In vivo E-selectin upregulation correlates early with infiltration of PMN, later with PBL entry: MAbs block both

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 ◽  
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.


1991 ◽  
Vol 173 (3) ◽  
pp. 699-703 ◽  
Author(s):  
E P Sampaio ◽  
E N Sarno ◽  
R Galilly ◽  
Z A Cohn ◽  
G Kaplan

Thalidomide selectively inhibits the production of human monocyte tumor necrosis factor alpha (TNF-alpha) when these cells are triggered with lipopolysaccharide and other agonists in culture. 40% inhibition occurs at the clinically achievable dose of the drug of 1 micrograms/ml. In contrast, the amount of total protein and individual proteins labeled with [35S]methionine and expressed on SDS-PAGE are not influenced. The amounts of interleukin 1 beta (IL-1 beta), IL-6, and granulocyte/macrophage colony-stimulating factor produced by monocytes remain unaltered. The selectivity of this drug may be useful in determining the role of TNF-alpha in vivo and modulating its toxic effects in a clinical setting.


2007 ◽  
Vol 15 (9) ◽  
pp. 1053-1060 ◽  
Author(s):  
A. Hennerbichler ◽  
F.T. Moutos ◽  
D. Hennerbichler ◽  
J.B. Weinberg ◽  
F. Guilak

2020 ◽  
Vol 10 (3) ◽  
pp. 458-463
Author(s):  
Nasim Dana ◽  
Golnaz Vaseghi ◽  
Shaghayegh Haghjooy Javanmard

Purpose : Although peroxisome proliferator-activated receptor γ (PPARγ) is known as a regulator of fatty acid storage, fat cell differentiation, glucose and lipid metabolism, recent studies show that PPARγ has anticancer effects. The mechanisms of PPARγ activation in melanoma cancer remain unclarified. Recently, increased TLR4 expression has been associated with the melanoma cancer progression. We investigated whether the anti-cancer effect of PPARγ is through regulating TLR4 signaling pathway. Methods: Mouse melanoma cells (B16F10) were treated in different groups: control, pioglitazone (1, 10, 100, 300 µmol/L), lipopolysaccharide (LPS) (5 µg/mL) and LPS + pioglitazone. In another experiment, they were treated with CLI-095 (1 μM), and after 1 hour pioglitazone was added and subsequently stimulated with LPS. MTT assay was performed to measure the cell viability in vitro. The expression of Tlr4, Myd88, Nf-κb genes were evaluated by quantitative reverse transcription PCR (qRT-PCR) in different groups. The concentration of tumor necrosis factor alpha and Interleukin 1 beta in the cell culture medium were measured by enzyme-linked immunosorbent assay (ELISA) kits. Results: We show that activation of PPARγ by its agonist, pioglitazone, reduces cell proliferation, Tlr-4, Myd-88, Nf-kb mRNA expression, and tumor necrosis factor-alpha (TNF-α) production but not interleukin-1 β (IL-1β) in B16F10 LPS–stimulated cells in vitro. Moreover, treatment of B16F10 cells with TLR4 inhibitor prior treatment with pioglitazone indicate that the anticancer effects of pioglitazone on melanoma cells was dependent on TLR4. Conclusion: The results indicate that pioglitazone has a beneficial protective effect against melanoma by affecting the TLR4 signaling pathway.


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