| 1. |
- Hägg, Daniel, 1974, et al.
(författare)
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Expression profiling of macrophages from subjects with atherosclerosis to identify novel susceptibility genes.
- 2008
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Ingår i: International journal of molecular medicine. - 1107-3756 .- 1791-244X. ; 21:6, s. 697-704
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Tidskriftsartikel (refereegranskat)abstract
- Although a number of environmental risk factors for atherosclerosis have been identified, heredity seems to be a significant independent risk factor. The aim of our study was to identify novel susceptibility genes for atherosclerosis. The screening process consisted of three steps. First, expression profiles of macrophages from subjects with atherosclerosis were compared to macrophages from control subjects. Secondly, the subjects were genotyped for promoter region polymorphisms in genes with altered gene expression. Thirdly, a population of subjects with coronary heart disease and control subjects were genotyped to test for an association with identified polymorphisms that affected gene expression. Twenty-seven genes were differentially expressed in both macrophages and foam cells from subjects with atherosclerosis. Three of these genes, IRS2, CD86 and SLC11A1 were selected for further analysis. Foam cells from subjects homozygous for the C allele at the -765C-->T SNP located in the promoter region of IRS2 had increased gene expression compared to foam cells from subjects with the nonCC genotype. Also, macrophages and foam cells from subjects homozygous for allele 2 at a repeat element in the promoter region of SLC11A1 had increased gene expression compared to macrophages and foam cells from subjects with the non22 genotype. Genotyping of 512 pairs of subjects with coronary heart disease (CHD) and matched controls revealed that subjects homozygous for C of the IRS2 SNP had an increased risk for CHD; odds ratio 1.43, p=0.010. Immunohistochemical staining of human carotid plaques showed that IRS2 expression was localised to macrophages and endothelial cells in vivo. Our method provides a reliable approach for identifying susceptibility genes for atherosclerosis, and we conclude that elevated IRS2 gene expression in macrophages may be associated with an increased risk of CHD.
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| 2. |
- Rönnbäck, Annica, et al.
(författare)
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Gene expression profiling of the rat hippocampus one month after focal cerebral ischemia followed by enriched environment
- 2005
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 385:2, s. 173-178
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Tidskriftsartikel (refereegranskat)abstract
- Functional recovery after experimental stroke in rats is enhanced by environmental enrichment by stimulating plastic changes in brain regions outside the lesion, but the molecular mechanisms are not known. We investigated the effect of environmental enrichment after focal cerebral ischemia on cognitive recovery and hippocampal gene expression using microarray analysis. Rats placed in enriched environment (EE) for 1 month after middle cerebral artery occlusion (MCAo) showed significantly improved spatial memory in the Morris water maze compared to rats housed alone after MCAo. Microarray analysis suggested several EE-induced differences in neuronal plasticity-related genes, but these changes could not be confirmed by quantitative real-time PCR. This study highlights some of the potential problems associated with gene expression profiling of brain tissues. Further studies at earlier time points and in additional subregions of the brain are of interest in the search for molecular mechanisms behind EE-induced neuronal plasticity after ischemic stroke.
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| 3. |
- Svensson, Per Anders, 1959, et al.
(författare)
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Identification of genes predominantly expressed in human macrophages
- 2004
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Ingår i: Atherosclerosis. - : Elsevier BV. ; 177, s. 287-290
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Tidskriftsartikel (refereegranskat)abstract
- Identification of cell and tissue specific genes may provide novel insights to signaling systems and functions. Macrophages play a key role in many diseases including atherosclerosis. Using DNA microarrays we compared the expression of approximately 10,000 genes in 56 human tissues and identified 23 genes with predominant expression in macrophages. The identified genes include both genes known to be macrophage specific and genes previously not well described in this cell type. Tissue distribution of two genes, liver X receptor (LXR) alpha and interleukin-1 receptor antagonist (IL1RN), was verified by real-time RT-PCR. We conclude that comparison of expression profiles from a large number of tissues can be used to identify genes that are predominantly expressed in certain tissues. Identification of novel macrophage specific genes may increase our understanding of the role of this cell in different diseases.
