Regulation of CCN1 (Cyr61) in a porcine model of intestinal ischemia/reperfusion.

Intestinal ischemia is a serious condition that may lead to both local and systemic inflammatory responses. Restoration of blood supply (reperfusion) to ischemic tissues often increases the extent of the tissue injury. Cysteine-rich angiogenic inducer 61 (Cyr61)/CCN1 is an extracellular matrix-associated signaling protein that has diverse functions. CCN1 is highly expressed at sites of inflammation and wound repair, and may modify cell responses. This study aimed to investigate regulation and cellular distribution of CCN1 in intestinal ischemia/reperfusion (I/R) injury in pigs. After intestinal I/R, increased expression of CCN1 was detected by quantitative RT-PCR, Western blot analysis and immunohistochemistry compared with non-ischemic intestine. Immunoflorescence staining revealed that CCN1 was mainly up-regulated in intestinal mucosa after intestinal I/R. Microvillus epithelial cells and vascular endothelial cells were strongly positive for CCN1 in intestinal I/R, while natural killer cells and/or subsets of neutrophils were only modestly positive for CCN1. Furthermore, blood samples taken from the portal and caval veins during ischemia and after reperfusion showed no change of the CCN1 levels, indicating that CCN1 was locally regulated. In conclusion, these observations show, for the first time, that the CCN1 molecule is up-regulated in response to intestinal I/R in a local manner.

Effects of infliximab and hydrocortisone on in vitro cytokine responses after stimulation with lipopolysaccharide.

BACKGROUND: Both glucocorticosteroids and biologic drugs such as the tumor necrosis factor (TNF)-α antagonist infliximab are used often in the treatment of rheumatoid arthritis or inflammatory bowel disease. In severe disease, or if allergic reactions occur during treatment with infliximab, combined therapy with these drugs often is instituted. Combining infliximab and glucocorticosteroids may increase substantially the risk of severe opportunistic infections or dissemination of malignant tumors because of their additive effects as immunosuppressants. METHODS: In a whole-blood in vitro model, we studied the influence of different doses of infliximab and hydrocortisone, either separately or in combination, on the synthesis of selected cytokines after stimulation with lipopolysaccharide (LPS). RESULTS: Hydrocortisone in therapeutic serum concentrations significantly inhibited the expression of a majority of the cytokines tested. Infliximab, in serum concentrations relevant to clinical situations, inhibited TNF-α activity significantly. This effect was potentiated when infliximab was combined with hydrocortisone. Similar effects were found using a low dose of infliximab combined with hydrocortisone. Infliximab alone inhibited the expression of the cytokines interleukin (IL)-1 receptor antagonist, monocyte chemoattractant protein-1, IL-8, and IL-12. Hydrocortisone in combination with low-dose infliximab potentiated the suppressive effects on TNF-α, IL-1ß, IL-8, and macrophage inflammatory protein-1α synthesis. CONCLUSIONS: Immune-modulating effects of infliximab were found both in clinically relevant doses and, most notably, in low doses reflecting serum concentrations found commonly in patients several months after the last injection. Infliximab potentiates the suppressive effects of hydrocortisone on cytokine synthesis.

Impact of hypertonic saline on the release of selected cytokines after stimulation with LPS or peptidoglycan in ex vivo whole blood from healthy humans.

The question of specific immunomodulating qualities of hypertonic saline (HTS) has not been settled. It has proven difficult to distinguish between immunomodulation directly attributable to HTS and influence because of favorable circulatory effects. The nature of immune activator may also play a role. In a whole-blood model, we have investigated these relations further, with special emphasize on osmolalities usually found after recommended dosing. Blood from 10 healthy donors was exposed to osmolalities ranging from 295 to 480 mOsm/kg and stimulated with the two clinically relevant stimulators peptidoglycan (1 µg/mL) or LPS (10 ng/mL) for 6 h at 37°C. Leukocyte response was evaluated by measuring selected cytokines in the supernatant. Moderate hyperosmolality alone boosted the release of CXCL8/IL-8. The peptidoglycan-stimulated synthesis of pivotal proinflammatory cytokines was inhibited in an osmolality-dependent way, but statistically significant only at osmolalities above those attained after routine use of HTS, i.e., 310 mOsm/kg or greater: IL-6 (P < 0.05 at 315 mOsm/kg), IL-1ß, and TNF-α (P < 0.05 at 335 mOsm/kg). Similar effects were seen for the chemokine CCL3 and the anti-inflammatory cytokine IL-10. In contrast, the effects in cells stimulated with LPS were either lower or absent. Thus, osmolalities usually found after clinical use of HTS only modestly influenced the selected immune parameters, regardless of stimulator.

