GLUT4 Expression Research Articles

Leaf extracts of Euclea natalensis A.D.C ameliorate biochemical abnormalities in high-fat-low streptozotocin-induced diabetic rats through modulation of the AMPK-GLUT4 pathway

ABSTRACT Euclea natalensis is a commonly used plant in traditional African medicine for treating several diseases, including diabetes. The objective of the present study was to evaluate the antidiabetic effects of the leaf extracts of Euclea natalensis and elucidate some of its mechanisms of action. High-fat diet – low Streptozotocin-induced diabetic Sprague Dawley rats were orally treated with the methanol and dichloromethane extracts (100 and 200 mg/kg bw), and their fasting blood glucose levels, body weights, and food and water intake were measured every seven days for 21 days. Biomarkers of oxidative stress, lipid profile, gluconeogenic enzyme activities, glucose transporter 4 (GLUT 4) protein expression, and AMP-activated protein kinase (AMPK) gene expression were also determined. The 200 mg/kg bw of methanol extracts significantly reduced fasting plasma glucose, glycated hemoglobin (HbAc1), triglycerides, and low-density lipoprotein levels. The extract increased insulin sensitivity and hepatic glycogen synthesis, decreased hepatic glucose output, and increased the activities of antioxidant enzymes in diabetic animals after 21 days of treatment. The methanol extract also significantly upregulated the relative expression of GLUT 4 protein via the promoted expression of skeletal muscle and hepatic AMPK. Histological investigation showed ameliorated pancreatic degeneration and expedited regeneration of islets of Langerhans in diabetic rats treated with the methanol extract compared with the dichloromethane extract. The findings demonstrated that Euclea natalensis has beneficial effects on the biochemical and cell abnormalities of type 2 diabetes, partly via the modulation of the AMPK – GLUT 4 pathway.

Correlation of Differentially Expressed lncRNAs with Intestinal Flora Imbalance, Small Intestinal Permeability, and Glucose Uptake in T2DM Mice.

Diabetes is a major global health concern. This study aimed to investigate the correlation between differentially expressed lncRNAs in mice with type 2 diabetes mellitus (T2DM) and alterations in the intestinal flora and intestinal pathology. A T2DM mouse model was constructed by feeding mice a high-fat diet. Serum fat metabolism-related indices and insulin levels were biochemically detected. Serum inflammatory factors (IL-1β, IL-6, TNF-α, IL-10) and endotoxin (LPS) were measured by ELISA. Histopathological changes in the small intestines of mice were observed by HE. The short-chain fatty acid (SCFA) content was analyzed using GC-MS. Analysis of altered intestinal flora in T2DM mice was performed using a 16sRNA sequencing assay. Differences in lncRNA expression profiles in small intestinal tissues were analyzed using RNA-seq assays. Spearman's correlation analysis was used to correlate the expression of candidate lncRNAs with changes in differential gut flora. Spearman's correlation analysis was used to analyze the correlation between the expression of candidate differentially expressed lncRNAs, small intestinal permeability, and glucose absorption. We found that serum levels of LPS, BUN, Scr, TC, TG, LDL-C, IL-1β, IL-6, and TNF-α were elevated and levels of HDL-C, insulin, and IL-10 were decreased in T2DM mice. The ileal enterochromes of T2DM mice were disorganized and broken, the number of enterochromes was reduced, the local epithelial cells were necrotic, and the plasma membrane layer was locally absent. In addition, the protein expression of ZO-1 and occludin was decreased, and the protein expression of SGLT-1 and GLUT-2 was elevated in the model group compared to the control group.The levels of Acetic acid, Propionic acid and Butyric acid were decreased and the levels of Isobutyric acid andIsovaleric acid were increased, the abundance of beneficial bacteria was decreased and the abundance of harmfulbacteria was increased in the feces of T2DM mice. RNA-seq identified nine differentially expressed lncRNAs (LINC00675, Gm33838, Gm11655, LOC6613926, LOC6613788, LOC6613791, LOC6613795, Arhgap27os3, and A330023F24Rik). In addition, we found significant correlations between differentially expressed lncRNAs and a variety of intestinal flora, as well as between small intestinal permeability and glucose absorption. A significant correlation was observed between differentially expressed lncRNAs in the intestinal tissues of T2DM mice and intestinal flora imbalance, small intestinal permeability, and glucose absorption.

