reactivation process
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Cyanobacteria are prokaryotic organisms characterised by their complex structures and a wide range of pigments. With their ability to fix CO2, cyanobacteria are interesting for white biotechnology as cell factories to produce various high-value metabolites such as polyhydroxyalkanoates, pigments, or proteins. White biotechnology is the industrial production and processing of chemicals, materials, and energy using microorganisms. It is known that exposing cyanobacteria to low levels of stressors can induce the production of secondary metabolites. Understanding of this phenomenon, known as hormesis, can involve the strategic application of controlled stressors to enhance the production of specific metabolites. Consequently, precise measurement of cyanobacterial viability becomes crucial for process control. However, there is no established reliable and quick viability assay protocol for cyanobacteria since the task is challenging due to strong interferences of autofluorescence signals of intercellular pigments and fluorescent viability probes when flow cytometry is used. We performed the screening of selected fluorescent viability probes used frequently in bacteria viability assays. The results of our investigation demonstrated the efficacy and reliability of three widely utilised types of viability probes for the assessment of the viability of Synechocystis strains. The developed technique can be possibly utilised for the evaluation of the importance of polyhydroxyalkanoates for cyanobacterial cultures with respect to selected stressor-repeated freezing and thawing. The results indicated that the presence of polyhydroxyalkanoate granules in cyanobacterial cells could hypothetically contribute to the survival of repeated freezing and thawing.
- MeSH
- fluorescence MeSH
- fluorescenční barviva * metabolismus chemie MeSH
- fyziologický stres * MeSH
- mikrobiální viabilita * MeSH
- polyhydroxyalkanoáty metabolismus MeSH
- průtoková cytometrie * MeSH
- sinice metabolismus fyziologie MeSH
- Synechocystis * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Úvod: V důsledku metabolických dějů dochází v živých strukturách k endogenní produkci chemiluminiscence, kterou také označujeme jako biologickou autochemiluminiscenci (BAL). Generování BAL je úzce spojeno s oxidačními procesy, tvorbou volných radikálů a obecně oxidačně-redukční homeostázou zkoumaného biologického materiálu. BAL byla již dříve studována v savčích buněčných modelech a tkáních. Doposud ovšem nebyl tento jev popsán v případě struktur zubní tkáně. Kromě endogenně generované BAL lze BAL indukovat i exogenně, a to jak fyzikálními (UV záření, mechanické poškození, teplo), tak i chemickými (oxidační činidla, např. H2O2) a biotickými (patogeny) faktory. Metodika: V předložené práci byla zkoumána endogenně produkovaná i exogenně indukovaná BAL v povrchových a vnitřních strukturách semiretinovaných a retinovaných třetích molárů, které byly indikovány k extrakci zubním lékařem pro jejich nevhodné uložení v čelisti u dvou pacientů (žena, 21 let, muž, 22 let). Detekce BAL byla provedena po mechanickém odstranění zubního plaku rotačním kartáčkem. Pomocí piezoelektrické pily byly připraveny podélné řezy vedené tak, aby došlo k odhalení všech vnitřních částí zubu. Takto připravené vzorky – celého vnitřního řezu a vnější části celého zubu – byly podrobeny detekci BAL ve světlotěsné komoře za použití fotonásobičového modulu. Následně byly vzorky ošetřeny roztokem oxidačního činidla 3% H2O2 a redukčního činidla 10 mM TCEP (tris(karboxyethyl)fosfin). Výsledky: U obou vzorků zubu bylo prokázáno, že produkují BAL. Produkce endogenní chemiluminiscence byla pozorována ve vnitřních strukturách zubu (18 600 pulzů/600 s), která byla přibližně 2,7krát vyšší než BAL detekovaná na povrchových strukturách zubu (6 900 pulzů/600 s). Po ošetření H2O2 došlo k významnému (až 14násobnému) nárůstu BAL pro vnitřní struktury zubu ve srovnání s bazální intenzitou endogenně produkované BAL. Aplikace TCEP (negativní kontrola) vedla k mírnému potlačení produkce BAL. Závěr: Výsledky této pilotní studie ukazují, že BAL může být produkována nejenom měkkými tkáněmi, ale i tvrdou zubní tkání. Získané výsledky by mohly být využity k výzkumu metabolické aktivity a reaktivity vnitřních i vnějších částí zubu, a to především v kontextu výzkumu oxidačněredukční homeostázy. Detekce BAL by také mohla být aplikována pro vývoj nových zobrazovacích technik.
