AIM:To investigate M2 isoform of pyruvate kinase(PKM2) expression in gastric cancers and evaluate its potential as a prognostic biomarker and an anticancer target.METHODS:All tissue samples were derived from gastric c...AIM:To investigate M2 isoform of pyruvate kinase(PKM2) expression in gastric cancers and evaluate its potential as a prognostic biomarker and an anticancer target.METHODS:All tissue samples were derived from gastric cancer patients underwent curative gastrectomy as a primary treatment.Clinical and pathological information were obtained from the medical records.Gene expression microarray data from 60 cancer and 19 noncancer gastric tissues were analyzed to evaluate the expression level of PKM2 mRNA.Tissue microarrays were constructed from 368 gastric cancer patients.Immunohistochemistry was used to measure PKM2 expression and PKM2 positivity of cancer was determined by proportion of PKM2-positive tumor cells and staining intensity.Association between PKM2 expression and the clinicopathological factors was evaluated and the correlation between PKM2 and cancer prognosis was evaluated.RESULTS:PKM2 mRNA levels were increased more than 2-fold in primary gastric cancers compared to adjacent normal tissues from the same patients(log transformed expression level:7.6 ± 0.65 vs 6.3 ± 0.51,P < 0.001).Moreover,differentiated type cancers had significantly higher PKM2 mRNA compared to undifferentiated type cancers(log transformed expression level:7.8 ± 0.70 vs 6.7 ± 0.71,P < 0.001).PKM2 protein was mainly localized in the cytoplasm of primary cancer cells and detected in 144 of 368(39.1%) human gastric cancer cases.PKM2 expression was not related with stage(P = 0.811),but strongly correlated with gastric cancer differentiation(P < 0.001).Differentiated type cancers expressed more PKM2 protein than did the undifferentiated ones.Well differentiated adenocarcinoma showed 63.6% PKM2-positive cells;in contrast,signet-ring cell cancers showed only 17.7% PKM2-positive cells.Importantly,PKM2 expression was correlated with shorter overall survival(P < 0.05) independent of stage only in signet-ring cell cancers.CONCLUSION:PKM2 expression might be an adverse prognostic factor for signet-ring cell carcinomas.Its function and potential as a prognostic marker should be further verified in gastric cancer.展开更多
AIM:To present a critical discussion of the efficacy of the faecal pyruvate kinase isoenzyme type M2(faecal M2-PK) test for colorectal cancer(CRC) screening based on the currently available studies.METHODS:A literatur...AIM:To present a critical discussion of the efficacy of the faecal pyruvate kinase isoenzyme type M2(faecal M2-PK) test for colorectal cancer(CRC) screening based on the currently available studies.METHODS:A literature search in PubMed and Embase was conducted using the following search terms:fecal Tumor M2-PK,faecal Tumour M2-PK,fecal M2-PK,faecal M2-PK,fecal pyruvate kinase,faecal pyruvate kinase,pyruvate kinase stool and M2-PK stool.RESULTS:Stool samples from 704 patients with CRC and from 11 412 healthy subjects have been investigated for faecal M2-PK concentrations in seventeen independent studies.The mean faecal M2-PK sensitivity was 80.3%;the specificity was 95.2%.Four studies compared faecal M2-PK head-to-head with guaiacbased faecal occult blood test(gFOBT).Faecal M2PK demonstrated a sensitivity of 81.1%,whereas the gFOBT detected only 36.9% of the CRCs.Eight independent studies investigated the sensitivity of faecal M2-PK for adenoma(n = 554),with the following sensitivities:adenoma < 1 cm in diameter:25%;adenoma > 1 cm:44%;adenoma of unspecified diameter:51%.In a direct comparison with gFOBT of adenoma > 1 cm in diameter,47% tested positive with the faecal M2-PK test,whereas the gFOBT detected only 27%.CONCLUSION:We recommend faecal M2-PK as a routine test for CRC screening.Faecal M2-PK closes a gap in clinical practice because it detects bleeding and nonbleeding tumors and adenoma with high sensitivity and specificity.展开更多
Gastrointestinal(GI) cancer is one of the most common causes of cancer-related deaths worldwide.Tumor markers are valuable in detecting post-surgical recurrence or in monitoring response to chemotherapy.Pyruvate kinas...Gastrointestinal(GI) cancer is one of the most common causes of cancer-related deaths worldwide.Tumor markers are valuable in detecting post-surgical recurrence or in monitoring response to chemotherapy.Pyruvate kinase isoform M2(PKM2),a glycolytic enzyme catalyzing conversion of phosphoenolpyruvate(PEP) to pyruvate,confers a growth advantage to the tumor cells and enables them to adapt to the tumor microenvironment.In this review,we have summarized current research on the expression and regulation of PKM2 in tumor cells,and its potential role in GI carcinogenesis and progression.Furthermore,we have also discussed the potential of PKM2 as a diagnostic and screening marker,and a therapeutic target in GI cancer.展开更多
BACKGROUND The understanding regarding genetic variation,pathophysiology,and complications associated with pyruvate kinase deficiency(PKD)in red blood cells has been explained largely,and supportive treatment is curre...BACKGROUND The understanding regarding genetic variation,pathophysiology,and complications associated with pyruvate kinase deficiency(PKD)in red blood cells has been explained largely,and supportive treatment is currently the main management strategy.Etiotropic managements,including transplantation and genome editing,supplying for substitute dugs of the pyruvate kinase,are all under research.CASE SUMMARY We herein report a 3-year-old boy with severe transfusion-dependent PKD cured by unrelated identical peripheral blood stem cell transplantation(PBSCT).Hemoglobin was corrected to a normal level by gene correction after PBSCT,with no complication related to the transplantation.CONCLUSION Hematopoietic stem cell transplantation could be a substitute for transfusiondependent PKD.展开更多
