Prion diseases are fatal neurodegenerative disorders affecting both humans and animals. The causative agent, prion, is extremely resistant to common disinfection procedures. Thus, effective prion ...inactivation strategies using relatively safe and less corrosive disinfectants are required. A solution containing CAC-717, mesoscopic crystals of calcium bicarbonate, exerts both antimicrobial and virucidal activities without apparent harmful effects. This study demonstrated that combined treatment with CAC-717 absorbed on ceramic (CAC-717 ceramic) and sodium dodecyl sulfate (SDS) substantially reduced the protein misfolding cyclic amplification (PMCA) seeding activity of Chandler strain scrapie mouse-brain homogenates (ScBH). Additionally, bioassays demonstrated that ScBH-inoculated mice treated with CAC-717 ceramic in combination with sodium dodecyl sulfate (SDS) did not develop disease. Furthermore, this combination effectively inactivated PMCA seeding activity on ScBH-coated stainless-steel wires below the detection limit. Overall, the findings suggest that combined treatment with CAC-717 ceramic and SDS represents a promising and less damaging approach for prion inactivation.
Precipitation Behavior of Wrought Fe-Ni-Based Alloy HR6W Iwamaru, Arata; Hisazawa, Hiromu; Terada, Yoshihiro
Journal of the Japan Institute of Metals and Materials,
2019/01/01, 20190101, Letnik:
83, Številka:
1
Journal Article
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Odprti dostop
Age-hardening behavior of Fe-Ni-based alloy HR6W was investigated at the temperature range between 973 K and 1073 K. Two-step increase in hardness is detected for the alloy at each temperature; the ...first increase in hardness results from the precipitation of M23C6 phase and the second one corresponds to that of Laves phase. The TTP (time-temperature precipitation) diagram for the alloy is established based on the results of hardness measurement and microstructure observation, where the precipitation of Laves phase is slower than that of M23C6 phase by three orders of magnitude and the nose temperature of Laves phase is above 1073 K. The M23C6 phase precipitates with plate-like morphology along grain-boundaries at the early stage of aging, followed by the precipitation of Laves phase with granular morphology with increasing aging time. It is found that the M23C6 and Laves phases are aligned under stress condition, due to their precipitation on the dislocations introduced during creep deformation.
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The proliferation epidermal growth factor (EGF) is known to acquire contradictory apoptotic activities upon conjugation with gold nanoparticles (GNPs) through hitherto unknown ...mechanisms. Here, we identified an essential role of membrane rafts in the drastic activity switching of EGF-GNPs through the following intracellular signaling. (1) In contrast to the rapid diffusion of activated EGF receptor after the soluble EGF stimulation, the receptor is confined within membrane rafts upon binding to the EGF-GNPs. (2) This initial receptor confinements switch its endocytosis process from normal clathrin-mediated endocytosis to caveolin-mediated one, changing the phosphorylation dynamics of essential downstream kinases, i.e., extracellular signal-regulated kinase and AKT. Importantly, the destruction of membrane rafts by β-cyclodextrin reversed this trafficking and signaling, restoring EGF-GNPs to lost anti-apoptotic property. These results reveal the importance of GNP-mediated signal condensation at membrane rafts in conferring the unique apoptotic activity on EGF-nanoparticle conjugates.
Epidermal growth factor (EGF) is a small secretory protein that induces cell proliferation upon binding to its receptor existed on cellular plasma membranes. One interesting feature of the protein in the nanobiology field is, its acquisition of apoptosis-inducing (cellular suicide) activity rather than proliferative one upon conjugation to gold nanoparticles through hitherto unknown mechanisms. Here, we identified the involvement of membrane rafts, plasma membrane nanodomains enriched with cholesterol, in the apoptosis processes by changing the receptor trafficking and downstream signal transduction pathways. Moreover, the destruction of lipid rafts restored the EGF-nanoparticle conjugates with lost anti-apoptotic activity. These finding highlight potential applications of EGF-nanoparticle conjugates to cancer therapy, as the EGF receptor are highly expressed in cancer cells.
Prion diseases are transmissible and progressive neurodegenerative disorders characterized by abnormal prion protein (PrPSc) accumulation in the central nervous system. Generation of synthetic PrPSc ...in a cell-free conversion system and examination of its transmissibility to animals would facilitate testing of the protein-only hypothesis and the understanding of the molecular basis of sporadic prion diseases.
In this study, we used recombinant prion protein from a baculovirus-insect cell expression system (Bac-rPrP) and insect cell-derived cofactors to determine whether Bac-rPrPSc is spontaneously produced in intermittent ultrasonic reactions. No spontaneous generation of Bac-rPrPSc was observed at 37 °C, but when the reaction temperature was increased to 45 °C, Bac-rPrPSc was generated in all trials. Some Bac-rPrPSc variants were transmissible to mice, but when the reaction was repeated for 40 rounds, the transmissibility was lost. Notably, a variety of Bac-rPrPSc variants, including non-transmissible ones, differing in resistance to proteinase K and cofactor dependence during amplification, was generated under the same experimental conditions, including the same sonication settings and cofactors. However, their characteristics also disappeared after 40 reaction rounds and the variety converged onto a single variant. These results indicate that various Bac-rPrPSc variants with different transmissibility to mice and structural properties are generated, which compete with each other and gradually converge onto a variant with a slightly faster amplification rate.
