Oncostatin M in combination with tumor necrosis factor ? induces cartilage damage and matrix metalloproteinase expression in vitro and in vivo

OBJECTIVE

To determine the effects of the proinflammatory cytokine combination of oncostatin M (OSM) and tumor necrosis factor alpha (TNFalpha) on cartilage destruction in both in vitro and in vivo model systems.

METHODS

The release of collagen and proteoglycan was assessed in bovine cartilage explant cultures, while messenger RNA (mRNA) from bovine chondrocytes was analyzed by Northern blotting. Immunohistochemistry was performed on sections prepared from murine joints following injection of adenovirus vectors encoding murine OSM and/or murine TNFalpha.

RESULTS

The combination of OSM + TNFalpha induced significant collagen release from bovine cartilage, accompanied by high levels of active collagenolytic activity. Northern blot analysis indicated that this cytokine combination synergistically induced matrix metalloproteinase 1 (MMP-1), MMP-3, and MMP-13 mRNA. The in vivo data clearly indicated that OSM + TNFalpha overexpression increased MMP levels and decreased levels of tissue inhibitor of metalloproteinases 1 (TIMP-1). Specifically, OSM + TNFalpha induced marked synovial hyperplasia, inflammation, and cartilage and bone destruction with a concomitant increase in MMP expression in both cartilage and synovium and decreased TIMP-1 expression in the articular cartilage. These effects were markedly greater than those seen with either cytokine alone.

CONCLUSION

This study demonstrates that OSM + TNFalpha represents a potent proinflammatory cytokine combination that markedly induces MMP production in both cartilage and synovium, thus promoting joint destruction.

Matrix metalloproteinase 10 promotion of collagenolysis via procollagenase activation: implications for cartilage degradation in arthritis

OBJECTIVE

We have previously reported the up-regulation of matrix metalloproteinase 10 (MMP-10) following treatment with the procatabolic stimulus of interleukin-1 (IL-1) and oncostatin M (OSM) in chondrocytes. Although MMP-10 is closely related to MMP-3, little is known about the role of MMP-10 in cartilage catabolism. The purpose of this study was to determine whether MMP-10 is expressed in connective tissue cells and to assess how it may contribute to cartilage collagenolysis.

METHODS

MMP gene expression was assessed by real-time polymerase chain reaction using RNA from human articular chondrocytes and synovial fibroblasts stimulated with IL-1 plus OSM or tumor necrosis factor alpha (TNFalpha) plus OSM. Synovial fluid levels of MMP-10 were determined by specific immunoassay. Recombinant procollagenases were used in activation studies. Immunohistochemistry assessed MMP-10 expression in diseased joint tissues.

RESULTS

MMP-10 expression was confirmed in both chondrocytes and synovial fibroblasts following stimulation with either IL-1 plus OSM or TNFalpha plus OSM, and MMP-10 was detected in synovial fluid samples from patients with various arthropathies. Exogenous MMP-10 significantly enhanced collagenolysis from IL-1 plus OSM-stimulated cartilage, and MMP-10 activated proMMP-1, proMMP-8, and proMMP-13. Immunohistochemistry revealed the presence of MMP-10 in the synovium and cartilage of an IL-1 plus OSM-induced model of arthritis as well as in samples of diseased human tissues.

CONCLUSION

We confirm that both synovial fibroblasts and articular chondrocytes express MMP-10 following treatment with procatabolic stimuli. Furthermore, the detectable levels of synovial fluid MMP-10 and the histologic detection of this proteinase in diseased joint tissues strongly implicate MMP-10 in the cartilage degradome during arthritis. The ability of MMP-10 to superactivate procollagenases that are relevant to cartilage degradation suggests that this activation represents an important mechanism by which this MMP contributes to tissue destruction in arthritis.

Long-term survival in 11,661 patients with multivessel coronary artery disease in the era of stenting: a report from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) Investigators

BACKGROUND

Studies of survival of patients with multivessel coronary artery disease (MVD) in the prestent era suggested that outcomes after coronary artery bypass surgery (CABG) are similar to those after percutaneous coronary intervention (PCI) in subsets of coronary severity. The purpose of this study of the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) was to examine the association between treatment and survival up to 5 years in patients with MVD enrolled from 1995 through 1998.

METHODS AND RESULTS

Data on patient characteristics were obtained at the time of the initial coronary angiography. Survival was determined through data linkage to the provincial Bureau of Vital Statistics. Risk-adjusted hazard ratios were calculated to compare different treatments. In the 11,661 patients with MVD, CABG was the initial therapy in 3782, PCI in 3540, and medical therapy in 4339. Cumulative 5-year survival was 91.4% with CABG, 91.9% with PCI, and 82.9% with medical therapy (P <.001). Hazard ratios were CABG: medical 0.53 (95% confidence interval [CI] 0.46-0.71), PCI: medical 0.65 (95% CI 0.56-0.74), and CABG: PCI 0.81 (95% CI 0.68-0.96). Analysis across coronary severity groups revealed a benefit of CABG compared with PCI only in the group with severe left main CAD: 0.30 (95% CI 0.17-0.54).