The purpose of this study is to investigate the perioperative changes of erythrocyte kinase (PK) activity. Thirty patients undergoing upper abdominal surgery were dirided into epidural blockade(EB) group or intra veno...The purpose of this study is to investigate the perioperative changes of erythrocyte kinase (PK) activity. Thirty patients undergoing upper abdominal surgery were dirided into epidural blockade(EB) group or intra venous procaine balanced anesthesia(IPBA) group. The blood level of glucose increased significantly at 60 min after the beginning of operations in both groups. Blood glucose levels on the first postoperative day were significantly higher than the baselines in both groups [(8. 29±1. 5)vs (4. 8±0.18) mmol/L (P< 0.01) in EB, (6.36±0.33) vs (4. 55±0.18 ) mmol/L (P<0. 01 ) in IPBA]. The concentrations of 2, 3-DPG in RBC were not significantly changed in both groups. The PK activity in RBC decreased signficantly at 60 min after the end of operation in both groups. The PK activity levels on the first postoperative day were significantly lower than the baselines in both groups [(7. 59±1. 01) vs (11. 62±1. 06) IU/gHb (P<0. 05) in EB; (7. 75±0. 94) vs (11. 84 ±1.12) IU/gHb (P<0. 05 ) in IPBA]. The results suggest that the PK activity is decreased and the concentration of 2, 3-DPG remians unchanged under the hyperglycemic response to surgical stress, which may be related to an inhibition of glycolysis in RBC.展开更多
By using Fab'-enzyme labelled immuno absorbent assay (ELISA) with sensitivity of picogram (10-12 g or pg) level, the M-type pyruvate kinase (M-PyK) in plasma was determined in 47 cases of normal healthy adult and ...By using Fab'-enzyme labelled immuno absorbent assay (ELISA) with sensitivity of picogram (10-12 g or pg) level, the M-type pyruvate kinase (M-PyK) in plasma was determined in 47 cases of normal healthy adult and 26 cases of hepatocellular carcinoma (HCC) patient. It was found that the upper limits of normal male and female were 1.1 and 1.4 ng/ml (expressed as M2-PyK) respectively. The plasma M-PyK in HCC patients was significant increased to above 5 times of average normal level, the positive rate was about 95%. In 6 cases of subclinical small hepatocarcinoma and 7 cases of HCC patient with normal serum alpha-fetal protein level, the mean plasma M-PyK value was also increased. Whereas the plasma M-PyK level in acute or chronic hepatitis and other benign diseases were normal. After the HCC being resected, the plasma M-PyK returned to normal, but increased again in the cases of recurrent hepatocarcinoma, suggesting that the increased M-PyK in the plasma of HCC patient was criginated from M2-type PyK in HCC tissue. Therefore, plasma M-PyK may become a new micro-level index of hepatocarcinoma.展开更多
Male germ cells employ specific metabolic pathways throughout their developmental stages.In a previous study,we discovered heightened expression of pyruvate kinase M(PKM),a pivotal glycolytic enzyme,in spermatogonia a...Male germ cells employ specific metabolic pathways throughout their developmental stages.In a previous study,we discovered heightened expression of pyruvate kinase M(PKM),a pivotal glycolytic enzyme,in spermatogonia and spermatids.To gain deeper insights into PKM's roles in spermatogenesis,sperm function,and male fertility,we engineered a conditional-knockout mouse model(Pkm-vkO mice)to selectively disrupt the Pkm gene within germ cells.Despite maintaining regular testicular histology and sperm morphology,the male Pkm-vko mice were infertility,characterized by significant impairments in sperm motility and adenosine triphosphate(ATP)generation.In addition,Pkm-null spermatozoa exhibited similar deficits in protein tyrosine phosphorylation linked to capacitation,as well as compromised performance in in vitro fertilization experiments.To conclude,PKM's presence is not obligatory for the entirety of spermatogenesis in male germ cells;however,it emerges as a critical factor influencing sperm motility and overall male fertility.展开更多
The prevention and control of rice bacterial leaf blight(BLB)disease has not yet been achieved due to the lack of effective agrochemicals and available targets.Herein,we develop a series of novel bissulfones and a nov...The prevention and control of rice bacterial leaf blight(BLB)disease has not yet been achieved due to the lack of effective agrochemicals and available targets.Herein,we develop a series of novel bissulfones and a novel target with a unique mechanism to address this challenge.The developed bissulfones can control Xanthomonas oryzae pv.oryzae(Xoo),and 2-(bis(methylsulfonyl)methylene)-N-(4-chlorophenyl)hydrazine-1-carboxamide(B_(7))is more effective than the commercial drugs thiodiazole copper(TC)and bismerthiazol(BT).Pyruvate kinase(PYK)in Xoo has been identified for the first time as the target protein of our bissulfone B_(7).PYK modulates bacterial virulence via a CRP-like protein(Clp)/two-component system regulatory protein(reg R)axis.The elucidation of this pathway facilitates the use of B_(7)to reduce PYK expression at the transcriptional level,block PYK activity at the protein level,and impair the interaction within the PYK-Clp-reg R complex via competitive inhibition,thereby attenuating bacterial biology and pathogenicity.This study offers insights into the molecular and mechanistic aspects underlying anti-Xoo strategies that target PYK.We believe that these valuable discoveries will be used for bacterial disease control in the future.展开更多
Both thymocytes and tumor cells express M2 type isoenzyme of pyruvate kinase(M2PK),which is different from R type isoenzyme of pyruvate kinase(RPK)that is expressed in erythrocytes.In this report,the effect of RPK and...Both thymocytes and tumor cells express M2 type isoenzyme of pyruvate kinase(M2PK),which is different from R type isoenzyme of pyruvate kinase(RPK)that is expressed in erythrocytes.In this report,the effect of RPK and M2PK on the transcription of human immunodeficiency virus type 1(HIV-1)was tested.The results indicated that M2PK could enhance HIV-1 transcription from its long terminal repeat(LTR)promoter,while RPK did not have such an effect.Specific down-regulation of M2PK could inhibit HIV-1 transcription from its LTR region.Furthermore,it was found that the C terminal region of M2PK is responsible for this effect.Collectively,the cellular factor M2PK that is expressed in thymocytes could facilitate the transcription of HIV-1.展开更多
