Temperature- and salinity-decoupled overproduction of hydroxyectoine by chromohalobacter salexigens

Hydroxyectoine overproduction by the natural producer Chromohalobacter salexigens is presented in this study. Genetically engineered strains were constructed that at low salinity coexpressed, in a vector derived from a native plasmid, the ectoine (ectABC) and hydroxyectoine (ectD) genes under the control of the ectA promoter, in a temperature-independent manner. Hy- droxyectoine production was further improved by increasing the copies of ectD and using a C. salexigens genetic background unable to synthesize ectoines

GPR120/FFAR4 Pharmacology: Focus on Agonists in Type 2 Diabetes Mellitus Drug Discovery

The G-protein coupled receptors (GPCRs) activated by free fatty acids (FFAs) have emerged as new and exciting drug targets, due to their plausible translation from pharmacology to medicines. This perspective aims to report recent research about GPR120/FFAR4 and its involvement in several diseases, including cancer, inflammatory conditions, and central nervous system disorders. The focus is to highlight the importance of GPR120 in Type 2 diabetes mellitus (T2DM). GPR120 agonists, useful in T2DM drug discovery, have been widely explored from a structure–activity relationship point of view. Since the identification of the first reported synthetic agonist TUG-891, the research has paved the way for the development of TUG-based molecules as well as new and different chemical entities. These molecules might represent the starting point for the future discovery of GPR120 agonists as antidiabetic drugs

Involvement of EupR, a response regulator of the NarL/FixJ family, in the control of the uptake of the compatible solutes ectoines by the halophilic bacterium Chromohalobacter salexigens

de Lucena DK, Pühler A, Weidner S. The role of sigma factor RpoH1 in the pH stress response of Sinorhizobium meliloti. BMC Microbiology. 2010;10(1): 256.Background: Environmental pH stress constitutes a limiting factor for S. meliloti survival and development. The response to acidic pH stress in S. meliloti is versatile and characterized by the differential expression of genes associated with various cellular functions. The purpose of this study was to gain detailed insight into the participation of sigma factors in the complex stress response system of S. meliloti 1021 using pH stress as an effector. Results: In vitro assessment of S meliloti wild type and sigma factor mutants provided first evidence that the sigma factor RpoH1 plays a major role in the pH stress response. Differential expression of genes related to rhizobactin biosynthesis was observed in microarray analyses performed with the rpoH1 mutant at pH 7.0. The involvement of the sigma factor RpoH1 in the regulation of S. meliloti genes upon pH stress was analyzed by comparing timecourse experiments of the wild type and the rpoH1 mutant. Three classes of S. meliloti genes could be identified, which were transcriptionally regulated in an RpoH1-independent, an RpoH1-dependent or in a complex manner. The first class of S. meliloti genes, regulated in an RpoH1-independent manner, comprises the group of the exopolysaccharide I biosynthesis genes and also the group of genes involved in motility and flagellar biosynthesis. The second class of S. meliloti genes, regulated in an RpoH1-dependent manner, is composed of genes known from heat shock studies, like ibpA, grpE and groEL5, as well as genes involved in translation like tufA and rplC. Finally, the third class of S. meliloti genes was regulated in a complex manner, which indicates that besides sigma factor RpoH1, further regulation takes place. This was found to be the case for the genes dctA, ndvA and smc01505. Conclusions: Clustering of time-course microarray data of S. meliloti wild type and sigma factor rpoH1 mutant allowed for the identification of gene clusters, each with a unique time-dependent expression pattern, as well as for the classification of genes according to their dependence on RpoH1 expression and regulation. This study provided clear evidence that the sigma factor RpoH1 plays a major role in pH stress response

Búsqueda de nuevas alternativas terapéuticas para el tratamiento de infecciones por adenovirus: cribado de pequeñas moléculas generadas por química combinatoria

Motivación: La incidencia de infecciones por adenovirus (HAdV) en pacientes receptores de órgano sólido y especialmente de receptores de progenitores hematopoyéticos, ha aumentado en los últimos años, presentando una elevada morbi- mortalidad (1, 2). Actualmente no existen tratamientos específicos para este tipo de infecciones. Nuestro objetivo fundamental fue identificar moléculas capaces de inhibir la infección por HAdV y determinar su mecanismo de acción como primer paso para el desarrollo de un nuevo antiviral específico frente a HAdV. Métodos: Partimos de una librería de 30 derivados de piperazina. Las moléculas que presentaron actividad inhibitoria > 50% de la infección por HAdV mediante ensayo en placa o mediante "single round infection" se seleccionaron para su caracterización posterior. Su citotoxicidad (CC50) se evaluó mediante cuantificación del XTT metabolizado. Se realizaron así mismo estudios dosis-respuesta de los compuestos activos. También se evaluó la capacidad de las moléculas de inhibir la replicación del virus, para lo cual se llevaron a cabo infecciones de 24h y se cuantificó la producción de "de novo" HAdV ADN mediante PCR cuantitativa a tiempo real (3). La cuantificación de la reducción de la progenie viral por la acción de las moléculas seleccionadas se realizó mediante un ensayo de producción viral y posterior titulación. Resultados: Las moléculas 511, 512 y 513 (50 µM) generaron inhibiciones >50% en el ensayo en placa. Sólo el compuesto 511 generaba una inhibición leve dosis-dependiente. Los valores de CC50 fueron 190, 546 y 85 µM, respectivamente, en base a los cuales el compuesto 513 fue descartado para su posterior caracterización por su elevada toxicidad. Los moléculas 511 y 512 (30 µM) produjeron inhibiciones de la replicación viral del 80% y del 50%, respectivamente. Las moléculas 511 y 512 (30 µM) generaron reducciones en la progenie viral del 44% y del 25%, respectivamente. Conclusiones: Las moléculas 511 y 512 inhiben de manera significativa la infección por HAdV a nivel de la replicación del ADN viral. La optimización de ambos compuestos supone un excelente punto de partida para la obtención de un nuevo agente antiviral específico frente a infecciones por HAdV

