Hippocampal gene expression profiling of a model of Alzheimer`s Disease upon treatment with the ACE inhibitor captopril
ABSTRACT: Extracellular senile plaques of amyloid beta (Abeta) are a pathological hallmark in brain of patients with Alzheimer`s Disease (AD). Abeta is generated by the amyloidogenic processing of the amyloid precursor protein (APP). Concomitant to Abeta load, AD brain is characterized by an increase in protein level and activity of the angiotensin-converting enzyme (ACE). ACE inhibitors are a widely used class of drugs with established benefits for patients with cardiovascular disease. However, the role of ACE and ACE inhibition in the development of Abeta plaques and the process of AD-related neurodegeneration is not clear since ACE was reported to degrade Abeta. To investigate the effect of ACE inhibition on AD-related pathomechanisms, we used Tg2576 mice with neuron-specific expression of APPSwe as AD model. From 12 months of age, substantial Abeta plaque load accumulates in the hippocampus of Tg2576 mice as a brain region, which is highly vulnerable to AD-related neurodegeneration. The effect of central ACE inhibition was studied by treatment of 12 month-old Tg2576 mice for six months with the brain penetrating ACE inhibitor captopril. At an age of 18 months, hippocampal gene expression profiling was performed of captopril-treated Tg2576 mice relative to untreated 18 month-old Tg2576 controls with high Abeta plaque load. As an additional control, we used 12 month-old Tg2576 mice with low Abeta plaque load. Whole genome microarray gene expression profiling revealed gene expression changes induced by the brain-penetrating ACE inhibitor captopril, which could reflect the neuro-regenerative potential of central ACE inhibition. Microarray gene expression profiling was performed of hippocampi isolated from aged, 18 month-old Tg2576 (APPSwe-transgenic) AD mice with high Abeta plaque load relative to age-matched Tg2576 mice, which were treated for 6 months with the centrally active ACE inhibitor captopril. Another study group consisted of 12 month-old Tg2576 mice with low Abeta plaque load. In total, three study groups were analyzed, i.e. (i) 18 month-old untreated Tg2576 mice with high Abeta plaque load, (ii) age-matched Tg2576 mice treated for 6 months with the brain-penetrating ACE inhibitor captopril (20 mg/kg body weight/day in drinking water), and (iii) untreated 12 month-old Tg2576 mice with low Abeta plaque load reflecting the time point when captopril treatment was initiated. Two biological replicates were made of each group, and total hippocampal RNA of four mice was pooled for one gene chip.
Project description:Microarray gene expression profiling of aorta genes of APOE-deficient mice receiving atherosclerosis treatment with the ACE inhibitor captopril. Hypercholesterolemic APOE-deficient mice were used as a standard model of atherosclerosis to study gene expression changes during atherosclerosis treatment with the ACE inhibitor captopril. Microarray analysis was performed of whole aortas isolated from captopril-treated APOE-deficient mice relative to untreated APOE-deficient mice with overt atherosclerosis, and nontransgenic control mice. Microarray gene expression profiling revealed that captopril-mediated atherosclerosis prevention involved inhibition of aorta-infiltrating immune cells such as pro-atherogenic T lymphocytes and macrophages. Experiment Overall Design: Microarray gene expression profiling was performed of whole aortas isolated from APOE-deficient mice with atherosclerosis relative to captopril-treated APOE-deficient mice, and nontransgenic control mice. Three study groups were analyzed, i.e. 8-months-old untreated APOE-deficient mice with overt atherosclerosis, age-matched APOE-deficient mice treated for 7 months with the angiotensin-converting enzyme (ACE) inhibitor, captopril (20 mg/kg in drinking water), and nontransgenic control C57BL/6J mice. Two biological replicates were made of each group, and total RNA of three aortas was pooled for one gene chip.
