Uncoupling protein 1(UCP1)is a proton transporter/channel residing on the inner mitochondrial membrane and is involved in cellular heat production.Using immunohistochemistry,we investigated the expression of UCP1 and ...Uncoupling protein 1(UCP1)is a proton transporter/channel residing on the inner mitochondrial membrane and is involved in cellular heat production.Using immunohistochemistry,we investigated the expression of UCP1 and UCP3 in a series of 98 patients with non-small cell lung cancer(NSCLC)treated with surgery.Expression patterns were correlated with histopathological variables,prognosis,and the expression of enzymes/proteins related to cell metabolism.Bronchial epithelium did not express UCP1 or UCP3,while alveolar cells strongly expressed UCP1.In tumors,strong expression of UCP1 and UCP3 was recorded in43/98(43.8%)and 27/98(27.6%)cases,respectively.UCP1 was significantly associated with squamous cell histology(P=0.05),whilst UCP3 was more frequently overexpressed in large cell carcinomas(P=0.08),and was inversely related to necrosis(P=0.009).In linear regression analysis,UCP1 was directly related to markers of glycolysis[hexokinase(HXKII)and phosphofructokinase(PFK1)]and anaerobic glucose metabolism[pyruvate dehydrogenase kinase(PDK1)and lactate dehydrogenase(LDH5)].UCP3 was directly linked with a glucose transporter(GLUT2),monocarboxylate transporter(MCT2),glycolysis markers(PFK1 and aldolase),and with the phosphorylation of pyruvate dehydrogenase(p PDH).Kaplan-Meier survival analysis showed that UCP3 was significantly related to poor prognosis in squamous cell carcinomas(P=0.04).UCP1 and UCP3 are overexpressed in a large subgroup of non-small cell lung tumors and their expression coincides with increased glucose absorption,intensified glycolysis,and anaerobic glucose usage.Whether UCPs are targets for therapeutic interventions in lung cancer is a hypothesis that demands further investigation.展开更多
Understanding the mechanism underlying signal variation is an important goal in the study of animal communication.Several potential causes have been proposed for signal variation,including environmental noise(e.g.wind...Understanding the mechanism underlying signal variation is an important goal in the study of animal communication.Several potential causes have been proposed for signal variation,including environmental noise(e.g.wind,sound),energy limitation,and predation risk,among others,but the physiological control of many signals are often unclear.Here,we examined the correlation between tail display signal variation and energy metabolic activity using an Asian agamid lizard Phrynocephalus vlangalii.Individual tail display signals were observed in the field,and blood lactate concentration as well as 2 energy metabolic enzymes was assayed.Our results showed that average tail coil speed was positively associated with blood lactate concentration,while tail coil duration was negatively associated with LDH activity.We also found that average tail lash speed was positively associated with blood lactate concentration,suggesting that the tail display behavior of P.vlangalii was regulated by anaerobic metabolism.Furthermore,the correlation between tail display behavior and energy metabolism was not sex-dependent.Taken together,our research provides insight into the physiological mechanisms underlying tail display variation in lizards,and suggests that tail display variation likely transmits important information on individual body condition and resource holding potential.展开更多
Organisms on rocky shores are frequently exposed to high temperatures,which cause impairment of cardiac function and retard cellular oxygen delivery.However,some gastropods can survive at several degrees Celsius highe...Organisms on rocky shores are frequently exposed to high temperatures,which cause impairment of cardiac function and retard cellular oxygen delivery.However,some gastropods can survive at several degrees Celsius higher than their Arrhenius break temperature of cardiac function(ABT),indicating the importance of anaerobic metabolism for their thermal tolerance.We measured the global molecular responses to heat stress in limpet Cellana toreuma using 454 GS-FLX to investigate the variations of genes involved in anaerobic metabolism at high temperatures.Next,the gene expression levels of 4 anaerobic enzymes and activity of alanopine dehydrogenase(AlDH),which is involved in opine pathway,were measured in response to elevated