Glucose Uptake In Cells Research Articles

NKD1 promotes glucose uptake in colon cancer cells by activating YWHAE transcription

Bo investigate the regulatory relationship between NKD1 and YWHAE and the mechanism of NKD1 for promoting tumor cell proliferation. HCT116 cells transfected with pcDNA3.0-NKD1 plasmid, SW620 cells transfected with NKD1 siRNA, HCT116 cells with stable NKD1 overexpression (HCT116-NKD1 cells), SW620 cells with nkd1knockout (SW620-nkd1-/- cells), and SW620-nkd1-/- cells transfected with pcDNA3.0-YWHAE plasmid were examined for changes in mRNA and protein expression levels of YWHAE using qRT-PCR and Western blotting. Chromatin immunoprecipitation (ChIP) assay was used to detect the binding of NKD1 to the promoter region of YWHAE gene. The regulatory effect of NKD1 on YWHAE gene promoter activity was analyzed by dual-luciferase reporter gene assay, and the interaction between NKD1 and YWHAE was analyzed with immunofluorescence assay. The regulatory effect of NKD1 on glucose uptake was examined in the tumor cells. In HCT116 cells, overexpression of NKD1 significantly enhanced the expression of YWHAE at both the mRNA and protein levels, while NKD1 knockout decreased its expression in SW620 cells (P < 0.001). ChIP assay showed that NKD1 protein was capable of binding to the YWHAE promoter sequence; dual luciferase reporter gene assay showed that NKD1 overexpression (or knockdown) in the colon cancer cells significantly enhanced (or reduced) the transcriptional activity of YWHAE promoter (P < 0.05). Immunofluorescence assay demonstrated the binding of NKD1 and YWHAE proteins in colon cancer cells. NKD1 knockout significantly reduced glucose uptake in colon cancer cells (P < 0.01), while YWHAE overexpression restored the glucose uptake in NKD1-knockout cells (P < 0.05). NKD1 protein activates the transcriptional activity of YWHAE gene to promote glucose uptake in colon cancer cells.

MicroRNA-96 targets the INS/AKT/GLUT4 signaling axis: Association with and effect on diabetic retinopathy

BackgroundmiR-96-5p is a highly expressed microRNA in the retina of subjects with diabetes. The INS/AKT/GLUT4 signaling axis is the main cell signaling pathway of glucose uptake in cells. Here, we investigated the role of miR-96-5p in this signaling pathway. MethodsExpression levels of miR-96-5p and its target genes were measured under high glucose conditions, in the retina of streptozotocin-induced diabetic mice, in the retina of AAV-2-eGFP-miR-96 or GFP intravitreal injected mice and in the retina of human donors with diabetic retinopathy (DR). MTT, wound healing, tube formation, Western blot, TUNEL, angiogenesis assays and hematoxylin-eosin staining of the retinal sections were performed. ResultsmiR-96-5p expression was increased under high glucose conditions in mouse retinal pigment epithelial (mRPE) cells, in the retina of mice receiving AAV-2 carrying miR-96 and STZ-treated mice. Expression of the miR-96-5p target genes related to the INS/AKT/GLUT4 signaling pathway was reduced following miR-96-5p overexpression. mmu-miR-96-5p expression decreased cell proliferation and thicknesses of retinal layers. Cell migration, tube formation, vascular length, angiogenesis, and TUNEL-positive cells were increased. ConclusionsIn in vitro and in vivo studies and in human retinal tissues, miR-96-5p regulated the expression of the PIK3R1, PRKCE, AKT1, AKT2, and AKT3 genes in the INS/AKT axis and some genes involved in GLUT4 trafficking, such as Pak1, Snap23, RAB2a, and Ehd1. Because disruption of the INS/AKT/GLUT4 signaling axis causes advanced glycation end product accumulation and inflammatory responses, the inhibition of miR-96-5p expression could ameliorate DR.

