GLUT4 Protein Levels Research Articles

Sodium selenite inhibits cervical cancer progression via ROS-mediated suppression of glucose metabolic reprogramming

AimsThis study aims to explore the inhibitory effect of selenium on cervical cancer through suppression of glucose metabolic reprogramming and its underlying mechanisms. MethodsSodium selenite (SS) treated HeLa and SiHa cells were assessed for proliferation using the CCK-8 assay and immunofluorescence. DNA synthesis was measured with the EdU assay. A nude mouse xenograft model evaluated SS's anti-cervical cancer effects. Reactive oxygen species (ROS) and mitochondrial membrane potential were measured using flow cytometry, DCFH-DA, and JC-1 probes, respectively. Apoptosis was detected via Annexin V/PI staining and Western blot. Glucose uptake, lactate production, and ATP generation were determined using 2-NBDG probes and assay kits. The mRNA and protein levels of glycolysis-related genes HK2, GLUT1, and PDK1 were measured using RT-qPCR and Western blot. Key findingsSS inhibited HeLa and SiHa cells viability in a dose- and time-dependent manner. Intraperitoneal injection of SS in nude mice significantly inhibited HeLa cell xenograft growth without evident hepatotoxicity or nephrotoxicity. SS inhibited glucose metabolic reprogramming in cancer cells primarily via ROS-mediated AKT/mTOR/HIF-1α pathway inhibition. Pretreatment with N-acetylcysteine (NAC) or MHY1485 (an mTOR activator) partially reversed the inhibitory effects of SS on glucose metabolic reprogramming, cell proliferation, and migration, as well as its pro-apoptotic effects. SignificanceSS exhibited anti-cervical cancer effects, likely through the induction of ROS generation and inhibition of glucose metabolic reprogramming in cervical cancer cells, thereby inhibiting cell proliferation and promoting apoptosis. These findings provide new insights into understanding the molecular mechanisms underlying SS for potential new drug development for cervical cancer.

Oroxylin A, a broad‑spectrum anticancer agent, relieves monocrotaline‑induced pulmonary arterial hypertension by inhibiting the Warburg effect in rats.

Pulmonary arterial hypertension (PAH) is a chronic and fatal disease characterized by pulmonary vascular remodeling, similar to the 'Warburg effect' observed in cancer, which is caused by reprogramming of glucose metabolism. Oroxylin A (OA), an active compound derived from Scutellaria baicalensis, which can inhibit glycolytic enzymes [hexokinase 2 (HK2), Lactate dehydrogenase (LDH), and pyruvate dehydrogenase kinase 1 (PDK1) by downregulating aerobic glycolysis to achieve the treatment of liver cancer. To the best of our knowledge, however, the impact of OA on PAH has not been addressed. Consequently, the present study aimed to evaluate the potential protective role and mechanism of OA against PAH induced by monocrotaline (MCT; 55 mg/kg). The mean pulmonary artery pressure (mPAP) was measured using the central venous catheter method; HE and Masson staining were used to observe pulmonary artery remodeling. Non‑targeted metabolomics was used to analyze the metabolic pathways and pathway metabolites in MCT‑PAH rats. Western Blot analysis was employed to assess the levels of glucose transporter 1 (Glut1), HK2), pyruvate kinase (PK), isocitrate dehydrogenase 2 (IDH2), pyruvate dehydrogenase kinase 1(PDK1), and lactate dehydrogenase (LDH) protein expression in both lung tissue samples from MCT‑PAH rats. The results demonstrated that intragastric administration of OA (40 and 80 mg/kg) significantly decreased mPAP from 43.61±1.88 mmHg in PAH model rats to 26.51±1.53 mmHg and relieve pulmonary artery remodeling. Untargeted metabolomic analysis and multivariate analysis indicated abnormal glucose metabolic pattern in PAH model rats, consistent with the Warburg effect. OA administration decreased this effect on the abnormal glucose metabolism. The protein levels of key enzymes involved in glucose metabolism were evaluated by western blotting, which demonstrated that OA could improve aerobic glycolysis and inhibit PAH by decreasing the protein levels of Glut1, HK2, LDH, PDK1 and increasing the protein levels of PK and IDH2. In conclusion, OA decreased MCT‑induced PAH in rats by reducing the Warburg effect.

