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:Hyperglycemia-mediated cardiac dysfunction is an acute initiator in the development of vascular complications, leading to cardiac fibrosis. To investigate the effects of hyperglycemia-mediated changes in cardiomyocytes, cells were cultured in-vitro under normoglycemic (5 mM or 25 mM D-glucose) and hyperglycemic (5 → 50 mM or 25 → 50 mM D-glucose) conditions, respectively. After 24-hours of hyperglycemic exposure, cells were collected for RNA-sequencing (RNA-seq) studies to further investigate the differentially expressed genes (DEG) related to inflammation and fibrosis in samples cultured under hyperglycemic-in comparison with normoglycemic-conditions. Western Blotting was done to evaluate the protein expression of YAP1/TAZ under hyperglycemia induced stress conditions, as it is known to be involved in fibrotic and vascular inflammatory-mediated conditions. RNA-seq revealed the DEG of multiple targets including matrix metalloproteinases and inflammatory mediators, whose expression was significantly altered in the 5 → 50 mM in comparison with the 25 → 50 mM condition. Western Blotting showed a significant upregulation of the protein expression of the YAP1/TAZ pathway under these conditions as well (5 → 50 mM). To further probe the relationship between the inflammatory extracellular-signal-regulated kinase (ERK 1/2) and its downstream effects on YAP1/TAZ expression we studied the effect of inhibition of the ERK 1/2 signaling cascade in the 5 → 50 mM condition. The application of an ERK 1/2 inhibitor inhibited the expression of the YAP1/TAZ protein in the 5 → 50 mM condition, and this strategy may be useful in preventing and improving hyperglycemia associated cardiovascular damage and inflammation.