Promotes Glucose Uptake Research Articles

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

Zinc Levels Affect the Metabolic Switch of T Cells by Modulating Glucose Uptake and Insulin Receptor Signaling.

T cell activation requires a metabolic reprogramming from oxidative phosphorylation to aerobic glycolysis to rapidly provide substrates for biosynthesis. An individual's zinc status plays an important role in balancing the activation of T cells and is required for a proper function of immune cells. Furthermore, zinc plays an important role during effector T cell polarization to T helper cell subsets or regulatory T cells, with effector T cells relying on glycolysis and regulatory T cells on oxidative phosphorylation. Therefore, the study aims to analyze if zinc also impacts on T cell activation on the level of intracellular metabolism. Mixed lymphocyte culture and anti-CD3/CD28 stimulation is used as in vitro models for T cell activation to investigate the effect of zinc supplementation and deprivation on metabolic switching. Promoted glucose uptake, insulin receptor expression, and signaling in both zinc conditions are observed, whereas key metabolic enzymes are stimulated mainly by zinc deprivation. Alterations in cytokine production suggest an immune-activating effect of zinc deprivation and a balancing effect of zinc supplementation. The results suggest a supportive effect of both zinc supplementation and deprivation on the metabolic switch during T cell activation, adding another level of immune regulation by zinc.

Capsaicin and Zinc Promote Glucose Uptake in C2C12 Skeletal Muscle Cells through a Common Calcium Signalling Pathway.

Capsaicin and zinc have recently been highlighted as potential treatments for glucose metabolism disorders; however, the effect of these two natural compounds on signalling pathways involved in glucose metabolism is still uncertain. In this study, we assessed the capsaicin- or zinc- induced activation of signalling molecules including calcium/calmodulin-dependent protein kinase 2 (CAMKK2), cAMP-response element-binding protein (CREB), and target of rapamycin kinase complex 1 (TORC1). Moreover, the expression status of genes associated with the control of glucose metabolism was measured in treated cells. The activation of cell signalling proteins was then evaluated in capsaicin- or zinc treated cells in the presence or absence of cell-permeant calcium chelator (BAPTA-AM) and the CAMKK inhibitor (STO-609). Finally, capsaicin- and zinc-induced glucose uptake was measured in the cells pre-treated with or without BAPTA-AM. Our results indicate that calcium flux induced by capsaicin or zinc led to activation of calcium signalling molecules and promoting glucose uptake in skeletal muscle cells. Pharmacological inhibition of CAMKK diminished activation of signalling molecules. Moreover, we observed an increase in intracellular cAMP levels in the cells after treatment with capsaicin and zinc. Our data show that capsaicin and zinc mediate glucose uptake in C2C12 skeletal muscle cells through the activation of calcium signalling.

Ficus benghalensis promotes the glucose uptake- Evidence with in silico and in vitro.

Ficus benghalensis L. is traditionally used to manage diabetes; also used in various herbal formulations, and is indicated as an insulin sensitizer. Hence, present work attempted in identifying the probable lead hits to promote glucose uptake via computational approach followed by experimental evaluation of hydroalcoholic extract of Ficus benghalensis L. bark in yeast cells. The in vitro assay for glucose uptake was performed in the baker yeast whereas in-silico study involved retrieving the phytoconstituents from open sources, and predicting for probable targets of diabetes followed by drug-likeness score, probable side effects, and ADMET profile. Homology modeling was performed to construct the target protein glucose transporter-2. In addition, the binding affinity of each ligand with glucose transporter was predicted using AutoDock 4.2. A total of 17 phytoconstituents from F. benghalensis were identified to possess the anti-diabetic effects. Among them, 4-methoxybenzoic acid scored the highest drug-likeness score and lupeol acetate had the maximum binding affinity of -8.02kcal/mol with 9 pi-interactions via Tyr324, Phe323, Ile319, Ile200, Ile28, Phe24, and Ala451. Similarly, the extract showed the highest glucose uptake efficacy in yeast cells at 500µg/mL. Herein the present study reflected the probable activity of the phytoconstituents from F. benghalensis in promoting the glucose uptake via the in silico and in vitro approaches.

