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1.
Phys Chem Chem Phys ; 26(25): 17796-17808, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38881336

RESUMEN

A family of dithienosilole-based dyes with alternating donor and acceptor conjugated groups, decorated with linear or branched alkyl chains at different positions on the backbone, have been obtained and investigated in different aggregation states. These dyes are characterized by almost panchromatic absorption and by near-IR emission, with good quantum yields in a variety of solvents with different polarity. We demonstrate that the nature and position of the alkyl substituents strongly govern the self-assembly of the dyes, whose packing is also sensitive to external stimuli, such as grinding and water addition. Thanks to computational results and theoretical modelling, we are able to interpret the results based on two possible preferential packings, characterized by distinct spectroscopic behaviour, whose abundance can be tuned according to the nature and position of the alkyl chains, as well as via external stimuli.

2.
J Biol Chem ; 298(1): 101500, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34929171

RESUMEN

In HIV, the polyprotein precursor Gag orchestrates the formation of the viral capsid. In the current view of this viral assembly, Gag forms low-order oligomers that bind to the viral genomic RNA triggering the formation of high-ordered ribonucleoprotein complexes. However, this assembly model was established using biochemical or imaging methods that do not describe the cellular location hosting Gag-gRNA complex nor distinguish gRNA packaging in single particles. Here, we studied the intracellular localization of these complexes by electron microscopy and monitored the distances between the two partners by morphometric analysis of gold beads specifically labeling Gag and gRNA. We found that formation of these viral clusters occurred shortly after the nuclear export of the gRNA. During their transport to the plasma membrane, the distance between Gag and gRNA decreases together with an increase of gRNA packaging. Point mutations in the zinc finger patterns of the nucleocapsid domain of Gag caused an increase in the distance between Gag and gRNA as well as a sharp decrease of gRNA packaged into virions. Finally, we show that removal of stem loop 1 of the 5'-untranslated region does not interfere with gRNA packaging, whereas combined with the removal of stem loop 3 is sufficient to decrease but not abolish Gag-gRNA cluster formation and gRNA packaging. In conclusion, this morphometric analysis of Gag-gRNA cluster formation sheds new light on HIV-1 assembly that can be used to describe at nanoscale resolution other viral assembly steps involving RNA or protein-protein interactions.


Asunto(s)
Productos del Gen gag , VIH-1 , Nucleoproteínas , Regiones no Traducidas 5' , Productos del Gen gag/genética , Productos del Gen gag/metabolismo , Genómica , VIH-1/genética , VIH-1/metabolismo , Microscopía Electrónica de Transmisión , Nucleoproteínas/genética , Nucleoproteínas/metabolismo , ARN Guía de Kinetoplastida , ARN Viral/genética , ARN Viral/metabolismo , Ensamble de Virus/genética
3.
J Virol ; 95(5)2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33298540

RESUMEN

Interferon-induced transmembrane protein 3 (IFITM3) is a cellular factor that reduces HIV-1 infectivity by an incompletely understood mechanism. We show here that viruses differing only in the envelope glycoprotein (Env) expressed on their surface have different sensitivities to IFITM3. Measurements of the sensitivity of viruses to neutralizing antibodies showed that IFITM3 increased the sensitivity of IFITM3-sensitive viruses to PG16, which targets the V1V2 loop, suggesting that IFITM3 promotes exposure of the PG16 epitope of IFITM3-sensitive viruses. Exchanges of V1V2 loops between the Env proteins of sensitive and resistant viruses revealed that V1V2 and V3 act together to modulate viral sensitivity to IFITM3. Co-immunoprecipitation experiments showed that IFITM3 interacted with both the precursor (gp160) and cleaved (gp120) forms of Env from IFITM3-sensitive viruses, but only with the precursor (gp160) form of Env from IFITM3-resistant viruses. This finding suggests that the interaction between the Env of resistant viruses and IFITM3 was inhibited once Env had been processed in the Golgi apparatus. This hypothesis was supported by immunofluorescence experiments, which showed a strong colocalization of IFITM3 with the Env of sensitive viruses, but only weak colocalization with the Env of resistant viruses on the plasma membrane of virus-producing cells. Together, these results indicate that IFITM3 interacts with Env, inducing conformational changes that may decrease viral infectivity. This antiviral action is, nevertheless, modulated by the nature of the Env, in particular its V1V2 and V3 loops, which after maturation may be able to escape this interaction.IMPORTANCE Interferon-induced transmembrane protein 3 (IFITM3) is a cellular factor that reduces HIV-1 infectivity by an incompletely understood mechanism. This study aimed to elucidate the role of the HIV-1 envelope glycoprotein (Env) in determining viral susceptibility to IFITM3. We found that viruses differing only in Env expressed on their surface had different sensitivities to IFITM3. By comparing the Env proteins of viruses that were highly sensitive or resistant to IFITM3, we obtained new insight in the mechanisms by which HIV-1 escapes this protein. We showed that IFITM3 interacts with the Env protein of sensitive viruses in virion-producing cells, inducing conformational changes that may decrease viral infectivity. However, this antiviral action is modulated by the nature of Env, particularly the V1V2 and V3 loops, which may be able to escape this interaction after processing in the Golgi.

