Migration inhibitory factor up-regulates vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 via Src, PI3 kinase, and NFkappaB

A novel nuclear factor-kappaB gene signature is differentially expressed in head and neck squamous cell carcinomas in association with TP53 status

PURPOSE

To determine if gene signatures differentially expressed in head and neck squamous cell carcinomas (HNSCC) are related to alterations in transcription factors nuclear factor-kappaB (NF-kappaB) and TP53 previously associated with decreased cell death, response to therapy, and worse prognosis.

EXPERIMENTAL DESIGN

Unique gene signatures expressed by HNSCC lines were identified by cDNA microarray, principal components, and cluster analyses and validated by quantitative reverse transcription-PCR (RT-PCR) and in situ hybridization. Bioinformatic analysis of the promoters and ontogeny of these clustered genes was done. Expression of proteins encoded by genes of a putative NF-kappaB signature, NF-kappaB p65, and TP53 were examined in HNSCC tissue specimens by immunostaining. Predicted promoter binding and modulation of expression of candidate NF-kappaB genes and cell survival were evaluated by p65 chromatin immunoprecipitation (ChIP) and small interfering RNA (siRNA) knockdown.

RESULTS

Two groups of HNSCC exhibiting distinct gene signatures were identified: cluster A enriched for histone genes, with a higher prevalence of TP53 promoter binding motifs; and cluster B enriched for injury response genes with NF-kappaB regulatory motifs. Coexpression of cluster B proteins was observed with strong NF-kappaB phospho-p65 and weak TP53 staining, and NF-kappaB phospho-p65 was inversely associated with TP53 (P = 0.02). Promoter binding of the NF-kappaB signature genes was confirmed by p65 ChIP, and down-modulation of their expression and cell death were induced by p65 siRNA.

CONCLUSION

NF-kappaB promotes expression of a novel NF-kappaB-related gene signature and cell survival in HNSCC that weakly express TP53, a subset previously associated with inactivated wild-type TP53, greater resistance to chemoradiotherapy, and worse prognosis.

Serum macrophage migration inhibitory factor (MIF) levels after allogeneic hematopoietic stem cell transplantation

Macrophage migration inhibitory factor (MIF) may play an important role in the pathogenesis of acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), as MIF plays an important role to regulate the production of tumor necrosis factor-alpha (TNF-alpha), one of the inflammatory cytokines which induces and exacerbates aGVHD. We examined the association between serum MIF levels and aGVHD vs. chronic GVHD (cGVHD) in allo-SCT patients in this study. We found a significant increase in the peak serum MIF (14.46 ng +/- 1.47 ng/ml) at onset in patients that developed aGVHD (n = 23, P = 0.009). We also found that mean serum MIF levels in patients who developed extensive type cGVHD within 6 months (12.58 +/- 2.18 ng/ml, n = 13) were significantly higher than MIF levels before allo-HSCT (7.86 +/- 1.17 ng/ml, n = 19, P = 0.04). Therefore, we speculated that serum MIF levels increase during the active phase of both aGVHD and cGVHD.

The role of macrophage migration inhibitory factor in the cascade of events leading to reperfusion-induced inflammatory injury and lethality

Ischemia and reperfusion (I/R) injury is associated with a systemic inflammatory response, characterized by intense tumor necrosis factor (TNF)-alpha production and TNF-alpha-dependent tissue injury. Macrophage migration inhibitory factor (MIF) is a potent proinflammatory cytokine that may induce TNF-alpha release and play an important role in innate immune and inflammatory responses. The aim of this work was to assess whether MIF was involved the inflammatory cascade and injury that follows intestinal I/R. To this end, wild-type (WT) and MIF-deficient (MIF(-/-)) mice underwent 60 minutes of ischemia followed by 60 minutes of reperfusion, after which they were culled for the assessment of inflammatory parameters. I/R was accompanied by an increase in circulating levels of MIF and an increase of vascular permeability, hemorrhage, and production of TNF-alpha in the intestine and lungs. The latter parameters were markedly suppressed in reperfused MIF(-/-) mice, and this was associated with decreased lethality (80% in WT versus 20% in MIF(-/-) mice). Interestingly, the reperfusion-associated neutrophil accumulation in the intestine and lungs was similar in WT and MIF(-/-) mice. Leukocytes isolated from lungs of MIF(-/-) mice were less activated, as assessed by their response to zymosan in a luminol-enhanced chemiluminescence assay. In conclusion, our results suggest that MIF plays an important role in the cascade of events leading to TNF-alpha production and reperfusion-induced tissue injury and lethality in mice.