Ze-Qi-Tang formula inhibits MDSCs glycolysis through the down-regulation of p21/Hif1α/Glut1 signal in psoriatic-like mice

BackgroundPsoriasis is a chronic immune-mediated inflammatory skin disease that affects the quality of life and mental health of approximately 150 million people worldwide. Ze-Qi-Tang (ZQT) is a classic compound used in China for lung disease; however, its mechanism of action in psoriasis remains unclear. This study aimed to investigate the therapeutic effect of the ZQT formula on psoriasis and explore the underlying molecular mechanisms. MethodsPeripheral blood samples were collected from patients with psoriasis and healthy individuals. Flow cytometry was used to detect changes in the proportions of myeloid-derived suppressor cells (MDSCs) and other immune cells. Psoriasis was induced in mice by the daily application of imiquimod. ZQT was administered separately or in combination with anti-Gr1 antibody to deplete MDSC. The glycolysis levels of the MDSCs were detected using a Seahorse analyzer. The p21/Hif1α/Glut1 pathway was identified and validated by mRNA sequence, RT-qPCR, WB, IF, and the application of p21 inhibitor UC2288. ResultsThe number of MDSCs was significantly increased in patients with psoriasis, with the increased expression of p21, Hif1α, and Glut1 in MDSCs. ZQT significantly alleviated psoriasis-like skin lesions in mice. ZQT formula significantly reduced the number of MDSCs in psoriatic-like mice and enhanced their suppressive capacity for T cells. The efficacy of ZQT in alleviating psoriatic dermatitis is compromised by MDSC depletion. ZQT decreased the expressions of p21, Hif1α, and Glut1-induced glycolysis in MDSCs, thereby inhibiting Th17 cell differentiation. ConclusionThese suggest that ZQT alleviates IMQ-induced psoriatic dermatitis, by inhibiting p21/Hif1α/Glut1-induced glycolysis in MDSCs.

Dihydromyricetin ameliorates hepatic steatosis and insulin resistance via AMPK/PGC-1α and PPARα-mediated autophagy pathway

BackgroundDihydromyricetin (DHM), a flavonoid compound of natural origin, has been identified in high concentrations in ampelopsis grossedentata and has a broad spectrum of biological and pharmacological functions, particularly in regulating glucose and lipid metabolism. The objective of this research was to examine how DHM affected nonalcoholic fatty liver disease (NAFLD) and its underlying mechanisms involved in the progression of NAFLD in a rat model subjected to a high-fat diet (HFD). Additionally, the study examines the underlying mechanisms in a cellular model of steatohepatitis using palmitic acid (PA)-treated HepG2 cells, with a focus on the potential correlation between autophagy and hepatic insulin resistance (IR) in the progress of NAFLD.MethodsSD rats were exposed to a HFD for a period of eight weeks, followed by a treatment with DHM (at doses of 50, 100, and 200 mg·kg−1·d−1) for additional six weeks. The HepG2 cells received a 0.5 mM PA treatment for 24 h, either alone or in conjunction with DHM (10 µM). The histopathological alterations were assessed by the use of Hematoxylin–eosin (H&E) staining. The quantification of glycogen content and lipid buildup in the liver was conducted by the use of PAS and Oil Red O staining techniques. Serum lipid and liver enzyme levels were also measured. Autophagic vesicle and autolysosome morphology was studied using electron microscopy. RT-qPCR and/or western blotting techniques were used to measure IR- and autophagy-related factors levels.ResultsThe administration of DHM demonstrated efficacy in ameliorating hepatic steatosis, as seen in both in vivo and in vitro experimental models. Moreover, DHM administration significantly increased GLUT2 expression, decreased G6Pase and PEPCK expression, and improved IR in the hepatic tissue of rats fed a HFD and in cells exhibiting steatosis. DHM treatment elevated Beclin 1, ATG 5, and LC3-II levels in hepatic steatosis models, correlating with autolysosome formation. The expression of AMPK levels and its downstream target PGC-1α, and PPARα were decreased in HFD-fed rats and PA-treated hepatocytes, which were reversed through DHM treatment. AMPK/ PGC-1α and PPARα knockdown reduced the impact of DHM on hepatic autophagy, IR and accumulation of hepatic lipid.ConclusionsOur findings revealed that AMPK/ PGC-1α, PPARα-dependent autophagy pathways in the pathophysiology of IR and hepatic steatosis has been shown, suggesting that DHM might potentially serve as a promising treatment option for addressing this disease.Graphical