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| 4. |
- Svensson, Per-Arne, 1969, et al.
(författare)
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Regulation and splicing of scavenger receptor class B type I in human macrophages and atherosclerotic plaques
- 2005
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Ingår i: BMC Cardiovasc Disord. - : Springer Science and Business Media LLC. - 1471-2261. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The protective role of high-density lipoprotein (HDL) in the cardiovascular system is related to its role in the reverse transport of cholesterol from the arterial wall to the liver for subsequent excretion via the bile. Scavenger receptor class B type I (SR-BI) binds HDL and mediates selective uptake of cholesterol ester and cellular efflux of cholesterol to HDL. The role of SR-BI in atherosclerosis has been well established in murine models but it remains unclear whether SR-BI plays an equally important role in atherosclerosis in humans. The aim of this study was to investigate the expression of SR-BI and its isoforms in human macrophages and atherosclerotic plaques. METHODS: The effect of hypoxia and minimally modified low-density lipoprotein (mmLDL), two proatherogenic stimuli, on SR-BI expression was studied in human monocyte-derived macrophages from healthy subjects using real-time PCR. In addition, SR-BI expression was determined in macrophages obtained from subjects with atherosclerosis (n = 15) and healthy controls (n = 15). Expression of SR-BI isoforms was characterized in human atherosclerotic plaques and macrophages using RT-PCR and DNA sequencing. RESULTS: SR-BI expression was decreased in macrophages after hypoxia (p < 0.005). In contrast, SR-BI expression was increased by exposure to mmLDL (p < 0.05). There was no difference in SR-BI expression in macrophages from patients with atherosclerosis compared to controls. In both groups, SR-BI expression was increased by exposure to mmLDL (p < 0.05). Transcripts corresponding to SR-BI and SR-BII were detected in macrophages. In addition, a third isoform, referred to as SR-BIII, was discovered. All three isoforms were also expressed in human atherosclerotic plaque. Compared to the other isoforms, the novel SR-BIII isoform was predicted to have a unique intracellular C-terminal domain containing 53 amino acids. CONCLUSION: We conclude that SR-BI is regulated by proatherogenic stimuli in humans. However, we found no differences between subjects with atherosclerosis and healthy controls. This indicates that altered SR-BI expression is not a common cause of atherosclerosis. In addition, we identified SR-BIII as a novel isoform expressed in human macrophages and in human atherosclerotic plaques.
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| 5. |
- Ahlin, Sofie, 1985, et al.
(författare)
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Macrophage Gene Expression in Adipose Tissue is Associated with Insulin Sensitivity and Serum Lipid Levels Independent of Obesity.
- 2013
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Ingår i: Obesity (Silver Spring, Md.). - : Wiley. - 1930-739X .- 1930-7381. ; 21:12
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Obesity is linked to both increased metabolic disturbances and increased adipose tissue macrophage infiltration. However, whether macrophage infiltration directly influences human metabolism is unclear. The aim of this study was to investigate if there are obesity-independent links between adipose tissue macrophages and metabolic disturbances. Design and Methods: Expression of macrophage markers in adipose tissue was analyzed by DNA microarrays in the SOS Sib Pair study and in patients with type 2 diabetes and a BMI-matched healthy control group. Results: The expression of macrophage markers in adipose tissue was increased in obesity and associated with several metabolic and anthropometric measurements. After adjustment for BMI, the expression remained associated with insulin sensitivity, serum levels of insulin, C-peptide, high density lipoprotein cholesterol (HDL-cholesterol) and triglycerides. In addition, the expression of most macrophage markers was significantly increased in patients with type 2 diabetes compared to the control group. Conclusion: Our study shows that infiltration of macrophages in human adipose tissue, estimated by the expression of macrophage markers, is increased in subjects with obesity and diabetes and associated with insulin sensitivity and serum lipid levels independent of BMI. This indicates that adipose tissue macrophages may contribute to the development of insulin resistance and dyslipidemia.
