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Systemic bis-phosphinic acid derivative restores chloride transport in Cystic Fibrosis mice
Get PDFMutations in the Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR) are responsible for Cystic Fibrosis (CF). The most common CF-causing mutation is the deletion of the 508th amino-acid of CFTR (F508del), leading to dysregulation of the epithelial fluid transport in the airway’s epithelium and the production of a thickened mucus favoring chronic bacterial colonization, sustained inflammation and ultimately respiratory failure. c407 is a bis-phosphinic acid derivative which corrects CFTR dysfunction in epithelial cells carrying the F508del mutation. This study aimed to investigate c407 in vivo activity in the F508del Cftrtm1Eur murine model of CF. Using nasal potential difference measurement, we showed that in vivo administration of c407 by topical, short-term intraperitoneal and long-term subcutaneous route significantly increased the CFTR dependent chloride (Cl−) conductance in F508del Cftrtm1Eur mice. This functional improvement was correlated with a relocalization of F508del-cftr to the apical membrane in nasal epithelial cells. Importantly, c407 long-term administration was well tolerated and in vitro ADME toxicologic studies did not evidence any obvious issue. Our data provide the first in vivo preclinical evidence of c407 efficacy and absence of toxicity after systemic administration for the treatment of Cystic Fibrosis
Depletion of the Origin Recognition Complex Subunits Delays Aging in Budding Yeast
Get PDFPrecise DNA replication is pivotal for ensuring the accurate inheritance of genetic information. To avoid genetic instability, each DNA fragment needs to be amplified only once per cell cycle. DNA replication in eukaryotes starts with the binding of the origin recognition complex (ORC) to the origins of DNA replication. The genes encoding ORC subunits have been conserved across eukaryotic evolution and are essential for the initiation of DNA replication. In this study, we conducted an extensive physiological and aging-dependent analysis of heterozygous cells lacking one copy of ORC genes in the BY4743 background. Cells with only one copy of the ORC genes showed a significant decrease in the level of ORC mRNA, a delay in the G1 phase of the cell cycle, and an extended doubling time. Here, we also show that the reducing the levels of Orc1-6 proteins significantly extends both the budding and average chronological lifespans. Heterozygous ORC/orcΔ and wild-type diploid cells easily undergo haploidization during chronological aging. This ploidy shift might be related to nutrient starvation or the inability to survive under stress conditions. A Raman spectroscopy analysis helped us to strengthen the hypothesis of the importance of lipid metabolism and homeostasis in aging
Highly different effects of phage therapy and antibiotic therapy on immunological responses of chickens infected with Salmonella enterica serovar Typhimurium
Get PDFThe appearance of bacteria resistant to most or even all known antibiotics has become a serious medical problem. One such promising and effective alternative form of therapy may be the use of phages, the administration of which is considered to be safe and highly effective, especially in animals with drug-resistant infections. Although there have been no reports to date suggesting that bacteriophages can cause any severe complications or adverse effects, we still know little about their interactions with animal organisms, especially in the context of the functioning of the immune system. Therefore, the aim of the present study was to compare the impact of the application of selected bacteriophages and antibiotics (enrofloxacin and colistin), commonly used in veterinary medicine, on immune functions in Salmonella enterica serovar Typhimurium-infected chickens. The birds were infected with S. Typhimurium and then treated with a phage cocktail (14 days), enrofloxacin (5 days), or colistin (5 days). The concentrations of a panel of pro-inflammatory cytokines (IL-1β, IL-6, IFN-γ, IL-8, and IL-12) and cytokines that reveal anti-inflammatory effects (IL-10 and IL-4), the percentage of lymphocytes, and the level of stress hormones (corticosterone and cortisol), which significantly modulate the immune responses, were determined in different variants of the experiment. The phage cocktail revealed anti-inflammatory effects when administered either 1 day after infection or 2 days after S. Typhimurium detection in feces, as measured by inhibition of the increase in levels of inflammatory response markers (IL-1β, IL-6, IFN-γ, IL-8, and IL-12). This was also confirmed by increased levels of cytokines that exert an anti-inflammatory action (IL-10 and IL-4) following phage therapy. Moreover, phages did not cause a negative effect on the number and activity of lymphocytes’ subpopulations crucial for normal immune system function. These results indicate for the first time that phage therapy not only is effective but also can be used in veterinary medicine without disturbing immune homeostasis, expressed as cytokine imbalance, disturbed percentage of key immune cell subpopulations, and stress axis hyperactivity, which were observed in our experiments as adverse effects accompanying the antibiotic therapy
Improvement of native structure-based peptides as efficient inhibitors of protein-protein interactions of SARS-CoV-2 spike protein and human ACE2