HM-chromanone from Portulaca oleracea L. inhibits protein tyrosine phosphatase 1B and mitigates glucose production in insulin-resistant HepG2 cells

This study aimed to identify the effect of (E)-5-hydroxy-7-methoxy-3-(2′-hydroxybenzyl)-4-chromanone (HM-chromanone), isolated from Portulaca oleracea L., on tyrosine phosphatase 1B (PTP1B) and glucose production in insulin-resistant HepG2 cells. The results revealed that HM-chromanone significantly decreases PTP1B expression and glucose production in insulin-resistant HepG2 cells. Furthermore, a molecular docking stimulation showed HM-chromanone inhibits PTP1B by binding to its active site. Additionally, HM-chromanone was found to significantly modulate insulin receptor substrate-1 (IRS1) by decreasing phosphorylated serine 307 and increasing phosphorylated tyrosine 612 and activating phosphatidylinositol 3-kinase (PI3K) in insulin-resistant HepG2 cells. Furthermore, HM-chromanone augmented the phosphorylation of Akt and forkhead box protein O1 in insulin-resistant HepG2 cells in a dose-dependent manner at the concentrations of 15–60 μM. Additionally, it significantly reduced the expression of glucose 6-phosphatase and phosphoenolpyruvate carboxykinase, which are main enzymes included in hepatic gluconeogenesis. Consequently, HM-chromanone was confirmed to significantly decrease glucose production and increase glucose uptake in insulin-resistant HepG2 cells.

Characterization of Green and Yellow Papaya (Carica papaya) for Anti-Diabetic Activity in Liver and Myoblast Cells and Wound-Healing Activity in Fibroblast Cells.

Obesity and diabetes, often characterized as "metabolic syndrome", have been recognized as two of the most important public health issues worldwide. The objective of the present research was to evaluate green and yellow papaya for anti-oxidation and anti-diabetic properties. Leaves, skin, pulp, and seed samples from papayas were freeze-dried and then extracted in water or 80% methanol. The extracts were used to determine total polyphenolic content and anti-oxidation activities, and to determine biological activities, including glucose uptake, Glut-2 expression, triglyceride reduction, and wound-healing activity. Our data demonstrated that methanol and water extracts of green and yellow papaya have similar concentrations of polyphenols in skin (10-20 mg/g dry powder), leaf (25-30 mg/g dry powder), and pulp (1-3 mg/g dry powder) fractions. However, both methanol and water extracts of seeds from yellow papaya have substantially higher concentrations of polyphenols compared to green papaya. Both water and methanol extracts of yellow papaya exhibited higher anti-oxidation activity compared to green papaya in skin (50-60%), pulp (200-300%), and seeds (10-800%). Old leaves also showed greater anti-oxidation activity (30-40%) compared to new leaves. Pulp extracts from both yellow and green papaya stimulated greater glucose uptake, but only pulp from green papaya stimulated glucose uptake in muscle cells. Similarly, pulp extract stimulated glucose transporter Glut-2 expression in liver cells. The skin, pulp, and seeds of green or yellow papaya showed triglyceride-lowering activity in liver cells by 60-80%, but samples taken from yellow papaya had a more potent effect. Seeds from both green and yellow papaya significantly stimulated the migration of fibroblasts in the wounded area by 2-2.5-fold compared to the untreated control. Consistent with these data, seeds from both green and yellow papaya also significantly stimulated collagen synthesis in fibroblast cells by almost 3-fold. In conclusion, our data indicate that different parts of papaya produce stimulatory effects on glucose uptake, Glut-2 expression, TG reduction, and wound-healing activities. This study concludes that different parts of the papaya can be beneficial for preventing diabetes and diabetes-related wound healing.

Phytochemical profiling, in vitro antioxidants, and antidiabetic efficacy of ethyl acetate fraction of Lespedeza cuneata on streptozotocin-induced diabetic rats.

In the recent past, phytomolecules are exponentially applied in discovering the antidiabetic drug due to less adverse effects. This work screened the active solvent fraction of Lespedeza cuneata based on the phytochemical, enzyme inhibition, and antioxidant properties. The antioxidant efficacy of the different fractions of the L. cuneata was assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing power, hydrogen peroxide, and hydroxyl radical scavenging assays. The digestiveenzyme (α-amylase and α-glucosidase) inhibitory activity was also evaluated. The phytochemical composition of ethyl acetate fraction of L. cuneata (Lc-EAF) was studied by UHPLC-QTOF-MS/MS. The effect of Lc-EAF treatments on glucose uptake was studied in insulin resistance HepG2 cells (IR-HepG2). Further, the antidiabetic effect of Lc-EAF in streptozotocin (STZ)-induced diabetic mice were demonstrated. Ethyl acetate, hexane, and methanol fractions of the L. cuneata showed notable antioxidant, α-amylase, and α-glucosidase inhibitory properties. Among the fractions, Lc-EAF was found to be the most potent. The Lc-EAF exhibited an IC50 of 205.32 ± 23.47µg/mL and 105.32 ± 13.93µg/mL for α-amylase and α-glucosidase inhibition, respectively. In addition, 75µg/mL of Lc-EAF exposure enhanced glucose uptake (68.23%) in IR-HepG2 cells. In vivo study indicated that treatmentof Lc-EAF (100mg/kg b.wt) maintained the blood glucose level through reduced insulin level while improving the lipid profile, hepatic, and renal markers. These findings suggest that Lc-EAF could be considered a prominent sourcefor antidiabetic, anti-hyperlipidemic, and anti-ROS potentials.

