RESUMEN
The blood-brain barrier (BBB) is an essential gatekeeper for the central nervous system and incidence of neurodevelopmental disorders (NDDs) is higher in infants with a history of intracerebral hemorrhage (ICH). We discovered a rare disease trait in thirteen individuals, including four fetuses, from eight unrelated families associated with homozygous loss-of-function variant alleles of ESAM which encodes an endothelial cell adhesion molecule. The c.115del (p.Arg39Glyfs∗33) variant, identified in six individuals from four independent families of Southeastern Anatolia, severely impaired the in vitro tubulogenic process of endothelial colony-forming cells, recapitulating previous evidence in null mice, and caused lack of ESAM expression in the capillary endothelial cells of damaged brain. Affected individuals with bi-allelic ESAM variants showed profound global developmental delay/unspecified intellectual disability, epilepsy, absent or severely delayed speech, varying degrees of spasticity, ventriculomegaly, and ICH/cerebral calcifications, the latter being also observed in the fetuses. Phenotypic traits observed in individuals with bi-allelic ESAM variants overlap very closely with other known conditions characterized by endothelial dysfunction due to mutation of genes encoding tight junction molecules. Our findings emphasize the role of brain endothelial dysfunction in NDDs and contribute to the expansion of an emerging group of diseases that we propose to rename as "tightjunctionopathies."
Asunto(s)
Encefalopatías , Moléculas de Adhesión Celular , Malformaciones del Sistema Nervioso , Trastornos del Neurodesarrollo , Animales , Ratones , Alelos , Encefalopatías/genética , Moléculas de Adhesión Celular/genética , Células Endoteliales/metabolismo , Hemorragias Intracraneales/genética , Malformaciones del Sistema Nervioso/genética , Trastornos del Neurodesarrollo/genética , Uniones Estrechas/genética , HumanosRESUMEN
Iron scarcity provokes a cellular response consisting of the strong expression of high-affinity systems to optimize iron uptake and mobilization. Aft1 is a primary transcription factor involved in iron homeostasis and controls the expression of high-affinity iron uptake genes in Saccharomyces cerevisiae. Aft1 responds to iron deprivation by translocating from the cytoplasm to the nucleus. Here, we demonstrate that the AGC kinase Ypk1, as well as its upstream regulator TOR Complex 2 (TORC2), are required for proper Aft1 nuclear localization following iron deprivation. We exclude a role for TOR Complex 1 (TORC1) and its downstream effector Sch9, suggesting this response is specific for the TORC2 arm of the TOR pathway. Remarkably, we demonstrate that Aft1 nuclear localization and a robust transcriptional response to iron starvation also require biosynthesis of sphingolipids, including complex sphingolipids such as inositol phosphorylceramide (IPC) and upstream precursors, e.g., long-chain bases (LCBs) and ceramides. Furthermore, we observe the deficiency of Aft1 nuclear localization and impaired transcriptional response in the absence of iron when TORC2-Ypk1 is impaired is partially suppressed by exogenous addition of the LCB dihydrosphingosine (DHS). This latter result is consistent with prior studies linking sphingolipid biosynthesis to TORC2-Ypk1 signaling. Taken together, these results reveal a novel role for sphingolipids, controlled by TORC2-Ypk1, for proper localization and activity of Aft1 in response to iron scarcity.
Asunto(s)
Proteínas de Saccharomyces cerevisiae , Hierro/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/genética , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Transducción de Señal , Esfingolípidos/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
We have investigated the effects that iron limitation provokes in Saccharomyces cerevisiae exponential cultures. We have demonstrated that one primary response is the induction of bulk autophagy mediated by TORC1. Coherently, Atg13 became dephosphorylated whereas Atg1 appeared phosphorylated. The signal of iron deprivation requires Tor2/Ypk1 activity and the inactivation of Tor1 leading to Atg13 dephosphorylation, thus triggering the autophagy process. Iron replenishment in its turn, reduces autophagy flux through the AMPK Snf1 and the subsequent activity of the iron-responsive transcription factor, Aft1. This signalling converges in Atg13 phosphorylation mediated by Tor1. Iron limitation promotes accumulation of trehalose and the increase in stress resistance leading to a quiescent state in cells. All these effects contribute to the extension of the chronological life, in a manner totally dependent on autophagy activation.
