BACKGROUND

Macrophage-migration inhibitory factor (MIF), one of the first cytokines described, has a broad range of proinflammatory properties. The genome sequencing project of Plasmodium falciparum identified a parasite homologue of MIF. The protein is expressed during the asexual blood stages of the parasite life cycle that cause malarial disease. The identification of a parasite homologue of MIF raised the question of whether it affects monocyte function in a manner similar to its human counterpart.

METHODS

Recombinant P. falciparum MIF (PfMIF) was generated and used in vitro to assess its influence on monocyte function. Antibodies generated against PfMIF were used to determine the expression profile and localization of the protein in blood-stage parasites. Antibody responses to PfMIF were determined in Kenyan children with acute malaria and in control subjects.

RESULTS

PfMIF protein was expressed in asexual blood-stage parasites, localized to the Maurer's cleft. In vitro treatment of monocytes with PfMIF inhibited random migration and reduced the surface expression of Toll-like receptor (TLR) 2, TLR4, and CD86.

CONCLUSIONS

These results indicate that PfMIF is released during blood-stage malaria and potentially modulates the function of monocytes during acute P. falciparum infection.

The state of oligomerization of macrophage migration inhibitory factor (MIF, also known as glycosylation inhibiting factor, GIF) in solution has been variously reported as monomer, dimer, trimer, or mixtures of all three. Several crystal structures show MIF to be a trimer. Sedimentation velocity shows a recombinant human MIF sample is quite homogeneous, with 98% as a species with s(20,w)=3.07 S and D(20,w)=8.29 x 10(-7) cm(2)/s. Using the partial specific volume calculated from the amino acid composition these values imply a mass of 33.56 kDa, well above that of dimer, but also 9% below the trimer mass of 37.035 kDa. Sedimentation equilibrium data at loading concentrations from 0.01 to 1 mg/ml show unequivocally that the self-association is extremely tight. However, the apparent mass is 33.53 kDa [95% confidence 33.25-33.82], again 9% below that expected for 100% trimer. To examine the possibility this protein has an unusual partial specific volume, sedimentation equilibrium was also done in H(2)O/D(2)O mixtures, giving 0.765+/-0.017 ml/g rather than the calculated 0.735 ml/g. With this revised partial specific volume, the equilibrium and velocity data each give M=37.9+/-2.8 kDa, fully consistent with a strongly-associated trimeric quaternary structure.

Small interfering RNAs (siRNAs) represent a novel tool to induce gene silencing in mammalian cells and clinical trials are currently ongoing to assess the therapeutic efficacy of siRNAs in various human diseases, including age-related macular degeneration and respiratory syncytial virus infection. However, previously reported off-target, nonspecific effects of siRNAs, including activation of type I IFNs and proinflammatory cytokines, remain an outstanding concern regarding use of these agents in vivo. Macrophage-migration inhibitory factor (MIF) is a pleiotropic cytokine with well-described roles in cell proliferation, tumorigenesis, and angiogenesis and represents a target gene for siRNA-based therapy in the treatment of breast cancer. However, in this study we describe an increase in MIF production from mammary adenocarcinoma (MCF-7) cells following transfection with MIF siRNA and various control siRNAs. This effect was shown to be dose-dependent and was attenuated in the presence of a double-stranded RNA-dependent protein kinase inhibitor, 2-aminopurine. Furthermore, treatment of MCF-7 cells with poly(I:C) also stimulated a PKR-dependent increase in MIF production from MCF-7 cells. The biological consequence of the siRNA-induced increase in MIF production from MCF-7 cells was a PKR-dependent increase in proliferation of breast cancer cells. Furthermore, in cDNAs prepared from a primary human breast cancer cohort, we demonstrated a significant correlation (Spearman rank correlation coefficient, r = 0.50, p < 0.0001, n = 63) between PKR- and MIF-mRNA expression. In conclusion, this study highlights the potential biological consequences of off-target, nonspecific effects of siRNAs and underlines the safety concerns regarding the use of siRNAs in the treatment of human diseases, such as cancer.

