RESUMEN
Harmful drinking is associated with significant negative health and social outcomes, but drinkers are reticent to recognise personal drinking problems, hindering natural recovery or help-seeking. Recent evidence suggests that social identity as a drinker is associated with various drinking-related factors but has not been examined in relation to likelihood of problem recognition. In a group of ninety-six harmful drinkers (61 females, M age = 34 years) we explored how identity components associated with ingroup self-investment and ingroup self-definition in combination with implicit identity as a drinker accounted for degrees of problem recognition. In addition to demographic information, addiction experience and drinking behaviour (AUDIT), respondents completed measures of ingroup self-investment (identity centrality, solidarity, and satisfaction), ingroup self-definition (ingroup homogeneity and self-stereotyping), a "self as drinker" identity implicit association test and problem recognition (four items from the Stages of Change Readiness and Treatment Eagerness Scale). After controlling for possible covariates (age, gender and alcohol addiction experience) increased problem recognition was accounted for by explicit and not implicit identity components. More specifically, increasing perceived chronic saliency of one's drinker identity (self-investment in the drinker ingroup) and not an implicit association between the self and being a drinker was related to increased likelihood of problem recognition. This suggests that how chronically and explicitly accessible the identity of the drinker is for individuals might operate to stimulate the willingness or motivation to recognise potential drinking related harm.
Asunto(s)
Motivación , Identificación Social , Humanos , Femenino , Masculino , Adulto , Persona de Mediana Edad , Alcoholismo/psicología , Consumo de Bebidas Alcohólicas/psicología , Encuestas y CuestionariosRESUMEN
Despite its inclusion in Sustainable Development Goal 5 to end all harmful gendered practices by 2030, child, early and forced marriages continue to be a pervasive problem globally. While there is consistent evidence on the physical health consequences of child marriage, there is a lack of evidence and inquiry into the mental health consequence. We completed a change-oriented Delphi study to establish consensus on priority areas of research and intervention in relation to the mental health consequences of child, early and forced marriages. Invited experts (n = 11), survivors (n = 27) and professionals (n = 30) participated in our Delphi. Four rounds of data collection included: a blended in-person and online workshop with invited experts, an online mixed-methods questionnaire, focus groups in Zimbabwe with women who are survivors of child marriage and a repeat questionnaire sent to the first round of experts. Quantitative data were analysed using descriptive statistics and ranking methods, consistent with other Delphi studies. Qualitative data were analysed using thematic network analysis. Findings coalesced around three areas: perspectives on the relationship between mental health and child marriage, policy actions and treatment-driven solutions. Consensus was reached on 16 items across these areas which included the need to prioritize psychosocial and social interventions to improve mental health outcomes for women and girls in existing marriages. They also called for new approaches to advocacy to drive awareness of this issue in policy circles. Implications for future practice are discussed.
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Matrimonio , Salud Mental , Humanos , Femenino , Niño , Grupos Focales , Identidad de Género , Encuestas y CuestionariosRESUMEN
BACKGROUND: Multiple studies focus on the experiences of visiting students from high resource regions that participated in clinical placements in lower resource countries but less focus on the experiences of the educators accompanying students. AIM: The purpose of this study was to explore the experiences of educators during an international clinical placement of nursing students in a country in West Africa. METHODS: We implemented a focussed ethnographic design. We purposively sampled educators who accompanied students on an international clinical placement. Data collection from 2018 to 2019 consisted of in-depth individual interviews. We utilized Roper and Shapira's (2000, 10.4135/9781483328294.) data analysis process, which includes coding keywords, identifying patterns and theorizing. FINDINGS: Three themes emerged from the data: rewards in accompanying students, challenges experienced and the need for mentoring and continuous support. Educators found it rewarding to see growth in students, how students developed as global citizens, how students developed critical thinking and problem-solving skills and create lifelong friendships. CONCLUSION: Educators who accompany nursing students to international clinical placement experience valuable learning and challenging issues. Educators must navigate, support and advance student learning when on an international placement. It is crucial to have adequate institutional support from both the home and host country.
