An Aerolysin-like Pore-Forming Protein Complex Targets Viral Envelope to Inactivate Herpes Simplex Virus Type 1.

Because most of animal viruses are enveloped, cytoplasmic entry of these viruses via fusion with cellular membrane initiates their invasion. However, the strategies in which host cells counteract cytoplasmic entry of such viruses are incompletely understood. Pore-forming toxin aerolysin-like proteins (ALPs) exist throughout the animal kingdom, but their functions are mostly unknown. In this study, we report that ßγ-crystallin fused aerolysin-like protein and trefoil factor complex (ßγ-CAT), an ALP and trefoil factor complex from the frog Bombina maxima, directly blocks enveloped virus invasion by interfering with cytoplasmic entry. ßγ-CAT targeted acidic glycosphingolipids on the HSV type 1 (HSV-1) envelope to induce pore formation, as indicated by the oligomer formation of protein and potassium and calcium ion efflux. Meanwhile, ßγ-CAT formed ring-like oligomers of ∼10 nm in diameter on the liposomes and induced dye release from liposomes that mimic viral envelope. Unexpectedly, transmission electron microscopy analysis showed that the ßγ-CAT-treated HSV-1 was visibly as intact as the vehicle-treated HSV-1, indicating that ßγ-CAT did not lyse the viral envelope. However, the cytoplasmic entry of the ßγ-CAT-treated HSV-1 into HeLa cells was totally hindered. In vivo, topical application of ßγ-CAT attenuated the HSV-1 corneal infection in mice. Collectively, these results uncovered that ßγ-CAT possesses the capacity to counteract enveloped virus invasion with its featured antiviral-acting manner. Our findings will also largely help to illustrate the putative antiviral activity of animal ALPs.

Characteristics of Retained Foreign Bodies in the Tongue: A Retrospective Study of 35 Cases.

PURPOSE: There are only a few case reports of foreign bodies (FBs) in the tongue. Delayed diagnosis or misdiagnosis is commonly reported. The purpose of this study was to identify the demographic, clinical, and radiological features that might facilitate the diagnosis of retained FBs in the tongue. METHODS: A retrospective case series was performed. Clinical and imaging data of patients with FBs in the tongue at Wuhan University Hospital of Stomatology were reviewed. The outcome variable was a preliminary, radiological, intraoperative, or pathological diagnosis. Covariates included age, sex, FB-related history, symptoms and signs, duration, and computed tomography (CT) imaging features. Descriptive statistics were computed for each study variable. RESULTS: Thirty-five patients were included. The sample's mean age was 54.5 ± 11.2 years, included 19 males (54.3%). Eighty percent of the patients reported FB-related history with a mean duration of 4 weeks. More than 70% of the patients presented with tongue swelling. Approximately half of the 35 cases were preliminarily misdiagnosed, and 15 of them were initially suspected to be tumors. After CT examinations, 33 of the 35 cases were diagnosed as FB. Characteristic CT imaging feature of the FB was a radiopaque line. Most FBs were located at the anterior two-thirds and marginal area of the tongue and in an oblique direction. The depth of FB was 0.61 ± 0.42 cm. The superficial ends of most FBs were close to the surface of the dorsum and the tongue margin. CONCLUSIONS: The possibility of a retained FB should be included in the differential diagnosis of a nonhealing wound or tongue enlargement when a radiopaque line is present on CT images of patients presenting with or without FB-related history. It may be easier to detect a FB in the tongue when a CT imaging postprocessing protocol, including thin-slice reconstruction and multiplanar reformation visualization and careful interpretation, is used.

Synthesis of novel 3/5(3,5)-(di)nitropaeonol hydrazone derivatives as nematicidal agents.

Eighteen novel 3/5(3,5)-(di)nitropaeonol hydrazone derivatives were prepared, and their structures well characterized by 1H NMR, HRMS, and mp. Due to the steric hindrance, the substituents on the C = N double bond of all hydrazine compounds (except E/Z = 4/1 for IV-1g, IV-1l, IV-2b, and E/Z = 3/2 for IV-1n, IV-3a) adopted E configuration. Among all compounds, four compounds 2, 4, IV-1j, and IV-1n exhibited potent nematicidal activity than their precursor paeonol, especially 5-nitropaeonol (2) and 3,5-dinitropaeonol (4) displayed the most potent nematicidal activity Heterodera glycines in vivo with LC50 values of 32.3307 and 36.7074 mg/L, respectively.

