in the intracellular redox equilibrium, especially in red blood cells (RBC). Under oxidative stress (induced by exposure to external agents like drugs, infections or diet) RBC carrying the deficient variant suffer irreversible damage resulting in their accelerated destruction. This hemolysis explains the clinical manifestations of the disease that include neonatal jaundice, induced acute hemolysis or chronic hemolytic anemia. This work summarizes the epidemiologic and clinical features of G6PD deficiency, and reviews the molecular pathophysiology of this disease with special emphasis on the genetical, structural and functional characterization of variants causing this pathology.(AU)
A deficiÛncia da Glicose-6-fosfato desidrogenase (G6PD) é a enzimopatia mais frequente, com uma prevalÛncia global do 4,9%, e com aproximadamente 330 a 400 milh§es de pessoas afetadas no mundo. A G6PD tem um importante papel no equilíbrio celular redox intracelular, especialmente nos eritrócitos; em condiþ§es de estresse oxidativo induzido, (por exemplo, pela exposiþÒo a agentes externos como fármacos, alimentos, ou infecþ§es) as hemácias portadoras da variante enzimática e com deficiÛncia da atividade enzimática, sofrem danos irreversíveis que condicionam a sua destruiþÒo acelerada. A hemólise explica o espectro de manifestaþ§es clínicas desta doenþa, que incluem icterícia neonatal, episódios de hemólise aguda induzida por agentes externos ou anemia hemolítica cr¶nica. Este trabalho faz uma resenha dos aspectos epidemiológicos e clínicos desta doenþa, e revisa os aspectos fisiopatológicos no nível bioquímico-molecular, com Ûnfase especial na caracterizaþÒo genética, estrutural e funcional das variantes associadas O deficiÛncia de G6PD.(AU)
RESUMO
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme deficiency worldwide, causing a wide spectrum of conditions with severity classified from the mildest (Class IV) to the most severe (Class I). To correlate mutation sites in the G6PD with the resulting phenotypes, we studied four naturally occurring G6PD variants: Yucatan, Nashville, Valladolid and Mexico City. For this purpose, we developed a successful over-expression method that constitutes an easier and more precise method for obtaining and characterizing these enzymes. The k(cat) (catalytic constant) of all the studied variants was lower than in the wild-type. The structural rigidity might be the cause and the most evident consequence of the mutations is their impact on protein stability and folding, as can be observed from the protein yield, the T50 (temperature where 50% of its original activity is retained) values, and differences on hydrophobic regions. The mutations corresponding to more severe phenotypes are related to the structural NADP+ region. This was clearly observed for the Classes III and II variants, which became more thermostable with increasing NADP+, whereas the Class I variants remained thermolabile. The mutations produce repulsive electric charges that, in the case of the Yucatan variant, promote increased disorder of the C-terminus and consequently affect the binding of NADP+, leading to enzyme instability.
Assuntos
Deficiência de Glucosefosfato Desidrogenase/enzimologia , Deficiência de Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/genética , Mutação , Estabilidade Enzimática , Glucosefosfato Desidrogenase/química , Glucosefosfato Desidrogenase/metabolismo , Humanos , Modelos Moleculares , Fenótipo , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , TemperaturaRESUMO
Giardiasis is highly prevalent in the developing world, and treatment failures with the standard drugs are common. This work deals with the proposal of omeprazole as a novel antigiardial drug, focusing on a giardial glycolytic enzyme used to follow the cytotoxic effect at the molecular level. We used recombinant technology and enzyme inactivation to demonstrate the capacity of omeprazole to inactivate giardial triosephosphate isomerase, with no adverse effects on its human counterpart. To establish the specific target in the enzyme, we used single mutants of every cysteine residue in triosephosphate isomerase. The effect on cellular triosephosphate isomerase was evaluated by following the remnant enzyme activity on trophozoites treated with omeprazole. The interaction of omeprazole with giardial proteins was analyzed by fluorescence spectroscopy. The susceptibility to omeprazole of drug-susceptible and drug-resistant strains of Giardia lamblia was evaluated to demonstrate its potential as a novel antigiardial drug. Our results demonstrate that omeprazole inhibits giardial triosephosphate isomerase in a species-specific manner through interaction with cysteine at position 222. Omeprazole enters the cytoplasmic compartment of the trophozoites and inhibits cellular triosephosphate isomerase activity in a dose-dependent manner. Such inhibition takes place concomitantly with the cytotoxic effect caused by omeprazole on trophozoites. G. lamblia triosephosphate isomerase (GlTIM) is a cytoplasmic protein which can help analyses of how omeprazole works against the proteins of this parasite and in the effort to understand its mechanism of cytotoxicity. Our results demonstrate the mechanism of giardial triosephosphate isomerase inhibition by omeprazole and show that this drug is effective in vitro against drug-resistant and drug-susceptible strains of G. lamblia.
Assuntos
Antiprotozoários/farmacologia , Inibidores Enzimáticos/farmacologia , Giardia lamblia/efeitos dos fármacos , Omeprazol/farmacologia , Proteínas de Protozoários/antagonistas & inibidores , Triose-Fosfato Isomerase/antagonistas & inibidores , Trofozoítos/efeitos dos fármacos , Albendazol/farmacologia , Cultura Axênica , Cisteína/química , Cisteína/metabolismo , Relação Dose-Resposta a Droga , Resistência a Medicamentos , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Giardia lamblia/enzimologia , Giardia lamblia/crescimento & desenvolvimento , Giardia lamblia/isolamento & purificação , Humanos , Metronidazol/farmacologia , Mutação , Nitrocompostos , Testes de Sensibilidade Parasitária , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espectrometria de Fluorescência , Tiazóis/farmacologia , Triose-Fosfato Isomerase/genética , Triose-Fosfato Isomerase/metabolismo , Trofozoítos/enzimologia , Trofozoítos/crescimento & desenvolvimentoRESUMO
OBJECTIVES: To evaluate whether daily administration of Lactobacillus reuteri DSM 17938 reduces the frequency and duration of diarrheal episodes and other health outcomes in day school children in Mexico. METHODS: Healthy children (born at term, aged 6-36 months) attending day care centers were enrolled in this randomized, double-blind, placebo-controlled trial. They received L reuteri DSM 17938 (dose 10(8) colony-forming unit; n = 168) or identical placebo (n = 168) by mouth, daily for 3 months, after which they were followed-up after a further 3 months without supplementation. RESULTS: Data from all children were included in the final analysis. L reuteri DSM 17938 significantly reduced the frequency and duration of episodes of diarrhea and respiratory tract infection at both 3 and 6 months (P < .05). Additionally, the number of doctor visits, antibiotic use, absenteeism from day school and parental absenteeism from work were significantly reduced in the L reuteri group (P < .05). A cost-benefit analysis revealed significant reductions in costs in the L reuteri-treated children. No adverse events related to the study product were reported. CONCLUSIONS: In healthy children attending day care centers, daily administration of L reuteri DSM 17938 had a significant effect in reducing episodes and duration of diarrhea and respiratory tract infection, with consequent cost savings for the community.