High-fat diet (HFD)-induced obesity has emerged as a state of chronic low-grade inflammation characterised by a progressive infiltration of immune cells, particularly macrophages, into obese adipose tissue. Adipose tissue macrophages (ATM) present immense plasticity. In early obesity, M2 anti-inflammatory macrophages acquire an M1 pro-inflammatory phenotype. Pro-inflammatory cytokines including TNF-α, IL-6 and IL-1β produced by M1 ATM exacerbate local inflammation promoting insulin resistance (IR), which consequently, can lead to type-2 diabetes mellitus (T2DM). However, the triggers responsible for ATM recruitment and activation are not fully understood. Adipose tissue-derived chemokines are significant players in driving ATM recruitment during obesity. Macrophage migration inhibitory factor (MIF), a chemokine-like inflammatory regulator, is enhanced during obesity and is directly associated with the degree of peripheral IR. This review focuses on the functional role of macrophages in obesity-induced IR and highlights the importance of the unique inflammatory cytokine MIF in propagating obesity-induced inflammation and IR. Given MIF chemotactic properties, MIF may be a primary candidate promoting ATM recruitment during obesity. Manipulating MIF inflammatory activities in obesity, using pharmacological agents or functional foods, may be therapeutically beneficial for the treatment and prevention of obesity-related metabolic diseases.

A T cell-derived lymphokine couples the recognition of alloantigens by human T inducer cells to monocyte effector procoagulant activity (PCA). This collaborative cellular response results in expression of the functional tissue factor gene product and initiation of the extrinsic coagulation protease cascade as an inflammatory sequelae to the immune response. We now provide initial characterization of this lymphokine, provide evidence that it is a unique lymphokine, and designate it as monocyte procoagulant inducing factor (MPIF). MPIF was produced by alloantigen-stimulated, nylon wool-purified T cells and was not diminished by irradiation. MPIF active supernatants induced PCA in isolated monocytes, and the effect was not modified by the presence of T cells with the responding monocytes, consistent with a direct effect on the monocyte effector cells rather than an indirect effect via an intermediate accessory T cell. Full expression of PCA by monocytes was complete within 4 to 6 hours. MPIF activity in mixed lymphocyte culture (MLC) supernatants (MLC-SN) was stable at pH 2.0 for 24 hr, but was diminished after exposure to pH 10.5 for 30 min. MPIF activity was stable at 56 degrees C but was labile at 63 degrees C or higher. When characterized by chromatography on Sephadex G-100 superfine at either pH 7.2 or 3.6, the activity was recovered in a major discrete peak of about 55,000 daltons, and minor peaks of activity at about 14,000 and greater than 150,000 daltons. There was no correlation between the presence or concentration of INF-gamma, INF-alpha, IL 1, IL 2, GM-CSF, CSF-1, TNF-alpha, TNF-beta (lymphotoxin), or migration inhibitory factor (MIF) with MPIF activity. Each of the previously defined cytokines was analyzed directly for MPIF activity. INF-gamma, INF-alpha, GM-CSF, TNF-alpha, and CSF-1 did not possess MPIF activity over a wide range of concentrations. IL 1 and IL 2 lacked activity at concentrations present in MLC medium positive for MPIF; however, at higher concentrations each demonstrated slight activity. There was a poor correlation between MPIF and MIF activities in MLC-SN, and the content of MIF was insufficient to account for the expressed level of MPIF activity. The lack of identity of these cytokines with MPIF was supported by selected MLC medium that lacked IL 1, IL 2, and MIF and yet contained high MPIF activity. MPIF was additionally distinguished from IL 1, IL 2, and MIF on the basis of separation in Sephadex G-100 superfine.(ABSTRACT TRUNCATED AT 400 WORDS)

At pharmacological levels, glucocorticosteroids inhibited two antigen-induced lymphocyte functions, in vitro proliferation and lymphokine synthesis. Lymphocyte production of both macrophage chemotactic factor (CTX) and macrophage inhibition factor (MIF) were decreased in the presence of hydrocortisone. The corticosteroid also blocked the action of MIF on macrophages but did not interfere with the action of CTX on macrophages. Thus, steroids can suppress the immune response at two different stages: by blocking lymphocyte activation and mediator synthesis and also by interfering with the interaction of certain effector molecules with their target cells. Furthermore, these findings suggested that MIF and CTX have distinct mechanisms of action on the effector macrophages, one being sensitive and one resistant to steroids.

Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator. Two functional polymorphisms were identified in the promoter region of MIF gene. We attempted to clarify the associations between these polymorphisms and ulcerative colitis (UC). The study was performed in 111 patients with UC and 209 subjects without UC. We employed the PCR-SSCP method to detect gene polymorphisms. Overall, 5/5-CATT genotype was a decreased risk for the development of UC (OR, 0.51; 95% CI, 0.26-0.99). In addition, 7/7-CATT genotype was significantly associated with chronic continuous phenotype and distal colitis phenotype (OR, 5.49; 95% CI, 1.19-25.3, and OR, 6.10; 95% CI, 1.32-28.2, respectively), whereas 5/5-CATT genotype had an inhibitory effect on the development of UC after 20years of age (OR, 0.33; 95% CI, 0.14-0.82). On the other hand, G-173C polymorphism did not affect the susceptibility to and the phenotypes of UC. Our results suggested that tetranucleotide CATT repeat of MIF gene promoter may be associated with the development of UC and the severity of inflammation in patients with UC.

The level of macrophage migration inhibitory factor (MIF) and the functions of dendritic cells (DC) are up-regulated in the peripheral blood, and the numbers of MIF-expressing cells and mature DC are increased at the colonic mucosa from patients with ulcerative colitis (UC). However, a functional relationship between MIF and DC, and the role of MIF in the pathogenesis of UC, are not clear. In this study, we showed that a pure population of peripheral blood DC is a new and still unknown source of MIF. DC from UC patients produced significantly higher levels of MIF (17 x 5 +/- 9 x 8 ng/ml, n = 10) compared with patients with Crohns disease (CD) (4 x 6 +/- 2 x 5 ng/ml, n = 5, P< 0 x 01) and control subjects (5 x 0 +/- 2 x 6 ng/ml, n = 10, P< 0 x 01). A double immunofluorescence study revealed the expression of MIF by CD83-positive mature DC at the colonic mucosa from UC patients. Blood DC treated with high amounts of MIF (500 ng/ml) showed a significantly higher stimulatory capacity (43287 +/- 5998 CPM, n = 5) in an allogenic mixed leucocyte reaction compared with untreated DC (27528 +/- 8823 CPM, n = 5, P< 0 x 05). Study of intracellular cytokine expression showed that MIF induced significant levels of interleukin (IL)-1 and IL-8 in monocytes and DC from UC and CD patients. These results showing the capacity of MIF to induce increased functional capacity of DC, and to produce IL-1 and IL-8 from monocytes and DC, indicate a role of MIF in the induction and/or perpetuation of the inflammatory environment in UC.

Hypoxia contributes to cytotoxic chemotherapy and radiation resistance and may play a role in the efficacy of antiangiogenesis cancer therapy. We have generated a series of cell lines derived from the colon adenocarcinoma models HT29 and HCT116 by exposing cells in vitro to repeated sublethal periods of profound hypoxia. These cell lines have altered sensitivity to hypoxia-induced apoptosis: those derived from HT29 are resistant, whereas those from HCT116 are more susceptible. We used cDNA selected subtractive hybridization to identify novel genes mediating sensitivity to hypoxia-induced apoptosis and isolated macrophage migration inhibitory factor (MIF) from the hypoxia-conditioned cell lines. MIF expression correlates with susceptibility of the cell lines to apoptosis. In hypoxia-resistant cells, the induction of apoptosis by hypoxia can be restored by the addition of exogenous recombinant MIF protein, suggesting that resistance may result in part from down-regulation of MIF production possibly through an autocrine loop. Inhibition of MIF using small interfering RNA in the susceptible lines conferred resistance to hypoxia-induced cell death. The relative expression of MIF in the hypoxia-conditioned cells implanted s.c. in severe combined immunodeficient mice in vivo was similar to that observed in vitro. In an analysis of 12 unrelated colon tumor cell lines, MIF expression and response to hypoxia varied widely. Cell lines in which MIF was inducible by hypoxia were more sensitive to oxaliplatin. In human colon tumor specimens analyzed by immunohistochemistry, MIF expression was similarly variable. There was no detectable expression of MIF in normal colon mucosa or adenoma but positive staining in all carcinomas tested. Taken together, these data indicate that MIF may be a determinant of hypoxia-induced apoptosis in vitro and that its variable expression in human colon cancers may indicate a functional role in vivo. We suggest that MIF expression in colorectal cancer may be a marker of susceptibility to therapies that may depend on induction of hypoxia, possibly including antiangiogenic therapy.

