A genomic DNA fragment containing the 5'-upstream sequence and part of the open reading frame corresponding to the cytosolic fructose-1,6-bisphosphatase (cyFBPase) cDNA was isolated by Genome Walking. The 1 195 li...A genomic DNA fragment containing the 5'-upstream sequence and part of the open reading frame corresponding to the cytosolic fructose-1,6-bisphosphatase (cyFBPase) cDNA was isolated by Genome Walking. The 1 195 lip 5'-flanking region which started from the translation initiation ATG codon was fused to reporter gene encoding beta-glucuronidase (GUS) and stably transferred to rice via particle bombardment. Strong GUS activity was detected in leaves and leaf sheaths of transgenic rice, but not in culms and roots. Histochemical localization revealed that GUS expression was exclusively restricted to mesophyll cells in transgenic rice. Our results indicate that the 1 195 bp fragment contains all the cis-elements required for directing mesophyll-specific expression pattern in rice.展开更多
Fructose-1,6-bisphosphatase（FBPase） is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplificatio...Fructose-1,6-bisphosphatase（FBPase） is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplification of cDNA ends（RACE） technology. The nucleotide sequence of PhcpFBPase consists of 1 400 bp, including a 5′ untranslated region（UTR） of 92 bp, a 3′？UTR of 69 bp, and an open reading frame（ORF） of 1 236 bp, which can be translated into a 412-amino-acid putative peptides with a molecular weight of 44.3 kDa and a theoretical pI of 5.23. Multiple sequence alignment indicated that the protein belonged to the chloroplast FBPase enzyme. Phylogenetic analysis showed that the protein assembled with the cpFBPase of a thermal tolerant unicellular red micro-algae Galdieria sulphuraria. Expression patterns analyzed by qRT-PCR revealed that the expression of PhcpFBPase gene in the thallus phage was 7-fold higher than in the conchocelis phage, which suggested the different mechanisms of inorganic carbon utilization among the different life phages of P. haitanensis. And the different response modes of PhcpFBPase mRNA levels to high temperature and desiccation stress indicated that PhcpFBPase played an important role in responsing to abiotic stress.展开更多
Aim To investigate the effects of FDP on different liver injury models to explore the possibility of FDP used as an oral liver protective agent. Methods Chronic liver injury model in rats was induced by carbon tetrach...Aim To investigate the effects of FDP on different liver injury models to explore the possibility of FDP used as an oral liver protective agent. Methods Chronic liver injury model in rats was induced by carbon tetrachloride （ CCl4 ） ; Acute liver injury model in mice was induced by aminogalactose （GAIN） or lipopolysaccharide （LPS）. Results In CCl4-induced chronic liver injury model, FDP （1 , 4 g·kg^-1·d^-1, q.d., for 10 weeks） significantly lowered ALT, AST,γ-glutamyl transpeptidase （γ-GT）, alkaline phosphatase （ALP）, and total bilirubin （T-BIL） in serum compared with vehicle; simultaneously it evidently elevated abnormal total protein （TP）, albumin （ALB） and total cholesterol （ T-CHO ） levels in serum; it also dose-dependently reduced hydroxyproline contents in hepatic tissue. 4 g·kg^-1·d^-1 of FDP apparently decreased incidence of hepatic cirrhosis, and alleviated pathological changes of liver tissue. In GaiN-induced model, 1.0 - 4. 0 g·kg^-1·d^-1 of FDP （ bid, for 3 d ） significantly lowered alanine aminotransferase （ ALT ） and aspartate aminotransferase （ AST ） levels in serum ; it also decreased liver coefficient. 4. 0 g·kg^-1·d^-1 of FDP significantly alleviated pathological changes of cell ultra-structures. In LPS-induced model, only high dose of FDP （4. 0 g·kg^-1·d^-1, bid, for 12 d） significantly decreased ALT level in serum. Conclusion This study first demonstrated the protective effect of oral FDP on chronic liver injury caused by CCl4, and confirmed its effect on acute liver injury at the same time, suggesting that Long-term oral FDP is efficacious against liver injury induced by different factors and can be used as an oral liver protective agent in clinic.展开更多
Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) an...Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) and activity of sarcoplosnic Ca2+-ATPase (SRCa2+-ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5 mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnl. CK-MB was detected by monoclonal antibody, Myo[Ca2+] was detected by fluorescent spectrophotometry and the activity of SRCa2+-ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnl and CK-MB, while at the same time decreased calcium concentration and increased SRCa2+-ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2+-ATPase activity in cardiomyocytes.展开更多
In the present experiment,fructose-1,6-diphosphate（FDP）and captopril（Cap）wereadded to the cold potassium cardioplegia solution and the levels of malondialdehyde（MDA）,cre-atine phosphokinase MB（CPK-MB）,thrombox...In the present experiment,fructose-1,6-diphosphate（FDP）and captopril（Cap）wereadded to the cold potassium cardioplegia solution and the levels of malondialdehyde（MDA）,cre-atine phosphokinase MB（CPK-MB）,thromboxane B（TXB<sub>2</sub>）and 6-keto-PGF<sub>1α</sub> in plasma weremeasured during open-heart surgery.Quantitative study of myocardial ultrastructure and obser-vation of cardiac resuscitation were also undertaken.The findings suggested that FDP,especiallywhen combined with Cap could significantly strengthen the protective effects of cold potassiumcardioplegia solution on ischemic myocardium.展开更多
A substance in the crude preparation of NADP+ has been found, which activates snake muscle fructose-1,6-bisphosphatase at pH 9.2 and inhibits the enzyme at pH 7.5. After isolation and extensive characterization, the s...A substance in the crude preparation of NADP+ has been found, which activates snake muscle fructose-1,6-bisphosphatase at pH 9.2 and inhibits the enzyme at pH 7.5. After isolation and extensive characterization, the substance has been determined to be AMP. The activation depends on the concentrations of Mg2+ and could be observed only at concentrations above 1 mmol/L. In the presence of AMP, snake muscle fructose-1,6-bisphosphatase resembles an alkaline enzyme. Kinetic studies indicate that AMP and Mg2+ competitively regulate the activity of the enzyme. AMP releases the inhibition of Mg2+ at high concentration at alkaline pH. It has been reported that fructose-1,6-bisphosphatase with a pH optimum in the alkaline region is caused by limited proteolysis. AMP is also able to make fructose-1,6-bisphosphatase to be an alkaline enzyme. This finding indicates that proteolysis may not be the only reason for shift of the optimum pH of fructose-1,6-bisphosphatase to alkaline side and it may imply some significance in physiological regulation.展开更多
Objective To investigate the roles of fructose-1,6-diphosphate(FDP)-added total parenteral nutrition (TPN)in septic animals and stressed patients.Methods Thirteen adult dogs were randomly assigned to one of two study ...Objective To investigate the roles of fructose-1,6-diphosphate(FDP)-added total parenteral nutrition (TPN)in septic animals and stressed patients.Methods Thirteen adult dogs were randomly assigned to one of two study groups 6 hours after the induction of severe intra-abdominal infection.Group TPN(n =6)received 70 kcal· kg-1· d-1 of nonprotein calorie(NPC)and 0.56 g· kg-1· d-1 of nitrogen.1 g/kg of FDP was also infused to the animals in group TPN + FDP(n = 7)everyday.In the clinical study,the control group received routine TPN,while the study group(n = 16)was treated with TPN plus FDP(5 g,two times a day)for 7 days.Results In dogs with TPN support,plasma ATP levels were not changed significantly,while the value in the TPN + FDP group increased significantly from 0.18 μmol/L to 0.46 μmol/L at 24 h and 0.51 μmol/L at 48 h(P ＜ 0.01).Muscular ATP increased markedly in the TPN + FDP group.Muscular creatine phosphate alues were not significantly changed in the TPN group,but the values increased in the TPN + FDP group from 4.06 μmol/g·wt at the beginning to 4.93 μmol/g· wt at 24 h and 5.60 μmol/g·wt at 48 h(P ＜ 0.05),with a cytochrome oxidase increase in immunohistochemistry stain.In the clinical study,plasma ATP levels increased and urinary 3-methylhistidine production significantly decreased with an improved value for positive accumulative nitrogen balance in the FDP-infused group.Conclusion Our results suggest that total parenteral nutrition support with the supplement of fructose-1,6-diphosphate has a positive role in body energy production and protein metabolism in septic animals and stressed patients.展开更多