Roles of integrin activation in eosinophil function and the eosinophilic inflammation of asthma

Eosinophilic inflammation is a characteristic feature of asthma. Integrins are highly versatile cellular receptors that regulate extravasation of eosinophils from the postcapillary segment of the bronchial circulation to the airway wall and airspace. Such movement into the asthmatic lung is described as a sequential, multistep paradigm, whereby integrins on circulating eosinophils become activated, eosinophils tether in flow and roll on bronchial endothelial cells, integrins on rolling eosinophils become further activated as a result of exposure to cytokines, eosinophils arrest firmly to adhesive ligands on activated endothelium, and eosinophils transmigrate to the airway in response to chemoattractants. Eosinophils express seven integrin heterodimeric adhesion molecules: alpha 4 beta 1 (CD49d/29), alpha 6 beta 1 (CD49f/29), alpha M beta 2 (CD11b/18), alpha L beta 2 (CD11a/18), alpha X beta 2 (CD11c/18), alpha D beta2 (CD11d/18), and alpha 4 beta 7 (CD49d/beta 7). The role of these integrins in eosinophil recruitment has been elucidated by major advances in the understanding of integrin structure, integrin function, and modulators of integrins. Such findings have been facilitated by cellular experiments of eosinophils in vitro, studies of allergic asthma in humans and animal models in vivo, and crystal structures of integrins. Here, we elaborate on how integrins cooperate to mediate eosinophil movement to the asthmatic airway. Antagonists that target integrins represent potentially promising therapies in the treatment of asthma.

LipoCardium: Endothelium-directed cyclopentenone prostaglandin-based liposome formulation that completely reverses atherosclerotic lesions

Atherosclerosis is a multifactorial inflammatory disease of blood vessels which decimates one in every three people in industrialized world. Despite the important newest clinical approaches, currently available strategies (e.g. nutritional, pharmacological and surgical) may only restrain the worsening of vascular disease. Since antiproliferative cyclopentenone prostaglandins (CP-PGs) are powerful anti-inflammatory agents, we developed a negatively charged liposome-based pharmaceutical formulation (LipoCardium) that specifically direct CP-PGs towards the injured arterial wall cells of atherosclerotic mice. In the blood stream, LipoCardium delivers its CP-PG contents only into activated arterial wall lining cells due to the presence of antibodies raised against vascular cell adhesion molecule-1 (VCAM-1), which is strongly expressed upon inflammation by endothelial cells and macrophage-foam cells as well. After 4 months in a high-lipid diet, all low-density lipoprotein receptor-deficient adult control mice died from myocardium infarction or stroke in less than 2 weeks, whereas LipoCardium-treated (2 weeks) animals (still under high-lipid diet) completely recovered from vascular injuries. In vitro studies using macrophage-foam cells suggested a tetravalent pattern for LipoCardium action: anti-inflammatory, antiproliferative (and pro-apoptotic only to foam cells), antilipogenic and cytoprotector (via heat-shock protein induction). These astonishing cellular effects were accompanied by a marked reduction in arterial wall thickness, neointimal hyperplasia and lipid accumulation, while guaranteed lifespan to be extended to the elderly age. Our findings suggest that LipoCardium may be safely tested in humans in a near future and may have conceptual implications in atherosclerosis therapy.

Interleukin-18 induces angiogenic factors in rheumatoid arthritis synovial tissue fibroblasts via distinct signaling pathways

OBJECTIVE

Interleukin-18 (IL-18) is a proinflammatory cytokine implicated in the pathogenesis of rheumatoid arthritis (RA). This study was undertaken to examine the role of IL-18 in up-regulating secretion of the angiogenic factors stromal cell-derived factor 1alpha (SDF-1alpha)/CXCL12, monocyte chemoattractant protein 1 (MCP-1)/CCL2, and vascular endothelial growth factor (VEGF) in RA synovial tissue (ST) fibroblasts, and the underlying signaling mechanisms involved.

METHODS

We used enzyme-linked immunosorbent assays, Western blotting, and chemical inhibitors/antisense oligodeoxynucleotides to signaling intermediates to assess the role of IL-18.

RESULTS

IL-18 significantly enhanced the production of SDF-1alpha/CXCL12, MCP-1/CCL2, and VEGF in RA ST fibroblasts, in a time- and concentration-dependent manner. IL-18-induced SDF-1alpha/CXCL12 up-regulation was dependent on JNK, p38 MAPK, phosphatidylinositol 3-kinase (PI3K), and NFkappaB. While IL-18-induced production of SDF-1alpha/CXCL12 was also dependent on protein kinase Cdelta (PKCdelta), production of MCP-1/CCL2 was dependent on PKCalpha, not PKCdelta. Additionally, RA ST fibroblast IL-18-induced MCP-1/CCL2 production was mediated by JNK, PI3K, and NFkappaB. In contrast, IL-18 did not induce secretion of RA ST fibroblast MCP-1/CCL2 or VEGF via p38 MAPK. IL-18-induced RA ST fibroblast production of VEGF was mediated mainly by JNK-2, PKCalpha, and NFkappaB. IL-18 induced phosphorylation of JNK, PKCdelta, p38 MAPK, and activating transcription factor 2 (ATF-2) in RA ST fibroblasts in a time-dependent manner, with JNK-2 being upstream of PKCdelta, ATF-2, and NFkappaB.

