Once upon a time, inflammation

Inflammation has accompanied humans since their first ancestors appeared on Earth. Aulus Cornelius Celsus (25 BC-50 AD), a Roman encyclopedist, offered a still valid statement about inflammation: "Notae vero inflammationis sunt quatuor: rubor et tumor cum calore and dolore", defining the four cardinal signs of inflammation as redness and swelling with heat and pain. While inflammation has long been considered as a morbid phenomenon, John Hunter (18th century) and Elie Metchnikoff (19th century) understood that it was a natural and beneficial event that aims to address a sterile or an infectious insult. Many other famous scientists and some forgotten ones have identified the different cellular and molecular players, and deciphered the different mechanisms of inflammation. This review pays tribute to some of the giants who made major contributions, from Hippocrates to the late 19th and first half of the 20th century. We particularly address the discoveries related to phagocytes, diapedesis, chemotactism, and fever. We also mention the findings of the various inflammatory mediators and the different approaches designed to treat inflammatory disorders.(AU)

Blocking junctional adhesion molecule C promotes the recovery of cisplatin-induced acute kidney injury

BACKGROUND/AIMS: Recent findings have demonstrated the occurrence of neutrophil transendothelial migration in the reverse direction (reverse TEM) and that endothelial junctional adhesion molecule C (JAM-C) is a negative regulator of reverse TEM. In this study, we tested the effects of a JAM-C blocking antibody on the resolution of kidney injuries and inflammation in a mouse model of cisplatin-induced acute kidney injury (AKI). METHODS: Cisplatin was administered via intraperitoneal injection. A JAM-C blocking antibody or a control immunoglobulin G was administered intraperitoneal at 1.5 mg/kg, with the injection being delayed until day 4 following cisplatin administration to restrict the effect of antibodies on recovery. RESULTS: After cisplatin injection, serum creatinine and histologic injuries peaked on day 4. Treatment with a JAM-C blocking antibody on days 4 and 5 promoted the functional and histologic recovery of cisplatin-induced AKI on days 5 and 6. Facilitating recovery with a JAM-C blocking antibody correlated with significantly increased circulating intercellular adhesion molecule 1+ Tamm-Horsfall protein+ neutrophils and significantly decreased renal neutrophil infiltration, indicating that facilitating reverse the TEM of neutrophils from the kidney to the peripheral circulation partially mediated the resolution of inflammation and recovery. CONCLUSIONS: These results demonstrated that reverse TEM is involved in the resolution of neutrophilic inflammation in cisplatin-induced AKI and that JAM-C is an important regulator of this process.

Fate of Neutrophils during the Recovery Phase of Ischemia/Reperfusion Induced Acute Kidney Injury

Effective clearance of inflammatory cells is required for resolution of inflammation. Here, we show in vivo evidence that apoptosis and reverse transendothelial migration (rTEM) are important mechanisms in eliminating neutrophils and facilitating recovery following ischemia/reperfusion injury (IRI) of the kidney. The clearance of neutrophils was delayed in the Bax knockout (KO)BM → wild-type (WT) chimera in which bone marrow derived cells are partially resistant to apoptosis, compared to WTBM → WT mice. These mice also showed delayed functional, histological recovery, increased tissue cytokines, and accelerated fibrosis. The circulating intercellular adhesion molecule-1 (ICAM-1)+ Gr-1+ neutrophils displaying rTEM phenotype increased during the recovery phase and blockade of junctional adhesion molecule-C (JAM-C), a negative regulator of rTEM, resulted in an increase in circulating ICAM-1+ neutrophils, faster resolution of inflammation and recovery. The presence of Tamm-Horsfall protein (THP) in circulating ICAM-1+ neutrophils could suggest that they are derived from injured kidneys. In conclusion, we suggest that apoptosis and rTEM are critically involved in the clearance mechanisms of neutrophils during the recovery phase of IRI.