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Bachillerato en Enfermería , Estudiantes de Enfermería , Docentes de Enfermería , Humanos , Aprendizaje , Mentores , Investigación Cualitativa , EnseñanzaRESUMEN
OBJECTIVES: The first UK national lockdown began on 23 March 2020, in response to the COVID-19 pandemic, and led to reduced STI/HIV service provision in the UK. We investigated sexual behaviour, use and need for sexual healthcare during the pandemic. METHODS: Participants (N=2018), including men (cis/transgender), transwomen and gender-diverse people reporting sex with another man (cis/transgender) or non-binary person assigned male at birth, completed an online cross-sectional survey (23 June 2020-14 July 2020), in response to adverts on social media and dating apps.Sexual behaviour, service use and unmet need for STI testing (any new male and/or multiple condomless anal sex (CAS) partners without STI testing) in the 3 months since lockdown began were examined and compared using multivariable analyses with an equivalent 3-month period in a 2017 survey (N=1918), conducted by the same research team. RESULTS: Since lockdown began, 36.7% of participants reported one or more new partners, 17.3% reported CAS with multiple partners, 29.7% HIV testing (among 1815 of unknown/negative status), 24.9% STI testing and 15.4% using pre-exposure prophylaxis (PrEP).Since lockdown began, 25.3% of participants had unmet need for STI testing. This was more likely among Asian versus white participants (adjusted OR (aOR)=1.76, (1.14 to 2.72), p=0.01); for participants living in Scotland (aOR=2.02, (1.40 to 2.91), p<0.001) or Northern Ireland (aOR=1.93, (1.02-3.63), p=0.04) versus England; and for those living with HIV (aOR=1.83, (1.32 to 2.53), p<0.001).Compared to 2017, the equivalent 2020 subsample were less likely to report new male partners (46.8% vs 71.1%, p<0.001), multiple CAS partners (20.3% vs 30.8%, p<0.001) and have unmet need for STI testing (32.8% vs 42.5%, p<0.001) in the past 3 months. CONCLUSIONS: We found potential for ongoing STI/HIV transmission among men who have sex with men during the initial UK lockdown, despite reduced sexual activity, and inequalities in service access. These findings will support public health planning to mitigate health risks during and after the COVID-19 response.
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COVID-19 , Infecciones por VIH , Minorías Sexuales y de Género , Enfermedades de Transmisión Sexual , COVID-19/epidemiología , COVID-19/prevención & control , Control de Enfermedades Transmisibles , Estudios Transversales , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Homosexualidad Masculina , Humanos , Recién Nacido , Masculino , Pandemias/prevención & control , Aceptación de la Atención de Salud , Salud Pública , Conducta Sexual , Enfermedades de Transmisión Sexual/diagnóstico , Enfermedades de Transmisión Sexual/epidemiología , Enfermedades de Transmisión Sexual/prevención & control , Reino Unido/epidemiologíaRESUMEN
Fast identification of microbial species in clinical samples is essential to provide an appropriate antibiotherapy to the patient and reduce the prescription of broad-spectrum antimicrobials leading to antibioresistances. MALDI-TOF-MS technology has become a tool of choice for microbial identification but has several drawbacks: it requires a long step of bacterial culture before analysis (≥24 h), has a low specificity and is not quantitative. We developed a new strategy for identifying bacterial species in urine using specific LC-MS/MS peptidic signatures. In the first training step, libraries of peptides are obtained on pure bacterial colonies in DDA mode, their detection in urine is then verified in DIA mode, followed by the use of machine learning classifiers (NaiveBayes, BayesNet and Hoeffding tree) to define a peptidic signature to distinguish each bacterial species from the others. Then, in the second step, this signature is monitored in unknown urine samples using targeted proteomics. This method, allowing bacterial identification in less than 4 h, has been applied to fifteen species representing 84% of all Urinary Tract Infections. More than 31,000 peptides in 190 samples were quantified by DIA and classified by machine learning to determine an 82 peptides signature and build a prediction model. This signature was validated for its use in routine using Parallel Reaction Monitoring on two different instruments. Linearity and reproducibility of the method were demonstrated as well as its accuracy on donor specimens. Within 4h and without bacterial culture, our method was able to predict the predominant bacteria infecting a sample in 97% of cases and 100% above the standard threshold. This work demonstrates the efficiency of our method for the rapid and specific identification of the bacterial species causing UTI and could be extended in the future to other biological specimens and to bacteria having specific virulence or resistance factors.
