Family C1 cysteine proteases: Biological diversity or redundancy?

Recent progress in the identification and partial characterization of novel genes encoding cysteine proteases of the papain family has considerably increased our knowledge of this family of enzymes. Kinetic data available to date for this large family indicate relatively broad, overlapping specificities for most enzymes, thus inspiring a growing conviction that they may exhibit functional redundancy. This is also supported in part by phenotypes of cathepsin knockout mice and suggests that several proteases can substitute for each other to degrade or process a given substrate. On the other hand, specific functions of one particular protease have also been documented. In addition, differences in cellular distribution and intracellular localization may contribute to defining specific functional roles for some of these proteases

In vitro antiatherogenicity of extracts from Halimeda incrassata seaweed: antioxidant activity and smooth muscle cell migration studies

Aim: The aim of this work was to evaluate the in vitro atheroprotective potential of the seaweed Halimeda incrassata in smooth muscle cell migration and lipoprotein oxidation in relation to its antioxidant activity. Material and methods: Antioxidant activity was determinate by DPPH• radical scavenging assay and ORAC method. The inhibitory effect of the aqueous extract on LDL oxidation mediated by Cu2+ ions was determinate by TBARS and conjugated diene quantification. The effect of the seaweed aqueous extract on smooth muscle cell migration was evaluated in MOVAS-1 mouse aortic smooth muscle cell. Results: The inhibitory effect of the aqueous extract on lipoprotein oxidation mediated by Cu2+ was demonstrated. Seaweed extract caused dose-dependent inhibition of TBARS (IC50 = 0.8 mg/mL) and conjugated dienes formation. The seaweed had a high antioxidant activity in the assays performed. The activity could be related to the phenolic content of Halimeda incrassata. Conclusions: In summary, the results of this study represent a further step in the characterization of the atheroprotective action of Halimeda incrassata and indicate the seaweed could be used for a nutraceutical and/or phytoterapeutic application.Objetivos: El objetivo de este trabajo fue evaluar el potencial ateroprotector in vitro del alga Halimeda incrassata en la migración de células de músculo liso de ratón y la oxidación de lipoproteínas en relación con su actividad antioxidante. Material y métodos: La actividad antioxidante fue determinada mediante los métodos de inhibición de radicales DPPH y la Capacidad antioxidante total (ORAC). La actividad inhibitoria de la oxidación de LDL mediada por iones Cu2+ se determinó por la cuantificación de TBARS y dienos conjugados. El efecto del extracto acuoso sobre la migración de las células de músculo liso se evaluó en la línea de células de músculo liso aórtica de ratón MOVAS-1. Resultados: Se demostró el efecto inhibidor del extracto sobre la oxidación de LDL mediada por Cu2+. El extracto del alga causa inhibición dosis-dependiente de la formación de TBARS (IC50 = 0,8 mg/mL) y dienos conjugados. Las algas tuvieron una alta actividad antioxidante en los ensayos realizados y podría estar relacionada con el contenido de compuestos fenólicos. Conclusiones: Los resultados de este trabajo representan un paso más en la caracterización de la acción ateroprotectora de Halimeda incrassata y evidencian sus posibles aplicaciones como nutracéutico y/o fitofármaco.The research was funded by IFS grant F/4897-1. Partial funding was also provided by CIHR grant MOP24447, the Canadian Research Chair award (D.B.) and a personal grant from GSEP, offered by the Canadian Bureau for International Education (A.C) and CNPq- (Brasil)

Taxane-containing induction chemotherapy followed by definitive chemoradiotherapy: Outcome in patients with locally advanced head and neck cancer

