scholarly journals Inflammatory cytokines TNFα, IL-1β, and IL-6 are induced in endotoxin- stimulated microglia through different signaling cascades

2021 ◽  
Vol 104 (4) ◽  
pp. 003685042110549
Author(s):  
Takashi Ishijima ◽  
Kazuyuki Nakajima

By using an animal model in which inflammatory cytokines are induced in lipopolysaccharide (LPS)-injected rat brain, we investigated the induction of tumor necrosis factor alpha (TNFα), interleukin-1beta (IL-1β), and IL-6. Immunoblotting and immunohistochemistry revealed that all three cytokines were transiently induced in the cerebral cortex at about 12 h after LPS injection. To clarify which glial cell type induced the cytokines, we examined the respective abilities of astrocytes and microglia in vitro. Primary microglia largely induced TNFα, IL-1β and IL-6 in response to LPS, but primary astrocytes induced only limited levels of TNFα. Thus, we used specific inhibitors to focus on microglia in surveying signaling molecules involved in the induction of TNFα, IL-1β, and IL-6. The experiments using mitogen-activated protein kinases (MAPK) inhibitors revealed that c-Jun N-terminal kinase (JNK)/p38, external signal regulated kinase (ERK)/JNK, and ERK/JNK/p38 are necessary for the induction of TNFα, IL-1β, and IL-6, respectively. The experiments using protein kinase C (PKC) inhibitor clarified that PKCα is required for the induction of all these cytokines in LPS-stimulated microglia. Furthermore, LPS-dependent IL-1β/IL-6 induction was suppressed by pretreatment with a nitric oxide (NO) scavenger, suggesting that NO is involved in the signaling cascade of IL-1β/IL-6 induction. Thus, an inducible NO synthase induced in the LPS-injected cerebral cortex might be related to the induction of IL-1β/IL-6 through the production of NO in vivo. Taken together, these results demonstrated that microglia induce different kinds of inflammatory cytokine through specific combinations of MAPKs and by the presence or absence of NO.

Author(s):  
Ingus Skadiņš ◽  
Juta Kroiča ◽  
Ilze Salma ◽  
Aigars Reinis ◽  
Marina Sokolova ◽  
...  

Abstract Local antibiotic therapy has several advantages over systemic antibiotic treatment. Using antibiotics in local biomaterial systems can reduce the number of microorganisms that can adhere to implanted biomaterials. In this in vitro study, antibacterial properties of hydroxyapatite biomaterials impregnated with antibiotics and biodegradable polymers were examined. The antibacterial efficiency of hydroxyapatite biomaterials impregnated with antibiotics and biodegradable polymers against Staphylococcus epidermidis and Pseudomonas aeruginosa was studied by evaluating the expression of inflammatory cytokines (Interleukin-10 (IL-10), -defensin-2 and tumour necrosis factor alpha (TNF- )) in tissue surrounding implanted biomaterials in vivo. The results of this study demonstrated that hydroxyapatite biomaterials impregnated with antibiotics and biodegradable polymers had a prolonged antibacterial effect in comparison to biomaterials without biodegradable polymers. Surrounding tissue displayed higher levels of inflammatory cytokines when implanted biomaterials had not been previously impregnated with antibiotics.


2000 ◽  
Vol 68 (9) ◽  
pp. 5139-5145 ◽  
Author(s):  
Lisl K. M. Shoda ◽  
Guy H. Palmer ◽  
Jorge Florin-Christensen ◽  
Monica Florin-Christensen ◽  
Dale L. Godson ◽  
...  

ABSTRACT The tick-transmitted hemoparasite Babesia bovis causes an acute infection that results in persistence and immunity against challenge infection in cattle that control the initial parasitemia. Resolution of acute infection with this protozoal pathogen is believed to be dependent on products of activated macrophages (Mφ), including inflammatory cytokines and nitric oxide (NO) and its derivatives.B. bovis stimulates inducible nitric oxide synthase (iNOS) and production of NO in bovine Mφ, and chemical donors of NO inhibit the growth of B. bovis in vitro. However, the induction of inflammatory cytokines in Mφ by babesial parasites has not been described, and the antiparasitic activity of NO produced by B. bovis-stimulated Mφ has not been definitively demonstrated. We report that monocyte-derived Mφ activated by B. bovisexpressed enhanced levels of inflammatory cytokines interleukin-1β (IL-1β), IL-12, and tumor necrosis factor alpha that are important for stimulating innate and acquired immunity against protozoal pathogens. Furthermore, a lipid fraction of B. bovis-infected erythrocytes stimulated iNOS expression and NO production by Mφ. Cocultures of Mφ and B. bovis-infected erythrocytes either in contact or physically separated resulted in reduced parasite viability. However, NO produced by bovine Mφ in response to B. bovis-infected erythrocytes was only partially responsible for parasite growth inhibition, suggesting that additional factors contribute to the inhibition of B. bovis replication. These findings demonstrate that B. bovis induces an innate immune response that is capable of controlling parasite replication and that could potentially result in host survival and parasite persistence.


