Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5...Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) Å, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.展开更多
Density functional theory BLYP (using Becke’s and Lee-Yang-Pars’s correlation functionals), ab initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrationa...Density functional theory BLYP (using Becke’s and Lee-Yang-Pars’s correlation functionals), ab initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of pyruvic acid. The scaled B3LYP/6-31G* frequencies correspond well with available experimental assignment of the functional vibrational modes and the mean absolut devation is only 12.3cm-1.展开更多
It is important to study the solvent effect on keto-enol tautomerism that has applications in many areas of chemical engineering.In this work,we use a multiscale reaction density functional theory(Rx DFT)to study the ...It is important to study the solvent effect on keto-enol tautomerism that has applications in many areas of chemical engineering.In this work,we use a multiscale reaction density functional theory(Rx DFT)to study the keto-enol tautomerism and isomerization of pyruvic acid.The results show that both effects of solvation and water assistance could reduce the reaction barriers.The water molecule participates the reaction as a catalyst to accept/give the protons with forming a hexagonal ring in the transition state.As a result of this temporary and intermediate hexagonal ring,the solute configuration undergoes a small variation during the reaction,giving a diminished contribution to the intrinsic reaction free energy.The solvent distribution shows a local ordering behavior near the solute that also reduces the contribution of solvation effect to the reaction barrier.Water assistance plays a major role in both pre-reaction and postreaction process.In terms of the driving force for the reaction,the effects of both solvation and water assistance are important.展开更多
BACKGROUND The pyruvate dehydrogenase E1 subunitβ(PDHB)gene which regulates energy metabolism is located in mitochondria.However,few studies have elucidated the role and mechanism of PDHB in different cancers.AIM To ...BACKGROUND The pyruvate dehydrogenase E1 subunitβ(PDHB)gene which regulates energy metabolism is located in mitochondria.However,few studies have elucidated the role and mechanism of PDHB in different cancers.AIM To comprehensive pan-cancer analysis of PDHB was performed based on bioinformatics approaches to explore its tumor diagnostic and prognostic value and tumor immune relevance in cancer.In vitro experiments were performed to examine the biological regulation of PDHB in liver cancer.METHODS Pan-cancer data related to PDHB were obtained from the Cancer Genome Atlas(TCGA)database.Analysis of the gene expression profiles of PDHB was based on TCGA and Genotype Tissue Expression Dataset databases.Cox regression analysis and Kaplan-Meier methods were used to assess the correlation between PDHB expression and survival prognosis in cancer patients.The correlation between PDHB and receiver operating characteristic diagnostic curve,clinicopathological staging,somatic mutation,tumor mutation burden(TMB),microsatellite instability(MSI),DNA methylation,and drug susceptibility in pan-cancer was also analyzed.Various algorithms were used to analyze the correlation between PDHB and immune cell infiltration and tumor chemotaxis environment,as well as the co-expression analysis of PDHB and immune checkpoint(ICP)genes.The expression and functional phenotype of PDHB in single tumor cells were studied by single-cell sequencing,and the functional enrichment analysis of PDHB-related genes was performed.The study also validated the level of mRNA or protein expression of PDHB in several cancers.Finally,in vitro experiments verified the regulatory effect of PDHB on the proliferation,migration,and invasion of liver cancer.RESULTS PDHB was significantly and differently expressed in most cancers.PDHB was significantly associated with prognosis in patients with a wide range of cancers,including kidney renal clear cell carcinoma,kidney renal papillary cell carcinoma,breast invasive carcinoma,and brain lower grade glioma.In some cancers,PDHB expression was clearly associated with gene mutations,clinicopathological stages,and expression of TMB,MSI,and ICP genes.The expression of PDHB was closely related to the infiltration of multiple immune cells in the immune microenvironment and the regulation of tumor chemotaxis environment.In addition,single-cell sequencing results showed that PDHB correlated with different biological phenotypes of multiple cancer single cells.This study further demonstrated that down-regulation of PDHB expression inhibited the proliferation,migration,and invasion functions of hepatoma cells.CONCLUSION As a member of pan-cancer,PDHB may be a novel cancer marker with potential value in diagnosing cancer,predicting prognosis,and in targeted therapy.展开更多
Primary biliary cholangitis(PBC)is a chronic cholestatic progressive liver disease and one of the most important progressive cholangiopathies in adults.Damage to cholangiocytes triggers the development of intrahepatic...Primary biliary cholangitis(PBC)is a chronic cholestatic progressive liver disease and one of the most important progressive cholangiopathies in adults.Damage to cholangiocytes triggers the development of intrahepatic cholestasis,which progresses to cirrhosis in the terminal stage of the disease.Accumulating data indicate that damage to biliary epithelial cells[(BECs),cholangiocytes]is most likely associated with the intracellular accumulation of bile acids,which have potent detergent properties and damaging effects on cell membranes.The mechanisms underlying uncontrolled bile acid intake into BECs in PBC are associated with pH change in the bile duct lumen,which is controlled by the bicarbonate(HCO3-)buffer system“biliary HCO3-umbrella”.The impaired production and entry of HCO3-from BECs into the bile duct lumen is due to epigenetic changes in expression of the X-linked microRNA 506.Based on the growing body of knowledge on the molecular mechanisms of cholangiocyte damage in patients with PBC,we propose a hypothesis explaining the pathogenesis of the first morphologic(ductulopenia),immunologic(antimitochondrial autoantibodies)and clinical(weakness,malaise,rapid fatigue)signs of the disease in the asymptomatic stage.This review focuses on the consideration of these mechanisms.展开更多