CONCLUSIONS

In a multicenter clinical setting, MVD patients treated with revascularization have significantly higher 5-year survival rate than do those treated medically. Risk-adjusted comparison reveals PCI treatment to be associated with long-term survival similar to treatment with CABG in all coronary severity subgroups except the group with severe left main coronary artery disease. Patient selection factors are likely to be contributing to these findings.

Interleukin-1 in combination with oncostatin M up-regulates multiple genes in chondrocytes: Implications for cartilage destruction and repair

OBJECTIVE

To identify the genes up-regulated by interleukin-1 (IL-1) in combination with oncostatin M (OSM) in chondrocytes that may be involved in mechanisms of cartilage repair and degradation.

METHODS

Gene microarray and real-time polymerase chain reaction (PCR) experiments were performed using RNA from SW1353 chondrocytes and primary human articular chondrocytes. Sections prepared from murine joints, injected with adenovirus vectors overexpressing IL-1 and/or OSM, were analyzed by immunohistochemistry for selected proteins.

RESULTS

The combination of IL-1 and OSM markedly up-regulated the expression of various genes, including matrix metalloproteinases (MMPs), cytokines, chemokines, extracellular matrix components, and genes involved in signal transduction. Real-time PCR confirmed a synergistic induction of several MMPs, activin A, pentraxin 3 (PTX-3), and IL-8. The in vivo findings further indicated that stimulation with IL-1 plus OSM induced protein expression of activin A, PTX-3, and KC (the murine homolog of IL-8), as compared with the changes induced by individual cytokine treatment and unstimulated controls.

CONCLUSION

The results confirm that the potent proinflammatory cytokine combination of IL-1 plus OSM synergistically and coordinately up-regulates many genes and several MMPs. Moreover, chondrocytes exhibit a potential repair response following this procatabolic stimulus such that the repair mechanisms are ultimately overwhelmed by degradative processes in the cartilage. This gene-profiling study provides insight into the complex processes that mediate joint disease in the inflammatory arthritides through the coordinated expression of multiple genes.

Differential Toll-like receptor-dependent collagenase expression in chondrocytes

OBJECTIVES

To characterise the catabolic response of osteoarthritic chondrocytes to Toll-like receptor (TLR) ligands.

METHODS

Induction of the collagenases, matrix metalloproteinase (MMP)1 and MMP13, by TLR ligands was assessed in chondrocytes by real-time reverse transcriptase (RT)-PCR. TLR signalling pathway activation and their involvement in collagenase induction were confirmed by immunoblotting and use of pathway inhibitors and siRNA. TLR expression was compared in the femoral head cartilage of normal controls and patients with osteoarthritis (OA) by real-time RT-PCR.

RESULTS

Ligands for TLR6/2 and TLR3 showed the greatest upregulation of MMP1 and MMP13 respectively, although all TLR ligands upregulated these MMPs. MMP1 and MMP13 induction by TLR3 and TLR1/2 or TLR6/2 ligands were dependent on Trif and MyD88, respectively. These inductions were dependent upon the nuclear factor (NF)kappaB pathway, but were differentially inhibited by various mitogen-activated protein kinase inhibitors, with MMP13 induction most reliant on the extracellular signal-regulated kinase pathway. In addition, ligands for TLR1/2 and TLR6/2, but not TLR3, induced significant collagenolysis in a cartilage resorption assay. Finally, TLR2 was significantly downregulated and TLR3 upregulated in OA, compared to normal, cartilage.

CONCLUSIONS

Activation of chondrocyte TLRs leads to differential collagenase gene activation. Treatment of chondrocytes with TLR1/2 or TLR6/2 ligands resulted in collagen resorption. The modulated expression of chondrocyte TLR2 and TLR3 in OA cartilage, compared to normal, may reflect a response to repair cartilage or prevent further extracellular matrix destruction. These data suggest modulation of TLR-mediated signalling as a potential therapeutic strategy for the treatment of OA.

