GLUT4 Research Articles

Cobalt chloride-induced hypoxia stimulates inflammatory response in adipocytes

Objective To explore the relationship between hypoxia induced by cobalt chloride( CoCl2 ) and inflammation in 3T3-LI adipocytes, and the underlying molecular mechanism. Methods 3T3-L1 pre-adipocytes were induced under standard differentiation process. Differentiated 3T3-L1 adipocytes were incubated with CoCl2 to induce hypoxia. The mRNA and protein expressions of hypoxia inducible factor-1 α ( HIF-1 α ), glucose transporter 1 ( Glut1 ), adipocytokines, and inflammatory cytokines, as well as the related signaling pathways were determined with quantitative realtime-PCR and Western-blot in this cell model. Results CoCl2 at the concentration of 200 μmol/L significantly up-regulated HIF-1 α and Glut1 expressions. After adipocytes were treated with CoCl2, the mRNA levels of endoplasmic reticulum stress marker genes, such as C/EBP homologous protein (CHOP) and glucose-regulated protein78 (GRP78) were markedly increased, adiponectin mRNA expression was significantly decreased, while resistin and leptin mRNA expressions were significantly increased. In addition, the mRNA expressions of cyclooxygenase 2, interleukin-6, and other inflammatory factors were also increased. The phosphorylation of IκBα,which could inhibit the activation of NF-κB, was stimulated by CoCl2. ConclusionsThe results indicate that hypoxia may induce inflammatory response via NF-κB activiation in adipocytes. Key words: Hypoxia; Adipocyte; Endoplasmic reticulumstress; Inflammation

Study on the expression of Glut1, HIF-1α and Ki-67 in hepatocellular carcinoma and their relationship

Objective To explore the expression of Glut1, HIF-1α and Ki-67 in hepatocellular carcinoma (HCC) and their relationship between their expression and clinicopathological features.Methods Immunohistochemical study (EnVision method) for Glut1, HIF-1a and Ki-67 were performed on tissue microarray which consisted of 171 cases of HCC, 55 cases of adjacent non-neoplastic liver tissues, and 22cases of normal liver tissues.Results The expression rate of Glut1 ,HIF-1α and ki-67 in 171 cases of HCC was 15.2％, 19.9％ and 66.1％, respectively, which was much higher than that in the adjacent non-neoplastic liver tissues (1.8％ ,1.8％and 5.5％) and normal liver tissues(all negative).The expressions of Glut1 and HIF-1α were positively correlated with the differentiation degree of HCC and TNM stage(P ＜0.01, P ＜0.05).The expression of ki-67 was positively correlated with the differentiation degree of HCC.There was a significant positive correlation between the expressions of Glut1 and HIF-1α in HCC (r1 =0.553, P ＜0.05), the expressions of Glut1 and HIF-1α were positively correlated with ki-67(r2 =0.560,r3 =0.613, P ＜0.05).Conclusions Glut1, HIF-1α and ki-67 may play a role in the tumorigenesis and progression of HCC in some degree.Combined detection of Glut1, HIF-1α and Ki-67 may be helpful to judge the degree of malignancy and potential metastasis and evaluate the prognosis. Key words: Glucose transport proteins,facilitative/ME,Hypoxia-inducible factor 1/ME; Ki-67antigen/ME; Carcinoma, hepatocellular/ME

W9, a medicinal plant of the Eastern James Bay Cree, mobilizes L6 muscle GLUT4 transporters and exerts antidiabetic effects in vivo

W9, a medicinal plant of the Eastern James Bay Cree, mobilizes L6 muscle GLUT4 transporters and exerts antidiabetic effects in vivo

Effect of Tinospora crispa on glucose uptake in skeletal muscle: role of glucose transporter 1 expression and extracellular signal-regulated kinase1/2 activation