Get PDFNew pathogens responsible for novel human disease outbreaks in the last two decades are mainly the respiratory system viruses. Not different was the last pandemic episode, caused by infection of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). One of the extensively explored targets, in the recent scientific literature, as a possible way for rapid development of COVID-19 specific drug(s) is the interaction between the receptor-binding domain of the virus’ spike (S) glycoprotein and human receptor angiotensin-converting enzyme 2 (hACE2). This protein-protein recognition process is involved in the early stages of the SARS-CoV-2 life cycle leading to the host cell membrane penetration. Thus, disrupting this interaction may block or significantly reduce the infection caused by the novel pathogen. Previously we have designed (by in silico structure-based analysis) three very short peptides having sequences inspirited by hACE2 native fragments, which effectively bind to the SARS-CoV-2 S protein and block its interaction with the human receptor. In continuation of the above mentioned studies, here we presented an application of molecular modeling approach resulting in improved binding affinity of the previously proposed ligand and its enhanced ability to inhibit meaningful host-virus protein-protein interaction. The new optimized hexapeptide binds to the virus protein with affinity one magnitude higher than the initial ligand and, as a very short peptide, has also great potential for further drug development. The peptide-based strategy is rapid and cost-effective for developing and optimizing efficient protein-protein interactions disruptors and may be successfully applied to discover antiviral candidates against other future emerging human viral infections
mTOR/α-ketoglutarate-mediated signaling pathways in the context of brain neurodegeneration and neuroprotection
Get PDFCerebral disorders are largely associated with impaired cellular metabolism, despite the regulatory mechanisms
designed to ensure cell viability and adequate brain function. Mechanistic target of rapamycin (mTOR) signaling
is one of the most crucial factors in the regulation of energy homeostasis and its imbalance is linked with a
variety of neurodegenerative diseases. Recent advances in the metabolic pathways’ modulation indicate the role
of α-ketoglutarate (AKG) as a major signaling hub, additionally highlighting its anti-aging and neuroprotective
properties, but the mechanisms of its action are not entirely clear. In this review, we analyzed the physiological and pathophysiological aspects of mTOR in the brain. We also discussed AKG’s multifunctional properties, as well as mTOR/AKG-mediated functional communications in cellular metabolism. Thus, this article provides a
broad overview of the mTOR/AKG-mediated signaling pathways, in the context of neurodegeneration and
endogenous neuroprotection, with the aim to find novel therapeutic strategies
The transient Spt4-Spt5 complex as an upstream regulator of non-coding RNAs during development
Get PDFThe Spt4-Spt5 complex is conserved and essential RNA polymerase elongation factor. To investigate the role of the Spt4-Spt5 complex in non-coding transcription during development, we used the unicellular model Paramecium tetraurelia. In this organism harboring both germline and somatic nuclei, massive transcription of the entire germline genome takes place during meiosis. This phenomenon starts a series of events mediated by different classes of non-coding RNAs that control developmentally programmed DNA elimination. We focused our study on Spt4, a small zinc-finger protein encoded in P. tetraurelia by two genes expressed constitutively and two genes expressed during meiosis. SPT4 genes are not essential in vegetative growth, but they are indispensable for sexual reproduction, even though genes from both expression families show functional redundancy. Silencing of the SPT4 genes resulted in the absence of double-stranded ncRNAs and reduced levels of scnRNAs – 25 nt-long sRNAs produced from these double-stranded precursors in the germline nucleus. Moreover, we observed that the presence of a germline-specific Spt4-Spt5m complex is necessary for transfer of the scnRNA-binding PIWI protein between the germline and somatic nucleus. Our study establishes that Spt4, together with Spt5m, is essential for expression of the germline genome and necessary for developmental genome rearrangements
The foraging behavior of nonbreeding Adélie penguins in the western Antarctic Peninsula during the breeding season
Get PDFInformation on marine predator at-sea distributions is key to understanding ecosystem and community dynamics and an important component of spatial management frameworks that aim to identify regions important for conservation. Tracking data from seabirds are widely used to define priority areas for conservation, but such data are often restricted to the breeding population. This also applies to penguins in Antarctica, where identification of important habitat for nonbreeders has received limited attention. Nonbreeding penguins are expected to have larger foraging distributions than breeding conspecifics, which may alter their interactions with physical environmental factors, conspecifics, other marine predators, and threats. We studied the movement behavior of nonbreeding Adélie penguins tracked during the 2016/2017 breed�ing season at King George Island in the South Shetland Islands, Antarctica. We quantify how nonbreeding penguins’ horizontal moment behavior varies in relation to environmental conditions and assess the extent of spatial overlap in the foraging ranges of nonbreeders and breeders, which were tracked over several years. Nonbreeders increased their prey search and area-restricted foraging behavior