Introduction: As a result of metabolic processes, the endogenous production of chemiluminescence occurs in living biological structures, which we also refer to as biological autochemiluminescence (BAL). The generation of BAL is closely connected with oxidation processes, the formation of free radicals, and in general the redox homeostasis of the investigated biological material. BAL has previously been studied in mammalian cells and tissues. So far, however, this phenomenon has not been described in dental tissue structures. In addition to endogenously generated BAL, BAL can be exogenously induced by physical (UV radiation, mechanical damage, heat), chemical (oxidizing agents, e.g. H2O2) or biotic (pathogens) factors. Methods: Endogenously and exogenously induced BAL were investigated on the surface and internal structures of semi-impacted and impacted third molars, which were indicated for extraction by a dentist due to their inappropriate placement in the jaw in two patients (a 21-year-old woman and a 22-year-old man). BAL detection was performed with samples after dental plaque was mechanically removed with a rotating brush. Using a piezosurgery unit with a saw headpiece, longitudinal sections were made to reveal all internal parts of the tooth. The samples prepared in this way – the entire internal section and the external part of the entire tooth – were subjected to BAL detection in a dark chamber using H7360-01 PMT photomultiplier. Subsequently, the samples were treated with a solution of the oxidizing agent 3% H2O2 or the reducing agent 10 mM TCEP (tris(carboxyethyl)phosphine). Results: Both tooth samples were shown to produce BAL. Endogenous chemiluminescence production was observed in the internal structures of the tooth (18,600 counts/600 s), which was 2.7-fold higher than the BAL detected on the tooth outer surfaces (6,900 counts/600 s). After H2O2 treatment, there was a significant (up to 14-fold) increase in BAL for internal tooth structures compared to the basal intensity of endogenously produced BAL. The application of TCEP (negative control) resulted in a residual suppression of BAL production. Conclusion: The results of this pilot study show that BAL can be produced not only by soft tissues but also by hard dental tissue. The obtained results could be used for further research of the metabolic activity and reactivity of the inner and outer parts of the tooth, especially in the context of redox biology research. BAL detection could also be applied in the development of new imaging techniques.
An organism is considered "alive" if it can grow, reproduce, respond to external stimuli, metabolize nutrients, and maintain stability. By this definition, both mitochondria and viruses exhibit the key characteristics of independent life. In addition to their capacity for self-replication under specifically defined conditions, both mitochondria and viruses can communicate via shared biochemical elements, alter cellular energy metabolism, and adapt to their local environment. To explain this phenomenon, we hypothesize that early viral prototype species evolved from ubiquitous environmental DNA and gained the capacity for self-replication within coacervate-like liquid droplets. The high mutation rates experienced in this environment streamlined their acquisition of standard genetic codes and adaptation to a diverse set of host environments. Similarly, mitochondria, eukaryotic intracellular organelles that generate energy and resolve oxygen toxicity, originally evolved from an infectious bacterial species and maintain their capacity for active functionality within the extracellular space. Thus, while mitochondria contribute profoundly to eukaryotic cellular homeostasis, their capacity for freestanding existence may lead to functional disruptions over time, notably, the overproduction of reactive oxygen species, a phenomenon strongly linked to aging-related disorders. Overall, a more in-depth understanding of the full extent of the evolution of both viruses and mitochondria from primordial precursors may lead to novel insights and therapeutic strategies to address neurodegenerative processes and promote healthy aging.
