First isolation of bovine coronavirus with a three-amino-acid deletion in the N gene causing severe respiratory and digestive disease in calve.

Bovine coronavirus (BCoV), a persistent threat to global cattle industry, has caused significant economic losses worldwide. In this study, a viral strain was isolated from the intestinal content of a diseased calve, and identified by cytopathic effects observation, indirect immunofluorescence assay and electron microscopy. Results showed that BCoV NXWZ2310 belonging to the GIIb genotype and has a three-amino-acid deletion in the serine-rich region of the N gene. Importantly, the BCoV NXWZ2310 strain exhibited strong pathogenicity, causing nasal discharge and watery diarrhea in calves for 8 and 10 days, respectively. Viral shedding was detected in nasal, throat and rectal swabs at levels reaching 106.228 copies/mL, 105.0 copies /mL and 106.692 copies/mL, respectively. Pathological examination showed that NXWZ2310 resulted in parenchymal lesions of the pulmonary lobe and significant intestinal lesions. Both the lungs and intestines displayed marked microscopic lesions with clear viral antigens present. BCoV NXWZ2310 strain with N-gene deletion mutations, caused severe respiratory and digestive disease in calves. Therefore, effective strategies are needed for the prevention and control of this isolate.

Effective inhibition of PDCoV infection in chimeric APN gene-edited neonatal pigs.

Porcine deltacoronavirus (PDCoV), an emerging enteropathogenic coronavirus, is a serious threat to piglets and has zoonotic potential. Here, we aimed to further explore the role of aminopeptidase N (APN) as a receptor for PDCoV and test the inhibitory effect of a chimeric APN protein strategy on PDCoV infection. PK-15 cells and LLC-PK1 cells expressing chimeric APN were selected and infected with PDCoV. Viral replication was significantly decreased in these chimeric APN cells compared with that in control group cells. To further characterize the effect of the chimeric APN strategy on PDCoV infection in vitro, primary intestinal epithelial cells isolated from chimeric APN pigs were inoculated with PDCoV. Viral challenge of these cells led to decreased PDCoV infection. More importantly, virally challenged chimeric APN neonatal piglets displayed reduced viral load, significantly fewer microscopic lesions in the intestinal tissue, and no diarrhea. Taken together, these findings deepen our understanding of the mechanism of PDCoV infection and provide a valuable model for the production of disease-resistant animals. IMPORTANCE: Porcine deltacoronavirus (PDCoV), an emerging enteropathogenic coronavirus, causes diarrhea in piglets and possesses the potential to infect humans. However, there are currently no effective measures for the prevention or control of PDCoV infection. Here, we have developed PK-15 cells, LLC-PK1 cells, and primary intestinal epithelial cells expressing chimeric APN, and viral challenge of these cells led to decreased PDCoV infection. Furthermore, virally challenged chimeric APN neonatal piglets displayed reduced viral load, significantly fewer microscopic lesions in the intestinal tissue, and no diarrhea. These data show that chimeric APN is a promising strategy to combat PDCoV infection.

A novel virus-like particles vaccine induces broad immune protective against deltacoronavirus in piglets.

Coronaviruses (CoVs) comprise a group of important human and animal pathogens that threaten public health because of their interspecies transmission potential to humans. However, virus-like particles (VLPs) constitute versatile tools in CoVs vaccine development due to their favorable immunological characteristics. Here, we engineered the VLPs composed of the spike (S), membrane (M), and envelope (E) structural proteins of the Porcine deltacoronavirus (PDCoV) and examined their immune responses in mice. Neutralization assays and flow Cytometry demonstrated that PDCoV VLPs induced highly robust neutralizing antibodies (NAbs) and elicited cellular immunity. To assess the protective efficacy of VLPs in newborn piglets, pregnant sows received vaccinations with either a PDCoV-inactivated vaccine or VLPs at 40 and 20 days before delivery. Five days post-farrowing, piglets were orally challenged with the PDCoV strain. Severe diarrhea, high viral RNA copies, and substantial intestinal villus atrophy were detected in piglets born to unimmunized sows. However, piglets from sows immunized with VLPs exhibited high NAbs titers and markedly reduced microscopic damage to the intestinal tissues, with no piglet showing diarrhea. Hence, the results indicate that the VLPs are a potential clinical candidate for PDCoV vaccination, while the strategy may serve as a platform for developing other coronavirus vaccines.

Prevalence and Evolutionary Characteristics of Bovine Coronavirus in China.