The regulation of MMPs and TIMPs in cartilage turnover

The treatment of cartilage with mediators initiates the breakdown of proteoglycan followed by collagen. This is accompanied by the modulation of different proteinases and inhibitors that include members of the MMP family and TIMPs. We have evidence that a chondrocyte membrane-associated metalloproteinase cleaves aggrecan. This activity is rapidly induced after stimulation with IL-1 and OSM and is not inhibited by TIMPs-1 and -2 but is inhibited by synthetic MMP inhibitors. This same combination of cytokines also upregulates the collagenases with the subsequent release of collagen fragments, and there is a close correlation between the amount of collagen released and collagenase activity produced. Collagen release can be prevented after treatment with specific inhibitors of MAP kinases, inhibitors of MMP transcription, synthetic metalloproteinase inhibitors, TIMPs and treatment of cartilage with agents that upregulate TIMPs. The results from bovine cartilage culture models show that collagen release occurs when TIMP levels are low, collagenases are upregulated and then subsequently activated.

The association of antihypertensive medication use with risk of cognitive decline and dementia: a meta-analysis of longitudinal studies

The association of antihypertensive medication use with cognitive decline (including mild cognitive impairment) or dementia (including Alzheimer's disease (AD), vascular dementia (VD) and any dementia) has still been an area of controversy. This study examined the association of antihypertensive medication use with cognitive decline or dementia using a quantitative meta-analysis of longitudinal studies. EMBASE and MEDLINE were searched for articles published up to Feb 2011. All studies that examined the relationship between antihypertensive medication use and the incidence of dementia or cognitive decline were included. Pooled relative risk (RR) was calculated using fixed and random-effects models. Fourteen studies met our inclusion criteria for this meta-analysis. All subjects were without dementia or cognitive impairment at baseline. There were subjects with (32,658) and without (36,905) antihypertensive medication use. The quantitative meta-analysis showed that there was no significant difference in incidence of AD (RR: 0.90, 95% confidence interval (CI): 0.79-1.03), cognitive decline (RR: 0.97; 95% CI: 0.92-1.03) and cognitive impairment (RR: 0.97; 95% CI: 0.92-1.03). The quantitative meta-analysis showed that the subjects with antihypertensive medication use were lower incidence of VD (RR: 0.67, 95% CI: 0.52-0.87) and any dementia (RR: 0.87; 95% CI: 0.77-0.96) than those without. The quantitative meta-analysis showed that antihypertensive medication use could decrease risk of the development of VD and any dementia, but could not decrease that of AD, cognitive decline and cognitive impairment.

Salmonella enterica Serovar Typhimurium Alters the Extracellular Proteome of Macrophages and Leads to the Production of Proinflammatory Exosomes

Salmonella enterica serovar Typhimurium is a Gram-negative bacterium, which can invade and survive within macrophages. Pathogenic salmonellae induce the secretion of specific cytokines from these phagocytic cells and interfere with the host secretory pathways. In this study, we describe the extracellular proteome of human macrophages infected with S Typhimurium, followed by analysis of canonical pathways of proteins isolated from the extracellular milieu. We demonstrate that some of the proteins secreted by macrophages upon S Typhimurium infection are released via exosomes. Moreover, we show that infected macrophages produce CD63+ and CD9+ subpopulations of exosomes at 2 h postinfection. Exosomes derived from infected macrophages trigger the Toll-like receptor 4-dependent release of tumor necrosis factor alpha (TNF-α) from naive macrophages and dendritic cells, but they also stimulate secretion of such cytokines as RANTES, IL-1ra, MIP-2, CXCL1, MCP-1, sICAM-1, GM-CSF, and G-CSF. Proinflammatory effects of exosomes are partially attributed to lipopolysaccharide, which is encapsulated within exosomes. In summary, we show for the first time that proinflammatory exosomes are formed in the early phase of macrophage infection with S Typhimurium and that they can be used to transfer cargo to naive cells, thereby leading to their stimulation.

PGE2 Augments Inflammasome Activation and M1 Polarization in Macrophages Infected With Salmonella Typhimurium and Yersinia enterocolitica

Eicosanoids are cellular metabolites, which shape the immune response, including inflammatory processes in macrophages. The effects of these lipid mediators on inflammation and bacterial pathogenesis are not clearly understood. Certain eicosanoids are suspected to act as molecular sensors for the recruitment of neutrophils, while others regulate bacterial uptake. In this study, gene expression analyses indicated that genes involved in eicosanoid biosynthesis including COX-1, COX-2, DAGL, and PLA-2 are differentially regulated in THP-1 human macrophages infected with Salmonella enterica Typhimurium or Yersinia enterocolitica. By using targeted metabolomics approach, we found that the eicosanoid precursor, arachidonic acid (AA) as well as its derivatives, including prostaglandins (PGs) PGF2α or PGE2/PGD2, and thromboxane TxB2, are rapidly secreted from macrophages infected with these Gram-negative pathogenic bacteria. The magnitude of eicosanoid biosynthesis in infected host cells depends on the presence of virulence factors of Y. enterocolitica and S. Typhimurium strains, albeit in an opposite way in Y. enterocolitica compared to S. Typhimurium infection. Trials with combinations of EP2/EP4 PGE2 receptor agonists and antagonists suggest that PGE2 signaling in these infection models works primarily through the EP4 receptor. Downstream of EP4 activation, PGE2 enhances inflammasome activation and represses M2 macrophage polarization while inducing key M1-type markers. PGE2 also led to a decreased numbers of Y. enterocolitica within macrophages. To summarize, PGE2 is a potent autocrine/paracrine activator of inflammation during infection in Gram-negative bacteria, and it affects macrophage polarization, likely controlling bacterial clearance by macrophages.

