Estudio de los genes KIPDCB y KIGSK-3 de la levadura "Kluyveromyces lactis"

[Resumen] En el presente trabajo se ha secuenciado una región de 5kb de DNA del cromosoma seis de la levadura Kluyveromyces Lactis, en la que se han identificado dos pautas de lectura abierta, las cuales se han subclonado y se ha realizado su análises funcional. La predición de función basada en homologías respecto a secuencias recopiladas en las bases de datos puso de manifiesto que uno de los genes (KLPDCB), de bajo nivel de expresion, posee una gran similitud con piruvato descarboxilasas de distintos orígenes, mientras que el otro (KLGSK-3) pertenece a una familia de protein-quinasas. Se han interrumpido ambos genes siendo los fenotipos mas característicos mostrados por los mutantes nulos: en el primer caso, disminución drástica del crecimiento en medios carentes de tiamina, en el segundo, ausencia de crecimiento en glucosa y etanol a 37 grados C. Y disminución del almacenamiento de glucógeno. También se han realizado análisis de la secuencia de los promotores así como análisis de expresión mediante Northern-Blot, Rt-Pcr y fusiones a genes marcadores, todo ello acompañado de una exhaustiva revisión bibliográfica

The Challenges and Opportunities of lncRNAs in Ovarian Cancer Research and Clinical Use

[Abstract] Ovarian cancer is one of the most lethal gynecological malignancies worldwide because it tends to be detected late, when the disease has already spread, and prognosis is poor. In this review we aim to highlight the importance of long non-coding RNAs (lncRNAs) in diagnosis, prognosis and treatment choice, to make progress towards increasingly personalized medicine in this malignancy. We review the effects of lncRNAs associated with ovarian cancer in the context of cancer hallmarks. We also discuss the molecular mechanisms by which lncRNAs become involved in cellular physiology; the onset, development and progression of ovarian cancer; and lncRNAs’ regulatory mechanisms at the transcriptional, post-transcriptional and post-translational stages of gene expression. Finally, we compile a series of online resources useful for the study of lncRNAs, especially in the context of ovarian cancer. Future work required in the field is also discussed along with some concluding remarks.This work was funded by Plan Estatal I + D + I by the Instituto de Salud Carlos III (ISCIII, Spain) under grant agreement AES number PI18/01714, cofounded by Fondo Europeo de Desarrollo Regional-FEDER (The European Regional Development Fund-ERDF) “A way of Making Europe,” and by Xunta de Galicia (Consolidación Grupos Referencia Competitiva contract number ED431C 2016-012). M.S.M. was funded by a predoctoral fellowship from FPU-2018 (Spain)Xunta de Galicia; ED431C 2016-01

Cellulases from thermophiles found by metagenomics

[Abstract] Cellulases are a heterogeneous group of enzymes that synergistically catalyze the hydrolysis of cellulose, the major component of plant biomass. Such reaction has biotechnological applications in a broad spectrum of industries, where they can provide a more sustainable model of production. As a prerequisite for their implementation, these enzymes need to be able to operate in the conditions the industrial process requires. Thus, cellulases retrieved from extremophiles, and more specifically those of thermophiles, are likely to be more appropriate for industrial needs in which high temperatures are involved. Metagenomics, the study of genes and gene products from the whole community genomic DNA present in an environmental sample, is a powerful tool for bioprospecting in search of novel enzymes. In this review, we describe the cellulolytic systems, we summarize their biotechnological applications, and we discuss the strategies adopted in the field of metagenomics for the discovery of new cellulases, focusing on those of thermophilic microorganisms.Xunta de Galicia.; ED431C2016-01

Genetic diagnosis of α1-antitrypsin deficiency using DNA from buccal swab and serum samples

