Fas and Fas ligand: a death factor and its receptor

HELLP Syndrome—Holistic Insight into Pathophysiology

HELLP syndrome, also known as the syndrome of hemolysis, elevated liver enzymes, and low platelets, represents a severe pregnancy complication typically associated with hypertension. It is associated with increased risks of adverse complications for both mother and fetus. HELLP occurs in 0.2–0.8% of pregnancies, and, in 70–80% of cases, it coexists with preeclampsia (PE). Both of these conditions show a familial tendency. A woman with a history of HELLP pregnancy is at high risk for developing this entity in subsequent pregnancies. We cannot nominate a single worldwide genetic cause for the increased risk of HELLP. Combinations of multiple gene variants, each with a moderate risk, with concurrent maternal and environmental factors are thought to be the etiological mechanisms. This review highlights the significant role of understanding the underlying pathophysiological mechanism of HELLP syndrome. A better knowledge of the disease’s course supports early detection, an accurate diagnosis, and proper management of this life-threatening condition.

Maternal circulating concentrations of soluble Fas and Elabela in early- and late-onset preeclampsia

OBJECTIVE

The Fas/Fas ligand (FASL) system and Elabela-apelin receptor signaling pathways are implicated in the pathophysiology of preeclampsia. The aim of the current study was to investigate whether a model combining the measurement of sFas and Elabela in the maternal circulation may serve as a clinical biomarker for early- and/or late-onset preeclampsia more effectively than measures of each biomarker individually.

METHODS

Blood samples were collected from 214 women in the following groups: (1) normal pregnancy sampled <34 weeks of gestation (n = 56); (2) patients who developed early-onset preeclampsia (n = 54); (3) normal pregnancy sampled ≥34 weeks of gestation (n = 52); (4) patients who developed late-onset preeclampsia (n = 52). Maternal circulating soluble Fas and Elabela concentrations were determined using sensitive and validated immunoassays. Two sample t-tests, multivariate logistic regression, and receiver operating characteristic curves were used for analyses.

RESULTS

(1) Women with early-onset preeclampsia, and those with late-onset preeclampsia with placental lesions of maternal vascular malperfusion, had increased concentrations of sFas compared to their gestational age-matched normal controls; (2) women with late-onset preeclampsia, but not those with early-onset preeclampsia, had increased concentrations of Elabela compared to their gestational age-matched counterparts; and (3) an increase in both Elabela and sFas concentrations was more strongly associated with late-onset preeclampsia than early-onset preeclampsia relative to models including either of the markers alone.

CONCLUSIONS

A combined model of maternal sFas and Elabela concentrations provides a stronger association with late-onset preeclampsia than either protein alone. This finding demonstrates the possibility to improve the classification of late-onset preeclampsia by combining the results of both molecular biomarkers.

BEWO trophoblast cells and Toxoplasma gondii infection modulate cell death mechanisms in THP-1 monocyte cells by interference in the expression of death receptor and intracellular proteins

Crosstalk between trophoblast and monocytes is essential for gestational success, and it can be compromised in congenital toxoplasmosis. Cell death is one of the mechanisms involved in the maintenance of pregnancy, and this study aimed to evaluate the role of trophoblast in the modulation of monocyte cell death in the presence or absence of Toxoplasma gondii infection. THP-1 cells were stimulated with supernatants of BeWo cells and then infected or not with T. gondii. The supernatants were collected and analyzed for the secretion of human Fas ligand, and cells were used to determine cell death and apoptosis, cell death receptor, and intracellular proteins expression. Cell death and apoptosis index were higher in uninfected THP-1 cells stimulated with supernatants of BeWo cells; however, apoptosis index was reduced by T. gondii infection. Macrophage migration inhibitory factor (MIF) and transforming growth factor (TGF)-β1, secreted by BeWo cells, altered the cell death and apoptosis rates in THP-1 cells. In infected THP-1 cells, the expression of Fas/CD95 and secretion of FasL was significantly higher; however, caspase 3 and phosphorylated extracellular-signal-regulated kinase (ERK1/2) were downregulated. Results suggest that soluble factors secreted by BeWo cells induce cell death and apoptosis in THP-1 cells, and Fas/CD95 can be involved in this process. On the other hand, T. gondii interferes in the mechanism of cell death and inhibits THP-1 cell apoptosis, which can be associated with active caspase 3 and phosphorylated ERK1/2. In conclusion, our results showed that human BeWo trophoblast cells and T. gondii infection modulate cell death in human THP-1 monocyte cells.

Changes in genotoxicity, inflammatory and oxidative stress parameters of workers in marble processing plants

Workers in marble processing plants are at high risk of exposure to high levels of marble dust containing silica, but there are limited studies evaluating the genotoxicity and oxidative stress parameters of workers occupationally exposed to marble dust. In this study, we aimed to clarify how marble dust affects genotoxicity and immunotoxicity mechanisms alongside oxidative stress in the workers in the marble processing plants of Iscehisar, Turkey. The oxidative stress and immune system parameters were determined spectrophotometrically using commercial kits. Genotoxicity was evaluated by Comet and micronucleus (MN) assays in the lymphocytes and buccal cells, respectively. The enzyme activities of superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and the levels of glutathione, and Clara cell secretory protein CC16 in workers (n = 48) were significantly lower than in controls (n = 41), whereas the levels of malondialdehyde, 8-oxo-7,8-dihydro-2'-deoxyguanosine, tumor necrosis factor-alpha, interleukin-1beta were significantly higher in workers. DNA damage in workers were significantly higher than in controls and there was a clear correlation between the increase in DNA damage and the duration of exposure. Marble workers had significantly higher MN frequencies when compared to controls. The results indicate the possibility of immunotoxic and genotoxic risks to workers in marble industry.

Serum Levels of Soluble Fas and Fas Ligand in Iranian Women with Pre-eclampsia

Background

The precise responsible mechanism of pre-eclampsia remains controversial however, recent data suggest a main role of the abnormal activation of the adaptive immune system and Apoptosis. In this study, we have measured serum levels of Fas/Fasl as two important members of extrinsic apoptotic pathway in patient with pre-eclampsia.

Methods

207 participants including 99 pre-eclampsia patients and 108 age and sex-matched normal pregnant women were involved in the case-control study. Plasma sample from each participant was collected and stored at -20 °C until batch processing.Serum levels of Fas and Fas ligand were measured by ELISA for each participant including 99 pre-eclampsia patients and 108 normal pregnant women. Following a test of statistical normality, nonparametric data were analyzed by Mann-Whitney.

Results

sFas levels in case group was significantly higher than controls; 584 (397-892) pg/ml in cases opposed to 341 (213-602) pg/ml in controls (p value< 0.01). sFasL in pre-eclampsia women was a little lower than controls; 255 (173-318) pg/ml and in case group compared to 265.5 (184-381.5) pg/ml in controls.

Conclusion

We have found the increased levels of sFas in patients with pre-eclampsia in compare with the healthy pregnant women. It seems that abnormality in sFAS is related with pre-eclampsia.