Nucleotide Binding Oligomerization Domain 1 Is an Essential Signal Transducer in Human Epithelial Cells Infected with Helicobacter pylori That Induces the Transepithelial Migration of Neutrophils

BACKGROUND/AIMS: The cytosolic host protein nucleotide binding oligomerization domain 1 (Nod1) has emerged as a key pathogen recognition molecule for innate immune responses in epithelial cells. The purpose of the study was to elucidate the mechanism by which Helicobacter pylori infection leads to transepithelial neutrophil migration in a Nod1-mediated manner. METHODS: Human epithelial cell lines AGS and Caco-2 were grown and infected with H. pylori. Interleukin (IL)-8 mRNA expression and IL-8 secretion were assessed, and nuclear factor kappaB (NF-kappaB) activation was determined. Stable transfections of AGS and Caco-2 cells with dominant negative Nod1 were generated. Neutrophil migration across the monolayer was quantified. RESULTS: Cytotoxin-associated gene pathogenicity island (cagPAI)(+) H. pylori infection upregulated IL-8 mRNA expression and IL-8 secretion in AGS and Caco-2 cells compared with controls. NF-kappaB activation, IL-8 mRNA expression and IL-8 secretion by cagPAI knockdown strains were reduced compared with those infected with the wild-type strain. NF-kappaB activation, IL-8 mRNA expression and IL-8 secretion in dominant-negative (DN)-Nod1 stably transfected cells were reduced compared with the controls. The transepithelial migration of neutrophils in DN-Nod1 stably transfected cells was reduced compared with that in controls. CONCLUSIONS: Signaling through Nod1 plays an essential role in neutrophil migration induced by the upregulated NF-kappaB activation and IL-8 expression in H. pylori-infected human epithelial cells.

KR-31543 reduces the production of proinflammatory molecules in human endothelial cells and monocytes and attenuates atherosclerosis in mouse model

KR-31543, (2S, 3R, 4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro-2-dimethyoxymethyl-3-hydroxy-2-methyl-2H-1-benz opyran is a new neuroprotective agent for ischemia-reperfusion damage. It has also been reported that KR-31543 has protective effects on lipid peroxidation and H2O2-induced reactive oxygen species production. In this study, we investigated the anti-inflammatory and anti-atherogenic properties of KR-31543. We observed that KR-31543 treatment reduced the production of MCP-1, IL-8, and VCAM-1 in HUVECs, and of MCP-1 and IL-6 in THP-1 human monocytes. We also examined the effect of KR-31543 on monocytes migration in vitro. KR-31543 treatment effectively reduced the migration of THP-1 human monocytes to the HUVEC monolayer in a dose-dependent manner. We next examined the effects of this compound on atherogenesis in LDL receptor deficient (Ldlr-/-) mice. After 10 weeks of western diet, the formation of atherosclerotic lesion in aorta was reduced in the KR-31543-treated group compared to the control group. The accumulation of macrophages in lesion was also reduced in KR-31543 treated group. However, the plasma levels of total cholesterol, HDL, LDL, and triglyceride were not affected by KR-31543 treatment. Taken together, these results show that KR-31543 has anti-inflammatory properties on human monocytes and endothelial cells, and inhibits fatty streak lesion formation in mouse model of atherosclerosis, suggesting the potential of KR-31543 for the treatment for atherosclerosis.

Blockade of vascular angiogenesis by Aspergillus usamii var. shirousamii-transformed Angelicae Gigantis Radix and Zizyphus jujuba

The matrix metalloproteinases (MMP) play an important role in tumor invasion, angiogenesis and inflammatory tissue destruction. Increased expression of MMP was observed in benign tissue hyperplasia and in atherosclerotic lesions. Invasive cancer cells utilize MMP to degrade the extracellular matrix and vascular basement membrane during metastasis, where MMP-2 has been implicated in the development and dissemination of malignancies. The present study attempted to examine the antiangiogenic activity of the medicinal herbs of Aspergillus usamii var. shirousamii-transformed Angelicae Gigantis Radix and Zizyphus jujube (tAgR and tZj) with respect to MMP-2 production and endothelial motility in phorbol 12-myristate 13-acetate (PMA)- or VEGF-exposed human umbilical vein endothelial cells (HUVEC). Nontoxic tAgR and tZj substantially suppressed PMA-induced MMP-2 secretion. In addition, 25 microg/mL tAgR and tZj prevented vascular endothelial growth factor-stimulated endothelial cell transmigration and tube formation. The results reveal that tAgR and tZj dampened endothelial MMP-2 production leading to endothelial transmigration and tube formation. tAgR and tZj-mediated inhibition of endothelial MMP may boost a therapeutic efficacy during vascular angiogenesis.