4.
J Viral Hepat ; 29(9): 719-726, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35633087

RESUMEN

It was recently suggested that the composition of circulating hepatitis B subviral particles (SVPs) could be used to differentiate the various stages in chronic hepatitis B virus (HBV) infection, with significantly lower proportions of L and M proteins in inactive carriers than in individuals with chronic hepatitis. L protein is abundant in virions and filamentous SVPs but almost absent from spherical SVPs. We, therefore, performed a morphometric analysis of SVPs in these two groups of patients, by conducting a retrospective analysis on sera from 15 inactive carriers and 11 patients with chronic hepatitis infected with various HBV genotypes. Subviral particles were concentrated by centrifugation on a sucrose cushion, with monitoring by transmission electron microscopy. The percentage of filamentous SVPs and filament length for 100 SVPs was determined with a digital camera. The L protein PreS1 promoter was sequenced from viral genomes by the Sanger method. No marked differences were found between patients, some of whom had only spherical SVPs, whereas others had variable percentages of filamentous SVPs (up to 28%), of highly variable length. High filament percentages were not associated with a particular sequence of the L protein promoter, HBV genotype or even disease stage. High levels of circulating filamentous SVPs are probably more strongly related to individual host factors than to viral strain characteristics or disease stage.


Asunto(s)
Hepatitis B Crónica , Hepatitis B , Genotipo , Antígenos de Superficie de la Hepatitis B , Virus de la Hepatitis B/genética , Humanos , Estudios Retrospectivos
5.
Cell Microbiol ; 22(8): e13205, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32216005

RESUMEN

Hepatitis B virus (HBV) is a leading cause of cirrhosis and hepatocellular carcinoma worldwide, with 250 million individuals chronically infected. Many stages of the HBV infectious cycle have been elucidated, but the mechanisms of HBV entry remain poorly understood. The identification of the sodium taurocholate cotransporting polypeptide (NTCP) as an HBV receptor and the establishment of NTCP-overexpressing hepatoma cell lines susceptible to HBV infection opens up new possibilities for investigating these mechanisms. We used HepG2-NTCP cells, and various chemical inhibitors and RNA interference (RNAi) approaches to investigate the host cell factors involved in HBV entry. We found that HBV uptake into these cells was dependent on the actin cytoskeleton and did not involve macropinocytosis or caveolae-mediated endocytosis. Instead, entry occurred via the clathrin-mediated endocytosis pathway. HBV internalisation was inhibited by pitstop-2 treatment and RNA-mediated silencing (siRNA) of the clathrin heavy chain, adaptor protein AP-2 and dynamin-2. We were able to visualise HBV entry in clathrin-coated pits and vesicles by electron microscopy (EM) and cryo-EM with immunogold labelling. These data demonstrating that HBV uses a clathrin-mediated endocytosis pathway to enter HepG2-NTCP cells increase our understanding of the complete HBV life cycle.


Asunto(s)
Clatrina/metabolismo , Endocitosis , Virus de la Hepatitis B/fisiología , Internalización del Virus , Clatrina/ultraestructura , Microscopía por Crioelectrón , Células Hep G2 , Virus de la Hepatitis B/ultraestructura , Interacciones Microbiota-Huesped , Humanos , Microscopía Electrónica , Interferencia de ARN , Proteínas del Envoltorio Viral/metabolismo
6.
Eur Spine J ; 30(5): 1125-1131, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-32860536

