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Background and Aim Wilson's disease (WD) is a rare inherited disease that causes systemic copper accumulation. This study examined the long‐term course of WD patients with liver disease. Methods The 12 patients (9 female patients) enrolled in the study had a median age of 28 years (range: 19–57 years) at their first visit to our hospital. Clinical course and fibrosis markers were assessed in all patients. Results The median age at diagnosis was 24 years (range: 5–42 years). One patient had acute liver failure (ALF) and 11 patients had chronic liver disease (CLD, 5 with cirrhosis). The patients were followed‐up for >20 years. The patient with ALF underwent liver transplantation; the postoperative course during the subsequent 20 years was good. Of the six patients with CLD, liver cirrhosis developed in four patients with interrupted chelating therapy. Two of the patients with cirrhosis died; one of these two patients died at 21 years after liver transplantation. However, the remaining patients with continued treatment exhibited a favorable clinical course for 30 years and none developed hepatocellular carcinoma (HCC). The duration of chelation therapy was significantly negatively correlated (P, The duration of chelation therapy for Wilson's disease complicated by liver disease was significantly negatively correlated with the fibrosis‐4 index and aspartate aminotransferase to platelet ratio index (APRI) score at the last visit.

Background IgA nephropathy (IgAN) begins with aberrant IgA deposition in glomeruli, progresses to IgM/IgG/complement codeposition, and results in chronic inflammation and glomerular damage. However, the mechanism that drives such phlogogenic cascade has been unclear. Recently, apoptosis inhibitor of macrophage (AIM) protein was shown to modulate macrophages' function in various pathologic conditions, thereby profoundly affecting the progression of renal disorders, including AKI. A spontaneous IgAN model, grouped ddY (gddY) mouse, revealed the requirement of AIM for the overall inflammatory glomerular injury following IgA deposition. Methods We established an AIM-deficient IgAN model (AIM -/- gddY) using CRISPR/Cas9 and compared its phenotype with that of wild-type gddY with or without recombinant AIM administration. An IgA-deficient IgAN model (IgA -/- gddY) was also generated to further determine the role of AIM. Results In both human and murine IgAN, AIM colocalized with IgA/IgM/IgG in glomeruli, whereas control kidneys did not exhibit AIM deposition. Although AIM -/- gddY showed IgA deposition at levels comparable with those of wild-type gddY, they did not exhibit glomerular accumulation of IgM/IgG complements, CD45+ leukocyte infiltration, and upregulation of inflammatory/fibrogenic genes, indicating protection from glomerular lesions and proteinuria/hematuria. Recombinant AIM administration reconstituted the IgAN phenotype, resulting in IgM/IgG/complement IgA codeposition. Neither spontaneous IgM/IgG codeposition nor disease was observed in IgA -/- gddY mice. Conclusions AIM may contribute to stable immune complex formation in glomeruli, thereby facilitating IgAN progression. Therefore, AIM deposition blockage or disassociation from IgM/IgG may present a new therapeutic target on the basis of its role in IgAN inflammation initiation.

A 47-year-old Japanese woman presented with epigastric discomfort and anorexia. Upper endoscopy showed type 4 advanced gastric cancer in the gastric antrum with stenosis of the pyloric portion. Abdominopelvic CT revealed peritoneal dissemination, and stage IV advanced gastric cancer was diagnosed. Laparoscopic gastrojejunostomy and enterostomy were performed. Trousseau syndrome occurred 7 days post-surgery. Despite appropriate treatment, the patient developed a pulmonary embolism 13 days later and died 18 days post-surgery. Even in young cancer patients without lifestyle disease complications, it is important to pay attention to Trousseau syndrome as part of cancer management.

Summary: The sterile inflammation caused by damage-associated molecular patterns (DAMPs) worsens the prognosis following primary injury such as ischemic stroke. However, there are no effective treatments to regulate DAMPs. Here, we report that AIM (or CD5L) protein reduces sterile inflammation by attenuating DAMPs and that AIM administration ameliorates the deleterious effects of ischemic stroke. AIM binds to DAMPs via charge-based interactions and disulfide bond formation. This AIM association promotes the phagocytic removal of DAMPs and neutralizes DAMPs by impeding their binding to inflammatory receptors. In experimental stroke, AIM-deficient mice exhibit severe neurological damage and higher mortality with greater levels of DAMPs and associated inflammation in the brain than wild-type mice, in which brain AIM levels increase following stroke onset. Recombinant AIM administration reduces sterile inflammation in the infarcted region, leading to a profound reduction of animal mortality. Our findings provide a basis for the therapies targeting DAMPs to improve ischemic stroke.

International audience; The influence of excess salt intake on acute kidney injury (AKI) has not been examined precisely except for some clinical data, unlike in chronic kidney disease. Here, we addressed the influence of high salt (HS) on AKI and its underlying mechanisms in terms of the activity of circulating apoptosis inhibitor of macrophage (AIM, also called CD5L) protein, a facilitator of AKI repair. HS loading in mice subjected to ischemia/reperfusion (IR) resulted in high mortality with advanced renal tubular obstruction and marked exacerbation in biomarkers of proximal renal tubular damage. This AKI exacerbation appeared to be caused mainly by the reduced AIM dissociation from IgM pentamer in serum, as IgM-free AIM is indispensable for the removal of intratubular debris to facilitate AKI repair. Injection of recombinant AIM (rAIM) ameliorated the AKI induced by IR/HS, dramatically improving the tubular damage and mouse survival. The repair of lethal AKI by AIM was dependent on AIM/ kidney injury molecule-1 (KIM-1) axis, as rAIM injection was not effective in KIM-1 deficient mice. Our results demonstrate that the inhibition of AIM dissociation from IgM is an important reason for the exacerbation of AKI by HS, that AIM is a strong therapeutic tool for severe AKI.

An internal system designed to ward off and remove unnecessary or hazardous materials is intrinsic to animals. In addition to exogenous pathogens, a number of self-molecules, such as apoptotic or necrotic dead cells, their debris, and the oxides or peroxides of their cellular components, are recognized as extraneous substances. It is essential to eliminate these internal pathogens as quickly as possible because their accumulation can cause chronic inflammation as well as autoimmune responses, possibly leading to onset or progression of certain diseases. Apoptosis inhibitor of macrophage (AIM, also called CD5L) is a circulating protein that is a member of the scavenger receptor cysteine-rich superfamily, and we recently found that during acute kidney injury, AIM associates with intraluminal dead cell debris accumulated in renal proximal tubules and enhances clearance of luminal obstructions, thereby facilitating repair. Thus, AIM acts as a marker for phagocytes so that they can efficiently recognize and engulf the debris as their targets. In this chapter, we give an overview of the professional and non-professional phagocytes, and how soluble scavenging molecules such as AIM contribute to improvement of diseases by stimulating phagocytic activity.