CONCLUSION

These data support the notion that IL-18 has a unique role in inducing the secretion of angiogenic SDF-1alpha/CXCL12, MCP-1/CCL2, and VEGF in RA ST fibroblasts, via distinct signaling intermediates.

The role of macrophage migration inhibitory factor in maintaining the immune privilege at the fetal–maternal interface

Macrophage migration inhibitory factor (MIF) is a pivotal regulator of the innate and adaptive immunity affecting the response and behavior of macrophages and lymphocytes. MIF is also implicated in other fundamental cellular processes including angiogenesis and cell proliferation. Several studies examined the expression of MIF in reproductive organs and tissues and its involvement in different aspects of human and animal reproduction. The goal of this review was to summarize these findings and discuss, in particular, the role of MIF in the maintenance of the immune privilege at the human fetal-maternal interface.

The macrophage migration inhibitory factor-glucocorticoid dyad: regulation of inflammation and immunity

The cytokine macrophage migration inhibitory factor (MIF) occupies a unique position in physiology by its ability to directly regulate the immunosuppressive actions of glucocorticoids. We review herein the interactions between MIF and glucocorticoids within the immune system and discuss the relevance of the MIF-glucocorticoid regulatory dyad in physiology and immunopathology. Therapeutic antagonism of MIF may be an effective approach for steroid-sparing therapies in patients with refractory autoimmune or inflammatory diseases.

Macrophage migration inhibitory factor (MIF) promotes cell survival by activation of the Akt pathway and role for CSN5/JAB1 in the control of autocrine MIF activity

The phosphoinositide-3-kinase (PI3K)/Akt signaling pathway plays an important role in cell survival and the development of cancer. Macrophage migration inhibitory factor (MIF) is a critical inflammatory cytokine that was recently associated with tumorigenesis and that potently inhibits apoptosis. This may involve inhibition of p53-dependent genes, but the initiating molecular mechanism of how MIF controls survival/apoptosis is unknown. Here, we show that MIF prevents apoptosis and promotes tumor cell survival by directly activating the Akt pathway. MIF enhanced Akt activity in primary and immortalized fibroblasts (MEF and NIH/3T3), HeLa cervix carcinoma cells and various breast cancer cell lines. Activation was abolished by kinase inhibitors Ly294002 and PP2 and in Src/Yes/Fyn(SYF)(-/-) and CD74(-/-)(MEFs), while being enhanced in CD74-overexpressing MEFs, demonstrating that the MIF-induced Akt pathway encompasses signaling through the MIF receptor CD74 and the upstream kinases Src and PI3K. Akt was activated by exogenous rMIF and autocrine MIF action, as revealed by experiments in MIF(-/-)MEFs and antibody blockade. siRNA knockdown of CSN5/JAB1, a tumor marker and MIF-binding protein, showed that JAB1 controls autocrine MIF-mediated Akt signaling by inhibition of MIF secretion. Akt activation by MIF led to phosphorylation of the proapoptotic proteins BAD and Foxo3a. Apoptosis inhibition by MIF was functionally associated with Akt activation as it was abolished by overexpression of the Akt pathway inhibitor PTEN and occurred independently of p53. This was shown by studying DNA damage-induced apoptosis in fibroblasts, the Fas death pathway in HeLa cells that do not express functional p53, and etoposide-induced apoptosis in breast carcinoma cells expressing mutant p53. Importantly, dependence of breast cancer cell survival on MIF correlated with Akt activation and the PTEN status of these cells. Thus, MIF can directly promote cell survival through activation of the PI3K/Akt pathway and this effect is critical for tumor cell survival.

Macrophage migration inhibitory factor induces macrophage recruitment via CC chemokine ligand 2

Macrophage migration inhibitory factor (MIF) was originally identified for its ability to inhibit the random migration of macrophages in vitro. MIF is now recognized as an important mediator in a range of inflammatory disorders. We recently observed that the absence of MIF is associated with a reduction in leukocyte-endothelial cell interactions induced by a range of inflammatory mediators, suggesting that one mechanism whereby MIF acts during inflammatory responses is by promoting leukocyte recruitment. However, it is unknown whether MIF is capable of inducing leukocyte recruitment independently of additional inflammatory stimuli. In this study, we report that MIF is capable of inducing leukocyte adhesion and transmigration in postcapillary venules in vivo. Moreover, leukocytes recruited in response to MIF were predominantly CD68(+) cells of the monocyte/macrophage lineage. Abs against the monocyte-selective chemokine CCL2 (JE/MCP-1) and its receptor CCR2, but not CCL3 and CXCL2, significantly inhibited MIF-induced monocyte adhesion and transmigration. CCL2(-/-) mice displayed a similar reduction in MIF-induced recruitment indicating a critical role of CCL2 in the MIF-induced response. This hypothesis was supported by findings that MIF induced CCL2 release from primary microvascular endothelial cells. These data demonstrate a previously unrecognized function of this pleiotropic cytokine: induction of monocyte migration into tissues. This function may be critical to the ability of MIF to promote diseases such as atherosclerosis and rheumatoid arthritis, in which macrophages are key participants.

