A novel approach for the improvement of stress resistance in wine yeasts

During wine production yeast cells are affected by several stress conditions that could affect their viability and fermentation efficiency. In this work we describe a novel genetic manipulation strategy designed to improve stress resistance in wine yeasts. This strategy involves modifying the expression of the transcription factor MSN2, which plays an important role in yeast stress responses. The promoter in one of the genomic copies of this gene has been replaced by the promoter of the SPI1 gene, encoding for a cell wall protein of unknown function. SPI1 is expressed at late phases of growth and is regulated by Msn2p. This modification allows self-induction of MSN2 expression. MSN2 gene transcription, Msn2p protein levels and cell viability increase under several stress conditions in the genetically modified strain. The expression of stress response genes regulated by Msn2p also increases under these situations. Cells containing this promoter change are able to carry out vinifications at 15 and 30 degrees C with higher fermentation rates during the first days of the process compared to the control strain.

Phylogenetic and in silico structural analysis of the Parkinson disease-related kinase PINK1

Parkinson disease (PD) is the second most common neurodegenerative disorder and is characterized by the loss of dopaminergic neurons in the substantia nigra. Mutations in PINK1 were shown to cause recessive familial PD, and today are proposed to be associated with the disease via mitochondrial dysfunction and oxidative damage. The PINK1 gene comprises eight exons, which encode a ubiquitously expressed 581 amino acid protein that contains an N-terminal mitochondrial targeting domain and a serine/threonine protein kinase. To better understand the relationship between PINK1 and PD we have first analyzed the evolutionary history of the gene showing its late emergence in evolution. In addition, we have modeled the three-dimensional structure of PINK1 and found some evidences that help to explain the effect of some PD-related mutations in this protein's function.

Structural and functional in silico analysis of LRRK2 missense substitutions

The LRRK2 gene (Leucine-Rich Repeat Kinase 2, PARK8) is mutated in a significant number of cases of autosomal dominant Parkinson's disease (PD) and in some sporadic cases of late-onset PD. LRRK2 is a large, complex protein that comprises several interaction domains: armadillo, ankyrin, leucine-rich repeats and WD40 domains; two catalytic domains: ROC-GTPase and serine/threonine kinase; and a COR domain (unknown function). Pathogenic mutations are scattered all over the domains of LRRK2, although the prevalence of mutations in some domains is higher (ROC-GTPase, COR and kinase). In this work, we model the structure of each domain to predict and explore the effects of described missense mutations and polymorphisms. The results allow us to postulate the possible effects of pathogenic mutations in the function of the protein, and hypothesize the importance of some polymorphisms that have not been linked directly to PD, but act as risk factors for the disease. In our analysis, we also study the effects of PD-related mutations in the kinase domain structure and in the phosphorylation of the activation loop to determine effects on kinase activity.

Cumulative Genetic Score and C9orf72 Repeat Status Independently Contribute to Amyotrophic Lateral Sclerosis Risk in 2 Case-Control Studies

BACKGROUND AND OBJECTIVES

Most patients with amyotrophic lateral sclerosis (ALS) lack a monogenic mutation. This study evaluates ALS cumulative genetic risk in an independent Michigan and Spanish replication cohort using polygenic scores.

METHODS

Participant samples from University of Michigan were genotyped and assayed for the chromosome 9 open reading frame 72 hexanucleotide expansion. Final cohort size was 219 ALS and 223 healthy controls after genotyping and participant filtering. Polygenic scores excluding the C9 region were generated using an independent ALS genome-wide association study (20,806 cases, 59,804 controls). Adjusted logistic regression and receiver operating characteristic curves evaluated the association and classification between polygenic scores and ALS status, respectively. Population attributable fractions and pathway analyses were conducted. An independent Spanish study sample (548 cases, 2,756 controls) was used for replication.

RESULTS

Polygenic scores constructed from 275 single-nucleotide variation (SNV) had the best model fit in the Michigan cohort. An SD increase in ALS polygenic score associated with 1.28 (95% CI 1.04-1.57) times higher odds of ALS with area under the curve of 0.663 vs a model without the ALS polygenic score (p value = 1 × 10-6). The population attributable fraction of the highest 20th percentile of ALS polygenic scores, relative to the lowest 80th percentile, was 4.1% of ALS cases. Genes annotated to this polygenic score enriched for important ALS pathomechanisms. Meta-analysis with the Spanish study, using a harmonized 132 single nucleotide variation polygenic score, yielded similar logistic regression findings (odds ratio: 1.13, 95% CI 1.04-1.23).

DISCUSSION

ALS polygenic scores can account for cumulative genetic risk in populations and reflect disease-relevant pathways. If further validated, this polygenic score will inform future ALS risk models.

