Assessing chronological aging in Saccharomyces cerevisiae.

Chronological age represents the time that passes between birth and a given date. To understand the complex network of factors contributing to chronological lifespan, a variety of model organisms have been implemented. One of the best studied organisms is the yeast Saccharomyces cerevisiae, which has greatly contributed toward identifying conserved biological mechanisms that act on longevity. Here, we discuss high- und low-throughput protocols to monitor and characterize chronological lifespan and chronological aging-associated cell death in S. cerevisiae. Included are propidium iodide staining with the possibility to quantitatively assess aging-associated cell death via flow cytometry or qualitative assessments via microscopy, cell viability assessment through plating and cell counting and cell death characterization via propidium iodide/AnnexinV staining and subsequent flow cytometric analysis or microscopy. Importantly, all of these methods combined give a clear picture of the chronological lifespan under different conditions or genetic backgrounds and represent a starting point for pharmacological or genetic interventions.

[Tuberculosis-Update 2022]. / Tuberkulose ­ Update 2022.

According to the annual global reports from the Word Health Organization (WHO), children under 15 years of age represent 11% of all cases of tuberculosis (TB) globally. Nearly 50% of these cases are children below 5 years old. This continuing medical education (CME) article provides an overview of the current recommendations and innovations based on the revised WHO guidelines on TB management in children and adolescents published in 2022.

ERS International Congress 2022: highlights from the Paediatrics Assembly.

This review has been prepared by the Early Career Members and Chairs of the European Respiratory Society (ERS) Assembly 7: Paediatrics. We here summarise the highlights of the advances in paediatric respiratory research presented at the ERS International Congress 2022. The eight scientific groups of this Assembly cover a wide range of research areas, including respiratory physiology and sleep, asthma and allergy, cystic fibrosis (CF), respiratory infection and immunology, neonatology and intensive care, respiratory epidemiology, bronchology, and lung and airway developmental biology. Specifically, we report on abstracts presented at the congress on the effect of high altitude on sleep, sleep disorders, the hypoxic challenge test, and measurements of ventilation inhomogeneity. We discuss prevention of preschool wheeze and asthma, and new asthma medications. In children with CF, we describe how to monitor the effect of CF transmembrane conductance regulator modulator therapy. We present respiratory manifestations and chronic lung disease associated with common variable immunodeficiency. Furthermore, we discuss how to monitor respiratory function in neonatal and paediatric intensive care units. In respiratory epidemiology, we present the latest news from population-based and clinical cohort studies. We also focus on innovative and interventional procedures for the paediatric airway, such as cryotherapy. Finally, we stress the importance of better understanding the molecular mechanisms underlying normal and abnormal lung development.

The rise of Candida auris: from unique traits to co-infection potential.

Candida auris is a multidrug resistant (MDR) fungal pathogen with a crude mortality rate of 30-60%. First identified in 2009, C. auris has been rapidly emerging to become a global risk in clinical settings and was declared an urgent health threat by the Centers for Disease Control and Prevention (CDC). A concerted global action is thus needed to successfully tackle the challenges created by this emerging fungal pathogen. In this brief article, we underline the importance of unique virulence traits,including its easy transformation, its persistence outside the host and its resilience against multiple cellular stresses, as well as of environmental factors that have mainly contributed to the rise of this superbug.

A hundred spotlights on microbiology: how microorganisms shape our lives.

Viral, bacterial, fungal and protozoal biology is of cardinal importance for the evolutionary history of life, ecology, biotechnology and infectious diseases. Various microbiological model systems have fundamentally contributed to the understanding of molecular and cellular processes, including the cell cycle, cell death, mitochondrial biogenesis, vesicular fusion and autophagy, among many others. Microbial interactions within the environment have profound effects on many fields of biology, from ecological diversity to the highly complex and multifaceted impact of the microbiome on human health. Also, biotechnological innovation and corresponding industrial operations strongly depend on microbial engineering. With this wide range of impact in mind, the peer-reviewed and open access journal Microbial Cell was founded in 2014 and celebrates its 100th issue this month. Here, we briefly summarize how the vast diversity of microbiological subjects influences our personal and societal lives and shortly review the milestones achieved by Microbial Cell during the last years.

Murals meet microbes: at the crossroads of microbiology and cultural heritage.

