A Novel Mouse Model of Nonalcoholic Steatohepatitis Suggests that Liver Fibrosis Initiates around Lipid-Laden Macrophages.

While the interaction of cells such as macrophages and hepatic stellate cells is known to be involved in the generation of fibrosis in nonalcoholic steatohepatitis (NASH), the mechanism remains unclear. This study employed a high-fat/cholesterol/cholate (HFCC) diet to generate a model of NASH-related fibrosis to investigate the pathogenesis of fibrosis. Two mouse strains: C57BL/6J, the one susceptible to obesity, and A/J, the one relatively resistant to obesity, developed hepatic histologic features of NASH, including fat deposition, intralobular inflammation, hepatocyte ballooning, and fibrosis, after 9 weeks of HFCC diet. The severity of hepatic inflammation and fibrosis was greater in A/J mice than in the C57BL/6J mice. A/J mice fed HFCC diet exhibited characteristic CD204-positive lipid-laden macrophage aggregation in hepatic parenchyma. Polarized light was used to visualize the Maltese cross, cholesterol crystals within the aggregated macrophages. Fibrosis developed in a ring shape from the periphery of the aggregated macrophages such that the starting point of fibrosis could be visualized histologically. Matrix-assisted laser desorption/ionization mass spectrometry imaging analysis detected a molecule at m/z 772.462, which corresponds to the protonated ion of phosphatidylcholine [P-18:1 (11Z)/18:0] and phosphatidylethanolamine [18:0/20:2 (11Z, 14Z)], in aggregated macrophages adjacent to the fibrotic lesions. In conclusion, the HFCC diet-fed A/J model provides an ideal tool to study fibrogenesis and enables novel insights into the pathophysiology of NASH-related fibrosis.

A polo-like kinase inhibitor identified by computational repositioning attenuates pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal fibrotic lung disease with few effective therapeutic options. Recently, drug repositioning, which involves identifying novel therapeutic potentials for existing drugs, has been popularized as a new approach for the development of novel therapeutic reagents. However, this approach has not yet been fully utilized in the field of pulmonary fibrosis. METHODS: The present study identified novel therapeutic options for pulmonary fibrosis using a systematic computational approach for drug repositioning based on integration of public gene expression signatures of drug and diseases (in silico screening approach). RESULTS: Among the top compounds predicted to be therapeutic for IPF by the in silico approach, we selected BI2536, a polo-like kinase (PLK) 1/2 inhibitor, as a candidate for treating pulmonary fibrosis using an in silico analysis. However, BI2536 accelerated mortality and weight loss rate in an experimental mouse model of pulmonary fibrosis. Because immunofluorescence staining revealed that PLK1 expression was dominant in myofibroblasts while PLK2 expression was dominant in lung epithelial cells, we next focused on the anti-fibrotic effect of the selective PLK1 inhibitor GSK461364. Consequently, GSK461364 attenuated pulmonary fibrosis with acceptable mortality and weight loss in mice. CONCLUSIONS: These findings suggest that targeting PLK1 may be a novel therapeutic approach for pulmonary fibrosis by inhibiting lung fibroblast proliferation without affecting lung epithelial cells. In addition, while in silico screening is useful, it is essential to fully determine the biological activities of candidates by wet-lab validation studies.

Spontaneous Occurrence of Various Types of Hepatocellular Adenoma in the Livers of Metabolic Syndrome-Associated Steatohepatitis Model TSOD Mice.

Male Tsumura-Suzuki Obese Diabetes (TSOD) mice, a spontaneous metabolic syndrome model, develop non-alcoholic steatohepatitis and liver tumors by feeding on a standard mouse diet. Nearly 70% of liver tumors express glutamine synthetase (GS), a marker of hepatocellular carcinoma. In contrast, approximately 30% are GS-negative without prominent nuclear or structural atypia. In this study, we examined the characteristics of the GS-negative tumors of TSOD mice. Twenty male TSOD mice were sacrificed at 40 weeks and a total of 21 tumors were analyzed by HE staining and immunostaining of GS, liver fatty acid-binding protein (L-FABP), serum amyloid A (SAA), and beta-catenin. With immunostaining for GS, six (29%) tumors were negative. Based on the histological and immunohistological characteristics, six GS-negative tumors were classified into several subtypes of human hepatocellular adenoma (HCA). One large tumor showed generally similar findings to inflammatory HCA, but contained small atypical foci with GS staining and partial nuclear beta-catenin expression suggesting malignant transformation. GS-negative tumors of TSOD mice contained features similar to various subtypes of HCA. Different HCA subtypes occurring in the same liver have been reported in humans; however, the diversity of patient backgrounds limits the ability to conduct a detailed, multifaceted analysis. TSOD mice may share similar mechanisms of HCA development as in humans. It is timely to review the pathogenesis of HCA from both genetic and environmental perspectives, and it is expected that TSOD mice will make further contributions in this regard.

