Naohiro Hosomura

Role of IL-17A in Neutrophil Recruitment and Hepatic Injury after Warm Ischemia–Reperfusion Mice

Recent evidence suggests that IL-17A regulates neutrophil-dependent organ injury. Accordingly, the purpose of this study was to determine the role of IL-17A in neutrophil recruitment after ischemia–reperfusion (I/R) and in subsequent liver injury. Two mouse models including wild-type and IL-17A knockout mice were evaluated for I/R injury. The medial largest lobe of the liver was clamped for 90 min. In another set of experiments, recombinant mouse (rm)IL-17A homodimer or rmIL-17A/F heterodimer were administered to knockout mice before I/R, and liver injury was investigated. Isolated Kupffer cells were incubated with rmIL-17A or rmIL-17F, and production of TNF-α was measured. Studies evaluating the extent of liver injury as measured by serum transaminase levels demonstrated similar levels in the acute phase (6 h) in these two models. In contrast, in the subacute phase (20 h) after I/R, both serum transaminase levels and percent of hepatic necrosis were significantly reduced in the knockout mice compared with the wild-type mice. This reduction in liver injury seen in the knockout mice was associated with suppression of chemokine and adhesion molecule expression and reduction in infiltration of neutrophils into the liver. Administration of rmIL-17A homodimer, but not IL-17A/F heterodimer, increased liver injury in the subacute phase of I/R in KO mice. TNF-α production by isolated Kupffer cells increased significantly in the cells incubated with rmIL-17A compared with rmIL-17F. These results indicate that IL-17A is a key regulator in initiating neutrophil-induced inflammatory responses and hepatic injury in the subacute phase after reperfusion.

HCV-related proteins activate Kupffer cells isolated from human liver tissues.

PurposeIt was reported from this laboratory that Kupffer cells (KCs) were activated in patients infected with HCV. Since dendritic cells, monocytes, and macrophages were activated by stimulation with HCV-related proteins, the specific aim of this study was to investigate the role of HCV-related proteins in activation of KCs, the signal pathway of activation of KCs mediated by Toll-like receptor (TLR) 4, and the influence of HCV infection on function of KCs.MethodsKupffer cells isolated from non-cancerous surgical specimen were co-cultured with HCV-related proteins (Core, NS3, NS4, and NS5), and production of cytokines (TNF-α, IL-1β, and IL-10) and hydrogen peroxide were assessed. Furthermore, effects of neutralization antibodies against the TLR2, TLR3, or TLR4, and cytochalasin B on the production TNF-α by KCs were investigated.ResultsKupffer cells produced markedly a proinflammatory cytokine TNF-α by stimulation with all HCV-related proteins studied, and values were as same as production by KCs stimulated with LPS. Importantly, this production in the case of NS3 was significantly blunted by about 60% by neutralization antibodies against the TLR4, but not cytochalasin B. Production of TNF-α by isolated KCs stimulated with LPS was significantly greater in the HCV-infected livers than the HCV/HBV-negative livers.ConclusionsThese results indicated that HCV-related proteins may cause prolonged activation of KCs in the HCV-infected liver, leading to accumulation of inflammatory cytokines that contribute to DNA damage and carcinogenesis. Furthermore, function of KCs was difference between patients infected with and without HCV infection.

Medium-chain triglycerides enhance mucous secretion and cell proliferation in the rat

BackgroundThe specific purpose of this study was to investigate the effects of medium-chain triglycerides (MCTs) on intestinal cell proliferation and mucous secretion of the small intestine in the rat.MethodsRats were fed chow diet and given MCTs or the same weight of corn oil (5 g/kg per day) by gavage daily for 2 weeks, and then tissue samples of the small intestines were harvested. Leptin concentration in the small intestine was measured. Cell proliferation and apoptosis in the small intestine was determined by immunohistochemistry. Diamine oxidase (DAO) activity was measured by colorimetric assay.ResultsIn rats fed only chow diet (normal rats), the number of goblet cells per villi was 14.2 ± 0.75 in the jejunum and 15.2 ± 1.12 in the ileum. The number of goblet cells increased significantly in rats given MCTs compared with rats given corn oil or normal rats. Ki-67-positive cells were detected on the entire villi and the crypts in the small intestine. Furthermore, the proliferative index and the apoptotic index were also significantly greater in rats given MCTs than rats given corn oil or normal rats. Moreover, DAO activity and leptin concentration in the small intestine were significantly greater in rats given MCTs than rats given corn oil or normal rats.ConclusionsMCTs enhance cell proliferation of the intestinal epithelium and mucous secretion from goblet cells in the small intestine. These effects may protect the gut in patients suffering from inflammatory bowel disease or enterogenous infection.

