Biomedical subjects

Carola Seifart

Publications and source records attributed to Carola Seifart.

7 recordsLinked to original sources

PubMed2006

High-throughput DNA methylation profiling using universal bead arrays.

We have developed a high-throughput method for analyzing the methylation status of hundreds of preselected genes simultaneously and have applied it to the discovery of methylation signatures that distinguish normal from cancer tissue samples. Through an adaptation of the GoldenGate genotyping assay implemented on a BeadArray platform, the methylation state of 1536 specific CpG sites in 371 genes (one to nine CpG sites per gene) was measured in a single reaction by multiplexed genotyping of 200 ng of bisulfite-treated genomic DNA. The assay was used to obtain a quantitative measure of the methylation level at each CpG site. After validating the assay in cell lines and normal tissues, we analyzed a panel of lung cancer biopsy samples (N = 22) and identified a panel of methylation markers that distinguished lung adenocarcinomas from normal lung tissues with high specificity. These markers were validated in a second sample set (N = 24). These results demonstrate the effectiveness of the method for reliably profiling many CpG sites in parallel for the discovery of informative methylation markers. The technology should prove useful for DNA methylation analyses in large populations, with potential application to the classification and diagnosis of a broad range of cancers and other diseases.

Base Sequence↗

PubMed2005

Deletions within a CA-repeat-rich region of intron 4 of the human SP-B gene affect mRNA splicing.

Length variants within a CA-repeat-rich region of intron 4 of the human SP-B (pulmonary surfactant protein-B) gene are associated with several lung diseases. The hypothesis that SP-B intron 4 affects mRNA splicing was studied. SP-B minigenes containing exons 1-6 with a normal-sized intron 4 (pBi4normal) or intron 4 containing deletions (pBi4del) of 193, 211, 264 or 340 bp were expressed in CHO (Chinese hamster ovary) cells by transient transfection. Two forms of SP-B transcripts, normal and incompletely spliced, were detected. With pBi4normal, normal-sized SP-B mRNA was the predominant form and a very low amount of incompletely spliced mRNA was present, whereas with the pBi4del variants the amount of normal SP-B mRNAs was lower and the amount of incompletely spliced mRNA was relatively high. Reverse transcription-PCR results and sequencing data indicated that the incompletely spliced SP-B RNA contained intron 4 sequence, and this incompletely spliced RNA was also observed in normal lung. Lung cancer tissues with intron 4 deletions exhibited a larger amount of abnormally spliced RNAs compared with normal lung tissue or cancerous tissue with normal-sized intron 4. The results indicate that intron 4 length variants affect SP-B mRNA splicing, and that this may contribute to lung disease.

Animals↗

PubMed2005

Cell-specific modulation of surfactant proteins by ambroxol treatment.

Ambroxol [trans-4-(2-amino-3,5-dibromobenzylamino)-cyclohexanole hydrochloride], a mucolytic agent, was postulated to provide surfactant stimulatory properties and was previously used to prevent surfactant deficiency. Currently, the underlying mechanisms are not exactly clear. Because surfactant homeostasis is regulated by surfactant-specific proteins (SP), we analyzed protein amount and mRNA expression in whole lung tissue, isolated type II pneumocytes and bronchoalveolar lavage of Sprague-Dawley rats treated with ambroxol i.p. (75 mg/kg body weight, twice a day [every 12 h]). The methods used included competitive polymerase chain reaction (RT-PCR), Northern blotting, Western immunoblotting, and immunohistochemistry. In isolated type II pneumocytes of ambroxol-treated animals, SP-C protein and mRNA content were increased, whereas SP-A, -B and -D protein, mRNA, and immunoreactivity remained unaffected. However, ambroxol treatment resulted in a significant increase of SP-B and in a decrease of SP-D in whole lung tissue with enhanced immunostaining for SP-B in Clara Cells. SP-A and SP-D were significantly decreased in BAL fluid of ambroxol-treated animals. The data suggest that surfactant protein expression is modulated in a cell-specific manner by ambroxol, as type II pneumocytes exhibited an increase in SP-C, whereas Clara cells exhibited an increase in the immunoreactivity for SP-B accounting for the increased SP-B content of whole lung tissue. The results indicate that ambroxol may exert its positive effects, observed in the treatment of diseases related to surfactant deficiency, via modulation of surfactant protein expression.

Ambroxol↗

PubMed2005

TNF-alpha, TNF-beta, IL-6, and IL-10 polymorphisms in patients with lung cancer.

