Dasatinib suppresses atherosclerotic lesions by suppressing cholesterol uptake in a mouse model of hypercholesterolemia.

Although the use of BCR-ABL1 tyrosine kinase inhibitors (TKIs) for chronic myeloid leukemia is known to cause vascular adverse events (VAEs), the frequency of VAEs during dasatinib administration is not high, and the same holds for atherosclerosis-related VAEs. However, its effect on atherosclerosis remains controversial. In this study, our primary objective was to investigate how dasatinib affects atherosclerosis. Ldlr-/-/Apobec1-/- mice, which are highly prone to develop atherosclerosis, were administered dasatinib. After 16 weeks, we evaluated their atherosclerotic lesions. We used bone-marrow-derived macrophages to investigate the uptake of oxidized low-density lipoprotein (LDL) complexed with DiI dye (DiI-oxLDL). RNA sequencing and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were performed to explore the potential effects of dasatinib on cholesterol metabolism. Dasatinib administration significantly reduced atherosclerotic lesions (P < 0.001 and P = 0.013) and DiI-oxLDL uptake (P < 0.001) unlike other TKIs. RNA sequencing and RT-qPCR suggested that Sort1, which encodes sortilin, a known regulator of LDL uptake, and Cd36 were potential targets of dasatinib. In conclusion, dasatinib induced elevated LDL-C levels, but oxLDL uptake in macrophages were suppressed, resulting in reducing atherosclerotic lesions. These results further our understanding of the differences in VAEs between dasatinib and other TKIs.

Aging impairs fibrosis-4 index after sustained virologic response by direct-acting antivirals in chronic hepatitis C infection.

INTRODUCTION AND OBJECTIVES: Sustained virologic response (SVR) is achieved in most cases of C-type liver disease after direct-acting antiviral (DAA) therapy. Although liver fibrosis improves, the degree of improvement is different. This study aimed to analyze the factors involved in improving liver fibrosis using the fibrosis 4 (FIB-4) index. MATERIAL AND METHODS: Patients were monitored for >3 years after SVR. At the start of therapy (SOT), liver fibrosis was categorized as either mild (<1.45 n = 28), moderate (1.45-3.25 n = 139), or advanced (>3.25 n = 236) based on the FIB-4 index. The FIB-4 index in the advanced group decreased significantly compared to that of the other two, so we selected the advanced group as the analysis target. SOT and end of therapy (EOT) factors that contributed to the FIB-4 index ≤3.25 at 3 years after therapy were examined using a multivariate analysis. RESULTS: Among the SOT factors, age (<72 years old), absence of liver cirrhosis (LC), alanine transferase (ALT) (≥50 U/L), platelet (PLT) (≥10.2 × 104/mm3), and total bilirubin (T.Bil) (<0.8 mg/dl) were the significant factors contributing to the improvement of the FIB-4 index. Among the EOT factors, age (<72 years), PLT (≥12.0 × 104/mm3), and hemoglobin (Hb) (≥12.1 g/dl) were the significant factors contributing to the improvement of FIB-4 index. CONCLUSIONS: Factors involved in the improvement of liver fibrosis after SVR were young age, absence of LC, low T.Bil., high ALT, high PLT, and high Hb levels. The levels of T.Bil, PLT, and Hb were considered to be related to portal hypertension. Aging strongly impaired the improvement in liver fibrosis.

Factors affecting the recovery of hepatic reserve after sustained virologic response by direct-acting antiviral agents in chronic hepatitis C virus-infected patients.

BACKGROUND AND AIM: Since the advent of direct-acting antiviral (DAA) therapy, the total eradication of hepatitis C virus has been achievable with the recovery of hepatic reserve after achievement of sustained virologic response (SVR). Hence, here, we examined the factors affecting the recovery of hepatic reserve. METHODS: We followed up 403 patients (male: 164, female: 239; genotype 1: 299, genotype 2: 104; median age: 69 years) for at least 3 years after they achieved SVR to DAA therapy. Of these patients, 75 (18.6%) had a history of hepatocellular carcinoma (HCC). Biochemical tests were periodically performed, and the hepatic reserve was evaluated based on the albumin-bilirubin grade. We examined background factors such as age, biochemical test results, HCC occurrence and portosystemic shunt by computed tomography. RESULTS: At the start of treatment, the albumin-bilirubin grades were grades 1, 2, and 3 in 241, 157, and 5 patients, respectively, and 3 years later, 117 of 162 (72%) patients with grade 2 or 3 improved to grade 1. Multivariate analysis identified the HCC occurrence after achievement of SVR (hazard ratio [HR]: 3.08, P < 0.0138), male sex (HR: 3.45, P = 0.0143), hemoglobin level of <11.5 g/dL (HR: 4.19, P = 0.0157), the presence of a portosystemic shunt (HR: 3.07, P = 0.0349), and alanine aminotransferase levels <45 U/L (HR: 2.67, P = 0.0425) as factors inhibiting improvement to grade 1. However, old age was not an inhibitory factor. CONCLUSION: Our results demonstrate that hepatic reserve could be improved even in elderly patients over a long course of time.

