RESUMEN
Trypanosome parasites control their virulence and spread by using quorum sensing (QS) to generate transmissible "stumpy forms" in their host bloodstream. However, the QS signal "stumpy induction factor" (SIF) and its reception mechanism are unknown. Although trypanosomes lack G protein-coupled receptor signaling, we have identified a surface GPR89-family protein that regulates stumpy formation. TbGPR89 is expressed on bloodstream "slender form" trypanosomes, which receive the SIF signal, and when ectopically expressed, TbGPR89 drives stumpy formation in a SIF-pathway-dependent process. Structural modeling of TbGPR89 predicts unexpected similarity to oligopeptide transporters (POT), and when expressed in bacteria, TbGPR89 transports oligopeptides. Conversely, expression of an E. coli POT in trypanosomes drives parasite differentiation, and oligopeptides promote stumpy formation in vitro. Furthermore, the expression of secreted trypanosome oligopeptidases generates a paracrine signal that accelerates stumpy formation in vivo. Peptidase-generated oligopeptide QS signals being received through TbGPR89 provides a mechanism for both trypanosome SIF production and reception.
Asunto(s)
Proteínas de Transporte de Membrana/fisiología , Percepción de Quorum/fisiología , Trypanosoma/metabolismo , Diferenciación Celular , Secuencia Conservada/genética , Proteínas de Unión al GTP/metabolismo , Proteínas de Transporte de Membrana/genética , Oligopéptidos/genética , Oligopéptidos/fisiología , Filogenia , Proteínas Protozoarias/metabolismo , Percepción de Quorum/genética , Transducción de Señal , Trypanosoma/fisiología , Trypanosoma brucei brucei/metabolismo , Tripanosomiasis Africana/parasitología , Virulencia/fisiologíaRESUMEN
Conjugative pili are widespread bacterial appendages that play important roles in horizontal gene transfer, in spread of antibiotic resistance genes, and as sites of phage attachment. Among conjugative pili, the F "sex" pilus encoded by the F plasmid is the best functionally characterized, and it is also historically the most important, as the discovery of F-plasmid-mediated conjugation ushered in the era of molecular biology and genetics. Yet, its structure is unknown. Here, we present atomic models of two F family pili, the F and pED208 pili, generated from cryoelectron microscopy reconstructions at 5.0 and 3.6 Å resolution, respectively. These structures reveal that conjugative pili are assemblies of stoichiometric protein-phospholipid units. We further demonstrate that each pilus type binds preferentially to particular phospholipids. These structures provide the molecular basis for F pilus assembly and also shed light on the remarkable properties of conjugative pili in bacterial secretion and phage infection.
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Proteínas de Escherichia coli/química , Escherichia coli/fisiología , Factor F/química , Fimbrias Bacterianas/química , Modelos Moleculares , Fosfolípidos/química , Sitios de Ligazón Microbiológica/genética , Microscopía por Crioelectrón , Proteínas de Escherichia coli/metabolismo , Factor F/genética , Fimbrias Bacterianas/genética , Fimbrias Bacterianas/metabolismo , Lípidos/química , Mutación , Fosfolípidos/metabolismo , Unión Proteica , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Sistemas de Secreción Tipo V/química , Sistemas de Secreción Tipo V/metabolismoRESUMEN
Liposomal amphotericin B is an important frontline drug for the treatment of visceral leishmaniasis, a neglected disease of poverty. The mechanism of action of amphotericin B (AmB) is thought to involve interaction with ergosterol and other ergostane sterols, resulting in disruption of the integrity and key functions of the plasma membrane. Emergence of clinically refractory isolates of Leishmania donovani and L. infantum is an ongoing issue and knowledge of potential resistance mechanisms can help to alleviate this problem. Here we report the characterisation of four independently selected L. donovani clones that are resistant to AmB. Whole genome sequencing revealed that in three of the moderately resistant clones, resistance was due solely to the deletion of a gene encoding C24-sterol methyltransferase (SMT1). The fourth, hyper-resistant resistant clone (>60-fold) was found to have a 24 bp deletion in both alleles of a gene encoding a putative cytochrome P450 reductase (P450R1). Metabolic profiling indicated these parasites were virtually devoid of ergosterol (0.2% versus 18% of total sterols in wild-type) and had a marked accumulation of 14-methylfecosterol (75% versus 0.1% of total sterols in wild-type) and other 14-alpha methylcholestanes. These are substrates for sterol 14-alpha demethylase (CYP51) suggesting that this enzyme may be a bona fide P450R specifically involved in electron transfer from NADPH to CYP51 during catalysis. Deletion of P450R1 in wild-type cells phenocopied the metabolic changes observed in our AmB hyper-resistant clone as well as in CYP51 nulls. Likewise, addition of a wild type P450R1 gene restored sterol profiles to wild type. Our studies indicate that P450R1 is essential for L. donovani amastigote viability, thus loss of this gene is unlikely to be a driver of clinical resistance. Nevertheless, investigating the mechanisms underpinning AmB resistance in these cells provided insights that refine our understanding of the L. donovani sterol biosynthetic pathway.