OBJECTIVE:To investigate the effect of Ruyanneixiao cream(RYNX) on the expression of hypoxia inducible factor-1α(HIF-1α), hexokinase 2(HK2),phosphofructokinase(PFK), and pyruvate kinase M2(PKM2) mRNA and protein in ...OBJECTIVE:To investigate the effect of Ruyanneixiao cream(RYNX) on the expression of hypoxia inducible factor-1α(HIF-1α), hexokinase 2(HK2),phosphofructokinase(PFK), and pyruvate kinase M2(PKM2) mRNA and protein in MCF-10 AT cells and in an animal model of precancerous mammary lesions.METHODS:Following treatment of MCF-10 AT cells with RYNX, tamoxifen(TAM) and YC-1 for 48 h,HIF-1α, HK2, PFK, PKM2 mRNA and protein expression was analyzed.Fifty female SD rats were randomly divided into control, model, TAM, and highand low-dose RYNX groups, with 10 rats in each group.A precancerous mammary lesion model was established for all groups except the control group.High-and low-dose RYNX cream containing TAM was coated on the breasts of animals in the corresponding groups.The rat mammary tissue was removed in the 10 th week and HIF-1α, HK2, PFK,PKM2 mRNA and protein was analyzed.RESULTS:In vitro analyses demonstrated that, compared with the matrix group, HIF-1α, HK2, PFK,PKM2 mRNA and protein expression was significantly decreased in the RYNX group(P < 0.05).Compared with the YC-1 + RYNX group, HK2, PFK,and PKM2 protein expression was significantly reduced in the RYNX group.HIF-1α, HK2, PFK, and PKM2 protein expression was increased significantly in the model group(P < 0.05) compared with the control group, while HIF-1α, HK2, PFK, and PKM2 mRNA and protein expression was significantly decreased in both the high-and low-dose RYNX groups(P < 0.05), with the effect being greater in the high-dose group.CONCLUSION:RYNX can block precancerous breast lesions by decreasing the expression of HK2,PFK, and PKM2 mRNA and protein via inhibition of HIF-1α mRNA and protein overexpression in a dose-dependent manner.展开更多
Alternative splicing of the pyruvate kinase M gene(PK-M)can generate the M2 isoform and promote aerobic glycolysis and tumor growth.However,the cancer-specific alternative splicing regulation of PK-M is not completely...Alternative splicing of the pyruvate kinase M gene(PK-M)can generate the M2 isoform and promote aerobic glycolysis and tumor growth.However,the cancer-specific alternative splicing regulation of PK-M is not completely understood.Here,we demonstrate that PK-M is regulated by reciprocal effects on the mutually exclusive exons 9 and 10,such that exon 9 is repressed and exon 10 is activated in cancer cells.Strikingly,exonic,rather than intronic,cis-elements are key determinants of PK-M splicing isoform ratios.Using a systematic sub-exonic duplication approach,we identify a potent exonic splicing enhancer in exon 10,which differs from its homologous counterpart in exon 9 by only two nucleotides.We identify SRSF3 as one of the cognate factors,and show that this serine/arginine-rich protein activates exon 10 and mediates changes in glucose metabolism.These findings provide mechanistic insights into the complex regulation of alternative splicing of a key regulator of the Warburg effect,and also have implications for other genes with a similar pattern of alternative splicing.展开更多
Pyruvate kinase （PK） is a key enzyme in glycolysis and carbon metabolism. Here, we isolated a rice （Oryza sativa） mutant, w59, with a white-core floury endosperm. Map-based cloning of w59 identified a mutation in ...Pyruvate kinase （PK） is a key enzyme in glycolysis and carbon metabolism. Here, we isolated a rice （Oryza sativa） mutant, w59, with a white-core floury endosperm. Map-based cloning of w59 identified a mutation in OsPKpα1, which encodes a plastidic isoform of PK （PKp）. OsPKpα1 localizes to the amyloplast stroma in the developing endosperm, and the mutation of OsPKpα1 in w59 decreases the plastidic PK activity, resulting in dramatic changes to the lipid biosynthesis in seeds. The w59 grains were also characterized by a marked decrease in starch content. Consistent with a decrease in number and size of the w59 amyloplasts, large empty spaces were observed in the central region of the w59 endosperm, at the early grain-filling stage. Moreover, a phylogenetic analysis revealed four potential rice isoforms of OsPKp. We validated the in vitro PK activity of these OsPKps through reconstituting active PKp complexes derived from inactive individual OsPKps, revealing the heteromeric structure of rice PKps, which was further confirmed using a protein- protein interaction analysis. These findings suggest a functional connection between lipid and starch synthesis in rice endosperm amyloplasts.展开更多
Tumor cells usually show abnormally high glycolysis rate to maintain the dynamic balance of energy.The growth of tumor cells can be affected by inhibiting the activity of pyruvate kinase(especially M2-type isozyme,PKM...Tumor cells usually show abnormally high glycolysis rate to maintain the dynamic balance of energy.The growth of tumor cells can be affected by inhibiting the activity of pyruvate kinase(especially M2-type isozyme,PKM2),the rate limiting enzyme of glycolysis.This is helpful to the treatment of tumor.Herein,metal organic frameworks(MOFs) were found to inhibit the activity of PKM2.Nanoscale ZIF-8 was synthesized by standing and ultrasonic method,respectively.The ZIF-8 has the performance of inhibiting PKM2.Further research showed that the inhibition ability was attributed to zinc ion in ZIF-8.Interestingly,the IC_(50) of ZIF-8 on PKM2 was one percent of that of zinc ion.This novel enzyme inhibitor is expected to be used in cancer therapy.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