Role of Trehalose in Salinity and Temperature Tolerance in the Model Halophilic Bacterium Chromohalobacter salexigens.

The disaccharide trehalose is considered as a universal stress molecule, protecting cells and biomolecules from injuries imposed by high osmolarity, heat, oxidation, desiccation and freezing. Chromohalobacter salexigens is a halophilic and extremely halotolerant γ-proteobacterium of the family Halomonadaceae. In this work, we have investigated the role of trehalose as a protectant against salinity, temperature and desiccation in C. salexigens. A mutant deficient in the trehalose-6-phosphate synthase gene (otsA::Ω) was not affected in its salt or heat tolerance, but double mutants ectoine- and trehalose-deficient, or hydroxyectoine-reduced and trehalose-deficient, displayed an osmo- and thermosensitive phenotype, respectively. This suggests a role of trehalose as a secondary solute involved in osmo- (at least at low salinity) and thermoprotection of C. salexigens. Interestingly, trehalose synthesis was osmoregulated at the transcriptional level, and thermoregulated at the post-transcriptional level, suggesting that C. salexigens cells need to be pre-conditioned by osmotic stress, in order to be able to quickly synthesize trehalose in response to heat stress. C. salexigens was more sensitive to desiccation than E. coli and desiccation tolerance was slightly improved when cells were grown at high temperature. Under these conditions, single mutants affected in the synthesis of trehalose or hydroxyectoine were more sensitive to desiccation than the wild-type strain. However, given the low survival rates of the wild type, the involvement of trehalose and hydroxyectoine in C. salexigens response to desiccation could not be firmly established

Isolation and characterization of salt-sensitive mutants of the moderate halophile Halomonas elongata and cloning of the ectoine synthesis genes

The moderate halophile Halomonas elongata Deustche Sommlung fur Mikroorganismen 3043 accumulated ectoine, hydroxyectoine, glutamate, and glutamine in response to osmotic stress (3 M NaCl). Two Tn1732-induced mutants, CHR62 and CHR63, that were severely affected in their salt tolerance were isolated. Mutant CHR62 could not grow above 0.75 M NaCl, and CHR63 did not grow above 1.5 M NaCl. These mutants did not synthesize ectoine but accumulated ectoine precursors, as shown by 13C NMR and mass spectroscopy. Mutant CHR62 accumulated low levels of diaminobutyric acid, and mutant CHR63 accumulated high concentrations of N-γ-acetyl-diaminobutyric acid. These results suggest that strain CHR62 could be defective in the gene for diaminobutyric acid acetyltransferase (ectB), and strain CHR63 could be defective in the gene for the ectoine synthase (ectC). Salt sensitivity of the mutants at 1.5-2.5 M NaCl could be partially corrected by cytoplasmic extracts of the wild-type strain, containing ectoine, and salt sensitivity of strain CHR62 could be partially repaired by the addition of extracts of strain CHR63, which contained N-γ-acetyldiaminobutyric acid. This is the first evidence for the role of N-γ-acetyldiaminobutyric acid as osmoprotectant. Finally, a cosmid from the H. elongata genomic library was isolated which complemented the Ect- phenotype of both mutants, indicating that it carried at least the genes ectB and ectC of the biosynthetic pathway of ectoin

Conformations in crystals and solutions of d(CACGTG), d(CCGCGG) and d(GGCGCC) studied by vibrational spectroscopy

Crystals of self camplementary DMA hexamers dCCACGTG>, dCCCGCGG> and d were grown bf vapour dlffuslon technlque and studled by mlcroRaman and mlcroiR spectroscop es. The ollgonucleotldes were studled ln parallel ln solutlon by vlbratlonal spectroscopy. A B->Z transltlon was detected by Raman spectroscopy cl.lrlng the crystalllzatlon procese for dCCACGTG>. Vlbratlonal spectroscopy shows that the dCGGCGCC> crystals adopt a B geametry. On the contrary the d sequence whlch ls shown to be able to undergo ln solutlon or ln fllms qulte easlly the B->Z transltlon, remalns trapped ln crystals ln a geametry whlch may correspond to an lntermedlate conformatlon often proposed ln modele of the B->Z transltlon. The crystals used ln thls study were characterlzed by X-ray dlffractlon. The unlt cell and space group have been determlned