Abstract 5873: LDH inhibition boosts effector T cells while destabilizing regulatory T cells and improves responses to CTLA-4 blockade

Abstract Tumor reliance on glycolysis is a hallmark of cancer and a mechanism of resistance to immunotherapy. This resistance is due to lactate-mediated immune suppression and competition for glucose between T cells and tumor cells within the tumor microenvironment. We have shown that CTLA-4 blockade is more effective in glycolysis-low tumors, or tumors lacking functional lactate dehydrogenase A (LDH-A), primarily due to functional destabilization of regulatory T cell suppression. LDH inhibitors (LDHi) have been reported to inhibit tumor glucose uptake and slow tumor cell proliferation in pre-clinical models of cancer. However, their effect on immune cells has not been explored in depth. In addition, the optimal conditions for pharmacological inhibition of LDH in combination with immunotherapy to maximize anti-tumor immune and therapeutic responses require further investigation. At baseline, tumor cells express higher levels of ldha and consume more glucose than tumor-infiltrating T cells, creating a therapeutic window for tumor-specific targeting of the glycolysis pathway. In vivo, LDHi relies on the adaptive immune system and the overexpression of tumor LDH to delay B16F10 murine melanoma progression. We found that treatment with LDHi has two effects: 1) reduction of tumor cell glucose uptake and 2) increase in glucose uptake by tumor-infiltrating T cells. Thus, LDH inhibition is an effective, tumor-specific strategy to reduce tumor cell glucose uptake and increase glucose availability within the tumor microenvironment, consequently boosting tumor-infiltrating T cell glucose uptake. In vitro, increased glucose levels improve effector T cell killing of tumor cells while reducing regulatory T cell suppressive ability. Accordingly, inhibiting LDH in combination with CTLA-4 blockade is more effective in controlling tumor progression compared to CTLA-4 blockade alone, and that this combination promotes effector T cell infiltration and activation, while destabilizing regulatory T cell function. Additionally, we observe serum LDH and lactate levels correlate with primary tumor burden as well as tumor LDH levels. Therefore, serum LDH may serve as a biomarker for tumor burden and tumor LDH, as well as clinical response to LDHi. This study provides a comprehensive rationale for combining immune checkpoint blockade with inhibitors of glycolysis for patients with highly glycolytic cancers. Citation Format: Svena Verma, Inna Serganova, Lauren Dong, Sadna Budhu, Levi Mangarin, Roberta Zappasodi, Taha Merghoub, Jedd D. Wolchok. LDH inhibition boosts effector T cells while destabilizing regulatory T cells and improves responses to CTLA-4 blockade. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5873.

Abstract 293: Non-metabolic regulatory functions of nuclear pyruvate kinase M2 induce a MAPK mediated phenotypic switch in invasive cancers

