Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 731
Filtrar
Más filtros

Intervalo de año de publicación
1.
Trends Biochem Sci ; 45(3): 228-243, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31473074

RESUMEN

Hundreds of metabolic enzymes work together smoothly in a cell. These enzymes are highly specific. Nevertheless, under physiological conditions, many perform side-reactions at low rates, producing potentially toxic side-products. An increasing number of metabolite repair enzymes are being discovered that serve to eliminate these noncanonical metabolites. Some of these enzymes are extraordinarily conserved, and their deficiency can lead to diseases in humans or embryonic lethality in mice, indicating their central role in cellular metabolism. We discuss how metabolite repair enzymes eliminate glycolytic side-products and prevent negative interference within and beyond this core metabolic pathway. Extrapolating from the number of metabolite repair enzymes involved in glycolysis, hundreds more likely remain to be discovered that protect a wide range of metabolic pathways.


Asunto(s)
Enzimas/metabolismo , Animales , Glucólisis , Humanos , Ratones
2.
Am J Hum Genet ; 108(6): 1151-1160, 2021 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-33979636

RESUMEN

We describe a genetic syndrome due to PGM2L1 deficiency. PGM2 and PGM2L1 make hexose-bisphosphates, like glucose-1,6-bisphosphate, which are indispensable cofactors for sugar phosphomutases. These enzymes form the hexose-1-phosphates crucial for NDP-sugars synthesis and ensuing glycosylation reactions. While PGM2 has a wide tissue distribution, PGM2L1 is highly expressed in the brain, accounting for the elevated concentrations of glucose-1,6-bisphosphate found there. Four individuals (three females and one male aged between 2 and 7.5 years) with bi-allelic inactivating mutations of PGM2L1 were identified by exome sequencing. All four had severe developmental and speech delay, dysmorphic facial features, ear anomalies, high arched palate, strabismus, hypotonia, and keratosis pilaris. Early obesity and seizures were present in three individuals. Analysis of the children's fibroblasts showed that glucose-1,6-bisphosphate and other sugar bisphosphates were markedly reduced but still present at concentrations able to stimulate phosphomutases maximally. Hence, the concentrations of NDP-sugars and glycosylation of the heavily glycosylated protein LAMP2 were normal. Consistent with this, serum transferrin was normally glycosylated in affected individuals. PGM2L1 deficiency does not appear to be a glycosylation defect, but the clinical features observed in this neurodevelopmental disorder point toward an important but still unknown role of glucose-1,6-bisphosphate or other sugar bisphosphates in brain metabolism.


Asunto(s)
Glucosa-6-Fosfato/análogos & derivados , Mutación , Trastornos del Neurodesarrollo/patología , Fosfotransferasas/genética , Alelos , Niño , Preescolar , Femenino , Glucosa-6-Fosfato/biosíntesis , Glicosilación , Humanos , Masculino , Trastornos del Neurodesarrollo/genética , Trastornos del Neurodesarrollo/metabolismo , Linaje
3.
Mol Genet Metab ; 142(2): 108486, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38733639

RESUMEN

Empagliflozin has been successfully repurposed for treating neutropenia and neutrophil dysfunction in patients with glycogen storage disease type 1b (GSD 1b), however, data in infants are missing. We report on efficacy and safety of empagliflozin in infants with GSD 1b. This is an international retrospective case series on 21 GSD 1b infants treated with empagliflozin (total treatment time 20.6 years). Before starting empagliflozin (at a median age of 8.1 months with a median dose of 0.3 mg/kg/day) 12 patients had clinical signs and symptoms of neutrophil dysfunction. Six of these previously symptomatic patients had no further neutropenia/neutrophil dysfunction-associated findings on empagliflozin. Eight patients had no signs and symptoms of neutropenia/neutrophil dysfunction before start and during empagliflozin treatment. One previously asymptomatic individual with a horseshoe kidney developed a central line infection with pyelonephritis and urosepsis during empagliflozin treatment. Of the 10 patients who were treated with G-CSF before starting empagliflozin, this was stopped in four and decreased in another four. Eleven individuals were never treated with G-CSF. While in 17 patients glucose homeostasis remained stable on empagliflozin, four showed glucose homeostasis instability in the introductory phase. In 17 patients, no other side effects were reported, while genital (n = 2) or oral (n = 1) candidiasis and skin infection (n = 1) were reported in the remaining four. Empagliflozin had a good effect on neutropenia/neutrophil dysfunction-related signs and symptoms and a favourable safety profile in infants with GSD 1b and therefore qualifies for further exploration as first line treatment.