Asunto(s)
Proteínas Relacionadas con la Autofagia/metabolismo , Hierro/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Autofagia/fisiología , Proteínas de Ciclo Celular/metabolismo , Medios de Cultivo/farmacología , Hierro/administración & dosificación , Mitocondrias/metabolismo , Nutrientes/administración & dosificación , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Transporte de Proteínas , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/crecimiento & desarrollo , Estrés Fisiológico , Factores de Transcripción/metabolismo , Trehalosa/metabolismoRESUMEN
The human monothiol glutaredoxin Glrx3 (PICOT) is ubiquitously distributed in cytoplasm and nuclei in mammalian cells. Its overexpression has been associated with the development of several types of tumors, whereas its deficiency might cause retardation in embryogenesis. Its exact biological role has not been well resolved, although a function as a chaperone distributing iron/sulfur clusters is currently accepted. Yeast humanization and the use of a mouse library have allowed us to find a new partner for PICOT: the human GMP synthase (hGMPs). Both proteins carry out collaborative functions regarding the downregulation of the Saccharomyces cerevisiae Gcn2 pathway under conditions of nutritional stress. Glrx3/hGMPs interact through conserved residues that bridge iron/sulfur clusters and glutathione. This mechanism is also conserved in budding yeast, whose proteins Grx3/Grx4, along with GUA1 (S. cerevisiae GMPs), also downregulate the integrated stress response (ISR) pathway. The heterologous expression of Glrx3/hGMPs efficiently complements Grx3/Grx4. Moreover, the heterologous expression of Glrx3 efficiently complements the novel participation in chronological life span that has been characterized for both Grx3 and Grx4. Our results underscore that the Glrx3/Grx3/Grx4 family presents an evolutionary and functional conservation in signaling events that is partly related to GMP function and contributes to cell life extension.IMPORTANCESaccharomyces cerevisiae is an optimal eukaryotic microbial model to study biological processes in higher organisms despite the divergence in evolution. The molecular function of yeast glutaredoxins Grx3 and Grx4 is enormously interesting, since both proteins are required to maintain correct iron homeostasis and an efficient response to oxidative stress. The human orthologous Glrx3 (PICOT) is involved in a number of human diseases, including cancer. Our research expanded its utility to human cells. Yeast has allowed the characterization of GMP synthase as a new interacting partner for Glrx3 and also for yeast Grx3 and Grx4, the complex monothiol glutaredoxins/GMPs that participate in the downregulation of the activity of the Gcn2 stress pathway. This mechanism is conserved in yeast and humans. Here, we also show that this family of glutaredoxins, Grx3/Grx4/Glrx3, also has a function related to life extension.
Asunto(s)
Ligasas de Carbono-Nitrógeno/genética , Proteínas Portadoras/genética , Regulación de la Expresión Génica , Glutarredoxinas/genética , Oxidorreductasas/genética , Proteínas de Saccharomyces cerevisiae/genética , Animales , Ligasas de Carbono-Nitrógeno/metabolismo , Proteínas Portadoras/metabolismo , Biblioteca de Genes , Glutarredoxinas/metabolismo , Humanos , Ratones , Oxidorreductasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Transducción de SeñalRESUMEN
Gastrointestinal lipase inhibitors are molecules of pharmaceutical interest due to their use as anti-obesity drugs. In this study, forty strains isolated from soil and sediments were identified with the ability to produce inhibition of gastrointestinal lipase activity. The biomass extract of these strains showed at least 50% inhibition in the hydrolysis of tributyrin by recombinant human pancreatic lipase (rHPL) or rabbit gastric lipase (RGL) by in vitro assays. Based on gene sequencing, the isolates were identified mainly as Streptomycetes. Moreover, none of the identified strains has been reported to be lipase inhibitor producers, so they can be viewed as potential sources for obtaining new drugs. IC50 values of the three best inhibitor extracts showed that AC104-10 was the most promising strain for production of gastrointestinal lipase inhibitors. AC104-10 shows 99% homology (16S rRNA gene fragment) to Streptomyces cinereoruber strain NBRC 12756. An inhibitory study over trypsin activity revealed that AC104-10 extract, as well as THL, had no significant effect on the activity of this protease, showing its specificity for lipases. In addition, analyzes by MALDI-TOF mass spectrometry of the enzyme-inhibitor complex revealed that there is a covalent interaction of the AC104-10 inhibitor with the catalytic serine of the pancreatic lipase, and that the molecular weight of the inhibitor is approximately 686.19 Da.