Resveratrol blunts tumor necrosis factor-alpha-induced monocyte adhesion and transmigration

The leukocyte recruitment and transmigration across the endothelial barrier into the vessel wall are crucial steps in atherosclerosis. Leukocyte trafficking on the endothelium is elicited by induction of endothelial adhesion molecules, and its transmigration is mediated by degradation of basement membrane proteins through enzymatic activity of matrix metalloproteinases (MMP). The current study investigated whether resveratrol, a polyphenol present in grapes and red wine, was capable of inhibiting leukocyte adhesion to tumor necrosis factor (TNF)-alpha-activated endothelium. It was found that resveratrol inhibited the TNF-alpha-activated endothelial expression of vascular cell adhesion molecule-1 in a dose-dependent manner. In addition, resveratrol hampered THP-1 monocyte adhesion to activated endothelial cells. This study further examined whether resveratrol interfered with transendothelial migration of leukocytes. The MMP-2 gelatinolytic activity of endothelial cells was enhanced by TNF-alpha, which was attenuated by an addition of > or =25 micrometer resveratrol. In addition, 25 micrometer resveratrol mitigated the MMP-9 activity of THP-1 cells, followed by a marked inhibition of transendothelial migration. These results demonstrated that resveratrol suppressed monocyte adhesion and migration induced by TNF-alpha through modulating expression of adhesion molecules and gelatinolytic activity of MMP. These findings suggest that dietary resveratrol may be therapeutic agent for inhibiting leukocyte recruitment into the subendothelium during inflammatory atherosclerosis.

Entry of Lymphocytes into the Brain and Expression of ICAM-1 on the Brain Endothelium / 대한해부학회지

To evaluate the entry of lymphocytes into the brain, we isolated lymphocytes from non-immunized Balb/C mice spleens and activated lymphocytes with anti-CD3 and anti-CD28 antibodies. Activated lymphocytes were labeled with fluorescent CSFE in order to identify their entry into the brain. Nonactivated fresh lymphocytes from spleen were also labeled with CSFE as a control. Before injecting CSFE-labeled lymphocytes into the tail vein, some recipient animals were pretreated with LPS intraperitoneally. Both the resting and activated lymphocytes entered the normal brain although their migration occurred with a low frequency. When the recipient mice were pretreated with LPS intraperitoneally, the number of migration of lymphocytes to the brain was increased, and the ICAM-1 expression was also increased in the brain endothelium. There was no significant difference in the migration into the brain between activated and nonactivated lymphocytes. These results suggested that activation state of lymphocytes, especially, antigen-non specific activation by anti-CD3 and anti-CD28 might not be a critical factor for the migration into the brain, and but the endothelial ICAM-1 expression faciliated the efficient transendothelial migration into the brain.

Regulation of Adhesion Molecule Expression and Stromal Cell-Derived Factor-1 Production in Human Bone Marrow Cells by Interferon-gamma, Tumor Necrosis Factor-alpha, and Transforming Growth Factor-beta1: Implications in Bone Marrow Homing of Hematopoietic / 대한혈액학회지

BACKGROUND: It is well known that harmonious interactions among adhesion molecules and stromal cell-derived factor-1 (SDF-1)-mediated chemoattraction signalling via CXCR4 are needed for bone marrow homing of hematopoietic stem cells and progenitor cells. The aim of this study was to define the role of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and transforming growth factor-beta 1 (TFG-beta1), known as hematopoiesis-inhibitory cytokines, in the regulation of the molecules in relation to the homing. METHODS: We investigated the effects of these cytokines on the expression of CXCR4 and adhesion molecules and the production of SDF-1 in bone marrow cells including CD34+ cells, bone marrow endothelial cells (BMEC-1 cells), and bone marrow stromal cells (BMSCs). We also examined whether the cytokines influence in vitro transmigration of hematopoietic progenitors. RESULTS: None of the cytokines influenced CXCR4 expression on CD34+ cells or SDF-1- mediated chemotaxis of the cells. IFN-gamma and TNF-alpha, but not TGF-beta up-regulated the expression of L-selectin, ICAM-1, and VLA-4 on CD34+ cells. However, the up-regulation was not translated into the enhanced transendothelial migration. IFN-gamma and TNF-alpha up-regulated the expression of VCAM-1 and ICAM-1 on BMEC-1 cells, and rendered the endothelium more suitable for transendothelial migration of hematopoietic progenitors. IFN-gamma and TNF-alpha also up-regulated the expression of VCAM-1 and ICAM-1 on primary human BMSCs. All three cytokines significantly attenuated SDF-1 production from primary BMSCs, and TNF-alpha diminished SDF-1 production from BMEC-1 cells. CONCLUSION: These data indicate that IFN-gamma, TNF-alpha, and TGF-beta1 play a role in the regulation of bone marrow homing of hematopoietic cells via up-regulation of adhesion molecule expression and down-modulation of SDF-1 production in bone marrow cells.