Background: Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol(Cel) is a natural anti-infl...Background: Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol(Cel) is a natural anti-inflammatory compound that shows potential against systemic inflammatory diseases. This study aimed to investigate the pharmacological activity and molecular mechanism of Cel in models of endotoxemia and sepsis.Methods: We evaluated the anti-inflammatory efficacy of Cel against endotoxemia and sepsis in mice and macrophage cultures treated with lipopolysaccharide(LPS). We screened for potential protein targets of Cel using activity-based protein profiling(ABPP). Potential targets were validated using biophysical methods such as cellular thermal shift assays(CETSA) and surface plasmon resonance(SPR). Residues involved in Cel binding to target proteins were identified through point mutagenesis, and the functional effects of such binding were explored through gene knockdown.Results: Cel protected mice from lethal endotoxemia and improved their survival with sepsis, and it significantly decreased the levels of pro-inflammatory cytokines in mice and macrophages treated with LPS(P <0.05). Cel bound to Cys424 of pyruvate kinase M2(PKM2), inhibiting the enzyme and thereby suppressing aerobic glycolysis(Warburg effect). Cel also bound to Cys106 in high mobility group box 1(HMGB1) protein, reducing the secretion of inflammatory cytokine interleukin(IL)-1β. Cel bound to the Cys residues in lactate dehydrogenase A(LDHA).Conclusions: Cel inhibits inflammation and the Warburg effect in sepsis via targeting PKM2 and HMGB1 protein.展开更多
Background:The expression of pyruvate kinase muscle 2(PKM2)is augmented in macrophages of patients with atherosclerotic coronary artery disease.The role of PKM2 in atherosclerosis is to be determined.Methods:Global an...Background:The expression of pyruvate kinase muscle 2(PKM2)is augmented in macrophages of patients with atherosclerotic coronary artery disease.The role of PKM2 in atherosclerosis is to be determined.Methods:Global and myeloid cell-specific PKM2 knock-in mice with ApoE^(-/-)background(ApoE^(-/-),PKM2^(KI/KI)and Lyz2-cre,ApoE^(-/-),and PKM2^(flox/flox))were produced to evaluate the clinical significance of PKM2 in atherosclerosis development.Wild-type and PKM2 knock-in macrophages were isolated to assess the function of PKM2 in macrophage phagocytosis.Atherosclerotic mice were treated with PKM2 inhibitor shikonin(SKN)to evaluate the therapeutic potential of PKM2 suppression in atherosclerosis.Results:Oxidized low-density lipoprotein(oxLDL)upregulated PKM2 in macrophages.PKM2 in return promoted the uptake of oxLDL by macrophages.Overexpressed PKM2 accelerated atherosclerosis in mice.SKN blocked the progress of mouse atherosclerosis.Conclusions:PKM2 accelerates macrophage phagocytosis and atherosclerosis.Targeting PKM2 is a potential therapy for atherosclerosis.展开更多
In the present, investigation effects of sub-lethal dose of purified paper wasp Ropalidia marginata venom toxins were evaluated on important metabolic enzymes i.e. ALP ACP, GPT, GOT, LDH, and AchE enzyme activity in s...In the present, investigation effects of sub-lethal dose of purified paper wasp Ropalidia marginata venom toxins were evaluated on important metabolic enzymes i.e. ALP ACP, GPT, GOT, LDH, and AchE enzyme activity in serum, liver, and gastrocnemius muscles of albino mice. Alkaline phosphatase was found to be increased up to 119.9% at the 6<sup>th</sup> hr of the toxin injection in comparison to control. This elevation may be due to cytolysis. Maximum increase i.e., 153.33% level of glutamate pyruvate transaminase (GPT) was found at 6 hrs of 40% of 24-h LD<sub>50</sub> treatment while it was found to be 151.1% at 6 hrs of 24 hr 80% of LD<sub>50</sub>, venom injection. A significant elevation was observed in LDH activity in serum, liver, and muscles, while the activity of AchE was decreased in serum, liver, and gastrocnemius muscles of albino mice after injecting the sub-lethal dose of Ropalidia marginata venom. This increase in the activity of LDH produces liver damage, massive disintegration and necrosis of hepatic cells. This elevation in LDH level led to a significant increase in the glucose catabolism and elevated oxidative stress in muscle and liver cells. It also displays insufficient oxygen supply and consequently leads to cell death. In experimental animals, venom toxin treatment decreased AchE level, and animals showed muscular paralysis. When mice were treated with 40% and 80% of 24-h LD<sub>50</sub> of purified venom caused a significant (p < 0.05) elevation in the level of ACP, GOT, GPT, and LDH while the reduction in ALP and AChE level. Present study will be useful in the development of prototypes for study of pharmacological and therapeutic effects of various venom toxins. For this purpose structure activity relationship of enzyme and venom toxin, its due interaction to various metabolic enzymes and receptors must be explored.展开更多
In the present investigation, in vivo effects of purified ticks’ saliva toxin were evaluated on the level of certain important cellular metabolic enzymes i.e. acid phosphatase (ACP), alkaline phosphatase (ALP), gluta...In the present investigation, in vivo effects of purified ticks’ saliva toxin were evaluated on the level of certain important cellular metabolic enzymes i.e. acid phosphatase (ACP), alkaline phosphatase (ALP), glutamate pyruvate transaminase, glutamate oxaloacetate transaminase and lactic dehydrogenase. For this purpose, sub-lethal doses, 40% and 80% of 24 h LD50 purified saliva toxins of Rhipicephalus microplus (Canestrini, 1888) were injected subcutaneously in the albino mice. In treated mice saliva toxins targeted membrane-bound enzymes i.e. serum acid phosphatase and alkaline phosphatase, its level was increased from 118.30% to 163.63% at the 6th hr in comparison to the control. Besides this, the levels of serum glutamate pyruvate transaminase (GPT) and glutamate oxaloacetate transaminase (GOT) and lactic dehydrogenase (LDH) also increased up to 161.11% (at 6th hr), 148.27 (at 8th hr) and 125.45% (at 6th hr) respectively in comparison to control. An increase in the level of LDH showed insufficient oxygen supply, massive disintegration of cells and leakage of the enzyme into the circulation. It clearly indicated the toxic effects of saliva toxins on the membrane of blood cells, hepatocytes and myocardial muscle cell functions in albino mice. On the other hand activity of acetyl cholinesterase was reduced by 65.51% at the 6th hr of the saliva toxin injection in comparison to the control. This inhibition of acetyl cholinesterase activity caused the accumulation of acetylcholine molecules at the synaptic junctions and led to prolonged activation of acetylcholine receptors. It caused permanent stimulation of nerves and muscle cells that may result in muscular paralysis and finally death of the animal.展开更多