CD95L and Anti-Tumor Immune Response: Current Understanding and New Evidence

The ability of FasL/CD95L to induce apoptosis in various Fas/CD95-expressing cells has been described in the context of hematopoiesis or thymic elimination of self-reactive T cells and resolution of an acute immune response under physiological conditions. At the same time, non-apoptotic CD95 activation is widely described in cancer and shown to stimulate invasiveness of cancer cells, promote cancer progression as well as stemness of cancer cells. This paper puts emphasis on the evolving understanding of expression and the non-apoptotic activities of the CD95/CD95L signaling pathway on the function of tumor cells, tumor microenvironment and immune cells. The emerging evidence to support the role of CD95/CD95L signaling in the anti-tumor immune response will be presented in the context of various malignancies and the modalities of potential therapeutic interventions via selective CD95L inhibition in combination with traditional interventions such as RT, chemotherapy and immune checkpoint inhibitors.

LncRNAs and Immunity: Coding the Immune System with Noncoding Oligonucleotides

Long noncoding RNAs (lncRNAs) represent key regulators of gene transcription during the inflammatory response. Recent findings showed lncRNAs to be dysregulated in human diseases, such as inflammatory bowel disease, diabetes, allergies, asthma, and cancer. These noncoding RNAs are crucial for immune mechanism, as they are involved in differentiation, cell migration and in the production of inflammatory mediators through regulating protein–protein interactions or their ability to assemble with RNA and DNA. The last interaction can occur in cis or trans and is responsible for all the possible lncRNAs biological effects. Our proposal is to provide an overview on lncRNAs roles and functions related to immunity and immune mediated diseases, since these elucidations could be beneficial to untangle the complex bond between them.

Trisomy 21 is Associated with Caspase-2 Upregulation in Cytotrophoblasts at the Maternal-Fetal Interface

Impaired placentation is implicated in poor perinatal outcomes associated with Trisomy 21. Earlier studies revealed abnormal cytotrophoblast differentiation along the invasive pathway as a contributing mechanism. To further elucidate the causes, we evaluated Caspase-2 expression at the protein level (immunolocalization and immunoblot) in samples from Trisomy 21 (n = 9) and euploid (n = 4) age-matched placentas. Apoptosis was investigated via the TUNEL assay. An immunolocalization approach was used to characterize Caspase-3, Fas (CD95), and Fas ligand in the same samples. Caspase-2 was significantly overexpressed in Trisomy 21 placentas, with the highest expression in villous cores and invasive cytotrophoblasts. Immunolocalization showed that Caspase-3 had a similar expression pattern as Caspase-2. Using the TUNEL approach, we observed high variability in the number of apoptotic cells in biopsies from different regions of the same placenta and among different placentas. However, Trisomy 21 placentas had more apoptotic cells, specifically in cell columns and basal plates. Furthermore, Caspase-2 co-immunolocalized with Fas (CD95) and FasL in TUNEL-positive extravillous cytotrophoblasts, but not in villous cores. These results help explain the higher levels of apoptosis among placental cells of Trisomy 21 pregnancies in molecular terms. Specifically, the co-expression of Caspase-2 and Caspase-3 with other regulators of the apoptotic process in TUNEL-positive cells suggests these molecules may cooperate in launching the observed apoptosis. Among trophoblasts, only the invasive subpopulation showed this pattern, which could help explain the higher rates of adverse outcomes in these pregnancies. In future experiments, this relationship will be further examined at a functional level in cultured human trophoblasts.

Cellular response and extracellular vesicles characterization of human macrophages exposed to fine atmospheric particulate matter

Exposure to fine atmospheric Particulate Matter (PM) is one of the major environmental causes involved in the development of inflammatory lung diseases, such as chronic obstructive pulmonary disease (COPD) or asthma. When PM is penetrating in the pulmonary system, alveolar macrophages represent the first line of defense, in particular by triggering a pro-inflammatory response, and also by their ability to recruit infiltrating macrophages from the bone marrow. The aim of this in vitro study was to evaluate the gene expression and cytokine production involved in the toxicological and inflammatory responses of infiltrating macrophages, as well as the Extracellular Vesicles (EVs) production, after their exposure to PM. The ability of these EVs to convey information related to PM exposure from exposed macrophages to pulmonary epithelial cells was also evaluated. Infiltrating macrophages respond to fine particles exposure in a conventional manner, as their exposure to PM induced the expression of Xenobiotic Metabolizing Enzymes (XMEs) such as CYP1A1 and CYP1B1, the enzymes involved in oxidative stress SOD2, NQO1 and HMOX as well as pro-inflammatory cytokines in a dose-dependent manner. Exposure to PM also induced a greater release of EVs in a dose-dependent manner. In addition, the produced EVs were able to induce a pro-inflammatory phenotype on pulmonary epithelial cells, with the induction of the release of IL6 and TNFα proinflammatory cytokines. These results suggest that infiltrating macrophages participate in the pro-inflammatory response induced by PM exposure and that EVs could be involved in this mechanism.

Placenta derived factors involved in the pathogenesis of the liver in the syndrome of haemolysis, elevated liver enzymes and low platelets (HELLP): A review

AIM

With this review we try to unravel if placenta-derived factors are able to initiate liver sinusoidal endothelial cells (LSEC) decay in HELLP syndrome and eventually cause the development of sinusoidal obstruction syndrome (SOS).

BACKGROUND

Haemolysis, Elevated Liver enzymes and Low Platelets (HELLP) syndrome is a severe complication of pregnancy. It is characterized by elevated liver enzymes, low platelet count and haemolytic anaemia. The risk of developing HELLP syndrome within a pregnancy is 0.1-0.8%. The mortality rate among women with HELLP syndrome is 0-24% and the perinatal death goes up to 37%. The aetiology of HELLP syndrome is not fully understood but the pathogenesis of the liver pathology in the HELLP syndrome resembles that of a SOS with endothelial damage of the LSECs which ultimately leads to liver failure.

OBJECTIVES

We hypothesize that placenta derived factors cause LSEC damage and thereby liver dysfunction.

METHODS

We searched in the PubMed database for relevant articles about placenta derived factors involved in endothelial activation especially in the liver. We yielded eventually 55 relevant articles.

RESULTS

Based on this literature search we associate that in HELLP syndrome there is an increase of soluble fms-like tyrosine kinase (sFlt1), vascular endothelial growth factor (VEGFR), soluble endoglin (sEng), galectin-1 (Gal-1), endothelin-1 (ET-1), Angiopoietin 2 (Angs-2), Asymmetric dimethylarginine (ADMA), activin B, inhibin A, Fas ligand (FasL) and heat shock protein 70 (Hsp70).

CONCLUSION

We assume that these eleven increased placenta derived factors are responsible for LSEC damage which eventually leads to liver failure. This concept shows a possible design of the complicated pathophysiology in HELLP syndrome. However further research is required.

Fas-Antisense Long Noncoding RNA and Acute Myeloid Leukemia: Is There any Relation?