RESUMEN

PURPOSE: Bracing is the treatment of choice for idiopathic scoliosis (IS), unfortunately factors underlying brace response remain unknown. Clinicians are currently unable to identify patients who may benefit from bracing, and therefore, better molecular stratification is critically needed. The aim of this study is to evaluate IS patient outcomes at skeletal maturity in relation to biological endophenotypes, and determine specific endophenotypes associated to differential bracing outcomes. This is a retrospective cohort with secondary cross-sectional comparative studies. METHODS: Clinical and radiological data were collected from 563 IS patients, stratified into biological endophenotypes (FG1, FG2, FG3) based on a cell-based test. Measured outcomes were maximum Cobb angle at skeletal maturity, and if severe, spinal deformity (≥ 45°) or surgery was attained. Treatment success/failure was determined by standard progression thresholds (Cobb ≥ 45° or surgery; Cobb angle progression ≥ 6°). Multivariable analyses were performed to evaluate associations between endophenotypes and clinical outcome. RESULTS: Higher Cobb angles at maturity for FG1 and FG2 patients were observed (p = 0.056 and p = 0.05), with increased likelihood of ≥ 45° and/or surgery for FG1 (OR = 2.181 [1.002-4.749] and FG2 (OR = 2.141 [1.038-4.413]) compared to FG3. FG3 was 9.31 [2.58-33.61] and 5.63 [2.11-15.05] times more likely for bracing success at treatment termination and based on the < 6° progression criterion, respectively, compared to FG1. CONCLUSION: Associations between biological endophenotypes and outcomes suggest differences in progression and/or bracing response among IS patients. Outcomes were most favorable in FG3 patients. The results pave the way for establishing personalized treatments, distinguishing who may benefit or not from treatment.


Asunto(s)
Distinciones y Premios , Escoliosis , Tirantes , Estudios Transversales , Progresión de la Enfermedad , Endofenotipos , Humanos , Estudios Retrospectivos , Resultado del Tratamiento
7.
J Virol ; 93(2)2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30404804

RESUMEN

Broadly neutralizing antibodies (bnAbs) are promising agents for prevention and/or treatment of HIV-1 infection. However, the diversity among HIV-1 envelope (Env) glycoproteins impacts bnAb potency and breadth. Neutralization data on the CRF02_AG clade are scarce although it is highly prevalent in West Africa and Europe. We assessed the sensitivity to bnAbs of a panel of 33 early transmitted CRF02_AG viruses over a 15-year period of the French epidemic (1997 to 2012). Env pseudotyped CRF02_AG viruses were best neutralized by the CD4 binding site (CD4bs)-directed bnAbs (VRC01, 3BNC117, NIH45-46G54W, and N6) and the gp41 membrane-proximal external region (MPER)-directed bnAb 10E8 in terms of both potency and breadth. We observed a higher resistance to bnAbs targeting the V1V2-glycan region (PG9 and PGT145) and the V3-glycan region (PGT121 and 10-1074). Combinations were required to achieve full coverage across this subtype. We observed increased resistance to bnAbs targeting the CD4bs linked to the diversification of CRF02_AG Env over the course of the epidemic, a phenomenon which was previously described for subtypes B and C. These data on the sensitivity to bnAbs of CRF02_AG viruses, including only recently transmitted viruses, will inform future passive immunization studies. Considering the drift of the HIV-1 species toward higher resistance to neutralizing antibodies, it appears necessary to keep updating existing panels for evaluation of future vaccine and passive immunization studies.IMPORTANCE Major progress occurred during the last decade leading to the isolation of human monoclonal antibodies, termed broadly neutralizing antibodies (bnAbs) due to their capacity to neutralize various strains of HIV-1. Several clinical trials are under way in order to evaluate their efficacy in preventive or therapeutic strategies. However, no single bnAb is active against 100% of strains. It is important to gather data on the sensitivity to neutralizing antibodies of all genotypes, especially those more widespread in regions where the prevalence of HIV-1 infection is high. Here, we assembled a large panel of clade CRF02_AG viruses, the most frequent genotype circulating in West Africa and the second most frequent found in several European countries. We evaluated their sensitivities to bnAbs, including those most advanced in clinical trials, and looked for the best combinations. In addition, we observed a trend toward increased resistance to bnAbs over the course of the epidemic.