Asunto(s)
Sedimentos Geológicos/microbiología , Streptomyces/aislamiento & purificación , Actinobacteria/genética , Actinobacteria/aislamiento & purificación , Actinobacteria/metabolismo , Animales , Productos Biológicos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/metabolismo , Humanos , Lagos/microbiología , Lipasa/antagonistas & inhibidores , Lipasa/metabolismo , ARN Ribosómico 16S , Microbiología del Suelo , Streptomyces/genética , Streptomyces/metabolismoRESUMEN
In major orthopaedic surgery, it is recommended to detect and correct preoperative anaemia several weeks prior to surgery. However, in many cases, the procedure is urgent or the patient is evaluated shortly before the intervention. As iron deficiency is the leading cause of perioperative anaemia, an exhaustive review of the literature was performed to assess the efficacy and safety of short-term perioperative intravenous, with or without erythropoietin, or postoperative oral or intravenous supplementation in major orthopaedic surgery. Overall, 20 studies met the inclusion criteria. There were 13 randomized trials (moderate quality) and seven observational studies (low to very low quality). The primary outcomes were reduction in transfusion requirements, haemoglobin increase and medication side-effects during the study period. Data analysis showed that postoperative oral iron administration neither increased haemoglobin nor reduced transfusion requirements, and it was associated with significant gastrointestinal adverse effects (15%). In contrast, for some patient populations, perioperative or postoperative administration of intravenous iron, with or without recombinant erythropoietin, may reduce transfusion requirements and/or hasten the recovery from postoperative, with few clinically relevant adverse effects (<2%). However, discrepancies between randomized trials and observational studies on the possible beneficial effects of short-term perioperative intravenous iron administration were found for patients undergoing surgery for hip fracture repair. Further studies are needed to elucidate when the treatment should be started, which combination of drugs should be used, and which patient groups would be most benefit.
Asunto(s)
Anemia/prevención & control , Hierro/uso terapéutico , Ortopedia/métodos , Complicaciones Posoperatorias/prevención & control , Administración Oral , Anemia/tratamiento farmacológico , Humanos , Infusiones Intravenosas , Hierro/administración & dosificación , Hierro/efectos adversos , Estudios Observacionales como Asunto , Complicaciones Posoperatorias/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Here we show that Mtl1, member of the cell wall integrity pathway of Saccharomyces cerevisiae, plays a positive role in chronological life span (CLS). The absence of Mtl1 shortens CLS and causes impairment in the mitochondrial function. This is reflected in a descent in oxygen consumption during the postdiauxic state, an increase in the uncoupled respiration and mitochondrial membrane potential and also a descent in aconitase activity. We demonstrate that all these effects are a consequence of signalling defects suppressed by TOR1 (target of rapamycin) and SCH9 deletion and less efficiently by Protein kinase A (PKA) inactivation. Mtl1 also plays a role in the regulation of both Bcy1 stability and phosphorylation, mainly in response to glucose depletion. In postdiauxic phase and in conditions of glucose depletion, Mtl1 negatively regulates TOR1 function leading to Sch9 inactivation and Bcy1 phosphorylation converging in PKA inhibition. Slt2/Mpk1 kinase partially contributes to Bcy1 phosphorylation, although additional targets are not excluded. Mtl1 links mitochondrial dysfunction with TOR and PKA pathways in quiescence, glucose being the main signalling molecule.
Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/genética , Mitocondrias/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Proteínas Serina-Treonina Quinasas/genética , Receptores de Superficie Celular/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiología , Aconitato Hidratasa/metabolismo , Pared Celular/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Regulación hacia Abajo , Regulación Fúngica de la Expresión Génica , Glucosa/metabolismo , Potencial de la Membrana Mitocondrial , Viabilidad Microbiana , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de Superficie Celular/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Proteínas ras/metabolismoRESUMEN
In general, it is recommended to incubate dermatophytes cultures for a minimum of 4 weeks. Several aspects of routine fungal cultures should be evaluated in order to implement appropriate and necessary changes. The aim of this study was to determine the optimum incubation time for routine dermatophytes cultures, analysing the time to find first fungal growth by visual observation. We recorded the time when the initial growth was detected for all dermatophyte isolates during a 4-year period. A total of 5459 dermatophyte cultures were submitted to our laboratory. From the total cultures, only 16 (1.42%) isolates were recovered over/after 17 days of incubation and only three dermatophyte species were recovered over 17 days. Fourteen isolates belong to Trichophyton rubrum, one isolate to Trichophyton mentagrophytes complex and one isolate to Epidermophyton floccosum. We concluded that an incubation period of 17 days is enough to establish a microbiological diagnosis of dermatophytosis.
Asunto(s)
Arthrodermataceae/crecimiento & desarrollo , Arthrodermataceae/aislamiento & purificación , Epidermophyton/crecimiento & desarrollo , Epidermophyton/aislamiento & purificación , Micología/métodos , Factores de Tiempo , Tiña/diagnóstico , Tiña/microbiología , Trichophyton/crecimiento & desarrollo , Trichophyton/aislamiento & purificaciónRESUMEN
Biocatalytic processes play a crucial role in the valorization of lignin; therefore, methods enabling the monitoring of enzymes such as ß-etherases, capable of breaking ß-O-4 aryl-ether bonds, are of significant biotechnological interest. A novel method for quantifying ß-etherase activity was developed based on the ß-ester bond formation between a chromophore and acetovainillone. The chromogenic substrate ß-(ρ-nitrophenoxy)-α-acetovanillone (PNPAV), was chemically synthesized. Kintetic monitoring of ρ-nitrophenolate release at 410 nm over 10 min, using recombinant LigF from Sphingobium sp SYK-6, LigF-AB and LigE-AB from Althererytrobacter sp B11, yielded enzimatic activities of 404. 3 mU/mg, 72 mU/mg, and 50 mU/mg, respectively. This method is applicable in a pH range of 7.0-9.0, with a sensitivity of up to 50 ng of enzyme, exhibiting no interference with lipolytic, glycolytic, proteolytic, and oxidoreductase enzymes.
Asunto(s)
Compuestos Cromogénicos , Sphingomonadaceae , Oxidorreductasas/química , Proteínas Bacterianas/química , Lignina/químicaRESUMEN
Oxidative stress causes transient actin cytoskeleton depolarization and also provokes vacuole fragmentation in wild-type cells. Under conditions of oxidative stress induced by hydrogen peroxide, the Slt2 protein is required to repolarize the actin cytoskeleton and to promote vacuole fusion. In this study, we show that grx3 grx4 and grx5 mutants are cellular models of endogenous oxidative stress. This stress is the result of alterations in iron homeostasis that lead to impairment of vacuolar function and also to disorganization of the actin cytoskeleton. Slt2 overexpression suppresses defects in vacuolar function and actin cytoskeleton organization in the grx3 grx4 mutant. Slt2 exerts this effect independently of the intracellular levels of reactive oxygen species (ROS) and of iron homeostasis. The deletion of SLT2 in the grx3 grx4 mutant results in synthetic lethality related to vacuolar function with substantial vacuole fragmentation. The observation that both Vps4 and Vps73 (two proteins related to vacuole sorting) suppress vacuole fragmentation and actin depolarization in the grx3 grx4 slt2 triple mutant strengthens the hypothesis that Slt2 plays a role in vacuole homeostasis related to actin dynamics. Here we show that in sod1, grx5, and grx3 grx4 slt2 mutants, all of which are affected by chronic oxidative stress, the overexpression of Slt2 favors vacuole fusion through a mechanism dependent on an active actin cytoskeleton.