The Kupffer Cell Inhibition Exacerbates but Splenectomy Prevents Mortality in a Rat Septic Peritonitis Model

OBJECTIVE The purpose of this study was to investigate whether inhibition of Kupffer cells (KCs) affects the expression of high mobility group box 1 (HMGB1) and mortality in septic peritonitis. The role of the spleen in septic peritonitis was also investigated. METHODS Rats were given liposome-entrapped dichloromethylene diphosphonate (lipo-MDP) to eliminate KCs or non-entrapped liposome (lipo) before cecal ligation and puncture (CLP), and serum HMGB1 levels and mortality were assessed after CLP. Furthermore, KCs and tissue macrophages were isolated, and production of HMGB1 was investigated. Effects of splenectomy on serum HMGB1 levels and mortality were also investigated after CLP. RESULTS Elimination of the Kupffer cells by lipo-MDP increased serum HMGB1 concentrations and mortality significantly. Furthermore, HMGB1 expression in both the periportal area of the liver and the spleen was greater in the lipo-MDP group than the lipo group. On the other hand, splenectomy blunted serum HMGB1 levels and improved mortality after CLP. The HMGB1 expression was greater in the spleen compared with the liver after CLP. Furthermore, production of HMGB1 was greatest in splenic macrophages in vitro. The number of ED3-positive cells increased significantly in non-splenectomized animals but not in splenectomized animals after CLP. In the lipo-MDP treated groups, the number of ED3-positive macrophages also increased in the liver from non-splenectomized animals but not in the splenectomized animals after CLP. CONCLUSIONS The liver and the spleen play key roles in host defense during septic peritonitis. Migrating macrophages into the liver are, in part, derived from the spleen after CLP.

Inhibition of the Kupffer Cell and Neutralization of IL-10 Increase the Expression of Chemokines in the Lung in a Rat Peritonitis Model

BACKGROUND Elimination of Kupffer cells (KCs) exacerbated acute lung injury and mortality by inhibiting serum interleukin (IL)-10 levels in a rat peritonitis model. Since infiltrating inflammatory cells play a pivotal role in organ injury, the specific purpose of this study was to determine whether elimination of the KC and systemic IL-10 affect the expression of inflammatory mediators and the number of infiltrating inflammatory cells in the lung in the peritonitis model. MATERIALS AND METHODS Rats were given saline or gadolinium chloride (GdCl(3)), a KC toxicant, 24 h before cecal ligation and puncture (CLP). Tissue and serum samples were harvested after CLP, and the expression of inflammatory mediators was investigated. In another set of experiments, anti-rat IL-10 antibodies (anti-IL-10 Abs) were injected immediately after CLP to investigate the effects of immunoneutralization of endogenous IL-10. RESULTS Serum levels of proinflammatory cytokines and chemokines were significantly greater in the GdCl(3) group than the control group after CLP. Furthermore, expression inflammatory mediators, as well as the number of infiltrating inflammatory cells in the lung were significantly greater in the GdCl(3) group than the control group. Alternatively, serum levels of inflammatory cytokines and chemokines, and the number of infiltrating inflammatory cells into the lung also increased significantly in rats treated with anti-IL-10 Abs compared with IgG after CLP. CONCLUSIONS Thus, depletion of KCs and neutralization of IL-10 increased the expression of chemokines and the number of infiltrating inflammatory cells in the lung, leading to exacerbated acute lung injury in sepsis.