Asunto(s)
Anticuerpos Neutralizantes/farmacología , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Adulto , Evolución Molecular , Femenino , Anticuerpos Anti-VIH/farmacología , VIH-1/clasificación , VIH-1/genética , Humanos , Inmunización Pasiva , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , Adulto Joven , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética
8.
J Virol ; 93(6)2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30567994

RESUMEN

We showed previously that during the HIV/AIDS epidemic, the envelope glycoprotein (Env) of HIV-1, and in particular, the gp120 subunit, evolved toward an increased resistance to neutralizing antibodies at a population level. Here, we considered whether the antigenic evolution of the HIV-1 Env is associated with modifications of its functional properties, focusing on cell entry efficacy and interactions with the receptor and coreceptors. We tested the infectivity of a panel of Env-pseudotyped viruses derived from patients infected by subtype B viruses at three periods of the epidemic (1987 to 1991, 1996 to 2000, and 2006 to 2010). Pseudotyped viruses harboring Env from patients infected during the most recent period were approximately 10-fold more infectious in cell culture than those from patients infected at the beginning of the epidemic. This was associated with faster viral entry kinetics: contemporary viruses entered target cells approximately twice as fast as historical viruses. Contemporary viruses were also twice as resistant as historical viruses to the fusion inhibitor enfuvirtide. Resistance to enfuvirtide correlated with a resistance to CCR5 antagonists, suggesting that contemporary viruses expanded their CCR5 usage efficiency. Viruses were equally captured by DC-SIGN, but after binding to DC-SIGN, contemporary viruses infected target cells more efficiently than historical viruses. Thus, we report evidence that the infectious properties of the envelope glycoprotein of HIV-1 increased during the course of the epidemic. It is plausible that these changes affected viral fitness during the transmission process and might have contributed to an increasing virulence of HIV-1.IMPORTANCE Following primary infection by HIV-1, neutralizing antibodies (NAbs) exert selective pressure on the HIV-1 envelope glycoprotein (Env), driving the evolution of the viral population. Previous studies suggested that, as a consequence, Env has evolved at the HIV species level since the start of the epidemic so as to display greater resistance to NAbs. Here, we investigated whether the antigenic evolution of the HIV-1 Env is associated with modifications of its functional properties, focusing on cell entry efficacy and interactions with the receptor and coreceptors. Our data provide evidence that the infectious properties of the HIV-1 Env increased during the course of the epidemic. These changes may have contributed to increasing virulence of HIV-1 and an optimization of transmission between individuals.


Asunto(s)
Infecciones por VIH/virología , VIH-1/metabolismo , VIH-1/patogenicidad , Productos del Gen env del Virus de la Inmunodeficiencia Humana/metabolismo , Anticuerpos Neutralizantes/inmunología , Línea Celular , Epidemias , Células HEK293 , Anticuerpos Anti-VIH/inmunología , Proteína gp120 de Envoltorio del VIH/inmunología , Proteína gp120 de Envoltorio del VIH/metabolismo , Infecciones por VIH/inmunología , VIH-1/inmunología , Humanos , Masculino , Pruebas de Neutralización/métodos , Receptores CCR5/metabolismo , Internalización del Virus , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
9.
Therapie ; 72(5): 609-613, 2017 Oct.
Artículo en Francés | MEDLINE | ID: mdl-28457571

RESUMEN

This meta-analysis assessed the analgesic effect of a single oral dose of paracetamol versus placebo in adults, in primary care. Parallel randomized studies were searched on MEDLINE®, CENTRAL®, and EMBASE®. We found five studies on sore throat (842 patients) and 12 studies on headache (3433 patients). None related to low back pain. Regardless of the outcome, paracetamol was superior to placebo (number need to treat [NNT]=4-5; standardized mean difference [SMD]=0.51-0.92). Additional clinical trials in other primary care conditions, like low back pain, must be conducted.


Asunto(s)
Acetaminofén/uso terapéutico , Analgésicos no Narcóticos/uso terapéutico , Atención Primaria de Salud , Humanos
10.
Brain ; 138(Pt 2): 336-55, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25567323