Using Rapid Amplification of cDNA ends (RACE) technique, the full-length cDNA en-coding a NaCl-induced fructose-1, 6- diphosphate aldolase (DsALDP) was obtained. It was shown that the DsALDP had a relatively high homo...Using Rapid Amplification of cDNA ends (RACE) technique, the full-length cDNA en-coding a NaCl-induced fructose-1, 6- diphosphate aldolase (DsALDP) was obtained. It was shown that the DsALDP had a relatively high homology (66%—73%) to chloroplast fructose-1, 6-diphos- phate aldolase (AldP) in many plants according to their amino acid sequences. The phylogenetic analysis further confirmed that AldP in alga is the nearest to DsALDP. As to its expression pattern, DsALDP was de novo synthesized by NaCl induction. Its expression level was significantly changed with inducing time. After the selected DsALDP cDNA subcloned into a binary vector pBI121, the new construct was introduced into tobacco by Agrobacterium tumefaciens. The results of Southern blot and RT-PCR analysis of four transgenic T1 plants indicated that DsALDP was integrated into genome of these transgenic plants and effectively expressed. Aldolase activities have been detected in T1-1, T1-2 and T1-3 plants by bioassay under 100—200 mmol/L NaCl. It was also observed that proline contents in them were differentially increased.展开更多
In order to overcome the elementary heterogeneous nucleation whileoctahydro trisodium salt of fructose- 1, 6-diphosphate (FDPNa_3·8H_2O) is crystallized with ethanol precipitation at low temperature,a new crystal...In order to overcome the elementary heterogeneous nucleation whileoctahydro trisodium salt of fructose- 1, 6-diphosphate (FDPNa_3·8H_2O) is crystallized with ethanol precipitation at low temperature,a new crystallization method with alcohol precipitation combined withsalt precipitation has been presented. The ethanol-sodium ac- etatesystem for crystallization of salt of fructose-1, 6-diphosphate isbased on the mechanism of crystallization of FDPNA_3·8H_2O in theethanol-low temperature system. It is found that crystal size may becontrolled by regulating Temperature of pH value of solution in thecrystallization process, and the crystal yield increases to 95/100from 78/100 Which obtained in the ethanol-low temperature system.展开更多
Permeable yeast cells were used in the batch production of fructose-1,6-diphosphate(FDP).The optimum reaction conditions were reported to be:reaction temperature 30℃,tolueneconcentration 8%(V/V),and initial ratio of ...Permeable yeast cells were used in the batch production of fructose-1,6-diphosphate(FDP).The optimum reaction conditions were reported to be:reaction temperature 30℃,tolueneconcentration 8%(V/V),and initial ratio of glucose to inorganic phosphorus(Pi)10:1.Addition ofAMP was found to be very beneficial to the FDP production.A multienzyme system model for FDPaccumulation was developed,in which FDP was regarded as a substrate of phosphor-fructokinase(PFK),to simulate the activation effect of FDP on PFK.The model simulations were in good agree-ment with the experimental data.展开更多
Regulatory T(T_(reg))cells constitute a dynamic population that is critical in autoimmunity.T_(reg) cell therapies for autoimmune diseases are mainly focused on enhancing their suppressive activities.However,recent st...Regulatory T(T_(reg))cells constitute a dynamic population that is critical in autoimmunity.T_(reg) cell therapies for autoimmune diseases are mainly focused on enhancing their suppressive activities.However,recent studies demonstrated that certain inflammatory conditions induce T_(reg) cell instability with diminished FoxP3 expression and convert them into pathogenic effector cells.Therefore,the identification of novel targets crucial to both T_(reg) cell function and plasticity is of vital importance to the development