Project description:Objective was to examine acute gene expression responses to physiologic oral glucose ingestion in human circulating leukocytes. Microarray study of human circulating leukocytes sampled before, 1 hour after and 2 hours after glucose ingestion was performed. The present study demonstrated 36 genes which showed acute gene expression change in human leukocytes within 1 hour after glucose ingestion and suggest that leukocytes participate in the inflammatory process induced by acute hyperglycemia. Microarray study of human circulating leukocytes sampled before, 1 hour after and 2 hours after glucose ingestion
Project description:Objective was to examine acute gene expression responses to physiologic oral glucose ingestion in human circulating leukocytes. Microarray study of human circulating leukocytes sampled before, 1 hour after and 2 hours after glucose ingestion was performed. The present study demonstrated 36 genes which showed acute gene expression change in human leukocytes within 1 hour after glucose ingestion and suggest that leukocytes participate in the inflammatory process induced by acute hyperglycemia.
Project description:Neutrophils play an active role in acute and chronic inflammation by exhibiting functional heterogeneity. Besides beneficial role in acute infections to eliminate pathogens, neutrophils also contribute to pathogenesis of diseases associated with sterile inflammation including vascular disorders, autoimmune diseases, Type 2 diabetes (T2D) and cancers. During T2D, hyperglycemia constitutively activate neutrophils. In the context of T2D associated complications, we examined influence of high glucose, homocysteine and LPS representing effector molecules of hyperglycemia, thrombosis, and infection respectively on human neutrophil activation to identify distinct signaling pathways by quantitative phosphoproteomics approach.
Project description:Skeletal muscle of insulin resistant individuals is characterized by lower fasting lipid oxidation and reduced ability to switch between lipid and glucose oxidation. The purpose of the present study was to examine if impaired metabolic switching could be induced by chronic hyperglycemia. Human myotubes were treated with or without chronic hyperglycemia (HG) (20 mmol/l glucose for 4 days), and the metabolism of [14C]oleic acid (OA) and [14C]glucose was studied. Acute glucose (5mmol/l) suppressed OA oxidation by 50% in normoglycemic (NG) (5.5 mmol/l glucose) cells. Myotubes exposed to chronic hyperglycemia showed a significantly reduced OA uptake and oxidation to CO2, whereas acid-soluble metabolites were increased. Glucose suppressibility, the ability of acute glucose to suppress lipid oxidation, was significantly reduced to 21%, while adaptability, the capacity to increase lipid oxidation with increasing fatty acid availability, was unaffected. Glucose uptake and oxidation was significantly reduced by about 40%. Substrate oxidation in presence of mitochondrial uncouplers showed that net and maximal oxidative capacities were significantly reduced after hyperglycemia, and the concentration of ATP was reduced by 25%. However, none of the measured mitochondrial genes were downregulated nor was mitochondrial content. Microarray showed that no genes were significantly regulated by chronic hyperglycemia. Addition of chronic lactate reduced both glucose and OA oxidation to the same extent as hyperglycemia, and this effect was specific for lactate. In conclusions, chronic hyperglycemia reduced substrate oxidation in skeletal muscle cells and impaired the metabolic switching. The effect is most likely due to an induced mitochondrial dysfunction.
Project description:Diabetes is associated with a more aggressive form of atherosclerosis. Thrombospondin-1 (TSP-1), an extracellular matrix protein, is an acute phase reactant that induces vascular smooth muscle (VSMC) migration and proliferation in areas of vascular injury, and is also upregulated in VSMCs exposed to hyperglycemia. We hypothesized that hyperglycemia amplifies the expression of genes induced by TSP-1 in VSMCs. Human aortic VSMCs were cultured in DMEM supplemented with 10 % FBS and 1% antibiotics, cells were used between passages three and five. VSMCs were preincubated in DMEM containing 0.2% FBS with 5 mM glucose (normoglycemia), 25 mM glucose (hyperglycemia), 25 mM mannose (osmotic control), TSP-1 (20µg/mL), 25 mM glucose + TSP-1 (20µg/mL) or 25 mM mannose + TSP-1 (20µg/mL). Data analysis revealed that TSP-1 stimulates gene expression relevant to the pathogenesis of atherosclerosis and diabetic vascular disease. Total RNA was extracted from replicate cultures of human aortic VSMCs and microarray analysis performed for a total of 18 samples (3 replicates per condition) using the Human Gene Array ST.
Project description:Diabetes is associated with a more aggressive form of atherosclerosis. Thrombospondin-1 (TSP-1), an extracellular matrix protein, is an acute phase reactant that induces vascular smooth muscle (VSMC) migration and proliferation in areas of vascular injury, and is also upregulated in VSMCs exposed to hyperglycemia. We hypothesized that hyperglycemia amplifies the expression of genes induced by TSP-1 in VSMCs. Human aortic VSMCs were cultured in DMEM supplemented with 10 % FBS and 1% antibiotics, cells were used between passages three and five. VSMCs were preincubated in DMEM containing 0.2% FBS with 5 mM glucose (normoglycemia), 25 mM glucose (hyperglycemia), 25 mM mannose (osmotic control), TSP-1 (20µg/mL), 25 mM glucose + TSP-1 (20µg/mL) or 25 mM mannose + TSP-1 (20µg/mL). Data analysis revealed that TSP-1 stimulates gene expression relevant to the pathogenesis of atherosclerosis and diabetic vascular disease.