Genetically Encoded Synthetic Beta Cells for Insulin Biosynthesis and Release under Hyperglycemic Conditions

AbstractAdvances in artificial/synthetic cells have drawn a new era of nanobiotechnology, which have shown broad prospects in biomedical applications. The rational nanoengineering of synthetic cells that can closely substitute the systematic biological functions of cells is a next grand challenge. Here, a genetically encoded synthetic beta cell, which can sense hyperglycemic conditions to initiate programmed biosynthesis and secretion of insulin is reported. By encapsulating different metal–organic framework‐based artificial organelles with distinctive bifunctionalities, the synthetic cell can undergo programmed, sequential subcellular events, including glucose sensing, initiation of insulin gene transcription and translation, and finally excretion of functional insulin, under hyperglycemic conditions. Glucose uptake assay suggests that the insulin produced by the synthetic cells can successfully promote glucose uptake into mammalian cells. The construction of a higher‐order cell cluster by ligand‐mediated super‐assembly of the synthetic cells is further demonstrated. Such a robust and smart synthetic system that closely mimics the cellular activities of beta cells in response to glucose levels is promising for improving clinical outcomes in diabetes treatment.

Phenylpropanoids and neolignans isolated from Myristica fragrans enhance glucose uptake in myotubes.

Nutmeg is the seed of Myristica fragrans or its powder and is used as a spice and a traditional medicine. The antidiabetic effect of nutmeg is not fully understood yet. In this study, we examine the isolation and identification of the active compounds of Myristica fragrans with regards to glucose uptake and elucidate their mechanism in L6 myotubes. Myrisiticin, licarin B, erythro-2-(4-allyl-2,6-dimethoxy-phenoxy)-1-(3,4-dimethoxyphenyl)-propan-1-ol (ADDP) and (7S,8R)-2-(4-allyl-2,6-dimethoxyphenoxy)-1-(3,4,5-trimethoxyphenyl)-propan-1-ol (ADTP) were isolated and identified as the active compounds. Myristicin or a mixture of ADDP and ADTP promoted the translocation of glucose transporter 4 (GLUT4) through phosphorylation of AMP-activated protein kinase in L6 myotubes 15 min after treatment, while licarin B promoted it 240 min after treatment. Oral administration of the fraction from Myristica fragrans containing these active compounds to ICR mice suppressed post-prandial hyperglycemia. Thus, Myristica fragrans is a promising functional food to prevent post-prandial hyperglycemia and type 2 diabetes mellitus by promoting glucose uptake in muscle.

Antihyperglycemic effect of an anthocyanin, cyanidin-3-O-glucoside, is achieved by regulating GLUT-1 via the Wnt/β-catenin-WISP1 signaling pathway.

Cyanidin-3-O-glucoside (C3G), an essential representative of anthocyanins, has been proved to possess a myriad of biological activities. However, the effects of C3G on glucose metabolism and its underlying molecular mechanisms remain elusive. The aim of the present study was to investigate the metabolic impact of C3G on db/db mice and to determine whether its consequent anti-diabetic effects were related to glucose transporter-1 (GLUT-1) by in vivo and in vitro studies. As a result, through diabetic db/db mice, C3G treatment was found to significantly reduce the fasting blood glucose level and increase glycogen synthesis, which were associated with upregulation of GLUT-1 expression in the liver of the mice. In addition, in liver cells of the HepG2 and L02 lines, we further discovered that C3G could effectively promote glucose consumption by regulating the Wnt/β-catenin-WISP1 signaling pathway. Nevertheless, such effects would be restricted when the expression of GLUT-1 was blocked by the inhibitor IWR-1. Meanwhile, molecular docking technology was applied to simulate the possible action sites of C3G at the molecular level, and the results indicated that C3G might bind to β-catenin. In conclusion, our study provided evidence of the antihyperglycemic effect of C3G in vivo and in vitro via regulating GLUT-1 expression and the related signaling pathways.

Diosgenin Promoted Glucose Uptake by Attenuation of High Glucose Induced Blockade of PI3K-Akt-GLUT4 Pathway and ER Stress

Diosgenin Promoted Glucose Uptake by Attenuation of High Glucose Induced Blockade of PI3K-Akt-GLUT4 Pathway and ER Stress

DIF-1 promotes glucose uptake in mouse C2C12 myotube cells

DIF-1 promotes glucose uptake in mouse C2C12 myotube cells

Stevioside Attenuates Insulin Resistance in Skeletal Muscle by Facilitating IR/IRS-1/Akt/GLUT 4 Signaling Pathways: An In Vivo and In Silico Approach.

