为调查大肠杆菌高产辅酶Q(CoQ)的可能性,首先研究大肠杆菌生物合成关键基因ubiCA强化表达对大肠杆菌CoQ产量的影响。本文构建了含有ubiCA基因的5个表达质粒,将其分别转入E.coli JM 83或BL 21(DE 3)菌株中,定量分析这些转化子的辅酶Q产...为调查大肠杆菌高产辅酶Q(CoQ)的可能性,首先研究大肠杆菌生物合成关键基因ubiCA强化表达对大肠杆菌CoQ产量的影响。本文构建了含有ubiCA基因的5个表达质粒,将其分别转入E.coli JM 83或BL 21(DE 3)菌株中,定量分析这些转化子的辅酶Q产量。结果表明ubiCA基因在ubiC自身启动子(pub iCA-lacZF)介导下的表达最有效,重组菌CoQ产量达到对照的3.5倍,由此推测ubiCA基因的表达可能与其启动子序列有关。展开更多
Upon infection into human red cell,Plasmodium falciparum differentiates into asexual and sexual(gametocyte) stages.The mitochondrion is a tubular-cristate organelle,functionally and structurally different between the ...Upon infection into human red cell,Plasmodium falciparum differentiates into asexual and sexual(gametocyte) stages.The mitochondrion is a tubular-cristate organelle,functionally and structurally different between the two stages.Genes and proteins involving metabolic and functional roles,protein targeting and import to this organelle, are comprehensively reviewed.The genes and proteins of the electron transport system are identified, partially characterized in human and rodent malaria parasites consisting of a single subunit of NADH dehydrogenase, two subunits of succinate dehydrogenase,cytochrome C reductase and cytochrome Coxidase.One of the primary functional roles of the mitochondrion in the parasite is the coordination of pyrimidine biosynthesis, the electron transport system and oxygen utilization through dihydroorotate dehydrogenase.All enzymes of tricarboxylic acid cycle,pyruvate dehydrogenase complex and some enzymes of ATP synthase,are identified and partially characterized using the completed P.falciparum genome.Some metabolic and functional roles of the organelle include oxidative phosphorylation,ubiquinone and heme biosynthesis,antioxidant defense and redox balance.Recent physiological studies involve membrane potential maintenance,cellular signaling and cation homeostasis.The organelle is a target for antimalarial drug,i.e.atovaquone.Based on the lines of evidence, we hypothesize that the parasite exhibits metabolic adaptation of the underdeveloped mitochondrial organelle to life in the mosquito vector and the human host.展开更多
BACKGROUND Pancreatic cancer is a leading cause of cancer-related deaths.Increased activity of the epidermal growth factor receptor(EGFR)is often observed in pancreatic cancer,and the small molecule EGFR inhibitor erl...BACKGROUND Pancreatic cancer is a leading cause of cancer-related deaths.Increased activity of the epidermal growth factor receptor(EGFR)is often observed in pancreatic cancer,and the small molecule EGFR inhibitor erlotinib has been approved for pancreatic cancer therapy by the food and drug administration.Nevertheless,erlotinib alone is ineffective and should be combined with other drugs to improve therapeutic outcomes.We previously showed that certain receptor tyrosine kinase inhibitors can increase mitochondrial membrane potential(Δψm),facilitate tumor cell uptake ofΔψm-sensitive agents,disrupt mitochondrial homeostasis,and subsequently trigger tumor cell death.Erlotinib has not been tested for this effect.AIM To determine whether erlotinib can elevateΔψm and increase tumor cell uptake ofΔψm-sensitive agents,subsequently triggering tumor cell death.METHODSΔψm-sensitive fluorescent dye was used to determine how erlotinib affectsΔψm in pancreatic adenocarcinoma(PDAC)cell lines.The viability of conventional and patient-derived primary PDAC cell lines in 2D-and 3D cultures was measured after treating cells sequentially with erlotinib and mitochondria-targeted ubiquinone(MitoQ),aΔψm-sensitive MitoQ.The synergy between erlotinib and MitoQ was then analyzed using SynergyFinder 2.0.The preclinical efficacy of the twodrug combination was determined using immune-compromised nude mice bearing PDAC cell line xenografts.RESULTS Erlotinib elevatedΔψm in PDAC cells,facilitating tumor cell uptake and mitochondrial enrichment ofΔψm-sensitive agents.MitoQ triggered caspase-dependent apoptosis in PDAC cells in culture if used at high doses,while erlotinib pretreatment potentiated low doses of MitoQ.SynergyFinder suggested that these drugs synergistically induced tumor cell lethality.Consistent with in vitro data,erlotinib and MitoQ combination suppressed human PDAC cell line xenografts in mice more effectively than single treatments of each agent.CONCLUSION Our findings suggest that a combination of erlotinib a展开更多