- MeSH
- energetický metabolismus MeSH
- lidé MeSH
- mitochondrie * metabolismus MeSH
- původ života * MeSH
- viry * metabolismus genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Obesity is considered an important factor contributing to the development of atherosclerosis. Inflammation plays a key role in endothelial dysfunction (ED), an initial stage of the atherosclerotic process. Several microRNAs (miRNAs) may play an important role in the inflammatory process, but there is a lack of information about their participation in the early stages of atherosclerosis development in patients with obesity. We aimed to assess the relations between plasma concentration of selected miRNAs, ED evaluated by reactive hyperemia index (RHI), inflammatory markers and other factors involved in the pathogenesis of atherosclerosis in adolescents and young adults with obesity. Participants (30 males, 30 females; aged 15 25 years) were divided into two groups: those with overweight/obesity (OW/O) (20 males, 20 females) and controls (C) (10 males, 10 females). The plasma concentrations of inflammatory markers, cytokines, adipocytokines, markers of lipid profile and glucose metabolism and selected miRNAs (miR 92, 126, -146a, -155) were analyzed. No significant differences in any of the miRNAs were found between the groups. MiR-146a correlated positively with RHI. Dividing the group by sex showed more significant associations between miRNA and analyzed parameters (IL-6, fasting glycemia) in men. Several observed correlations indicate a potential role of miRNAs in inflammation, the atherosclerotic process and glycemic control, primarily in male subjects with obesity. The relatively low number of observed associations between assessed parameters related to obesity and the pathogenesis of its complications could be attributed to the early stage of the atherosclerotic process in young subjects with obesity, where only subtle abnormalities are expectedly found. Key words Endothelial dysfunction, Atherosclerosis, Obesity, MicroRNA, Reactive hyperemia index.
- MeSH
- ateroskleróza * krev genetika MeSH
- biologické markery krev MeSH
- cirkulující mikroRNA * krev genetika MeSH
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- obezita * krev komplikace genetika MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Mitochondria represent pivotal cellular organelles endowed with multifaceted functionalities encompassing cellular respiration, metabolic processes, calcium turnover, and the regulation of apoptosis, primarily through the generation of reactive oxygen species (ROS). Perturbations in mitochondrial dynamics have been intricately linked to the etiology of numerous cardiovascular pathologies, such as heart failure, ischemic heart disease, and various cardiomyopathies. Notably, recent attention has been directed towards the detrimental impact of micro- and nanoplastic pollution on mitochondrial integrity, an area underscored by a paucity of comprehensive investigations. Given the escalating prevalence of plastic particle contamination and the concomitant burden of cardiovascular disease in aging populations, understanding the interplay between mitochondria within the cardiovascular system and micro- and nanoplastic pollution assumes paramount importance. This review endeavors to elucidate the current albeit limited comprehension surrounding this complex interplay. Key words Mitochondria, Nanoplastics, Microplastics, Cardiovascular system, Endothelial function, Oxidative phosphorylation.
- MeSH
- kardiovaskulární nemoci metabolismus MeSH
- kardiovaskulární systém * metabolismus účinky léků MeSH
- lidé MeSH
- mikroplasty toxicita MeSH
- mitochondrie * metabolismus účinky léků MeSH
- nanočástice MeSH
- reaktivní formy kyslíku metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
An excessive increase in reactive oxygen species (ROS) levels is one of the main causes of mitochondrial dysfunction. However, when ROS levels are maintained in balance with antioxidant mechanisms, ROS fulfill the role of signaling molecules and modulate various physiological processes. Recent advances in mitochondrial bioenergetics research have revealed a significant interplay between mitochondrial peroxiredoxins (PRDXs) and monoamine oxidase-A (MAO-A) in regulating ROS levels. Both proteins are associated with hydrogen peroxide (H2O2), MAO-A as a producer and PRDXs as the primary antioxidant scavengers of H2O2. This review focuses on the currently available knowledge on the function of these proteins and their interaction, highlighting their importance in regulating oxidative damage, apoptosis, and metabolic adaptation in the heart. PRDXs not only scavenge excess H2O2, but also act as regulatory proteins, play an active role in redox signaling, and maintain mitochondrial membrane integrity. Overexpression of MAO-A is associated with increased oxidative damage, leading to mitochondrial dysfunction and subsequent progression of cardiovascular diseases (CVD), including ischemia/reperfusion injury and heart failure. Considering the central role of oxidative damage in the pathogenesis of many CVD, targeting PRDXs activation and MAO-A inhibition may offer new therapeutic strategies aimed at improving cardiac function under conditions of pathological load related to oxidative damage. Keywords: Mitochondria, Peroxiredoxin, Monoamine oxidase-A, Reactive oxygen species, Cardioprotective signaling.
