OBJECTIVE: To elucidate the clinical and genetic characteristics of familial cases with Glucose transporter type 1 deficiency syndrome (Glut1DS). METHODS: A survey of family history was conducted on children (proband) with Glut1DS who had visited Peking University First Hospital between November 2008 and April 2024 by focusing on the clinical manifestations of family members. Peripheral venous blood (2 mL) was collected from the pediatric patients and their parents. Genomic DNA was extracted and sequenced subsequently. Sanger sequencing was performed to validate the identified variant sites of the SLC2A1 gene in the probands and their family members. The pathogenicity of suspected variants was analyzed according to the 2015 American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines for the Interpretation of Sequence Variants. The clinical features, auxiliary examinations, and mutational characteristics of family members with SLC2A1 variants were analyzed. This study has been approved by the Clinical Research Ethics Committee of Peking University First Hospital (Ethics No. 2021 Research 332). RESULTS: Among 87 cases with Glut1DS, 10 families with autosomal dominate inherited cases were identified, accounting for 11.0% of the cases. Of the 11 children, 8 were boys and 3 were girls. The onset of the disease had ranged from 3 months to 120 months (median 6 months), with 4 cases of early-onset classic type, 2 cases of late-onset classic type, and 5 cases of non-classic type. Six children had seizures, and 7 exhibited movement disorders. Seven children underwent developmental assessment, of which 3 had mild developmental delay, 2 were borderline, and 2 were normal. Nine children underwent lumbar puncture. The cerebrospinal fluid glucose levels ranged from 1.45 to 2.25 mmol/L (median 1.86 mmol/L), and the cerebrospinal fluid to blood glucose ratios ranged from 0.29 to 0.44 (median 0.35). Among the 8 fathers with SLC2A1 gene variants, 4 were asymptomatic, 2 developed paroxysmal exercise-induced movement disorders (PED) in childhood and adulthood, respectively. 1 had poor memory since childhood, 1 developed migraines during adolescence, and his sister was an asymptomatic carrier. The father with childhood-onset PED had a cerebrospinal fluid test with CSF glucose of 1.85 mmol/L. Of the 3 mothers with SLC2A1 gene mutations, 1 was an asymptomatic carrier; 2 developed PED in childhood and after the age of 20, respectively. The mother who developed PED in childhood also had psychomotor developmental delay. Genetic testing results revealed that among 10 families, 8 carried missense variants, 1 carried a nonsense variant, and 1 carried a small fragment insertion leading to a frameshift variant. Among the 11 cases, SLC2A1 gene variants in 8 children were inherited from their fathers, while in 3 cases, the variants were inherited from their mothers. The pathogenicity of the genetic variants was evaluated according to the Standards and Guidelines for the Interpretation of Sequence Variants published by the ACMG. Among the 8 variants identified in the 10 families, 4 were classified as pathogenic variants, 1 as likely pathogenic, and 3 as variants of uncertain significance (VUS). Four variant sites, including c.204_205insTCTC (p.V69fs), c.412G>C (p.G138R), c.431T>G (p.V144G), and c.875A>G (p.Y292C), were not previously reported in the literature. Among these, the latter three were categorized as VUS. CONCLUSION Familial Glut1DS account for 11.0% of the cases in China, with the majority of SLC2A1 gene variants inherited from the fathers, predominantly missense mutations, and with an autosomal dominant inheritance pattern. Probands tend to have earlier onset and more severe symptoms than their parents, who often present with mild or no symptoms.
Humans ; Male ; Female ; Glucose Transporter Type 1/deficiency* ; Monosaccharide Transport Proteins/deficiency* ; Child ; Child, Preschool ; Carbohydrate Metabolism, Inborn Errors/genetics* ; Mutation ; Infant ; Pedigree ; Adolescent ; Adult

Glucose transporters (GLUTs) are pivotal membrane proteins that facilitate the passive transport of glucose into cells. However, their aberrant overexpression is closely linked to the Warburg effect and chemotherapy resistance of tumors. GLUTs are complex multi-pass transmembrane proteins that require detergents for extraction from the cell membrane during preparation. The persistent presence of detergents in the sample can disrupt lipid-protein interactions, potentially leading to conformational distortion and functional losses of GLUTs, severely hindering the research into their structures and transport mechanisms. To eliminate detergent interference and preserve its authentic conformation, this study employs nanodisc technology and utilizes the self-assembly of the membrane scaffold protein MSP1E3D1 and phospholipids to produce a biomimetic membrane environment, thereby overcoming the limitations of conventional methods. The C-terminal His10-tagged GLUT1 was heterologously expressed in the insect cell Sf9/Bac-to-Bac system, and the GLUT1-nanodisc complex was obtained after detergent solubilization, affinity chromatography purification via anti-His antibody resin, and self-assembly. The successfully reconstituted nanodisc complex was further purified by Ni-NTA affinity chromatography. Nanodisc reconstitution produced monodisperse GLUT1 particles that retained native secondary structure, as confirmed by far-UV circular dichroism (CD) spectroscopy and dynamic light scattering (DLS). Unlike conventional detergent micelles, which lack a true lipid bilayer, distort transmembrane-helix topology, and occlude ligand-binding sites, the nanodisc platform embeds GLUT1 in a phospholipid bilayer that preserves its authentic conformation while eliminating detergent interference. The resulting GLUT1-nanodisc complex is therefore a superior scaffold for high-resolution cryo-EM structural analysis, permitting detailed interrogation of the transporter's conformational cycle, its interactions with partner proteins, and downstream structure-guided, high-throughput drug screening.
Nanostructures/chemistry* ; Glucose Transporter Type 1/biosynthesis* ; Humans ; Animals ; Phospholipids/chemistry* ; Detergents/chemistry*

OBJECTIVES: To examine how the glucose transporter SLC2A1 influences the proliferation and migration of lung adenocarcinoma (LUAD) and explore the underlying molecular mechanisms. METHODS: We examined the differential expression of SLC2A1 between normal and LUAD tissues in the TCGA database and its prognostic implications. Immunohistochemistry was used to detect SLC2A1 protein levels in clinical samples of LUAD and adjacent tissues, and the association of SLC2A1 expression levels with clinicopathological features of the patients was analyzed. In PC9 cells with stable SLC2A1 overexpression or knockdown, the effects of SLC2A1 expression level on cell proliferation and migration were assessed using CCK-8 and Transwell assays, and the changes in expressions of ferroptosis- and autophagy-related proteins were measured; the occurrence of ferroptosis was confirmed using ROS and Fe²⁺ fluorescence staining. RESULTS: SLC2A1 expression was significantly higher in LUAD tumor tissues than in normal lung tissues (P<0.05) and was associated with worse pathological parameters and prognosis of the patients (P<0.05). In PC9 cells, SLC2A1 overexpression significantly promoted cell proliferation, invasion and migration, and SLC2A1 knockdown significanty increased cell death and inhibited cell invasion and proliferation. SLC2A1 knockdown caused obvious activation of cell ferroptosis, reduced GPX4 and xCT expressions, and increased intracellular levels of ROS and Fe²⁺. SLC2A1 knockdown also resulted in increased cell autophagy shown by increased LC3B expression, which could be reversed by treatement with 3-MA. CONCLUSIONS High SLC2A1 expression is correlated with poor prognosis of patients with LUAD, and inhibiting SLC2A1 can induce ferroptosis and autophagy of LUAD cells, suggesting the potential of SLC2A1 as a target for LUAD diagnosis and treatment.
Humans ; Ferroptosis/genetics* ; Cell Proliferation ; Adenocarcinoma of Lung/genetics* ; Lung Neoplasms/genetics* ; Cell Line, Tumor ; Cell Movement ; Glucose Transporter Type 1/genetics* ; Prognosis ; Autophagy ; Neoplasm Invasiveness ; Female ; Male

Metformin has robust glucose-lowering effects and multiple benefits beyond hypoglycemic effects. It can also be used in combination with various hypoglycemic drugs and is cost effective. In the absence of the strong indications of glucagon like peptide-1 receptor agonist (GLP-1RA) or sodium glucose cotransporter 2 inhibitor (SGLT2i) for cardiorenal protection, metformin should be used as the first-line pharmacological treatment for newly diagnosed type 2 diabetes and the basic drug for the combined treatment of hypoglycemic drugs. Metformin does not increase the risk of liver and kidney function damage, but patients with renal dysfunction should adjust the dosage of metformin based on estimated glomerular filtration rate (eGFR) levels. Moreover, the correct use of metformin does not increase the risk of lactic acidosis. Because long-term use of metformin is associated with a decrease in vitamin B₁₂ levels, patients with insufficient intake or absorption of vitamin B₁₂ should be regularly monitored and appropriately supplemented with vitamin B₁₂. In view of the new progress made in the basic and clinical research related to metformin, the consensus updating expert group updated the consensus on the basis of the Expert Consensus on the Clinical Application of Metformin (2018 Edition).
Humans ; Consensus ; Diabetes Mellitus, Type 2/complications* ; Hypoglycemic Agents ; Metformin/therapeutic use* ; Sodium-Glucose Transporter 2 Inhibitors/therapeutic use* ; Vitamins/therapeutic use* ; China

This study aims to explore the mechanism of Yanghe Decoction(YHD) against subcutaneous tumor in pulmonary metastasis from breast cancer, which is expected to lay a basis for the treatment of breast carcinoma with YHD. The chemical components of medicinals in YHD, and the targets of the components were retrieved from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP) and SwissTargetPrediction. The disease-related targets were searched from GeneCards and Online Mendelian Inheritance in Man(OMIM). Excel was employed to screen the common targets and plot the Venn diagram. The protein-protein interaction network was constructed. R language was used for Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment. A total of 53 female SPF Bablc/6 mice were randomized into normal group(same volume of normal saline, ig), model group(same volume of normal saline, ig), and low-dose and high-dose YHD groups(YHD, ig, 30 days), with 8 mice in normal group and 15 mice in each of the other groups. Body weight and tumor size was measured every day. Curves for body weight variation and growth of tumor in situ were plotted. In the end, the subcutaneous tumor sample was collected and observed based on hematoxylin and eosin(HE) staining. The mRNA and protein levels of hypoxia inducible factor-1α(HIF-1α), pyruvate kinase M2(PKM2), lactate dehydrogenase A(LDHA), and glucose transporter type 1(GLUT1) were detected by PCR and Western blot. A total of 213 active components of YHD and 185 targets against the disease were screened out. The hypothesis that YHD may regulate glycolysis through HIF-1α signaling pathway to intervene in breast cancer was proposed. Animal experiment confirmed that the mRNA and protein levels of HIF-1α, PKM2, LDHA, and GLUT1 in the high-and low-dose YHD groups were lower than those in the model group. YHD has certain inhibitory effect on subcutaneous tumor in pulmonary metastasis from breast cancer in the early stage, which may intervene pulmonary metastasis from breast cancer by regulating glycolysis through HIF-1α signaling pathway.
Female ; Mice ; Animals ; Glucose Transporter Type 1/genetics* ; Network Pharmacology ; Animal Experimentation ; Saline Solution ; Drugs, Chinese Herbal/therapeutic use* ; Medicine, Chinese Traditional ; Signal Transduction ; Glycolysis ; RNA, Messenger ; Neoplasms/drug therapy* ; Molecular Docking Simulation

Humans ; Diabetes Mellitus, Type 2/drug therapy* ; Sodium-Glucose Transporter 2 Inhibitors/therapeutic use* ; Arrhythmias, Cardiac/etiology* ; Glucose ; Sodium

OBJECTIVE: To explore the pathogenesis of erythrocytosis by detecting the key enzymes of glucose metabolism and glucose transporter in bone marrow erythrocytes of chronic mountain sickness (CMS), and analyzing its correlation with hemoglobin. METHODS: Twenty CMS patients hospitalized in Qinghai Provincial People's Hospital from January 2019 to December 2020 were selected as CMS group. Twenty males with leukocyte count > 3.5×10⁹/L who had accepted bone marrow aspiration and had normal result were taken as control group. The mRNA and protein expression of key enzymes and glucose transporter in glucose metabolism in bone marrow CD71⁺ erythrocytes were detected by real time qPCR and Western blot, respectively. Glucose, lactic acid and 2,3-diphosphoglycerate in the bone marrow supernatant and serum were tested by ELISA. The mRNA and protein expression of key enzymes and glucose transporter, glucose, lactic acid and 2,3-diphosphoglycerate of the two groups were compared. Pearson correlation was used to analyze the correlation between key enzymes, glucose transporter in glucose metabolism in bone marrow CD71⁺ erythrocytes and hemoglobin. RESULTS: The expression of HK2, GLUT1 and GLUT2 mRNA in the CMS group were higher than those in the control group (P<0.001), while the expression of HK1, OGDH and COX5B mRNA were not different. The expression of HK2, GLUT1 and GLUT2 protein in the CMS group were higher than those in the control group (P<0.05). The levels of glucose and lactic acid in the bone marrow supernatant and serum in the CMS group were not different from those in the control group, while the level of 2,3-diphosphoglycerate was higher (P<0.001). Both HK2 and GLUT2 proteins were positively correlated with hemoglobin (r=0.511, 0.717). CONCLUSION CMS patients may increase glycolysis by increasing the expression of HK2, and promote the utilization of glucose through high expression of GLUT1 and GLUT2 to meet the need of energy supply.
Male ; Humans ; Altitude Sickness/metabolism* ; Glucose Transporter Type 1 ; 2,3-Diphosphoglycerate ; Hemoglobins ; Chronic Disease ; RNA, Messenger ; Phenotype ; Glucose

Humans ; Diabetes Mellitus, Type 2/drug therapy* ; Sodium-Glucose Transporter 2 Inhibitors/therapeutic use* ; Arrhythmias, Cardiac/etiology* ; Glucose ; Sodium

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce cardiovascular mortality in patients with diabetes mellitus but the protective mechanism remains elusive. Here we demonstrated that the SGLT2 inhibitor, Empagliflozin (EMPA), suppresses cardiomyocytes autosis (autophagic cell death) to confer cardioprotective effects. Using myocardial infarction (MI) mouse models with and without diabetes mellitus, EMPA treatment significantly reduced infarct size, and myocardial fibrosis, thereby leading to improved cardiac function and survival. In the context of ischemia and nutritional glucose deprivation where autosis is already highly stimulated, EMPA directly inhibits the activity of the Na⁺/H⁺ exchanger 1 (NHE1) in the cardiomyocytes to regulate excessive autophagy. Knockdown of NHE1 significantly rescued glucose deprivation-induced autosis. In contrast, overexpression of NHE1 aggravated the cardiomyocytes death in response to starvation, which was effectively rescued by EMPA treatment. Furthermore, in vitro and in vivo analysis of NHE1 and Beclin 1 knockout mice validated that EMPA's cardioprotective effects are at least in part through downregulation of autophagic flux. These findings provide new insights for drug development, specifically targeting NHE1 and autosis for ventricular remodeling and heart failure after MI in both diabetic and non-diabetic patients.
Animals ; Diabetes Mellitus ; Diabetes Mellitus, Type 2/drug therapy* ; Glucose ; Humans ; Mice ; Myocardial Infarction/metabolism* ; Sodium-Glucose Transporter 2 Inhibitors/therapeutic use* ; Ventricular Remodeling

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