pH-dependent gating mechanism of the Helicobacter pylori urea channel revealed by cryo-EM.

The urea channel of Helicobacter pylori (HpUreI) is an ideal drug target for preventing gastric cancer but incomplete understanding of its gating mechanism has hampered development of inhibitors for the eradication of H. pylori. Here, we present the cryo-EM structures of HpUreI in closed and open conformations, both at a resolution of 2.7 Å. Our hexameric structures of this small membrane protein (~21 kDa/protomer) resolve its periplasmic loops and carboxyl terminus that close and open the channel, and define a gating mechanism that is pH dependent and requires cooperativity between protomers in the hexamer. Gating is further associated with well-resolved changes in the channel-lining residues that modify the shape and length of the urea pore. Site-specific mutations in the periplasmic domain and urea pore identified key residues important for channel function. Drugs blocking the urea pore based on our structures should lead to a new strategy for H. pylori eradication

Fisioterapia en el síndrome subacromial del hombro. Revisión sistemática cualitativa.

Trabajo Fin de Grado (TFG)Antecedentes: El dolor de hombro es un problema muy frecuente, se estima que un tercio de la población sufre o sufrirá a lo largo de la vida dolor de hombro en alguna ocasión. El síndrome subacromial es la causa más común. La fisioterapia es la terapia de elección frente al síndrome subacromial, con una gran variedad abordajes fisioterapéuticos como los ejercicios terapéuticos, la terapia manual, el ultrasonido, la acupuntura, etc. Objetivo: El objetivo de este trabajo es conocer la efectividad de distintas modalidades fisioterapéuticas para el tratamiento del síndrome subacromial, así como determinar cuál es la modalidad más efectiva. Material y método: Se realizaron búsquedas bibliográficas entre noviembre de 2013 y julio de 2014, en las principales bases de datos de ciencias de la salud: PubMed, PEDro, Cochrane Plus, Web of Science, y Science Direct, complementa estas con una búsqueda manual en las revistas del área Cuestiones de Fisioterapia, y Fisioterapia. Tras aplicar los criterios de inclusión y exclusión, se analizó la calidad de los artículos incluidos mediante el factor de impacto, y las escalas SIGN y PEDro. Resultados: Se incluyeron 33 artículos en la revisión, 32 ensayos clínicos aleatorios y 1 metaanálisis. Trece artículos evaluaban los ejercicios terapéuticos, 5 el ultrasonido, 2 el láser, 2 la magnetoterapia, 1 la microonda, 4 la terapia manual, 3 el kinesiotape, y 3 otras técnicas. Conclusión: Los ejercicios terapéuticos son la modalidad fisioterapéutica con mayor efectividad para disminuir el dolor y mejorar la funcionalidad en los pacientes con síndrome subacromial. Debería ser considerado como la base del tratamiento, ya que la combinación de los ejercicios terapéuticos con otras modalidades terapéuticas como la acupuntura, kinesiotape y terapia manual pueden ofrecer resultados aún mejores.Background: Shoulder pain is a common complaint, it's estimated that one third of the population throughout life suffers shoulder pain, where the impingement syndrome is the cause in more than 50%. Physiotherapy is the therapy of choice used for impingement syndrome; there are many different types of techniques such as therapeutic exercises, manual therapy, ultrasound, acupuncture, etc. Objective: The aim of this work is to discover the effectiveness of several physiotherapy modalities for treating impingement syndrome, and to determine which one is the most effective. Methods: Searches were conducted between November 2013 and July 2014 in the major health-science databases: PubMed, PEDro, Cochrane, Web of Science, and Science Direct, supplemented by a manual search in journals Cuestiones de Fisioterapia and Fisioterapia. After applying the inclusion and exclusion criteria, the quality of included articles was evaluated by the impact factor and SIGN scale. Results: Finally, 33 articles were included in this review, 32 randomized clinical trials and 1 meta-analysis. Thirteen of them evaluated therapeutic exercises, 5 of ultrasound, 2 of laser, 2 of pulsed electromagnetic field, 1 of microwave, 4 of manual therapy, 3 of kinesiotape, and 3 of other techniques. Conclusion: The therapeutic exercise program is the most effective technique for treating the shoulder impingement syndrome to decreasing pain and to improving function. It should be considered as the mainstay of the treatment program, the combination of therapeutic exercises with other techniques such as acupuncture, manual therapy and kinesiotape, also can provides better results.Grado en Fisioterapi

Fisioterapia en el síndrome subacromial del hombro. Revisión sistemática cualitativa.