Our cultural heritage consists of manifold cultural expressions and represents a defining feature of our societies that needs to be further inherited to future generations. Even though humankind always fought a daily struggle for survival, at the same time, it seemed to have a spiritual need that went far beyond mere materialistic satisfaction and nowadays manifests in sometimes very ancient, yet brilliant artistic works. This fundamental legacy is endangered by several instances, including biodeterioration. Indeed, microorganisms play a significant role in the decline of all forms of tangible cultural heritage, including movable, immovable and underwater cultural heritage. Microbial colonization, biofilm formation and damaging metabolite production eventually result in critical decay. Thus, efforts to mitigate the negative impact of damaging microorganisms have been pursued with diverse physical, chemical and biological approaches. Intriguingly, recent advances have unveiled that specific microorganisms and microbial-based technologies also have the potential for cultural heritage preservation and present unique advantages. This short piece provides a quick overview on the duality of microorganisms in the conservation and restoration of cultural heritage.

Wheeze and cough measurements at night in children with respiratory symptoms.

BACKGROUND: Nocturnal cough and wheeze are important symptoms when diagnosing any respiratory disease in a child, but objective measurements of these symptoms are not performed. METHODS: The aim of our study was to analyze the use of an automated detection system to assess breath sounds objectively in comparison to cough and wheeze questionnaires and to evaluate its feasibility in clinical practice. RESULTS: Forty-nine recordings of thirty-nine children were processed (asthma n = 13; cystic fibrosis n = 2; pneumonia n = 5; suspicion of habit cough n = 7; prolonged, recurrent or chronic cough n = 13), and cough and asthma scores were compared to the objective nocturnal recordings. Time for audio-validation of recordings took between 2 and 40 min (mean: 14.22 min, (SD): 10.72). Accuracy of the automated measurement was higher for cough than for wheezing sounds. Nocturnal cough readings but not wheeze readings correlated with some of the corresponding scores. CONCLUSION: To our knowledge this is the first study using a new device to assess nocturnal cough and obstructive breath sounds objectively in children with a wide variety of respiratory diseases. The assessment proved user friendly. We obtained additional information on nighttime symptoms, which would otherwise have remained obscure. Further studies to assess possible diagnostic and therapeutic benefits of this device are needed.

Fungal infections in humans: the silent crisis.

Annually, over 150 million severe cases of fungal infections occur worldwide, resulting in approximately 1.7 million deaths per year. Alarmingly, these numbers are continuously on the rise with a number of social and medical developments during the past decades that have abetted the spread of fungal infections. Additionally, the long-term therapeutic application and prophylactic use of antifungal drugs in high-risk patients have promoted the emergence of (multi)drug-resistant fungi, including the extremely virulent strain Candida auris. Hence, fungal infections are already a global threat that is becoming increasingly severe. In this article, we underline the importance of more and effective research to counteract fungal infections and their consequences.

Digesting the crisis: autophagy and coronaviruses.

Autophagy is a catabolic pathway with multifaceted roles in cellular homeostasis. This process is also involved in the antiviral response at multiple levels, including the direct elimination of intruding viruses (virophagy), the presentation of viral antigens, the fitness of immune cells, and the inhibition of excessive inflammatory reactions. In line with its central role in immunity, viruses have evolved mechanisms to interfere with or to evade the autophagic process, and in some cases, even to harness autophagy or constituents of the autophagic machinery for their replication. Given the devastating consequences of the current COVID-19 pandemic, the question arises whether manipulating autophagy might be an expedient approach to fight the novel coronavirus SARS-CoV-2. In this piece, we provide a short overview of the evidence linking autophagy to coronaviruses and discuss whether such links may provide actionable targets for therapeutic interventions.

Transcriptional and epigenetic control of regulated cell death in yeast.

Unicellular organisms like yeast can undergo controlled demise in a manner that is partly reminiscent of mammalian cell death. This is true at the levels of both mechanistic and functional conservation. Yeast offers the combination of unparalleled genetic amenability and a comparatively simple biology to understand both the regulation and evolution of cell death. In this minireview, we address the capacity of the nucleus as a regulatory hub during yeast regulated cell death (RCD), which is becoming an increasingly central question in yeast RCD research. In particular, we explore and critically discuss the available data on stressors and signals that specifically impinge on the nucleus. Moreover, we also analyze the current knowledge on nuclear factors as well as on transcriptional control and epigenetic events that orchestrate yeast RCD. Altogether we conclude that the functional significance of the nucleus for yeast RCD in undisputable, but that further exploration beyond correlative work is necessary to disentangle the role of nuclear events in the regulatory network.