temperature.A total of 19 heat shock proteins(HSPs)were determined using real-time PCR at different temperatures.At high temperatures,the extensive upregulation of HSP genes was an effective but energetically expensive form of protection to prevent thermal damage.The upregulation of hypoxia-inducible factor 1 alpha mRNA indicated the condition of cellular hypoxia and the high gene expression and enzyme activity of AlDH suggested that opine pathway was the main anaerobic pathway.These results implied that anaerobic metabolism was enhanced to provide energy in the face of thermal stress.Our findings highlight the ecological significance of the anaerobic metabolism of gastropods to thermal adaptation.For predicting the ecological impact of global warming on the distribution of gastropods,the role of anaerobic pathways should be evaluated.展开更多
Once thought to be a waste product of oxygen limited(anaerobic)metabolism,lactate is now known to form continuously under fully oxygenated(aerobic)conditions.Lactate shuttling between producer(driver)and consumer cell...Once thought to be a waste product of oxygen limited(anaerobic)metabolism,lactate is now known to form continuously under fully oxygenated(aerobic)conditions.Lactate shuttling between producer(driver)and consumer cells fulfills at least 3 purposes;lactate is:(1)a major energy source,(2)the major gluconeogenic precursor,and(3)a signaling molecule.The Lactate Shuttle theory is applicable to diverse fields such as sports nutrition and hydration,resuscitation from acidosis and Dengue,treatment of traumatic brain injury,maintenance of glycemia,reduction of inflammation,cardiac support in heart failure and following a myocardial infarction,and to improve cognition.Yet,dysregulated lactate shuttling disrupts metabolic flexibility,and worse,supports oncogenesis.Lactate production in cancer(the Warburg effect)is involved in all main sequela for carcinogenesis:angiogenesis,immune escape,cell migration,metastasis,and self-sufficient metabolism.The history of the tortuous path of discovery in lactate metabolism and shuttling was discussed in the 2019 American College of Sports Medicine Joseph B.Wolffe Lecture in Orlando,FL.展开更多
Poikilothermic animals living in high-altitude environments can be greatly affected by the anaerobic metabolism and lactate recycling, which are catalyzed by an enzyme called lactate dehydrogenase(LDH). However, the f...Poikilothermic animals living in high-altitude environments can be greatly affected by the anaerobic metabolism and lactate recycling, which are catalyzed by an enzyme called lactate dehydrogenase(LDH). However, the function and possible regulatory mechanisms of their anaerobic glycolysis remained elusive. We compared the difference in LDH between a native high-altitude(4 353 m) lizard, Phrynocephalus erythrurus, and a closely related species, Phrynocephalus przewalskii that lives in intermediate altitude environment(1 400 m). The activity of LDH, the concentration of lactate, the distribution of isoenzyme, and the mRNA amounts of Ldh-A and Ldh-B were determined. In cardiac muscle, the lactate-forming activity of P. erythrurus in LDH was higher than of P. przewalskii LDH at all three temperatures tested(10 °C, 25 °C and 35 °C), while lactate-oxidation activity of LDH was significantly different between the two species only at 25 °C and 35 °C. In skeletal muscle, both lactate-forming and lactate-oxidation rates of P. erythrurus were lower than that of P. przewalskii. There was a higher proportion of H subunit and a significantly higher expression of Ldh-B, with a concomitant decrease of lactate concentration in P. erythrurus. These results indicate that P. erythrurus may have a strong potential for anaerobic metabolism, which is likely adapted to the hypoxic environment at high altitudes. Furthermore, P. erythrurus is capable of oxidizing more lactate than P. przewalskii. The Ldh-A cDNA of the two species consists of a 999 bp open reading frame(ORF), which encodes 332 amino acids, while Ldh-B cDNA consists of a 1 002 bp ORF encoding 333 amino acids. LDHA has the same amino acid sequence between the two species, but three amino acid substitutions(V12 I, N21S and N318K) were observed in LDHB. Structure analysis of LDH indicated that the substitutions of residues Val12 and Asp21 in P. erythrurus could be responsible for the highaltitude adaptation. The LDH characteristics of LDH in P. erythrurus suggest unique adaptation strategies of anaerobic metabolism in hypoxia and cold environments at high altitudes for poikilothermic animals.展开更多
