To assess targeting of an epothilone folate conjugate(BMS-753493) to the folate receptor(FR)-overexpressed tumor in mice bearing both FRt and FR– tumors,a series of experiments were conducted by quantitative whole-bo...To assess targeting of an epothilone folate conjugate(BMS-753493) to the folate receptor(FR)-overexpressed tumor in mice bearing both FRt and FR– tumors,a series of experiments were conducted by quantitative whole-body autoradiography(QWBA) and LC–MS/MS following i.v.administration of BMS-753493 or its active moiety,BMS-748285 in mice bearing FRt(98M109) and FR–(M109) tumors.QWBA showed [3H]BMS-753493–derived radioactivity was extensively distributed to various tissues.The FR over-expressing 98M109 tumors showed consistently higher level of radioactivity than FR-negative tumors(i.e.,M109 tumors) up to 48 h post dose of [3H]BMS-753493,despite the magnitude of difference between the tumors is relatively small(generally 3 5-fold).The radioactivity level in 98M109 tumors was 2 12-fold of normal tissues except intestine/content at 48 h post dose.No selective radioactivity uptake into 98M109 tumors over M109 or normal tissues was observed after i.v.administration of the active epothilone,[3H]BMS-748285.LC–MS/MS measurements demonstrated that the concentrations of BMS-748285,presumably from hydrolysis of the folate conjugate,in 98M109 tumors were greater than those in M109 tumors after i.v.administration of BMS-753493(2–3-fold) whereas no differential uptake in the tumors following BMS-748285 administration.Those data were consistent with radioactivity determinations.Those results demonstrated that the folate conjugation in BMS-753493 enabled moderately preferential distribution of the active epothilone to FR overexpressing 98M109 tumors,thereby supporting targeted delivery of cytotoxics through the folate receptor.展开更多
Scar formation after spinal cord injury is regarded as an obstacle to axonal regeneration and functional recovery.Epothilone B provides moderate microtubule stabilization and is mainly used for anti-tumor therapy.It a...Scar formation after spinal cord injury is regarded as an obstacle to axonal regeneration and functional recovery.Epothilone B provides moderate microtubule stabilization and is mainly used for anti-tumor therapy.It also reduces scar tissue formation and promotes axonal regeneration after spinal cord injury.The aim of the present study was to investigate the effect and mechanism of the microtubule-stabilizing reagent epothilone B in decreasing fibrotic scarring through its action on pericytes after spinal cord injury.A rat model of spinal cord injury was established via dorsal complete transection at the T10 vertebra.The rats received an intraperitoneal injection of epothilone B（0.75 mg/kg） at 1 and 15 days post-injury in the epothilone B group or normal saline in the vehicle group.Neuron-glial antigen 2,platelet-derived growth factor receptor β,and fibronectin protein expression were dramatically lower in the epothilone B group than in the vehicle group,but β-tubulin protein expression was greater.Glial fibrillary acidic protein at the injury site was not affected by epothilone B treatment.The Basso,Beattie,and Bresnahan locomotor scores were significantly higher in the epothilone B group than in the vehicle group.The results of this study demonstrated that epothilone B reduced the number of pericytes,inhibited extracellular matrix formation,and suppressed scar formation after spinal cord injury.展开更多
A mild and highly efficient synthesis of C7-C14 and C15-C21 fragments of epothilone B and D is described in which racemic C7-C14 fragment is prepared from nerol through four steps, and C15-C21 fragment is obtained fro...A mild and highly efficient synthesis of C7-C14 and C15-C21 fragments of epothilone B and D is described in which racemic C7-C14 fragment is prepared from nerol through four steps, and C15-C21 fragment is obtained from 1, 3-dichloroacetone, thioacetamide and propionaldehyde.展开更多
Myxobacteria are famous for their capacity for social behavior and natural product biosynthesis.The unique sociality of myxobacteria is not only an intriguing scientific topic but also the main limiting factor for the...Myxobacteria are famous for their capacity for social behavior and natural product biosynthesis.The unique sociality of myxobacteria is not only an intriguing scientific topic but also the main limiting factor for their ma-nipulation.After more than half a century of research,a series of genetic techniques for myxobacteria have been developed,rendering these mysterious bacteria manipulable.Here,we review the advances in genetic manipu-lation of myxobacteria,with a particular focus on the exploitation of secondary metabolism.We emphasize the necessity and urgency of constructing the myxobacterial chassis for synthetic biology research and the exploita-tion of untapped secondary metabolism.展开更多