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Bacterias/clasificación , Proteínas Bacterianas/orina , Bacteriuria/orina , Cromatografía Liquida/métodos , Aprendizaje Automático , Espectrometría de Masas en Tándem/métodos , Bacterias/aislamiento & purificación , Humanos , Péptidos/orina , Proteómica , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Werner syndrome (WS) is a premature aging disorder caused by mutations in a protein containing both a DNA exonuclease and DNA helicase domain. Mice lacking the helicase domain of the Wrn protein orthologue exhibit transcriptomic and metabolic alterations, some of which are reversed by vitamin C. Recent studies on these animals indicated that the mutant protein is associated with enriched endoplasmic reticulum (ER) fractions of tissues resulting in an ER stress response. In this study, we identified proteins that exhibit actual level differences in the ER enriched fraction between the liver of wild type and Wrn mutant mice using quantitative proteomic profiling with label-free Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Multiple Reaction Monitoring (MRM) and immunoblotting were performed to validate findings in a secondary independent cohort of wild type and Wrn mutant mice. DAVID 6.7 (NIH) was used for functional annotation analysis and indicated that the identified proteins exhibiting level changes between untreated wild type, Wrn mutant, and vitamin C treated Wrn mutant mice (ANOVA P-value < 0.05) were involved in fatty acid and steroid metabolism pathways (Bonferroni P-value = 0.0137). Finally, when we compared the transcriptomic and the proteomic data of our mouse cohorts only ~7% of the altered mRNA profiles encoding for ER gene products were consistent with their corresponding protein profiles measured by the label-free quantification methods. These results suggest that a great number of ER gene products are regulated at the post-transcriptional level in the liver of Wrn mutant mice exhibiting an ER stress response.
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Ácido Ascórbico/metabolismo , Retículo Endoplásmico/metabolismo , Metabolismo de los Lípidos , Hígado/metabolismo , Helicasa del Síndrome de Werner/genética , Síndrome de Werner/genética , Animales , Retículo Endoplásmico/genética , Estrés del Retículo Endoplásmico , Ratones , Ratones Endogámicos C57BL , Mutación , Proteoma/genética , Proteoma/metabolismo , Proteómica , Transcriptoma , Síndrome de Werner/metabolismo , Helicasa del Síndrome de Werner/metabolismoRESUMEN
This study aimed at establishing a sensitive multiple reaction monitoring-mass spectrometry (MRM-MS) method for the quantification of the drug metabolizing cytochrome P450 (CYP)3A4 enzyme in human liver homogenates. Liver samples were subjected to trypsin digestion. MRM-MS analyses were performed using three transitions optimized on one purified synthetic peptide unique to CYP3A4 and the standardizing protein, calnexin. Coefficient of variations for the precision and reproducibility of the MRM-MS measurement were also determined. The method was applied to liver samples from ten non-cholestatic donors and 34 cholestatic patients with primary biliary cholangitis (n = 12; PBC), primary sclerosing cholangitis (n = 10; PSC) or alcoholic liver disease (n = 12; ALD). The established method presented high sensitivity with limit of detection lower than 5 fmol, and was successfully applied for the absolute and relative quantification of CYP3A4 in both whole liver homogenate and microsomal fractions. When all groups were analyzed together, a significant correlation was observed for the MRM-based CYP3A4 protein quantification in homogenates and microsomes (r = 0.49, p < 0.001). No statistically significant difference was detected between CYP3A4 levels in PSC, PBC, ALD and control samples. Finally, the MRM-MS quantification of CYP3A4 in homogenates also correlated (r = 0.44; p < 0.05) with the level of enzyme activity in the same samples, as determined by measuring the chenodeoxycholic to hyocholic acid conversion. The established method provides a sensitive tool to evaluate the CYP3A4 protein in human liver homogenates from patients with normal or chronic/severe hepatic injury.