A simple and fastthree-component synthesis of new and biologically active hexahydro-2-quinolinecarboxylic acid scaf-fold 4 was carried out using cyclocondensation reaction of arylmethylidenepyruvic acids 1, 1,3-cycloh...A simple and fastthree-component synthesis of new and biologically active hexahydro-2-quinolinecarboxylic acid scaf-fold 4 was carried out using cyclocondensation reaction of arylmethylidenepyruvic acids 1, 1,3-cyclohexandiones 2 and ammonium acetate 3 under solvent-free conditions and at room temperature. This protocol has the advantages of facility, easy work-up, high yields, short reaction time and environmentally friendly character.展开更多
AIM: To investigate the inhibitory effects and mechanism of high mobility group box(HMGB)1 A-box in lipopolysaccharide(LPS)-induced intestinal inflammation.METHODS: Overexpression of HMGB1 A-box in human intestinal ep...AIM: To investigate the inhibitory effects and mechanism of high mobility group box(HMGB)1 A-box in lipopolysaccharide(LPS)-induced intestinal inflammation.METHODS: Overexpression of HMGB1 A-box in human intestinal epithelial cell lines(SW480 cells) was achieved using the plasmid p EGFP-N1. HMGB1 A-box-overexpressing SW480 cells were stimulated with LPS and co-culturing with human monocyte-like cell lines(THP-1 cells) using a Transwell system, compared with another HMGB1 inhibitor ethyl pyruvate(EP). The m RNA and protein levels of HMGB1/toll-like receptor(TLR) 4 signaling pathways [including HMGB1, TLR4, myeloid differentiation factor88(MYD88), Phosphorylated Nuclear Factor κB(p NF-κB) p65] in the stimulated cells were determined by realtime polymerase chain reaction and Western blotting. The levels of the proinflammatory mediators [including HMGB1, interleukin(IL)-1β, IL-6 and tumor necrosis factor(TNF)-α] in the supernatants of the stimulated cells were determined by ELISA.RESULTS: EP downregulated the m RNA and protein levels of HMGB1, inhibited the TLR4 signaling pathways(TLR4, MYD88 and p NF-κB p65) and reduced the secretion of proinflammatory mediators(HMGB1, IL-1β, IL-6 and TNF-α) in the SW480 and THP-1 cells activated by LPS but not in the unstimulated cells. Activated by LPS, the overexpression of HMGB1 A-box in the SW480 cells also inhibited the HMGB1/TLR4 signaling pathways and reduced the secretion of these proinflammatory mediators in the THP-1 cells but not in the transfected and unstimulated cells. CONCLUSION: HMGB1 A-box, not only EP, can reduce LPS-induced intestinal inflammation through inhibition of the HMGB1/TLR4 signaling pathways.展开更多
BACKGROUND: The pathogenesis and progression of acute liver failure (ALF) are closely associated with intestinal endotoxemia because of the high permeability of the intestinal wall. Treatment with ethyl pyruvate (EP) ...BACKGROUND: The pathogenesis and progression of acute liver failure (ALF) are closely associated with intestinal endotoxemia because of the high permeability of the intestinal wall. Treatment with ethyl pyruvate (EP) has been shown to protect liver failure effectively. The current study aimed to explore the relationship between proinflammatory cytokines and intestinal permeability, and to investigate whether EP administration might prevent the release of multiple proinflammatory cytokines and decrease intestinal permeability and therefore, protect the liver from injury. METHODS: The ALF model was induced by D-galactosamine in rats. The rats were randomly divided into control (saline i.p.), model (D-galactosamine, 1.2 g/kg, i.p.), prevention [EP injection (40 mg/kg) 2 hours ahead of D-galactosamine] and treatment groups (EP injection 2 hours after D-galactosamine) Samples were obtained at 12 and 24 hours after ALF induction respectively. The histology of liver and intestinal tissue was accessed. Serum alanine aminotransferase, endotoxin, D(-) lactate, diamine oxidase (DAO), tumor necrosis factor-alpha (TNF-α), interferon-γ (IFN-γ) and high mobility group box-1 (HMGB1) were evaluated. The survival of rats was also recorded. RESULTS: The rats in model group showed severe damage to liver tissue and intestinal mucosa 12 and 24 hours after ALF induction. EP significantly improved liver or intestinal injury In addition, serum endotoxin, D(-)-lactate, DAO, TNF-α IFN-γ and HMGB1 levels were significantly increased in the model group compared with the control group. There was a positive correlation between intestinal permeability andproinflammatory cytokines. EP significantly reduced serum endotoxin, D(-)-lactate, DAO, TNF-α, IFN-γ and HMGB1 levels. The median survival time was significantly prolonged in both prevention and treatment groups (126 and 120 hours compared with 54 hours in the model group). CONCLUSIONS: EP has protective and therapeutic effects on intestinal mucosa. EP decreases intestinal permeability, and inhibits the release of multiple proinflammatory cytokines in rats with ALF.展开更多
AIM:To search for further immunodominant peptides of the pyruvate dehydrogenase complex E2-component (PDC-E2) recognized by antimitochondrial antibodies (AMA) in primary biliary cirrhosis (PBC). METHODS:Sera from 95 p...AIM:To search for further immunodominant peptides of the pyruvate dehydrogenase complex E2-component (PDC-E2) recognized by antimitochondrial antibodies (AMA) in primary biliary cirrhosis (PBC). METHODS:Sera from 95 patients with PBC were tested by enzyme-linked immunosorbent assay against 33 synthetic overlapping peptides (25 amino acids; aa) covering the entire length of the E2-subunit of PDC-E2. Furthermore,the inner lipoyl peptide 167-184 was used in an unlip oylated and a lipoylated form as well as coupled to ovalbumin. Sera from 11 AMA negative/ANA posit ive PBC patients,63 patients with other liver disorders and 22 healthy blood donors served as controls.RESULTS:Of the 95 PBC-sera,74% reacted with the peptide 475-499 and 58% with the pept ide 407-431 located within the catalytic domain of PDC-E2. Patients with other disorders or healthy controls were positive in only up to 18%. Antibodies to the unlipoylatedand lip oylated pept ide 167-184 within the inner lipoyl domain were found in only 5% and 11% of the PBC sera,respectively; using ovalbumin-coupled peptides,the incidence increased up to 57% (unlipoylated form). CONCLUSION:Peptides within the catalytic site of PDC-E2 rather than the previously reported lipoyl binding peptide 167-184 may represent major immunodomin ant epitopes recognized by AMA in PBC.展开更多
BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate de...BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate dehydrogenase kinase 1 in myeloma. STAT3 and pyruvate kinase M2(PKM2) can also be activated and enhance the Warburg effect in hepatocellular carcinoma. Precancerous lesions are critical to human and rodent hepatocarcinogenesis. However, the underlying molecular mechanism for the development of liver precancerous lesions remains unknown. We hypothesized that STAT3 promotes the Warburg effect possibly by upregulating p-PKM2 in liver precancerous lesions in rats.AIM To investigate the mechanism of the Warburg effect in liver precancerous lesions in rats.METHODS A model of liver precancerous lesions was established by a modified Solt-Farber method. The liver pathological changes were observed by HE staining and immunohistochemistry. The transformation of WB-F344 cells induced with Nmethyl-N'-nitro-N-nitrosoguanidine and hydrogen peroxide was evaluated by the soft agar assay and aneuploidy. The levels of glucose and lactate in the tissue and culture medium were detected with a spectrophotometer. The protein levels of glutathione S-transferase-π, proliferating cell nuclear antigen(PCNA), STAT3,and PKM2 were examined by Western blot and immunofluorescence.RESULTS We found that the Warburg effect was increased in liver precancerous lesions in rats. PKM2 and p-STAT3 were upregulated in activated oval cells in liverprecancerous lesions in rats. The Warburg effect, p-PKM2, and p-STAT3 expression were also increased in transformed WB-F344 cells. STAT3 activation promoted the clonal formation rate, aneuploidy, alpha-fetoprotein expression,PCNA expression, G1/S phase transition, the Warburg effect, PKM2 phosphorylation, and nuclear translocation in transformed WB-F344 cells.Moreover, the Warburg effect was inhibited by stattic, a specific inhibitor of STAT3, and further reduced in transformed WB-F344 cells after the intervention for PKM2.CONCLUSION The Warburg effect is initiated in liver precancerous lesions in rats. STAT3 activation promotes the Warburg effect by enhancing the phosphorylation of PKM2 in transformed WB-F344 cells.展开更多
Type A lactic acidosis resulted from hypoxic mitochondrial dysfunction is an independent predictor of mortality for critically ill patients. However, current therapeutic agents are still in shortage and can even be ha...Type A lactic acidosis resulted from hypoxic mitochondrial dysfunction is an independent predictor of mortality for critically ill patients. However, current therapeutic agents are still in shortage and can even be harmful. This paper reviewed data regarding lactic acidosis treatment and recommended that pyruvate might be a potential alkalizer to correct type A lactic acidosis in future clinical practice. Pyruvate is a key energy metabolic substrate and a pyruvate dehydrogenase(PDH) activator with several unique beneficial biological properties, including anti-oxidant and antiinflammatory effects and the ability to activate the hypoxia-inducible factor-1(HIF-1α)-erythropoietin(EPO) signal pathway. Pyruvate preserves glucose metabolism and cellular energetics better than bicarbonate, lactate, acetate and malate in the efficient correction of hypoxic lactic acidosis and shows few side effects. Therefore, application of pyruvate may be promising and safe as a novel therapeutic strategy in hypoxic lactic acidosis correction accompanied with multi-organ protection in critical care patients.展开更多
AIM:To investigate the expression and prognostic role of pyruvate dehydrogenase(PDH) in gastric cancer(GC).METHODS:This study included 265 patients(194 male,71 female,mean age 59 years(range,29-81 years) with GC who u...AIM:To investigate the expression and prognostic role of pyruvate dehydrogenase(PDH) in gastric cancer(GC).METHODS:This study included 265 patients(194 male,71 female,mean age 59 years(range,29-81 years) with GC who underwent curative surgery at the First Affiliated Hospital of China Medical University from January 2006 to May 2007.All patients were followed up for more than 5 years.Patient-derived paraffin embedded GC specimens were collected for tissue microarrays(TMAs).We examined PDH expression by immunohistochemistry in TMAs containing tumor tissue and matched nonneoplastic mucosa.Immunoreactivity was evaluated independently by two researchers.Overall survival(OS) rates were determined using the Kaplan-Meier estimator.Correlations with other clinicopathologic factors were evaluated by two-tailed χ2 tests or a two-tailed t-test.The Cox proportional-hazard model was used in univariate analysis and multivariate analysis to identify factors significantly correlated with prognosis.RESULTS:Immunohistochemistry showed that 35.47% of total cancer tissue specimens had cytoplasmic PDH staining.PDH expression was much higher in normal mucosa specimens(75.09%;P = 0.001).PDH expression was correlated with Lauren grade(70.77% in intestinal type vs 40.0% in diffuse type;P = 0.001),lymph node metastasis(65.43% with no metastasis vs 51.09% with metastasis;P = 0.033),lymphatic invasion(61.62% with no invasion vs 38.81% with invasion;P = 0.002),histologic subtypes(70.77% in intestinal type vs 40.0% in diffuse type;P = 0.001) and tumor-node-metastasis(TNM) stage(39% in poorly differentiated vs 65.91% in well differentiated and 67.11% in moderately differentiated;P = 0.001) in GC.PDH expression in cancer tissue was significantly associated with higher OS(P < 0.001).The multivariate analysis adjusted for age,Lauren classification,TNM stage,lymph node metastasis,histological type,tumor size,depth of invasion and lymphatic invasion showed that the PDH expression in GC was an independent prognostic factor for higher OS(HR = 0.608,95%CI:0.504-0.734,P < 0.001).CONCLUSION:Our study indicated that PDH expression is an independent prognostic factor in GC patients and that positive expression of PDH may be predictive of favorable outcomes.展开更多
Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and t...Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.展开更多
文摘Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) &ARING;, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.
