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Biomedical subjects

Bo Franzén

Publications and source records attributed to Bo Franzén.

12 recordsLinked to original sources
PubMed2006

Evaluation of two sample preparation methods for prostate proteome analysis.

For laboratory techniques that require well-preserved proteins, such as 2-DE, fresh tissue must be harvested and processed as fast as possible to avoid proteolytic degradation. We describe a modified method for harvesting tissue from radical prostatectomy specimens for proteome analysis and compare it with the standard technique. Cells were scraped from cut surfaces of 11 prostate specimens. A fraction of the material was smeared on a glass slide and Giemsa stained for morphological control. The sample was collected in a medium with protease inhibitors, and the protein material was prepared for 2-DE. Filtering and Percoll centrifugation were omitted. Sample locations were noted on a specimen map. From the same area, a tissue block was harvested for comparison. The block was processed with the conventional technique including mechanical disintegration, filtering and Percoll centrifugation. Quality measures of 2-DE were similar with both methods. With the scrape sampling technique, control smears showed abundant epithelial cells and a cleaner background and processing was faster than with tissue block sampling. For proteomic analysis, the scrape sample technique has several advantages over the tissue block method.

Electrophoresis, Gel, Two-Dimensional↗
PubMed2006

Correlation of protein expression, Gleason score and DNA ploidy in prostate cancer.

The prognosis of prostate cancer correlates with tumor differentiation. Gleason score and DNA ploidy are two prognostic factors that correlate with prognosis. We analyzed differences in protein expression in prostate cancer of high and low aggressiveness according to these measures. From 35 prostatectomy specimens, 29 cancer samples and 10 benign samples were harvested by scraping cells from cut surfaces. DNA ploidy was assessed by image cytometry. Protein preparations from cell suspensions were examined by 2-DE. Protein spots that differed quantitatively between sample groups were identified by MS fingerprinting of tryptic fragments and MS/MS sequence analysis. We found 39 protein spots with expression levels that were raised or lowered in correlation with Gleason score and/or DNA ploidy pattern (31 overexpressed in high-malignant cancer, 8 underexpressed). Of these, 30 were identified by MS. Among overexpressed proteins were heat-shock, structural and membrane proteins and enzymes involved in gene silencing, protein synthesis/degradation, mitochondrial protein import (metaxin 2), detoxification (GST-pi) and energy metabolism. Stroma-associated proteins were generally underexpressed. The protein expression of prostate cancer correlates with tumor differentiation. Potential prognostic markers may be found among proteins that are differentially expressed and the clinical value of these should be validated.

Aged↗
PubMed2005

Extraction and proteomic analysis of proteins from normal and multiple sclerosis postmortem brain.

In this study, a reproducible fractionation procedure was developed to reduce levels of the abundant cytoskeletal proteins that are present in normal and pathological central nervous system (CNS) tissues. The fractionation and proteomic analysis techniques employed greatly facilitated comparison of the spectrum of proteins in normal postmortem brain with proteins in samples from patients with multiple sclerosis, an inflammatory demyelinating disease in which complex changes in protein expression occur as lesions develop. This approach may be of value for the proteomic identification and quantitation of proteins which undergo disease-related changes in CNS disorders, and also for protein expression studies on normal adult and developing CNS tissues.

Aged↗
PubMed2005

Differential protein expression in anatomical zones of the prostate.