Utilizing anaerobic metabolisms for the production of biotechnologically relevant products presents potential advantages,such as increased yields and reduced energy dissipation.However,lower energy dissipation may ind...Utilizing anaerobic metabolisms for the production of biotechnologically relevant products presents potential advantages,such as increased yields and reduced energy dissipation.However,lower energy dissipation may indicate that certain reactions are operating closer to their thermodynamic equilibrium.While stoichiometric analyses and genetic modifications are frequently employed in metabolic engineering,the use of thermodynamic tools to evaluate the feasibility of planned interventions is less documented.In this study,we propose a novel metabolic engineering strategy to achieve an efficient anaerobic production of poly-(R)-3-hydroxybutyrate(PHB)in the model organism Escherichia coli.Our approach involves re-routing of two-thirds of the glycolytic flux through non-oxidative glycolysis and coupling PHB synthesis with NADH re-oxidation.We complemented our stoichiometric analysis with various thermodynamic approaches to assess the feasibility and the bottlenecks in the proposed engineered pathway.According to our calculations,the main thermodynamic bottleneck are the reactions catalyzed by the acetoacetyl-CoAβ-ketothiolase(EC 2.3.1.9)and the acetoacetyl-CoA reductase(EC 1.1.1.36).Furthermore,we calculated thermodynamically consistent sets of kinetic parameters to determine the enzyme amounts required for sustaining the conversion fluxes.In the case of the engineered conversion route,the protein pool necessary to sustain the desired fluxes could account for 20%of the whole cell dry weight.展开更多
Adaptations of ciliates to hypoxic environments have arisen independently several times.Studies on mitochondrion-related organelle(MRO)metabolisms from distinct anaerobic ciliate groups provide evidence for understand...Adaptations of ciliates to hypoxic environments have arisen independently several times.Studies on mitochondrion-related organelle(MRO)metabolisms from distinct anaerobic ciliate groups provide evidence for understanding the transitions from mitochondria to MROs within eukaryotes.To deepen our knowledge about the evolutionary patterns of ciliate anaerobiosis,mass-culture and single-cell transcriptomes of two anaerobic species,Metopus laminarius(class Armophorea)and Plagiopyla cf.narasimhamurtii(class Plagiopylea),were sequenced and their MRO metabolic maps were compared.In addition,we carried out comparisons using publicly available predicted MRO proteomes from other ciliate classes(i.e.,Armophorea,Litostomatea,Muranotrichea,Oligohymenophorea,Parablepharismea and Plagiopylea).We found that single-cell transcriptomes were similarly comparable to their mass-culture counterparts in predicting MRO metabolic pathways of ciliates.The patterns of the components of the MRO metabolic pathways might be divergent among anaerobic ciliates,even among closely related species.Notably,our findings indicate the existence of group-specific functional relics of electron transport chains(ETCs).Detailed group-specific ETC functional patterns are as follows:full oxidative phosphorylation in Oligohymenophorea and Muranotrichea;only electron-transfer machinery in Armophorea;either of these functional types in Parablepharismea;and ETC functional absence in Litostomatea and Plagiopylea.These findings suggest that adaptation of ciliates to anaerobic conditions is group-specific and has occurred multiple times.Our results also show the potential and the limitations of detecting ciliate MRO proteins using single-cell transcriptomes and improve the understanding of the multiple transitions from mitochondria to MROs within ciliates.展开更多