In recent years, lncRNAs have been considered as potential predictive biomarkers for prognosis of different human cancers. One example is the FAS antisense RNA 1 (FAS-AS1) located in the 10q23.31 region which is transcribed from the opposite strand of the FAS gene. FAS has an important role in regulation of apoptotic pathways and there is an inverse correlation between FAS-AS1 expression level and production of the soluble form of Fas, so that it might have potential as a therapeutic target to improve chemotherapy effectiveness. In the present study we therefore evaluated FAS-AS1 expression in blood samples of de novo AML patients and healthy controls using real-time quantitative reverse transcription-PCR (qRT-PCR). Our results indicated that the expression level of FAS-AS1 lncRNA demonstrated no significant difference between AML patients and healthy individuals. We conclude from the obtained data that FAS-AS1 is not an informative and reliable biomarker for AML diagnosis, although our results need to be confirmed in further studies.

Long noncoding RNA identification in lymphoma

It has been found that long noncoding RNA (lncRNA) are abnormally expressed in lymphoma and play an important role in its pathogenesis. Through the detection and analysis of lncRNA, it was found that lncRNA could be used as an excellent biomarker for the diagnosis and prognosis of cancer. In lymphoma, abnormal lncRNA expression is associated with the patient's clinical characteristics, it can be used to determine the prognosis of the patient and serve as a therapeutic target in the disease.

FasL and the NKG2D receptor are required for the secretion of the Tag7/PGRP-S-Hsp70 complex by the cytotoxic CD8+ lymphocytes

Tag7 (PGRP-S or PGLYRP1), while possessing an antimicrobial activity, also exhibits an antitumor effect when in complex with the major heat shock protein Hsp70. The cytotoxic Tag7-Hsp70 complex is secreted by lymphocytes after interaction with the HLA-negative tumors. Previously, we have shown that IL-2 induces formation of the CD4⁺ and CD8⁺ cytotoxic subpopulations of human lymphocytes, which kill tumor cells through the FasL-Fas interaction. Here, we show that only the CD8⁺ T cells are able to secrete the Tag7-Hsp70 complex. For its secretion the same proteins on the surface of the lymphocytes and target cells, which are involved in the contact lysis, are necessary as well. The interaction of Fas receptor with FasL leads to an activation of the Tag7-Hsp70 complex in the lymphocyte membrane fraction, and here FasL acts as a receptor that induces intracellular signaling in lymphocytes. An interaction of the MicA stress ligand with the NKG2D receptor is necessary for the release of this cytotoxic complex. It is possible, that CD8⁺ T lymphocytes interacting with a target cell can both carry out the contact killing of these cells and to secrete the cytotoxic factor. © 2016 IUBMB Life, 69(1):30-36, 2017.

Morphological Examination and Transcriptomic Profiling To Identify Prednisolone Treatment in Beef Cattle

In livestock production corticosteroids are licensed only for therapy; nevertheless, they are often illegally used as growth promoters. The aim of this study was to identify morphological or biomolecular alterations induced by prednisolone (PDN) in experimentally treated beef cattle, because PDN and its metabolites are no longer detectable by LC-MS/MS methods in biological fluids. Moreover, PDN does not induce any histological alterations in the thymus, different from dexamethasone treatments. Therefore, a marker of illicit treatment for this growth promoter could be useful. Eight male Italian Friesian beef cattle were administered prednisolone acetate 30 mg day^-1 per os for 35 days, and seven beef cattle represented the control group. Six days after drug withdrawal, the animals were slaughtered. Morphological and morphometric modifications were evaluated in the epididymis and testis, whereas transcriptomic changes induced by PDN administration were investigated in peripheral blood mononuclear cells (PBMCs) at different sampling times and in skeletal muscle and testis sampled at slaughtering. In the epididymis, spermatozoa number decreased in PDN-treated animals, and in some cases they were totally absent. Correspondingly, in the testis of treated animals, down-regulation for serine/threonine kinase 11 (STK11) gene expression was detected (p < 0.01). DNA microarray analysis revealed a total of 133 differentially expressed genes in skeletal muscle and testis, and 907 and 1416 in PBMCs after 33 days of treatment and at slaughtering, respectively. Histological investigations on epididymal content could represent a promising marker for PDN treatment in beef cattle and could be used as a screening method to identify animals worthy of further investigation with official methods. Moreover, the clear transcriptomic signature of PDN treatment evidenced in PBMCs supported the possibility of using this matrix to monitor the illicit treatment in vivo during ranching.

Structural Characterizations of the Fas Receptor and the Fas-Associated Protein with Death Domain Interactions

The Fas receptor is a representative death receptor, and the Fas-associated protein with death domain (FADD) is a crucial adapter protein needed to support the Fas receptor's activity. The Fas-FADD interactions constitute an important signaling pathway that ultimately induces apoptosis or programmed cell death in biological systems. The interactions responsible for this cell-death process are governed by the binding process of the Fas ligand to the Fas, followed by the caspase cascade activation. Using a computational approach, the present communication explores certain essential structural aspects of the Fas-FADD death domains and their interfacial interactions.

MicroRNA 196B regulates FAS-mediated apoptosis in colorectal cancer cells

Using miRNA microarray analysis, we identified 31 miRNAs that were significantly up-regulated or down-regulated in colon cancer tissues. We chose MIR196B, which was specifically up-regulated in colon cancer, for further study. We identified 18 putative MIR196B target genes by comparing between the mRNAs down-regulated in MIR196B-overexpressed cells and the assumed MIR196B target genes predicted by public bioinformatics tools. The association between MIR196B and FAS was verified in this study. FAS expression was constitutively elevated in normal human colorectal tissues. However, its expression was often reduced in human colorectal cancer. The decrease in FAS expression could be responsible for the reduction of apoptosis in colorectal cancer cells. In colorectal cancer tissue, we showed that MIR196B up-regulation was mutually followed by down regulation of FAS expression. We also showed that MIR196B directly repressed FAS expression in colorectal cells. Furthermore, anti-MIR196B up-regulated FAS expression and increased apoptosis in colorectal cancer cell lines. Our results suggest that the up-regulation of MIR196B modulates apoptosis in colorectal cancer cells by partially repressing FAS expression and that anti-MIR196B could be a potential candidate as an anti-cancer drug in colorectal cancer therapy.

sHLA-G involved in the apoptosis of decidual natural killer cells following Toxoplasma gondii infection

This study aims to assess whether soluble HLA-G (sHLA-G) is involved in apoptosis of decidual natural killer (dNK) cells following Toxoplasma gondii infection. dNK cells or NK-92 cells were infected with T. gondii and co-cultured with trophoblast cells or BeWo cells. Infected co-cultured cells were treated without or with sHLA-G neutralizing antibody. Uninfected co-cultured cells were used as controls. Apoptosis of dNK cells were analyzed by flow cytometry and confocal microscope. Real-time PCR and Western blot were used to determine caspase 3 and caspase 8 expression. sHLA-G in supernatant were measured by enzyme-linked immunosorbent assay (ELISA). In infection groups, sHLA-G was increased, while dNK apoptosis proteins caspase 3 and caspase 8 were up-regulated, but significantly decreased in the presence of sHLA-G neutralizing antibody compared to controls. Under the situation of T. gondii-infected dNK cells co-cultured with trophoblast cells, the up-regulation of sHLA-G could induce dNK cells apoptosis which ultimately may contribute to the abnormal pregnancy outcomes with T. gondii infection.

