Chlorinated paraffins (CPs) are environmental pollutants extensively used in industries. While the use of short-chain chlorinated paraffins (SCCPs) has been restricted since 2017, the use of medium-chain chlorinated paraffins (MCCPs) has risen as their replacement. Due to lipophilic character, it can be expected that CPs enter the cells; however, the in vitro accumulation potential of CPs remains poorly understood. In this study, we aimed to explore the ability of SCCPs and MCCPs to accumulate in fat cells. We utilized an in vitro model of mouse 3T3-L1 preadipocytes and adipocytes. Using gas chromatography coupled with high-resolution mass spectrometry operated in negative chemical ionization mode, we determined the intracellular amounts of CPs. These compounds accumulated at rates of 8.5 ± 0.1 μg/gcells/h for SCCPs and 7.8 ± 0.3 μg/gcells/h for MCCPs when an initial concentration of 120 ng/ml was present in the medium. This rate increased approximately tenfold when the concentration of CPs was raised to 1200 ng/ml. CPs content in adipocytes steadily increased over 5 days, whereas preadipocytes accumulated 15-20 times less CPs. This highlights the importance of cellular lipid content, which was about 12 times higher in adipocytes. Furthermore, we found that the level of chlorine content in the CPs molecules significantly influenced their accumulation. Our results demonstrate that MCCPs exhibit a similar accumulation potential to SCCPs, with lipid content playing a crucial role. As with SCCPs, restrictions on the use of MCCPs in industry should be considered to mitigate their environmental and health impacts.
- MeSH
- buňky 3T3-L1 * MeSH
- chlorované uhlovodíky * metabolismus toxicita MeSH
- halogenace * MeSH
- látky znečišťující životní prostředí toxicita metabolismus MeSH
- metabolismus lipidů účinky léků MeSH
- myši MeSH
- parafín * MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- tukové buňky * metabolismus účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Since the emergence of SARS-CoV-2, mutations in all subunits of the RNA-dependent RNA polymerase (RdRp) of the virus have been repeatedly reported. Although RdRp represents a primary target for antiviral drugs, experimental studies exploring the phenotypic effect of these mutations have been limited. This study focuses on the phenotypic effects of substitutions in the three RdRp subunits: nsp7, nsp8, and nsp12, selected based on their occurrence rate and potential impact. We employed nano-differential scanning fluorimetry and microscale thermophoresis to examine the impact of these mutations on protein stability and RdRp complex assembly. We observed diverse impacts; notably, a single mutation in nsp8 significantly increased its stability as evidenced by a 13°C increase in melting temperature, whereas certain mutations in nsp7 and nsp8 reduced their binding affinity to nsp12 during RdRp complex formation. Using a fluorometric enzymatic assay, we assessed the overall effect on RNA polymerase activity. We found that most of the examined mutations altered the polymerase activity, often as a direct result of changes in stability or affinity to the other components of the RdRp complex. Intriguingly, a combination of nsp8 A21V and nsp12 P323L mutations resulted in a 50% increase in polymerase activity. To our knowledge, this is the first biochemical study to demonstrate the impact of amino acid mutations across all components constituting the RdRp complex in emerging SARS-CoV-2 subvariants.
- MeSH
- COVID-19 virologie MeSH
- koronavirová RNA-replikasa * genetika metabolismus chemie MeSH
- lidé MeSH
- mutace * MeSH
- RNA-dependentní RNA-polymerasa genetika chemie metabolismus MeSH
- SARS-CoV-2 * genetika enzymologie MeSH
- stabilita proteinů MeSH
- vazba proteinů MeSH
- virové nestrukturální proteiny * genetika chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
We explored how a simple retrovirus, Mason-Pfizer monkey virus (M-PMV) to facilitate its replication process, utilizes DHX15, a cellular RNA helicase, typically engaged in RNA processing. Through advanced genetic engineering techniques, we showed that M-PMV recruits DHX15 by mimicking cellular mechanisms, relocating it from the nucleus to the cytoplasm to aid in viral assembly. This interaction is essential for the correct packaging of the viral genome and critical for its infectivity. Our findings offer unique insights into the mechanisms of viral manipulation of host cellular processes, highlighting a sophisticated strategy that viruses employ to leverage cellular machinery for their replication. This study adds valuable knowledge to the understanding of viral-host interactions but also suggests a common evolutionary history between cellular processes and viral mechanisms. This finding opens a unique perspective on the export mechanism of intron-retaining mRNAs in the packaging of viral genetic information and potentially develop ways to stop it.