Abstract 3610: Utilizing fructose metabolism to fuel anti-tumor immunity

Abstract Consumption of fructose in the form of high fructose corn syrup is elevated in the western diet, but it is not fully understood how fructose metabolism influences anti-tumor immunity. Fructose is canonically metabolized in the intestine and the liver and can shunt into glycolysis. In certain tumor types, fructose metabolism becomes deregulated, allowing tumor cells to metabolize fructose to power their biosynthetic processes. Similarly, reprogramming immune cells to be able to efficiently metabolize fructose may help us power immunotherapy to work in difficult to treat cancers, especially in individuals who have high fructose in their blood or in the tumor microenvironment (TME). Imparting effector T cells with the ability to use fructose for fuel can overcome one of the major metabolic limitations of the TME: limited nutrient supply. As T cells become activated, they alter their metabolism to support growth and proliferation. Activated CD8+ T cells upregulate their glycolysis which results in increased biosynthetic processes, such as synthesis of macromolecules and effector cytokines. However, tumor cells also consume substantial amounts of glucose, resulting in a glucose-depleted microenvironment, which could be one of the major barriers to immunotherapy working in solid tumors. Therefore, we engineered T cells to overexpress a fructose transporter, GLUT5, which is normally not expressed in the immune compartment at high levels. We hypothesized that increased fructose uptake by CD8+ T cells will ameliorate exhaustion caused by the glucose-low tumor microenvironment. Indeed, we determined that GLUT5 T cells are more efficient in killing in low glucose supplemented with fructose. We also observed that GLUT5 expression restores T cell glycolytic capacity under fructose to that of unexhausted T cells under glucose replete conditions. Similarly, GLUT5-expressing T cells proliferate faster in vitro and exhibit an improved ability to control B16 tumor growth in vivo. Additionally, combining GLUT5 cell infusion with checkpoint inhibition resulted in durable tumor control and prolonged mouse survival. Further, engineered CD19-targeted CAR T cells with expression of GLUT5 were more metabolically active and cytotoxic in low glucose conditions, mimicking the TME. In conclusion, GLUT5 expression in effector CD8+ and CAR T cells may allow immunotherapy to function in solid tumors under low glucose conditions. Citation Format: Tanya Schild, Rachel Chirayil, Lyric Haughton, Patrick Wallisch, Marjan Berishaj, David A. Scheinberg, Kayvan R. Keshari. Utilizing fructose metabolism to fuel anti-tumor immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3610.

Abstract 378: PHD3 dependent stabilization of β3-adrenoceptor induces HIF-1αactivation in Ewing sarcoma

Abstract Hypoxia is a condition of oxygen deficiency which occurs in most growing solid tumors and stimulates a cascade of cell signals through a family of transcription factors named as hypoxia inducible factors (HIFs) that transactivate several regulatory genes involved in tumor proliferation. β3-adrenoceptors (β3-ARs) are involved in several hypoxic scenarios and in pathological conditions where hypoxia leads to important steps for cancer progression. Studies showed that β-AR blockade of mice suppressed hypoxia induction of renal HIF-1α accumulation, erythropoietin production, and erythropoiesis in vivo. In this work we assumed that through PHD3 activity, β3-AR mediates hypoxia sensing needed for HIF-1α stabilization, thus we investigated a putative correlation between β3-AR/HIF-1α and PHD3. Data showed a similar outcome of β3-ARs and HIF-1α at short time of hypoxia, and that β3-AR antagonist, SR59230A reduced HIF-1α protein expression under hypoxia. β3-AR silencing under hypoxia revealed an evident reduction of HIF-1α protein expression that confirmed the β3-AR modulation of HIF-1α expression. SR59230A treatment strongly reduced the HIF-1α target genes as GLUT1, HK-2 and HIF-1α expression at long time treatment confirming the β3-AR modulation of HIF-1α transcriptional activity. Conversely, the HIF-1α-transcriptional inhibitor Topotecan did not affect β3-AR expression confirming that β3-AR mediates HIF-1α activation. Immunofluorescence and nuclear-cytoplasmic fragmentation showed that β3-AR co-localized with the nucleus under hypoxia, more than normoxia, and presence of both β3-AR and HIF-1α in the nucleus. Co-immunoprecipitation of β3-AR/HIF-1α revealed that under hypoxia, HIF-1α dissociates from β3-AR binding, but this process was abrogated by SR59230A. HIF-1α, released under hypoxia from the link with β3-AR, can play its transcriptional activity in the nucleus, while the binding with β3-AR blocks its transcriptional activity. Moreover, the β3-AR upregulation under hypoxia occurs trough an early inhibition of PHD3 activity that did not influence HIF-1α expression. Hypoxic PHD2 inhibition results after PHD3 leading to HIF-1α upregulation. Moreover, the blockade β3-AR by SR59230A, inhibited HIF-1α upregulation by increasing PHD2 activity. Citation Format: Amada Pasha, Laura Zocca, Francesco Carrozzo, Cristina Banella, Rachele Amato, Annalisa Tondo, Claudio Favre, Maura Calvani. PHD3 dependent stabilization of β3-adrenoceptor induces HIF-1αactivation in Ewing sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 378.