Objective We aimed to determine the outcome of combination therapy with tofacitinib (TOF) in a case series of refractory rapidly progressive interstitial lung disease (ILD) associated with anti-melanoma differentiation-associated 5 gene (MDA5) antibody-positive (Ab+) DM. Patients who had poor prognostic factors and failed to respond to immunosuppressive therapy were selected for TOF treatment. Methods Five patients with anti-MDA5 Ab+ DM-ILD who failed to respond to triple therapy with high dose glucocorticoids, CSA and CYC were given additional TOF (10 mg/day). To identify the poor prognostic factors, data from 15 consecutive patients (seven survived and eight died) with anti-MDA5 Ab+ DM-ILD before induction of TOF were analysed. Results Three poor prognostic factors were identified: serum ferritin level >1000 ng/ml before therapy; ground-glass opacities in all six lung fields before therapy; and worsening of pulmonary infiltrates during therapy. All six patients who had all of the three factors and received triple therapy died before TOF therapy. There were five patients who had all of the three prognostic factors and failed to respond to triple therapy, but were able to receive the combination therapy with TOF; among them, three survived and two died. The survival rate of patients who received TOF was significantly better than that of the historical controls with immunosuppressive therapy before TOF. The patients who received TOF experienced complicated adverse events, particularly viral infection. Conclusion Combination therapy with TOF might have the potential to control refractory anti-MDA5 Ab+ DM-ILD.

Fungal peritonitis in a patient on peritoneal dialysis (PD) is a refractory injury accompanied by severe inflammation, predisposing patients to a poor prognosis. Defective clearance of necrotic tissue interferes with amelioration of tissue injury and induces abnormal tissue remodeling. In the recent reports, apoptosis inhibitor of macrophage (AIM, also called CD5L) prevents obesity, hepatocellular carcinoma and acute kidney injury. Here, we investigated potential roles of AIM in prevention of progression of fungal peritonitis models. AIM−/− mice subjected to zymosan-induced peritonitis exhibited progressive inflammation and sustained peritoneal necrosis tissue on day 28 after the disease induction, whereas there was an improvement in AIM+/+ mice. This appeared to be caused by deposition of AIM at the necrotic peritoneum in AIM+/+ mice. In vitro, AIM enhanced the engulfment of necrotic debris by macrophages derived from zymosan-induced peritonitis, M1- and M2a-like bone marrow derived macrophages, as well as by mesothelial cells. In addition, administration of recombinant AIM dramatically ameliorated severe inflammation associated with necrosis in zymosan-induced peritonitis of AIM−/− mice. Our observations suggest that AIM appears to be involved in the repair process of zymosan-induced peritonitis, and thus, could be the basis of development of new therapeutic strategies for PD-related fungal peritonitis.

Background: By autoantibodies, myositis is recently classified into subgroups with distinctive clinical features. Cytokines play critical roles in the development of the clinical features. However, it is not fully unknown whether myositis subgroups defined by autoantibodies have unique cytokine profiles. Objectives: To clarify the relationship between cytokine profiles and autoantibodies in myositis. Methods: Subjects were myositis patients who admitted Dokkyo Medical University and whose serum before starting therapy were available. Serum cytokine levels (IL-1a, 1b, 2, 4,5, 6, 10,12, 13,15,17, 23,IFN-g, TNF-a, IFN-a, b,IP-10 and MCP-1) in sera from the patients and controls were measured using Q-Plex™ Multiplex Arrays. Demographic and clinical data were obtained by reviewing medical record retrospectively. Results: Subjects were 45 myositis patients with male/female; 22/23 and 59.4 years of mean age. Amyopathic dermatomyositis (ADM), classical DM and polymyositis (PM) were 21, 11 and12 cases, respectively. Autoantibodies were anti-MDA5+ in 21, anti-ARS+ in18 and anti-TIF1g+ in 5 cases. ILD and malignancy was complicated in 39 and 5 cases, respectively. Serum cytokine levels were measured. As shown in Fig.1, IP-10 levels were increased in all types of myositis patients, but not in controls. In ant-MDA5 Ab + myositis, IL-6, IL-10, IL-15, TNF-a, IFN-a and MCP-1 levels were increased. In anti-ARS Ab+ cases, IFN-b levels were elevated as well as TNF-a and MCP-1. Through the correlation analysis between cytokine levels, cytokine groups were identified (Fig.2). In anti-MDA5 Ab+ cases, 2 cytokine groups were identified; one includes IFN-a, IL-15, TNF-a and IL-10, and the other involved IL-6, MCP-1. Both groups connected with IP-10. In In anti-ARS Ab+ cases, 2 groups were found; one included TNF-a, MCP-1and IP-10, and the other had IFN-b as a sole component. Conclusion: Cytokine profiles differ among subgroups in myositis. In anti-DDA5+ myositis, IL-15 and IFN-a with strong correlation and IL-6 were characteristic cytokines, while IFN-b was a unique one in anti-ARS+ myositis Disclosure of Interests: None declared

A skewed TCR repertoire does not directly trigger inflammation in adipose tissue, Obesity is accompanied by chronic, low-grade inflammation in adipose tissue, which is associated with insulin resistance and consequent multiple metabolic diseases. In addition to M1 macrophage infiltration, multiple involvements of adipose tissue T lymphocytes in the progression of inflammation have been highlighted recently. Here, we isolated a specific Vα5/Vβ8.2 TCR-bearing T cell that accumulated in obese adipose tissue of mice, and generated transgenic mice expressing this TCR. Under lean conditions with a normal chow diet, CD4+FoxP3+ Treg cells and M2 macrophages increased in adipose tissue with ageing in wild-type mice, but not in transgenic mice. However, both mice exhibited no obvious adipose tissue inflammation such as the formation of crown-like structures (CLSs) of infiltrating macrophages. When fed a high-fat diet, the proportion of adipose tissue Treg cells was markedly small at a similar level in transgenic and wild-type mice. Both types of mice exhibited comparable inflammatory states in adipose tissue, including vast formation of macrophage CLSs, accompanied by insulin resistance. Together, our findings suggest that the absence of an increase in Treg cells and M2 macrophages is not sufficient to initiate inflammatory macrophage infiltration in lean adipose tissue and also provide a new view about the involvement of T cells in promoting obesity-associated inflammation.

Objective: We aimed to analyze the clinical and histopathologic features of cancer-associated myositis (CAM) in relation to anti–transcriptional intermediary factor 1 γ antibody (anti-TIF1-γ-Ab), a marker of cancer association. Methods: We retrospectively studied 349 patients with idiopathic inflammatory myopathies (IIMs), including 284 patients with pretreatment biopsy samples available. For the classification of IIMs, the European Neuromuscular Center criteria were applied. Patients with CAM with (anti-TIF1-γ-Ab[+] CAM) and without anti-TIF1-γ-Ab (anti-TIF1-γ-Ab[−] CAM) were compared with patients with IIM without cancers within and beyond 3 years of myositis diagnosis. Results: Cancer was detected in 75 patients, of whom 36 (48%) were positive for anti-TIF1-γ-Ab. In anti-TIF1-γ-Ab(+) patients with CAM, cancers were detected within 1 year of myositis diagnosis in 35 (97%) and before 1 year of myositis diagnosis in 1. All the anti-TIF1-γ-Ab(+) patients with CAM satisfied the dermatomyositis (DM) criteria, including 2 possible DM sine dermatitis cases, and were characterized histologically by the presence of perifascicular atrophy, vacuolated fibers (VFs), and dense C5b-9 deposits on capillaries (dC5b-9). In contrast, 39 anti-TIF1-γ-Ab(−) patients with CAM were classified into various subgroups, and characterized by a higher frequency of necrotizing autoimmune myopathy (NAM). Notably, all 7 patients with CAM classified into the NAM subgroup were anti-TIF1-γ-Ab(−) and exhibited no dC5b-9 or VFs. Conclusions: CAM includes clinicohistopathologically heterogeneous disease entities. Among CAM entities, anti-TIF1-γ-Ab(+) CAM has characteristically shown a close temporal association with cancer detection and the histopathologic findings of dC5b-9 and VFs, and CAM with NAM is a subset of anti-TIF1-γ-Ab(−) CAM.