Mounting evidence suggests that macrophage migration inhibitory factor (MIF) may serve as an important link between chronic inflammation and cancer development. The proinflammatory and proangiogenic activities of MIF position it as a potentially important player in the development and progression of nonmelanoma skin cancer (NMSC). To assess the role of MIF in the development and progression of NMSC, we exposed MIF(-/-) BALB/c mice to acute and chronic ultraviolet B (UVB) irradiation. Our studies demonstrate that MIF(-/-) BALB/c mice have a significantly diminished acute inflammatory response to UVB exposure compared to wild-type mice, as measured by myeloperoxidase activity, dermal neutrophil infiltration, and edematous response. Relative to wild-type mice, MIF(-/-) mice also show significantly lower vascular endothelial growth factor (VEGF) concentrations in whole skin and significantly lower 8-oxo-dG adduct concentrations in epidermal DNA following UVB exposure. Furthermore, MIF(-/-) mice showed significant increases in p53 activity, epidermal thickness, and epidermal cell proliferation following acute UVB insult. In response to chronic UVB exposure, MIF(-/-) mice showed a 45% reduction in tumor incidence, significantly less angiogenesis, and delayed tumor progression when compared to their wild-type counterparts. These data indicate that MIF plays an important role in UVB-induced NMSC development and progression.

BACKGROUND

Recent evidence suggests that macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays a pathogenic role in glomerulonephritis. Renal expression of MIF is up-regulated in infiltrating and intrinsic renal cells, which include glomerular epithelial cells. The aim of the current study was to further clarify the role of MIF produced by podocytes in the process of renal disease.

METHODS

We generated transgenic mice carrying a murine MIF cDNA driven by cytomegalovirus enhancer and beta-actin/beta-globin promoter, a hybrid promoter transactivated in podocytes in vivo.

RESULTS

MIF expression was markedly up-regulated in podocytes in neonatal and adult transgenic kidneys. A longitudinal study of the MIF transgenic mice demonstrated a progressive matrix increase in mesangium accompanied by collagen IV accumulation, representing no significant glomerular cell hypercellularity. The glomeruli in transgenic kidney were not accompanied by influx of macrophages and T cells at the early stage of disease progression. Although a significant number of the mice showing higher expression of MIF died from renal failure at 8 weeks, most of them survived with significant proteinuria and progressive renal failure. Podocytes of transgenic mice frequently underwent characteristic ultrastructural changes, such as cell flattening, contracted foot processes, and villous transformation. In addition, immunohistochemical expression of synaptopodin, an actin-associated protein distributed in differentiated podocyte foot process, was significantly attenuated in transgenic kidney.

CONCLUSIONS

Our results indicate that podocyte-expressed MIF could induce an injury of podocytes themselves, thereby accelerating the progression of glomerulosclerosis and leading to end-stage renal failure.

Recent advances suggest that toll-like receptors, various cytokines, cicosanoids, free radicals and macrophage migration inhibitory factor (MIF) play an important role in the pathobiology of septicemia and septic shock. Anti-MIF antibodies can decrease the plasma concentrations of tumor necrosis factor (TNF), lower bacterial circulating counts and enhance survival of animals with septicemia and septic shock. Monocyte expression of MHC-class II antigens, neutrophil expression of the integrin CD11b/CD18 and neutrophil activation can be related to the development of, and/or recovery from, post-operative sepsis. Thus, biological variations in the response of an individual to a given stimulus, appears to determine his/her ability or inability to develop and also recover from sepsis and septic shock. This suggests that it may be possible to predict the development of septicemia and septic shock in a given individual and take appropriate action both to prevent and treat them adequately.