Circulating Cell Adhesion Molecules in Patients with Type 2 Diabetes Mellitus / 대한임상병리학회지

BACKGROUND: Cell adhesion molecules (CAMs) have been shown to be highly expressed in atherosclerotic lesions. Membrane-bound CAMs allow the tethering and rolling of monocytes and lymphocytes as well as the firm attachment and transendothelial migration of leukocytes. Soluble forms of CAMs may serve as monitors for increased expression of membrane-bound CAMs and thus may reflect progressive formation of atherosclerotic lesions. We assessed the role of the solu-ble CAMs in patients with type 2 Diabetes. METHODS: Serum levels of soluble E-selectin (sE-selectin), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured by enzyme immunoassay (R and D Systems, Minneapolis, USA) in patients with type 2 Diabetes (n=69) and normal control subjects (n=38). RESULTS: Fasting blood sugar, serum cholesterol, and blood pressure were significantly (P < 0.001) higher in diabetic patients than in control subjects. Serum sE-selectin, sICAM-1, and sVCAM-1 concentrations in diabetic patients were significantly (P < 0.001) higher than in the control subjects (69.7 +/- 32.0, 257.1 +/- 73.0 and 813.8 +/- 322.6 ng/mL versus 43.3 +/- 19.5, 173.1 +/- 66.8, and 400.4 +/- 77.4 ng/mL, respectively). The serum sICAM-1 concentrations in diabetic patients with microalbu-minuria were significantly (P=0.004) higher than in those patients without microalbuminuria (311.3 +/- 79.0 ng/mL versus 245.2 +/- 60.2 ng/mL). However, the sE-selectin and sVCAM-1 concentrations in diabetic patients with microalbuminuria were only slightly (P < 0.10) higher than in the patients without microalbuminuria. CONCLUSIONS: These results suggest that three kinds of circulating CAMs measured in this study increased significantly in patients with type 2 Diabetes. It is considered that circulating CAMs may be markers for atherosclerotic lesions in patients with type 2 Diabetes with symptomatic and asymptomatic atherosclerosis.

A Study of Receptor Expression in Leukocytes by Quantitative Fluorescence Measurement

PURPOSE: It is well known that the receptors for Fcgamma moiety of IgG(FcgammaR) are instrumental in antibody-mediated clearance of microorganisms by granulocytes and monocytes, and immune regulation in lymphocytes. Furthermore, complement receptor-3(CR3) is also important in neutrophilic adhesion, diapedesis, and phagocytic functions. In an attempt to examine their roles in neonates, we compared the expressions of FcgammaRs and CR3 in cord blood leukocytes with those expressed in leukocytes in samples of blood obtained from adult subjects. METHODS: Cord blood was obtained from 30 full-term newborn and peripheral blood from 30 adult volunteers. In both groups, we measured three Fcgamma receptors and one adhesion molecule, CR3 on granulocytes, monocytes and lymphocytes using a whole blood method with flow cytometry and quantitative bead standards to enumerate the cell surface receptors. RESULTS:Compared to those observed in adult blood, the proportions of FcgammaRI+ granulocytes were significantly higher in cord blood. By contrast, the proportions of FcgammaRII+ or FcgammaRIII+ granulocytes and the number of FcgammaRIII were significantly lower in cord blood. The proportions of FcgammaRI+, FcgammaRII+, and CD18+ bearing monocytes and the number of FcgammaRII in lymphocytes were also significantly lower in cord blood as compared to adult blood. CONCLUSION: There were differences in the proportions of cells expressing FcgammaRs and CR3 and in the number of FcgammaRs and CR3 in granulocytes, monocytes, and lymphocytes between cord blood and peripheral blood from adult subjects. These may contribute to the difference in immune capability that is known to exist between neonates and adult subjects.