Endogenous lipoid pneumonia is an uncommon inflammatory pulmonary disease that is caused by lipids from an endogenous source, the treatment for which has not been established. We report the first case of endogenous lipoid pneumonia presenting as lung consolidation and which was associated with rheumatoid arthritis. Treatment was successful with intensive immunosuppressive therapy. When a physician finds lung consolidation in a patient with active rheumatic disease, lipoid pneumonia should be considered.

To clarify the clinical features of organizing pneumonia (OP) associated with rheumatoid arthritis (RA) and to determine whether development of OP is related to RA activity.A cross-sectional study was conducted, in which medical records of 499 consecutive RA patients who visited our hospital during one month were reviewed. OP was diagnosed by pathological findings by trans-bronchial biopsy or by clinical features (typical computed tomography findings, no causative agents, good response to glucocorticoids, and lack of response to antibiotics).Among 499 patients, OP was found in 19 patients and the estimated prevalence was 1.9-4.8%. No differences in clinical features were noted between the OP and non-OP groups. The mean age of OP development was 57.2 years and the period from the onset of RA to OP ranged from -4 to +34 years. Although 14 patients presented OP after the onset of RA, two developed OP before RA and three developed OP simultaneously with RA. Patients receiving tumor necrosis factor inhibitors also developed OP. RA disease activity just before onset of OP was low in 8 of 14 RA cases. At the onset of OP, only two patients showed exacerbations of arthritis, whereas most patients presented with fever and serum C-reactive protein (CRP) elevations. Glucocorticoids were effective for OP in all patients who received them. Relapse occurred in 4 of 19 cases.OP develops in approximately 4% of RA patients, which occurs independently from arthritis activity and at any time in RA patients.

Apoptosis inhibitor of macrophage (AIM) expressed on macrophages prolongs inflammation by protecting macrophages from apoptosis. Most circulating AIM co-exists with immunoglobulin M (IgM). AIM’s pathophysiological role in relation to IgM remains unclear. Here we evaluated the glomerular expression/deposition of AIM and IgM in the kidney using immunohistochemistry and its associations with clinical manifestations in 43 patients with biopsy-confirmed kidney diseases. Kidney biopsy tissue from all patients was immunostained for AIM and IgM. Staining patterns and percent stained areas within the glomeruli were determined. Cells expressing AIM were identified by co-staining with macrophage and endothelial cell surface markers. Correlations between staining results and clinical parameters were evaluated using univariate and multivariate analyses. AIM was deposited in various areas, such as mesangial and capillary area. A part of AIM expression was localized to CD68-positive macrophages in the glomerulus. Amount of glomerular expression was positively correlated with urinary protein in patients with severe proteinuria (urinary protein ≥0.5 g/day) and kidney dysfunction [estimated glomerular filtration ratio (eGFR)

Background:Interstitial lung disease (ILD), frequent lung involvement, determine the prognosis of patients with RA. The presence of ILD also influences the selection of RA therapy. However, it is not fully elucidated what groups of RA-ILD patients worsen ILD.Objectives:To identify the risk factors for worsening of ILD in RA patients under biological DMARD (bDAMARDs) therapy; particularly to determine whether types of bDMARDs are associated with exacerbation of ILD.Methods:A retrospective cohort study was conducted. Subjects were consecutive 91 RA-ILD patients who received HR-CT examination at starting and during bDMARDs therapy. Clinical data were collected by reviewing.ILD was diagnosed, when patients showed ground-glass opacity (GGO), consolidation, reticular pattern or honeycomb; the former two were acute and the latter two were chronic ILD lesions. The extent of each lesion was scored and recorded. When the score was increased, the lesion was judged as worsened. The incidence of exacerbation of ILD under an indicated agent was calculated as follows; the sum of (exposure period of the agent/exposure period of any agent) in patients with the exacerbation was divided by total exposure period of the agent.Results:Subjects were 36 males and 55 females with a mean age of 66.8 years. At the entry, GGO, consolidation, reticular and honeycomb were found in16, 20, 63 and 17, respectively. Acute and chronic ILD were observed in 34 and 68, respectively. ILD worsened in 35 (38.5%). Between patients with and without ILD exacerbation, no differences were found in demographics (sex, age, disease duration, the positivity for anti-CCP ab and RF) and radiographic findings of pulmonary abnormalities. Disease activities at as 1st and sequential CT examinations were similar in both groups.The incidences of the worsening of ILD varied according to bDMARDs (Fig 1). The incidence of total ILD worsening was high in TCZ compared to TNF and ABT. The incidence of acute ILD worsening was similar among the three groups. However, the worsening of chronic ILD was more frequently found in TCZ than other bDMARDs. The incidence of death by respiratory failure was similar in TNF, ABT, and TCZ (Fig. 2).Fig. 1Conclusion:TCZ might be a risk factor for exacerbation of ILD, particularly of chronic ILD.Fig. 2Disclosure of Interests:None declared

Owing to changes in lifestyle, nonalcoholic fatty liver disease (NAFLD) is becoming a common form of chronic liver injury. NAFLD comprises a wide variety of disease stages, from simple steatosis to nonalcoholic steatohepatitis, which is a risk factor for the development of hepatocellular carcinoma (HCC). Because animal models for NAFLD are needed to investigate the precise pathogenesis, we aimed to establish a new mouse model employing mice deficient for apoptosis inhibitor of macrophage (AIM-/-), which exhibit accelerated lipid storage in the liver and high susceptibility to developing HCC in response to a high-fat diet (HFD). AIM-/- mice were fed the D09100301 diet, which contains 40 kcal% fat (trans fat 30 kcal%), high cholesterol (2%), and 40 kcal% carbohydrates (20 kcal% fructose), and then features of obesity and NAFLD including steatosis, inflammation, fibrosis, and HCC development were analyzed. Although a comparable grade of liver steatosis was promoted in AIM-/- mice by the D09100301 diet and the standard HFD (60 kcal% largely lard fat), significantly less lipid storage in visceral fat was observed when the mice were fed the D09100301 diet. Accelerated liver inflammation was promoted by the D09100301 diet compared with the HFD, but interestingly, HCC development was decreased in mice fed the D09100301 diet. Our findings suggest that AIM-/- mice fed the D09100301 diet exhibited a phenotype that resembled nonobese NAFLD patients and thus could be an appropriate tool to study the pathophysiology by which obesity increases the risk of HCC.