Abstract 4448: Effects of adagrasib on cholesterol, lipid and glucose gene expression regulation in tumor xenograft models and patient samples

Abstract Introduction: Clinically active KRASG12C inhibitors have represented a key research breakthrough and led to novel treatment options for lung, colorectal and other cancer patients harboring this mutation. While treatment with KRASG12C inhibitors are clinically active in the majority of patients, the depth and duration of response is variable and most patients ultimately progress. This variation in therapeutic response highlights the need for a better understanding of drug mechanism of action and the identification of rational combination strategies. Oncogenic KRAS mutations hyperactivate the MAPK pathway, create an immunosuppressive tumor microenvironment, and promote glycolysis even in the presence of oxygen commonly known as the Warburg effect. This altered metabolic state is marked by increased glucose uptake and lactate production, providing necessary substrates for rapid tumor growth. Results: Pharmacological inhibition of KRASG12C with a potent and selective KRASG12C inhibitor, adagrasib, revealed marked alterations of metabolic gene expression programs in tumor samples collected from mouse xenograft studies and repeat biopsies provided by patients enrolled on adagrasib clinical trials. Upregulation of genes involved in reverse cholesterol transport including ApoE, NR1H3 (LXRa) and ABCA1 was observed across both preclinical tumor xenografts and patient samples following adagrasib treatment. Additionally, decreased expression of Glut1 and low-density lipoprotein receptor (LDLR) genes were also observed in both tumor models and patients suggesting that adagrasib treatment results in an extensive shift in uptake and utilization of cholesterol, lipid, and glucose. The impact of adagrasib treatment on circulating metabolic parameters in tumor xenograft-bearing mice were investigated in follow up studies. Conclusions: Taken together, these data suggest adagrasib modulates cholesterol efflux, glucose and lipid pathways and alters tumor and systemic metabolic regulation. Additional research may yield a targetable collateral vulnerability and rational combinatorial strategy. Citation Format: Fabiola Shelton, Natalie Hoffman, David Trinh, Xousaen M. Helu, Andrew Calinisan, Allan Hebbert, Larry Yan, David M. Briere, Laura Hover, Julio Fernandez-Benet, Kenna Anderes, James G. Christensen, Jill Hallin, Peter Olson. Effects of adagrasib on cholesterol, lipid and glucose gene expression regulation in tumor xenograft models and patient samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4448.

Evaluation of Efficacy of Curcumin and Caffeic Acid Phenethyl Ester in Breast Cancer by Preclinical Studies.

CAPE and curcumin are a class of phenolics. While curcumin is obtained from turmeric, CAPE is found in Baccharis sarothroides and Populus deltoides. Both agents are reported to produce activities in some cancer types. The combined and comparative effects of the two agents in breast cancer have not yet reported. We evaluated the potential of CAPE and curcumin in both in vitro and in vivo breast cancer models. Human breast cancer cell lines, MDA-MB-231 and MCF-7, were exposed to CAPE and curcumin, followed by functional assays such as cell cytotoxicity, cell proliferation and colony formation, cell cycle, mitochondrial membrane potential, apoptosis, and monodansylcadaverine (MDC) staining for autophagy. Computational analyses and mouse models were also used. Employing computational analyses, both agents were found to exhibit drug-like properties. Both molecules interacted with the key molecules of the NF-κB pathway. CAPE and curcumin inhibited cell proliferation, colony formation, and invasion, triggering apoptosis in breast cancer cells. CAPE was found to be more effective than curcumin. Two agents working together were more effective than each agent working alone. Both agents suppressed the expression of survivin, Bcl-xL and GLUT-1. The level of cleaved PARP was increased by both agents. Both phenolics observed an induction in ROS generation. Further, both molecules triggered a dissipation in mitochondrial membrane potential. In mice models implanted with Ehrlich-Lettre ascites carcinoma (EAC) cells, both drugs inhibited the growth of the tumour. The phenolics also modulated the metabolic parameters in tumour-bearing mice. The observations suggest that the combination of curcumin plus CAPE may be better in comparison to individual molecules. Other: The study opens a window for analysing the efficacy of the combination of CAPE and curcumin in animal studies. This will provide a basis for examining the combined efficacy of two agents in a clinical trial.