Asunto(s)
Actinas/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Estrés Oxidativo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/enzimología , Vacuolas/enzimología , Peróxido de Hidrógeno/toxicidad , Viabilidad Microbiana/efectos de los fármacos , Multimerización de Proteína , Saccharomyces cerevisiae/genética , Vacuolas/metabolismoRESUMEN
PURPOSE: Pyridoxine-dependent epilepsy seizure (PDE; OMIM 266100) is a disorder associated with severe seizures that can be controlled pharmacologically with pyridoxine. In the majority of patients with PDE, the disorder is caused by the deficient activity of the enzyme α-aminoadipic semialdehyde dehydrogenase (antiquitin protein), which is encoded by the ALDH7A1 gene. The aim of this work was the clinical, biochemical, and genetic analysis of 12 unrelated patients, mostly from Spain, in an attempt to provide further valuable data regarding the wide clinical, biochemical, and genetic spectrum of the disease. METHODS: The disease was confirmed based on the presence of α-aminoadipic semialdehyde (α-AASA) in urine measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) and pipecolic acid (PA) in plasma and/or cerebrospinal fluid (CSF) measured by high performance liquid chromatography (HPLC)/MS/MS and by sequencing analysis of messenger RNA (mRNA) and genomic DNA of ALDH7A1. KEY FINDINGS: Most of the patients had seizures in the neonatal period, but they responded to vitamin B6 administration. Three patients developed late-onset seizures, and most patients showed mild-to-moderate postnatal developmental delay. All patients had elevated PA and α-AASA levels, even those who had undergone pyridoxine treatment for several years. The clinical spectrum of our patients is not limited to seizures but many of them show associated neurologic dysfunctions such as muscle tone alterations, irritability, and psychomotor retardation. The mutational spectrum of the present patients included 12 mutations, five already reported (c.500A>G, c.919C>T, c.1429G>C c.1217_1218delAT, and c.1482-1G>T) and seven novel sequence changes (c.75C>T, c.319G>T, c.554_555delAA, c.757C>T, c.787 + 1G>T, c.1474T>C, c.1093-?_1620+?). Only one mutation, p.G477R (c.1429G>C), was recurrent; this was detected in four different alleles. Transcriptional profile analysis of one patient's lymphoblasts and ex vivo splicing analysis showed the silent nucleotide change c.75C>T to be a novel splicing mutation creating a new donor splice site inside exon 1. Antisense therapy of the aberrant mRNA splicing in a lymphoblast cell line harboring mutation c.75C>T was successful. SIGNIFICANCE: The present results broaden our knowledge of PDE, provide information regarding the genetic background of PDE in Spain, afford data of use when making molecular-based prenatal diagnosis, and provide a cellular proof-of concept for antisense therapy application.
Asunto(s)
Epilepsia/tratamiento farmacológico , Epilepsia/genética , Terapia Genética/métodos , Oligonucleótidos Antisentido/uso terapéutico , Deficiencia de Vitamina B 6/complicaciones , Aldehído Deshidrogenasa/genética , Línea Celular , Análisis Mutacional de ADN , Epilepsia/etiología , Exones/genética , Femenino , Humanos , Hiperlisinemias/orina , Lactante , Recién Nacido , Linfocitos/efectos de los fármacos , Masculino , Mutación/genética , Polimorfismo de Nucleótido Simple , Empalme del ARN , Sacaropina Deshidrogenasas/deficiencia , Sacaropina Deshidrogenasas/orina , Espectrometría de Masas en TándemRESUMEN
Lignin, a complex heteropolymer present in plant cell walls, is now recognized as a valuable renewable resource with potential applications in various industries. The lignin biorefinery concept, which aims to convert lignin into value-added products, has gained significant attention in recent years. ß-etherases, enzymes that selectively cleave ß-O-4 aryl ether bonds in lignin, have shown promise in lignin depolymerization. In this study, the ß-etherase LigF from Altererythrobacter sp. B11 was cloned, expressed, purified, and biochemically characterized. The LigF-AB11 enzyme exhibited optimal activity at 32 °C and pH 8.5 when catalyzing the substrate PNP-AV. The enzyme displayed mesophilic behavior and demonstrated higher activity at moderate temperatures. Stability analysis revealed that LigF-AB11 was not thermostable, with a complete loss of activity at 60 °C within an hour. Moreover, LigF-AB11 exhibited excellent pH stability, retaining over 50 % of its activity after 1 h under pH conditions ranging from 3.0 to 11.0. Metal ions and surface impregnation agents were found to affect the enzyme's activity, highlighting the importance of considering these factors in enzymatic processes for lignin depolymerization. This study provides valuable insights into the biochemical properties of LigF-AB11 and contributes to the development of efficient enzymatic processes for lignin biorefineries. Further optimization and understanding of ß-etherases will facilitate their practical application in the valorization of lignin.
