Saccharomyces cerevisiae is an important unicellular yeast species within the biotechnological and the food and beverage industries. A significant application of this species is the production of ...ethanol, where concentrations are limited by cellular toxicity, often at the level of the cell membrane. Here, we characterize 61 S. cerevisiae strains for ethanol tolerance and further analyze five representatives with various ethanol tolerances. The most tolerant strain, AJ4, was dominant in coculture at 0 and 10% ethanol. Unexpectedly, although it does not have the highest noninhibitory concentration or MIC, MY29 was the dominant strain in coculture at 6% ethanol, which may be linked to differences in its basal lipidome. Although relatively few lipidomic differences were observed between strains, a significantly higher phosphatidylethanolamine concentration was observed in the least tolerant strain, MY26, at 0 and 6% ethanol compared to the other strains that became more similar at 10%, indicating potential involvement of this lipid with ethanol sensitivity. Our findings reveal that AJ4 is best able to adapt its membrane to become more fluid in the presence of ethanol and that lipid extracts from AJ4 also form the most permeable membranes. Furthermore, MY26 is least able to modulate fluidity in response to ethanol, and membranes formed from extracted lipids are least leaky at physiological ethanol concentrations. Overall, these results reveal a potential mechanism of ethanol tolerance and suggest a limited set of membrane compositions that diverse yeast species use to achieve this.
Many microbial processes are not implemented at the industrial level because the product yield is poorer and more expensive than can be achieved by chemical synthesis. It is well established that microbes show stress responses during bioprocessing, and one reason for poor product output from cell factories is production conditions that are ultimately toxic to the cells. During fermentative processes, yeast cells encounter culture media with a high sugar content, which is later transformed into high ethanol concentrations. Thus, ethanol toxicity is one of the major stresses in traditional and more recent biotechnological processes. We have performed a multilayer phenotypic and lipidomic characterization of a large number of industrial and environmental strains of
to identify key resistant and nonresistant isolates for future applications.
Stuck and sluggish fermentations are among the main problems in winemaking industry leading to important economic losses. Several factors have been described as causes of stuck and sluggish ...fermentations, being exposure to extreme temperatures barely studied. The objective of this study was to identify thermal conditions leading to stuck and sluggish fermentations, focusing on the impact of an abrupt and transient decrease/increase of temperature on fermentation performance and yeast viability/vitality. Different strains of Saccharomyces cerevisiae, SBB11, T73, and PDM were evaluated in synthetic grape must fermentations. Cold shocks (9 °C and 1.5 °C for 16 h) carried out on different days during the fermentation process were unable to alter fermentation performance. Conversely, shock temperatures higher than 32 °C, applied in early stages of the process, lead to sluggish fermentation showing a delay directly related to the temperature increase. Fermentation delay was associated with a decrease in cell vitality. The impact of the heat shock on fermentation performance was different depending on the strain evaluated and nitrogen supplementation (with or without diammonium phosphate addition). None of the conditions evaluated produced a stuck fermentation and importantly, in all cases must nutrition improved fermentation performance after a heat shock.
•Cold shocks during alcoholic fermentation do not alter the fermentation performance.•Heat shocks during the first days of fermentation conduct to sluggish fermentations.•Fermentation delay after heat shock is attributable to decreased cell vitality.•DAP supplementation improves the global fermentation performance after a heat shock.•Sensitivity to heat shocks is strain dependent.
Background:
Mutations in cohesin complex genes have been described commonly in several types of cancer, with an incidence of 8% in myeloid diseases and myelodysplastic syndromes (MDS), and have been ...linked to marrow fibrosis by our group in a prior publication (Ramos F et al. Oncotarget 2016). However, their clinical impact is still undetermined.
Aims:
To identify mutations in cohesin complex genes in MDS patients by next generation sequencing (NGS) and to analyze their implications at clinical level (correlation with clinical characteristics and outcome).
Methods:
A cohort of 850 myeloid samples was analyzed by targeted deep sequencing (Nextera Rapid Capture Custom Enrichment) using an Illumina ® custom panel of 117 myeloid‐related genes, including cohesin complex genes: STAG1, STAG2, SMC1A, SMC3 and RAD21. A final selection of 324 patients with clinical, biological and follow‐up data were selected.
Results:
The median age was 75 years (p10‐p90: 57–84); 59% were male. According to the WHO 2008 classification most of the patients had RCMD (40%), and RAEB 1–2 (30%), while 11% had a MDS associated with isolated del(5q), and the remaining subtypes RCUD, RARS, U‐MDS were observed in less than 10% each. Regarding IPSS‐R, the majority of patients had very low (27%) and low (44%) risk, with 85% of the series having normal karyotype or clonal alterations of very good or good risk. The median follow‐up was 2.5 years (range 0.01–15.6) and during this time 50% of patients died and 30% progressed to acute myeloid leukemia (AML).
NGS study identified a 9.3% of patients with mutations in cohesin complex genes: STAG2 (6.5%), SMC3 (1.5%) and SMC1A (1.2%). In the global cohort, mutations in cohesin genes were associated with RAEB‐1 and RAEB‐2 subtypes (p = 0.003), intermediate IPSS‐R (p = 0.010), intermediate cytogenetic risk (p = 0.026) and a lower platelet count (p = 0.004). In addition, cohesin‐mutated patients showed a shorter overall survival (3 vs. 5 years, p = 0.06). Moreover, mutations in these genes were associated with a higher rate of progression to AML (p = 0.004) and a shorter time to AML progression (1.5 vs. 9.1 years, p < 0.001).