Project description:Acute liver failure is a serious clinical manifestation resulting from sudden liver injury, which can be triggered by various factors. One of the most frequent causes of acute liver failure is excessive ingestion of acetaminophen (APAP), which is known to damage hepatocytes directly by reducing glutathione levels in cells, ultimately leading to hepatocyte death.PGE2 can play a dual role in inflammation, either promoting or inhibiting the inflammatory response, depending on the cell type, local concentration, receptor type, and tissue microenvironment. Early studies have shown that PGE2 significantly alleviated acute liver failure induced by galactosamine/lipopolysaccharide, APAP, and carbon tetrachloride. However, the precise mechanism by which PGE2 alleviates APAP-induced acute liver failure remains unclear. The aim of this study is to investigate the mechanisms underlying the protective effects of PGE2 against APAP-induced hepatocyte injury.
Project description:Acute liver failure is a serious clinical manifestation resulting from sudden liver injury, which can be triggered by various factors. One of the most frequent causes of acute liver failure is excessive ingestion of acetaminophen (APAP), which is known to damage hepatocytes directly by reducing glutathione levels in cells, ultimately leading to hepatocyte death.PGE2 can play a dual role in inflammation, either promoting or inhibiting the inflammatory response, depending on the cell type, local concentration, receptor type, and tissue microenvironment. Early studies have shown that PGE2 significantly alleviated acute liver failure induced by galactosamine/lipopolysaccharide, APAP, and carbon tetrachloride. However, the precise mechanism by which PGE2 alleviates APAP-induced acute liver failure remains unclear. The aim of this study is to investigate the mechanisms underlying the protective effects of PGE2 against APAP-induced hepatocyte injury.
Project description:Acute liver failure is a serious clinical manifestation resulting from sudden liver injury, which can be triggered by various factors. One of the most frequent causes of acute liver failure is excessive ingestion of acetaminophen (APAP), which is known to damage hepatocytes directly by reducing glutathione levels in cells, ultimately leading to hepatocyte death.PGE2 can play a dual role in inflammation, either promoting or inhibiting the inflammatory response, depending on the cell type, local concentration, receptor type, and tissue microenvironment. Early studies have shown that PGE2 significantly alleviated acute liver failure induced by galactosamine/lipopolysaccharide, APAP, and carbon tetrachloride. However, the precise mechanism by which PGE2 alleviates APAP-induced acute liver failure remains unclear. The aim of this study is to investigate the mechanisms underlying the protective effects of PGE2 against APAP-induced hepatocyte injury.
Project description:Salmonella causes inflammation in infected hosts. Inflammation is a well-characterized defensive mechanism of innate immunity. The recognition and engagement of lipopolysaccharide (LPS) endotoxins in the outer membranes of Salmonella to Toll-like receptor 4 of immune cells (macrophages and dendritic cells) trigger inflammatory responses characterized by secretion of pro-inflammatory cytokines, including TNF-beta, IL-1 and IL-6. These cytokines cause fever, anorexia, bodyweight losses, and catabolism of skeletal muscles and adipose tissues. However, molecular events underlying innate immune responses and metabolic activities during the later stage of inflammation are poorly understood. Additionally, the effects of prebiotics and antibiotics on innate immunity and nutrient metabolism are not yet reported. The objective of this study is to investigate the effects of a mannanoligosaccharide (MOS) prebiotic and virginiamycin (VIRG) sub-therapeutic antibiotic on innate immunity and glucose metabolism during late inflammation. We induced Salmonella LPS-systemic inflammation in a chicken model. Differentially regulated gene expressions were measured using 2 colour focussed oligonucleotide chicken-specific microarrays. Microarray analysis was performed on liver, intestinal and skeletal muscle tissues. We found that late inflammation was principally modulated by interleukin 3 (IL 3) and that glucose was mobilized from gluconeogenesis occurring in the intestines only. MOS and VIRG modulated innate immunity and metabolic genes differently. In contrast to VIRG, MOS terminated inflammatory responses earlier. Our results indicate IL 3 gene up-regulation in VIRG-fed chickens. To meet the higher energy requirements of VIRG chickens, genes for intestinal gluconeogenesis and liver glycolysis were respectively induced. Our study reveals the potential mechanisms by which prebiotic and antibiotic modulated innate immunity and glucose metabolism during late inflammation. 14-day old chickens were injected i.p. with saline or LPS. For each tissue and experimental conditions (saline or LPS challenge), a total of 12 microarrays (6 MOS birds + 6 VIRG birds) were used in a 2 x 2 factorial design and complete interwoven loop arrangement. We compared gene expression from prebiotic-fed birds with antibiotic-fed birds without including reference RNA. LPS challenge, antibiotic or prebiotic, innate immunity, glucose metabolism