scholarly journals Inhibition of TNF-α production contributes to the attenuation of LPS-induced hypophagia by pentoxifylline

2000 ◽  
Vol 279 (6) ◽  
pp. R2113-R2120 ◽  
Author(s):  
M. H. Porter ◽  
B. J. Hrupka ◽  
G. Altreuther ◽  
M. Arnold ◽  
W. Langhans

Cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) are assumed to mediate anorexia during bacterial infections. To improve our understanding of the role that these two cytokines serve in mediating infection during anorexia, we investigated the ability of pentoxifylline (PTX), a potent inhibitor of TNF-α production, to block the anorectic effects of the bacterial products lipopolysaccharide (LPS) and muramyl dipeptide (MDP) in rats. Intraperitoneally injected PTX (100 mg/kg body wt) completely eliminated the anorectic effect of intraperitoneally injected LPS (100 μg/kg body wt) and attenuated the anorectic effect of a higher dose of intraperitoneally injected LPS (250 μg/kg body wt). Concurrently, PTX pretreatment suppressed low-dose LPS-induced TNF-α production by more than 95% and IL-1β production 39%, as measured by ELISA. Similarly, high-dose LPS-induced TNF-α production was reduced by ∼90%. PTX administration also attenuated the tolerance that is normally observed with a second injection of LPS. In addition, PTX pretreatment attenuated the hypophagic effect of intraperitoneally injected MDP (2 mg/kg body wt) but had no effect on the anorectic response to intraperitoneally injected recombinant human TNF-α (150 ug/kg body wt). The results suggest that suppression of TNF-α production is sufficient to attenuate LPS- and MDP-induced anorexia. This is consistent with the hypothesis that TNF-α plays a major role in the anorexia associated with bacterial infection.

1998 ◽  
Vol 275 (6) ◽  
pp. R2028-R2034 ◽  
Author(s):  
Anna K. Sundgren-Andersson ◽  
Pernilla Östlund ◽  
Tamas Bartfai

Tumor necrosis factor-α (TNF-α) is a pleiotropic cytokine that orchestrates an array of local and systemic effects. For instance, acute exposure to a high dose of TNF-α results in septic shock and fever. We have used interleukin-1β (IL-1β)- and interleukin-6 (IL-6)-deficient mice, along with their wild-type equivalents, to define a role for TNF-α in fever. Briefly, the mice produced prostaglandin E2-dependent fevers in response to recombinant murine TNF-α (rmTNF-α). Furthermore, rmTNF-α (12 μg/mouse ip) triggered a febrile response in IL-1β-deficient mice as well as in their corresponding wild-type controls. In contrast, the IL-6-deficient mice were resistant to rmTNF-α (4.5 μg/mouse ip), although their wild-type counterparts readily mounted a fever. In the IL-6-deficient mice, moreover, the febrile response to rmTNF-α could be restored by a central administration of rat recombinant IL-6 (500 ng/mouse icv). We thus conclude that TNF-α can trigger fever independent of IL-1β but dependent on IL-6. We also suggest that central, rather than peripheral, IL-6 (plasma IL-6 was measured 2 h after pyrogenic challenge) is essential in TNF-α-induced fever.


2021 ◽  
Vol 22 (13) ◽  
pp. 6717
Author(s):  
Camille Jacques ◽  
Ilaria Floris ◽  
Béatrice Lejeune

Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) are two cytokines involved in the perpetuation of the chronic inflammation state characterizing rheumatoid arthritis (RA). Significant advances in the treatment of this pathology have been made over the past ten years, partially through the development of anti-TNF and anti-IL-1 therapies. However, major side effects still persist and new alternative therapies should be considered. The formulation of the micro-immunotherapy medicine (MIM) 2LARTH® uses ultra-low doses (ULD) of TNF-α, IL-1β, and IL-2, in association with other immune factors, to gently restore the body’s homeostasis. The first part of this review aims at delineating the pivotal roles played by IL-1β and TNF-α in RA physiopathology, leading to the development of anti-TNF and anti-IL-1 therapeutic agents. In a second part, an emphasis will be made on explaining the rationale of using multiple therapeutic targets, including both IL-1β and TNF-α in 2LARTH® medicine. Particular attention will be paid to the ULD of those two main pro-inflammatory factors in order to counteract their overexpression through the lens of their molecular implication in RA pathogenesis.


