Macrophage behaviour 72 hours after implantation of biodegradable polymer-based sirolimus-eluting stent in a case of ST elevation myocardial infarction.

While the vascular healing process after drug-eluting stent implantation is not fully elucidated, it is generally accepted that macrophages play an important role in inflammation. It is also known that macrophages involved in the pathogenesis of atherosclerosis may stem from several origins, that is, monocyte-derived macrophages versus resident macrophages. However, little is known about the role of human macrophages on reperfusion of culprit coronary arteries in patients with atherosclerotic disease who have sustained acute coronary syndrome. In this present case report, we describe the presence of cluster of differentiation (CD) 163-positive macrophages in close proximity to the stent struts at the luminal site 72 hours after drug-eluting stent implantation in the culprit coronary lesion for ST elevation myocardial infarction by postmortem examination.

VEGF-C/VEGFR-3 signalling in macrophages ameliorates acute lung injury.

BACKGROUND: Successful recovery from acute lung injury requires inhibition of neutrophil influx and clearance of apoptotic neutrophils. However, the mechanisms underlying recovery remain unclear. We investigated the ameliorative effects of vascular endothelial growth factor (VEGF)-C/VEGF receptor 3 (VEGFR-3) signalling in macrophages in lipopolysaccharide (LPS)-induced lung injury. METHODS: LPS was intranasally injected into wild-type and transgenic mice. Gain and loss of VEGF-C/VEGFR-3 signalling function experiments employed adenovirus-mediated intranasal delivery of VEGF-C (Ad-VEGF-C vector) and soluble VEGFR-3 (sVEGFR-3) or anti-VEGFR-3 blocking antibodies and mice with a deletion of VEGFR-3 in myeloid cells. RESULTS: The early phase of lung injury was significantly alleviated by the overexpression of VEGF-C with increased levels of bronchoalveolar lavage (BAL) fluid interleukin-10 (IL-10), but worsened in the later phase by VEGFR-3 inhibition upon administration of Ad-sVEGFR-3 vector. Injection of anti-VEGFR-3 antibodies to mice in the resolution phase inhibited recovery from lung injury. The VEGFR-3-deleted mice had a shorter survival time than littermates and more severe lung injury in the resolution phase. Alveolar macrophages in the resolution phase digested most of the extrinsic apoptotic neutrophils and VEGF-C/VEGFR-3 signalling increased efferocytosis via upregulation of integrin αv in the macrophages. We also found that incubation with BAL fluid from acute respiratory distress syndrome (ARDS) patients, but not from controls, decreased VEGFR-3 expression and the efficiency of IL-10 expression and efferocytosis in human monocyte-derived macrophages. CONCLUSIONS: VEGF-C/VEGFR-3 signalling in macrophages ameliorates experimental lung injury. This mechanism may also provide an explanation for ARDS resolution.

Drebrin: A new oncofetal biomarker associated with prognosis of lung adenocarcinoma.

OBJECTIVES: With the aim of searching for novel oncofetal tumor biomarkers of lung adenocarcinoma other than carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP), we developed a strategy involving monoclonal antibodies generated from embryonic tissue of miniature swine. MATERIALS AND METHODS: Using immunohistochemistry, we selected suitable hybridoma clones that were reactive against swine fetal lung but not adult lung using tissue microarray loading of human normal lung, lung cancer, and fetal and adult swine tissues. RESULTS: The selected clones included several that were uniquely reactive against both swine fetal lung and human lung adenocarcinoma, and protein microarray revealed that the antigen they recognized was "drebrin" (DBN1). We then examined the association between the pattern of drebrin expression and the clinicopathological characteristics of lung adenocarcinoma using surgically resected samples of human lung adenocarcinoma. Two hundred formalin-fixed and paraffin-embedded tumor samples were immunostained for drebrin using clone B246, one of the clones that were reactive against drebrin. The cases were divided into those with strong (n=85) and weak (n=115) drebrin expression. In terms of disease-free survival, cases showing strong drebrin expression had a significantly poorer prognosis than those with weak drebrin expression (p=0.033). CONCLUSION: The present findings indicate that "drebrin" is a unique oncofetal protein that can be applied as a new biomarker of lung adenocarcinoma.

