BACKGROUND: In our previous report, we observed the increaseed epidermal glucose concentrations and decreased hexokinase actiuities of diabetic patients which were ciimpared to those of normal individuals. And we considered that, there were some derrangement of lipid metabolism and glycolysis of diabetic epidermis. OBJECTIVES: This study wns planed to prove the above possible changes of lipid metabolism and glycolysis of diabetic epidermis. METHODS: The epidermal enzymatic activties of glucose-6-phophate dehydrogenase(G6PDH), phosphofructokinase(PFK), 1-glycerophosphate dehydrogenase(GOPDH) and b-hydroxybutyryl CoA dehydrogenase(HBDH) were assayed in the skin samples obtained friom diabetic patients and normal individuals by the fluorometric: method. RESULTS: Teh epidermal PFK activities of diabetic patients were decreased(3.49+1.35(mmole/hr/kg dry weight)) compared to that of normal individuals(5.00+0.56(mmcle/hr/kg dry weight))(p<0.05). The epidermal HBDH activities of diabetic patients were decreised(0.28+0.10(mole/hr/kg dry weight)) compared to that of normal individuals(0.49+0.20(mole/hr/kg dry weight)(p<0.01). The mean epidermal G6PDH activity of diabetic patients was decreasec. compased to that of normal individuals, but there was no statisical significance. The mean epidermal 3OPDH activittes of diabetic patients and normal individual; showed no significant difference. CONCLUSION: We consider that the decreased epidermal HBDH actiities of diabetic patients can decrease keton body formatiori, and the abnormal glycolysis can exist in the diabetic epidermis because the decreased enzymatic activities of diabetic epidermal PFK may decrease the velocity of glycolysis.
Diabetes Mellitus ; Epidermis ; Glucose ; Glycolysis ; Hexokinase ; Humans ; Lipid Metabolism ; Skin

It is well estabilshed that the xerosis is closely related to diabeic pruritus. Although the causes of xerosis are thought to bie the abnormalities of sweating and autonomic nervous system, the exact mechanism of the xerosis in diabetic skin is still unknown. This study was designed to investigate the possible derangement of glucose metabolism in the skin of diabetes mellitus patients with xerosis. The epidemal glucose content and hexokonase activities were masured in the skin samples obtained from normal individuals and diabetes mellitus patients with xerosis The epidermal glucose content was measured by the enzymatic cycling method. The enzymatic activities of hexokinase were assayed by fluorometric method. The epidermal glucose content of diabetic patients increaed approximately twice [27.46+9.52 (mmole/kg /dry weight) that of normal individuals [13.90+4.79(mmole/kg /dry weight)] (p<0. 0001). The epidermal hexokinase activities of diabetes patients were significantly decreased [0.56+0.15(mole/hr/kg/dry weight)] compared to that of normal indivduals [0.96+0.24(mole/hr/kg dry weight)] (p<0.0001). There were no significant differences in the epidermal glucose content and enzyme activities of hexokinase between the diabetic patients with: erosis and diabetic patients without xerosis. These data indicated that decreased activities of hexokinase could reduce the glucose phopkiorylation and uptake into keratinocytes, and which could lead to accumulat. glucose in the interstitial space of diabetic epidermis. And the decreased hexokinase activities may exert on lipid metabolism and glycolysis of diabetic epiidermis, because hexokinase is a key enzyme of hexose monophosphate pathway and glycolysis.
Autonomic Nervous System ; Diabetes Mellitus ; Epidermis ; Glucose ; Glycolysis ; Hexokinase* ; Humans ; Keratinocytes ; Lipid Metabolism ; Metabolism ; Pruritus ; Skin ; Sweat ; Sweating

OBJECTIVETo investigate the effects of hypoxia on the glycolysis in cultured rat hepatocytes.

METHODSMixed gas with different concentrations of O(2), CO(2) and N(2) was prepared for the in vitro culture of normal rat hepatocytes. The cell strains were set to be A, B, C groups, which were observed at 1, 2, 4, 8 and 16 hours after hypoxia with normal hepatocytes as the control. Biochemical methods were employed to determine the activities of the key enzymes during hepatocytic glycolysis such as hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), lactate dehydrogenase (LDH) and the change of the content of lactic acid (LA) in the culture fluid.