The expression of macrophage migration inhibitory factor (MIF) in prostate tissue was investigated by immunohistochemistry (IHC), enzyme-linked immunosorbent assay (ELISA), and Northern blot analysis using a prostate tissue bank. MIF expression was examined in each of the following established prostate tissue categories: prepubertal, pubertal, adult normal, benign hyperplastic (BPH), focal carcinoma within the prostate, and metastatic prostate cancer. IHC showed that all samples tested were positive for MIF protein, which localized to the glandular epithelial cells with no apparent staining of stroma. The most intense staining was observed in the metastatic prostatic adenocarcinoma and the human prostatic adenocarcinoma cell line LNCaP. Using quantitative ELISA, MIF expression was found to be at least three times higher in metastatic adenocarcinoma than in normal, BPH, or focal carcinoma in the adult prostate. This study is the first to report that prostate glandular epithelial cells express MIF. The exact role of MIF in prostate development and disease progression requires further study.

BACKGROUND

This study aimed to determine the potential diagnostic value of migration-inhibitory factor (MIF) for gastric cancer in patients presenting with dyspepsia and its prognostic value for gastric cancer.

METHODS

A cohort of 97 patients with histologically confirmed gastric adenocarcinoma and 222 patients with dyspepsia were recruited. Enzyme-linked immunosorbent assay was used to measure serum MIF and carcinoembryonic antigen (CEA).

RESULTS

The serum MIF concentrations were 6554.0 +/- 204.1 pg/mL and 1453.7 +/- 79.9 pg/mL, respectively, in gastric cancer patients and dyspeptic patients (P < .001). Serum MIF levels increased with the advancing gastric pathologies (P < .001). With the cutoff value of 3230 pg/mL, serum MIF had sensitivity, specificity, and accuracy of 83.5%, 92.3%, and 89.7%, respectively, in diagnosing gastric cancer, whereas the rates were 60.8%, 83.3%, and 76.5%, respectively, for serum CEA. Gastric cancer patients with serum MIF levels above 6600 pg/mL had a lower 5-year survival rate than those with serum MIF level below that level (P = .012). Higher serum CEA levels were also associated with poor survival. The prediction for 5-year survival was even better (P = .0001), using a combination of serum MIF and CEA.

CONCLUSIONS

Serum MIF level, which correlates with gastric MIF expression, is a better molecular marker than CEA in diagnosing gastric cancer in patients presenting with dyspepsia. A combination of serum MIF and CEA predicts 5-year survival better than the individual test.

The occurrence of local and systemic cell-mediated immunity (CMI) in swine against transmissible gastroenteritis (TGE) virus, a coronavirus that infects the epithelial cells of the small intestine of swine, has been investigated. Leukocyte suspensions prepared from intestinal lamina propria (LP) and spleen were each incubated with and without inactivated TGE virus. The supernatants from these cultures were tested for the presence of macrophage migration inhibition factor (MIF) by the indirect MIF test using guinea pig peritoneal exudate cells as the source of macrophages. All swine serologically negative for TGE antibodies (i.e., unexposed to TGE virus) were also negative for MIF production by lymphocytes from both sources. In 10 of 10 animals given TGE virus subcutaneously, MIF production by splenic lymphocytes was significantly greater (p less than or equal to 0.01) than by LP lymphocytes, and in 9 of 10 of these animals MIF production by LP lymphocytes was negligible (percentage of inhibition of migration less than 3%).

OBJECTIVE

Macrophage migration inhibitory factor 1alpha (MIF), a cytokine with immunoregulatory functions has been suggested to be involved in atherosclerotic plaque development. However, little is known about MIF-inducing conditions in the atherosclerotic process and the association of MIF with plaque instability.