Singlet oxygen -derived nerve growth factor exacerbates airway hyperresponsiveness in a mouse model of asthma with mixed inflammation.

BACKGROUND: Refractory asthma, which is caused by several factors including neutrophil infiltration is a serious complication of bronchial asthma. We previously reported that nerve growth factor (NGF) is involved in AHR. NGF-derived induction of hyperalgesia is dependent on neutrophils; however, this relationship remains unclear in respiratory disease. In this study, we examined the roles of neutrophils and NGF in refractory asthma. METHODS: Using intranasal house dust mite sensitization, we established a mouse model of asthma with mixed inflammation (Mix-in). AHR, NGF production and hyperinnervation of the lungs were examined with or without different inhibitory treatments. The levels of the singlet oxygen markers, 10- and 12-(Z,E)-hydroxyoctadecadienoic acids (HODE) in the lungs, were measured by liquid chromatography-tandem mass spectrometry. An in vitro experiment was also performed to evaluate the direct effect of singlet oxygen on NGF production. RESULTS: NGF production and hyperinnervation were higher in Mix-in mice than in conventional eosinophilic-asthmatic mice and were positively correlated with AHR. Asthmatic parameters were inhibited by NGF neutralizing Abs and myeloperoxidase (MPO) inhibition. The 10- and 12-(Z,E)-HODEs levels were increased in the lungs and were positively correlated with MPO activity and NGF production. NGF was produced by bronchial epithelial cells in vitro upon stimulation with singlet oxygen. CONCLUSIONS: Our findings suggest that neutrophil MPO-derived singlet oxygen induces increased NGF production, leading to AHR and 10- and 12-(Z,E)-HODEs production. These findings may help to develop new therapies targeting this mechanism and to establish a new biomarker for non-type 2 and refractory asthma.

Lysophosphatidic Acid Regulates the Differentiation of Th2 Cells and Its Antagonist Suppresses Allergic Airway Inflammation.

BACKGROUND: Lysophosphatidic acid (LPA), a prototypic member of a large family of lysophospholipids, has been recently shown to play a role in immune responses to respiratory diseases. The involvement of LPA in allergic airway inflammation has been reported, but the mechanism remains unclear. OBJECT: We analyzed the biological activity of LPA in vitro and in vivo and investigated its role in allergic inflammation in mice using an LPA receptor 2 (LPA2) antagonist. METHODS: We used a murine model with acute allergic inflammation, in which mice are sensitized and challenged with house dust mite, and analyzed airway hyperresponsiveness (AHR), pathological findings, Th2 cytokines, and IL-33 in bronchoalveolar lavage fluid (BALF) and lung homogenates. The effect of LPA on Th2 differentiation and cytokine production was examined in vitro using naive CD4+ T cells isolated from splenocytes. We also investigated in vivo the effects of LPA on intranasal administration in mice. RESULTS: The LPA2 antagonist suppressed the increase of AHR, the number of total cells, and eosinophils in BALF and lung tissue. It also decreased the production of IL-13 in BALF and IL-33 and CCL2 in the lung. LPA promoted Th2 cell differentiation and IL-13 production by Th2 cells in vitro. Nasal administration of LPA significantly increased the number of total cells and IL-13 in BALF via regulating the production of IL-33 and CCL-2-derived infiltrating macrophages. CONCLUSION: These findings suggest that LPA plays an important role in allergic airway inflammation and that the blockade of LPA2 might have therapeutic potential for bronchial asthma.