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| 6. |
- Andersson-Assarsson, Johanna C., 1974, et al.
(författare)
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Evolution of age-related mutation-driven clonal haematopoiesis over 20 years is associated with metabolic dysfunction in obesity
- 2023
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Ingår i: Ebiomedicine. - 2352-3964. ; 92
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Tidskriftsartikel (refereegranskat)abstract
- Background Haematopoietic clones caused by somatic mutations with >= 2% variant allele frequency (VAF) increase with age and are linked to risk of haematological malignancies and cardiovascular disease. Recent observations suggest that smaller clones (VAF<2%) are also associated with adverse outcomes. Our aims were to determine the prevalence of clonal haematopoiesis driven by clones of variable sizes in individuals with obesity treated by usual care or bariatric surgery (a treatment that improves metabolic status), and to examine the expansion of clones in relation to age and metabolic dysregulation over up to 20 years.Methods Clonal haematopoiesis-driver mutations (CHDMs) were identified in blood samples from participants of the Swedish Obese Subjects intervention study. Using an ultrasensitive assay, we analysed single-timepoint samples from 1050 individuals treated by usual care and 841 individuals who had undergone bariatric surgery, and multiple-timepoint samples taken over 20 years from a subset (n = 40) of the individuals treated by usual care.Findings In this explorative study, prevalence of CHDMs was similar in the single-timepoint usual care and bariatric surgery groups (20.6% and 22.5%, respectively, P = 0.330), with VAF ranging from 0.01% to 31.15%. Clone sizes increased with age in individuals with obesity, but not in those who underwent bariatric surgery. In the multiple-timepoint analysis, VAF increased by on average 7% (range -4% to 24%) per year and rate of clone growth was negatively associated with HDL-cholesterol (R = -0.68, 1.74 E-04).Interpretation Low HDL-C was associated with growth of haematopoietic clones in individuals with obesity treated by usual care.
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| 7. |
- Benson, Mikael, 1954, et al.
(författare)
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DNA microarray analysis of chromosomal susceptibility regions to identify candidate genes for allergic disease: A pilot study
- 2004
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 1651-2251 .- 0001-6489. ; 124:7, s. 813-819
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Tidskriftsartikel (refereegranskat)abstract
- Objective-To examine whether DNA microarray analysis of chromosomal susceptibility regions for allergy can help to identify candidate genes. Material and Methods-Nasal biopsies were obtained from 23 patients with allergic rhinitis and 12 healthy controls. RNA was extracted from the biopsies and pooled into three patient and three control pools. These were then analysed in duplicate with DNA microarrays containing 12626 genes. Candidate genes were further examined in nasal biopsies (real-time polymerase chain reaction) and blood samples (single nucleotide polymorphisms) from other patients with allergic rhinitis and from controls. Results-A total of 37 differentially expressed genes were identified according to criteria involving both the size and consistency of the gene expression levels. The chromosomal location of these genes was compared with the chromosomal susceptibility regions for allergic disease. Using a statistical method, five genes were identified in these regions, including serine protease inhibitor, Kazal type, 5 (SPINK5) and HLA-DRB2. The relevance of these genes was examined in other patients with allergic rhinitis and in controls; none of the genes were differentially expressed in nasal biopsies. Moreover, no association between allergic rhinitis and SPINK5 polymorphisms was found, at either the genotype or haplotype level. Conclusions-DNA microarray analysis of chromosomal susceptibility regions did not lead to identification of candidate genes that could be validated in a new material. However, because gene polymorphisms may cause differential gene expression, further studies, including validation data, are needed to examine this approach.
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| 8. |
- Benson, Mikael, 1954, et al.