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Citocromo P-450 CYP3A/genética , Microsomas Hepáticos/química , Proteómica , Citocromo P-450 CYP3A/clasificación , Sistema Enzimático del Citocromo P-450/genética , Humanos , Hígado/lesiones , Hígado/metabolismo , Microsomas Hepáticos/metabolismo , Espectrometría de Masas en TándemRESUMEN
Insulin resistance (IR) is associated with increased production of triglyceride-rich lipoproteins of intestinal origin. In order to assess whether insulin resistance affects the proteins involved in lipid metabolism, we used two mass spectrometry based quantitative proteomics techniques to compare the intestinal proteome of 14 IR patients to that of 15 insulin sensitive (IS) control patients matched for age and waist circumference. A total of 3886 proteins were identified by the iTRAQ (Isobaric Tags for Relative and Absolute Quantitation) mass spectrometry approach and 2290 by the SWATH-MS strategy (Serial Window Acquisition of Theoretical Spectra). Using these two methods, 208 common proteins were identified with a confidence corresponding to FDR < 1%, and quantified with p-value < 0.05. The quantification of those 208 proteins has a Pearson correlation coefficient (r2) of 0.728 across the two techniques. Gene Ontology analyses of the differentially expressed proteins revealed that annotations related to lipid metabolic process and oxidation reduction process are overly represented in the set of under-expressed proteins in IR subjects. Furthermore, both methods quantified proteins of relevance to IR. These data also showed that SWATH-MS is a promising and compelling alternative to iTRAQ for protein quantitation of complex mixtures.
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Duodeno/patología , Resistencia a la Insulina , Proteínas/metabolismo , Espectrometría de Masas en Tándem/métodos , Duodeno/metabolismo , Humanos , Masculino , ProteomaRESUMEN
BACKGROUND: Medical care is increasingly complex and must draw upon the distinct, yet complementary skills of various health disciplines. Healthcare student integration through interprofessional education (IPE) activity is considered one way to promote early, and subsequently sustain, the principles of teamwork. However, It has been demonstrated that each profession has distinct profession-based subcultures, or common attitudes, beliefs and values, even among undergraduate students before commencing their training. We sought to evaluate if undergraduate pharmacy and nursing student in the Middle East had similarly formed attitudes and perceptions of each others' roles. METHODS: Focus group and semi-structured interviews were conducted with undergraduate pharmacy and nursing students enrolled at Qatar University College of Pharmacy and University of Calgary - Qatar Nursing programs. An eight-question topic guide was developed following comprehensive literature review of reports of other interdisciplinary assessments (either quantitative and qualitative). Working theories were drawn by the two primary investigators based on relevant topic characteristics such as expressed roles and purposes for interacting with one other, patients, and physicians, to develop explanatory constructs for the findings and identify patterns in the data. Qualitative analysis of interviews were supported by NVivo10 (©) (QSR International 2013) software. RESULTS: One shared themes across both health professional groups evolved during data analysis: perceptions of collaborative roles. Discipline specific themes included pharmacist knowledge and visibility (nursing students) and nurses as informants and roles in total patient care (pharmacy students). As expected, students with little or no curricular-based structured experiential training yet largely drew upon personal experiences, whereas senior students, who did have some amount of professional context, often mirrored those that have been found in other studies investigating this interdisciplinary partnership in the clinical setting. Basic understanding of one another's roles were exhibited, but tended to closely follow traditional scripts that are particularly pervasive in the Middle East. CONCLUSION: Concepts arising from our work reinforces the importance of reaching interdisciplinary understanding through assorted formal and informal exposures and can inform ways in which future IPE initiatives can be developed among the various health professional training programs.
