scholarly journals Enhanced Cerebral Expression of MCT1 and MCT2 in a Rat Ischemia Model Occurs in Activated Microglial Cells

2009 ◽  
Vol 29 (7) ◽  
pp. 1273-1283 ◽  
Author(s):  
Tiago JTP Moreira ◽  
Karin Pierre ◽  
Fumihiko Maekawa ◽  
Cendrine Repond ◽  
Aleta Cebere ◽  
...  

Monocarboxylate transporters (MCTs) are essential for the use of lactate, an energy substrate known to be overproduced in brain during an ischemic episode. The expression of MCT1 and MCT2 was investigated at 48 h of reperfusion from focal ischemia induced by unilateral extradural compression in Wistar rats. Increased MCT1 mRNA expression was detected in the injured cortex and hippocampus of compressed animals compared to sham controls. In the contralateral, uncompressed hemisphere, increases in MCT1 mRNA level in the cortex and MCT2 mRNA level in the hippocampus were noted. Interestingly, strong MCT1 and MCT2 protein expression was found in peri-lesional macrophages/microglia and in an isolectin B4+/S100β+ cell population in the corpus callosum. In vitro, MCT1 and MCT2 protein expression was observed in the N11 microglial cell line, whereas an enhancement of MCT1 expression by tumor necrosis factor-α (TNF-α) was shown in these cells. Modulation of MCT expression in microglia suggests that these transporters may help sustain microglial functions during recovery from focal brain ischemia. Overall, our study indicates that changes in MCT expression around and also away from the ischemic area, both at the mRNA and protein levels, are a part of the metabolic adaptations taking place in the brain after ischemia.

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yajie Yang ◽  
Yaokun Zhang ◽  
Yiyuan Kang ◽  
Chen Hu ◽  
Yanli Zhang ◽  
...  

The aim of this study is to evaluate the biological safety of tantalum (Ta) particles and to further explore the effects of Ta particles on human monocyte toxicity and inflammatory cytokine expression. Human monocyte leukemia (THP-1) cells were cultured with Ta and hydroxyapatite (HA) particles. Cell counting kit-8 method was used to evaluate the cytotoxicity of Ta and HA particles. The apoptosis effects were evaluated by flow cytometry, and the protein expression levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA. The protein levels of inflammation-related signaling pathways including nuclear factor-kappa B (NF-κB) and extracellular regulated kinase (ERK) were detected by western blotting. The cytotoxicity test showed that the toxicity level of Ta in vitro was grade l, which is within the clinically acceptable range. Compared with the HA control, Ta had no significant effect on THP-1 cell apoptosis, IL-6, and TNF-α release. The phosphorylated levels of NF-κB and ERK at 3 h in the Ta group were lower than those in the HA and control groups ( P < 0.001 both). These results reveal Ta particles behave good biosafety properties and provide some new insights for the future clinical use of Ta.


1997 ◽  
Vol 273 (6) ◽  
pp. R1885-R1890 ◽  
Author(s):  
Tom Van Der Poll ◽  
Stephen F. Lowry

Epinephrine has been found to inhibit the production of the proinflammatory cytokine tumor necrosis factor (TNF)-α and to enhance the production of anti-inflammatory cytokine interleukin (IL)-10. To determine the effect of epinephrine on IL-1β production, the following experiments were performed: 1) blood obtained from subjects at 4–21 h after the start of a continuous infusion of epinephrine (30 ng ⋅ kg−1⋅ min−1) produced less IL-1β after ex vivo stimulation with lipopolysaccharide (LPS), compared with blood drawn from subjects infused with saline; 2) in whole blood in vitro, epinephrine caused a dose-dependent decrease in LPS-induced IL-1β production, which was likely mediated via adrenergic receptors; and 3) inhibition of TNF and enhancement of IL-10 both contributed to epinephrine-induced inhibition of IL-1β production. Epinephrine, either endogenously produced or administered as a component of sepsis treatment, may attenuate excessive activity of proinflammatory cytokines early in the course of systemic infection.


