Effect of hIAPP aggregation on gene expression by mouse bone marrow-derived macrophages after 12 hours
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE23534 | GEO | 2010/08/11
SECONDARY ACCESSION(S): PRJNA131753
REPOSITORIES: GEO
Similar Datasets
Project description:The purpose of this experiment was to determine changes in gene expression by bone marrow-derived macrophages (BMDMs) treated with synthetic human vs. rodent islet amyloid polypeptide (IAPP). Synthetic human IAPP at 15 uM aggregates to form fibrils in vitro, whereas rodent IAPP is non-amyloidogenic. We hypothesized that interaction of macrophages with human IAPP aggregates can activate pro-inflammatory signalling pathways in macrophages, as described for other amyloidogenic peptides. This array includes eight samples from one experiment, with two groups of four replicates each. Each replicate represents BMDMs from one well of a 24-well plate. The control group was treated with 15 uM rat IAPP for 12 hours prior to total RNA extraction; the experimental group was treated with 15 uM human IAPP.
2010-08-11 | E-GEOD-23534 | biostudies-arrayexpress
Project description:The islet amyloid polypeptide (IAPP), a pancreas-produced peptide, has beneficial functions in its monomeric form. However, IAPP aggregates, related to type 2 diabetes mellitus (T2DM), are toxic not only for the pancreas, but also for the brain. In the latter, IAPP is often found in vessels, where it is highly toxic for pericytes, cells that have contractile properties and regulate capillary blood flow. The aim of this study is to assess whether IAPP oligomers alter the morphology and contractility of pericytes using an in vitro brain vasculature model and evaluate the association between IAPP and capillary contraction in human brain tissue.
2023-03-11 | PXD035048 | Pride
Project description:Complement inhibitor C4b-binding protein (C4BP) is synthesized in liver and pancreas and composed of 7 identical alpha chains and one unique beta chain. We showed previously that C4BP binds islet amyloid polypeptide (IAPP) and affects fibril formation in vitro. Now we found that polymeric C4BP inhibited lysis of human erythrocytes incubated with monomeric IAPP while no erythrocyte lysis was observed after incubation with preformed IAPP fibrils. In contrast, monomeric alpha chain of C4BP had significantly reduced activity. Further, addition of monomeric IAPP to a rat insulinoma cell line (INS-1) resulted in decreased cell viability, which was restored in the presence of physiological concentrations of C4BP. Accordingly, addition of C4BP rescued the ability of INS-1 cells and isolated rat islets to respond to glucose stimulation with insulin secretion, which was impaired in the presence of IAPP alone. C4BP was internalized together with IAPP into INS-1 cells and therefore we aimed to study its effect on gene expression. Pathway analyses of mRNA expression microarray data indicated that cells exposed to C4BP and IAPP in comparison to IAPP alone increased expression of genes involved in cholesterol synthesis. Depletion of cholesterol through methyl-β-cyclodextrin or cholesterol oxidase abolished the protective effect of C4BP on IAPP cytotoxicity of INS-1 cells. Also, inhibition of phosphoinositide 3-kinase but not NF-κB had a similar effect. Taken together, one of the mechanisms by which C4BP protects beta-cells from IAPP cytotoxicity is by enhancing cholesterol synthesis. The INS-1 cells were grown as 5 separate clones for 10 passages before plating in a 12-well plate (Nunc) at 100.000 cells per well and grown in complete RPMI 1640 medium to 70% confluency for approximately 48 h. The cells were then challenged by adding 77 μM monomeric IAPP alone or together with C4BP (0.6 μM). DMSO (1%) used as solvent for IAPP as well as C4BP (0.6 μM) alone were used as controls. RNA was extracted after 10h incubation and analysis carried out using Rat Gene 2.0 array chip (Affymetrix).
2016-08-25 | E-GEOD-79224 | biostudies-arrayexpress
Project description:Complement inhibitor C4b-binding protein (C4BP) is synthesized in liver and pancreas and composed of 7 identical alpha chains and one unique beta chain. We showed previously that C4BP binds islet amyloid polypeptide (IAPP) and affects fibril formation in vitro. Now we found that polymeric C4BP inhibited lysis of human erythrocytes incubated with monomeric IAPP while no erythrocyte lysis was observed after incubation with preformed IAPP fibrils. In contrast, monomeric alpha chain of C4BP had significantly reduced activity. Further, addition of monomeric IAPP to a rat insulinoma cell line (INS-1) resulted in decreased cell viability, which was restored in the presence of physiological concentrations of C4BP. Accordingly, addition of C4BP rescued the ability of INS-1 cells and isolated rat islets to respond to glucose stimulation with insulin secretion, which was impaired in the presence of IAPP alone. C4BP was internalized together with IAPP into INS-1 cells and therefore we aimed to study its effect on gene expression. Pathway analyses of mRNA expression microarray data indicated that cells exposed to C4BP and IAPP in comparison to IAPP alone increased expression of genes involved in cholesterol synthesis. Depletion of cholesterol through methyl-β-cyclodextrin or cholesterol oxidase abolished the protective effect of C4BP on IAPP cytotoxicity of INS-1 cells. Also, inhibition of phosphoinositide 3-kinase but not NF-κB had a similar effect. Taken together, one of the mechanisms by which C4BP protects beta-cells from IAPP cytotoxicity is by enhancing cholesterol synthesis.