RESULTS(1) The LDH activity of the rat hepatocytes increased significantly at all the time points of hypoxia in A and B groups when compared with that in control group (P < 0.05), while the activity increased obviously in C group since 2 hours after hypoxia (P < 0.05). (2) The HK activity of the cells in A group increased significantly at 1, 2, 4 and 16 hours after hypoxia and that in B and C groups increased obviously at 1 hour when compared with control group (P < 0.05). While the cellular PFK activity in A group increased markedly at 1 and 4 hours after hypoxia and that in B and C groups increased evidently at 4 hours after hypoxia (P < 0.05). The cellular PK activity in all the three groups increased at all the hypoxic time points (P < 0.05). (3) The cellular LA content in A and B groups began to increase since 2 hours and that in C group did so since 4 hours after hypoxia and increased along with the time lapse (P < 0.05).

CONCLUSIONhypoxia might initiate glycolysis.

Animals ; Cell Hypoxia ; Cells, Cultured ; Glycolysis ; Hepatocytes ; enzymology ; metabolism ; Hexokinase ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Lactic Acid ; metabolism ; Oxygen ; metabolism ; Phosphofructokinases ; metabolism ; Pyruvate Kinase ; metabolism ; Rats

Positron Emission Tomography(PET) is a new imaging modality to make biochemical metabolic images. Because biochemical changes precede anatomical changes in most of diseases including cancer, PET can detect earlier changes of diseases than conventional anatomical imaging modalities. PET can also characterize biochemical property of diseases. A PET center is composed of a medical cyclotron, synthesis system of radiopharmaceuticals and scanner. For PET oncology, several positron-emitting radiopharmaceuticals have been developed. Among them, F-18-fluorodeoxyglucose (FDG) is most frequently used. Higher rate of glucose metabolism has been observed in cancer cells. Like glucose, FDG is transported into the cancer cells and converted to FDG-6-phosphate by hexokinase. FDG-6-phosphate is trapped in the cytoplasm, and emits gamma rays to make PET images. The current application of FDG PET in oncology is in detection, differentiation, and staging of the primary tumors, grading malignancy, monitoring therapeutic response, and early detection of recurrence. Nowadays, PET is an established procedure for staging the diseases and detecting the recurrence in many cancers, especially the lung, colorectal, and head and neck cancers, melanoma, and lymphoma. PET is a regular part of medical insurance reimbursement in many developed countries, and becomes a valuable research tool in oncology as well as an important imaging modality in managing cancer patients.
Cyclotrons ; Cytoplasm ; Developed Countries ; Electrons* ; Gamma Rays ; Glucose ; Head ; Hexokinase ; Humans ; Insurance ; Lung ; Lymphoma ; Melanoma ; Metabolism ; Neck ; Radiopharmaceuticals ; Recurrence

Objective: To investigate the regulatory relationship of Protein Phosphatase 2 Regulatory Subunit B"Alpha ( PPP2R3A) and hexokinase 1 ( HK1) in glycolysis of hepatocellular carcinoma (HCC). Methods: In HepG2 and Huh7 cells, PPP2R3A expression was silenced by small interfering RNA (siRNA) and overexpression by plasmid transfection. The PPP2R3A-related genes were searched by RNA sequencing. Glycolysis levels were measured by glucose uptake and lactate production. QRT-PCR, ELISA, western blot and immunofluorescence assay were performed to detect the changes of PPP2R3A and HK1. Cell proliferation, migration and invasion assay were used to study the roles of HK1 regulation by PPP2R3A. Results: RNA sequencing data revealed that PPP2R3A siRNA significantly downregulated the expression of HK1. PPP2R3A gene overexpression promotes, while gene silencing suppresses, the level of HK1 and glycolysis in HCC cells. In HCC tissue samples, PPP2R3A and HK1 were colocalized in the cytoplasm, and their expression showed a positive correlation. HK1 inhibition abrogated the promotion of glycolysis, proliferation, migration and invasion by PPP2R3A overexpression in liver cancer cells. Conclusion Our findings showed the correlation of PPP2R3A and HK1 in the glycolysis of HCC, which reveals a new mechanism for the oncogenic roles of PPP2R3A in cancer.
Carcinoma, Hepatocellular/pathology* ; Cell Line, Tumor ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Glycolysis ; Hexokinase/metabolism* ; Humans ; Liver Neoplasms/pathology* ; Protein Phosphatase 2/metabolism* ; RNA, Small Interfering/metabolism*