Background: Tinospora crispa (TC) has been used for years as diabetic remedy in Thai-traditional medicine. It has recently been reported that the aqueous extract from TC’s dried stem enhances glucose transport of L6 myotubes. Objective: Investigate the effects of the water-ethanol extract of T. crispa (WETC) on glucose transport in a rat muscle cell-line L6 myotubes, and explore the mechanism of action of T. crispa in muscle cells. Materials and methods: Glucose uptake rate was determined with the [3H] 2-deoxyglucose uptake method and the cell viability was assessed by sulforhodamine B (SRB) assay. Expressions of glucose transporter 1 (GLUT1), GLUT4, extracellular signal regulated kinase 1/2 (ERK1/2), and AMP-activated protein kinase (AMPK) were measured by quantitative Reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis. Results: At 400 μg/mL, WETC significantly stimulated glucose uptake into L6 myotubes after 24 hours incubation (246.10.1% above basal; p <0.05). The enhancement of glucose transport by WETC was blocked by cycloheximide, a protein synthesis inhibitor. The up-regulation of GLUT1 protein was accompanied by a significant increased in GLUT1 mRNA expression. ERK1/2 was significantly activated in WETC-treated L6 myotubes. In addition, WETC treatment increased AMPK activity in L6 myotubes. Conclusion: T. crispa increased glucose transport activity of L6 myotubes by enhancing GLUT1 expression, a result of AMPK stimulation. Keywords: AMPK, ERK1/2, Glucose uptake, GLUT1, GLUT4, Tinospora crispa

Effects of tumor suppressor in lung cancer-1 overexpression on gene expressions involved in glucose and lipid metabolism in liver cells

The effects of tumor suppressor in lung cancer-1(TSLC1)upregulation on gene expressions involved in glucose and lipid metabolism in Hepa1-6 cells were investigated.The results showed that TSLC1 overexpression decreased fatty acid synthase and acetyl CoA carboxylase expressions(P<0.05 or P<0.01),increased adipose triglyceride lipase expression(P<0.05),and did not change hormone-sensitive lipase,glucose transporter (GLUT)1,and GLUT4 expressions.These results suggest that TSLC1 overexpression may promote lipolysis and inhibit adipogenesis in liver cells. Key words: Tumor suppressor in lung cancer-1; Hepal-6 cells; Glucose-lipid metabolism; Gene expression

Effect of novel gene JAZF1 overexpression on glucose and lipid metabolism in 3T3-L1 adipocytes

Objective To observe the effects of JAZF1 (Juxtaposed with another zinc finger gene 1 ) overexpression on glucose and lipid metabolism in 3T3-L1 adipocytes. Methods The tissue distribution of JAZF1 in healthy C57BL/6J mice was detected by real-time quantitative PCR( RT-QPCR). Expression vector for JAZF1 gene was constructed and transfected into 3T3-L1 adipocytes. The mRNA levels of JAZF1, GLUT1, GLUT4, FAS, ACC, SREBP1, ATGL, and HSL implicated in glucose and lipid metabolism were determined by RT-QPCR; JAZF1 protein level was measured by Western blot. Intracelluar lipid accumulation were measured by oil red O staining method. Results In JAZF1-transfected adipocytes, JAZF1 mRNA and protein levels were significantly higher than control cells after 48 h. The mRNA level of HSL was increased significantly (P<0. 05) in JAZF1 transfection group compared with negative control and empty vector group, and the expressions of FAS, ACC, SREBP1 mRNA were decreased significantly(all P<0.01). However, the mRNA levels of ATGL, GLUT1, GLUT4 were not changed. Intracelluar lipid accumulation was decreased significantly (P<0.05 ) by oil red O staining and colorimetric in JAZF1 -transfected cells compared with negative control and empty vector group. Conclusions There was an extensive expression of JAZF1 in various tissues of C57BL/6J mice,indicating that JAZF1 might play a role in maintaining normal physiological function. These results show that overexpression of JAZF1 in 3T3-L1 cells can reduce lipid synthesis, increase lipolysis, and improve lipid accumulation. JAZF1 might provide a new potential therapeutic target for obesity and diabetes. Key words: JAZF1; 3T3-L1 cells; Glucose metabolism; Lipid metabolism; Real-time quantitative PCR; Lipid accumulation

Role of beta-catenin signaling pathway in EMT of human prostate cancer induced by HIF-1alpha