Asunto(s)
Compuestos de Bencidrilo , Glucósidos , Enfermedad del Almacenamiento de Glucógeno Tipo I , Neutropenia , Neutrófilos , Humanos , Enfermedad del Almacenamiento de Glucógeno Tipo I/tratamiento farmacológico , Enfermedad del Almacenamiento de Glucógeno Tipo I/complicaciones , Neutropenia/tratamiento farmacológico , Masculino , Femenino , Lactante , Compuestos de Bencidrilo/uso terapéutico , Compuestos de Bencidrilo/administración & dosificación , Estudios Retrospectivos , Neutrófilos/efectos de los fármacos , Glucósidos/uso terapéutico , Glucósidos/farmacología , Glucósidos/administración & dosificación , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Resultado del Tratamiento , Factor Estimulante de Colonias de Granulocitos/uso terapéutico
4.
Mol Genet Metab ; 141(3): 108144, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38277989

RESUMEN

Glycogen storage disease type Ib (GSD Ib, biallelic variants in SLC37A4) is a rare disorder of glycogen metabolism complicated by neutropenia/neutrophil dysfunction. Since 2019, the SGLT2-inhibitor empagliflozin has provided a mechanism-based treatment option for the symptoms caused by neutropenia/neutrophil dysfunction (e.g. mucosal lesions, inflammatory bowel disease). Because of the rarity of GSD Ib, the published evidence on safety and efficacy of empagliflozin is still limited and does not allow to develop evidence-based guidelines. Here, an international group of experts provides 14 best practice consensus treatment recommendations based on expert practice and review of the published evidence. We recommend to start empagliflozin in all GSD Ib individuals with clinical or laboratory signs related to neutropenia/neutrophil dysfunction with a dose of 0.3-0.4 mg/kg/d given as a single dose in the morning. Treatment can be started in an outpatient setting. The dose should be adapted to the weight and in case of inadequate clinical treatment response or side effects. We strongly recommend to pause empagliflozin immediately in case of threatening dehydration and before planned longer surgeries. Discontinuation of G-CSF therapy should be attempted in all individuals. If available, 1,5-AG should be monitored. Individuals who have previously not tolerated starches should be encouraged to make a new attempt to introduce starch in their diet after initiation of empagliflozin treatment. We advise to monitor certain safety and efficacy parameters and recommend continuous, alternatively frequent glucose measurements during the introduction of empagliflozin. We provide specific recommendations for special circumstances like pregnancy and liver transplantation.


Asunto(s)
Compuestos de Bencidrilo , Glucósidos , Enfermedad del Almacenamiento de Glucógeno Tipo I , Neutropenia , Humanos , Neutrófilos/metabolismo , Consenso , Enfermedad del Almacenamiento de Glucógeno Tipo I/complicaciones , Enfermedad del Almacenamiento de Glucógeno Tipo I/tratamiento farmacológico , Enfermedad del Almacenamiento de Glucógeno Tipo I/genética , Neutropenia/tratamiento farmacológico , Neutropenia/etiología , Proteínas de Transporte de Monosacáridos , Antiportadores/metabolismo
5.
Med Microbiol Immunol ; 213(1): 15, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39008129

RESUMEN

Chlamydiae are a large group of obligate endosymbionts of eukaryotes that includes the Chlamydiaceae family, comprising several animal pathogens. Among Chlamydiaceae, Chlamydia trachomatis causes widespread ocular and urogenital infections in humans. Like many bacterial pathogens, all Chlamydiae manipulate host cells by injecting them with type III secretion effector proteins. We previously characterized the C. trachomatis effector CteG, which localizes at the host cell Golgi and plasma membrane during distinct phases of the chlamydial infectious cycle. Here, we show that CteG is a Chlamydiaceae-specific effector with over 60 homologs phylogenetically categorized into two distinct clades (CteG I and CteG II) and exhibiting several inparalogs and outparalogs. Notably, cteG I homologs are syntenic to C. trachomatis cteG, whereas cteG II homologs are syntenic among themselves but not with C. trachomatis cteG. This indicates a complex evolution of cteG homologs, which is unique among C. trachomatis effectors, marked by numerous events of gene duplication and loss. Despite relatively modest sequence conservation, nearly all tested CteG I and CteG II proteins were identified as type III secretion substrates using Yersinia as a heterologous bacterial host. Moreover, most of the type III secreted CteG I and CteG II homologs were delivered by C. trachomatis into host cells, where they localized at the Golgi region and cell periphery. Overall, this provided insights into the evolution of bacterial effectors and revealed a Chlamydiaceae family of type III secreted proteins that underwent substantial divergence during evolution while conserving the capacity to localize at specific host cell compartments.


Asunto(s)
Proteínas Bacterianas , Chlamydia trachomatis , Filogenia , Sistemas de Secreción Tipo III , Humanos , Chlamydia trachomatis/genética , Chlamydia trachomatis/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Sistemas de Secreción Tipo III/metabolismo , Sistemas de Secreción Tipo III/genética , Factores de Virulencia/metabolismo , Factores de Virulencia/genética , Células HeLa , Yersinia/genética , Yersinia/metabolismo , Transporte de Proteínas , Interacciones Huésped-Patógeno , Evolución Molecular , Chlamydiaceae/genética , Chlamydiaceae/metabolismo , Chlamydiaceae/clasificación
6.
Brain ; 146(7): 2672-2693, 2023 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-36848323

