Search

Aim: To explore the effects of HSP90 on rotavirus (RV) replication. Materials & methods: The interaction between NSP2 and HSP90 was analyzed by immunoprecipitation assay, and co-localization confirmed by an immunofluorescence assay. The viral titer was measured by immunofluorescence assay and viral protein expression investigated by western blotting. Results: The interaction between NSP2 and HSP90 was confirmed. Knockdown of HSP90 using siRNA resulted in a decrease in NSP2 expression and virus titer. HSP90 inhibitor 17-AAG significantly decreased NSP2 and NSP5 expression, as well as the virus titer, while proteasome inhibitor MG132 restored the protein amount and the viral titer. Conclusion: HSP90 is involved in rotavirus replication, and inhibition of HSP90 promotes the degradation of NSP2 through the proteasome pathway. Rotavirus is a type of virus that causes severe diarrhea, especially in children. The virus infects the cell in our bodies. These cells have proteins which carry out important functions and can help the growth of the virus. One of these proteins, called HSP90, interacts with a protein of the virus, called NSP2. After infection, these proteins move to the same place within the cell. Decreasing the level of HSP90 also decreases the level of NSP2, slowing the growth of the virus. Understanding how HSP90 and NSP2 work will help to develop new drugs to treat rotavirus infection. Article highlights Background Heat shock protein 90 (HSP90) appears to play an essential role in viral replication, but little is known regarding the role of HSP90 in rotavirus (RV) infection. Methods RV laboratory strain SA11 was used in this study. Virus titers were measured by Fluorescent formation units assay and viral protein expression checked by WB. The interaction of HSP90 and NSP2 was confirmed by immunoprecipitation (IP) and confocal laser microscope. siRNA used to knockdown the expression of HSP90 and HSP90 activity was inhibited. Results The HSP90 inhibition resulted in decreased RV replication. Knockdown of HSP90 by siRNA decreased RV protein levels and virus replication. HSP90 interacted with virus protein NSP2. Inhibition of the proteasome pathway decreased viral protein degradation. Conclusion HSP90 was used by RV to facilitate virus replication by chaperoning viral proteins and preventing their degradation via the proteasome. [ABSTRACT FROM AUTHOR]

Aim: The preparation of a VSVΔG*-S pseudovirus carrying the spike (S) protein of SARS-CoV-2 and its preliminary application. Materials & methods: 293T cells were transfected with pCAGGS-SARS-2-S and infected with VSVΔG viruses. The VSVΔG*-S pseudovirus was collected by centrifugation. The pseudovirus was used to investigate the neutralization ability of serum from SARS-CoV-2 patients and the ability of peptides to inhibit the virus. Results: A VSVΔG*-S pseudovirus was successfully prepared. Patient serum and peptides could neutralize the pseudovirus infection as determined by measuring the expression of GFP. Conclusion: This pseudovirus system can be used to screen polypeptides and fusion inhibitors and measure neutralizing activity, which will benefit the study of SARS-CoV-2. The virus SARS-CoV-2 is the cause of COVID-19 disease. This virus is harmful and easily spreads between people, so when being worked with in a laboratory, it must be under high-security conditions. Laboratories with this level of safety are not common, so this reduces the ability to study SARS-CoV-2. In this study, we engineered a modified version of the virus, called a pseudovirus, that can be worked with in a lower security laboratory. [ABSTRACT FROM AUTHOR]

Background: Toxoplasma gondii ( T. gondii ) is a widespread, zoonotic protozoan intracellular parasite with a complex life cycle, which can cause toxoplasmosis, a potentially serious disease. During the invasion process, T. gondii proteins first bind to the relevant host cell receptors, such as glycosaminoglycan molecule (GAG-binding motif), which is one of the main receptors for parasites or virus to infect host cells. However, research on TGME49_216510 ( T. gondii Trx21), a protein from Toxoplasma gondii , is limited., Methods: Bioinformatics analysis of the Trx21 protein was performed firstly. And specific primers were then designed using the conserved domain and GAG-binding motif to amplify, express, and purify a fragment of the Trx21 protein. The purified Trx21-GST protein was used for antioxidant and cell adhesion experiments. Simultaneously, mice were immunized with Trx21-His to generate specific polyclonal antibodies for subcellular localization analysis., Results: The Trx21 protein, consisting of 774 amino acids, included a transmembrane region, three GAG-binding motifs, and a Thioredoxin-like domain. The recombinant Trx21-His protein had a molecular mass of about 31 kDa, while the Trx21-GST protein had a molecular mass of about 55 kDa, which was analyzed by SDS-PAGE and Western blot. Subcellular localization analysis by IFA revealed that Trx21 is predominantly distributed in the cytoplasm of T. gondii . Furthermore, Trx21 exhibited a protective effect on supercoiled DNA against metal-catalyzed oxidation (MCO) and demonstrated adhesion abilities to Vero cells., Conclusions: These results indicate that Trx21 plays an important role in host cell interaction and oxidative damage., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Shi, Cheng, Luo, Cheng, Gan, Liu, Chen and Yang.)

Background: Peridural fibrosis (PF) is a normal complication after lumbar surgery. It is a challenge for both surgeons and patients. Rapamycin (RPM), a novel antibiotic with anti-proliferative and immunosuppressive properties, has been shown to be effective in preventing uncontrolled scar proliferation diseases. The object of the present research was to investigate the effects of RPM on inhibiting PF in vitro and in vivo., Material and Methods: In vitro, the fibroblasts collected and isolated from the rat tail skin were cultured with/without RPM and cell counting was performed. In vivo, the double-blinded study was conducted in 60 healthy Wistar rats divided randomly into 3 groups: 1) RPM treatment group; 2) Vehicle treatment group; 3) Control group. Rats underwent a L1-L2 level laminectomy with a satisfactory anesthetization. Four weeks post-operatively, the Rydell score, histological analysis, hydroxyproline content, vimentin expressional level, and inflammatory cytokines expressional levels were assessed., Results: In vitro, RPM showed ability to prevent fibroblast proliferation. In vivo, the laminectomy was well tolerated by all rats, which were killed 4 weeks post-operatively. The Rydell score, histological evaluation, hydroxyproline content, vimentin expression level, and inflammatory activity showed the positive effect of RPM in preventing peridural adhesion, inhibiting fibrotic formation and collagen synthesis, and down-regulating inflammation., Conclusions: In the present primary study, RPM showed good efficacy in preventing the proliferation of fibroblasts. RPM can prevent rat peridural adhesion through inhibiting collagen synthesis, fibroblasts proliferation, and inflammatory activity.