Bovine coronavirus (BCoV), bovine rotavirus, bovine viral diarrhea virus, and bovine astrovirus are the most common intestinal pathogenic viruses causing diarrhea in cattle. We collected 1646 bovine fecal samples from January 2020 to August 2023. BCoV was the major pathogen detected, with a positive rate of 34.02% (560/1646). Of the 670 diarrheal samples and 976 asymptomatic samples, 209 and 351 were BCoV-positive, respectively. Studying the relevance of diarrhea associated with BCoV has shown that the onset of diarrheal symptoms post-infection is strongly correlated with the cattle's age and may also be related to the breed. We amplified and sequenced the hemagglutinin esterase (HE), spike protein, and whole genomes of the partially positive samples and obtained six complete HE sequences, seven complete spike sequences, and six whole genomes. Molecular characterization revealed that six strains were branched Chinese strains, Japanese strains, and partial American strains from the GⅡb subgroup. Strains HBSJZ2202 and JSYZ2209 had four amino acid insertions on HE. We also analyzed ORF1a and found disparities across various regions within GIIb, which were positioned on separate branches within the phylogenetic tree. This work provides data for further investigating the epidemiology of BCoV and for understanding and analyzing BCoV distribution and dynamics.

An inactivated PDCoV vaccine induces robust neutralizing antibodies and immune protection in pigs lasting for three months.

Porcine deltacoronavirus (PDCoV), a novel enteropathogenic coronavirus, causes diarrhea mainly in suckling piglets and has the potential to infect humans. Whereas, there is no commercially available vaccine which can effectively prevent this disease. In this study, to ascertain the duration of immune protection of inactivated PDCoV vaccine, suckling piglets were injected subcutaneously with inactivated PDCoV vaccine using a prime/boost strategy at 3 and 17-day-old. Neutralizing antibody assay showed that the level of the inactivated PDCoV group was still ≥1:64 at three months after prime vaccination. The three-month-old pigs were orally challenged with PDCoV strain CZ2020. Two pigs in challenge control group showed mild to severe diarrhea at 10-11 day-post-challenge (DPC), while the inactivated PDCoV group had no diarrhea. High levels of viral shedding, substantial intestinal villus atrophy, and positive straining of viral antigens in ileum were detected in challenge control group, while the pigs in inactivated PDCoV group exhibited significantly reduced viral load, minor intestinal villi damage and negative straining of viral antigens. These results demonstrated that PDCoV was pathogenic against three-month-old pigs and inactivated PDCoV vaccine can provide effective protection in pigs lasting for three months.

A novel recombinant S-based subunit vaccine induces protective immunity against porcine deltacoronavirus challenge in piglets.

IMPORTANCE: As an emerging porcine enteropathogenic coronavirus that has the potential to infect humans, porcine deltacoronavirus (PDCoV) is receiving increasing attention. However, no effective commercially available vaccines against this virus are available. In this work, we designed a spike (S) protein and receptor-binding domain (RBD) trimer as a candidate PDCoV subunit vaccine. We demonstrated that S protein induced more robust humoral and cellular immune responses than the RBD trimer in mice. Furthermore, the protective efficacy of the S protein was compared with that of inactivated PDCoV vaccines in piglets and sows. Of note, the immunized piglets and suckling pig showed a high level of NAbs and were associated with reduced virus shedding and mild diarrhea, and the high level of NAbs was maintained for at least 4 months. Importantly, we demonstrated that S protein-based subunit vaccines conferred significant protection against PDCoV infection.

WTAP affects intracranial aneurysm progression by regulating m6A methylation modification.

Intracranial aneurysm (IA) is a type of cerebrovascular disease that mainly occurs in the circle of Willis. Abnormalities in RNA methylation at the N6-methyladenosine (m6A) site have been associated with numerous types of human diseases. WTAP recruits the m6A methyltransferase complexes to the mRNA targets, and its expression is positively correlated with m6A methylation levels. This research aimed to explore the potential mechanisms of m6A methylation in IA. A selective arterial ligation method was used to establish an IA rat model; thereafter, the m6A methylation level and m6A methylation-related genes were determined in blood and circle of Willis samples using a commercial kit and real-time quantitative PCR, respectively. Subsequently, rat brain microvascular endothelial cells (rBMVECs) were treated with TNF-α, and the expression of m6A methylation-related genes within the cells were assessed. Lastly, the effects of WTAP on TNF-α-induced rBMVECs were further investigated through in vitro experiments. In result, the m6A RNA methylation level evidently declined in the blood and circle of Willis' samples of the IA rats, as compared to the corresponding samples from the control rats (P < 0.05). Compared to the results in the control rats/cells, WTAP expression was significantly downregulated, whereas ALKBH1 expression was evidently upregulated in the blood and circle of Willis samples of the TNF-α-induced rBMVECs of IA rats. Consequently, TNF-α-induced rBMVECs and rBMVECs with WTAP overexpression were successfully established. TNF-α inhibited the viability of the rBMVECs, promoted apoptosis, and significantly upregulated cleaved-caspase3 and downregulated WTAP expression. In contrast, WTAP overexpression significantly reversed these changes caused by TNF-α (P < 0.05). In conclusion, WTAP overexpression may modulate the growth of TNF-α-induced rBMVECs by enhancing WTAP expression and its m6A methylation.