Apart from cigarette smoking, genetic factors seem to be of importance in the development of lung cancer. The present case-control study investigated frequencies of five inflammatory response gene polymorphisms (TNF-alpha-308, TNF-beta-Intron1-252, IL-6-174, IL-10-819 and IL-10-1082) in patients with lung cancer and controls. The study population consisted of 117 patients with lung cancer (77 patients with NSCLC, including 40 Squamous Cell Carcinoma and 26 Adenocarcinoma, and 40 patients with SCLC), 117 matched controls without pulmonary disease and 243 healthy individuals (population control). Genotype analyses revealed no difference in genotype frequencies using matched-pair analysis. However, in comparison to the population control, the IL-10-1082 genotypes carrying the G allele appeared with higher frequency in the SCLC group (p=0.006) [SCLC: 84.6%, population controls: 64.6%]. This yields an odds ratio of 3.01 for SCLC (95% CI = [1.21, 7.48]). No associations were seen for all other polymorphisms analysed. The study raises the possibility of a correlation between the IL-10-1082_G allele and the presence of SCLC in a German population. The functional IL-10-1082 polymorphism correlates with altered IL-10 levels and might influence lung cancer susceptibility by altered inflammatory responses in the airways.

Adenocarcinoma↗

PubMed2002

Surfactant protein B intron 4 variation in German patients with COPD and acute respiratory failure.

Chronic obstructive pulmonary disease (COPD) is a major health problem. Genetic factors that contribute to the disease have been postulated. The pulmonary surfactant protein B (SP-B), which is essential for normal lung function, is considered as a candidate gene for COPD in this case-control study. We studied the SP-B intron 4 size variants in 346 individuals. This group consisted of 118 patients with chronic bronchitis or COPD, including 24 patients with acute respiratory failure (ARF) in COPD, 118 matched controls without pulmonary disease and 110 healthy individuals (population control). The frequency of intron 4 variants was similar in either control group (10.9%, 14.4%, respectively), with a small increase in the COPD group (18.6%). This increase was due to a high increase of intron 4 variants in the ARF subgroup (37.5%, p = 0.003, OR 4.9, 95% CI: 1.76-13.6). The data indicate that SP-B intron 4 variants may associate with increased risk of ARF in COPD and may be used as a marker of susceptibility in this disease subgroup.

Acute Disease↗

PubMedDate not supplied

Exposure of differentiated airway epithelial cells to volatile smoke in vitro.

BACKGROUND: Cigarette smoke (CS) is the predominant pathogenetic factor in the development of chronic bronchitis and chronic obstructive pulmonary disease. The knowledge about the cellular and molecular mechanisms underlying the smoke-induced inflammation in epithelial cells is limited. OBJECTIVES: The aim of this study was to develop an in vitro model to monitor the effects of volatile CS on differentiated airway epithelial cells. METHODS: The airway epithelial cell line MM-39 and primary human bronchial epithelial cells were cultivated as air-liquid interface cultures and exposed directly to volatile CS. We used two types of exposure models, one using ambient air, the other using humidified and warm air. Cytokine levels were measured by quantitative PCR and ELISA. Phosphorylation of p38 MAP kinase was assessed by Western blot analysis. To reduce the smoke-induced inflammation, antisense oligonucleotides directed against the p65 subunit of NF-kappaB were applied. RESULTS: Exposure of epithelia to cold and dry air resulted in a significant inflammatory response. In contrast, exposure to humidified warm air did not elicit a cellular response. Stimulation with CS resulted in upregulation of mRNA for IL-6 and IL-8 and protein release. Exposure to CS combined with heat-inactivated bacteria synergistically increased levels of the cytokines. Reactions of differentiated epithelial cells to smoke are mediated by the MAP kinase p38 and the transcription factor NF-kappaB. CONCLUSIONS: We developed an exposure model to examine the consequences of direct exposure of differentiated airway epithelial cells to volatile CS. The model enables to measure the cellular reactions to smoke exposure and to determine the outcome of therapeutic interventions.

Atmosphere Exposure Chambers↗

PubMedDate not supplied

The lung, an organ for absorption?

This review summarizes information concerning the mechanisms of absorption of substances across the pulmonary epithelium. Inhalation is now increasingly used as a route of administration, although the scientific understanding of these mechanisms is rather limited. The aim of this study is to draw attention to these questions.

Absorption↗