Objective:To identify and validate secreted effector proteins of Chlamydia psittaci ( C. psittaci) through bioinformatic prediction and experimental verification, and to characterize their subcellular localization in host cells. Methods:Potential effector proteins were predicted using bioinformatics tools. Candidate effectors were fused to β-lactamase through the constructed expression vectors, and these vectors were transformed into C. psittaci. The secretion of these candidate effectors was evaluated by β-lactamase translocation assays. Eukaryotic expression vectors of confirmed effectors were transfected into host cells to determine their intracellular localization patterns. Results:Bioinformatic analysis identified 29 candidate effector proteins. Experimental validation confirmed the secretion of five effectors, with four exhibiting cytoplasmic localization and one displaying nuclear localization in host cells.Conclusion:This study characterizes five novel C. psittaci secreted effector proteins, providing critical insights for investigating the molecular pathogenesis of psittacosis.

Dipeptidyl peptidase 4(DPP4)is one of the binding receptors for the spike(S)protein of porcine hemagglutinating encephalomyelitis virus(PHEV).To identify the key amino acid binding sites at the interface of DPP4 protein and PHEV spike protein and explore the impact of their mu-tations on viral infection,recombinant plasmids of porcine DPP4,murine DPP4 and human DPP4(pDPP4,mDPP4,hDPP4)and spike protein truncations(S311-608,S13-298)were constructed and co-transfected into HEK293T cells to detect the protein binding by co-immunoprecipitation(CoIP).Simultaneously,the expression of PHEV proteins and genes was detected in DPP4-over-expressing HeLa cells infected by PHEV using Western blot and RT-qPCR.homologues were overexpressed in HeLa cells which were not susceptible to and then inoculated with the virus,and.Subsequently,the important pDPP4 amino acid sites at the interaction interface were mutated one by one using a point mutation kit to construct mutant overexpression plasmids.The mutant and wild-type pDPP4 were co-transfected into HEK293T cells with the spike protein truncations re-spectively to assay the protein interaction ability by co-immunoprecipitation.After HeLa cells over-expressing the mutant and wild-type pDPP4 were infected by PHEV,the replication level of PHEV was detected by Western blot and RT-qPCR.Compared with hDPP4,the pDPP4 and mDPP4 had significantly stronger binding to PHEV spike protein,which significantly promote PHEV infection.Moreover,mutation of pDPP4 glycosylation sites significantly enhanced the inter-action with PHEV spike protein,and the mutation of glycosylation sites(N229,N321)dramatical-ly promoted PHEV infection.The above results indicated that DPP4 glycosylation modification plays an important shielding role in the process of PHEV invading target cells mediated by spike protein.

Dipeptidyl peptidase 4(DPP4)is one of the binding receptors for the spike(S)protein of porcine hemagglutinating encephalomyelitis virus(PHEV).To identify the key amino acid binding sites at the interface of DPP4 protein and PHEV spike protein and explore the impact of their mu-tations on viral infection,recombinant plasmids of porcine DPP4,murine DPP4 and human DPP4(pDPP4,mDPP4,hDPP4)and spike protein truncations(S311-608,S13-298)were constructed and co-transfected into HEK293T cells to detect the protein binding by co-immunoprecipitation(CoIP).Simultaneously,the expression of PHEV proteins and genes was detected in DPP4-over-expressing HeLa cells infected by PHEV using Western blot and RT-qPCR.homologues were overexpressed in HeLa cells which were not susceptible to and then inoculated with the virus,and.Subsequently,the important pDPP4 amino acid sites at the interaction interface were mutated one by one using a point mutation kit to construct mutant overexpression plasmids.The mutant and wild-type pDPP4 were co-transfected into HEK293T cells with the spike protein truncations re-spectively to assay the protein interaction ability by co-immunoprecipitation.After HeLa cells over-expressing the mutant and wild-type pDPP4 were infected by PHEV,the replication level of PHEV was detected by Western blot and RT-qPCR.Compared with hDPP4,the pDPP4 and mDPP4 had significantly stronger binding to PHEV spike protein,which significantly promote PHEV infection.Moreover,mutation of pDPP4 glycosylation sites significantly enhanced the inter-action with PHEV spike protein,and the mutation of glycosylation sites(N229,N321)dramatical-ly promoted PHEV infection.The above results indicated that DPP4 glycosylation modification plays an important shielding role in the process of PHEV invading target cells mediated by spike protein.