Analysis on the genome of a teschovirus type 1 isolates with swine diarrhea.

Porcine Teschoviruses (PTVs) are associated with polioencephalomyelitis and various diseases, including reproductive and gastrointestinal disorders of pigs and wild boars, but rarely detected in the feces of pigs. In this study, a sample of swine diarrhea that tested positive for PTVs is subjected to high-throughput sequencing. The viral genome was 7221 nucleotides (nt) in length, which was consisted of twelve genes. Phylogenetic analysis showed and it was closely related to the PTV-HNMY(MG755212.1). The nucleotide homology of VP1 gene of PTVs JS2021 with PTV-1AF 296102.1 reached 82.97%, belonging to a branch of PTV-1 serotype. The nucleotide homology of VP1 protein with other serotypes of PTV is quite different from that of other serotypes of PTV. Bioinformatics analysis showed that PTVs have four capsid proteins, namely VP1, VP2, VP3 and VP4. The VP1 encodes a 29 kDa protein, which is the main protective antigen, a theoretical isoelectric point of 6.73, no transmembrane domain, no signal peptide and potential phosphorylation site. The VP1 protein is an unstable hydrophilic intracellular protein, which contains four secondary structures: irregular curl (c), extended chain (e), α-helix (h) and ß-folded (t). The tertiary structure is heart-shaped and has multiple B cell epitopes. By analyzing the tertiary structure, we found that the amino acid at position 129 of VP1 mutated and reduction a larger alpha helix. This may lead to the main cause of piglet diarrhea. These findings enriched our knowledge of the viruses in the role of swine diarrhea, and help to develop an effective strategy for disease prevention and control.

Analysis of spatial distribution characteristics and main influencing factors of heavy metals in road dust of Tianjin based on land use regression models.

Land use regression (LUR) models are mainly used for the simulation and prediction of conventional atmospheric pollutants. Whether the LUR models can be expanded to study more toxic and hazardous pollutants (such as heavy metals) remains to be verified. Combined with the factors of road, land use type, population, pollution enterprise, meteorology, and terrain, the LUR models were used to simulate the spatial distribution characteristics of heavy metals in road dust and determine the main influencing factors. Samples of road surface dust were collected from 144 evenly distributed points in Tianjin, China, with 108 modelling points and 36 verification points. The R2 values of the LUR models of Cd, Cr, Cu, Ni, and Pb contents were 0.301, 0.412, 0.399, 0.496, and 0.377, and their error rates were 2.72%, 4.96%, 4.64%, 8.91%, and 4.94%, respectively. The error rates of the kriging interpolation models were 3.33%, 6.50%, 5.14%, 18.30%, and 22.87%, which were all greater than those of the LUR models. The estimation effect of the LUR models was more refined than that of the kriging interpolation models. The contents of most heavy metals (except Ni) in road dust of the central area in Tianjin were generally higher than those of the surrounding areas. The heavy metal contents in road dust of Tianjin were mainly affected by road variables and meteorological variables. The LUR models were suitable for small-scale spatial prediction of heavy metals in urban road dust within urban areas.

Prognostic Significance of Translocator Protein in Brain Tissue Following Traumatic Brain Injury.

