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
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
Consumption of food while drinking alcohol has been suggested to play important roles in alleviating the physiological and pharmacological influences of alcohol. Vegetables are believed to provide health benefits, but...Consumption of food while drinking alcohol has been suggested to play important roles in alleviating the physiological and pharmacological influences of alcohol. Vegetables are believed to provide health benefits, but there is little evidence for their influence on the effects of alcohol consumption. The present study aimed to investigate the effect of a common vegetable, tomato, on alcohol metabolism. In a randomized, controlled, crossover study with12 Japanese healthy men aged between 24 and 56 years, drinking tomato juice containing 5% (v/v) alcohol (TJAlc) significantly attenuated the elevation of blood ethanol level and subsequently increased the level of acetate compared with a water-based alcoholic beverage with an equal dose of alcohol (0.4 g/kg body weight). Significantly higher levels of blood pyruvate and lactate were also observed in subjects who had consumed TJAlc compared with those consuming the water-based beverage. Additionally, a biphasic alcohol effects scale method showed that subjective feelings for alcohol-induced stimulant effects were significantly enhanced by drinking TJAlc. Animal experiments using male Sprague Dawleyrats suggested that the effect on blood biomarkers was attributable to the serum fraction of tomato (TS), which largely consisted of aqueous compounds, but not lipophilic compounds such as the carotenoid lycopene. Furthermore, it was suggested the TS possibly included potent compound(s) in addition to alanine, glutamine, and citric acid, all of which have previously been reported to affect alcohol metabolism. Administration of TS clearly increased the activity of NAD (H)-dependent enzymes such as lactate-(LDH), alcohol-, and aldehyde-dehydrogenase in rat liver cytosols. These findings suggest that aqueous compound(s) in tomato promote alcohol metabolism, probably through increasing pyruvate level, enhancing LDH activity, and improving the ratio of NAD to NADH.展开更多
Solvent and kinetic isotope effects in the reaction of oxidative deamination of L-alanine, catalyzed by L-alanine dehydrogenase, AIaDH, （EC 1.4.1.1） were determined using a non-competitive spectroscopic method. The ...Solvent and kinetic isotope effects in the reaction of oxidative deamination of L-alanine, catalyzed by L-alanine dehydrogenase, AIaDH, （EC 1.4.1.1） were determined using a non-competitive spectroscopic method. The progress of the reaction was monitored spectrophotometrically by measuring the increasing absorbance of the reduced form of NADH at 340 nm. L-alanine, stereospecifically labeled with deuterium was synthesized by enzymatic reductive amination of pyruvate in presence of [（4R）-2H]-NADH, which was obtained by deuterium transfer from deuteriated formic acid to NAD~ catalyzed by FDH （formate dehydrogenase） （EC 1.2.1.2）. [2-2H]-L-alanine, the product of enzymatic synthesis catalyzed by AIaDH, was obtained with 75% deuterium enrichment and values of isotopic effects were approximated to the values corresponding to 100% of deuterium incorporation. The enzyme AIaDH isolated from Bacillus subtilis shows pro-R stereospecificity, what indicates that hydrogen is exclusively transferred from pro-R position at C-4 of the nicotinamide ring of NADH to C-2 of pyruvate to form L-alanine. Some intrinsic mechanistic details of enzymatic oxidative deamination of L-alanine were discussed using determined numerical values of kinetic and solvent isotope effects on Vmax and Vmax,│KM展开更多
The activation of spinal astrocytes accounts for opioid-induced hyperalgesia(OIH),but the underlying mechanisms remain elusive.The presence of astrocyte-neuron lactate shuttle(ANLS)makes astrocytes necessary for some ...The activation of spinal astrocytes accounts for opioid-induced hyperalgesia(OIH),but the underlying mechanisms remain elusive.The presence of astrocyte-neuron lactate shuttle(ANLS)makes astrocytes necessary for some neural function and communication.The aim of this study was to explore the role of ANLS in the occurrence and maintenance of OIH.After 7 days consecutive morphine injection,a mice OIH model was established and astrocytic pyruvate dehydrogenase kinase 4(PDK4),phosphorylated pyruvate dehydrogenase(p-PDH)and accumulation of L-lactate was elevated in the spinal dorsal horn.Intrathecally administration of inhibitors of PDK,lactate dehydrogenase 5 and monocarboxylate transporters to decrease the supply of L-lactate on neurons was observed to attenuate hypersensitivity behaviors induced by repeated morphine administration and downregulate the expression of markers of central sensitization in the spinal dorsal horns.The astrocyte line and the neuronal line were co-cultured to investigate the mechanisms in vitro.In this study,we demonstrated that morphine-induced hyperalgesia was sustained by lactate overload consequent upon aberrant function of spinal ANLS.In this process,PDK-p-PDH-lactate axis serves a pivotal role,which might therefore be a new target to improve long-term opioid treatment strategy in clinical practice.展开更多
以运动发酵单胞菌的总DNA为模板,PCR扩增Zym om onas m obilis中的乙醇脱氢酶基因(adhB)和丙酮酸脱羧酶基因(p d c)。首先进行单个基因表达,基因表达产物经SDS-PAGE电泳分析和乙醛指示平板检测,确认有酶活性后,将这2个基因串联构建多顺...以运动发酵单胞菌的总DNA为模板,PCR扩增Zym om onas m obilis中的乙醇脱氢酶基因(adhB)和丙酮酸脱羧酶基因(p d c)。首先进行单个基因表达,基因表达产物经SDS-PAGE电泳分析和乙醛指示平板检测,确认有酶活性后,将这2个基因串联构建多顺反子表达质粒pSE-p d c-adhB,转入大肠杆菌DH 5α内,得重组工程菌株。工程菌株经IPTG诱导,分别在含10%葡萄糖和10%木糖培养基中于37℃培养72 h,有乙醇产生,酒精产率分别为对照菌株21倍和5倍。展开更多
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.