Tryptophan supplements in high-carbohydrate diets by improving insulin response and glucose transport through PI3K-AKT-GLUT2 pathways in blunt snout bream (Megalobrama amblycephala)

The aim of this experiment was to elucidate the metabolic ramifications of tryptophan supplementation in the context of high-carbohydrate diet-feeding, which is important for improving feeding strategies in aquaculture in order to improve fish carbohydrate metabolism. Juvenile blunt snout bream with an initial mean body mass of 55.0±0.5 g were allocated to consume one of three experimental diets: CN, a normal diet with carbohydrate content of 30% (w/w); HC, a diet with high carbohydrate content of 43% (w/w); and HL, a high-carbohydrate diet to which 0.8% L-tryptophan (L-trp) had been added. These diets were fed for 8 weeks, and the effects of the carbohydrate and tryptophan contents of the diets were assessed.Histological analysis using Hematoxylin and Eosin (H&E) and Oil Red O staining revealed that high-carbohydrate intake was associated with abnormal hepatocyte morphology and excessive liver lipid accumulation, which were notably ameliorated by tryptophan supplementation. A significant increase in plasma glucose, glucagon, AGEs (advanced glycation end products), triglycerides, total cholesterol, and a significant decrease in insulin and hepatic glycogen after a high-carbohydrate diet in terms of plasma indices, compared to the control group. Almost all of them were restored to the normal level in the HL group. The present study might preliminarily suggest that tryptophan supplementation ameliorates the imbalance in glucose metabolism of this species induced by a high-carbohydrate diet. Transcriptomics showed that glucose metabolism under high carbohydrate was mainly regulated by the PI3K-AKT signaling pathway. The mRNA expression and protein levels of GLUT2 also varied with this pathway, which would suggest that sustained activation of this pathway with the addition of tryptophan accelerates glucose transport and insulin secretion under high-carbohydrate diet. Subsequent GTT and ITT experiments have also demonstrated that tryptophan improves glucose tolerance and insulin tolerance in blunt snout bream on a high-carbohydrate diet.In conclusion, these findings elucidate the positive regulatory effect of tryptophan on the PI3K-AKT-GLUT2 pathway under a high carbohydrate diet and provide a theoretical basis for the subsequent rational application of high carbohydrate diets in the future.

S100A2 upregulates GLUT1 expression to promote glycolysis in the progression of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor. Among the S100 protein family members, the imbalance of S100 calcium-binding protein A2 (S100A2) was related to the pathogenesis of several types of cancer, and S100A2 has been reported to be upregulated in the plasma of NPC patients; however, its specific role in NPC pathogenesis remains unclear. Thus, this study aims to determine the potential role of S100A2 in NPC to provide novel insights into NPC management. C666-1 and NPC/HK-1 cells were transfected with S100A2 silencing/overexpression (si/oe) constructs. For in vivo investigations, NPC/HK-1 cells were transfected with si/oe-S100A2 to induce tumor formation in nude mice. Cellular viability and apoptosis were assessed using the CCK8 assay, colony-forming assay, and flow cytometry. Glucose uptake and lactate production levels were quantified using biochemical assays. S100A2 expression was measured via RT-qPCR, Western blot, immunohistochemistry, and immunofluorescence were performed to determine the levels of S100A2, PI3K, AKT, p-PI3K, p-AKT, GLUT1, HK-2, LDHA, and ki-67 proteins. S100A2 expression levels were significantly higher in NPC cancer tissues than in adjacent tissues. Similarly, C666-1 and NPC/HK-1 cells exhibited increased S100A2 expression, and silencing S100A2 significantly inhibited NPC cell viability, proliferation, glucose uptake, and lactate production, and induced apoptosis and decreased the protein levels of GLUT1, LDHA, and HK2 in NPC cells. Conversely, S100A2 overexpression enhanced these characteristics in NPC cells but could be mitigated by the PI3K/AKT inhibitor (LY294002). Silencing S100A2 suppressed the tumor formation of NPC/HK-1 cells, while S100A2 overexpression promoted tumor formation and could be hindered by a GLUT1 inhibitor (WZB117). S100A2 is upregulated in cancer tissues of NPC patients and was found to promote proliferation, glycolysis, and tumor formation in NPC cells through its interaction with GLUT1.

Moderate-Intensity Constant and High-Intensity Interval Training Confer Differential Metabolic Benefits in Skeletal Muscle, White Adipose Tissue, and Liver of Candidates to Undergo Bariatric Surgery.

Background/Objectives: Bariatric surgery candidates require presurgical physical training, therefore, we compared the metabolic effects of a constant moderate-intensity training program (MICT) vs. a high-intensity interval training (HIIT) in this population. Methods: Seventeen participants performed MICT (n = 9, intensity of 50% of heart rate reserve (HRR) and/or 4-5/10 subjective sensation of effort (SSE)) or HIIT (n = 8, 6 cycles of 2.5 min at 80% of the HRR and/or 7-8/10 of SSE, interspersed by 6 cycles of active rest at 20% of the FCR) for 10 sessions for 4 weeks. After training, tissue samples (skeletal muscle, adipose tissue, and liver) were extracted, and protein levels of adiponectin, GLUT4, PGC1α, phospho-AMPK/AMPK, collagen 1 and TGFβ1 were measured. Results: Participants who performed MICT showed higher protein levels of PGC-1α in skeletal muscle samples (1.1 ± 0.27 vs. 0.7 ± 0.4-fold change, p < 0.05). In the liver samples of the people who performed HIIT, lower protein levels of phospho-AMPK/AMPK (1.0 ± 0.37 vs. 0.52 ± 0.22-fold change), PGC-1α (1.0 ± 0.18 vs. 0.69 ± 0.15-fold change), and collagen 1 (1.0 ± 0.26 vs. 0.59 ± 0.28-fold change) were observed (all p < 0.05). In subcutaneous adipose tissue, higher adiponectin levels were found only after HIIT training (1.1 ± 0.48 vs. 1.9 ± 0.69-fold change, p < 0.05). Conclusions: Our results show that both MICT and HIIT confer metabolic benefits in candidates undergoing bariatric surgery; however, most of these benefits have a program-specific fashion. Future studies should aim to elucidate the mechanisms behind these differences.