RESUMEN

Severe progressive neurological paediatric disease mucopolysaccharidosis III type C is caused by mutations in the HGSNAT gene leading to deficiency of acetyl-CoA: α-glucosaminide N-acetyltransferase involved in the lysosomal catabolism of heparan sulphate. To understand the pathophysiology of the disease we generated a mouse model of mucopolysaccharidosis III type C by germline inactivation of the Hgsnat gene. At 6-8 months mice showed hyperactivity, and reduced anxiety. Cognitive memory decline was detected at 10 months and at 12-13 months mice showed signs of unbalanced hesitant walk and urinary retention. Lysosomal accumulation of heparan sulphate was observed in hepatocytes, splenic sinus endothelium, cerebral microglia, liver Kupffer cells, fibroblasts and pericytes. Starting from 5 months, brain neurons showed enlarged, structurally abnormal mitochondria, impaired mitochondrial energy metabolism, and storage of densely packed autofluorescent material, gangliosides, lysozyme, phosphorylated tau, and amyloid-ß. Taken together, our data demonstrate for the first time that deficiency of acetyl-CoA: α-glucosaminide N-acetyltransferase causes lysosomal accumulation of heparan sulphate in microglial cells followed by their activation and cytokine release. They also show mitochondrial dysfunction in the neurons and neuronal loss explaining why mucopolysaccharidosis III type C manifests primarily as a neurodegenerative disease.


Asunto(s)
Enfermedades Mitocondriales/patología , Mucopolisacaridosis III/patología , Neuritis/patología , Enfermedades Neurodegenerativas/patología , Acetiltransferasas/deficiencia , Acetiltransferasas/genética , Animales , Conducta Animal , Metabolismo Energético/fisiología , Gangliósidos/metabolismo , Glicosaminoglicanos/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteínas Asociadas a Microtúbulos/metabolismo , Enfermedades Mitocondriales/etiología , Mucopolisacaridosis III/complicaciones , Mucopolisacaridosis III/psicología , Neuritis/etiología , Enfermedades Neurodegenerativas/etiología , Enfermedades Neurodegenerativas/psicología , Examen Neurológico , Deficiencias en la Proteostasis/patología
11.
PLoS Pathog ; 9(7): e1003477, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23853594

RESUMEN

We compared the neutralization sensitivity of early/transmitted HIV-1 variants from patients infected by subtype B viruses at 3 periods of the epidemic (1987-1991, 1996-2000, 2006-2010). Infectious pseudotyped viruses expressing envelope glycoproteins representative of the viral quasi-species infecting each patient were tested for sensitivity to neutralization by pools of sera from HIV-1 chronically infected patients and by an updated panel of 13 human monoclonal neutralizing antibodies (HuMoNAbs). A progressive significantly enhanced resistance to neutralization was observed over calendar time, by both human sera and most of the HuMoNAbs tested (b12, VRC01, VRC03, NIH45-46(G54W), PG9, PG16, PGT121, PGT128, PGT145). Despite this evolution, a combination of two HuMoNAbs (NIH45-46(G54W) and PGT128) still would efficiently neutralize the most contemporary transmitted variants. In addition, we observed a significant reduction of the heterologous neutralizing activity of sera from individuals infected most recently (2003-2007) compared to patients infected earlier (1987-1991), suggesting that the increasing resistance of the HIV species to neutralization over time coincided with a decreased immunogenicity. These data provide evidence for an ongoing adaptation of the HIV-1 species to the humoral immunity of the human population, which may add an additional obstacle to the design of an efficient HIV-1 vaccine.


Asunto(s)
Anticuerpos Neutralizantes/metabolismo , Epidemias , Flujo Genético , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-1/inmunología , Anticuerpos Monoclonales/metabolismo , Especificidad de Anticuerpos , Antígenos Virales/biosíntesis , Antígenos Virales/genética , Antígenos Virales/metabolismo , Estudios de Cohortes , Monitoreo Epidemiológico , Epítopos/genética , Francia/epidemiología , Infecciones por VIH/epidemiología , Infecciones por VIH/transmisión , VIH-1/genética , VIH-1/metabolismo , Humanos , Inmunidad Humoral , Fenómenos Inmunogenéticos , Glicoproteínas de Membrana/antagonistas & inhibidores , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Filogenia , ARN Viral/sangre , ARN Viral/metabolismo , Proteínas del Envoltorio Viral/antagonistas & inhibidores , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/metabolismo
12.
J Clin Microbiol ; 52(11): 4010-6, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25232163