To further study the negative impact of these mutations, analyses were carried out for each IPSS‐R groups, separately. Interestingly, in low IPSS‐R patients, these analyses showed that cohesin mutations were the sole factor significantly associated with an earlier progression to AML (p < 0.001), while hemoglobin, platelet and neutrophil count, blasts in bone marrow and cytogenetic were not related to the outcome (Table 1). In addition, in the multivariate analysis, the presence of cohesin mutations was associated with a shorter overall survival in this subgroup of patients (HR = 0.291 (95% CI, 0.113–0.752); p = 0.011) (Table 2).
Summary/Conclusion:
Mutations in cohesin complex genes (mainly STAG2) are associated with a worse prognosis due to a higher rate of AML evolution and a shorter time to progression to AML in the global cohort. Of note, mutations in the cohesin complex were associated with a potential prognostic impact in low risk IPSS‐R subgroup. Therefore, analysis of these mutations, especially in this subgroup of patients, should be carried out.
Lenalidomide is an analog of thalidomide, with potent anticancer activity demonstrated in several hematological malignancies. It has immunomodulatory properties, being able to enhance the activation ...of different types of immune cells, which results in antitumor activities. Dendritic cells (DCs) are pivotal in the immune response, and different immunotherapeutic approaches targeting these cells are being developed. Since little is known about the effect of lenalidomide on DCs, the goal of the present work was to investigate the phenotype and function of human monocyte-derived DCs differentiated in the presence of lenalidomide (L-DCs). Our results showed that L-DCs display a unique phenotype, with increased cell surface expression of some maturation markers such as CD1d, CD83, CD86, and HLA-DR. This phenotype correlates with a lower expression of the E3 ubiquitin-ligase MARCH-I in L-DCs, upregulating the cell surface expression of CD86 and HLA-DR. In addition, immature L-DCs express higher amounts of DC-SIGN on the cell surface than control immature DCs. After LPS stimulation, production of IL-6 and TNF-α was severely decreased, whereas IL-12 and IL-10 secretion was dramatically upregulated in L-DCs, compared to that in the controls. Functionally, L-DCs are more effectively recognized by NKT cells in cytotoxicity experiments. Furthermore, L-DCs display higher opsonin-independent antigen uptake capability than control DCs. Mixed lymphocyte reaction experiments showed that L-DCs could stimulate naïve CD4 T-cells, polarizing them toward a predominant Th1 phenotype. In summary, DCs derived from monocytes in the presence of lenalidomide present a semi-mature phenotype, increased phagocytic capacity, reduced production of proinflammatory cytokines, and the ability to polarize T-cells toward predominant Th1-type responses; these are qualities that might be useful in the development of new immunotherapeutic treatments.
Molecular epidemiology of circulating clinical isolates is crucial to improve prevention strategies. The Spanish Working Group on multidrug resistant tuberculosis (MDR-TB) is a network that monitors ...the MDR-TB isolates in Spain since 1998. The aim of this study was to present the study of the MDR-TB and extensively drug-resistant tuberculosis (XDR-TB) patterns in Spain using the different recommended genotyping methods over time by a national coordinated system. Based on the proposed genotyping methods in the European Union until 2018, the preservation of one method, MIRU-VNTR, applied to selected clustered strains permitted to maintain our study open for 20 years. The distribution of demographic, clinical and epidemiological characteristics of clustered and non-clustered cases of MDR/XDR tuberculosis with proportion differences as assessed by Pearson's chi-squared or Fisher's exact test was compared. The differences in the quantitative variables using the Student's-t test and the Mann-Whitney U test were evaluated. The results obtained showed a total of 48.4% of the cases grouped in 77 clusters. Younger age groups, having a known TB case contact (10.2% vs 4.7%) and XDR-TB (16.5% vs 1.8%) were significantly associated with clustering. The largest cluster corresponded to a Mycobacterium bovis strain mainly spread during the nineties. A total of 68.4% of the clusters detected were distributed among the different Spanish regions and six clusters involving 104 cases were grouped in 17 and 18 years. Comparison of the genotypes obtained with those European genotypes included in The European Surveillance System (TESSy) showed that 87 cases had become part of 20 European clusters. The continuity of MDR strain genotyping in time has offered a widespread picture of the situation that allows better management of this public health problem. It also shows the advantage of maintaining one genotyping method over time, which allowed the comparison between ancient, present and future samples.
Obsessive-compulsive disorder (OCD) is a clinically heterogeneous condition. Although structural brain alterations have been consistently reported in OCD, their interaction with particular clinical ...subtypes deserves further examination. Among other approaches, a two-group classification in patients with autogenous and reactive obsessions has been proposed. The purpose of the present study was to assess, by means of a voxel-based morphometry analysis, the putative brain structural correlates of this classification scheme in OCD patients. Ninety-five OCD patients and 95 healthy controls were recruited. Patients were divided into autogenous (n = 30) and reactive (n = 65) sub-groups. A structural magnetic resonance image was acquired for each participant and pre-processed with SPM8 software to obtain a volume-modulated gray matter map. Whole-brain and voxel-wise comparisons between the study groups were then performed. In comparison to the autogenous group, reactive patients showed larger gray matter volumes in the right Rolandic operculum. When compared to healthy controls, reactive patients showed larger volumes in the putamen (bilaterally), while autogenous patients showed a smaller left anterior temporal lobe. Also in comparison to healthy controls, the right middle temporal gyrus was smaller in both patient subgroups. Our results suggest that autogenous and reactive obsessions depend on partially dissimilar neural substrates. Our findings provide some neurobiological support for this classification scheme and contribute to unraveling the neurobiological basis of clinical heterogeneity in OCD.
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