Identification of genes and transcription factors associated with glucocorticoid response in lens epithelial cells

Prolonged glucocorticoids (GCs) treatment may lead to the formation of posterior subcapsular cataracts. The present study aimed to investigate differential gene expression in lens epithelial cells (LECs) in response to GCs using DNA microarray profiling. The gene expression profile of GSE13040 was downloaded from the Gene Expression Omnibus database, which includes 12 human LECs treated with vehicle or dexamethasone (Dex) for 4 or 16 h with six samples at each time period, of which three samples were treated with vehicle (control group) and three samples were treated with Dex (Dex group) at each time point. The differentially expressed genes (DEGs) were identified between the control group and the Dex group at each time period with the thresholds of P<0.05 and |logFC|>1. The DEGs were further analyzed using bioinformatics methods. Firstly, DEGs were subject to a hierarchical cluster analysis. Subsequently, the functional enrichment analysis was performed for the common DEGs between the two time periods. Finally, the transcription factors and binding sites of DEGs associated with response to GC stimulus were analyzed. A total of 696 and 949 DEGs were identified at 4 h and 16 h, respectively. Hierarchical cluster analysis revealed that DEG expression was higher in the Dex group than in the control group (P<0.05). A total of 13 significant functions were enriched for the 72 common DEGs at the two time periods. Chemokine (C-C motif) ligand 2 (CCL2), dual-specificity phosphatase-1 (DUSP1) and FAS were associated with the response to GC stimulus and the transcription factor c-Jun bound to promoter regulation regions of CCL2, DUSP1 and FAS. In conclusion, the transcription factors and binding sites of DEGs associated with the response of LECs to GCs may provide potential gene targets for designing and developing drugs to protect against GC-induced cataract formation.

Prognostic role of apoptosis-related gene functional variants in advanced non-small-cell lung cancer patients treated with first-line platinum-based chemotherapy

Background

Single-nucleotide polymorphisms in apoptosis-related genes have been shown to play a role in the efficacy of platinum-based chemotherapy and may influence clinical outcomes. Our study aimed to evaluate the correlations of four functional single-nucleotide polymorphisms − FAS −670 A>G, FAS ligand −844 T>C, survivin −31 G>C, and survivin 9386 C>T – with drug response and clinical outcomes in advanced non-small-cell lung cancer patients who received platinum-based chemotherapy.

Materials and methods

Polymorphisms were evaluated using the polymerase chain reaction-based restriction fragment-length polymorphism technique.

Results

Patients with the CC genotype of FAS −670 A>G had worse overall survival (OS) than those with the CT or TT genotype (P=0.044), with median OS values of 20.1 months, 22.8 months, and 26.0 months, respectively. Furthermore, progression-free survival was associated with the FAS −670 A>G polymorphism (P=0.032). In addition, patients with the TC and CC genotypes of survivin 9386 C>T experienced improved survival compared with patients with the TT genotype (median OS 31.4 months and 22.8 months, respectively).

Conclusion

The functional FAS −670 A>G and survivin 9386 C>T polymorphisms are potential independent prognostic factors in advanced non-small-cell lung cancer patients treated with platinum-based chemotherapy.

Silica exposure and altered regulation of autoimmunity

Silica particles and asbestos fibers, which are known as typical causatives of pneumoconiosis, induce lung fibrosis. Moreover, silicosis patients often complicate with autoimmune diseases, and asbestos-exposed patients suffer from malignant diseases such as pleural mesothelioma and lung cancer. We have been conducting experimental studies to investigate altered regulation of self-tolerance caused by silica exposure, including analyses using specimens such as plasma and immunocompetent cells obtained from silicosis patients, as a means of examining the supposition that silica exposure induces molecular and cellular biological alterations of immune cells. These approaches have resulted in the detection of several specific autoantibodies, alterations of CD95/Fas and its related molecules, and evidence of chronic activation of responder T cells and regulatory T cells following silica exposure. In this review, we present details of our investigations as an introduction to scientific approaches examining the immunological effects of environmental and occupational substances.

Pathophysiology of JIA-associated uveitis

Juvenile idiopathic arthritis (JIA)-associated uveitis is an intriguing manifestation of JIA and an important contributor of long-term damage. Its pathophysiology is still poorly understood. This review summarizes current concepts. JIA is both a multifactorial and polygenetic disease. In the past 2 decades, multiple studies have indicated that the genetic contribution to both JIA and JIA-associated uveitis is modest. From an ophthalmological point of view, much of the pathophysiological data is derived from studies in experimental uveitis animal models. The pathophysiology of the arthritic manifestations of JIA has been studied extensively in humans. These studies have focused on the principal cells of the adaptive immune system, in particular different subsets of regulatory and effector T cells, as well as on antigen presenting cells or dendritic cells. With advancing technology and advancing knowledge of the underlying mechanisms of JIA-associated uveitis, new targets for therapy might evolve in the coming years.

A polygene network model for the complex pathological phenotypes of collagen disease

Almost 70 years after the description of 'collagen disease' by P. Klemperer et al., it is still controversial whether the diversity and similarity of pathological manifestations among the collagen diseases depends on ambiguity in diagnosis or is an intrinsic quality of the collagen diseases themselves. A genome wide analysis of the MRL mouse models of collagen disease may shed some light on the complex pathological manifestations. Study of the susceptibility loci to each type ofcollagen disease (such as glomerulonephritis, vasculitis, arthritis, sialoadenitis and dacryoadenitis) in the mice, revealed that these lesions developed because of a cumulative effect of multiple gene loci, none of which can induce the related phenotype alone. This may indicate that collagen disease develops in 'a polygenic system', as proposed by K. Mather in 1949. Each lesion in the mice developed because of an additive effect of the polygenes, which is also, in part, hierarchical. Some of the polygenes seemed to be common to those in other collagen diseases as well. Some of the positional candidate genes involved an allelic polymorphism in the coding or promoter regions, thus possibly causing a qualitative or quantitative difference in their function, respectively. As a result, a particular combination of the polygenes with such an allelic polymorphism may thus play a critical role in leading the cascade reaction to developing collagen disease, and also the regular variation in the pathological manifestations. We herein describe this as a polygene network of collagen disease.