RESUMEN

The presence of HIV-1 non-B subtypes in Western Europe is commonly attributed to migration of individuals from non-European countries, but the possible role of domestic infections with non-B subtypes is not well investigated. The French mandatory anonymous reporting system for HIV is linked to a virological surveillance using assays for recent infection (<6 months) and serotyping. During the first semester of years 2007 to 2010, any sample corresponding to a non-B recent infection was analyzed by sequencing a 415-bp env region, followed by phylogenetic analysis and search for transmission clusters. Two hundred thirty-three recent HIV-1 infections with non-B variants were identified. They involved 5 subtypes and 7 circulating recombinant forms (CRFs). Ninety-two cases (39.5%) were due to heterosexual transmissions, of which 39 occurred in patients born in France. Eighty-five cases (36.5%) were identified in men having sex with men (MSM). Forty-three recent non-B infections (18.5%) segregated into 14 clusters, MSM being involved in 11 of them. Clustered transmission events included 2 to 7 cases per cluster. The largest cluster involved MSM infected by a CRF02_AG variant. In conclusion, we found that the spread of non-B subtypes in France occurs in individuals of French origin and that MSM are particularly involved in this dynamic.


Asunto(s)
Infecciones por VIH/transmisión , Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Análisis por Conglomerados , Femenino , Francia/epidemiología , Genotipo , Infecciones por VIH/epidemiología , VIH-1/clasificación , VIH-1/genética , Humanos , Masculino , Epidemiología Molecular , Filogenia , Análisis de Secuencia de ADN , Homología de Secuencia , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética
13.
J Virol ; 87(24): 13609-18, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24109215

RESUMEN

Hepatitis C virus (HCV) remains a challenging public health problem worldwide. The identification of viral variants establishing de novo infections and definition of the phenotypic requirements for transmission would facilitate the design of preventive strategies. We explored the transmission of HCV variants in three cases of acute hepatitis following needlestick accidents. We used single-genome amplification of glycoprotein E1E2 gene sequences to map the genetic bottleneck upon transmission accurately. We found that infection was likely established by a single variant in two cases and six variants in the third case. Studies of donor samples showed that the transmitted variant E1E2 amino acid sequences were identical or closely related to those of variants from the donor virus populations. The transmitted variants harbored a common signature site at position 394, within hypervariable region 1 of E2, together with additional signature amino acids specific to each transmission pair. Surprisingly, these E1E2 variants conferred no greater capacity for entry than the E1E2 derived from nontransmitted variants in lentiviral pseudoparticle assays. Mutants escaping the antibodies of donor sera did not predominate among the transmitted variants either. The fitness parameters affecting the selective outgrowth of HCV variants after transmission in an immunocompetent host may thus be more complex than those suggested by mouse models. Human antibodies directed against HCV envelope effectively cross-neutralized the lentiviral particles bearing E1E2 derived from transmitted variants. These findings provide insight into the molecular mechanisms underlying HCV transmission and suggest that viral entry is a potential target for the prevention of HCV infection.


Asunto(s)
Hepacivirus/metabolismo , Hepatitis C/transmisión , Hepatitis C/virología , Proteínas del Envoltorio Viral/metabolismo , Secuencia de Aminoácidos , Animales , Femenino , Hepacivirus/química , Hepacivirus/clasificación , Hepacivirus/genética , Humanos , Masculino , Ratones , Datos de Secuencia Molecular , Filogenia , Alineación de Secuencia , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/genética
14.
Cytotherapy ; 16(8): 1073-9, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24934305

RESUMEN

BACKGROUND AIMS: Decreased bone formation with age is believed to arise, at least in part, because of the influence of the senescent microenvironment. In this context, it is unclear whether multipotent stromal cell (MSC)-based therapies would be effective for the treatment of bone diseases. METHODS: With the use of a heterotopic bone formation model, we investigated whether MSC-derived osteogenesis is impaired in aged mice compared with young mice. RESULTS: We found that bone formation derived from MSCs is not reduced in aged mice. These results are supported by the unexpected finding that conditioned media collected from ionizing radiation-induced senescent MSCs can stimulate mineralization and delay osteoclastogenesis in vitro. CONCLUSIONS: Overall, our results suggest that impaired bone formation with age is mainly cell-autonomous and provide a rationale for the use of MSC-based therapies for the treatment of bone diseases in the elderly.


Asunto(s)
Tratamiento Basado en Trasplante de Células y Tejidos , Células Madre Mesenquimatosas/citología , Células Madre Multipotentes/citología , Osteogénesis , Anciano , Envejecimiento/patología , Animales , Células de la Médula Ósea , Diferenciación Celular/genética , Medios de Cultivo Condicionados , Humanos , Ratones
15.
Inorg Chem ; 53(6): 2841-7, 2014 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-24571287

RESUMEN

The ligand-exchange reaction has been investigated to synthesize nickel bis(dithiolene) complexes bearing one hydroxyl functional group aimed at being grafted thereafter onto polymer materials. This reaction leads easily to heteroleptic complexes with the ethylene-1,2-dithiolato core substituted by either alkyl or aryl moieties. Details on synthetic parameters are given. A direct link between the electronic properties of the obtained molecules and those of the parent complexes involved in the ligand-exchange reaction is highlighted and also demonstrates that this reaction is a powerful method for preparing nickel complexes with tailor-made frontier orbital energies.

