4,491 research outputs found
Ambra1 is an essential regulator of autophagy and apoptosis in SW620 cells: Pro-survival role of Ambra1
Recent research has revealed a role for Ambra1, an autophagy-related gene-related (ATG) protein, in the autophagic pro-survival response, and Ambra1 has been shown to regulate Beclin1 and Beclin1-dependent autophagy in embryonic stem cells. However, whether Ambra1 plays an important role in the autophagy pathway in colorectal cancer cells is unknown. In this study, we hypothesized that Ambra1 is an important regulator of autophagy and apoptosis in CRC cell lines. To test this hypothesis, we confirmed autophagic activity in serum-starved SW620 CRC cells by assessing endogenous microtubule-associated protein 1 light chain 3 (LC3) localization, the presence of autophagosomes (transmission electron microscopy) and LC3 protein levels (Western blotting). Ambra1 expression was detected by Western blot in SW620 cells treated with staurosporine or etoposide. Calpain and caspase inhibitors were employed to verify whether calpains and caspases were responsible for Ambra1 cleavage. To examine the role of Ambra1 in apoptosis, Ambra1 knockdown cells were treated with staurosporine and etoposide. Cell apoptosis and viability were measured by annexin-V and PI staining and MTT assays. We determined that serum deprivation-induced autophagy was associated with Ambra1 upregulation in colorectal cancer cell lines. Ambra1 expression decreased during staurosporine- or etoposide-induced apoptosis. Calpains and caspases may be responsible for Ambra1 degradation. When Ambra1 expression was reduced by siRNA, SW620 cells were more sensitive to staurosporine- or etoposide-induced apoptosis. In addition, starvation-induced autophagy decreased. Finally, Co-immunoprecipitation of Ambra1 and Beclin1 demonstrated that Ambra1 and Beclin1 interact in serum-starved or rapamycin-treated SW620 cells, suggesting that Ambra1 regulates autophagy in CRC cells by interacting with Beclin1. In conclusion, Ambra1 is a crucial regulator of autophagy and apoptosis in CRC cells that maintains the balance between autophagy and apoptosis
Akumulacija i specijacija kadmija, cinka i olova u tlu na podruÄju rudarenja olova i cinka
An exploratory study on soil contamination of Cd, Zn, Pb was carried out in the surroundings of a historical, abandoned Pb-Zn mining area in Hunan Province, China. The accumulation in soils and representative plants of Cd, Zn, Pb and their chemical speciation were investigated. The obtained results indicated that Cd, Zn and Pb presented a significant contamination compared with Environmental Quality Standards for Soils in China (GB 15618-1995). The geoaccumulation index suggested the degree of contamination: PbĀ >Ā Cd >Ā Zn. The modified BCR sequential extraction results showed that Cd, Zn, and Pb exist in soil in a relatively unstable form, and will exert a bad effect on the plants grown in the soil. Heavy metals in oranges collected in the sampling area were tested to identify the extent of pollution. The results confirmed that the sampled oranges were polluted with Pb, which exceeded the national food safety standard by 3.4āāā6.3 times. Heavy metals in branches and leaves showed different accumulation characteristics than the fruits.
This work is licensed under a Creative Commons Attribution 4.0 International License.Istražena je kontaminacija kadmijem, cinkom i olovom oko napuÅ”tenog podruÄja rudarenja olova i cinka u kineskoj pokrajini Hunan. ProuÄena je akumulacija u tlu i reprezentativnim biljkama te kemijska specijacija teÅ”kih metala. U usporedbi sa standardima GB15618-1995 zabilježena je znaÄajna kontaminacija kadmijem, cinkom i olovom. Prema geokemijskom indeksu razina kontaminacije slijedi niz PbĀ >Ā CdĀ >Ā Zn. Modificirana sekvencijska ekstrakcija prema BCR-u pokazuje da se teÅ”ki metali u tlu nalaze u obliku relativno nestabilnih oblika i da Äe nepovoljno utjecati na biljni svijet. ZagaÄenje je ispitano na uzorcima naranÄi iz istraživanog podruÄja. NaranÄe su kontaminirane olovom, a sadržaj olova veÄi je od 3,4 do 6,3 puta od razine koju dopuÅ”taju nacionalni standardi za sigurnost hrane. Akumulacija teÅ”kih metala u liÅ”Äu i granama pokazuje drugaÄije karakteristike.