of therapeutic approaches in autoimmunity.In this study,we found that conditional Pp6 knockout(cKO)in T_(reg) cells led to spontaneous autoinflammation,immune cell activation,and diminished levels of FoxP3 in CD4^(+)T cells in mice.Loss of Pp6 in T_(reg) cells exacerbated two classical mouse models of T_(reg)-related autoinflammation.Mechanistically,Pp6 deficiency increased CpG motif methylation of the FoxP3 locus by dephosphorylating Dnmt1 and enhancing Akt phosphorylation at Ser473/Thr308,leading to impaired FoxP3 expression in T_(reg) cells.In summary,our study proposes Pp6 as a critical positive regulator of FoxP3 that acts by decreasing DNA methylation of the FoxP3 gene enhancer and inhibiting Akt signaling,thus maintaining T_(reg) cell stability and preventing autoimmune diseases.展开更多
Enzymes 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 and -4 (PFKFB-3 and PFKFB-4) play a significant role in the regulation of glycolysis in cancer cells as well as its proliferation and survival. The expres...Enzymes 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 and -4 (PFKFB-3 and PFKFB-4) play a significant role in the regulation of glycolysis in cancer cells as well as its proliferation and survival. The expression of these mRNAs is increased in malignant tumors and strongly induced in different cancer cell lines by hypoxia inducible factor (HIF) through active HIF binding sites in promoter region of PFKFB-4 and PFKFB-3 genes. Moreover, the expression and hypoxia responsibility of PFKFB-4 and PFKFB-3 was also shown for pancreatic (Panc1, PSN-1, and MIA PaCa-2) as well as gastric (MKN45 and NUGC3) cancer cells. At the same time, their basal expression level and hypoxia responsiveness vary in the different cells studied: the highest level of PFKFB-4 protein expression was found in NUGC3 gastric cancer cell line and lowest in Panc1 cells, with a stronger response to hypoxia in the pancreatic cancer cell line. Overexpression of different PFKFB in pancreatic and gastric cancer cells under hypoxic condition is correlated with enhanced expression of vascular endothelial growth factor (VEGF) and Glut1 mRNA as well as with increased level of HIF-1α protein. Increased expression of different PFKFB genes was also demonstrated in gastric, lung, breast, and colon cancers as compared to corresponding non-malignant tissue counterparts from the same patients, being more robust in the breast and lung tumors. Moreover, induction of PFKFB-4 mRNA expression in the breast and lung cancers is stronger than PFKFB-3 mRNA. The levels of both PFKFB-4 and PFKFB-3 proteins in non-malignant gastric and colon tissues were more pronounced than in the non-malignant breast and lung tissues. It is interesting to note that Panc1 and PSN-1 cells transfected with dominant/negative PFKFB-3 (dnPFKFB-3) showed a lower level of endogenous PFKFB-3, PFKFB-4, and VEGF mRNA expressions as well as a decreased proliferation rate of these cells. Moreover, a similar effect had dnPFKFB-4. In conclusion, there is strong evidence that PFKFB-4 and PFKFB-3 isoenzymes are induced under hypoxia in pancreatic and other cancer cell lines, are overexpressed in gastric, colon, lung, and breast malignant tumors and undergo changes in their metabolism that contribute to the proliferation and survival of cancer cells. Thus, targeting these PFKFB may therefore present new therapeutic opportunities.展开更多
文摘A genomic DNA fragment containing the 5'-upstream sequence and part of the open reading frame corresponding to the cytosolic fructose-1,6-bisphosphatase (cyFBPase) cDNA was isolated by Genome Walking. The 1 195 lip 5'-flanking region which started from the translation initiation ATG codon was fused to reporter gene encoding beta-glucuronidase (GUS) and stably transferred to rice via particle bombardment. Strong GUS activity was detected in leaves and leaf sheaths of transgenic rice, but not in culms and roots. Histochemical localization revealed that GUS expression was exclusively restricted to mesophyll cells in transgenic rice. Our results indicate that the 1 195 bp fragment contains all the cis-elements required for directing mesophyll-specific expression pattern in rice.