Background Rheumatoid arthritis (RA) is a systemic inflammatory disease that affects joints and various organs. The lung is one of the most common site of extra-articular involvement. Interstitial lung disease (ILD) is one form of the lung involvement and influences prognosis of the patients. RA-ILD frequently developed acute exacerbation. Once acute exacerbation occurs, the prognosis of patients is poor. However, it is not fully elucidated what the risk factors for severe exacerbation of ILD are. Objectives The purpose of thisstudy was to identify the risk factors for severe exacerbation of ILD in RApatients during bDMARDs therapy.The purpose of this study was to identify therisk factors for exacerbation of ILD in RA patients under the bDMARDs therapy. Methods A retrospective cohort study. Subjects were consecutive 208 RA patients who were treated with bDMARDs from 2004 to 2015 in our department and received HRCT scan before and during the therapy. Based on HR-CT imaging, pulmonary abnormalities were classified into 4 categories (ILD, nodular lesions, airway disease (AD) and others) and 20 lesions such as ground-glass opacity (GGO), reticular pattern, bronchiolitis and bronchiectasis. We recorded their existence and distribution before andduring the therapy and examined their changes. Severe exacerbation of ILD was judged when patients revealed newly emerging/worsening of ILD lesions regardless of pre-existing pulmonary lesions and deceased or had to stop bDMARDs due to exacerbation of ILD. To identify risk factors, logistic regression analysis was conducted. Results Subjects were 208 RApatients, M/F; 64/144, mean age; 59.2 years old, disease duration; 7.9 years positive for RF in 84.1%. bDMARDs used for the longest period were TNFinhibitors in 79.8% of the subjects, abatacept in 15.4% and tocilizmab in 4.8%. Pulmonary abnormalities were found in 146 (70.2%) of RA patients before bDMARDs (ILD 81,(38.9%); nodular lesions 45, (21.6%); and ADs, 115, (55.3%)). GGO, consolidation, reticular pattern and honey combing was found in 14.8%, 19.8%, 51.9%, and 17.3% of ILD patients. Most of ILD lesions coexisted with ADs. During the observation period (3.26±2.61 years), newly emerging/worsening pulmonary lesions were found in 42.3% of patients and the incidence of which was 13.7/100person year. The incidence of newly development and worsening of ILD were 7.0/100 person years and 1.5/100 person years, respectively. Severe exacerbation of ILD was developed in 13 patients (6.3%) and the incidence of which was 2.0/100 person year. Of 13 patients, 9 died of respiratory failure. All patients with severe exacerbation revealed GGO/consolidation.Interestingly, all these active ILD lesions were newly emerging lesions, however, most of the patients had pre-existing pulmonary lesions. We identified risk factors for severe exacerbation of ILD (Table1). The risk factors for severe exacerbation of ILD were older age and pre-existing pulmonary lesions of ILD and of ADs, particularly reticular pattern, honeycomb and bronchiectasis. Sero-positivity and choice of biologics were not identified as risk factors. Conclusions The incidence of severe exacerbation of ILD was 2.0/100 person years. The risk factors forsevere exacerbation of ILD were older age and pre-existing reticular pattern,honeycomb and bronchiectasis. Disclosure of Interest: None declared

Tissue macrophage-derived apoptosis inhibitor of macrophage (AIM, encoded by cd5l gene) is a circulating protein that has suppressive functions in a broad range of diseases including obesity, liver steatosis, hepatocellular carcinoma (HCC), and acute kidney injury (AKI). In healthy states, high levels of AIM circulate in the inactivated state by associating with the immunoglobulin M (IgM) pentamer in the blood, whereas during AKI, AIM dissociates from IgM and gains disease repair activity. Here, we assessed whether AIM activation via its release from IgM is required to ameliorate other diseases. To this end, we employed a mouse line in which mouse AIM was replaced with feline AIM (AIM-felinized mice). Because feline AIM rarely dissociates from IgM due to its extremely high binding affinity for IgM, these mice exhibited deficient AKI repair as in cats. When fed a high-fat diet (HFD), similar to AIM-deficient (AIM−/−) mice, AIM-felinized mice exhibited enhanced triacylglycerol deposition in visceral adipocytes and hepatocytes, resulting in more prominent obesity and fatty liver than in wild-type mice. In contrast, the incidence of HCC after a 1-year HFD was remarkably lower in AIM-felinized mice than in AIM−/− mice, suggesting that AIM produced by liver Kupffer macrophages might directly facilitate the elimination of HCC cells. Accordingly, the marked deposition of AIM accompanied by accumulation of Kupffer cells was obvious during HCC tumour development in AIM-felinized mice. Δsµ mice, which harbour almost no circulating AIM due to the lack of secreted IgM, showed a phenotype comparable with that of AIM-felinized mice in prevention of those diseases. Thus, blood AIM released from IgM contributes to suppression of obesity and fatty liver as in AKI, whereas macrophage-derived noncirculating AIM mainly prevents HCC development. Our study depicted two different modes of disease prevention/repair facilitated by AIM, which could be the basis for HCC therapy that works by increasing AIM expression in macrophages.

Acute kidney injury (AKI) is associated with prolonged hospitalization and high mortality, and it predisposes individuals to chronic kidney disease. To date, no effective AKI treatments have been established. Here we show that the apoptosis inhibitor of macrophage (AIM) protein on intraluminal debris interacts with kidney injury molecule (KIM)-1 and promotes recovery from AKI. During AKI, the concentration of AIM increases in the urine, and AIM accumulates on necrotic cell debris within the kidney proximal tubules. The AIM present in this cellular debris binds to KIM-1, which is expressed on injured tubular epithelial cells, and enhances the phagocytic removal of the debris by the epithelial cells, thus contributing to kidney tissue repair. When subjected to ischemia-reperfusion (IR)-induced AKI, AIM-deficient mice exhibited abrogated debris clearance and persistent renal inflammation, resulting in higher mortality than wild-type (WT) mice due to progressive renal dysfunction. Treatment of mice with IR-induced AKI using recombinant AIM resulted in the removal of the debris, thereby ameliorating renal pathology. We observed this effect in both AIM-deficient and WT mice, but not in KIM-1-deficient mice. Our findings provide a basis for the development of potentially novel therapies for AKI.

A diagnostic marker is needed enabling early and specific diagnosis of hepatocellular carcinoma (HCC) associated with non-alcoholic steatohepatitis (NASH). Our recent findings have indicated that circulating apoptosis inhibitor of macrophage (AIM), which usually associates with IgM pentamer in the blood, is activated by its dissociation from IgM. We investigated the serum levels of IgM-free AIM for AIM activation and its possible relationship with development of HCC in NASH. Serum levels of IgM-associated and IgM-free AIM were evaluated in patients with non-alcoholic fatty liver, NASH, and NASH-HCC using enzyme-linked immunosorbent assays and immunoblots. Liver biopsy specimens were graded and staged using Brunt’s classification. Forty-two patients with fatty liver, 141 with NASH, and 26 with NASH-HCC were evaluated. Patients with stage 4 or grade 3 NASH (with or without HCC) exhibited significantly higher levels of both IgM-free and total AIM than those with fatty liver, whereas the ratio of IgM-free-to-total AIM was equivalent in these groups. Among patients with the same fibrosis stage of NASH, those with HCC had significantly higher IgM-free but not total AIM levels, resulting in a proportional increase in the IgM-free/total AIM ratio. Analysis of the areas under the receiver operating characteristic curves indicated the high sensitivity of the IgM-free AIM for NASH-HCC. Our observations suggest the activation of AIM in blood in the presence of NASH-HCC, with a significant increase in IgM-free AIM levels. IgM-free AIM serum levels appear to be a sensitive diagnostic marker for NASH-HCC.

