BHK-21 Research Articles

The Polypyrimidine Tract-Binding Protein Is a Transacting Factor for the Dengue Virus Internal Ribosome Entry Site

Dengue virus (DENV) is an enveloped, positive sense, single-stranded RNA virus belonging to the Flaviviridae. Translation initiation of the DENV mRNA (vRNA) can occur following a cap-dependent, 5′-3’end-dependent internal ribosome entry site (IRES)-independent or IRES-dependent mechanism. This study evaluated the activity of DENV IRES in BHK-21 cells and the role of the polypyrimidine-tract binding protein (PTB) isoforms PTB1, PTB2, and PTB4 as IRES-transacting factors (ITAFs) for the DENV IRES. The results show that DENV-IRES activity is stimulated in DENV-replicating BHK-21 cells and cells expressing the Foot-and-mouth disease virus leader or Human rhinovirus 2A proteases. Protease activity was necessary, although a complete shutdown of cap-dependent translation initiation was not a requirement to stimulate DENV IRES activity. Regarding PTB, the results show that PTB1 > PTB2 > PTB4 stimulates DENV-IRES activity in BHK-21 cells. Mutations in the PTB RNA recognition motifs (RRMs), RRM1/RRM2 or RRM3/RRM4, differentially impact PTB1, PTB2, and PTB4’s ability to promote DENV IRES-mediated translation initiation in BHK-21 cells. PTB1-induced DENV-IRES stimulation is rescinded when RRM1/RRM2 or RRM3/RRM4 are disrupted. Mutations in RRM1/RRM2 or RRM3/RRM4 do not affect the ITAF activity of PTB2. Mutating RRM3/RRM4, but not RRM1/RRM2, abolishes the ability of PTB4 to stimulate the DENV IRES. Thus, PTB1, PTB2, and PTB4 are ITAFs for the DENV IRES.

Tin(IV) Complexes With 2‐Formylpyridine Thiosemicarbazones: Structural and Cytotoxic Activity Studies on Bacterial, Fungal, and Cancer Cells

ABSTRACTTin complexes, Sn(IV)‐TSC 1·MeOH and Sn(IV)‐TSC 2, with thiosemicarbazones possessing an N2S ligation system [TSC 1 = 4‐(4‐nitrophenyl)‐1‐((pyridin‐2‐yl)methylene)thiosemicarbazide and TSC 2 = 4‐(2‐methoxyphenyl)‐1‐((pyridin‐2‐yl)methylene)thiosemicarbazide] were prepared and structurally characterized. These complexes are found in the space groups P and P21/n, respectively, with their tin atoms in octahedral environments established by three chlorine atoms and an anionic thiosemicarbazone ligand. All compounds (20 mg/mL in DMSO) were tested for their antibacterial [against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa] and antifungal [against Aspergillus flavus and Candida albicans] properties. The ligand TSC 2 displayed inhibitions in the S. aureus and E. coli cultures (with zones of 11 and 10 mm, respectively), whereas Sn(IV)‐TSC 1·MeOH and Sn(IV)‐TSC 2 inhibited all bacteria with 11–15 and 14–16 mm, respectively. In the fungal cultures, only Sn(IV)‐TSC 1·MeOH (10 mm) showed an inhibition zone against A. flavus. The ligands' antiproliferative activities were determined against human cancer cells of the lung, breast, liver, and colon, and both ligands afforded the highest activity against the breast MCF‐7 cells. The complexation enhanced the ligands' activities as TSC 1, TSC 2, Sn(IV)‐TSC 1·MeOH, and Sn(IV)‐TSC 2 afforded respective IC50 values of 52.4, 153.7, 18.3, and 63.9 μM. However, against normal baby hamster kidney (BHK) cells, these compounds showed IC50 data of 54.8, 82.7, 16.1, and 15.3 μM, respectively.

Turn-On Fluorescence Probe for Cancer-Related γ-Glutamyltranspeptidase Detection.