4,4'Dimethoxychalcone: a natural flavonoid that promotes health through autophagy-dependent and -independent effects.

The age-induced deterioration of the organism results in detrimental and ultimately lethal pathologies. The process of aging itself involves a plethora of different mechanisms that should be subverted concurrently to delay and/or prevent age-related maladies. We have identified a natural compound, 4,4'-dimethoxychalcone (DMC), which promotes longevity in yeast, worms and flies, and protects mice from heart injury and liver toxicity. Interestingly, both the DMC-mediated lifespan extension and the cardioprotection depend on macroautophagy/autophagy whereas hepatoprotection does not. DMC induces autophagy by inhibiting specific GATA transcription factors (TFs), independently of the TORC1 kinase pathway. The autophagy-independent beneficial effects of DMC might involve its antioxidative properties. DMC treatment results in a phylogenetically conserved, systemic impact on the metabolome, which is most prominently characterized by changes in cellular amino acid composition. Altogether, DMC exerts multiple, geroprotective effects by igniting distinct pathways, and thus represents a potential pharmacological agent that delays aging through multipronged effects.

α-Ketoglutarate inhibits autophagy.

The metabolite α-ketoglutarate is membrane-impermeable, meaning that it is usually added to cells in the form of esters such as dimethyl -ketoglutarate (DMKG), trifluoromethylbenzyl α-ketoglutarate (TFMKG) and octyl α-ketoglutarate (O-KG). Once these compounds cross the plasma membrane, they are hydrolyzed by esterases to generate α-ketoglutarate, which remains trapped within cells. Here, we systematically compared DMKG, TFMKG and O-KG for their metabolic and functional effects. All three compounds similarly increased the intracellular levels of α-ketoglutarate, yet each of them had multiple effects on other metabolites that were not shared among the three agents, as determined by mass spectrometric metabolomics. While all three compounds reduced autophagy induced by culture in nutrient-free conditions, TFMKG and O-KG (but not DMKG) caused an increase in baseline autophagy in cells cultured in complete medium. O-KG (but neither DMKG nor TFMK) inhibited oxidative phosphorylation and exhibited cellular toxicity. Altogether, these results support the idea that intracellular α-ketoglutarate inhibits starvation-induced autophagy and that it has no direct respiration-inhibitory effect.

Targeting GATA transcription factors - a novel strategy for anti-aging interventions?

GATA transcription factors (TFs) are a conserved family of zinc-finger TFs that fulfill diverse functions across eukaryotes. Accumulating evidence suggests that GATA TFs also play a role in lifespan regulation. In a recent study, we have identified a natural compound, 4,4' dimethoxychalcone (DMC) that extends lifespan depending on reduced activity of distinct GATA TFs. Prolonged lifespan by DMC treatment depends on autophagy, a protective cellular self-cleaning mechanism. In yeast, DMC reduces the activity of the GATA TF Gln3 and, at the same time, deletion of GLN3 increases autophagy levels during cellular aging per se. Here, we examine current data on the involvement of GATA TFs in the regulation of both autophagy and lifespan in different organisms and explore, if GATA TFs are suitable targets for anti-aging interventions.

The flavonoid 4,4'-dimethoxychalcone promotes autophagy-dependent longevity across species.

Ageing constitutes the most important risk factor for all major chronic ailments, including malignant, cardiovascular and neurodegenerative diseases. However, behavioural and pharmacological interventions with feasible potential to promote health upon ageing remain rare. Here we report the identification of the flavonoid 4,4'-dimethoxychalcone (DMC) as a natural compound with anti-ageing properties. External DMC administration extends the lifespan of yeast, worms and flies, decelerates senescence of human cell cultures, and protects mice from prolonged myocardial ischaemia. Concomitantly, DMC induces autophagy, which is essential for its cytoprotective effects from yeast to mice. This pro-autophagic response induces a conserved systemic change in metabolism, operates independently of TORC1 signalling and depends on specific GATA transcription factors. Notably, we identify DMC in the plant Angelica keiskei koidzumi, to which longevity- and health-promoting effects are ascribed in Asian traditional medicine. In summary, we have identified and mechanistically characterised the conserved longevity-promoting effects of a natural anti-ageing drug.

