Star forming regions of the southern galaxy

A catalog of southern dust cloud properties is being compiled to aid in the planning and analysis of radio spectral line surveys in the southern hemisphere. Ultimately, images of dust temperature and column density will be produced. For the interim, a list of the 60 and 100 micron fluxes was prepared for the cores and adjacent backgrounds of 65 prominent dust clouds. Dust temperatures and column densities were derived

Discovery and characterizatopn of small molecular weight metallocarboxypeptidase inhibitors

Descripció del recurs: el 02 de novembre de 2010Las hidrolasas son enzimas que catalizan la ruptura del enlace amida o peptódico, y por lo tanto son denominadas también proteasas o peptidasas. Las proteasas constituyen cerca del 2 % del genoma humano, lo que representa unos 600 productos génicos. De acuerdo con el residuo catalóticamente activo, existen seis grandes grupos de peptidasas. En este trabajo nos centraremos en la familia M14 de peptidasas, también denominadas metalocarboxipeptidasas (CPs) debido a que su actividad catalótica reside en el ion zinc presente en el sitio activo de la enzima. En el genoma humano, se han identificado al menos 26 genes que codifican carboxipeptidasas. Las peptidasas de la familia M14 que actúan en el tracto gastrointestinal son las principales metaloproteasas responsables de la obtención de aminoácidos libres de la proteína de la dieta. En otros compartimientos corporales, las CPs pueden llevar a cabo tareas especializadas y altamente reguladas como ser la maduración de neuropéptidos, citokinas y hormonas peptódicas. En algunos casos, una actividad catalótica fuera de control puede conducir a enfermedades. Cada vez existe una mayor evidencia experimental que demuestra la actividad carboxipeptidasa en procesos como la pancreatitis aguda, la diabetes, la inflamación, la fibrinólisis y el cáncer. A pesar de ciertos avances en algunos aspectos, la actividad específica de las CPs es pobremente conocida. Además, las carboxipeptidasas son blancos terapéuticos interesantes para el desarrollo de fármacos, y por lo tanto se ha decidido emplear una aproximación multi-disciplinaria para la identificación y caracterización de nuevas moléculas de bajo peso molecular capaces de interferir la actividad carboxipeptidasa. Así, en este trabajo se han combinado modernas herramientas computacionales, screening in vitro, modelado molecular y cristalografía de rayos X con el fin de obtener nuevas entidades quφmicas como base para el desarrollo de fármacos. Con base en herramientas computacionales, aplicando el método de Optimal Docking Areaö, se han caracterizado sitios de unión proteína-proteína y proteína-ligando en la superficie de las peptidasas de la familia M14. A partir de aquí, se identificó una nueva clase de compuestos químicos capaces de explotar las diferencias existentes entre enzimas de la familia por unión a regiones hidrofóbicas. Otros inhibidores fueron identificados mediante un screening in silico de grandes colecciones de compuestos. Ensayos in vitro demostraron que los compuestos líderes inhibieron de manera potente a las carboxipeptidasas blanco con otras características interesantes como la posibilidad de coordinación del ion zinc catalítico por intermedio de un anillo oxadiazol. A través de una colaboración con el Departamento de Química Orgánica se obtuvieron y caracterizaron nuevos compuestos químicos con conectividades atómicas novedosas que, inesperadamente, demostraron ser potentes inhibidores de carboxipeptidasas. Una clase adicional de molécula de bajo peso molecular caracterizada corresponde a inhibidores que se unen covalentemente al enzima blanco. En este caso, se logró obtener la estructura tridimensional del complejo a resolución atómica mediante cristalografφa de rayos X, lo que ha permitido el dise±o basado en la estructura de una nueva generación de compuestos. Basados en otros datos de cristalografía de rayos X y análisis computacional, se ha revisado y ampliado el mecanismo de acción catalítica de las peptidasas de la familia M14 a partir de una nueva forma cristalina de CPB a alta resolución. En conjunto, nuestro trabajo ha permitido la obtención de nuevas moléculas líderes de bajo peso molecular que podrían servir como base para futuros desarrollos en el diseño de fármacos y agentes de diagnóstico o imaginería dirigidos a metalocarboxipeptidasas fisiológicamente activas.Hydrolases are enzymes catalyzing the breakdown of the amide or peptide bond, and are therefore called proteases or peptidases as well. In the human genome, proteases made up about 2% of the genome, or about 600 gene products. There are six major groups of peptidases according to the catalytic residue. In our work we focused on the M14 family of peptidases, also called metallocarboxypeptidases (CPs) because of their catalytic activity hinges on the zinc ion present in the active site of the enzyme. In the human genome there are identified at least 26 genes encoding for CPs. M14 peptidases in the gastrointestinal tract are the main metalloproteases responsible of the liberation of free aminoacids from the protein content of the diet. In other compartments of the body, CPs may perform specialized and tightly controlled tasks such as neuropeptide, cytokine and hormone maturation. In some instances an imbalance in their activity leads to disease states in man. Increasing evidence shows carboxypeptidase involvement in acute pancreatitis, diabetes, inflammation, fibrinolysis and cancer. Although some aspects have become clearer, much of their activity remain poorly understood. Besides, carboxypeptidases are interesting targets for drug development, and therefore we pursued a multidisciplinary approach to identify and characterize novel small molecular weight compounds able to interfere carboxypeptidase activity. In this work we combined modern computational tools, in vitro screening, molecular modelling and X-ray crystallography to obtain new chemical entities useful as scaffolds for drug design. Based on a bioinformatics tools, the Optimal Docking Area method, we identified protein-protein and protein-ligand binding sites over the surface of M14 peptidases. This knowledge was employed to find out a new class of small molecular weight inhibitors which exploit the differential binding provided by hydrophobic patches. A further class of inhibitors was identified from in silico screening of collections of compounds. In vitro analysis revealed that the leads were potent inhibitors against the target proteases with interesting features like an oxadiazole zinc-chelating moiety. Compounds obtained from the Organic Chemistry Department were also screened, and unexpectedly, afforded some good inhibitors with unprecedented atomic bonding. One further class involved inhibitors that attach covalently to the target enzyme. In this case the structure of the complex obtained at high resolution by X-ray crystallography allowed the structure-guided design of new generation of compounds. The catalytic mechanism of M14 peptidases was also revisited based on our crystallographic and computational analysis of a new CPB crystal form at high resolution. Overall, our study provided new lead small molecular weight inhibitors which can be the foundation for further developments in the design of drugs and bioimaging or diagnostic agents targeted to physiologically-relevant metallocarboxypeptidases