Role of Macrophage Colony-Stimulating Factor in Polymicrobial Sepsis According to Studies Using Osteopetrotic (op/op) Mice

BACKGROUND The specific purpose of this study was to investigate the role of macrophage colony-stimulating factor (M-CSF)-induced macrophages in mouse polymicrobial sepsis model. MATERIALS AND METHODS M-CSF deficient (op/op) mice and their littermate mice w ere subjected the cecal ligation and puncture (CLP). Survival was assessed for the following 7 d after the CLP operation, and histopathologic findings were evaluated 12h after CLP. After CLP, expression of inflammatory mediators in serum was assessed by enzyme immunosorbent assay (ELISA). Furthermore, isolated peritoneal macrophages were stimulated with lipopolysaccharide (LPS) (10μg/mL) for 4h, and cytokine concentration in the supernatant was then measured by ELISA. Moreover, phagocytosis of isolated macrophages was assessed using fluorescent rates beads. In another set of experiments, effects of neutralization antibodies against high mobility group box 1 (HMGB1) were investigated in CLP model. RESULTS Mortality was increased in op/op mice compared with op/? mice after CLP. Furthermore, serum HMGB1 levels were also significantly greater in op/op mice than op/? mice. Production of HMGB1 by isolated peritoneal macrophages was significantly greater in op/op mice than op/? mice. Furthermore, the phagocytosis index was significantly blunted in op/op mice compared with op/? mice. Importantly, treatment with neutralization antibodies against HMGB1 markedly prevented acute lung injury and mortality in op/op mice. CONCLUSION Matured macrophages by M-CSF play pivotal role by scavenging endotoxin in inflammation. Furthermore, HMGB1 is involved in pathophysiology in polymicrobial sepsis, consistent with previous reports.

Dietary medium-chain triglycerides prevent chemically induced experimental colitis in rats

The effects of dietary medium-chain triglycerides (MCTs) on experimental colitis induced by 2,4,6-trinitrobenzene sulphonic acid (TNBS) were investigated in rats. Male Wistar rats were given an intracolonic injection of TNBS and were then fed liquid diets containing MCTs or corn oil (AIN93) as controls. Serum and tissue samples were collected 1 week after TNBS enema. The severity of colitis was evaluated pathologically, and tissue myeloperoxidase (MPO) activity was measured. Furthermore, messenger RNA (mRNA) and protein levels for inflammatory cytokines and a chemokine were assessed by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. In another set of experiments, the protein expression of Toll-like receptor (TLR)-4 in the colon was measured 1 week after feeding of liquid diets. To investigate the effects of MCTs on macrophages, RAW246.7 macrophages were incubated with media containing albumin conjugated with MCT or linoleic acid, which is the major component of corn oil. Then, the production of tumor necrosis factor-alpha (TNF-alpha) was measured. Dietary MCTs blunted significantly the protein levels of TLR-4 in the colon. Furthermore, the expression of TLR-4 was significantly blunted in RAW264.7 cells incubated with MCTs compared with cells incubated with linoleic acid. Induction of interleukin 1beta (IL-1beta), TNF-alpha, and macrophage inflammatory protein-2 (MIP-2) in the colon was attenuated by dietary MCT. Furthermore, MPO activities in the colonic tissue were significantly blunted in animals fed the MCT diets compared with those fed the control diets. As a result, dietary MCTs improved chemically induced colitis significantly. MCTs most likely are useful for the therapy of inflammatory bowel disease as an anti-inflammatory immunomodulating nutrient.

Non‐occlusive mesenteric ischemia after chemotherapy for metastatic melanoma

genetic test and performed a mutation analysis of the NF1 gene. Total RNA was extracted from the peripheral blood and constitutional DNA was synthesized using reverse transcription polymerase chain reaction (PCR). The PCR product was directly sequenced and the base sequence compared against records stored in GenBank (NC_000017.10, NM_000267.3) using GENETYX version 11 software (GENETYX, Tokyo, Japan). The deletion of c.7808_8053del was identified in exon 54 to exon 56, suggesting that this deletion caused truncated neurofibromin molecules due to an in-frame deletion. (Fig. 1b). Only six cases of non-segmental, late-onset NF1, including our patient, have been reported. The onset of the pigment spots and neurofibromas in all of the reported cases occurred in the third decade of life or later, and there was no family history. Most of these cases revealedmild symptomswithout Lisch nodules. Mosaicism may be responsible for the late onset of hereditary diseases. Mosaicism is defined as the presence of two or more populations of cells with different genotypes in one individual. An example of typical mosaicism is segmental NF1, which is caused by a postzygotic mutation of NF1. Later, somatic mutations may cause localized diseases such as the segmental form, while early somatic mutations may give rise to a generalized cutaneous form. A generalized form of mosaicism has been reported to present generalized but milder manifestations such as fewer neurofibromas and/or pigment spots. Other possible causes of mild manifestations may include the benign nature of a leaky NF1-splice mutation. A specific, small mutation, a 3-bp in-frame deletion in exon 17 of the NF1 gene, has been identified in a milder phenotype of NF1. Later onset of the cutaneous manifestations and the absence of ophthalmologic manifestations may arise from mosaicism or specific, small mutations, though we were unable to confirm the presence of them in our case.