- MeSH
- lidé MeSH
- monoaminoxidasa * metabolismus MeSH
- oxidační stres MeSH
- peroxiredoxiny * metabolismus MeSH
- reaktivní formy kyslíku * metabolismus MeSH
- signální transdukce * MeSH
- srdeční mitochondrie metabolismus enzymologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Hypoglykémie sú symptómom pomerne širokej skupiny ochorení s rôznou epidemiológiou, etiológiou, klinickým obrazom, liečbou a prognózou. Deti sú náchylnejšie na rozvoj hypoglykémie ako dospelí, nakoľko ich regulačné procesy na udržiavanie stabilnej glykémie majú menšiu kapacitu. Etiologicky ide o rozmanitú skupinu ochorení, pričom viaceré sú typické pre detský vek. Medzi najčastejšie formy hypoglykémií u detí patria liečba inzulínom pri diabetes mellitus, idiopatické ketotické hypoglykémie, hyperinzulinizmus (v novorodeneckom období), k menej častým, avšak závažným príčinám patria deficity kontra egulačných hormónov, niektoré dedičné poruchy metabolizmu, prípadne intoxikácie. Ich diagnostika je často komplexná, pričom na odlíšenie jednotlivých foriem hypoglykémií je kľúčové stanovenie ketolátok. Liečba a prognóza závisí najmä od typu hypoglykémie. Článok sa venuje nediabetickým hypoglykémiám u detí.
Hypoglycemia is a symptom of a relatively broad group of diseases with different epidemiology, etiology, clinical picture, treatment and prognosis. Children are more susceptible to developing hypoglycemia than adults, as their regulatory processes to maintain stable glycaemia have less capacity. Etiologically, hypoglycemia is a diverse group of diseases, with several being typical of childhood. The most common forms of hypoglycemia in children include insulin treatment in diabetes mellitus, idiopathic ketotic hypoglycemia, hyperinsulinism (in neonatal period), less common but serious causes include deficits of counterregulatory hormones, some inherited metabolic disorders, or intoxication. Their diagnosis is often complex. Determination of ketone bodies is crucial to differentiate the various forms of hypoglycemia. Treatment and prognosis depend mainly on the type of hypoglycemia. This article is dedicated to Non-diabetic hypoglycemias in children.
- MeSH
- diferenciální diagnóza MeSH
- glykogenóza diagnóza genetika metabolismus MeSH
- hladovění komplikace metabolismus patofyziologie MeSH
- hyperinzulinismus diagnóza komplikace MeSH
- hypoglykemie * diagnóza etiologie komplikace terapie MeSH
- ketolátky krev MeSH
- ketóza diagnóza metabolismus MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
Acetaldehyde can be found in human cells as a byproduct of various metabolic pathways, including oxidative processes such as lipid peroxidation. This secondary product of lipid peroxidation plays a role in various pathological processes, leading to various types of civilization diseases. In this study, the formation of free acetaldehyde induced by oxygen-centred radicals was studied in monocyte-like cell line U937. Exposure of U937 cells to peroxyl/alkoxyl radicals induced by azocompound resulted in the formation of free acetaldehyde. Acetaldehyde is formed by the cleavage of fatty acids, which represents the breakdown of fatty acids into smaller fragments initiated by the cyclization of lipid peroxyl radical and β-scission of lipid alkoxyl radical. The cleavage of fatty acids alters the integrity of the plasma and nuclear membrane, leading to the loss of cell viability. Understanding the pathological processes of acetaldehyde formation is an active area of research with potential implications for preventing and treating various diseases associated with oxidative stress.