The design and development of fluorescent materials for detecting cancer-related enzymes are crucial for cancer diagnosis and treatment. Herein, we present a substituted rhodamine derivative for the chromogenic and fluorogenic detection of the cancer-relevant enzyme γ-glutamyltranspeptidase (GGT). Initially, the probe is non-chromic and non-emissive due to its spirolactam form, which hinders extensive electronic delocalization over broader pathway. However, selective enzymatic cleavage of the side-coupled group triggers spirolactam ring opening, resulting in electronic flow across the rhodamine skeleton, and reduces the band gap for low-energy electronic transitions. This transformation turns the reaction mixture from colorless to intense pink, with prominent UV and fluorescence bands. The sensor's selectivity was tested against various human enzymes, including urease, alkaline phosphatase, acetylcholinesterase, tyrosinase, and cyclooxygenase, and showed no response. Absorption and fluorescence titration analyses of the probe upon incremental addition of GGT into the probe solution revealed a consistent increase in both absorption and emission spectra, along with intensified pink coloration. The cellular toxicity of the receptor was evaluated using the MTT assay, and bioimaging analysis was performed on BHK-21 cells, which produced bright red fluorescence, demonstrating the probe's excellent cell penetration and digestion capabilities for intracellular analytical detection. Molecular docking results supported the fact that probe-4 made stable interactions with the GGT active site residues.

Stable Polymer-Lipid Hybrid Nanoparticles Based on mcl-Polyhydroxyalkanoate and Cationic Liposomes for mRNA Delivery.

Background/Objectives: The development of polymer-lipid hybrid nanoparticles (PLNs) is a promising area of research, as it can help increase the stability of cationic lipid carriers. Hybrid PLNs are core-shell nanoparticle structures that combine the advantages of both polymer nanoparticles and liposomes, especially in terms of their physical stability and biocompatibility. Natural polymers such as polyhydroxyalkanoate (PHA) can be used as a matrix for the PLNs' preparation. Methods: In this study, we first obtained stable cationic hybrid PLNs using a cationic liposome (CL) composed of a polycationic lipid 2X3 (1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride), helper lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine), and the hydrophobic polymer mcl-PHA, which was produced by the soil bacterium Pseudomonas helmantisensis P1. Results: The new polymer-lipid carriers effectively encapsulated and delivered model mRNA-eGFP (enhanced green fluorescent protein mRNA) to BHK-21 cells. We then evaluated the role of mcl-PHA in increasing the stability of cationic PLNs in ionic solutions using dynamic light scattering data, electrophoretic mobility, and transmission electron microscopy techniques. Conclusions: The results showed that increasing the concentration of PBS (phosphate buffered saline) led to a decrease in the stability of the CLs. At high concentrations of PBS, the CLs aggregate. In contrast, the presence of isotonic PBS did not result in the aggregation of PLNs, and the particles remained stable for 120 h when stored at +4 °C. The obtained results show that PLNs hold promise for further in vivo studies on nucleic acid delivery.

Heightened mitochondrial respiration in CF cells is normalised by triple CFTR modulator therapy through mechanisms involving calcium

BackgroundCystic fibrosis (CF) is associated with increased resting energy expenditure. However, the introduction of elexacaftor/tezacaftor/ivacaftor (ETI) has resulted in a paradigm shift in nutritional status for many people with CF, with increase body mass index and reduction in the need for nutritional support. While these changes are likely to reflect improved clinical status and an associated downregulation of energy expenditure, they may also reflect drug-induced alterations in metabolic perturbations within CF cells. We hypothesise that some of these changes relate to normalisation of mitochondrial respiration in CF. MethodsUsing wild-type (WT) and F508del/F508del CFTR human bronchial epithelial cell lines (HBE cell lines) and baby hamster kidney (BHK) cells we examined the impact of ETI on cellular metabolism. We monitored mitochondrial respiration, using Seahorse extracellular flux assays and monitored mitochondrial reactive oxygen species (mROS) and intracellular calcium levels by flow cytometry. ResultsIncreased mitochondrial respiration was found in HBE cell lines and BHK cells expressing CFTR F508del/F508del when assessing basal, maximal, spare respiratory capacities and ATP production, as well as increased mitochondrial ROS generated via forward electron transport. ETI significantly decreased basal, maximal, spare respiratory capacity and ATP production to WT levels or below. Calcium blocker, BAPTA-AM normalised mitochondrial respiration, suggesting a calcium-mediated mechanism. ETI decreased intracellular calcium levels in CF cells to the same extent as BAPTA-AM, highlighting the importance of calcium and chloride in mitochondrial respiration in CF. ConclusionsCF cell lines exhibit increased mitochondrial respiration, which can be downregulated by ETI therapy through mechanisms involving calcium.