Asunto(s)
Resistencia a Medicamentos , Leishmania donovani , Leishmaniasis Visceral , Esterol 14-Desmetilasa , Leishmania donovani/enzimología , Esterol 14-Desmetilasa/metabolismo , Esterol 14-Desmetilasa/genética , Leishmaniasis Visceral/parasitología , Leishmaniasis Visceral/tratamiento farmacológico , Anfotericina B/farmacología , Proteínas Protozoarias/metabolismo , Proteínas Protozoarias/genética , NADPH-Ferrihemoproteína Reductasa/metabolismo , NADPH-Ferrihemoproteína Reductasa/genética , Antiprotozoarios/farmacología , Humanos , Ergosterol/metabolismoRESUMEN
Host-specific plant pathogens must coordinate their life cycles with the availability of a host plant. Although this is frequently achieved through a response to specific chemical cues derived from the host plant, little is known about the molecular basis of the response to such cues and how these are used to trigger activation of the life cycle. In host-specific plant-parasitic cyst nematodes, unhatched juvenile nematodes lie dormant in the eggshell until chemical cues from a suitable host plant are detected and the hatching process is initiated. The molecular mechanisms by which hatch is linked to the presence of these chemical cues is unknown. We have identified a novel annexin-like protein that is localised to the eggshell of the potato cyst nematode Globodera rostochiensis. This annexin is unique in having a short peptide insertion that structural modelling predicts is present in one of the calcium-binding sites of this protein. Host-induced gene silencing of the annexin impacts the ability of the nematode to regulate and control permeability of the eggshell. We show that in the presence of the chemicals that induce hatching annexin lipid binding capabilities change, providing the first molecular link between a nematode eggshell protein and host-derived cues. This work demonstrates how a protein from a large family has been recruited to play a critical role in the perception of the presence of a host and provides a new potential route for control of cyst nematodes that impact global food production.
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Parásitos , Tylenchoidea , Animales , Anexinas , Cáscara de Huevo , Plantas , Estadios del Ciclo de VidaRESUMEN
Shiga toxin-producing Escherichia coli (STEC) is an important waterborne pathogen capable of causing serious gastrointestinal infections with potentially fatal complications, including haemolytic-uremic syndrome. All STEC serogroups harbour genes that encode at least one Shiga toxin (stx1 and/or stx2), which constitute the primary virulence factors of STEC. Loop-mediated isothermal amplification (LAMP) enables rapid real-time pathogen detection with a high degree of specificity and sensitivity. The aim of this study was to develop and validate an on-site portable diagnostics workstation employing LAMP technology to permit rapid real-time STEC detection in environmental water samples. Water samples (n=28) were collected from groundwater wells (n=13), rivers (n=12), a turlough (n=2) and an agricultural drain (n=1) from the Corrib catchment in Galway. Water samples (100 ml) were passed through a 0.22 µm filter, and buffer was added to elute captured cells. Following filtration, eluates were tested directly using LAMP assays targeting stx1, stx2 and E. coli phoA genes. The portable diagnostics workstation was used in field studies to demonstrate the on-site testing capabilities of the instrument. Real-time PCR assays targeting stx1 and stx2 genes were used to confirm the results. The limit of detection for stx1, stx2 and phoA LAMP assays were 2, 2 and 6 copies, respectively. Overall, stx1, stx2 and phoA genes were detected by LAMP in 15/28 (53.6â%), 9/28 (32.2â%) and 24/28 (85.7â%) samples, respectively. For confirmation, the LAMP results for stx1 and stx2 correlated perfectly (100â%) with those obtained using PCR. The portable diagnostics workstation exhibited high sensitivity throughout the on-site operation, and the average time from sample collection to final result was 40 min. We describe a simple, transferable and efficient diagnostic technology for on-site molecular analysis of various water sources. This method allows on-site testing of drinking water, enabling evidence-based decision-making by public health and water management authorities.