RESUMEN
Biomarkers are useful in community-acquired pneumonia (CAP). Recently, midregional (MR) proadrenomedullin (proADM) has been shown to be of potential prognostic use. We sought to determine whether this prognostic role depends on the cause of CAP. We conducted a prospective cohort study of immunocompetent patients with CAP. Pneumonia Severity Index (PSI) and CURB-65 score (confusion (abbreviated mental test score of ≤ 8), urea ≥ 7 mol · L(-1), respiratory rate ≥ 30 breaths · min(-1), blood pressure <90 mmHg systolic or <60 mmHg diastolic, and age ≥ 65 yrs), blood C-reactive protein, procalcitonin, MR-proADM, and microbiological studies were systematically performed. Patients were grouped as bacterial, viral/atypical and mixed CAP, and were followed up at 30, 90 and 180 days, and 1 yr. We recruited 228 CAP patients. Identification of at least one pathogen was achieved in 155 (68%) patients. MR-proADM levels closely correlated with increasing severity scores, and showed an important predictive power for complications and short- and long-term mortality (1 yr). Its addition to PSI and CURB-65 significantly improved their prognostic accuracy. A MR-proADM cut-off of 0.646 nmol · L(-1) identified 92% of patients scored as PSI classes IV and V as high risk. MR-proADM outcome prediction power was not affected by different aetiologies. MR-proADM has high short- and long-term prognostic accuracy, and increases the accuracy of clinical scores. The prognostic value of MR-proADM is not modified by different possible CAP aetiologies.
Asunto(s)
Adrenomedulina/sangre , Infecciones Comunitarias Adquiridas/sangre , Neumonía Bacteriana/sangre , Neumonía Viral/sangre , Precursores de Proteínas/sangre , Anciano , Biomarcadores/sangre , Presión Sanguínea , Proteína C-Reactiva/análisis , Calcitonina/sangre , Péptido Relacionado con Gen de Calcitonina , Confusión/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/sangre , Neumonía Bacteriana/complicaciones , Neumonía Bacteriana/microbiología , Neumonía Bacteriana/mortalidad , Neumonía Viral/complicaciones , Neumonía Viral/mortalidad , Neumonía Viral/virología , Pronóstico , Estudios Prospectivos , Frecuencia Respiratoria , Índice de Severidad de la Enfermedad , Fumar/epidemiología , Urea/sangreRESUMEN
Mtl1 is a cell surface sensor and member of the Pkc1-MAPK pathway that senses oxidative stress and nutrient starvation. Here we demonstrate that the Mtl1 cytoplasmic domain physically interacts with the GEF (GTPase Exchange Factor) protein Rom2 of the CWI (Cell wall Integrity) pathway. Mtl1 is N-glycosylated protein, highly O-mannosylated by Pmt1, Pmt4 and mostly by Pmt2. Mtl1 localises to the bud, septum, the tip of the shmoo and the cell periphery. The O-mannosylation deficiency that occurs in both the pmt1 and pmt2 mutants adversely affects the distribution of Mtl1 on the septum and also hinders Mtl1 localisation in the tip of the shmoo. Here we present results demonstrating that: (i) O-mannosylation and, more specifically that affecting Mtl1 protein is required for cell survival in response to both oxidative stress and TOR blockade; (ii) Slt2 activity is impaired upon rapamycin treatment in both pmt2 and mtl1 mutants; (iii) Mtl1 is transcriptionally upregulated in quiescent conditions, (iv) O-mannosylation mediated by Pmt1 and Pmt2 favours Mtl1 protein stability. We propose a relevant role for Mtl1 O-mannosylation mediated by both Pmt1 and Pmt2 in the response to oxidative stress and in rapamycin treatment.