BACKGROUND: Commutable reference materials (RMs) are suitable for end-users for evaluating the metrological traceability of values obtained using routine measurement systems. We assessed the performance of 6 routine measurement systems with validated secondary RMs. METHODS: We tested the homogeneity, stability, and commutability of 5 minimally processed human serum pools according to the standard guidelines. The serum pools were assigned values as per the reference procedure of the United States Centers for Disease Control and were used to evaluate the trueness of results from 6 commercial measurement systems based on enzymatic methods: 3 glucose oxidase (GOD) and 3 hexokinase (HK) methods. RESULTS: The prepared RMs were validated to be sufficiently homogenous, stable, and commutable with the patient samples. Method bias varied for different systems: GOD01, -0.17 to 2.88%; GOD02, 1.66 to 4.58%; GOD03, -0.17 to 3.14%; HK01, -3.48 to -0.85%; HK02, -3.83 to -0.11%, and HK03, -1.82 to -0.27%. CONCLUSIONS: We observed that the prepared serum glucose RMs were qualified for trueness assessment. Most of the measurement systems met the minimal quality specifications.
Blood Chemical Analysis/instrumentation/*standards ; Blood Glucose/*analysis ; Glucose Oxidase/metabolism ; Hexokinase/metabolism ; Humans ; Reagent Kits, Diagnostic ; Reference Standards ; Regression Analysis

This research aimed to study the effect of distillage recycling on ethanol fermentation, the key glycolytic enzymes and cell composition of the self-flocculating yeast. With the self-flocculating yeast SPSC01 and medium composed of 220 g/L glucose, 8 g/L yeast extract and 6 g/L peptone, continuous ethanol fermentation was carried out at the dilution rate of 0.04 h(-1) with a 1.5 L tank bioreactor. Fermentation broth was collected every 3 days, and ethanol and other volatile byproducts were removed by distillation, but the stillage with high boiling byproducts was recycled to prepare the medium instead of fresh water. The system was run for 20 days, during which ethanol and biomass concentrations in the effluent decreased continuously, indicating the significant inhibition of the high boiling byproducts accumulated within the system. Thus, the activities of the key enzymes of the glycolytic pathway: hexokinase, 6-phosphofructose kinase, and pyruvate kinase were analyzed, and it was observed that all of them were inhibited. Furthermore, the biosynthesis of the stress response metabolites glycerol and trehalose was investigated, and it was found that glycerol production that can protect yeast cells against osmotic pressure stress was enhanced, but trehalose biosynthesis that can protect yeast cells against ethanol inhibition was not improved, correspondingly. And in the meantime, the biosynthesis of the major intracellular components proteins and hydrocarbons was adjusted, correspondingly.
Bioreactors ; microbiology ; Ethanol ; metabolism ; Fermentation ; Flocculation ; Glycerol ; metabolism ; Glycolysis ; Hexokinase ; metabolism ; Industrial Microbiology ; methods ; Phosphofructokinase-1 ; metabolism ; Saccharomyces cerevisiae ; enzymology ; genetics ; metabolism ; Schizosaccharomyces ; enzymology ; genetics ; metabolism ; Trehalose ; metabolism ; Triticum ; metabolism ; Zea mays ; metabolism

Cancer cells are known to show increased rates of glycolysis metabolism. Based on this, PET studies using F-18-fluorodeoxyglucose have been used for the detection of primary and metastatic tumors. To account for this increased glucose uptake, a variety of mechanisms has been proposed. Glucose influx across the cell membrane is mediated by a family of structurally related proteins known as glucose transporters (Gluts). Among 6 isoforms of Gluts, Glut-1 and/or Glut-3 have been reported to show increased expression in various tumors. Increased level of Glut mRNA transcription is supposed to be the basic mechanism of Glut overexpression at the protein level. Some oncogens such as src or ras intensely stimulate Glut-1 by means of increased Glut-1 mRNA levels. Hexokinase activity is another important factor in glucose uptake in cancer cells. Especially hexokinase type II is considered to be involved in glycolysis of cancer cells. Much of the hexokinase of tumor cells is bound to outer membrane of mitochondria by the porin, a hexokinase receptor. Through this interaction, hexokinase may gain preferred access to ATP synthesized via oxidative phosphorylation in the inner mitochondria compartment. Other biologic factors such as tumor blood flow, blood volume, hypoxia, and infiltrating cells in tumor tissue are involved. Relative hypoxia may activate the anaerobic glycolytic pathway. Surrounding macrophages and newly formed granulation tisssue in tumor showed greater glucose uptake than did viable cancer cells. To expand the application of FDG PET in oncology, it is important for nuclear medicine physicians to understand the related mechanisms of glucose uptake in cancer tissue.
Adenosine Triphosphate ; Anoxia ; Biological Factors ; Blood Volume ; Carcinogens ; Cell Membrane ; Glucose* ; Glycolysis ; Hexokinase ; Humans ; Macrophages ; Membranes ; Metabolism ; Mitochondria ; Nuclear Medicine ; Oxidative Phosphorylation ; Protein Isoforms ; RNA, Messenger