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Técnicas de Amplificación de Ácido Nucleico , Escherichia coli Shiga-Toxigénica , Microbiología del Agua , Técnicas de Amplificación de Ácido Nucleico/métodos , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/instrumentación , Sensibilidad y Especificidad , Ríos/microbiología , Toxina Shiga I/genética , Agua Subterránea/microbiologíaRESUMEN
Anti-viral surface coatings are under development to prevent viral fomite transmission from high-traffic touch surfaces in public spaces. Copper's anti-viral properties have been widely documented, but the anti-viral mechanism of copper surfaces is not fully understood. We screened a series of metal and metal oxide surfaces for anti-viral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19). Copper and copper oxide surfaces exhibited superior anti-SARS-CoV-2 activity; however, the level of anti-viral activity was dependent on the composition of the carrier solution used to deliver virus inoculum. We demonstrate that copper ions released into solution from test surfaces can mediate virus inactivation, indicating a copper ion dissolution-dependent anti-viral mechanism. The level of anti-viral activity is, however, not dependent on the amount of copper ions released into solution per se. Instead, our findings suggest that degree of virus inactivation is dependent on copper ion complexation with other biomolecules (e.g., proteins/metabolites) in the virus carrier solution that compete with viral components. Although using tissue culture-derived virus inoculum is experimentally convenient to evaluate the anti-viral activity of copper-derived test surfaces, we propose that the high organic content of tissue culture medium reduces the availability of "uncomplexed" copper ions to interact with the virus, negatively affecting virus inactivation and hence surface anti-viral performance. We propose that laboratory anti-viral surface testing should include virus delivered in a physiologically relevant carrier solution (saliva or nasal secretions when testing respiratory viruses) to accurately predict real-life surface anti-viral performance when deployed in public spaces.IMPORTANCEThe purpose of evaluating the anti-viral activity of test surfaces in the laboratory is to identify surfaces that will perform efficiently in preventing fomite transmission when deployed on high-traffic touch surfaces in public spaces. The conventional method in laboratory testing is to use tissue culture-derived virus inoculum; however, this study demonstrates that anti-viral performance of test copper-containing surfaces is dependent on the composition of the carrier solution in which the virus inoculum is delivered to test surfaces. Therefore, we recommend that laboratory surface testing should include virus delivered in a physiologically relevant carrier solution to accurately predict real-life test surface performance in public spaces. Understanding the mechanism of virus inactivation is key to future rational design of improved anti-viral surfaces. Here, we demonstrate that release of copper ions from copper surfaces into small liquid droplets containing SARS-CoV-2 is a mechanism by which the virus that causes COVID-19 can be inactivated.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Cobre/farmacología , Antivirales , Óxidos , IonesRESUMEN
PURPOSE: Assess incidence, severity, and glucose excursion outcomes in thyroid eye disease (TED) patients receiving the insulin-like growth factor-1 receptor inhibitor teprotumumab from 3 clinical trials. DESIGN: Analysis of pooled glycemic data over time. PARTICIPANTS: Eighty-four teprotumumab- and 86 placebo-treated active TED patients from the phase 2 and phase 3 (OPTIC) controlled clinical trials and 51 teprotumumab-treated patients from the OPTIC extension (OPTIC-X) trial. METHODS: Eight intravenous infusions were given over 21 weeks. Phase 2 serum glucose was measured at weeks 1, 4, 15, and 21, with fasting measurements at weeks 1 and 4. Serum glucose was measured at each study visit in OPTIC and OPTIC-X, with fasting measurements at weeks 1 and 4 (in patients without diabetes) or all visits (in patients with diabetes). In all studies, hemoglobin A1c (HbA1c) was measured at baseline, 12, and 24 weeks plus weeks 36 and 48 in OPTIC-X. MAIN OUTCOME MEASURES: Serum glucose and HbA1c. RESULTS: In the phase 2 and 3 studies, 9 hyperglycemic episodes occurred in 8 teprotumumab patients; mean HbA1c level increased 0.22% from baseline to week 24 (to 5.8%; range, 5.0%-7.9%) versus 0.04% in patients receiving the placebo (to 5.6%; range, 4.6%-8.1%). At study end, 78% (59/76) of teprotumumab patients and 87% (67/77) of patients receiving placebo had normoglycemic findings. Normoglycemia was maintained in 84% (57/68) of patients receiving teprotumumab and 93% (64/69) of patients receiving placebo. Among baseline prediabetic patients, 43% (3/7) remained prediabetic in both groups, and 29% (2/7) of teprotumumab patients and 14% (1/7) of patients receiving placebo had diabetic findings at week 24. OPTIC-X patients trended toward increased fasting glucose and HbA1c whether initially treated or retreated with teprotumumab. Fasting glucose commonly rose after 2 or 3 infusions and stabilized thereafter. Most hyperglycemic incidents occurred in patients with baseline prediabetes/diabetes but were controlled with medication. No evidence was found for progression or increased incidence of hyperglycemia with subsequent doses. CONCLUSIONS: Serious glycemic excursions are uncommon in patients with normoglycemia before teprotumumab therapy. Patients with controlled diabetes or impaired glucose tolerance can be treated safely if baseline screening, regular monitoring of glycemic control, and timely treatment of hyperglycemia are practiced. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Anticuerpos Monoclonales Humanizados , Glucemia , Hemoglobina Glucada , Oftalmopatía de Graves , Humanos , Glucemia/metabolismo , Masculino , Hemoglobina Glucada/metabolismo , Femenino , Anticuerpos Monoclonales Humanizados/uso terapéutico , Persona de Mediana Edad , Oftalmopatía de Graves/tratamiento farmacológico , Oftalmopatía de Graves/sangre , Método Doble Ciego , Adulto , Infusiones Intravenosas , AncianoRESUMEN
The protozoan parasites Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. are responsible for continued propagation of neglected tropical diseases such as African sleeping sickness, Chagas disease and leishmaniasis respectively. Following a report that captopril targets Leishmania donovani dipeptidyl carboxypeptidase, a series of simple proline amides and captopril analogues were synthesized and found to exhibit 1-2 µM in vitro inhibition and selectivity against Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. The results were corroborated with computational docking studies. Arguably, the synthetic proline amides represent the structurally simplest examples of in vitro pan antiprotozoal compounds.