RESUMEN

Spinal cord injury (SCI) is an as yet untreatable neuropathology that causes severe dysfunction and disability. Cell-based therapies hold neuroregenerative and neuroprotective potential, but, although being studied in SCI patients for more than two decades, long-term efficacy and safety remain unproven, and which cell types result in higher neurological and functional recovery remains under debate. In a comprehensive scoping review of 142 reports and registries of SCI cell-based clinical trials, we addressed the current therapeutical trends and critically analysed the strengths and limitations of the studies. Schwann cells, olfactory ensheathing cells (OECs), macrophages and various types of stem cells have been tested, as well as combinations of these and other cells. A comparative analysis between the reported outcomes of each cell type was performed, according to gold-standard efficacy outcome measures like the ASIA impairment scale, motor and sensory scores. Most of the trials were in the early phases of clinical development (phase I/II), involved patients with complete chronic injuries of traumatic aetiology and did not display a randomized comparative control arm. Bone marrow stem cells and OECs were the most commonly tested cells, while open surgery and injection were the main methods of delivering cells into the spinal cord or submeningeal spaces. Transplantation of support cells, such as OECs and Schwann cells, resulted in the highest ASIA Impairment Scale (AIS) grade conversion rates (improvements in ∼40% of transplanted patients), which surpassed the spontaneous improvement rate expected for complete chronic SCI patients within 1 year post-injury (5-20%). Some stem cells, such as peripheral blood-isolated and neural stem cells, offer potential for improving patient recovery. Complementary treatments, particularly post-transplantation rehabilitation regimes, may contribute highly to neurological and functional recovery. However, unbiased comparisons between the tested therapies are difficult to draw, given the great heterogeneity of the design and outcome measures used in the SCI cell-based clinical trials and how these are reported. It is therefore crucial to standardize these trials when aiming for higher value clinical evidence-based conclusions.


Asunto(s)
Enfermedades del Sistema Nervioso , Traumatismos de la Médula Espinal , Humanos , Tratamiento Basado en Trasplante de Células y Tejidos , Recuperación de la Función , Médula Espinal , Ensayos Clínicos como Asunto
7.
Cell Mol Life Sci ; 80(9): 259, 2023 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-37594549

RESUMEN

Neutropenia and neutrophil dysfunction in glycogen storage disease type 1b (GSD1b) and severe congenital neutropenia type 4 (SCN4), associated with deficiencies of the glucose-6-phosphate transporter (G6PT/SLC37A4) and the phosphatase G6PC3, respectively, are the result of the accumulation of 1,5-anhydroglucitol-6-phosphate in neutrophils. This is an inhibitor of hexokinase made from 1,5-anhydroglucitol (1,5-AG), an abundant polyol in blood. 1,5-AG is presumed to be reabsorbed in the kidney by a sodium-dependent-transporter of uncertain identity, possibly SGLT4/SLC5A9 or SGLT5/SLC5A10. Lowering blood 1,5-AG with an SGLT2-inhibitor greatly improved neutrophil counts and function in G6PC3-deficient and GSD1b patients. Yet, this effect is most likely mediated indirectly, through the inhibition of the renal 1,5-AG transporter by glucose, when its concentration rises in the renal tubule following inhibition of SGLT2. To identify the 1,5-AG transporter, both human and mouse SGLT4 and SGLT5 were expressed in HEK293T cells and transport measurements were performed with radiolabelled compounds. We found that SGLT5 is a better carrier for 1,5-AG than for mannose, while the opposite is true for human SGLT4. Heterozygous variants in SGLT5, associated with a low level of blood 1,5-AG in humans cause a 50-100% reduction in 1,5-AG transport activity tested in model cell lines, indicating that SGLT5 is the predominant kidney 1,5-AG transporter. These and other findings led to the conclusion that (1) SGLT5 is the main renal transporter of 1,5-AG; (2) frequent heterozygous mutations (allelic frequency > 1%) in SGLT5 lower blood 1,5-AG, favourably influencing neutropenia in G6PC3 or G6PT deficiency; (3) the effect of SGLT2-inhibitors on blood 1,5-AG level is largely indirect; (4) specific SGLT5-inhibitors would be more efficient to treat these neutropenias than SGLT2-inhibitors.


Asunto(s)
Neutropenia , Animales , Humanos , Ratones , Antiportadores , Células HEK293 , Riñón , Proteínas de Transporte de Membrana , Proteínas de Transporte de Monosacáridos/genética , Neutropenia/genética , Transportador 2 de Sodio-Glucosa/genética
8.
An Acad Bras Cienc ; 96(suppl 2): e20230744, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39016362

RESUMEN

The Brazil-Malvinas Confluence (BMC) is a significant biological frontier where distinct currents meet, fostering optimal conditions for phytoplankton development. In this study we tested the hypothesis that eddys promote an increase in phytoplankton biomass at the Brazil-Malvinas Confluence (BMC), altering species diversity. Phytoplankton were collected with Niskin bottles and nutrient concentrations assessed at two depths (Surface and Deep Chlorophyll Maximum Layer - DCML) in areas outside and under the influence of Cold-Core (CCE) and Warm-Core (WCE) Eddies. Environmental variables were determined in situ using a CTD profiler. Four regions were separated based on environmental variables and phytoplankton species, namely, the Brazil Current (BC), Malvinas Current (MC), CCE, and WCE. Species diversity was higher in the eddies. The conditions of the WCE were different from those of the CCE, with low temperature and salinity and high cell density values in the latter. The phylum Bacillariophyta was predominant in terms of species richness in all regions and was responsible for the higher cell density in the MC, while dinoflagellates were dominant in the BC and eddies. Therefore, eddy activity alters the structure, diversity and biomass of the phytoplankton community in the BMC.