Development of Lymphatic Capillary Network Along the Alveolar Walls of Autopsied Human Lungs with Pneumonia.

BACKGROUND: Limited information is available regarding the lymphatic vasculature during pneumonia. OBJECTIVE: To characterize lymphatic vasculatures in autopsied cadavers with pneumonia. METHODS: Paraffin-embedded lung tissues obtained from 20 autopsied cadavers with complicated pneumonia and 10 control cadavers without pneumonia were used for immunohistochemical analyses using primary antibodies against podoplanin, vascular endothelial growth factor receptor-3 (VEGFR-3), CD34, vascular endothelial growth factor (VEGF)-C, VEGF-D, CD73, and CD163. RESULTS: There was no difference in the vascular density of podoplanin+ usual lymphatics between the individuals with and without pneumonia. In half of the cadavers with pneumonia, however, a network of podoplanin+ cells lying together in a side-by-side bead-like arrangement appeared along the alveolar septa; however, this was absent in the control cadavers. The podoplanin+ cells in the network were characterized by a weaker expression of podoplanin, relative to usual lymphatics, and the occasional presence of ductal structures. Although podoplanin+ cells were not coexpressed with VEGFR-3, a part of the network was connected to CD73+ afferent lymphatics. The network showed an intertwined relationship with CD34+ capillaries, suggesting that the network represents lymphatic capillaries. The number of CD163+ macrophages was significantly increased in individuals with the network than those without the network, while a significant decrease in neutrophils was observed. VEGF-C expressed in CD163+ macrophages and type II epithelial cells was observed in the cadavers with the network. CONCLUSION: The development of lymphatic capillary networks along the alveolar septa rather than the usual lymphangiogenesis was noted in autopsied individuals with pneumonia.

Nuclear factor erythroid 2-related factor 2 is a critical target for the treatment of glucocorticoid-resistant lupus nephritis.

BACKGROUND: Dimethyl fumarate (DMF), a nuclear factor erythroid 2-related factor 2 (Nrf2) activator, has been proven effective for the systemic treatment of multiple sclerosis. The aim of this study is to evaluate the anti-inflammatory effects of Nrf2 activators on human renal mesangial cells (HRMCs) and the development of lupus nephritis (LN) in mice. METHODS: To assess Nrf2 activation in vitro, HRMCs were treated with safe doses of Nrf2 activators and prednisolone. The expression levels of Nrf2 and its target genes were measured using quantitative reverse transcription PCR and enzyme-linked immunosorbent assay. The anti-inflammatory effects of these compounds were assessed by measuring tumor necrosis factor alpha-induced cytokine secretion. Experimental LN was induced in female BALB/c mice by a single intraperitoneal injection of pristane. The urine albumin-to-creatinine ratio was measured at 20 weeks after injection. Pathological changes as well as protein and mRNA expression levels were assessed in the kidney obtained at the experimental end point. Oral administration of DMF or prednisolone to these mice was initiated after pristane injection. RESULTS: Nrf2 activators such as sulforaphane and DMF showed anti-inflammatory effects in HRMCs, whereas glucocorticoid (prednisolone) showed partial effects. Moreover, DMF ameliorated the development of kidney diseases in pristane-induced LN mice, whereas glucocorticoid had no effect. CONCLUSIONS: Nrf2 activators showed stronger anti-inflammatory and organ-protective effects than glucocorticoid in the kidney. Thus, Nrf2 activators are potential therapeutic targets in glucocorticoid-resistant LN in humans.

Molecular Diversity of Macrophages in Allergic Reaction: Comparison between the Allergenic Modes; Th1- and -Th2-Derived Immune Conditions.