Asunto(s)
Captopril , Trypanosoma brucei brucei , Trypanosoma cruzi , Captopril/farmacología , Captopril/química , Captopril/síntesis química , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma brucei brucei/enzimología , Trypanosoma cruzi/efectos de los fármacos , Trypanosoma cruzi/enzimología , Relación Estructura-Actividad , Simulación del Acoplamiento Molecular , Tripanocidas/farmacología , Tripanocidas/química , Tripanocidas/síntesis química , Estructura Molecular , Leishmania/efectos de los fármacos , Leishmania/enzimología , Antiprotozoarios/farmacología , Antiprotozoarios/química , Antiprotozoarios/síntesis química , HumanosRESUMEN
Haemonchus contortus is a parasitic haematophagous nematode that primarily affects small ruminants and causes significant economic loss to the global livestock industry. Treatment of haemonchosis typically relies on broad-spectrum anthelmintics, resistance to which is an important cause of treatment failure. Resistance to levamisole remains less widespread than to other major anthelmintic classes, prompting the need for more effective and accurate surveillance to maintain its efficacy. Loop-primer endonuclease cleavage loop-mediated isothermal amplification (LEC-LAMP) is a recently developed diagnostic method that facilitates multiplex target detection with single nucleotide polymorphism (SNP) specificity and portable onsite testing. In this study, we designed a new LEC-LAMP assay and applied it to detect the levamisole resistance marker S168T in H. contortus. We explored multiplexing probes for both the resistant S168T and the susceptible S168 alleles in a single-tube assay. We then included a generic probe to detect the acr-8 gene in the multiplex assay, which could facilitate the quantification of both resistance markers and overall genetic material from H. contortus in a single step. Our results showed promising application of these technologies, demonstrating a proof-of-concept assay which is amenable to detection of resistance alleles within the parasite population, with the potential for multiplex detection, and point-of-care application enabled by lateral flow end-point detection. However, further optimisation and validation is necessary.
Asunto(s)
Antihelmínticos , Haemonchus , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Animales , Levamisol/farmacología , Haemonchus/genética , Resistencia a Medicamentos/genética , Antihelmínticos/farmacología , Antihelmínticos/uso terapéuticoRESUMEN
OBJECTIVE: In thyroid eye disease (TED), inflammation and expansion of orbital muscle and periorbital fat result in diplopia and proptosis, severely impacting patient quality of life (QOL). The reported health state utility (HSU) scores, which are QOL measures, allow quantification of TED impact and improvement with therapies; however, no current QOL instrument has been validated with HSU scores for TED. Here, we used the disease-specific Graves Ophthalmopathy Quality of Life (GO-QOL) questionnaire and HSU scores to validate QOL impact. METHODS: The GO-QOL scores from patients in 2 randomized, masked, placebo-controlled teprotumumab trials (N=171) were compared with 6 HSU values based on severity of proptosis/diplopia in those studies. Patient GO-QOL and HSU scores were compared at baseline and after 6-month treatment via regression analyses. GO-QOL and HSU scores were correlated for validation and quantification of QOL impact by severity state and to estimate quality-adjusted life year improvement. RESULTS: GO-QOL scores were correlated with TED severity, indicating that worse severity was associated with lower (worse) GO-QOL scores. Less severe health states were represented by higher (better) GO-QOL scores. Importantly, GO-QOL scores were positively correlated with utility scores of the 6 health states, allowing for conversion of the GO-QOL scores to utility scores. A positive (improved) 0.013 utility change was found for each 1-point (positive) improvement in GO-QOL score produced by teprotumumab versus placebo. CONCLUSION: Patients with moderate-to-severe active TED health states demonstrate increasing TED severity associated with declining utility values and worsening GO-QOL scores. These results indicate that the GO-QOL scores can be used to bridge to the HSU scores for benefit quantification.