Trabajo Fin de Grado (TFG)Antecedentes: El dolor de hombro es un problema muy frecuente, se estima que un tercio de la población sufre o sufrirá a lo largo de la vida dolor de hombro en alguna ocasión. El síndrome subacromial es la causa más común. La fisioterapia es la terapia de elección frente al síndrome subacromial, con una gran variedad abordajes fisioterapéuticos como los ejercicios terapéuticos, la terapia manual, el ultrasonido, la acupuntura, etc. Objetivo: El objetivo de este trabajo es conocer la efectividad de distintas modalidades fisioterapéuticas para el tratamiento del síndrome subacromial, así como determinar cuál es la modalidad más efectiva. Material y método: Se realizaron búsquedas bibliográficas entre noviembre de 2013 y julio de 2014, en las principales bases de datos de ciencias de la salud: PubMed, PEDro, Cochrane Plus, Web of Science, y Science Direct, complementa estas con una búsqueda manual en las revistas del área Cuestiones de Fisioterapia, y Fisioterapia. Tras aplicar los criterios de inclusión y exclusión, se analizó la calidad de los artículos incluidos mediante el factor de impacto, y las escalas SIGN y PEDro. Resultados: Se incluyeron 33 artículos en la revisión, 32 ensayos clínicos aleatorios y 1 metaanálisis. Trece artículos evaluaban los ejercicios terapéuticos, 5 el ultrasonido, 2 el láser, 2 la magnetoterapia, 1 la microonda, 4 la terapia manual, 3 el kinesiotape, y 3 otras técnicas. Conclusión: Los ejercicios terapéuticos son la modalidad fisioterapéutica con mayor efectividad para disminuir el dolor y mejorar la funcionalidad en los pacientes con síndrome subacromial. Debería ser considerado como la base del tratamiento, ya que la combinación de los ejercicios terapéuticos con otras modalidades terapéuticas como la acupuntura, kinesiotape y terapia manual pueden ofrecer resultados aún mejores.Background: Shoulder pain is a common complaint, it's estimated that one third of the population throughout life suffers shoulder pain, where the impingement syndrome is the cause in more than 50%. Physiotherapy is the therapy of choice used for impingement syndrome; there are many different types of techniques such as therapeutic exercises, manual therapy, ultrasound, acupuncture, etc. Objective: The aim of this work is to discover the effectiveness of several physiotherapy modalities for treating impingement syndrome, and to determine which one is the most effective. Methods: Searches were conducted between November 2013 and July 2014 in the major health-science databases: PubMed, PEDro, Cochrane, Web of Science, and Science Direct, supplemented by a manual search in journals Cuestiones de Fisioterapia and Fisioterapia. After applying the inclusion and exclusion criteria, the quality of included articles was evaluated by the impact factor and SIGN scale. Results: Finally, 33 articles were included in this review, 32 randomized clinical trials and 1 meta-analysis. Thirteen of them evaluated therapeutic exercises, 5 of ultrasound, 2 of laser, 2 of pulsed electromagnetic field, 1 of microwave, 4 of manual therapy, 3 of kinesiotape, and 3 of other techniques. Conclusion: The therapeutic exercise program is the most effective technique for treating the shoulder impingement syndrome to decreasing pain and to improving function. It should be considered as the mainstay of the treatment program, the combination of therapeutic exercises with other techniques such as acupuncture, manual therapy and kinesiotape, also can provides better results.Grado en Fisioterapi

Fenofibrate Enhances the In Vitro Differentiation of Foxp3+ Regulatory T Cells in Mice

Foxp3+ regulatory T cells (Tregs) play a critical role in maintaining immune self-tolerance. Reduced number and activity of Tregs are usually found in autoimmune and inflammatory diseases, and enhancing the differentiation of Tregs may be a promising therapeutic strategy. Some reports suggested an anti-inflammatory and anti-autoimmune potential for fenofibrate, a hypolipidemic drug used worldwide, whose lipid effects are mediated by the activation of peroxisome proliferator-activated receptor α (PPARα). In the present paper, we found that fenofibrate dose-dependently increased transforming growth factor-β and interleukin-2-induced Treg differentiation in vitro, by 1.96-fold from 0 to 20 μM (12.59 ± 1.34% to 24.69 ± 3.03%, P < 0.05). Other PPARα activators, WY14643 (100 μM), gemfibrozil (50 μM), and bezafibrate (30 μM), could not enhance Treg differentiation. In addition, PPARα could not upregulate the promoter activity of the Treg-specific transcription factor Foxp3. Fenofibrate might exert its function by enhancing Smad3 phosphorylation, a critical signal in Treg differentiation, via Akt suppression. Our work reveals a new PPARα independent anti-inflammatory mechanism of fenofibrate in up-regulating mouse Treg differentiation

Genome organization and interaction with capsid protein in a multipartite RNA virus.