Type-2 diabetes mellitus (T2DM), the leading global health burden of this century majorly develops due to obesity and hyperglycemia-induced oxidative stress in skeletal muscles. Hence, developing novel drugs that ameliorate these pathological events is an immediate priority. The study was designed to analyze the possible role of Stevioside, a characteristic sugar from leaves of Stevia rebaudiana (Bertoni) on insulin signaling molecules in gastrocnemius muscle of obesity and hyperglycemia-induced T2DM rats. Adult male Wistar rats rendered diabetic by administration of high fat diet (HFD) and sucrose for 60 days were orally administered with SIT (20 mg/kg/day) for 45 days. Various parameters were estimated including fasting blood glucose (FBG), serum lipid profile, oxidative stress markers, antioxidant enzymes and expression of insulin signaling molecules in diabetic gastrocnemius muscle. Stevioside treatment improved glucose and insulin tolerances in diabetic rats and restored their elevated levels of FBG, serum insulin and lipid profile to normalcy. In diabetic gastrocnemius muscles, Setvioside normalized the altered levels of lipid peroxidase (LPO), hydrogen peroxide (H2O2) and hydroxyl radical (OH*), antioxidant enzymes (CAT, SOD, GPx and GSH) and molecules of insulin signaling including insulin receptor (IR), insulin receptor substrate-1 (IRS-1) and Akt mRNA levels. Furthermore, Stevioside enhanced glucose uptake (GU) and oxidation in diabetic muscles by augmenting glucose transporter 4 (GLUT 4) synthesis very effectively in a similar way to metformin. Results of molecular docking analysis evidenced the higher binding affinity with IRS-1 and GLUT 4. Stevioside effectively inhibits oxidative stress and promotes glucose uptake in diabetic gastrocnemius muscles by activating IR/IRS-1/Akt/GLUT 4 pathway. The results of the in silico investigation matched those of the in vivo study. Hence, Stevioside could be considered as a promising phytomedicine to treat T2DM.

Ivermectin accelerates autophagic death of glioma cells by inhibiting glycolysis through blocking GLUT4 mediated JAK/STAT signaling pathway activation

This study aimed to investigate the regulatory effect of ivermectin (IVM) on energy metabolism in glioma progression, and provide a reference for the treatment of glioma. Glioma cells were treated with IVM to measure cell viability, autophagy marker protein expression, ATP content, glucose uptake, pyruvate content, and expression of key enzymes of glycolysis. Glucose transporter 4 (GLUT4) or siGLUT4 was transfected in IVM treated U87 cells to investigate the effect of GLUT4 on cellular glycolysis and autophagy. The JAK2 inhibitor AZD-1480 was introduced to explore the specific mechanism by which IVM regulates glycolysis and autophagy. Rat models of glioma xenograft were constructed and treated with 10mg/kg IVM to observe tumor growth and examine the expression levels of GLUT4 and autophagy marker proteins in tumor tissues. IVM inhibited glioma cell survival and promoted cell death. IVM promoted LC3-II protein expression and inhibited p62/SQSTM1 protein expression in glioma cells. IVM decreased adenosine-triphosphate (ATP) and pyruvate content, promoted glucose uptake, and reduced HK2 and PFK1 protein expression in U87 cells. IVM inhibited GLUT4 protein expression, and overexpression of GLUT4 promoted glycolysis and inhibited autophagic cell death in U87 cells. IVM inhibited glycolysis by blocking GLUT4 mediated the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway activation. IVM inhibited tumor growth in vivo, decreased the protein expression of GLUT4, JAK2, HK2, and PFK1 in tumor tissues, decreased the phosphorylation levels of STAT3/STAT5, and promoted the expression of autophagy marker proteins. IVM accelerates autophagic death of glioma cells by inhibiting glycolysis through blocking GLUT4 mediated JAK/STAT signaling pathway activation.

Polygonatum sibiricum polysaccharides (PSP) improve the palmitic acid (PA)-induced inhibition of survival, inflammation, and glucose uptake in skeletal muscle cells