Asunto(s)
Anticuerpos Monoclonales Humanizados , Oftalmopatía de Graves , Calidad de Vida , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Anticuerpos Monoclonales Humanizados/uso terapéutico , Exoftalmia , Oftalmopatía de Graves/psicología , Oftalmopatía de Graves/tratamiento farmacológico , Estado de Salud , Índice de Severidad de la Enfermedad , Encuestas y CuestionariosRESUMEN
Thyroid-associated ophthalmopathy (TAO) represents a disfiguring and potentially blinding autoimmune component of Graves' disease. It appears to be driven, at least in part, by autoantibodies targeting the thyrotropin receptor (TSHR)/insulin-like growth factor I receptor (IGF-IR) complex. Actions mediated through either TSHR or IGF-IR are dependent on IGF-IR activity. CD34+ fibrocytes, monocyte lineage cells, reside uniquely in the TAO orbit, where they masquerade as CD34+ orbital fibroblasts. Fibrocytes present antigens to T cells through their display of the major histocompatibility complex class II (MHC II) while providing costimulation through B7 proteins (CD80, CD86, and programmed death-ligand 1 [PD-L1]). Here, we demonstrate that teprotumumab, an anti-IGF-IR inhibitor, attenuates constitutive expression and induction by the thyroid-stimulating hormone of MHC II and these B7 members in CD34+ fibrocytes. These actions are mediated through reduction of respective gene transcriptional activity. Other IGF-IR inhibitors (1H7 and linsitinib) and knocking down IGF-IR gene expression had similar effects. Interrogation of circulating fibrocytes collected from patients with TAO, prior to and following teprotumumab treatment in vivo during a phase 2 clinical trial, demonstrated reductions in cell-surface MHC II and B7 proteins similar to those found following IGF-IR inhibitor treatment in vitro. Teprotumumab therapy reduces levels of interferon-γ and IL-17A expression in circulating CD4+ T cells, effects that may be indirect and mediated through actions of the drug on fibrocytes. Teprotumumab was approved by the US Food and Drug Administration for TAO. Our current findings identify potential mechanisms through which teprotumumab might be eliciting its clinical response systemically in patients with TAO, potentially by restoring immune tolerance.
Asunto(s)
Fibroblastos , Oftalmopatía de Graves/metabolismo , Receptor IGF Tipo 1/antagonistas & inhibidores , Anticuerpos Monoclonales Humanizados/farmacología , Autoanticuerpos/metabolismo , Células Cultivadas , Citocinas/metabolismo , Fibroblastos/efectos de los fármacos , Fibroblastos/inmunología , Fibroblastos/metabolismo , Humanos , Receptores de Tirotropina/metabolismoRESUMEN
BACKGROUND: Thyroid eye disease is a debilitating, disfiguring, and potentially blinding periocular condition for which no Food and Drug Administration-approved medical therapy is available. Strong evidence has implicated the insulin-like growth factor I receptor (IGF-IR) in the pathogenesis of this disease. METHODS: In a randomized, double-masked, placebo-controlled, phase 3 multicenter trial, we assigned patients with active thyroid eye disease in a 1:1 ratio to receive intravenous infusions of the IGF-IR inhibitor teprotumumab (10 mg per kilogram of body weight for the first infusion and 20 mg per kilogram for subsequent infusions) or placebo once every 3 weeks for 21 weeks; the last trial visit for this analysis was at week 24. The primary outcome was a proptosis response (a reduction in proptosis of ≥2 mm) at week 24. Prespecified secondary outcomes at week 24 were an overall response (a reduction of ≥2 points in the Clinical Activity Score plus a reduction in proptosis of ≥2 mm), a Clinical Activity Score of 0 or 1 (indicating no or minimal inflammation), the mean change in proptosis across trial visits (from baseline through week 24), a diplopia response (a reduction in diplopia of ≥1 grade), and the mean change in overall score on the Graves' ophthalmopathy-specific quality-of-life (GO-QOL) questionnaire across trial visits (from baseline through week 24; a mean change of ≥6 points is considered clinically meaningful). RESULTS: A total of 41 patients were assigned to the teprotumumab group and 42 to the placebo group. At week 24, the percentage of patients with a proptosis response was higher with teprotumumab than with placebo (83% [34 patients] vs. 10% [4 patients], P<0.001), with a number needed to treat of 1.36. All secondary outcomes were significantly better with teprotumumab than with placebo, including overall response (78% of patients [32] vs. 7% [3]), Clinical Activity Score of 0 or 1 (59% [24] vs. 21% [9]), the mean change in proptosis (-2.82 mm vs. -0.54 mm), diplopia response (68% [19 of 28] vs. 29% [8 of 28]), and the mean change in GO-QOL overall score (13.79 points vs. 4.43 points) (P≤0.001 for all). Reductions in extraocular muscle, orbital fat volume, or both were observed in 6 patients in the teprotumumab group who underwent orbital imaging. Most adverse events were mild or moderate in severity; two serious events occurred in the teprotumumab group, of which one (an infusion reaction) led to treatment discontinuation. CONCLUSIONS: Among patients with active thyroid eye disease, teprotumumab resulted in better outcomes with respect to proptosis, Clinical Activity Score, diplopia, and quality of life than placebo; serious adverse events were uncommon. (Funded by Horizon Therapeutics; OPTIC ClinicalTrials.gov number, NCT03298867, and EudraCT number, 2017-002763-18.).
Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Oftalmopatía de Graves/tratamiento farmacológico , Receptor IGF Tipo 1/antagonistas & inhibidores , Adulto , Anciano , Anticuerpos Monoclonales Humanizados/efectos adversos , Diplopía/tratamiento farmacológico , Método Doble Ciego , Esquema de Medicación , Exoftalmia/tratamiento farmacológico , Oftalmopatía de Graves/diagnóstico por imagen , Humanos , Análisis de Intención de Tratar , Imagen por Resonancia Magnética , Persona de Mediana Edad , Órbita/diagnóstico por imagen , Receptor IGF Tipo 1/inmunología , AutoinformeRESUMEN
OBJECTIVE: Patients with myelin oligodendrocyte glycoprotein antibody (MOG-IgG)-associated disease (MOGAD) suffer from severe optic neuritis (ON) leading to retinal neuro-axonal loss, which can be quantified by optical coherence tomography (OCT). We assessed whether ON-independent retinal atrophy can be detected in MOGAD. METHODS: Eighty patients with MOGAD and 139 healthy controls (HCs) were included. OCT data was acquired with (1) Spectralis spectral domain OCT (MOGAD: N = 66 and HCs: N = 103) and (2) Cirrus high-definition OCT (MOGAD: N = 14 and HCs: N = 36). Macular combined ganglion cell and inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) were quantified. RESULTS: At baseline, GCIPL and pRNFL were lower in MOGAD eyes with a history of ON (MOGAD-ON) compared with MOGAD eyes without a history of ON (MOGAD-NON) and HCs (p < 0.001). MOGAD-NON eyes had lower GCIPL volume compared to HCs (p < 0.001) in the Spectralis, but not in the Cirrus cohort. Longitudinally (follow-up up to 3 years), MOGAD-ON with ON within the last 6-12 months before baseline exhibited greater pRNFL thinning than MOGAD-ON with an ON greater than 12 months ago (p < 0.001). The overall MOGAD cohort did not exhibit faster GCIPL thinning compared with the HC cohort. INTERPRETATION: Our study suggests the absence of attack-independent retinal damage in patients with MOGAD. Yet, ongoing neuroaxonal damage or edema resolution seems to occur for up to 12 months after ON, which is longer than what has been reported with other ON forms. These findings support that the pathomechanisms underlying optic nerve involvement and the evolution of OCT retinal changes after ON is distinct in patients with MOGAD. ANN NEUROL 2022;92:476-485.
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Síndromes de Inmunodeficiencia/complicaciones , Glicoproteína Mielina-Oligodendrócito/inmunología , Neuritis Óptica/complicaciones , Degeneración Retiniana/etiología , Estudios de Casos y Controles , Estudios de Cohortes , Humanos , Estudios Longitudinales , Neuritis Óptica/diagnóstico por imagen , Neuritis Óptica/etiología , Retina/diagnóstico por imagen , Neuronas Retinianas , Tomografía de Coherencia Óptica/métodosRESUMEN
BACKGROUND: The novel optic neuritis (ON) diagnostic criteria include intereye differences (IED) of optical coherence tomography (OCT) parameters. IED has proven valuable for ON diagnosis in multiple sclerosis but has not been evaluated in aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorders (AQP4+NMOSD). We evaluated the diagnostic accuracy of intereye absolute (IEAD) and percentage difference (IEPD) in AQP4+NMOSD after unilateral ON >6 months before OCT as compared with healthy controls (HC). METHODS: Twenty-eight AQP4+NMOSD after unilateral ON (NMOSD-ON), 62 HC and 45 AQP4+NMOSD without ON history (NMOSD-NON) were recruited by 13 centres as part of the international Collaborative Retrospective Study on retinal OCT in Neuromyelitis Optica study. Mean thickness of peripapillary retinal nerve fibre layer (pRNFL) and macular ganglion cell and inner plexiform layer (GCIPL) were quantified by Spectralis spectral domain OCT. Threshold values of the ON diagnostic criteria (pRNFL: IEAD 5 µm, IEPD 5%; GCIPL: IEAD: 4 µm, IEPD: 4%) were evaluated using receiver operating characteristics and area under the curve (AUC) metrics. RESULTS: The discriminative power was high for NMOSD-ON versus HC for IEAD (pRNFL: AUC 0.95, specificity 82%, sensitivity 86%; GCIPL: AUC 0.93, specificity 98%, sensitivity 75%) and IEPD (pRNFL: AUC 0.96, specificity 87%, sensitivity 89%; GCIPL: AUC 0.94, specificity 96%, sensitivity 82%). The discriminative power was high/moderate for NMOSD-ON versus NMOSD-NON for IEAD (pRNFL: AUC 0.92, specificity 77%, sensitivity 86%; GCIP: AUC 0.87, specificity 85%, sensitivity 75%) and for IEPD (pRNFL: AUC 0.94, specificity 82%, sensitivity 89%; GCIP: AUC 0.88, specificity 82%, sensitivity 82%). CONCLUSIONS: Results support the validation of the IED metrics as OCT parameters of the novel diagnostic ON criteria in AQP4+NMOSD.