Activated macrophages have been classified into classical (M1) and alternative (M2) macrophages. We aimed to establish a method to yield enough number of macrophages to analyze their molecular, biological and immunological functions. We used drugs; adjuvant albumin from chicken egg whites--Imject Alum (OVA-Alum) and OVA Complete Freund Adjuvant (OVA-CFA), to induce macrophages to M2 and M1 respectively. We analyzed the phenotype of purified macrophages induced under these immune conditions, using flow cytometry (FACS) to detect cell-surface molecules and the enzyme-linked immunosorbent assay (ELISA) was used to detect cytokines. The cDNA microarray was employed to measure changes in expression level of cell surface protein between M1 and M2 macrophages. Phenotype analysis of purified macrophages, induced under these immune conditions, showed macrophages induced by OVA-Alum was almost M2 while the proportion of M1 macrophages induced by OVA-CFA was significantly higher. The results also showed higher expression level of macrophage galactose N- acetyl-galactosamine specific lectin-2 protein (MGL1/2-PE), a known M2 macrophage marker, on the surface of Alum-induced macrophages. On the basis of these preliminary data, ELISA results revealed that after macrophage stimulation with lipopolysaccharides (LPS), the level of interleukin (IL)-10 produced by Alum- induced macrophages was higher than the level of IL-10 produced by CFA-induced macrophages. In contrast, the level of tumor necrosis factor-alpha (TNF-α) produced by CFA-induced macrophages was higher than Alum-induced macrophages. The cDNA microarray confirmed previous results and suggest immunoglobulin-like type 2 receptor alpha (Pilra) as a new marker for M1, macrophage galactose N-acetylgalactosamine-specific lectin 2 (Mgl2) as M2 macrophages marker.

Interleukin-17 is a critical target for the treatment of ankylosing enthesitis and psoriasis-like dermatitis in mice.

Ankylosis is a major pathological manifestation of spondyloarthropathy. The aim of this study was to evaluate the effects of anti-IL-17 therapy on spontaneous ankylosing enthesitis in mice. In this study, we used male DBA/1 mice as a spontaneous ankylosis model. Serum IL-17 concentrations were determined using enzyme-linked immunosorbent assay. Male DBA/1 mice from different litters were mixed and caged together preceding the treatment at 10 weeks (wk) of age (prophylaxis) or 21 wk of age (intervention). Treatment with anti-IL-17 antibodies or saline was initiated after caging in groups of mice and administered weekly. The onset of tarsal ankylosis was assessed by ankle swelling and histopathological examination. Pathological changes and mRNA expression levels were assessed in joints and ears obtained at the experimental end-point. We found that circulating IL-17 increased with the onset of ankylosis in male DBA/1 mice, coinciding with the onset of dermatitis. The symptoms of dermatitis corresponded to the pathological characteristics of psoriasis: acanthosis with mild hyperkeratosis, scaling, epidermal microabscess formation and augmented expression of K16, S100A8 and S100A9. Prophylactic administration of anti-IL-17 antibodies significantly prevented the development of both ankylosis and dermatitis in male DBA/1 mice caged together. On the other hand, administration of anti-IL-17 antibodies after disease onset had a lesser but significant effect on ankylosis progression but did not affect dermatitis progression. In conclusion, IL-17 is a key mediator in the pathogenic process of tarsal ankylosis and psoriasis-like dermatitis in male DBA/1 mice caged together. Thus, IL-17 is a potential therapeutic target in ankylosing enthesitis and psoriasis in humans.

Classification of Physiological 18F-fluorodeoxyglucose Uptake in the Large Intestine: a Preliminary Study.

Varying degrees of physiological uptake of 18F-fluorodeoxyglucose (FDG) are often noted in the large intestine and can be problematic when interpreting positron emission tomography (PET) images. In relation to colorectal tumor detection with FDG PET, we tentatively classified physiological FDG uptake in the large intestine according to its patterns and intensity. Subjects were 144 asymptomatic individuals (109 men, 35 women; mean age 57.5 ± 10.1 years) in our cancer screening program who underwent total colonoscopy within 24 days of FDG PET study and showed no evidence of colonic lesions on colonoscopy. Distinct FDG uptake on FDG PET images was classified into four types: focal, defined as distinctly nodular and visible on at least 4 axial; localized, 2 to 8 cm with SUVmean ≥ 4; diffuse, > 8 cm with SUVmean ≥ 4; and mixed, of more than one type. SUVmeans were examined by placing multiple circular regions of interest of 1 cm in diameter on the axial images. We found 21 distinct FDG uptakes matching our criteria in 20 of 144 subjects (13.9%): focal (n = 4), localized (n = 1), diffuse (n = 14), and mixed (n = 1; focal and diffuse). With regard to colorectal tumor detection, 6 subjects (4.2%) with focal or localized type of uptake were considered at risk of false-positive tumor identification, and 15 subjects (10.4%) with diffuse type of uptake were considered at risk of their tumors being missed at the site of FDG uptake. To confirm the feasibility of our criteria, this classification should be tested with a larger number of subjects.

