Research, Research Articles
Microbiota and metabolome dynamics induced by Shiga toxin-producing E. coli in an in vitro model of an infant’s colon
Mariana Izquierdo1,a, Deborah O’Sullivan2,a, Ophélie Uriot2, Morgane Brun2, Claude Durif2, Sylvain Denis2, Pablo Gallardo1, Cormac G M Gahan3-5, Lucie Etienne-Mesmin2, Stéphanie Blanquet-Diot2,b and Mauricio J. Farfan1.b
This study provides new evidence of the impact of EHEC in the microbiota and metabolome dynamics in an in vitro gut model that could be useful in understanding their physiopathology in this at-risk population, considering inter-individual variabilities in gut microbiota.
Ampicillin treatment in persister cell studies may cause non-physiological artifacts
Michel Fasnacht1,2, Hena Comic1,2, Isabella Moll1,2
This study shows at the example of L2 how insufficient purification of ampicillin persister cells can lead to the generation of non-physiological artifacts and provides a novel tool to improve the removal of residual cell debris.
Clostridium scindens promotes gallstone formation by inducing intrahepatic neutrophil extracellular traps through CXCL1 produced by colonic epithelial cells
Wenchao Yao1,a, Yuanhang He2,3,a, Zhihong Xie2,3, Qiang Wang2,3, Yang Chen2,4, Jingjing Yu2,3, Xuxu Liu2,3, Dongbo Xue2,3 , Liyi Wang2,3 and Chenjun Hao2,3
Through in vivo and in vitro experiments, we validated the reliability of C. scindens stimulating colonic epithelial cells to produce TLR2, activating the NF-κB signaling pathway, promoting CXCL1 expres-sion, and inducing intrahepatic neutrophil NETosis, which may be associated with gallstone formation.
Integrative Omics reveals changes in the cellular landscape of peroxisome-deficient pex3 yeast cells
Tjasa Kosir1,a, Hirak Das2,a, Marc Pilegaard Pedersen1, Ann-Kathrin Richard2, Marco Anteghini3,4, Vitor Martins dos Santos4,5, Silke Oeljeklaus2, Ida J. van der Klei1 and Bettina Warscheid2
To uncover the consequences of peroxisome deficiency, we compared Saccharomyces cerevisiae wild-type with pex3 cells, which lack peroxisomes, employing quantitative proteomics and transcriptomics technologies.
Microwave-assisted preparation of yeast cells for ultrastructural analysis by electron microscopy
Moritz Mayera, Christina Schuga, Stefan Geimer, Till Klecker and Benedikt Westermann
Budding yeast Saccharomyces cerevisiae is widely used as a model organism to study the biogenesis and architecture of organellar membranes, which can be visualized by transmission electron microscopy (TEM).
A complex remodeling of cellular homeostasis distinguishes RSV/SARS-CoV-2 co-infected A549-hACE2 expressing cell lines
Claudia Vanetti1, Irma Saulle1,2, Valentina Artusa1,2, Claudia Moscheni1, Gioia Cappelletti1, Silvia Zecchini1, Sergio Strizzi1, Micaela Garziano1,2, Claudio Fenizia1,2, Antonella Tosoni1, Martina Broggiato1, Pasquale Ogno1, Manuela Nebuloni1, Mario Clerici2,3, Daria Trabattoni1, Fiona Limanaqi1 and Mara Biasin1
Given the common tropism of SARS-CoV-2 and RSV, and the unclear consequences of their mutual influence, we developed an in vitro lung epithelial cell model to study the molecular mechanisms and cellular pathways modulated in viral co-infection.
RidA proteins contribute to fitness of S. enterica and E. coli by reducing 2AA stress and moderating flux to isoleucine biosynthesis
Ronnie L. Fulton, Bryce R. Sawyer and Diana M Downs
This study solidifies the established role of RidA in removing 2AA, while also presenting evidence for a role of RidA in enhancing flux towards isoleucine biosynthesis in E. coli. Overall, these data emphasize that metabolic networks can generate distinct responses to perturbation, even when the individual components are conserved.
Fecal gelatinase does not predict mortality in patients with alcohol-associated hepatitis
Yongqiang Yang1,a, Philipp Hartmann2,3,a and Bernd Schnabl1,4
This study aimed to investigate the significance of fecal gelatinase on clinical outcomes in patients with alcohol-associated hepatitis. In conclusion, in our cohort, fecal gelatinase does not predict mortality and does not indicate higher disease severity in patients with alcohol-associated hepatitis.
Direct detection of stringent alarmones (pp)pGpp using malachite green
Muriel Schicketanz1, Magdalena Petrová2, Dominik Rejman2, Margherita Sosio3, Stefano Donadio3 and Yong Everett Zhang1
In this study, we demonstrate the surprising discovery of a commercially available, low-cost malachite green (MG) detection kit, originally designed for orthophosphate (Pi) detection, for detecting (p)ppGpp and its analogues, especially pGpp
A humanized yeast-based toolkit for monitoring phosphatidylinositol 3-kinase activity at both single cell and population levels
November 12, 2018
In this study, a humanized yeast system for functional studies on higher eukaryotic Phosphatidylinositol 3-kinase (PI3K) was developed by restricting PI3K activity in yeast to specific plasma membrane microdomains, utilizing engineered reporters to monitor activity at a single-cell level and employing novel tools to study the performance of yeast plasma membrane (PM) microdomain-directed PI3K, revealing location-specific effects on yeast growth and endocytosis.