Dual effects of ipecac alkaloids with potent antiviral activity against foot-and-mouth disease virus as replicase inhibitors and direct virucides

ABSTRACT Foot-and-Mouth Disease (FMD) is a contagious, blistering disease caused by the Foot-and-Mouth Disease virus (FMDV), which affects livestock globally. Currently, no commercial antiviral agent is available for effective disease control. This study investigated the antiviral potential of natural-derived alkaloids against FMDV in BHK-21 cells. Twelve alkaloids were assessed for their antiviral activities at various stages of FMDV infection, including pre-viral entry, post-viral entry, and prophylactic assays, as well as attachment and penetration assays by evaluating cytopathic effect reduction and directed-virucidal effects. The results showed that ipecac alkaloids, cephaeline (CPL) and emetine (EMT), exhibited dual effects with robust antiviral efficacy by reducing cytopathic effect and inhibiting FMDV replication in a dose-dependent manner. Evaluation through immunoperoxidase monolayer assay and RT-PCR indicated effectiveness at post-viral entry stage, with sub-micromolar EC50 values for CPL and EMT at 0.05 and 0.24 µM, respectively, and high selective indices. Prophylactic effects prevented infection with EC50 values of 0.23 and 0.64 µM, respectively. Directed-virucidal effects demonstrated significant reduction of extracellular FMDV, with CPL exhibiting a dose-dependent effect. Furthermore, the replicase (3Dpol) inhibition activity was identified using the FMDV minigenome assay, which revealed strong inhibition with IC50 values of 0.15 µM for CPL and 4.20 µM for EMT, consistent with the decreased negative-stranded RNA production. Molecular docking confirmed the interaction of CPL and EMT with residues in the active site of FMDV 3Dpol. In conclusion, CPL and EMT exhibited promising efficacy through their dual effects and provide an alternative approach for controlling FMD in livestock.

Enhanced Anticancer and Biological Activities of Environmentally Friendly Ni/Cu-ZnO Solid Solution Nanoparticles

The study investigates the impact of incorporating Ni and Cu into the lattice of ZnO nanoparticles (NPs) to enhance their anticancer and antioxidant properties. Characterization techniques including pXRD, FTIR, UV-visible absorption spectroscopy, FESEM, and EDAX confirm the successful synthesis and structural modifications of Ni/Cu-ZnO NPs. Anticancer activity against breast cancer (MDA) and normal skin (BHK-21) cells reveals dose-dependent cytotoxicity, with Ni/Cu-ZnO NPs exhibiting higher efficacy against MDA cells while being less harmful to BHK-21 cells. Morphological studies corroborate these findings. Additionally, antioxidant assays using TAC, FRAP, and DPPH assay demonstrate the superior antioxidant activity of Ni/Cu-ZnO NPs matched to pure ZnO. Overall, the synergistic effect of Ni and Cu incorporation leads to improved therapeutic potential, making Ni/Cu-ZnO NPs promising candidates for cancer therapy and antioxidant applications.Molecular docking recreations were performed using Auto Dock Vina software to gain more insights and validate the observed biological activities of un-doped ZnO and bi-metal doped ZnO NPs, we investigated the interaction and binding affinities of pure ZnO and bimetallic metal co-doped ZnO for their antioxidant and anticancer studies. Ni/Cu-ZnO have shown good antioxidants and exhibited remarkable anticancer activities.

Exploring the antiviral activities of the FDA-approved drug sulfadoxine and its derivatives against Chikungunya virus.

Currently, there is no antiviral licensed to treat chikungunya fever, a disease caused by the infection with Alphavirus chikungunya (CHIKV). Treatment is based on analgesic and anti-inflammatory drugs to relieve symptoms. Our study aimed to evaluate the antiviral activity of sulfadoxine (SFX), an FDA-approved drug, and its derivatives complexed with silver(I) (AgSFX), salicylaldehyde Schiff base (SFX-SL), and with both Ag and SL (AgSFX-SL) against CHIKV. The anti-CHIKV activity of SFX and its derivatives was investigated using BHK-21 cells infected with CHIKV-nanoluc, a marker virus-carrying nanoluciferase reporter. Dose-response and time of drug-addition assays were performed in order to assess the antiviral effects of the compounds, as well as in silico data and ATR-FTIR analysis for insights on their mechanisms of action. The SFX inhibited 34% of CHIKV replication, while AgSFX, SFX-SL, and AgSFX-SL enhanced anti-CHIKV activity to 84%, 89%, and 95%, respectively. AgSFX, SFX-SL, and AgSFX-SL significantly decreased viral entry and post-entry to host cells, and the latter also protected cells against infection. Additionally, molecular docking calculations and ATR-FTIR analysis demonstrated interactions of SFX-SL, AgSFX, and AgSFX-SL with CHIKV. Collectively, our findings suggest that the addition of metal ions and/or Schiff base to SFX improved its antiviral activity against CHIKV.