FAS-antisense 1 lncRNA and production of soluble versus membrane Fas in B-cell lymphoma

Impaired Fas-mediated apoptosis is associated with poor clinical outcomes and cancer chemoresistance. Soluble Fas receptor (sFas), produced by skipping of exon 6, inhibits apoptosis by sequestering Fas ligand. Serum sFas is associated with poor prognosis of non-Hodgkin's lymphomas. We found that the alternative splicing of Fas in lymphomas is tightly regulated by a long-noncoding RNA corresponding to an antisense transcript of Fas (FAS-AS1). Levels of FAS-AS1 correlate inversely with production of sFas, and FAS-AS1 binding to the RBM5 inhibits RBM5-mediated exon 6 skipping. EZH2, often mutated or overexpressed in lymphomas, hyper-methylates the FAS-AS1 promoter and represses the FAS-AS1 expression. EZH2-mediated repression of FAS-AS1 promoter can be released by DZNeP (3-Deazaneplanocin A) or overcome by ectopic expression of FAS-AS1, both of which increase levels of FAS-AS1 and correspondingly decrease expression of sFas. Treatment with Bruton's tyrosine kinase inhibitor or EZH2 knockdown decreases the levels of EZH2, RBM5 and sFas, thereby enhancing Fas-mediated apoptosis. This is the first report showing functional regulation of Fas repression by its antisense RNA. Our results reveal new therapeutic targets in lymphomas and provide a rationale for the use of EZH2 inhibitors or ibrutinib in combination with chemotherapeutic agents that recruit Fas for effective cell killing.

Macrophages: are they involved in endometriosis, abortion and preeclampsia and how?

Macrophages hold a key role in both regulating and executing the body's own immune response under various conditions. Hence, although endometriosis, preeclampsia and abortions are clinically different, all three are regarded to involve highly complex immunological processes. The aim of our current work was to evaluate the role of macrophages within these gynaecological disorders. Macrophages have been shown to invade endometriosis lesions and to mediate propagation of endometriotic cyst growth. However this is the first time that significant GPER up-regulation in macrophages is demonstrated. This highlights a potential alternative way through which estrogen may modulate immune response of macrophages in endometriosis. In addition, during spontaneous miscarriages the macrophage population increases significantly. This deregulation may possibly support an inflammatory scheme further triggering abortive procedures. Macrophage-mediated apoptosis of extravillous trophoblasts (EVT) has been associated with preeclampsia. Larger numbers of apoptotic EVT were detected in preeclamptic placentas compared with normal. In preeclamptic placentas, decidual macrophages were found to be Fas ligand (FasL)-positive. Our results highlight a new aspect of macrophage biology in endometriosis and pregnancy physiology and patho-physiology. Further studies with larger samples are needed to verify the current results and evaluate their clinical impact. Our data strongly indicate that macrophages hold key roles in various gynaecological disorders and might be crucial to further elucidate their patho-physiology.

Systemic immune response after laparoscopic and open cholecystectomy

The laparoscopic approach is thought to reduce the postoperative immunologic and metabolic effects of an open operation. This study was designed with the aim of comparing the systemic immune response after laparoscopic and open cholecystectomy. Seventeen patients with gallbladder stones were assigned to undergo either a laparoscopic (n = 9) or open (n = 8) approach. The postoperative immune response was assessed by measuring the serum levels of soluble Fas (sFas), soluble L-selectin (sL-selectin), and transforming growth factor-beta1 (TGFbeta1) preoperatively and 2 hours, 1 day, and 2 days postoperatively. Both approaches resulted in a significant decrease in sFas levels 1 and 2 days postoperatively. The open approach evoked a transient increase in sL-selectin levels 2 hours postoperatively. Moreover, the open approach resulted in a persistent, significant increase in TGFbeta1 levels postoperatively. Comparison of open versus laparoscopic cholecystectomy has shown no significant difference in sFas level and a statistically significant increase of sL-selectin (within 2 hours) and TGFbeta levels after open surgery. Although both laparoscopic and open cholecystectomy evoked an alteration of the systemic immune response, our data showed that such immune response may be less after the laparoscopic approach.

Association of FAS and FAS ligand genes polymorphism and risk of systemic lupus erythematosus

FAS/FASL pathway plays a critical role in maintaining peripheral immune tolerance; therefore, the apoptosis genes, Fas and Fas ligand (FasL), could be suitable candidate genes in human SLE susceptibility. Materials and Methods. In this case-control study, 106 SLE patients and 149 sex, age, and ethnicity matched healthy controls were genotyped for the Fas A-670G and FasLC-844T polymorphisms by polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). Results. The frequency of -670AA genotype was significantly higher in SLE patients than control group and the risk of SLE was 2.1-fold greater in subjects with AA genotype (P = 0.03). The frequency of -670A allele was significantly higher in SLE patients than in controls too (58% versus 49%, P = 0.03). The -844CC genotype frequency was significantly higher in SLE patients than in healthy controls and the risk of SLE was 2.8-fold greater in these subjects (P = 0.01). The C allele frequency was significantly higher in patients than in controls (69% versus 49%, P = 0.001). Increased SLE risk was observed in individuals with combined effect of Fas-670AA and FasL-844CC genotypes (P = 0.001). Conclusion. Fas-670AA and FasL-844CC genotypes were associated with SLE risk, and combined effect of -670AA and -844CC genotypes might increase SLE susceptibility.

Evolution of vertebrate immunity

All multicellular organisms protect themselves against pathogens using sophisticated immune defenses. Functionally interconnected humoral and cellular facilities maintain immune homeostasis in the absence of overt infection and regulate the initiation and termination of immune responses directed against pathogens. Immune responses of invertebrates, such as flies, are innate and usually stereotyped; those of vertebrates, encompassing species as diverse as jawless fish and humans, are additionally adaptive, enabling more rapid and efficient immune reactivity upon repeated encounters with a pathogen. Many of the attributes historically defining innate and adaptive immunity are in fact common to both, blurring their functional distinction and emphasizing shared ancestry and co-evolution. These findings provide indications of the evolutionary forces underlying the origin of somatic diversification of antigen receptors and contribute to our understanding of the complex phenotypes of human immune disorders. Moreover, informed by phylogenetic considerations and inspired by improved knowledge of functional networks, new avenues emerge for innovative therapeutic strategies.

Co-expression of multiple cytokines and their receptors in primary clear cell sarcoma of the pubic bone with features of a small round cell tumor

We present the case of an 81-year-old man with primary clear cell sarcoma (CCS) of the pubic bone with an associated aggressive clinical course. The patient's laboratory tests showed marked leukocytosis, elevated levels of C-reactive protein and multiple cytokines, including interleukin-6 (IL-6) and granulocyte colony-stimulating factor (G-CSF). Histological examination showed monomorphic small cells predominantly arranged as a diffuse sheet with morphological features of a small round cell tumor (SRCT). Immunohistochemical staining indicated that the tumor cells were positive for HMB45, S100, Melan A, IL-6, IL-6 receptor, G-CSF, and G-CSF receptor and negative for cytokeratin (AE1/AE3) and epithelial membrane antigen. To the best of our knowledge, this is the first case report of aggressive primary CCS of the pubic bone with features of SRCT showing the production and co-expression of multiple cytokines and their receptors. Thus, we suggest that proliferation through an IL-6- and G-CSF-associated autocrine mechanism may play an important role in the aggressive clinical course and poor prognosis of some CCSs showing features of SRCT.