A RAS inhibitor reduces allergic airway remodeling via regulating IL-33-derived type 2 innate lymphoid cells.

Purpose: IL-33 is known to induce corticosteroid-resistant eosinophilic inflammation and airway remodeling by activating type 2 innate lymphoid cells (ILC2s). Although the RAS signal pathway plays an important role in IL-33-induced ILC2s activation and airway remodeling, it is not known if RAS inhibitors are effective against refractory asthma. We examined the effects of the RAS inhibitor XRP44X in refractory asthma. Methods: RAS activity were examined by BAL fluid and T-cells isolated from spleen cells in Dermatophagoides pteronyssinus (Dp)-sensitized/challenged acute allergic airway inflammation model. A chronic allergic airway inflammation mouse model was generated by challenged with Dp. XRP44X and/or fluticasone were administrated nasally to different experimental groups. The effects of nasal simultaneous administration of XRP44X or fluticasone were assessed in mice administrated with IL-33 or Dp. Results: RAS activity in CD4+ T cells stimulated by Dp were suppressed by XRP44X. Although fluticasone and XRP44X only improved allergic airway inflammation in mice, XRP44X in combination with fluticasone produced further improvement in not only eosinophilic inflammation but also bronchial subepithelial thickness. XRP44X suppressed IL-5 and IL-13 production from ILC2s, although this effect was not suppressed by fluticasone. IL-33-induced airway inflammation resistant to fluticasone was ameliorated by XRP44X via regulating the accumulation of lung ILC2s. Conclusion: The RAS signal pathway plays a crucial role in allergen-induced airway remodeling associated with ILC2s. XRP44X may have therapeutic potential for refractory asthma.

Verification of the Impact of Blood Glucose Level on Liver Carcinogenesis and the Efficacy of a Dietary Intervention in a Spontaneous Metabolic Syndrome Model.

Metabolic syndrome (MS) is a risk factor for type 2 diabetes mellitus, vascular inflammation, atherosclerosis, and renal, liver, and heart diseases. Non-alcoholic steatohepatitis (NASH) is a progressive representative liver disease and may lead to the irreversible calamities of cirrhosis and hepatocellular carcinoma. Metabolic disorders such as hyperglycemia have been broadly reported to be related to hepatocarcinogenesis in NASH; however, direct evidence of a link between hyperglycemia and carcinogenesis is still lacking. Tsumura Suzuki Obese Diabetic (TSOD) mice spontaneously develop metabolic syndrome, including obesity, insulin resistance, and NASH-like liver phenotype, and eventually develop hepatocellular carcinomas. TSOD mice provide a spontaneous human MS-like model, even with significant individual variations. In this study, we monitored mice in terms of their changes in blood glucose levels, body weights, and pancreatic and liver lesions over time. As a result, liver carcinogenesis was delayed in non-hyperglycemic TSOD mice compared to hyperglycemic mice. Moreover, at the termination point of 40 weeks, liver tumors appeared in 18 of 24 (75%) hyperglycemic TSOD mice; in contrast, they only appeared in 5 of 24 (20.8%) non-hyperglycemic mice. Next, we investigated three kinds of oligosaccharide that could lower blood glucose levels in hyperglycemic TSOD mice. We monitored the levels of blood and urinary glucose and assessed pancreatic lesions among the experimental groups. As expected, significantly lower levels of blood and urinary glucose and smaller deletions of Langerhans cells were found in TSOD mice fed with milk-derived oligosaccharides (galactooligosaccharides and lactosucrose). At the age of 24 weeks, mild steatohepatitis was found in the liver but there was no evidence of liver carcinogenesis. Steatosis in the liver was alleviated in the milk-derived oligosaccharide-administered group. Taken together, suppressing the increase in blood glucose level from a young age prevented susceptible individuals from diabetes and the onset of NAFLD/NASH, as well as carcinogenesis. Milk-derived oligosaccharides showed a lowering effect on blood glucose levels, which may be expected to prevent liver carcinogenesis.

Blockade of Pan-Fibroblast Growth Factor Receptors Mediates Bidirectional Effects in Lung Fibrosis.

FGFs (fibroblast growth factors) are major factors associated with the pathogenesis of pulmonary fibrosis. On the one hand, nintedanib, a tyrosine kinase inhibitor targeting several growth factor receptors, including the FGF receptor (FGFR), has been approved for the treatment of idiopathic pulmonary fibrosis. On the other hand, recent reports suggest that FGFs are required for epithelial recovery. In this study, we focused on FGF signaling to both fibroblasts and alveolar epithelial cells (AECs), and we examined the effect of a pan-FGFR blocker on experimental pulmonary fibrosis in mice. The effects of BGJ398, a pan-FGFR inhibitor, on the migration and proliferation of fibroblasts and AECs were assessed using Transwell migration or [3H]thymidine incorporation assays. The expression of FGFR was analyzed using IB or flow cytometry. We also investigated the effect of BGJ398 on pulmonary fibrosis induced by bleomycin in mice. Both lung fibroblasts and AECs expressed FGFRs. BGJ398 significantly inhibited the proliferation and migration of lung fibroblasts stimulated with FGF2. BGJ398 also reduced the proliferation of AECs in response to FGF2. Although the administration of BGJ398 ameliorated pulmonary fibrosis in bleomycin-treated mice, it increased mortality resulting from alveolar injury and inhibition of AEC regeneration. These data suggest that the total inhibition of FGFR signaling can suppress lung fibrosis by inhibiting fibroblast activities, although alveolar injury is simultaneously caused.

The Tyrosine Kinase Inhibitor TAS-115 Attenuates Bleomycin-induced Lung Fibrosis in Mice.

The signaling pathways of growth factors, including platelet-derived growth factor, can be considered specific targets for overcoming the poor prognosis of idiopathic pulmonary fibrosis. Nintedanib, the recently approved multiple kinase inhibitor, has shown promising antifibrotic effects in patients with idiopathic pulmonary fibrosis; however, its efficacy is still limited, and in some cases, treatment discontinuation is necessary owing to toxicities such as gastrointestinal disorders. Therefore, more effective agents with less toxicity are still needed. TAS-115 is a novel multiple tyrosine kinase inhibitor that preferably targets platelet-derived growth factor receptor (PDGFR), vascular endothelial growth factor receptor, and c-FMS in addition to other molecules. In this study, we evaluated the antifibrotic effect of TAS-115 on pulmonary fibrosis in vitro and in vivo. TAS-115 inhibited the phosphorylation of PDGFR on human lung fibroblast cell line MRC-5 cells and suppressed their platelet-derived growth factor-induced proliferation and migration. Furthermore, TAS-115 inhibited the phosphorylation of c-FMS, a receptor of macrophage colony-stimulating factor, in murine bone marrow-derived macrophages and decreased the production of CCL2, another key molecule for inducing pulmonary fibrosis, under the stimulation of macrophage colony-stimulating factor. Importantly, the inhibitory effects of TAS-115 on both PDGFR and c-FMS were 3- to 10-fold higher than those of nintedanib. In a mouse model of bleomycin-induced pulmonary fibrosis, TAS-115 significantly inhibited the development of pulmonary fibrosis and the collagen deposition in bleomycin-treated lungs. These data suggest that strong inhibition of PDGFR and c-FMS by TAS-115 may be a promising strategy for overcoming the intractable pathogenesis of pulmonary fibrosis.

The novel inhibitor PRI-724 for Wnt/ß-catenin/CBP signaling ameliorates bleomycin-induced pulmonary fibrosis in mice.

Purpose/Aim of the Study: Wnt/ß-catenin signaling was reported to be activated in pulmonary fibrosis, and was focused on as a target for antifibrotic therapy. However, the mechanism how the inhibition of Wnt/ß-catenin signaling ameliorate pulmonary fibrosis has not been fully elucidated. The purpose of this study is to explore the target cells of Wnt/ß-catenin inhibition in pulmonary fibrosis and to examine the antifibrotic effect of the novel inhibitor PRI-724 specifically disrupting the interaction of ß-catenin and CBP. Materials and Methods: The effect of C-82, an active metabolite of PRI-724, on the expression of TGF-ß1 and α-smooth muscle actin (SMA) was examined on fibroblasts and macrophages. We also examined the effects of PRI-724 in mouse model of bleomycin-induced pulmonary fibrosis. Results: The activation and increased accumulation of ß-catenin in the canonical pathway were detected in lung fibroblasts as well as macrophages stimulated by Wnt3a using Western blotting. Treatment with C-82 reduced CBP protein and increased p300 protein binding to ß-catenin in the nucleus of lung fibroblasts. In addition, C-82 inhibited the expression of SMA in lung fibroblasts treated with TGF-ß, indicating the inhibition of myofibroblast differentiation. In the fibrotic lungs induced by bleomycin, ß-catenin was stained strongly in macrophages, but the staining of ß-catenin in alveolar epithelial cells and fibroblasts was weak. The administration of PRI-724 ameliorated pulmonary fibrosis induced by bleomycin in mice when administered with a late, but not an early, treatment schedule. Analysis of bronchoalveolar fluid (BALF) showed a decreased number of alveolar macrophages. In addition, the level of TGF-ß1 in BALF was decreased in mice treated with PRI-724. C-82 also inhibited the production of TGF-ß1 by alveolar macrophages. Conclusions: These results suggest that the ß-catenin/CBP inhibitor PRI-724 is a potent antifibrotic agent that acts by modulating the activity of macrophages in the lungs.

Neutrophils induce smooth muscle hyperplasia via neutrophil elastase-induced FGF-2 in a mouse model of asthma with mixed inflammation.

BACKGROUND: Bronchial asthma is traditionally characterized by chronic allergic inflammation, including eosinophilia and elevated Th2 cytokines. Recently, IL-17-derived neutrophil infiltration was shown to correlate with asthma severity and airway remodelling. OBJECTIVE: To investigate the role of IL-17-derived neutrophils in airway remodelling in chronic bronchial asthma. METHODS: We utilized house dust mite antigen-induced mouse models of asthma. Intranasal sensitization and chronic antigen challenge caused a mixed allergic inflammation that included eosinophils and neutrophils (Mix-in group). We neutralized IL-17 and fibroblast growth factor (FGF-2) and investigated the mechanism of airway remodelling in the Mix-in group. RESULTS: The Mix-in group displayed neutrophilic infiltration and high levels of IL-17 in lung tissue. The Mix-in group also exhibited more bronchial smooth muscle hyperplasia. IL-17 neutralization decreased the magnitude of all of these effects in the Mix-in group. Antibody arrays revealed an increase in FGF-2 in the Mix-in Group relative to the Eo-ip group, and FGF-2 elevation was associated with smooth muscle hypertrophy/hyperplasia. High concentrations of neutrophil elastase enhanced E-cadherin/ß-catenin signalling in bronchial epithelial cells. Neutrophil elastase inhibitor treatment decreased FGF-2 production and E-cadherin/ß-catenin signalling, which inhibited smooth muscle hyperplasia. CONCLUSION: The IL-17/neutrophil axis may play an important role in airway remodelling by contributing to smooth muscle hypertrophy/hyperplasia in mixed allergic inflammation and accordingly represents an attractive therapeutic target for severe asthma.

Anti-fibrotic efficacy of nintedanib in pulmonary fibrosis via the inhibition of fibrocyte activity.

BACKGROUND: Nintedanib, a tyrosine kinase inhibitor that is specific for platelet-derived growth factor receptors (PDGFR), fibroblast growth factor receptors (FGFR), and vascular endothelial growth factor receptors (VEGFR), has recently been approved for idiopathic pulmonary fibrosis. Fibrocytes are bone marrow-derived progenitor cells that produce growth factors and contribute to fibrogenesis in the lungs. However, the effects of nintedanib on the functions of fibrocytes remain unclear. METHODS: Human monocytes were isolated from the peripheral blood of healthy volunteers. The expression of growth factors and their receptors in fibrocytes was analyzed using ELISA and Western blotting. The effects of nintedanib on the ability of fibrocytes to stimulate lung fibroblasts were examined in terms of their proliferation. The direct effects of nintedanib on the differentiation and migration of fibrocytes were also assessed. We investigated whether nintedanib affected the accumulation of fibrocytes in mouse lungs treated with bleomycin. RESULTS: Human fibrocytes produced PDGF, FGF2, and VEGF-A. Nintedanib and specific inhibitors for each growth factor receptor significantly inhibited the proliferation of lung fibroblasts stimulated by the supernatant of fibrocytes. Nintedanib inhibited the migration and differentiation of fibrocytes induced by growth factors in vitro. The number of fibrocytes in the bleomycin-induced lung fibrosis model was reduced by the administration of nintedanib, and this was associated with anti-fibrotic effects. CONCLUSIONS: These results support the role of fibrocytes as producers of and responders to growth factors, and suggest that the anti-fibrotic effects of nintedanib are at least partly mediated by suppression of fibrocyte function.

Animal models for analyzing metabolic syndrome-associated liver diseases.

Metabolic syndrome (MS) is a worldwide healthcare issue and a dominant risk factor for the development of incurable diseases affecting the entire body. The hepatic manifestations of MS include nonalcoholic fatty liver disease (NAFLD) and its progressive variant, nonalcoholic steatohepatitis (NASH). NASH is known to progress to liver cirrhosis and hepatocellular carcinoma (HCC). Excellent animal models for determining the mechanism of pathogenesis and establishing therapeutic treatment of NASH/HCC are strongly required worldwide. We recently reported that two previously established mouse models of obesity and diabetes mellitus, namely, Tsumura-Suzuki Obese Diabetes (TSOD) mice and MSG mice, developed MS-associated NASH and that their clinical course and pathological characteristics closely mimicked those of human MS-NASH patients. Interestingly, most of the mice developed HCC with advancing age, and the pathological and functional characteristics of this condition were identical to those of human HCC. We further established a novel mouse model of HCC based on type 1 diabetes (DIAR-nSTZ mice) and reported its histopathological features. By comparing various aspects of these mouse models, specific and useful characteristics in a suitable model of MS-associated liver diseases, including hepato-carcinogenesis, can be highlighted.

Exogenous fatty acid binding protein 4 promotes human prostate cancer cell progression.

Epidemiologic studies have found that obesity is associated with malignant grade and mortality in prostate cancer. Several adipokines have been implicated as putative mediating factors between obesity and prostate cancer. Fatty acid binding protein 4 (FABP4), a member of the cytoplasmic fatty acid binding protein multigene family, was recently identified as a novel adipokine. Although FABP4 is released from adipocytes and mean circulating concentrations of FABP4 are linked with obesity, effects of exogenous FABP4 on prostate cancer progression are unclear. In this study, we examined the effects of exogenous FABP4 on human prostate cancer cell progression. FABP4 treatment promoted serum-induced prostate cancer cell invasion in vitro. Furthermore, oleic acid promoted prostate cancer cell invasion only if FABP4 was present in the medium. These promoting effects were reduced by FABP4 inhibitor, which inhibits FABP4 binding to fatty acids. Immunostaining for FABP4 showed that exogenous FABP4 was taken up into DU145 cells in three-dimensional culture. In mice, treatment with FABP4 inhibitor reduced the subcutaneous growth and lung metastasis of prostate cancer cells. Immunohistochemical analysis showed that the number of apoptotic cells, positive for cleaved caspase-3 and cleaved PARP, was increased in subcutaneous tumors of FABP4 inhibitor-treated mice, as compared with control mice. These results suggest that exogenous FABP4 might promote human prostate cancer cell progression by binding with fatty acids. Additionally, exogenous FABP4 activated the PI3K/Akt pathway, independently of binding to fatty acids. Thus, FABP4 might be a key molecule to understand the mechanisms underlying the obesity-prostate cancer progression link.

Surfactant protein D attenuates sub-epithelial fibrosis in allergic airways disease through TGF-ß.

BACKGROUND: Surfactant protein D (SP-D) can regulate both innate and adaptive immunity. Recently, SP-D has been shown to contribute to the pathogenesis of airway allergic inflammation and bleomycin-induced pulmonary fibrosis. However, in allergic airways disease, the role of SP-D in airway remodeling remains unknown. The objective of this study was to determine the contribution of functional SP-D in regulating sub-epithelial fibrosis in a mouse chronic house dust mite model of allergic airways disease. METHODS: C57BL/6 wild-type (WT) and SP-D-/- mice (C57BL/6 background) were chronically challenged with house dust mite antigen (Dermatophagoides pteronyssinus, Dp). Studies with SP-D rescue and neutralization of TGF-ß were conducted. Lung histopathology and the concentrations of collagen, growth factors, and cytokines present in the airspace and lung tissue were determined. Cultured eosinophils were stimulated by Dp in presence or absence of SP-D. RESULTS: Dp-challenged SP-D-/- mice demonstrate increased sub-epithelial fibrosis, collagen production, eosinophil infiltration, TGF-ß1, and IL-13 production, when compared to Dp-challenged WT mice. By immunohistology, we detected an increase in TGF-ß1 and IL-13 positive eosinophils in SP-D-/- mice. Purified eosinophils stimulated with Dp produced TGF-ß1 and IL-13, which was prevented by co-incubation with SP-D. Additionally, treatment of Dp challenged SP-D-/- mice with exogenous SP-D was able to rescue the phenotypes observed in SP-D-/- mice and neutralization of TGF-ß1 reduced sub-epithelial fibrosis in Dp-challenged SP-D-/- mice. CONCLUSION: These data support a protective role for SP-D in the pathogenesis of sub-epithelial fibrosis in a mouse model of allergic inflammation through regulation of eosinophil-derived TGF-ß.

Idiopathic pleuroparenchymal fibroelastosis is characterized by an elevated serum level of surfactant protein-D, but Not Krebs von den Lungen-6.

PURPOSE: Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a recently reported rare disease entity characterized by fibrotic thickening of the pleural and subpleural parenchyma predominantly in the upper lobes in idiopathic interstitial pneumonias (IIPs). Because the clinical features of this rare disease are not fully elucidated, we examined the clinical characteristics of IPPFE, especially for serum interstitial biomarkers, surfactant protein-D (SP-D), and Krebs von den Lungen-6 (KL-6). METHODS AND RESULTS: Four consecutive cases of IPPFE who fulfilled the diagnostic criteria were studied. All cases were more than 60 years of age, and were classified as underweight by body mass index. A severe restrictive ventilatory defect was found in all cases on admission. High-resolution computed tomography showed intense pleural thickening associated with fibrosis predominant in upper lobes. Histopathological findings were also confirmed in three out of four cases. Interestingly, the serum level of SP-D was markedly elevated in all cases, while KL-6 was within normal range in three out of four cases. As compared with major IIPs such as idiopathic pulmonary fibrosis and fibrotic nonspecific interstitial pneumonia, IPPFE significantly showed higher frequency of cases with a unique pattern of serum biomarkers, which is characterized by an elevated level of SP-D with a normal range of KL-6. CONCLUSIONS: In IPPFE, SP-D might tend to be elevated, while KL-6 was within a normal range. Further study is required to determine the pathogenesis and clinical significance of the elevated SP-D in IPPFE.

A case of pleural mesothelioma with immunohistochemical staining positive for Krebs von den Lungen-6.

A 71-year-old male visited a hospital with a chief complaint of exertional dyspnea. A chest CT revealed multiple nodular lesions on the parietal pleura. Thoracoscopic pleural biopsy was performed resulting in a diagnosis of pleural mesothelioma with epithelioid type. When chemotherapy was initially initiated, his serum level of Krebs von den Lungen-6 (KL-6) was high. However, once chemotherapy was started, the serum KL-6 level gradually decreased with tumor shrinkage. Immunohistochemical staining revealed the expression of KL-6 from the tumor cells. This is the first report of KL-6 production directly from tumor cells in epithelial-type pleural mesothelioma.

Surfactant protein-D regulates effector cell function and fibrotic lung remodeling in response to bleomycin injury.

RATIONALE: Surfactant protein (SP)-D and SP-A have been implicated in immunomodulation in the lung. It has been reported that patients with idiopathic pulmonary fibrosis (IPF) often have elevated serum levels of SP-A and SP-D, although their role in the disease is not known. OBJECTIVES: The goal of this study was to test the hypothesis that SP-D plays an important role in lung fibrosis using a mouse model of fibrosis induced by bleomycin (BLM). METHODS: Triple transgenic inducible SP-D mice (iSP-D mice), in which rat SP-D is expressed in response to doxycycline (Dox) treatment, were administered BLM (100 U/kg) or saline subcutaneously using miniosmotic pumps. MEASUREMENTS AND MAIN RESULTS: BLM-treated iSP-D mice off Dox (SP-D off) had increased lung fibrosis compared with mice on Dox (SP-D on). SP-D deficiency also increased macrophage-dominant cell infiltration and the expression of profibrotic cytokines (transforming growth factor [TGF]-ß1, platelet-derived growth factor-AA). Alveolar macrophages isolated from BLM-treated iSP-D mice off Dox (SP-D off) secreted more TGF-ß1. Fibrocytes, which are bone marrow-derived mesenchymal progenitor cells, were increased to a greater extent in the lungs of the BLM-treated iSP-D mice off Dox (SP-D off). Fibrocytes isolated from BLM-treated iSP-D mice off Dox (SP-D off) expressed more of the profibrotic cytokine TGF-ß1 and more CXCR4, a chemokine receptor that is important in fibrocyte migration into the lungs. Exogenous SP-D administered intratracheally attenuated BLM-induced lung fibrosis in SP-D(-/-) mice. CONCLUSIONS: These data suggest that alveolar SP-D regulates numbers of macrophages and fibrocytes in the lungs, profibrotic cytokine expression, and fibrotic lung remodeling in response to BLM injury.

Definitive Confirmation of Erythropoietic Protoporphyria via Re-biopsy Three Years After Initial Liver Biopsy at Age 15.

Erythropoietic protoporphyria (EPP) is a rare inherited disorder of porphyrin metabolism that can cause liver damage and cholestatic hepatocellular failure. We report a case of EPP in a teenaged male who underwent liver biopsy for investigation of liver dysfunction of unknown cause. The diagnosis was not made until a re-biopsy approximately three years later, when the patient presented with recurrent skin lesions and elevated blood and urinary protoporphyrin levels. The liver biopsies contained brownish deposits that exhibited birefringence under polarized light and porphyrin fluorescence under fluorescence spectroscopy. EPP should be considered in young patients with unexplained liver dysfunction, skin symptoms, and seasonal changes in symptoms. Fluorescence spectroscopy of liver biopsy tissue can be a useful tool in the diagnosis of EPP.

Accumulation of α-synuclein in hepatocytes in nonalcoholic steatohepatitis and its usefulness in pathological diagnosis.

BACKGROUNDS: Nonalcoholic steatohepatitis (NASH) is characterized by fat deposition, inflammation, and hepatocellular damage. The diagnosis of NASH is confirmed pathologically, and hepatocyte ballooning is an important finding for definite diagnosis. Recently, α-synuclein deposition in multiple organs was reported in Parkinson's disease. Since it was reported that α-synuclein is taken up by hepatocytes via connexin 32, the expression of α-synuclein in the liver in NASH is of interest. The accumulation of α-synuclein in the liver in NASH was investigated. Immunostaining for p62, ubiquitin, and α-synuclein was performed, and the usefulness of immunostaining in pathological diagnosis was examined. METHODS: Liver biopsy tissue specimens from 20 patients were evaluated. Several antibodies against α-synuclein, as well as antibodies against connexin 32, p62, and ubiquitin were used for immunohistochemical analyses. Staining results were evaluated by several pathologists with varying experience, and the diagnostic accuracy of ballooning was compared. RESULTS: Polyclonal α-synuclein antibody, not the monoclonal antibody, reacted with eosinophilic aggregates in ballooning cells. Expression of connexin 32 in degenerating cells was also demonstrated. Antibodies against p62 and ubiquitin also reacted with some of the ballooning cells. In the pathologists' evaluations, the highest interobserver agreement was obtained with hematoxylin and eosin (H&E)-stained slides, followed by slides immunostained for p62 and α-synuclein, and there were cases with different results between H&E staining and immunostaining CONCLUSION: These results indicate the incorporation of degenerated α-synuclein into ballooning cells, suggesting the involvement of α-synuclein in the pathogenesis of NASH. The combination of immunostaining including polyclonal α-synuclein may contribute to improving the diagnosis of NASH.