Detection of oncostatin M in synovial fluid from patients with rheumatoid arthritis

OBJECTIVE

To measure oncostatin M (OSM) in synovial fluid from patients with rheumatoid arthritis (RA) and osteoarthritis (OA).

METHODS

20 samples of synovial fluid from patients with RA and 10 samples from patients with OA were examined using an OSM specific sandwich ELISA.

RESULTS

OSM was detected at concentrations ranging from 2.36 to 901.82 pg/ml in 18 (90%) of 20 samples of synovial fluid from RA patients. There was no detectable OSM in synovial fluid from OA patients. In the RA patients, the OSM concentration in synovial fluid correlated significantly with the synovial fluid white blood cell count (r = 0.67, p < 0.01), but not with other laboratory parameters of disease activity.

CONCLUSION

These findings suggest that OSM may contribute to joint inflammation in RA.

Insulin-like growth factor 1 blocks collagen release and down regulates matrix metalloproteinase-1, -3, -8, and -13 mRNA expression in bovine nasal cartilage stimulated with oncostatin M in combination with interleukin 1alpha

OBJECTIVE

To investigate the effect of insulin-like growth factor 1 (IGF1) on the release of collagen, and the production and expression of matrix metalloproteinases (MMPs) induced by the proinflammatory cytokine interleukin 1alpha (IL1alpha) in combination with oncostatin M (OSM) from bovine nasal cartilage and primary human articular chondrocytes.

METHODS

Human articular chondrocytes and bovine nasal cartilage were cultured with and without IGF1 in the presence of IL1alpha or IL1alpha + OSM. The release of collagen was measured by an assay for hydroxyproline. Collagenase activity was determined with the diffuse fibril assay using 3H acetylated collagen. The expression of MMP-1, MMP-3, MMP-8, MMP-13, and tissue inhibitor of metalloproteinase 1 (TIMP-1) mRNA was analysed by northern blot.

RESULTS

IGF1 can partially inhibit the release of collagen induced by IL1alpha or IL1alpha + OSM from bovine nasal cartilage. This was accompanied by a reduced secretion and activation of collagenase by bovine nasal cartilage. IGF1 can also down regulate IL1alpha or IL1alpha + OSM induced MMP-1, MMP-3, MMP-8, and MMP-13 mRNA expression in human articular chondrocytes and bovine chondrocytes. It had no significant effect on the production and expression of TIMP-1 mRNA in chondrocytes.

CONCLUSION

This study shows for the first time that IGF1 can partially block the release of collagen from cartilage and suggests that down regulation of collagenases by IGF1 may be an important mechanism in preventing cartilage resorption initiated by proinflammatory cytokines.

Analysis of Atrial and Ventricular Performance by Tissue Doppler Imaging in Patients with Atrial Septal Defects before and after Surgical and Catheter Closure

OBJECTIVE

To compare the effects of surgical and device closure of atrial septal defects on atrial and ventricular performance assessed by the novel tissue Doppler derived strain rate.

BACKGROUND

Despite the increasing number of transcatheter closures, there is no information comparing the effect of the transcatheter closure technique on atrial performance with that of conventional surgery. Tissue Doppler derived strain rate can effectively quantify local myocardial function independent of the overall heart motion.

DESIGN AND PATIENTS

Twenty-four patients [aged 21.5 (6-70) years] with isolated atrial septal defect of the secondum type before and 1 week after surgical (n = 12) or Amplatzer Septal Occluder closure (n = 12) and 30 healthy controls [aged 26.0 (2-58) years] were studied. Atrial and ventricular strain rate curves were assessed in the middle of their corresponding lateral walls in an apical four-chamber view. The systolic, early diastolic, and late diastolic strain rates peaks were measured.

RESULTS

Compared to preclosure condition, the right atrial late diastolic (P < 0.01), right ventricular systolic (P < 0.01), right ventricular early diastolic (P < 0.01), and left atrial late diastolic peak (P < 0.01) strain rates were reduced after surgery but not after Amplatzer Septal Occluder closure. The LV parameters did not significantly differ before and after atrial septal defect closure by either technique.

