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1.
EMBO J ; 41(10): e109191, 2022 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-35451084

RESUMEN

The paralogous human proteins UPF3A and UPF3B are involved in recognizing mRNAs targeted by nonsense-mediated mRNA decay (NMD). UPF3B has been demonstrated to support NMD, presumably by bridging an exon junction complex (EJC) to the NMD factor UPF2. The role of UPF3A has been described either as a weak NMD activator or an NMD inhibitor. Here, we present a comprehensive functional analysis of UPF3A and UPF3B in human cells using combinatory experimental approaches. Overexpression or knockout of UPF3A as well as knockout of UPF3B did not substantially change global NMD activity. In contrast, the co-depletion of UPF3A and UPF3B resulted in a marked NMD inhibition and a transcriptome-wide upregulation of NMD substrates, demonstrating a functional redundancy between both NMD factors. In rescue experiments, UPF2 or EJC binding-deficient UPF3B largely retained NMD activity. However, combinations of different mutants, including deletion of the middle domain, showed additive or synergistic effects and therefore failed to maintain NMD. Collectively, UPF3A and UPF3B emerge as fault-tolerant, functionally redundant NMD activators in human cells.


Asunto(s)
Degradación de ARNm Mediada por Codón sin Sentido , Proteínas de Unión al ARN , Humanos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Transcriptoma
2.
Cell Mol Neurobiol ; 44(1): 59, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39150567

RESUMEN

Primary open-angle glaucoma (POAG) is subdivided depending on eye pressure. Patients with normal-tension glaucoma (NTG) have never had high intraocular pressure (IOP) measured while patients with ocular hypertension (OHT) have high eye pressure but no signs of glaucoma. Although IOP is considered to be a risk factor for all glaucoma patients, it is reasonable to assume that other risk factors such as inflammation play a role. We aimed to characterize the proteome and cytokine profile during hypoxia in plasma from patients with NTG (n = 10), OHT (n = 10), and controls (n = 10). Participants were exposed to hypoxia for two hours, followed by 30 min of normoxia. Samples were taken before ("baseline"), during ("hypoxia"), and after hypoxia ("recovery"). Proteomics based on liquid chromatography coupled with mass spectrometry (LC-MS) was performed. Cytokines were measured by Luminex assays. Bioinformatic analyses indicated the involvement of complement and coagulation cascades in NTG and OHT. Regulation of high-density lipoprotein 3 (HDL3) apolipoproteins suggested that changes in cholesterol metabolism are related to OHT. Hypoxia decreased the level of tumor necrosis factor-α (TNF-α) in OHT patients compared to controls. Circulating levels of interleukin-1ß (IL-1ß) and C-reactive protein (CRP) were decreased in NTG patients compared to controls during hypoxia. After recovery, plasma interleukin-6 (IL-6) was upregulated in patients with NTG and OHT. Current results indicate an enhanced systemic immune response in patients with NTG and OHT, which correlates with pathogenic events in glaucoma. Apolipoproteins may have anti-inflammatory effects, enabling OHT patients to withstand inflammation and development of glaucoma despite high IOP.


Asunto(s)
Citocinas , Glaucoma de Baja Tensión , Hipertensión Ocular , Proteómica , Humanos , Citocinas/sangre , Masculino , Femenino , Glaucoma de Baja Tensión/sangre , Proteómica/métodos , Hipertensión Ocular/sangre , Persona de Mediana Edad , Anciano , Presión Intraocular/fisiología
3.
Nucleic Acids Res ; 50(10): 5899-5918, 2022 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-35640609

