Fas mRNA (fa + mrna)

Distribution by Scientific Domains

Selected Abstracts

Effect of H. pylori on the Expression of TRAIL, FasL and their Receptor Subtypes in Human Gastric Epithelial Cells and their Role in Apoptosis

HELICOBACTER, Issue 5 2004
Jan Hendrik Martin
ABSTRACT Background and Aims., In the human stomach expression of TNF-related apoptosis inducing ligand (TRAIL) and its receptors and the modulatory role of Helicobacter pylori are not well described. Therefore, we investigated the effect of H. pylori on the expression of TRAIL, FasL and their receptors (TRAIL-R1-R4, Fas) in gastric epithelial cells and examined their role in apoptosis. Materials and Methods., mRNA and protein expression of TRAIL, FasL and their receptors were analyzed in human gastric epithelial cells using RT-PCR, Western blot, and immunohistochemistry. Gastric epithelial cells were incubated with FasL, TRAIL and/or H. pylori, and effects on expression, cell viability and epithelial apoptosis were monitored. Apoptosis was analyzed by histone ELISA, DAPI staining and immunohistochemistry. Results., TRAIL, FasL and their receptor subtypes were expressed in human gastric mucosa, gastric epithelial cell primary cultures and gastric cancer cells. TRAIL, FasL and H. pylori caused a time- and concentration-dependent induction of DNA fragmentation in gastric cancer cells with synergistic effects. In addition, H. pylori caused a selective up-regulation of TRAIL, TRAIL-R1 and Fas mRNA and protein expression in gastric cancer cells. Conclusions., Next to FasL and Fas, TRAIL and all of its receptor subtypes are expressed in the human stomach and differentially modulated by H. pylori. TRAIL, FasL and H. pylori show complex interaction mediating apoptosis in human gastric epithelial cells. These findings might be important for the understanding of gastric epithelial cell kinetics in patients with H. pylori infection. [source]

Expression of Fas and Fas ligand in human testicular germ cell tumours

E. Baldini
Summary In the present study, we analysed the expression of Fas ligand (FasL) and its cognate receptor Fas in 14 seminomatous testicular germ cell tumours (TGCT) and six normal testicular tissues obtained following orchiectomy. Tissue samples have been processed to prepare either total RNA or protein extracts or fixed and embedded in paraffin for immunohistochemistry (IHC) experiments. Quantitative RT-PCR experiments demonstrated in TGCT a significant (p < 0.01) increase of the FasL mRNA expression of 21.1 5.4 fold, with respect to normal tissues. On the contrary, in the same cancer tissues, the levels of Fas mRNA were significantly (p < 0.01) reduced to 0.27 0.06 fold. These observations were confirmed in western blot experiments showing a significant increase of FasL and a concomitant decrease of Fas proteins in testicular cancer tissues, with respect to normal testis. Moreover, IHC experiments showed a strong FasL immuno-reactivity in six out of eight TGCT samples analysed, while Fas immuno-positivity was found in cancer cells of only two TGCT tissues. In addition, in all tumour samples, infiltrating lymphocytes were Fas positive. However, no correlation could be observed between Fas or FasL mRNA variations and clinical parameters such as patient's age, TNM stage or tumour size. We also compared the serum levels of soluble FasL (sFasL) of 15 patients affected by seminomatous TGCT, of four patients with non-seminomatous TGCT and six age-matched healthy males. No significant differences in sFasL serum level could be identified. In conclusion, our data demonstrated that the majority of seminomas are characterized by an increased expression of FasL and a concomitant reduction of Fas, with respect to human normal testis, and that sFasL serum level is not a tumour marker for patients affected by TGCT. [source]

The protective action of scutellarin against immunological liver injury induced by concanavalin A and its effect on pro-inflammatory cytokines in mice