Background Rheumatoid arthritis (RA) is a systemic inflammatory disease that affects joints and various organs including the lung. The pulmonary involvement is critical for prognosis of the patients and decision of the treatment. Moreover, the pulmonary involvement showed various abnormalities such as interstitial pneumonia (ILD) and airway disease (AD). Importantly, a pulmonary abnormality coexists with other ones in RA patients. There have been large numbers of studies on the prevalence of pulmonary abnormalities and clinical features of patients with these lesions. However, it remains to be elucidated what existence pattern of pulmonary abnormalities RA patients have. Objectives To reveal the existence pattern of the pulmonary abnormalities in RA patients using cluster analysis, and to clarify the clinical features of patients with multiple pulmonary abnormalities. Methods Subjects were consecutive 208 RA patients who were treated with bDMARDs as the first one from Feb. 2004 to Sep. 2015 in our department and received HRCT scan before and after the therapy. Pulmonary abnormalities were classified into 4 categories (ILD, nodular lesions, AD and other) and 20 lesions such as ground-glass opacity, reticular pattern, bronchiolitis and bronchiectasis and were examined their existence and distribution. Cluster analysis was conducted according to the existence of the lesions by Ward method. Clinical features were analyzed through reviewing medical records. Results Subjects were 208 RA cases (M/F; 64/144, mean age 59.2 year-old, disease duration 13.1 years). Pulmonary lesions were found in 146 (70.2%) of RA patients before treatment Imaging findings were 81of ILD (39%),45 of nodular lesion (21.6%) and 115 of AD (55%). Cluster analysis showed 6 clustered (Fig.), 1; no pulmonary lesions, 2; AD without bronchoectasia, 3; AD with bronchoectasia, 4; AD with curved linear opacities, 5; AD with nodular lesions, and 6; reticular pattern with AD. AD was common abnormalities and coexisted with other pulmonary lesions in RA. AD was found in 79%, 78% and 71% of patients with pulmonary abnormalities, ILD and nodular lesions, respectively. AD alone, AD with ILD, and AD with nodular pattern were found in 16.3%, 8.6% and 28.9%, respectively, while patients without pulmonary lesions were 29.8% in RA. AD was frequently associated with ILD and nodule compare to non-AD. No differences were found in gender, smoking history, disease duration and disease activity between patients with and without AD. New emergence or exacerbation of pulmonary abnormalities developed in AD patients compared to those without pulmonary abnormalities or AD. No significant differences were found in clinical features, among AD alone, AD with ILD and AD with nodules. Conclusions Pulmonary abnormalities were found in 70% in RA. AD was found in 55% of RA patients and coexisted with other pulmonary lesions such as ILD and nodular lesions. Patients with AD frequently showed newly emerging or worsening pulmonary lesions, regardless of the coexistence of other pulmonary lesions. Thus, AD is shared and critical pulmonary abnormality in RA. Disclosure of Interest None declared

Apoptosis inhibitor of macrophage (AIM) plays roles in survival of macrophages. In this study, we cloned canine AIM cDNA and observed its transcriptional expression levels in various tissues. The coding sequence of canine AIM was 1,023 bp encoding 340 amino acid residues, which had around 65% homology with those of the human, mouse and rat. Transcriptional expression of AIM was observed in the spleen, lung, liver and lymph node, which confirmed the expression of canine AIM in tissue macrophages. Moreover, AIM was highly expressed in one of the canine histiocytic sarcoma cell lines. CD36, the receptor of AIM, was also expressed in various tissues and these cell lines. These findings are useful to reveal the actual functions of canine AIM.

SummaryNatural immunoglobulin M (IgM) is reactive to autoantigens and is believed to be important for autoimmunity. Blood pentameric IgM loaded with antigens forms a large immune complex (IC) that contains various elements, including apoptosis inhibitor of macrophage (AIM). Here we demonstrate that this IgM-AIM association contributes to autoantibody production under obese conditions. In mice fed a high-fat diet, natural IgM increased through B cell TLR4 stimulation. AIM associated with IgM and protected AIM from renal excretion, increasing blood AIM levels along with the obesity-induced IgM augmentation. Meanwhile, the AIM association inhibited IgM binding to the Fcα/μ receptor on splenic follicular dendritic cells, thereby protecting the IgM IC from Fcα/μ receptor-mediated internalization. This supported IgM-dependent autoantigen presentation to B cells, stimulating IgG autoantibody production. Accordingly, in obese AIM-deficient (AIM−/−) mice, the increase of multiple IgG autoantibodies observed in obese wild-type mice was abrogated. Thus, the AIM-IgM association plays a critical role in the obesity-associated autoimmune process.

Apoptosis inhibitor of macrophage (AIM, encoded by cd5l) is a multi-functional circulating protein that has a beneficial role in the regulation of a broad range of diseases, some of which are ameliorated by AIM administration in mice. In blood, AIM is stabilized by association with IgM pentamers and maintains its high circulating levels. The mechanism regulating the excessive accumulation of blood AIM remains unknown, although it is important, since a constitutive increase in AIM levels promotes chronic inflammation. Here we found a physiological AIM-cleavage process that induces destabilization of AIM and its excretion in urine. In blood, IgM-free AIM appeared to be cleaved and reduced in size approximately 10 kDa. Cleaved AIM was unable to bind to IgM and was selectively filtered by the glomerulus, thereby excreted in urine. Amino acid substitution at the cleavage site resulted in no renal excretion of AIM. Interestingly, cleaved AIM retained a comparable potency with full-length AIM in facilitating the clearance of dead cell debris in injured kidney, which is a key response in the recovery of acute kidney injury. Identification of AIM-cleavage and resulting functional modification could be the basis for designing safe and efficient AIM therapy for various diseases.

Renal failure is one of the most important social problems for its incurability and high costs for patients’ health care. Through clarification of the underlying mechanism for the high susceptibility of cats to renal disease, we here demonstrates that the effective dissociation of serum AIM protein from IgM is necessary for the recovery from acute kidney injury (AKI). In cats, the AIM-IgM binding affinity is 1000-fold higher than that in mice, which is caused by the unique positively-charged amino-acid cluster present in feline AIM. Hence, feline AIM does not dissociate from IgM during AKI, abolishing its translocation into urine. This results in inefficient clearance of lumen-obstructing necrotic cell debris at proximal tubules, thereby impairing AKI recovery. Accordingly, mice whose AIM is replaced by feline AIM exhibit higher mortality by AKI than in wild-type mice. Recombinant AIM administration into the mice improves their renal function and survival. As insufficient recovery from AKI predisposes patients to chronic, end-stage renal disease, feline AIM may be involved crucially in the high mortality of cats due to renal disease. Our findings could be the basis of the development of novel AKI therapies targeting AIM-IgM dissociation, and may support renal function in cats and prolong their lives.