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Estudios Interdisciplinarios , Relaciones Interprofesionales , Estudiantes de Enfermería , Estudiantes de Farmacia , Actitud del Personal de Salud , Curriculum , Educación en Enfermería/métodos , Educación en Farmacia/métodos , Evaluación Educacional , Femenino , Grupos Focales , Humanos , Entrevistas como Asunto , Masculino , Medio Oriente , Qatar , Investigación Cualitativa , Adulto JovenRESUMEN
Insulin is internalized with its cognate receptor into the endosomal apparatus rapidly after binding to hepatocytes. We performed a bioinformatic screen of Golgi/endosome hepatic protein fractions and found that ATIC, which is a rate-limiting enzyme in the de novo purine biosynthesis pathway, and PTPLAD1 are associated with insulin receptor (IR) internalization. The IR interactome (IRGEN) connects ATIC to AMPK within the Golgi/endosome protein network (GEN). Forty-five percent of the IR Golgi/endosome protein network have common heritable variants associated with type 2 diabetes, including ATIC and AMPK. We show that PTPLAD1 and AMPK are rapidly compartmentalized within the plasma membrane (PM) and Golgi/endosome fractions after insulin stimulation and that ATIC later accumulates in the Golgi/endosome fraction. Using an in vitro reconstitution system and siRNA-mediated partial knockdown of ATIC and PTPLAD1 in HEK293 cells, we show that both ATIC and PTPLAD1 affect IR tyrosine phosphorylation and endocytosis. We further show that insulin stimulation and ATIC knockdown readily increase the level of AMPK-Thr172 phosphorylation in IR complexes. We observed that IR internalization was markedly decreased after AMPKα2 knockdown, and treatment with the ATIC substrate AICAR, which is an allosteric activator of AMPK, increased IR endocytosis in cultured cells and in the liver. These results suggest the presence of a signaling mechanism that senses adenylate synthesis, ATP levels, and IR activation states and that acts in regulating IR autophosphorylation and endocytosis.
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Vías Biosintéticas , Endosomas/metabolismo , Aparato de Golgi/metabolismo , Insulina/metabolismo , Nucleótido Desaminasas/metabolismo , Purinas/biosíntesis , Transducción de Señal , Adenilato Quinasa/metabolismo , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacología , Animales , Vías Biosintéticas/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Biología Computacional , Endocitosis/efectos de los fármacos , Endosomas/efectos de los fármacos , Femenino , Técnicas de Silenciamiento del Gen , Aparato de Golgi/efectos de los fármacos , Células HEK293 , Humanos , Hidroliasas , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Cinética , Hígado/efectos de los fármacos , Hígado/metabolismo , Espectrometría de Masas , Fosforilación/efectos de los fármacos , Proteómica , Ratas Sprague-Dawley , Receptor de Insulina/metabolismo , Ribonucleótidos/farmacología , Transducción de Señal/efectos de los fármacos , Sus scrofaRESUMEN
Cafeteria roenbergensis virus (CroV) is a giant virus of the Mimiviridae family that infects the marine phagotrophic flagellate C. roenbergensis. CroV possesses a DNA genome of ~730 kilobase pairs that is predicted to encode 544 proteins. We analyzed the protein composition of purified CroV particles by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and identified 141 virion-associated CroV proteins and 60 host proteins. Data are available via ProteomeXchange with identifier PXD000993. Predicted functions could be assigned to 36% of the virion proteins, which include structural proteins as well as enzymes for transcription, DNA repair, redox reactions and protein modification. Homologs of 36 CroV virion proteins have previously been found in the virion of Acanthamoeba polyphaga mimivirus. The overlapping virion proteome of CroV and Mimivirus reveals a set of conserved virion protein functions that were presumably present in the last common ancestor of the Mimiviridae.