Alkali surface modification of titanium for biomedical implants

AbstractNanostructures were successfully created on titanium (Ti) substrates through alkali treatment. By varying the concentration, temperature, and duration of the alkali treatment, different nanostructure surfaces were achieved on Ti. FE‐SEM analysis revealed a transition from a smooth to a nanoporous surface structure. The alkali treatment notably decreased the contact angle of Ti from 64° to 48°. Raman spectroscopy of Ti treated with 5 M NaOH at 80 °C for 24 h showed distinct titanate peaks at 188, 190, and 270 cm−1, confirming the formation of titanate compounds on the Ti surface. EIS measurements further demonstrated that the treated Ti exhibited reduced chemical activity, increased surface roughness, and porosity of approximately 40–50% compared to untreated Ti. In vitro biocompatibility tests using baby hamster kidney cells indicated positive cell attachment and proliferation after 72 h of culturing on the alkali‐treated Ti. These modifications enhance the surface properties and expand the potential applications of titanium in biomedical, industrial, and environmental technologies.

Characterization of a mammalian orthoreovirus isolated from the large flying fox, Pteropus vampyrus, in Indonesia.

Fruit bats serve as an important reservoir for many zoonotic pathogens, including Nipah virus, Hendra virus, Marburg virus and Lyssavirus. To gain a deeper insight into the virological characteristics, pathogenicity and zoonotic potential of bat-borne viruses, recovery of infectious viruses from field samples is important. Here, we report the isolation and characterization of a mammalian orthoreovirus (MRV) from a large flying fox (Pteropus vampyrus) in Indonesia, which is the first detection of MRV in Southeast Asia. MRV was recovered from faecal samples of three different P. vampyrus in Central Java. Nucleotide sequence analysis revealed that the genome of the three MRV isolates shared more than 99% nucleotide sequence identity. We tentatively named one isolated strain as MRV12-52 for further analysis and characterization. Among 10 genome segments, MRV12-52 S1 and S4, which encode the cell-attachment protein and outer capsid protein, had 93.6 and 95.1% nucleotide sequence identities with known MRV strains, respectively. Meanwhile, the remaining genome segments of MRV12-52 were divergent with 72.9-80.7 % nucleotide sequence identities. Based on the nucleotide sequence of the S1 segment, MRV12-52 was grouped into serotype 2, and phylogenetic analysis demonstrated evidence of past reassortment events. In vitro characterization of MRV12-52 showed that the virus efficiently replicated in BHK-21, HEK293T and A549 cells. In addition, experimental infection of laboratory mice with MRV12-52 caused severe pneumonia with 75% mortality. This study highlights the presence of pathogenic MRV in Indonesia, which could serve as a potential animal and public health concern.

Increased Virulence of Culicoides Midge Cell-Derived Bluetongue Virus in IFNAR Mice.

Bluetongue (BT) is a Culicoides midge-borne hemorrhagic disease affecting cervids and ruminant livestock species, resulting in significant economic losses from animal production and trade restrictions. Experimental animal infections using the α/β interferon receptor knockout IFNAR mouse model and susceptible target species are critical for understanding viral pathogenesis, virulence, and evaluating vaccines. However, conducting experimental vector-borne transmission studies with the vector itself are logistically difficult and experimentally problematic. Therefore, experimental infections are induced by hypodermic injection with virus typically derived from baby hamster kidney (BHK) cells. Unfortunately, for many U.S. BTV serotypes, it is difficult to replicate the severity of the disease seen in natural, midge-transmitted infections by injecting BHK-derived virus into target host animals. Using the IFNAR BTV murine model, we compared the virulence of traditional BHK cell-derived BTV-17 with C. sonorensis midge (W8) cell-derived BTV-17 to determine whether using cells of the transmission vector would provide an in vitro virulence aspect of vector-transmitted virus. At both low and high doses, mice inoculated with W8-BTV-17 had an earlier onset of viremia, earlier onset and peak of clinical signs, and significantly higher mortality compared to mice inoculated with BHK-BTV-17. Our results suggest using a Culicoides W8 cell-derived inoculum may provide an in vitro vector-enhanced infection to more closely represent disease levels seen in natural midge-transmitted infections while avoiding the logistical and experimental complexity of working with live midges.

