40 research outputs found
Expression of the transcriptional regulator Egr-1 in experimental glomerulonephritis: Requirement for mesangial cell proliferation
Expression of the transcriptional regulator Egr-1 in experimental glomerulonephritis: Requirement for mesangial cell proliferation. The early growth response gene-1 (Egr-1), a zinc finger transcriptional regulator, was induced in a rat model of mesangioproliferative glomerulonephritis (GN). Northern blot analysis revealed a maximal 14.9-fold increase in glomerular Egr-1 mRNA at day 6 of GN. By immunohistochemistry Egr-1 protein expression was demonstrated to be mainly confined to glomerular mesangial cells (MC). To test whether Egr-1 directly regulates MC proliferation, cultured MCs were stimulated with platelet-derived growth factor (PDGF) after preincubation with different Egr-1 antisense oligonucleotides (ASOs). PDGF-induced Egr-1 mRNA levels were inhibited by up to 75% and protein levels by up to 91%. In addition Egr-1-specific ASOs blocked PDGF-induced rise in 3H-thymidine uptake by 83% and almost completely abrogated increase in MC number. We conclude that Egr-1 induction is of critical importance for PDGF-induced mitogenic signaling in MCs, and inhibition of Egr-1 in vivo may offer an approach to oppose glomerular MC proliferation in glomerular inflammatory disease
Opposing function of MYBBP1A in proliferation and migration of head and neck squamous cell carcinoma cells
BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent and lethal cancers worldwide and mortality mostly results from loco-regional recurrence and metastasis. Despite its significance, our knowledge on molecular, cellular and environmental mechanisms that drive disease pathogenesis remains largely elusive, and there are limited therapeutic options, with only negligible clinical benefit. METHODS: We applied global gene expression profiling with samples derived from a recently established mouse model for oral cancer recurrence and identified a list of genes with differential expression between primary and recurrent tumors. RESULTS: One differentially expressed gene codes for Myb-binding protein 1a (MYBBP1A), which is known as a transcriptional co-regulator that physically interacts with nuclear transcription factors, such as NFÎşB and p53. We confirmed significantly reduced MYBBP1A protein levels on tissue sections of recurrent mouse tumors compared to primary tumors by immunohistochemistry, and found aberrant MYBBP1A protein levels also in tumor samples of HNSCC patients. Interestingly, silencing of MYBBP1A expression in murine SCC7 and in human HNSCC cell lines elicited increased migration but decreased cell growth. CONCLUSION: We provide experimental evidence that MYBBP1A is an important molecular switch in the regulation of tumor cell proliferation versus migration in HNSCC and it will be a major challenge for the future to proof the concept whether regulation MYBBP1A expression and/or function could serve as a novel option for anti-cancer therapy
Invertebrate neurophylogeny: suggested terms and definitions for a neuroanatomical glossary
<p>Abstract</p> <p>Background</p> <p>Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups, but no consensus on the exact meaning exists. This impedes our understanding of the architecture of the invertebrate nervous system in general and of evolutionary transformations of nervous system characters between different taxa.</p> <p>Results</p> <p>We provide a glossary of invertebrate neuroanatomical terms with a precise and consistent terminology, taxon-independent and free of homology assumptions. This terminology is intended to form a basis for new morphological descriptions. A total of 47 terms are defined. Each entry consists of a definition, discouraged terms, and a background/comment section.</p> <p>Conclusions</p> <p>The use of our revised neuroanatomical terminology in any new descriptions of the anatomy of invertebrate nervous systems will improve the comparability of this organ system and its substructures between the various taxa, and finally even lead to better and more robust homology hypotheses.</p
Systemic Th1 Immunization of Mice against Helicobacter pylori Infection with CpG Oligodeoxynucleotides as Adjuvants Does Not Protect from Infection but Enhances Gastritis