Blood ◽  
1998 ◽  
Vol 91 (2) ◽  
pp. 475-483 ◽  
Author(s):  
Keith E. Norman ◽  
Gary P. Anderson ◽  
Hartmut C. Kolb ◽  
Klaus Ley ◽  
Beat Ernst

Abstract Leukocyte rolling is the earliest observable event in their recruitment from the circulation to inflamed tissue. This rolling is mediated largely by interaction between the selectin family of adhesion molecules and their glycosylated ligands. Although the nature of these ligands and their interaction with the selectins is not fully understood, it is accepted that expression of fucosylated sialylated glycans such as sialyl Lewisx (sLex) is required for function. Despite findings that sLex inhibits binding of leukocytes to E-selectin in vitro, and has beneficial effects in inflammatory disease models, inhibition of E-selectin–dependent leukocyte rolling in vivo has not been described. Functional overlap between the selectins has been noted and reduction of rolling by E-selectin antibodies only occurs if P-selectin is absent or blocked. We demonstrate that leukocyte rolling velocity in tumor necrosis factor alpha (TNFα)-stimulated mouse cremaster is increased following treatment with either sLex or the sLex-mimetic CGP69669A and that rolling is dramatically reduced if CGP69669A is applied in the presence of anti–P-selectin antibody. These effects are characteristic of E-selectin antagonism. In contrast, surgically stimulated (L- or P-selectin–dependent) rolling is unaffected by either sLex or CGP69669A. Our data demonstrate that CGP69669A is an effective and selective antagonist of E-selectin in vivo.


Blood ◽  
2000 ◽  
Vol 96 (10) ◽  
pp. 3585-3591 ◽  
Author(s):  
Keith E. Norman ◽  
Andreas G. Katopodis ◽  
Gebhard Thoma ◽  
Frank Kolbinger ◽  
Anne E. Hicks ◽  
...  

Abstract Selectin-dependent rolling is the earliest observable event in the recruitment of leukocytes to inflamed tissues. Several glycoproteins decorated with sialic acid, fucose, and/or sulfate have been shown to bind the selectins. The best-characterized selectin ligand is P-selectin glycoprotein-1 (PSGL-1) that supports P-selectin– dependent rolling in vitro and in vivo. In vitro studies have suggested that PSGL-1 may also be a ligand for E- and L-selectins. To study the in vivo function of PSGL-1, without the influence of other leukocyte proteins, the authors observed the interaction of PSGL-1–coated microspheres in mouse venules stimulated to express P- and/or E-selectin. Microspheres coated with functional recombinant PSGL-1 rolled in surgically stimulated and tumor necrosis factor alpha (TNFα)-stimulated mouse venules. P-selectin deficiency or inhibition abolished microsphere rolling in surgically and TNFα-stimulated venules, whereas E-selectin deficiency or inhibition increased microsphere rolling velocity in TNFα-stimulated venules. The results suggest that P-selectin–PSGL-1 interaction alone is sufficient to mediate rolling in vivo and that E-selectin–PSGL-1 interaction supports slow rolling.


2016 ◽  
Vol 5 (3) ◽  
pp. 836-847 ◽  
Author(s):  
Crystal S. Lewis ◽  
Luisa Torres ◽  
Jeremy T. Miyauchi ◽  
Cyrus Rastegar ◽  
Jonathan M. Patete ◽  
...  

Abstract Understanding the nature of interactions between nanomaterials, such as commercially ubiquitous hematite (α-Fe2O3) nanorhombohedra (N-Rhomb) and biological systems is of critical importance for gaining insight into the practical applicability of nanomaterials. Microglia represent the first line of defense in the central nervous system (CNS) during severe injury or disease such as Parkinson's and Alzheimer's disease as illustrative examples. Hence, to analyze the potential cytotoxic effect of N-Rhomb exposure in the presence of microglia, we have synthesized Rhodamine B (RhB)-labeled α-Fe2O3 N-Rhomb, with lengths of 47 ± 10 nm and widths of 35 ± 8 nm. Internalization of RhB-labeled α-Fe2O3 N-Rhomb by microglia in the mouse brain was observed, and a dose-dependent increase in the cellular iron content as probed by cellular fluorescence was detected in cultured microglia after nanoparticle exposure. The cells maintained clear functional viability, exhibiting little to no cytotoxic effects after 24 and 48 hours at acceptable, physiological concentrations. Importantly, the nanoparticle exposure did not induce microglial cells to produce either tumor necrosis factor alpha (TNFα) or interleukin 1-beta (IL1β), two pro-inflammatory cytokines, nor did exposure stimulate the production of nitrites and reactive oxygen species (ROS), which are common indicators for the onset of inflammation. Finally, we propose that under the conditions of our experiments, i.e. in the presence of RhB labeled-α-Fe2O3 N-Rhomb maintaining concentrations of up to 100 μg mL−1 after 48 hours of incubation, the in vitro and in vivo internalization of RhB-labeled α-Fe2O3 N-Rhomb are likely to be clathrin-dependent, which represents a conventional mechanistic uptake route for most cells. Given the crucial role that microglia play in many neurological disorders, understanding the potential cytotoxic effects of these nanostructures is of fundamental importance if they are to be used in a therapeutic setting.