The prostate has three anatomical zones: the peripheral (PZ), the transition (TZ), and the central (CZ) zone. It is proposed that the CZ may be of mesodermal origin, whereas the other two are of endodermal origin. Proteome patterns in the zones were characterized to test for differences. Cells were scraped from macroscopically normal areas of PZ, TZ, and CZ in radical prostatectomy specimens. After exclusion of samples with cancer or prostatic intraepithelial neoplasia, 18 cases remained for analysis. Cells were collected in a medium with protease inhibitors, and the protein material was prepared for two-dimensional gel electrophoresis. The proteins in spots that differed quantitatively between regions were identified via mass spectrometric fingerprinting of tryptic fragments and selected tandem mass spectrometry sequence analysis. Ten proteins with significant zonal differential expression were identified, eight with underexpression in the CZ versus the PZ and the TZ (arginase II, ATP synthase, cytokeratin 8, lamin A/C, peroxiredoxin 4, protein disulfide isomerase A3, tropomyosin, and vimentin), and two with overexpression in the CZ (peroxiredoxin 2 and creatine kinase B). The PZ and TZ, although differing in terms of incidence of cancer and hyperplasia, have epithelium with highly similar major protein expression profiles. However, the protein profile of the CZ differs from that of the other regions, suggesting functional differences.

Aged↗
PubMed2005

Proteome analysis of skin distinguishes acute guttate from chronic plaque psoriasis.

Psoriasis is a disease with considerable heterogeneity in clinical presentation. This is the first study using two-dimensional gel electrophoresis to compare global protein expression patterns in lesional and non-lesional skin from subjects with acute guttate psoriasis associated with streptococcal throat infection and chronic plaque psoriasis. Samples from experimentally induced contact eczema and normal skin from healthy controls were also included. Proteins with statistically significant differences in expression were used in hierarchical cluster analyses resulting in separation of the different samples into groups. Chronic plaque and guttate psoriasis samples were distinctly separated, indicating that they represent discrete phenotypes at the protein expression level. Interestingly, there was a trend in which guttate psoriasis lesions clustered closer to eczema than to chronic plaque psoriasis lesions, indicating that the duration of the inflammatory reaction may affect clustering. Several of the differentially expressed proteins were identified by mass spectrometry.

Acute Disease↗
PubMed2005

Gene and protein expression profiling of the microvascular compartment in experimental autoimmune encephalomyelitis in C57Bl/6 and SJL mice.

Dysfunction of the blood-brain barrier (BBB) is a hallmark of inflammatory diseases of the central nervous system (CNS) such as multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). The molecular mechanisms leading to BBB breakdown are not well understood. In order to find molecules involved in this process, we used oligonucleotide microarrays and proteomics to analyze gene and protein expression of the microvascular compartment isolated from brains of C57Bl/6 and SJL/N mice afflicted with EAE and the microvascular compartment isolated from healthy controls. Out of the 6500 known genes and expressed sequence tags (ESTs) studied, expression of 288 genes was found to be changed. Of these genes 128 were altered in the microvascular compartment in both EAE models. Six proteins were identified to be present at altered levels. In addition to the expected increased expression of genes coding for molecules involved in leukocyte recruitment, genes not yet ascribed to EAE pathogenesis were identified. Thus, proteomics and gene array screens of the microvascular compartment are valid approaches, that can be used to define novel candidate molecules involved in EAE pathogenesis at the level of the BBB.

Animals↗
PubMed2005

Proteomic analysis of protein expression in prostate cancer.

OBJECTIVE: To investigate protein expression in prostate cancer using 2-dimensional gel electrophoresis (2-DE) and mass spectrometry. STUDY DESIGN: Cells were collected from 29 peripheral zone tumors and from benign tissue by scraping cut surfaces of radical prostatectomy specimens. Samples were suspended in a medium with protease inhibitors and prepared for 2-DE. Gels were analyzed, and protein spots that differed quantitatively between tumor and benign tissue were identified via mass spectrometric fingerprinting of tryptic fragments and tandem mass spectrometry sequence analysis. RESULTS: In total, 63 spots differed between cancer and benign samples (p < 0.01); 56 were overexpressed (> 1.5 fold) in cancer and 7 underexpressed (< 0.6 fold). Among overexpressed proteins were transcription factors (nucleoside diphosphate kinase 1) and enzymes involved in gene silencing (chromobox protein), protein synthesis (39S ribosomal protein L12, BiP protein, protein disulfide isomerase), degradation (cytosol aminopeptidase, endopeptidase Clp, inorganic pyrophosphatase) and energy metabolism (acyl-CoA dehydrogenase, isocitrate dehydrogenase, NADH-ubiquinone oxidoreductase, pyruvate dehydrogenase), heat-shock proteins (60 and 70 kd), structural proteins (cytokeratins) and membrane proteins (stomatinlike protein 2). CONCLUSION: The protein profile of prostate cancer differs from that of benign tissue. Several potential target proteins for detection or evaluation of prognosis in prostate cancer were identified.