Asunto(s)
Acuaporinas , Neuromielitis Óptica , Neuritis Óptica , Humanos , Neuromielitis Óptica/diagnóstico , Estudios Retrospectivos , Benchmarking , Neuritis Óptica/diagnóstico , Tomografía de Coherencia Óptica/métodos , Autoanticuerpos , Acuaporina 4RESUMEN
PURPOSE: Review the historical context of research and changing therapeutic landscape of thyroid-associated ophthalmopathy (TAO) by focusing on the relationship between TAO, CD34+ fibrocytes, thyrotropin receptor (TSHR), and insulin-like growth factor-I receptor (IGF-IR). METHODS: A literature review using search terms, including fibrocytes, IGF-IR, TSHR, TAO, and thyroid eye disease. RESULTS: The mechanisms involved in TAO have been partially identified. Substantial progress has been made over several decades, including 1) recognizing the interplay between the professional immune system and orbital tissues; 2) TSHR and IGF-IR act interdependently in mediating the pathogenesis of TAO; 3) Multiple cytokines and specific immune cells are involved in activating and remodeling orbital tissue; 4) Recognition of these mechanisms is allowing the development of target therapies such as teprotumumab, a monoclonal antibody IGF-IR inhibitor approved by the US Food and drug administration for treatment of TAO; and 5) It appears that teprotumumab acts on the systemic immune system peripheral to the orbit. CONCLUSION: Additional molecules targeting IGF-IR and other plausible disease mechanisms are currently under development. This activity in the TAO therapeutic space portends even greater improvements in patient care.
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Oftalmopatía de Graves , Estados Unidos , Humanos , Oftalmopatía de Graves/tratamiento farmacológico , Anticuerpos Monoclonales , Inhibidores de Proteínas Quinasas , Receptores de Tirotropina , United States Food and Drug AdministrationRESUMEN
C/EBP homologous protein (CHOP), also known as growth arrest and DNA damage-inducible protein 153 (GADD153), belongs to the CCAAT/enhancer-binding protein (C/EBP) family. CHOP expression is induced by unfolded protein response (UPR), and sustained CHOP activation acts as a pivotal trigger for ER stress-induced apoptosis. MicroRNA-616 is located within an intron of the CHOP gene. However, the regulation of miR-616 expression during UPR and its function in breast cancer is not clearly understood. Here we show that the expression of miR-616 and CHOP (host gene of miR-616) is downregulated in human breast cancer. Both miR-5p/-3p arms of miR-616 are expressed with levels of the 5p arm higher than the 3p arm. During conditions of ER stress, the expression of miR-616-5p and miR-616-3p arms was concordantly increased primarily through the PERK pathway. Our results show that ectopic expression of miR-616 significantly suppressed cell proliferation and colony formation, whereas knockout of miR-616 increased it. We found that miR-616 represses c-MYC expression via binding sites located in its protein coding region. Furthermore, we show that miR-616 exerted growth inhibitory effects on cells by suppressing c-MYC expression. Our results establish a new role for the CHOP locus by providing evidence that miR-616 can inhibit cell proliferation by targeting c-MYC. In summary, our results suggest a dual function for the CHOP locus, where CHOP protein and miR-616 can cooperate to inhibit cancer progression.
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Neoplasias de la Mama , MicroARNs , Femenino , Humanos , Neoplasias de la Mama/genética , Proliferación Celular/genética , Genes myc , MicroARNs/genética , Respuesta de Proteína Desplegada/genética , Proteínas Proto-Oncogénicas c-mycRESUMEN
X-box binding protein 1 (XBP1) is a transcription factor that plays a crucial role in the unfolded protein response (UPR), a cellular stress response pathway involved in maintaining protein homeostasis in the endoplasmic reticulum (EnR). While the role of XBP1 in UPR is well-characterised, emerging evidence suggests its involvement in endocrine resistance in breast cancer. The transcriptional activity of spliced XBP1 (XBP1s) is a major component of its biological effects, but the targets of XBP1s in estrogen receptor (ER)-positive breast cancer are not well understood. Here, we show that the expression of miR-378 and PPARGC1B (host gene of miR-378) is downregulated during UPR. Using chemical and genetic methods, we show that XBP1s is necessary and sufficient for the downregulation of miR-378 and PPARGC1B. Our results show that overexpression of miR-378 significantly suppressed cell growth, colony formation, and migration of ER-positive breast cancer cells. Further, we found that expression of miR-378 sensitised the cells to UPR-induced cell death and anti-estrogens. The expression of miR-378 and PPARGC1B was downregulated in breast cancer, and higher expression of miR-378 is associated with better outcomes in ER-positive breast cancer. We found that miR-378 upregulates the expression of several genes that regulate type I interferon signalling. Analysis of separate cohorts of breast cancer patients showed that a gene signature derived from miR-378 upregulated genes showed a strong association with improved overall and recurrence-free survival in breast cancer. Our results suggest a growth-suppressive role for miR-378 in ER-positive breast cancer where downregulation of miR-378 by XBP1 contributes to endocrine resistance in ER-positive breast cancer.
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Neoplasias de la Mama , MicroARNs , Humanos , Femenino , Proteína 1 de Unión a la X-Box/genética , Neoplasias de la Mama/genética , Proliferación Celular/genética , Mama , MicroARNs/genética , Proteínas de Unión al ARNRESUMEN
Thyroid-associated ophthalmopathy (TAO), the ocular manifestation of Graves' disease, is a process in which orbital connective tissues and extraocular muscles undergo inflammation and remodeling. The condition seems to result from autoimmune responses to antigens shared by the thyroid and orbit. The thyrotropin receptor (TSHR), expressed at low levels in orbital tissues, is a leading candidate antigen. Recent evidence suggests that another protein, the insulin-like growth factor-I receptor (IGF-IR), is overexpressed in TAO, and antibodies against IGF-IR have been detected in patients with the disease. Furthermore, TSHR and IGF-IR form a physical and functional complex, and signaling initiated at TSHR requires IGF-IR activity. Identification of therapy for this rare disease has proven challenging and currently relies on nonspecific and inadequate agents, thus representing an important unmet need. A recently completed therapeutic trial suggests that inhibiting IGF-IR activity with a monoclonal antibody may be an effective and safe treatment for active TAO.