16.
Arthritis Rheum ; 65(4): 993-1003, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23310948

RESUMEN

OBJECTIVE: To decipher the molecular mechanisms down-regulating PITX1 expression in primary osteoarthritis (OA). METHODS: The functional activity of different PITX1 promoter regions was assessed by luciferase reporter assay. Tandem mass spectrometry coupled to protein sequencing was performed using nuclear extracts prepared from OA chondrocytes, in order to identify proteins bound to DNA regulatory elements. Expression analyses of selected candidate proteins were performed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry methods, using cartilage sections and articular chondrocytes from non-OA control subjects and patients with OA. Gain-of-function and loss-of-function experiments were performed in normal and OA chondrocytes, respectively, to study their effects on PITX1 regulation. The results were validated by real-time RT-PCR and immunohistochemistry in STR/Ort mice, a well-known animal model of OA. RESULTS: PITX1 promoter analyses led to the identification of prohibitin 1 (PHB1) bound to a distal E2F1 transcription factor site. Aberrant accumulation of PHB1 was detected in the nuclei of OA articular chondrocytes, and overexpression of PHB1 in control cells was sufficient to inhibit endogenous PITX1 expression at the messenger RNA and protein levels. Conversely, knockdown of PHB1 in OA articular chondrocytes resulted in up-regulation of PITX1. Studies of early molecular changes in STR/Ort mice revealed a similar nuclear accumulation of PHB1, which correlated with Pitx1 repression. CONCLUSION: Collectively, these data define an unrecognized role for PHB1 in repressing PITX1 expression in OA chondrocytes.


Asunto(s)
Cartílago Articular/metabolismo , Condrocitos/metabolismo , Factor de Transcripción E2F1/metabolismo , Osteoartritis/metabolismo , Factores de Transcripción Paired Box/metabolismo , Proteínas Represoras/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Cartílago Articular/citología , Estudios de Casos y Controles , Condrocitos/citología , Modelos Animales de Enfermedad , Regulación hacia Abajo , Factor de Transcripción E2F1/genética , Femenino , Perfilación de la Expresión Génica , Humanos , Masculino , Ratones , Persona de Mediana Edad , Osteoartritis/genética , Osteoartritis de la Rodilla/genética , Osteoartritis de la Rodilla/metabolismo , Factores de Transcripción Paired Box/genética , Prohibitinas , Proteínas Represoras/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Adulto Joven
17.
Genes (Basel) ; 15(4)2024 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-38674415

RESUMEN

Studies have revealed anthropometric discrepancies in girls with adolescent idiopathic scoliosis (AIS) compared to non-scoliotic subjects, such as a higher stature, lower weight, and lower body mass index. While the causes are still unknown, it was proposed that metabolic hormones could play a role in AIS pathophysiology. Our objectives were to evaluate the association of GLP1R A316T polymorphism in AIS susceptibility and to study its relationship with disease severity and progression. We performed a retrospective case-control association study with controls and AIS patients from an Italian and French Canadian cohort. The GLP1R rs10305492 polymorphism was genotyped in 1025 subjects (313 non-scoliotic controls and 712 AIS patients) using a validated TaqMan allelic discrimination assay. Associations were evaluated by odds ratio and 95% confidence intervals. In the AIS group, there was a higher frequency of the variant genotype A/G (4.2% vs. 1.3%, OR = 3.40, p = 0.016) and allele A (2.1% vs. 0.6%, OR = 3.35, p = 0.017) than controls. When the AIS group was stratified for severity (≤40° vs. >40°), progression of the disease (progressor vs. non-progressor), curve type, or body mass index, there was no statistically significant difference in the distribution of the polymorphism. Our results support that the GLP1R A316T polymorphism is associated with a higher risk of developing AIS, but without being associated with disease severity and progression.


