RESUMO
Pancreatic ßcells are the only cells that synthesize insulin to regulate blood glucose levels. Various conditions can affect the mass of pancreatic ßcells and decrease insulin levels. Diabetes mellitus is a disease characterized by insulin resistance and chronic hyperglycemia, mainly due to the loss of pancreatic ßcells caused by an increase in the rate of apoptosis. Additionally, hyperglycemia has a toxic effect on ßcells. Although the precise mechanism of glucotoxicity is not fully understood, several mechanisms have been proposed. The most prominent changes are increases in reactive oxygen species, the loss of mitochondrial membrane potential and the activation of the intrinsic pathway of apoptosis due to p53. The present review analyzed the location of p53 in the cytoplasm, mitochondria and nucleus in terms of posttranslational modifications, including phosphorylation, OGlcNAcylation and polyADPribosylation, under hyperglycemic conditions. These modifications protect p53 from degradation by the proteasome and, in turn, enable it to regulate the intrinsic pathway of apoptosis through the regulation of antiapoptotic and proapoptotic elements. Degradation of p53 occurs in the proteasome and depends on its ubiquitination by Mdm2. Understanding the mechanisms that activate the death of pancreatic ßcells will allow the proposal of treatment alternatives to prevent the decrease in pancreatic ßcells.
Assuntos
Apoptose , Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Processamento de Proteína Pós-Traducional , Proteína Supressora de Tumor p53 , Proteína Supressora de Tumor p53/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Humanos , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , AnimaisRESUMO
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
Trypanosoma cruzi is the causative agent of American trypanosomiasis, which mainly affects populations in Latin America. Benznidazole is used to control the disease, with severe effects in patients receiving this chemotherapy. Previous studies have demonstrated the inhibition of triosephosphate isomerase from T. cruzi, but cellular enzyme inhibition has yet to be established. This study demonstrates that rabeprazole inhibits both cell viability and triosephosphate isomerase activity in T. cruzi epimastigotes. Our results show that rabeprazole has an IC50 of 0.4 µM, which is 14.5 times more effective than benznidazole. Additionally, we observed increased levels of methyl-glyoxal and advanced glycation end products after the inhibition of cellular triosephosphate isomerase by rabeprazole. Finally, we demonstrate that the inactivation mechanisms of rabeprazole on triosephosphate isomerase of T. cruzi can be achieved through the derivatization of three of its four cysteine residues. These results indicate that rabeprazole is a promising candidate against American trypanosomiasis.
Assuntos
Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Humanos , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/farmacologia , Rabeprazol/farmacologia , Rabeprazol/uso terapêutico , Reposicionamento de Medicamentos , Doença de Chagas/tratamento farmacológico , Tripanossomicidas/farmacologiaRESUMO
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
Amoebiasis is a human parasitic disease caused by Entamoeba histolytica. The parasite can invade the large intestine and other organs such as liver; resistance to the host tissue oxygen is a condition for parasite invasion and survival. Thioredoxin reductase of E. histolytica (EhTrxR) is a critical enzyme mainly involved in maintaining reduced the redox system and detoxifying the intracellular oxygen; therefore, it is necessary for E. histolytica survival under both aerobic in vitro and in vivo conditions. In the present work, it is reported that rabeprazole (Rb), a drug widely used to treat heartburn, was able to inhibit the EhTrxR recombinant enzyme. Moreover, Rb affected amoebic proliferation and several functions required for parasite virulence such as cytotoxicity, oxygen reduction to hydrogen peroxide, erythrophagocytosis, proteolysis, and oxygen and complement resistances. In addition, amoebic pre-incubation with sublethal Rb concentration (600 µM) promoted amoebic death during early liver infection in hamsters. Despite the high Rb concentration used to inhibit amoebic virulence, the wide E. histolytica pathogenic-related functions affected by Rb strongly suggest that its molecular structure can be used as scaffold to design new antiamoebic compounds with lower IC50 values.
