Identification of genes upregulated in the inflamed colonic lesions of Crohn's disease

Coordinated Expression of Caspase 8, 3 and 7 mRNA in Temporal Cortex of Alzheimer Disease: Relationship to Formic Acid Extractable Aβ42 Levels

Recent studies support the hypothesis that Alzheimer disease (AD)-associated amyloid-beta protein (Abeta) may induce apoptosis mediated by a caspase cascade. To assess whether mRNA levels of caspase-3, 7, 8 and 9 change in AD brain, and whether these changes correlate with neurofibrillary tangles, Abeta40 or Abeta42 protein levels or senile plaques, 25 AD and 21 non-demented control brains were examined. Elevated mRNA levels of caspases-7 and 8 measured by a quantitative PCR method were observed in the AD temporal neocortex as compared to the control brains. No significant differences were noticed in levels of caspases-3 or 9 between AD and control brains. Multiple regression analysis demonstrated that, within subjects, the mRNA levels of caspase-8 strongly correlated with both caspse-3 and caspase-7 independently of postmortem interval. Further, there was a strong positive correlation of caspase-8 levels with formic acid extractable Abeta42 levels. Our results suggest that the transcriptional activation of key components of the apoptotic cascade correlates with accumulation of Abeta 42. Thus, a principal caspase pathway from caspase-8 to caspase-3 and/or 7 may contribute to neuron loss in AD brain.

A functional role of flip in conferring resistance of Crohn's disease lamina propria lymphocytes to FAS-mediated apoptosis

BACKGROUND & AIMS

There is evidence that, in Crohn's disease (CD), lamina propria T lymphocytes (LPLs) are resistant to FAS-mediated apoptosis and that this defect contributes to the mucosal T-cell accumulation. In this study we examined the functional role of Flip, a Flice inhibitor protein, in the resistance of CD LPL to FAS-mediated apoptosis.

METHODS

Biopsy specimens and LPLs were taken from CD and ulcerative colitis (UC) patients and normal controls and analyzed for Flip by Western blotting. We also examined whether inhibition of Flip by antisense oligonucleotide restored the susceptibility of CD LPLs to FAS-induced apoptosis. LPL apoptosis was assessed by flow cytometry.

RESULTS

After FAS stimulation, the rate of apoptosis of CD3+ LPLs was higher in normal controls and patients with UC than in patients with CD. Enhanced expression of both long and short Flip isoforms was seen in biopsy specimens and purified CD3+ and CD45RO+ LPLs of CD patients in comparison with UC patients and normal controls. No increase in Flip was documented in untreated celiac disease mucosa, thus suggesting the possibility that induction of Flip in the gut does not simply rely on the ongoing inflammation. Finally, we showed that inhibition of Flip by antisense oligonucleotide reverted the resistance of CD LPLs to FAS-induced apoptosis.

CONCLUSIONS

Data suggest a role for Flip in the resistance of CD LPLs to FAS-mediated apoptosis.

Tumour necrosis factor-alpha and apoptosis in the rat temporomandibular joint

The purpose of this investigation was to investigate the roles that tumour necrosis factor-alpha (TNF-alpha) and apoptosis play during acute inflammation of the temporomandibular joint (TMJ). Adult male Sprague-Dawley rats were injected with complete Freund's adjuvant (CFA) into the TMJ or kept as uninjected controls. The TMJ tissues were removed 2 days post-injection to mimic conditions of acute inflammation and analysed for changes in expression of TNF-alpha, the receptor TNF-R1, caspase-3 and -8, and apoptosis. Concentrations of TNF-alpha, TNF-R1, caspase-3 and -8, and apoptosis were significantly elevated in CFA-injected animals compared to uninjected controls. Tissue incubation with TNF-alpha caused a significant increase in caspase-3 and -8. Also, levels of apoptosis were significantly increased during inflammation, which could be inhibited by the addition of either anti-TNF-alpha neutralising antibody or caspase inhibitors. TNF-alpha may play a significant role in the onset of acute CFA-induced TMJ inflammation, and activation of apoptosis signalling pathways may be involved.

Differential gene expression in skeletal muscle after induction of heart failure: impact of cytokines on protein phosphatase 2A expression

Different intrinsic alterations of skeletal muscle metabolism and gene expression have been described in chronic heart failure (CHF). As proposed skeletal muscle alterations in CHF may contribute to exercise intolerance and early muscular fatigue. However the exact molecular changes occurring in the skeletal muscle are still unclear. The aim of this study was to characterize the pattern of differential gene expression in an animal model of CHF and to study the regulation of one selected gene. Rats were subjected to LAD ligation or sham operation. mRNA was isolated from musculus quadriceps of both groups and differential gene expression was determined by subtractive hybridization. Quantitative RT-PCR and cell culture experiments were performed to further characterize the changed expression of protein phosphatase 2A (PP2A) in human skeletal muscle biopsies as well as the cytokine dependent regulation of PP2A expression. Out of 800 picked clones differential expression of 24 distinct genes could be identified by sequencing and reverse Northern blotting. PP2A expression demonstrated a significant upregulation in skeletal muscle biopsies from patients with CHF as compared to healthy controls (9.7 +/- 1.9 vs. 4.2 +/- 0.7 arbitrary units; p<0.05). Incubation of rat skeletal muscle myoblasts with a combination of TNF-alpha, IL-1beta, and gamma-IFN caused a 3-fold upregulation of PP2A expression vs. untreated cells. These results suggest that CHF is accompanied by changes in expression of genes involved in energy metabolism, contractility, and apoptosis in the skeletal muscle. The upregulation of PP2A, an important regulator in intracellular signaling and apoptosis, may be due to an increase of inflammatory cytokines.