Recent reports have suggested that oral vaccination of mice against Helicobacter pylori is dependent on a Th1-mediated immune response. However, oral vaccination in mice neither induces sterilizing immunity nor leads to complete protection from disease. Therefore, in this study we investigated whether a systemic subcutaneous immunization against H. pylori by using CpG oligodeoxynucleotides as a Th1 adjuvant could achieve protection in a mouse model of H. pylori infection. CpG oligodeoxynucleotides are known for their ability to induce nearly entirely Th1-biased immune responses and may be approved for human use in future. Immunization of mice with H. pylori lysate and CpG induced a strong local and systemic Th1 immune response. Despite this strong Th1 response, mice were not protected from infection with H. pylori yet had a 10-fold reduction in the number of H. pylori in the gastric mucosa compared to nonimmunized mice. Of note, reduction of the bacterial density in immunized mice was accompanied by a significantly enhanced gastritis. Hence, systemic Th1 immunization of mice, even though being able to reduce the bacterial load in the stomach, is associated with aggravated pathology
Generation and Characterization of Human Monoclonal scFv Antibodies against Helicobacter pylori Antigens
Infection with Helicobacter pylori is chronic despite a vigorous cellular and humoral immune response and causes severe pathology in some patients. In this study, phage display was used as a new approach in order to investigate the role of the host's humoral immune response in the pathogenesis of H. pylori gastritis. Human monoclonal single-chain Fv (scFv) antibody fragments against H. pylori cell lysate and the H. pylori urease were isolated from an immune phage display library, constructed from peripheral blood lymphocytes of an H. pylori-infected patient. After affinity selection, 23% of the clones tested showed binding activity against a lysate of the H. pylori Sydney strain in enzyme-linked immunosorbent assay (ELISA) and 9% bound the H. pylori urease. Further characterization by PCR-fingerprint analysis and sequencing revealed that two closely related H. pylori binders and one antiurease scFv could be isolated. The selected scFvs were highly specific as analyzed by ELISA and immunoblots using various bacterial lysates and recombinant proteins. Analysis of the humoral immune response following H. pylori infection using human monoclonal antibodies might contribute to a better understanding of the pathogenesis of the disease. Moreover, using immune phage display libraries, it might be possible for relevant epitopes of H. pylori antigens to be determined, which might be of use for vaccine development
Effects of polysaccharide isolated from Streptococcus thermophilus CRL1190 on human gastric epithelial cells
EPS1190 was isolated from skim milk fermented with Stretococcus thermophilus CRL1190. The polysaccha-ride consisted of 33% glucose and 66% galactose with 1,4- and 1,4,6-galactose residues as main buildingblocks beside a high amount of 1,4-linked glucose. The polymer was characterized additionally con-cerning viscosity and zeta potential. EPS1190 stimulated cellular vitality and proliferation of humanstomach AGS cells and human buccal KB cells significantly. EPS1190 stimulated phagocytosis rate ofmurine macrophages RAW264.7 significantly. NO-release or anti-inflammatory effects by inhibition ofLPS-induced NO release were not observed. Confocal laser scanning microscopy revealed that EPS1190 ispartially internalized into AGS cells via endosomes. The bioadhesive absorption of FITC-labeled EPS1190into the mucus layer on the apical side of the epithelium using histological tissue sections from humanstomach was observed. Specific interaction of EPS1190 with mucin can be excluded as shown by micro-viscosimetry studies. EPS1190 increased the adhesion of H. pylori to AGS cells, which resulted in increasedsecretion of proinflammatory cytokines TNFa, IL-6 and IL-8. Summarizing, EPS1190 seems to stimulateepithelial cell regeneration and immunological innate defense mechanisms, which again can rationalizedthe use of this polysaccharide as cytoprotective compound in probiotioc preparations.Fil: Marcial, Guillermo Emilio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Tucumán. Centro de Referencia Para Lactobacilos (i); Argentina; University of MĂĽnster. Institute for Pharmaceutical Biology and Phytochemistry; Alemania;Fil: Messing, Jutta. University of MĂĽnster. Institute for Pharmaceutical Biology and Phytochemistry; Alemania;Fil: Menchicchi, Bianca. University of MĂĽnster. Institute of Plant Biology and Biotechnology; Alemania;Fil: Goycoolea, Francisco. University of MĂĽnster. Institute of Plant Biology and Biotechnology; Alemania;Fil: Faller, Gerhard. St. Vincentius Hospital. Institute for Pathology; Alemania;Fil: Font, Graciela Maria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Tucumán. Centro de Referencia Para Lactobacilos (i); Argentina; Universidad Nacional de Tucumán. Facultad de BioquĂmica, QuĂmica y Farmacia. Instituto de MicrobiologĂa; Argentina;Fil: Hensel, Andreas. University of MĂĽnster. Institute for Pharmaceutical Biology and Phytochemistry; Alemania