Project description:Evolution of glomerulonephritis (GN) to tubulointerstitial disease is a universal antecedent to the development of chronic kidney disease (CKD). There is also evidence that angiotensin converting enzyme (ACE) inhibition may attenuate the development of CKD in some forms of glomerulonephritis. We tested the role of ACE inhibition in a model of GN in which complement-dependent tubulointerstitial disease develops. GN was induced in C57BL/6 mice with intraperitoneal injections of horse spleen apoferritin (HSA) using lipopolysaccharide (LPS) as an adjuvant. Four groups of six animals were studied: saline-injected control mice treated with captopril or water, and GN mice treated with captopril or water. GN developed in all HSA-treated animals. In those receiving captopril, however, proteinuria (albumin/creatinine ratio) was significantly reduced by captopril treatment. Array screening was used to examined the expression of collagen-related genes and determine if these effects could be mediated by regulation of collagen genes. Six genes were identified for further analysis by quantitative RT-PCR. This model demonstrates that tubulointerstitial disease can be attenuated by ACE inhibition, with clinical, histologic, and gene expression measures. All protocols were approved by the Institutional Animal Care and Use Committee at SUNY Upstate Medical University. We employed four groups of six mice each: saline-injected control mice with and without captopril, and GN with and without captopril. C57BL/6 mice were purchased from The Jackson Laboratories (Bar Harbor, ME). Glomerulonephritis (GN) was induced by intraperitoneal (i.p.) injection of 10 mg of apoferritin from horse spleen (HSA, Sigma, St. Louis, MO) five days per week, with i.p. injection of 100 micrograms lipopolysaccharide (LPS, from Salmonella minnesota; EMD Biosciences, La Jolla, CA), as adjuvant, three times per week. Control animals received equal volumes of 0.15 M NaCl by i.p. injection. Injections were begun when the mice were approximately eight weeks of age and were continued for six weeks. Captopril, at 100 mg/kg/day was given in the drinking water. After 9 weeks, the animals were euthanized and kidneys were removed for RNA purification and analysis.
Project description:Microarray gene expression profiling of aorta genes of APOE-deficient mice receiving atherosclerosis treatment with the ACE inhibitor captopril. Hypercholesterolemic APOE-deficient mice were used as a standard model of atherosclerosis to study gene expression changes during atherosclerosis treatment with the ACE inhibitor captopril. Microarray analysis was performed of whole aortas isolated from captopril-treated APOE-deficient mice relative to untreated APOE-deficient mice with overt atherosclerosis, and nontransgenic control mice. Microarray gene expression profiling revealed that captopril-mediated atherosclerosis prevention involved inhibition of aorta-infiltrating immune cells such as pro-atherogenic T lymphocytes and macrophages. Overall design: Microarray gene expression profiling was performed of whole aortas isolated from APOE-deficient mice with atherosclerosis relative to captopril-treated APOE-deficient mice, and nontransgenic control mice. Three study groups were analyzed, i.e. 8-months-old untreated APOE-deficient mice with overt atherosclerosis, age-matched APOE-deficient mice treated for 7 months with the angiotensin-converting enzyme (ACE) inhibitor, captopril (20 mg/kg in drinking water), and nontransgenic control C57BL/6J mice. Two biological replicates were made of each group, and total RNA of three aortas was pooled for one gene chip.
Project description:Characterizing the detergent insoluble brain proteome of sporadic late-onset Alzheimer’s disease (LOAD) has identified proteins and pathways associated with disease pathogenesis. Similar studies in early onset Alzheimer’s disease cases due to presenilin-1 mutations (PS1-EOAD), along with more detailed correlations with insoluble proteomes from LOAD and AD transgenic rodents, are limited. We therefore utilized quantitative proteomics to identify proteins that were significantly changing in the PS1-EOAD insoluble proteome versus controls. Comparison with the LOAD insoluble proteome identified common pathologic AD markers in addition to unique PS1-EOAD insoluble proteins. Similarly, weighted correlation network analysis (WGCNA) identified PS1-EOAD and LOAD co-expression modules with both like and disparate expression levels. Finally, we compared the human PS1-EOAD insoluble proteome to transgenic AD mouse and rat insoluble proteomes to understand how well these models mimic the human disease. Although many common AD pathologic findings were found in the rodents, there were multiple PS1-EOAD proteome changes not well recapitulated in the animal models. These proteomic studies highlight unique PS1-EOAD proteome changes as compared to LOAD and identify limitations to using AD transgenic rodents to study some aspects of AD.