An insight into the mechanistic role of (-)-Ampelopsin F from Vatica chinensis L. in inducing insulin secretion in pancreatic beta cells

Resveratrol oligomers, ranging from dimers to octamers, are formed through regioselective synthesis involving the phenoxy radical coupling of resveratrol building blocks, exhibiting remarkable therapeutic potential, including antidiabetic properties. In this study, we elucidate the mechanistic insights into the insulin secretion potential of a resveratrol dimer, (-)-Ampelopsin F (AmF), isolated from the acetone extract of Vatica chinensis L. stem bark in Pancreatic Beta-TC-6 cell lines. The AmF (50 µM) treated cells exhibited a 3.5-fold increase in insulin secretion potential as compared to unstimulated cells, which was achieved through the enhancement of mitochondrial membrane hyperpolarization, elevation of intracellular calcium concentration, and upregulation of GLUT2 and glucokinase expression in pancreatic Beta-TC-6 cell lines. Furthermore, AmF effectively inhibited the activity of DPP4, showcasing a 2.5-fold decrease compared to the control and a significant 6.5-fold reduction compared to the positive control. These findings emphasize AmF as a potential lead for the management of diabetes mellitus and point to its possible application in the next therapeutic initiatives.

Aberrantly Glycosylated GLUT1 as a Poor Prognosis Marker in Aggressive Bladder Cancer.

Muscle-invasive bladder cancer (MIBC) remains a pressing health concern due to conventional treatment failure and significant molecular heterogeneity, hampering the development of novel targeted therapeutics. In our quest for novel targetable markers, recent glycoproteomics and bioinformatics data have pinpointed (glucose transporter 1) GLUT1 as a potential biomarker due to its increased expression in tumours compared to healthy tissues. This study explores this hypothesis in more detail, with emphasis on GLUT1 glycosylation patterns and cancer specificity. Immunohistochemistry analysis across a diverse set of human bladder tumours representing all disease stages revealed increasing GLUT1 expression with lesion severity, extending to metastasis, while remaining undetectable in healthy urothelium. In line with this, GLUT1 emerged as a marker of reduced overall survival. Revisiting nanoLC-EThcD-MS/MS data targeting immature O-glycosylation on muscle-invasive tumours identified GLUT1 as a carrier of short glycosylation associated with invasive disease. Precise glycosite mapping uncovered significant heterogeneity between patient samples, but also common glycopatterns that could provide the molecular basis for targeted solutions. Immature O-glycosylation conferred cancer specificity to GLUT1, laying the molecular groundwork for enhanced targeted therapeutics in bladder cancer. Future studies should focus on a comprehensive mapping of GLUT1 glycosites for highly specific cancer-targeted therapy development for bladder cancer.

Interference with MTHFD2 induces ferroptosis in ovarian cancer cells through ERK signaling to suppress tumor malignant progression.

Ovarian cancer (OC) is a deadliest gynecological cancer with the highest mortality rate. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), a crucial tumor-promoting factor, is over-expressed in several malignancies including OC. The present study aimed to explore the role and mechanisms of MTHFD2 in OC malignant progression. Thus, cell proliferation, cycling, apoptosis, migration, and invasion were evaluated by CCK-8 assay, EdU assay, flow cytometry, wound healing, transwell assay and western blotting. Additionally, glycolysis was assessed by measuring the level of glucose and lactate production, as well as the expressions of GLUT1, HK2 and PKM2. Then the expression of ferroptosis-related proteins and ERK signaling was detected using western blotting. Ferroptosis was detected through the measurement of iron level, GSH, MDA and ROS activities. The results revealed that MTHFD2 was highly expressed in OC cells. Besides, interference with MTHFD2 induced ferroptosis, promoted ROS accumulation, destroyed mitochondrial function, reduced ATP content and inhibited glycolysis in OC cells. Subsequently, we further found that interference with MTHFD2 affected mitochondrial function and glycolysis in OC cells through ERK signaling. Moreover, interference with MTHFD2 affected ferroptosis to inhibit the malignant progression of OC cells. Collectively, our present study disclosed that interference with MTHFD2 induced ferroptosis in OC to inhibit tumor malignant progression through regulating ERK signaling.

Mitigation of extreme winter stress in European seabass, Dicentrarchus labrax through dietary supplementation