2016-08-25 | GSE79224 | GEO
Project description:Islet amyloid polypeptide (IAPP) is the main component of amyloid deposits in type 2 diabetic patients. Cells overexpressing the human transcript of IAPP (hIAPP) present defects in insulin secretion. In this dataset, we include the expression data obtained from the rat pancreatic beta-cells INS1E stably transfected with human (hIAPP) or rat (rIAPP) IAPP, which lead to the overexpression of the different variants of IAPP protein. We also include INS1E cells with empty vector as control. 6 samples were analyzed from 3 INS1E clones stably transfected with different IAPP transcripts.
2014-10-03 | E-GEOD-57573 | biostudies-arrayexpress
Project description:Amyloidogenic proteins, characterized by their ability to form fibrillar aggregates with β sheet structure play an important role in several degenerative diseases, including Parkinson’s disease. Numerous amyloidogenic proteins, such as α synuclein, are intrinsically disordered (or contain ID regions, hence they also present as highly dynamic conformational ensembles in these regions. Aggregation is an inherent property of the polypeptide chains and under non physiological, appropriate conditions most of the proteins can aggregate and form polymers of various structures. Since amyloid fib ril s and oligomers are associated with a great variety of human diseases, inhibition of protein aggregation has great importance and it can be addressed by using small molecules, peptides or proteins. Our research aim was to study the potential application of modified forms of different amyloidogenic proteins as inhibitor molecules by introducing structural constraints in them. Under various conditions, different amyloidogenic proteins’ (α-synuclein and β2-microglobulin) monomer molecules have been cross linked intramolecularly and the heterogeneous mixtures has been fractionated by HPLC. The inhibitory potential of the isolated and effective molecules has been experimentally investigated by various methods ThT assay, TEM, CD spectroscopy). Furthermore, the locations of the crosslinks in the molecules were determined by mass spectrometry, and their structures are modeled in silico. Our results revealed that conformational constrains applied by cross linking on amyloidogenic proteins block their amyloid formation. Moreover, these molecules exhibited inhibitory effect on the aggregation of the unmodified proteins, as well.
2023-10-24 | PXD042501 | Pride
Project description:Islet amyloid polypeptide (IAPP) is the main component of amyloid deposits in type 2 diabetic patients. Cells overexpressing the human transcript of IAPP (hIAPP) present defects in insulin secretion. In this dataset, we include the expression data obtained from the rat pancreatic beta-cells INS1E stably transfected with human (hIAPP) or rat (rIAPP) IAPP, which lead to the overexpression of the different variants of IAPP protein. We also include INS1E cells with empty vector as control.
2014-10-03 | GSE57573 | GEO
Project description:The islet in type 2 diabetes (T2D) is characterized by amyloid deposits derived from islet amyloid polypeptide (IAPP), a protein co-expressed with insulin by β-cells. In common with amyloidogenic proteins implicated in neurodegeneration, human IAPP (hIAPP) forms membrane permeant toxic oligomers implicated in misfolded protein stress. Here, we establish that hIAPP misfolded protein stress activates HIF1α/PFKFB3 signaling, this increases glycolysis disengaged from oxidative phosphorylation with mitochondrial fragmentation and perinuclear clustering, considered a protective posture against increased cytosolic Ca2+ characteristic of toxic oligomer stress. In contrast to tissues with the capacity to regenerate, β-cells in adult humans are minimally replicative, and therefore fail to execute the second pro-regenerative phase of the HIF1α/PFKFB3 injury pathway. Instead, β-cells in T2D remain trapped in the pro-survival first phase of the HIF1α injury repair response with metabolism and the mitochondrial network adapted to slow the rate of cell attrition at the expense of β-cell function.
2020-04-17 | MTBLS951 | MetaboLights
Project description:Amyloidogenic peptides are therapeutic in EAE, reducing systemic levels of IL6, TNF, and INFg. The fibrils are bound and endocytosed in peritoneal MFs and B1a cells. Differential gene expression was used to further understand the process.
2015-09-15 | GSE73026 | GEO
Project description:Islet transplantation for treatment of diabetes is limited by availability of donor islets and requirements for immunosuppression. Stem cell-derived islets might circumvent these issues. SC-islets effectively control glucose metabolism post transplantation, but do not yet achieve full function in vitro with currently published differentiation protocols. We aimed to identify markers of mature subpopulations of SC-β cells by studying transcriptional changes associated with in vivo maturation of SC-β cells using RNA-seq and co-expression network analysis. The β cell-specific hormone islet amyloid polypeptide (IAPP) emerged as the top candidate to be such a marker. IAPP+ cells had more mature β cell gene expression and higher cellular insulin content than IAPP- cells in vitro. IAPP+ INS+ cells were more stable in long-term culture than IAPP- INS+ cells and retained insulin expression after transplantation into mice. Finally, we conducted a small molecule screen to identify compounds that enhance IAPP expression. Aconitine up-regulated IAPP and could help to optimize differentiation protocols.
2024-04-15 | GSE263366 | GEO