Keynote lecture in the 13th Japanese Society of Immunotoxicology (JSIT 2006) : -Pathophysiological Development and Immunotoxicology: what we have found from research related to silica and silicate such as asbestos-

Silica and silicates may disturb immune functions such as autoimmunity and tumor immunity, because people who are exposed to the materials sometimes develop autoimmune and malignant diseases, respectively. Although silica-induced disorders of autoimmunity have been explained as adjuvant-type effects of silica, more precise analyses are needed and should reflect the recent progress in immunomolecular findings. A brief summary of our investigations related to the immunological effects of silica/asbestos is presented. Recent advances in immunomolecular studies led to detailed analyses of the immunological effects of asbestos and silica. Both affect immuno-competent cells and these effects may be associated with the pathophysiological development of complications in silicosis and asbestos-exposed patients such as the occurrence of autoimmune disorders and malignant tumors, respectively. In addition, immunological analyses may lead to the development of new clinical tools for the modification of the pathophysiological aspects of diseases such as the regulation of autoimmunity or tumor immunity using cell-mediated therapies, various cytokines, and molecule-targeting therapies. In particular, as the incidence of asbestos-related malignancies is increasing and such malignancies have been a medical and social problem since the summer in 2005 in Japan, efforts should be focused on developing a cure for these diseases to eliminate the nation wide anxiety about these malignancies.

Serum apoptosis markers in HIV-infected patients with human herpesvirus type 8 and herpes simplex virus type 2 co-infection

This study aimed to examine the influence of human herpesvirus type 8 (HHV-8) and herpes simplex virus type 2 (HSV-2) co-infections on apoptosis serum markers in human immunodeficiency virus (HIV)-infected patients. Sera from 110 HIV-infected and 59 HIV-uninfected individuals were analyzed for soluble Fas (sFas), sFas ligand (sFasL), caspase-8, and Bcl-2. The findings of HIV-infected patients with no co-infection (n = 37), HIV-infected patients with HHV-8 co-infection (n = 22), HIV-infected patients with HSV-2 co-infection (n = 51), and patients with HSV-2 co-infection and no HIV infection (n = 20) were compared to controls (reference group) with no HIV, HSV-2, and HHV-8 co-infections (n = 39). Soluble Fas and sFasL concentrations were the highest in HIV and HHV-8 co-infected patients (medians, 912.7 pg/ml and 74.3 pg/mL, respectively). No difference in caspase-8 concentrations was found, whereas Bcl-2 concentrations were the highest in HIV and HHV-8 co-infected individuals. Older age was associated with higher sFas (p < 0.001) and lower sFasL (p = 0.04) concentrations. In a robust regression model adjusted for age, the log-transformed sFas concentrations were significantly lower in HIV-infected patients with no co-infections (β = -0.244; p < 0.001) and higher in HIV and HHV-8 co-infected patients (β = 0.216; p = 0.012) compared to the reference group. Soluble FasL was significantly lower in HIV-infected patients with no co-infections (β = -0.284; p = 0.005) and in HIV-infected patients with HSV-2 co-infection (β = -0.381; p < 0.001) compared to the reference group. Soluble FasL was also higher in HIV and HHV-8 co-infected patients compared to controls (β = 0.248; p = 0.036). Our results suggest that HHV-8 and HSV-2 may have a significant effect on Fas-FasL-mediated apoptosis in HIV-1 patients. HHV-8 upregulates while HSV-2 downregulates sFas and sFasL.

Decidual macrophages are significantly increased in spontaneous miscarriages and over-express FasL: a potential role for macrophages in trophoblast apoptosis

Decidual macrophages (DM) are the second most abundant population in the fetal-maternal interface. Their role has been so far identified as being local immuno-modulators favoring the maternal tolerance to the fetus. Herein we investigated tissue samples from 11 cases of spontaneous miscarriages and from 9 cases of elective terminations of pregnancy. Using immunohistochemistry and dual immunofluorescence we have demonstrated that in spontaneous miscarriages the DM are significantly increased. Additionally, we noted a significant up-regulation of macrophage FasL expression. Our results further support a dual role for DM during pregnancy and miscarriages. We hypothesize that the baseline DM population in normal pregnancy is in line with an M2 phenotype supporting the ongoing gestation. In contrast, during spontaneous miscarriages, the increased FasL-expressing population could be a part of an M1 phenotype participating in Fas/FasL-related apoptosis. Our results highlight a new aspect of macrophage biology in pregnancy physiology and pathophysiology. Further studies with larger samples are needed to verify the current results and evaluate their clinical impact.

Aberrant expression of corticotropin-releasing hormone in pre-eclampsia induces expression of FasL in maternal macrophages and extravillous trophoblast apoptosis

Corticotropin-releasing hormone (CRH) and its receptors are expressed in human placenta. Recently, the impaired function of this system has been associated with a number of complications of pregnancy, including pre-eclampsia. The aim of the study was to test the hypothesis that CRH participates in the pathophysiology of pre-eclampsia through the induction of macrophage-mediated apoptosis of extravillous trophoblasts (EVTs). We found that the expression of CRH was increased in the EVT of the placental bed biopsy specimens from pre-eclamptic pregnancies (1.8-fold increase; P < 0.05). In addition, significantly larger numbers of apoptotic EVT were detected in pre-eclamptic placentas compared with normal ones (P < 0.05), and only in pre-eclamptic placentas, decidual macrophages were found to be Fas ligand (FasL)-positive. In vitro studies on the effect of CRH on human macrophages suggested that CRH induced the expression of the FasL protein in human macrophages and potentiated their ability to induce the apoptosis of a Fas-expressing EVT-based hybridoma cell line in co-cultures. These findings demonstrate a possible mechanism by which the aberrant expression of CRH in pre-eclampsia may activate the FasL-positive decidual macrophages, impair the physiological turnover of EVT and eventually disturb placentation.

Interleukin-6 enhances porcine parthenote development in vitro, through the IL-6/Stat3 signaling pathway

Signal transducer and activator of transcription-3 (Stat3) plays a central role in interleukin-6 (IL-6)-mediated cell proliferation by inhibiting apoptosis in a variety of cell types. The Stat3 pathway is essential for embryonic development. The aim of this study was to determine the effects of recombinant IL-6 on the viability and development of porcine diploid parthenotes cultured in vitro. Four-cell parthenotes, derived in vitro, were cultured to the blastocyst stage, with or without recombinant IL-6. The addition of 10 or 100 ng/ml of recombinant swine IL-6 into PZM3 medium increased the development rate of parthenotes to the blastocyst stage (P<0.05). When supplemented with 10 ng/ml of recombinant swine IL-6, the number of parthenotes at the blastocyst stage increased (P<0.05) and apoptosis decreased (P<0.05). Real-time RT-PCR experiments revealed that the addition of recombinant swine IL-6 decreased the mRNA expression of the pro-apoptotic gene Caspase3 (P<0.01) but increased the expression levels of the anti-apoptotic genes Bcl2l1 and Survivin. IL-6 receptors and Stat3 mRNA expression were upregulated after treatment with 10 ng/ml recombinant swine IL-6. Immunoblots and fluorescence labeling experiments showed that the levels of phosphorylated Stat3 were upregulated. These results suggest that recombinant swine IL-6 prevents apoptosis of porcine parthenotes and enhances porcine embryo viability through the IL-6/Stat3 signaling pathway in vitro.