Blood ◽  
2009 ◽  
Vol 113 (21) ◽  
pp. 5111-5120 ◽  
Author(s):  
Michael D. Milsom ◽  
Bernhard Schiedlmeier ◽  
Jeff Bailey ◽  
Mi-Ok Kim ◽  
Dandan Li ◽  
...  

AbstractEctopic delivery of HOXB4 elicits the expansion of engrafting hematopoietic stem cells (HSCs). We hypothesized that inhibition of tumor necrosis factor-α (TNF-α) signaling may be central to the self-renewal signature of HOXB4. Because HSCs derived from Fanconi anemia (FA) knockout mice are hypersensitive to TNF-α, we studied Fancc−/− HSCs to determine the physiologic effects of HOXB4 on TNF-α sensitivity and the relationship of these effects to the engraftment defect of FA HSCs. Overexpression of HOXB4 reversed the in vitro hypersensitivity to TNF-α of Fancc−/− HSCs and progenitors (P) and partially rescued the engraftment defect of these cells. Coexpression of HOXB4 and the correcting FA-C protein resulted in full correction compared with wild-type (WT) HSCs. Ectopic expression of HOXB4 resulted in a reduction in both apoptosis and reactive oxygen species in Fancc−/− but not WT HSC/P. HOXB4 overexpression was also associated with a significant reduction in surface expression of TNF-α receptors on Fancc−/− HSC/P. Finally, enhanced engraftment was seen even when HOXB4 was expressed in a time-limited fashion during in vivo reconstitution. Thus, the HOXB4 engraftment signature may be related to its effects on TNF-α signaling, and this pathway may be a molecular target for timed pharmacologic manipulation of HSC during reconstitution.


1999 ◽  
Vol 276 (2) ◽  
pp. H671-H678 ◽  
Author(s):  
David W. A. Beno ◽  
Robert E. Kimura

Previous investigators have demonstrated that the tumor necrosis factor-α (TNF-α) response to endotoxin is inhibited by exogenous corticosterone or catecholamines both in vitro and in vivo, whereas others have reported that surgical and nonsurgical stress increase the endogenous concentrations of these stress-induced hormones. We hypothesized that elevated endogenous stress hormones resultant from experimental protocols attenuated the endotoxin-induced TNF-α response. We used a chronically catheterized rat model to demonstrate that the endotoxin-induced TNF-α response is 10- to 50-fold greater in nonstressed (NS) rats compared with either surgical-stressed (SS, laparotomy) or nonsurgical-stressed (NSS, tail vein injection) models. Compared with the NS group, the SS and NSS groups demonstrated significantly lower mean peak TNF-α responses at 2 mg/kg and 6 μg/kg endotoxin [NS 111.8 ± 6.5 ng/ml and 64.3 ± 5.9 ng/ml, respectively, vs. SS 3.9 ± 1.1 ng/ml ( P < 0.01) and 1.3 ± 0.5 ng/ml ( P < 0.01) or NSS 5.2 ± 3.2 ng/ml ( P < 0.01) at 6 μg/kg]. Similarly, baseline concentrations of corticosterone and catecholamines were significantly lower in the NSS group [84.5 ± 16.5 ng/ml and 199.8 ± 26.2 pg/ml, respectively, vs. SS group 257.2 ± 35.7 ng/ml ( P< 0.01) and 467.5 ± 52.2 pg/ml ( P < 0.01) or NS group 168.6 ± 14.4 ng/ml ( P < 0.01) and 1,109.9 ± 140.7 pg/ml ( P < 0.01)]. These findings suggest that the surgical and nonsurgical stress inherent in experimental protocols increases baseline stress hormones, masking the endotoxin-induced TNF-α response. Subsequent studies of endotoxic shock should control for the effects of protocol-induced stress and should measure and report baseline concentrations of corticosterone and catecholamines.


Pteridines ◽  
1996 ◽  
Vol 7 (3) ◽  
pp. 72-76
Author(s):  
Tadashi Lizuka ◽  
Mitsuyo Sasaki ◽  
Hitomi Kamisako ◽  
Ko Oishi ◽  
Shigeru Uemura ◽  
...  