基金This work was supported by the Natural Science Foundation of Shandong Province. the National Key Laboratory Foundation of Cry
文摘Density functional theory BLYP (using Becke’s and Lee-Yang-Pars’s correlation functionals), ab initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of pyruvic acid. The scaled B3LYP/6-31G* frequencies correspond well with available experimental assignment of the functional vibrational modes and the mean absolut devation is only 12.3cm-1.
基金National Natural Science Foundation of China(Nos.21978079,and 21878078).
文摘It is important to study the solvent effect on keto-enol tautomerism that has applications in many areas of chemical engineering.In this work,we use a multiscale reaction density functional theory(Rx DFT)to study the keto-enol tautomerism and isomerization of pyruvic acid.The results show that both effects of solvation and water assistance could reduce the reaction barriers.The water molecule participates the reaction as a catalyst to accept/give the protons with forming a hexagonal ring in the transition state.As a result of this temporary and intermediate hexagonal ring,the solute configuration undergoes a small variation during the reaction,giving a diminished contribution to the intrinsic reaction free energy.The solvent distribution shows a local ordering behavior near the solute that also reduces the contribution of solvation effect to the reaction barrier.Water assistance plays a major role in both pre-reaction and postreaction process.In terms of the driving force for the reaction,the effects of both solvation and water assistance are important.
基金Supported by The 2021 Central-Guided Local Science and Technology Development FundLanzhou COVID-19 Prevention and Control Technology Research Project,No.2020-XG-1Gansu Province Outstanding Graduate Student"Innovation Star"Project,No.2022CXZX-748,No.2022CXZX-746.
文摘BACKGROUND The pyruvate dehydrogenase E1 subunitβ(PDHB)gene which regulates energy metabolism is located in mitochondria.However,few studies have elucidated the role and mechanism of PDHB in different cancers.AIM To comprehensive pan-cancer analysis of PDHB was performed based on bioinformatics approaches to explore its tumor diagnostic and prognostic value and tumor immune relevance in cancer.In vitro experiments were performed to examine the biological regulation of PDHB in liver cancer.METHODS Pan-cancer data related to PDHB were obtained from the Cancer Genome Atlas(TCGA)database.Analysis of the gene expression profiles of PDHB was based on TCGA and Genotype Tissue Expression Dataset databases.Cox regression analysis and Kaplan-Meier methods were used to assess the correlation between PDHB expression and survival prognosis in cancer patients.The correlation between PDHB and receiver operating characteristic diagnostic curve,clinicopathological staging,somatic mutation,tumor mutation burden(TMB),microsatellite instability(MSI),DNA methylation,and drug susceptibility in pan-cancer was also analyzed.Various algorithms were used to analyze the correlation between PDHB and immune cell infiltration and tumor chemotaxis environment,as well as the co-expression analysis of PDHB and immune checkpoint(ICP)genes.The expression and functional phenotype of PDHB in single tumor cells were studied by single-cell sequencing,and the functional enrichment analysis of PDHB-related genes was performed.The study also validated the level of mRNA or protein expression of PDHB in several cancers.Finally,in vitro experiments verified the regulatory effect of PDHB on the proliferation,migration,and invasion of liver cancer.RESULTS PDHB was significantly and differently expressed in most cancers.PDHB was significantly associated with prognosis in patients with a wide range of cancers,including kidney renal clear cell carcinoma,kidney renal papillary cell carcinoma,breast invasive carcinoma,and brain lower grade glioma.In some cancers,PDHB expression was clearly associated with gene mutations,clinicopathological stages,and expression of TMB,MSI,and ICP genes.The expression of PDHB was closely related to the infiltration of multiple immune cells in the immune microenvironment and the regulation of tumor chemotaxis environment.In addition,single-cell sequencing results showed that PDHB correlated with different biological phenotypes of multiple cancer single cells.This study further demonstrated that down-regulation of PDHB expression inhibited the proliferation,migration,and invasion functions of hepatoma cells.CONCLUSION As a member of pan-cancer,PDHB may be a novel cancer marker with potential value in diagnosing cancer,predicting prognosis,and in targeted therapy.
文摘Primary biliary cholangitis(PBC)is a chronic cholestatic progressive liver disease and one of the most important progressive cholangiopathies in adults.Damage to cholangiocytes triggers the development of intrahepatic cholestasis,which progresses to cirrhosis in the terminal stage of the disease.Accumulating data indicate that damage to biliary epithelial cells[(BECs),cholangiocytes]is most likely associated with the intracellular accumulation of bile acids,which have potent detergent properties and damaging effects on cell membranes.The mechanisms underlying uncontrolled bile acid intake into BECs in PBC are associated with pH change in the bile duct lumen,which is controlled by the bicarbonate(HCO3-)buffer system“biliary HCO3-umbrella”.The impaired production and entry of HCO3-from BECs into the bile duct lumen is due to epigenetic changes in expression of the X-linked microRNA 506.Based on the growing body of knowledge on the molecular mechanisms of cholangiocyte damage in patients with PBC,we propose a hypothesis explaining the pathogenesis of the first morphologic(ductulopenia),immunologic(antimitochondrial autoantibodies)and clinical(weakness,malaise,rapid fatigue)signs of the disease in the asymptomatic stage.This review focuses on the consideration of these mechanisms.