文摘Uncoupling protein 1(UCP1)is a proton transporter/channel residing on the inner mitochondrial membrane and is involved in cellular heat production.Using immunohistochemistry,we investigated the expression of UCP1 and UCP3 in a series of 98 patients with non-small cell lung cancer(NSCLC)treated with surgery.Expression patterns were correlated with histopathological variables,prognosis,and the expression of enzymes/proteins related to cell metabolism.Bronchial epithelium did not express UCP1 or UCP3,while alveolar cells strongly expressed UCP1.In tumors,strong expression of UCP1 and UCP3 was recorded in43/98(43.8%)and 27/98(27.6%)cases,respectively.UCP1 was significantly associated with squamous cell histology(P=0.05),whilst UCP3 was more frequently overexpressed in large cell carcinomas(P=0.08),and was inversely related to necrosis(P=0.009).In linear regression analysis,UCP1 was directly related to markers of glycolysis[hexokinase(HXKII)and phosphofructokinase(PFK1)]and anaerobic glucose metabolism[pyruvate dehydrogenase kinase(PDK1)and lactate dehydrogenase(LDH5)].UCP3 was directly linked with a glucose transporter(GLUT2),monocarboxylate transporter(MCT2),glycolysis markers(PFK1 and aldolase),and with the phosphorylation of pyruvate dehydrogenase(p PDH).Kaplan-Meier survival analysis showed that UCP3 was significantly related to poor prognosis in squamous cell carcinomas(P=0.04).UCP1 and UCP3 are overexpressed in a large subgroup of non-small cell lung tumors and their expression coincides with increased glucose absorption,intensified glycolysis,and anaerobic glucose usage.Whether UCPs are targets for therapeutic interventions in lung cancer is a hypothesis that demands further investigation.
基金supported by grants from the National Natural Science Foundation of China[31872233,31572273].
文摘Understanding the mechanism underlying signal variation is an important goal in the study of animal communication.Several potential causes have been proposed for signal variation,including environmental noise(e.g.wind,sound),energy limitation,and predation risk,among others,but the physiological control of many signals are often unclear.Here,we examined the correlation between tail display signal variation and energy metabolic activity using an Asian agamid lizard Phrynocephalus vlangalii.Individual tail display signals were observed in the field,and blood lactate concentration as well as 2 energy metabolic enzymes was assayed.Our results showed that average tail coil speed was positively associated with blood lactate concentration,while tail coil duration was negatively associated with LDH activity.We also found that average tail lash speed was positively associated with blood lactate concentration,suggesting that the tail display behavior of P.vlangalii was regulated by anaerobic metabolism.Furthermore,the correlation between tail display behavior and energy metabolism was not sex-dependent.Taken together,our research provides insight into the physiological mechanisms underlying tail display variation in lizards,and suggests that tail display variation likely transmits important information on individual body condition and resource holding potential.
基金supported by grants from the National Natural Science Foundation of China(41276126,41476115)the National Basic Research Program of China(2013CB956504)the Program for New Century Excellent Talents of Ministry of Education and Nature Science Funds for Distinguished Young Scholars of Fujian Province,China.
文摘Organisms on rocky shores are frequently exposed to high temperatures,which cause impairment of cardiac function and retard cellular oxygen delivery.However,some gastropods can survive at several degrees Celsius higher than their Arrhenius break temperature of cardiac function(ABT),indicating the importance of anaerobic metabolism for their thermal tolerance.We measured the global molecular responses to heat stress in limpet Cellana toreuma using 454 GS-FLX to investigate the variations of genes involved in anaerobic metabolism at high temperatures.Next,the gene expression levels of 4 anaerobic enzymes and activity of alanopine dehydrogenase(AlDH),which is involved in opine pathway,were measured in response to elevated temperature.A total of 19 heat shock proteins(HSPs)were determined using real-time PCR at different temperatures.At high temperatures,the extensive upregulation of HSP genes was an effective but energetically expensive form of protection to prevent thermal damage.The upregulation of hypoxia-inducible factor 1 alpha mRNA indicated the condition of cellular hypoxia and the high gene expression and enzyme activity of AlDH suggested that opine pathway was the main anaerobic pathway.These results implied that anaerobic metabolism was enhanced to provide energy in the face of thermal stress.Our findings highlight the ecological significance of the anaerobic metabolism of gastropods to thermal adaptation.For predicting the ecological impact of global warming on the distribution of gastropods,the role of anaerobic pathways should be evaluated.