RESUMEN

The exon junction complex (EJC) is an RNA-binding multi-protein complex with critical functions in post-transcriptional gene regulation. It is deposited on the mRNA during splicing and regulates diverse processes including pre-mRNA splicing and nonsense-mediated mRNA decay (NMD) via various interacting proteins. The peripheral EJC-binding protein RNPS1 was reported to serve two insufficiently characterized functions: suppressing mis-splicing of cryptic splice sites and activating NMD in the cytoplasm. The analysis of transcriptome-wide effects of EJC and RNPS1 knockdowns in different human cell lines supports the conclusion that RNPS1 can moderately influence NMD activity, but is not a globally essential NMD factor. However, numerous aberrant splicing events strongly suggest that the main function of RNPS1 is splicing regulation. Rescue analyses revealed that the RRM and C-terminal domain of RNPS1 both contribute partially to regulate RNPS1-dependent splicing events. We defined the RNPS1 core interactome using complementary immunoprecipitations and proximity labeling, which identified interactions with splicing-regulatory factors that are dependent on the C-terminus or the RRM domain of RNPS1. Thus, RNPS1 emerges as a multifunctional splicing regulator that promotes correct and efficient splicing of different vulnerable splicing events via the formation of diverse splicing-promoting complexes.


Asunto(s)
Ribonucleoproteínas , Transcriptoma , Exones , Humanos , Empalme del ARN/genética , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo
4.
J Am Soc Nephrol ; 34(5): 772-792, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36758124

RESUMEN

SIGNIFICANCE STATEMENT: AKI is a major clinical complication leading to high mortality, but intensive research over the past decades has not led to targeted preventive or therapeutic measures. In rodent models, caloric restriction (CR) and transient hypoxia significantly prevent AKI and a recent comparative transcriptome analysis of murine kidneys identified kynureninase (KYNU) as a shared downstream target. The present work shows that KYNU strongly contributes to CR-mediated protection as a key player in the de novo nicotinamide adenine dinucleotide biosynthesis pathway. Importantly, the link between CR and NAD+ biosynthesis could be recapitulated in a human cohort. BACKGROUND: Clinical practice lacks strategies to treat AKI. Interestingly, preconditioning by hypoxia and caloric restriction (CR) is highly protective in rodent AKI models. However, the underlying molecular mechanisms of this process are unknown. METHODS: Kynureninase (KYNU) knockout mice were generated by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and comparative transcriptome, proteome and metabolite analyses of murine kidneys pre- and post-ischemia-reperfusion injury in the context of CR or ad libitum diet were performed. In addition, acetyl-lysin enrichment and mass spectrometry were used to assess protein acetylation. RESULTS: We identified KYNU as a downstream target of CR and show that KYNU strongly contributes to the protective effect of CR. The KYNU-dependent de novo nicotinamide adenine dinucleotide (NAD+) biosynthesis pathway is necessary for CR-associated maintenance of NAD+ levels. This finding is associated with reduced protein acetylation in CR-treated animals, specifically affecting enzymes in energy metabolism. Importantly, the effect of CR on de novo NAD+ biosynthesis pathway metabolites can be recapitulated in humans. CONCLUSIONS: CR induces the de novo NAD+ synthesis pathway in the context of IRI and is essential for its full nephroprotective potential. Differential protein acetylation may be the molecular mechanism underlying the relationship of NAD+, CR, and nephroprotection.


Asunto(s)
Lesión Renal Aguda , Daño por Reperfusión , Humanos , Ratones , Animales , NAD/metabolismo , Restricción Calórica , Daño por Reperfusión/prevención & control , Lesión Renal Aguda/metabolismo , Hipoxia
5.
Basic Res Cardiol ; 118(1): 36, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37656254

RESUMEN

Cardiotoxicity is a major complication of anthracycline therapy that negatively impacts prognosis. Effective pharmacotherapies for prevention of anthracycline-induced cardiomyopathy (AICM) are currently lacking. Increased plasma levels of the neutrophil-derived enzyme myeloperoxidase (MPO) predict occurrence of AICM in humans. We hypothesized that MPO release causally contributes to AICM. Mice intravenously injected with the anthracycline doxorubicin (DOX) exhibited higher neutrophil counts and MPO levels in the circulation and cardiac tissue compared to saline (NaCl)-treated controls. Neutrophil-like HL-60 cells exhibited increased MPO release upon exposition to DOX. DOX induced extensive nitrosative stress in cardiac tissue alongside with increased carbonylation of sarcomeric proteins in wildtype but not in Mpo-/- mice. Accordingly, co-treatment of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with DOX and MPO aggravated loss of hiPSC-CM-contractility compared to DOX treatment alone. DOX-treated animals exhibited pronounced cardiac apoptosis and inflammation, which was attenuated in MPO-deficient animals. Finally, genetic MPO deficiency and pharmacological MPO inhibition protected mice from the development of AICM. The anticancer efficacy of DOX was unaffected by MPO deficiency. Herein we identify MPO as a critical mediator of AICM. We demonstrate that DOX induces cardiac neutrophil infiltration and release of MPO, which directly impairs cardiac contractility through promoting oxidation of sarcomeric proteins, cardiac inflammation and cardiomyocyte apoptosis. MPO thus emerges as a promising pharmacological target for prevention of AICM.