The Saccharomyces cerevisiae flavodoxin-like proteins Ycp4 and Rfs1 play a role in stress response and in the regulation of genes related to metabolism

SPI1 is a gene whose expression responds to many environmental stimuli, including entry into stationary phase. We have performed a screening to identify genes that activate SPI1 promoter when overexpressed. The phosphatidylinositol-4-phosphate 5-kinase gene MSS4 was identified as a positive activator of SPI1. Another SPI1 transcriptional regulator isolated was the flavodoxin-like gene YCP4. YCP4 and its homolog RFS1 regulate the expression of many genes during the late stages of growth. The double deletion mutant in YCP4 and its homolog RFS1 has an impact on gene expression related to metabolism by increasing the expression of genes involved in hexose transport and glycolysis, and decreasing expression of genes of amino acid metabolism pathways. Genes related to mating and response to pheromone show a decreased expression in the double mutant, while transcription of genes involved in translational elongation is increased. Deletion of these genes, together with the third member of the family, PST2, has a complex effect on the stress response. For instance, double mutant ycp4Δrfs1Δ has an increased response to oxidative stress, but a decreased tolerance to cell-damaging agent SDS. Additionally, this mutation affects chronological aging and slightly increases fermentative capacity.

Clinical profile of motor neuron disease patients with lower urinary tract symptoms and neurogenic bladder

INTRODUCTION

Lower urinary tract symptoms (LUTS) are frequent in motor neuron disease (MND) patients, but clinical factors related to them are unknown. We describe differences in LUTS among MND phenotypes and their relationship with other clinical characteristics, including prognosis.

METHODS

For this study, we collected clinical data of a previously published cohort of patients diagnosed with classical amyotrophic lateral sclerosis (cALS), progressive muscular atrophy (PMA) or primary lateral sclerosis (PLS) with and without LUTS. Familial history was recorded and the C9ORF72 expansion was analysed in the entire cohort. Patients were followed-up for survival until August 2016.

RESULTS

Fifty-five ALS patients (37 cALS, 10 PMA and 8 PLS) were recruited. Twenty-four reported LUTS and neurogenic bladder (NB) could be demonstrated in nine of them. LUTS were not influenced by age, phenotype, disability, cognitive or behavioural impairment, or disease progression, but female sex appeared to be a protective factor (OR=0.39, p=0.06). Neither family history nor the C9ORF72 expansion was linked to LUTS or NB. In the multivariate analysis, patients reporting LUTS early in the disease course tended to show poorer survival.

CONCLUSIONS

In this study, LUTS appear to be more frequent in male MND patients, but are not related to age, clinical or genetic characteristics. When reported early, LUTS could be a sign of rapid disease spread and poor prognosis. Further prospective longitudinal and neuroimaging studies are warranted to confirm this hypothesis.

Ubiquitin ligase Rsp5p is involved in the gene expression changes during nutrient limitation in Saccharomyces cerevisiae

Rsp5p is an essential ubiquitin ligase involved in many different cellular events, including amino acid transporters degradation, transcription initiation and mRNA export. It plays important role in both stress resistance and adaptation to the change of nutrients. We have found that ubiquitination machinery is necessary for the correct induction of the stress response SPI1 gene at the entry of the stationary phase. SPI1 is a gene whose expression is regulated by the nutritional status of the cell and whose deletion causes hypersensitivity to various stresses, such as heat shock, alkaline stress and oxidative stress. Its regulation is mastered by Rsp5p, as mutations in this gene lead to a lower SPI1 expression. In this process, Rsp5p is helped by several proteins, such as Rsp5p-interacting proteins Bul1p/2p, the ubiquitin conjugating protein Ubc1p and ubiquitin proteases Ubp4p and Ubp16p. Moreover, a mutation in the RSP5 gene has a global effect at the gene expression level when cells enter the stationary phase. Rsp5p particularly controls the levels of the ribosomal proteins mRNAs at this stage. Rsp5p is also necessary for a correct induction of p-bodies under stress conditions, indicating that this protein plays an important role in the post-transcriptional fate of mRNA under nutrient starvation.

Nature of the Inactivation Curves of Bacillus Pumilus Spores Heated Using Non‐isothermal and Isothermal Treatments

ABSTRACT: Isothermal and non‐isothermal heat resistance studies were carried out on Bacillus pumilus spores. The non‐isothermal study revealed a non‐linear behavior of the survivor curve, which was revealed as a tail after an isothermal study. Results indicated that the spores obtained by isolating cells from colonies of the tail section were more heat resistant than the original ones (D104°c= 0.15 and 1.9 min for spores from the original population and from the tail, respectively). Application of the Weibull distribution model to analyze the tail produced good results at the 3 temperatures studied. Nevertheless, when the model was applied to curves having both concave downward and concave upward sections a poor result was obtained, with an accuracy factor greater than 1.

Assessing the role of TUBA4A gene in frontotemporal degeneration

The tubulin alpha 4a (TUBA4A) gene has been recently associated with amyotrophic lateral sclerosis. Interestingly, some of the mutation carriers were also diagnosed with frontotemporal degeneration (FTD) or mild cognitive impairment. With the aim to investigate the role of TUBA4A in FTD, we screened TUBA4A in a series of 814 FTD patients from Spain. Our data did not disclose any nonsense or missense variant in the cohort, thus suggesting that TUBA4A mutations are not associated with FTD.