New BRAF knockin mice provide a pathogenetic mechanism of developmental defects and a therapeutic approach in cardio-facio-cutaneous syndrome.

Cardio-facio-cutaneous (CFC) syndrome is one of the 'RASopathies', a group of phenotypically overlapping syndromes caused by germline mutations that encode components of the RAS-MAPK pathway. Germline mutations in BRAF cause CFC syndrome, which is characterized by heart defects, distinctive facial features and ectodermal abnormalities. To define the pathogenesis and to develop a potential therapeutic approach in CFC syndrome, we here generated new knockin mice (here Braf(Q241R/+)) expressing the Braf Q241R mutation, which corresponds to the most frequent mutation in CFC syndrome, Q257R. Braf(Q241R/+) mice manifested embryonic/neonatal lethality, showing liver necrosis, edema and craniofacial abnormalities. Histological analysis revealed multiple heart defects, including cardiomegaly, enlarged cardiac valves, ventricular noncompaction and ventricular septal defects. Braf(Q241R/+) embryos also showed massively distended jugular lymphatic sacs and subcutaneous lymphatic vessels, demonstrating lymphatic defects in RASopathy knockin mice for the first time. Prenatal treatment with a MEK inhibitor, PD0325901, rescued the embryonic lethality with amelioration of craniofacial abnormalities and edema in Braf(Q241R/+) embryos. Unexpectedly, one surviving pup was obtained after treatment with a histone 3 demethylase inhibitor, GSK-J4, or NCDM-32b. Combination treatment with PD0325901 and GSK-J4 further increased the rescue from embryonic lethality, ameliorating enlarged cardiac valves. These results suggest that our new Braf knockin mice recapitulate major features of RASopathies and that epigenetic modulation as well as the inhibition of the ERK pathway will be a potential therapeutic strategy for the treatment of CFC syndrome.

Epigallocatechin gallate inhibits oxidative stress-induced DNA damage and apoptosis in MRL-Fas(lpr) mice with autoimmune sialadenitis via upregulation of heme oxygenase-1 and Bcl-2.

Pathogenic effects of reactive oxygen species (ROS) in the salivary glands of patients with Sjögren's syndrome have been demonstrated. Epigallocatechin gallate (EGCG), which is a catechin derivative and exhibits potent antioxidant activity, has been reported to ameliorate autoimmune sialadenitis in a murine model, but the mechanism underlying its protective action remains to be investigated. Herein, we examined the effects of EGCG administration to MRL/MpJ-lpr/lpr (MRL-Fas(lpr)) mice on disease severity of autoimmune sialadenitis and protein expression levels of 11 sialadenitis-related molecules - heme oxygenase-1 (HO-1) (antioxidant); thymidine glycol (marker of DNA damage); gp91phox/NADPH oxidase 2 (prooxidant); single-stranded DNA (ssDNA) and cleaved caspase 3 (apoptotic cell markers); p53 and Bax (proapoptotic molecules); Bcl-2 (antiapoptotic molecule); SSA/Ro, SSB/La, and Ifi202 (autoantigens). In EGCG-treated mice, the severity of sialadenitis was substantially decreased. Expression levels of thymidine glycol, gp91phox, ssDNA, cleaved caspase 3, p53, Bax, SSA/Ro, SSB/La, and Ifi202 in duct epithelial cells of salivary glands from EGCG-treated mice were reduced, whereas HO-1 and Bcl-2 were overexpressed. Results of correlation analysis among sialadenitis severity and 11 sialadenitis related-molecules, and those of partial correlation analysis between apoptotic related-molecules and sialadenitis severity or HO-1 suggested that the consecutive pathogenic cycle including activated autoimmune reactions, ROS synthesis, DNA damage and p53-dependent apoptosis was associated with the pathogenesis of autoimmune sialadenitis in MRL-Fas(lpr) mice. Overexpression of HO-1 and Bcl-2 mediated by EGCG blocked this pathogenic cycle, subsequently resulting in the inhibition of ROS-mediated DNA damage and apoptosis, and protected salivary gland tissues from oxidative stress. Clinically, green tea catechin may have therapeutic efficacy for Sjögren's syndrome.

