scholarly journals The effects of carnosine pretreatment on the inflammatory response and the PI3K/Akt signaling pathway following hypoxia-ischemia in neonatal rats

2019 ◽  
Author(s):  
Xiangmin Zhang ◽  
Lei Xia ◽  
Zhiheng Huang ◽  
Falin Xu
Keyword(s):  
Tumor Necrosis Factor ◽  
Signaling Pathway ◽  
Tumor Necrosis ◽  
Akt Signaling ◽  
Mrna Levels ◽  
Akt Signaling Pathway ◽  
Tnf Α ◽  
Hypoxia Ischemia ◽  
Pretreated Group ◽  
Necrosis Factor

AbstractAn increasing number of studies have demonstrated that carnosine plays a neuroprotective role in many types of brain injury. We have previously shown that carnosine has both short-term and long-lasting neuroprotective effects in a hypoxia–ischemia(HI) rat model. In the mature brain, post-ischemia neuronal survival involves in activation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway, whether the activation of PI3K/Akt pathway also plays an important role in the immature brain still remain unclear.The goal of this study is to detect the effection of carnosine on inflammation response following HI, further evidencing neuroprotection of carnosine. We measured total Akt, phospho-Akt (p-AKT) and tumor necrosis factor receptor 1 (TNFR1) protein levels by western blot assay and tumor necrosis factor-α (TNF-α) and TNFR1 mRNA expression using real-time RT-PCR. We found the carnosine-pretreated group had statistically significant downregulation of TNF-α mRNA levels 24 h after HI (P < 0.05). Similar results were observed when we measured TNFR1 mRNA levels both 24h and 72h after HI (P < 0.05). And the TNFR1 protein expression after HI was markedly decreased at 24 and 72 h post-HI in the carnosine-pretreated rats(P < 0.05). Nevertheless, the rats pretreated with carnosine showed a marked increase in p-Akt levels (P< 0.05). And the pro-apoptotic protein Bad was also examined using immunohistochemistry after 24 and 72 h of all groups. We found significantly fewer Bad-positive cells in the carnosine-pretreated group at each time point after HI (P < 0.05). These findings suggest that carnosine pretreatment inhibits the HI-induced inflammatory response, and neuroprotection mechanism of carnosine involved in activation of the PI3K/Akt signaling pathway.

Inhibition of the PI3K-Akt Signaling Pathway Reduces Tumor Necrosis Factor-α Production in Response to Titanium Particles in Vitro

2007 ◽  
Vol 89 (5) ◽  
pp. 1019-1027 ◽  
Author(s):  
Matthew V. Smith ◽  
Michael J. Lee ◽  
Andrew S. Islam ◽  
Jacqueline L. Rohrer ◽  
Victor M. Goldberg ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Signaling Pathway ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Akt Signaling ◽  
Akt Signaling Pathway ◽  
Factor Α ◽  
Necrosis Factor

scholarly journals Inhibition by Interleukin-1β and Tumor Necrosis Factor-α of the Insulin-Like Growth Factor I Messenger Ribonucleic Acid Response to Growth Hormone in Rat Hepatocyte Primary Culture*

Endocrinology ◽  
1997 ◽  
Vol 138 (3) ◽  
pp. 1078-1084 ◽  
Author(s):  
Jean-Paul Thissen ◽  
Josiane Verniers
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Mrna Levels ◽  
Factor I ◽  
Tnf Α ◽  
Igf I ◽  
Necrosis Factor ◽  
I Gene

Abstract The cytokines are the putative mediators of the catabolic reaction that accompanies infection and trauma. Evidence suggests that their catabolic actions are indirect and potentially mediated through changes in hormonal axis such as the hypothalamo-pituitary-adrenal axis. Insulin-like growth factor I (IGF-I) is a GH-dependent growth factor that regulates the protein metabolism. To determine whether cytokines can directly inhibit the production of IGF-I by the liver, we investigated the regulation of IGF-I gene expression by interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α (10 ng/ml) in a model of rat primary cultured hepatocytes. Hepatocytes were isolated by liver collagenase perfusion and cultured on Matrigel 48 h before experiments. Each experiment was performed in at least three different animals. In the absence of GH, IL-1β and TNF-α did not affect the IGF-I messenger RNA (mRNA) basal levels, whereas IL-6 increased it by a factor of 2.5 after 24 h (P &lt; 0.05). GH (500 ng/ml) alone stimulated the IGF-I gene expression markedly (5- to 10-fold increase) after 24 h (P &lt; 0.001). IL-1β, and TNF-α to a lesser extent, dramatically inhibited the IGF-I mRNA response to GH (IL-1β: −82%, P &lt; 0.001 and TNF-α: −47%, P &lt; 0.01). The half-maximal inhibition of the IGF-I mRNA response to GH was observed for a concentration of IL-1β between 0.1 and 1 ng/ml. Moreover, IL-1β abolished the IL-6-induced IGF-I mRNA response. In contrast, IL-6 did not impair the IGF-I mRNA response to GH. To determine the potential role of the GH receptor (GHR) and the GH-binding protein (GHBP) in this GH resistance, we assessed the GHR and GHBP mRNAs response to these cytokines. GH alone did not affect the GHR/GHBP mRNA levels. IL-1β markedly decreased the GHR and GHBP mRNA levels (respectively, −68% and −60%, P &lt; 0.05). Neither TNF-α nor IL-6 affected the GHR/GHBP gene expression. In conclusion, our results show that IL-1β, and TNF-α to a lesser extent, blunt the IGF-I mRNA response to GH. The resistance to GH induced by IL-1β might be mediated by a decrease of GH receptors, as suggested by the marked reduction of GHR mRNA. These findings suggest that decreased circulating IGF-I, in response to infection and trauma, may be caused by a direct effect of cytokines at the hepatocyte level.