Background: Induction chemotherapy followed by definitive chemoradiotherapy is an intensified treatment approach for locally advanced squamous cell carcinoma of the head and neck (HNSCC) that might be associated with high rates of toxicity. Materials and methods: The data of 40consecutive patients who underwent induction chemotherapy with docetaxel-containing regimens followed by intensity-modulated radiotherapy (IMRT) and concomitant systemic therapy for unresectable locally advanced HNSCC were retrospectively analyzed. Primary objectives were RT-related acute and late toxicity. Secondary objectives were response to induction chemotherapy, locoregional recurrence-free survival (LRRFS), overall survival (OS), and influencing factors for LRRFS and OS. Results: The median follow-up for surviving patients was 21months (range, 2-53months). Patients received a median of three cycles of induction chemotherapy followed by IMRT to 72Gy. Three patients died during induction chemotherapy and one during chemoradiotherapy. Acute RT-related toxicity was of grade 3 and 4 in 72 and 3 % of patients, respectively, mainly dysphagia and dermatitis. Late RT-related toxicity was mainly xerostomia and bone/cartilage necrosis and was of grade 3 and 4 in 15 % of patients. One- and 2-year LRRFS and OS were 72 and 49 % and 77 and 71 %, respectively. Conclusion: Induction chemotherapy followed by chemoradiotherapy using IMRT was associated with a high rate of severe acute and late RT-related toxicities in this selected patient cohort. Four patients were lost because of fatal complications. Induction chemotherapy did not compromise the delivery of full-dose RT; however, the use of three cycles of concomitant cisplatin was impaire

Antiaterogenicidad in vitro de extractos del alga marina Halimeda incrassata: actividad antioxidante y estudios de migración en células de la musculatura lisa

Aim: The aim of this work was to evaluate the in vitro atheroprotective potential of the seaweed Halimeda incrassata in smooth muscle cell migration and lipoprotein oxidation in relation to its antioxidant activity.Material and methods: Antioxidant activity was determinate by DPPH• radical scavenging assay and ORAC method. The inhibitory effect of the aqueous extract on LDL oxidation mediated by Cu2+ ions was determinate by TBARS and conjugated diene quantification. The effect of the seaweed aqueous extract on smooth muscle cell migration was evaluated in MOVAS-1 mouse aortic smooth muscle cell.Results: The inhibitory effect of the aqueous extract on lipoprotein oxidation mediated by Cu2+ was demonstrated. Seaweed extract caused dose-dependent inhibition of TBARS (IC50 = 0.8 mg/mL) and conjugated dienes formation. The seaweed had a high antioxidant activity in the assays performed. The activity could be related to the phenolic content of Halimeda incrassata.Conclusions: In summary, the results of this study represent a further step in the characterization of the atheroprotective action of Halimeda incrassata and indicate the seaweed could be used for a nutraceutical and/or phytoterapeutic application.Objetivos: El objetivo de este trabajo fue evaluar el potencial ateroprotector in vitro del alga Halimeda incrassata en la migración de células de músculo liso de ratón y la oxidación de lipoproteínas en relación con su actividad antioxidante.Material y métodos: La actividad antioxidante fue determinada mediante los métodos de inhibición de radicales DPPH y la Capacidad antioxidante total (ORAC). La actividad inhibitoria de la oxidación de LDL mediada por iones Cu2+ se determinó por la cuantificación de TBARS y dienos conjugados. El efecto del extracto acuoso sobre la migración de las células de músculo liso se evaluó en la línea de células de músculo liso aórtica de ratón MOVAS-1.Resultados: Se demostró el efecto inhibidor del extracto sobre la oxidación de LDL mediada por Cu2+. El extracto del alga causa inhibición dosis-dependiente de la formación de TBARS (IC50 = 0,8 mg/mL) y dienos conjugados. Las algas tuvieron una alta actividad antioxidante en los ensayos realizados y podría estar relacionada con el contenido de compuestos fenólicos.Conclusiones: Los resultados de este trabajo representan un paso más en la caracterización de la acción ateroprotectora de Halimeda incrassata y evidencian sus posibles aplicaciones como nutracéutico y/o fitofármaco

The Importance of pH in Regulating the Function of the Fasciola hepatica Cathepsin L1 Cysteine Protease