基金suppor ted by the National Key Research and Development Program of China(2020YFA0908000)the Innovation Team and Talents Cultivation Program of the National Administration of Traditional Chinese Medicine(ZYYCXTD-C-202002)+1 种基金the National Natural Science Foundation of China(82074098,81841001)the Fundamental Research Funds for the Central Public Welfare Research Institutes(ZXKT18003)。
文摘Background: Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol(Cel) is a natural anti-inflammatory compound that shows potential against systemic inflammatory diseases. This study aimed to investigate the pharmacological activity and molecular mechanism of Cel in models of endotoxemia and sepsis.Methods: We evaluated the anti-inflammatory efficacy of Cel against endotoxemia and sepsis in mice and macrophage cultures treated with lipopolysaccharide(LPS). We screened for potential protein targets of Cel using activity-based protein profiling(ABPP). Potential targets were validated using biophysical methods such as cellular thermal shift assays(CETSA) and surface plasmon resonance(SPR). Residues involved in Cel binding to target proteins were identified through point mutagenesis, and the functional effects of such binding were explored through gene knockdown.Results: Cel protected mice from lethal endotoxemia and improved their survival with sepsis, and it significantly decreased the levels of pro-inflammatory cytokines in mice and macrophages treated with LPS(P <0.05). Cel bound to Cys424 of pyruvate kinase M2(PKM2), inhibiting the enzyme and thereby suppressing aerobic glycolysis(Warburg effect). Cel also bound to Cys106 in high mobility group box 1(HMGB1) protein, reducing the secretion of inflammatory cytokine interleukin(IL)-1β. Cel bound to the Cys residues in lactate dehydrogenase A(LDHA).Conclusions: Cel inhibits inflammation and the Warburg effect in sepsis via targeting PKM2 and HMGB1 protein.
基金National Key R&D program of China,Grant/Award Number:2021YFC2500700The National Natural Science Foundation of China+1 种基金Grant/Award Number:81730078The Chinese Academy of Medical Sciences Initiative for Innovative Medicine,Grant/Award Number:2021-I2M-1-049。
文摘Background:The expression of pyruvate kinase muscle 2(PKM2)is augmented in macrophages of patients with atherosclerotic coronary artery disease.The role of PKM2 in atherosclerosis is to be determined.Methods:Global and myeloid cell-specific PKM2 knock-in mice with ApoE^(-/-)background(ApoE^(-/-),PKM2^(KI/KI)and Lyz2-cre,ApoE^(-/-),and PKM2^(flox/flox))were produced to evaluate the clinical significance of PKM2 in atherosclerosis development.Wild-type and PKM2 knock-in macrophages were isolated to assess the function of PKM2 in macrophage phagocytosis.Atherosclerotic mice were treated with PKM2 inhibitor shikonin(SKN)to evaluate the therapeutic potential of PKM2 suppression in atherosclerosis.Results:Oxidized low-density lipoprotein(oxLDL)upregulated PKM2 in macrophages.PKM2 in return promoted the uptake of oxLDL by macrophages.Overexpressed PKM2 accelerated atherosclerosis in mice.SKN blocked the progress of mouse atherosclerosis.Conclusions:PKM2 accelerates macrophage phagocytosis and atherosclerosis.Targeting PKM2 is a potential therapy for atherosclerosis.
文摘In the present, investigation effects of sub-lethal dose of purified paper wasp Ropalidia marginata venom toxins were evaluated on important metabolic enzymes i.e. ALP ACP, GPT, GOT, LDH, and AchE enzyme activity in serum, liver, and gastrocnemius muscles of albino mice. Alkaline phosphatase was found to be increased up to 119.9% at the 6<sup>th</sup> hr of the toxin injection in comparison to control. This elevation may be due to cytolysis. Maximum increase i.e., 153.33% level of glutamate pyruvate transaminase (GPT) was found at 6 hrs of 40% of 24-h LD<sub>50</sub> treatment while it was found to be 151.1% at 6 hrs of 24 hr 80% of LD<sub>50</sub>, venom injection. A significant elevation was observed in LDH activity in serum, liver, and muscles, while the activity of AchE was decreased in serum, liver, and gastrocnemius muscles of albino mice after injecting the sub-lethal dose of Ropalidia marginata venom. This increase in the activity of LDH produces liver damage, massive disintegration and necrosis of hepatic cells. This elevation in LDH level led to a significant increase in the glucose catabolism and elevated oxidative stress in muscle and liver cells. It also displays insufficient oxygen supply and consequently leads to cell death. In experimental animals, venom toxin treatment decreased AchE level, and animals showed muscular paralysis. When mice were treated with 40% and 80% of 24-h LD<sub>50</sub> of purified venom caused a significant (p < 0.05) elevation in the level of ACP, GOT, GPT, and LDH while the reduction in ALP and AChE level. Present study will be useful in the development of prototypes for study of pharmacological and therapeutic effects of various venom toxins. For this purpose structure activity relationship of enzyme and venom toxin, its due interaction to various metabolic enzymes and receptors must be explored.
文摘In the present investigation, in vivo effects of purified ticks’ saliva toxin were evaluated on the level of certain important cellular metabolic enzymes i.e. acid phosphatase (ACP), alkaline phosphatase (ALP), glutamate pyruvate transaminase, glutamate oxaloacetate transaminase and lactic dehydrogenase. For this purpose, sub-lethal doses, 40% and 80% of 24 h LD50 purified saliva toxins of Rhipicephalus microplus (Canestrini, 1888) were injected subcutaneously in the albino mice. In treated mice saliva toxins targeted membrane-bound enzymes i.e. serum acid phosphatase and alkaline phosphatase, its level was increased from 118.30% to 163.63% at the 6th hr in comparison to the control. Besides this, the levels of serum glutamate pyruvate transaminase (GPT) and glutamate oxaloacetate transaminase (GOT) and lactic dehydrogenase (LDH) also increased up to 161.11% (at 6th hr), 148.27 (at 8th hr) and 125.45% (at 6th hr) respectively in comparison to control. An increase in the level of LDH showed insufficient oxygen supply, massive disintegration of cells and leakage of the enzyme into the circulation. It clearly indicated the toxic effects of saliva toxins on the membrane of blood cells, hepatocytes and myocardial muscle cell functions in albino mice. On the other hand activity of acetyl cholinesterase was reduced by 65.51% at the 6th hr of the saliva toxin injection in comparison to the control. This inhibition of acetyl cholinesterase activity caused the accumulation of acetylcholine molecules at the synaptic junctions and led to prolonged activation of acetylcholine receptors. It caused permanent stimulation of nerves and muscle cells that may result in muscular paralysis and finally death of the animal.