AIM: To measure the expression of translocator protein (TSPO) in brain tissue following traumatic brain injury (TBI), and to determine whether TSPO can predict patient outcomes. MATERIAL AND METHODS: TBI patients requiring removal of intracranial hematoma were recruited from Wujin Hospital Affiliated with Jiangsu University between January 2018 and March 2021. TBI patients were divided into unfavorable and favorable groups according to the Glasgow Outcome Scale (GOS) score. The level of TSPO in brain samples was analyzed by Western blot and immunocytochemistry. RESULTS: The expression of TSPO in the unfavorable group was higher than that in the favorable group. Double immunofluorescence staining showed that the percentages of TSPO positive cells among IBA1 positive and GFAP positive cells were 45.2± 3.1% and 3.5±0.6% respectively. After adjusting for age, sex, Computed tomography (CT), intracranial pressure (ICP) and Glasgow coma scale (GCS), we found that each 1-unit increase in TSPO was associated with a 40% higher occurrence of an unfavorable outcome (OR =1.4, 95% CI 0.4-5.6). The area under the receiver operating characteristic curve (AUC), specificity, and sensitivity of TSPO were 0.87, 76.7%, 88.2% respectively. CONCLUSION: Our study demonstrated that higher TSPO expression was associated with a higher occurrence of unfavorable outcomes.

miR-34a regulates phenotypic modulation of vascular smooth muscle cells in intracranial aneurysm by targeting CXCR3 and MMP-2.

MicroRNAs (miRNAs) dysregulation is tightly related to diseases including tumor, neuro disease and cardiovascular disease. In this study, we investigated the potential biological effects of miR-34a and its target CXCR3 in phenotypic modulation of vascular smooth muscle cells (VSMCs) of intracranial aneurysms (IAs). MiR-34a was found to be down-regulated in IAs patients tested by Real-time PCR and decreased in GEO data. Meanwhile, our study also showed miR-34a inhibited matrix metalloproteinases (MMPs) and migration of VSMCs. Besides, CXCR3 is a direct target of miR-34a identified via luciferase assay. CXCR3 showed inhibitory effect on SM-MHC, SM22 while promoted MMPs expression, cell proliferation and migration in VSMCs. MiR-34a reversed the effect of CXCR3 in VSMCs. In addition, MMP-2 is a competitive endogenous RNA (ceRNA) of CXCR3 sharing common miR-34a target. CXCR3 increased MMP-2 level through competitive endogenous RNA regulation by sponging endogenous miR-34a. In conclusion, miR-34a is down-regulated in IAs while CXCR3 is the direct target of miR-34a that regulates phenotypic modulation of VSMCs. CXCR3 increased MMP-2 level through competitive endogenous RNA regulation by sharing common miR-34a targets.

Design and Simulation of a Multi-Sheet Beam Terahertz Radiation Source Based on Carbon-Nanotube Cold Cathode.

Carbon nanotube (CNT) cold cathodes are proving to be compelling candidates for miniaturized terahertz (THz) vacuum electronic devices (VEDs) owning to their superior field-emission (FE) characteristics. Here, we report on the development of a multi-sheet beam CNT cold cathode electron optical system with concurrently high beam current and high current density. The microscopic FE characteristics of the CNT film emitter is captured through the development of an empirically derived macroscopic simulation model which is used to provide representative emission performance. Through parametrically optimized macroscale simulations, a five-sheet-beam triode electron gun has been designed, and has been shown to emit up to 95 mA at 3.2 kV. Through careful engineering of the electron gun geometric parameters, a low-voltage compact THz radiation source operating in high-order TM 5 , 1 mode is investigated to improve output power and suppress mode competition. Particle in cell (PIC) simulations show the average output power is 33 W at 0.1 THz, and the beam-wave interaction efficiency is approximately 10%.

Metformin inhibits glioma cells stemness and epithelial-mesenchymal transition via regulating YAP activity.

This work aims to study the roles and mechanisms of metformin in glioma cells stemness and epithelial-mesenchymal transition. Here, we found that metformin suppressed glioma cells spheroid formation and size, inhibited the expression of glioma stemness-related marker, CD133. Additionally, Metformin attenuated TGF-ß-induced epithelial-mesenchymal transition in glioma cells. Mechanistically, metformin inhibited the nuclear abundance of YAP, a key effector of Hippo pathway, subsequently leading to its cytoplasmic retention, and thus reduced YAP transcriptional modulating activity. Importantly, overexpression of a mutant form of YAP (YAP-5SA) attenuated the inhibition of metformin on glioma cells stemness and epithelial-mesenchymal transition. Thus, metformin inhibits glioma cells stemness and epithelial-mesenchymal transition via regulating YAP activity.

Transition radiation from graphene plasmons by a bunch beam in the terahertz regime.

The terahertz band is an increasingly important spectrum in a wide range of applications from bioimaging and medical diagnostics to security and wireless communications. We propose a tunable terahertz coherent radiation source based on graphene plasmon-induced transition radiation. The transition radiation in terahertz regime arises from the graphene plasmons, which are excited by a normally incident bunched electron beam. We analyze the field-intensities and spectral-angular distributions of the transition radiation with respect to Fermi energy, substrate dielectric permittivity, and electron bunch energy for both the coherent and incoherent radiation. The effect of electron bunching on the radiation pattern is discussed. The mechanism of plasmon frequency-selective transition radiation is discovered.