Immunohistochemical Localization of REG Ia Protein in Salivary Gland Tumors

The regenerating gene( Reg) Ia protein has a trophic effect on gastric epithelial cells, and its overexpressionis reported in gastrointestinal cancers. The salivary gland is a component of the digestive system, andtherefore, REG Ia protein may play some role in the pathophysiology of salivary gland tumors. In the presentstudy, we determined the immunohistochemical localization of REG Ia protein in salivary gland tumorsand moreover investigated its relationship to clinicopathological features. Twenty-eight patients with salivarygland tumor were enrolled. The specimens resected by surgery from those patients were examinedusing immunohistochemistry for REG Ia protein and Ki67. Five of the 16 pleomorphic adenomas (31.3%)were positive for REG Ia protein. Regarding salivary gland carcinomas, four of five mucoepidermoid carcinomas(80%), three of five adenoid cystic carcinomas (60%), one of two polymorphous low-grade adenocarcinomas(50%) were also positive for REG Ia protein. However, no relationships were found betweenREG Ia protein expression and clinicopathological features. Regarding the Ki67 expression, strong signalwas observed in the tumor cells of patients with salivary gland adenoma as well as carcinoma. REG Ia proteinis expressed not only in adenocarcinoma but also precancerous adenoma cells proliferating actively,suggesting that REG Ia protein may play a role at least in part in the development of salivary gland tumors

Rastres genètics de colls d'ampolla en poblacions de llop europees

El llop ibèric ha estat en el llindar de l'extinció, potser molt més a prop del que inicialment es va pensar. Investigadors de la UAB i de la UPF-CSIC han realitzat un estudi comparatiu entre el llop ibèric i el llop rus i han trobat que o bé es van subestimar els efectes genètics dels delmes de la població del llop ibèric (anomenats colls d'ampolla) durant el segle passat, o bé hi ha una sobreestimació del nombre actual de llops a la Península Ibèrica. L'estudi posa en relleu la necessitat d'assegurar el futur del llop mitjançant el creixement constant de les poblacions, sempre que sigui possible, així com la importància d'evitar la fragmentació poblacional i del territori.El lobo ibérico ha estado en el umbral de la extinción, quizás mucho más cerca de lo que inicialmente se pensó. Investigadores de la UAB y de la UPF-CSIC han realizado un estudio comparativo entre el lobo ibérico y el lobo ruso y han hallado que o bien se subestimaron los efectos genéticos de los diezmos de la población del lobo ibérico (llamados cuellos de botella) durante el siglo pasado, o bien hay una sobreestimación del número actual de lobos en la Península Ibérica. El estudio pone de relieve la necesidad de asegurar el futuro del lobo mediante el crecimiento constante de las poblaciones, siempre que sea posible, así como la importancia de evitar la fragmentación poblacional y del territorio