Objective:To identify and validate secreted effector proteins of Chlamydia psittaci ( C. psittaci) through bioinformatic prediction and experimental verification, and to characterize their subcellular localization in host cells. Methods:Potential effector proteins were predicted using bioinformatics tools. Candidate effectors were fused to β-lactamase through the constructed expression vectors, and these vectors were transformed into C. psittaci. The secretion of these candidate effectors was evaluated by β-lactamase translocation assays. Eukaryotic expression vectors of confirmed effectors were transfected into host cells to determine their intracellular localization patterns. Results:Bioinformatic analysis identified 29 candidate effector proteins. Experimental validation confirmed the secretion of five effectors, with four exhibiting cytoplasmic localization and one displaying nuclear localization in host cells.Conclusion:This study characterizes five novel C. psittaci secreted effector proteins, providing critical insights for investigating the molecular pathogenesis of psittacosis.

Positive-sense RNA viruses modify intracellular calcium stores, endoplasmic reticulum and Golgi apparatus (Golgi) to generate membranous replication organelles known as viral factories. Viral factories provide a conducive and substantial enclave for essential virus replication via concentrating necessary cellular factors and viral proteins in proximity. Here, we identified the vital role of a broad-spectrum antiviral, peruvoside in limiting the formation of viral factories. Mechanistically, we revealed the pleiotropic cellular effect of Src and PLC kinase signaling via cyclin-dependent kinase 1 signaling leads to Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1 (GBF1) phosphorylation and Golgi vesiculation by peruvoside treatment. The ramification of GBF1 phosphorylation fosters GBF1 deprivation consequentially activating downstream antiviral signaling by dampening viral factories formation. Further investigation showed signaling of ERK1/2 pathway via cyclin-dependent kinase 1 activation leading to GBF1 phosphorylation at Threonine 1337 (T1337). We also showed 100% of protection in peruvoside-treated mouse model with a significant reduction in viral titre and without measurable cytotoxicity in serum. These findings highlight the importance of dissecting the broad-spectrum antiviral therapeutics mechanism and pave the way for consideration of peruvoside, host-directed antivirals for positive-sense RNA virus-mediated disease, in the interim where no vaccine is available.

The development of drug-resistant influenza and new pathogenic virus strains underscores the need for antiviral therapeutics. Currently, neuraminidase (NA) inhibitors are commonly used antiviral drugs approved by the US Food and Drug Administration (FDA) for the prevention and treatment of influenza. Here, we show that vitisin B (VB) inhibits NA activity and suppresses H1N1 viral replication in MDCK and A549 cells. Reactive oxygen species (ROS), which frequently occur during viral infection, increase virus replication by activating the NF-κB signaling pathway, downmodulating glucose-6-phosphate dehydrogenase (G6PD) expression, and decreasing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant response activity. VB decreased virus-induced ROS generation by increasing G6PD expression and Nrf2 activity, and inhibiting NF-κB translocation to the nucleus through IKK dephosphorylation. In addition, VB reduced body weight loss, increased survival, decreased viral replication and the inflammatory response in the lungs of influenza A virus (IAV)-infected mice. Taken together, our results indicate that VB is a promising therapeutic candidate against IAV infection, complements existing drug limitations targeting viral NA. It modulated the intracellular ROS by G6PD, Nrf2 antioxidant response pathway, and NF-κB signaling pathway. These results demonstrate the feasibility of a multi-targeting drug strategy, providing new approaches for drug discovery against IAV infection.

Background: and Purpose Recent studies suggested an increased incidence of cerebral venous thrombosis (CVT) during the coronavirus disease 2019 (COVID-19) pandemic. We evaluated the volume of CVT hospitalization and in-hospital mortality during the 1st year of the COVID-19 pandemic compared to the preceding year. Methods: We conducted a cross-sectional retrospective study of 171 stroke centers from 49 countries. We recorded COVID-19 admission volumes, CVT hospitalization, and CVT in-hospital mortality from January 1, 2019, to May 31, 2021. CVT diagnoses were identified by International Classification of Disease-10 (ICD-10) codes or stroke databases. We additionally sought to compare the same metrics in the first 5 months of 2021 compared to the corresponding months in 2019 and 2020 (ClinicalTrials.gov Identifier: NCT04934020). Results: There were 2,313 CVT admissions across the 1-year pre-pandemic (2019) and pandemic year (2020); no differences in CVT volume or CVT mortality were observed. During the first 5 months of 2021, there was an increase in CVT volumes compared to 2019 (27.5%; 95% confidence interval [CI], 24.2 to 32.0; P<0.0001) and 2020 (41.4%; 95% CI, 37.0 to 46.0; P<0.0001). A COVID-19 diagnosis was present in 7.6% (132/1,738) of CVT hospitalizations. CVT was present in 0.04% (103/292,080) of COVID-19 hospitalizations. During the first pandemic year, CVT mortality was higher in patients who were COVID positive compared to COVID negative patients (8/53 [15.0%] vs. 41/910 [4.5%], P=0.004). There was an increase in CVT mortality during the first 5 months of pandemic years 2020 and 2021 compared to the first 5 months of the pre-pandemic year 2019 (2019 vs. 2020: 2.26% vs. 4.74%, P=0.05; 2019 vs. 2021: 2.26% vs. 4.99%, P=0.03). In the first 5 months of 2021, there were 26 cases of vaccine-induced immune thrombotic thrombocytopenia (VITT), resulting in six deaths. Conclusions During the 1st year of the COVID-19 pandemic, CVT hospitalization volume and CVT in-hospital mortality did not change compared to the prior year. COVID-19 diagnosis was associated with higher CVT in-hospital mortality. During the first 5 months of 2021, there was an increase in CVT hospitalization volume and increase in CVT-related mortality, partially attributable to VITT.