基金the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases(CHEMAL)the National Science and Technology Development Agency of Thailand (Career Development Award)the Thailand Research Fund(Basic Research)
文摘Upon infection into human red cell,Plasmodium falciparum differentiates into asexual and sexual(gametocyte) stages.The mitochondrion is a tubular-cristate organelle,functionally and structurally different between the two stages.Genes and proteins involving metabolic and functional roles,protein targeting and import to this organelle, are comprehensively reviewed.The genes and proteins of the electron transport system are identified, partially characterized in human and rodent malaria parasites consisting of a single subunit of NADH dehydrogenase, two subunits of succinate dehydrogenase,cytochrome C reductase and cytochrome Coxidase.One of the primary functional roles of the mitochondrion in the parasite is the coordination of pyrimidine biosynthesis, the electron transport system and oxygen utilization through dihydroorotate dehydrogenase.All enzymes of tricarboxylic acid cycle,pyruvate dehydrogenase complex and some enzymes of ATP synthase,are identified and partially characterized using the completed P.falciparum genome.Some metabolic and functional roles of the organelle include oxidative phosphorylation,ubiquinone and heme biosynthesis,antioxidant defense and redox balance.Recent physiological studies involve membrane potential maintenance,cellular signaling and cation homeostasis.The organelle is a target for antimalarial drug,i.e.atovaquone.Based on the lines of evidence, we hypothesize that the parasite exhibits metabolic adaptation of the underdeveloped mitochondrial organelle to life in the mosquito vector and the human host.
基金Supported by NIH/National Cancer Institute Grant,No.R01CA138441 and No.R01CA269452UW Madison Centene Pancreas Cancer Collaborative Award,No.21-8568.
文摘BACKGROUND Pancreatic cancer is a leading cause of cancer-related deaths.Increased activity of the epidermal growth factor receptor(EGFR)is often observed in pancreatic cancer,and the small molecule EGFR inhibitor erlotinib has been approved for pancreatic cancer therapy by the food and drug administration.Nevertheless,erlotinib alone is ineffective and should be combined with other drugs to improve therapeutic outcomes.We previously showed that certain receptor tyrosine kinase inhibitors can increase mitochondrial membrane potential(Δψm),facilitate tumor cell uptake ofΔψm-sensitive agents,disrupt mitochondrial homeostasis,and subsequently trigger tumor cell death.Erlotinib has not been tested for this effect.AIM To determine whether erlotinib can elevateΔψm and increase tumor cell uptake ofΔψm-sensitive agents,subsequently triggering tumor cell death.METHODSΔψm-sensitive fluorescent dye was used to determine how erlotinib affectsΔψm in pancreatic adenocarcinoma(PDAC)cell lines.The viability of conventional and patient-derived primary PDAC cell lines in 2D-and 3D cultures was measured after treating cells sequentially with erlotinib and mitochondria-targeted ubiquinone(MitoQ),aΔψm-sensitive MitoQ.The synergy between erlotinib and MitoQ was then analyzed using SynergyFinder 2.0.The preclinical efficacy of the twodrug combination was determined using immune-compromised nude mice bearing PDAC cell line xenografts.RESULTS Erlotinib elevatedΔψm in PDAC cells,facilitating tumor cell uptake and mitochondrial enrichment ofΔψm-sensitive agents.MitoQ triggered caspase-dependent apoptosis in PDAC cells in culture if used at high doses,while erlotinib pretreatment potentiated low doses of MitoQ.SynergyFinder suggested that these drugs synergistically induced tumor cell lethality.Consistent with in vitro data,erlotinib and MitoQ combination suppressed human PDAC cell line xenografts in mice more effectively than single treatments of each agent.CONCLUSION Our findings suggest that a combination of erlotinib a