Assuntos
Amebicidas/farmacologia , Entamoeba histolytica/efeitos dos fármacos , Entamoeba histolytica/patogenicidade , Inibidores Enzimáticos/farmacologia , Rabeprazol/farmacologia , Amebicidas/uso terapêutico , Animais , Cricetinae , Entamoeba histolytica/crescimento & desenvolvimento , Entamoeba histolytica/metabolismo , Entamebíase/parasitologia , Entamebíase/prevenção & controle , Inibidores Enzimáticos/uso terapêutico , Oxirredução/efeitos dos fármacos , Rabeprazol/uso terapêutico , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Virulência/efeitos dos fármacosRESUMO
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
Human triosephosphate isomerase (TIM) deficiency is a very rare disease, but there are several mutations reported to be causing the illness. In this work, we produced nine recombinant human triosephosphate isomerases which have the mutations reported to produce TIM deficiency. These enzymes were characterized biophysically and biochemically to determine their kinetic and stability parameters, and also to substitute TIM activity in supporting the growth of an Escherichia coli strain lacking the tim gene. Our results allowed us to rate the deleteriousness of the human TIM mutants based on the type and severity of the alterations observed, to classify four "unknown severity mutants" with altered residues in positions 62, 72, 122 and 154 and to explain in structural terms the mutation V231M, the most affected mutant from the kinetic point of view and the only homozygous mutation reported besides E104D.
Assuntos
Anemia Hemolítica Congênita não Esferocítica/enzimologia , Erros Inatos do Metabolismo dos Carboidratos/enzimologia , Mutação , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/deficiência , Triose-Fosfato Isomerase/metabolismo , Anemia Hemolítica Congênita não Esferocítica/genética , Erros Inatos do Metabolismo dos Carboidratos/genética , Estabilidade Enzimática , Humanos , Cinética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Conformação Proteica , Triose-Fosfato Isomerase/genéticaRESUMO
The analysis of transcript levels of specific genes is important for understanding transcriptional regulation and for the characterization of gene function. Real-time quantitative reverse transcriptase PCR (RT-qPCR) has become a powerful tool to quantify gene expression. The objective of this study was to identify reliable housekeeping genes in Giardia lamblia. Twelve genes were selected for this purpose, and their expression was analyzed in the wild type WB strain and in two strains with resistance to nitazoxanide (NTZ) and metronidazole (MTZ), respectively. RefFinder software analysis showed that the expression of the genes is different in the three strains. The integrated data from the four analyses showed that the NADH oxidase (NADH) and aldolase (ALD) genes were the most steadily expressed genes, whereas the glyceraldehyde-3-phosphate dehydrogenase gene was the most unstable. Additionally, the relative expression of seven genes were quantified in the NTZ- and MTZ-resistant strains by RT-qPCR, using the aldolase gene as the internal control, and the results showed a consistent differential pattern of expression in both strains. The housekeeping genes found in this work will facilitate the analysis of mRNA expression levels of other genes of interest in G. lamblia.
Assuntos
Regulação da Expressão Gênica , Genes Essenciais , Giardia lamblia/genética , Animais , Antiprotozoários/farmacologia , Primers do DNA , Giardia lamblia/efeitos dos fármacos , Metronidazol/farmacologia , Nitrocompostos , Reação em Cadeia da Polimerase em Tempo Real , Tiazóis/farmacologiaRESUMO
BACKGROUND: Proton pump inhibitors (PPIs) are extensively used in clinical practice because of their effectiveness and safety. Omeprazole is one of the best-selling drugs worldwide and, with other PPIs, has been proposed to be potential drugs for the treatment of several diseases. We demonstrated that omeprazole shows cytotoxic effects in Giardia and concomitantly inactivates giardial triosephosphate isomerase (GlTIM). Therefore, we evaluated the efficiency of commercially available PPIs to inactivate this enzyme. METHODS: We assayed the effect of PPIs on the GlTIM WT, single Cys mutants, and the human counterpart, following enzyme activity, thermal stability, exposure of hydrophobic regions, and susceptibility to limited proteolysis. RESULTS: PPIs efficiently inactivated GlTIM; however, rabeprazole was the best inactivating drug and was nearly ten times more effective. The mechanism of inactivation by PPIs was through the modification of the Cys 222 residue. Moreover, there are important changes at the structural level, the thermal stability of inactivated-GlTIM was drastically diminished and the structural rigidity was lost, as observed by the exposure of hydrophobic regions and their susceptibility to limited proteolysis. CONCLUSIONS: Our results demonstrate that rabeprazole is the most potent PPI for GlTIM inactivation and that all PPIs tested have substantial abilities to alter GITIM at the structural level, causing serious damage. GENERAL SIGNIFICANCE: This is the first report demonstrating the effectiveness of commercial PPIs on a glycolytic parasitic enzyme, with structural features well known. This study is a step forward in the use and understanding the implicated mechanisms of new antigiardiasic drugs safe in humans.
Assuntos
Desenho de Fármacos , Giardia lamblia/efeitos dos fármacos , Inibidores da Bomba de Prótons/farmacologia , Triose-Fosfato Isomerase/antagonistas & inibidores , Estabilidade Enzimática , Giardia lamblia/enzimologia , Humanos , Interações Hidrofóbicas e Hidrofílicas , Espectrometria de Massas , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/fisiologiaRESUMO
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy in the world. More than 160 mutations causing the disease have been identified, but only 10% of these variants have been studied at biochemical and biophysical levels. In this study we report on the functional and structural characterization of three naturally occurring variants corresponding to different classes of disease severity: Class I G6PD Durham, Class II G6PD Santa Maria, and Class III G6PD A+. The results showed that the G6PD Durham (severe deficiency), and the G6PD Santa Maria and A+ (less severe deficiency) (Class I, II and III, respectively) affect the catalytic efficiency of these enzymes, are more sensitive to temperature denaturing, and affect the stability of the overall protein when compared to the wild type WT-G6PD. In the variants, the exposure of more and buried hydrophobic pockets was induced and monitored with 8-Anilinonaphthalene-1-sulfonic acid (ANS) fluorescence, directly affecting the compaction of structure at different levels and probably reducing the stability of the protein. The degree of functional and structural perturbation by each variant correlates with the clinical severity reported in different patients.
Assuntos
Variação Genética , Glucosefosfato Desidrogenase/química , Glucosefosfato Desidrogenase/genética , Modelos Moleculares , Conformação Molecular , Mutação , Catálise , Ativação Enzimática , Expressão Gênica , Glucosefosfato Desidrogenase/metabolismo , Humanos , Cinética , Estabilidade Proteica , Proteínas Recombinantes , Relação Estrutura-Atividade , TermodinâmicaRESUMO
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
Deamidation, the loss of the ammonium group of asparagine and glutamine to form aspartic and glutamic acid, is one of the most commonly occurring post-translational modifications in proteins. Since deamidation rates are encoded in the protein structure, it has been proposed that they can serve as molecular clocks for the timing of biological processes such as protein turnover, development and aging. Despite the importance of this process, there is a lack of detailed structural information explaining the effects of deamidation on the structure of proteins. Here, we studied the effects of deamidation on human triosephosphate isomerase (HsTIM), an enzyme for which deamidation of N15 and N71 has been long recognized as the signal for terminal marking of the protein. Deamidation was mimicked by site directed mutagenesis; thus, three mutants of HsTIM (N15D, N71D and N15D/N71D) were characterized. The results show that the N71D mutant resembles, structurally and functionally, the wild type enzyme. In contrast, the N15D mutant displays all the detrimental effects related to deamidation. The N15D/N71D mutant shows only minor additional effects when compared with the N15D mutation, supporting that deamidation of N71 induces negligible effects. The crystal structures show that, in contrast to the N71D mutant, where minimal alterations are observed, the N15D mutation forms new interactions that perturb the structure of loop 1 and loop 3, both critical components of the catalytic site and the interface of HsTIM. Based on a phylogenetic analysis of TIM sequences, we propose the conservation of this mechanism for mammalian TIMs.