Studying Huntington's Disease in Yeast: From Mechanisms to Pharmacological Approaches.

Huntington's disease (HD) is a neurodegenerative disorder that leads to progressive neuronal loss, provoking impaired motor control, cognitive decline, and dementia. So far, HD remains incurable, and available drugs are effective only for symptomatic management. HD is caused by a mutant form of the huntingtin protein, which harbors an elongated polyglutamine domain and is highly prone to aggregation. However, many aspects underlying the cytotoxicity of mutant huntingtin (mHTT) remain elusive, hindering the efficient development of applicable interventions to counteract HD. An important strategy to obtain molecular insights into human disorders in general is the use of eukaryotic model organisms, which are easy to genetically manipulate and display a high degree of conservation regarding disease-relevant cellular processes. The budding yeast Saccharomyces cerevisiae has a long-standing and successful history in modeling a plethora of human maladies and has recently emerged as an effective tool to study neurodegenerative disorders, including HD. Here, we summarize some of the most important contributions of yeast to HD research, specifically concerning the elucidation of mechanistic features of mHTT cytotoxicity and the potential of yeast as a platform to screen for pharmacological agents against HD.

Increased severity of respiratory syncytial virus airway infection due to passive smoke exposure.

OBJECTIVE: Aim of this study was to analyze whether children with objectively measured second-hand cigarette smoke (SHS) exposure suffer from a more severe course of disease when hospitalized with lower respiratory tract infection (LRTI) due to respiratory syncytial virus (RSV). METHODS: This prospective study was conducted at the Department of Pediatrics, Wilhelminen-Hospital, Vienna, Austria in children aged below 1 year without a history of preceding lung disease and with acute symptoms of LRTI and a positive nasopharyngeal swab for RSV. On admission, urinary cotinine was measured as a marker of recent SHS and clinical severity of LRTI was assessed by oxygen saturation SpO2 and the "admission clinical severity score" (CSSA). Parents/caregivers were asked to complete a customized questionnaire assessing risks for SHS and demographic characteristics. RESULTS: After inclusion of 217 patients, data of 185 patients with a mean (SD) age of 106 days (80) were analyzed. Twenty-five patients (13.5%) were "cotinine-positive" (COT+) defined as a urinary cotinine level of ≥7 µg/L. SpO2 on admission was significantly lower in children recently exposed to SHS defined objectively by COT+ (94.8% ±2.0) in urine on admission compared to children not recently exposed (COT-) (96.8% ±3.0; P < 0.01). Disease severity, assessed via mean clinical severity score on admission (CSSA) for COT+ and COT- was 2.56 and 1.71, respectively (P = 0.03). CONCLUSIONS: Recent exposure to SHS was associated with lower O2 saturation and higher clinical severity score, measured by urine cotinine levels in children hospitalized for RSV infection under 1 year of age.

Yeast as a tool to identify anti-aging compounds.

In the search for interventions against aging and age-related diseases, biological screening platforms are indispensable tools to identify anti-aging compounds among large substance libraries. The budding yeast, Saccharomyces cerevisiae, has emerged as a powerful chemical and genetic screening platform, as it combines a rapid workflow with experimental amenability and the availability of a wide range of genetic mutant libraries. Given the amount of conserved genes and aging mechanisms between yeast and human, testing candidate anti-aging substances in yeast gene-deletion or overexpression collections, or de novo derived mutants, has proven highly successful in finding potential molecular targets. Yeast-based studies, for example, have led to the discovery of the polyphenol resveratrol and the natural polyamine spermidine as potential anti-aging agents. Here, we present strategies for pharmacological anti-aging screens in yeast, discuss common pitfalls and summarize studies that have used yeast for drug discovery and target identification.

Microbial wars: Competition in ecological niches and within the microbiome.

Many microbial communities live in highly competitive surroundings, in which the fight for resources determines their survival and genetic persistence. Humans live in a close relationship with microbial communities, which includes the health- and disease-determining interactions with our microbiome. Accordingly, the understanding of microbial competitive activities are essential at physiological and pathophysiological levels. Here we provide a brief overview on microbial competition and discuss some of its roles and consequences that directly affect humans.