文摘Once thought to be a waste product of oxygen limited(anaerobic)metabolism,lactate is now known to form continuously under fully oxygenated(aerobic)conditions.Lactate shuttling between producer(driver)and consumer cells fulfills at least 3 purposes;lactate is:(1)a major energy source,(2)the major gluconeogenic precursor,and(3)a signaling molecule.The Lactate Shuttle theory is applicable to diverse fields such as sports nutrition and hydration,resuscitation from acidosis and Dengue,treatment of traumatic brain injury,maintenance of glycemia,reduction of inflammation,cardiac support in heart failure and following a myocardial infarction,and to improve cognition.Yet,dysregulated lactate shuttling disrupts metabolic flexibility,and worse,supports oncogenesis.Lactate production in cancer(the Warburg effect)is involved in all main sequela for carcinogenesis:angiogenesis,immune escape,cell migration,metastasis,and self-sufficient metabolism.The history of the tortuous path of discovery in lactate metabolism and shuttling was discussed in the 2019 American College of Sports Medicine Joseph B.Wolffe Lecture in Orlando,FL.
基金supported by the National Natural Science Foundation of China (No. 31501860 to Xiaolong TANG, No. 31272313 and No. 31472005 to Qiang CHEN) Fundamental Research Funds for the Central Universities (lzujbky-2017-150 to Xiaolong TANG)Natural Science Foundation of Gansu Province: 1506RJYA243
文摘Poikilothermic animals living in high-altitude environments can be greatly affected by the anaerobic metabolism and lactate recycling, which are catalyzed by an enzyme called lactate dehydrogenase(LDH). However, the function and possible regulatory mechanisms of their anaerobic glycolysis remained elusive. We compared the difference in LDH between a native high-altitude(4 353 m) lizard, Phrynocephalus erythrurus, and a closely related species, Phrynocephalus przewalskii that lives in intermediate altitude environment(1 400 m). The activity of LDH, the concentration of lactate, the distribution of isoenzyme, and the mRNA amounts of Ldh-A and Ldh-B were determined. In cardiac muscle, the lactate-forming activity of P. erythrurus in LDH was higher than of P. przewalskii LDH at all three temperatures tested(10 °C, 25 °C and 35 °C), while lactate-oxidation activity of LDH was significantly different between the two species only at 25 °C and 35 °C. In skeletal muscle, both lactate-forming and lactate-oxidation rates of P. erythrurus were lower than that of P. przewalskii. There was a higher proportion of H subunit and a significantly higher expression of Ldh-B, with a concomitant decrease of lactate concentration in P. erythrurus. These results indicate that P. erythrurus may have a strong potential for anaerobic metabolism, which is likely adapted to the hypoxic environment at high altitudes. Furthermore, P. erythrurus is capable of oxidizing more lactate than P. przewalskii. The Ldh-A cDNA of the two species consists of a 999 bp open reading frame(ORF), which encodes 332 amino acids, while Ldh-B cDNA consists of a 1 002 bp ORF encoding 333 amino acids. LDHA has the same amino acid sequence between the two species, but three amino acid substitutions(V12 I, N21S and N318K) were observed in LDHB. Structure analysis of LDH indicated that the substitutions of residues Val12 and Asp21 in P. erythrurus could be responsible for the highaltitude adaptation. The LDH characteristics of LDH in P. erythrurus suggest unique adaptation strategies of anaerobic metabolism in hypoxia and cold environments at high altitudes for poikilothermic animals.