A secreted pore-forming protein modulates cellular endolysosomes to augment antigen presentation.

Bacterial pore-forming toxin aerolysin-like proteins are widely distributed in animals and plants. Emerging evidence supports their roles in host innate immunity, but their direct actions in adaptive immunity remain elusive. In this study, we found that ßγ-CAT, an aerolysin-like protein and trefoil factor complex identified in the frog Bombina maxima, modulated several steps of endocytic pathways during dendritic cell antigen presentation. The protein augmented the antigen uptake of dendritic cells and actively neutralized the acidification of cellular endocytic organelles to favor antigen presentation. In addition, the release of functional exosome-like extracellular vesicles was largely enhanced in the presence of ßγ-CAT. The cellular action of ßγ-CAT increased the number of major histocompatibility complex (MHC) I-ovalbumin and MHC II molecules on dendritic cell surfaces and the released exosome-like extracellular vesicles. An enhanced antigen presentation capacity of dendritic cell for priming of naive T cells was detected in the presence of ßγ-CAT. Collectively, these effects led to strong cytotoxic T lymphocyte responses and antigen-specific antibody responses. Our findings provide evidence that a vertebrate-secreted pore-forming protein can augment antigen presentation by directly modulating cellular endocytic and exocytic pathways, leading to robust activation of adaptive immunity.

Pore-forming toxin-like protein complex expressed by frog promotes tissue repair.

Tissue repair is a highly dynamic process, and the immediate onset of acute inflammation has been considered necessary for repair. Pore-forming proteins are important, both in pathogen invasion and host immunity. However, their roles in wound healing and tissue repair are unclear. ßγ-crystallin fused aerolysin-like protein (α-subunit) and trefoil factor (ß-subunit) complex (ßγ-CAT) is a complex of a bacterial pore-forming toxin aerolysin-like protein and trefoil factor identified in the frog Bombina maxima. In this study, we established mouse cutaneous wound models to explore the effects of ßγ-CAT on skin wound healing. ßγ-CAT accelerated the healing of full-thickness wounds by improving re-epithelialization. This complex relieved dermal edema and promoted scarless healing. ßγ-CAT treatment resulted in a rapid release of IL-1ß, which initiated an acute inflammation response in the early stage of healing. Meanwhile, the expression levels of TGF-ß1, VEGF, and bFGF and the recruitment of M2 macrophages around the wound significantly increased after ßγ-CAT treatment. ßγ-CAT protected skin wounds against methicillin-resistant Staphylococcus aureus by improving neutrophil recruitment at the site of the wound. Overall, our results suggest that ßγ-CAT can promote tissue repair and protect skin wounds against antibiotic-resistant bacterial infection by triggering the acute inflammatory response. This is the first example that aerolysin-like pore-forming proteins widely existing in plants and animals may act in wound healing and tissue repair.-Gao, Z.-H., Deng, C.-J., Xie, Y.-Y., Guo, X.-L., Wang, Q.-Q., Liu, L.-Z., Lee, W.-H., Li, S.-A., Zhang, Y. Pore-forming toxin-like protein complex expressed by frog promotes tissue repair.

Effect of fracture orientation on detection accuracy of vertical root fractures in non-endodontically treated teeth using cone beam computed tomography.

OBJECTIVES: This study aimed to investigate the effect of fracture orientation on the detection accuracy of vertical root fractures (VRFs) in non-endodontically treated teeth using four different cone beam computed tomography (CBCT) units. MATERIALS AND METHODS: Thirty eight out of 148 extracted human permanent teeth were chosen randomly, and VRFs were artificially induced to result in 20 mesiodistally and 18 buccolingually oriented root fractures. The fracture width was subsequently measured. All the teeth were scanned with four CBCT units. CBCT images were evaluated independently by two observers. Area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were calculated for each observer and fracture orientation. The AUC between the two fracture orientations was compared using Z test. RESULTS: The mean fracture width was 140 µm (standard deviation 26.8 µm). A statistically significant difference was found between the mesiodistal and buccolingual VRFs for the AUC from the CBCT unit 3D Accuitomo 170 (p = 0.02). There were no statistically significant differences between the mesiodistal and buccolingual VRFs for AUCs from the CBCT units NewTom VGi (p = 0.21), ProMax 3D Mid (p = 0.23), and i-CAT FLX (p = 0.21). CONCLUSION: Fracture orientations of teeth with VRFs in non-endodontically treated teeth may play a role in the detection accuracy of CBCT images, but this effect seems to be dependent on the CBCT unit used. CLINICAL RELEVANCE: Although for most of the CBCT units tested, the fracture orientation of VRF in non-endodontically treated teeth seems not to play a role for the diagnosis, clinical data is needed to further assess the impact of different devices on VRF detection.