The consumption of fructose, including the use of high-fructose corn syrup as a sweetener, has increased continuously in recent decades. Although the involvement of fructose in the development of metabolic diseases has been emphasized recently, whether fructose intake increases susceptibility to steatosis-associated hepatocellular carcinoma (HCC) is unclear. Here, we investigated this issue using mice lacking a circulating protein, apoptosis inhibitor of macrophage (AIM, encoded by cd5l). AIM does not induce carcinogenesis of hepatocytes, but provokes necrotic death specifically in AIM-bound cancer cells through complement cascade activation, thereby preventing HCC tumor development in wild-type mice. When subjected to a high-fructose diet (HFrD), AIM-deficient (AIM–/–) mice showed liver steatosis and subsequent liver inflammation as well as fibrosis, but at much milder levels compared with mice fed a high-fat diet. However, AIM–/– mice were markedly susceptible to HCC tumor development, whereas no wild-type mice developed the disease. Systemic metabolic states, including obesity and insulin resistance, were similar in both types of mice after HFrD challenge, indicating no influence of AIM on HFrD-induced metabolic changes. Our results suggest that dietary fructose increases the risk for liver carcinogenesis and that individuals with low blood AIM levels may be susceptible to HCC under chronic fructose intake.

Under fasting conditions, triacylglycerol in adipose tissue undergoes lipolysis to supply fatty acids as energy substrates. Such lipolysis is regulated by hormones, which activate lipases via stimulation of specific signalling cascades. We previously showed that macrophage-derived soluble protein, AIM induces obesity-associated lipolysis, triggering chronic inflammation in fat tissue which causes insulin resistance. However, the mechanism of how AIM mediates lipolysis remains unknown. Here we show that AIM induces lipolysis in a manner distinct from that of hormone-dependent lipolysis, without activation or augmentation of lipases. In vivo and in vitro, AIM did not enhance phosphorylation of hormone-sensitive lipase (HSL) in adipocytes, a hallmark of hormone-dependent lipolysis activation. Similarly, adipose tissue from obese AIM-deficient and wild-type mice showed comparable HSL phosphorylation. Consistent with the suppressive effect of AIM on fatty acid synthase activity, the amount of saturated and unsaturated fatty acids was reduced in adipocytes treated with AIM. This response ablated transcriptional activity of peroxisome proliferator-activated receptor (PPARγ), leading to diminished gene expression of lipid-droplet coating proteins including fat-specific protein 27 (FSP27) and Perilipin, which are indispensable for triacylglycerol storage in adipocytes. Accordingly, the lipolytic effect of AIM was overcome by a PPARγ-agonist or forced expression of FSP27, while it was synergized by a PPARγ-antagonist. Overall, distinct modes of lipolysis appear to take place in different physiological situations; one is a supportive response against nutritional deprivation achieved by enhancing lipase activity, and the other is a pathological consequence of obesity, causing subclinical inflammation and metabolic disorders, mediated by abolishing droplet-coating proteins.

Trimethoprim-sulphamethoxazole (TMP-STX), an agent used for prophylaxis against pneumocystis pneumonia (PCP) in immunocompromised hosts, causes serious adverse effects (AEs) in some patients. The objective of this study was to identify the risk factors for AEs caused by TMP-STX in connective tissue disease (CTD) patients and to describe the clinical features of the AEs.The medical records of 539 patients (CTDs 312, pulmonary diseases 227) receiving TMP-STX for prophylaxis against PCP were reviewed retrospectively. Patients with human immunodeficiency virus were excluded. Univariate and multivariate analyses were conducted to identify the risk factors.Adverse events caused by TMP-STX occurred in 22 of 312 (7.05 %) CTD patients, while only six of 227 (2.64 %) pulmonary disease patients developed AEs. The incidence of AEs was significantly higher in systemic lupus erythematosus (SLE) (11.0 %) and mixed connective tissue disease (MCTD) (33.3 %) patients than in other CTD patients. AEs occurred in 25 % of patients with anti-RNP antibody. Univariate analysis revealed that SLE, MCTD, and anti-RNP antibody were risk factors for AEs in CTD patients. Further multivariate analyses demonstrated that only anti-RNP antibody positivity was a risk factor for AEs. Systemic inflammation, including fever, was a characteristic manifestation of the AEs in CTD patients, particularly those with anti-RNP antibody.Positivity for anti-RNP antibody is a risk factor for AEs caused by TMP-STX in CTD patients. Systemic inflammation, including fever, might be a characteristic feature of the AEs in CTD patients, particularly those with anti-RNP antibody.

A 58-year old Japanese woman who had been diagnosed with and managed for systemic sclerosis (SSc) with pulmonary arterial hypertension died suddenly. However, the autopsy revealed marked right ventricular dilatation, and the myocardium had been replaced by fatty tissue. These findings were consistent with arrhythmogenic right ventricular dysplasia (ARVD). A literature search identified nine cases of SSc with ARVD in Japan, including this case; this number is significantly higher than the value estimated from the prevalences of ARVD and SSc in Japan, suggesting an association between these two rare diseases.

Metabolic syndrome (MetS) is a cascade of metabolic diseases, starting with obesity and progressing to atherosclerosis, and is often fatal because of serious cardiovascular problems such as heart/brain infarction and hemorrhage. Accumulating evidence has revealed a critical involvement of inflammatory responses triggered by lesional macrophages in the pathogenesis of MetS. Importantly, we found that macrophages are associated with disease progression, not only in the induction of inflammation but also in the production of apoptosis inhibitor of macrophages (AIM), which we initially identified as a soluble factor expressed by macrophages. In atherosclerotic plaques, AIM is highly expressed by foam macrophages and inhibits apoptosis of these cells, which results in the accumulation of macrophages, causing inflammatory responses within the lesion, and ultimately disease progression. In adipose tissue, macrophage-derived AIM is incorporated into adipocytes through CD36-mediated endocytosis, thereby reducing the activity of cytosolic fatty acid synthase. This unique response stimulates lipolysis, resulting in a decrease in adipocyte size, which is physiologically relevant to the prevention of obesity. The lipolytic response also stimulates inflammation of adipocytes in association with the induction of metabolic disorders subsequent to obesity. Thus, AIM is involved in the progression of MetS in both an advancing and inhibitory fashion. Regulation of AIM could therefore be therapeutically applicable for MetS.

Macrophages infiltrate adipose tissue in obesity and are involved in the induction of inflammation, thereby contributing to the development of obesity-associated metabolic disorders. Here, we show that the macrophage-derived soluble protein AIM is endocytosed into adipocytes via CD36. Within adipocytes, AIM associates with cytosolic fatty acid synthase (FAS), thereby decreasing FAS activity. This decreases lipid droplet size, stimulating the efflux of free fatty acids and glycerol from adipocytes. As an additional consequence of FAS inhibition, AIM prevents preadipocyte maturation. In vivo, the increase in adipocyte size and fat weight induced by high-fat diet (HFD) was accelerated in AIM-deficient (AIM(-)(/-)) mice compared to AIM(+/+) mice. Moreover, injection of recombinant AIM in AIM(-)(/-) mice suppresses the increase in fat mass induced by HFD. Interestingly, metabolic rates are comparable in AIM(-)(/-) and AIM(+/+) mice, suggesting that AIM specifically influences adipocyte status. Thus, this AIM function in adipocytes may be physiologically relevant to obesity progression.