Asunto(s)
Cardiomiopatías , Células Madre Pluripotentes Inducidas , Peroxidasa , Animales , Humanos , Ratones , Antraciclinas/toxicidad , Cardiomiopatías/inducido químicamente , Cardiomiopatías/prevención & control , Doxorrubicina/toxicidad , Inflamación , Peroxidasa/genética
6.
Int J Mol Sci ; 19(3)2018 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-29518953

RESUMEN

Non-healing wounds continue to be a clinical challenge for patients and medical staff. These wounds have a heterogeneous etiology, including diabetes and surgical trauma wounds. It is therefore important to decipher molecular signatures that reflect the macroscopic process of wound healing. To this end, we collected wound sponge dressings routinely used in vacuum assisted therapy after surgical trauma to generate wound-derived protein profiles via global mass spectrometry. We confidently identified 311 proteins in exudates. Among them were expected targets belonging to the immunoglobulin superfamily, complement, and skin-derived proteins, such as keratins. Next to several S100 proteins, chaperones, heat shock proteins, and immune modulators, the exudates presented a number of redox proteins as well as a discrete neutrophil proteomic signature, including for example cathepsin G, elastase, myeloperoxidase, CD66c, and lipocalin 2. We mapped over 200 post-translational modifications (PTMs; cysteine/methionine oxidation, tyrosine nitration, cysteine trioxidation) to the proteomic profile, for example, in peroxiredoxin 1. Investigating manually collected exudates, we confirmed presence of neutrophils and their products, such as microparticles and fragments containing myeloperoxidase and DNA. These data confirmed known and identified less known wound proteins and their PTMs, which may serve as resource for future studies on human wound healing.


Asunto(s)
Neutrófilos/metabolismo , Proteoma , Proteómica , Herida Quirúrgica/metabolismo , Biomarcadores , Biología Computacional/métodos , Femenino , Citometría de Flujo , Humanos , Masculino , Espectrometría de Masas , Persona de Mediana Edad , Proteómica/métodos , Herida Quirúrgica/patología , Factores de Tiempo , Cicatrización de Heridas
7.
Appl Environ Microbiol ; 82(7): 2031-2038, 2016 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-26801572

RESUMEN

Novel decontamination technologies, including cold low-pressure plasma and blue light (400 nm), are promising alternatives to conventional surface decontamination methods. However, the standardization of the assessment of such sterilization processes remains to be accomplished. Bacterial endospores of the genera Bacillus and Geobacillus are frequently used as biological indicators (BIs) of sterility. Ensuring standardized and reproducible BIs for reliable testing procedures is a significant problem in industrial settings. In this study, an electrically driven spray deposition device was developed, allowing fast, reproducible, and homogeneous preparation of Bacillus subtilis 168 spore monolayers on glass surfaces. A detailed description of the structural design as well as the operating principle of the spraying device is given. The reproducible formation of spore monolayers of up to 5 × 10(7) spores per sample was verified by scanning electron microscopy. Surface inactivation studies revealed that monolayered spores were inactivated by UV-C (254 nm), low-pressure argon plasma (500 W, 10 Pa, 100 standard cubic cm per min), and blue light (400 nm) significantly faster than multilayered spores were. We have thus succeeded in the uniform preparation of reproducible, highly concentrated spore monolayers with the potential to generate BIs for a variety of nonpenetrating surface decontamination techniques.