Asunto(s)
Biodiversidad , Biomasa , Fitoplancton , Fitoplancton/clasificación , Fitoplancton/crecimiento & desarrollo , Brasil , Estaciones del Año , Clorofila/análisis , Movimientos del Agua , Temperatura
9.
Int J Mol Sci ; 25(3)2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-38338793

RESUMEN

Hypothyroidism compromises the testicular redox status and is associated with reduced sperm quality and infertility in men. In this regard, studies have demonstrated the antioxidant potential of kisspeptin in reproductive and metabolic diseases. In this study, we evaluate the effects of kisspeptin-10 (Kp10) on the testicular redox, as well as mediators of the unfolded protein response (UPR) in adult rats with hypothyroidism. Adult male Wistar rats were randomly separated into the Control (n = 15), Hypo (n = 13) and Hypo + Kp10 (n = 14) groups, and hypothyroidism was induced with 6-propyl-2-thiouracil (PTU) for three months. In the last month, half of the hypothyroid animals received Kp10. Testis samples were collected for enzymatic, immunohistochemical and/or gene evaluation of mediators of oxidative stress (TBARs, lipid hydroperoxides (LOOH), ROS, peroxynitrite, SOD, CAT and GPX), endoplasmic reticulum stress (GRP78, ATF6, PERK, CHOP, HO-1 and sXBP1) and antiapoptocytes (BCL-2). Hypothyroidism increased apoptosis index, TBARS and LOOH concentrations, and reduced testicular gene expression of Sod1, Sod2 and Gpx1, as well as the expression of Grp78, Atf6, Ho1 and Chop. Treatment with Kp10, in turn, reduced testicular apoptosis and the production of peroxynitrite, while increased SOD1 and GPX ½ expression, and enzymatic activity of CAT, but did not affect the lower expression of UPR mediators caused by hypothyroidism. This study demonstrated that hypothyroidism causes oxidative stress and dysregulated the UPR pathway in rat testes and that, although Kp10 does not influence the low expression of UPR mediators, it improves the testicular redox status, configuring it as an important antioxidant factor in situations of thyroid dysfunction.


Asunto(s)
Antioxidantes , Hipotiroidismo , Humanos , Ratas , Masculino , Animales , Antioxidantes/metabolismo , Testículo/metabolismo , Kisspeptinas/metabolismo , Ratas Wistar , Superóxido Dismutasa-1/genética , Chaperón BiP del Retículo Endoplásmico , Ácido Peroxinitroso/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Semen/metabolismo , Oxidación-Reducción , Hipotiroidismo/tratamiento farmacológico , Hipotiroidismo/metabolismo , Estrés Oxidativo , Respuesta de Proteína Desplegada
10.
Int J Environ Health Res ; 34(5): 2248-2263, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37485862

RESUMEN

Dengue, a disease with multifactorial determinants, is linked to population susceptibility to circulating viruses and the extent of vector infestation. This study aimed to analyze the temporal trends of dengue cases and deaths in Belo Horizonte, Minas Gerais, Brazil, from 2007 to 2020. Data from the Notifiable Diseases Information System (Sinan) were utilized for the investigation. To assess the disease's progression over the study period and predict its future incidence, time series analyses were conducted using a generalized additive model (GAM) and a seasonal autoregressive integrated moving average (SARIMA) model. Over the study period, a total of 463,566 dengue cases and 125 deaths were reported. Notably, there was an increase in severe cases and deaths, marking hyperendemics characterized by simultaneous virus circulation (79.17% in 2016-50% in 2019). The generalized additive model revealed a non-linear pattern with epidemic peaks in 2010, 2013, 2016, and 2019, indicating an explosive pattern of dengue incidence. The SARIMA (3,1,1) (0,0,0)12 model was validated for each year (2015 to 2019). Comparing the actual and predicted numbers of dengue cases, the model demonstrated its effectiveness for predicting cases in the municipality. The rising number of dengue cases emphasizes the importance of vector surveillance and control. Enhanced models and predictions by local health services will aid in anticipating necessary control measures to combat future epidemics.