CONCLUSIONS

In contrast to surgery, transcatheter closure of atrial septal defect preserves atrial and right ventricular function. Tissue Doppler derived strain rate can be applied to provide quantitative analysis of regional atrial and ventricular performance.

Factors influencing the induction of infertility in a mouse model of Chlamydia trachomatis ascending genital tract infection

In women, infections due to Chlamydia trachomatis frequently result in long-term sequelae including chronic abdominal pain, ectopic pregnancy and infertility. In an attempt to characterise the pathogenesis of the infection, female C3H (H-2k) mice were inoculated intravaginally with different doses of C. trachomatis and then mated with proven male breeder mice. The inoculated mice developed a broad spectrum of clinical manifestations ranging from infertility to asymptomatic shedding. The dose inducing infertility in 50% of the mice was c. 10(5) inclusion-forming units of C. trachomatis. In another group of mice sampled at intervals after intravaginal inoculation, C. trachomatis was recovered from the upper genital tract starting at 24 h after infection. A higher percentage of animals infected during the luteal phase of the oestrous cycle had positive cultures from the middle and upper genital tract than when mice were inoculated during the follicular phase. These results indicate that rapid therapeutic intervention is required to avoid the sequelae resulting from C. trachomatis genital infection, and suggest that hormonal factors play a role in the pathogenesis of the disease.

Pulmonary and caval blood flow patterns in patients with intracardiac and extracardiac Fontan: a magnetic resonance study

AIMS

We compared in vivo blood flow and pulsatility after different types of Fontan operation using magnetic resonance imaging.

MATERIAL AND METHODS

A total of 37 consecutive patients (mean age 19+/-7.9 years, 7.3+/-3.2 years after Fontan operation), 7 with atriopulmonary anastomosis (APC), 18 with intra-atrial lateral tunnel (LTFO) and 12 with extracardiac Fontan (ECFO) were studied using magnetic resonance phase-contrast velocity mapping. Blood flow (volume flow) in the superior vena cava (SVC), inferior vena cava (IVC) and both pulmonary arteries were measured and a pulsatility index was calculated for each vessel.

RESULTS

For all modifications, the blood flow distribution between the SVC and IVC was normal (1:2). Patients with APC had a normal pulsatility, a dilated right atrium, partial backward flow in the IVC and physiological blood flow distribution between the pulmonary arteries. LTFO and ECFO patients had no retrograde flow in the IVC, equal blood flow distribution between the pulmonary arteries and very low or absent pulsatility.

CONCLUSIONS

MRI allows hemodynamic quantification and characterization of various types of Fontan modifications and may be a valuable tool to predict Fontan failure. Despite showing normal pulsatility, patients with APC have right atrial dilatation and partial backward flow in the IVC, demonstrating suboptimal Fontan circulation. LTFO and ECFO both produce unidirectional antegrade flow in the IVC but pulsatility is very low or absent, which may promote poor pulmonary artery growth and increase of pulmonary vascular resistance contributing to late Fontan failure.

Oncostatin M (OSM) stimulates resorption and inhibits synthesis of proteoglycan in porcine articular cartilage explants

Oncostatin M (OSM) is structurally and functionally similar to leukaemia inhibitory factor (LIF), interleukin 6 (IL-6), interleukin 11 (IL-11) and ciliary neurotrophic factor (CNTF). We have previously shown that LIF stimulates proteoglycan release and suppresses proteoglycan synthesis in pig and goat cartilage explants. The aim of this study was to determine whether OSM and related cytokines influence proteoglycan metabolism in pig cartilage explants. Slices of pig articular cartilage were incubated for 6 days in serum free DMEM with or without cytokines. The total proteoglycan content in papain digested cartilage explants and medium was determined by the 1,9 dimethylmethylene blue method. Cytokine activity was assessed by determining the percentage release of total proteoglycan. To evaluate proteoglycan synthesis, cartilage was cultured for 48 h under the same conditions and in the final 6 h the tissue was cultured in sulphate free DMEM containing 35SO4. The radioactivity in the medium and tissue was determined in cetylpyridinium chloride precipitates. Biosynthetic activity was expressed as DPM per mg wet weight of cartilage. Dose dependent stimulation of proteoglycan release and suppression of proteoglycan synthesis were observed with rhOSM. IL-6, IL-11 and CNTF also inhibited proteoglycan synthesis in a dose dependent manner but the degree of inhibition was less than that for OSM and these cytokines had no significant effect on proteoglycan release. New biological effects have been identified for OSM and the related cytokines CNTF and IL-11. All three of these cytokines, like LIF and IL-6, suppress proteoglycan synthesis in pig cartilage explants. This common effect suggests that the gp130 subunit of the receptors for these cytokines may represent a common signalling pathway whereby proteoglycan synthesis is regulated. Whilst OSM and LIF stimulate proteoglycan catabolism; IL-6 IL-11 and OSM do not. Thus these effects are not always coupled and activation of gp130 alone may not be a sufficient signal for proteoglycan catabolism.