Erjingpill bionic cerebrospinal fluid alleviates LPS-induced inflammatory response in BV2 cells by inhibiting glycolysis via mTOR

Ethnopharmacological relevanceErjingpill, a well-known prescription documented in the classic Chinese medical text “Shengji Zonglu,” has been proven to have effective alleviating effects on neuroinflammation in Alzheimer's disease (AD). Although the alterations in microglial cell glycolysis are known to play a crucial role in the development of neuroinflammation, it remains unclear whether the anti-neuroinflammatory effects of Erjingpill are associated with its impact on microglial cell glycolysis. Aim of the studyThis study aims to determine whether Erjingpill exerts anti-neuroinflammatory effects by influencing microglial cell glycolysis. Materials and methodsFirstly, Erjingpill decoction was prepared into an Erjingpill bionic cerebrospinal fluid (EBCF) through a process of in vitro intestinal absorption, hepatocyte incubation, and blood-brain barrier (BBB) transcytosis. Subsequently, UPLC/Q-TOF-MS/MS technology was used to analyze the compounds in Erjingpill and EBCF. Next, an in vitro neuroinflammation model was established by LPS-induced BV2 cells. The impact of EBCF on BV2 cell proliferation activity was evaluated using the CCK-8 assay, while the NO release was assessed using the Griess assay. Additionally, mRNA levels of pro-inflammatory factors (IL-1β, IL-6, TNF-α, and COX-2), anti-inflammatory factors (IL-10, IL-4, Arg-1, and TGF-β), M1 microglial markers (iNOS, CD86), M2 microglial markers (CD36, CD206), and glycolytic enzymes (HK2, GLUT1, PKM, and LDHA) were measured using qPCR. Furthermore, protein expression of microglial activation marker Iba-1, M1 marker iNOS, and M2 marker CD206 were identified through immunofluorescence, while concentrations of pro-inflammatory cytokines IL-1β and TNF-α were measured using ELISA. Enzymatic activity of glycolytic enzymes (HK, PK, and LDH) was assessed using assay kits, and the protein levels of pro-inflammatory factors (IL-1β, iNOS, and COX-2), anti-inflammatory factors (IL-10 and Arg-1), and key glycolytic proteins GLUT1 and PI3K/AKT/mTOR were detected by Western blot. ResultsThrough the analysis of Erjingpill and EBCF, 144 compounds were identified in Erjingpill and 40 compounds were identified in EBCF. The results demonstrated that EBCF effectively inhibited the elevation of inflammatory factors and glycolysis levels in LPS-induced BV2 cells, promoted polarization of M1 microglial cells towards the M2 phenotype, and suppressed the PI3K/AKT/mTOR inflammatory pathway. Moreover, EBCF alleviated LPS-induced BV2 cell inflammatory response by modulating mTOR to inhibit glycolysis. ConclusionsEBCF exhibits significant anti-neuroinflammatory effects, likely attributed to its modulation of mTOR to inhibit microglial cell glycolysis. This study furnishes experimental evidence supporting the clinical utilization of Erjingpill for preventing and treating AD.

The Effect of Different Exercise Modalities on Sertoli-germ Cells Metabolic Interactions in High-fat Diet-induced Obesity Rat Models: Implication on Glucose and Lactate Transport, Igf1, and Igf1R-dependent Pathways.

The study aimed to uncover a unique aspect of obesity-related metabolic disorders in the testicles induced by a high-fat diet (HFD) and explored the potential mitigating effects of exercise modalities on male fertility. Thirty mature male Wistar rats were randomly assigned to control, HFD-sole, moderate-intensity exercise with HFD (HFD+MICT), high-intensity continuous exercise with HFD (HFD+HICT), and high-intensity interval exercise with HFD (HFD+HIIT) groups (n=6/group). Intracytoplasmic carbohydrate (ICC) storage, expression levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R, and testicular lactate and lactate dehydrogenase (LDH) levels were assessed. ICC storage significantly decreased in HFD-sole rats, along with decreased mRNA and protein levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R. The HFD-sole group exhibited a notable reduction in testicular lactate and LDH levels (p<0.05). Conversely, exercise, particularly HIIT, upregulated ICC storage, expression levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R, and enhanced testicular lactate and LDH levels. These results confirm that exercise, especially HIIT, has the potential to mitigate the adverse effects of HFD-induced obesity on testicular metabolism and male fertility. The upregulation of metabolite transporters, LDH, lactate levels, Igf1, and Igf1R expression may contribute to maintaining metabolic interactions and improving the glucose/lactate conversion process. These findings underscore the potential benefits of exercise in preventing and managing obesity-related male fertility issues.