文摘A simple and fastthree-component synthesis of new and biologically active hexahydro-2-quinolinecarboxylic acid scaf-fold 4 was carried out using cyclocondensation reaction of arylmethylidenepyruvic acids 1, 1,3-cyclohexandiones 2 and ammonium acetate 3 under solvent-free conditions and at room temperature. This protocol has the advantages of facility, easy work-up, high yields, short reaction time and environmentally friendly character.
基金Supported by National Natural Science Foundation of China,No.81160056the Youth Science Foundation of Jiangxi Provincial,China,No.20132BAB215017
文摘AIM: To investigate the inhibitory effects and mechanism of high mobility group box(HMGB)1 A-box in lipopolysaccharide(LPS)-induced intestinal inflammation.METHODS: Overexpression of HMGB1 A-box in human intestinal epithelial cell lines(SW480 cells) was achieved using the plasmid p EGFP-N1. HMGB1 A-box-overexpressing SW480 cells were stimulated with LPS and co-culturing with human monocyte-like cell lines(THP-1 cells) using a Transwell system, compared with another HMGB1 inhibitor ethyl pyruvate(EP). The m RNA and protein levels of HMGB1/toll-like receptor(TLR) 4 signaling pathways [including HMGB1, TLR4, myeloid differentiation factor88(MYD88), Phosphorylated Nuclear Factor κB(p NF-κB) p65] in the stimulated cells were determined by realtime polymerase chain reaction and Western blotting. The levels of the proinflammatory mediators [including HMGB1, interleukin(IL)-1β, IL-6 and tumor necrosis factor(TNF)-α] in the supernatants of the stimulated cells were determined by ELISA.RESULTS: EP downregulated the m RNA and protein levels of HMGB1, inhibited the TLR4 signaling pathways(TLR4, MYD88 and p NF-κB p65) and reduced the secretion of proinflammatory mediators(HMGB1, IL-1β, IL-6 and TNF-α) in the SW480 and THP-1 cells activated by LPS but not in the unstimulated cells. Activated by LPS, the overexpression of HMGB1 A-box in the SW480 cells also inhibited the HMGB1/TLR4 signaling pathways and reduced the secretion of these proinflammatory mediators in the THP-1 cells but not in the transfected and unstimulated cells. CONCLUSION: HMGB1 A-box, not only EP, can reduce LPS-induced intestinal inflammation through inhibition of the HMGB1/TLR4 signaling pathways.
基金supported by a grant from the National Natural Science Foundation of China (81071342)
文摘BACKGROUND: The pathogenesis and progression of acute liver failure (ALF) are closely associated with intestinal endotoxemia because of the high permeability of the intestinal wall. Treatment with ethyl pyruvate (EP) has been shown to protect liver failure effectively. The current study aimed to explore the relationship between proinflammatory cytokines and intestinal permeability, and to investigate whether EP administration might prevent the release of multiple proinflammatory cytokines and decrease intestinal permeability and therefore, protect the liver from injury. METHODS: The ALF model was induced by D-galactosamine in rats. The rats were randomly divided into control (saline i.p.), model (D-galactosamine, 1.2 g/kg, i.p.), prevention [EP injection (40 mg/kg) 2 hours ahead of D-galactosamine] and treatment groups (EP injection 2 hours after D-galactosamine) Samples were obtained at 12 and 24 hours after ALF induction respectively. The histology of liver and intestinal tissue was accessed. Serum alanine aminotransferase, endotoxin, D(-) lactate, diamine oxidase (DAO), tumor necrosis factor-alpha (TNF-α), interferon-γ (IFN-γ) and high mobility group box-1 (HMGB1) were evaluated. The survival of rats was also recorded. RESULTS: The rats in model group showed severe damage to liver tissue and intestinal mucosa 12 and 24 hours after ALF induction. EP significantly improved liver or intestinal injury In addition, serum endotoxin, D(-)-lactate, DAO, TNF-α IFN-γ and HMGB1 levels were significantly increased in the model group compared with the control group. There was a positive correlation between intestinal permeability andproinflammatory cytokines. EP significantly reduced serum endotoxin, D(-)-lactate, DAO, TNF-α, IFN-γ and HMGB1 levels. The median survival time was significantly prolonged in both prevention and treatment groups (126 and 120 hours compared with 54 hours in the model group). CONCLUSIONS: EP has protective and therapeutic effects on intestinal mucosa. EP decreases intestinal permeability, and inhibits the release of multiple proinflammatory cytokines in rats with ALF.
文摘AIM:To search for further immunodominant peptides of the pyruvate dehydrogenase complex E2-component (PDC-E2) recognized by antimitochondrial antibodies (AMA) in primary biliary cirrhosis (PBC). METHODS:Sera from 95 patients with PBC were tested by enzyme-linked immunosorbent assay against 33 synthetic overlapping peptides (25 amino acids; aa) covering the entire length of the E2-subunit of PDC-E2. Furthermore,the inner lipoyl peptide 167-184 was used in an unlip oylated and a lipoylated form as well as coupled to ovalbumin. Sera from 11 AMA negative/ANA posit ive PBC patients,63 patients with other liver disorders and 22 healthy blood donors served as controls.RESULTS:Of the 95 PBC-sera,74% reacted with the peptide 475-499 and 58% with the pept ide 407-431 located within the catalytic domain of PDC-E2. Patients with other disorders or healthy controls were positive in only up to 18%. Antibodies to the unlipoylatedand lip oylated pept ide 167-184 within the inner lipoyl domain were found in only 5% and 11% of the PBC sera,respectively; using ovalbumin-coupled peptides,the incidence increased up to 57% (unlipoylated form). CONCLUSION:Peptides within the catalytic site of PDC-E2 rather than the previously reported lipoyl binding peptide 167-184 may represent major immunodomin ant epitopes recognized by AMA in PBC.