基金The National Natural Science Foundation of China under contract Nos 41176151 and 41276177the National High Technology Research&Development Program of China under contract No.2012AA100811the Funds for Distinguished Young Scientists of Fujian Province of China under contract No.2010J06016
文摘Fructose-1,6-bisphosphatase（FBPase） is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplification of cDNA ends（RACE） technology. The nucleotide sequence of PhcpFBPase consists of 1 400 bp, including a 5′ untranslated region（UTR） of 92 bp, a 3′？UTR of 69 bp, and an open reading frame（ORF） of 1 236 bp, which can be translated into a 412-amino-acid putative peptides with a molecular weight of 44.3 kDa and a theoretical pI of 5.23. Multiple sequence alignment indicated that the protein belonged to the chloroplast FBPase enzyme. Phylogenetic analysis showed that the protein assembled with the cpFBPase of a thermal tolerant unicellular red micro-algae Galdieria sulphuraria. Expression patterns analyzed by qRT-PCR revealed that the expression of PhcpFBPase gene in the thallus phage was 7-fold higher than in the conchocelis phage, which suggested the different mechanisms of inorganic carbon utilization among the different life phages of P. haitanensis. And the different response modes of PhcpFBPase mRNA levels to high temperature and desiccation stress indicated that PhcpFBPase played an important role in responsing to abiotic stress.
文摘Aim To investigate the effects of FDP on different liver injury models to explore the possibility of FDP used as an oral liver protective agent. Methods Chronic liver injury model in rats was induced by carbon tetrachloride （ CCl4 ） ; Acute liver injury model in mice was induced by aminogalactose （GAIN） or lipopolysaccharide （LPS）. Results In CCl4-induced chronic liver injury model, FDP （1 , 4 g·kg^-1·d^-1, q.d., for 10 weeks） significantly lowered ALT, AST,γ-glutamyl transpeptidase （γ-GT）, alkaline phosphatase （ALP）, and total bilirubin （T-BIL） in serum compared with vehicle; simultaneously it evidently elevated abnormal total protein （TP）, albumin （ALB） and total cholesterol （ T-CHO ） levels in serum; it also dose-dependently reduced hydroxyproline contents in hepatic tissue. 4 g·kg^-1·d^-1 of FDP apparently decreased incidence of hepatic cirrhosis, and alleviated pathological changes of liver tissue. In GaiN-induced model, 1.0 - 4. 0 g·kg^-1·d^-1 of FDP （ bid, for 3 d ） significantly lowered alanine aminotransferase （ ALT ） and aspartate aminotransferase （ AST ） levels in serum ; it also decreased liver coefficient. 4. 0 g·kg^-1·d^-1 of FDP significantly alleviated pathological changes of cell ultra-structures. In LPS-induced model, only high dose of FDP （4. 0 g·kg^-1·d^-1, bid, for 12 d） significantly decreased ALT level in serum. Conclusion This study first demonstrated the protective effect of oral FDP on chronic liver injury caused by CCl4, and confirmed its effect on acute liver injury at the same time, suggesting that Long-term oral FDP is efficacious against liver injury induced by different factors and can be used as an oral liver protective agent in clinic.
文摘Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) and activity of sarcoplosnic Ca2+-ATPase (SRCa2+-ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5 mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnl. CK-MB was detected by monoclonal antibody, Myo[Ca2+] was detected by fluorescent spectrophotometry and the activity of SRCa2+-ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnl and CK-MB, while at the same time decreased calcium concentration and increased SRCa2+-ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2+-ATPase activity in cardiomyocytes.
基金The project was supported by the National Natural Science Foundation of China No.3880772
文摘In the present experiment,fructose-1,6-diphosphate（FDP）and captopril（Cap）wereadded to the cold potassium cardioplegia solution and the levels of malondialdehyde（MDA）,cre-atine phosphokinase MB（CPK-MB）,thromboxane B（TXB<sub>2</sub>）and 6-keto-PGF<sub>1α</sub> in plasma weremeasured during open-heart surgery.Quantitative study of myocardial ultrastructure and obser-vation of cardiac resuscitation were also undertaken.The findings suggested that FDP,especiallywhen combined with Cap could significantly strengthen the protective effects of cold potassiumcardioplegia solution on ischemic myocardium.
文摘A substance in the crude preparation of NADP+ has been found, which activates snake muscle fructose-1,6-bisphosphatase at pH 9.2 and inhibits the enzyme at pH 7.5. After isolation and extensive characterization, the substance has been determined to be AMP. The activation depends on the concentrations of Mg2+ and could be observed only at concentrations above 1 mmol/L. In the presence of AMP, snake muscle fructose-1,6-bisphosphatase resembles an alkaline enzyme. Kinetic studies indicate that AMP and Mg2+ competitively regulate the activity of the enzyme. AMP releases the inhibition of Mg2+ at high concentration at alkaline pH. It has been reported that fructose-1,6-bisphosphatase with a pH optimum in the alkaline region is caused by limited proteolysis. AMP is also able to make fructose-1,6-bisphosphatase to be an alkaline enzyme. This finding indicates that proteolysis may not be the only reason for shift of the optimum pH of fructose-1,6-bisphosphatase to alkaline side and it may imply some significance in physiological regulation.