Asunto(s)
Bacillus subtilis/efectos de la radiación , Descontaminación/métodos , Esporas Bacterianas/efectos de la radiación , Bacillus subtilis/crecimiento & desarrollo , Descontaminación/instrumentación , Presión , Esporas Bacterianas/crecimiento & desarrollo , Rayos Ultravioleta
8.
Appl Microbiol Biotechnol ; 98(14): 6205-13, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24841116

RESUMEN

Plasma is ionized gas, which is found in various forms in nature and can also be generated artificially. A variety of cold atmospheric-pressure plasmas are currently being investigated for their clinical utility, and first studies reporting on the treatment of patients showed that plasma treatment may support the wound healing process. One of the benefits of plasma treatment is the effective inactivation of bacteria including tenacious pathogens such as Pseudomonas aeruginosa or multiresistant Staphylococcus aureus (MRSA). Neither the molecular mechanisms promoting wound healing nor those underlying bacterial inactivation are fully understood yet. The review has a focus on plasma jets, a particular type of cold atmospheric-pressure plasma sources featuring an indirect treatment whereby the treated substrates do not come into contact with the plasma directly but are exposed to the plasma-emitted reactive species and photons. Such plasma jets are being employed as tools in basic research regarding the effects of plasmas on biological samples. This review provides a brief overview on the recent clinical investigations into the benefits of cold atmospheric-pressure plasmas. It then describes our current understanding of the mechanisms leading to bacterial inactivation and inactivation of biomacromolecules gained by employing plasma jets.


Asunto(s)
Bacterias/efectos de los fármacos , Desinfectantes/farmacología , Sustancias Macromoleculares/antagonistas & inhibidores , Gases em Plasma/farmacología , Presión Atmosférica , Viabilidad Microbiana/efectos de los fármacos
9.
Nat Commun ; 15(1): 6879, 2024 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-39128917

RESUMEN

Mechanical stress during muscle contraction is a constant threat to proteome integrity. However, there is a lack of experimental systems to identify critical proteostasis regulators under mechanical stress conditions. Here, we present the transgenic Caenorhabditis elegans model OptIMMuS (Optogenetic Induction of Mechanical Muscle Stress) to study changes in the proteostasis network associated with mechanical forces. Repeated blue light exposure of a muscle-expressed Chlamydomonas rheinhardii channelrhodopsin-2 variant results in sustained muscle contraction and mechanical stress. Using OptIMMuS, combined with proximity labeling and mass spectrometry, we identify regulators that cooperate with the myosin-directed chaperone UNC-45 in muscle proteostasis. One of these is the TRIM E3 ligase NHL-1, which interacts with UNC-45 and muscle myosin in genetic epistasis and co-immunoprecipitation experiments. We provide evidence that the ubiquitylation activity of NHL-1 regulates myosin levels and functionality under mechanical stress. In the future, OptIMMuS will help to identify muscle-specific proteostasis regulators of therapeutic relevance.


Asunto(s)
Animales Modificados Genéticamente , Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Optogenética , Proteostasis , Estrés Mecánico , Ubiquitina-Proteína Ligasas , Ubiquitinación , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Animales , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Miosinas/metabolismo , Miosinas/genética , Contracción Muscular/fisiología , Músculos/metabolismo , Chaperonas Moleculares
10.
Cell Rep ; 43(7): 114374, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-38900641

RESUMEN

Morphological studies of skeletal muscle tissue provide insights into the architecture of muscle fibers, the surrounding cells, and the extracellular matrix (ECM). However, a spatial proteomics analysis of the skeletal muscle including the muscle-tendon transition zone is lacking. Here, we prepare cryotome muscle sections of the mouse soleus muscle and measure each slice using short liquid chromatography-mass spectrometry (LC-MS) gradients. We generate 3,000 high-resolution protein profiles that serve as the basis for a network analysis to reveal the complex architecture of the muscle-tendon junction. Among the protein profiles that increase from muscle to tendon, we find proteins related to neuronal activity, fatty acid biosynthesis, and the renin-angiotensin system (RAS). Blocking the RAS in cultured mouse tenocytes using losartan reduces the ECM synthesis. Overall, our analysis of thin cryotome sections provides a spatial proteome of skeletal muscle and reveals that the RAS acts as an additional regulator of the matrix within muscle-tendon junctions.