Pathological Approach for Surveillance of Ulcerative Colitis-associated cancer:Usefulness of Immunohistochemistry for p53

The patients with long-standing ulcerative colitis( UC) have a high-risk of neoplastic lesions in the colonicmucosa. The UC-associated neoplastic lesion is difficult to detect by endoscopic examination or diagnosehistologically. In the present study, we aimed to clarify whether immunohistochemistry for p53 is useful todiscriminate the UC-associated neoplasia from inflammed regenerating epithelium. Tissue samples were obtainedfrom colorectomy specimens from 20 patients with long-standing UC (range 6-29 years). The surfaceof microstructure of the tissues was observed by stereomicroscopy, and the sections were examined usingimmunohistochemistry for p53. All of T2-4 carcinomas were detectable by endoscopic examination beforesurgery, whereas considerable number of dysplasias (52.5%), Tis carcinomas (33.3%), and T1 carcinomas(60.0%) were undetectable. Fifty-three of 67 UC-associated neoplastic lesions (79.1%) were of flat-typemacroscopically. The detection rate of flat-type neoplasias( 45.3%) was significantly lower than that of protrudingones (100%). The positivity of p53 overexpression was 0 % in UC-II, 52.5 % in UC-III, and 70.4 %in UC-IV, respectively. UC-II lesions had lower positivity of p53 overexpression than UC-III( P=0.027) or-IV lesions( P=0.003). Immunohistochemical analysis of p53 protein is useful to discriminate the UC-associatedneoplasia from inflammed regenerating epithelium

CreA-mediated repression of gene expression occurs at low monosaccharide levels during fungal plant biomass conversion in a time and substrate dependent manner

Funding Information: The work conducted by the U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility, was supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 . CK, EB was supported by a grant of the Applied and Engineering Sciences division of NWO , and the Technology Program of the Ministry of Economic Affairs 016.130.609 to RPdV. PD was supported by a grant of the Netherlands Scientific Organization NWO 824.15.023 to RPdV. The Academy of Finland grant no. 308284 to MRM is acknowledged. Publisher Copyright: © 2021 The Author(s)Carbon catabolite repression enables fungi to utilize the most favourable carbon source in the environment, and is mediated by a key regulator, CreA, in most fungi. CreA-mediated regulation has mainly been studied at high monosaccharide concentrations, an uncommon situation in most natural biotopes. In nature, many fungi rely on plant biomass as their major carbon source by producing enzymes to degrade plant cell wall polysaccharides into metabolizable sugars. To determine the role of CreA when fungi grow in more natural conditions and in particular with respect to degradation and conversion of plant cell walls, we compared transcriptomes of a creA deletion and reference strain of the ascomycete Aspergillus niger during growth on sugar beet pulp and wheat bran. Transcriptomics, extracellular sugar concentrations and growth profiling of A. niger on a variety of carbon sources, revealed that also under conditions with low concentrations of free monosaccharides, CreA has a major effect on gene expression in a strong time and substrate composition dependent manner. In addition, we compared the CreA regulon from five fungi during their growth on crude plant biomass or cellulose. It showed that CreA commonly regulated genes related to carbon metabolism, sugar transport and plant cell wall degrading enzymes across different species. We therefore conclude that CreA has a crucial role for fungi also in adapting to low sugar concentrations as occurring in their natural biotopes, which is supported by the presence of CreA orthologs in nearly all fungi.Peer reviewe

Presenilin-dependent intramembrane cleavage of ephrin-B1

BACKGROUND: Presenilin-dependent γ-secretase cleavage of several transmembrane proteins, including amyloid-β precursor protein and Notch, mediates the intramembrane proteolysis to liberate their intracellular domains that are involved in cellular signaling. Considering γ-secretase inhibitors as therapeutics for Alzheimer's disease, understanding the physiologically and biologically important substrate for γ-secretase activity in brains is emerging issue. To elucidate the molecular mechanism and physiological role of γ-secretase, we screened candidate molecules for γ-secretase substrates. RESULTS: We show that ephrin-B1, that participates in cell-cell repulsive and attractive signaling together with its Eph receptor, constitutively undergoes ectodomain shedding and that the residual membrane-tethered fragment is sequentially cleaved by γ-secretase to release the intracellular domain. Furthermore, overexpression of membrane-tethered ephrin-B1 caused protrusion of numerous cellular processes consisted of F-actin, that required the preservation of the most C-terminal region of ephrin-B1. In contrast, soluble intracellular domain translocated into the nucleus and had no effect on cell morphology. CONCLUSION: Our findings suggest that ephrin-B is a genuine substrate for γ-secretase and regulates the cytoskeletal dynamics through intramembrane proteolysis