Asunto(s)
Manosiltransferasas/metabolismo , Estrés Oxidativo , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Receptores de Superficie Celular/metabolismo , Proteínas de Saccharomyces cerevisiae/antagonistas & inhibidores , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/enzimología , Secuencia de Aminoácidos , Regulación Fúngica de la Expresión Génica , Glicosilación , Manosiltransferasas/genética , Datos de Secuencia Molecular , Unión Proteica , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de Superficie Celular/química , Receptores de Superficie Celular/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Alineación de Secuencia , Proteínas ras/genética , Proteínas ras/metabolismoRESUMEN
Ferritin proteins have an enormous capacity to store iron in cells. In search for the best conditions to accumulate and store bioavailable iron, we made use of a double mutant null for the monothiol glutaredoxins GRX3 and GRX4. The strain grx3grx4 accumulates high iron concentrations in the cytoplasm, making the metal easily available for ferritin chelation. Here, we perform a comparative study between human (L and H) and soya bean ferritins (H1 and H2) function in the eukaryotic system Saccharomyces cerevisiae. We demonstrate that the four human and soya bean ferritin chains are successfully expressed in our model system. Upon coexpression of either both human or soya bean ferritin chains, respiratory conditions along with iron supplementation led us to obtain the maximum yields of iron stored in yeast described to date. Human and soya bean ferritin chains are functional and present equivalent properties as promoters of cell survival in iron overload conditions. The best system revealed that the four human and soya bean ferritins possess a novel function as anti-ageing proteins in conditions of iron excess. In this respect, both ferritin chains with oxidoreductase capacity (human-H and soya bean-H2) bear the highest capacity to extend life suggesting the possibility of an evolutionary conservation.
Asunto(s)
Fabaceae , Proteínas de Saccharomyces cerevisiae , Saccharomycetales , Ferritinas/genética , Ferritinas/metabolismo , Humanos , Hierro/metabolismo , Oxidorreductasas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMEN
In Saccharomyces cerevisiae, the cell integrity pathway plays a role in the oxidative stress response. In this study, we show that the Pkc1 protein mediates oxidative signalling by helping to downregulate ribosomal gene expression when cells are exposed to hydrogen peroxide. An active actin cytoskeleton is required for this function, because the cells blocked in actin polymerisation were unable to repress ribosomal gene transcription. Following the invertase secretion pattern, we hypothesize that oxidative stress induced by hydrogen peroxide could have affected the latter steps of secretion. This would explain why the Pkc1 function was required to repress ribosomal biogenesis.
Asunto(s)
Actinas/metabolismo , Estrés Oxidativo/fisiología , Proteína Quinasa C/metabolismo , Proteínas Ribosómicas/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Vías Secretoras/efectos de los fármacos , Actinas/efectos de los fármacos , Actinas/genética , Citoesqueleto/fisiología , Regulación Fúngica de la Expresión Génica , Peróxido de Hidrógeno/farmacología , Polimerizacion , Proteína Quinasa C/efectos de los fármacos , Proteína Quinasa C/genética , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiología , Proteínas de Saccharomyces cerevisiae/genética , Vías Secretoras/fisiología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
PURPOSE: Cervical traumatic spinal cord-injured patients often way require both anterior cervical spine stabilization and tracheostomy in the first few days after the injury. The infectious complication of tracheostomy can interfere with the evolution of the fixation surgery. The aim of our study was to evaluate the safety of tracheostomy performed early after anterior cervical spine stabilization. MATERIALS AND METHODS: We reviewed the clinical records of 28 patients admitted to our hospital intensive care unit. In all cases, percutaneous tracheostomy was performed using the percutaneous dilation technique. RESULTS: The average time interval between the fixation surgery and tracheostomy was 8.25 ± 5.57 days. We had complications in tracheostomy in only 3 cases: minor bleeding occurred in 1 patient and stomal infection, not propagated to the fixation surgery wound, was observed in 2 patients. Two patients died without causal relation to these interventions. CONCLUSIONS: The early performance of tracheostomy after cervical spinal fixation surgery is safe, still realized early and nearly this, at least if the tracheostomy is performed by percutaneous method.