Abstract Accumulating evidence suggests that PKM2, the differentially spliced pyruvate kinase isoform that is expressed in most cancers and embryonic tissue, is linked with epithelial-mesenchymal transition (EMT). However, how PKM2 may drive this process of tumor invasiveness remains unclear. Here we demonstrate that in metastatic hormone-sensitive and ovarian cancer cells PKM2 undergoes modification by phosphorylation on its Serine 37 residue (pS37) and that this modified protein displays distinct localization patterns in response to pro-migratory cues emanating from an artificial nanopatterned substrate mimicking the tumor associated extracellular matrix. We find that in epithelial-mesenchymal (EM) hybrid cohorts, migrating cells undergo phenotypic switching from followers to leaders and the PKM2-pS37 signals correlate with different cell phenotypes (less/more invasive and leaders vs followers). This phenotypic switching occurs as a function of cell distance from the leading edge in an expanding epithelial sheet. We found that the putative novel non-metabolic functions of PKM2 are attributed to its autoregulation that results in not only a PKM2-pS37 upregulation but also an induction in PKM2 expression via ERK signaling. Cues emanating from either the extracellular matrix (mediated via Integrin/FAK) or through growth factor signaling (EGFR signaling), culminating in ERK activation induce PKM2 phosphorylation at S37. Thus, our data suggest that an increase in PKM2pS37 is accompanied by a switch to less enzymatically active molecular complexes which can translocate to the nucleus and increase PKM2 expression through an auto-positive feedback loop resulting in increased total PKM2 concentration and function in the leader cells. To further confirm the existence of this positive feedback loop we developed a mathematical model for PKM2 regulation. This model allows for the evaluation of inputs emerging from the extracellular matrix, such as the integrin/FAK signaling, and growth factor receptor signaling both of which regulate PKM2 expression through ERK activation in a switch-like fashion. The mathematical model includes non-linearity in the phosphorylation of S37 on PKM2 and the non-linearity in the nuclear localization and upregulation of PKM2. Further experimental analysis supports the functional role of the switch, as the observed PKM2 expression states correlate with the expression of characteristic EMT markers and invasion-promoting pseudo-hypoxic stress in the leader cells. Importantly, the small molecule activator of PKM2, TEPP 46, can restore a more epithelial-like state, decrease invasion, and increase glucose uptake in these EM hybrid ovarian cancer cells. Taken together, our results highlight a link between PKM2 and cancer aggressiveness driven by novel regulatory mechanisms that support both metabolic rewiring and invasive spread of tumor cells. Citation Format: Kiran Vanaja, Maria Apostolidi, Andre Levchenko, Jesse Rinehart. Non-metabolic regulatory functions of nuclear pyruvate kinase M2 induce a MAPK mediated phenotypic switch in invasive cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 293.

Perturbated glucose metabolism augments epithelial cell proinflammatory function in chronic rhinosinusitis

Glucose concentrations are increased in nasal secretions in chronic rhinosinusitis (CRS). However, the glucose metabolism and its contribution to disease pathogenesis in CRS remain unexplored. We sought to explore the glucose metabolism and its effect on the function of nasal epithelial cells in CRS with and without nasal polyps (CRSwNP and CRSsNP). Glucose metabolites were detected with mass spectrometry. The mRNA levels of glucose transporters (GLUTs), metabolic enzymes, and inflammatory mediators were detected by quantitative RT-PCR. The protein expression of GLUTs was studied by immunofluorescence staining, Western blotting, and flow cytometry. Glucose uptake was measured by using fluorescent glucose analog. Human nasal epithelial cells (HNECs) were cultured. Bioenergetic analysis was performed with Seahorse XF analyzer. Gene expression in HNECs was profiled by RNA sequencing. Increased glucose concentrations in nasal secretions was confirmed in both CRSsNP and CRSwNP. GLUT4, GLUT10, and GLUT11 were abundantly expressed in HNECs, whose expression was upregulated by inflammatory cytokines and D-glucose and was increased in CRS. Glucose uptake, glycolysis and tricarboxylic acid cycle metabolites, metabolic enzymes, and extracellular acidification rate and oxygen consumption rates were increased in HNECs in CRSsNP and CRSwNP, with a predominant shift to glycolysis. HNECs treated with high-level apical D-glucose showed enhanced glucose uptake, predominant glycolysis, and upregulated production of IL-1α, IL-1β, TNF-α, CCL20, and CXCL8, which was suppressed by 2-deoxy-D-glucose, an inhibitor of glycolysis. Increased glucose in nasal secretions promotes glucose uptake and predominant glycolysis in epithelial cells, augmenting the proinflammatory function of epithelial cells in CRS.

Dietary Methionine Restriction Improves Gastrocnemius Muscle Glucose Metabolism through Improved Insulin Secretion and H19/IRS-1/Akt Pathway in Middle-Aged Mice

Methionine restriction (MR) improves glucose metabolism. In skeletal muscle, H19 is a key regulator of insulin sensitivity and glucose metabolism. Therefore, this study aims to reveal the underlying mechanism of H19 upon MR on glucose metabolism in skeletal muscle. Middle-aged mice were fed MR diet for 25 weeks. Mouse islets β cell line β-TC6 cells and mouse myoblast cell line C2C12 cells were used to establish the apoptosis or insulin resistance model. Our findings showed that MR increased B-cell lymphoma-2 (Bcl-2) expression, deceased Bcl-2 associated X protein (Bax), cleaved cysteinyl aspartate-specific proteinase-3 (Caspase-3) expression in pancreas, and promoted insulin secretion of β-TC6 cells. Meanwhile, MR increased H19 expression, insulin Receptor Substrate-1/insulin Receptor Substrate-2 (IRS-1/IRS-2) value, protein Kinase B (Akt) phosphorylation, glycogen synthase kinase-3β (GSK3β) phosphorylation, and hexokinase 2 (HK2) expression in gastrocnemius muscle and promoted glucose uptake in C2C12 cells. But these results were reversed after H19 knockdown in C2C12 cells. In conclusion, MR alleviates pancreatic apoptosis and promotes insulin secretion. And MR enhances gastrocnemius muscle insulin-dependent glucose uptake and utilization via the H19/IRS-1/Akt pathway, thereby ameliorating blood glucose disorders and insulin resistance in high-fat-diet (HFD) middle-aged mice.