Asunto(s)
Dengue , Humanos , Dengue/epidemiología , Brasil/epidemiología , Ciudades , Incidencia , Estaciones del Año
11.
Curr Issues Mol Biol ; 45(9): 7617-7629, 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37754263

RESUMEN

Toxicological studies on medicinal plants are essential to ensure their safety and effectiveness in treating various diseases. Despite the species Chrysobalanus icaco L. being popularly used in the treatment of several diseases due to the pharmacological properties of its bioactive compounds, there are few studies in the literature regarding its toxicity regarding reproduction. Therefore, the purpose of this study was to assess the potential embryotoxic and teratogenic effects of the aqueous extract of C. icaco leaves (AECi) on Wistar rats. Animals were given AECi at doses of 100, 200, and 400 mg/kg during the pre-implantation and organogenesis periods. Data were analyzed using ANOVA followed by Tukey's test and Kruskal-Wallis. Pregnant rats treated during the pre-implantation period showed no signs of reproductive toxicity. Rats that received AECi at 100, 200, and 400 mg/kg during organogenesis did not exhibit any signs of maternal systemic toxicity or significant differences in gestational and embryotoxic parameters. Some skeletal changes were observed in the treated groups. Therefore, it can be suggested that AECi at doses of 100, 200, and 400 mg/kg is safe for treated animals and does not induce reproductive toxicity under the experimental conditions applied, but it also caused low systemic toxicity.

12.
Mol Genet Metab ; 140(3): 107712, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38353183

RESUMEN

Glycogen storage disease type Ib (GSD1b) and G6PC3-deficiency are rare autosomal recessive diseases caused by inactivating mutations in SLC37A4 (coding for G6PT) and G6PC3, respectively. Both diseases are characterized by neutropenia and neutrophil dysfunction due to the intracellular accumulation of 1,5-anhydroglucitol-6-phosphate (1,5-AG6P), a potent inhibitor of hexokinases. We recently showed that the use of SGLT2 inhibitor therapy to reduce tubular reabsorption of its precursor, 1,5-anhydroglucitol (1,5-AG), a glucose analog present in blood, successfully restored the neutropenia and neutrophil function in G6PC3-deficient and GSD1b patients. The intra-individual variability of response to the treatment and the need to adjust the dose during treatment, especially in pediatric populations, can only be efficiently optimized if the concentration of 1,5-AG in blood is monitored during treatment, together with the patients' clinical signs and symptoms. Monitoring the 1,5-AG levels would be greatly simplified if it could be performed on dry blood spots (DBS) which are easy to collect, store and transport. The challenge is to know if a suitable method can be developed to perform accurate and reproducible assays for 1,5-AG using DBS. Here, we describe and validate an assay that quantifies 1,5-AG in DBS using isotopic dilution quantitation by LC-MS/MS that should greatly facilitate patients' follow-up. 1,5-AG levels measured in plasma and DBS give comparable values. This assay was used to monitor the levels of 1,5-AG in DBS from 3 G6PC3-deficient and 6 GSD1b patients during treatment with SGLT2 inhibitors. We recommend this approach to verify the adequate therapeutical response and compliance to the treatment in G6PC3-deficient and GSD1b patients treated with SGLT2 inhibitors.


Asunto(s)
Desoxiglucosa , Enfermedad del Almacenamiento de Glucógeno Tipo I , Neutropenia , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Niño , Humanos , Cromatografía Liquida , Espectrometría de Masas en Tándem , Enfermedad del Almacenamiento de Glucógeno Tipo I/tratamiento farmacológico , Enfermedad del Almacenamiento de Glucógeno Tipo I/genética , Enfermedad del Almacenamiento de Glucógeno Tipo I/complicaciones , Neutropenia/genética , Glucosa-6-Fosfatasa/genética , Glucosa-6-Fosfatasa/metabolismo , Monoéster Fosfórico Hidrolasas , Proteínas de Transporte de Monosacáridos , Antiportadores
13.
Cell Mol Life Sci ; 79(8): 421, 2022 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-35834009

RESUMEN

Transaminases play key roles in central metabolism, transferring the amino group from a donor substrate to an acceptor. These enzymes can often act, with low efficiency, on compounds different from the preferred substrates. To understand what might have shaped the substrate specificity of this class of enzymes, we examined the reactivity of six human cytosolic transaminases towards amino acids whose main degradative pathways do not include any transamination. We also tested whether sugars and sugar phosphates could serve as alternative amino group acceptors for these cytosolic enzymes. Each of the six aminotransferases reacted appreciably with at least three of the alternative amino acid substrates in vitro, albeit at usually feeble rates. Reactions with L-Thr, L-Arg, L-Lys and L-Asn were consistently very slow-a bias explained in part by the structural differences between these amino acids and the preferred substrates of the transaminases. On the other hand, L-His and L-Trp reacted more efficiently, particularly with GTK (glutamine transaminase K; also known as KYAT1). This points towards a role of GTK in the salvage of L-Trp (in cooperation with ω-amidase and possibly with the cytosolic malate dehydrogenase, MDH1, which efficiently reduced the product of L-Trp transamination). Finally, the transaminases were extremely ineffective at utilizing sugars and sugar derivatives, with the exception of the glycolytic intermediate dihydroxyacetone phosphate, which was slowly but appreciably transaminated by some of the enzymes to yield serinol phosphate. Evidence for the formation of this compound in a human cell line was also obtained. We discuss the biological and evolutionary implications of our results.