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
Activities of hexokinase （HK）, pyruvate kinase （PK）, superoxide dismutase （SOD） and catalase （CAT） and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber （Apostichop...Activities of hexokinase （HK）, pyruvate kinase （PK）, superoxide dismutase （SOD） and catalase （CAT） and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber （Apostichopus japonicus Selenka） to rapid temperature changes in laboratory. Animals were subjected to a higher temperature （from 10 to 20℃） （Tinc treatment） or to a lower temperature （from 20 to 10℃） （Tddec treatment） for 72 h. At 1, 3, 12, 24, 72 h of exposure, animals were removed and prepared for further analysis. Results showed that the effect of acute temperature changes on enzyme activities was significant. In Tinc treatment, activities of SOD and CAT increased immediately. The significant enhancement of SOD and CAT activities suggested that oxidative stress increases significantly when ambient temperature increasing from 10 to 20℃. The up-regulation of Flsp70 in Tinc and Tdec treatments indicated that Hsp70 was a bioindicator of thermal stress in the sea cucumber, and the expression pattern depended on the thermal treatment.展开更多
Nonspherocytic hereditary anemias are occasionally accompanied by significant iron overload but the significance for the development of chronic liver disease is not clear. We described two cases of patients with chron...Nonspherocytic hereditary anemias are occasionally accompanied by significant iron overload but the significance for the development of chronic liver disease is not clear. We described two cases of patients with chronic liver d isease and severeiron overload due to chronic hereditary hemolysis. Both patients have had signs of liver cirrhosis and severe hemolysis since childhood. A hereditary pyruvate kinase deficiency (PKD) was discovered as the underlying reason for the hemolysis.Sequencing of the pyruvate kinase gene showed a mutation within exon 11. Liver histology in both patients revealed cirrhosis and a severe iron overload but primary hemochromatosis was excluded by HFE-gene analysis.An iron reduction therapy with desferrioxamine led to significant decrease of serum ferritin and sustained clinical improvement. PKD-induced hemolysis may cause severe iron overload even in the absence of HFE-genotype abnormalities. This secondary iron overload can lead to chronic liver disease and cirrhosis. Therefore, the iron metabolism of PKD patients has to be closely monitored and iron overload should be consequently treated.展开更多
Objective:To investigate the therapeutic effect of evodiamine(EVO)on the expression of hexokinase(HK),lactate dehydrogenase A(LDHA),and pyruvate kinase M(PKM),key enzymes of glycolysis,in the tumor-bearing mice after ...Objective:To investigate the therapeutic effect of evodiamine(EVO)on the expression of hexokinase(HK),lactate dehydrogenase A(LDHA),and pyruvate kinase M(PKM),key enzymes of glycolysis,in the tumor-bearing mice after modeling mouse colon cancer cells(CT26).Methods:A tumor-bearing mouse model was generated by administering axillary injection of CT26 and intraperitoneally injecting different doses of EVO.The therapeutic effects of EVO on CT26 tumor-bearing mice were evaluated by measuring the thymus and spleen indices,tumor volume,tumor suppression rate,and other related indicators in the tumor tissues of mice in each group after the administration of EVO,in addition,histopathological changes in the tumor tissues of the mice in the groups were studied by hematoxylin and eosin staining.The expression levels of HK,LDHA,and PKM in the tumor tissues of each group of mice were measured by performing Western blot to investigate the mechanism of EVO treatment in CT26 tumor-bearing mice.Results:EVO inhibited the growth of tumors in CT26-bearing mice and enhanced their splenic and thymic indices.Western blot results showed that EVO reduced the expression levels of HK,LDHA,and PKM proteins in the tumor tissues of CT26 tumor-bearing mice.Conclusion:EVO has a therapeutic effect on CT26 tumor-bearing mice,and its mechanism of action may be related to the low expression of key enzymes HK,LDHA and PKM of glycolysis in tumor tissues.展开更多
To further research the regulatory network of pyruvate dehydrogenase kinase （designated as TaPDK） in physiological male-sterility （PHYMS） of wheat induced by chemical hybridizing agent （CHA） SQ-1, an anther cDNA...To further research the regulatory network of pyruvate dehydrogenase kinase （designated as TaPDK） in physiological male-sterility （PHYMS） of wheat induced by chemical hybridizing agent （CHA） SQ-1, an anther cDNA library was constructed, and the proteins interacting with TaPDK were screened via yeast two-hybrid technique. Subsequently, a few candidate proteins in nucleotide expression levels were detected by real-time quantitative PCR. Yeast-two hybrid screening was performed by mating yeast strain Y2HGold containing BD-TaPDK bait plasmid with yeast strain Y187 including anther cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium （SD/-Ade/-His/-Leu/-Trp） （QDO）, and further were incubated on QDO medium containing AbA and X-α-Gal. The interactions between TaPDK and the proteins obtained from positive colonies were further confirmed by co-transformation validation. After plasmids DNA were extracted from blue colonies and sequenced, the sequences results were analyzed by bioinformatic methods. Finally, 24 colonies were obtained, including eight genes, namely non-specific lipid-transfer protein precursor （TanLTP）, polyubiquitin （TaPUbi）, glyceraldehyde-3-phosphate dehydrogenase, proliferating cell nuclear antigen （TaPCNA）, CBS domain containing protein （TaCBS）, actin, guanine nucleotide-binding protein beta subunit, chalcone synthase, and three new genes with unknown function. The results of quantitative RT-PCR showed that the expression levels of TanLTP, TaPUbi, and TaPCNA were obviously up-regulated in PHYMS anther, and TaCBS expression was only increased at the tricellular stage in PHYMS anther compared with in fertile lines. Whereas, the expression of TaPDK was obviously down-regulated in PHYMS lines. Collectively, these datas indicated that the majority of candidate proteins might be related to pollen abortion in PHYMS lines, which further suggested that TaPDK plays multiple roles in pollen development, besides participating in regulating pyruvate dehydrogenase complex activity.展开更多