Genetic evolutionary analysis of a strain of Senecavirus A in Anhui and the establishment of its detection method

BackgroundSenecavirus A (SVA) is the only member of the genus Senecavirus in the family Picornaviridae, and is one of the pathogens of porcine blistering disease. SVA has been reported in the United States, Canada, China, Thailand, and Colombia. MethodsIn this study, positive SVA infection was detected by RT-PCR in sick materials collected from pig farms of different sizes in Anhui Province. ResultsIn this study, a virulent strain of SVA was successfully obtained by viral isolation on BHK21 cells and named SVA-CH-AHAU-1. Meanwhile, a simple, rapid and accurate nano-PCR method for the detection of SVA infection was established in this study, using the recombinant plasmid pClone-SVA-3D as a template. ConclusionsThe complete genome of SVA-CH-AHAU-1 is 7286 bp, including a 5′ non-coding region (UTR), an open reading frame (ORF) of 6546 nucleotides, encoding 2182 amino acids (aa), and a 3’ UTR with Poly(A) features, and phylogenetic analysis showed that this isolate had the highest nucleotide homology (97.9 %) with the US isolate US-15-41901SD. In this study, the virulent strain SVA-CH-AHAU-1 was found to recombine in the ORF region with isolates SVA-CH-SDGT-2017 and SVA/Canada/ON/FMA-2015-0024 T2/2015. The complete genome has been submitted to GeneBank with the accession number OM654411. In addition, our results suggest that the established nano-PCR assay can be used as an economical, reliable and sensitive method for the field diagnosis of SVA method, especially in resource-limited areas.

Genetic trans-complementation of L-protease fails to rescue the infectious foot-and-mouth disease virus from the Lbpro defective genome

Outbreaks of the foot-and-mouth disease (FMD) have major economic impact on the global livestock industry by affecting the animal health and product safety. L-protease, a non-structural protein of FMDV, is a papain-like cysteine proteinase involved in viral protein processing as well as cleavage of host proteins for promoting the virus growth. FMDV synthesizes two forms of leader proteinase, Lpro (Labpro and Lbpro), where the deletion of Labpro is lethal and Lbpro deletion is reported to be attenuated. Defective replicons have been used by trans-complementing the deleted gene to produce one time replicating virus; thus, the bio-safety procedure can be compromised in the production units. Attempts are made to rescue of ΔLbproFMDV Asia1 virus by co-expressing the Lbpro protein carried in pcDNA plasmid. Mutant FMDV cDNA, pAsia-ΔLbpro, was constructed by PCR mediated mutagenesis using inverse primers. Transfection of BHK-21 cells with in-vitro transcribed RNA from the constructs failed to produce an infective mutant FMDV. Genetic trans-complementation of the Lbpro, which was done by co-transfecting the pcDNALbpro plasmid DNA along with the pAsia-ΔLbpro RNA in BHK-21 cells also failed to produce viable virus. Expression experiments of reporter genes and indirect immune-fluorescence confirmed the production of the viral proteins in wild type FMDV pAsiaWT; however, it was absent in the pAsia-ΔLbpro indicating that the leaderless virus was unable to produce infectious progeny and infect the cells. Failure to produce virus either by Lbpro deleted mutant clone or by genetic complementation suggests little chance of reversion of the disabled virus with large deletions of FMDV genome.

Protein characterization of an Indonesian isolate of foot and mouth disease virus inactivated with formaldehyde and binary ethylenimine.