Ovo djelo je dano na koriÅ”tenje pod licencom Creative Commons Imenovanje 4.0 meÄunarodna
Case Report: Metagenomic next-generation sequencing applied in diagnosing psittacosis caused by Chlamydia psittaci infection
BackgroundChlamydia psittaci is the causative agent of psittacosis in humans, while its rapid identification is hampered due to the lack of specificity of laboratory testing methods.Case presentationThis study reports four cases of C. psittaci infection after contact with a domestic parrot, all belonging to the same family. Common manifestations like fever, cough, headache, nausea, and hypodynamia appeared in the patients. Metagenomic next-generation sequencing (mNGS) aided the etiological diagnosis of psittacosis, revealing 58318 and 7 sequence reads corresponding to C. psittaci in two cases. The detected C. psittaci was typed as ST100001 in the Multilocus-sequence typing (MLST) system, a novel strain initially reported. Based on the results of pathogenic identification by mNGS, the four patients were individually, treated with different antibiotics, and discharged with favorable outcomes.ConclusionIn diagnosing psittacosis caused by a rare C. psittaci agent, mNGS provides rapid etiological identification, contributing to targeted antibiotic therapy and favorable outcomes. This study also reminds clinicians to raise awareness of psittacosis when encountering family members with a fever of unknown origin
Effects of the Timing of Note Taking on Repeated Listening among Advanced Chinese Japanese Learners: Focusing on the Timing of Note Taking and Working Memory Span
This study aimed to investigate the effects of the timing of note taking on repeated listening for advanced Chinese learners of Japanese. The two independent variables were participantsā working memory capacity and the timing of the note taking. The main results were as follows: In the free recall test, there was a marginal significance that participants with a low working-memory capacity demonstrated better performance when taking notes during the first trail than participants with a high working-memory capacity. However in the fill-in-blank test, regardless of the timing of the note taking, a difference according to the size of working memory capacity was not found. Further, it was found that taking notes during the first trail left a stronger memory trace, whereas taking notes during the second trail was helpful for the understanding of target passages. These results suggest that learners with a smaller memory span can perform better with note taking and learners with a larger memory span are better of taking notes after the first trail
Infiltrated IL-17A-producing gamma delta T cells play a protective role in sepsis-induced liver injury and are regulated by CCR6 and gut commensal microbes
IntroductionSepsis is a common but serious disease in intensive care units, which may induce multiple organ dysfunctions such as liver injury. Previous studies have demonstrated that gamma delta (Ī³Ī“) T cells play a protective role in sepsis. However, the function and mechanism of Ī³Ī“ T cells in sepsis-induced liver injury have not been fully elucidated. IL-17A-producing Ī³Ī“ T cells are a newly identified cell subtype.MethodsWe utilized IL-17A-deficient mice to investigate the role of IL-17A-producing Ī³Ī“ T cells in sepsis using the cecum ligation and puncture (CLP) model.ResultsOur findings suggested that these cells were the major source of IL-17A and protected against sepsis-induced liver injury. Flow cytometry analysis revealed that these Ī³Ī“ T cells expressed VĪ³4 TCR and migrated into liver from peripheral post CLP, in a CCR6-dependent manner. When CLP mice were treated with anti-CCR6 antibody to block CCR6-CCL20 axis, the recruitment of VĪ³4+ Ī³Ī“ T cells was abolished, indicating a CCR6-dependent manner of migration. Interestingly, pseudo germ-free CLP mice treated with antibiotics showed that hepatic IL-17A+ Ī³Ī“ T cells were regulated by gut commensal microbes. E. coli alone were able to restore the protective effect in pseudo germ-free mice by rescuing hepatic IL-17A+ Ī³Ī“ T cell population.ConclusionOur research has shown that VĪ³4+ IL-17A+ Ī³Ī“ T cells infiltrating into the liver play a crucial role in protecting against sepsis-induced liver injury. This protection was contingent upon the recruitment of CCR6 and regulated by gut commensal microbes