ABSTRACT Polygonatum sibiricum polysaccharides (PSP) can decrease the levels of fasting blood glucose, total cholesterol, and triglyceride (TG) in hyperlipidemic and diabetic animals. It can also reduce inflammatory cytokines and promote glucose uptake in adipocytes. However, the underlying molecular mechanisms of PSP in improving insulin resistance (IR) in skeletal muscle remain unclear. In this study, palmitic acid (PA) induced an IR model in L6 myotubes. After treatment, cell proliferation was measured using the CCK8. miR-340-3p, glucose transporter 4 (GLUT-4), and interleukin-1 receptor-associated kinase 3 (IRAK3) expression was measured by qRT-PCR. IRAK3 protein levels were measured by Western blotting. Glucose in the cell supernatant, TG concentration in L6 myotubes, and the levels of IL-1β, IL-6, and TNF-α were measured by an ELISA. We found that cell survival, glucose uptake, and GLUT-4 expression in L6 myotubes were significantly suppressed, while lipid accumulation and inflammatory factor levels were enhanced by PA stimulation. Furthermore, PSP treatment markedly alleviated these effects. Interestingly, PSP also significantly reduced the upregulated expression of miR-340-3p in the L6 myotube model of IR. Furthermore, overexpression of miR-340-3p reversed the beneficial effects of PSP in the same IR model. miR-340-3p can bind to the 3′-untranslated regions of IRAK3. Additionally, PA treatment inhibited IRAK3 expression, whereas PSP treatment enhanced IRAK3 expression in L6 myotubes. Additionally, miR-340-3p also inhibited IRAK3 expression in L6 myotubes. Taken together, PSP improved inflammation and glucose uptake in PA-treated L6 myotubes by regulating miR-340-3p/IRAK3, suggesting that PSP may be suitable as a novel therapeutic agent for IR.

Biological significance of MYC and CEBPD coamplification in urothelial carcinoma: Multilayered genomic, transcriptional and posttranscriptional positive feedback loops enhance oncogenic glycolysis.

Background and purposeThe aim of this study is to decipher the underlying mechanisms of CCAAT/enhancer‐binding protein delta (CEBPD)‐enhanced glycolysis as well as the biological significance of CEBPD and MYC coamplification in urothelial carcinoma (UC).MethodsIn vitro analyses were conducted to examine the effects of altered CEBPD or MYC expression on UC cells. The in vivo effects of CEBPD overexpression in a high‐glucose environment on tumour growth were investigated in xenografted induced diabetic severe combined immunodeficiency/beige mice. Data mining was used to cross‐validate the associations between CEBPD and MYC copy number and transcriptional expression, quantitative reverse transcription‐polymerase chain reaction, immunohistochemistry, chromogenic in situ hybridization, and in situ hybridization targeting microRNA were performed on 635 UC patient samples and xenograft samples. UC patient survival in relation to diabetes was validated by using the National Health Insurance Research Database.Results CEBPD and MYC coamplification (29.6%) occurred at a high frequency, MYC expression promoted chromosomal instability, facilitating CEBPD copy number gain and expression. CEBPD promoted glucose uptake and lactate production by upregulating SLC2A1 and HK2, leading to mitochondrial fission, increased extracellular acidification rate and decreased oxygen consumption rate to fuel cell growth. CEBPD upregulated HK2 expression through multiple regulation pathways including MYC stabilization, suppression of FBXW7 transactivation and MYC‐independent transcriptional suppression of hsa‐miR‐429. Clinical and xenografted experiments confirmed the growth advantage of CEBPD in relation to glucose metabolic dysregulation and the significant correlations between the expression of these genes.ConclusionsWe confirmed that CEBPD has an oncogenic role in UC by activating AKT signalling and initiating metabolic reprogramming from mitochondrial oxidative phosphorylation to glycolysis to satisfy glucose addiction. These novel CEBPD‐ and MYC‐centric multilayered positive feedback loops enhance cancer growth that could complement theranostic approaches.

A novel regulatory mechanism of geniposide for improving glucose homeostasis mediated by circulating RBP4

BackgroundSystemic insulin signal transduction is influenced by the inter-tissue crosstalk, which might be the potential therapeutic strategy for T2DM. Although anti-diabetic function of geniposide has been previously reported, the underlying mechanism was not completely clear in light of the complex pathogenesis of T2DM. PurposeThe present experiment is devoted to investigate the potential effects of geniposide on systemic insulin sensitivity mediated by hepatokine-RBP4 in high fat diet (HFD)-fed mice. MethodsThe HFD-fed wild type mice were administered with geniposide (25 or 50 mg/kg/d) by intraperitoneal injection, and the normal saline and Metformin were used as negative control group and positive control group, respectively. After administration for 4 weeks, the food intake, body weight, glucose tolerance tests, insulin tolerance tests and serum biochemical indices were examined, along with insulin signaling pathway-associated proteins and hepatic histomorphological analysis. The liver, gastrocnemius and mouse primary hepatocytes were also harvested for molecular mechanism study. ResultsAfter geniposide treatment for 4 weeks, the blood glucose level was reduced in HFD-fed mice. Furthermore, geniposide treatment improved insulin sensitivity both in the liver and gastrocnemius (GAS). In terms of mechanism, geniposide disturbed circulating RBP4 level including its synthesis, secretion and homeostasis. Moreover, geniposide modified fuel selection and promoted glucose uptake in skeletal muscle and reduced glycogen storage, which were closely related to impaired circulating RBP4 homeostasis, leading to ameliorative systemic insulin sensitivity. ConclusionOur current study proposes a novel regulatory mechanism of geniposide for improving glucose homeostasis through regulating circulating RBP4 level, which also provides new strategies for the prevention and treatment of T2DM.