Zinc deficiency in patients with chronic liver disease in Japan.

AIM: This study aimed to determine the distributions of serum zinc levels and the prevalence of zinc deficiency in patients with chronic liver disease (CLD) in actual clinical practice, and to analyze the association between serum zinc levels and clinical characteristics. METHODS: This study analyzed 1973 patients with CLD, including 749 with liver cirrhosis, who were admitted to Sapporo Kosei General Hospital in 2017. RESULTS: Zinc deficiency, defined as a serum zinc level of <60 µg/dL, was observed in 555 patients overall (28.1%), including 182 (14.9%) patients without liver cirrhosis and 373 (49.8%) with liver cirrhosis. When marginal zinc deficiency was included, zinc deficiency (serum zinc level <80 µg/dL) was observed in 1594 (80.8%) patients overall, including 924 (75.5%) patients without liver cirrhosis and 670 (89.5%) with liver cirrhosis. Serum zinc levels were most strongly correlated with serum albumin levels. Of the 257 CLD patients with an albumin level of <3.5 g/dL, 234 (91.1%) had a serum zinc level of <60 µg/dL. CONCLUSIONS: Zinc deficiency is common in patients with CLD. Serum zinc levels should be regularly measured, particularly in patients with liver cirrhosis.

Evaluation of treatment with zinc acetate hydrate in patients with liver cirrhosis complicated by zinc deficiency.

AIM: In Japan, no zinc preparation had been approved for therapeutic purposes before March 2017. Zinc acetate hydrate was recently approved for the treatment of hypozincemia. We evaluated the efficacy and safety of treatment with zinc acetate hydrate. METHODS: A total of 97 patients with cirrhosis complicated by hypozincemia were treated with zinc acetate hydrate, and their serum zinc normalization rates; factors contributing to normalization; changes in blood ammonia levels; branched-chain amino acids-to-tyrosine ratios; levels of albumin, hemoglobin, alkaline phosphatase, serum copper, and iron; incidence of adverse events; improvement in subjective symptoms; and serum zinc levels taken at 3 months post-treatment were determined. RESULTS: The cumulative serum zinc normalization rates, when normalization was defined as achievement of a serum zinc level ≥80 µg/dL, after 2, 4, and 6 months of treatment were 64.9%, 80.3%, and 82.5%, respectively. Multivariate analysis identified an albumin level of ≥3.3 g/dL and branched-chain amino acids to tyrosine ratio of ≥3.46 as factors contributing to zinc normalization within 3 months of treatment. Treatment resulted in a significant decrease in blood ammonia and serum copper levels, and significant increases in branched-chain amino acids-to-tyrosine ratios and alkaline phosphatase levels. Seven (7.2%) patients prematurely discontinued treatment due to hypocupremia. By the end of treatment, subjective symptoms had resolved in 46.2% of patients. By 3 months post-treatment, serum zinc levels had reverted to levels close to those at baseline. CONCLUSIONS: Treatment with zinc acetate hydrate resulted in normalization of serum zinc levels at a high rate. The main reasons for discontinuation of treatment included hypocupremia.

The association between serum zinc levels and subjective symptoms in zinc deficiency patients with chronic liver disease.

This study aimed to analyze the association between serum zinc levels and major subjective symptoms in zinc deficiency patients with chronic liver disease. 578 patients with chronic liver disease were enrolled. The patients, whose serum zinc level of <80 µg/dl, completed a questionnaire to determine whether they had subjective symptoms of the five conditions (taste disorder, aphthous stomatitis, dermatitis, alopecia, and anorexia). Then, the association between these subjective symptoms and serum zinc levels was analyzed. In total, 193 patients (33.4%) experienced any subjective symptoms. The prevalence of each symptom was as follows: 36 patients with taste disorder (6.2%), 46 with aphthous stomatitis (8.0%), 77 with dermatitis (13.3%), 46 with alopecia (8.0%), and 53 with anorexia (9.2%). In total, 70.8%, 34.1%, and 26.1% patients with serum zinc levels of <40, ≥40 to <60, and ≥60 to <80 µg/dl, respectively, had these symptoms. When zinc deficiency was defined as a serum zinc level of <80 µg/dl, approximately one-third of patients displayed symptoms presumably originating from zinc deficiency. As serum zinc levels decreased, the prevalence of these symptoms increased. Dermatitis, especially, was relevant to zinc.