基金Supported by Faculty Research Grant of Yonsei University College of Medicine for 2011,6-2011-0113,6-2011-0146A Faculty Research Grant of Department of Internal Medicine,Yonsei University College of Medicine for 2010Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education,Science and Technology,No. 2010-0024248
文摘AIM:To investigate M2 isoform of pyruvate kinase(PKM2) expression in gastric cancers and evaluate its potential as a prognostic biomarker and an anticancer target.METHODS:All tissue samples were derived from gastric cancer patients underwent curative gastrectomy as a primary treatment.Clinical and pathological information were obtained from the medical records.Gene expression microarray data from 60 cancer and 19 noncancer gastric tissues were analyzed to evaluate the expression level of PKM2 mRNA.Tissue microarrays were constructed from 368 gastric cancer patients.Immunohistochemistry was used to measure PKM2 expression and PKM2 positivity of cancer was determined by proportion of PKM2-positive tumor cells and staining intensity.Association between PKM2 expression and the clinicopathological factors was evaluated and the correlation between PKM2 and cancer prognosis was evaluated.RESULTS:PKM2 mRNA levels were increased more than 2-fold in primary gastric cancers compared to adjacent normal tissues from the same patients(log transformed expression level:7.6 ± 0.65 vs 6.3 ± 0.51,P < 0.001).Moreover,differentiated type cancers had significantly higher PKM2 mRNA compared to undifferentiated type cancers(log transformed expression level:7.8 ± 0.70 vs 6.7 ± 0.71,P < 0.001).PKM2 protein was mainly localized in the cytoplasm of primary cancer cells and detected in 144 of 368(39.1%) human gastric cancer cases.PKM2 expression was not related with stage(P = 0.811),but strongly correlated with gastric cancer differentiation(P < 0.001).Differentiated type cancers expressed more PKM2 protein than did the undifferentiated ones.Well differentiated adenocarcinoma showed 63.6% PKM2-positive cells;in contrast,signet-ring cell cancers showed only 17.7% PKM2-positive cells.Importantly,PKM2 expression was correlated with shorter overall survival(P < 0.05) independent of stage only in signet-ring cell cancers.CONCLUSION:PKM2 expression might be an adverse prognostic factor for signet-ring cell carcinomas.Its function and potential as a prognostic marker should be further verified in gastric cancer.
文摘AIM:To present a critical discussion of the efficacy of the faecal pyruvate kinase isoenzyme type M2(faecal M2-PK) test for colorectal cancer(CRC) screening based on the currently available studies.METHODS:A literature search in PubMed and Embase was conducted using the following search terms:fecal Tumor M2-PK,faecal Tumour M2-PK,fecal M2-PK,faecal M2-PK,fecal pyruvate kinase,faecal pyruvate kinase,pyruvate kinase stool and M2-PK stool.RESULTS:Stool samples from 704 patients with CRC and from 11 412 healthy subjects have been investigated for faecal M2-PK concentrations in seventeen independent studies.The mean faecal M2-PK sensitivity was 80.3%;the specificity was 95.2%.Four studies compared faecal M2-PK head-to-head with guaiacbased faecal occult blood test(gFOBT).Faecal M2PK demonstrated a sensitivity of 81.1%,whereas the gFOBT detected only 36.9% of the CRCs.Eight independent studies investigated the sensitivity of faecal M2-PK for adenoma(n = 554),with the following sensitivities:adenoma < 1 cm in diameter:25%;adenoma > 1 cm:44%;adenoma of unspecified diameter:51%.In a direct comparison with gFOBT of adenoma > 1 cm in diameter,47% tested positive with the faecal M2-PK test,whereas the gFOBT detected only 27%.CONCLUSION:We recommend faecal M2-PK as a routine test for CRC screening.Faecal M2-PK closes a gap in clinical practice because it detects bleeding and nonbleeding tumors and adenoma with high sensitivity and specificity.
基金supported by the grants from ‘San Ming’ Project of Shenzhen city,China(No.SZSM201612051)Municipal Health Planning Commission Fund of Shenzhen city,China(No.201601004,No.SZXJ2017078 and No.SXZJ2018084)
文摘Gastrointestinal(GI) cancer is one of the most common causes of cancer-related deaths worldwide.Tumor markers are valuable in detecting post-surgical recurrence or in monitoring response to chemotherapy.Pyruvate kinase isoform M2(PKM2),a glycolytic enzyme catalyzing conversion of phosphoenolpyruvate(PEP) to pyruvate,confers a growth advantage to the tumor cells and enables them to adapt to the tumor microenvironment.In this review,we have summarized current research on the expression and regulation of PKM2 in tumor cells,and its potential role in GI carcinogenesis and progression.Furthermore,we have also discussed the potential of PKM2 as a diagnostic and screening marker,and a therapeutic target in GI cancer.
文摘BACKGROUND The understanding regarding genetic variation,pathophysiology,and complications associated with pyruvate kinase deficiency(PKD)in red blood cells has been explained largely,and supportive treatment is currently the main management strategy.Etiotropic managements,including transplantation and genome editing,supplying for substitute dugs of the pyruvate kinase,are all under research.CASE SUMMARY We herein report a 3-year-old boy with severe transfusion-dependent PKD cured by unrelated identical peripheral blood stem cell transplantation(PBSCT).Hemoglobin was corrected to a normal level by gene correction after PBSCT,with no complication related to the transplantation.CONCLUSION Hematopoietic stem cell transplantation could be a substitute for transfusiondependent PKD.