Host Pore-Forming Protein Complex Neutralizes the Acidification of Endocytic Organelles to Counteract Intracellular Pathogens.

Many intracellular pathogens invade cells via endocytic organelles and have adapted to the drop in pH along the endocytic pathway. However, the strategy by which the host cell counteracts this pathogen adaptation remains unclear. ßγ-CAT is an aerolysin-like pore-forming protein and trefoil factor complex in the frog Bombina maxima. We report here that ßγ-CAT, as a host-secreted factor with an intrinsic channel-forming property, is the first example of a molecule that actively neutralizes the acidification of endocytic organelles to counteract Listeria monocytogenes infection. Immunodepletion of endogenous ßγ-CAT largely impaired the control of L. monocytogenes by frog cells. ßγ-CAT elevates the pH of L. monocytogenes-containing vacuoles to limit the vacuole escape of L. monocytogenes to cytosol. Furthermore, ßγ-CAT promotes intracellular L. monocytogenes clearance via autophagy and by that the nonlytic expulsion of the bacteria from host cells. Finally, ßγ-CAT attenuated the dissemination of L. monocytogenes in vivo. These findings reveal a novel host strategy and effectors that combat pathogen adaptation to acidic conditions along the endocytic pathway.

Prohibitin is involved in the activated internalization and degradation of protease-activated receptor 1.

The protease-activated receptor 1 (PAR1) is a G-protein-coupled receptor that is irreversibly activated by either thrombin or metalloprotease 1. Due this irrevocable activation, activated internalization and degradation are critical for PAR1 signaling termination. Prohibitin (PHB) is an evolutionarily conserved, ubiquitously expressed, pleiotropic protein and belongs to the stomatin/prohibitin/flotillin/HflK/C (SPFH) domain family. In a previous study, we found that PHB localized on the platelet membrane and participated in PAR1-mediated human platelet aggregation, suggesting that PHB likely regulates the signaling of PAR1. Unfortunately, PHB's exact function in PAR1 internalization and degradation is unclear. In the current study, flow cytometry revealed that PHB expressed on the surface of endothelial cells (HUVECs) but not cancer cells (MDA-MB-231). Further confocal microscopy revealed that PHB dynamically associates with PAR1 in a time-dependent manner following induction with PAR1-activated peptide (PAR1-AP), though differently between HUVECs and MDA-MB-231 cells. Depletion of PHB by RNA interference significantly inhibited PAR1 activated internalization and led to sustained Erk1/2 phosphorylation in the HUVECs; however, a similar effect was not observed in MDA-MB-231 cells. For both the endothelial and cancel cells, PHB repressed PAR1 degradation, while knockdown of PHB led to increased PAR1 degradation, and PHB overexpression inhibited PAR1 degradation. These results suggest that persistent PAR1 signaling due to the absence of membrane PHB and decreased PAR1 degradation caused by the upregulation of intracellular PHB in cancer cells (such as MDA-MB-231 cells) may render cells highly invasive. As such, PHB may be a novel target in future anti-cancer therapeutics, or in more refined cancer malignancy diagnostics.

[Pollution Characteristics and Health Risk Assessment of Heavy Metals in PM2.5 of Different Air Masses During Heating Season in Tianjin].

In order to explore the pollution characteristics and health risks of heavy metals in PM2.5 in Tianjin, heavy metal samples (Pb, Cd, Cr, As, Zn, Mn, Co, Ni, Cu, and V) in PM2.5 were analyzed from November 2020 to March 2021 using the Xact-625 heavy metal online analyzer. The spatial and temporal distribution characteristics were analyzed using the HYSPLIT model, and the health risks of heavy metals were analyzed using the US EPA risk assessment model. The results indicated that the average total concentration of the 10 heavy metal elements was (261.56±241.74) ng·m-3, among which the concentrations of Cr ï¼»converted Cr(Ⅵ)ï¼½ and As were higher than the annual average limit of the National Ambient Air Quality Standard (GB 3095-2012). According to the back trajectory results, the medium-distance transmissions from northwest areas (NO.1), the long-distance transmissions from northwest areas (NO.2), the transmissions from southwest areas (NO.3), and the transmissions from northeast areas (NO.4) were the major sources in Tianjin City. The heavy metals of different air masses presented different pollution characteristics and health risks; the concentration of PM2.5, the total concentration of the 10 heavy metal elements, and the total carcinogenic risk of the five heavy metal elements of the NO.3 air mass were the highest, whereas the total non-carcinogenic risk of the 10 heavy metal elements of the NO.2 air mass was higher than that of the other two air mass. The health risk assessment showed that Mn posed non-carcinogenic risks to children, and Cr and As presented carcinogenic risk. Meanwhile, Cd of the NO.3 air masses also presented carcinogenic risk.

