RESUMEN
Chrysodeixis includens (Walker, [1858]) is one of the most important defoliator of soybean in Brazil because of its extensive geographical distribution and high tolerance to insecticides compared with other species of caterpillars. Because of this, we conducted bioassays to evaluate the efficacy of pyrethroid λ-cyhalothrin on a C. includens resistant strain (MS) and a susceptible (LAB) laboratory strain. High throughput RNA sequencing (RNA-seq) of larval head and body tissues were performed to identify potential molecular mechanisms underlying pyrethroid resistance. Insecticide bioassays showed that MS larvae exhibit 28.9-fold resistance to pyrethroid λ-cyhalothrin relative to LAB larvae. RNA-seq identified evidence of metabolic resistance in the head and body tissues: 15 cytochrome P450 transcripts of Cyp6, Cyp9, Cyp4, Cyp304, Cyp307, Cyp337, Cyp321 families, 7 glutathione-S-transferase (Gst) genes, 7 α-esterase genes from intracellular and secreted catalytic classes, and 8 UDP-glucuronosyltransferase (Ugt) were overexpressed in MS as compared with LAB larvae. We also identified overexpression of GPCR genes (CiGPCR64-like and CiGPCRMth2) in the head tissue. To validate RNA-seq results, we performed RT-qPCR to assay selected metabolic genes and confirmed their expression profiles. Specifically, CiCYP9a101v1, CiCYP6ae149, CiCYP6ae106v2, CiGSTe13, CiCOE47, and CiUGT33F21 exhibited significant overexpression in resistant MS larvae. In summary, our findings detailed potential mechanisms of metabolic detoxification underlying pyrethroid resistance in C. includens.
Asunto(s)
Insecticidas , Mariposas Nocturnas , Piretrinas , Animales , Brasil , Perfilación de la Expresión Génica , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Mariposas Nocturnas/genéticaRESUMEN
INTRODUCTION AND AIM: Direct-acting antiviral (DAA) agents are highly effective for treatment of chronic hepatitis C virus (HCV) yet access to treatment remains a serious challenge. The aim of this study was to identify barriers to treatment initiation with DAA-containing regimens in an urban clinic setting. MATERIALS AND METHODS: A retrospective cohort of all chronic HCV patients seen in an urban academic practice in Jacksonville, FL, USA from 1/2014 to 1/2017 was analyzed. Baseline characteristics were recorded and a review of medical records was performed to identify barriers to treatment initiation and overall success rates. RESULTS: Two-hundred and forty patients with chronic HCV were analyzed. Fifty-six percent of patients were African-American and 63% were insured through Medicaid/county programs or uninsured. Sixty-nine percent had barriers to initiating antiviral therapy categorized as psychosocial (n=112), provider (n=26), medical (n=20), and insurance-related factors (n=7). The most commonly encountered psychosocial barriers included failure to keep appointments (79/240, 33%), active substance abuse (18/240, 8%), and failure to obtain laboratory testing (11/240, 5%). Overall, only 27% of patients evaluated were initiated on DAA-containing regimens with 18% reaching SVR12 within the 36-month study period. CONCLUSION: In conclusion, only 27% of patients who presented to an urban academic practice with chronic HCV received DAA-containing regimens over a 36-month period. Psychosocial issues were the major barriers to antiviral therapy. These findings illustrate the need for an integrated approach that addresses psychosocial factors as well as comorbidities and adherence to care in order to increase rates of HCV treatment in at risk patients.