(författare)
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DNA microarray analysis of transforming growth factor-β and related transcripts in nasal biopsies from patients with allergic rhinitis
- 2002
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Ingår i: Cytokine. ; 18:1, s. 20-25
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Tidskriftsartikel (refereegranskat)abstract
- Decreased activity of anti-inflammatory cytokines like transforming growth factor (TGF)-β may contribute to allergic inflammation. In vivo effects of TGF-β-effects are difficult to infer from local concentrations, since TGF-β-effects depend on a complex system of regulatory proteins and receptors. Instead the effects of TGF-β might be inferred by examining TGF-β-inducible transcripts. In this study DNA microarrays were used to examine local expression of TGF-β, TGF-β-regulatory and -inducible transcripts in nasal biopsies from patients with symptomatic allergic rhinitis and healthy controls. In addition, nasal fluids were analysed with cytological and immunological methods. Nasal fluid eosinophils, albumin, eosinophil granulae proteins and IgE, but not TGF-β, were higher in patients than in controls. DNA microarray analysis of nasal mucosa showed expression of transcripts encoding TGF-β, TGF-β-regulatory proteins and -receptors at variable levels in patients and controls. By comparison, analysis of 28 TGF-β-inducible transcripts indicated that 23 of these had lower measurement values in patients than in controls, while one was higher, and the remaining four were absent in both patients and controls. In summary, TGF-β and a complex system of regulatory genes and receptors are expressed in the nasal mucosa. Low expression of TGF-β-inducible transcripts may indicate decreased TGF-β activity in allergic rhinitis. DNA microarray analysis may be a way to study cytokine effects in vivo.
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| 9. |
- Benson, Mikael, 1954, et al.
(författare)
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DNA microarrays to study gene expression in allergic airways.
- 2002
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Ingår i: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology. - : Wiley. - 0954-7894 .- 1365-2222. ; 32:2, s. 301-8
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Tidskriftsartikel (refereegranskat)abstract
- Allergic rhinitis results from interactions between a large number of cells and mediators in different compartments of the body. DNA microarrays allow simultaneous measurement of expression of thousands of genes in the same tissue sample.
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| 10. |
- Boguszewski, C L, et al.
(författare)
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Cloning of two novel growth hormone transcripts expressed in human placenta.
- 1998
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 83:8, s. 2878-85
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Tidskriftsartikel (refereegranskat)abstract
- Several isoforms of human GH (hGH) are produced by two related genes expressed in the pituitary (hGH-N) and in the placenta (hGH-V). These genes consist of five exons (denoted 1-5) separated by four introns (denoted A-D). In the present report, two new transcripts of the hGH-V gene are described. The coding region of the hGH-V gene was amplified by RT-PCR using placental complementary DNA as template. DNA sequencing of several clones revealed two novel transcripts. One had a 45-bp deletion caused by the use of an alternative splice acceptor site within exon 3, similar to that in the hGH-N gene, predicting a 20-kDa isoform of hGH-V. The other transcript was generated by the use of an alternative splice donor site causing a 4-bp deletion in the end of exon 4, predicting a 24-kDa protein with 219 amino acids, which we refer to as hGH-V3. The carboxy-terminal sequence of hGH-V3 differs from 22-kDa hGH-V and hGH-V2, the two previously reported transcripts of the hGH-V gene, and does not contain a predicted transmembrane domain as described for hGH-V2. Ligase chain reaction was then used to analyze the possible use of the same splicing pattern in transcripts derived from the other genes of the hGH-gene cluster. Alternatively spliced transcripts encoding the 20-kDa hGH isoform were detected from the hGH-N and hGH-V genes, but not from the human chorionic somatomammotropin-A/B genes. The alternative splicing generating hGH-V3 was only demonstrated in transcripts derived from the hGH-V gene. Using competitive RT-PCR, the expression of hGH-V3 was estimated to be 10% of the hGH-V messenger RNA in full-term normal placentas and in placentas from pathological pregnancies. The 20-kDa hGH-V was detected in two of four full-term normal placentas, whereas a weak signal was observed in one of the pathological placentas. We conclude that the hGH-V primary transcript undergoes alternative splicing pathways generating at least four different messenger RNAs, predicting the expression of different hGH isoforms, including two with a complete sequence divergence in the carboxy-terminus.
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