文摘The purpose of this study is to investigate the perioperative changes of erythrocyte kinase (PK) activity. Thirty patients undergoing upper abdominal surgery were dirided into epidural blockade(EB) group or intra venous procaine balanced anesthesia(IPBA) group. The blood level of glucose increased significantly at 60 min after the beginning of operations in both groups. Blood glucose levels on the first postoperative day were significantly higher than the baselines in both groups [(8. 29±1. 5)vs (4. 8±0.18) mmol/L (P< 0.01) in EB, (6.36±0.33) vs (4. 55±0.18 ) mmol/L (P<0. 01 ) in IPBA]. The concentrations of 2, 3-DPG in RBC were not significantly changed in both groups. The PK activity in RBC decreased signficantly at 60 min after the end of operation in both groups. The PK activity levels on the first postoperative day were significantly lower than the baselines in both groups [(7. 59±1. 01) vs (11. 62±1. 06) IU/gHb (P<0. 05) in EB; (7. 75±0. 94) vs (11. 84 ±1.12) IU/gHb (P<0. 05 ) in IPBA]. The results suggest that the PK activity is decreased and the concentration of 2, 3-DPG remians unchanged under the hyperglycemic response to surgical stress, which may be related to an inhibition of glycolysis in RBC.
文摘By using Fab'-enzyme labelled immuno absorbent assay (ELISA) with sensitivity of picogram (10-12 g or pg) level, the M-type pyruvate kinase (M-PyK) in plasma was determined in 47 cases of normal healthy adult and 26 cases of hepatocellular carcinoma (HCC) patient. It was found that the upper limits of normal male and female were 1.1 and 1.4 ng/ml (expressed as M2-PyK) respectively. The plasma M-PyK in HCC patients was significant increased to above 5 times of average normal level, the positive rate was about 95%. In 6 cases of subclinical small hepatocarcinoma and 7 cases of HCC patient with normal serum alpha-fetal protein level, the mean plasma M-PyK value was also increased. Whereas the plasma M-PyK level in acute or chronic hepatitis and other benign diseases were normal. After the HCC being resected, the plasma M-PyK returned to normal, but increased again in the cases of recurrent hepatocarcinoma, suggesting that the increased M-PyK in the plasma of HCC patient was criginated from M2-type PyK in HCC tissue. Therefore, plasma M-PyK may become a new micro-level index of hepatocarcinoma.
基金supported by the National Natural Science Foundation of China(No.81571488 and No.81771637).
文摘Male germ cells employ specific metabolic pathways throughout their developmental stages.In a previous study,we discovered heightened expression of pyruvate kinase M(PKM),a pivotal glycolytic enzyme,in spermatogonia and spermatids.To gain deeper insights into PKM's roles in spermatogenesis,sperm function,and male fertility,we engineered a conditional-knockout mouse model(Pkm-vkO mice)to selectively disrupt the Pkm gene within germ cells.Despite maintaining regular testicular histology and sperm morphology,the male Pkm-vko mice were infertility,characterized by significant impairments in sperm motility and adenosine triphosphate(ATP)generation.In addition,Pkm-null spermatozoa exhibited similar deficits in protein tyrosine phosphorylation linked to capacitation,as well as compromised performance in in vitro fertilization experiments.To conclude,PKM's presence is not obligatory for the entirety of spermatogenesis in male germ cells;however,it emerges as a critical factor influencing sperm motility and overall male fertility.
基金supported by the National Key Research and Development Program of China(2022YFD1700300)Program of Introducing Talents of Discipline to Universities of China(111Program,D20023)the Key Technologies R&D Program of Guizhou Province in China(2017-5788-1)。
文摘The prevention and control of rice bacterial leaf blight(BLB)disease has not yet been achieved due to the lack of effective agrochemicals and available targets.Herein,we develop a series of novel bissulfones and a novel target with a unique mechanism to address this challenge.The developed bissulfones can control Xanthomonas oryzae pv.oryzae(Xoo),and 2-(bis(methylsulfonyl)methylene)-N-(4-chlorophenyl)hydrazine-1-carboxamide(B_(7))is more effective than the commercial drugs thiodiazole copper(TC)and bismerthiazol(BT).Pyruvate kinase(PYK)in Xoo has been identified for the first time as the target protein of our bissulfone B_(7).PYK modulates bacterial virulence via a CRP-like protein(Clp)/two-component system regulatory protein(reg R)axis.The elucidation of this pathway facilitates the use of B_(7)to reduce PYK expression at the transcriptional level,block PYK activity at the protein level,and impair the interaction within the PYK-Clp-reg R complex via competitive inhibition,thereby attenuating bacterial biology and pathogenicity.This study offers insights into the molecular and mechanistic aspects underlying anti-Xoo strategies that target PYK.We believe that these valuable discoveries will be used for bacterial disease control in the future.
基金This work was supported by the National Basic Research Program of China(973 Program)(No.2006CB504305)National Special Research Program of Major Infectious Diseases(No.2008ZX10001-002)the 111 Project(No.B06018).
文摘Both thymocytes and tumor cells express M2 type isoenzyme of pyruvate kinase(M2PK),which is different from R type isoenzyme of pyruvate kinase(RPK)that is expressed in erythrocytes.In this report,the effect of RPK and M2PK on the transcription of human immunodeficiency virus type 1(HIV-1)was tested.The results indicated that M2PK could enhance HIV-1 transcription from its long terminal repeat(LTR)promoter,while RPK did not have such an effect.Specific down-regulation of M2PK could inhibit HIV-1 transcription from its LTR region.Furthermore,it was found that the C terminal region of M2PK is responsible for this effect.Collectively,the cellular factor M2PK that is expressed in thymocytes could facilitate the transcription of HIV-1.