as sea surface temperature and bottom depths decreased, and in response to increasing sea ice concentration. Nonbreeders tended to transit (high directional movement) over the relatively deep Central Basin of the Bransfield Strait. The majority of foraging behavior occurred within the colder, Weddell Sea–sourced water of the Antarctic Coastal Current (incubation) and in the Weddell Sea (crèche). The utilization distributions of breeders and non-breeders overlapped in the central Bransfield Strait. Spatial segregation was greater during the crèche stage of breeding compared to incubation and brood, because chick provisioning still constrained the foraging range of breeders to a scale of a few tens of kilometers, while nonbreeders commenced with premolt foraging trips into the Weddell Sea. Our results show that breeding and nonbreeding penguins may not be impacted similarly by local nvironmental variability, given that their spatial and temporal scales of foraging differ during some part of the austral summer. Our study highlights the need to account for different life history stages when characterizing foraging behavior of marine predator populations.This is particularly important for “sentinel” species monitored as part of marine conservation and ecosystem-based management programs
A cap 0-dependent mRNA capture method to analyze the yeast transcriptome
Get PDFAnalysis of the protein coding transcriptome by the
RNA sequencing requires either enrichment of the
desired fraction of coding transcripts or depletion
of the abundant non-coding fraction consisting
mainly of rRNA. We propose an alternative mRNA
enrichment strategy based on the RNA-binding
properties of the human IFIT1, an antiviral protein
recognizing cap 0 RNA. Here, we compare for
Saccharomyces cerevisiae an IFIT1-based mRNA
pull-down with yeast targeted rRNA depletion by
the RiboMinus method. IFIT1-based RNA capture
depletes rRNA more effectively, producing high
quality RNA-seq data with an excellent coverage of
the protein coding transcriptome, while depleting
cap-less transcripts such as mitochondrial or some
non-coding RNAs. We propose IFIT1 as a cost
effective and versatile tool to prepare mRNA libraries
for a variety of organisms with cap 0 mRNA
ends, including diverse plants, fungi and eukaryotic
microbes
Strategies of urban trees for mitigating salt stress: a case study of eight plant species
Get PDFStreet trees are exposed to relatively high stress levels, and the average lifespan of street trees is shortened compared to those of trees living under controlled natural conditions. Soil salinity adversely affects trees at all stages of growth and development. This study attempts to determine how the urban environment, with particular emphasis on salt stress, affects tree species with different levels of salinity sensitivity. The aim of this study was to identify the strategies of eight tree species for mitigating salt stress based on the determination of the chemical composition of the macroelements in the leaves, the ionic imbalance, and the ability of the trees to synthesize and accumulate polyprenols in the leaves. The obtained results suggest that individual species implemented different strategies in response to salt stress. The low sensitivity species: Q. rubra, R. pseudoacacia, G. triacanthos and A. campestre. blocked the uptake of Cl and Na to the leaves. The mediumsensitivity species: P. x hispanica blocked the uptake of Cl and Na and G. biloba maintained very high contents of Cl and Na in its leaves without leaf damage and synthesized large amounts of polyprenols. G. triacanthos and A. campestre synthesized large amounts of polyprenols. The high-sensitivity species (T. x euchlora and A. platanoides) exhibited very high contents
of Cl and Na in their leaves, which were significantly damaged and had a pronounced ionic imbalance. These effects were not compensated for by the increased synthesis of polyprenols. In conclusion, the accumulation of polyprenols in leaf tissue may be one of the strategies that increase the resistance of plants to salt stress. Plants have many other methods of mitigating salt stress
In Silico Predictions of Ecological Plasticity Mediated by Protein Family Expansions in Early-Diverging Fungi
Get PDFEarly-diverging fungi (EDF) are ubiquitous and versatile. Their diversity is reflected in their genome sizes and complexity. For instance, multiple protein families have been reported to expand or disappear either in particular genomes or even whole lineages. The most commonly mentioned are CAZymes (carbohydrate-active enzymes), peptidases and transporters that serve multiple biological roles connected to, e.g., metabolism and nutrients intake. In order to study the link between ecology and its genomic underpinnings in a more comprehensive manner, we carried out a systematic in silico survey of protein family expansions and losses among EDF with diverse lifestyles. We found that 86 protein families are represented differently according to EDF ecological features (assessed by median count differences). Among these there are 19 families of proteases, 43 CAZymes and 24 transporters. Some of these protein families have been recognized before as serine and metallopeptidases, cellulases and other nutrition-related enzymes. Other clearly pronounced differences refer to cell wall remodelling and glycosylation. We hypothesize that these protein families altogether define the preliminary fungal adaptasome. However, our findings need experimental validation. Many of the protein families have never been characterized in fungi and are discussed in the light of fungal ecology for the first tim