Parametrically Optimized Carbon Nanotube-Coated Cold Cathode Spindt Arrays.

Here, we investigate, through parametrically optimized macroscale simulations, the field electron emission from arrays of carbon nanotube (CNT)-coated Spindts towards the development of an emerging class of novel vacuum electron devices. The present study builds on empirical data gleaned from our recent experimental findings on the room temperature electron emission from large area CNT electron sources. We determine the field emission current of the present microstructures directly using particle in cell (PIC) software and present a new CNT cold cathode array variant which has been geometrically optimized to provide maximal emission current density, with current densities of up to 11.5 A/cm² at low operational electric fields of 5.0 V/µm.

A Fully-Sealed Carbon-Nanotube Cold-Cathode Terahertz Gyrotron.

Gigahertz to terahertz radiation sources based on cold-cathode vacuum electron technology are pursued, because its unique characteristics of instant switch-on and power saving are important to military and space applications. Gigahertz gyrotron was reported using carbon nanotube (CNT) cold-cathode. It is reported here in first time that a fully-sealed CNT cold-cathode 0.22 THz-gyrotron is realized, typically with output power of 500 mW. To achieve this, we have studied mechanisms responsible for CNTs growth on curved shape metal surface, field emission from the sidewall of a CNT, and crystallized interface junction between CNT and substrate material. We have obtained uniform growth of CNTs on and direct growth from cone-cylinder stainless-steel electrode surface, and field emission from both tips and sidewalls of CNTs. It is essential for the success of a CNT terahertz gyrotron to have such high quality, high emitting performance CNTs. Also, we have developed a magnetic injection electron gun using CNT cold-cathode to exploit the advantages of such a conventional gun design, so that a large area emitting surface is utilized to deliver large current for electron beam. The results indicate that higher output power and higher radiation frequency terahertz gyrotron may be made using CNT cold-cathode electron gun.

Effect of recombinant human erythropoietin on serum S100B protein and interleukin-6 levels after traumatic brain injury in the rat.

Erythropoietin (EPO) has a neuroprotective effect in the animal model of ischemia/hypoxia, but the mechanisms underlying the EPO effect in traumatic brain injury (TBI) are not well understood. This study examined the potential neuroprotective mechanisms of recombinant human EPO (rhEPO) in rats after TBI. Sixty healthy adult male Sprague-Dawley rats were randomly divided into 5 groups: 1000 U/kg rhEPO-treated, 3000 U/kg rhEPO-treated, 5000 U/kg rhEPO-treated, citicoline, and normal saline (control) groups. The TBI model was based on the modified Feeney's free falling model. Serum samples were collected at 6 hours, 24 hours, 3 days, 5 days, and 7 days after trauma. The serum S100B protein and interleukin-6 (IL-6) levels were measured after treatment in each group with double antibody sandwich enzyme-linked immunosorbent assay. Both serum S100B protein and IL-6 levels were significantly lower in 3000 U/kg rhEPO-treated and 5000 U/kg rhEPO-treated groups (p < 0.001). The decrease in serum S100B protein level was correlated with the dosage of rhEPO. Medium doses of rhEPO achieved the optimum decreases in the serum IL-6 level. Therefore, inhibition of the composition and secretion of S100B protein and IL-6 levels by EPO might be one of the mechanisms involved in decreasing inflammatory reaction in the brain, and may be responsible for the neuroprotective effect after TBI.

S100B protein and its clinical effect on craniocerebral injury.

OBJECTIVE: To explore the role of S100B protein in the early diagnosis, treatment, and prognosis judgement of craniocerebral injury. METHODS: In this study, we reviewed the domestic and foreign research reports about the relationship between S100B protein and craniocerebral injury. RESULTS: The concentration of S100B protein had a different increase based on the degree of injury in early stage after craniocerebral injury, and the increasing degree of S100B protein showed a positive correlation with the grading of pathogenetic condition and prognosis of craniocerebral injury. CONCLUSIONS: S100B protein may be taken as a specific index of early diagnosis, grading of pathogenetic condition, and prognosis judgement after craniocerebral injury. To grasp and regulate the mechanism of neurotoxicity and to elucidate the therapeutic effect of S100B protein will be a research direction in clinical treatment of craniocerebral injury.