- MeSH
- acetaldehyd * MeSH
- lidé MeSH
- mastné kyseliny metabolismus MeSH
- monocyty * metabolismus MeSH
- peroxidace lipidů MeSH
- reaktivní formy kyslíku MeSH
- U937 buňky MeSH
- volné radikály metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Úvod: Dutina ústní představuje komplexní systém, kde probíhá vzájemná chemická komunikace mezi tkáněmi, mikrobiotou a složkami sliny a potravy. Tento článek je zaměřen na hormetické efekty a elektrofilní sloučeniny, které mohou hrát roli v obranných mechanismech proti oxidačnímu stresu a zánětlivým procesům. Hormetické efekty, vyvolané subletálními nebo subtoxickými stresory, mohou aktivovat reparační mechanismy a posílit odolnost tkání proti poškození. Metodika: Analýza byla provedena prostřednictvím vyhledávání ve třech elektronických databázích: Web of Science, PubMed a Scopus. V rámci rešerše jsme se soustředili na studie publikované mezi lety 2000 a 2023, které se zabývaly oxidačně-redukčními procesy, zánětlivými stavy a aktivací Nrf2 dráhy v ústní dutině. Vyloučeny byly studie zaměřené na nádorová onemocnění. Závěr: Elektrofilní sloučeniny působí jako jeden z činitelů zasahujících do homeostázy dutiny ústní a mohou tak představovat terapeutický potenciál v zubním lékařství, konkrétně v parodontologii. Zjištění založená na in vitro a preklinických studiích však vyžadují další ověření v klinických podmínkách, přičemž je třeba zvážit i interakce s orální mikrobiotou.
Introduction: The oral cavity is a complex system in which mutual chemical communication occurs between tissues, microbiota, and components of saliva and food. This paper focuses on hormetic effects and electrophilic compounds, which can play a role in defense mechanisms against oxidative stress and inflammatory processes. Hormetic effects, induced by sublethal or subtoxic stressors, can activate repair mechanisms and enhance tissue resistance to damage. Methods: The analysis was conducted through searches in three electronic databases: Web of Science, PubMed, and Scopus. Our research focused on studies published between 2000 and 2023 that dealt with redox processes, inflammatory conditions, and activation of the Nrf2 pathway in the oral cavity. Studies focused on cancerous diseases were excluded. Conclusion: Electrophilic compounds act as one of the agents that interfere with the homeostasis of the oral cavity, and can thus find therapeutic potential in dentistry, specifically in periodontology. However, findings based on in vitro and preclinical studies require further verification under clinical conditions, and also considering interactions with oral microbiota.
Fasting is a common dietary intervention known for its protective effects against metabolic and cardiovascular diseases. While its effects are mostly systemic, understanding tissue-specific changes in the heart is crucial for the identification of the mechanisms underlying fasting-induced cardioprotection. In this study, we performed a proteomic analysis of the fasting heart and attempted to clarify the molecular basis of fasting-induced cardioprotection. Our investigation identified a total of 4,652 proteins, with 127 exhibiting downregulation and 118 showing upregulation after fasting. Annotation analysis highlighted significant changes in processes such as lipid metabolism, the peroxisome pathway, and reactive oxygen species metabolism. Notably, the HIF-1 signaling pathway emerged as one of the focal points, with various HIF-1 targets exhibiting differential responses to fasting. Further experiments demonstrated downregulation of HIF-1α at both transcript and protein levels. Intriguingly, while gene expression of Egln3 decreased, its protein product PHD3 remained unaffected by fasting. The unchanged levels of pro-inflammatory cytokines indicated that the observed reduction in Hif1a expression did not stem from a decrease in basal inflammation. These findings underscore the complex regulation of the well-established cardioprotective HIF-1 signaling within the heart during 3-day fasting.
- Publikační typ
- časopisecké články MeSH