Epithelial-mesenchymal transition (EMT) is an important process in tumor development. Several studies suggest that the beta-catenin signal pathway may play an important role in EMT. However, there is no direct evidence showing that this pathway actually determines the EMT induced by exogenous signal. Our previous study has successfully proved that over-expression of HIF-1alpha could induce EMT in LNCaP cells, but not in PC-3. So the present study was intended to indicate that the signal of HIF-1alpha for inducing prostate cancer cell to undergo EMT might pass through the beta-catenin pathway. Firstly, we analyzed the expression of HIF-1alpha and its target proteins in LNCaP/HIF1alpha and PC-3/HIF1alpha by Western blot. And then EMT-associated proteins were detected by Western blot. Furthermore the potency of invasiveness and proliferation of several cell lines were evaluated by transwell and MTT assay. Lastly the expressions of beta-catenin and GSK-3beta in these cells were analyzed by Western blot and RT-PCR. HIF-1alpha, Glut-1 and VEGF were highly expressed in LNCaP/HIF1alpha and PC-3/HIF1alpha. And PC-3, LNCaP and PC-3/HIF1alpha were EMT-negative cell lines whereas LNCaP/HIF1alpha and IA8 had undergone EMT process. LNCaP/HIF1alpha, IA8 and PC-3/HIF1alpha exhibited a much stronger potency of invasiveness and proliferation than those of PC-3 and LNCaP. The protein levels of total GSK-3beta and phospho-GSK-3beta in LNCaP/HIF1alpha, IA8 and PC-3/HIF1alpha cells significantly decreased; however, the relative ratios of p-GSK3beta/t-GSK3beta increased. Consistently, beta-catenin protein expression increased in LNCaP/HIF1alpha and IA8 cells, but not in PC-3/HIF1alpha; RT-PCR confirmed these results, except for an enhanced transcription activity of beta-catenin mRNA in PC-3/HIF1alpha. The activation of the beta-catenin signaling pathway correlates with the characteristic of EMT and potency of invasiveness and proliferation. And it may be one critical factor directly controlling the process of EMT induced by HIF-1alpha in prostate cancer.

On the expression of cardiac adiponectin and its receptor 1 by telmisartan tn diabetic rats

Objective To observe the effects of telmisartan on the expression of cardiac adiponectin and its receptor 1 in diabetic rats.and to investigate the protective roles and mechanisms of telmisartan on cardiomyopathy of diabetic rats.Methods Thirty male Wistar rats were randomly divided inlo control group.diabetic group,and telmisartan group.Diabetes mellitus was induced by high-fat and high-sugar diet and intraperitoneal injection of a low dose of streptozotocin.After establishment of diabetes model.telmisartan(5 mg·kg~(-1)·d~(-1))was administered by lavage for 12 weeks in telmisartan group.At termination,the cardiac function was detected.Plasma and myocardial adiponectin levels were assayed by enzyme immunoassay.mRNA expression of adiponectin receptor 1(adipoR1)was assayed by RT-PCR,and protein expression of adipoR1,phosphorylated-AMPK-α,and glucose transporter 4(GluT4)were determined by Western blotting in myocardium.Results After12 weeks,the ratio of heart to body weight was increased[(4.38±0.07 vs 2.99±0.67)g/kg,P<0.05],but adiponectin levels in plasma and myocardium were decreased[(1.09±0.03 vs 1.87±0.05)μg/ml,(0.12±0.02vs 0.21±0.02)μg/mg protein,both P<0.05]in diabetic rats.In myocardium of diabetic rats,the protein and mRNA of adipoR1 were also decreased(0.35±0.08 vs 0.78±0.11,0.34±0.07 vs 0.77±0.08,both P<0.05).so were the expressions of phosphorylated-AMPK-α and GluT_4(0.47±0.12 vs 0.72±0.10,0.41±0.09 vs 0.79±0.08.both P<0.05).The cardiac function was also significantly decreased in diabetic group.The ratio of heart to body weight was significantly decreased in telmisartan group[(3.49±0.39 vs 4.38±0.07)g/kg,P<0.05].Both of plasma and myocardial adiponectin levels were increased[(1.4±0.02 vs 1.09±0.03)μg/ml,(0.16±0.01 vs 0.12±0.02)μg/mg protein,P<0.05],as well as mRNA(0.48±0.06 vs 0.35±0.08)and protein expression of adipoR1(0.47±0.09 vs 0.34±0.07),phosphorylated-AMPK-α(0.57±0.10 vs 0.47±0.12),and GluT_4(0.52±0.10 vs 0.41 ±0.09,all P<0.05)in myocardium.The cardiac function was obviously improved after telmisartan treatment(P < 0.05).Conclusion The levels of myocardial adiponectin and its receptor 1 are decreased in diabetic rats.Telmisartan up-regulates the levels of myocardial adiponectin and its receptor 1 and may promote myocardial glucose oxidation,resulting in the improvement of heart function in diabetic rats. Key words: Telmisartan; Diabetes mellitus,experimental; Adiponectin receptor 1 ; Cardiomyopathy

