In response to severe environmental stresses eukaryotic cells shut down translation and accumulate components of the translational machinery in stress granules (SGs). Since they contain mainly mRNA, translation initiation factors and 40S ribosomal subunits, they have been referred to as dominant accumulations of stalled translation preinitiation complexes. Here we present evidence that the robust heat shock-induced SGs of S. cerevisiae also contain translation elongation factors eEF3 (Yef3p) and eEF1Bγ2 (Tef4p) as well as translation termination factors eRF1 (Sup45p) and eRF3 (Sup35p). Despite the presence of the yeast prion protein Sup35 in heat shock-induced SGs, we found out that its prion-like domain is not involved in the SGs assembly. Factors eEF3, eEF1Bγ2 and eRF1 were accumulated and co-localized with Dcp2 foci even upon a milder heat shock at 42°C independently of P-bodies scaffolding proteins. We also show that eEF3 accumulations at 42°C determine sites of the genuine SGs assembly at 46°C. We suggest that identification of translation elongation and termination factors in SGs might help to understand the mechanism of the eIF2α factor phosphorylation-independent repression of translation and SGs assembly.

• MeSH
• cytoplazmatická granula metabolismus   MeSH
• elongační faktory chemie   metabolismus   MeSH
• fyziologický stres MeSH
• molekulární sekvence - údaje MeSH
• peptidy - faktory ukončení chemie   metabolismus   MeSH
• reakce na tepelný šok * MeSH
• ribonukleoproteiny metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny chemie   metabolismus   MeSH
• Saccharomyces cerevisiae metabolismus   MeSH
• sekvence aminokyselin MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In the current study, singlet oxygen formation by lipid peroxidation induced by heat stress (40 °C) was studied in vivo in unicellular green alga Chlamydomonas reinhardtii. Primary and secondary oxidation products of lipid peroxidation, hydroperoxide and malondialdehyde, were generated under heat stress as detected using swallow-tailed perylene derivative fluorescence monitored by confocal laser scanning microscopy and high performance liquid chromatography, respectively. Lipid peroxidation was initiated by enzymatic reaction as inhibition of lipoxygenase by catechol and caffeic acid prevented hydroperoxide formation. Ultra-weak photon emission showed formation of electronically excited species such as triplet excited carbonyl, which, upon transfer of excitation energy, leads to the formation of either singlet excited chlorophyll or singlet oxygen. Alternatively, singlet oxygen is formed by direct decomposition of hydroperoxide via Russell mechanisms. Formation of singlet oxygen was evidenced by the nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl detected by electron paramagnetic resonance spin-trapping spectroscopy and the imaging of green fluorescence of singlet oxygen sensor green detected by confocal laser scanning microscopy. Suppression of singlet oxygen formation by lipoxygenase inhibitors indicates that singlet oxygen may be formed via enzymatic lipid peroxidation initiated by lipoxygenase.

• MeSH
• Chlamydomonas reinhardtii metabolismus   MeSH
• lipoxygenasa metabolismus   MeSH
• malondialdehyd metabolismus   MeSH
• peroxidace lipidů fyziologie   MeSH
• reakce na tepelný šok fyziologie   MeSH
• rostlinné proteiny metabolismus   MeSH
• singletový kyslík metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

This study aimed to investigate whether heat stress (HS) prevents a decrease in succinate dehydrogenase (SDH) activity and heat shock protein 60 (HSP60) and superoxide dismutase 2 (SOD2) contents in the extensor digitorum longus of streptozotocin (STZ)-induced diabetic rats. Twelve-week-old male Wistar rats were assigned to one of the four groups (n=6/group): control (Con), HS, diabetes mellitus (DM), and diabetes mellitus and heat stress (DM+HS). Diabetes was induced by the administration of STZ (50 mg/kg). HS was initiated 7 days after STZ treatment and performed at 42 °C for 30 min 5 times a week for 3 weeks. SDH activity was decreased in the DM and DM+HS groups. However, SDH activity was greater in the DM+HS group than in the DM group. Although HSP60 content was lower in the DM group than in the Con group, it was maintained in the DM+HS groups and was higher than that in the DM group. SOD2 content was decreased only in the DM group. These findings suggest that HS prevents the decrease in SDH activity in the skeletal muscle induced by DM. According to this mechanism, the maintenance of SOD2 and HSP60 by HS may suppress the increase in oxidative stress.