文摘Objective To investigate the roles of fructose-1,6-diphosphate(FDP)-added total parenteral nutrition (TPN)in septic animals and stressed patients.Methods Thirteen adult dogs were randomly assigned to one of two study groups 6 hours after the induction of severe intra-abdominal infection.Group TPN(n =6)received 70 kcal· kg-1· d-1 of nonprotein calorie(NPC)and 0.56 g· kg-1· d-1 of nitrogen.1 g/kg of FDP was also infused to the animals in group TPN + FDP(n = 7)everyday.In the clinical study,the control group received routine TPN,while the study group(n = 16)was treated with TPN plus FDP(5 g,two times a day)for 7 days.Results In dogs with TPN support,plasma ATP levels were not changed significantly,while the value in the TPN + FDP group increased significantly from 0.18 μmol/L to 0.46 μmol/L at 24 h and 0.51 μmol/L at 48 h(P ＜ 0.01).Muscular ATP increased markedly in the TPN + FDP group.Muscular creatine phosphate alues were not significantly changed in the TPN group,but the values increased in the TPN + FDP group from 4.06 μmol/g·wt at the beginning to 4.93 μmol/g· wt at 24 h and 5.60 μmol/g·wt at 48 h(P ＜ 0.05),with a cytochrome oxidase increase in immunohistochemistry stain.In the clinical study,plasma ATP levels increased and urinary 3-methylhistidine production significantly decreased with an improved value for positive accumulative nitrogen balance in the FDP-infused group.Conclusion Our results suggest that total parenteral nutrition support with the supplement of fructose-1,6-diphosphate has a positive role in body energy production and protein metabolism in septic animals and stressed patients.
文摘Using Rapid Amplification of cDNA ends (RACE) technique, the full-length cDNA en-coding a NaCl-induced fructose-1, 6- diphosphate aldolase (DsALDP) was obtained. It was shown that the DsALDP had a relatively high homology (66%—73%) to chloroplast fructose-1, 6-diphos- phate aldolase (AldP) in many plants according to their amino acid sequences. The phylogenetic analysis further confirmed that AldP in alga is the nearest to DsALDP. As to its expression pattern, DsALDP was de novo synthesized by NaCl induction. Its expression level was significantly changed with inducing time. After the selected DsALDP cDNA subcloned into a binary vector pBI121, the new construct was introduced into tobacco by Agrobacterium tumefaciens. The results of Southern blot and RT-PCR analysis of four transgenic T1 plants indicated that DsALDP was integrated into genome of these transgenic plants and effectively expressed. Aldolase activities have been detected in T1-1, T1-2 and T1-3 plants by bioassay under 100—200 mmol/L NaCl. It was also observed that proline contents in them were differentially increased.
基金Supported by the National Eighth Five-Year Key Project of China.
文摘In order to overcome the elementary heterogeneous nucleation whileoctahydro trisodium salt of fructose- 1, 6-diphosphate (FDPNa_3·8H_2O) is crystallized with ethanol precipitation at low temperature,a new crystallization method with alcohol precipitation combined withsalt precipitation has been presented. The ethanol-sodium ac- etatesystem for crystallization of salt of fructose-1, 6-diphosphate isbased on the mechanism of crystallization of FDPNA_3·8H_2O in theethanol-low temperature system. It is found that crystal size may becontrolled by regulating Temperature of pH value of solution in thecrystallization process, and the crystal yield increases to 95/100from 78/100 Which obtained in the ethanol-low temperature system.