- MeSH
- buněčné jádro metabolismus virologie MeSH
- DEAD-box RNA-helikasy metabolismus genetika MeSH
- genom virový MeSH
- HEK293 buňky MeSH
- lidé MeSH
- Masonův-Pfizerův opičí virus * genetika metabolismus fyziologie MeSH
- replikace viru genetika fyziologie MeSH
- RNA virová * metabolismus genetika MeSH
- RNA-helikasy metabolismus genetika MeSH
- sestavení viru * genetika fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Mitochondrial autophagy (mitophagy) is very important process for the maintenance of cellular homeostasis, functionality and survival. Its dysregulation is associated with high risk and progression numerous serious diseases (e.g., oncological, neurodegenerative and cardiovascular ones). Therefore, targeting mitophagy mechanisms is very hot topic in the biological and medicinal research. The interrelationships between the regulation of mitophagy and iron homeostasis are now becoming apparent. In short, mitochondria are central point for the regulation of iron homeostasis, but change in intracellular cheatable iron level can induce/repress mitophagy. In this review, relationships between iron homeostasis and mitophagy are thoroughly discussed and described. Also, therapeutic applicability of mitophagy chelators in the context of individual diseases is comprehensively and critically evaluated.
Staphylococcus aureus, a notorious pathogen with versatile virulence, poses a significant challenge to current antibiotic treatments due to its ability to develop resistance mechanisms against a variety of clinically relevant antibiotics. In this comprehensive review, we carefully dissect the resistance mechanisms employed by S. aureus against various antibiotics commonly used in clinical settings. The article navigates through intricate molecular pathways, elucidating the mechanisms by which S. aureus evades the therapeutic efficacy of antibiotics, such as β-lactams, vancomycin, daptomycin, linezolid, etc. Each antibiotic is scrutinised for its mechanism of action, impact on bacterial physiology, and the corresponding resistance strategies adopted by S. aureus. By synthesising the knowledge surrounding these resistance mechanisms, this review aims to serve as a comprehensive resource that provides a foundation for the development of innovative therapeutic strategies and alternative treatments for S. aureus infections. Understanding the evolving landscape of antibiotic resistance is imperative for devising effective countermeasures in the battle against this formidable pathogen.
- MeSH
- antibakteriální látky * farmakologie terapeutické užití MeSH
- bakteriální léková rezistence MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- stafylokokové infekce * farmakoterapie mikrobiologie MeSH
- Staphylococcus aureus * účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Statins, the drugs used for the treatment of hypercholesterolemia, have come into the spotlight not only as chemoadjuvants, but also as potential stem cell modulators in the context of regenerative therapy. In our study, we compared the in vitro effects of all clinically used statins on the viability of human pancreatic cancer (MiaPaCa-2) cells, non-cancerous human embryonic kidney (HEK 293) cells and adipose-derived mesenchymal stem cells (ADMSC). Additionally, the effect of statins on viability of MiaPaCa-2 and ADMSC cells spheroids was tested. Furthermore, we performed a microarray analysis on ADMSCs treated with individual statins (12 μM) and compared the importance of the effects of statins on gene expression between stem cells and pancreatic cancer cells. Concentrations of statins that significantly affected cancer cells viability (< 40 μM) did not affect stem cells viability after 24 h. Moreover, statins that didn ́t affect viability of cancer cells grown in a monolayer, induce the disintegration of cancer cell spheroids. The effect of statins on gene expression was significantly less pronounced in stem cells compared to pancreatic cancer cells. In conclusion, the low efficacy of statins on non-tumor and stem cells at concentrations sufficient for cancer cells growth inhibition, support their applicability in chemoadjuvant tumor therapy.