2019 ◽  
Vol 88 ◽  
pp. 149-150 ◽  
Author(s):  
Erkoseoglu Ilknur ◽  
Kadioglu Mine ◽  
Cavusoglu Irem ◽  
Sisman Mulkiye ◽  
Aran Turhan ◽  
...  

2005 ◽  
Vol 60 (4) ◽  
pp. 471-475 ◽  
Author(s):  
Barbara Orzeszko ◽  
Tomasz Świtaj ◽  
Anna B. Jakubowska-Mućka ◽  
Witold Lasek ◽  
Andrzej Orzeszko ◽  
...  

Certain adamantylated heterocycles were previously shown to enhance the secretion of tumor necrosis factor alpha (TNF-α) by murine melanoma cells that have been transduced with the gene for human TNF-α and constitutively expressed this cytokine. The stimulatory potency of those compounds depended, among other factors, on the structure of the linker between the adamantyl residue and the heterocyclic core. In the present study, a series of (1-adamantyl)alkylsulfanyl derivatives of heterocyclic compounds was prepared by alkylation of the corresponding thioheterocyles. Of the novel adamantylalkylthio compounds tested in the aforementioned cell line, 2-(2-adamantan-1-ylethylsulfanyl)- 4-methyl-pyrimidine was found to be the most active


2017 ◽  
Vol 9 ◽  
pp. 117957351770927 ◽  
Author(s):  
Rudy Chang ◽  
Kei-Lwun Yee ◽  
Rachita K Sumbria

Tumor necrosis factor α (TNF-α) plays a central role in the pathophysiology of Alzheimer’s disease (AD). Food and Drug Administration–approved biologic TNF-α inhibitors are thus a potential treatment for AD, but they do not cross the blood-brain barrier. In this short review, we discuss the involvement of TNF-α in AD, challenges associated with the development of existing biologic TNF-α inhibitors for AD, and potential therapeutic strategies for targeting TNF-α for AD therapy.


2002 ◽  
Vol 283 (4) ◽  
pp. G947-G956 ◽  
Author(s):  
Nathan W. Werneburg ◽  
M. Eugenia Guicciardi ◽  
Steven F. Bronk ◽  
Gregory J. Gores

Cathepsin B (Cat B) is released from lysososomes during tumor necrosis factor-α (TNF-α) cytotoxic signaling in hepatocytes and contributes to cell death. Sphingosine has recently been implicated in lysosomal permeabilization and is increased in the liver by TNF-α. Thus the aims of this study were to examine the mechanisms involved in TNF-α-associated lysosomal permeabilization, especially the role of sphingosine. Confocal microscopy demonstrated Cat B-green fluorescent protein and LysoTracker Red were both released from lysosomes after treatment of McNtcp.24 cells with TNF-α/actinomycin D, a finding compatible with lysosomal destabilization. In contrast, endosomes labeled with Texas Red dextran remained intact, suggesting lysosomes were specifically targeted for permeabilization. LysoTracker Red was released from lysosomes in hepatocytes treated with TNF-α or sphingosine in Cat B(+/+) but not Cat B(−/−) hepatocytes, as assessed by a fluorescence-based assay. With the use of a calcein release assay in isolated lysosomes, sphingosine permeabilized liver lysosomes isolated from Cat B(+/+) but not Cat B(−/−) liver. C6ceramide did not permeabilize lysosomes. In conclusion, these data implicate a sphingosine-Cat B interaction inducing lysosomal destabilization during TNF-α cytotoxic signaling.


2009 ◽  
Vol 36 (4) ◽  
pp. 837-842 ◽  
Author(s):  
ANA FILIPA MOURÃO ◽  
JOANA CAETANO-LOPES ◽  
PAULA COSTA ◽  
HELENA CANHÃO ◽  
MARIA JOSÉ SANTOS ◽  
...  