Asunto(s)
Músculo Esquelético , Proteómica , Tendones , Animales , Proteómica/métodos , Músculo Esquelético/metabolismo , Tendones/metabolismo , Ratones , Matriz Extracelular/metabolismo , Masculino , Ratones Endogámicos C57BL , Sistema Renina-Angiotensina/fisiología , Adaptación Fisiológica , Proteoma/metabolismo , Losartán/farmacología
11.
iScience ; 27(2): 108898, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38322992

RESUMEN

Myeloperoxidase (MPO) is an enzyme that functions in host defense. MPO is released into the vascular lumen by neutrophils during inflammation and may adhere and subsequently penetrate endothelial cells (ECs) coating vascular walls. We show that MPO enters the nucleus of ECs and binds chromatin independently of its enzymatic activity. MPO drives chromatin decondensation at its binding sites and enhances condensation at neighboring regions. It binds loci relevant for endothelial-to-mesenchymal transition (EndMT) and affects the migratory potential of ECs. Finally, MPO interacts with the RNA-binding factor ILF3 thereby affecting its relative abundance between cytoplasm and nucleus. This interaction leads to change in stability of ILF3-bound transcripts. MPO-knockout mice exhibit reduced number of ECs at scar sites following myocardial infarction, indicating reduced neovascularization. In summary, we describe a non-enzymatic role for MPO in coordinating EndMT and controlling the fate of endothelial cells through direct chromatin binding and association with co-factors.

12.
Sci Adv ; 9(13): eade1792, 2023 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-36989351

RESUMEN

The blueprints of developing organs are preset at the early stages of embryogenesis. Transcriptional and epigenetic mechanisms are proposed to preset developmental trajectories. However, we reveal that the competence for the future cardiac fate of human embryonic stem cells (hESCs) is preset in pluripotency by a specialized mRNA translation circuit controlled by RBPMS. RBPMS is recruited to active ribosomes in hESCs to control the translation of essential factors needed for cardiac commitment program, including Wingless/Integrated (WNT) signaling. Consequently, RBPMS loss specifically and severely impedes cardiac mesoderm specification, leading to patterning and morphogenetic defects in human cardiac organoids. Mechanistically, RBPMS specializes mRNA translation, selectively via 3'UTR binding and globally by promoting translation initiation. Accordingly, RBPMS loss causes translation initiation defects highlighted by aberrant retention of the EIF3 complex and depletion of EIF5A from mRNAs, thereby abrogating ribosome recruitment. We demonstrate how future fate trajectories are programmed during embryogenesis by specialized mRNA translation.


Asunto(s)
Células Madre Embrionarias Humanas , Humanos , Células Madre Embrionarias Humanas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ribosomas/metabolismo , Corazón , Transducción de Señal , Proteínas de Unión al ARN/metabolismo
13.
Nutr Metab (Lond) ; 20(1): 8, 2023 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-36755289

RESUMEN

The multitude of obesogenic diets used in rodent studies can hardly be overviewed. Since standardization is missing and assuming that individual compositions provoke individual effects, the choice of quality, quantity and combination of diet ingredients seems to be crucial for the outcome and interpretation of obesity studies. Therefore, the present study was conducted to compare the individual effects of three commonly used obesogenic diets, mainly differing in sugar and fat content. Besides basic phenotypic and metabolic characterization, one main aspect was a comparative liver proteome analysis. As expected, the obtained results picture differentiated consequences mainly depending on fat source and/or fat- and sugar quantity. By confirming the general presumption that the choice of nutritional composition is a pivotal factor, the present findings demonstrate that a conscious selection is indispensable for obtaining reliable and sound results in obesity research. In conclusion, we strongly recommend a careful selection of the appropriate diet in advance of a new experiment, taking into account the specific research question.