Phylogenetic origin and transcriptional regulation at the post-diauxic phase of SPI1, in Saccharomyces cerevisiae

The gene SPI1, of Saccharomyces cerevisiae, encodes a cell wall protein that is induced in several stress conditions, particularly in the postdiauxic and stationary phases of growth. It has a paralogue, SED1, which shows some common features in expression regulation and in the null mutant phenotype. In this work we have identified homologues in other species of yeasts and filamentous fungi, and we have also elucidated some aspects of the origin of SPI1, by duplication and diversification of SED1. In terms of regulation, we have found that the expression in the post-diauxic phase is regulated by genes related to the PKA pathway and stress response (MSN2/4, YAK1, POP2, SOK2, PHD1, and PHO84) and by genes involved in the PKC pathway (WSC2, PKC1, and MPK1).

Relationship between COVID-19 Pandemic Confinement and Worsening or Onset of Depressive Disorders

Several studies indicate that the pandemic and associated confinement measures may have had an impact on mental health, producing the onset or persistence of symptoms such as stress, anxiety, depression, and fear. This systematic review aims to identify the factors influencing the onset or worsening of depressive symptoms during COVID-19-related confinement. Our systematic search produced 451 articles from selected databases, 398 of which were excluded based on established criteria, while 53 were selected for review. Most studies have reported an increase in the prevalence of depressive symptoms in the general population during the first weeks of confinement. The predominant risk factors associated with the appearance of depressive symptoms included female sex, low educational level, young age, economic difficulties, comorbidities, and a history of previous depressive episodes. People with a pre-existing diagnosis of depressive disorder generally experienced a worsening of their symptoms during confinement in most of the reviewed studies. Moreover, symptomatology persisted at higher levels post-confinement, without significant improvement despite relief in confinement measures. Therefore, ongoing evaluations of post-pandemic depressive symptoms are necessary to advance the knowledge of the relationship between pandemics and depression, allowing accurate conclusions and associations to be made.

Genetic and constitutional factors are major contributors to substantia nigra hyperechogenicity

Hyperechogenicity of substantia nigra (SNh) is a frequent finding in amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD) and other movement disorders (MD) patients, but its meaning is unclear. To ascertain the contribution of different factors to SNh area, we measured it in 108 ALS, 102 PD, 91 other MD patients and 91 healthy controls. Demographical data were collected in all patients and controls. In ALS patients, we also recorded clinical variables, performed genetic analysis and measured baseline levels of ferritin. After family history and genetic testing, ALS patients were classified as familial (15) or sporadic (93). ALS, PD and other MD patients had a larger SNh area than controls. Left SNh and male gender, but not age, associated with larger SNh area in both patients and controls. Familial ALS patients showed larger SNh area than sporadic ones and familial ALS was the only clinical variable in the multivariate analysis to be associated with larger SNh area in ALS patients. Our results suggest that SNh associates with genetic and constitutional factors (male gender, handedness), some of which predispose to certain neurodegenerative diseases. This evidence supports the idea of SNh as an inborn marker of unspecific neuronal vulnerability.

Other Proteins Involved in Parkinson's Disease and Related Disorders

In order to explain the molecular causes of Parkinson's Disease (PD) it is important to understand the effect that mutations described as causative of the disease have at the functional level. In this special issue, several authors have been reviewing the effects in PD and other parkinsonisms of mutations described in LRRK2, α-synuclein, PINK1-Parkin-DJ-1, UCHL1, ATP13A2, GBA, VPS35, FBOX7 and HTRA2. In this review, we compile the knowledge about other proteins with a more general role in neurodegenerative diseases (MAPT) or for which less data is available due to its recent discovery (EIF4G1, DNAJC13), the lack of structural or functional data (as for PLA2G6 or DNAJC6), or even their doubtful association with the disease (as for GIGYF2, SYNJ1 and SPR). Also the cellular pathways involved in this disease are reviewed, with the goal of having an overview of the effects on the proteins and its possible role in the disease. This knowledge could also serve as the basis for designing tools that may potentially be used as a treatment for the disease, such as inhibitory or activating molecules, as well as other involved in regulating the half-life of the proteins involved.

Special Issue "Mechanisms and Novel Therapeutic Approaches for Neurodegenerative Diseases"

Neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), are among the major health problems of the elderly, and represent a major global health challenge due to their increasing prevalence and complex pathophysiological mechanisms [...].

Special Issue "Molecular and Genetic Aspects of SARS-CoV-2 Infection and COVID-19 Disease"

We are pleased to present the first and second editions of this Special Issue, titled "Molecular and Genetic Aspects of SARS-CoV-2 Infection and COVID-19 Disease", of the International Journal of Molecular Sciences [...].