Asunto(s)
Antivirales/uso terapéutico , Accesibilidad a los Servicios de Salud , Hepatitis C Crónica/tratamiento farmacológico , Cooperación del Paciente , Servicios Urbanos de Salud , Citas y Horarios , Quimioterapia Combinada , Femenino , Florida/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Accesibilidad a los Servicios de Salud/economía , Hepatitis C Crónica/economía , Hepatitis C Crónica/etnología , Hepatitis C Crónica/psicología , Humanos , Seguro de Salud , Masculino , Persona de Mediana Edad , Cooperación del Paciente/etnología , Cooperación del Paciente/psicología , Estudios Retrospectivos , Trastornos Relacionados con Sustancias/etnología , Trastornos Relacionados con Sustancias/psicología , Respuesta Virológica Sostenida , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: The cytochromes P450 (P450s) are a large superfamily of heme-containing monooxygenases involved in the oxidative metabolism of an enormous diversity of substrates. These enzymes require electrons for their activity, and the electrons are supplied by NAD(P)H through a P450 electron donor system, which is generally a cytochrome P450 reductase (CPR). The yeast Xanthophyllomyces dendrorhous has evolved an exclusive P450-CPR system that specializes in the synthesis of astaxanthin, a carotenoid with commercial potential. For this reason, the aim of this work was to identify and characterize other potential P450 genes in the genome of this yeast using a bioinformatic approach. RESULTS: Thirteen potential P450-encoding genes were identified, and the analysis of their deduced proteins allowed them to be classified in ten different families: CYP51, CYP61, CYP5139 (with three members), CYP549A, CYP5491, CYP5492 (with two members), CYP5493, CYP53, CYP5494 and CYP5495. Structural analyses of the X. dendrorhous P450 proteins showed that all of them have a predicted transmembrane region at their N-terminus and have the conserved domains characteristic of the P450s, including the heme-binding region (FxxGxRxCxG); the PER domain, with the characteristic signature for fungi (PxRW); the ExxR motif in the K-helix region and the oxygen-binding domain (OBD) (AGxDTT); also, the characteristic secondary structure elements of all the P450 proteins were identified. The possible functions of these P450s include primary, secondary and xenobiotic metabolism reactions such as sterol biosynthesis, carotenoid synthesis and aromatic compound degradation. CONCLUSIONS: The carotenogenic yeast X. dendrorhous has thirteen P450-encoding genes having potential functions in primary, secondary and xenobiotic metabolism reactions, including some genes of great interest for fatty acid hydroxylation and aromatic compound degradation. These findings established a basis for future studies about the role of P450s in the carotenogenic yeast X. dendrorhous and their potential biotechnological applications.
Asunto(s)
Basidiomycota/enzimología , Basidiomycota/genética , Sistema Enzimático del Citocromo P-450/genética , Genómica , Secuencia de Aminoácidos , Sistema Enzimático del Citocromo P-450/química , Perfilación de la Expresión Génica , FilogeniaRESUMEN
Bark beetles (Curculionidae: Scolytinae) and associated microorganisms must overcome a complex tree's defence system, which includes toxic monoterpenes, to successfully complete their life cycle. A number of studies have suggested these microorganisms could have ecological roles related with the nutrition, detoxification, and semiochemical production. In particular, in filamentous fungi symbionts, cytochrome P450 (CYP) have been involved with terpenoid detoxification and biotransformation processes. Candida oregonensis has been isolated from the gut, ovaries, and frass of different bark beetle species, and it is a dominant species in the Dendroctonus rhizophagus gut. In this study, we identify, characterise, and infer the phylogenetic relationships of C. oregonensis CYP genes. The results indicate that the cytochrome P450 complement (CYPome) is composed of nine genes (CYP51F1, CYP61A1, CYP56D1, CYP52A59, CYP52A60, CYP52A61, CYP52A62, CYP5217A8, and CYP5217B1), which might participate in primary metabolic reactions such as sterol biosynthesis, biodegradation of xenobiotic, and resistance to environmental stress. The prediction of the cellular location suggests that these CYPs to be anchored to the plasma membrane, membranes of the endoplasmic reticulum, mitochondria, and peroxisomes. These findings lay the foundation for future studies about the functional role of P450s, not only for yeasts, but also for the insects with which they interact.
Asunto(s)
Candida/clasificación , Candida/enzimología , Sistema Enzimático del Citocromo P-450/genética , Filogenia , Gorgojos/microbiología , Animales , Candida/genética , Candida/aislamiento & purificación , Membrana Celular/enzimología , Tracto Gastrointestinal/microbiología , Membranas Intracelulares/enzimología , Homología de SecuenciaRESUMEN