14.
Nat Aging ; 3(11): 1345-1357, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37783816

RESUMEN

In humans, aggregation of polyglutamine repeat (polyQ) proteins causes disorders such as Huntington's disease. Although plants express hundreds of polyQ-containing proteins, no pathologies arising from polyQ aggregation have been reported. To investigate this phenomenon, we expressed an aggregation-prone fragment of human huntingtin (HTT) with an expanded polyQ stretch (Q69) in Arabidopsis thaliana plants. In contrast to animal models, we find that Arabidopsis sp. suppresses Q69 aggregation through chloroplast proteostasis. Inhibition of chloroplast proteostasis diminishes the capacity of plants to prevent cytosolic Q69 aggregation. Moreover, endogenous polyQ-containing proteins also aggregate on chloroplast dysfunction. We find that Q69 interacts with the chloroplast stromal processing peptidase (SPP). Synthetic Arabidopsis SPP prevents polyQ-expanded HTT aggregation in human cells. Likewise, ectopic SPP expression in Caenorhabditis elegans reduces neuronal Q67 aggregation and subsequent neurotoxicity. Our findings suggest that synthetic plant proteins, such as SPP, hold therapeutic potential for polyQ disorders and other age-related diseases involving protein aggregation.


Asunto(s)
Arabidopsis , Agregado de Proteínas , Animales , Humanos , Arabidopsis/genética , Péptidos/genética , Neuronas/metabolismo , Caenorhabditis elegans/genética
15.
J Bacteriol ; 194(8): 1849-59, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22287514

RESUMEN

The copper-regulated Rhodobacter capsulatus cutO (multicopper oxidase) gene confers copper tolerance and is carried in the tricistronic orf635-cutO-cutR operon. Transcription of cutO strictly depends on the promoter upstream of orf635, as demonstrated by lacZ reporter fusions to nested promoter fragments. Remarkably, orf635 expression was not affected by copper availability, whereas cutO and cutR were expressed only in the presence of copper. Differential regulation was abolished by site-directed mutations within the orf635-cutO intergenic region, suggesting that this region encodes a copper-responsive mRNA element. Bioinformatic predictions and RNA structure probing experiments revealed an intergenic stem-loop structure as the candidate mRNA element. This is the first posttranscriptional copper response mechanism reported in bacteria.


Asunto(s)
Proteínas Bacterianas/metabolismo , Cobre/farmacología , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Oxidorreductasas/metabolismo , Rhodobacter capsulatus/enzimología , Transcripción Genética/efectos de los fármacos , Proteínas Bacterianas/genética , ADN Intergénico , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Operón , Oxidorreductasas/genética , Regiones Promotoras Genéticas , Interferencia de ARN , ARN Bacteriano , Rhodobacter capsulatus/genética , Rhodobacter capsulatus/metabolismo
16.
Biometals ; 25(5): 995-1008, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22767205

RESUMEN

To identify copper homeostasis genes in Rhodobacter capsulatus, we performed random transposon Tn5 mutagenesis. Screening of more than 10,000 Tn5 mutants identified tellurite resistance gene trgB as a so far unrecognized major copper tolerance determinant. The trgB gene is flanked by tellurite resistance gene trgA and cysteine synthase gene cysK2. While growth of trgA mutants was only moderately restricted by tellurite, trgB and cysK2 mutants were severely affected by tellurite, which implies that viability under tellurite stress requires increased cysteine levels. Mutational analyses revealed that trgB was the only gene in this chromosomal region conferring cross-tolerance towards copper. Expression of the monocistronic trgB gene required promoter elements overlapping the trgA coding region as shown by nested deletions. Neither copper nor tellurite affected trgB transcription as demonstrated by reverse transcriptase PCR and trgB-lacZ fusions. Addition of tellurite or copper gave rise to increased cellular tellurium and copper concentrations, respectively, as determined by inductively coupled plasma-optical emission spectroscopy. By contrast, cellular iron concentrations remained fairly constant irrespective of tellurite or copper addition. This is the first study demonstrating a direct link between copper and tellurite response in bacteria.


