Response of tumour necrosis factor-α to delayed in vitro monocyte stimulation in patients with septic shock is related to outcome

2002 ◽  
Vol 102 (3) ◽  
pp. 315-320 ◽  
Author(s):  
Olivier APPOLONI ◽  
Jean-Louis VINCENT ◽  
Jean DUCHATEAU

We hypothesized that cytokine production following delayed in vitro cell stimulation (to reproduce physiological cellular status at baseline) may be related to outcome in patients with septic shock. A total of 20 patients were included in a prospective clinical study, conducted in a medico-surgical intensive care unit in a university hospital. Blood samples were obtained at the onset of septic shock; these were treated to retain the cells, but to wash out autologous plasma (containing potential inflammatory stimuli such as cytokines, bacterial products and drugs) and replace it with foetal calf serum. Each treated sample was divided into two sets of four aliquots, to be stimulated either immediately or after an overnight period of resting incubation at 37°C. The rest period was to allow recovery from potentially reversible endogenous or pharmacologically induced alterations in cellular response, in order to reproduce a near physiological state at baseline. In vitro cellular challenges used low-dose (0.2ng/ml) or high-dose (1ng/ml) CD14-dependent lipopolysaccharide and CD14-independent pokeweed mitogen to induce the production of tumour necrosis factor-α (TNF-α), and interleukins-1β and -10. Levels of TNF-α, interleukin-1β and interleukin-10 were significantly higher (P < 0.05) when cell stimulation was delayed for 16h, indicating a functional down-regulation of cells during septic shock. Moreover, TNF-α responses obtained with high-dose lipopolysaccharide were significantly greater in cells from patients who subsequently survived septic shock (n = 13; median value 1392pg/ml; range 592-2048pg/ml) than in cells from non-survivors (n = 7; median value 708 pg/ml; range 520-1344pg/ml). These observations support the existence of individual differences in the inflammatory response that could influence patient outcome following septic shock.

2001 ◽  
Vol 101 (3) ◽  
pp. 267-274 ◽  
Author(s):  
Thomas A. HEMING ◽  
Sanat K. DAVÉ ◽  
Divina M. TUAZON ◽  
Ashok K. CHOPRA ◽  
Johnny W. PETERSON ◽  
...  

Cellular acid–base status has been found to exert selective actions on the effector functions of activated macrophages (mϕ). We examined the effects of extracellular pH (pHo) on the production of tumour necrosis factor-α (TNF-α) induced by lipopolysaccharide (LPS) in resident alveolar mϕ. Cells were obtained by bronchoalveolar lavage of rabbits, activated in vitro with LPS, and cultured at pHo 5.5, 6.5 or 7.4 for up to 18 h. The relative abundance of TNF-α mRNA peaked at ~ 2 h. The peak transcript abundance was increased at lower pHo values. This finding probably reflected pre-transcription/transcription effects of pH, in as much as the stability of TNF-α mRNA induced with phorbol ester was unaffected by the experimental pHo values. TNF-α secretion by LPS-treated mϕ decreased at lower pHo values. The TNF-α content of mϕ-conditioned media decreased progressively with decrements in pHo. The reduced TNF-α secretion at pHo 5.5 was accompanied by an increase in the cytosolic TNF-α content (compared with that at pHo 7.4), indicating that pHo altered TNF-α secretion due, in part, to the intracellular retention of synthesized cytokine (i.e. a post-translation effect). The data show that pHo has multiple effects (pre-transcription/transcription and post-translation) on TNF-α production induced by LPS in resident alveolar mϕ. These results suggest that the role of alveolar mϕ in inflammatory responses is modulated by pHo, which may be important in tumours/abscesses and sites of infection where the external milieu is acidic.


2011 ◽  
Vol 435 (2) ◽  
pp. 381-390 ◽  
Author(s):  
Christopher J. Clarke ◽  
Emily A. Cloessner ◽  
Patrick L. Roddy ◽  
Yusuf A. Hannun

Activation of N-SMase (neutral sphingomyelinase) is an established part of the response of cytokines such as TNF (tumour necrosis factor)-α. However, it remains unclear which of the currently cloned N-SMase isoforms (nSMase1, nSMase2 and nSMase3) are responsible for this activity. In MCF-7 cells, we found that TNF-α induces late, but not early, increases in N-SMase activity, and that nSMase2 is the primary isoform activated, most likely through post-transcriptional mechanisms. Surprisingly, overexpression of tagged or untagged nSMase3 in multiple cell lines had no significant effect on in vitro N-SMase activity. Moreover, only overexpression of nSMase2, but not nSMase1 or nSMase3, had significant effects on cellular sphingolipid levels, increasing ceramide and decreasing sphingomyelin. Additionally, only siRNA (small interfering RNA) knockdown of nSMase1 significantly decreased basal in vitro N-SMase activity of MCF-7 cells, whereas nSMase2 but not nSMase3 siRNA inhibited TNF-α-induced activity. Taken together, these results identify nSMase2 as the major TNF-α-responsive N-SMase in MCF-7 cells. Moreover, the results suggest that nSMase3 may not possess in vitro N-SMase activity and does not affect cellular sphingolipid levels in the cell lines evaluated. On the other hand, nSMase1 contributes to in vitro N-SMase activity, but does not affect cellular sphingolipids much.


1995 ◽  
Vol 144 (3) ◽  
pp. 457-462 ◽  
Author(s):  
G Haskó ◽  
I J Elenkov ◽  
V Kvetan ◽  
E S Vizi

Abstract The effect of selective block of α2-adrenoreceptors on plasma levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and corticosterone induced by bacterial lipopolysaccharide (LPS) was investigated in mice using ELISA and RIA. It was found that the LPS-induced TNF-α response was significantly blunted in mice pretreated with CH-38083, a novel and highly selective α2-adrenoreceptor antagonist (the α2/α1 ratio is >2000). In contrast, LPS-induced increases in both corticosterone and IL-6 plasma levels were further increased by CH-38083. Since it has recently been shown that the selective block of α2-adrenoreceptors located on noradrenergic axon terminals resulted in an increase in the release of noradrenaline (NA), both in the central and peripheral nervous systems, and, in our experiments, that propranolol prevented the effect of α2-adrenoreceptor blockade on TNF-α plasma levels induced by LPS, it seems likely that the excessive stimulation by NA of β-adrenoreceptors located on cytokine-secreting immune cells is responsible for this action. Since it is generally accepted that increased production of TNF-α is involved in the pathogenesis of inflammation and endotoxin shock on the one hand, and corticosterone and even IL-6 are known to possess anti-inflammatory properties on the other hand, it is suggested that the selective block of α2-adrenoreceptors might be beneficial in the treatment of inflammation and/or endotoxin shock. Journal of Endocrinology (1995) 144, 457–462


2016 ◽  
Vol 36 (1) ◽  
Author(s):  
Abbas Jawad Al-Shabany ◽  
Alan John Moody ◽  
Andrew David Foey ◽  
Richard Andrew Billington

Bacterial lipopolysaccharide induces changes in intracellular NAD+ levels in a pro-inflammatory, but not an anti-inflammatory, macrophage model that are correlated with the release of the pro-inflammatory cytokine tumour necrosis factor-α (TNF-α).


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