Modulation of the expression of matrix metalloproteinase and tissue inhibitors of metalloproteinases by TGF-beta1 and IGF-1 in primary human articular and bovine nasal chondrocytes stimulated with TNF-alpha

Tumour necrosis factor-alpha (TNF-alpha) was able to promote collagen breakdown from bovine cartilage in explant culture. This release was dependent upon matrix metalloproteinases (MMPs) and could be prevented by transforming growth factor-beta1 (TGF-beta1) or insulin-like growth factor-1. Both growth factors reduced the expression and secretion of collagenase enzymes, and TGF-beta1 induced tissue inhibitor of metalloproteinase production. This study shows for the first time that these anabolic growth factors can protect cartilage against TNF-alpha-induced destruction.

Androgen activates PEG10 to promote carcinogenesis in hepatic cancer cells

The molecular mechanism of striking higher prevalence of hepatocellular carcinoma (HCC) in male subjects has not yet been fully elucidated. Here, we report that androgen receptor (AR) is differentially expressed in different HCC cell lines. AR agonist dihydrotestosterone (DHT) enhances HCC cell growth and apoptotic resistance. Antagonist flutamide (FLU) blocks the effects of DHT on the HCC cell lines. Paternally expressed gene 10 (PEG10) is expressed in HCC cell lines at substantial high level. Using small interfering RNAs against AR and PEG10 in AR- and PEG10-expressing BEL-7404 hepatoma cells and HuH7 hepatoma cells (HuH7) cells, and AR-transfection technique in AR-lacking and PEG10-expressing HepG2 cells, we have confirmed that through upregulation and activation of PEG10, DHT enhances HCC cell growth and apoptotic resistance. We have further demonstrated that DHT upregulates expression of human telomerase reverse transcriptase (hTERT) in HCC cell lines in a PEG10-dependent manner. Moreover, AR directly interacts in vivo with androgen-responsive elements in the regions of promoter and exon 2 of PEG10 gene in HCC cell lines. DHT promotes the hepatoma formation in vivo nude mice through PEG10 activation. AR antagonists (FLU and valproate) inhibit the hepatoma formation. These findings suggest that PEG10 plays an essential role in hepatocarcinogenesis. The PEG10 inhibition can be a novel approach for therapy of HCC.

Perceptual style and behavioral pattern of individuals with functional gastrointestinal disorders

The present research examined the perceptual style and coping pattern characterizing individuals with functional gastrointestinal disorders. A matched case-control design was adopted to compare differences among the target group of individuals with functional gastrointestinal disorders (n = 40), a pain control group of individuals with rheumatism (n = 40), and the community control group of healthy individuals (n = 40). Perceptual style was measured by both monitoring and blunting responses to hypothetical stressful situations, and coping pattern was measured by the use of coping strategies in real-life stressful events. Results revealed that participants with functional gastrointestinal disorders differed from their healthy and rheumatic counterparts in having higher monitoring and lower blunting scores and using action-oriented coping strategies regardless of the controllability of stressful situations.

Percutaneous transluminal coronary angioplasty without on-site surgical facilities

Percutaneous transluminal coronary angioplasty (PTCA) is associated with a low risk of serious complications, the most important of which is acute coronary occlusion needing emergency surgery. There is a consensus among many cardiologists and cardiac surgeons that all PTCA procedures need on-site surgical backup. A task force report on PTCA by the American College of Cardiology/American Heart Association mandates the presence of an on-site cardiovascular surgical team. Since 1981, we have performed PTCA without the benefit of on-site surgery but with backup surgery provided at a regional cardiac surgical center located 6 kilometers away. Up to the end of 1991, 762 patients have undergone 847 PTCAs. Most patients had 1-vessel angioplasty (94.6%). The primary success rate since 1981 was 76%, and from January 1990 to December 1991 it was 87% (n = 313). Complications included death in 7 patients (0.9%), myocardial infarction in 16 (2.1%) and emergency surgery in 12 (1.6%). Surgical backup was provided on a next available operating room basis. The average time from decision to transfer to onset of surgery was 164 minutes (range 75 to 320). All patients survived surgery, but 42% developed a new Q-wave myocardial infarction. These patients were followed up until the end of 1991, and are all alive. The results are similar to those reported from centers with and without on-site surgery. With careful selection of patients and a formal, coordinated plan for backup surgery, PTCA can be safely performed without on-site surgery.