Zheng Huai Tan
Scutellarin is a natural compound from a Chinese herb. The purpose of this paper was to study the protective effect of scutellarin on concanavalin A (Con A)-induced immunological liver injury and its effect on liver nuclear factor ,B (NF-,B), tumor necrosis factor , (TNF-,), interferon , (IFN-,), and inducible nitric oxide synthase (iNOS) expression in mice. Mouse liver injury was produced by injection of Con A 25 mg kg,1 via the tail vein. Scutellarin 50 or 100 mg kg,1 was peritoneally administered to mice 9 or 1 h before injection of Con A. The levels of serum alanine aminotransferase (ALT) and asparatate aminotransferase (AST), NO2,/NO3, and TNF - , were determined with biochemical kits, and ELISA using Quantikine Mouse TNF-, kit according the manufacturer's instructions. Liver lesions were examined by light microscope. The expression of TNF-,, IFN-,, iNOS and Fas mRNA in the livers was detected by RT-PCR; and the expression of c-Fos, c-Jun, iNOS and I,B proteins was measured by Western Blotting. As a result, pretreatment with scutellarin 100 mg kg,1 significantly decreased the serum ALT, AST, NO2,/NO3,and TNF-, levels, and also reduced liver lesions induced by Con A. Scutellarin 100 mg kg,1 down-regulated expression of TNF-, and iNOS mRNA, and c-Fos, c-Jun and iNOS protein, while scutellarin enhanced the degradation of I,B, in the livers of mice injected with Con A. The results suggest that scutellarin has a protective action against Con A-induced liver injury in mice, and its active mechanism may be related to the inhibition of the NF-,B-TNF-,-iNOS transduction pathway. [source]

Expression Pattern of Apoptotic Genes in Vitrified-Thawed Bovine Oocytes

VM Anchamparuthy
Contents This study describes a method for quantification of transcripts from low numbers of bovine oocytes using real time RT-PCR. The objective was to evaluate the expression pattern of apoptotic genes (Fas, FasL, Bax and Bcl-2) in vitrified-thawed oocytes. Oocytes were evaluated at germinal vesicle stage; at 15 h of maturation; after vitrification and warming at 15 h of maturation and at 9 h of additional maturation. All transcripts showed an increase in at least 1.2-fold change post-vitrification warming, but the levels tended to decrease at 9 h of maturation post-vitrification warming. Transcript abundance for Fas mRNA was 1.4-fold for oocytes after vitrification and warming. The level of Fas mRNA upon maturation was 0.8-fold. The increase in the abundance of FasL mRNA was 2.1, while it was 0.5-fold relative to control. Vitrification resulted in 1.5-fold change in Bax mRNA expression in oocytes. After 9 h of maturation post-vitrification warming, the level for Bax mRNA was 0.6-fold. The mRNA for Bcl-2 was nearly the same after vitrification and warming. The abundance of mRNA for Bcl-2 was 1.2-fold in vitrified oocytes and fell (p = 0.05) to 0.5 at 9 h of maturation post-vitrification and warming. The up-regulation of apoptotic genes in vitrified oocytes may be an early indicator of reduced developmental competence following vitrification. Yet, results from terminal deoxynucleotidyl transferase dUTP nick end labelling and caspase assays did not support the evidence of apoptosis in embryos derived from large numbers of vitrified oocytes. [source]

Alternatively spliced transcripts of Fas mRNAs in feline lymphoid cells

T. Mizuno
Summary Fas belongs to the tumour necrosis factor receptor family and transduces the death signal after binding to the Fas ligand. Five feline lymphoma cell lines were shown, by reverse transcription,polymerase chain reaction, to express six species of Fas transcripts. Based on sequence comparison of these Fas transcripts with the genomic Fas gene, five of the six transcripts were found to be generated through alternative splicing and to encode five different Fas proteins lacking the transmembrane domain. We also detected such alternatively spliced transcripts in primary tumour tissues from cats with naturally occurring lymphoma. These results suggest a possible association of the alternatively spliced Fas variants with the pathogenesis of feline lymphoma. [source]