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-footed animals. It is a major threat to livestock production worldwide, causing significant economic losses. Inactivation of FMD virus (FMDV) is crucial for vaccine development and control of outbreaks. However, traditional inactivation methods can sometimes damage the viral protein, affecting vaccine efficacy. Therefore, finding new inactivating agents that effectively inactivate the virus while preserving the integrity of its proteins is an important research area. This study investigated the optimal materials (0.04% formaldehyde, 0.001 M binary ethylenimine [BEI], or a combination) for inactivating and preserving the specific molecular weight of Serotype O FMDV protein. This study used serotype O FMDV isolated from several areas of East Java. The virus was inoculated into baby hamster kidney-21 cells, and the titer was calculated using the TCID50 Assay. The virus was inactivated using 0.04% formaldehyde, 0.001 M BEI, or a combination of 0.04% formaldehyde and 0.001 M BEI. Inactive viral proteins were characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blotting. Serotype O FMDV can be inactivated using 0.04% formaldehyde while preserving specific FMDV proteins, specifically VP0 and VP3 with a molecular weight (MW) of 36 kDa and VP3 with a MW of 24 kDa. Serotype O FMDV can be inactivated by 0.001 M BEI while preserving specific FMDV proteins, specifically VP0 with a MW of 35 kDa, VP3 with a MW of 28 kDa, and VP1 with a MW of 23 kDa. FMDV serotype O can be inactivated using a combination of 0.04% formaldehyde and 0.001 M BEI while preserving specific FMDV proteins, specifically VP0 and VP3 with a MW of 36 kDa and VP3 with a MW of 24 kDa. This study found that 0.04% formaldehyde, alone or in combination with 0.001 M BEI, was effective for inactivating and preserving the specific molecular weight of Serotype O FMDV protein. The limitation of this study was the inactivations of the virus have not yet been tested for their potency on experimental animals. Further research is warranted to investigate the inactivation kinetics of these materials, including their potency on experimental animals. Additionally, a comparison of the inactivation rates between 0.04% formaldehyde alone and the combination with BEI would help to determine the optimal inactivation agent for future applications.

Preparation and properties of Hydroxyapatite-Ti composite thin films by co-sputtering method for biocompatibility applications

In this paper, we report on enhancing the biocompatibility properties of Hydroxyapatite-Titanium (HA-Ti) thin films fabricated using the co-sputtering method. By adjusting the HA/Ti ratio through varying the sputtering power of Ti, we obtained HA-Ti thin films with different crystal structures, morphologies, and hydrophilic properties. HA-Ti thin films sputtered at different titanium powers of 80, 100, 120, 140, and 160 W will obtain thin films with larger grain sizes and poorer crystallinity, respectively. However, their hydrophilic properties increase as the contact angle decreases from 78° to 20° degrees. In vitro BHK cell tests indicated that the HA-Ti thin film had excellent biocompatibility. Therefore, this material is suitable for biological applications and has significant potential in medical implant technology.

Isolation and identification of a novel porcine-related recombinant mammalian orthoreovirus type 3 strain from cattle in Guangxi Province, China.

The Mammalian orthoreovirus (MRV) infects various mammals, including humans, and is linked to gastrointestinal, respiratory, and neurological diseases. A recent outbreak in Liuzhou, Guangxi, China, led to the isolation of a new MRV strain, GXLZ2301, from fecal samples. This strain replicates in multiple cell lines and forms lattice-like structures. Infected cells exhibit single-cell death and syncytia formation. The virus's titers peaked at 107.2 TCID50/0.1 mL in PK-15 and BHK cells, with the lowest at 103.88 TCID50/0.1 mL in A549 cells. Electron microscopy showed no envelope with a diameter of about 70 nm. Genetic analysis revealed GXLZ2301 as a recombinant strain with gene segments from humans, cows, and pigs, similar to type 3 MRV strains from Italy (2015-2016). Pathogenicity tests indicated that while the bovine MRV strain did not cause clinical symptoms in mice, it caused significant damage to the gut, lungs, liver, kidneys, and brain. The emergence of this MRV strain may pose a threat to the health of animals and humans, and it is recommended that its epidemiology and recombination be closely monitored.

VP0 Myristoylation Is Essential for Senecavirus A Replication.

Many picornaviruses require the myristoylation of capsid proteins for viral replication. Myristoylation is a site-specific lipidation to the N-terminal G residue of viral proteins, which is catalyzed by the ubiquitous eukaryotic enzyme N-myristoyltransferase (NMT) by allocating the myristoyl group to the N-terminal G residue. IMP-1088 and DDD85646 are two inhibitors that can deprive NMT biological functions. Whether Senecavirus A (SVA) uses NMT to modify VP0 and regulate viral replication remains unclear. Here, we found that NMT inhibitors could inhibit SVA replication. NMT1 knock-out in BHK-21 cells significantly suppressed viral replication. In contrast, the overexpression of NMT1 in BHK-21 cells benefited viral replication. These results indicated that VP0 is a potential NMT1 substrate. Moreover, we found that the myristoylation of SVA VP0 was correlated to the subcellular distribution of this protein in the cytoplasm. Further, we evaluated which residues at the N-terminus of VP0 are essential for viral replication. The substitution of N-terminal G residue, the myristoylation site of VP0, produced a nonviable virus. The T residue at the fifth position of the substrates facilitates the binding of the substrates to NMT. And our results showed that the T residue at the fifth position of VP0 played a positive role in SVA replication. Taken together, we demonstrated that SVA VP0 myristoylation plays an essential role in SVA replication.