A novel autoantibody against ephrin type B receptor 2 in acute necrotizing encephalopathy.

Acute necrotizing encephalopathy (ANE) is characterized by symmetrical brain necrosis, suggested to be due to breakdown of the blood-brain barrier (BBB). We experienced a rare case of ANE complicated with systemic lupus erythematosus (SLE), and found that the patient's serum (V10-5) had binding activity to human umbilical vein endothelial cells (HUVECs). By SARF (Serological identification system for Autoantigens using a Retroviral vector and Flow cytometry) method using V10-5 IgG, a clone bound to V10-5 IgG was isolated. This cell clone was integrated with cDNA identical to EphB2, which plays critical roles in neuronal cells and endothelial cells. HUVECs and human brain microvascular endothelial cells expressed EphB2 and the V10-5 IgG bound specifically to EphB2-transfected cells. Anti-EphB2 antibody was not detected in other SLE patients without ANE. In this report, we identified EphB2 as a novel autoantigen, and anti-EphB2 antibody may define a novel group of brain disorders. Anti-EphB2 antibody can interfere not only with endothelial cells including those of the BBB (acting as an anti-endothelial cell antibody), but also neuronal cells (acting as an anti-neuronal antibody) if the BBB has been breached. Future studies should determine the clinical prevalence and specificity of anti-EphB2 antibody, and the molecular mechanisms by which anti-EphB2 antibody mediates neuronal and vascular pathological lesions.

Enhanced apoptosis by disruption of the STAT3-IκB-ζ signaling pathway in epithelial cells induces Sjögren's syndrome-like autoimmune disease.

Sjögren's syndrome (SS) is an autoimmune disease characterized by exocrinopathy that leads to dry eye and mouth. Although lymphocyte infiltration into exocrine glands and the generation of autoantibodies have been reported in SS, its pathogenic mechanism remains elusive. Here, we show that mice lacking the transcriptional regulator IκB-ζ developed SS-like inflammation characterized by lymphocyte-infiltrated dacryoadenitis and SS-associated autoantibodies. In particular, epithelial cells, but not hematopoietic cells, lacking IκB-ζ were essential for the development of inflammation. IκB-ζ-deficient epithelial cells in the lacrimal glands exhibited enhanced apoptosis even in the absence of lymphocytes. Administration of caspase inhibitors ameliorated the inflammation, indicating the critical role of caspase-mediated apoptosis. Furthermore, epithelial cell-specific STAT3-deficient mice developed SS-like inflammation with impaired IκB-ζ expression in the lacrimal glands. Thus, this study reveals a pathogenic mechanism of SS in which dysfunction of epithelial cells caused by disruption of STAT3-mediated IκB-ζ induction elicits the activation of self-reactive lymphocytes.

A bacterial artificial chromosome transgene with polymorphic Cd72 inhibits the development of glomerulonephritis and vasculitis in MRL-Faslpr lupus mice.