The role of inflammasome in chronic viral hepatitis
Infections of hepatotropic viruses cause a wide array of liver diseases including acute hepatitis, chronic hepatitis and the consequently developed cirrhosis and hepatocellular carcinoma (HCC). Among the five classical hepatotropic viruses, hepatitis B virus (HBV) and hepatitis C virus (HCV) usually infect human persistently and cause chronic hepatitis, leading to major troubles to humanity. Previous studies have revealed that several types of inflammasomes are involved in the infections of HBV and HCV. Here, we summarize the current knowledge about their roles in hepatitis B and C. NLRP3 inflammasome can be activated and regulated by HBV and HCV. It is found to exert antiviral function or mediates inflammatory response in viral infections depending on different experimental models. Besides NLRP3 inflammasome, IFI16 and AIM2 inflammasomes participate in the pathological process of hepatitis B, and NALP3 inflammasome may sense HCV infection in hepatocytes. The inflammasomes affect the pathological process of viral hepatitis through its downstream secretion of inflammatory cytokines interleukin-1Ī² (IL-1Ī²) and IL-18 or induction of pyroptosis resulting from cleaved gasdermin D (GSDMD). However, the roles of inflammasomes in different stages of viral infection remains mainly unclear. More proper experimental models of viral hepatitis should be developed for specific studies in future, so that we can understand more about the complexity of inflammasome regulation and multifunction of inflammasomes and their downstream effectors during HBV and HCV infections
Superconductivity emerged from density-wave order in a kagome bad metal
Unconventional superconductivity (USC) in a highly correlated kagome system
has been theoretically proposed for years, yet the experimental realization is
hard to achieve. The recently discovered vanadium-based kagome materials, which
exhibit both superconductivity and charge density wave (CDW) orders, are
nonmagnetic and weakly correlated, thus unlikely host USC as theories proposed.
Here we report the discovery of a chromium-based kagome bad metal,
CsCrSb, which is contrastingly characterised by significant electron
correlations and frustrated magnetism. Successive phase transitions at 54
K with stripe-like structural modulations are observed, probably
associated with CDW and antiferromagnetic spin-density-wave (SDW) orderings.
Under moderately high pressures of 4-8 GPa, these density-wave orders are
suppressed and, remarkably, superconductivity emerges with a maximum
of 6.4 K. A quantum critical point at 4
GPa is revealed, by which non-Fermi-liquid behaviours show up, reminiscent of
USC in iron-based superconductors. The electronic structure calculations
indicate that the electron filling is close to the characteristic flat bands of
the kagome lattice. Our work offers an unprecedented platform for investigating
the mechanism of USC in a correlated kagome system.Comment: 26 pages, 10 figure
Oxygen evolution reaction over catalytic single-site Co in a well-defined brookite TiOā nanorod surface
Efficient electrocatalysts for the oxygen evolution reaction (OER) are paramount to the development of electrochemical devices for clean energy and fuel conversion. However, the structural complexity of heterogeneous electrocatalysts makes it a great challenge to elucidate the surface catalytic sites and OER mechanisms. Here, we report that catalytic single-site Co in a well-defined brookite TiOā nanorod (210) surface (Co-TiOā) presents turnover frequencies that are among the highest for Co-based heterogeneous catalysts reported to date, reaching 6.6āĀ±ā1.2 and 181.4āĀ±ā28āsā»Ā¹ at 300 and 400āmV overpotentials, respectively. Based on grand canonical quantum mechanics calculations and the single-site Co atomic structure validated by in situ and ex situ spectroscopic probes, we have established a full description of the catalytic reaction kinetics for Co-TiOā as a function of applied potential, revealing an adsorbate evolution mechanism for the OER. The computationally predicted Tafel slope and turnover frequencies exhibit exceedingly good agreement with experiment
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