scholarly journals Monocyte Function in the Fetus and the Preterm Neonate: Immaturity Combined with Functional Impairment

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Zoe Iliodromiti ◽  
Anastasis Anastasiadis ◽  
Michail Varras ◽  
Kalliopi I. Pappa ◽  
Charalambos Siristatidis ◽  
...  

It is well known that the innate immunity system, involving the contribution of monocytes and macrophages, may dysfunction in fetuses and preterm neonates. Monocytes are capable of differentiating into dendritic cells (DCs) or into mucosal macrophages during certain infections and of producing inflammatory mediators such as TNF-α(tumor necrosis factor-alpha), nitric oxide, and reactive oxygen species. Fetuses as well as neonates are prone to infections as a result of a defective mechanism within the above mononuclear system. Monocyte function in fetuses and preterm neonates depends on the phagocytic and oxidative capacity of macrophages and their antigen-adhesion ability. Functional rather than anatomical impairment is probably the underlying cause, while a defective production of cytokines, such as TNF-α, IL-6 (Interleukin 6), IL-1β(Interleukin 1 beta), and G-CSF (Granulocyte Colony-Stimulating Factor), has also been involved. The insufficient production of the above inflammatory mediators and the phenomenon of endotoxin intolerance, which latter occurs during entry of any antigen into the premature neonate, place preterm neonates at higher risk for infections. Existing research data are herein presented which, however, are deficient and fragmental, this accounting for the fact that the precise pathophysiology of these disturbances is not yet fully clarified.

2019 ◽  
Vol 8 (6) ◽  
pp. 772 ◽  
Author(s):  
Li Liu ◽  
Youde Jiang ◽  
Jena J. Steinle

The role of high mobility group box 1 (HMGB1) in acute diabetic retinal damage has been demonstrated. We recently reported that glycyrrhizin, a HMGB1 inhibitor, protected the diabetic retina against neuronal, vascular, and permeability changes. In this study, we wanted to investigate the role of exchange protein for cAMP 1 (Epac1) on HMGB1 and the actions of glycyrrhizin. Using endothelial cell specific knockout mice for Epac1, we made some mice diabetic using streptozotocin, and treated some with glycyrrhizin for up to 6 months. We measured permeability, neuronal, and vascular changes in the Epac1 floxed and knockout mice. We also investigated whether Epac1 and glycyrrhizin work synergistically to reduce the retinal inflammatory mediators, tumor necrosis factor alpha (TNFα) and interleukin-1-beta (IL1β), as well as sirtuin 1 (SIRT1) levels. Epac1 and glycyrrhizin reduced inflammatory mediators with synergistic actions. Glycyrrhizin also increased SIRT1 levels in the Epac1 mice. Overall, these studies demonstrate that glycyrrhizin and Epac1 can work together to protect the retina. Finally, glycyrrhizin may regulate HMGB1 through increased SIRT1 actions.


Diabetes ◽  
1993 ◽  
Vol 42 (7) ◽  
pp. 1026-1031 ◽  
Author(s):  
K. Yamada ◽  
N. Takane ◽  
S. Otabe ◽  
C. Inada ◽  
M. Inoue ◽  
...  

1991 ◽  
Vol 261 (5) ◽  
pp. R1096-R1103 ◽  
Author(s):  
M. Shibata ◽  
C. M. Blatteis

This study was undertaken to determine whether the reported different courses of the febrile responses to the cytokines interleukin-1 beta (IL-1), interferon-alpha 2 (IFN), and tumor necrosis factor-alpha (TNF) might have neuroelectrophysiological correlates. The reactions of individual thermosensitive neurons in the preoptic area (POA) were evaluated by recording their extracellular single-unit firing rates (FR) in slices of guinea pig POA perfused with artificial cerebrospinal fluid (aCSF), human recombinant IL-1 (50-500 ng), IFN (1,000-8,000 U), and TNF (400-5,000 ng) (all doses per min/ml aCSF); thermosensitivity was assessed by FR responses to changes of perfusate temperature (32-42 degrees C). Overall, these cytokines depressed the FR of warm-sensitive units and excited those of cold-sensitive units, in agreement with expectations. However, the responses of individual neurons treated with two or all three cytokines were dissimilar: 61% of the units tested reacted differentially to two or three cytokines, 32% exhibited identical responses, and 7% had no response to any cytokine. These results support the possibility that IL-1, IFN, and TNF may affect not the same but rather distinct neurons functionally connected to common pyrogenic effectors. Thus they suggest that differential neuronal substrates may be utilized by each cytokine to exert its pyrogenic effect.


1989 ◽  
Vol 259 (2) ◽  
pp. 585-588 ◽  
Author(s):  
E E Golds ◽  
P Mason ◽  
P Nyirkos

Exposure of human synovial cells and fibroblasts in monolayer culture to interleukin 1 results in prominent secretion of proteins with Mr values of 6000 and 7000. By N-terminal sequence analysis, the Mr-6000 protein is identified as the protein encoded by a recently described gro mRNA. The Mr-7000 protein is identical to a neutrophil chemotactic factor released from monocytes. Stimulation of normal human fibroblasts with tumour necrosis factor alpha also results in expression and secretion of these two proteins. In addition to these cytokine-induced proteins, we have identified beta 2-microglobulin as an Mr-8000 protein constitutively secreted by synovial cells.


1994 ◽  
Vol 14 (10) ◽  
pp. 6561-6569
Author(s):  
L Klampfer ◽  
T H Lee ◽  
W Hsu ◽  
J Vilcek ◽  
S Chen-Kiang

Tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) activate transcription of the TSG-6 gene in normal human fibroblasts through a promoter region (-165 to -58) that encompasses an AP-1 and a NF-IL6 site. We show by deletion analysis and substitution mutagenesis that both sites are necessary for activation by TNF-alpha. Activation by IL-1 requires the NF-IL6 site and is enhanced by the AP-1 site. These results suggest that the NF-IL6 and AP-1 family transcription factors functionally cooperate to mediate TNF-alpha and IL-1 signals. Consistent with this possibility, IL-1 and TNF-alpha markedly increase the binding of Fos and Jun to the AP-1 site, and NF-IL6 activates the native TSG-6 promoter. Activation by NF-IL6 requires an intact NF-IL6 site and is modulated by the ratio of activator to inhibitor NF-IL6 isoforms that are translated from different in-frame AUGs. However, the inhibitor isoform can also bind to the AP-1 site and repress AP-1 site-mediated transcription. The finding that the inhibitor isoform antagonizes activation of the native TSG-6 promoter by IL-1 and TNF-alpha suggests that NF-IL6 has a physiologic role in these cytokine responses. Thus, the functionally distinct NF-IL6 isoforms cooperate with Fos and Jun to positively and negatively regulate the native TSG-6 promoter by TNF-alpha and IL-1.


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