We report the asymmetric reconstruction of the single-stranded RNA (ssRNA) content in one of the three otherwise identical virions of a multipartite RNA virus, brome mosaic virus (BMV). We exploit a sample consisting exclusively of particles with the same RNA content-specifically, RNAs 3 and 4-assembled in planta by agrobacterium-mediated transient expression. We find that the interior of the particle is nearly empty, with most of the RNA genome situated at the capsid shell. However, this density is disordered in the sense that the RNA is not associated with any particular structure but rather, with an ensemble of secondary/tertiary structures that interact with the capsid protein. Our results illustrate a fundamental difference between the ssRNA organization in the multipartite BMV viral capsid and the monopartite bacteriophages MS2 and Qβ for which a dominant RNA conformation is found inside the assembled viral capsids, with RNA density conserved even at the center of the particle. This can be understood in the context of the differing demands on their respective lifecycles: BMV must package separately each of several different RNA molecules and has been shown to replicate and package them in isolated, membrane-bound, cytoplasmic complexes, whereas the bacteriophages exploit sequence-specific "packaging signals" throughout the viral RNA to package their monopartite genomes

Malaria parasite translocon structure and mechanism of effector export.

The putative Plasmodium translocon of exported proteins (PTEX) is essential for transport of malarial effector proteins across a parasite-encasing vacuolar membrane into host erythrocytes, but the mechanism of this process remains unknown. Here we show that PTEX is a bona fide translocon by determining structures of the PTEX core complex at near-atomic resolution using cryo-electron microscopy. We isolated the endogenous PTEX core complex containing EXP2, PTEX150 and HSP101 from Plasmodium falciparum in the 'engaged' and 'resetting' states of endogenous cargo translocation using epitope tags inserted using the CRISPR-Cas9 system. In the structures, EXP2 and PTEX150 interdigitate to form a static, funnel-shaped pseudo-seven-fold-symmetric protein-conducting channel spanning the vacuolar membrane. The spiral-shaped AAA+ HSP101 hexamer is tethered above this funnel, and undergoes pronounced compaction that allows three of six tyrosine-bearing pore loops lining the HSP101 channel to dissociate from the cargo, resetting the translocon for the next threading cycle. Our work reveals the mechanism of P. falciparum effector export, and will inform structure-based design of drugs targeting this unique translocon

GPU accelerated biochemical network simulation

Motivation: Mathematical modelling is central to systems and synthetic biology. Using simulations to calculate statistics or to explore parameter space is a common means for analysing these models and can be computationally intensive. However, in many cases, the simulations are easily parallelizable. Graphics processing units (GPUs) are capable of efficiently running highly parallel programs and outperform CPUs in terms of raw computing power. Despite their computational advantages, their adoption by the systems biology community is relatively slow, since differences in hardware architecture between GPUs and CPUs complicate the porting of existing code

GPU accelerated biochemical network simulation

Motivation: Mathematical modelling is central to systems and synthetic biology. Using simulations to calculate statistics or to explore parameter space is a common means for analysing these models and can be computationally intensive. However, in many cases, the simulations are easily parallelizable. Graphics processing units (GPUs) are capable of efficiently running highly parallel programs and outperform CPUs in terms of raw computing power. Despite their computational advantages, their adoption by the systems biology community is relatively slow, since differences in hardware architecture between GPUs and CPUs complicate the porting of existing code

A unified mechanism for intron and exon definition and back-splicing.

The molecular mechanisms of exon definition and back-splicing are fundamental unanswered questions in pre-mRNA splicing. Here we report cryo-electron microscopy structures of the yeast spliceosomal E complex assembled on introns, providing a view of the earliest event in the splicing cycle that commits pre-mRNAs to splicing. The E complex architecture suggests that the same spliceosome can assemble across an exon, and that it either remodels to span an intron for canonical linear splicing (typically on short exons) or catalyses back-splicing to generate circular RNA (on long exons). The model is supported by our experiments, which show that an E complex assembled on the middle exon of yeast EFM5 or HMRA1 can be chased into circular RNA when the exon is sufficiently long. This simple model unifies intron definition, exon definition, and back-splicing through the same spliceosome in all eukaryotes and should inspire experiments in many other systems to understand the mechanism and regulation of these processes