Mycena, a symbiont of Gastrodia elata, promotes seed germination of G. elata and plays a crucial role in the sexual reproduction of G. elata. However, the lack of genetic transformation system of Mycena blocks the research on the interaction mechanism of the two. In order to establish the protoplast transformation system of Mycena, this study analyzed the protoplast enzymatic hydrolysis system, screened the resistance markers and regeneration medium, and explored the transient transformation. After hydrolysis of Mycena hyphae with complexes enzymes for 8 h and centrifugation at 4 000 r·min~(-1), high-concentration and quality protoplast was obtained. The optimum regeneration medium for Mycena was RMV, and the optimum resistance marker was 50 mg·mL~(-1) hygromycin. The pLH-HygB-HuSHXG-GFP-HdSHXG was transformed into the protoplast of Mycena which then expressed GFP. The established protoplast transformation system of Mycena laid a foundation for analyzing the functional genes of Mycena and the molecular mechanism of the symbiosis of Mycena and G. elata.
Agaricales ; Gastrodia/genetics* ; Protoplasts ; Symbiosis/genetics* ; Transformation, Genetic

Oxaliplatin, a third-generation platinum derivative, is the mainstay of current antineoplastic medications for advanced colorectal cancer therapy. However, peripheral neuropathic complications, especially cold allodynia, undermine the lifeprolonging outcome of this anti-cancer agent. Rosavin, a phenylpropanoid derived originally from Rhodiola rosea, exhibits a wide range of therapeutic properties. The present study explored whether and how rosavin alleviates oxaliplatin-induced cold hypersensitivity in mice. In the acetone drop test, cold allodynia behavior was observed from days 3 to 5 after a single injection of oxaliplatin (6 mg/kg, i.p.). Cold allodynia was significantly attenuated following rosavin treatment (10 mg/kg, i.p.). Specific endogenous 5-HT depletion by three consecutive pretreatments with parachlorophenylalanine (150 mg/kg/day, i.p.) abolished the analgesic action of rosavin; this effect was not observed following pretreatment with naloxone (opioid receptor antagonist, 10 mg/kg, i.p.). Furthermore, 5-HT1A receptor antagonist WAY-100635 (0.16 mg/kg, i.p.), but not 5-HT3 receptor antagonist MDL-72222 (1 mg/kg, i.p.), blocked rosavin-induced analgesia. These results suggest that rosavin may provide a novel approach to alleviate oxaliplatin-induced cold allodynia by recruiting the activity of 5-HT1A receptors.

Oxaliplatin, a third-generation platinum derivative, is the mainstay of current antineoplastic medications for advanced colorectal cancer therapy. However, peripheral neuropathic complications, especially cold allodynia, undermine the lifeprolonging outcome of this anti-cancer agent. Rosavin, a phenylpropanoid derived originally from Rhodiola rosea, exhibits a wide range of therapeutic properties. The present study explored whether and how rosavin alleviates oxaliplatin-induced cold hypersensitivity in mice. In the acetone drop test, cold allodynia behavior was observed from days 3 to 5 after a single injection of oxaliplatin (6 mg/kg, i.p.). Cold allodynia was significantly attenuated following rosavin treatment (10 mg/kg, i.p.). Specific endogenous 5-HT depletion by three consecutive pretreatments with parachlorophenylalanine (150 mg/kg/day, i.p.) abolished the analgesic action of rosavin; this effect was not observed following pretreatment with naloxone (opioid receptor antagonist, 10 mg/kg, i.p.). Furthermore, 5-HT1A receptor antagonist WAY-100635 (0.16 mg/kg, i.p.), but not 5-HT3 receptor antagonist MDL-72222 (1 mg/kg, i.p.), blocked rosavin-induced analgesia. These results suggest that rosavin may provide a novel approach to alleviate oxaliplatin-induced cold allodynia by recruiting the activity of 5-HT1A receptors.