Project description:GFAP and vimentin deficiency alters gene expression in astrocytes and microglia in wild-type mice and changes the transcriptional response of reactive glia in mouse model for Alzheimer's disease. Reactive astrocytes with an increased expression of intermediate filament (IF) proteins Glial Fibrillary Acidic Protein (GFAP) and Vimentin (VIM) surround amyloid plaques in Alzheimer's disease (AD). The functional consequences of this upregulation are unclear. To identify molecular pathways coupled to IF regulation in reactive astrocytes, and to study the interaction with microglia, we examined WT and APPswe/PS1dE9 (AD) mice lacking either GFAP, or both VIM and GFAP, and determined the transcriptome of cortical astrocytes and microglia from 15- to 18-month-old mice. Genes involved in lysosomal degradation (including several cathepsins) and in inflammatory response (including Cxcl5, Tlr6, Tnf, Il1b) exhibited a higher AD-induced increase when GFAP, or VIM and GFAP, were absent. The expression of Aqp4 and Gja1 displayed the same pattern. The downregulation of neuronal support genes in astrocytes from AD mice was absent in GFAP/VIM null mice. In contrast, the absence of IFs did not affect the transcriptional alterations induced by AD in microglia, nor was the cortical plaque load altered. Visualizing astrocyte morphology in GFAP-eGFP mice showed no clear structural differences in GFAP/VIM null mice, but did show diminished interaction of astrocyte processes with plaques. Microglial proliferation increased similarly in all AD groups. In conclusion, absence of GFAP, or both GFAP and VIM, alters AD-induced changes in gene expression profile of astrocytes, showing a compensation of the decrease of neuronal support genes and a trend for a slightly higher inflammatory expression profile. However, this has no consequences for the development of plaque load, microglial proliferation, or microglial activation. 2 cell types from 6 conditions: cortical microglia and cortical astrocytes from 15-18 month old APPswe/PS1dE9 mice compared to wildtype littermates. Biological replicates: microglia from APPswe/PS1dE9, N=7, microglia from WT, N=7, astrocytes from APPswe/PS1dE9, N=4, microglia from WT, N=4
Project description:Oligomeric forms of amyloid-beta peptide (Abeta) are presumed to play a pivotal role in the pathogenesis of Alzheimer’s disease (AD). However, it is still unclear how Abeta oligomers contribute to AD pathogenesis in patient neural cells. We generated induced pluripotent stem cells (iPSCs) from a familial AD patient and differentiated them into neural cells. Abeta oligomers were accumulated in neural cells of AD bearing amyloid precursor protein (APP)-E693delta mutation. To uncover Abeta oligomers in AD(APP-E693delta) neural cells, we analyzed gene expression profiles of control and the AD neural cells Overall design: comparison between control (n=3) and AD (n=3)
Project description:Our previous work in a Drosophila model of Alzheimer's disease (AD) has shown that we can intervene into the pathways to slow or prevent AD progression. Lithium was able to rescue toxicity in the Drosophila AD model which corresponded with a reduction in Abeta levels. Furthermore, we have demonstrated that Lithium affects Abeta protein translation. To this end, we were interested in studying the effect of Lithium on Abeta using microarray analyses, to determine if we could uncover any interesting downstream pathways. Flies were expressing a mutant version of Abeta, the Arctic mutation, which increases the aggregation or production of Abeta (UAS-ArcAb42/+;elavGS/+). We collected flies 2 days post eclosion that either had no Arctic Abeta protein, or expressed Arctic with or without Lithium treatment for 17 days post eclosion. Samples were homogenised using RLT buffer with betamercaptoethanol.
Project description:Attempt to identify genes whose expression changed in the kidney cortex with angiotensin converting enzyme inhibition. Eleven week-old male C57BL6 mice were treated with captopril at 10mg/kg/day in drinking water for 7 days. The kidney cortex was surgically excised and total RNA was isolated using Trizol (Invitrogen) from three treated and three control mice and was further purified using RNeasy MinElute Cleanup spin columns (Qiagen) according to manufacturer’s instructions. Probes generated from the resulting RNA were hybridized to Illumina Expression BeadChips (mouseWG-6_V2).
Project description:Olfaction is often deregulated in Alzheimer´s disease (AD) patients, being also impaired in transgenic Tg2576 AD mouse model, which overexpress the Swedish mutated form of human amyloid precursor protein (APP). However, little is known about the molecular mechanisms that accompany the neurodegeneration of olfactory structures in Tg2576 mice. For that, we have applied proteome- and transcriptome-wide approaches to probe molecular disturbances in the olfactory bulb (OB) dissected from aged Tg2576 mice (18 months of age) respect to age matched wild-type (WT) littermates. Overall design: Olfactory bulbs from 3 WT mice vs olfactory bulbs from 3 Tg2576 transgenic mice
Project description:Abnormal metal accumulation is associated with Alzheimer’s disease (AD) and has a relevant role in affecting amyloid beta-peptide (Abeta) aggregation and neurotoxicity.In the present study, employing a microarray analysis of 35,129 genes, we analyzed gene expression profile changes due to exposure to Abeta-Zn or Abeta-Cu complexes in neuronal-like cells (SH-SY5Y). Microarray data indicated that Abeta-Zn or Abeta-Cu complexes selectively alter expression of genes mainly related to cell death, inflammatory responses, and apoptosis.Taken together these findings indicate that Abeta-Zn or Abeta-Cu show some commonalities in affecting AD-related target functions. The overall modulatory activity on these genes supports the idea of a possible net result leading to mechanisms that counteract toxic effects of Abeta-Zn or Abeta-Cu. Overall design: Analysis used a neuronal cell lines, the SH-SY5Y, exposed to either AB, the AB-Cu or AB-Zn complex or Cu or Zn alone. The SH-SY5Y without treatment were used that a control. For the exposure to AB, six replicates were performed (three dye swap and three non-dye swap), while for exposure to AB-Cu, AB-Zn, Zn and Cu two replicates each were made (one dye swap and one non-dye swap).