Climate change is driving the dangerous confluence of extreme weather events. Among others, aquatic ecosystems are the most affected one. This study sheds light on how dietary supplements affect the physiological responses of European seabass during extreme winter exposure. Fish were provided with three dietary supplements: vitamins C and E (diet-1), propolis (diet-2), and phycocyanin (diet-3) for 45 days. They were then exposed to a simulated extreme winter cold (7 °C) for 20 days. The results showed that dietary supplements do not have a significant impact on weight, growth rate, and protein efficiency ratio before cold exposure. Levels of Na + and Cl − in the fish remained stable across all diets during both control (20 °C) and 7 °C exposure. However, on the 20th day of cold exposure, fish fed diet-3 exhibited notably higher levels of K+ compared to the other two diets, whereas blood glucose was significantly lower in fish fed diet-1. On day 20, significantly higher GPT activities were observed in fish fed diet-1. No significant effects of dietary supplementation were observed in fish serum cholesterol and protein levels. Before cold stress, fish fed the control diet exhibited significantly lower triglyceride levels (p < 0.05). However, during cold exposure, triglyceride levels increased in fish fed diet-1 and the control diet. On day 20, fish fed diet-3 exhibited a comparatively higher lactate content. Conversely, cortisol levels were significantly lower (p < 0.05) in fish fed diets 2 and 3 on the same day. No dietary effects were observed on fish muscle HSP70 gene expression. On days 10 and 20, SREBP1 was significantly upregulated in fish fed all diets. On day 20 of cold exposure, FADS2 and GLUT2 genes were downregulated in the fish fed control diet compared to those fed diets 2 and 3. Before cold stress, fish on the control diet showed higher TNF-1α expression in the spleen. SREBP1 showed a significant upregulation on day 10 in fish fed diet-2. FADS2 gene expression remained unchanged during cold stress. GLUT2 expression showed no noticeable effects throughout the study. Overall, during extreme cold exposure, we observed decreased levels of blood cortisol, transaminase, dehydrogenase, and metabolites, along with a comparatively higher upregulation of growth, metabolic, and immune genes in fish fed diets supplemented with propolis, phycocyanin, and vitamins C&E. These results suggest that dietary supplements can help European seabass cope better with extreme cold, at least for short periods of up to 20 days.

Role of IL-18 in adipose tissue remodeling and metabolic dysfunction.

Proinflammatory cytokines are increased in obese adipose tissue, including inflammasome key masters. Conversely, IL-18 protects against obesity and metabolic dysfunction. We focused on the IL-18 effect in controlling adipose tissue remodeling and metabolism. We used C57BL/6 wild-type (WT) and interleukine-18 deficient (IL-18-/-) male mice fed a chow diet and samples from bariatric surgery patients. IL-18-/- mice showed increased adiposity and proinflammatory cytokine levels in adipose tissue, leading to glucose intolerance. IL-18 was widely secreted by stromal vascular fraction but not adipocytes from mice's fatty tissue. Chimeric model experiments indicated that IL-18 controls adipose tissue expansion through its presence in tissues other than bone marrow. However, IL-18 maintains glucose homeostasis when present in bone marrow cells. In humans with obesity, IL-18 expression in omental tissue was not correlated with BMI or body fat mass but negatively correlated with IRS1, GLUT-4, adiponectin, and PPARy expression. Also, the IL-18RAP receptor was negatively correlated with IL-18 expression. IL-18 signaling may control adipose tissue expansion and glucose metabolism, as its absence leads to spontaneous obesity and glucose intolerance in mice. We suggest that resistance to IL-18 signaling may be linked with worse glucose metabolism in humans with obesity.

Isolation of feline islets of Langerhans by selective osmotic shock produces glucose responsive islets.

Pancreatic islet isolation is essential for studying islet physiology, pathology, and transplantation, and feline islets could be an important model for human type II diabetes mellitus (T2D). Traditional isolation methods utilizing collagenases inflict damage and, in cats, may contribute to the difficulty in generating functional islets, as demonstrated by glucose-stimulated insulin secretion (GSIS). GLUT2 expression in β cells may allow for adaptation to hyperosmolar glucose solutions while exocrine tissue is selectively disrupted. Here we developed a protocol for selective osmotic shock (SOS) for feline islet isolation and evaluated the effect of different hyperosmolar glucose concentrations (300 mmol/L and 600 mmol/L) and incubation times (20 min and 40 min) on purity, morphology, yield, and GSIS. Across protocol treatments, islet yield was moderate and morphology excellent. The treatment of 600 mmol/L glucose solution with 20 min incubation resulted in the highest stimulation index by GSIS. Glucose responsiveness was demonstrated, permitting future in vitro studies. This research opens avenues for understanding feline islet function and transplantation possibilities and enables an additional islet model for T2D.

Tumor-associated macrophages drive glycolysis through the IL-8/STAT3/GLUT3 signaling pathway in pancreatic cancer progression

Glycolytic metabolism is a hallmark of pancreatic ductal adenocarcinoma (PDAC), and tumor-associated stromal cells play important roles in tumor metabolism. We previously reported that tumor-associated macrophages (TAMs) facilitate PDAC progression. However, little is known about whether TAMs are involved in regulating glycolysis in PDAC. Here, we found a positive correlation between CD68+ TAM infiltration and FDG maximal standardized uptake (FDG SUVmax) on PET-CT images of PDAC. We discovered that the glycolytic gene set was prominently enriched in the high TAM infiltration group through Gene Set Enrichment Analysis using The Cancer Genome Atlas database. Mechanistically, TAMs secreted IL-8 to promote GLUT3 expression in PDAC cells, enhancing tumor glycolysis both in vitro and in vivo, whereas this effect could be blocked by the IL-8 receptor inhibitor reparixin. Furthermore, IL-8 promoted the translocation of phosphorylated STAT3 into the nucleus to activate the GLUT3 promoter. Overall, we demonstrated that TAMs boosted PDAC cell glycolysis through the IL-8/STAT3/GLUT3 signaling pathway. Our cumulative findings suggest that the abrogation of TAM-induced tumor glycolysis by reparixin might exhibit an antitumor impact and offer a potential therapeutic target for PDAC.