Rare Sugar Metabolism and Impact on Insulin Sensitivity along the Gut-Liver-Muscle Axis In Vitro.

Rare sugars have recently attracted attention as potential sugar replacers. Understanding the biochemical and biological behavior of these sugars is of importance in (novel) food formulations and prevention of type 2 diabetes. In this study, we investigated whether rare sugars may positively affect intestinal and liver metabolism, as well as muscle insulin sensitivity, compared to conventional sugars. Rare disaccharide digestibility, hepatic metabolism of monosaccharides (respirometry) and the effects of sugars on skeletal muscle insulin sensitivity (impaired glucose uptake) were investigated in, respectively, Caco-2, HepG2 and L6 cells or a triple coculture model with these cells. Glucose and fructose, but not l-arabinose, acutely increased extracellular acidification rate (ECAR) responses in HepG2 cells and impaired glucose uptake in L6 cells following a 24 h exposure at 28 mM. Cellular bioenergetics and digestion experiments with Caco-2 cells indicate that especially trehalose (α1-1α), D-Glc-α1,2-D-Gal, D-Glc-α1,2-D-Rib and D-Glc-α1,3-L-Ara experience delayed digestion and reduced cellular impact compared to maltose (α1-4), without differences on insulin-stimulated glucose uptake in a short-term setup with a Caco-2/HepG2/L6 triple coculture. These results suggest a potential for l-arabinose and specific rare disaccharides to improve metabolic health; however, additional in vivo research with longer sugar exposures should confirm their beneficial impact on insulin sensitivity in humans.

Glycopolymer-Based Hydrogels Impair Energy Metabolism via Delivering Mannose and Depleting Glucose for Tumor Suppression

Carbohydrates serve as a key biomacromolecule, not only as the major building blocks in living organisms, but also as intermediates in energy metabolism via glycolysis. The quest for developing a carbohydrate-based macromolecular system to interfere with aberrant energy metabolism of tumors is a challenging topic. Here we report a class of artificial glycopolymers containing phenolic hydroxyl-functionalized segments that can be cross-linked to form hydrogels by the enzymatic cascade reaction using glucose oxidase (GOD) and horseradish peroxidase (HRP). Glycopolymer-based hydrogels can deliver and sustainably release the antiglycolytic agent mannose at the tumor site; meanwhile, glucose is exhausted gradually during the course of gelation. Glucose uptake and hyperactive glycolysis of tumor cells are concurrently blocked by the enzyme cascade and mannose, respectively, as validated by synergistic tumor suppression in vitro. Finally, the superiority of glycopolymer-based hydrogels loading mannose and enzyme cascade is evaluated in a murine tumor model, demonstrating the ability to impair energy metabolism and retard tumor growth. This work allows glycopolymer-based biomaterials to be promising in intervening energy metabolism for tumor eradication.

Hypoglycemic and H2O2-induced oxidative injury protective effects and the phytochemical profiles of the ethyl acetate fraction from Radix Paeoniae Alba.

Radix Paeonia Alba (RPA) is often used as food and medicine. This study aimed to enrich and identify the antioxidant and hypoglycemic bioactive compounds from RPA. The results indicated that the ethyl acetate fraction (EAF) showed the highest total phenolic content, DPPH, ABTS+ scavenging ability, and α-glucosidase inhibition ability (IC50 = 7.27 μg/ml). The EAF could alleviate H2O2-induced oxidative stress in HepG2 cells by decreasing the MDA and ROS levels, improving cell apoptosis, increasing the enzyme activity of GPX-Px, CAT, SOD, Na+/K+-ATP, and Ca2+/Mg2+-ATP, and stimulating T-AOC expression, which also enhanced the glucose uptake of insulin-resistant HepG2 cells. In addition, the EAF significantly reduced the fasting blood glucose level and improved glucose tolerance in diabetic mice. An HPLC-QTOF-MS/MS analysis displayed that procyanidin, digallic acid isomer, methyl gallate, tetragalloylglucose isomer, dimethyl gallic acid, and paeoniflorin were the major compounds in the EAF. These findings are meaningful for the application of the EAF in the medicinal or food industry to prevent and treat oxidative stress and diabetes mellitus.