Effects of Short-Term Incubation of Hematopoietic Cells with Hematopoietic Growth Factors on CXCR4 Expression and Stromal Cell-Derived Factor-1-Mediated Transendothelial Migration / 대한혈액학회지

BACKGROUND: There has been contradictory reports regarding the homing potential of hematopoietic cells briefly exposed to hematopoietic growth factors in vitro. To get a resolution to this controversy, we investigated the effects of short-term growth factor treatment of hematopoietic cells on the expression of CXCR4 and adhesion molecules, and the chemotaxis in response to stromal cell-derived factor-1 (SDF-1), which is widely accepted to play a critical role in bone marrow (BM) homing of hematopoietic stem cells. METHODS: BM and cord blood(CB) CD34+ cells were incubated with various hematopoietic growth factors including IL-1beta, IL-3, IL-6, G-CSF, GM-CSF, stem cell factor (SCF), flk-2 ligand, and thrombopoietin, alone or in combination for up to 48 hours. Before and after the incubation, the expression of CXCR4 and adhesion molecules of CD34+ cells was analyzed using flow cytometry. SDF-1-mediated transmembrane or transendothelial migration of CD34+ cells, cobblestone area-forming cells (CAFCs), and/or long-term culture-initiating cells (LTC-ICs) was measured using Transwell(TM) system. RESULTS: VLA-4 was moderately up-regulated by the incubation of the cells with IL-3 and SCF, and ICAM-1 was slightly up-regulated by IL-1 and IL-3. The expression of L-selectin, PECAM-1 or LFA-1 was not altered by any growth factors. With the incubation of the cells in the absence of growth factors or SDF-1, CXCR4 expression of CD34+ cells was rapidly increased, reaching a plateau at 24 hours. The spontaneous up-regulation was abrogated with the addition of SDF-1. In agreement with the up-regulation of CXCR4, CD34+ cells incubated for 40 hours showed much enhanced chemotaxis in response to SDF-1 compared to non-incubated cells (24.7 3.5% vs. 7.0 1.6%, P=0.01). Any growth factors examined in this study did not alter the CXCR4 expression of CD34+ cells. Neither did growth factors affect the transendothelial migration of LTC-ICs toward bone marrow stromal cells as well as the SDF-1-induced transmembrane chemotaxis of CD34+ cells and CAFCs. CONCLUSION: Short-term treatment of hemo-topoietic cells with hematopoietic growth factors does not alter the expression of CXCR4 or SDF-1-mediated transendothelial chemotaxis.

Oxidized LDL is a Chemoattractant for the Eosinophils and Neutrophils / 결핵

BACKGROUND: Rhinovirus infection of the airways results in increased permeability of the airway vascular endothelium with the influx of plasma proteins, including lipids such as LDL. In vitro studies on the effect of oxLDL on leukocytes has shown many proinflammatory effects on multiple leukocytes. We hypothesized that oxLDL is one mechanism for recruiting granulocytes to the airways during a RV infection. Therefore, chemotaxis and transendothelial migration, in response to nLDL, was determined for these granulocytes. METHODS: nLDL was oxidized with 5mM Cu2SO4 for 20-24 hours. 3-5×10(5) cells were loaded into the Transwell filter while the chemotatic agonists were placed in the lower well for chemotaxis. Confluent monolayers on HPMEC were grown on Transwell filters for transendothelial migration. The filters were washed and eosinophils and neutrophils loaded on to the filter with the chemotatic agonist was were placed in the lower well. The wells were incubated for 3 hours. The number of migrating cells was counted on a hemocytometer. RESULTS: OxLDL, but not nLDL, is chemotatic for eosinophils and neutrophils. The level of granulocytes chemotaxis was dependent on both the concentration of LDL and its degree of oxidation. OxLDL stimulates eosinophil and neutrophils migration across HPMEC monolayers (±IL-1β preactivation) in a dose dependent manner. CONCLUSION: Increased vascular permeability during a RV infection may lead to the influx and oxidation of LDL. The resulting oxLDL. is one possible mechanism for the recruitment of neutrophils and eosinophils to the airway interstitial matrix. Once in the airways, granulocytes can further interact with oxLDL to promote airway inflammation.