Summary In Kawasaki disease patients, increases in excretion of urinary neopterin coincided with fever and monocytosis in peripheral blood. We examined the products of neopterin, tumor necrosis factor-α (TNFα) and Interleukin-1 β (1L-1β) from healthy adult macrophages/monocytes (Mφ>/M), after stimulation with several activators to obtain some understanding of Kawasaki disease. Upon stimulation with either lipopolysaccharide (LPS) or polyinosinate-polycytidylate (Poly I:C), the Mφ/M released neopterin and pyogenic products (TNF-α or 1L-1β). The release of neopterin was eliminated by the addition of the anti-interferon-y antibody. The production of both TNF-α, 1L-1β and neopterin from Mφ/M upon stimulation of LPS was augmented in a co-culture with low dose recombinant interferon-y (rIFN-γ). Upon stimulation with rIFN-γ alone, however, the Mφ/M released neopterin but not the pyogenic products. A preliminary examination failed to detect. any difference in the response of the Mφ/M in adults annd children after stimulation with LPS. We concluded that some endotoxins could trigger the onset of Kawasaki disease and that endogenous IFN-γ can play an important role in the abnormality of Kawasaki disease patients


2000 ◽  
Vol 279 (3) ◽  
pp. H946-H951 ◽  
Author(s):  
Elizabeth M. Wagner

The pro-inflammatory characteristics of tumor necrosis factor-α (TNF-α) have been extensively characterized in in vitro systems. Furthermore, this cytokine has been shown to play a pivotal role in airways inflammation in asthma. Since the airway vasculature also performs an essential function in inflammatory cell transit to the airways, experiments were performed to determine the effects of TNF-α on bronchial vascular resistance (BVR). In anesthetized, ventilated sheep, the bronchial artery (BA) was cannulated and perfused with autologous blood. BVR was defined as inflow pressure/flow and averaged 6.3 ± 0.2 mmHg · ml−1 · min−1 (±SE) for the 25 sheep studied. Recombinant human TNF-α (10 μg for 20 or 40 min) infused directly into the BA resulted in a significant decrease in BVR to 87% of baseline ( P < 0.05). This vasodilation was followed by a reversal of tone by 120 min and a sustained increase in BVR to 126% of baseline ( P < 0.05). Since others have shown TNF-α caused coronary vasoconstriction through endothelial release of endothelin-1 (ET-1), an ET-1 antagonist was used to block bronchial vasoconstriction. BQ-123, a selective ETA receptor antagonist, was delivered to the bronchial vasculature prior to TNF-α challenge. Attenuation of bronchial vasoconstriction was observed at 120 min ( P < 0.03). Thus TNF-α causes bronchial vasoconstriction by the secondary release of ET-1. Although TNF-α exerts pro-inflammatory actions on most cells of the airways, vasoactive properties of this cytokine likely further contribute to the inflammatory status of the airways.


2010 ◽  
Vol 79 (4) ◽  
pp. 559-569 ◽  
Author(s):  
Barbara Jana ◽  
Marlena Koszykowska ◽  
Aneta Andronowska

The present study was undertaken to determine the effect of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) on prostaglandin (PG)F2α and PGE2 secretion as well as cyclooxygenase-2 (COX-2) protein expression in myometrium collected on days 25, 30 and 40 of pregnancy in pigs. Myometrial slices were incubated for 16 h with IL-1β, IL-6 and TNF-α (1 or 10 ng/ml of medium) or two combinations of the three cytokines (1 or 10 ng/ml of each cytokine per combination). We demonstrated the stimulatory effect of IL-1β and IL-6 on PGF2α and PGE2 secretion from myometrium collected on all examined days of pregnancy, excepting of influence of IL-6 on release of PGF2α by tissue from day 30. In turn, TNF-α was able to stimulate only PGE2 secretion by myometrium of 40-day-pregnant gilts. The three cytokines applied in combination augmented release of PGE2 from myometrium collected on days 30 and 40 of pregnancy. Stimulation of PGE2 secretion by cytokines used individually was more frequent than that of PGF2α. Moreover, an enhancement in PGF2α and/or PGE2 release was accompanied by an increase of COX-2 protein expression. Our study shows the ability of cytokines to stimulate PGF2α and PGE2 release by porcine myometrium from the first third of pregnancy. Obtained data suggest that locally PGs produced in myometrium influencing the uterine contraction activity may be important for the maintenance of myometrial quiescence during pregnancy and confirm also that the complex cytokine network is an important regulatory mechanism of PGs production during pregnancy.