The standardized Jamu pahitan, an Indonesian antidiabetic formulation, stimulating the glucose uptake and insulin secretion in the in-vitro models

Jamu pahitan is a polyherbal formulation commonly used for the traditional management of diabetes in Indonesia and is mainly prepared from Andrographis paniculata (Burm.f.) Nees. It is widely varied in herbal composition for every region has their own plant component addition to the formulation. A version of the formulation used in the greater Surakarta area contained five plant constituents. This study evaluated the in-vitro glucose uptake and insulin secretion stimulatory activities of Jamu pahitan to provide scientific evidence on its efficacy and safety of use. The water and ethanol extracts of three Jamu pahitan formulations were prepared. The total phenolic content (TPC) of the extracts was evaluated by the standard Folin-Ciocalteau method. Their effects on the viability of L6 skeletal muscle and RIN-m5F pancreatic cells were evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The glucose utilized by L6 myotubes treated with Jamu pahitan was assessed indirectly by the glucose oxidase method. The insulin secreted by RIN-m5F treated with the formulation extracts was analyzed by the enzyme-linked immunosorbent assay (ELISA). The correlation between TPC and the profile of safety and efficacy of the formulation was statistically evaluated. The water extracts of Jamu pahitan were safe and exerted significant glucose uptake and insulin secretion stimulatory activity in L6 and RIN-m5F, respectively. The ethanol extracts showed more potent effects than their water counterpart, albeit they exerted cytotoxic effects on the cells at the higher tested concentrations. The formulations at lower concentrations stimulated the proliferation of RIN-m5F. In addition, the TPC was strongly correlated with the glucose uptake and insulin secretion stimulatory activities and also the IC50 of the cells in positive manner. The present study supported the use of Jamu pahitan for the traditional management of diabetes in Indonesia by stimulating glucose uptake in the muscle cells and improving insulin secretion in β-cells.

Investigating the effects of Ceylon cinnamon water extract on HepG2 cells for Type 2 diabetes therapy.

Cinnamon and its extracts have been used as herbal remedies for many ailments, including for reducing insulin resistance and diabetes complications. Type 2 diabetes mellitus (T2DM) is a rapidly growing health concern around the world. Although many drugs are available for T2DM treatment, side effects and costs can be considerable, and there is increasing interest in natural products for managing chronic health conditions. Cinnamon may decrease the expression of genes associated with T2DM risk. The purpose of this study was to evaluate the effects of cinnamon water extract (CWE) compared with metformin on T2DM-related gene expression. HepG2 human hepatoma cells, widely used in drug metabolism and hepatotoxicity studies, were treated with different concentrations of metformin or CWE for 24 or 48 h. Cell viability was assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and glucose uptake was compared in untreated and CWE- or metformin-treated cells under high-glucose conditions. Finally, total RNA was extracted and analyzed by RNA sequencing (RNA-seq), and bioinformatics analyses were performed to compare the transcriptional effects of CWE and metformin. We found cell viability was better in cells treated with CWE than in metformin-treated cells, demonstrating that CWE was not toxic at tested doses. CWE significantly increased glucose uptake in HepG2 cells, to the same degree as metformin (1.4-fold). RNA-seq data revealed CWE and metformin both induced significantly increased (1.3- to 1.4-fold) glucose uptake gene expression compared with untreated controls. Transcriptional differences between CWE and metformin were not significant. The effects of 0.125 mg mL-1 CWE on gene expression were comparable to 1.5 mg mL-1 (9.5 mM) metformin. In addition, gene expression at 0.125 mg mL-1 CWE was comparable to 1.5 mg mL-1 (9.5 mM) metformin. Our results reveal that CWE's effects on cell viability, glucose uptake, and gene expression in HepG2 cells are comparable to those of metformin, suggesting CWE may be an effective dietary supplement for mitigating T2DM-related metabolic dysfunction.