Lactobacillus acidophilus NX2-6 Improved High-Fat Diet-Induced Glucose Metabolism Disorder Independent of Promotion of Insulin Secretion in Mice.

High-fat diet (HFD) contributes to metabolic inflammation and glucose metabolism disorder, thereby resulting in the pathogenesis of metabolic syndrome. Accumulating evidence has revealed that some probiotics could improve HFD-induced metabolic inflammation and glucose metabolism disorder. Our previous study has discovered that Lactobacillus acidophilus NX2-6 exhibited in vitro lipid-lowering, antioxidative, and anti-inflammatory activities. This study mainly investigated whether L. acidophilus NX2-6 improved HFD-induced glucose metabolism disorder. The results exhibited that L. acidophilus NX2-6 effectively reduced blood glucose levels and improved glucose tolerance by activating the insulin signaling pathway, promoting glucose uptake, glycolysis, and intestinal gluconeogenesis and suppressing hepatic gluconeogenesis, independent of regulation of glycogen synthesis in the liver and muscle. Enhanced insulin sensitivity was associated with L. acidophilus NX2-6-mediated suppression of inflammatory cascades in the target organs. Meanwhile, L. acidophilus NX2-6 also improved hepatic energy metabolism via the FGF21/AMPKα/PGC-1α/NRF1 pathway. However, L. acidophilus NX2-6 did not affect apoptosis, pyroptosis, inflammation, and endoplasmic reticulum stress in the pancreas of HFD-fed mice. In conclusion, our results indicated that L. acidophilus NX2-6 improved glucose metabolism disorder through enhancing insulin sensitivity, suppressing metabolic inflammation, and promoting energy expenditure.

Drosophila Solute Carrier 5A5 Regulates Systemic Glucose Homeostasis by Mediating Glucose Absorption in the Midgut.

The small intestine is the initial site of glucose absorption and thus represents the first of a continuum of events that modulate normal systemic glucose homeostasis. A better understanding of the regulation of intestinal glucose transporters is therefore pertinent to our efforts in curbing metabolic disorders. Using molecular genetic approaches, we investigated the role of Drosophila Solute Carrier 5A5 (dSLC5A5) in regulating glucose homeostasis by mediating glucose uptake in the fly midgut. By genetically knocking down dSLC5A5 in flies, we found that systemic and circulating glucose and trehalose levels are significantly decreased, which correlates with an attenuation in glucose uptake in the enterocytes. Reciprocally, overexpression of dSLC5A5 significantly increases systemic and circulating glucose and trehalose levels and promotes glucose uptake in the enterocytes. We showed that dSLC5A5 undergoes apical endocytosis in a dynamin-dependent manner, which is essential for glucose uptake in the enterocytes. Furthermore, we showed that the dSLC5A5 level in the midgut is upregulated by glucose and that dSLC5A5 critically directs systemic glucose homeostasis on a high-sugar diet. Together, our studies have uncovered the first Drosophila glucose transporter in the midgut and revealed new mechanisms that regulate glucose transporter levels and activity in the enterocyte apical membrane.

Epithelial mesenchymal transition regulator TWIST1 transcription factor stimulates glucose uptake through upregulation of GLUT1, GLUT3, and GLUT12 in vitro.

TWIST1 is a major regulator of epithelialmesenchymal transition process, essential in cancer metastasis. Cancer cells increase glucose uptake capabilities to meet their high energy requirements. In this study, we explored the potential role of TWIST1 on glucose transport into the 293T cells in an insulin-dependent and insulin-independent manner. For this purpose, the ectopic expression of TWIST1 was successfully performed by electroporation. The altered mRNA expressions of GLUT-1, -3, -4, and -12, insulin receptor (InsR), and insulin receptor substrate (IRS)-1 and -2 were assessed in control and TWIST1-overexpressing cells. Glucose uptake rates of the cells were evaluated by fluorometric glucose uptake assay. Our findings showed that the transcriptional expression levels of GLUT-1, -3, and -12 genes were significantly upregulated by TWIST1. However, TWIST1 did not alter the mRNA and protein expressions of the InsR, its substrates (IRS-1 and -2), and GLUT-4 genes in 293T cells which are main factors for insulin-stimulated glucose uptake pathway. Also, the glucose transport activities were significantly increased in TWIST1-overexpressing cells compared to controls due to fetal bovine serum (FBS) stimulation, but there was a slight non-significant difference in insulin stimulation. Thus, our data suggest that TWIST1 could promote glucose uptake independently of insulin and is possible to be evaluated as a metabolic marker in cancer. Further investigations are needed to clarify the precise molecular mechanisms underlying the cells' glucose uptake and consumption during tumorigenesis.