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Genoma Viral/genética , Mimiviridae/metabolismo , Proteoma , Estramenopilos/virología , Proteínas Virales/metabolismo , Virión/metabolismo , Secuencia de Aminoácidos , Cromatografía Liquida , Reparación del ADN , ADN Viral/genética , Mimiviridae/genética , Datos de Secuencia Molecular , Motivos de Nucleótidos , Oxidación-Reducción , Regiones Promotoras Genéticas/genética , Espectrometría de Masas en Tándem , Transcripción Genética , Proteínas Virales/genética , Estructuras Virales , Virión/genéticaRESUMEN
Insulin resistance (IR) is associated with elevated plasma levels of triglyceride-rich lipoproteins (TRLs) of intestinal origin. However, the mechanisms underlying the overaccumulation of apolipoprotein (apo)B-48-containing TRLs in individuals with IR are not yet fully understood. This study examined the relationships between apoB-48-containing TRL kinetics and the expression of key intestinal genes and proteins involved in lipid/lipoprotein metabolism in 14 obese nondiabetic men with IR compared with 10 insulin-sensitive (IS) men matched for waist circumference. The in vivo kinetics of TRL apoB-48 were assessed using a primed-constant infusion of L-[5,5,5-D3]leucine for 12 h with the participants in a constantly fed state. The expression of key intestinal genes and proteins involved in lipid/lipoprotein metabolism was assessed by performing real-time PCR quantification and LC-MS/MS on duodenal biopsy specimens. The TRL apoB-48 pool size and production rate were 102% (P < 0.0001) and 87% (P = 0.01) greater, respectively, in the men with IR versus the IS men. On the other hand, intestinal mRNA levels of sterol regulatory element binding factor-2, hepatocyte nuclear factor-4α, and microsomal triglyceride transfer protein were significantly lower in the men with IR than in the IS men. These data indicate that IR is associated with intestinal overproduction of lipoproteins and significant downregulation of key intestinal genes involved in lipid/lipoprotein metabolism.
Asunto(s)
Apolipoproteína B-48/metabolismo , Duodeno/metabolismo , Dislipidemias/genética , Resistencia a la Insulina , Transcriptoma , Adulto , Apolipoproteína B-100/genética , Apolipoproteína B-100/metabolismo , Apolipoproteína B-48/genética , Glucemia , Estudios de Casos y Controles , Regulación hacia Abajo , Dislipidemias/metabolismo , Ácidos Grasos no Esterificados/sangre , Homeostasis , Humanos , Cinética , Metabolismo de los Lípidos , Masculino , Persona de Mediana Edad , Triglicéridos/metabolismo , Adulto JovenRESUMEN
Cellular factors associated with the parvovirus minute virus of mice (MVM) during infection are thought to play important roles in the MVM life cycle but only a few of these have been identified. Here we used a proteomic-based approach in order to identify host-binding partners of MVM. Using purified MVM as bait for immunoprecipitation assays, a total of 150 proteins were identified in MVM immunoprecipitates by quantitative liquid chromatography-tandem mass spectrometry. Galectin-3 was one of six proteins showing a statistically significant enrichment across replicates. Small interfering RNA depletion studies revealed an important role for galectin-3 in MVM endocytosis and infectivity in LA9 mouse fibroblast cells. Galectin-3-depleted cells were less susceptible to MVM infection than control cells and showed a significant reduction of MVM cellular uptake, but not of MVM binding to the cell surface. Our results indicate an important role for galectin-3 in the cellular uptake of MVM. We propose that galectin-3 facilitates the access of MVM to its receptor(s) at the plasma membrane and in this way promotes MVM endocytosis.
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Galectina 3/fisiología , Virus Diminuto del Ratón/fisiología , Receptores Virales/fisiología , Internalización del Virus , Animales , Endocitosis/fisiología , Ratones , Virus Diminuto del Ratón/genética , Virus Diminuto del Ratón/patogenicidad , Proteómica , Replicación Viral/genéticaRESUMEN
Upon DNA damage induction, DNA-dependent poly(ADP-ribose) polymerases (PARPs) synthesize an anionic poly(ADP-ribose) (pADPr) scaffold to which several proteins bind with the subsequent formation of pADPr-associated multiprotein complexes. We have used a combination of affinity-purification methods and proteomics approaches to isolate these complexes and assess protein dynamics with respect to pADPr metabolism. As a first approach, we developed a substrate trapping strategy by which we demonstrate that a catalytically inactive Poly(ADP-ribose) glycohydrolase (PARG) mutant can act as a physiologically selective bait for the isolation of specific pADPr-binding proteins through its macrodomain-like domain. In addition to antibody-mediated affinity-purification methods, we used a pADPr macrodomain affinity resin to recover pADPr-binding proteins and their complexes. Second, we designed a time course experiment to explore the changes in the composition of pADPr-containing multiprotein complexes in response to alkylating DNA damage-mediated PARP activation. Spectral count clustering based on GeLC-MS/MS analysis was complemented with further analyses using high precision quantitative proteomics through isobaric tag for relative and absolute quantitation (iTRAQ)- and Stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics. Here, we present a valuable resource in the interpretation of systems biology of the DNA damage response network in the context of poly(ADP-ribosyl)ation and provide a basis for subsequent investigations of pADPr-binding protein candidates.