基金Supported by the National Natural Science Foundation of China,No.81070319the Beijing Natural Science Foundation of China,No.7102013the Beijing Municipal Education Commission Research Program,China,No.KM201610025004
文摘BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate dehydrogenase kinase 1 in myeloma. STAT3 and pyruvate kinase M2(PKM2) can also be activated and enhance the Warburg effect in hepatocellular carcinoma. Precancerous lesions are critical to human and rodent hepatocarcinogenesis. However, the underlying molecular mechanism for the development of liver precancerous lesions remains unknown. We hypothesized that STAT3 promotes the Warburg effect possibly by upregulating p-PKM2 in liver precancerous lesions in rats.AIM To investigate the mechanism of the Warburg effect in liver precancerous lesions in rats.METHODS A model of liver precancerous lesions was established by a modified Solt-Farber method. The liver pathological changes were observed by HE staining and immunohistochemistry. The transformation of WB-F344 cells induced with Nmethyl-N'-nitro-N-nitrosoguanidine and hydrogen peroxide was evaluated by the soft agar assay and aneuploidy. The levels of glucose and lactate in the tissue and culture medium were detected with a spectrophotometer. The protein levels of glutathione S-transferase-π, proliferating cell nuclear antigen(PCNA), STAT3,and PKM2 were examined by Western blot and immunofluorescence.RESULTS We found that the Warburg effect was increased in liver precancerous lesions in rats. PKM2 and p-STAT3 were upregulated in activated oval cells in liverprecancerous lesions in rats. The Warburg effect, p-PKM2, and p-STAT3 expression were also increased in transformed WB-F344 cells. STAT3 activation promoted the clonal formation rate, aneuploidy, alpha-fetoprotein expression,PCNA expression, G1/S phase transition, the Warburg effect, PKM2 phosphorylation, and nuclear translocation in transformed WB-F344 cells.Moreover, the Warburg effect was inhibited by stattic, a specific inhibitor of STAT3, and further reduced in transformed WB-F344 cells after the intervention for PKM2.CONCLUSION The Warburg effect is initiated in liver precancerous lesions in rats. STAT3 activation promotes the Warburg effect by enhancing the phosphorylation of PKM2 in transformed WB-F344 cells.
基金supported by the National Natural Science Foundation of China(No.81700181,No.81600148)
文摘Type A lactic acidosis resulted from hypoxic mitochondrial dysfunction is an independent predictor of mortality for critically ill patients. However, current therapeutic agents are still in shortage and can even be harmful. This paper reviewed data regarding lactic acidosis treatment and recommended that pyruvate might be a potential alkalizer to correct type A lactic acidosis in future clinical practice. Pyruvate is a key energy metabolic substrate and a pyruvate dehydrogenase(PDH) activator with several unique beneficial biological properties, including anti-oxidant and antiinflammatory effects and the ability to activate the hypoxia-inducible factor-1(HIF-1α)-erythropoietin(EPO) signal pathway. Pyruvate preserves glucose metabolism and cellular energetics better than bicarbonate, lactate, acetate and malate in the efficient correction of hypoxic lactic acidosis and shows few side effects. Therefore, application of pyruvate may be promising and safe as a novel therapeutic strategy in hypoxic lactic acidosis correction accompanied with multi-organ protection in critical care patients.
基金Grants from the research projects in Liaoning Province Science and Technology Department,No.2007225017,No.2009225011-2 and No.2011415052Science and Technology projects in Shenyang City,No.F11-264-1-19
文摘AIM:To investigate the expression and prognostic role of pyruvate dehydrogenase(PDH) in gastric cancer(GC).METHODS:This study included 265 patients(194 male,71 female,mean age 59 years(range,29-81 years) with GC who underwent curative surgery at the First Affiliated Hospital of China Medical University from January 2006 to May 2007.All patients were followed up for more than 5 years.Patient-derived paraffin embedded GC specimens were collected for tissue microarrays(TMAs).We examined PDH expression by immunohistochemistry in TMAs containing tumor tissue and matched nonneoplastic mucosa.Immunoreactivity was evaluated independently by two researchers.Overall survival(OS) rates were determined using the Kaplan-Meier estimator.Correlations with other clinicopathologic factors were evaluated by two-tailed χ2 tests or a two-tailed t-test.The Cox proportional-hazard model was used in univariate analysis and multivariate analysis to identify factors significantly correlated with prognosis.RESULTS:Immunohistochemistry showed that 35.47% of total cancer tissue specimens had cytoplasmic PDH staining.PDH expression was much higher in normal mucosa specimens(75.09%;P = 0.001).PDH expression was correlated with Lauren grade(70.77% in intestinal type vs 40.0% in diffuse type;P = 0.001),lymph node metastasis(65.43% with no metastasis vs 51.09% with metastasis;P = 0.033),lymphatic invasion(61.62% with no invasion vs 38.81% with invasion;P = 0.002),histologic subtypes(70.77% in intestinal type vs 40.0% in diffuse type;P = 0.001) and tumor-node-metastasis(TNM) stage(39% in poorly differentiated vs 65.91% in well differentiated and 67.11% in moderately differentiated;P = 0.001) in GC.PDH expression in cancer tissue was significantly associated with higher OS(P < 0.001).The multivariate analysis adjusted for age,Lauren classification,TNM stage,lymph node metastasis,histological type,tumor size,depth of invasion and lymphatic invasion showed that the PDH expression in GC was an independent prognostic factor for higher OS(HR = 0.608,95%CI:0.504-0.734,P < 0.001).CONCLUSION:Our study indicated that PDH expression is an independent prognostic factor in GC patients and that positive expression of PDH may be predictive of favorable outcomes.
基金the National Basic Research Program (973 Program, 2012CB114306)the National Natural Science Foundation of China (31061140457+6 种基金 31071360 31271641)the National Key Technology Support Program of China (2011BAD16B14 2012BAD04B08)China National Public Welfare Industry (Agriculture) Plan (200803030 201203079)Jiangsu Advantages of Key Construction Projects (JS 2011)
文摘Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.