SNF1β-Modulated Glucose Uptake and the Balance between Polyunsaturated Fatty Acids and Carbohydrates in Mortierella alpina.

A sucrose nonfermenting protein kinase 1 (SNF1) complex is an important metabolic regulator in fungi that is critical to cell metabolism and stress response. In this study, the role of an SNF1 β-subunit in the oleaginous fungus Mortierella alpina (MaSip2) was investigated. The MaSip2 contained a glycogen-binding domain and a conserved SNF1-complex interaction region; its transcriptional level during lipogenesis shared high consistency with a previously reported SNF1 γ-subunit (MaSnf4). Overexpression of MaSip2 in M. alpina significantly promoted glucose uptake and resulted in 34.1% increased total biomass, leading to 44.8% increased arachidonic acid yield after 7 day fermentation. MaSip2 also regulated the balance between polyunsaturated fatty acids and carbohydrates in M. alpina. Intracellular metabolite analysis revealed increased carbohydrate-related metabolite accumulation in MaSip2 overexpression strains. On the contrary, knockdown of MaSip2 increased the total fatty acid unsaturation degree, especially under low-temperature conditions. This research improved our knowledge of SNF1 complex in M. alpina and provided a target gene for enhancing glucose utilization and modulating fatty acid composition for better application of oleaginous fungi.

In vitro and in silico characterization of adiponectin-receptor agonist dipeptides

The aim of this study is to develop a dipeptide showing an adiponectin receptor 1 (AdipoR1) agonistic effect in skeletal muscle L6 myotubes. Based on the structure of the AdipoR1 agonist, AdipoRon, 15 synthetic dipeptides were targeted to promote glucose uptake in L6 myotubes. Tyr-Pro showed a significant increase in glucose uptake among the dipeptides, while other dipeptides, including Pro-Tyr, failed to exert this effect. Tyr-Pro induces glucose transporter 4 (Glut4) expression in the plasma membrane, along with adenosine monophosphate-activated protein kinase (AMPK) activation. In AdipoR1-knocked down cells, the promotion by Tyr-Pro was ameliorated, indicating that Tyr-Pro may directly interact with AdipoR1 as an agonist, followed by the activation of AMPK/Glut4 translocation in L6 myotubes. Molecular dynamics simulations revealed that a Tyr-Pro molecule was stably positioned in the two potential binding pockets (sites 1 and 2) of the seven-transmembrane receptor, AdipoR1, anchored in a virtual 1-palmitoyl-2-oleoyl-phosphatidylcholine membrane. In conclusion, we demonstrated the antidiabetic function of the Tyr-Pro dipeptide as a possible AdipoR1 agonist.

TM4SF5-dependent crosstalk between hepatocytes and macrophages to reprogram the inflammatory environment.

Chronic injury to hepatocytes results in inflammation, steatohepatitis, fibrosis, and nonalcoholic fatty liver disease (NAFLD). The tetraspanin TM4SF5 is implicated in fibrosis and cancer. We investigate the role of TM4SF5 in communication between hepatocytes and macrophages (MΦs) and its possible influence on the inflammatory microenvironment that may lead to NAFLD. TM4SF5 induction in differentiated MΦs promotes glucose uptake, glycolysis, and glucose sensitivity, leading to M1-type MΦ activation. Activated M1-type MΦs secrete pro-inflammatory interleukin-6 (IL-6), which induces the secretion of CCL20 and CXCL10 from TM4SF5-positive hepatocytes. Although TM4SF5-dependent secretion of these chemokines enhances glycolysis in M0 MΦs, further chronic exposure reprograms MΦs for an increase in the proportion of M2-type MΦs in the population, which may support diet- and chemical-induced NAFLD progression. We suggest that TM4SF5 expression in MΦs and hepatocytes is critically involved in modulating the inflammatory environment during NAFLD progression.