A chemical genetic screen reveals a role for proteostasis in capsule and biofilm formation by Cryptococcus neoformans
October 31, 2018
This study demonstrates that the bipolar disorder drug lithium inhibits the formation of key virulence factors, biofilm, and polysaccharide capsule, in Cryptococcus neoformans by dysregulating the ubiquitin/proteasome system, shedding light on the impact of lithium and providing insights into potential alternative pharmaceutical approaches for combating this fungal pathogen.
Nutritional and meiotic induction of transiently heritable stress resistant states in budding yeast
October 29, 2018
This study demonstrates that transient exposures to environmental stresses induce persistent states of elevated stress resistance in yeast cells, termed cellular memory, suggesting a form of epigenetic inheritance, and shows that this phenomenon occurs not only in meiotically produced spores but also in haploid cells subjected to glucose withdrawal, adding new insights into the developmentally and nutritionally induced cellular memory.
Specific mutations in the permease domain of septal protein SepJ differentially affect functions related to multicellularity in the filamentous cyanobacterium Anabaena
October 16, 2018
In this study, the multifunctional roles of the SepJ protein in the multicellular function of the Anabaena filament were investigated, revealing that specific amino acids and stretches within the protein are essential for the formation of long filaments, heterocyst differentiation, and intercellular communication, shedding light on the structure and diverse functions of SepJ in the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120.
Trehalose-6-phosphate promotes fermentation and glucose repression in Saccharomyces cerevisiae
October 1, 2018
This study examined the capability of trehalose-6-phosphate synthase (TPS1) homologues from various species to complement the phenotypic defects of a Saccharomyces cerevisiae tps1 mutant, resulting in the classification of complementation into different groups based on metabolic patterns and fermentation capacity, shedding light on the role of TPS1 and trehalose-6-phosphate (T6P) as critical factors in sugar fermentation and glucose repression.
Single telomere length analysis in Ustilago maydis, a high-resolution tool for examining fungal telomere length distribution and C-strand 5’-end processing
August 7, 2018
This article introduces the development of single telomere length analysis (STELA) for Ustilago maydis, a basidiomycete fungus, enabling the precise measurement of telomere lengths and distributions. The study demonstrates STELA's utility in revealing the existence of relatively short telomeres in wild-type cells, preferential loss of long telomeres in a mutant defective in telomere replication, and the characterization of telomere C-strand 5’ ends, highlighting U. maydis as a strong model for telomere research.
Temporal analysis of the autophagic and apoptotic phenotypes in Leishmania parasites
August 1, 2018
This article details a comprehensive analysis of miltefosine-induced cell death and autophagy in Leishmania major, providing criteria for clear identification of apoptotic and autophagic cells, demonstrating the sequential nature of autophagy followed by apoptosis in nutrient-deprived conditions, and cautioning against using the generic kinase inhibitor staurosporine as a Leishmania apoptosis inducer, with the aim of improving the understanding of these processes and their targeting for new anti-leishmanial drugs.
Snf1 cooperates with the CWI MAPK pathway to mediate the degradation of Med13 following oxidative stress
June 25, 2018
This article explores the response of eukaryotic cells to environmental stress, highlighting the role of the conserved cyclin C-Cdk8 kinase in determining pro-survival or pro-death programs. Specifically, it discusses how oxidative stress triggers the destruction of Med13 by the SCFGrr1 ubiquitin ligase, releasing cyclin C to promote mitochondrial fission and cell death in Saccharomyces cerevisiae. Additionally, it reveals that the AMP kinase Snf1 activates a separate degron in Med13, contributing to the complex regulation of Med13 degradation following H2O2 stress through the coordination of the cell wall integrity and MAPK pathways.
Importance of polyphosphate in the Leishmania life cycle
June 22, 2018
This article explores the importance of polyphosphate (polyP) in Leishmania parasites, emphasizing the role of the polyP polymerase VTC4 and its impact on parasite survival at higher temperatures. Additionally, it discusses the effects of VTC4 knockout in mouse infections, noting a delay in lesion formation and strong pathology in L. major VTC4 knockout, without confirmation through complementation and no alteration in L. guyanensis infections in mice with VTC4 knockdown.
Antagonism between salicylate and the cAMP signal controls yeast cell survival and growth recovery from quiescence
March 26, 2018
This article describes the effects of salicylate, the main metabolite of aspirin, on S. cerevisiae cells. It outlines how salicylate influences glucose transport, sugar phosphate biosynthesis, and apoptosis, particularly in MnSOD-deficient cells. Furthermore, it emphasizes the significant impact of salicylate on the exit from a quiescent state, inhibiting growth recovery and viability in long-term stationary phase cells. The passage also discusses the potential therapeutic implications of understanding the antagonistic relationship between cAMP and salicylate in targeting quiescent cancer cells with stem-like properties.