RESULTS

Forty-two carotid endatherectomy samples from 36 patients and 4 aortic samples from young accident victims (as healthy controls) were analyzed for MIF staining. MIF expressing tissues in the atherosclerotic plaques are mainly mononuclear cells (MNCs), but also endothelial cells of intimal microvessels (MVECs). The magnitude and the intensity of their MIF expression was associated with the progression of plaques from early lesions (Stary I-III) to complicated plaque stages (Stary IV-VIII). In highly inflammatory and neovascularized regions of the plaques the colocalization of MIF expressing MNCs with CD40-L+ and angiotensin II (Ang II)-producing MNCs could be established. This finding supports the notion that CD40-L fusion protein and Ang II are able to induce MIF production in the monocytic cell line THP-1. Furthermore hypoxia (< or =1% O2) as a further proinflammatory and especially proangiogenetic factor was able to stimulate MIF secretion by THP-1, human monocytes and HUVECs. Hyperglycemia and insulin remained without effect.

CONCLUSIONS

MIF is expressed in advanced atherosclerotic lesions in close correlation with signs of instability, such as mononuclear cell inflammation and neointimal microvessel formation. Furthermore, the colocalization of MIF with Ang II-producing MNCs and CD40-L+ cells in these plaques and the finding that proathero- and -angiogenic mediators such as CD40-L, Ang II and hypoxia are able to stimulate MIF expression in vitro suggest an important role of MIF in the modulation of atherosclerotic plaque stability.

Nitric oxide (NO) is an essential mediator for a variety of biological functions, including defence against a range of pathogens. However, excessive production of NO as a result of immunological stimulation, will lead to important immunopathologies. Therefore the production of NO is necessarily under tight regulation. The regulatory mechanisms so far known to control NO synthesis include cytokines (induction of NO synthase by IFN-gamma, TNF alpha, MIF and LPS, and down regulation by IL-4, IL-10 and TGF beta), feedback inhibition by NO itself, inhibition by pretreatment with LPS and glycoinositol-phospholipids and up regulation by lipophosphoglycan from the protozoa parasite, Leishmania major.

Macrophage migration inhibitory factor (MIF) is a multifunctional protein and a major mediator of innate immunity. Although X-ray crystallography revealed that MIF exists as a homotrimer, its oligomerization state in vivo and the factors governing its oligomerization and stability remain poorly understood. The C-terminal region of MIF is highly conserved and participates in several intramolecular interactions that suggest a role in modulating the stability and biochemical activity of MIF. To determine the importance of these interactions, point mutations (A48P, L46A), insertions (P107) at the monomer-monomer interfaces, and C-terminal deletion (Delta 110-114NSTFA and Delta 105-114NVGWNNSTFA) variants were designed and their structural properties, thermodynamic stability, oligomerization state, catalytic activity and receptor binding were characterized using a battery of biophysical methods. The C-terminal deletion mutants DeltaC5 huMIF 1-109 and DeltaC10 huMIF 1-104 were enzymatically inactive and thermodynamically less stable than wild type MIF. Analytical ultracentrifugation studies demonstrate that both C-terminal mutants sediment as trimers and exhibit similar binding to CD74 as the wild type protein. Disrupting the conformation of the C-terminal region 105-114 and increasing its conformational flexibility through the insertion of a proline residue at position 107 was sufficient to reproduce the structural, biochemical and thermodynamic properties of the deletion mutants. P107 MIF forms an enzymatically inactive trimer and exhibits reduced thermodynamic stability relative to the wild type protein. To provide a rationale for the changes induced by these mutations at the molecular level, we also performed molecular dynamics simulations on these mutants in comparison to the wild type MIF. Together, our studies demonstrate that intersubunit interactions involving the C-terminal region 105-114, including a salt-bridge interaction between Arg73 of one monomer and the carboxy terminus of a neighboring monomer, play critical roles in modulating tertiary structure stabilization, enzymatic activity, and thermodynamic stability of MIF, but not its oligomerization state and receptor binding properties. Our results suggest that targeting the C-terminal region could provide new strategies for allosteric modulation of MIF enzymatic activity and the development of novel inhibitors of MIF tautomerase activity.