•Distinct prion variants were spontaneously generated by intermittent sonication.•Recombinant prion protein from the baculovirus-insect cell was used as a substrate.•The reaction temperature had to be set from 37 °C to 45 °C.•Prion variants were generated even under the same environment.•Competition between variants occurred as reaction rounds were repeated.
MicroRNA (miRNA) is an emerging subclass of small non-coding RNAs that regulates gene expression and has a pivotal role for many physiological processes including cancer development. Recent reports ...revealed the role of miRNAs as ideal biomarkers and therapeutic targets due to their tissue- or disease-specific nature. Head and neck cancer (HNC) is a major cause of cancer-related mortality and morbidity, and laryngeal cancer has the highest incidence in it. However, the molecular mechanisms involved in laryngeal cancer development remain to be known and highly sensitive biomarkers and novel promising therapy is necessary.
To explore laryngeal cancer-specific miRNAs, RNA from 5 laryngeal surgical specimens including cancer and non-cancer tissues were hybridized to microarray carrying 723 human miRNAs. The resultant differentially expressed miRNAs were further tested by using quantitative real time PCR (qRT-PCR) on 43 laryngeal tissue samples including cancers, noncancerous counterparts, benign diseases and precancerous dysplasias. Significant expressional differences between matched pairs were reproduced in miR-133b, miR-455-5p, and miR-196a, among which miR-196a being the most promising cancer biomarker as validated by qRT-PCR analyses on additional 84 tissue samples. Deep sequencing analysis revealed both quantitative and qualitative deviation of miR-196a isomiR expression in laryngeal cancer. In situ hybridization confirmed laryngeal cancer-specific expression of miR-196a in both cancer and cancer stroma cells. Finally, inhibition of miR-196a counteracted cancer cell proliferation in both laryngeal cancer-derived cells and mouse xenograft model.
Our study provided the possibilities that miR-196a might be very useful in diagnosing and treating laryngeal cancer.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Two Cheviot ewes homozygous for the A136L141R154Q171 (AL141RQ) prion protein (PrP) genotype were exposed intracerebrally to brain pools prepared using four field cases of atypical scrapie from the ...United Kingdom. Animals were clinically normal until the end of the experiment, when they were culled 7 years post-inoculation. Limited accumulation of disease-associated PrP (PrPSc) was observed in the cerebellar molecular layer by immunohistochemistry, but not by western blot or enzyme-linked immunosorbent assay. In addition, PrPSc was partially localized in astrocytes and microglia, suggesting that these cells have a role in PrPSc processing, degradation or both. Our results indicate that atypical scrapie is transmissible to AL141RQ sheep, but these animals act as clinically silent carriers with long incubation times.
A Corriedale ewe was confirmed as the first atypical scrapie case during an active surveillance program for transmissible spongiform encephalopathies in small ruminants in Japan. The animal was ...homozygous for the AF141RQ haplotype of PRNP. The animal showed clinical neurological signs possibly due to listeriosis before culling. Western blot analysis showed an unusual multiple banded pattern with a low-molecular fragment at ~7 kDa. Histopathology revealed suppurative meningoencephalitis caused by listeriosis in the brainstem. Fine granular to globular immunostaining of disease-associated prion proteins was mainly detected in the neuropil of the spinal tract of the trigeminal nerve and in the white matter of the spinocerebellar tract. Based on these results, this case was conclusively diagnosed as atypical scrapie with encephalitic listeriosis.
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•Compound MM-1 is a promising APOBEC3G stabilizer of elusive mechanism of action.•Comprehensive in silico study revealed their potential to interrupt Vif/Elongin C binding.•The ...prediction was validated through synthesis and biochemical in vitro assay of MM-1.•MM-1 proved an explicit negative impact on Vif/Elongin C interaction.
In 2014, two novel and promising benzimidazole-based APOBEC3G stabilizers MM-1 and MM-2 (MMs) were uncovered with an elusive mechanism of action. Vif-APOBEC3G axis has been recognized as a novel therapeutic target for anti HIV-1 drug development. The unexplored mechanism of MMs hindered their further development into lead compounds. To recognize their underlying mechanism we adopted an exhaustive in silico workflow by which we tested their ability to interrupt Vif complex network formation. The preliminary outcome guided us to a high likelihood of MMs interaction within Elongin C binding site, which in turn, perturbs Vif/Elongin C binding and ultimately undermines Vif action. To validate our estimation, we synthesized only MM-1 as a model to complement our study by in vitro assay for a real-time understanding. An immunoprecipitation experiment confirmed the capacity of MM-1 to interrupt Vif/Elongin C interaction. This is an integral study that lies at the interface between theoretical and experimental approaches showing the potential of molecular modelling to address issues related to drug development.
Atypical scrapie in goats has only been reported in European countries. The present study reports the identification of the first case of atypical scrapie in goats in Japan. The genotype of the ...animal was ALRQ/ALHQ at codons 136, 141, 154, and 171 in prion protein (PrP). Western blot analysis showed a multiplex proteinase K-resistant prion protein (PrP-res) band pattern with a band <15 kDa that was clearly distinguishable from the triplet PrP-res band pattern observed in classical scrapie cases. Histopathological and immunohistological examination showed mild vacuolation and fine granular to globular immunolabelling of disease-associated PrP in the dorsal horn of cervical spinal cord. Collectively, our results confirmed that this goat was affected by atypical scrapie.
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