LRP16通过下调PPARγ表达抑制细胞葡萄糖摄取

：Objective To investigate the effect of leukemia-relatedprotein-16 (LRP16) gene on cell glucose uptake and its molecular mechanism.Methods LRP16over-expression cell lines were made via translating LRP16 gene expression vectorpcDNA3.1-16 and control plasmid pcDNA3.1 into 3T3-L1,C2C12,and HepG2 cell.The effect ofLRP16 gene on cell glucose uptake was detected using 2-deoxy-[~3 H]-D-glucose.Western blotwas used to detect the effect of LRP16 gene on the expression levels of PPARγ,GLUT-4,and GLUT 2 protein.ResultsCell lines with over-expression of LRP16 gene were successfully established,the expressionlevel of LRP16 was two fold higher than control cells.The insulin-stimulated glucoseuptakes in control 3T3-L1,C2C12,and HepG2 cells were higher than cells withover-expression of LRP16 gene(P＜0.01).The expression levels of PPARγand GLUT-4 or GLUT-2 protein in control cellswere higher than cells with over-expression of LRP16 gene (P＜0.05).Conclusion LRP16 inhibits cell glucose uptake viadecreasing the expression of PPARγ protein. Key words: Leukemia-related protein-16; Glucose transporter-4; Glucose transporter-2; PPAR

Effect of Shenfu injectio on insulin resistance in rabbits undergoing cardiopulmonary bypass

Objective To investigate the effect of Shenfu injectio on insulin resistance in rabbits undergoing cardiopulmonary bypass (CPB) . Methods Thirty New Zealand white rabbits of both sexes weighing 2.2-2.5 kg were randomly divided into 3 groups (n = 10 each): group I sham operation (group S); group Ⅰ CPB and group Ⅰ CPB + Shenfu injectio (group SFI). In group IE (group SFI) Shenfii injectio 10 ml/kg was injected intraperitoneally (IP) once a day for 2 days and at 30 min before anesthesia. In group Ⅱ and Ⅲ the duration between aortic cross-clamping and unclamping was 60 min. MAP was maintained at 50-60 mm Hg during CPB. The plasma glucose and insulin concentrations were measured immediately after induction of anesthesia (T_1), immediately after aortic cross-clamping (T_2) , and at 5, 35 and 75 min after aortic unclamping (T_3, T_4 , T_5) and insulin resistance index (HOMA-IR) was calculated. The expression of insulin receptor substrate-1 (IRS-1), phosphatidyl-inositol 3 kinase (PI3Kp85) and glucose transporters (CLUT4) in skeletal muscle was detected at 150 min of CPB by immuno-histochemistry. Results Compared with the baseline values at T_1 , plasma glucose and insulin concentrations and HOMA-IR were significantly increased at T_(2-5) in all 3 groups ( P < 0.05) . CPB significantly increased the plasma glucose and insulin concentrations and HOMA-IR at T_(2-5) in group Ⅱ and Ⅲ as compared with group S ( P < 0.05). The expression of PI3Kp85 and GLUT4 in muscle was significantly decreased in group Ⅱ and Ⅲ as compared with group S ( P < 0.05). Shenfu injectio significantly decreased plasma glucose concentration and HOMA-IR and increased plasma insulin concentration in group fD as compared with group Ⅱ . Shenfu injectio significantly attenuated the CPB-induced changes in IRS-1, PI3Kp85 and GLUT4 expression in muscle. Conclusion Shenfu injectio can ameliorate CPB-induced insulin resistance and the mechanism may be related to the up-regulation of the expression of insulin signal transduction molecules in skeletal muscle. Key words: SHENFU DECOCTION; Cardiopulmonary bypass; Insulin resistance

Distribution, GLUT-1 expression and early surgical intervention for infantile hemangioma on the face

To investigate the development, distribution and GLUT-1 expression of infantile hemangioma and to discuss the early surgical intervention for better results and avoiding severe complication. The lesion site of each case was recorded and analyzed by SPSS V13.0 to study the distribution. The operation was guided by the principle of plastic surgery to remove the hemangioma. The GLUT-1 expression was detected by immunohistochemical technique in all the resected samples. All the results were satisfactory. The GLUT-1 expression was positive in all the cases. The incidences in different sites were significantly different (P < 0.05). 71.7% of the hemangiomas were located at upper and lower lip, periorbital region and facial midline. It indicates that hemangioma is not randomly distributed. Most of them were located at the fusion of facial prominences during embryological development. Infantile facial hemangioma maybe originated from endothelial progenitor cells of placenta which migrate and implant on the fusion of facial prominences. Early surgical intervention is one of the best choice for infantile facial hemangioma.

Astragalus polysaccharides improves glycolipid metabolism in myocardium of diabetic hamsters

The effect of astragalns polysaccharides (AlaS)on diabetic cardiomyopathy was investigated. The mRNA expressions of PPAR-a and GLUT4, pathology of adipose tissue and myocardium, and myocardial uhrastructure were studied. The pathological changes of adipose tissue and myocardium, as well as myocardial uhrastructure were well-improved; the gene expressions of PPAR-α and GLUT4 were raised in APSgroup. APS may be partially effective in treating diabetic cardiomyopathy. Key words: Astragalus polysaccharide; Diabetes; PPAR-α; GLUT4; Cardiomyopathy; Ultrastructure

Expression of hexokinases and glucose transporters in treated and untreated oesophageal adenocarcinoma.

The aim of this study was to assess the expression pattern of the high glucose affinity glucose transporters GLUT 1, 2, 3, 4, 8 and 9 and of hexokinases I, II and III in newly diagnosed oesophageal adenocarcinoma by means of immunohistochemistry. Twenty patients eligible to undergo primary surgery and 18 patients with incomplete pathological response following induction radio chemotherapy, all suffering from oesophageal adenocarcinoma, were included in the study. The intensity and amount of positive tumour cells in the immuno-reaction (histology score (Hscore)) for GLUT 1, 3, 4, 8 and 9 as well as for hexokinase I, II and III were assessed independently by two experienced observers, blinded to the clinical results. In patients that underwent primary surgery, Hscores of GLUT8 (micro 6.7; sd3.3) and GLUT1 (micro 5.5; sd: 5.3) were significantly higher than Hscores of GLUT9 (micro 2.2; sd 1.5) and GLUT3 (micro 3.2, sd: 2.5). Hscores of hexokinase I (micro : 8.3; sd: 4.3), II (micro 5.5, sd: 4.0) and III (I 1.5, sd: 0.7) were all significantly different from each other (p<0.04). In patients that underwent radio-chemotherapy prior to surgical tumour resection, micro Hscores were 6.9 (sd: 4.4) for GLUT1, 6.8 (sd: 5.3) for GLUT3, 5.9 (sd: 4.2) for GLUT8, 3.4 for GLUT9 (sd: 2.7) and 2.3 (sd: 3.6) for GLUT 4. Hscores of GLUT1 and GLUT3 were significantly higher than Hscores of GLUT4. Finally, Hscores of patients with radio-chemotherapy for GLUT3, hexokinase II and III were significantly higher when compared to patients that underwent primary surgery.

GLUT4, Clathrin, and Glucose

GLUT4, Clathrin, and Glucose

Musclin gene overexpression in skeletal muscle of rats with long-term high-fat diet and its correlation with insulin resistance

The expression of musclin gene in skeletal muscle of rats fed with high-fat diet and its correlation to insulin resistance.diabetes mellitus and GLUT4 were explored.The results showed that musclin expressin was up-regulated(1.39±0.36 vs 0.31±0.07,P<0.01)in skeletal muscle of rats fed with high-fat diet, suggesting that this finding may be related with insulin resistance and involvement of GLUT-4 expression(1.27 4± 0.32 vs 1.84±0.24.P<0.01). Key words: Insulin resistance; Musclin; Glucose transporter 4; Gene expression

Research of the relationship between insulin signal transduction and glucose transportation in rats after trauma

To investigate the relationship between insulin post-receptor signal transduction and the change of glucose transportation by skeleton muscle after surgical trauma in rats. Small intestine bowel resection was performed to establish the surgical trauma model in rats. The content and the phosphorylation state of two key proteins in the insulin signaling pathway: insulin receptor substrate-1 (IRS-1) and protein kinase B (PKB/Akt) in skeletal muscle were measured respectively. The 3H labeled glucose uptake experiment was carried out to evaluate the glucose transportation function in both groups. Finally, the expression and the distribution of glucose transporter 4 (GLUT4) in skeletal muscle were detected respectively. The total content of IRS-1 and PKB/Akt in skeletal muscle in both groups had no difference. The phosphorylation of tyrosine (Tyr) residue of IRS-1 in the operation group was attenuated by 31% (P = 0.018), whereas the phosphorylation of serine (Ser) residue of IRS-1 was significantly enhanced by 63% compared with the control group (P = 0.000). Accordingly, the phosphorylation state of PKB/Akt (activated) was attenuated by 48% in the operation group (P = 0.000). The rate of 2-Deoxy-D-[1-3H] glucose transported by skeletal muscle in the operation group was significantly lower than that in the control group. Both the expressions of GLUT-4 mRNA and the total content of GLUT-4 protein in two groups had no significant difference. But the expression of GLUT4 in the plasma membrane was decreased in the operation group than that in the control group. Insulin resistance was associated with enhanced Ser phosphorylation of IRS-1, which impaired its interaction with its downstream target PKB/Akt. Such impaired interactions abolished the ability of IRS-1 to undergo insulin-induced Tyr phosphorylation and further propagate the insulin receptor signal. Uncoupling of signal transduction led to decrease in glucose uptake which associated with a defect in insulin-stimulated glucose transport and GLUT-4 translocation.

Expression of GLUT-1 glucose transporter in epithelial tumors of the ovary

Objective To evaluate the expression of the GLUT-1 glucose transporter in borderline and malignant epithelial neoplasms of the ovary. Methods Histologic sections of tumor tissues from 100 epithelial neoplasms of the ovary were stained for GLUT-1 using polyclonal GLUT-1 antibody and the labeled streptavidin procedure. Chi-square analysis was used to assess if their expression was associated with clinicopathoiogic characteristics of the tumors. Results Normal ovarian surface epithelial cell were either negative or weakly positive. The intensity of the stain was significantly stronger in malignant than borderline tumors (P<0.001). In malignant neoplasms, the intensity of the stain for GLUT-1 increased with histology. Conclusion Overexpression of the GLUT-1 transporter is associated with the histology and grade of the minors. These data suggest that the expression of this transporter may be closely related to the malignant transformation of epithelial ovarian tumors. Key words: Glucose transport proteins, facilitative; Ovarian neoplasms; Neoplasms, cystic, mucinous and serous

Expression of hypoxia-inducible factor 1 alpha and glucose transporter 1 and its significance in human breast carcinoma

Objective To investigate the expression of hypoxia-inducible 1 alpha(HIF-lα)and glucose transporter 1(Glut1)in human breast cancer and its relationship to proliferating cell nuclear antigen (PCNA)protein and clinical pathologic factors.Methods Immunohistochemical staining was used to measure the expression of HIF-lα.Glut1 and PCNA in human breast fibroadenoma,usual hyperplasia and breast carcinoma.Results HIF-1α expression was not found in breast fibroadenoma and hyperplastic Iesions.In contrast.the positive rate of HIF-1α was found in the ductal carcinoma in situ 55%(DCIS,11/20)and the invasive breast carcinoma 85%(51/60).Glut1 positivity in breast carcinoma was 58.8%(47/80).The totsl positive rate of PCNA in breast carcinoma was 75%(60/80),that in DCIS was 65%(13/20)and that in invasive carcinoma was 78.3%(47/60).There was a positive correlation between HIF-lα and Glut 1 level (r=0.653,P＜0.01),a positive correlation between HIF-1α and PCNA level(r=0.693,P＜0.01);and also a positive correlation between Glutl and PCNA level(t=0.742.P＜0.01).conclusion The overexpression of HIF-lα and its target gene Glut1 played important roles in carcinogenesis and progression of breast carcinoma and closely correlated with cell proliferation of breast carcinoma and may become a new target for treatment of breast carcinoma. Key words: Breast neoplasms; Hypoxia-inducible factor 1,alpha subuolit; Nueleocytoplasmic transport proteins; Cell proliferation