Systemic lupus erythematosus is considered to be under the control of polygenic inheritance, developing according to the cumulative effects of susceptibility genes with polymorphic alleles; however, the mechanisms underlying the roles of polygenes based on functional and pathological genomics remain uncharacterized. In this study, we substantiate that a CD72 polymorphism in the membrane-distal extracellular domain impacts on both the development of glomerulonephritis and vasculitis in a lupus model strain of mice, MRL/MpJ-Fas(lpr), and the reactivity of BCR signal stimulation. We generated mice carrying a bacterial artificial chromosome transgene originating from C57BL/6 (B6) mice that contains the Cd72(b) locus (Cd72(B6) transgenic [tg]) or the modified Cd72(b) locus with an MRL-derived Cd72(c) allele at the polymorphic region corresponding to the membrane-distal extracellular domain (Cd72(B6/MRL) tg). Cd72(B6) tg mice, but not Cd72(B6/MRL) tg mice, showed a significant reduction in mortality following a marked improvement of disease associated with decreased serum levels of IgG3 and anti-dsDNA Abs. The number of splenic CD4(-)CD8(-) T cells in Cd72(B6) tg mice was decreased significantly in association with a reduced response to B cell receptor signaling. These results indicate that the Cd72 polymorphism affects susceptibility to lupus phenotypes and that novel functional rescue by a bacterial artificial chromosome transgenesis is an efficient approach with wide applications for conducting a genomic analysis of polygene diseases.

An innovative method to identify autoantigens expressed on the endothelial cell surface: serological identification system for autoantigens using a retroviral vector and flow cytometry (SARF).

Autoantibodies against integral membrane proteins are usually pathogenic. Although anti-endothelial cell antibodies (AECAs) are considered to be critical, especially for vascular lesions in collagen diseases, most molecules identified as autoantigens for AECAs are localized within the cell and not expressed on the cell surface. For identification of autoantigens, proteomics and expression library analyses have been performed for many years with some success. To specifically target cell-surface molecules in identification of autoantigens, we constructed a serological identification system for autoantigens using a retroviral vector and flow cytometry (SARF). Here, we present an overview of recent research in AECAs and their target molecules and discuss the principle and the application of SARF. Using SARF, we successfully identified three different membrane proteins: fibronectin leucine-rich transmembrane protein 2 (FLRT2) from patients with systemic lupus erythematosus (SLE), intercellular adhesion molecule 1 (ICAM-1) from a patient with rheumatoid arthritis, and Pk (Gb3/CD77) from an SLE patient with hemolytic anemia, as targets for AECAs. SARF is useful for specific identification of autoantigens expressed on the cell surface, and identification of such interactions of the cell-surface autoantigens and pathogenic autoantibodies may enable the development of more specific intervention strategies in autoimmune diseases.

Sjögren's syndrome-like autoimmune sialadenitis in MRL-Faslpr mice is associated with expression of glucocorticoid-induced TNF receptor-related protein (GITR) ligand and 4-1BB ligand.

Although costimulatory molecules have been shown to play crucial roles in the immune response, their involvement in the pathogenesis of Sjögren's syndrome is incompletely understood. In this study, we evaluated the relationship between the severity of spontaneous Sjögren's syndrome-like autoimmune sialadenitis in MRL/MpJ-lpr/lpr (MRL-Fas(lpr)) mice and the expression of 6 costimulatory molecules that play important roles in the immune response: CD80, CD86, OX40 ligand (OX40L), 4-1BB ligand (4-1BBL), glucocorticoid-induced TNF receptor-related protein ligand (GITRL), and B cell-activating factor of the tumor necrosis factor family (BAFF). Expression of the costimulatory molecules in the submandibular salivary glands of age-matched autoimmune MRL-Fas(lpr) mice and non-autoimmune MRL/MpJ-+/+(MRL/+) and C3H/HeJ-lpr/lpr (C3H-Fas(lpr)) mice was examined immunohistochemically and scored on a scale of 0 to 3. The severity of sialadenitis was evaluated histologically and scored on a scale of 0 to 3. We found that all of the costimulatory molecules were expressed in duct epithelial cells of salivary glands from MRL-Fas(lpr) mice, whereas immunoreactivity was absent or weak in the MRL/+ mice. The staining intensity for all 6 costimulatory molecules was significantly higher in the MRL-Fas(lpr) than in the MRL/+ mice. Partial correlation analysis was performed to assess the degree of association between costimulatory molecule staining scores and disease scores, which clearly revealed a significant correlation for only GITRL and 4-1BBL. These molecules showed negligible immunoreactivity in the submandibular glands of C3H-Fas(lpr) mice, suggesting that their expression was independent of the Fas(lpr) mutation. In conclusion, the expression of GITRL and 4-1BBL in salivary gland duct epithelial cells is associated with background genes in the MRL strain, but not with the Fas(lpr) mutation itself, and contributes significantly to the pathogenesis of autoimmune sialadenitis in MRL-Fas(lpr) mice. These results suggest that GITRL and 4-1BBL may be effective targets for the development of therapies for Sjögren's syndrome.