BACKGROUND: The uridine nucleotide analogue sofosbuvir is a selective inhibitor of hepatitis C virus (HCV) NS5B polymerase. We assessed the safety and efficacy of sofosbuvir in combination with pegylated interferon alfa-2a (peginterferon) and ribavirin in non-cirrhotic treatment-naive, patients with HCV. METHODS: For this open-label, randomised phase 2 trial, we recruited patients from 42 centres in the USA and Puerto Rico between March 23, 2011, and Sept 21, 2011. Patients were eligible for inclusion if they had chronic HCV infection (genotypes 1, 4, 5, or 6), were aged 18 years or older, and had not previously received treatment for HCV infection. Using a computer-generated randomisation sequence, we randomly assigned patients with HCV genotype-1 to one of three cohorts (A, B, and C; in a 1:2:3 ratio), with randomisation stratified by IL28B (CC vs non-CC allele) and HCV RNA (<800,000 IU/mL vs ≥800,000 IU/mL). Patients received sofosbuvir 400 mg plus peginterferon and ribavirin for 12 weeks (cohort A) or for 24 weeks (cohort B), or 12 weeks of sofosbuvir plus peginterferon and ribavirin followed by 12 weeks of either sofosbuvir monotherapy or sofosbuvir plus ribavirin (cohort C). We enrolled patients with all other eligible genotypes in cohort B. The primary efficacy endpoint was sustained virological response at post-treatment week 24 (SVR24) by intention-to-treat analysis. This trial is registered with ClinicalTrials.gov, number NCT01329978. RESULTS: We enrolled 316 patients with HCV genotype-1: 52 to cohort A, 109 to cohort B, and 155 to cohort C. We assigned 11 patients with HCV genotype-4 and five patients with genotype-6 to cohort B (we detected no patients with genotype 5). In patients with HCVgenotype-1, SVR24 was achieved by 46 patients (89%, 95% CI 77-96) in cohort A, 97 patients (89%, 82-94) in cohort B, and by 135 (87%, 81-92) in cohort C. We detected no difference in the proportion of patients achieving SVR24 in cohort A compared with cohort B (p=0·94), or in cohort C (p=0·78). Nine (82%) of 11 patients with genotype-4 and all five with genotype-6 achieved SVR24. Seven patients, all with genotype-1 infection, relapsed after completion of assigned treatment. The most common adverse events that led to the discontinuation of any study drug--anaemia and neutropenia--were associated with peginterferon and ribavirin treatment. Three (6%) patients in cohort A, 18 (14%) patients in cohort B, and three (2%) patients in cohort C discontinued treatment because of an adverse event. INTERPRETATION: Our findings suggest that sofosbuvir is well tolerated and that there is no additional benefit of extending treatment beyond 12 weeks, but these finding will have to be substantiated in phase 3 trials. These results lend support to the further assessment of a 12 week sofosbuvir regimen in a broader population of patients with chronic HCV genotype-1 infection, including those with cirrhosis. FUNDING: Gilead Sciences.
Asunto(s)
Antivirales/administración & dosificación , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/administración & dosificación , Polietilenglicoles/administración & dosificación , Ribavirina/administración & dosificación , Uridina Monofosfato/análogos & derivados , Quimioterapia Combinada , Femenino , Hepacivirus/genética , Hepatitis C Crónica/genética , Hepatitis C Crónica/virología , Humanos , Masculino , Persona de Mediana Edad , Puerto Rico , Proteínas Recombinantes/administración & dosificación , Sofosbuvir , Resultado del Tratamiento , Estados Unidos , Uridina Monofosfato/administración & dosificaciónRESUMEN
BACKGROUND & AIMS: Sofosbuvir (formerly GS-7977) is a pyrimidine nucleotide analog inhibitor of the hepatitis C virus (HCV) NS5B polymerase. We assessed the safety, tolerability, antiviral activity, and pharmacokinetics of sofosbuvir plus pegylated-interferon (PegIFN)/ribavirin (RBV) in a 28-day, dose-ranging trial in treatment-naïve patients infected with genotype 1 HCV. METHODS: In this double-blind study, 64 patients were randomized (1:1:1:1) to receive one of three once-daily doses of oral sofosbuvir (100, 200, or 400mg) or placebo plus PegIFN/RBV for 28 days, after which all patients continued to receive PegIFN/RBV alone for a further 44 weeks. RESULTS: Patients in the sofosbuvir/PegIFN/RBV groups experienced mean reductions in HCV RNA >5 log10 IU/ml (-5.3 for 100 mg, -5.1 for 200 mg and -5.3 for 400 mg) vs. -2.8 log10 IU/ml for placebo/PegIFN/RBV after 28 days. Rapid virologic response (RVR) rates were markedly higher after sofosbuvir treatment (88-94%) than placebo (21%), as were rates of sustained virologic response (SVR) at post-treatment Week 24 (56%, 83%, and 80% for sofosbuvir 100, 200, and 400 mg, respectively, vs. 43% for placebo). The number of patients experiencing virologic breakthrough and post-treatment relapse was higher in the sofosbuvir 100 mg group than sofosbuvir 200 and 400 mg groups. Sofosbuvir was well tolerated; the most frequent adverse events were fatigue and nausea. CONCLUSIONS: These results support further studies with sofosbuvir at 200 mg and 400 mg to determine the optimal dose and treatment duration of sofosbuvir in HCV genotype 1.