GBP2 as a potential prognostic predictor with immune-related characteristics in glioma.

Guanylate binding protein 2 (GBP2) is a member of the guanine binding protein family, and its relationship with prognostic outcomes and tumor immune microenvironments in glioma remains elusive. We found GBP2 were increased in glioma tissues at both mRNA and protein levels. Kaplan-Meier curves revealed that high GBP2 expression was linked with worse survival of glioma patients, and multivariate Cox regression analysis indicated that high GBP2 expression was an independent prognostic factor for glioma. Combined analysis in immune database revealed that the expression of GBP2 was significantly related to the level of immune infiltration and immunomodulators. Single-cell analysis illustrated the high expression of GBP2 in malignant glioma cells showed the high antigen presentation capability, which were confirmed by real-time polymerase chain reaction (qRT-PCR) data. Additionally, the hsa-mir-26b-5p and hsa-mir-335-5p were predicted as GBP2 regulators and were validated in U87 and U251 cells. Our results first decipher immune-related characteristics and noncoding regulators of GBP2 in glioma, which may provide insights into associated immunotherapies and prognostic predictor.

Biotemplate derived three dimensional nitrogen doped graphene@MnO2 as bifunctional material for supercapacitor and oxygen reduction reaction catalyst.

Natural diatomite with abundant pores was used as a biotemplate for the massive production of three-dimensional (3D) porous graphene by chemical vapor deposition method. Subsequent template removal and nitrogen doping treatment yield nitrogen doped 3D graphene with preserved shape and complex internal features of the diatomite. After further deposition with MnO2 nanosheets, the N-doped 3D graphene@MnO2 (N-G@MnO2) hybrid exhibited excellent supercapacitor and good oxygen reduction reaction (ORR) performance. Accordingly, the porous N-G@MnO2 electrode exhibited a high specific capacitance (411.5 F g-1) and a good cycling performance (88.3% capacitance retention after 4000 charge/discharge cycling test). When tested in a two-electrode configuration, N-G@MnO2 achieved a wide potential window up to 1.8 V with a high energy density of 46.1 Wh kg-1. Furthermore, the as-prepared N-G@MnO2 showed good performance in oxygen reduction reaction, which is comparable to those of commercially available Pt/C electrode. The enhanced capacitive and electrocatalytic properties and stability is due to the synergistic interactions between the porous 3D graphene and MnO2 nanosheets. The results indicate that the 3D N-G@MnO2 could be useful for supercapacitor and ORR catalyst.

Endogenous pore-forming protein complex targets acidic glycosphingolipids in lipid rafts to initiate endolysosome regulation.

Bacterial pore-forming toxin aerolysin-like proteins (ALPs) are widely distributed in animals and plants. However, functional studies on these ALPs remain in their infancy. ßγ-CAT is the first example of a secreted pore-forming protein that functions to modulate the endolysosome pathway via endocytosis and pore formation on endolysosomes. However, the specific cell surface molecules mediating the action of ßγ-CAT remain elusive. Here, the actions of ßγ-CAT were largely attenuated by either addition or elimination of acidic glycosphingolipids (AGSLs). Further study revealed that the ALP and trefoil factor (TFF) subunits of ßγ-CAT bind to gangliosides and sulfatides, respectively. Additionally, disruption of lipid rafts largely impaired the actions of ßγ-CAT. Finally, the ability of ßγ-CAT to clear pathogens was attenuated in AGSL-eliminated frogs. These findings revealed a previously unknown double binding pattern of an animal-secreted ALP in complex with TFF that initiates ALP-induced endolysosomal pathway regulation, ultimately leading to effective antimicrobial responses.

The novel roles of circular RNAs in metabolic organs.