文摘To assess targeting of an epothilone folate conjugate(BMS-753493) to the folate receptor(FR)-overexpressed tumor in mice bearing both FRt and FR– tumors,a series of experiments were conducted by quantitative whole-body autoradiography(QWBA) and LC–MS/MS following i.v.administration of BMS-753493 or its active moiety,BMS-748285 in mice bearing FRt(98M109) and FR–(M109) tumors.QWBA showed [3H]BMS-753493–derived radioactivity was extensively distributed to various tissues.The FR over-expressing 98M109 tumors showed consistently higher level of radioactivity than FR-negative tumors(i.e.,M109 tumors) up to 48 h post dose of [3H]BMS-753493,despite the magnitude of difference between the tumors is relatively small(generally 3 5-fold).The radioactivity level in 98M109 tumors was 2 12-fold of normal tissues except intestine/content at 48 h post dose.No selective radioactivity uptake into 98M109 tumors over M109 or normal tissues was observed after i.v.administration of the active epothilone,[3H]BMS-748285.LC–MS/MS measurements demonstrated that the concentrations of BMS-748285,presumably from hydrolysis of the folate conjugate,in 98M109 tumors were greater than those in M109 tumors after i.v.administration of BMS-753493(2–3-fold) whereas no differential uptake in the tumors following BMS-748285 administration.Those data were consistent with radioactivity determinations.Those results demonstrated that the folate conjugation in BMS-753493 enabled moderately preferential distribution of the active epothilone to FR overexpressing 98M109 tumors,thereby supporting targeted delivery of cytotoxics through the folate receptor.
基金supported by a grant from the Science and Technology Developing Program of Shandong Provincial Government of China,No.2010GSF10254a grant from the Medical and Health Science and Technology Plan Project of Shandong Province of China,No.2015WS0504
文摘Scar formation after spinal cord injury is regarded as an obstacle to axonal regeneration and functional recovery.Epothilone B provides moderate microtubule stabilization and is mainly used for anti-tumor therapy.It also reduces scar tissue formation and promotes axonal regeneration after spinal cord injury.The aim of the present study was to investigate the effect and mechanism of the microtubule-stabilizing reagent epothilone B in decreasing fibrotic scarring through its action on pericytes after spinal cord injury.A rat model of spinal cord injury was established via dorsal complete transection at the T10 vertebra.The rats received an intraperitoneal injection of epothilone B（0.75 mg/kg） at 1 and 15 days post-injury in the epothilone B group or normal saline in the vehicle group.Neuron-glial antigen 2,platelet-derived growth factor receptor β,and fibronectin protein expression were dramatically lower in the epothilone B group than in the vehicle group,but β-tubulin protein expression was greater.Glial fibrillary acidic protein at the injury site was not affected by epothilone B treatment.The Basso,Beattie,and Bresnahan locomotor scores were significantly higher in the epothilone B group than in the vehicle group.The results of this study demonstrated that epothilone B reduced the number of pericytes,inhibited extracellular matrix formation,and suppressed scar formation after spinal cord injury.
基金the National Natural Science Foundation of China (No.20214),Ministry of Education Natural Science Foundation and Education Commission of Hubei Province
文摘A mild and highly efficient synthesis of C7-C14 and C15-C21 fragments of epothilone B and D is described in which racemic C7-C14 fragment is prepared from nerol through four steps, and C15-C21 fragment is obtained from 1, 3-dichloroacetone, thioacetamide and propionaldehyde.
基金This work was financially supported by the National Key Re-search and Development Programs of China(2018YFA0900400,2018YFA0901704 and 2021YFC2101000)the Natural Science Foundation of Shandong Province(ZR2019BC041).
文摘Myxobacteria are famous for their capacity for social behavior and natural product biosynthesis.The unique sociality of myxobacteria is not only an intriguing scientific topic but also the main limiting factor for their ma-nipulation.After more than half a century of research,a series of genetic techniques for myxobacteria have been developed,rendering these mysterious bacteria manipulable.Here,we review the advances in genetic manipu-lation of myxobacteria,with a particular focus on the exploitation of secondary metabolism.We emphasize the necessity and urgency of constructing the myxobacterial chassis for synthetic biology research and the exploita-tion of untapped secondary metabolism.