A recombinant Getah Virus expressing a GFP gene for rapid neutralization testing and antiviral drug screening assay

Getah virus (GETV) is a re-emerging mosquito-borne RNA virus that induces fever, hind limb edema, swollen submandibular lymph nodes, and urticaria in horses. In pigs, the virus often results in stillbirths among pregnant sows, and neurological symptoms leading to death in piglets. Currently, there are no specific treatments or drugs available for GETV infection. The use of reporter viruses to monitor viral replication and spread in real-time within infected cells and animals provides a powerful tool for targeting antiviral drugs throughout the viral life cycle. Their fluorescence-tracked characteristics greatly facilitate virus neutralization tests (VNTs). In this study, we engineered two recombinant viruses by inserting different reporter protein genes at the 3′ end of the structural protein gene, an unreported location that can accommodate exogenous genes. The rGEEiLOV and rGEEGFP viruses demonstrated genetic stability for at least five passages and replicated at a rate similar to that of the parental virus in BHK-21 cells. The rGEEGFP virus facilitated viral neutralization testing. Additionally, we used the reporter virus rGEEGFP to confirm ivermectin, a broad-spectrum antiparasitic agent, as a potential inhibitor of GETV in vitro. Ivermectin appears to inhibit the early replication stages of the virus and can block cell-to-cell viral transmission. In conclusion, rGEEGFP holds significant potential for antiviral screening to identify specific inhibitors against GETV and for use in viral neutralization tests.

Naturally Derived Terpenoids Targeting the 3Dpol of Foot-and-Mouth Disease Virus: An Integrated In Silico and In Vitro Investigation.

Foot-and-mouth disease virus (FMDV) belongs to the Picornaviridae family and is an important pathogen affecting cloven-hoof livestock. However, neither effective vaccines covering all serotypes nor specific antivirals against FMDV infections are currently available. In this study, we employed virtual screening to screen for secondary metabolite terpenoids targeting the RNA-dependent RNA polymerase (RdRp), or 3Dpol, of FMDV. Subsequently, we identified the potential antiviral activity of the 32 top-ranked terpenoids, revealing that continentalic acid, dehydroabietic acid (abietic diterpenoids), brusatol, bruceine D, and bruceine E (tetracyclic triterpenoids) significantly reduced cytopathic effects and viral infection in the terpenoid-treated, FMDV-infected BHK-21 cells in a dose-dependent manner, with nanomolar to low micromolar levels. The FMDV minigenome assay demonstrated that brusatol and bruceine D, in particular, effectively blocked FMDV 3Dpol activity, exhibiting IC50 values in the range of 0.37-0.39 µM and surpassing the efficacy of the antiviral drug control, ribavirin. Continentalic acid and bruceine E exhibited moderate inhibition of FMDV 3Dpol. The predicted protein-ligand interaction confirmed that these potential terpenoids interacted with the main catalytic and bystander residues of FMDV 3Dpol. Additionally, brusatol and bruceine D exhibited additive effects when combined with ribavirin. In conclusion, terpenoids from natural resources show promise for the development of anti-FMD agents.

Synthesis of Strontium Substituted Hydroxyapatite Coating on Titanium Via Hydrothermal Method

In this study, strontium substituted hydroxyapatite (SrHA) was successfully deposited onto etched titanium substrates in H2SO4 and HCl solution. The deposition was achieved by hydrothermal method by immersing the substrates in a solution containing Ca(NO3)2.4H2O, NH4H2PO4, and 5% Sr(NO3)2, followed by heating at 200°C for 12 hours. X-ray diffraction (XRD) analysis confirmed that all SrHA coatings exhibited a crystalline hydroxyapatite structure. Field-emission scanning electron microscopy (FE-SEM) revealed that the microstructure of the SrHA coatings exhibited. Bioactivity and in vitro biocompatibility testing of the SrHA-coated titanium substrates using SBF solution and baby hamster kidney (BHK) cells demonstrated positive results.