Modulation of apoptosis pathways by oxidative stress and autophagy in β cells

Human islets isolated for transplantation are exposed to multiple stresses including oxidative stress and hypoxia resulting in significant loss of functional β cell mass. In this study we examined the modulation of apoptosis pathway genes in islets exposed to hydrogen peroxide, peroxynitrite, hypoxia, and cytokines. We observed parallel induction of pro- and antiapoptotic pathways and identified several novel genes including BFAR, CARD8, BNIP3, and CIDE-A. As BNIP3 is an inducer of autophagy, we examined this pathway in MIN6 cells, a mouse beta cell line and in human islets. Culture of MIN6 cells under low serum conditions increased the levels of several proteins in autophagy pathway, including ATG4, Beclin 1, LAMP-2, and UVRAG. Amino acid deprivation led to induction of autophagy in human islets. Preconditioning of islets with inducers of autophagy protected them from hypoxia-induced apoptosis. However, induction of autophagy during hypoxia exacerbated apoptotic cell death. ER stress led to induction of autophagy and apoptosis in β cells. Overexpression of MnSOD, an enzyme that scavenges free radicals, resulted in protection of MIN6 cells from cytokine-induced apoptosis. Ceramide, a mediator of cytokine-induced injury, reduced the active phosphorylated form of Akt and downregulated the promoter activity of the antiapoptotic gene bcl-2. Furthermore, cytokine-stimulated JNK pathway downregulated the bcl-2 promoter activity which was reversed by preincubation with SP600125, a JNK inhibitor. Our findings suggest that β cell apoptosis by multiple stresses in islets isolated for transplantation is the result of orchestrated gene expression in apoptosis pathway.

Three-dimensional microscopy characterization of death receptor 5 expression by over-activated human primary CD4+ T cells and apoptosis

Activation-induced cell death is a natural process that prevents tissue damages from over-activated immune cells. TNF-Related apoptosis ligand (TRAIL), a TNF family member, induces apoptosis of infected and tumor cells by binding to one of its two death receptors, DR4 or DR5. TRAIL was reported to be secreted by phytohemagglutinin (PHA)-stimulated CD4(+) T cells in microvesicles.We investigate here TRAIL and DR5 regulation by activated primary CD4(+) T cells and its consequence on cell death. We observed that PHA induced CD4(+) T cell apoptosis in a dose-dependent manner. Thus, we investigated molecules involved in PHA-mediated cell death and demonstrated that TRAIL and DR5 were over-expressed on the plasma membrane of PHA-stimulated CD4(+) T cells. Surprisingly, DR5 was constitutively expressed in naive CD4(+) T cells at messenger RNA (mRNA) and protein levels. Thus, using 3 dimensional microscopy and intracellular staining assays, we show that DR5 is constitutively expressed in CD4(+) T cells and is pre-stocked in the cytoplasm. When cells are stimulated by PHA, DR5 is relocalized from cytoplasm to plasma membrane. Small interference RNA (siRNA) and blocking antibody assays demonstrate that TRAIL/DR5 interaction is mainly responsible for PHA-mediated CD4(+) T cell apoptosis. Thus, membrane DR5 expression leading to TRAIL-mediated apoptosis may represent one of the pathways responsible for eradication of over-activated CD4(+) T cells during immune responses.

The expression of Fas/FasL and apoptosis in yak placentomes

To clarify the status and distribution of Fas and Fas-Ligand (FasL) in yak's placentomes, immunohistochemistry (IHC) was carried out to analyze the expression and location of Fas and FasL in paraffin embedded sections. The area of positive stained sites was selected and measured using image analyses software (Image Pro-Plus 6.0). So the positive index (PI) was calculated to estimate the intensity of protein expression according to the percentage of positive area in corresponding compartment of the placentomes. In cotyledonary villi, Fas mainly presented on the villous trophoblast cells in early pregnancy. The positive index reached a maximum of 20.7±8.8 at the third month of pregnancy. Then Fas was declined rapidly along with the progress of gestation and the value was 2.8±1.3 after the 7th month of pregnancy. However, in caruncular crypts, Fas was mainly localized to isolated cells or clustered cells of the uterine stroma underlying the caruncular epithelium. The intensity was lower and the positive index was changed between 4.7±0.9 and 8.5±1.6 throughout gestation. For FasL, it gave a distinct immunostained distribution. In cotyledonary villi, FasL was localized dominantly and strongly in the cytoplasm of binuclear, mononuclear and trinuclear trophoblast giant cells (TGC). The positive index of FasL maintained a moderate level all through the gestation. In caruncular crypts, the expression of FasL was weak and the positive index was declined. Only in the first two months, maternal uterine epithelial cells intensely expressed FasL and the index reached to the maximum of 19.8±5.2. The result of subcellular localization of Fas ligand using immunoelectron microscopy technology indicated that FasL was subcellular located in some intracellular vesicles of TGC. This means the vesicles of trophoblast giant cells itself can express FasL. By the TUNEL method, apoptosis was detected in yak placentomes. The amount of apoptotic cells was rare. The fetal chorionic trophoblast cells and caruncular crypt epithelium cells demonstrated higher percentage of apoptosis in middle pregnancy, which suggested that apoptosis plays an important role in placental cellular regeneration. In addition, the apoptosis of maternal caruncular stromal cells provides a local mechanism for maternal immunotolerance to the fetus and this mechanism was mediated by Fas-FasL pathway.

Apoptosis, proliferation and Fas ligand expression in placental trophoblast from pregnancies complicated by HELLP syndrome or pre-eclampsia

OBJECTIVE

To investigate apoptosis, proliferation and Fas ligand expression of placental trophoblast in the hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome and in pre-eclampsia (PE), and to compare this with normal pregnancies.

DESIGN

Prospective study.

SETTING

University hospital in Croatia.

SAMPLE

Placentae from women with HELLP syndrome (n=10), PE (n=10) and normal pregnancies (n=10).

METHODS

The HELLP syndrome was diagnosed with platelets <100×10(9) /L, aspartate aminotransferase (AST) and alanine transaminase (ALT) >70 U/L and lactic acid dehydrogenase (LDH) > 600 U/L. Pre-eclampsia was diagnosed at blood pressure >140/90 mmHg, with proteinuria >300 mg/L/24 hours. For detection of apoptosis and proliferation in villous trophoblast, antibodies M30 and Ki-67 were used. Expression of Fas ligand was assessed using immunohistochemistry and the semiquantitative HSCORE method.

MAIN OUTCOME MEASURES

Apoptosis, proliferation and Fas ligand expression in villous trophoblast.

RESULTS

Apoptosis, proliferation and Fas ligand expression were higher in villous trophoblast in HELLP syndrome than in the PE group (p=0.015, p=0.018 and p=0.002, respectively) and the control group (p=0.000, p=0.012 and p=0.049, respectively). Placentae from the PE group had higher levels of apoptosis (p=0.019), lower Fas ligand expression (p=0.029) and no difference in proliferation (p=0.887) compared with the control group.