Asunto(s)
Cobre/toxicidad , Rhodobacter capsulatus/efectos de los fármacos , Rhodobacter capsulatus/genética , Telurio/toxicidad , Cobre/metabolismo , Cisteína Sintasa/genética , Farmacorresistencia Bacteriana/genética , Genes Bacterianos , Hierro/metabolismo , Viabilidad Microbiana/efectos de los fármacos , Viabilidad Microbiana/genética , Mutagénesis Insercional , Mutación , Rhodobacter capsulatus/metabolismo , Telurio/metabolismo
17.
Transl Res ; 244: 32-46, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35189406

RESUMEN

Caloric Restriction (CR) extends lifespan and augments cellular stress-resistance from yeast to primates, making CR an attractive strategy for organ protection in the clinic. Translation of CR to patients is complex, due to problems regarding adherence, feasibility, and safety concerns in frail patients. Novel tailored dietary regimens, which modulate the dietary composition of macro- and micronutrients rather than reducing calorie intake promise similar protective effects and increased translatability. However, a direct head-to-head comparison to identify the most potent approach for organ protection, as well as overlapping metabolic consequences have not been performed. We systematically analyzed six dietary preconditioning protocols - fasting mimicking diet (FMD), ketogenic diet (KD), dietary restriction of branched chained amino acids (BCAA), two dietary regimens restricting sulfur-containing amino acids (SR80/100) and CR - in a rodent model of renal ischemia-reperfusion injury (IRI) to quantify diet-induced resilience in kidneys. Of the administered diets, FMD, SR80/100 and CR efficiently protect from kidney damage after IRI. Interestingly, these approaches show overlapping changes in oxidative and hydrogen sulfide (H2S)-dependent cysteine catabolism as a potential common mechanism of organ protection.


Asunto(s)
Cisteína , Daño por Reperfusión , Animales , Restricción Calórica , Dieta , Humanos , Longevidad
18.
Adv Sci (Weinh) ; 8(10): 2003395, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-34026437

RESUMEN

Reactive oxygen species (ROS/RNS) are produced during inflammation and elicit protein modifications, but the immunological consequences are largely unknown. Gas plasma technology capable of generating an unmatched variety of ROS/RNS is deployed to mimic inflammation and study the significance of ROS/RNS modifications using the model protein chicken ovalbumin (Ova vs oxOva). Dynamic light scattering and circular dichroism spectroscopy reveal structural modifications in oxOva compared to Ova. T cells from Ova-specific OT-II but not from C57BL/6 or SKH-1 wild type mice presents enhanced activation after Ova addition. OxOva exacerbates this activation when administered ex vivo or in vivo, along with an increased interferon-gamma production, a known anti-melanoma agent. OxOva vaccination of wild type mice followed by inoculation of syngeneic B16F10 Ova-expressing melanoma cells shows enhanced T cell number and activation, decreased tumor burden, and elevated numbers of antigen-presenting cells when compared to their Ova-vaccinated counterparts. Analysis of oxOva using mass spectrometry identifies three hot spots regions rich in oxidative modifications that are associated with the increased T cell activation. Using Ova as a model protein, the findings suggest an immunomodulating role of multi-ROS/RNS modifications that may spur novel research lines in inflammation research and for vaccination strategies in oncology.


Asunto(s)
Vacunas contra el Cáncer/inmunología , Inflamación/inmunología , Melanoma/tratamiento farmacológico , Ovalbúmina/inmunología , Gases em Plasma/química , Linfocitos T/inmunología , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Inflamación/metabolismo , Activación de Linfocitos/inmunología , Melanoma/inmunología , Melanoma/metabolismo , Ratones , Ratones Endogámicos C57BL , Ovalbúmina/química , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo
19.
PLoS One ; 16(3): e0247125, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33647028