基金Supported by National Natural Science Foundation Project of China(No.81673979,81473688,81173265)Traditional Chinese Medicine Administration Project of Guangdong Province,China(No.20141070)+3 种基金the Science and Technology Program of Guangdong,China(No.2014A020212672,2014A020210015)the Natural Science Foundation of Guangdong,China(No.2016A030313114,2015A030313333)Scientific Research Cultivation and Innovation of Jinan University Special Fund for Basic Scientific Research of Central University(No.21615464,21615412)the New Century Talent Support Program by the Ministry of Education(No.NCET-13-0827)
文摘OBJECTIVE:To investigate the effect of Ruyanneixiao cream(RYNX) on the expression of hypoxia inducible factor-1α(HIF-1α), hexokinase 2(HK2),phosphofructokinase(PFK), and pyruvate kinase M2(PKM2) mRNA and protein in MCF-10 AT cells and in an animal model of precancerous mammary lesions.METHODS:Following treatment of MCF-10 AT cells with RYNX, tamoxifen(TAM) and YC-1 for 48 h,HIF-1α, HK2, PFK, PKM2 mRNA and protein expression was analyzed.Fifty female SD rats were randomly divided into control, model, TAM, and highand low-dose RYNX groups, with 10 rats in each group.A precancerous mammary lesion model was established for all groups except the control group.High-and low-dose RYNX cream containing TAM was coated on the breasts of animals in the corresponding groups.The rat mammary tissue was removed in the 10 th week and HIF-1α, HK2, PFK,PKM2 mRNA and protein was analyzed.RESULTS:In vitro analyses demonstrated that, compared with the matrix group, HIF-1α, HK2, PFK,PKM2 mRNA and protein expression was significantly decreased in the RYNX group(P < 0.05).Compared with the YC-1 + RYNX group, HK2, PFK,and PKM2 protein expression was significantly reduced in the RYNX group.HIF-1α, HK2, PFK, and PKM2 protein expression was increased significantly in the model group(P < 0.05) compared with the control group, while HIF-1α, HK2, PFK, and PKM2 mRNA and protein expression was significantly decreased in both the high-and low-dose RYNX groups(P < 0.05), with the effect being greater in the high-dose group.CONCLUSION:RYNX can block precancerous breast lesions by decreasing the expression of HK2,PFK, and PKM2 mRNA and protein via inhibition of HIF-1α mRNA and protein overexpression in a dose-dependent manner.
基金supported by a fellowship from the Agency for Science,Technology and Research,Singapore.
文摘Alternative splicing of the pyruvate kinase M gene(PK-M)can generate the M2 isoform and promote aerobic glycolysis and tumor growth.However,the cancer-specific alternative splicing regulation of PK-M is not completely understood.Here,we demonstrate that PK-M is regulated by reciprocal effects on the mutually exclusive exons 9 and 10,such that exon 9 is repressed and exon 10 is activated in cancer cells.Strikingly,exonic,rather than intronic,cis-elements are key determinants of PK-M splicing isoform ratios.Using a systematic sub-exonic duplication approach,we identify a potent exonic splicing enhancer in exon 10,which differs from its homologous counterpart in exon 9 by only two nucleotides.We identify SRSF3 as one of the cognate factors,and show that this serine/arginine-rich protein activates exon 10 and mediates changes in glucose metabolism.These findings provide mechanistic insights into the complex regulation of alternative splicing of a key regulator of the Warburg effect,and also have implications for other genes with a similar pattern of alternative splicing.
基金supported by grants from the National Key Research and Development Program of China(2016YFD0100101-08)the National Transformation Science and Technology Program(2016ZX08001006)+3 种基金the Jiangsu Science and Technology Development Program(BE2015363)the Agricultural Science and Technology Innovation Fund project of Jiangsu Province(CX(16)1029)the Key Laboratory of Biology,Genetics and Breeding of Japonica Rice in the Mid-lower Yangtze River,Ministry of Agriculture,Chinathe Jiangsu Collaborative Innovation Center for Modern Crop Production
文摘Pyruvate kinase （PK） is a key enzyme in glycolysis and carbon metabolism. Here, we isolated a rice （Oryza sativa） mutant, w59, with a white-core floury endosperm. Map-based cloning of w59 identified a mutation in OsPKpα1, which encodes a plastidic isoform of PK （PKp）. OsPKpα1 localizes to the amyloplast stroma in the developing endosperm, and the mutation of OsPKpα1 in w59 decreases the plastidic PK activity, resulting in dramatic changes to the lipid biosynthesis in seeds. The w59 grains were also characterized by a marked decrease in starch content. Consistent with a decrease in number and size of the w59 amyloplasts, large empty spaces were observed in the central region of the w59 endosperm, at the early grain-filling stage. Moreover, a phylogenetic analysis revealed four potential rice isoforms of OsPKp. We validated the in vitro PK activity of these OsPKps through reconstituting active PKp complexes derived from inactive individual OsPKps, revealing the heteromeric structure of rice PKps, which was further confirmed using a protein- protein interaction analysis. These findings suggest a functional connection between lipid and starch synthesis in rice endosperm amyloplasts.
基金financial support from the National Natural Science Foundation of China (Nos.61975214, U20A20335,81630053)Beijing Natural Science Foundation (Nos.4202075, 2202057, 7212208)。
文摘Tumor cells usually show abnormally high glycolysis rate to maintain the dynamic balance of energy.The growth of tumor cells can be affected by inhibiting the activity of pyruvate kinase(especially M2-type isozyme,PKM2),the rate limiting enzyme of glycolysis.This is helpful to the treatment of tumor.Herein,metal organic frameworks(MOFs) were found to inhibit the activity of PKM2.Nanoscale ZIF-8 was synthesized by standing and ultrasonic method,respectively.The ZIF-8 has the performance of inhibiting PKM2.Further research showed that the inhibition ability was attributed to zinc ion in ZIF-8.Interestingly,the IC_(50) of ZIF-8 on PKM2 was one percent of that of zinc ion.This novel enzyme inhibitor is expected to be used in cancer therapy.