Insulin secretion and glucose transport are the major mechanisms to balance glucose homeostasis. Recently, we found that the death effector domain-containing DEDD inhibits cyclin-dependent kinase-1 (Cdk1) function, thereby preventing Cdk1-dependent inhibitory phosphorylation of S6 kinase-1 (S6K1), downstream of phosphatidylinositol 3-kinase (PI3K), which overall results in maintenance of S6K1 activity. Here we newly show that DEDD forms a complex with Akt and heat-shock protein 90 (Hsp90), and supports the stability of both proteins. Hence, in DEDD(-/-) mice, Akt protein levels are diminished in skeletal muscles and adipose tissues, which interferes with the translocation of glucose-transporter 4 (GLUT4) upon insulin stimulation, leading to inefficient incorporation of glucose in these organs. Interestingly, as for the activation of S6K1, suppression of Cdk1 is involved in the stabilization of Akt protein by DEDD, since diminishment of Cdk1 in DEDD(-/-) cells via siRNA expression or treatment with a Cdk1-inhibitor, increases both Akt and Hsp90 protein levels. Such multifaceted involvement of DEDD in glucose homeostasis by supporting both insulin secretion (via maintenance of S6K1 activity) and glucose uptake (via stabilizing Akt protein), may suggest an association of DEDD-deficiency with the pathogenesis of type 2 diabetes mellitus.

We report the case of a patient with systemic lupus erythematosus (SLE) who first revealed hemophagocytic syndrome (HPS), which was treated successfully with glucocorticoid and intravenous cyclophosphamide. The patient then demonstrated refractory thrombotic thrombocytopenic purpura (TTP) with normal a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS)-13 activity that responded well to rituximab. After rituximab treatment, the patient showed a flare of HPS that was controlled by additional intravenous cyclophosphamide treatment. This case showed that TTP with normal ADAMTS-13 activity is B-cell dependent and indicated that B-cell depletion might exacerbate some autoimmune conditions in SLE.

Background: Apoptosis Inhibitor of Macrophage (AIM), which is involved in a variety of inflammatory diseases, has been reported to be stabilized by association with IgM pentamer and resulting in accumulation in blood (Arai S . Cell Rep 2013;3:1-12). On the other hand, AIM is reported to be increased in bronchoalveolar lavage fluid from patients with asthma (Wu J . Mol Cell Proteomics 2005;4:1251-64). Aim: To investigate the association of serum AIM and AIM/IgM ratio with development of asthma and its severity. Methods: We recruited 206 subjects with asthma who participated in the Hokkaido-based Investigative Cohort Analysis for Refractory Asthma (Hi-CARAT), including 127 subjects with severe asthma and 79 subjects with mild-to-moderate asthma, and 72 healthy subjects who received health checkups. Serum AIM and IgM levels were measured by EILSA. Differences among the groups were analyzed using the Kruskal-Wallis test and the Mann-Whitney U test after stratification by sex. Results: Serum AIM levels were not different between subjects with asthma and healthy subjects in both male and female (median 4.3 vs. 4.8 µg/ml, p=0.13 for male and 4.8 vs. 4.5 µg/ml, p=0.39 for female). On the other hand, serum AIM/IgM ratio was significantly lower in subjects with severe asthma compared with healthy subjects in both male and female (median 0.048 vs. 0.058, p=3.1×10 -5 for male and 0.042 vs. 0.050, p=7.0×10 -4 for female) and also compared with subjects with mild-to-moderate asthma in male (0.048 vs.0.054, p=0.0064) but not in female (0.042 vs. 0.044, p=0.29). Conclusion: Lower serum AIM/IgM ratio was associated with severe asthma. A change in the binding state of serum AIM and IgM may be associated with the pathogenesis of severe asthma.

Purpose To study the genotypes, allelic frequencies, and polymorphisms of apolipoprotein E (Apo E) in unrelated Japanese patients with polypoidal choroidal vasculopathy (PCV) or exudative age-related macular degeneration (AMD) and control subjects without macular degeneration. Design Cross-sectional study. Methods Blood samples from 225 subjects older than 50 years were used. The 225 subjects included 58 patients with PCV, 85 with AMD, and 82 without macular degeneration. Coding exons of the Apo E gene were amplified by polymerase chain reaction, and the DNA sequences were determined by direct sequencing with an automated sequencer. Results Apo E e3/e3 was the most frequent genotype with a prevalence of 79.3% in PCV patients, 76.5% in AMD patients, and 67.1% in the control subjects. However, the differences in the percentages were not statistically significant among the three groups. The most frequently found allele in the three groups was e3. Patients with PCV and AMD were less likely to have e2 and e4 than the control subjects, but the differences were not statistically significant. Five minor Apo E single nucleotide polymorphisms, including e5 and e7, were found. Conclusion Japanese patients with PCV and AMD were less likely to have e2 and e4 polymorphisms, but the differences from the normals were not statistically significant for the Apo E genotypes and allelic frequencies.

Endotoxin-induced uveitis (EIU) is an animal model of acute ocular inflammation. Cytokines, chemokines, and nitric oxide (NO) have been reported to play important roles. We have determined whether heme oxygenase (HO)-1, a heat shock protein, can suppress EIU. EIU was induced by a footpad injection of lipopolysaccharide (LPS) in male Lewis rats. Hemin, an inducer of HO-1, was injected intraperitoneally 1 hr prior to the LPS injection. HO-1 and HO-2 expression in the iris-ciliary body (ICB) was studied by real time PCR and Western blot analysis. The number of infiltrating cells and the protein concentration in the aqueous humor (AqH) were evaluated by microscopy and by protein assay. The expression of inducible nitric oxide synthase (iNOS), interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, and IL-1beta mRNA was determined by real time PCR. The concentration of nitrate plus nitrite, and levels of IL-6 and TNF-alpha in the AqH were also evaluated by Griess reagents and by enzyme-linked immunosorbent assay, respectively. The expression of HO-1 mRNA and protein, induced by LPS, was enhanced significantly by pre-injection of hemin (P0.001). HO-2 was constitutively present in the ICB and was not up-regulated by LPS or by hemin. The number of infiltrating cells and the concentration of protein in the AqH was significantly elevated by LPS injection, and hemin significantly reduced the number of cells and the protein concentration (P0.0001). The expression of iNOS and IL-6 mRNA and protein were down-regulated by hemin (P0.001). Hemin is effective in inducing HO-1 and in reducing the ocular inflammation induced by LPS probably by down-regulating NO and pro-inflammatory cytokine expression.

It has been of much interest whether there is functional redundancy between the constitutively signaling pre-Talpha/TCRbeta (pre-TCR) and ligated TCRalphabeta complexes, which independently operate the two distinct checkpoints during thymocyte development, i.e., the pre-TCR involved in beta-selection at the CD4(-)CD8(-) double-negative stage and the TCRalphabeta being crucial for positive/negative selection at the CD4(+)CD8(+) double-positive stage. We found that the pre-TCR expressed on double-positive cells in TCRalpha-deficient (TCRalpha(-/-)) mice produced a small number of mature CD8(+) T cells. Surprisingly, when pre-Talpha was overexpressed, resulting in augmentation of pre-TCR expression, there was a striking increase of the CD8(+) T cells. In addition, even in the absence of up-regulation of pre-TCR expression, a similar increase of CD8(+) T cells was also observed in TCRalpha(-/-) mice overexpressing Egr-1, which lowers the threshold of signal strength required for positive selection. In sharp contrast, the CD8(+) T cells drastically decreased in the absence of pre-Talpha on a TCRalpha(-/-) background. Thus, the pre-TCR appears to functionally promote positive selection of CD8(+) T cells. The biased production of CD8(+) T cells via the pre-TCR might also support the potential involvement of signal strength in CD4/CD8 lineage commitment.

Owing to rapid and drastic changes in lifestyle and eating habits in modern society, obesity and obesity-associated diseases are among the most important public health problems. Hence, the development of therapeutic approaches to regulate obesity is strongly desired. In view of previous work showing that apoptosis inhibitor of macrophage (AIM) blocks lipid storage in adipocytes, thereby preventing obesity caused by a high-fat diet, we here explored a strategy to augment circulating AIM levels. We synthesized the Fc portion of the soluble human immunoglobulin (Ig)M heavy chain and found that it formed a pentamer containing IgJ as natural IgM does, and effectively associated with AIM in vitro. When we injected the synthesized Fc intravenously into mice lacking circulating IgM, it associated with endogenous mouse AIM, protecting AIM from renal excretion and preserving the circulating AIM levels. As the synthesized Fc lacked the antigen-recognizing variable region, it provoked no undesired immune response. In addition, a challenge with the Fc-human AIM complex in wild-type mice, which exhibited normal levels of circulating IgM and AIM, successfully maintained the levels of the human AIM in mouse blood. We also observed that the human AIM was effectively incorporated into adipocytes in visceral fat tissue, suggesting its functionality against obesity. Thus, our findings reveal potent strategies to safely increase AIM levels, which could form the basis for developing novel therapies for obesity.

Apoptosis inhibitor of macrophages (AIMs), a homologue of human Spα, is a mouse soluble member of the scavenger receptor cysteine-rich superfamily (SRCR-SF). This family integrates a group of proteins expressed by innate and adaptive immune cells for which no unifying function has yet been described. Pleiotropic functions have been ascribed to AIM, from viability support in lymphocytes during thymic selection to lipid metabolism and anti-inflammatory effects in autoimmune pathologies. In the present report, the pathogen binding properties of AIM have been explored. By using a recombinant form of AIM (rAIM) expressed in mammalian cells, it is shown that this protein is able to bind and aggregate Gram-positive and Gram-negative bacteria, as well as pathogenic and saprophytic fungal species. Importantly, endogenous AIM from mouse serum also binds to microorganisms and secretion of AIM was rapidly induced in mouse spleen macrophages following exposure to conserved microbial cell wall components. Cytokine release induced by well-known bacterial and fungal Toll-like receptor (TLR) ligands on mouse splenocytes was also inhibited in the presence of rAIM. Furthermore, mouse models of pathogen-associated molecular patterns (PAMPs)-induced septic shock of bacterial and fungal origin showed that serum AIM levels changed in a time-dependent manner. Altogether, these data suggest that AIM plays a general homeostatic role by supporting innate humoral defense during pathogen aggression.

BackgroundHepatocellular carcinoma (HCC), the fifth most common cancer type and the third highest cause of cancer death worldwide, develops in different types of liver injuries, and is mostly associated with cirrhosis. However, non-alcoholic fatty liver disease often causes HCC with less fibrosis, and the number of patients with this disease is rapidly increasing. The high mortality rate and the pathological complexity of liver diseases and HCC require blood biomarkers that accurately reflect the state of liver damage and presence of HCC.Methods and findingsHere we demonstrate that a circulating protein, apoptosis inhibitor of macrophage (AIM) may meet this requirement. A large-scale analysis of healthy individuals across a wide age range revealed a mean blood AIM of 4.99 ± 1.8 µg/ml in men and 6.06 ± 2.1 µg/ml in women. AIM levels were significantly augmented in the younger generation (20s-40s), particularly in women. Interestingly, AIM levels were markedly higher in patients with advanced liver damage, regardless of disease type, and correlated significantly with multiple parameters representing liver function. In mice, AIM levels increased in response to carbon tetrachloride, confirming that the high AIM observed in humans is the result of liver damage. In addition, carbon tetrachloride caused comparable states of liver damage in AIM-deficient and wild-type mice, indicating no influence of AIM levels on liver injury progression. Intriguingly, certain combinations of AIM indexes normalized to liver marker score significantly distinguished HCC patients from non-HCC patients and thus could be applicable for HCC diagnosis.ConclusionAIM potently reveals both liver damage and HCC. Thus, our results may provide the basis for novel diagnostic strategies for this widespread and fatal disease.

Obesity is associated with various metabolic and cardiovascular diseases caused by chronic, low-grade inflammation that is initially observed in obese adipose tissue. In addition, many etiological studies in humans have shown a strong correlation between obesity and inflammatory autoimmune diseases. In this review, we focus on the involvement of apoptosis inhibitor of macrophage (AIM), a macrophage-derived blood protein, in both types of immune response. Through differential mechanisms, AIM thereby plays key roles in the pathogenesis of atherosclerosis, metabolic diseases, and obesity-associated autoimmune diseases. Thus, the regulation of blood AIM levels or AIM function has the potential to serve as a next-generation therapy against these inflammatory diseases brought about by modern lifestyle.

Peptidylarginine deiminase 4 (PAD4) functions as a transcriptional coregulator by catalyzing the conversion of histone H3 arginine residues to citrulline residues. Although the high level of PAD4 expression in bone marrow cells suggests its involvement in haematopoiesis, its precise contribution remains unclear. Here we show that PAD4, which is highly expressed in lineage− Sca-1+ c-Kit+ (LSK) cells of mouse bone marrow compared with other progenitor cells, controls c-myc expression by catalyzing the citrullination of histone H3 on its promoter. Furthermore, PAD4 is associated with lymphoid enhancer-binding factor 1 and histone deacetylase 1 at the upstream region of the c-myc gene. Supporting these findings, LSK cells, especially multipotent progenitors, in PAD4-deficient mice show increased proliferation in a cell-autonomous fashion compared with those in wild-type mice. Together, our results strongly suggest that PAD4 regulates the proliferation of multipotent progenitors in the bone marrow by controlling c-myc expression., Histone citrullination by peptidylarginine deiminase 4 (PAD4) regulates transcription but its physiological role is unclear. Here Nakashima et al. show that PAD4 controls proliferation of multipotent haematopoietic cells by modulating c-myc expression.