Asunto(s)
Receptor del Péptido 1 Similar al Glucagón , Polimorfismo de Nucleótido Simple , Escoliosis , Humanos , Escoliosis/genética , Femenino , Adolescente , Italia/epidemiología , Masculino , Receptor del Péptido 1 Similar al Glucagón/genética , Estudios de Casos y Controles , Predisposición Genética a la Enfermedad , Canadá/epidemiología , Estudios Retrospectivos , Niño , Mutación
18.
Kidney Int Rep ; 9(5): 1333-1342, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38707810

RESUMEN

Introduction: Hepatitis E virus (HEV) can cause chronic infection (≥3 months) and cirrhosis in immunocompromised patients, especially kidney transplant recipients. Low alanine aminotransferase (ALT) levels and high HEV intrahost diversity have previously been associated with evolution toward chronicity in these patients. We hypothesized that additional clinical and viral factors could be associated with the risk of chronic HEV infection. Methods: We investigated a series of 27 kidney transplant recipients with HEV infection, including 20 patients with chronic hepatitis E. Results: High tacrolimus trough concentration at diagnosis was the most relevant marker associated with chronic hepatitis E (9.2 vs. 6.4 ng/ml, P = 0.04). Most HEV genetic changes selected during HEV infection were compartmentalized between plasma and feces. Conclusion: This compartmentalization highlights the diversity and complexity of HEV replication compartments. Tacrolimus trough concentration at diagnosis of HEV infection could allow an early identification of patients at high risk of chronic hepatitis E and guide treatment initiation.

19.
Int J Mol Sci ; 14(3): 6345-58, 2013 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-23519105

RESUMEN

The defect of the melatonin signaling pathway has been proposed to be one of the key etiopathogenic factors in adolescent idiopathic scoliosis (AIS). A previous report showed that melatonin receptor, MT2, was undetectable in some AIS girls. The present study aimed to investigate whether the abnormal MT2 expression in AIS is quantitative or qualitative. Cultured osteoblasts were obtained from 41 AIS girls and nine normal controls. Semi-quantification of protein expression by Western blot and mRNA expression by TaqMan real-time PCR for both MT1 and MT2 were performed. Anthropometric parameters were also compared and correlated with the protein expression and mRNA expression of the receptors. The results showed significantly lower protein and mRNA expression of MT2 in AIS girls compared with that in normal controls (p = 0.02 and p = 0.019, respectively). No differences were found in the expression of MT1. When dichotomizing the AIS girls according to their MT2 expression, the group with low expression was found to have a significantly longer arm span (p = 0.036). The results of this study showed for the first time a quantitative change of MT2 in AIS that was also correlated with abnormal arm span as part of abnormal systemic skeletal growth.

20.
Sci Rep ; 13(1): 1896, 2023 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-36732593

RESUMEN

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and fibromyalgia (FM) are two chronic complex diseases with overlapping symptoms affecting multiple systems and organs over time. Due to the absence of validated biomarkers and similarity in symptoms, both disorders are misdiagnosed, and the comorbidity of the two is often unrecognized. Our study aimed to investigate the expression profiles of 11 circulating miRNAs previously associated with ME/CFS pathogenesis in FM patients and individuals with a comorbid diagnosis of FM associated with ME/CFS (ME/CFS + FM), and matched sedentary healthy controls. Whether these 11 circulating miRNAs expression can differentiate between the two disorders was also examined. Our results highlight differential circulating miRNAs expression signatures between ME/CFS, FM and ME/CFS + FM, which also correlate to symptom severity between ME/CFS and ME/CFS + FM groups. We provided a prediction model, by using a machine-learning approach based on 11 circulating miRNAs levels, which can be used to discriminate between patients suffering from ME/CFS, FM and ME/CFS + FM. These 11 miRNAs are proposed as potential biomarkers for discriminating ME/CFS from FM. The results of this study demonstrate that ME/CFS and FM are two distinct illnesses, and we highlight the comorbidity between the two conditions. Proper diagnosis of patients suffering from ME/CFS, FM or ME/CFS + FM is crucial to elucidate the pathophysiology of both diseases, determine preventive measures, and establish more effective treatments.


Asunto(s)
MicroARN Circulante , Síndrome de Fatiga Crónica , Fibromialgia , MicroARNs , Humanos , Síndrome de Fatiga Crónica/diagnóstico , Síndrome de Fatiga Crónica/genética , Fibromialgia/diagnóstico , Fibromialgia/genética , MicroARN Circulante/genética , Enfermedad Crónica , Biomarcadores
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