FGF19 Promotes the Proliferation and Insulin Secretion from Human Pancreatic β Cells Via the IRS1/GLUT4 Pathway.

Type 2 diabetes mellitus (T2DM) is a commonly observed complication associated with obesity. The effect of fibroblast growth factor 19 (FGF19), a promising therapeutic agent for metabolic disorders, on pancreatic β cells in obesity-associated T2DM remains poorly understood. Human pancreatic β cells were cultured with high glucose (HG) and palmitic acid (PA), followed by treatment with FGF19. The cell proliferation, apoptosis, and insulin secretion were evaluated by CCK-8, qRT-PCR, ELISA, flow cytometry, and western blotting. The expression of the insulin receptor substrate (IRS)/glucose transporter (GLUT) pathway was evaluated. The interaction between FGF19 and IRS1 was predicted using the STRING database and verified by co-immunoprecipitation and immunofluorescence. The regulatory effects of the IRS1/GLUT4 pathway on human pancreatic β cells were assessed by overexpressing IRS1 and silencing IRS1 and GLUT4. HG+PA treatment reduced the human pancreatic β cell proliferation and insulin secretion and promoted cell apoptosis. However, FGF19 treatment restored these alterations and significantly increased the expressions of IRS1, GLUT1, and GLUT4 in the IRS/GLUT pathway. Furthermore, FGF19 and IRS1 were found to interact. IRS1 overexpression partially promoted the proliferation of pancreatic β cells and insulin secretion through GLUT4. Additionally, the silencing of IRS1 or GLUT4 attenuated the therapeutic effects of FGF19. In conclusion, FGF19 partly promoted the proliferation and insulin secretion of human pancreatic β cells and inhibited apoptosis by upregulating the IRS1/GLUT4 pathway. These findings establish a theoretical framework for the clinical utilization of FGF19 in the treatment of obesity-associated T2DM.

Comparison of Immunohistochemical Expression of Calretinin, Map2, S-100 and Glut1 in Rectal Biopsies from Suspected Hirschsprung’s Disease

Background: This study aimed to compare the immunohistochemical expression of calretinin, Map2, S-100, and Glut1 in rectal biopsy samples from patients suspected of Hirschsprung’s disease (HD).Methods and Results: Rectal biopsy samples from 40 patients with suspected HD were analyzed using hematoxylin and eosin (H&amp;E) and immunohistochemistry (IHC). Immunohistochemical stains were assessed after previous routine histology interpretation, which was classified as “Positive or in favor for HD” and “Equivocal or negative for HD.” The staining patterns for calretinin, Map2, S-100, and Glut1 were analyzed regarding the following structures: lamina propria small nerve fibrils, submucosal small nerve fibrils,submucosal nerve fibers, and submucosal ganglia. The IHC stains for calretinin and Map2 were score-ranked as 0 – negative and 1 – positive. The IHC stain for S-100 was score-ranked as 0 – normal and 1 – hypertrophic. The IHC stain for Glut1 was ranked as 0 – normal perineural and 1 – conspicuous perineural accentuation Calretinin had 92% accuracy, the highest sensitivity (80%) and specificity (92.00%).Map2 also had the same accuracy as calretinin but lower sensitivity (46.67%). Regarding S-100 and Glut1, these two markers did not support a conclusive diagnosis. The accuracy for S-100 and Glut1 was 66.7% and 60%, respectively. Conclusion: Calretinin remains the currently most valuable single IHC marker in diagnosing difficult cases of HD.