Asunto(s)
Antivirales/administración & dosificación , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Interferón-alfa/administración & dosificación , Polietilenglicoles/administración & dosificación , Ribavirina/administración & dosificación , Uridina Monofosfato/análogos & derivados , Adulto , Antivirales/efectos adversos , Antivirales/farmacocinética , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Quimioterapia Combinada , Femenino , Hepacivirus/clasificación , Humanos , Masculino , Persona de Mediana Edad , Proteínas Recombinantes/administración & dosificación , Sofosbuvir , Factores de Tiempo , Resultado del Tratamiento , Uridina Monofosfato/administración & dosificación , Uridina Monofosfato/efectos adversos , Uridina Monofosfato/farmacocinética , Adulto JovenRESUMEN
INTRODUCTION: Balapiravir (R1626, RG1626) is the prodrug of a nucleoside analogue inhibitor of the hepatitis C virus (HCV) RNA-dependent RNA polymerase (R1479, RG1479). This phase 2, double-blind international trial evaluated the optimal treatment regimen of balapiravir plus peginterferon alfa-2a (40KD)/ribavirin. MATERIAL AND METHODS: Treatment-naive genotype 1 patients (N = 516) were randomized to one of seven treatment groups in which they received balapiravir 500, 1,000, or 1,500 mg twice daily, peginterferon alfa-2a (40KD) 180 or 90 µg/week and ribavirin 1,000/1,200 mg/day or peginterferon alfa-2a (40KD)/ribavirin. The planned treatment duration with balapiravir was reduced from 24 to 12 weeks due to safety concerns. RESULTS: The percentage of patients with undetectable HCV RNA was consistently higher in all balapiravir groups from week 2 to 12. However, high rates of dose modifications and discontinuations of one/all study drugs compromised the efficacy assessment and resulted in similar sustained virological response rates in the balapiravir groups (range 32-50%) and the peginterferon alfa-2a (40KD)/ribavirin group (43%). Balapiravir was discontinued for safety reasons in 28-36% of patients (most often for lymphopenia) and the percentage of patients with serious adverse events (especially hematological, infection, ocular events) was dose related. Serious hematological adverse events (particularly neutropenia, lymphopenia) were more common in balapiravir recipients. Two deaths in the balapiravir/peginterferon alfa-2a/ribavirin combination groups were considered possibly related to study medication. CONCLUSION: Further development of balapiravir for the treatment of chronic hepatitis C has been halted because of the unacceptable benefit to risk ratio revealed in this study (www.ClinicalTrials.gov NCT 00517439).
Asunto(s)
Genotipo , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Nucleósidos/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Adolescente , Adulto , Anciano , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Quimioterapia Combinada , Determinación de Punto Final , Femenino , Hepatitis C Crónica/sangre , Humanos , Interferón-alfa/efectos adversos , Cooperación Internacional , Masculino , Persona de Mediana Edad , Nucleósidos/efectos adversos , Polietilenglicoles/efectos adversos , ARN Viral/sangre , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico , Ribavirina/efectos adversos , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Intense consumer pressure strongly affects the structural organization and function of marine ecosystems, while also having a profound effect on the phenotype of both predator and prey. Allelochemicals produced by prey often render their tissues unpalatable or toxic to a majority of potential consumers, yet some marine consumers have evolved resistance to host chemical defenses. A key challenge facing marine ecologists seeking to explain the vast differences in consumer tolerance of dietary allelochemicals is understanding the biochemical and molecular mechanisms underlying diet choice. The ability of marine consumers to tolerate toxin-laden prey may involve the cooperative action of biotransformation enzymes, including the inducible cytochrome P450s (CYPs), which have received little attention in marine invertebrates despite the importance of allelochemicals in their evolution. RESULTS: Here, we investigated the diversity, transcriptional response, and enzymatic activity of CYPs possibly involved in allelochemical detoxification in the generalist gastropod Cyphoma gibbosum, which feeds exclusively on chemically defended gorgonians. Twelve new genes in CYP family 4 were identified from the digestive gland of C. gibbosum. Laboratory-based feeding studies demonstrated a 2.7- to 5.1-fold induction of Cyphoma CYP4BK and CYP4BL transcripts following dietary exposure to the gorgonian Plexaura homomalla, which contains high concentrations of anti-predatory prostaglandins. Phylogenetic analysis revealed that C. gibbosum CYP4BK and CYP4BL were most closely related to vertebrate CYP4A and CYP4F, which metabolize pathophysiologically important fatty acids, including prostaglandins. Experiments involving heterologous expression of selected allelochemically-responsive C. gibbosum CYP4s indicated a possible role of one or more CYP4BL forms in eicosanoid metabolism. Sequence analysis further demonstrated that Cyphoma CYP4BK/4BL and vertebrate CYP4A/4F forms share identical amino acid residues at key positions within fatty acid substrate recognition sites. CONCLUSIONS: These results demonstrate differential regulation of CYP transcripts in a marine consumer feeding on an allelochemical-rich diet, and significantly advance our understanding of both the adaptive molecular mechanisms that marine consumers use to cope with environmental chemical pressures and the evolutionary history of allelochemical-metabolizing enzymes in the CYP superfamily.