基金supported by the joint research program NWO-FAPESP of the Dutch Organization for Scientific Research(NWO)and the Sao Paulo Research Foundation(FAPESP)(code NWO:BBE.2017.013code FAPESP:2017/50249-6)+1 种基金The contributions of Karel Olavarria and Diana Z.Sousa were also supported by a SIAM Gravitation Grant(024.002.002)from the Dutch Ministry of Education,Culture and Science(OCW)and by the Centre for Living Technologies,a part of the Alliance TU/e,WUR,UU,UMC Utrecht(www.ewuu.nl)The contribution of Mark C.M.van Loosdrecht was supported by the SIAM Gravitation Grant(024.002.002).
文摘Utilizing anaerobic metabolisms for the production of biotechnologically relevant products presents potential advantages,such as increased yields and reduced energy dissipation.However,lower energy dissipation may indicate that certain reactions are operating closer to their thermodynamic equilibrium.While stoichiometric analyses and genetic modifications are frequently employed in metabolic engineering,the use of thermodynamic tools to evaluate the feasibility of planned interventions is less documented.In this study,we propose a novel metabolic engineering strategy to achieve an efficient anaerobic production of poly-(R)-3-hydroxybutyrate(PHB)in the model organism Escherichia coli.Our approach involves re-routing of two-thirds of the glycolytic flux through non-oxidative glycolysis and coupling PHB synthesis with NADH re-oxidation.We complemented our stoichiometric analysis with various thermodynamic approaches to assess the feasibility and the bottlenecks in the proposed engineered pathway.According to our calculations,the main thermodynamic bottleneck are the reactions catalyzed by the acetoacetyl-CoAβ-ketothiolase(EC 2.3.1.9)and the acetoacetyl-CoA reductase(EC 1.1.1.36).Furthermore,we calculated thermodynamically consistent sets of kinetic parameters to determine the enzyme amounts required for sustaining the conversion fluxes.In the case of the engineered conversion route,the protein pool necessary to sustain the desired fluxes could account for 20%of the whole cell dry weight.
基金supported by the National Natural Science Foundation of China(Grant Number 32070406)Guangdong Basic and Applied Basic Research Foundation(Grant Number 2022A1515010773)the Science and Technology Planning Project of Guangzhou(Grant Number 202102080168).
文摘Adaptations of ciliates to hypoxic environments have arisen independently several times.Studies on mitochondrion-related organelle(MRO)metabolisms from distinct anaerobic ciliate groups provide evidence for understanding the transitions from mitochondria to MROs within eukaryotes.To deepen our knowledge about the evolutionary patterns of ciliate anaerobiosis,mass-culture and single-cell transcriptomes of two anaerobic species,Metopus laminarius(class Armophorea)and Plagiopyla cf.narasimhamurtii(class Plagiopylea),were sequenced and their MRO metabolic maps were compared.In addition,we carried out comparisons using publicly available predicted MRO proteomes from other ciliate classes(i.e.,Armophorea,Litostomatea,Muranotrichea,Oligohymenophorea,Parablepharismea and Plagiopylea).We found that single-cell transcriptomes were similarly comparable to their mass-culture counterparts in predicting MRO metabolic pathways of ciliates.The patterns of the components of the MRO metabolic pathways might be divergent among anaerobic ciliates,even among closely related species.Notably,our findings indicate the existence of group-specific functional relics of electron transport chains(ETCs).Detailed group-specific ETC functional patterns are as follows:full oxidative phosphorylation in Oligohymenophorea and Muranotrichea;only electron-transfer machinery in Armophorea;either of these functional types in Parablepharismea;and ETC functional absence in Litostomatea and Plagiopylea.These findings suggest that adaptation of ciliates to anaerobic conditions is group-specific and has occurred multiple times.Our results also show the potential and the limitations of detecting ciliate MRO proteins using single-cell transcriptomes and improve the understanding of the multiple transitions from mitochondria to MROs within ciliates.