Background: α1-Antitrypsin deficiency (AATD) is associated with a high risk of developing lung and liver disease. Despite being one of the most common hereditary disorders worldwide, AATD remains under-diagnosed and prolonged delays in diagnosis are usual. The aim of this study was to validate the use of buccal swab samples and serum circulating DNA for the complete laboratory study of AATD. Methods: Sixteen buccal swab samples from previously characterized AATD patients were analyzed using an allele-specific genotyping assay and sequencing method. In addition, 19 patients were characterized by quantification, phenotyping and genotyping using only serum samples. Results: the 16 buccal swab samples were correctly characterized by genotyping. Definitive results were obtained in the 19 serum samples analyzed by quantification, phenotyping and genotyping, thereby performing the complete AATD diagnostic algorithm. Conclusions: Buccal swab samples may be useful to expand AATD screening programs and family studies. Genotyping using DNA from serum samples permits the application of the complete diagnostic algorithm without delay. These two methods will be useful for obtaining more in depth knowledge of the real prevalence of patients with AATD

Comparative Metagenomic Analysis of Two Hot Springs From Ourense (Northwestern Spain) and Others Worldwide

[Abstract] With their circumneutral pH and their moderate temperature (66 and 68°C, respectively), As Burgas and Muiño da Veiga are two important human-use hot springs, previously studied with traditional culture methods, but never explored with a metagenomic approach. In the present study, we have performed metagenomic sequence-based analyses to compare the taxonomic composition and functional potential of these hot springs. Proteobacteria, Deinococcus-Thermus, Firmicutes, Nitrospirae, and Aquificae are the dominant phyla in both geothermal springs, but there is a significant difference in the abundance of these phyla between As Burgas and Muiño da Veiga. Phylum Proteobacteria dominates As Burgas ecosystem while Aquificae is the most abundant phylum in Muiño da Veiga. Taxonomic and functional analyses reveal that the variability in water geochemistry might be shaping the differences in the microbial communities inhabiting these geothermal springs. The content in organic compounds of As Burgas water promotes the presence of heterotrophic populations of the genera Acidovorax and Thermus, whereas the sulfate-rich water of Muiño da Veiga favors the co-dominance of genera Sulfurihydrogenibium and Thermodesulfovibrio. Differences in ammonia concentration exert a selective pressure toward the growth of nitrogen-fixing bacteria such as Thermodesulfovibrio in Muiño da Veiga. Temperature and pH are two important factors shaping hot springs microbial communities as was determined by comparative analysis with other thermal springs.This study received financial support from the following organizations: Xunta de Galicia (Consolidación GRC) co-financed by FEDER (Grant Number ED431C 2020/08) and Ministerio de Ciencia, Innovación y Universidades (MICINN) (Grant Number RTI2018-099249-B-I00). The work of M-ED was supported by a FPU fellowship (Ministerio de Educación Cultura y Deporte) FPU12/05050. The metagenome sequencing of As Burgas water was performed by M-ED in the Dinsdale Lab (Department of Biology, San Diego State University), as part of a short stay financed by the Short-Term Mobility program of the FPU scholarshipXunta de Galicia; ED431C 2020/0

Exploring the Taxonomical and Functional Profile of As Burgas Hot Spring Focusing On Thermostable β-galactosidases

[Abstract] In the present study we investigate the microbial community inhabiting As Burgas geothermal spring, located in Ourense (Galicia, Spain). The approximately 23 Gbp of Illumina sequences generated for each replicate revealed a complex microbial community dominated by Bacteria in which Proteobacteria and Aquificae were the two prevalent phyla. An association between the two most prevalent genera, Thermus and Hydrogenobacter, was suggested by the relationship of their metabolism. The high relative abundance of sequences involved in the Calvin–Benson cycle and the reductive TCA cycle unveils the dominance of an autotrophic population. Important pathways from the nitrogen and sulfur cycle are potentially taking place in As Burgas hot spring. In the assembled reads, two complete ORFs matching GH2 beta-galactosidases were found. To assess their functional characterization, the two ORFs were cloned and overexpressed in E. coli. The pTsbg enzyme had activity towards o-Nitrophenyl-β-D-galactopyranoside (ONPG) and p-Nitrophenyl-β-D-fucopyranoside, with high thermal stability and showing maximal activity at 85 °C and pH 6, nevertheless the enzyme failed to hydrolyze lactose. The other enzyme, Tsbg, was unable to hydrolyze even ONPG or lactose. This finding highlights the challenge of finding novel active enzymes based only on their sequence.Xunta de Galicia; ED431C 2020/08Ministerio de Ciencia, Innovación y Universidades; RTI2018-099249-B-I00Ministerio de Educación Cultura y Deporte; FPU12/0505