Asunto(s)
Aminoácidos , Transaminasas , Citosol/metabolismo , Humanos , Cinética , Especificidad por Sustrato , Azúcares , Transaminasas/metabolismo
14.
Curr Microbiol ; 80(8): 251, 2023 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-37351656

RESUMEN

The high incidence of Candida albicans infections has raised concerns regarding side effects and drug resistance, compounded by a limited number of alternative drugs. Silver nanoparticles (AgNPs) have prominent antimicrobial activity, but effective administration remains a challenge. In this study, AgNPs were synthesized via a green chemistry approach, using glucose as a reducing agent, and incorporated into an agar matrix to form a film (AgFilm). The AgNPs and AgFilm were characterized by Ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and atomic force microscopic (AFM). The UV-Vis spectra of the AgNPs and AgFilm showed bands at 415 and 413 nm, respectively. The PXRD and UV-Vis data suggest that the growth of AgNPs was effectively inhibited in the AgFilm. The diameter of AgNPs dispersed in AgFilm was 76 ± 42 nm, and the thickness of the film and 35 ± 3 µm. The antifungal activity of AgFilm was evaluated against 20 strains of C. albicans, demonstrating high antifungal activity with an inhibition zone of 19 ± 2 mm. Therefore, AgFilm could be a promising option for the treatment of superficial C. albicans infections.


Asunto(s)
Antifúngicos , Nanopartículas del Metal , Antifúngicos/farmacología , Plata/farmacología , Nanopartículas del Metal/química , Microscopía Electrónica de Rastreo , Extractos Vegetales/química , Espectroscopía Infrarroja por Transformada de Fourier , Antibacterianos/farmacología
15.
Dermatol Online J ; 29(4)2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37921813

RESUMEN

Chordoma is an uncommon, indolent malignant tumor arising from notochordal remnants. The incidence of distant metastasis varies between 30 and 40% in different series. Even though local involvement of the skin by direct invasion of chordoma is common, distant skin metastasis are rare, with less than 30 cases reported in the literature. The present clinical case illustrates the slow-growing natural history of a sacral chordoma, which evolved with lung metastasis, followed three years later by skin metastasis, thus giving us the opportunity to review the diagnostic approach, as well as the clinical and histopathological characteristics of this rare tumor.


Asunto(s)
Cordoma , Neoplasias Pulmonares , Neoplasias Cutáneas , Neoplasias de la Columna Vertebral , Humanos , Cordoma/patología , Cordoma/secundario , Sacro/patología , Neoplasias de la Columna Vertebral/patología , Neoplasias Cutáneas/patología , Neoplasias Pulmonares/patología
16.
J Biol Chem ; 296: 100699, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33895133

RESUMEN

N-acetylneuraminate (Neu5Ac), an abundant sugar present in glycans in vertebrates and some bacteria, can be used as an energy source by several prokaryotes, including Escherichia coli. In solution, more than 99% of Neu5Ac is in cyclic form (≈92% beta-anomer and ≈7% alpha-anomer), whereas <0.5% is in the open form. The aldolase that initiates Neu5Ac metabolism in E. coli, NanA, has been reported to act on the alpha-anomer. Surprisingly, when we performed this reaction at pH 6 to minimize spontaneous anomerization, we found NanA and its human homolog NPL preferentially metabolize the open form of this substrate. We tested whether the E. coli Neu5Ac anomerase NanM could promote turnover, finding it stimulated the utilization of both beta and alpha-anomers by NanA in vitro. However, NanM is localized in the periplasmic space and cannot facilitate Neu5Ac metabolism by NanA in the cytoplasm in vivo. We discovered that YhcH, a cytoplasmic protein encoded by many Neu5Ac catabolic operons and belonging to a protein family of unknown function (DUF386), also facilitated Neu5Ac utilization by NanA and NPL and displayed Neu5Ac anomerase activity in vitro. YhcH contains Zn, and its accelerating effect on the aldolase reaction was inhibited by metal chelators. Remarkably, several transition metals accelerated Neu5Ac anomerization in the absence of enzyme. Experiments with E. coli mutants indicated that YhcH expression provides a selective advantage for growth on Neu5Ac. In conclusion, YhcH plays the unprecedented role of providing an aldolase with the preferred unstable open form of its substrate.


Asunto(s)
Fructosa-Bifosfato Aldolasa/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Escherichia coli/enzimología , Fructosa-Bifosfato Aldolasa/química , Modelos Moleculares , Ácido N-Acetilneuramínico/química , Periplasma/metabolismo , Conformación Proteica , Transporte de Proteínas , Estereoisomerismo
17.
Ann Rheum Dis ; 81(5): 695-709, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34972811