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.
文摘Consumption of food while drinking alcohol has been suggested to play important roles in alleviating the physiological and pharmacological influences of alcohol. Vegetables are believed to provide health benefits, but there is little evidence for their influence on the effects of alcohol consumption. The present study aimed to investigate the effect of a common vegetable, tomato, on alcohol metabolism. In a randomized, controlled, crossover study with12 Japanese healthy men aged between 24 and 56 years, drinking tomato juice containing 5% (v/v) alcohol (TJAlc) significantly attenuated the elevation of blood ethanol level and subsequently increased the level of acetate compared with a water-based alcoholic beverage with an equal dose of alcohol (0.4 g/kg body weight). Significantly higher levels of blood pyruvate and lactate were also observed in subjects who had consumed TJAlc compared with those consuming the water-based beverage. Additionally, a biphasic alcohol effects scale method showed that subjective feelings for alcohol-induced stimulant effects were significantly enhanced by drinking TJAlc. Animal experiments using male Sprague Dawleyrats suggested that the effect on blood biomarkers was attributable to the serum fraction of tomato (TS), which largely consisted of aqueous compounds, but not lipophilic compounds such as the carotenoid lycopene. Furthermore, it was suggested the TS possibly included potent compound(s) in addition to alanine, glutamine, and citric acid, all of which have previously been reported to affect alcohol metabolism. Administration of TS clearly increased the activity of NAD (H)-dependent enzymes such as lactate-(LDH), alcohol-, and aldehyde-dehydrogenase in rat liver cytosols. These findings suggest that aqueous compound(s) in tomato promote alcohol metabolism, probably through increasing pyruvate level, enhancing LDH activity, and improving the ratio of NAD to NADH.
文摘Solvent and kinetic isotope effects in the reaction of oxidative deamination of L-alanine, catalyzed by L-alanine dehydrogenase, AIaDH, （EC 1.4.1.1） were determined using a non-competitive spectroscopic method. The progress of the reaction was monitored spectrophotometrically by measuring the increasing absorbance of the reduced form of NADH at 340 nm. L-alanine, stereospecifically labeled with deuterium was synthesized by enzymatic reductive amination of pyruvate in presence of [（4R）-2H]-NADH, which was obtained by deuterium transfer from deuteriated formic acid to NAD~ catalyzed by FDH （formate dehydrogenase） （EC 1.2.1.2）. [2-2H]-L-alanine, the product of enzymatic synthesis catalyzed by AIaDH, was obtained with 75% deuterium enrichment and values of isotopic effects were approximated to the values corresponding to 100% of deuterium incorporation. The enzyme AIaDH isolated from Bacillus subtilis shows pro-R stereospecificity, what indicates that hydrogen is exclusively transferred from pro-R position at C-4 of the nicotinamide ring of NADH to C-2 of pyruvate to form L-alanine. Some intrinsic mechanistic details of enzymatic oxidative deamination of L-alanine were discussed using determined numerical values of kinetic and solvent isotope effects on Vmax and Vmax,│KM
基金the National Natural Science Foundation of China(82171486)Natural Science Foundation of Shanghai to T.X.(21ZR1448400)+2 种基金the Interdisciplinary Program of Shanghai Jiao Tong University to T.X.(YG2021ZD23)General Science Foundation of Shanghai Sixth People's Hospital to T.X.(YNMS202114)the Young Scholarship Program of the National Natural Science Foundation of China to Xiaqing Ma(82201366)and by Shanghai Sailing Program(21YF1434200).
文摘The activation of spinal astrocytes accounts for opioid-induced hyperalgesia(OIH),but the underlying mechanisms remain elusive.The presence of astrocyte-neuron lactate shuttle(ANLS)makes astrocytes necessary for some neural function and communication.The aim of this study was to explore the role of ANLS in the occurrence and maintenance of OIH.After 7 days consecutive morphine injection,a mice OIH model was established and astrocytic pyruvate dehydrogenase kinase 4(PDK4),phosphorylated pyruvate dehydrogenase(p-PDH)and accumulation of L-lactate was elevated in the spinal dorsal horn.Intrathecally administration of inhibitors of PDK,lactate dehydrogenase 5 and monocarboxylate transporters to decrease the supply of L-lactate on neurons was observed to attenuate hypersensitivity behaviors induced by repeated morphine administration and downregulate the expression of markers of central sensitization in the spinal dorsal horns.The astrocyte line and the neuronal line were co-cultured to investigate the mechanisms in vitro.In this study,we demonstrated that morphine-induced hyperalgesia was sustained by lactate overload consequent upon aberrant function of spinal ANLS.In this process,PDK-p-PDH-lactate axis serves a pivotal role,which might therefore be a new target to improve long-term opioid treatment strategy in clinical practice.
文摘以运动发酵单胞菌的总DNA为模板,PCR扩增Zym om onas m obilis中的乙醇脱氢酶基因(adhB)和丙酮酸脱羧酶基因(p d c)。首先进行单个基因表达,基因表达产物经SDS-PAGE电泳分析和乙醛指示平板检测,确认有酶活性后,将这2个基因串联构建多顺反子表达质粒pSE-p d c-adhB,转入大肠杆菌DH 5α内,得重组工程菌株。工程菌株经IPTG诱导,分别在含10%葡萄糖和10%木糖培养基中于37℃培养72 h,有乙醇产生,酒精产率分别为对照菌株21倍和5倍。