Serinol-Based Benzoic Acid Esters as New Scaffolds for the Development of Adenovirus Infection Inhibitors: Design, Synthesis, and In Vitro Biological Evaluation

Over the years, human adenovirus (HAdV) has progressively been recognized as a significant viral pathogen. Traditionally associated with self-limited respiratory, gastrointestinal, and conjunctival infections, mainly in immunocompromised patients, HAdV is currently considered to be a pathogen presenting significant morbidity and mortality in both immunosuppressed and otherwise healthy individuals. Currently available therapeutic options are limited because of their lack of effectivity and related side effects. In this context, there is an urgent need to develop effective anti-HAdV drugs with suitable therapeutic indexes. In this work, we identified new serinol-derived benzoic acid esters as novel scaffolds for the inhibition of HAdV infections. A set of 38 compounds were designed and synthesized, and their antiviral activity and cytotoxicity were evaluated. Four compounds (13, 14, 27, and 32) inhibited HAdV infection at low micromolar concentrations (2.82–5.35 μM). Their half maximal inhibitory concentration (IC50) values were lower compared to that of cidofovir, the current drug of choice. All compounds significantly reduced the HAdV DNA replication process, while they did not block any step of the viral entry. Our results showed that compounds 13, 14, and 32 seem to be targeting the expression of the E1A early gene. Moreover, all four derivatives demonstrated a significant inhibition of human cytomegalovirus (HCMV) DNA replication. This new scaffold may represent a potential tool useful for the development of effective anti-HAdV drugs.This work has been supported by Ministerio de Ciencia, Innovación y Universidades, Plan Estatal 2017-2020 Retos-Proyectos I+D+i (PID2019-104767RB-I00), Ministerio de Economı́a y Competitividad, Plan Estatal 2013-2016 Retos-Proyectos I + D + i (CTQ2016-78580-C2-2-R) and by Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economia, Industria y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0009), cofinanced by European Development Regional Fund “A way to achieve Europe”, the Instituto de Salud Carlos III, Proyectos de Investigación en Salud (PI17/01055; PI18/01191) and Proyectos de Desarrollo Tecnológico en Salud (DTS17/00130), the Spanish Adenovirus Network (AdenoNet, BIO2015/68990-REDT), and the program “Nicolás Monardes” (C-0059-2018), Servicio Andaluz de Salud, Junta de Andalucía. M.V.-H. also thanks Ministerio de Economı́a y Competitividad, Plan Estatal 2013-2016 Excelencia I+D+i (CTQ2016-78703-P)

THDP17 decreases ammonia production through glutaminase inhibition. A new drug for hepatic encephalopathy therapy

Ammonia production is implicated in the pathogenesis of hepatic encephalopathy (HE), being intestinal glutaminase activity the main source for ammonia. Management of ammonia formation can be effective in HE treatment by lowering intestinal ammonia production. The use of glutaminase inhibitors represents one way to achieve this goal. In this work, we have performed a search for specific inhibitors that could decrease glutaminase activity by screening two different groups of compounds: i) a group integrated by a diverse, highly pure small molecule compounds derived from thiourea ranging from 200 to 800 Daltons; and ii) a group integrated by commonly use compounds in the treatment of HE. Results shown that THDP-17 (10 µM), a thiourea derivate product, could inhibit the intestinal glutaminase activity (57.4±6.7%). Inhibitory effect was tissue dependent, ranging from 40±5.5% to 80±7.8% in an uncompetitive manner, showing Vmax and Km values of 384.62 µmol min−1, 13.62 mM with THDP-17 10 µM, respectively. This compound also decreased the glutaminase activity in Caco-2 cell cultures, showing a reduction of ammonia and glutamate production, compared to control cultures. Therefore, the THDP-17 compound could be a good candidate for HE management, by lowering ammonia productio

Análisis, desarrollo e implantación de un sistema web de consulta y reserva on-line de grupos de prácticas para el alumnado

La libre elección del grupo de prácticas (tan demandada por el alumnado) y presente ahora mismo en la Facultad de Farmacia de la Universidad de Sevilla necesita una herramienta que facilite la gestión de dicha oferta práctica tanto a los Departamentos como, y principalmente, al alumnado. El proyecto que aquí se presenta consiste, como se recoge en su título, en el desarrollo e implantación de un sistema que permita al alumnado conocer la oferta de grupos de prácticas de todas las asignaturas de la Licenciatura, además de la posibilidad de inscripción en el grupo deseado, todo ello de una forma totalmente virtual. Además de proporcionarle en todo momento información de su calendario de prácticas. El proyecto era en cierta forma ambicioso dado que pretendíamos establecer un sistema que unificase la oferta de la docencia práctica de todas las asignaturas de los estudios de Farmacia, con toda su variedad: prácticas de laboratorio, prácticas en el aula y prácticas en aula de informática, y además, que fuera un sistema flexible que permitiera también (en caso de ser necesario) incorporar docencias prácticas de otros estudios, por ejemplo estudios de postgrado