Roles of Keap1-Nrf2 system in upper aerodigestive tract carcinogenesis.

Cancers in the upper aerodigestive tract, including cancers of the tongue and the esophagus, are the third leading cause of cancer-related deaths in the world, and oxidative stress is well recognized as one of the major risk factors for carcinogenesis. The Keap1-Nrf2 system plays a critical role in cellular defense against oxidative stress, but little is known about its association with upper aerodigestive tract carcinogenesis. In this study, we examined whether loss of Nrf2-function exacerbates carcinogenesis by using an experimental carcinogenesis model that is induced by 4-nitroquinoline-1-oxide (4NQO). We found that Nrf2-knockout (Nrf2-KO) mice were more susceptible to 4NQO-induced tongue and esophageal carcinogenesis than wild-type mice, which suggests that Nrf2 is important for cancer prevention. We also examined how the suppression of Keap1 function or the induction of Nrf2 activity affected 4NQO carcinogenesis. Keap1-knockdown (Keap1-KD) mice were resistant to 4NQO-induced tongue and esophageal carcinogenesis. Importantly, no growth advantage was observed in tongue tumors in the Keap1-KD mice. These results show that the Keap1-Nrf2 system regulates an important defense mechanism against upper aerodigestive tract carcinogenesis. In addition to several important functions of Nrf2 that lead to cancer chemoprevention, we hypothesize that a mechanical defense of thickened keratin layers may also be a chemopreventive factor because thickened, stratified, squamous epithelium was found on the tongue of Keap1-KD mice.

A novel autoantibody against fibronectin leucine-rich transmembrane protein 2 expressed on the endothelial cell surface identified by retroviral vector system in systemic lupus erythematosus.

INTRODUCTION: Anti-endothelial cell antibodies (AECAs) are thought to be critical for vasculitides in collagen diseases, but most were directed against molecules localized within the cell and not expressed on the cell surface. To clarify the pathogenic roles of AECAs, we constructed a retroviral vector system for identification of autoantigens expressed on the endothelial cell surface. METHODS: AECA activity in sera from patients with collagen diseases was measured with flow cytometry by using human umbilical vein endothelial cells (HUVECs). A cDNA library of HUVECs was retrovirally transfected into a rat myeloma cell line, from which AECA-positive clones were sorted with flow cytometry. cDNA of the cells was analyzed to identify an autoantigen, and then the clinical characteristics and the functional significance of the autoantibody were evaluated. RESULTS: Two distinct AECA-positive clones were isolated by using serum immunoglobulin G (IgG) from a patient with systemic lupus erythematosus (SLE). Both clones were identical to cDNA of fibronectin leucine-rich transmembrane protein 2 (FLRT2). HUVECs expressed FLRT2 and the prototype AECA IgG bound specifically to FLRT2-transfected cells. Anti-FLRT2 antibody activity accounted for 21.4% of AECAs in SLE. Furthermore, anti-FLRT2 antibody induced complement-dependent cytotoxicity against FLRT2-expressing cells. CONCLUSIONS: We identified the membrane protein FLRT2 as a novel autoantigen of AECAs in SLE patients by using the retroviral vector system. Anti-FLRT2 antibody has the potential to induce direct endothelial cell cytotoxicity in about 10% of SLE patients and could be a novel molecular target for intervention. Identification of such a cell-surface target for AECAs may reveal a comprehensive mechanism of vascular injury in collagen diseases.

The effect of glucagon on FDG uptake in skeletal muscle.