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Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Oftalmopatía de Graves/tratamiento farmacológico , Glándula Tiroides/efectos de los fármacos , Animales , Oftalmopatía de Graves/metabolismo , Humanos , Producción de Medicamentos sin Interés Comercial/métodos , Enfermedades Raras/tratamiento farmacológico , Enfermedades Raras/metabolismo , Receptor IGF Tipo 1/metabolismo , Receptores de Tirotropina/metabolismo , Glándula Tiroides/metabolismoRESUMEN
This review highlights the key role of fatty acid desaturases in the synthesis of naturally occurring, more common and not unsaturated fatty acids. The three major classes of fatty acid desaturases, such as acyl-lipid, acyl-acyl carrier protein and acyl-coenzyme A, are described in detail, with particular attention to the cellular localisation, the structure, the substrate and product specificity and the expression and regulation of desaturase genes. The review also gives an insight into the biocatalytic reaction of fatty acid desaturation by covering the general and more class-specific mechanistic studies around the synthesis of unsaturated fatty acids Finally, we conclude the review by looking at the numerous novel applications for desaturases in order to meet the very high demand for polyunsaturated fatty acids, taking into account the opportunity for the development of new, more efficient, easily reproducible, sustainable bioengineering advances in the field.
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Proteína Transportadora de Acilo , Ácidos Grasos Insaturados , Proteína Transportadora de Acilo/genética , Proteína Transportadora de Acilo/metabolismo , Ácidos Grasos Insaturados/metabolismo , Ácido Graso Desaturasas/genética , Ácido Graso Desaturasas/química , Ácido Graso Desaturasas/metabolismo , Coenzima A/metabolismo , Ácidos Grasos/metabolismo , Especificidad por SustratoRESUMEN
PURPOSE: To evaluate teprotumumab safety/efficacy in patients with thyroid eye disease (TED) who were nonresponsive or who experienced a disease flare. DESIGN: The Treatment of Graves' Orbitopathy to Reduce Proptosis with Teprotumumab Infusions in an Open-Label Clinical Extension Study (OPTIC-X) is a teprotumumab treatment and re-treatment trial following the placebo-controlled teprotumumab Phase 3 Treatment of Graves' Orbitopathy (Thyroid Eye Disease) to Reduce Proptosis with Teprotumumab Infusions in a Randomized, Placebo-Controlled, Clinical Study (OPTIC) trial. PARTICIPANTS: Patients who previously received placebo (n = 37) or teprotumumab (n = 14) in OPTIC. METHODS: OPTIC nonresponders or those who flared (≥2-mm increase in proptosis, ≥2-point increase in clinical activity score [CAS], or both) during follow-up were treated for the first time (previous placebo patients) or re-treated with teprotumumab in OPTIC-X with 8 infusions over 24 weeks. MAIN OUTCOME MEASURES: Proptosis response and safety. Secondary outcomes included proptosis, CAS, subjective diplopia, and quality-of-life. RESULTS: Thirty-three of 37 placebo-treated OPTIC patients (89.2%) became proptosis responders (mean ± standard deviation, -3.5 ± 1.7 mm) when treated with teprotumumab in OPTIC-X. The responses were equivalent to the OPTIC study. In these responders, proptosis, CAS of 0 or 1, and diplopia responses were maintained in 29 of 32 patients (90.6%), 20 of 21 patients (95.2%), and 12 of 14 patients (85.7%), respectively, at follow-up week 48. The median TED duration was 12.9 months versus 6.3 months in those treated with teprotumumab in the OPTIC study. Of the 5 OPTIC teprotumumab nonresponders re-treated in OPTIC-X, 2 responded, 1 showed a proptosis reduction of 1.5 mm from OPTIC baseline, and 2 discontinued treatment early. Of the OPTIC teprotumumab responders who experienced flare, 5 of 8 patients (62.5%) responded when re-treated (mean proptosis reduction, 1.9 ± 1.2 mm from OPTIC-X baseline and 3.3 ± 0.7 mm from OPTIC baseline). Compared with published double-masked trials and their integrated follow-up, no new safety signals were identified. Mild hearing impairment was reported; 4 events occurred during the first course of treatment, and 2 events reoccurred after re-treatment. CONCLUSIONS: Patients with TED of longer disease duration responded similarly to those treated earlier in the disease course. Patients with an insufficient initial response or flare may benefit from additional teprotumumab therapy. No new safety risk was identified; however additional postmarketing pharmacovigilance is ongoing.