Occluded left main stem coronary artery. Report of five patients and review of published reports

Five patients aged 24 to 62 years presenting with a long history of angina were found to have complete occlusion of the left main coronary artery. In one patient the right coronary artery was also completely blocked. All patients had a dominant right coronary artery which was significantly diseased in only one patient. Ventricular function was severely impaired in only one patient. These patients illustrate the importance of collateral information in this condition. Coronary bypass grafting was performed in three patients who are now symptomatic at follow-up between nine and 17 months.

Transforming growth factor beta 1 and insulin-like growth factor 1 block collagen degradation induced by oncostatin M in combination with tumour necrosis factor alpha from bovine cartilage

Oncostatin M (OSM) in combination with tumour necrosis factor alpha (TNF alpha) promotes marked collagen breakdown from bovine cartilage in explant culture. This release was dependent upon matrix metalloproteinases and could be prevented by transforming growth factor beta 1 (TGF beta 1) or insulin-like growth factor 1. Both growth factors reduced the expression and secretion of collagenase enzymes, and TGF beta 1 induced tissue inhibitor of metalloproteinase production. This study shows for the first time that these anabolic growth factors can protect cartilage against OSM+TNF alpha induced destruction.

Oncostatin M in combination with tumour necrosis factor {alpha} induces a chondrocyte membrane associated aggrecanase that is distinct from ADAMTS aggrecanase-1 or -2

OBJECTIVE

To determine whether oncostatin M (OSM) + tumour necrosis factor alpha (TNFalpha) induces aggrecanase activity in chondrocyte membranes, to determine the effects of transforming growth factor beta1 (TGFbeta1), interleukin 4 (IL4), and tissue inhibitor of metalloproteinases (TIMPs) on this activity, and to determine whether this activity is due to a known ADAMTS aggrecanase.

METHODS

Aggrecanase activity and ability of agents to prevent membrane associated aggrecanase activity were assessed by Western blotting. Expression of known aggrecanases was measured by real time polymerase chain reaction in bovine nasal and human articular chondrocytes.

RESULTS

Chondrocyte membrane associated aggrecanase activity and increased mRNA expression of ADAMTS-1, -4, -5, and -9, but not ADAMTS-4 or -15, were enhanced after stimulation by OSM+TNFalpha in bovine chondrocytes. This activity was inhibited by TIMP-3. In human chondrocytes, OSM+TNFalpha also enhanced ADAMTS-1 and -4 expression, but not that of other ADAMTSs. TNFalpha alone induced ADAMTS-9 expression, whereas OSM addition caused suppression. Both TGFbeta1 and IL4 blocked membrane associated aggrecanase activity and decreased OSM+TNFalpha-induced expression of ADAMTS-9 in bovine and human chondrocytes. IL4 down regulated ADAMTS-4 mRNA, whereas TGFbeta1 increased this expression in both bovine and human chondrocytes.

CONCLUSIONS

OSM+TNFalpha up regulates membrane associated aggrecanase activity and several ADAMTS aggrecanase mRNAs in chondrocytes. The chondroprotective effects of IL4 and TIMP-3 suggest that they may have therapeutic benefit for aggrecanolysis, whereas the differential inhibitory effects of TGFbeta1 may limit its therapeutic potential. Induced membrane associated aggrecanase activity is distinct from known soluble ADAMTS aggrecanases and merits further investigation.

Antigen-encapsulating host extracellular vesicles derived from Salmonella-infected cells stimulate pathogen-specific Th1-type responses in vivo

Salmonella Typhimurium is a causative agent of nontyphoidal salmonellosis, for which there is a lack of a clinically approved vaccine in humans. As an intracellular pathogen, Salmonella impacts many cellular pathways. However, the intercellular communication mechanism facilitated by host-derived small extracellular vesicles (EVs), such as exosomes, is an overlooked aspect of the host responses to this infection. We used a comprehensive proteome-based network analysis of exosomes derived from Salmonella-infected macrophages to identify host molecules that are trafficked via these EVs. This analysis predicted that the host-derived small EVs generated during macrophage infection stimulate macrophages and promote activation of T helper 1 (Th1) cells. We identified that exosomes generated during infection contain Salmonella proteins, including unique antigens previously shown to stimulate protective immune responses against Salmonella in murine studies. Furthermore, we showed that host EVs formed upon infection stimulate a mucosal immune response against Salmonella infection when delivered intranasally to BALB/c mice, a route of antigen administration known to initiate mucosal immunity. Specifically, the administration of these vesicles to animals stimulated the production of anti-Salmonella IgG antibodies, such as anti-OmpA antibodies. Exosomes also stimulated antigen-specific cell-mediated immunity. In particular, splenic mononuclear cells isolated from mice administered with exosomes derived from Salmonella-infected antigen-presenting cells increased CD4+ T cells secreting Th1-type cytokines in response to Salmonella antigens. These results demonstrate that small EVs, formed during infection, contribute to Th1 cell bias in the anti-Salmonella responses. Collectively, this study helps to unravel the role of host-derived small EVs as vehicles transmitting antigens to induce Th1-type immunity against Gram-negative bacteria. Understanding the EV-mediated defense mechanisms will allow the development of future approaches to combat bacterial infections.