Glucagon is used as an anti-motility agent during gastrointestinal tract examinations. We experienced subjects with enhanced 18F-fluorodeoxyglucose (FDG) uptake in whole-body skeletal muscle when conducting positron emission tomography (PET). The subjects had been administered glucagon during gastroscopy just prior to PET. This observation prompted us to perform the present retrospective study to determine whether or not glucagon enhances FDG uptake in skeletal muscle. We randomly selected 30 cases, including subjects who had undergone PET and gastroscopy on the same day as cancer screening procedures, and classified them into three groups. In the NO group (n = 10), no medications were used prior to PET. In the SC group (n = 10), scopolamine butylbromide (10 mg) was intravenously administered during endoscopy. In the GL group (n = 10), glucagon (0.5 mg) was intravenously administered during endoscopy. Both drugs were administered 45-60 min prior to FDG administration. The mean standardized uptake value (SUV) for gluteal muscle was 0.7 ± 0.14, 0.69 ± 0.15, and 0.99 ± 0.7 in the NO, SC, and GL groups, respectively. The SUV in the GL group was highest, but the difference was not statistically significant. In the subject with the highest SUV (3.04; GL group), the quality of the oncologic PET image was impaired, perhaps because of a relative decrease of FDG distribution in the chest and abdomen. Because previous literature showed that via hyperglycemia and hyperinsulinemia glucagon has the effect of increasing FDG uptake in skeletal muscle, the use of glucagon should be avoided just prior to FDG PET, although in our subjects, no statistical proof that glucagon enhances FDG uptake in skeletal muscle was obtained.

Indispensable roles of OX40L-derived signal and epistatic genetic effect in immune-mediated pathogenesis of spontaneous pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) refers to a spectrum of diseases with elevated pulmonary artery pressure. Pulmonary arterial hypertension (PAH) is a disease category that clinically presents with severe PH and that is histopathologically characterized by the occlusion of pulmonary arterioles, medial muscular hypertrophy, and/or intimal fibrosis. PAH occurs with a secondary as well as a primary onset. Secondary PAH is known to be complicated with immunological disorders. The aim of the present study is to histopathologically and genetically characterize a new animal model of PAH and clarify the role of OX40 ligand in the pathogenesis of PAH. RESULTS: Spontaneous onset of PAH was stably identified in mice with immune abnormality because of overexpression of the tumor necrosis factor (TNF) family molecule OX40 ligand (OX40L). Histopathological and physical examinations revealed the onset of PAH-like disorders in the C57BL/6 (B6) strain of OX40L transgenic mice (B6.TgL). Comparative analysis performed using different strains of transgenic mice showed that this onset depends on the presence of OX40L in the B6 genetic background. Genetic analyses demonstrated a susceptibility locus of a B6 allele to this onset on chromosome 5. Immunological analyses revealed that the excessive OX40 signals in TgL mice attenuates expansion of regulatory T cells the B6 genetic background, suggesting an impact of the B6 genetic background on the differentiation of regulatory T cells. CONCLUSION: Present findings suggest a role for the OX40L-derived immune response and epistatic genetic effect in immune-mediated pathogenesis of PAH.

Scattered regulatory regions of the chicken immunoglobulin-ß gene and two adjacent promoters of ubiquitously expressed genes interact with the immunoglobulin-ß promoter in DT40 cells.

Recent studies indicate that several transcription units assemble to form a 'transcription factory' where active transcription occurs in the nuclei. Previously, we generated chicken B-lymphocyte-derived DT40 cells lacking six transcriptional regulatory regions scattered in and around the immunoglobulin (Ig)-ß gene. The deletions caused a complete shut down of transcription and epigenetic regulation of the Ig-ß gene, demonstrating that the scattered regulatory regions cooperated in the transcriptional and epigenetic regulation of the gene. However, the in vivo 3-dimensional spatial relationships between the Ig-ß promoter and these six regulatory regions were not investigated. In this study, we used chromosome conformation capture (3C) technology and demonstrated that the Ig-ß promoter physically interacted with the scattered regulatory regions. We found that the Ig-ß promoter also interacted with two downstream promoters of ubiquitously expressed genes, rad motif 1 (RDM1) and Plekhm1, to form a transcription factory, but not with three ubiquitously expressed genes, BAF60b, p45/SUG, and RRMJ3, located upstream of the Ig-ß gene. In this factory, the chromatin from the three promoters and the scattered regulatory regions of the Ig-ß gene formed a complex structure with many chromatin loops.