• MeSH
• aktivace enzymů fyziologie   MeSH
• chaperon hsp60 metabolismus   MeSH
• experimentální diabetes mellitus metabolismus   MeSH
• kosterní svaly enzymologie   metabolismus   MeSH
• krevní glukóza metabolismus   MeSH
• krysa rodu rattus MeSH
• mitochondriální proteiny metabolismus   MeSH
• potkani Wistar MeSH
• reakce na tepelný šok fyziologie   MeSH
• streptozocin MeSH
• sukcinátdehydrogenasa metabolismus   MeSH
• superoxiddismutasa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• tělesná námaha MeSH
• termoregulace MeSH

Elevated summer temperature is reported to be the leading cause of stress in dairy and beef cows, which negatively affects various reproductive functions. Follicular cells respond to heat stress (HS) by activating the expression of heat shock family proteins (HSPs) and other antioxidants. HS is reported to negatively affect the bi-directional communication between the follicular cells and the oocyte, which is partly mediated by follicular fluid extracellular vesicles (EVs) released from surrounding cells. As carriers of bioactive molecules (DNA, RNA, protein, and lipids), the involvement of EVs in mediating the stress response in follicular cells is not fully understood. Here we used an in vitro model to decipher the cellular and EV-coupled miRNAs of bovine granulosa cells in response to HS. Moreover, the protective role of stress-related EVs against subsequent HS was assessed. For this, bovine granulosa cells from smaller follicles were cultured in vitro and after sub-confluency, cells were either kept at 37 °C or subjected to HS (42 °C). Results showed that granulosa cells exposed to HS increased the accumulation of ROS, total oxidized protein, apoptosis, and the expression of HSPs and antioxidants, while the viability of cells was reduced. Moreover, 14 and 6 miRNAs were differentially expressed in heat-stressed granulosa cells and the corresponding EVs, respectively. Supplementation of stress-related EVs in cultured granulosa cells has induced adaptive response to subsequent HS. However, this potential was not pronounced when the cells were kept under 37 °C. Taking together, EVs generated from granulosa cells exposed to HS has the potential to shuttle bioactive molecules to recipient cells and make them robust to subsequent HS.

• MeSH
• apoptóza MeSH
• extracelulární vezikuly genetika   metabolismus   patologie   MeSH
• folikulární buňky metabolismus   patologie   MeSH
• nemoci skotu epidemiologie   genetika   prevence a kontrola   MeSH
• ovariální folikul metabolismus   patologie   MeSH
• poruchy vyvolané tepelným stresem genetika   patofyziologie   veterinární   MeSH
• reakce na tepelný šok * MeSH
• regulace genové exprese MeSH
• skot MeSH
• stanovení celkové genové exprese MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The effects of heat stress are spatially heterogeneous owing to local variations in climate response, population density, and social conditions. Using global climate and impact models from the Inter-Sectoral Impact Model Intercomparison Project, our analysis shows that the frequency and intensity of heat events increase, especially in tropical regions (geographic perspective) and developing countries (national perspective), even with global warming held to the 1.5 °C target. An additional 0.5 °C increase to the 2 °C warming target leads to >15% of global land area becoming exposed to levels of heat stress that affect human health; almost all countries in Europe will be subject to increased fire danger, with the duration of the fire season lasting 3.3 days longer; 106 countries are projected to experience an increase in the wheat production-damage index. Globally, about 38%, 50%, 46%, 36%, and 48% of the increases in exposure to health threats, wildfire, crop heat stress for soybeans, wheat, and maize could be avoided by constraining global warming to 1.5 °C rather than 2 °C. With high emissions, these impacts will continue to intensify over time, extending to almost all countries by the end of the 21st century: >95% of countries will face exposure to health-related heat stress, with India and Brazil ranked highest for integrated heat-stress exposure. The magnitude of the changes in fire season length and wildfire frequency are projected to increase substantially over 74% global land, with particularly strong effects in the United States, Canada, Brazil, China, Australia, and Russia. Our study should help facilitate climate policies that account for international variations in the heat-related threats posed by climate change.

• MeSH
• globální oteplování * MeSH
• kukuřice setá MeSH
• požáry v divočině * MeSH
• pšenice MeSH
• reakce na tepelný šok MeSH
• roční období MeSH
• vysoká teplota MeSH
• zemědělské plodiny * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cíl práce: Shrnutí současných poznatků o proteinech tepelného šoku (HSPs) humánního a bakteriálního(chlamydiového) původu a jejich účasti při poruchách fertility.Typ studie: Přehledný článek vhodný pro doškolování lékařů (gynekologů, porodníků).Název a sídlo pracoviště: Výzkumný ústav veterinárního lékařství, Brno.Předmět a metoda studie: Předmětem studie je protein tepelného šoku - hsp60 jako významný epitopChlamydia trachomatis. Proteiny tepelného šoku jsou indukovány jako odpověď na různé stresovéinzulty ze zevního prostředí (hypertermie, UV záření, volné radikály kyslíku, těžké kovy, etanolapod.) a některými procesy v souvislosti s buněčným cyklem. Senzibilizace proteinem tepelnéhošoku C. trachomatis a následné vylučování vysoce homologního lidského proteinu tepelného šokujsou kooperující faktory při vzniku poruch plodnosti. IgA protilátky proti hsp60 se vyskytují veznačném procentu v cervikálním hlenu žen a v seminální plazmě mužů s poruchami plodnosti.Závěr: Předcházející infekce C. trachomatis a z ní rezultující senzibilizace chlamydiálním šokovýmproteinem znamená vždy špatnou prognózu pro výsledek reprodukce a zhoršuje pravděpodobnostvýsledku fertilizace in vitro.