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.
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Activities of hexokinase （HK）, pyruvate kinase （PK）, superoxide dismutase （SOD） and catalase （CAT） and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber （Apostichopus japonicus Selenka） to rapid temperature changes in laboratory. Animals were subjected to a higher temperature （from 10 to 20℃） （Tinc treatment） or to a lower temperature （from 20 to 10℃） （Tddec treatment） for 72 h. At 1, 3, 12, 24, 72 h of exposure, animals were removed and prepared for further analysis. Results showed that the effect of acute temperature changes on enzyme activities was significant. In Tinc treatment, activities of SOD and CAT increased immediately. The significant enhancement of SOD and CAT activities suggested that oxidative stress increases significantly when ambient temperature increasing from 10 to 20℃. The up-regulation of Flsp70 in Tinc and Tdec treatments indicated that Hsp70 was a bioindicator of thermal stress in the sea cucumber, and the expression pattern depended on the thermal treatment.
文摘Nonspherocytic hereditary anemias are occasionally accompanied by significant iron overload but the significance for the development of chronic liver disease is not clear. We described two cases of patients with chronic liver d isease and severeiron overload due to chronic hereditary hemolysis. Both patients have had signs of liver cirrhosis and severe hemolysis since childhood. A hereditary pyruvate kinase deficiency (PKD) was discovered as the underlying reason for the hemolysis.Sequencing of the pyruvate kinase gene showed a mutation within exon 11. Liver histology in both patients revealed cirrhosis and a severe iron overload but primary hemochromatosis was excluded by HFE-gene analysis.An iron reduction therapy with desferrioxamine led to significant decrease of serum ferritin and sustained clinical improvement. PKD-induced hemolysis may cause severe iron overload even in the absence of HFE-genotype abnormalities. This secondary iron overload can lead to chronic liver disease and cirrhosis. Therefore, the iron metabolism of PKD patients has to be closely monitored and iron overload should be consequently treated.
基金the Affiliated Fuzhou First Hospital of Fujian Medical University,the Fuzhou Science and Technology planning project(2020-WS-123).
文摘Objective:To investigate the therapeutic effect of evodiamine(EVO)on the expression of hexokinase(HK),lactate dehydrogenase A(LDHA),and pyruvate kinase M(PKM),key enzymes of glycolysis,in the tumor-bearing mice after modeling mouse colon cancer cells(CT26).Methods:A tumor-bearing mouse model was generated by administering axillary injection of CT26 and intraperitoneally injecting different doses of EVO.The therapeutic effects of EVO on CT26 tumor-bearing mice were evaluated by measuring the thymus and spleen indices,tumor volume,tumor suppression rate,and other related indicators in the tumor tissues of mice in each group after the administration of EVO,in addition,histopathological changes in the tumor tissues of the mice in the groups were studied by hematoxylin and eosin staining.The expression levels of HK,LDHA,and PKM in the tumor tissues of each group of mice were measured by performing Western blot to investigate the mechanism of EVO treatment in CT26 tumor-bearing mice.Results:EVO inhibited the growth of tumors in CT26-bearing mice and enhanced their splenic and thymic indices.Western blot results showed that EVO reduced the expression levels of HK,LDHA,and PKM proteins in the tumor tissues of CT26 tumor-bearing mice.Conclusion:EVO has a therapeutic effect on CT26 tumor-bearing mice,and its mechanism of action may be related to the low expression of key enzymes HK,LDHA and PKM of glycolysis in tumor tissues.
基金supported by the National High-Tech R&D Program of China(2011AA10A106)the National Natural Science Foundation of China(31071477,31171611)the Key Scientific and Technological Innovation Special Projects of Shaanxi"13115",China(2010ZDKG-68,2011KTZB02-01-01)
文摘To further research the regulatory network of pyruvate dehydrogenase kinase （designated as TaPDK） in physiological male-sterility （PHYMS） of wheat induced by chemical hybridizing agent （CHA） SQ-1, an anther cDNA library was constructed, and the proteins interacting with TaPDK were screened via yeast two-hybrid technique. Subsequently, a few candidate proteins in nucleotide expression levels were detected by real-time quantitative PCR. Yeast-two hybrid screening was performed by mating yeast strain Y2HGold containing BD-TaPDK bait plasmid with yeast strain Y187 including anther cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium （SD/-Ade/-His/-Leu/-Trp） （QDO）, and further were incubated on QDO medium containing AbA and X-α-Gal. The interactions between TaPDK and the proteins obtained from positive colonies were further confirmed by co-transformation validation. After plasmids DNA were extracted from blue colonies and sequenced, the sequences results were analyzed by bioinformatic methods. Finally, 24 colonies were obtained, including eight genes, namely non-specific lipid-transfer protein precursor （TanLTP）, polyubiquitin （TaPUbi）, glyceraldehyde-3-phosphate dehydrogenase, proliferating cell nuclear antigen （TaPCNA）, CBS domain containing protein （TaCBS）, actin, guanine nucleotide-binding protein beta subunit, chalcone synthase, and three new genes with unknown function. The results of quantitative RT-PCR showed that the expression levels of TanLTP, TaPUbi, and TaPCNA were obviously up-regulated in PHYMS anther, and TaCBS expression was only increased at the tricellular stage in PHYMS anther compared with in fertile lines. Whereas, the expression of TaPDK was obviously down-regulated in PHYMS lines. Collectively, these datas indicated that the majority of candidate proteins might be related to pollen abortion in PHYMS lines, which further suggested that TaPDK plays multiple roles in pollen development, besides participating in regulating pyruvate dehydrogenase complex activity.