Electrophoresis, Gel, Two-Dimensional↗
PubMed2003

Gene and protein expression profiling of human cerebral endothelial cells activated with tumor necrosis factor-alpha.

An increase in permeability of the blood-brain barrier is a critical event in the pathophysiological process of multiple sclerosis and other neurodegenerative diseases. Tumor necrosis factor alpha (TNFalpha) is known to play a crucial role in this process and is a powerful activator of endothelial cell inflammatory responses. Although many reports describe effects of TNFalpha activation in endothelial cells, the molecular mechanisms specific for activation of cerebral endothelial cells remains unclear. The objective of this study was to identify potential pharmaceutical targets for the treatment of multiple sclerosis using molecular profiling techniques. Gene expression measurements (Affymetrix Hu6800 oligonucleotide arrays) and proteomics (two-dimensional gel electrophoresis and mass spectrometry) were applied to analyze early alterations in human cerebral endothelial cells (HCEC) activated by TNFalpha. Human umbilical vein endothelial cells (HUVEC) were used as the reference system. The results presented show that HCEC and HUVEC respond similarly with respect to cell adhesion molecules, chemotaxis, apoptosis and oxidative stress molecules. However, nuclear factors NFkB1 and NFkB2, plasminogen activator inhibitor 1 and cofilin 1 are examples of cerebral specific responses. Our results indicate involvements of the urokinase plasminogen activator system and cytoskeletal rearrangements unique to TNFalpha activation of cerebral endothelial cells.

Antineoplastic Agents↗
PubMed2003

Dihydropyrimidinase related protein-2 as a biomarker for temperature and time dependent post mortem changes in the mouse brain proteome.

Proteome analysis in the central nervous system area represents a large and important challenge in drug discovery. One major problem is to obtain representative and well characterized tissues of high quality for analysis. We have used brain tissues from normal mice to study the effect of post mortem time (up to 32 h) and temperature (4 degrees C and room temperature) on protein expression patterns. A number of proteins were identified using mass spectrometry and potential markers were localized. One of the proteins identified, dihydropyrimidinase related protein-2 (DRP-2), occurs as multiple spots in two-dimensional electrophoresis gels. The ratio between the truncated form of DRP-2 (fDRP-2) and full length DRP-2 is suggested as an internal control that can be used as a biomarker of post mortem time and post mortem temperature between unrelated brain protein samples. Results of this study may be useful in future efforts to detect disease specific alterations in proteomic studies of human post mortem brain tissues.

Animals↗
PubMed2002

Molecular classification of borderline ovarian tumors using hierarchical cluster analysis of protein expression profiles.

Ovarian tumors range from benign to aggressive malignant tumors, including an intermediate class referred to as borderline carcinoma. The prognosis of the disease is strongly dependent on tumor classification, where patients with borderline tumors have much better prognosis than patients with carcinomas. We here describe the use of hierarchical clustering analysis of quantitative protein expression data for classification of this type of tumor. An accurate classification was not achieved using an unselected set of 1,584 protein spots for clustering analysis. Different approaches were used to select spots that were differentially expressed between tumors of different malignant potential and to use these sets of spots for classification. When sets of proteins were selected that differentiated benign and malignant tumors, borderline tumors clustered in the benign group. This is consistent with the biologic properties of these tumors. Our results indicate that hierarchical clustering analysis is a useful approach for analysis of protein profiles and show that this approach can be used for differential diagnosis of ovarian carcinomas and borderline tumors.

Adult↗