Macrophage colony-stimulating factor expressed in non-cancer tissues provides predictive powers for recurrence in hepatocellular carcinoma

AIM To investigate the role of macrophage colony-stimulating factor (M-CSF) in patients with hepatocellular carcinoma (HCC) after surgery. METHODS Expression of M-CSF, distribution of M2 macrophages (MΦs), and angiogenesis were assessed in the liver, including tumors and peritumoral liver tissues. The prognostic power of these factors was assessed. Mouse isolated hepatic MΦs or monocytes were cultured with media containing M-CSF. The concentration of vascular endothelial growth factor (VEGF) in media was assessed. Furthermore, the role of the M-CSF-matured hepatic MΦs on proliferation of the vascular endothelial cell (VEC) was investigated. RESULTS A strong correlation between the expressions of M-CSF and CD163 was observed in the peritumoral area. Also, groups with high density of M-CSF, CD163 or CD31 showed a significantly shorter time to recurrence (TTR) than low density groups. Multivariate analysis revealed the expression of M-CSF or hepatic M2MΦs in the peritumoral area as the most crucial factor responsible for shorter TTR. Moreover, the expression of M-CSF and hepatic M2MΦs in the peritumoral area had better predictable power of overall survival. Values of VEGF in culture media were significantly greater in the hepatic MΦs compared with the monocytes. Proliferation of the VEC was greatest in the cells co-cultured with hepatic MΦs when M-CSF was present in media. CONCLUSION M-CSF increases hepatocarcinogenesis, most likely by enhancing an angiogenic factor derived from hepatic MΦ and could be a useful target for therapy against HCC.

miR-122-5p as a novel biomarker for alpha-fetoprotein-producing gastric cancer

AIM To investigate the clinical utility of alpha-fetoprotein (AFP)-producing gastric cancer (AFPGC)-specific microRNA (miRNA) for monitoring and prognostic prediction of patients. METHODS We performed a comprehensive miRNA array-based approach to compare miRNA expression levels between AFP-positive and AFP-negative cells in three patients with primary AFPGC. We next examined the expression levels of the selected miRNAs in five AFPGC and ten non-AFPGC tissue samples by quantitative reverse transcription-polymerase chain reaction to validate their utility. We also investigated the expression levels of the selected miRNA not only in tissue but also in plasma samples. Moreover, we investigated the relationship between plasma AFP levels and plasma selected miRNA expression levels, and also investigated the correlation of the selected miRNA expression levels and malignant potential. RESULTS Among the five miRNAs selected from the miRNA array results, the expression levels of miR-122-5p were significantly higher in the AFPGC patients than in the non-AFPGC patients (P < 0.05). In tissue samples, miR-122-5p expression level tended to be lower in the non-AFPGC tissue than the normal gastric mucosa. Conversely, in the AFPGC tissue, miR-122-5p expression level was significantly higher in the AFPGC tissue than both the normal gastric mucosa and the non-AFPGC tissue samples (P < 0.05). Plasma miR-122-5p expression levels were also significantly higher in the AFPGC patients than the health volunteers and the non-AFPGC patients (P < 0.05) and were strongly correlated with plasma AFP levels (r = 0.7975, P < 0.0001). Moreover, the correlation of miR-122-5p expression in tissue samples with malignant potential was stronger than that of plasma AFP level in the AFPGC patients. In contrast, no correlation was found between miR-122-5p expression levels and liver metastasis in the non-AFPGC patients. CONCLUSION miR-122-5p might be a useful biomarker for early detection and disease monitoring in AFPGC.