Rapid detection of Mmalton α1-antitrypsin deficiency allele by real-time PCR and melting curves in whole blood, serum and dried blood spot samples

Background: α1-Antitrypsin deficiency (AATD) is an autosomal codominant disorder associated with a high risk of developing lung and liver disease. The most common deficient alleles are known as Z and S. However, another deficient variant, called Mmalton, which causes a deficiency similar to variant Z, is considered to be the second cause of severe AATD in Spain. Nevertheless, the Mmalton allele is not recognizable by usual diagnostic techniques and therefore, its real prevalence is underestimated. We describe a rapid real-time PCR and melting curves assay designed for the detection of Mmalton AATD. Methods: we tested the applicability of this new technique for the identification of the Mmalton allele in AATD screening using whole blood, dried blood spot (DBS) and serum samples. Mmalton heterozygote and homozygote samples and samples without this allele were included in the study. Results: this new assay is able to detect homozygous and heterozygous genotypes in the same reaction and in a single step, giving matching results with those obtained by SERPINA1 gene sequencing. Conclusions: this technology is optimal for working with small amounts of DNA, such as in DBS and even with residual DNA present in serum samples, allowing improvement in routine algorithms of AATD diagnosis or large-scale screening. This method will be useful for obtaining more in depth knowledge of the real incidence of the Mmalton variant

Association between circulating alpha-1 antitrypsin polymers and lung and liver disease

Alpha-1 antitrypsin deficiency; Circulating polymers; EmphysemaDeficiència d'alfa-1 antitripsina; Polímers circulants; EmfisemaDeficiencia de alfa-1 antitripsina; Polímeros circulantes; EnfisemaBackground Alpha-1 antitrypsin deficiency (AATD) is considered one of the most common genetic diseases and is characterised by the misfolding and polymerisation of the alpha-1 antitrypsin (AAT) protein within hepatocytes. The relevance of circulating polymers (CP) of AAT in the pathogenesis of lung and liver disease is not completely understood. Therefore, the main objective of our study was to determine whether there is an association between the levels of CP of AAT and the severity of lung and liver disease. Method This was a cross-sectional study in patients with different phenotypes of AATD and controls. To quantify CP, a sandwich ELISA was performed using the 2C1 monoclonal antibody against AAT polymers. Sociodemographic data, clinical characteristics, and liver and lung parameters were collected. Results A cohort of 70 patients was recruited: 32 Pi*ZZ (11 on augmentation therapy); 29 Z-heterozygous; 9 with other genotypes. CP were compared with a control group of 47 individuals (35 Pi*MM and 12 Pi*MS). ZZ patients had the highest concentrations of CP (p < 0.001) followed by Z heterozygous. The control group and patients with Pi*SS and Pi*SI had the lowest CP concentrations. Pi*ZZ also had higher levels of liver stiffness measurements (LSM) than the remaining AATD patients. Among patients with one or two Z alleles, two patients with lung and liver impairment showed the highest concentrations of CP (47.5 µg/mL), followed by those with only liver abnormality (n = 6, CP = 34 µg/mL), only lung (n = 18, CP = 26.5 µg/mL) and no abnormalities (n = 23, CP = 14.3 µg/mL). Differences were highly significant (p = 0.004). Conclusions Non-augmented Pi*ZZ and Z-patients with impaired lung function and increased liver stiffness presented higher levels of CP than other clinical phenotypes. Therefore, CP may help to identify patients more at risk of developing lung and liver disease and may provide some insight into the mechanisms of disease.This study was supported by funding from Grifols to the Catalan Center for Research in Alpha-1 antitrypsin deficiency of the Vall d’Hebron Research Institute (VHIR) in the Vall d’Hebron Barcelona Hospital Campus, Barcelona, Spain and with a grant from the Fundació Catalana de Pneumologia (FUCAP)