RESUMEN

Effective control of infection by human immunodeficiency virus type 1 (HIV-1), the causative agent of the acquired immunodeficiency syndrome (AIDS), requires continuous and life-long use of anti-retroviral therapy (ART) by people living with HIV-1 (PLWH). In the absence of ART, HIV-1 reemergence from latently infected cells is ineffectively suppressed due to suboptimal innate and cytotoxic T lymphocyte responses. However, ART-free control of HIV-1 infection may be possible if the inherent immunological deficiencies can be reversed or restored. Herein we present a novel approach for modulating the immune response to HIV-1 that involves the use of non-thermal plasma (NTP), which is an ionized gas containing various reactive oxygen and nitrogen species (RONS). J-Lat cells were used as a model of latent HIV-1 infection to assess the effects of NTP application on viral latency and the expression of pro-phagocytic and pro-chemotactic damage-associated molecular patterns (DAMPs). Exposure of J-Lat cells to NTP resulted in stimulation of HIV-1 gene expression, indicating a role in latency reversal, a necessary first step in inducing adaptive immune responses to viral antigens. This was accompanied by the release of pro-inflammatory cytokines and chemokines including interleukin-1ß (IL-1ß) and interferon-γ (IFN-γ); the display of pro-phagocytic markers calreticulin (CRT), heat shock proteins (HSP) 70 and 90; and a correlated increase in macrophage phagocytosis of NTP-exposed J-Lat cells. In addition, modulation of surface molecules that promote or inhibit antigen presentation was also observed, along with an altered array of displayed peptides on MHC I, further suggesting methods by which NTP may modify recognition and targeting of cells in latent HIV-1 infection. These studies represent early progress toward an effective NTP-based ex vivo immunotherapy to resolve the dysfunctions of the immune system that enable HIV-1 persistence in PLWH.


Asunto(s)
Infecciones por VIH/tratamiento farmacológico , Inmunidad/fisiología , Gases em Plasma/uso terapéutico , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Antirretrovirales/uso terapéutico , Linfocitos T CD4-Positivos/inmunología , VIH-1/patogenicidad , Humanos , Inmunidad/efectos de los fármacos , Células Jurkat , Activación de Linfocitos/efectos de los fármacos , Gases em Plasma/metabolismo , Células THP-1 , Activación Viral/efectos de los fármacos , Latencia del Virus/efectos de los fármacos , Replicación Viral/efectos de los fármacos
20.
Nutrients ; 13(11)2021 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-34835991

RESUMEN

Maternal obesity greatly affects next generations, elevating obesity risk in the offspring through perinatal programming and flawed maternal and newborn nutrition. The exact underlying mechanisms are poorly understood. Interleukin-6 (IL-6) mediates its effects through a membrane-bound receptor or by trans-signaling (tS), which can be inhibited by the soluble form of the co-receptor gp130 (sgp130). As IL-6 tS mediates western-style diet (WSD) effects via chronic low-grade inflammation (LGI) and LGI is an important mediator in brain-adipose tissue communication, this study aims at determining the effects of maternal obesity in a transgenic mouse model of brain-restricted IL-6tS inhibition (GFAPsgp130) on offspring's short- and long-term body composition and epigonadal white adipose tissue (egWAT) metabolism. Female wild type (WT) or transgenic mice were fed either standard diet (SD) or WSD pregestationally, during gestation, and lactation. Male offspring received SD from postnatal day (P)21 to P56 and were metabolically challenged with WSD from P56 to P120. At P21, offspring from WT and transgenic dams that were fed WSD displayed increased body weight and egWAT mass, while glucose tolerance testing showed the strongest impairment in GFAPsgp130WSD offspring. Simultaneously, egWAT proteome reveals a characteristic egWAT expression pattern in offspring as a result of maternal conditions. IL-6tS inhibition in transgenic mice was in tendency associated with lower body weight in dams on SD and their respective offspring but blunted by the WSD. In conclusion, maternal nutrition affects offspring's body weight and egWAT metabolism predominantly independent of IL-6tS inhibition, emphasizing the importance of maternal and newborn nutrition for long-term offspring health.


Asunto(s)
Encéfalo/metabolismo , Interleucina-6/metabolismo , Obesidad Materna/metabolismo , Transducción de Señal , Adipoquinas/genética , Adipoquinas/metabolismo , Tejido Adiposo Blanco/metabolismo , Animales , Biomarcadores/sangre , Peso Corporal , Dieta , Dieta Occidental , Femenino , Prueba de Tolerancia a la Glucosa , Insulina/metabolismo , Masculino , Ratones Endogámicos C57BL , Obesidad Materna/sangre , Fenotipo , Embarazo , Proteoma/metabolismo , Proteómica , ARN Mensajero/genética , ARN Mensajero/metabolismo
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