Quantitative analysis of paradoxical interventricular septal motion following corrective surgery of tetralogy of fallot

This study aimed to quantify paradoxical interventricular septal motion (PSM) among 20 patients following tetralogy of Fallot (TOF) repair without severe pulmonary regurgitation and 20 age-matched normal subjects. PSM was quantified using the echocardiography-derived paradox index. Tissue Doppler-derived strain rate was used to assess the longitudinal and radial systolic function of the interventricular septum (IVS). The tissue Doppler-derived Tei index was used to assess the global left ventricular function. Compared to the control group, the paradox index in patients after repair of TOF was significantly higher (p = 0.001), whereas the regional IVS longitudinal (p = 0.02) and radial (p = 0.001) systolic strain rate peaks were significantly reduced. The paradox index in the patient group correlated inversely with the IVS radial peak systolic strain rate (r = -0.64, p = 0.004) and positively with QRS duration (r = 0.50, p = 0.02). The left ventricular (LV) Tei-index correlated significantly with the paradox index (r = 0.71, p = 0.001) and with the septal radial systolic strain rate peak (r = 0.59, p = 0.004). We conclude that electrical delay and reduced regional septal systolic function were the main causes for paradoxical septal motion among patients following TOF repair without significant pulmonary regurgitation. The reduced LV systolic function among this group of patients is mainly secondary to diminished septal systolic function and the paradoxical septal motion.

Assessment of myocardial function of the systemic right ventricle in patients with D-transposition of the great arteries after atrial switch operation by tissue Doppler echocardiography

INTRODUCTION

The long-term follow-up of patients with D-transposition of the great arteries after atrial switch operation shows specific problems such as tricuspid valve insufficiency, rhythm disturbances and failure of the morphologic right ventricle in systemic position. Assessment of the myocardial contractility of the subaortic right ventricle by conventional echocardiography is limited. The usage of tissue Doppler echocardiography with strain combined with strain rate imaging provides a new approach for quantitative analysis of longitudinal myocardial function. The aim of this study was to assess patterns of wall motion and regional contractile function of the systemic right ventricle in patients after atrial switch operation for D-transposition of the great arteries and to compare them to those of normal subjects.

PATIENTS AND METHODS

Twenty-four patients with Dtransposition of the great arteries after atrial switch operation with a mean age of 21.3 (range, 13 to 31) years and a postoperative period of 16.9 years were examined and compared to 22 control individuals with a mean age of 21.5 (range, 3 to 43) years. Tissue Doppler studies were obtained from apical 4- chamber view to determine regional systolic (Syst(T)) and diastolic (E(T), A(T)) velocities as well as E(T)/A(T) ratio at the basal free wall. The presystolic isovolumic contraction peak was assessed and the ratio of the presystolic peak velocity to the isovolumic acceleration time as the IVA index was calculated. Strain and peak systolic and diastolic strain rates were assessed on basal, middle and apical segments of the right ventricular free wall. Data obtained from the morphologic right systemic ventricle in patients were compared to those derived from the left and the right ventricle in controls.

RESULTS

The right ventricular free wall systolic velocities were significantly reduced in patients compared to velocities obtained from the normal right and left ventricle. On the other hand, the IVA index was only reduced in patients compared to the IVA index in the normal subpulmonary right ventricle. Compared to data obtained from the normal systemic left ventricle, the IVA index in patients was not significantly different. In contrast, strain and strain rate parameters in all analyzed segments mostly showed a highly significant reduction compared to normal right and left ventricular data.

CONCLUSION

Tissue Doppler echocardiography is a promising tool for the evaluation of regional myocardial contractile function of the morphologic right systemic ventricle in patients following atrial switch operation for D-transposition of the great arteries. Presystolic, systolic and diastolic regional ventricular function was reduced in the systemic right ventricle. However, further comparative studies using other quantitative parameters of global and regional myocardial function derived from cardiac catheterization or MRI should be performed in order to evaluate the reliability of tissue Doppler echocardiography for the assessment of global right ventricular function in these patients.