scholarly journals Upregulation of p75 Tumor Necrosis Factor Alpha Receptor in Mycobacterium avium-Infected Mice: Evidence for a Functional Role

1999 ◽  
Vol 67 (11) ◽  
pp. 5762-5767 ◽  
Author(s):  
Angelo Corti ◽  
Lanfranco Fattorini ◽  
Ove Fredrik Thoresen ◽  
Maria Luisa Ricci ◽  
Anna Gallizia ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Mycobacterium Avium ◽  
Bacterial Growth ◽  
Tumor Necrosis ◽  
Mrna Levels ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT The bacterial growth and the production of tumor necrosis factor alpha (TNF-α) and TNF receptors (TNF-Rs) in the spleen and blood of BALB/c mice challenged with Mycobacterium avium complex (MAC) were monitored. Infection developed in two phases: the first, up to day 21, was associated with rapid MAC multiplication in the spleen and a drop in the mycobacteremia, and the second was associated with control of the infection in both compartments. In the spleen, TNF-α and TNF-RII mRNA levels peaked on day 21 and then slowly decreased; however, no increase in the level of TNF-RI mRNA was observed throughout these experiments. The level of circulating soluble TNF-RII (sTNF-RII) was transiently increased after day 21. In a model in which overproduction of bioactive TNF-α was triggered in response to a second infection with MAC, an increased production of sTNF-RII by cultured splenocytes was also observed. Administration of an antagonist anti-TNF-RII monoclonal antibody (MAb 6G1) to infected mice inhibited the bacterial growth in the spleen, suggesting that the TNF-RII and/or sTNF-RII was functionally involved in the mechanisms that control the infection. Overall, these observations suggest that upregulation of TNF-RII or sTNF-RII contributes to modulation of the TNF-α antibacterial activity in MAC infections.

scholarly journals Interleukin-10 Upregulates Tumor Necrosis Factor Receptor Type-II (p75) Gene Expression in Endotoxin-Stimulated Human Monocytes

Blood ◽  
1997 ◽  
Vol 90 (10) ◽  
pp. 4162-4171 ◽  
Author(s):  
Harold L. Dickensheets ◽  
Sherry L. Freeman ◽  
Michael F. Smith ◽  
Raymond P. Donnelly
Keyword(s):  
Gene Expression ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Soluble Form ◽  
Luciferase Expression ◽  
Mrna Levels ◽  
Type Ii ◽  
Tnf Α ◽  
Ifn Γ ◽  
Necrosis Factor

Abstract Interferon-γ (IFN-γ) upregulates expression of certain genes in monocytes, including cell-surface molecules such as HLA class II, B7, and ICAM-1. IFN-γ also potentiates production of cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-12. Conversely, IL-10 downregulates expression of many of these same genes and often antagonizes the effects of IFN-γ. IL-10 is known to inhibit TNF-α production in lipopolysaccharide (LPS)-stimulated monocytes; however, the effects of IL-10 on TNF receptor (TNF-R) expression are not well defined. We examined the effects of IL-10 on production of both membrane-associated (m) and soluble (s) TNF-R type II (sTNF-RII) by purified human CD14+ monocytes. We also compared the effects of IFN-γ and IL-10 on production of TNF-α and sTNF-RII by these cells. Monocytes constitutively expressed low levels of TNF-RII mRNA and mTNF-RII protein. LPS stimulation induced rapid, but transient loss (shedding) of mTNF-RII molecules and a delayed, but marked increase in TNF-RII mRNA levels. IL-10 increased expression of both mTNF-RII and sTNF-RII by LPS-stimulated monocytes, whereas IFN-γ decreased their expression. The increased levels of sTNF-RII in cultures of IL-10–treated monocytes correlated directly with increased levels of TNF-RII mRNA and inversely with the levels of TNF-α mRNA. The ability of IL-10 to upregulate TNF-RII gene expression was transcriptionally mediated because actinomycin D blocked this effect. Furthermore, IL-10 treatment did not alter the half-life of TNF-RII mRNA transcripts in LPS-stimulated monocytes. To further examine the mechanism by which IL-10 potentiates TNF-RII gene expression, a 1.8-kb fragment of the human TNF-RII promoter cloned into a luciferase expression vector (pGL2-basic) was transfected into the IL-10–responsive macrophage cell line, RAW264.7. Although IL-10 alone induced only minimal promoter activity in these cells, it markedly increased the LPS-induced response, providing further evidence that the ability of IL-10 to amplify TNF-RII gene expression is transcriptionally controlled. Together, these findings demonstrate that IL-10 coordinately downregulates expression of TNF-α and upregulates expression of TNF-RII, particularly the soluble form of this receptor, in monocytes.

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