- MeSH
- buněčné sféroidy účinky léků MeSH
- HEK293 buňky MeSH
- lidé MeSH
- mezenchymální kmenové buňky * účinky léků metabolismus MeSH
- nádorové buněčné linie MeSH
- nádory slinivky břišní * farmakoterapie patologie metabolismus MeSH
- statiny * farmakologie MeSH
- viabilita buněk * účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
For most retroviruses, including HIV, association with the plasma membrane (PM) promotes the assembly of immature particles, which occurs simultaneously with budding and maturation. In these viruses, maturation is initiated by oligomerization of polyprotein precursors. In contrast, several retroviruses, such as Mason-Pfizer monkey virus (M-PMV), assemble in the cytoplasm into immature particles that are transported across the PM. Therefore, protease activation and specific cleavage must not occur until the pre-assembled particle interacts with the PM. This interaction is triggered by a bipartite signal consisting of a cluster of basic residues in the matrix (MA) domain of Gag polyprotein and a myristoyl moiety N-terminally attached to MA. Here, we provide evidence that myristoyl exposure from the MA core and its insertion into the PM occurs in M-PMV. By a combination of experimental methods, we show that this results in a structural change at the C-terminus of MA allowing efficient cleavage of MA from the downstream region of Gag. This suggests that, in addition to the known effect of the myristoyl switch of HIV-1 MA on the multimerization state of Gag and particle assembly, the myristoyl switch may have a regulatory role in initiating sequential cleavage of M-PMV Gag in immature particles.
- MeSH
- infekční lékařství * MeSH
- interakce hostitele a patogenu MeSH
- Publikační typ
- úvodní články MeSH
Chlorované parafíny jsou relativně novou a stále nedostatečně prozkoumanou skupinou kontaminantů životního prostředí. Chlorované parafíny s krátkým uhlíkatým řetězcem řadíme od roku 2017 na seznam perzistentních organických polutantů. Použití těchto forem je tedy v průmyslu regulováno. Nicméně chlorované parafíny se středním či dlouhým řetězcem, které disponují velice podobnými fyzikálně‐ ‐chemickými vlastnostmi, jsou doposud používány a jejich produkce i konzumace převážně v oblasti Číny strmě vzrůstá. Chlorované parafíny mají schopnost bioakumulace ve tkáních a mohou též ovlivňovat buněčný metabolismus. Se svým nízkým stupněm biotransfor‐ mace představují bezprostřední hrozbu pro lidské zdraví.
Chlorinated paraffins are a relatively new and still understudied component of environmental contaminants. Chlorinated paraffins with a short carbon chain have been included in the list of persistent organic pollutants since 2017. The use of these forms is therefore regu‐ lated in the industry. However, chlorinated paraffins with a medium or long chain, which have very similar physico‐chemical properties, are still used and their production and consumption, mainly in the area of China, is increasing steeply. Chlorinated paraffins have the ability to bioaccumulate in tissues and can also affect cellular metabolism. With their low degree of biotransformation, they represent the closest threat to human health.
- MeSH
- lidé MeSH
- parafín * škodlivé účinky MeSH
- znečištění životního prostředí MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
The emergence of multidrug-resistant microbial pathogens poses a significant threat, severely limiting the options for effective antibiotic therapy. This challenge can be overcome through the photoinactivation of pathogenic bacteria using materials generating reactive oxygen species upon exposure to visible light. These species target vital components of living cells, significantly reducing the likelihood of resistance development by the targeted pathogens. In our research, we have developed a nanocomposite material consisting of an aqueous colloidal suspension of graphene oxide sheets adorned with nanoaggregates of octahedral molybdenum cluster complexes. The negative charge of the graphene oxide and the positive charge of the nanoaggregates promoted their electrostatic interaction in aqueous medium and close cohesion between the colloids. Upon illumination with blue light, the colloidal system exerted a potent antibacterial effect against planktonic cultures of Staphylococcus aureus largely surpassing the individual contributions of the components. The underlying mechanism behind this phenomenon lies in the photoinduced electron transfer from the nanoaggregates of the cluster complexes to the graphene oxide sheets, which triggers the generation of reactive oxygen species. Thus, leveraging the unique properties of graphene oxide and light-harvesting octahedral molybdenum cluster complexes can open more effective and resilient antibacterial strategies.
- MeSH
- antibakteriální látky farmakologie MeSH
- lidé MeSH
- molybden farmakologie MeSH
- reaktivní formy kyslíku MeSH
- stafylokokové infekce * MeSH
- Staphylococcus aureus * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