The Great Oxidation Event (GOE) is currently viewed as a protracted process during which atmospheric oxygen increased above ∼10(-5) times the present atmospheric level (PAL). This threshold represents an estimated upper limit for sulfur isotope mass-independent fractionation (S-MIF), an Archean signature of atmospheric anoxia that begins to disappear from the rock record at 2.45 Ga. However, an increasing number of papers have suggested that the timing for oxidative continental weathering, and by conventional thinking the onset of atmospheric oxygenation, was hundreds of million years earlier than previously thought despite the presence of S-MIF. We suggest that this apparent discrepancy can be resolved by the earliest oxidative-weathering reactions occurring in benthic and soil environments at profound redox disequilibrium with the atmosphere, such as biological soil crusts and freshwater microbial mats covering riverbed, lacustrine, and estuarine sediments. We calculate that oxygenic photosynthesis in these millimeter-thick ecosystems provides sufficient oxidizing equivalents to mobilize sulfate and redox-sensitive trace metals from land to the oceans while the atmosphere itself remained anoxic with its attendant S-MIF signature. As continental freeboard increased significantly between 3.0 and 2.5 Ga, the chemical and isotopic signatures of benthic oxidative weathering would have become more globally significant from a mass-balance perspective. These observations help reconcile evidence for pre-GOE oxidative weathering with the history of atmospheric chemistry, and support the plausible antiquity of a terrestrial biosphere populated by cyanobacteria well before the GOE.

OBJECTIVE

MIF is a proinflammatory cytokine involved in reproduction. Systemic activation of maternal inflammatory cell responses may play an important role in the pathogenesis of preeclampsia (PE). We hypothesized that MIF could be involved in preeclampsia.

METHODS

Concentration of immunoreactive MIF was assayed by enzyme-linked immunoassorbent assay (ELISA) in maternal serum samples obtained from 41 term control pregnancies and 21 severe preeclamptic pregnancies (14 delivered before and 7 at or after 34 weeks).

RESULTS

MIF serum levels were significantly higher in preeclamptic pregnancies (median 12.74 ng/ml) than in control group (median 5.3n g/ml) p = 0.001. MIF concentration was significantly higher when delivery occurred <34 weeks (median 17.80 ng/ml; range 2.80-80.20) than in the group delivered>> or = 34 weeks (median 6.16 ng/ml; range 1.62-23.65) p = 0.037.

CONCLUSIONS

High maternal serum levels MIF in pregnancies complicated by severe preeclampsia strongly support the role of inflammation in the pathogenesis of this disease.

Mifepristone (MIF) is an antiprogestin with potent anti-glucocorticoid and anti-androgen activity. MIF also appears to have anti-tumor activity independent of its ability to bind to nuclear receptors. In this study, we tested the ability of MIF to inhibit the growth of ER and PR negative breast cancer cells. In addition, because high-dose anti-estrogen treatment has been shown to inhibit ER and PR negative breast cancer cells, we compared the anti-proliferative activity of MIF to that of the anti-estrogen 4-hydroxytamoxifen (TAM) or combination hormonal therapy (MIF + TAM). MIF and TAM therapy induced a significant time- and dose-dependent growth inhibition and, ultimately, induced cell death in MDA-231 cells as evidenced by increased DNA fragmentation, cytochrome c release from the mitochondria, and the activation of caspase-3. The anti-proliferative activity of TAM plus MIF combination treatment was at least additive as compared to either monotherapy. The earliest indicator of TAM and MIF cytostatic and cytotoxic action on MDA-231 cells was a significant (p<0.05) induction of TGFbeta1 secretion into the growth medium within 4 h of treatment. Secreted TGFbeta1 levels at 24 and 48 h were significantly higher in the TAM plus MIF treatment group as compared to cells treated with TAM or MIF alone. TGFbeta1 neutralizing antibody or addition of mannose-6-phosphate (M6P), a reagent also used to inhibit TGFbeta1, significantly attenuated the TAM and/or MIF-induced cell growth inhibition and cell death. In summary, our results indicate that MIF used in combination with TAM can effectively kill estrogen-insensitive human breast cancer cells. Our study further implies that agents that effectively increase TGFbeta1 levels in ER negative breast cancer cells may be one treatment approach for hormone-independent breast cancers.