2002 ◽  
Vol 283 (1) ◽  
pp. R218-R226 ◽  
Author(s):  
Alexander V. Gourine ◽  
Valery N. Gourine ◽  
Yohannes Tesfaigzi ◽  
Nathalie Caluwaerts ◽  
Fred Van Leuven ◽  
...  

α2-Macroglobulin (α2M) is not only a proteinase inhibitor in mammals, but it is also a specific cytokine carrier that binds pro- and anti-inflammatory cytokines implicated in fever, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). To define the role of α2M in regulation of febrile and cytokine responses, wild-type mice and mice deficient in α2M (α2M −/−) were injected with lipopolysaccharide (LPS). Changes in body temperature as well as plasma levels of IL-1β, IL-6, and TNF-α and hepatic TNF-α mRNA level during fever in α2M −/− mice were compared with those in wild-type control mice. The α2M −/− mice developed a short-term markedly attenuated (ANOVA, P < 0.05) fever in response to LPS (2.5 mg/kg ip) compared with the wild-type mice. At 1.5 h after injection of LPS, the plasma concentration of TNF-α, but not IL-1β or IL-6, was significantly lower (by 58%) in the α2M −/− mice compared with their wild-type controls (ANOVA, P < 0.05). There was no difference in hepatic TNF-α mRNA levels between α2M −/− and wild-type mice 1.5 h after injection of LPS. These data support the hypotheses that 1) α2M is important for the normal development of LPS-induced fever and 2) a putative mechanism of α2M involvement in fever is through the inhibition of TNF-α clearance. These findings indicate a novel physiological role for α2M.


2009 ◽  
Vol 296 (6) ◽  
pp. H1850-H1858 ◽  
Author(s):  
Jiyeon Yang ◽  
Yoonjung Park ◽  
Hanrui Zhang ◽  
Xiangbin Xu ◽  
Glen A. Laine ◽  
...  

We hypothesized that the interaction between tumor necrosis factor-α (TNF-α)/nuclear factor-κB (NF-κB) via the activation of IKK-β may amplify one another, resulting in the evolution of vascular disease and insulin resistance associated with diabetes. To test this hypothesis, endothelium-dependent (ACh) and -independent (sodium nitroprusside) vasodilation of isolated, pressurized coronary arterioles from mLepr db (heterozygote, normal), Lepr db (homozygote, diabetic), and Lepr db mice null for TNF-α ( dbTNF−/ dbTNF−) were examined. Although the dilation of vessels to sodium nitroprusside was not different between Lepr db and mLepr db mice, the dilation to ACh was reduced in Lepr db mice. The NF-κB antagonist MG-132 or the IKK-β inhibitor sodium salicylate (NaSal) partially restored nitric oxide-mediated endothelium-dependent coronary arteriolar dilation in Lepr db mice, but the responses in mLepr db mice were unaffected. The protein expression of IKK-α and IKK-β were higher in Lepr db than in mLepr db mice; the expression of IKK-β, but not the expression of IKK-α, was attenuated by MG-132, the antioxidant apocynin, or the genetic deletion of TNF-α in diabetic mice. Lepr db mice showed an increased insulin resistance, but NaSal improved insulin sensitivity. The protein expression of TNF-α and NF-κB and the protein modification of phosphorylated (p)-IKK-β and p-JNK were greater in Lepr db mice, but NaSal attenuated TNF-α, NF-κB, p-IKK-β, and p-JNK in Lepr db mice. The ratio of p-insulin receptor substrate (IRS)-1 at Ser307 to IRS-1 was elevated in Lepr db compared with mLepr db mice; both NaSal and the JNK inhibitor SP-600125 reduced the p-IRS-1-to-IRS-1 ratio in Lepr db mice. MG-132 or the neutralization of TNF-α reduced superoxide production in Lepr db mice. In conclusion, our results indicate that the interaction between NF-κB and TNF-α signaling induces the activation of IKK-β and amplifies oxidative stress, leading to endothelial dysfunction in type 2 diabetes.


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