Anti-Inflammatory and Anti-Diabetic Activity of Ferruginan, a Natural Compound from Olea ferruginea

Inflammation is a complex response of the human organism and relates to the onset of various disorders including diabetes. The current research work aimed at investigating the anti-inflammatory and anti-diabetic effects of ferruginan, a compound isolated from Olea ferruginea. Its in vitro anti-inflammatory activity was determined by using the heat-induced hemolysis assay, while the anti-diabetic effect of the compound was studied by the yeast cell glucose uptake assay. Ferruginan exhibited a maximum of 71.82% inhibition of inflammation and also increased the uptake of glucose by yeast cells by up to 74.96% at the highest tested concentration (100 µM). Moreover, ferruginan inhibited α-amylase dose-dependently, by up to 75.45% at the same concentration. These results indicated that ferruginan possesses promising anti-inflammatory and anti-diabetic properties in vitro, even if at high concentrations. To provide preliminary hypotheses on the potentially multi-target mechanisms underlying such effects, docking analyses were performed on α-amylase and on various molecular targets involved in inflammation such as 5′-adenosine monophosphate-activated protein kinase (AMPK, PDB ID 3AQV), cyclooxygenase (COX-1, PDB ID 1EQG, and COX-2, 1CX2), and tumor necrosis factor alpha (TNF-α, PDB ID 2AZ5). The docking studies suggested that the compound may act on α-amylase, COX-2, and AMPK.

Knockout of ENO1 leads to metabolism reprogramming and tumor retardation in pancreatic cancer.

The shift in glucose utilization from oxidative phosphorylation to glycolysis is the hallmark of tumor cells. The overexpression of ENO1, one of the key enzymes in the glycolysis process, has been identified in several cancers, however, its role in pancreatic cancer (PC) is yet unclear. This study identifies ENO1 as an indispensable factor in the progression of PC. Interestingly, ENO1-knockout could inhibit cell invasion and migration and prevent cell proliferation in pancreatic ductal adenocarcinoma (PDAC) cells (PANC-1 and MIA PaCa-2); meanwhile, tumor cell glucose uptake and lactate excretion also decreased significantly. Furthermore, ENO1-knockout reduced colony formation and tumorigenesis in both in vitro and in vivo tests. In total, after ENO1 knockout, 727 differentially expressed genes (DEGs) were identified in PDAC cells by RNA-seq. Gene Ontology enrichment analysis revealed that these DEGs are mainly associated with components such as the 'extracellular matrix' and 'endoplasmic reticulum lumen', and participate in the regulation of signal receptor activity. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the identified DEGs are associated with pathways, such as 'fructose and mannose metabolism', 'pentose phosphate pathway, and 'sugar metabolism for amino and nucleotide. Gene Set Enrichment Analysis showed that ENO1 knockout promoted the upregulation of oxidative phosphorylation and lipid metabolism pathways-related genes. Altogether, these results indicated that ENO1-knockout inhibited tumorigenesis by reducing cell glycolysis and activating other metabolic pathways by altering the expression of G6PD, ALDOC, UAP1, as well as other related metabolic genes. Concisely, ENO1, which plays a vital role in the abnormal glucose metabolism in PC, can be exploited as a target to control carcinogenesis by reducing aerobic glycolysis.

Discovery of Novel Thiazolidinedione-Derivatives with Multi-Modal Antidiabetic Activities In Vitro and In Silico.

Diabetes mellitus (DM) and related complications continue to exert a significant burden on health care systems globally. Although conventional pharmacological therapies are beneficial in the management of this metabolic condition, it is still necessary to seek novel potential molecules for its management. On this basis, we have synthesised and evaluated the anti-diabetic properties of four novel thiazolidinedione (TZD)-derivatives. The TZD derivatives were synthesised through the pharmacophore hybridisation strategy based on N-arylpyrrole and TZD. The resultant derivatives at different concentrations were screened against key enzymes of glucose metabolism and glucose utilisation in the liver (HEP-G2) cell line. Additionally, peroxisome proliferator-activated receptor-γ activation was performed through docking studies. Docking of these molecules against PPAR-γ predicted strong binding, similar to that of rosiglitazone. Hence, TZDD2 was able to increase glucose uptake in the liver cells as compared to the control. The enzymatic inhibition assays showed a relative inhibition activity; with all four derivatives exhibiting ≥ 50% inhibition activity in the α-amylase inhibition assay and a concentration dependent activity in the α-glucosidase inhibition assay. All four derivatives exhibited ≥30% inhibition in the aldose reductase inhibition assay, except TZDD1 at 10 µg/mL. Interestingly, TZDD3 showed a decreasing inhibition activity. In the dipeptidyl peptidase-4 inhibition assay, TZDD2 and TZDD4 exhibited ≥20% inhibition activity.