The role of adhesion molecules in osteocalcin-induced effects on glucose and lipid metabolism in adipocytes

Recent findings suggest that uncarboxylated osteocalcin (GluOC) promotes glucose and lipid metabolism via its putative receptor GPRC6A; however, its direct effect on adipocytes remains elusive. In this study, we elucidated the effects of GluOC on adipocytes, with an emphasis on the role of cell adhesion molecules. We determined that GluOC promoted the expression of adipocyte adhesion molecule (ACAM) and its transcription factor Krüppel-like factor 4 and enhanced the cortical actin filament assembly, which ameliorated lipid droplet hypertrophy. Additionally, GluOC upregulated the expression of integrin αVβ3 and activation of focal adhesion kinase (FAK) and prevented insulin receptor substrate 1 (IRS1) degradation by inhibiting the ubiquitin–proteasome system via the FAK–PLC–PKC axis, which activated IRS1–Akt-mediated glucose transporter 4 (GLUT4) transport. Furthermore, we showed that GluOC elevated the expression of the insulin-independent glucose transporters GLUT1 and GLUT8, which facilitated insulin stimulation-independent glucose transport. The GluOC-induced activation of integrin αVβ3 signaling promoted microtubule assembly, which improved glucose and lipid metabolism via its involvement in intracellular vesicular transport. GluOC treatment also suppressed collagen type 1 formation, which might prevent adipose tissue fibrosis in obese individuals. Overall, our results imply that GluOC promotes glucose and lipid metabolism via ACAM, integrin αVβ3, and GLUT1 and 8 expression, directly affecting adipocytes.

Neoadjuvant Radiochemotherapy Alters the Immune and Metabolic Microenvironment in Oral Cancer-Analyses of CD68, CD163, TGF-β1, GLUT-1 and HIF-1α Expressions.

The first-line treatment of oral squamous cell carcinoma (OSCC) involves surgical tumor resection, followed by adjuvant radio(chemo)therapy (R(C)T) in advanced cases. Neoadjuvant radio- and/or chemotherapy has failed to show improved survival in OSCC. Recently, neoadjuvant immunotherapy has shown promising therapeutic efficacy in phase 2 trials. In this context, the addition of radio- and chemotherapy is being reconsidered. Therefore, a better understanding of the tumor-biologic effects of neoadjuvant RCT would be beneficial. The current study was conducted on a retrospective cohort of patients who received neoadjuvant RCT for the treatment of oral cancer. The aim of the study was to evaluate the influence of neoadjuvant RCT on the immunological tumor microenvironment (TME) and hypoxic and glucose metabolisms. A cohort of 45 OSSC tissue samples from patients were analyzed before and after RCT (total 50.4 Gy; 1.8 Gy 5× weekly; Cisplatin + 5-Fluorouracil). Immunohistochemistry for CD68, CD163, TGF-β, GLUT-1 and HIF-1α was performed using tissue microarrays and automated cell counting. Differences in expression before and after RCT and associations with histomorphological parameters (T-status, N-status) were assessed using the Mann-Whitney U test. Tumor resection specimens after neoadjuvant RCT showed a significant decrease in CD68 infiltration and a significant increase in CD163 cell density. The CD68/CD163 ratio was significantly lower after RCT, indicating a shift toward M2 polarization. The GLUT-1 and HIF-1α expressions were significantly lower after RCT. Larger tumors (T3/T4) showed a lower GLUT-1 expression. Other biomarkers were not associated with the T- and N-status. Neoadjuvant RCT with 50.4 Gy induced a shift toward the M2 polarization of macrophages in the TME. This change in immune composition is not favorable and may be prognostically negative and counteract immunotherapeutic approaches. In addition, the decreased expressions in GLUT-1 and HIF-1α indicate reductions in the glucose metabolism and hypoxic energy metabolism in response to "high dose" neoadjuvant RCT, which may be therapeutically desirable.

Regulation of myo-miR-24-3p on the Myogenesis and Fiber Type Transformation of Skeletal Muscle.

Skeletal muscle plays critical roles in providing a protein source and contributing to meat production. It is well known that microRNAs (miRNAs) exert important effects on various biological processes in muscle, including cell fate determination, muscle fiber morphology, and structure development. However, the role of miRNA in skeletal muscle development remains incompletely understood. In this study, we observed a critical miRNA, miR-24-3p, which exhibited higher expression levels in Tongcheng (obese-type) pigs compared to Landrace (lean-type) pigs. Furthermore, we found that miR-24-3p was highly expressed in the dorsal muscle of pigs and the quadriceps muscle of mice. Functionally, miR-24-3p was found to inhibit proliferation and promote differentiation in muscle cells. Additionally, miR-24-3p was shown to facilitate the conversion of slow muscle fibers to fast muscle fibers and influence the expression of GLUT4, a glucose transporter. Moreover, in a mouse model of skeletal muscle injury, we demonstrated that overexpression of miR-24-3p promoted rapid myogenesis and contributed to skeletal muscle regeneration. Furthermore, miR-24-3p was found to regulate the expression of target genes, including Nek4, Pim1, Nlk, Pskh1, and Mapk14. Collectively, our findings provide evidence that miR-24-3p plays a regulatory role in myogenesis and fiber type conversion. These findings contribute to our understanding of human muscle health and have implications for improving meat production traits in livestock.