CONCLUSIONS

There is an increase in apoptosis, proliferation and Fas ligand expression in placentae from women with HELLP syndrome compared with placentae from PE and normal pregnancies. Our findings indicate the possibility of differential mechanisms behind HELLP syndrome and PE.

Aberrant expression of apoptosis-related molecules in endometriosis: a possible mechanism underlying the pathogenesis of endometriosis

Endometriosis, a disease affecting 3% to 10% of women of reproductive age, is characterized by the ectopic growth of endometrial tissue under the influence of estrogen. It is also becoming recognized as a condition in which ectopic endometrial cells exhibit abnormal proliferative and apoptotic regulation in response to appropriate stimuli. Apoptosis plays a critical role in maintaining tissue homeostasis and represents a normal function to eliminate excess or dysfunctional cells. Accumulated evidence suggests that, in healthy women, endometrial cells expelled during menstruation do not survive in ectopic locations because of programmed cell death, while decreased apoptosis may lead to the ectopic survival and implantation of these cells, resulting in the development of endometriosis. Both the inability of endometrial cells to transmit a "death" signal and the ability of endometrial cells to avoid cell death have been associated with increased expression of antiapoptotic factors and decreased expression of preapoptotic factors. Further investigations may elucidate the role of apoptosis-associated molecules in the pathogenesis of endometriosis. Medical treatment with apoptosis-inducing agents may be novel and promising therapeutic strategy for endometriosis.

Evaluating the role of rheumatoid factors for the development of rheumatoid arthritis in a mouse model with a newly established ELISA system

Enzyme-linked immunosorbent assays (ELISA) have been widely used to determine quantitatively autoantibodies. However, the processes for the purification and immobilization of antigens in conventional ELISA methods include multiple steps, which have hampered the application for screening of autoantibodies. Here, we have developed a novel ELISA system using the plates pre-coated with glutathione casein to capture recombinant proteins fused to N-terminal glutathione S-transferase (GST). The GST-fused proteins were synthesized with the wheat germ cell-free protein production system. Thus, the present system combined the GST-capture ELISA with the cell-free protein production system, which allowed immobilization of the recombinant proteins with one-step purification. Using this ELISA method, we determined whether rheumatoid factors (RF), which have been considered as one of the representative disease-specific autoantibodies for rheumatoid arthritis (RA), were genetically associated with severity of arthritis in a mouse model for RA, MRL/Mp-lpr/lpr (MRL/lpr). GST-fused human IgG1-Fc (GST-Fc), synthesized with the robotic protein synthesizer, were used as reactants for RF. Serum samples for RF were prepared from 11 lines of a recombinant inbred mouse strain, MXH/lpr, which was established from intercrosses between MRL/lpr and non-arthritic C3H/HeJ-lpr/lpr (C3H/lpr) strains, composed of a different genomic recombination derived from the parental strains in each line. A correlation of RF titers with the severity of the arthritis in these lines was not significant, indicating genetic dissociation of RF from arthritis and that RF is not necessarily required for the development of RA. The present method may provide high-throughput screening for determining the disease-specific autoantibodies in autoimmune diseases.

Up-regulation of Fas reverses cisplatin resistance of human small cell lung cancer cells

Background/Aim

Fas/FasL system is a major regulator of apoptosis. The mechanisms by which Fas mediates cisplatin resistance remain unclear. The aim of this study is to explore the effect of Fas over-expression on cisplatin resistance of small cell lung cancer cells and its possible mechanisms.

Materials and methods

Fas was over-expressed in H446/CDDP cells by infection with the adenoviruses containing Fas. Sensitivity of Fas-overexpressed H446/CDDP cells to cisplatin was evaluated using MTT assay. Expressions of Fas, GST-π and ERCC1 were detected by RT-PCR and Western blot analysis. Apoptosis rate was examined by FACS.

Results

Over-expression of Fas in H446/CDDP cells significantly decreased the expressions of GST-π and ERCC1 at mRNA and protein levels, and increased the cell apoptosis. Furthermore, up-regulation of Fas significantly decreased the tolerance of H446/CDDP cells to cisplatin.

Conclusion

Over-expression of Fas reverses drug resistance of H446/CDDP cells, possibly due to the increased cell sensitivity to apoptosis and the decreased expressions of GST-π and ERCC1.

Fetomaternal immunotolerance

Implantation of mammalian conceptus in uterine cavity is the result of evolutionary adaptation, through high level of physiological procedures to ensure its success. However the majority of pregnancy losses occur before or during implantation. It is expected that exploring and defining the molecular and physiological road map during the crucial time of implantation will enable us to decode and effectively treat fertility defects. Immunological, hormonal and molecular factors participate in the feto-maternal cross talk during implantation and designate the effectiveness of the process. The atypical expression of major histocompatibility complex and other protein-antigens, such as Fas/FasL and petformin in human trophoblast, the modified function of cellular constituents of the feto-maternal interface, as well as the specific role of some hormones and cytokines, represent substantive parameters of feto-maternal immunotolerance during implantation.

Peculiar subcellular localization of Fas antigen in human and mouse spermatozoa

The highly polarized structure and function of mammalian spermatozoa dictate that these cells compartmentalize specific metabolic and signaling pathways to regions where they are needed. Fas was initially identified as membrane receptor for pro-apoptotic signals, has been recently recognized as a molecule with pleiotropic functions. In this article, we provide evidence of a peculiar Fas localization: it is closely associated to the perinucleus, mainly at the level of the inner acrosomal membrane, as well as in the inner compartment of mitochondria. Immunoelectron microscopy and Western blot analysis indicated that intracellular Fas was associated with mitochondria in mouse epididymal spermatozoa. Accordingly, also in human ejaculated sperm, immunofluorescence analysis showed Fas localized in the middle piece of sperm flagellum where mitochondria are grouped. The potential functional implications of these findings are discussed.

Sodium valproate, a histone deacetylase inhibitor, decreases the secretion of soluble Fas by human osteosarcoma cells and increases their sensitivity to Fas-mediated cell death

PURPOSE

Effects of valproic acid (VPA), a histone deacetylase inhibitor, on the susceptibility to cell death induced by agonistic anti-Fas antibody were examined using four human osteosarcoma cell lines.

METHOD

Cell growth, secretion of soluble Fas, expression of cell-surface Fas, and sensitivity to Fas-mediated cell death were examined using cell proliferation assay, flow cytometry, enzyme-linked immunosorbent assay, and agonistic anti-Fas antibody, respectively.

RESULTS

VPA suppressed the growth of all the four osteosarcoma cell lines and the secretion of soluble Fas from these cells. VPA showed no or slight suppressive effect on the expression of cell-surface Fas in the four osteosarcoma cell lines, but increased the sensitivity of three of four osteosarcoma cell lines to Fas-mediated cell death.

CONCLUSION

VPA enhances the susceptibility of human osteosarcoma cells to Fas-ligand-induced cell death by decreasing the secretion of soluble Fas and increasing the sensitivity to Fas-mediated cell death.