Astragaloside IV ameliorates insulin induced insulin resistance in HepG2 cells through reactive oxygen species mediated c-Jun N-terminal kinase pathway.

To investigate the effects and elucidate the mechanism of Astragaloside IV (AS-IV) for insulin resistance (IR) and type 2 diabet es mellitus (T2DM). CCK8 kit was used to detect cell viability, glucose detection kit was used to detect the concentration of glucose in cell supernatant, reactive oxygen species (ROS) detection kit and Western blot were used to explore the mechanism of Astragaloside IV (AS-IV) in improving IR. A diabetic rat model was also established by feeding high sugar and fat diet and streptozotocin (STZ) injection. After treatment with AS-IV, rosiglitazone (ROZ), or normal saline, the fasting blood glucose (FBG), C peptide (C-P), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and the glucose tolerance were assessed. AS-IV could effectively reduce the content of ROS and increase the glucose uptake in high insulin-treated IR-type HepG2 cells. The results of molecular mechanisms indicated that AS-IV could improve insulin resistance by reducing JNK phosphorylation and regulating c-Jun N-terminal kinase (JNK) downstream protein expression. Additionally, AS-IV could significantly reduce the levels of FBG, TNF-α, IL-6 and the glucose tolerance in diabetic rats ( < 0.05 or < 0.01). The high and medium dose groups of AS-IV could significantly increase the C-P levels in diabetic rats ( < 0.05 or < 0.01). Our results indicated that AS-IV improve liver IR through the JNK pathway and ROS, which meant a new molecular target for the treatment of diabetes. The AS-IV also helped to prevent and improved the insulin resistance of rats.

Metabolic Phenotype Intricacies on Altered Glucose Metabolism of Breast Cancer Cells upon Glut-1 Inhibition and Mimic Hypoxia In Vitro.

Breast cancer is the frequently diagnosed cancer and the leading cancer death among women. The growing tumour of the breast is composed of both normoxic and hypoxic cells, and the heterogeneity of tumour affects the targeted treatment strategies against breast cancer. The functional and therapeutic status of the Warburg effect is mostly recognized, and the genes involved in glycolysis have become a target for anticancer therapeutic strategies. Glut-1 is essential for basal glucose uptake among the glucose transporters and could act as a potential target for anticancer therapy. In the present study, we explored the alteration in the metabolic phenotype of SKBR-3 cells, representing HER-2 overexpressed breast cancer cell line, with Glut-1 inhibition by a synthetic small molecule inhibitor WZB117 in the presence or absence of cobalt chloride (CoCl2) induced biochemical hypoxia in vitro. We found that WZB117 and CoCl2 in combination could inhibit metabolic phenotype characteristics such as glucose uptake, cell migration, lactate and ATP production in SKBR-3 cells. Also, Glut-1 inhibition induced apoptosis and cell cycle arrest at the G0-G1 phase even under CoCl2-induced mimic hypoxia. Our findings suggest that Glut-1 inhibition by WZB117 could overcome the protective effect of CoCl2 mimic hypoxia by regulating glycolysis and altering the metabolic phenotype of breast cancer cells. The considering excellent efficacy and minimal toxicity suggest that WZB117 may be a promising anticancer drug to the current therapies.

Effects of 6-Shogaol on Glucose Uptake and Intestinal Barrier Integrity in Caco-2 Cells.

As the main bioactive component in dried ginger, 6-shogaol has potential hypoglycemic activity, but its mechanism is still unclear. The process of carbohydrate digestion and glucose absorption is closely related to the enzymatic activity of epithelial brush cells, expression of glucose transporters, and permeability of intestinal epithelial cells. Therefore, this study explored the hypoglycemic mechanism of 6-shogaol from the perspective of glucose uptake, absorption transport, and protection of intestinal barrier function. Based on molecular docking, the binding energy of 6-shogaol and α-glucosidase is -6.24 kcal/mol, showing a high binding affinity. Moreover, a-glucosidase enzymatic activity was reduced (-78.96%) when the 6-shogaol concentration was 500 µg/mL. After 6-shogaol intervention, the glucose uptake was reduced; the relative expression of glucose transporters GLUT2 and SGLT1 were down regulated; and tight junction proteins ZO-1, Occludin and Claudin were up regulated in differentiated Caco-2 cells. This study confirmed that 6-shogaol effectively inhibits the activity of α-glucosidase and has beneficial effects on glucose uptake, protection of intestinal barrier function, and promotion of intestinal material absorption.