Objective.Considering the relevance of tumor necrosis factor-α (TNF-α) in the pathophysiology of juvenile idiopathic arthritis (JIA), it is likely that polymorphisms in its promoter area may be relevant in disease susceptibility and activity. We investigated if clinical measures of JIA activity and TNF-α serum concentrations were associated with TNF-α −308 genotypes.Methods.Portuguese patients with JIA in 5 pediatric rheumatology centers were recruited consecutively, along with a control group of healthy subjects. Demographic and clinical data and blood samples were collected from each patient. DNA was extracted for analysis of TNF-α gene promoter polymorphisms at position −308 by restriction fragment-length polymorphism.Results.One hundred fourteen patients and 117 controls were evaluated; 57% of patients presented the oligoarticular subtype, 25% the polyarticular subtype, 8% the systemic subtype, and 9% had enthesitis-related arthritis and 5% psoriatic arthritis. Twenty-four percent of the patients presented the −308 GA/AA genotypes and 76% the −308 GG genotype, similar to findings in controls. Patients with the −308 GA/AA genotype had higher degree of functional impairment, erythrocyte sedimentation rate, 100-mm visual analog scale score for disease activity, and TNF-α levels compared to those with the −308 GG genotype.Conclusion.TNF-α −308 GA/AA genotypes were found to be related to higher inflammatory activity and worse measures of disease activity in Portuguese patients with JIA. They were not associated with susceptibility to JIA.


2008 ◽  
Vol 19 (3) ◽  
pp. 855-864 ◽  
Author(s):  
Yoshinori Takei ◽  
Ronald Laskey

Although nerve growth factor (NGF) promotes survival of neurons, tumor necrosis factor α (TNF-α) contributes to cell death triggered by NGF depletion, through TNF-α receptor (TNFR) 1. In contrast to this effect, TNF-α can promote neural cell survival via TNF-α receptor TNFR2. Although these findings demonstrate pivotal roles of TNF-α and NGF in cell fate decisions, cross-talk between these signaling pathways has not been clarified. We find that NGF can induce TNF-α synthesis through the nuclear factor-κB transcription factor. This provides a new basis for examining the cross-talk between NGF and TNF-α. Inhibition of TNFR2 shows opposite effects on two downstream kinases of NGF, extracellular signal-regulated kinase (Erk) and Akt. It increases Erk activation by NGF, and this increased activation induces differentiation of neuroblastoma cell lines. Reciprocally, inhibition of TNFR2 decreases Akt activation by NGF. Consistent with an essential role of Akt in survival signaling, inhibition of TNF-α signaling decreases NGF-dependent survival of neurons from rat dorsal root ganglia. Thus, NGF and NGF-induced TNF-α cooperate to activate Akt, promoting survival of normal neural cells. However, the NGF-induced TNF-α suppresses Erk activation by NGF, blocking NGF-induced differentiation of neuroblastoma cells. TNFR2 signaling could be a novel target to modulate cell responses to NGF.


1995 ◽  
Vol 146 (2) ◽  
pp. 279-286 ◽  
Author(s):  
R C Olney ◽  
D M Wilson ◽  
M Mohtai ◽  
P J Fielder ◽  
R L Smith

Abstract IGF-I is the major anabolic factor for cartilage matrix production. Chondrocytes and cartilage treated with interleukin-1α (IL-1α), and chondrocytes from several models of inflammatory joint disease, exhibit reduced responsiveness to IGF-I. Since the IGF-binding proteins (IGFBPs) modulate the effects of IGF-I, we examined the effect of IL-1α and tumor necrosis factor-α (TNF-α) on IGFBP production by normal human articular chondrocytes in primary culture. Western ligand blots and immunoprecipitation of conditioned medium samples showed that articular chondrocytes produced IGFBPs-2, −3 and −4 and glycosylated IGFBP-4. Both IL-1α and TNF-α increased chondrocyte production of IGFBP-3, but did not alter IGFBP-4 production. The activity of a neutral metalloprotease with the ability to cleave IGFBP-3 was also increased by IL-1α. These data suggest that the cytokines IL-1α and TNF-α may act to reduce IGF-I access to chondrocytes by increasing production of IGFBP-3. This may be a factor in the decreased matrix production in the inflammatory arthritides. Journal of Endocrinology (1995) 146, 279–286


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