Elevated glucose promotes MMP13 and ADAMTS5 production by osteoarthritic chondrocytes under oxygenated but not hypoxic conditions.

Type 2 diabetes is linked with increased incidence and severity of osteoarthritis. The purpose of this study was to determine the effect of extracellular glucose within the normal blood glucose and hyperglycemic range on catabolic enzyme production by chondrocytes isolated from osteoarthritic (OA) and macroscopically normal (MN) human cartilage under oxygenated (18.9% oxygen) and hypoxic (1% oxygen) conditions. OA and MN chondrocytes were maintained in 4, 6, 8, or 10 mM glucose for 24 h. Glucose consumption, GLUT1 glucose transporter levels, MMP13 and ADAMTS5 production, and levels of RUNX2, a transcriptional regulator of MMP13, ADAMTS5, and GLUT1, were assessed by enzyme-linked assays, RT-qPCR and/or western blot. Under oxygenated conditions, glucose consumption and GLUT1 protein levels were higher in OA but not MN chondrocytes in 10 mM glucose compared to 4 mM. Both RNA and protein levels of MMP13 and ADAMTS5 were also higher in OA but not MN chondrocytes in 10 mM compared to 4 mM glucose under oxygenated conditions. Expression of RUNX2 was overall lower in MN than OA chondrocytes and there was no consistent effect of extracellular glucose concentration on RUNX2 levels in MN chondrocytes. However, protein (but not RNA) levels of RUNX2 were elevated in OA chondrocytes maintained in 10 mM versus 4 mM glucose under oxygenated conditions. In contrast, neither RUNX2 levels or MMP13 or ADAMTS5 expression were increased in OA chondrocytes maintained in 10 mM compared to 4 mM glucose in hypoxia. Elevated extracellular glucose leads to increased glucose consumption and increased RUNX2 protein levels, promoting production of MMP13 and ADAMTS5 by OA chondrocytes in oxygenated but not hypoxic conditions. These findings suggest that hyperglycaemia may exacerbate chondrocyte-mediated cartilage catabolism in the oxygenated superficial zone of cartilage in vivo in patients with undertreated type 2 diabetes, contributing to increased OA severity.

Unraveling the significance of PPP1R1A gene in pancreatic β-cell function: A study in INS-1 cells and human pancreatic islets

Background and aimsThe protein phosphatase 1 regulatory inhibitor subunit 1A (PPP1R1A) has been linked with insulin secretion and diabetes mellitus. Yet, its full significance in pancreatic β-cell function remains unclear. This study aims to elucidate the role of the PPP1R1A gene in β-cell biology using human pancreatic islets and rat INS-1 (832/13) cells. ResultsDisruption of Ppp1r1a in INS-1 cells was associated with reduced insulin secretion and impaired glucose uptake; however, cell viability, ROS, apoptosis or proliferation were intact. A significant downregulation of crucial β-cell function genes such as Ins1, Ins2, Pcsk1, Cpe, Pdx1, Mafa, Isl1, Glut2, Snap25, Vamp2, Syt5, Cacna1a, Cacna1d and Cacnb3, was observed upon Ppp1r1a disruption. Furthermore, silencing Pdx1 in INS-1 cells altered PPP1R1A expression, indicating that PPP1R1A is a target gene for PDX1. Treatment with rosiglitazone increased Ppp1r1a expression, while metformin and insulin showed no effect. RNA-seq analysis of human islets revealed high PPP1R1A expression, with α-cells showing the highest levels compared to other endocrine cells. Muscle tissues exhibited greater PPP1R1A expression than pancreatic islets, liver, or adipose tissues. Co-expression analysis revealed significant correlations between PPP1R1A and genes associated with insulin biosynthesis, exocytosis machinery, and intracellular calcium transport. Overexpression of PPP1R1A in human islets augmented insulin secretion and upregulated protein expression of Insulin, MAFA, PDX1, and GLUT1, while silencing of PPP1R1A reduced Insulin, MAFA, and GLUT1 protein levels. ConclusionThis study provides valuable insights into the role of PPP1R1A in regulating β-cell function and glucose homeostasis. PPP1R1A presents a promising opportunity for future therapeutic interventions.

Curcumin Inhibits the PPARδ-p-Akt-GLUT1 Pathway and Ameliorates the Antiproliferative Effects of Doxorubicin in MDA-MB-231 Cells.

The aim of the present study was to examine whether GLUT1 was involved in the antiproliferative activity of curcumin and doxorubicin by understanding mechanistically how curcumin regulated GLUT1. Expression level of GLUT1 in MCF-7 and MDA-MB-231 cells were quantitated using quantitative real-time PCR and western blot. GLUT1 activity was inhibited in MDA-MB-231 cells with the pharmacological inhibitor WZB117 to assess the anti-proliferative effects of doxorubicin using MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). To examine cell proliferation, trypan blue assay was used in cells transfected with GLUT1 siRNA or plasmid overexpressing GLUT1 with doxorubicin and/or commercially available curcumin. The role of PPARδ and Akt on the regulation of GLUT1 by curcumin was examined by overexpressing these proteins and western blot was employed to examine their protein expression. The data revealed that there was a 1.5 fold increase in GLUT1 mRNA and protein levels in MDA-MB-231 compared to MCF-7. By inhibiting GLUT1 in triple negative breast cancer cell line, MDA-MB-231 with either the pharmacological inhibitor WZB117 or with GLUT1 siRNA, we observed the enhanced antiproliferative effects of doxorubicin. Additional observations indicated these effects can be reversed by the overexpression of GLUT1. Treatment of MDA-MB-231 with curcumin also revealed downregulation of GLUT1, with further growth suppressive effects when combined with doxorubicin. Overexpression of GLUT1 blocked the growth suppressive role of curcumin and doxorubicin (p< 0.05). Mechanistically, we also observed that the regulation of GLUT1 by curcumin was mediated by the Peroxisome proliferator-activated receptor (PPAR) δ/Akt pathway. Our study demonstrates that regulation of GLUT1 by curcumin via the PPARδ/Akt signaling improves the efficacy of doxorubicin by promoting its growth inhibitory effects in MDA-MB-231 cells.

Maternal Protein Restriction Inhibits Insulin Signaling and Insulin Resistance in the Skeletal Muscle of Young Adult Rats.

Infants with fetal growth restriction (FGR) are at a risk of developing metabolic syndromes in adulthood. We hypothesized that skeletal muscle degeneration by nutrition-restricted FGR results in abnormal insulin signaling and epigenetic changes. To develop a protein-restricted FGR model, rats were fed a low-protein diet (7% protein) during the gestational period; rats fed a normal diet (20% protein) were used as controls. At 8 and 12 weeks of age, the pups were subjected to oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) to evaluate insulin resistance. At 12 weeks, the mRNA and protein levels of insulin signaling pathway molecules in the skeletal muscles were examined. DNA methylation of promoters was detected. DNA extracted from skeletal muscles was used as a template for methylation-specific PCR analysis of GLUT4. The body weight of FGR rats from birth to 8 weeks was significantly lower than that of the controls; no significant difference was observed between the groups at 12 weeks. In the OGTT and ITT, the incremental area under the curve (iAUC) was significantly higher in FGR rats than in the controls at 12 weeks. The mRNA and protein levels of Akt2 and GLUT4 in the plantar muscles were significantly lower in FGR rats than in the controls. GLUT4 methylation was comparable between the groups. Protein-restricted FGR rats showed insulin resistance and altered insulin signaling in skeletal muscles after 12 weeks. However, we could not demonstrate the involvement of DNA methylation in this model.

IL-27 increases energy storage in white adipocytes by enhancing glucose uptake and fatty acid esterification

ABSTRACT The cytokine interleukin (IL)-27 has been reported to induce thermogenesis in white adipocytes. However, it remains unknown whether IL-27-mediated adipocyte energy dissipation is paralleled by an elevated energy supply from lipids and/or carbohydrates. We hypothesized that IL-27 increases lipolysis and glucose uptake in white adipocytes, thereby providing substrates for thermogenesis. Unexpectedly, we found that treatment of 3T3-L1 adipocytes with IL-27 reduced intra- and extracellular free fatty acid (FFA) concentrations and that phosphorylation of hormone-sensitive lipase (HSL) was not affected by IL-27. These results were confirmed in subcutaneous white adipocytes. Further, application of IL-27 to 3T3-L1 adipocytes increased intracellular triglyceride (TG) content but not mitochondrial ATP production nor expression of enzymes involved in beta-oxidation indicating that elevated esterification rather than oxidation causes FFA disappearance. In addition, IL-27 significantly increased GLUT1 protein levels, basal glucose uptake as well as glycolytic ATP production, suggesting that increased glycolytic flux due to IL-27 provides the glycerol backbone for TG synthesis. In conclusion, our findings suggest IL-27 increases glucose uptake and TG deposition in white adipocytes.

METTL3 regulates glucose transporter expression in placenta exposed to hyperglycemia through the mTOR signaling pathway.

Alterations in the placental expression of glucose transporters (GLUTs), the crucial maternal-fetal nutrient transporters, have been found in women with hyperglycemia in pregnancy (HIP). However, there is still uncertainty about the underlying effect of the high-glucose environment on placental GLUTs expression in HIP. We quantitatively evaluated the activity of mammalian target of rapamycin (mTOR) and expression of GLUTs (GLUT1, GLUT3, and GLUT4) in the placenta of women with normal pregnancies (CTRL, n = 12) and pregnant women complicated with poorly controlled type 2 diabetes mellitus (T2DM, n = 12) by immunohistochemistry. In addition, BeWo cells were treated with different glucose concentrations to verify the regulation of hyperglycemia. Then, changes in the expression of GLUTs following the activation or suppression of the mTOR pathway were also assessed using MHY1485/rapamycin (RAPA) treatment or small interfering RNA (siRNA)-mediated silencing approaches. Moreover, we further explored the alteration and potential upstream regulatory role of methyltransferase-like 3 (METTL3) when exposed to hyperglycemia. mTOR, phosphorylated mTOR (p-mTOR), and GLUT1 protein levels were upregulated in the placenta of women with T2DM compared with those CTRL. In BeWo cells, mTOR activity increased with increasing glucose concentration, and the expression of GLUT1, GLUT3, and GLUT4 as well as GLUT1 cell membrane translocation were upregulated by hyperglycemia to varying degrees. Both the drug-mediated and genetic depletion of mTOR signaling in BeWo cells suppressed GLUTs expression, whereas MHY1485-induced mTOR activation upregulated GLUTs expression. Additionally, high glucose levels upregulated METTL3 expression and nuclear translocation, and decreasing METTL3 levels suppressed GLUTs expression and mTOR activity and vice versa . Furthermore, in METTL3 knockdown BeWo cells, the inhibitory effect on GLUTs expression was eliminated by activating the mTOR signaling pathway using MHY1485. High-glucose environment-induced upregulation of METTL3 in trophoblasts regulates the expression of GLUTs through mTOR signaling, contributing to disordered nutrient transport in women with HIP.

Protective effect of Xinmai'an tablets via mediation of the AMPK/SIRT1/PGC-1α signaling pathway on myocardial ischemia-reperfusion injury in rats

BackgroundXinmai'an tablets are a compound Chinese medicine comprising six traditional Chinese medicines that have been clinically applied to treat cardiovascular diseases such as premature ventricular contractions for many years. However, pharmacological effects and underlying mechanisms of Xinmai'an tablet in protecting against myocardial ischemia-reperfusion injury (MIRI) were barely ever studied. PurposeTo investigate the cardioprotective properties of Xinmai'an tablet against MIRI and the underlying molecular mechanism in rats. MethodsWe initially established the UHPLC-QTRAP-MS/MS analysis method to ensure the controllable quality of Xinmai'an tablet. We further identified the cardioprotective effects of Xinmai'an tablet against MIRI using TTC staining, hematoxylin and eosin, echocardiography, the transmission electron microscope analysis, biochemical analysis, and ELISA. We then investigated whether the safeguarding effect of Xinmai'an tablet on MIRI model rats was related to AMPK/SIRT1/PGC-1α pathway via western blotting. ResultsXinmai'an tablet decreased myocardial infarct size; ameliorated cardiac function; alleviated myocardial and mitochondrial damage; and suppressed oxidative stress injury, vascular endothelial damage, and apoptosis response in MIRI model rats. Mechanistically, our results showed that Xinmai'an tablet can dramatically activate the AMPK/SIRT1/PGC-1αpathway and subsequently diminish mitochondrial oxidative stress damage. This was evidenced by increased ATP, Na+-K+-ATPase, and Ca2+-Mg2+-ATPase levels, upregulation of GLUT4, p-AMPK, SIRT1, and PGC-1α protein levels; and reduced GLUT1 protein level. ConclusionTo the knowledge of the author of this article, this study is the first report of Xinmai'an tablet attenuating MIRI, potentially associated with the activation of the AMPK/SIRT1/PGC-1α pathway and subsequent reduction of mitochondrial oxidative stress damage. These findings reveal a novel pharmacological effect and mechanism of action of Xinmai'an tablet and highlight a promising therapeutic drug for ischemic cardiovascular diseases.

CircYIPF6 regulates glioma cell proliferation, apoptosis, and glycolysis through targeting miR-760 to modulate PTBP1 expression.

Recent studies have highlighted that circular RNAs regulate cancer-related genes' expression by functioning as microRNA sponges in cancers. Herein, we investigated the function and molecular mechanism of circYIPF6 in glioma. 5-Ethynyl-2'-deoxyuridine assay, colony formation, and flow cytometry were performed to assess the proliferation and apoptosis of glioma cells. The levels of glycolytic metabolism were evaluated by measuring the glucose uptake and lactate production. The protein levels of Bax, Bcl2, GLUT1, LDHA, and PTBP1 were examined by western blot. The interplay between miR-760 and circYIPF6 or PTBP1 was confirmed by a dual-luciferase reporter. The effect of circYIPF6 silencing on the growth of glioma in vivo was determined by a xenograft experiment. circYIPF6 was significantly upregulated in glioma. Knockdown of circYIPF6 suppressed glioma cell proliferation and glycolysis while promoting cell apoptosis. Mechanistic studies revealed that circYIPF6 targeted miR-760 and could abundantly sponge miR-760 to inhibit the expression of its downstream target gene PTBP1. Functional rescue experiments showed that both miR-760 inhibition and PTBP1 overexpression could attenuate the regulatory effect of circYIPF6 silencing on glioma cells. Furthermore, circYIPF6 knocking down effectively impeded glioma growth in vivo. These findings suggested that circYIPF6 participated in the proliferation, apoptosis, and glycolysis of glioma through the miR-760/PTBP1 axis.

Alterations of materno-placento-fetal glucose homeostasis after a single course of antenatal betamethasone

IntroductionIntrauterine growth impairment is associated with long-term metabolic changes (perinatal programming). We recently demonstrated that antenatal betamethasone (BET) decreased head circumference in term born females. Since glucose is the main energy source for fetal growth, BET-induced changes in maternal glucose homeostasis, a reduced transplacental glucose transfer or an altered fetal glucose utilization may be linked with the observed growth impairment. Methods86 pregnant women exposed to BET (single course, <34 + 0 weeks of gestation (wks)) were compared to 92 gestational-age/sex-matched controls. Glucose, insulin, leptin, insulin-like growth factors (IGF-1, IGF-2) and their binding proteins (IGFBP-1, IGFBP-3) were measured in maternal and umbilical cord blood samples. Homeostasis Model Assessment (HOMA-IR) was calculated. Placental glucose transporter 1 and 3 (GLUT1, GLUT3) protein levels were determined. Statistics were performed for overall and subgroup analysis (gestational age, sex). ResultsAfter BET maternal HOMA-IR was elevated, IGFBP-1 reduced. In female pregnancies, glucose levels ≥37 + 0 wks and IGF-1 levels <37 + 0 wks were tendentially increased. Placental GLUT1 and GLUT3 protein levels were not significantly altered. Fetal umbilical venous glucose levels ≥37 + 0 wks were increased. HOMA-IR tended to be elevated in females. DiscussionGrowth impairment after BET appears neither caused by maternal nor fetal hypoglycemia nor changes of GLUT1 and GLUT3 total protein levels. Nonetheless, glucose homeostasis of mothers and daughters was altered even beyond the BET time frame (hyperglycemia, enhanced insulin resistance). Despite glucose supply was sufficient, an anabolic effect was apparently absent. Overall, our results highlight the relevance of adequate glucose management after BET and peripartum.

The effect of Apigenin on glycometabolism and cell death in an anaplastic thyroid cancer cell line

Aims and backgroundA more pronounced characteristic of cancer cells is the energy dependence on glucose, which mitigated by glucose transporters. The comprehension of the regulatory mechanisms behind the Warburg effect holds promise for developing therapeutic interventions for cancers. Studies are lacking which targeted the GLUTs for treatment of malignancy of thyroid tumors. In our current investigation, we have undertaken this study to determine the potential of Apigenin, plant derived flavonoid in modulating tumor apoptosis by targeting GLUTs expression in SW1736 cell line of anaplastic thyroid carcinoma. Material methodsFlow cytometry with propidium iodide staining was used to determine cell apoptosis. For glucose uptake detection, the “GOD-PAP” enzymatic colorimetric test was used to measure the direct glucose levels inside the cells. To determine the expression of GLUT1 and GLUT3 mRNA in the SW1736 cell line qRT-PCR was employed. Protein levels of GLUT1 and GLUT3 in the SW1736 cell line were detected with western blotting. Also, the scratch wound healing assay was conducted for cell migration. ResultsAccording to qRT-PCR analysis, the levels of GLUT1 and GLUT3 mRNA were lower in the group that received Apigenin relative to the control group. The Apigenin treatment of SW1736 cells decreased protein expression of the GLUT1 and GLUT3 levels in conformity to qRT-PCR. The scratch assays revealed that Apigenin treatment of cancer cell lines inhibited cell migration as compared to control. ConclusionThese findings demonstrate the possibility of targeting the glucose facilitators' pathway for making thyroid cancer cells more susceptible to programmed cell death.

(m-CF3-PhSe)2 counteracts metabolic disturbances and hypothalamic inflammation in a lifestyle rodent model.

An unhealthy lifestyle is associated with metabolic disorders and neuroinflammation. In this study, the efficacy of m-trifluoromethyl-diphenyl diselenide [(m-CF3-PhSe)2] against lifestyle model-related metabolic disturbances and hypothalamic inflammation in young mice was investigated. From postnatal day 25 (PND25) to 66, male Swiss mice were subjected to a lifestyle model, an energy-dense diet (20:20% lard: corn syrup) and sporadic ethanol (3x/week). Ethanol was administrated intragastrically (i.g., 2g/kg) to mice from PND45 to 60. From PND60 to 66, mice received (m-CF3-PhSe)2 (5mg/kg/day; i. g). (m-CF3-PhSe)2 reduced relative abdominal adipose tissue weight, hyperglycemia, and dyslipidemia in mice exposed to the lifestyle-induced model. (m-CF3-PhSe)2 normalized hepatic cholesterol and triglyceride levels, and the activity of G-6-Pase increased in lifestyle-exposed mice. (m-CF3-PhSe)2 was effective in modulating hepatic glycogen levels, citrate synthase and hexokinase activities, protein levels of GLUT-2, p-IRS/IRS, p-AKT/AKT, redox homeostasis, and inflammatory profile of mice exposed to a lifestyle model. (m-CF3-PhSe)2 counteracted hypothalamic inflammation and the ghrelin receptor levels in mice exposed to the lifestyle model. (m-CF3-PhSe)2 reversed the decreased levels of GLUT-3, p-IRS/IRS, and the leptin receptor in the hypothalamus of lifestyle-exposed mice. In conclusion, (m-CF3-PhSe)2 counteracted metabolic disturbances and hypothalamic inflammation in young mice exposed to a lifestyle model.

Oncolytic Avian Reovirus σA-Modulated Upregulation of the HIF-1α/C-myc/glut1 Pathway to Produce More Energy in Different Cancer Cell Lines Benefiting Virus Replication.

Our previous reports proved that the structural protein σA of avian reovirus (ARV) is an energy activator which can regulate cellular metabolism that is essential for virus replication. This study has further demonstrated that the ARV protein σA is able to upregulate the HIF-1α/myc/glut1 pathway in three cancer cell lines (A549, B16-F10, and HeLa) to alter the metabolic pathway of host cells. Quantitative real-time RT-PCR and Western blotting results have revealed that σA protein could enhance both mRNA and the protein levels of HIF-1α, c-myc, and glut1 in these cancer cell lines. In this work, ATeam immunofluorescence staining was used to reveal that knockdown of HIF-1α, c-myc, and glut1 by shRNAs decreased cellular ATP levels. Our data reveal that the ARV σA protein can downregulate lactate fermentation and upregulate glutaminolysis. The σA protein upregulates glutaminase, which converts glutamate into the TCA cycle intermediate α-ketoglutarate, activating the TCA cycle. In the lactate fermentation pathway, ARV σA protein suppresses lactate dehydrogenase A (LDHA), implying the Warburg effect does not occur in these cancer cell lines. This study provides a novel finding revealing that ARV σA protein upregulates glycolysis and glutaminolysis to produce energy using the HIF-1α/c-myc/glut1 pathway to benefit virus replication in these cancer cell lines.

Soy protein compared with whey protein ameliorates insulin resistance by regulating lipid metabolism, AMPK/mTOR pathway and gut microbiota in high-fat diet-fed mice.

The findings of soy protein versus whey protein supplementation on glycemic regulation are inconsistent. The aim of the present study was to investigate the preventive effect of soy protein isolate (SPI) and whey protein isolate (WPI) on a high-fat diet (HFD) induced insulin resistance and its potential molecular mechanisms. Male C57BL/6J mice were randomly divided into seven groups (n = 12): normal control, HFD plus 10% SPI, HFD plus 20% SPI, HFD plus 30% SPI, HFD plus 10% WPI, HFD plus 20% WPI, and HFD plus 30% WPI. After 12 weeks of feeding, compared with the WPI groups, serum concentration of insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and liver weight were significantly lower in the SPI groups. Compared with the WPI groups, the mRNA levels of CD36, SLC27A1, PPARγ and AMPKα were significantly higher, and those of LPL, SREBP1c, FASN and ACC1 were significantly lower in the liver in the SPI groups. In the liver or gastrocnemius muscle, compared with the WPI groups, the mRNA levels of GLUT4, IRS-1, PI3K and AKT were significantly higher, and those of mTOR and S6K1 were significantly lower, and the protein levels of GLUT4, p-AMPKα/AMPKα, p-PI3K/PI3K and p-AKT/AKT were significantly higher, and those of p-IRS-1Ser307/IRS-1, p-mTOR/mTOR and p-S6K1/S6K1 were significantly lower in the SPI groups. The Chao1 and ACE indices were higher, and the relative abundance of Staphylococcus and Weissella was lower in the SPI groups than those in the WPI groups. In conclusion, soy protein was more effective than whey protein in preventing IR in HFD-fed mice by regulating lipid metabolism, the AMPK/mTOR pathway, and gut microbiota.