CD44 is the signaling component of the macrophage migration inhibitory factor-CD74 receptor complex

The macrophage migration inhibitory factor (MIF) receptor (CD74) was cloned recently, but the signaling mechanism is not evident. We hypothesized that signaling requires an additional molecule such as CD44, which activates nonreceptor tyrosine kinases. We utilized the CD74- and CD44-deficient COS-7/M6 cell to create stable transfectants expressing CD74, CD44, and a truncated CD44 lacking its intracytoplasmic signaling domain. CD74 alone mediated MIF binding; however, MIF-induced ERK1 and ERK2 kinase phosphorylation required the coexpression of full-length CD44. MIF binding was associated with the serine phosphorylation of CD74 and CD44. Investigations that used siRNA or kinase inhibitors indicate that MIF-induced ERK1 and ERK2 activation through CD44 required the Src tyrosine kinase. Studies of CD74, CD44, and CD74-CD44 transformants and corresponding mutant cells showed that CD74 and CD44 were necessary for MIF protection from apoptosis. These data establish CD44 as an integral member of the CD74 receptor complex leading to MIF signal transduction.

Dehydroepiandrosterone administration modulates endothelial and neutrophil adhesion molecule expression in vitro

Introduction

The steroid hormone dehydroepiandrosterone (DHEA) exerts protecting effects in the treatment of traumatic and septic complications in several animal models. This effect goes along with reduced amounts of infiltrating immune cells in organs such as lung and liver. However, the underlying mechanisms of DHEA action are still not known. Adhesion molecules are important for the extravasation of neutrophils into organs where they may exhibit detrimental effects. Therefore, we investigated the in vitro effect of DHEA on the expression pattern of adhesion molecules of human endothelial cells and neutrophils.

Methods

Endothelial cells derived from human umbilical cord were subjected to an lipopolysaccharide (LPS) challenge. DHEA was administered in two different concentrations, 10^-5 M and 10^-8 M, as a single stimulus or in combination with LPS challenge. After two, four and 24 hours, fluorescence activated cell sorter (FACS) analysis for vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and E-selectin was performed. Neutrophils were freshly isolated from blood of 10 male healthy volunteers, stimulated the same way as endothelial cells and analyzed for surface expression of L-selectin, CD11b and CD18.

Results

In the present study, we were able to demonstrate effects of DHEA on the expression of every adhesion molecule investigated. DHEA exhibits opposite effects to those seen upon LPS exposure. Furthermore, these effects are both time and concentration dependent as most DHEA specific effects could be detected in the physiological concentration of 10^-8 M.

Conclusion

Thus, we conclude that one mechanism by which DHEA may exert its protection in animal models is via the differential regulation of adhesion molecule expression.

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) reduces vascular endothelial growth factor expression in allergen-induced airway inflammation

Vascular endothelial growth factor (VEGF) plays a pivotal role in the pathogenesis of bronchial asthma. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) has been implicated in regulating cell survival signaling through the phosphoinositide 3-kinase (PI3K)/Akt pathway. The key role of PI3K in VEGF-mediated signal transduction is established. However, the effects of PTEN on VEGF-mediated signaling in asthma are unknown. This study aimed to determine the effect of PI3K inhibitors and PTEN on VEGF expression in allergen-induced airway inflammation. We have used a female C57BL/6 mouse model for asthma to determine the role of PTEN in allergen-induced airway inflammation, specifically in the expression of VEGF. Allergen-induced airway inflammation leads to increased activity of PI3K in lung tissue. These mice develop the following typical pathophysiological features of asthma in the lungs: increased numbers of inflammatory cells of the airways; airway hyper-responsiveness; increased expression of interleukin (IL)-4, IL-5, IL-13, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, regulated on activation normal T cell expressed and secreted (RANTES), and eotaxin; increased vascular permeability; and increased levels of VEGF. Administration of PI3K inhibitors or adenoviruses carrying PTEN cDNA reduced the symptoms of asthma and decreased the increased levels of plasma extravasation and VEGF in allergen-induced asthmatic lungs. These results indicate that PTEN reduces VEGF expression in allergen-induced airway inflammation.