Effects of high-dose corticosteroids on post-traumatic inflammatory mediators.

OBJECTIVE: Plasma concentrations of inflammatory mediators are substantially increased in major orthopaedic surgery. It was our hypothesis that corticosteroids would reduce the post-operative levels of inflammatory mediators in patients with ankylosing spondylitis, and we performed a single-centre randomised controlled trial. PATIENTS AND METHODS: In 20 consecutive patients, an osteotomy of the lumbar spine was done. By concealed random allocation, 10 of the patients were given 10 mg/kg of methylprednisolone pre-operatively. The control patients received the same amount of saline. Samples of arterial blood and local blood from the surgical site were sampled and analysed for inflammatory cytokines and prostaglandin E2. RESULTS: There were significant increments in systemic levels of IL-6, IL-10 and sTNF-R1. Corticosteroids significantly reduced the increases of IL-6 and significantly increased the levels of IL-10 and sTNF-R1. Locally, the expressions of TNF-alpha, IL-1beta, IL-6 and sTNF-R1 were significantly increased in both groups post-operatively. Corticosteroids significantly increased the local expressions of IL-10 and sTNF-R1. There were significantly higher local than systemic levels of inflammatory mediators except for TNF-alpha. CONCLUSION: This study shows that in traumatic injury there are generally higher local than systemic expressions of inflammatory mediators, and that the main anti-inflammatory effects of high-dose corticosteroids are suppression of systemic IL-6 and increased expressions of IL-10 and sTNF-R1, both systemically and locally.

The phosphatidylinositol 3-kinase/protein kinase B signaling pathway is activated by lipoteichoic acid and plays a role in Kupffer cell production of interleukin-6 (IL-6) and IL-10.

Sepsis caused by gram-positive bacteria lacking lipopolysaccharide (LPS) has become a major and increasing cause of mortality in intensive-care units. We have recently demonstrated that the gram-positive-specific bacterial cell wall component lipoteichoic acid (LTA) stimulates the release of the proinflammatory cytokines in Kupffer cells in culture. In the present study, we have started to assess the signal transduction events by which LTA induces the production of tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and the anti-inflammatory cytokine IL-10 in rat Kupffer cells. LTA was found to trigger phosphorylation of mitogen-activated protein kinases (MAPK) (p38 MAPK and ERK 1/2) and protein kinase B (PKB). Compared to LPS, LTA was more potent in inducing PKB phosphorylation after 40 min, although we found that the cytokine responses were similar. For both bacterial molecules, blocking phosphatidylinositol 3-kinase (PI3-K; Ly294002) or Janus kinase 2 (JAK-2; AG490) particularly affected the induction of IL-6 and IL-10 release, whereas TNF-alpha levels were strongly reduced by inhibition of Src family tyrosine kinases (PP2). All three cytokines were reduced by inhibition of p38 MAPK (SB202190) or the broad-range tyrosine kinase inhibitor genistein, whereas IL-6 release was particularly blocked by inhibition of ERK 1/2 (PD98059). Divergences in the regulatory pathways controlling TNF-alpha, IL-10, and IL-6 production in Kupffer cells following LPS or LTA stimulation may create a basis for understanding how the balance between pro- and anti-inflammatory cytokines is regulated in the liver following infections by gram-positive or gram-negative bacteria.

Tranexamic acid given into the wound reduces postoperative blood loss by half in major orthopaedic surgery.

OBJECTIVE: To evaluate the effect of locally applied tranexamic acid on postoperative blood loss and measures of fibrinolysis in drained blood. DESIGN: Prospective study. SETTING: University hospital, Norway. PATIENTS: 30 patients operated on for low back pain by screw fixation of the lumbar spine, 16 of who were randomised to be given topical tranexamic acid. MAIN OUTCOME MEASURES: Postoperative blood loss after 18 hours. Concentrations of plasmin/alpha2-antiplasmin (PAP) and D-dimer in arterial and drained blood at the time of wound closure and in drained blood after 1 hour. RESULTS: In the tranexamic group median (interquartile) blood loss was reduced by half from 525 (325-750) ml to 252 (127-465) ml, p = 0.02. In drained blood after one hour the increase in the concentration of PAP was 150 (109-170)% and D-dimer 150 (107-272)% in the tranexamic group compared with the control group where the increase in PAP was 320 (140-540)% and D-dimer 260 (161-670)%. CONCLUSION: Tranexamic acid applied in the wound inhibits blood loss by up to a half in major orthopaedic surgery probably because it prevents excessive fibrinolysis.