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Daño del ADN , Poli(ADP-Ribosa) Polimerasas/metabolismo , Proteoma/metabolismo , Reparación del ADN , Células HEK293 , Células HeLa , Humanos , Marcaje Isotópico , Complejos Multiproteicos/aislamiento & purificación , Mapas de Interacción de Proteínas , Proteómica/métodos , Estrés Fisiológico/genéticaRESUMEN
mTORC1 [mTOR (mammalian target of rapamycin) complex 1] regulates diverse cell functions. mTORC1 controls the phosphorylation of several proteins involved in mRNA translation and the translation of specific mRNAs, including those containing a 5'-TOP (5'-terminal oligopyrimidine). To date, most of the proteins encoded by known 5'-TOP mRNAs are proteins involved in mRNA translation, such as ribosomal proteins and elongation factors. Rapamycin inhibits some mTORC1 functions, whereas mTOR-KIs (mTOR kinase inhibitors) interfere with all of them. mTOR-KIs inhibit overall protein synthesis more strongly than rapamycin. To study the effects of rapamycin or mTOR-KIs on synthesis of specific proteins, we applied pSILAC [pulsed SILAC (stable isotope-labelling with amino acids in cell culture)]. Our results reveal, first, that mTOR-KIs and rapamycin differentially affect the synthesis of many proteins. Secondly, mTOR-KIs inhibit the synthesis of proteins encoded by 5'-TOP mRNAs much more strongly than rapamycin does, revealing that these mRNAs are controlled by rapamycin-insensitive outputs from mTOR. Thirdly, the synthesis of certain other proteins shows a similar pattern of inhibition. Some of them appear to be encoded by 'novel' 5'-TOP mRNAs; they include proteins which, like known 5'-TOP mRNA-encoded proteins, are involved in protein synthesis, whereas others are enzymes involved in intermediary or anabolic metabolism. These results indicate that mTOR signalling may promote diverse biosynthetic processes through the translational up-regulation of specific mRNAs. Lastly, a SILAC-based approach revealed that, although rapamycin and mTOR-KIs have little effect on general protein stability, they stabilize proteins encoded by 5'-TOP mRNAs.
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Biosíntesis de Proteínas/efectos de los fármacos , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Isótopos de Carbono , Factor 4E Eucariótico de Iniciación/metabolismo , Células HeLa , Humanos , Indoles/farmacología , Marcaje Isotópico , Morfolinas/farmacología , Isótopos de Nitrógeno , Biosíntesis de Proteínas/genética , Purinas/farmacología , ARN Mensajero/metabolismo , Ribosomas/metabolismo , Sirolimus/farmacologíaRESUMEN
Mice that were intranasally vaccinated with live or dead Chlamydia muridarum with or without CpG-containing oligodeoxynucleotide 1862 elicited widely disparate levels of protective immunity to genital tract challenge. We found that the frequency of multifunctional T cells coexpressing IFN-γ and TNF-α with or without IL-2 induced by live C. muridarum most accurately correlated with the pattern of protection against C. muridarum genital tract infection, suggesting that IFN-γ(+)-producing CD4(+) T cells that highly coexpress TNF-α may be the optimal effector cells for protective immunity. We also used an immunoproteomic approach to analyze MHC class II-bound peptides eluted from dendritic cells (DCs) that were pulsed with live or dead C. muridarum elementary bodies (EBs). We found that DCs pulsed with live EBs presented 45 MHC class II C. muridarum peptides mapping to 13 proteins. In contrast, DCs pulsed with dead EBs presented only six MHC class II C. muridarum peptides mapping to three proteins. Only two epitopes were shared in common between the live and dead EB-pulsed groups. This study provides insights into the role of Ag presentation and cytokine secretion patterns of CD4(+) T effector cells that correlate with protective immunity elicited by live and dead C. muridarum. These insights should prove useful for improving vaccine design for Chlamydia trachomatis.