The helminth parasite Fasciola hepatica secretes cathepsin L cysteine proteases to invade its host, migrate through tissues and digest haemoglobin, its main source of amino acids. Here we investigated the importance of pH in regulating the activity and functions of the major cathepsin L protease FheCL1. The slightly acidic pH of the parasite gut facilitates the auto-catalytic activation of FheCL1 from its inactive proFheCL1 zymogen; this process was ∼40-fold faster at pH 4.5 than at pH 7.0. Active mature FheCL1 is very stable at acidic and neutral conditions (the enzyme retained ∼45% activity when incubated at 37°C and pH 4.5 for 10 days) and displayed a broad pH range for activity peptide substrates and the protein ovalbumin, peaking between pH 5.5 and pH 7.0. This pH profile likely reflects the need for FheCL1 to function both in the parasite gut and in the host tissues. FheCL1, however, could not cleave its natural substrate Hb in the pH range pH 5.5 and pH 7.0; digestion occurred only at pH≤4.5, which coincided with pH-induced dissociation of the Hb tetramer. Our studies indicate that the acidic pH of the parasite relaxes the Hb structure, making it susceptible to proteolysis by FheCL1. This process is enhanced by glutathione (GSH), the main reducing agent contained in red blood cells. Using mass spectrometry, we show that FheCL1 can degrade Hb to small peptides, predominantly of 4–14 residues, but cannot release free amino acids. Therefore, we suggest that Hb degradation is not completed in the gut lumen but that the resulting peptides are absorbed by the gut epithelial cells for further processing by intracellular di- and amino-peptidases to free amino acids that are distributed through the parasite tissue for protein anabolism

Treatment Efficacy, Clinical Utility, and Cost-Effectiveness of Multidisciplinary Biopsychosocial Rehabilitation Treatments for Persistent Low Back Pain: A Systematic Review

Study Design: Systematic review. Objectives: To review the current literature on the treatment efficacy, clinical utility, and cost-effectiveness of multidisciplinary biopsychosocial rehabilitation (MBR) for patients suffering from persistent (nonspecific) lower back pain (LBP) in relation to pain intensity, disability, health-related quality of life, and work ability/sick leave. Methods: We carried out a systematic search of Web of Science, Cochrane Library, PubMed Central, EMBASE, and PsycINFO for English- and German-language literature published between January 2010 and July 2017. Study selection consisted of exclusion and inclusion phases. After screening for duplication, studies were excluded on the basis of criteria covering study design, number of participants, language of publication, and provision of information about the intervention. All the remaining articles dealing with the efficacy, utility, or cost-effectiveness of intensive (more than 25 hours per week) MBR encompassing at least 3 health domains and cognitive behavioral therapy–based psychological education were included. Results: The search retrieved 1199 publications of which 1116 were duplicates or met the exclusion criteria. Seventy of the remaining 83 articles did not meet the inclusion criteria; thus 13 studies were reviewed. All studies reporting changes in pain intensity or disability over 12 months after MBR reported moderate effect sizes and/or p-values for both outcomes. The effects on health-related quality of life were mixed, but MBR substantially reduced costs. Overall MBR produced an enduring improvement in work ability despite controversy and variable results. Conclusions: MBR is an effective treatment for nonspecific LBP, but there is room for improvement in cost-effectiveness and impact on sick leave, where the evidence was less compelling

RNA Interference in Schistosoma mansoni Schistosomula: Selectivity, Sensitivity and Operation for Larger-Scale Screening

RNA interference (RNAi) is a technique to selectively suppress mRNA of individual genes and, consequently, their cognate proteins. RNAi using double-stranded (ds) RNA has been used to interrogate the function of mainly single genes in the flatworm, Schistosoma mansoni, one of a number of schistosome species causing schistosomiasis. In consideration of large-scale screens to identify candidate drug targets, we examined the selectivity and sensitivity (the degree of suppression) of RNAi for 11 genes produced in different tissues of the parasite: the gut, tegument (surface) and otherwise. We used the schistosomulum stage prepared from infective cercariae larvae which are accessible in large numbers and adaptable to automated screening platforms. We found that RNAi suppresses transcripts selectively, however, the sensitivity of suppression varies (40%–>75%). No obvious changes in the parasite occurred post-RNAi, including after targeting the mRNA of genes that had been computationally predicted to be essential for survival. Additionally, we defined operational parameters to facilitate large-scale RNAi, including choice of culture medium, transfection strategy to deliver dsRNA, dose- and time-dependency, and dosing limits. Finally, using fluorescent probes, we show that the developing gut allows rapid entrance of dsRNA into the parasite to initiate RNAi