Asunto(s)
Vértebras Cervicales/lesiones , Fijación Interna de Fracturas , Insuficiencia Respiratoria/etiología , Fracturas de la Columna Vertebral/cirugía , Traqueostomía/efectos adversos , Adulto , Anciano , Vértebras Cervicales/cirugía , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Insuficiencia Respiratoria/epidemiología , España/epidemiología , Fracturas de la Columna Vertebral/diagnóstico , Tasa de Supervivencia , Traqueostomía/métodos , Índices de Gravedad del Trauma , Adulto JovenRESUMEN
Fifty-two men who had suffered a first episode ischemic heart disease reported their degree of life satisfaction, the strategies they used to adjust to the illness, and the symptoms of anxiety and depression they felt. The multiple regression analyses carried out indicated that emotional distress was associated with a lower level of life satisfaction. In the analyses of anxiety symptoms, the use of negative adjustment strategies was also a significant predictor. Lastly, a significant Life Satisfaction x Type of Adjustment interaction was obtained. According to this, the patients who felt more satisfaction with their lives used more positive strategies to adjust to the illness and fewer negative ones, than the group of patients who were less satisfied. In conclusion, life satisfaction predicts emotional wellbeing of patients with ischemic heart disease and it enhances the implementation of appropriate strategies to cope with the disease. Moreover, although life satisfaction has been considered a stable measure, we suggest it may change as the experience of illness limits individuals' important goals.
Asunto(s)
Adaptación Psicológica , Angina de Pecho/psicología , Ansiedad/psicología , Depresión/psicología , Infarto del Miocardio/psicología , Isquemia Miocárdica/psicología , Calidad de Vida/psicología , Rol del Enfermo , Adulto , Anciano , Angina de Pecho/diagnóstico , Ansiedad/diagnóstico , Mecanismos de Defensa , Depresión/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Inventario de Personalidad/estadística & datos numéricos , Psicometría , Apoyo SocialRESUMEN
BACKGROUND: Mucopolysaccharidosis type VII (Sly syndrome) is an ultra-rare neurometabolic disorder caused by inherited deficiency of the lysosomal enzyme ß-glucuronidase. Precise data regarding its epidemiology are scarce, but birth prevalence is estimated to vary from 0.02 to 0.24 per 100,000 live births. The clinical course and disease progression are widely heterogeneous, but most patients have been reported to show signs such as skeletal deformities or cognitive delay. Additionally, detection criteria are not standardized, resulting in delayed diagnosis and treatment. METHODS: We present a cohort of 9 patients with mucopolysaccharidosis VII diagnosed in the Iberian Peninsula, either in Spain or Portugal. The diagnostic approach, genetic studies, clinical features, evolution and treatment interventions were reviewed. RESULTS: We found that skeletal deformities, hip dysplasia, hydrops fetalis, hepatosplenomegaly, hernias, coarse features, respiratory issues, and cognitive and growth delay were the most common features identified in the cohort. In general, patients with early diagnostic confirmation who received the appropriate treatment in a timely manner presented a more favorable clinical evolution. CONCLUSIONS: This case series report helps to improve understanding of this ultra-rare disease and allows to establish criteria for clinical suspicion or diagnosis, recommendations, and future directions for better management of patients with Sly syndrome.
Asunto(s)
Mucopolisacaridosis VII , Europa (Continente) , Humanos , Mucopolisacaridosis VII/diagnóstico , Mucopolisacaridosis VII/genética , Portugal , EspañaRESUMEN
Mtl1protein is a cell wall receptor belonging to the CWI pathway. Mtl1 function is related to glucose and oxidative stress signaling. In this report, we show data demonstrating that Mtl1 plays a critical role in the detection of a descent in glucose concentration, in order to activate bulk autophagy machinery as a response to nutrient deprivation and to maintain cell survival in starvation conditions. Autophagy is a tightly regulated mechanism involving several signaling pathways. The data here show that in Saccharomyces cerevisiae, Mtl1 signals glucose availability to either Ras2 or Sch9 proteins converging in Atg1 phosphorylation and autophagy induction. TORC1 complex function is not involved in autophagy induction during the diauxic shift when glucose is limited. In this context, the GCN2 gene is required to regulate autophagy activation upon amino acid starvation independent of the TORC1 complex. Mtl1 function is also involved in signaling the autophagic degradation of mitochondria during the stationary phase through both Ras2 and Sch9, in a manner dependent on either Atg33 and Atg11 proteins and independent of the Atg32 protein, the mitophagy receptor. All of the above suggest a pivotal signaling role for Mtl1 in maintaining correct cell homeostasis function in periods of glucose scarcity in budding yeast.