In this study, we aimed to evaluate the toxic effects, changes in life span, and expression of various metabolism-related genes in Caenorhabditis elegans, using RNA interference (RNAi) and mutant strains, after 3-bromopyruvate (3-BrPA) treatment. C. elegans was treated with various concentrations of 3-BrPA on nematode growth medium (NGM) plates, and their survival was monitored every 24 h. The expression of genes related to metabolism was measured by the real-time fluorescent quantitative polymerase chain reaction (qPCR). Nematode survival in the presence of 3-BrPA was also studied after silencing three hexokinase (HK) genes. The average life span of C. elegans cultured on NGM with 3-BrPA was shortened to 5.7 d compared with 7.7 d in the control group. hxk-1, hxk-2, and hxk-3 were overexpressed after the treatment with 3-BrPA. After successfully interfering hxk-1, hxk-2, and hxk-3, the 50% lethal concentration (LC₅₀) of all mutant nematodes decreased with 3-BrPA treatment for 24 h compared with that of the control. All the cyp35 genes tested were overexpressed, except cyp-35B3. The induction of cyp-35A1 expression was most obvious. The LC₅₀ values of the mutant strains cyp-35A1, cyp-35A2, cyp-35A4, cyp-35B3, and cyp-35C1 were lower than that of the control. Thus, the toxicity of 3-BrPA is closely related to its effect on hexokinase metabolism in nematodes, and the cyp-35 family plays a key role in the metabolism of 3-BrPA.
Animals ; Caenorhabditis elegans/metabolism* ; Caenorhabditis elegans Proteins/genetics* ; Cytochrome P-450 Enzyme System/genetics* ; Hexokinase/physiology* ; Pyruvates/toxicity* ; RNA, Messenger/analysis*

OBJECTIVETo investigate the influence of microtubule intervention drugs on glycolytic key enzymes in myocardial cells after hypoxia.

METHODSThe primary passage of cultured myocardial cells from neonatal rats were divided into A group (with hypoxia), B group (with hypoxia and administration of l0 micromol/L colchicine), C group (with hypoxia and administration of 5 micromol/L taxol), D group (with hypoxia and administration of 10 micromol/L taxol), E group (with hypoxia and administration of 15 micromol/L taxol). The morphology of microtubule was observed with laser scanning microscope (LSM). The cell vitality was assayed by cell counting kit (CCK). The activities of hexokinase (HK), pyruvate kinase (PK), phosphofructokinase (PFK) and lactate dehydrogenase (LDH) were assayed with colorimetry.

RESULTSIn group B and E, the microtubule structure was damaged heavily, and the cell vitality was decreased significantly [The cell vitality was (89.99 +/- 3.47)% in B group and (84.56 +/- 6.61)% in E group, respectively, at 1.0 post hypoxia hour (PHH), and hoth values were obviously lower than that in A group (97.44 +/- 1.76)%, P < 0.01]. The HK, PK and PFK activities decreased obviously. The activities of HK, PK and PFK in group C were similar to those of the A group. Compared with that in other groups, the degree of damage of microtubule structure in D group was milden. The activities of HK, PK and PFK in D group during 0.5 - 6.0 PHH were significantly higher than those in A group. The activity of LDH in each group was increased after hypoxia.

CONCLUSIONProper concentration of microtubule-stabilizing drugs can alleviate the damages to microtubule structure, and enhance the activity of glycolytic key enzymes of myocardial cells at early stage of hypoxia.

Animals ; Cell Hypoxia ; Cells, Cultured ; Glycolysis ; drug effects ; Hexokinase ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Microtubules ; drug effects ; metabolism ; Myocytes, Cardiac ; enzymology ; metabolism ; Phosphofructokinase-1 ; metabolism ; Pyruvate Kinase ; metabolism ; Rats ; Rats, Sprague-Dawley