Project description:free fatty acids(palmitate, oleate, linoleate) 0.7mM and tnf-alpha (0 20,100 ng/ml) were subjected to HepG2 cell line to study the cytotoxicity induced by these two factors Keywords: stress response
Project description:The regulation of complex cellular activities in palmitate treated HepG2 cells, and the ensuing cytotoxic phenotype, involves cooperative interactions between genes. While previous approaches have largely focused on identifying individual target genes, elucidating interacting genes has thus far remained elusive. We applied the concept of information synergy to reconstruct a ?gene-cooperativity? network for palmititate-induced cytotoxicity in liver cells. Our approach integrated gene expression data with metabolic profiles to select a subset of genes for network reconstruction. Subsequent analysis of the network revealed insulin signaling as the most significantly enriched pathway, and desmoplakin (DSP) as its top neighbor. We determined that palmitate significantly reduces DSP expression, and treatment with insulin restores the lost expression of DSP. Insulin resistance is a common pathological feature of fatty liver and related ailments, whereas loss of DSP has been noted in liver carcinoma. Reduced DSP expression can lead to loss of cell-cell adhesion via desmosomes, and disrupt the keratin intermediate filament network. Our findings suggest that DSP expression may be perturbed by palmitate and, along with insulin resistance, may play a role in palmitate induced cytotoxicity, and serve as potential targets for further studies on non-alcoholic fatty liver disease (NAFLD). free fatty acids(palmitate, oleate, linoleate) 0.7mM and tnf-alpha (0 20,100 ng/ml) were subjected to HepG2 cell line to study the cytotoxicity induced by these two factors. control(Hepg2 medium and BSA medium) treatment(combinations of TNFa+FFAs) two biological replicates for each condition, color swap for each sample
Project description:We report the transcriptome of human endothelial cells (cell line: TIME) after supplementation with polyunsaturated fatty acids (PUFA) and/or stimulation with pro-inflammatory cytokines. The fatty acids docosahexaenoic acid (DHA, C22:6n3) or arachidonic acid (AA, C20:4n6) were included in the culture medium in concentrations of 15 µmol/L using ethanol as a vehicle (0.2 % v/v final ethanol concentration). Cells were cultured in the enriched media totaling 144 h. Stimulation of cells was performed in the last 24 h of fatty acid supplementation by addition of the cytokines IL-1β, TNF-α, and IFN-γ each in a concentration of 5 ng/ml.
Project description:Effect of TNF-alpha on microRNAs levels in Human Umbilical Endothelial Cells (HUVECs). HUVEC that were treated or not for 2 or 24 hours with TNF (10 ng/ml). Duplicate samples (1 or 2) of two different isolations of HUVEC (A or B)
Project description:TNF-alpha has a number of pro-atherogenic effects in macrovascular endothelial cells, including induction of leukocyte adhesion molecules and chemokines. We investigated the role of acyl-CoA synthetase 3 (ACSL3) in the response of cultured human macrovascular endothelial cells to TNF-alpha. TNF-alpha induced ACSL3 both in human umbilical vein endothelial cells (HUVECs) and in human coronary artery endothelial cells (HCAECs). RNA sequencing demonstrated that knockdown of ACSL3 had no marked effects on the TNF-alpha transcriptome in HCAECs. Instead, ACSL3 was required for TNF-alpha-induced lipid droplet formation from fatty acids.
Project description:Maternal obesity during pregnancy leads to a pro-inflammatory milieu in the placenta. We conducted a global transcriptomic profiling in BeWo cells following palmitic acid (PA, 500 uM) and/or TNF-alpha (10 ng/ml) treatment for 24 h. Microarray analysis revealed that placental cytotrophoblasts increased expression of genes related to inflammation, stress response and immediate-early factors in response to plamitic acid, TNF-alpha or a combination of both. Our results suggest that fatty acids and inflammatory cytokines induce inflammation in placental cells via activation of JNK-Egr-1 signaling. global transcriptomic profiling in BeWo cells following palmitic acid (PA, 500 uM) and/or TNF-alpha (10 ng/ml) treatment for 24 h
Project description:The response of HepG2-SF cells exposed to 100 µM fatty acids during 7 days was investigated using stable isotope labeling by amino acids in cell culture (SILAC) for analysis of the full proteome
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.