Lassa hemorrhagic fever,caused by Lassa mammarenavirus(LASV)infection,accumulates up to 5000 deaths every year.Currently,there is no vaccine available to combat this disease.In this study,a library of 200 bioactive co...Lassa hemorrhagic fever,caused by Lassa mammarenavirus(LASV)infection,accumulates up to 5000 deaths every year.Currently,there is no vaccine available to combat this disease.In this study,a library of 200 bioactive compounds was virtually screened to study their drug-likeness with the capacity to block theα-dystroglycan(α-DG)receptor and prevent LASV influx.Following rigorous absorption,distribution,metabolism,and excretion(ADME)and quantitative structure-activity relationship(QSAR)profiling,molecular docking was conducted with the top ligands against theα-DG receptor.The compounds chrysin,reticuline,and 3-caffeoylshikimic acid emerged as the top three ligands in terms of binding affinity.Post-docking analysis revealed that interactions with Arg76,Asn224,Ser259,and Lys302 amino acid residues of the receptor protein were important for the optimum binding affinity of ligands.Molecular dynamics simulation was performed comprehensively to study the stability of the protein-ligand complexes.In-depth assessment of root-mean-square deviation(RMSD),root mean square fluctuation(RMSF),polar surface area(PSA),B-Factor,radius of gyration(Rg),solvent accessible surface area(SASA),and molecular surface area(MolSA)values of the protein-ligand complexes affirmed that the candidates with the best binding affinity formed the most stable protein-ligand complexes.To authenticate the potentialities of the ligands as target-specific drugs,an in vivo study is underway in real time as the continuation of the research.展开更多
P2X7 purinoceptor promotes survival or cytotoxicity depending on extraceUular adenosine triphosphate （ATP） stimulus Intensity controlling its ion channel or P2X7-dependent large pore （LP） functions. Mechanisms gov...P2X7 purinoceptor promotes survival or cytotoxicity depending on extraceUular adenosine triphosphate （ATP） stimulus Intensity controlling its ion channel or P2X7-dependent large pore （LP） functions. Mechanisms governing this operational divergence and functional idiosyncrasy are ill-understood. We have discovered a feedback loop where sustained activation of P2X7 triggers release of active matrix metalloproteinase 2 （MMP-2）, which halts ion channel and LP responses via the MMP-2-dependent receptor cleavage. This mechanism operates in cells as diverse as macrophages, dystrophic myoblasts, P2X7-transfected HEK293, and human tumour cells. Given that serum-born MMP-2 activity also blocked receptor functions, P2X7 responses in vivo may decrease in organs with permeable capillaries. Therefore, this mechanism represents an Important fine-tuning of P2X7 functions, reliant on both cell-autonomous and extraneous factors. Indeed, it allowed evasion from the ATP-induced cvtotoxicity in macrophages and human cancer ceils with high P2X7 expression levels. Finally, we demonstrate that P2X7 ablation eliminated getatinase activity in inflamed dystrophic muscles in vivo. Thus, P2X7 antagonists could be used as an alternative to highly toxic MMP inhibitors in treatments of inflammatory diseases and cancers.展开更多
文摘Lassa hemorrhagic fever,caused by Lassa mammarenavirus(LASV)infection,accumulates up to 5000 deaths every year.Currently,there is no vaccine available to combat this disease.In this study,a library of 200 bioactive compounds was virtually screened to study their drug-likeness with the capacity to block theα-dystroglycan(α-DG)receptor and prevent LASV influx.Following rigorous absorption,distribution,metabolism,and excretion(ADME)and quantitative structure-activity relationship(QSAR)profiling,molecular docking was conducted with the top ligands against theα-DG receptor.The compounds chrysin,reticuline,and 3-caffeoylshikimic acid emerged as the top three ligands in terms of binding affinity.Post-docking analysis revealed that interactions with Arg76,Asn224,Ser259,and Lys302 amino acid residues of the receptor protein were important for the optimum binding affinity of ligands.Molecular dynamics simulation was performed comprehensively to study the stability of the protein-ligand complexes.In-depth assessment of root-mean-square deviation(RMSD),root mean square fluctuation(RMSF),polar surface area(PSA),B-Factor,radius of gyration(Rg),solvent accessible surface area(SASA),and molecular surface area(MolSA)values of the protein-ligand complexes affirmed that the candidates with the best binding affinity formed the most stable protein-ligand complexes.To authenticate the potentialities of the ligands as target-specific drugs,an in vivo study is underway in real time as the continuation of the research.
文摘P2X7 purinoceptor promotes survival or cytotoxicity depending on extraceUular adenosine triphosphate （ATP） stimulus Intensity controlling its ion channel or P2X7-dependent large pore （LP） functions. Mechanisms governing this operational divergence and functional idiosyncrasy are ill-understood. We have discovered a feedback loop where sustained activation of P2X7 triggers release of active matrix metalloproteinase 2 （MMP-2）, which halts ion channel and LP responses via the MMP-2-dependent receptor cleavage. This mechanism operates in cells as diverse as macrophages, dystrophic myoblasts, P2X7-transfected HEK293, and human tumour cells. Given that serum-born MMP-2 activity also blocked receptor functions, P2X7 responses in vivo may decrease in organs with permeable capillaries. Therefore, this mechanism represents an Important fine-tuning of P2X7 functions, reliant on both cell-autonomous and extraneous factors. Indeed, it allowed evasion from the ATP-induced cvtotoxicity in macrophages and human cancer ceils with high P2X7 expression levels. Finally, we demonstrate that P2X7 ablation eliminated getatinase activity in inflamed dystrophic muscles in vivo. Thus, P2X7 antagonists could be used as an alternative to highly toxic MMP inhibitors in treatments of inflammatory diseases and cancers.
