ABSTRACT
A series of SARS-CoV-2 variants of concern (VOCs) have evolved in humans during the COVID-19 pandemic--Alpha, Beta, Gamma, Delta, and Omicron. Here, we used global proteomic and genomic analyses during infection to understand the molecular responses driving VOC evolution. We discovered VOC-specific differences in viral RNA and protein expression levels, including for N, Orf6, and Orf9b, and pinpointed several viral mutations responsible. An analysis of the host response to VOC infection and comprehensive interrogation of altered virus-host protein-protein interactions revealed conserved and divergent regulation of biological pathways. For example, regulation of host translation was highly conserved, consistent with suppression of VOC replication in mice using the translation inhibitor plitidepsin. Conversely, modulation of the host inflammatory response was most divergent, where we found Alpha and Beta, but not Omicron BA.1, antagonized interferon stimulated genes (ISGs), a phenotype that correlated with differing levels of Orf6. Additionally, Delta more strongly upregulated proinflammatory genes compared to other VOCs. Systematic comparison of Omicron subvariants revealed BA.5 to have evolved enhanced ISG and proinflammatory gene suppression that similarly correlated with Orf6 expression, effects not seen in BA.4 due to a mutation that disrupts the Orf6-nuclear pore interaction. Our findings describe how VOCs have evolved to fine-tune viral protein expression and protein-protein interactions to evade both innate and adaptive immune responses, offering a likely explanation for increased transmission in humans. One sentence summarySystematic proteomic and genomic analyses of SARS-CoV-2 variants of concern reveal how variant-specific mutations alter viral gene expression, virus-host protein complexes, and the host response to infection with applications to therapy and future pandemic preparedness.
ABSTRACT
An outbreak of the novel coronavirus SARS-CoV-2, the causative agent of COVID-19 respiratory disease, has infected over 290,000 people since the end of 2019, killed over 12,000, and caused worldwide social and economic disruption1,2. There are currently no antiviral drugs with proven efficacy nor are there vaccines for its prevention. Unfortunately, the scientific community has little knowledge of the molecular details of SARS-CoV-2 infection. To illuminate this, we cloned, tagged and expressed 26 of the 29 viral proteins in human cells and identified the human proteins physically associated with each using affinity-purification mass spectrometry (AP-MS), which identified 332 high confidence SARS-CoV-2-human protein-protein interactions (PPIs). Among these, we identify 66 druggable human proteins or host factors targeted by 69 existing FDA-approved drugs, drugs in clinical trials and/or preclinical compounds, that we are currently evaluating for efficacy in live SARS-CoV-2 infection assays. The identification of host dependency factors mediating virus infection may provide key insights into effective molecular targets for developing broadly acting antiviral therapeutics against SARS-CoV-2 and other deadly coronavirus strains.
ABSTRACT
Objective: To investigate the effect of midkine (MK) gene silencing on chemosensitivity of human liver cancer 5-fluorouracil (5-Fu)-resistant cell line Bel/Fu, and to explore its possible mechanism. Methods: The specific sequence targeting MK gene (MK-siRNA) was transfected into Bel/Fu cells, then the expression levels of MK mRNA and protein were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. Bel/Fu cells were transfected with MK-siRNA and treated with 5-Fu, then the proliferation and apoptosis of Bel/Fu cells were detected by MTT and FCM assay, respectively. Furthermore, the expression levels of phosphorylated-phosphoinositide 3-kinase (p-PI3K), phosphorylated-protein kinase B (p-PKB, p-Akt), nuclear factor-kappa B (NF-?B), Bcl-2, survivin and caspase-3 proteins were detected by Western blotting. Results: The expression levels of MK mRNA and protein in Bel/Fu cells transfected with MK-siRNA were significantly down-regulated (both P < 0.05). The half inhibitory concentration (IC50) of 5-Fu in Bel/Fu cells transfected with MK-siRNA was (472± 21) μg/mL, significantly lower than that in untransfected blank control group (2 035 ± 34) μg/mL (P < 0.05). The apoptotic rate of Bel/Fu cells transfected with MK-siRNA was (32.10±3.61)%, significantly higher than that in untransfected blank control group (7.90±0.91)% (P < 0.01). The expression levels of p-PI3K, p-Akt, NF-?B, Bcl-2 and survivin proteins were significantly down-regulated (all P < 0.05), while the expression level of caspase-3 was significantly up-regulated (P < 0.05) in Bel/Fu cells transfected with MK-siRNA. Conclusion: MK gene silencing can enhance the chemosensitivity of hepatocellular cancer Bel/Fu cells to 5-Fu. The mechanism may be involved in activation of PI3K/Akt signal pathway.
ABSTRACT
Objective To study the effect of enhanced MK gene expression in hepatic carcinoma cells.Methods The recombinant plasmid pIRES2-EGFP-MK was transfected into SMMC 7721 cells.The mRNA and protein expression levels of MK gene in these cells were determined by real-time PCR,Western blotting and flow cytometry.The intracellular DNR accumulation of these cells was measured by flow cytometry.To investigate the effect of MK gene mediated multidrug resistance,MTT assay was employed to determine the cellular sensitivity of different chemotherapeutic drugs in MK-overexpressed SMMC 7721 cells.Results The mRNA and protein expression levels of MK gene significantly increased after the recombinant plasmid pIRES2-EGFP-MK transfected into SMMC 7721 cells,suggesting that the recombinant plasmid pIRES2-EGFP-MK can enhance the transcription of MK effectively.The DNR accumulation of MK transfected cells decreased significantly (4.06 ± 0.88,P ＜ 0.05),and IC50 of MK transfected cells to ADM/5-FU increased significantly (15 ± 3,27 ± 4,P ＜ 0.05).Conclusions After the recombinant plasmid pIRES2-EGFP-MK transfected into hepatic carcinoma cells,expression of midkine increased,enhancing the resistance of hepatic carcinoma cells to chemotherapeutic drugs.
ABSTRACT
Objective:To assess the efficacy of terbinafine combined with fluconazole in the treatment of recurrent vulvovaginal candidiasis(RVVC).Method:94 patients with recurrent vulvovaginal candidiasis were randomly divided into three groups.30 cases in the terbinafine monotherapy group were treated with an oral 250mg-dose of terbinafine once daily; 31 cases in the fluconazole monotherpy group were treated with an oral 150mg-dose of fluconazole once daily;33 cases in the combined therapy group were given terbinafine and fluconazole together,and the usage and dosage were the same as those of the monotherapy groups.The treatment period of the three groups was 7 days.The efficacy was evaluated in the second week,sixth month and twelfth month after the treatment.Result:In the second week or sixth month or twelfth month after the treatment,the clinical cure rate,clinical effective rate and fungous clearance rate of the combined therapy group were higher than those of the monotherapy groups,which had statistically significant difference.Conclusion:The combined therapy with terbinafine and fluconazole can effectively improve the clinical signs and symptoms of RVVC patients and eliminate candida,which is more effective than the monotherapy with terbinafine or fluconazole.