RESUMEN

OBJECTIVES: To describe the safety of vaccines against SARS-CoV-2 in people with inflammatory/autoimmune rheumatic and musculoskeletal disease (I-RMD). METHODS: Physician-reported registry of I-RMD and non-inflammatory RMD (NI-RMDs) patients vaccinated against SARS-CoV-2. From 5 February 2021 to 27 July 2021, we collected data on demographics, vaccination, RMD diagnosis, disease activity, immunomodulatory/immunosuppressive treatments, flares, adverse events (AEs) and SARS-CoV-2 breakthrough infections. Data were analysed descriptively. RESULTS: The study included 5121 participants from 30 countries, 90% with I-RMDs (n=4604, 68% female, mean age 60.5 years) and 10% with NI-RMDs (n=517, 77% female, mean age 71.4). Inflammatory joint diseases (58%), connective tissue diseases (18%) and vasculitis (12%) were the most frequent diagnostic groups; 54% received conventional synthetic disease-modifying antirheumatic drugs (DMARDs), 42% biological DMARDs and 35% immunosuppressants. Most patients received the Pfizer/BioNTech vaccine (70%), 17% AstraZeneca/Oxford and 8% Moderna. In fully vaccinated cases, breakthrough infections were reported in 0.7% of I-RMD patients and 1.1% of NI-RMD patients. I-RMD flares were reported in 4.4% of cases (0.6% severe), 1.5% resulting in medication changes. AEs were reported in 37% of cases (37% I-RMD, 40% NI-RMD), serious AEs in 0.5% (0.4% I-RMD, 1.9% NI-RMD). CONCLUSION: The safety profiles of SARS-CoV-2 vaccines in patients with I-RMD was reassuring and comparable with patients with NI-RMDs. The majority of patients tolerated their vaccination well with rare reports of I-RMD flare and very rare reports of serious AEs. These findings should provide reassurance to rheumatologists and vaccine recipients and promote confidence in SARS-CoV-2 vaccine safety in I-RMD patients.


Asunto(s)
Antirreumáticos , COVID-19 , Enfermedades Musculoesqueléticas , Enfermedades Reumáticas , Anciano , Antirreumáticos/efectos adversos , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19/efectos adversos , Femenino , Humanos , Inmunosupresores/efectos adversos , Masculino , Persona de Mediana Edad , Enfermedades Musculares , Enfermedades Musculoesqueléticas/inducido químicamente , Enfermedades Musculoesqueléticas/tratamiento farmacológico , Enfermedades Musculoesqueléticas/epidemiología , Sistema de Registros , Enfermedades Reumáticas/tratamiento farmacológico , Reumatólogos , SARS-CoV-2 , Vacunación/efectos adversos
18.
Blood ; 136(9): 1033-1043, 2020 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-32294159

RESUMEN

Neutropenia and neutrophil dysfunction cause serious infections and inflammatory bowel disease in glycogen storage disease type Ib (GSD-Ib). Our discovery that accumulating 1,5-anhydroglucitol-6-phosphate (1,5AG6P) caused neutropenia in a glucose-6-phosphatase 3 (G6PC3)-deficient mouse model and in 2 rare diseases (GSD-Ib and G6PC3 deficiency) led us to repurpose the widely used antidiabetic drug empagliflozin, an inhibitor of the renal glucose cotransporter sodium glucose cotransporter 2 (SGLT2). Off-label use of empagliflozin in 4 GSD-Ib patients with incomplete response to granulocyte colony-stimulating factor (GCSF) treatment decreased serum 1,5AG and neutrophil 1,5AG6P levels within 1 month. Clinically, symptoms of frequent infections, mucosal lesions, and inflammatory bowel disease resolved, and no symptomatic hypoglycemia was observed. GCSF could be discontinued in 2 patients and tapered by 57% and 81%, respectively, in the other 2. The fluctuating neutrophil numbers in all patients were increased and stabilized. We further demonstrated improved neutrophil function: normal oxidative burst (in 3 of 3 patients tested), corrected protein glycosylation (2 of 2), and normal neutrophil chemotaxis (1 of 1), and bactericidal activity (1 of 1) under treatment. In summary, the glucose-lowering SGLT2 inhibitor empagliflozin, used for type 2 diabetes, was successfully repurposed for treating neutropenia and neutrophil dysfunction in the rare inherited metabolic disorder GSD-Ib without causing symptomatic hypoglycemia. We ascribe this to an improvement in neutrophil function resulting from the reduction of the intracellular concentration of 1,5AG6P.


Asunto(s)
Compuestos de Bencidrilo/uso terapéutico , Glucósidos/uso terapéutico , Enfermedad del Almacenamiento de Glucógeno Tipo I/complicaciones , Hexosafosfatos/sangre , Neutropenia/tratamiento farmacológico , Neutrófilos/patología , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Compuestos de Bencidrilo/efectos adversos , Glucemia/análisis , Quimiotaxis de Leucocito/efectos de los fármacos , Preescolar , Reposicionamiento de Medicamentos , Resistencia a Medicamentos , Femenino , Glucósidos/efectos adversos , Enfermedad del Almacenamiento de Glucógeno Tipo I/sangre , Enfermedad del Almacenamiento de Glucógeno Tipo I/inmunología , Factor Estimulante de Colonias de Granulocitos/uso terapéutico , Granulocitos/química , Humanos , Recién Nacido , Proteína 2 de la Membrana Asociada a los Lisosomas/sangre , Masculino , Neutropenia/sangre , Uso Fuera de lo Indicado , Estallido Respiratorio/efectos de los fármacos , Inhibidores del Cotransportador de Sodio-Glucosa 2/efectos adversos , Adulto Joven
19.
J Inherit Metab Dis ; 45(4): 759-768, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35506446