Circular RNAs (circRNAs) with a covalently closed loop structure which was different with linear RNAs, recently re-merged as novel regulator and exerted function in multiple biological processes. Through deep RNA sequencing (RNA-seq) technology coupled with bioinformatic analyses, a number of circRNAs has been identified. Moreover, circRNAs exhibit tissue- and development-specific expression indicating their potential biological significance. Actually, function of circRNAs as miRNA sponge has been well demonstrated in some diseases, besides, circRNAs also could function as RNA binding protein sponge and regulate alternative splicing and gene transcription. Notably, Emerging evidences showed that circRNAs played a pivotal role on the development of diseases including atherosclerotic vascular disease, neurological disorders and liver diseases, and served as diagnostic or predictive biomarkers of some diseases. This review mainly discusses the current advance of circRNAs as regulator involved in many diseases, and highlights circRNAs which have been well elucidated biological and pathogenic mechanism.

A high concentration of DMSO activates caspase-1 by increasing the cell membrane permeability of potassium.

Dimethyl sulfoxide (DMSO) is widely used in the laboratory and in clinical situations because it is soluble in both aqueous and organic media and can be used to treat many types of diseases. Thus, it is meaningful to assess the comprehensive and in-depth biological activities of DMSO. Here, we showed that a high concentration of DMSO induced pro-inflammatory cytokine interleukin-1ß (IL-1ß) secretion from the monocytic cell line THP-1. DMSO-induced IL-1ß secretion was dependent on intracellular caspase-1 activation. Further study revealed that the activation of caspase-1 by DMSO relied on NLRP3 inflammasome formation. It is generally accepted that the NLRP3 inflammasome is activated by reactive oxygen species generation or potassium efflux; however, the common NLRP3 inflammasome trigger remains controversial. Here, we showed that although DMSO is a ROS scavenger, this chemical increases membrane permeability and potassium efflux, and the formation of the NLRP3 inflammasome reflects the increased membrane permeability and potassium efflux induced by DMSO. The present study reveals a new characteristic of DMSO, which should be considered when using this chemical in either the laboratory or the clinic.

Merging of memory effect and anion intercalation: MnOx-decorated MgAl-LDO as a high-performance nano-adsorbent for the removal of methyl orange.

MnOx-decorated MgAl layered double oxide (M-LDO) was fabricated via merging of memory effect and anion intercalation, accompanied by the reduction/calcination process. The as-obtained nanocomposites were characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD) and N2 adsorption-desorption. To clarify the detailed formation mechanism, optimized calcination temperature/time and temperature for methyl orange (MO) adsorption were investigated. Adsorption experiments showed that the adsorption behaviour fitted well with a Langmuir isotherm and pseudo-second-order model, and the maximum adsorption capacity calculated from the Langmuir model was 555.55 mg g(-1). The adsorption process was exothermic and spontaneous in nature. Moreover, the used adsorbent could be regenerated for at least five cycles (94% removal retained) through a thermal procedure, indicating that the M-LDO hybrid is a promising adsorbent with promising ability to remove anionic dye pollutants from wastewater.

Characterization and optimization of glycerol/sebacate ratio in poly(glycerol-sebacate) elastomer for cell culture application.

Poly(glycerol-sebacate) (PGS) is an elastomeric biodegradable polyester. Our previous series of studies have showed that PGS has good biocompatibility. In view of the potential use of PGS in bioengineering, we attempt to characterize the PGS polymer with different ratio of glycerol and sebacic acid, and the cell adhesion and growth on these polymers. PGSs with different proportion of glycerol and sebacic acid were synthesized by polycondensation reaction. The microstructure of the series PGSs were characterized by infrared spectroscopy and X-ray diffraction analysis (XRD). Results showed that, with the increase of the ratio of sebacic acid in PGS from 1:0.8, 1:1, to 1:1.2 (ratio of glycerol to sebacic acid), the main diffraction peak in XRD, the sol content and gel swelling increased but then decreased, suggesting that the degree of crosslinking and the inherent degree of order of the series PGS increased and then decreased. With the increase of sebacic acid proportion, water absorption increased and then decreased, and the water absorption ranged from 9.62% to 10.66%. The mass loss of the series of samples in degradation experiments ranged from 24.63% to 40.06% on the 32nd day of degradation. Cell culture data suggested that the polymer with the ratio of 1:0.8 for glycerol and sebacate was suitable for cell adhesion and growth. In conclusion, PGS can be used as the cell culture matrix by modifying the composition ratio of glycerol and sebacic acid to improve the properties of cell adhesion and growth.