1996 ◽  
Vol 270 (1) ◽  
pp. H183-H193 ◽  
Author(s):  
R. M. Binns ◽  
S. T. Licence ◽  
A. A. Harrison ◽  
E. T. Keelan ◽  
M. K. Robinson ◽  
...  

The endothelial molecule E-selectin binds most leukocyte subsets in vitro. Yet its role in regulating the very different kinetics of inflammatory infiltration of different leukocyte subsets in vivo is unclear. The kinetics of E-selectin upregulation and polymorphonuclear leukocyte (PMN) and blood lymphocyte (PBL) localization in inflammation induced by interleukin-1 alpha (IL-1 alpha), tumor necrosis factor-alpha (TNF-alpha), phytohemagglutinin (PHA), and phorbol myristate acetate (PMA) were investigated in a well-established inbred pig trafficking model. They differed markedly both for these three labeled indicators of inflammation and in each of the four inflammatory processes. In each, E-selectin upregulation correlated with early PMN entry and later with PBL infiltration but was more protracted than both. The importance of E-selectin was confirmed by marked inhibition of PMN and PBL entry (up to > 60%) by F(ab')2 anti-E-selectin. Involvement of other molecules was illustrated by similar or greater inhibition with anti-CD18 F(ab')2. We conclude that, like CD18, E-selectin is necessary for most PMN and PBL infiltration but alone is insufficient, consistent with the involvement of several alternative multistep molecular mechanisms in this entry.


Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1216-1225 ◽  
Author(s):  
F Rosselli ◽  
J Sanceau ◽  
E Gluckman ◽  
J Wietzerbin ◽  
E Moustacchi

Abstract We have previously shown an unbalanced cytokine production in Fanconi anemia (FA) cells, ie, an underproduction of interleukin 6 (IL-6) during growth. Among a number of cytokines analyzed, the only other anomalies detected concern tumor necrosis factor alpha (TNF alpha). In comparison to normal cells, this cytokine is overproduced by FA lymphoblasts from the four genetic complementation groups. Indeed, up to an eight-fold increase in TNF alpha is observed in the growth medium of FA cells. Moreover, addition of anti-TNF alpha antibodies partially corrects the FA hypersensitivity to treatment by mitomycin C (MMC). Treatment of FA cells with IL-6, which partially restored an almost normal sensitivity to MMC of FA cells also reduces the TNF alpha overproduction in FA lymphoblasts. No anomalies at the molecular level (Southern and Northern blot analyses) are detected for the TNF alpha gene and its mRNA. We have investigated the in vivo situation by assaying TNF alpha levels in the serum from FA homozygotes and obligate heterozygotes. In contrast to normal healthy donors or to aplastic anemia patients in whom serum TNF alpha is present only in trace amounts, all 36 FA patients and 21 FA parents monitored show a significantly (P < .001) higher level of serum TNF alpha activity. Consequently, abnormal TNF alpha production seems to be associated with the FA genetic background.


2002 ◽  
Vol 9 (4) ◽  
pp. 892-897 ◽  
Author(s):  
Jean-San Chia ◽  
Huei-Ting Lien ◽  
Po-Ren Hsueh ◽  
Pei-Min Chen ◽  
Andy Sun ◽  
...  

ABSTRACT Production of proinflammatory cytokines is implicated in the pathogenesis of viridans streptococcus-induced α-streptococcal shock syndrome and infective endocarditis. Streptococcus mutans, one of the opportunistic pathogens causing infective endocarditis, was reported previously to stimulate monocytes and epithelial and endothelial cells in vitro to produce various cytokines. We found that glucosyltransferases (GTFs) GtfC and GtfD of S. mutans stimulated predominantly the production of interleukin-6 (IL-6) from T cells cultured in vitro. The level of IL-6 but not of tumor necrosis factor alpha in blood was significantly elevated when rats were injected intravenously with S. mutans GS-5, whereas IL-6 was detected at a much lower level when rats were challenged with NHS1DD, an isogenic mutant defective in the expression of GTFs. The serum IL-6 level was elevated in patients with endocarditis caused by different species of viridans streptococci which express GTF homologues. Affinity column-purified GTFs reduced the levels of detectable IL-2 of T cells stimulated by another bacterial antigen, tetanus toxoid. These results suggested that GTFs might modulate the production of Th1-type cytokines and that GTFs of S. mutans play a significant role in stimulating the production of the proinflammatory cytokine IL-6 in vivo.


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