RESUMEN

Neutropenia and neutrophil dysfunction found in deficiencies in G6PC3 and in the glucose-6-phosphate transporter (G6PT/SLC37A4) are due to accumulation of 1,5-anhydroglucitol-6-phosphate (1,5-AG6P), an inhibitor of hexokinase made from 1,5-anhydroglucitol (1,5-AG), an abundant polyol present in blood. Lowering blood 1,5-AG with an SGLT2 inhibitor greatly improved neutrophil counts and function in G6PC3-deficient mice and in patients with G6PT-deficiency. We evaluate this treatment in two G6PC3-deficient children. While neutropenia was severe in one child (PT1), which was dependent on granulocyte cololony-stimulating factor (GCSF), it was significantly milder in the other one (PT2), which had low blood 1,5-AG levels and only required GCSF during severe infections. Treatment with the SGLT2-inhibitor empagliflozin decreased 1,5-AG in blood and 1,5-AG6P in neutrophils and improved (PT1) or normalized (PT2) neutrophil counts, allowing to stop GCSF. On empagliflozin, both children remained infection-free (>1 year - PT2; >2 years - PT1) and no side effects were reported. Remarkably, sequencing of SGLT5, the gene encoding the putative renal transporter for 1,5-AG, disclosed a rare heterozygous missense mutation in PT2, replacing the extremely conserved Arg401 by a histidine. The higher urinary clearance of 1,5-AG explains the more benign neutropenia and the outstanding response to empagliflozin treatment found in this child. Our data shows that SGLT2 inhibitors are an excellent alternative to treat the neutropenia present in G6PC3-deficiency.


Asunto(s)
Enfermedad del Almacenamiento de Glucógeno Tipo I , Neutropenia , Proteínas de Transporte de Sodio-Glucosa/metabolismo , Animales , Antiportadores/genética , Compuestos de Bencidrilo , Glucosa-6-Fosfatasa/genética , Glucosa-6-Fosfatasa/metabolismo , Glucósidos/uso terapéutico , Enfermedad del Almacenamiento de Glucógeno Tipo I/tratamiento farmacológico , Enfermedad del Almacenamiento de Glucógeno Tipo I/genética , Humanos , Ratones , Proteínas de Transporte de Monosacáridos/genética , Mutación , Neutropenia/tratamiento farmacológico , Neutropenia/genética , Monoéster Fosfórico Hidrolasas/genética
20.
BMC Vet Res ; 18(1): 273, 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35831890

RESUMEN

BACKGROUND: Mastitis is one of the major diseases in dairy cattle, as it causes great economic losses to producers due to the reduction of milk production and changes in the quality of the product. The disease is mainly caused by bacteria of the genus Staphylococcus spp., these microorganisms can express various virulence factors, such as biofilms for example. In herds with organic management, producers and technicians use unconventional ways to treat and control the disease, such as homeopathy. However, it is not known if this type of treatment is able to control pathogenic bacteria such as those of the genus Staphylococcus, of relevance to animal and human health. Thus, the objective of this study was to investigate the production of biofilm in vitro and its genes by Staphylococcus spp. isolated in the milk of cows treated with homeopathy, as well as the persistence of microorganisms in animals. METHODS: Ninety-nine isolates of Staphylococcus spp. from cows treated and not treated with homeopathy were identified by internal transcribed space-polymerase chain reaction and investigated for the presence of the icaABCD, bap, aap, atlE, and bhp genes and in vitro biofilm production using the adhesion method on polystyrene plates. The enzyme restriction profile was determined by Pulsed-Field Gel Electrophoresis. Clusters of S. aureus and S. epidermidis with three or more isolates had an isolate selected for Multilocus Sequence Typing. RESULTS: The frequency of S. aureus isolations was similar in treated and untreated cows, while 71.4% of the coagulase-negative identified were isolated in cows treated with homeopathy. The distribution of the operon ica genes was similar in animals with and without treatment, except for the icaD gene, more frequent in treated cows. Production of biofilm was associated with presence of one or more genes from the icaADBC operon. S. aureus revealed a greater diversity and greater dissemination in cows treated and not treated with homeopathy. Sequence Types ST1, ST5, and ST126 were identified in S. aureus. CONCLUSIONS: The presence of biofilm-associated genes and the in vitro production of biofilms, combined with the persistence of clonal profiles of Staphylococcus spp. demonstrate other forms of control for bovine mastitis should be researched for organic production herds.


Asunto(s)
Enfermedades de los Bovinos , Homeopatía , Mastitis Bovina , Infecciones Estafilocócicas , Animales , Biopelículas , Bovinos , Femenino , Homeopatía/veterinaria , Humanos , Mastitis Bovina/microbiología , Mastitis Bovina/terapia , Leche/microbiología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus/genética , Staphylococcus aureus/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA