OBJECTIVE: To analyze the clinical phenotype and variant of SLC2A1 gene in a Chinese pedigree affected with glucose transporter type 1 deficiency syndrome (GLUT1-DS). METHODS: Clinical data of a child who was treated due to delayed motor and language development and his family members were collected. DNA was extracted from peripheral blood samples and subjected to high-throughput medical exome sequencing. Candidate variant was verified by Sanger sequencing of his parents and sister. The genotype-phenotype correlation was explored. RESULTS: The child, his mother and sister had common manifestations such as delayed mental and motor development, poor exercise tolerance, easy fatigue and paroxysmal dystonia, but the difference was that the child and his mother had microcephaly and seizures, while his sister did not. A heterozygous missense SLC2A1 c.191T>C (p.L64P) variant was identified in all affected members, which was unreported previously. CONCLUSION The missense SLC2A1 c.191T>C (p.L64P) variant probably underlay the disease in the proband and his mother and sister. Variability of the clinical phenotypes has reflected the genetic and phenotypic diversity of GLUT1-DS. Detection of the novel variant has enriched the spectrum of GLUT1-DS mutations.
Carbohydrate Metabolism, Inborn Errors ; China ; Glucose Transporter Type 1/genetics* ; Humans ; Monosaccharide Transport Proteins/deficiency* ; Mutation ; Pedigree ; Phenotype

D-Mannitol has wide applications in food, pharmaceutical, and chemical industries. In this study, we constructed a genetically stable Escherichia coli strain for D-mannitol production by integrating mannitol dehydrogenase (mdh) and fructose permease (fupL) genes of Leuconostoc pseudomesenteroides ATCC 12291 into chromosome of E. coli ATCC 8739 and inactivating other fermentation pathways (including pyruvate formate-lyase, lactate dehydrogenase, fumarate reductase, alcohol dehydrogenase, methylglyoxal synthase and pyruvate oxidase). Using mineral salts medium with glucose and fructose as carbon sources, the engineered strain could produce 1.2 mmol/L D-mannitol after anaerobic fermentation for 6 days. Based on the coupling of cell growth and D-mannitol production, metabolic evolution was used to improve D-mannitol production. After evolution for 80 generations, D-mannitol titer increased 2.6-fold and mannitol dehydrogenase activity increased 2.8-fold. Genetically stable strains constructed in this work could ferment sugars to produce D-mannitol without the addition of antibiotics, inducers and formate, which was favorable for industrial production.
Escherichia coli ; genetics ; metabolism ; Fermentation ; Industrial Microbiology ; methods ; Leuconostoc ; enzymology ; Mannitol ; metabolism ; Mannitol Dehydrogenases ; genetics ; Metabolic Engineering ; methods ; Monosaccharide Transport Proteins ; genetics

OBJECTIVETo investigate the clinical features, diagnosis and treatment of glucose transporter 1 deficiency syndrome (GLUT1-DS), as well as the diagnostic value of movement disorders.

METHODSThe clinical data of four children with GLUT1-DS were collected, and their clinical features, treatment, and follow-up results were analyzed.

RESULTSThere were two boys and two girls, with an age of onset of 2-15 months. Clinical manifestations included movement disorders, seizures, and developmental retardation. Seizures were the cause of the first consultation in all cases. The four children all had persistent ataxia, dystonia, and dysarthria; two had persistent tremor, two had paroxysmal limb paralysis, and two had eye movement disorders. Paroxysmal symptoms tended to occur in fatigue state. All four children had reductions in the level of cerebrospinal fluid glucose and its ratio to blood glucose, as well as SLC2A1 gene mutations. The four children were given a ketogenic diet, at a ketogenic ratio of 2:1 to 3:1, and achieved complete remission of paroxysmal symptoms within 5 weeks.

CONCLUSIONSGLUT1-DS should be considered for epileptic children with mental retardation and motor developmental delay complicated by various types of movement disorders. The ketogenic diet is effective at a ketogenic ratio of 2:1 to 3:1 for the treatment of GLUT1-DS.

Carbohydrate Metabolism, Inborn Errors ; diagnosis ; genetics ; therapy ; Child ; Child, Preschool ; Female ; Humans ; Male ; Monosaccharide Transport Proteins ; deficiency ; genetics ; Movement Disorders ; diagnosis ; genetics ; therapy

DNase I footprinting assay using liver nuclear extracts revealed six protected regions between nucleotide -600 and +110 and hence named Box I-VI. Upstream promoter element (UPE), a DNA element playing crucial role in transcriptional control of the tissue specific expression of pancreatic beta-cell, has been detected within the proximal region of rat GLUT2 promoter. This region is included in Box VI. The protein-DNA interaction in this region (Box VI) was confirmed by mobility shift assay using liver nuclear extracts. Deletion of the region between -585 bp and -146 bp resulted in dramatic changes in promoter activity when they were expressed in liver and beta-cell derived cell line. When -585/-146 construct was expressed in liver, the activity was decreased to 46%, whereas the activity in beta-cell line, HIT-T15 cell, was increased by 84% when compared to -146/+190 construct. These opposing phenomena can be explained by the fact that beta-cell specifically expresses the UPE binding protein. Assuming that there may be Box VI-binding protein playing negative roles both in hepatocyte and beta-cell, and that the protein acts as a negative regulator of GLUT2 gene, the UPE binding protein in the beta-cell may overcome the inhibition by binding to the protein.
Animal ; Binding Sites ; Cell Line ; Comparative Study ; DNA Footprinting ; Deoxyribonuclease I ; Gene Expression Regulation ; Islets of Langerhans/metabolism* ; Islets of Langerhans/cytology ; Liver/metabolism* ; Liver/cytology ; Monosaccharide Transport Proteins/genetics ; Monosaccharide Transport Proteins/biosynthesis* ; Promoter Regions (Genetics)* ; Protein Binding ; Rats ; Transcription Factor AP-1

The 5'- and 3'-side half of liver type glucose transporter (GLUT2) cDNA was amplified from total RNA or mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). The amplified 5'-side fragment of GLUT2 cDNA was inserted into pGEM4Z and named pGLGT1, and the 3'-side fragment of GLUT2 cDNA was inserted into the HindIII site of pGLGT1 to construct pGLGT2 which contains an entire open reading frame of GLUT2 cDNA. The GLUT2 cDNA in pGLGT2 was transferred to an eukaryotic expression vector (pMAM) to construct pMLGT, which was expressed in the insulin-sensitive Chinese hamster ovary (CHO) cells. Western blot analysis showed that the GLUT2 gene in pMLGT was expressed in the transfected CHO cells successfully. The GLUT2 content in the plasma membrane fraction of insulin-treated CHO cells expressing GLUT2 increased 3.8-fold compared to that of the control group. This result suggests that GLUT2, which is not subjected to translocation by insulin in the cells of its major distribution, can be translocated if it is expressed in the suitable cells sensitive to insulin action.
Animal ; Base Sequence ; CHO Cells ; *Cloning, Molecular ; Hamsters ; Insulin/*pharmacology ; Liver/*metabolism ; Molecular Sequence Data ; Monosaccharide Transport Proteins/*genetics/*metabolism ; Oligonucleotide Probes/genetics ; Support, Non-U.S. Gov't ; *Translocation (Genetics)

OBJECTIVETo investigate the effect of the escharectomy during burn shock stage on expression of glucose translator-4 (GLUT4) mRNA in skeletal muscle and adipose tissue.

METHODS30% TBSA scalded rats were employed. Escharectomy were conducted at 8 h, 24 h, 168 h after burns respectively. Insulin, glucagon, cortisol and glucose levels in serum were analyzed. RT-PCR were employed to analyze GLUT4 mRNA expression in skeletal muscle and adipose tissue.

RESULTSGlucagon, cortisol and glucose levels in serum were declined in groups which escharectomy were conducted during burn shock stage. GLUT4 mRNA expression in both skeletal muscle and adipose tissue were downregulated after burns and escharectomy conducted during burn shock stage made it restored to near normal.

CONCLUSIONGLUT4 mRNA expression will declined after major burns in skeletal muscle and adipose tissue. Escharectomy during shock stage could make it upregulated, which will be helpful to improve glucose metabolism and hypermetabolism after major burns.

Adipose Tissue ; metabolism ; Animals ; Blood Glucose ; Burns ; physiopathology ; surgery ; Gene Expression ; Glucagon ; blood ; Hydrocortisone ; blood ; Insulin ; blood ; Male ; Monosaccharide Transport Proteins ; genetics ; Muscle, Skeletal ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Shock, Traumatic ; physiopathology

An antisense approach was attempted to investigate the role of antisense GLUT1 RNA in suppressing tumor cell phenotypes using N-ras-transformed NIH 3T3 cells. The established cell line transformed by ras showed typical biological characteristics of cancer cells, such as increased glucose transport, GLUT1 mRNA contents, and the ability to form colonies on the soft agar. In this system, the plasmids (pMAM-GLUT1(rev)) which can transcribe the antisense GLUT1 RNA were transfected and the accompanying changes in the phenotypes of the ras-transformed cells were observed. The expression of antisense GLUT1 RNA by induction with dexamethasone reduced the glucose transport by 30% (1.97 +/- 0.13 nmoles) after 4 min incubation when compared to the non-induction group of transformed cell (2.85 +/- 0.19 nmoles). Also, the number of colonies sized over 50 microns on the soft agar was reduced significantly in the antisense RNA expressing group compared to non-induction group. These results suggest that the expression of antisense GLUT1 RNA reduced the glucose transport and transforming potential in soft agar possibly by hybridization with GLUT1 mRNA in N-ras-transformed NIH 3T3 cells.
3T3 Cells/metabolism ; Animal ; Base Sequence ; Cell Line, Transformed ; Cell Transformation, Neoplastic/metabolism/*pathology ; *Genes, ras ; Human ; Mice ; Molecular Sequence Data ; Monosaccharide Transport Proteins/*genetics ; Phenotype ; RNA, Antisense/*metabolism ; Support, Non-U.S. Gov't ; Tumor Cells, Cultured/metabolism/pathology

The expression of the GLUT2 glucose transporter gene in liver is suppressed in cultured hepatoma cell lines and primary cultured hepatocytes. Earlier report showed that CCAAT/enhancer binding protein (C/EBP) regulates the promoter activity of the rat GLUT2 glucose transporter gene in liver cells. C/EBPa and C/EBPb activated the promoter activity by binding to at least two regions of the promoter and one of the C/EBP binding sites, named as site F, also has the AP-1 binding consensus. In this study, we investigated whether the AP-1 can influence on C/EBP binding to this site. The addition of recombinant c-Jun protein with liver extract caused the attenuation of C/EBP binding to site F with the appearance of a new shifted band. The shifted band was competed out with the addition of unlabeled AP-1 consensus oligonucleotide, indicating that c-Jun also can bind to site F. Another C/EBP site on GLUT2 promoter, site H, did not bind AP-1. Analysis of the DNA-protein complex revealed that C/EBP and c-Jun bind to site F in mutually exclusive manner rather than form heterodimeric complex with each other. From these results, it is suggested that the transcriptional activation of C/EBP may be influenced by c-Jun protein in certain status of the liver cells, such as acute phase response, as well as hepatocarcinogenesis.
Animals ; Base Sequence ; Binding Sites ; CCAAT-Enhancer-Binding Proteins/*metabolism ; Cell Nucleus/metabolism ; Cells, Cultured ; Liver/cytology/metabolism ; Male ; Molecular Sequence Data ; Monosaccharide Transport Proteins/*genetics/metabolism ; Promoter Regions (Genetics)/*physiology ; Proto-Oncogene Proteins c-jun/genetics/*metabolism ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins/genetics/metabolism ; Transcription Factor AP-1/genetics/metabolism

OBJECTIVETo demonstrate the impact of hypoxia on ER-alpha in both breast cancer tissue and cell line, and its relationship with hypoxia-related parameters.

METHODSExpression of ER-alpha in 51 breast cancer patients with ER positive determined by ligand-binding assay was examined by immunohistochemistry and compared with CA-IX and Glut-1. Impact of hypoxia on breast cancer cell line MCF-7 (ER-alpha positive) was observed by Western Blot and RT-PCR.

RESULTSOf 51 breast cancer patients, 49 were ER-alpha positive. Regional decrease of ER-alpha expression was consistently observed in peri-necrotic regions as compared to distant regions in both in-situ carcinomas (n=29, P <0.0001) and invasive carcinomas (n=20, P=0.0001), which was closely associated with the induction of CA-IX and Glut-1 in hypoxia (P <0.0001). The decreased expression of ER-alpha protein and mRNA in breast cancer cell lines were attributed to hypoxia and not to other stress factors, such as reduced glucose, low pH, and products released from necrotic or hypoxic cells. Chronic intermittent hypoxia could cause persistent down-regulation of ER-alpha in the MCF-7 breast cancer cell line.

CONCLUSIONRegional hypoxia in breast cancer is associated with the reduced ER-alpha expression, and intermittent hypoxia can cause persistent down-regulation. Hypoxia may therefore contribute to the progression of ER-alpha negative status and potentially to the development of resistance to endocrine therapy.

Antigens, Neoplasm ; metabolism ; Breast ; metabolism ; pathology ; Breast Neoplasms ; metabolism ; pathology ; Carbonic Anhydrase IX ; Carbonic Anhydrases ; metabolism ; Carcinoma in Situ ; metabolism ; pathology ; Carcinoma, Ductal, Breast ; metabolism ; pathology ; Cell Hypoxia ; Cell Line, Tumor ; Down-Regulation ; Estrogen Receptor alpha ; genetics ; metabolism ; Female ; Glucose Transporter Type 1 ; Humans ; Hypoxia ; metabolism ; Monosaccharide Transport Proteins ; metabolism ; RNA, Messenger ; biosynthesis ; genetics

In the present study, we show that the expression of type 2 glucose transporter isoform (GLUT2) could be regulated by PPAR-gamma in the liver. Rosiglitazone, PPAR-gamma agonist, activated the GLUT2 mRNA level in the primary cultured hepatocytes and Alexander cells, when these cells were transfected with PPAR-gamma/RXR-alpha. We have localized the peroxisome proliferator response element in the mouse GLUT2 promoter by serial deletion studies and site-directed mutagenesis. Chromatin immunoprecipitation assay using ob/ob mice also showed that PPAR-gamma rather than PPAR-alpha binds to the -197/-184 region of GLUT2 promoter. Taken together, liver GLUT2 may be a direct target of PPAR-gamma ligand contributing to glucose transport into liver in a condition when PAPR-gamma expression is increased as in type 2 diabetes or in severe obesity.
Animals ; Cells, Cultured ; Chromatin Immunoprecipitation ; Gene Expression Regulation ; Genes, Reporter ; Hepatocytes/*metabolism ; Liver/metabolism ; Male ; Mice ; Mice, Inbred ICR ; Mice, Transgenic ; Monosaccharide Transport Proteins/*biosynthesis/genetics ; Mutagenesis, Site-Directed ; PPAR alpha/genetics/metabolism ; PPAR gamma/agonists/genetics/*metabolism ; *Promoter Regions (Genetics) ; Protein Isoforms/biosynthesis ; Research Support, Non-U.S. Gov't ; *Response Elements ; Thiazolidinediones/pharmacology