Objective: Summarization of recent knowledge on heat shock proteins (HSPs) of human andbacterial (chlamydial) origin and their participation in fertility disturbances.Design: Review article for training of physicians (gynecologists and obstetricians).Setting: Veterinary Research Institute, Brno.Method and results: The subject of the study is heat shock protein - hsp60 as a significant epitopeChlamydia trachomatis. Heat shock proteins are induced as a response to various stress insults fromexternal environment (hyperthermy, UV radiation, free oxygen radicals, heavy metals, ethanol etc.)and certain processes related to the cell cycle. Sensitization with the heat shock protein Chlamydiatrachomatis and subsequent excretion of highly homologous human heat shock protein are co-operatingfactors in the development of fertility disturbances. Significant levels of IgA antibodies tohsp60 occur in cervical mucus of women and in seminal plasma of men with fertility disturbances.Conclusion: Preceding infection C. trachomatis and resulting sensitization with chlamydial heatshock protein indicate an unfavourable prognosis of the reproductive outcome and impairs theperspective of a successful in vitro fertilization.

• MeSH
• Chlamydia trachomatis patogenita   MeSH
• dospělí MeSH
• lidé MeSH
• proteiny teplotního šoku fyziologie   MeSH
• protilátky krev   MeSH
• těhotenství MeSH
• ženská infertilita diagnóza   etiologie   terapie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• přehledy MeSH
• srovnávací studie MeSH

Recognition of pathogen-associated molecular patterns (PAMPs) is crucial for plant defence against pathogen attack. The best characterized PAMP is flg22, a 22 amino acid conserved peptide from flagellin protein. In Arabidopsis thaliana, flg22 is recognized by the flagellin sensing 2 (FLS2) receptor. In this study, we focused on biotic stress responses triggered by flg22 after exposure to temporary heat stress (HS). It is important to study the reactions of plants to multiple stress conditions because plants are often exposed simultaneously to a combination of both abiotic and biotic stresses. Transient early production of reactive oxygen species (ROS) is a well-characterized response to PAMP recognition. We demonstrate the strong reduction of flg22-induced ROS production in A. thaliana after HS treatment. In addition, a decrease in FLS2 transcription and a decrease of the FLS2 presence at the plasma membrane are shown after HS. In summary, our data show the strong inhibitory effect of HS on flg22-triggered events in A. thaliana. Subsequently, temporary HS strongly decreases the resistance of A. thaliana to Pseudomonas syringae. We propose that short exposure to high temperature is a crucial abiotic stress factor that suppresses PAMP-triggered immunity, which subsequently leads to the higher susceptibility of plants to pathogens.

• MeSH
• alarminy metabolismus   MeSH
• Arabidopsis účinky léků   genetika   imunologie   mikrobiologie   MeSH
• flagelin farmakologie   MeSH
• genetická transkripce účinky léků   MeSH
• imunita rostlin * účinky léků   MeSH
• nemoci rostlin imunologie   mikrobiologie   MeSH
• odolnost vůči nemocem imunologie   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• Pseudomonas syringae účinky léků   fyziologie   MeSH
• reakce na tepelný šok * účinky léků   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• respirační vzplanutí účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• krysa rodu rattus MeSH
• neurony metabolismus   MeSH
• proteiny teplotního šoku MeSH
• reakce na tepelný šok MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH

Stress granules (SGs) are membrane-less assemblies arising upon various stresses in eukaryotic cells. They sequester mRNAs and proteins from stressful conditions and modulate gene expression to enable cells to resume translation and growth after stress relief. SGs containing the translation initiation factor eIF3a/Rpg1 arise in yeast cells upon robust heat shock (HS) at 46 °C only. We demonstrate that the destabilization of Rpg1 within the PCI domain in the Rpg1-3 variant leads to SGs assembly already at moderate HS at 42 °C. These are bona fide SGs arising upon translation arrest containing mRNAs, which are components of the translation machinery, and associating with P-bodies. HS SGs associate with endoplasmatic reticulum and mitochondria and their contact sites ERMES. Although Rpg1-3-labeled SGs arise at a lower temperature, their disassembly is delayed after HS at 46 °C. Remarkably, the delayed disassembly of HS SGs after the robust HS is reversed by TDP-43, which is a human protein connected with amyotrophic lateral sclerosis. TDP-43 colocalizes with HS SGs in yeast cells and facilitates cell regrowth after the stress relief. Based on our results, we propose yeast HS SGs labeled by Rpg1 and its variants as a novel model system to study functions of TDP-43 in stress granules disassembly.

• MeSH
• cytoplazmatická granula fyziologie   MeSH
• DNA vazebné proteiny genetika   metabolismus   MeSH
• endoplazmatické retikulum metabolismus   MeSH
• eukaryotický iniciační faktor 3 chemie   genetika   metabolismus   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• mitochondrie metabolismus   MeSH
• reakce na tepelný šok * MeSH
• Saccharomyces cerevisiae - proteiny genetika   metabolismus   MeSH
• Saccharomyces cerevisiae genetika   růst a vývoj   metabolismus   MeSH
• stabilita proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH