GLUT4 mRNA Levels Research Articles

DEHP and Its Metabolite MEHP Alter the Insr and Glut4 Gene Expression by Blunting the Interaction of Transcription Factors in L6 Myotubes.

Endocrine-disrupting chemicals (EDCs) play an important role in the incidence of type-2 diabetes. Di-2-ethyl hexyl Phthalate (DEHP) is one of the endocrine-disrupting chemicals used as a plasticizer to impart flexibility and softness to plastic-containing materials. Mono-2-ethylhexyl Phthalate (MEHP), a DEHP's primary metabolite, is preferentially absorbed once metabolized. A previous study from our laboratory showed that DEHP and MEHP altered the key proteins such as insulin receptor (INSR) and glucose transporter-4 (GLUT4) in L6 myotubes. In a sequel to the previous study, the present study hypothesized that DEHP and its metabolite MEHP may alter the Insr and Glut4 gene expression in L6 myotubes. Therefore, to find out the molecular mechanism behind the decreased INSR and GLUT4 protein levels in the previous study, the direct effect of DEHP and its metabolite MEHP in regulating Insr and Glut4 gene transcription in L6 myotubes was studied. The L6 myotubes were exposed to 50 and 100μM DEHP and MEHP for 24h, followed by insulin stimulation for 20min. We observed decreased Insr and Glut4 mRNA levels in DEHP and MEHP-treated groups. Western blot data showed decreased protein levels of MEF2A and MyoD in treated groups. ChIP assay detected a decreased association of MEF2A and MyoD to the Glut4 gene promoter and HMGA1 to the Insr gene promoter. The study revealed that DEHP and MEHP diminished the Insr and Glut4 gene expression through weakened interaction of their transcription factors on the respective promoter.

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.

Antihyperglycemic activity of a novel polyherbal formula (HF344), a mixture of fifteen herb extracts, for the management of type 2 diabetes: Evidence from in vitro, ex vivo, and in vivo studies

Antihyperglycemic effects of a novel polyherbal formula (HF344), comprising fifteen Thai herbal extracts, were elucidated for pharmacological mechanisms and potential for managing type 2 diabetes mellitus, by employing in vitro, ex vivo, and in vivo approaches. LC/MS analysis of HF344 extract revealed several phytoconstituents, with piperine identified as the major active compound. HF344 extract significantly enhanced insulin secretion in RINm5F cells in vitro and inhibited glucose uptake into the everted sacs of the mouse small intestine ex vivo in a concentration-dependent manner compared to the control (p < 0.05). It exhibited potent α-glucosidase inhibition in vitro, with an IC50 of 96.74 μg/mL. Moreover, HF344 extract upregulated mRNA levels of GLUT1 in L6 skeletal myoblasts, suggesting increased glucose uptake into skeletal muscle. In addition, in vivo antihyperglycemic effects were assessed in streptozotocin (STZ)-nicotinamide (NA)-induced diabetic mice. Acute oral toxicity testing confirmed the HF344 extract's safety, with an LD50 exceeding 2000 mg/kg. Oral administration of HF344 extract (500 and 1000 mg/kg) in STZ-NA-induced diabetic mice significantly reduced the area under the fasting blood glucose (FBG)-time curve (AUC) in the oral glucose tolerance test (OGTT) model and treatment for 28-day reduced the FBG levels as compared with control (p < 0.05). This was accompanied by increased serum insulin levels and improved insulin resistance. HF344 extract also demonstrated a concentration-dependent inhibitory effect on malondialdehyde (MDA) production in vitro, with an IC50 of 7.24 μg/mL. Oral treatment with HF344 extract decreased MDA production in the homogenized muscle ex vivo collected from STZ-NA-induced mice. Furthermore, pretreatment with HF344 extract effectively restored the survival of RINm5F cells from STZ-induced damage. These findings suggest that HF344 is a promising polyherbal formula for managing blood glucose levels, enhancing insulin production, and providing antioxidant benefits in T2DM. Further research is required to evaluate the clinical efficacy and safety profiles of HF344.

Effects of Feeding Rates on Growth Performance and Liver Glucose Metabolism in Juvenile Largemouth Bronze Gudgeon (Coreius guichenoti).

The experiment was conducted to investigate the effects of feeding rates on growth performance, liver glycolysis, gluconeogenesis, glycogen synthesis, and glycogen decomposition in juvenile largemouth bronze gudgeon (Coreius guichenoti). A total number of 600 fish were randomly distributed into 12 cylindrical plastic tanks with 50 fish per tank and triplicate tanks per treatment. Fish were fed with 2%, 3%, 4%, and 5% feeding rates (body weight per day) three times day-1 for 8 w. The results indicated that the feeding rates significantly increased the body weight, weight gain rate, and specific growth rate (p < 0.05), while showing no significant effects on the condition factor and survival rate (p > 0.05). The feed conversion ratio was significantly enhanced by the feeding rate (p < 0.05), although no significant differences were observed when the feeding rate exceeded 3% (p > 0.05). The plasma glucose levels in the 4% and 5% groups were significantly higher than those in the 2% and 3% groups. Compared with other groups, the 5% group significantly increased the crucial rate-limiting enzyme activities and mRNA levels of glycolysis (PFKL and PK) (p < 0.05), while showing no significant differences on enzyme activities (PC, PEPCK, and G6P) and mRNA (pepck and g6p) levels of gluconeogenesis (p > 0.05). In addition, the mRNA levels of hepatic glut2 and glut4 in the 5% group reached the highest levels (p < 0.05). When the feeding rate exceeded 3%, hepatic glycogen and lipid accumulation were significantly increased, leading to a fatty liver phenotype. Meanwhile, the mRNA level of liver glycogen synthetase (gysl) was significantly increased (p < 0.05), while no significant difference was observed in glycogen phosphorylase (pygl) (p > 0.05). In summary, under the conditions of this study, a feeding rate exceeding 3% significantly accelerated hepatic glycogen and lipid accumulation, which ultimately induced fatty liver formation.

Therapeutic effects of stevia aqueous extract alone or in combination with metformin in induced polycystic ovary syndrome rats: Gene expression, hormonal balance, and metabolomics aspects

This study aimed to assess the individual and combined effects of SAE and Met on the expression of genes related to insulin signaling, oxidative stress, hormonal imbalance, insulin resistance, and dyslipidemia in rats with induced PCOS. The estrous cycle of 50 adult Wistar female rats was monitored through vaginal smears. Subsequently, the rats were randomly assigned into five groups of 10, including control (receiving 1ml of carboxymethyl cellulose for 49 days), induction (letrozole at 1mg/kg/d for 21 days), SAE, Met, and SAE/Met. SAE and Met were orally administered at doses of 400mg/kg/d and 250mg/kg/d on day 22 and continued for an additional 28 days. Vaginal smears were analyzed, and gene expression levels of GLUT4, SIRT1, TNF-α, and INSR were evaluated using RT-qPCR. Antioxidant parameters were assessed using detection kits. Treatment with SAE and Met restored a regular estrous cycle pattern in PCOS rats. Furthermore, SAE and Met treatment improved hormonal balance, dyslipidemia, and hyperglycemia in the rats. Administration of SAE and Met significantly elevated levels of antioxidant enzymes SOD and GPx in ovarian tissue (P<0.001). Additionally, mRNA levels of GLUT4, SIRT1, and INSR were significantly increased in ovarian tissue following SAE and Met treatment, while TNF-α gene expression decreased significantly (P<0.0001). The findings suggest that SAE and Met aqueous extract exert protective effects on letrozole-induced PCOS in rats by modulating gene expression associated with insulin signaling and oxidative stress.

Moderate aerobic training enhances the effectiveness of insulin therapy through hypothalamic IGF1 signaling in rat model of Alzheimer's disease

Alzheimer's disease (AD) is a neurological condition that is connected with a decline in a person's memory as well as their cognitive ability. One of the key topics of AD research has been the exploration of metabolic causes. We investigated the effects of treadmill exercise and intranasal insulin on learning and memory impairment and the expression of IGF1, BDNF, and GLUT4 in hypothalamus. The animals were put into 9 groups at random. In this study, we examined the impact of insulin on spatial memory in male Wistar rats and analyzed the effects of a 4-week pretreatment of moderate treadmill exercise and insulin on the mechanisms of improved hypothalamic glucose metabolism through changes in gene and protein expression of IGF1, BDNF, and GLUT4. We discovered that rat given Aβ25–35 had impaired spatial learning and memory, which was accompanied by higher levels of Aβ plaque burden in the hippocampus and lower levels of IGF1, BDNF, and GLUT4 mRNA and protein expression in the hypothalamus. Additionally, the administration of exercise training and intranasal insulin results in the enhancement of spatial learning and memory impairments, the reduction of plaque burden in the hippocampus, and the enhancement of the expression of IGF1, BDNF, and GLUT4 in the hypothalamus of rats that were treated with Aβ25–35. Our results show that the improvement of learning and spatial memory due to the improvement of metabolism and upregulation of the IGF1, BDNF, and GLUT4 pathways can be affected by pretreatment exercise and intranasal insulin.

Effects of asiaticoside on the model of gestational diabetes mellitus in HTR-8/svneo cells via PI3K/AKT pathway

Background Asiaticoside (AS) has been reported to improve the changes induced by high glucose stimulation, and it may have potential therapeutic effects on gestational diabetes mellitus (GDM). This study aims to explore the effect of AS on the cell model of GDM and the action mechanism of the PI3K/AKT pathway. Methods The GDM model was established in HTR-8/Svneo cells with a high glucose (HG) medium. After the cytotoxicity assay of AS, cells were divided into the control group, HG group and HG + AS group to conduct control experiment in cells. The cell proliferation and migration were detected by CCK-8 assay and scratch test, respectively. The mRNA levels of PI3K, AKT2, mTORC1, and GLUT4 in PI3K/AKT signalling pathway were measured by RT-PCR, and the protein expressions of these signalling molecules were monitored by western blot. Results AS showed a promotion effect on the cell proliferation rate of HTR-8/Svneo cells, and 80 μmol/L AS with a treatment time of 48 h had no cytotoxicity. The cell proliferation rate, migration rate, mRNA levels and protein expressions of PI3K, AKT2, mTORC1, and GLUT4 in the HG group were significantly lower than those in the control group, which were significantly increased in the HG + AS group (p < 0.05). Conclusions AS can facilitate the cell proliferation and migration in the cell model of GDM, and might play a role in GDM treatment via PI3K/AKT pathway.

RGS10 mitigates high glucose-induced microglial inflammation via the reactive oxidative stress pathway and enhances synuclein clearance in microglia.

Microglia play a critical role in maintaining brain homeostasis but become dysregulated in neurodegenerative diseases. Regulator of G-protein Signaling 10 (RGS10), one of the most abundant homeostasis proteins in microglia, decreases with aging and functions as a negative regulator of microglia activation. RGS10-deficient mice exhibit impaired glucose tolerance, and high-fat diet induces insulin resistance in these mice. In this study, we investigated whether RGS10 modulates microglia activation in response to hyperglycemic conditions, complementing our previous findings of its role in inflammatory stimuli. In RGS10 knockdown (KD) BV2 cells, TNF production increased significantly in response to high glucose, particularly under proinflammatory conditions. Additionally, glucose uptake and GLUT1 mRNA levels were significantly elevated in RGS10 KD BV2 cells. These cells produced higher ROS and displayed reduced sensitivity to the antioxidant N-Acetyl Cysteine (NAC) when exposed to high glucose. Notably, both BV2 cells and primary microglia that lack RGS10 exhibited impaired uptake of alpha-synuclein aggregates. These findings suggest that RGS10 acts as a negative regulator of microglia activation not only in response to inflammation but also under hyperglycemic conditions.

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.

Plasma adiponectin/leptin ratio associates with subcutaneous abdominal and omental adipose tissue characteristics in women

BackgroundA better understanding of adipose tissue (AT) dysfunction, which includes morphological and functional changes such as adipocyte hypertrophy as well as impaired adipogenesis, lipid storage/mobilization, endocrine and inflammatory responses, is needed in the context of obesity. One dimension of AT dysfunction, secretory adiposopathy, often assessed as a low plasma adiponectin (A)/leptin (L) ratio, is commonly observed in obesity. The aim of this study was to examine markers of AT development and metabolism in 67 women of varying age and adiposity (age: 40-62 years; body mass index, BMI: 17-41 kg/m2) according to levels of adiponectinemia, leptinemia or the plasma A/L ratio.MethodsBody composition, regional AT distribution and circulating adipokines were determined. Lipolysis was measured from glycerol release in subcutaneous abdominal (SCABD) and omental (OME) adipocytes under basal, isoproterenol-, forskolin (FSK)- and dibutyryl-cyclic AMP (DcAMP)-stimulated conditions. Adipogenesis (C/EBP-α/β/δ, PPAR-γ2 and SREBP-1c) and lipid metabolism (β2-ARs, HSL, FABP4, LPL and GLUT4) gene expression (RT-qPCR) was assessed in both fat depots. Participants in the upper versus lower tertile of adiponectin, leptin or the A/L ratio were compared.ResultsBasal lipolysis was similar between groups. Women with a low plasma A/L ratio were characterized by higher adiposity and larger SCABD and OME adipocytes (p<0.01) compared to those with a high ratio. In OME adipocytes, women in the low adiponectinemia tertile showed higher isoproterenol-stimulated lipolysis (0.01<p<0.05), while those in the high leptinemia tertile displayed increased lipolytic response to this agent (p<0.05). However, lipolysis stimulated by isoproterenol was enhanced in both compartments (0.01<p<0.05) in women with a low plasma A/L ratio. AT abundance of selected transcripts related to adipogenesis or lipid metabolism did not differ between women with or without secretory adiposopathy, except for lower GLUT4 mRNA levels in OME fat.ConclusionsSecretory adiposopathy assessed as the plasma A/L ratio, more so than adiponectin or leptin levels alone, discriminates low and elevated lipolysis in OME and SCABD adipocytes despite similar AT expression of selected genes involved in lipid metabolism.

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.

Expression of the C-allele of intronic rs8192675 in SLC2A2 is associated with improved glucose response to metformin.

Glucose is a critical nutrient for energy metabolism. The SLC2A2 gene is essential for glucose sensing and homeostasis, as it encodes the facilitated glucose transporter GLUT2. During diabetes treatment, the C-allele of rs8192675 in SLC2A2 has been found to regulate the action of metformin and reduce the absolute level of HbA1c more effectively than the T-allele. In this study, stable HEK293T cell lines carrying the CC, CT, and TT genotypes of rs8192675 in SLC2A2 were generated using CRISPR/Cas9-mediated genome editing. GLUT2 mRNA and protein levels were elevated in cell clones with the TC genotype compared to those with the CC genotype but were reduced relative to the TT genotype. Additionally, high concentrations of glucose or fructose induced more GLUT2 protein production in CT-genotype cells than that induced in CC-genotype cells, yet less than that induced in TT-genotype cells. Metformin induced a greater increase in GLUT2 expression and a smaller increase in activated AMPK protein expression in CC-genotype cells than those induced in TT-genotype cells, resulting in a remarkable reduction in activated mTOR and S6 levels. This study directly supports the biological mechanism linking the C-allele of rs8192675 with improved treatment outcomes in metformin therapy for diabetes.

Melittin inactivates YAP/HIF-1α pathway via up-regulation of LATS2 to inhibit hypoxia-induced proliferation, glycolysis and angiogenesis in NSCLC

BackgroundNSCLC is one of the most common causes of death. The hypoxia microenvironment contributes to cancer progression. The purpose was to explore the effects and mechanism of melittin on NSCLC cells in the hypoxic microenvironment. MethodsNSCLC cell lines (A549 and H1299) were cultured in normoxia or hypoxia conditions with or without melittin treatment. The viability of the cells was detected via MTT assay and the proliferation ability was evaluated by EdU assay. QRT-PCR was performed to evaluate GLUT1, LDHA, HK2, VEGF and LATS2 mRNA levels. Glucose transport was assessed by the 2-NBDG uptake assay. The angiogenesis was determined by the tubule formation assay. The protein expressions of GLUT1, LDHA, HK2, VEGF, LATS2, YAP, p-YAP and HIF-1α were detected via western blotting assay. The tumor formation assay was conducted to examine the roles of melittin and LATS2 in vivo. ResultsMelittin inhibited hypoxia-induced cell viability, proliferation, glycolysis and angiogenesis as well as suppressed YAP binding to HIF-1α in NSCLC. Melittin inactivated the YAP/HIF-1α pathway via up-regulation of LATS2, ultimately inhibiting cancer progression of NSCLC. Moreover, melittin suppressed tumor growth via up-regulation of LATS2 in vivo. ConclusionMelittin inactivated the YAP/HIF-1α pathway via up-regulation of LATS2 to contribute to the development of NSCLC. Therefore, melittin is expected to become a potential prognostic drug for the therapy of NSCLC.

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.

Exercise-related alterations in MCT1 and GLUT4 expressions in the liver and pancreas of rats with STZ-induced diabetes.

The liver and pancreas tissues play a central role in controlling glucose homeostasis. In patients with type I diabetes mellitus (T1DM), the function of these tissues is impaired. The positive effects of exercise have been shown in diabetic patients. To demonstrate the positive effects of exercise in T1DM, we examined the effects of moderate-intensity endurance training (MIET) on the liver enzymes and expression of MCT1 and GLUT4 genes. Male Wistar rats were allocated into 4 groups of control (C), training (T), diabetic control (DC), and diabetes + training (DT). The serum levels of liver enzymes such as alanine aminotransferase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) were determined by ELIZA. MCT1 and GLUT4 mRNA expressions in the liver and pancreas tissues were evaluated through real-time qPCR after 10weeks of training. The mRNA levels of MCT1 and GLUT4 decreased in DC group and increased in DT group. T1DM led to weight loss, but the weight loss was less in the DT group. T1DM caused an increase in liver enzymes such as ALT, AST and ALP, whereas endurance training preserved enzymatic levels. These results suggested that MIET increases levels of MCT1 and GLUT4 liver and pancreas in the diabetic rats and improves liver function tests. Upregulation of MCT1 and GLUT4 can probably improve the function of liver and pancreas tissues and promote glucose homeostasis in T1DM.

Polygonatum cyrtonema Hua Polysaccharide Alleviates Fatigue by Modulating Osteocalcin-Mediated Crosstalk between Bones and Muscles.

Osteocalcin was reported to regulate muscle energy metabolism, thus fighting fatigue during exercise. The current work aimed to investigate the anti-fatigue effect and the underlying mechanism of a homogeneous polysaccharide (PCPY-1) from Polgonatum cyrtonema after structure characterization. In the exhaustive swimming mouse model and the co-culture system of BMSCs/C2C12 cells, PCPY-1 significantly stimulated BMSC differentiation into osteoblasts as determined by ALP activity, matrix mineralization, and the protein expressions of osteogenic markers BMP-2, phosphor-Smad1, RUNX2, and osteocalcin. Meanwhile, PCPY-1 remarkably enhanced myoblast energy metabolism by upregulating osteocalcin release and GPRC6A protein expression; the phosphorylation levels of CREB and HSL; the mRNA levels of GLUT4, CD36, FATP1, and CPT1B; and ATP production in vitro and in vivo. Accordingly, PCPY-1 exhibited good anti-fatigue capacity in mice as confirmed by fatigue-related indicators. Our findings indicated PCPY-1 could enhance osteocalcin-mediated communication between bones and muscles, which was conducive to muscle energy metabolism and ATP generation, thus alleviating fatigue in exhausted swimming mice.

Resveratrol Regulates Glucose and Lipid Metabolism in Diabetic Rats by Inhibition of PDK1/AKT Phosphorylation and HIF-1α Expression.

To explore the underlying mechanism of the anti-diabetic effect of resveratrol (RSV) on regulating glycolipid metabolism in diabetic rats induced by streptozotocin (STZ) and a high-fat diet (HFD). Male Wistar rats were randomized into three groups. Two groups were fed a high-fat diet and intraperitoneally injected with STZ (35 mg/kg), with one group also treated with RSV (30 mg/kg/d), and the third, control group was fed a normal diet. After 12 weeks, blood lipid levels and fasting blood glucose (FBG) were assessed. Histopathological changes were evaluated by hematoxylin-eosin (HE) staining and periodic acid-Schiff (PAS) staining. The protein expression of hypoxia-inducible factor 1α (HIF-1α) was assessed by Western blotting and immunofluorescence, and the proteins level of 3-phosphoinositide-dependent protein kinase 1 (PDK1), phosphorylated-PDK1 (p-PDK1), phosphorylated-protein kinase B (p-AKT), glucose transporter 1 (GLUT1) and low-density lipoprotein receptor (LDLR) in the liver were analyzed by Western blotting. The mRNA levels of Hif-1α, Glut1 and Ldlr in the liver were determined by RT-qPCR. RSV treatment significantly reduced liver/body weight ratio (L/W, P < 0.05), FBG (P < 0.01) and serum concentrations of total cholesterol (TC, P < 0.05), triglycerides (TG, P < 0.01) and low-density lipoprotein-cholesterol (LDL-C, P < 0.05) in diabetic rats. RSV also improved diabetic symptoms, attenuated liver steatosis and increased liver glycogen accumulation. RSV treatment significantly downregulated the proteins expression of p-PDK1 and p-AKT (P < 0.01) and the levels of HIF-1α (P < 0.05) and GLUT1 (P < 0.01), while significantly upregulating the level of LDLR (P < 0.05). RSV was effective in improving glycolipid metabolism in diabetic rats, probably by inhibiting the PDK1/AKT/HIF-1α pathway and regulation of its downstream target levels. These findings may provide new insight into the mechanism of action of RSV in the treatment of diabetes.

Plant Polyphenol Gossypol Induced Cell Death and Its Association with Gene Expression in Mouse Macrophages

Gossypol is a complex plant polyphenol reported to be cytotoxic and anti-inflammatory, but little is known about its effect on gene expression in macrophages. The objective of this study was to explore gossypol's toxicity and its effect on gene expression involved in the inflammatory response, glucose transport and insulin signaling pathways in mouse macrophages. Mouse RAW264.7 macrophages were treated with multiple concentrations of gossypol for 2-24 h. Gossypol toxicity was estimated by MTT assay and soluble protein content. qPCR analyzed the expression of anti-inflammatory tristetraprolin family (TTP/ZFP36), proinflammatory cytokine, glucose transporter (GLUT) and insulin signaling genes. Cell viability was greatly reduced by gossypol, accompanied with a dramatic reduction in soluble protein content in the cells. Gossypol treatment resulted in an increase in TTP mRNA level by 6-20-fold and increased ZFP36L1, ZFP36L2 and ZFP36L3 mRNA levels by 26-69-fold. Gossypol increased proinflammatory cytokine TNF, COX2, GM-CSF, INFγ and IL12b mRNA levels up to 39-458-fold. Gossypol treatment upregulated mRNA levels of GLUT1, GLUT3 and GLUT4 genes as well as INSR, AKT1, PIK3R1 and LEPR, but not APP genes. This study demonstrated that gossypol induced macrophage death and reduced soluble protein content, which was accompanied with the massive stimulation of anti-inflammatory TTP family and proinflammatory cytokine gene expression, as well as the elevation of gene expression involved in glucose transport and the insulin signaling pathway in mouse macrophages.

Eccentric and concentric exercises induce different adaptions in adipose tissue biology.

Alterations in adipose tissue (AT) metabolism related to inflammation and adipokine's production lead to perturbations in its capacity to store lipids and release fatty acids (FA) during feeding/fasting transition or during exercise. Exercise has a beneficial effect on AT metabolism, but conventional trainings are not always suitable for patients with functional limitations. Dynamic eccentric (ECC) exercise prevents the accumulation of AT and may then overcome those limitations. Consequently, this study aimed at investigating AT's adaptations after ECC training. Nine-week-old male rats were randomly assigned to a control sedentary or three-trained groups for which treadmill slopes modulated exercise oxygen consumption (VO2) and mechanical work (n = 15 per group): (1) + 15% uphill-concentric group (CONC), (2) - 15% downhill group (ECC15, same mechanical work as CONC) and (3) - 30% downhill group (ECC30, same VO2, or oxygen cost as CONC). Body composition and energy expenditure (EE) were measured before and after 8weeks of training. Subcutaneous AT was collected to study total FA profile and gene expression. Higher total EE was driven by lean mass gain in trained animals. In AT, there was a decrease in arachidonic acid with CONC or ECC15 training. Increased adiponectin, leptin, lipases, Glut4 and Igf1 mRNA levels in ECC15 group suggested major metabolic adaption in AT. In conclusion, ECC could induce beneficial modifications in AT fatty acid profile and the expression of key genes related to metabolism and insulin sensitivity.