基金Supported by the National Natural Science Foundation of China
文摘Permeable yeast cells were used in the batch production of fructose-1,6-diphosphate(FDP).The optimum reaction conditions were reported to be:reaction temperature 30℃,tolueneconcentration 8%(V/V),and initial ratio of glucose to inorganic phosphorus(Pi)10:1.Addition ofAMP was found to be very beneficial to the FDP production.A multienzyme system model for FDPaccumulation was developed,in which FDP was regarded as a substrate of phosphor-fructokinase(PFK),to simulate the activation effect of FDP on PFK.The model simulations were in good agree-ment with the experimental data.
基金This work is supported by grants from the National Natural Science Foundation of China(No.82070509,81930088,81725018)Innovative Research Team of High-Level Local Universities in Shanghai,and the Natural Science Foundation of Shanghai Science and Technology Committee,China(No.20ZR1447400).
文摘Regulatory T(T_(reg))cells constitute a dynamic population that is critical in autoimmunity.T_(reg) cell therapies for autoimmune diseases are mainly focused on enhancing their suppressive activities.However,recent studies demonstrated that certain inflammatory conditions induce T_(reg) cell instability with diminished FoxP3 expression and convert them into pathogenic effector cells.Therefore,the identification of novel targets crucial to both T_(reg) cell function and plasticity is of vital importance to the development of therapeutic approaches in autoimmunity.In this study,we found that conditional Pp6 knockout(cKO)in T_(reg) cells led to spontaneous autoinflammation,immune cell activation,and diminished levels of FoxP3 in CD4^(+)T cells in mice.Loss of Pp6 in T_(reg) cells exacerbated two classical mouse models of T_(reg)-related autoinflammation.Mechanistically,Pp6 deficiency increased CpG motif methylation of the FoxP3 locus by dephosphorylating Dnmt1 and enhancing Akt phosphorylation at Ser473/Thr308,leading to impaired FoxP3 expression in T_(reg) cells.In summary,our study proposes Pp6 as a critical positive regulator of FoxP3 that acts by decreasing DNA methylation of the FoxP3 gene enhancer and inhibiting Akt signaling,thus maintaining T_(reg) cell stability and preventing autoimmune diseases.
文摘Enzymes 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 and -4 (PFKFB-3 and PFKFB-4) play a significant role in the regulation of glycolysis in cancer cells as well as its proliferation and survival. The expression of these mRNAs is increased in malignant tumors and strongly induced in different cancer cell lines by hypoxia inducible factor (HIF) through active HIF binding sites in promoter region of PFKFB-4 and PFKFB-3 genes. Moreover, the expression and hypoxia responsibility of PFKFB-4 and PFKFB-3 was also shown for pancreatic (Panc1, PSN-1, and MIA PaCa-2) as well as gastric (MKN45 and NUGC3) cancer cells. At the same time, their basal expression level and hypoxia responsiveness vary in the different cells studied: the highest level of PFKFB-4 protein expression was found in NUGC3 gastric cancer cell line and lowest in Panc1 cells, with a stronger response to hypoxia in the pancreatic cancer cell line. Overexpression of different PFKFB in pancreatic and gastric cancer cells under hypoxic condition is correlated with enhanced expression of vascular endothelial growth factor (VEGF) and Glut1 mRNA as well as with increased level of HIF-1α protein. Increased expression of different PFKFB genes was also demonstrated in gastric, lung, breast, and colon cancers as compared to corresponding non-malignant tissue counterparts from the same patients, being more robust in the breast and lung tumors. Moreover, induction of PFKFB-4 mRNA expression in the breast and lung cancers is stronger than PFKFB-3 mRNA. The levels of both PFKFB-4 and PFKFB-3 proteins in non-malignant gastric and colon tissues were more pronounced than in the non-malignant breast and lung tissues. It is interesting to note that Panc1 and PSN-1 cells transfected with dominant/negative PFKFB-3 (dnPFKFB-3) showed a lower level of endogenous PFKFB-3, PFKFB-4, and VEGF mRNA expressions as well as a decreased proliferation rate of these cells. Moreover, a similar effect had dnPFKFB-4. In conclusion, there is strong evidence that PFKFB-4 and PFKFB-3 isoenzymes are induced under hypoxia in pancreatic and other cancer cell lines, are overexpressed in gastric, colon, lung, and breast malignant tumors and undergo changes in their metabolism that contribute to the proliferation and survival of cancer cells. Thus, targeting these PFKFB may therefore present new therapeutic opportunities.