Macrophage migration inhibitory factor (MIF) is a pleiotrophic lymphocyte and macrophage cytokine; it is likely to play an important role in innate immunity. Genome-wide search for atopy susceptibility genes recently identified human chromosome 22q11, where the gene encoding MIF resides, as a region of interest for atopic traits. Both the -173G/C and -794 [CATT]5-8 repeat polymorphisms in the MIF promoter region are associated with altered levels of MIF gene transcription in vitro. We, therefore, hypothesized that these potentially functional polymorphisms may influence susceptibility to atopy and asthma. A case-control analysis examined the genetic influence of these promoter polymorphisms on the development of atopy and asthma in a Japanese population (n = 584). Evidence for significant association between the -173G/C and -794 [CATT]5-8 repeat polymorphisms and atopy was found; odds ratio for homozygotes of -173C allele was 3.67 (compared with homozygotes of -173G allele, 95% confidence interval = 1.43-9.46, p < 0.01), and odds ratio for noncarriers of the -794 [5-CATT] allele was 3.51 (compared with 5-CATT repeat homozygotes, 95% confidence interval = 1.82-6.78, p < 0.0005). No associations with asthma were detected. These results indicate that promoter polymorphisms in the MIF promoter region are risk factors for atopy and implicate MIF in the pathogenesis of atopy in a Japanese population.

BACKGROUND

The cause of follicular occlusion, a key early event in the pathogenesis of hidradenitis suppurativa (HS), also known as acne inversa, remains unknown.

OBJECTIVE

To identify changes, if any, in the antimicrobial peptide (AMP) and cytokine expression profile of HS affected human skin.

METHODS

Quantitative immunohistomorphometry was used to compare the in situ protein expression of selected AMPs and cytokines in lesional HS skin from 18 patients with that in healthy skin (n = 12). The lesional skin from patients with HS was histologically subclassified based on the predominance of inflammation vs. scarring.

RESULTS

Compared with healthy controls, significantly increased immunoreactivity for cathelicidin (LL-37) was noted in the apocrine sweat gland and distal outer root sheath (ORS) of the hair follicle (HF) epithelium in lesional HS skin. Immunoreactivity for LL-37, psoriasin, human β-defensin 3 (hBD3), α-melanocyte stimulating hormone (α-MSH), macrophage migration inhibitory factor (MIF), tumour necrosis factor (TNF)-α and interleukin (IL)-8 was significantly increased in HS epidermis. LL-37 and TNF-α immunoreactivity was also increased in the dermis of lesional HS skin. In contrast, lysozyme expression was decreased in the epidermis of lesional HS skin, while that of TNF-α and IL-8 was decreased in the proximal ORS of HFs in HS lesions. These differences were most pronounced in HS with predominant inflammation.

CONCLUSIONS

Our observations raise the question as to whether excessive secretion of AMPs by the skin, in particular by the apocrine sweat glands, distal HF epithelium, and epidermis, may attract inflammation and thus facilitate or promote HS development.

OBJECTIVE

We aim at the association of macrophage migration inhibitory factor (MIF) with neovascularization and survival of nasopharyngeal carcinoma (NPC), and determine whether MIF is a valuable prognostic predictor for NPC patients.

METHODS

One hundred and forty one cases of NPC and 25 normal tissues of nasopharynx were collected. The expression of MIF and interleukin 8 (IL-8) was evaluated in tissues microarray by immunostaining. Intratumoral microvessel density (IMD) in relation to immunostainings and clinicopathological factors were analyzed statistically as well as the follow-up data of patients.

RESULTS

High-expression of both MIF (69.5%) and IL-8 (56.0%) were significantly associated with increased microvessels and lymph node metastasis. High-expression of MIF, IL-8 and higher level of IMD were correlated with either patients' overall survival or disease-specific survival in univariate analysis, but only angiogenesis and lymph node status exhibited in relation to survival of patients as independent prognostic factor of NPC by multivariate analysis. In addition, high-expression of MIF and higher level of IMD were closely associated with locoregional failure of NPC patients.

CONCLUSIONS

MIF may contribute to lymph node metastasis in NPC by inducing angiogenesis through the way of upregulation of IL-8 expression in an autocrine EBV-independent pathway.