Expression of placental glucose transporters in pregnant women with abnormal glycometabolism

Objective To investigate the expression of glucose transporters(GLUTs)in placentas of pregnant women with abnormal glyeometabolism,and to explore its effect on glucose transport between mother and fetus and its relation with the birth weight.Methods Placentas of 41 pregnant women with abnormal glycometabolism(7 cases of DM,10 GDM A1,10 GIGT and 14 GDMA2)and 15 normal pregnant women as control were selected.The expression of GLUT1 and GLUT3was detected by immunohistochemistry.The birth weight was measured at delivery.Results GLUT1 was expressed in the syncytiotrophoblasts and cytotrophoblasts,whereas GLUT3 in some endothelial cells.The expressions of GLUT1 and GLUT3 were significantly different among the five groups(P＜0.01).Positive correlation was shown between the GLUT1 expression and the birth weight(rs=0.532,P＜0.01),but not in GLUT3 expression.Conclusions The expression of GLUT1 and GLUT3 in placentas of pregnancy with abnormal glycometabolism is enhanced,and GLUT1 may play a predominant role in the fetal glucose uptake. Key words: Glucose transport proteins,facilitative; Placenta; Pregnancy complications; Glucose metabolism disorders

Changes of myocardial enzymes related to glycolysis and fatty acid metabolism in chronic myocardial ischemia: experiment with pigs

To investigate the changes myocardial enzymes related to glycolysis and fatty acid metabolism in chronic myocardial ischemia and to evaluate the relationship between the gene expression of glycolytic metabolism related enzymes and myocardial viability. Fourteen Chinese experimental pigs underwent placement of arterial ring into the left anterior descending coronary artery so as to establish models of myocardial ischemia and infarction. (18)F-2-deoxy-2-fluoro-D-glucose single photon emission computed tomography was conducted to observe the viability of the myocardium. One week later the pigs were killed with their hearts taken out. Specimens of ischemic zone, infarction zone, and non-ischemic zone were obtained. RT-PCR was used to detect the mRNA expression of glucose transporter (GLUT) 1, GLUT4, medium-chain acyl-CoA dehydrogenase (MCAD), and heart-fatty acid binding protein (H-FABP). Immunohistochemistry was used to examine the protein expression of Glut1 and Glut4. Periodic Acid Schiff-hematoxylin staining was conducted to detect the glycogen. Pathological examination showed 5 pigs with myocardial infarction and 5 pigs with ischemia. In the pigs with ischemia, the mRNA expression levels of GLUT1 and GLUT4 in the ischemic zone were 9466 +/- 9033 and 60 398 +/- 64 699 respectively, both significantly higher than those in the control zone (5854 +/- 5287 and 34 188 +/- 44 714 respectively, P = 0.043, P = 0.043). the RNA expression of H-FABP in the ischemic zone was 18 123 +/- 15 925, significantly lower than that in the control zone (50 718 +/- 62 412, P = 0.043), and there was no significant difference in the mRNA expression level of MCAD. In the pigs with infarction the mRNA expression of level of H-FABP in the infarction zone was 21 919 +/- 15 224, significantly lower than that in the control zone (87 545 +/- 92 990, P = 0.043), and there were not significant differences in the mRNA expression levels of the GLUT1, GLUT4, and MCAD genes (all P > 0.05). The mRNA expression of GLUT1 in the myocardial segments with perfusion/metabolism mismatch was significantly higher than that in the myocardial segments with perfusion/metabolism match (19 794 20 454 vs 5134 + 6022, P = 0.046). The ischemic cardiac myocytes showed hypertrophy and positive staining of anti-GLUT1 polyclonal antibody. The changes of mRNA and protein expression of enzymes related to glycolysis and fatty acid metabolism after myocardial ischemia play an important role in glycolytic metabolism during myocardial ischemia.