Predictors of hepatocellular carcinoma after hepatitis C virus eradication following direct-acting antiviral treatment: relationship with serum zinc.

The recently approved direct-acting antivirals (DAA) agents are effective in terms of sustained virologic response (SVR) rates and are well tolerated in most hepatitis C virus (HCV) patients. This study aimed to analyze the association between serum zinc levels in patients who developed hepatocellular carcinoma (HCC) following HCV eradication after DAA treatment. The retrospective study included 769 HCV-infected patients who achieved SVR after DAA treatment. We calculated the annual incidence rate of HCC and identified risk factors associated with HCC development. We also assessed serum zinc and clinical factors at both baseline and end of treatment (EOT). During follow-up (median duration 35 months), HCC occurred in 18/769 (2.3%) patients. From the multivariate analysis, serum zinc <60 µg/dl [hazard ratio (HR) 5.936] and AFP ≥6.0 ng/dl (HR 5.862) at baseline, baseline-zinc <60 µg/dl (HR 6.283), EOT-serum zinc <63 µg/dl (HR 6.011), baseline-AFP ≥6.0 ng/dl (HR 8.163), and EOT-M2BPGi ≥2.5 (HR 12.194) at baseline and EOT were independently associated with increased HCC risk. In patients who achieved HCV eradication following DAA treatment, serum zinc levels before and at EOT could be a risk factor for developing HCC.

Seleno-L-Methionine Suppresses Immunoglobulin E-Mediated Allergic Response in RBL-2H3 Cells.

The effect of seleno-L-methionine (SeMet) on immunoglobulin (Ig) E-mediated allergic responses were investigated using rat basophilic leukemia RBL-2H3 cells. Cells were first treated with or without SeMet, sensitized with anti-dinitrophenyl IgE and stimulated with the antigen dinitrophenyl-human serum albumin, before the measurement of degranulation, calcium mobilization, mRNA expression and protein secretion of interleukin (IL)-4 and tumor necrosis factor (TNF)-α, and phosphorylation of spleen tyrosine kinase (Syk), Akt, and mitogen-activated protein kinases (MAPKs). The antigen-induced ß-hexosaminidase release, a degranulation marker, was significantly inhibited by SeMet treatment. SeMet also significantly suppressed antigen-induced calcium mobilization. Antigen-induced increases in the mRNA expression and protein secretion of IL-4 and TNF-α were both significantly attenuated by SeMet treatment. In addition, SeMet significantly suppressed antigen-induced phosphorylation of Syk, Akt, and MAPKs. These results demonstrate that SeMet suppresses antigen-induced degranulation, and mRNA expression and protein secretion of IL-4 and TNF-α, and inhibits antigen-induced mobilization of calcium and activation of Syk, Akt, and MAPKs. Our study provides valuable information that may be useful in the prevention and treatment of allergic diseases.

Analysis of hepatitis B surface antigen (HBsAg) using high-sensitivity HBsAg assays in hepatitis B virus carriers in whom HBsAg seroclearance was confirmed by conventional assays.

AIM: We investigated the utility of high-sensitivity hepatitis B surface antigen (HBsAg) assays compared with conventional HBsAg assays. METHODS: Using serum samples from 114 hepatitis B virus (HBV) carriers in whom HBsAg seroclearance was confirmed by conventional HBsAg assays (cut-off value, 0.05 IU/mL), the amount of HBsAg was re-examined by high-sensitivity HBsAg assays (cut-off value, 0.005 IU/mL). Cases negative for HBsAg in both assays were defined as consistent cases, and cases positive for HBsAg in the high-sensitivity HBsAg assay only were defined as discrepant cases. RESULTS: There were 55 (48.2%) discrepant cases, and the range of HBsAg titers determined by high-sensitivity HBsAg assays was 0.005-0.056 IU/mL. Multivariate analysis showed that the presence of nucleos(t)ide analog therapy, liver cirrhosis, and negative anti-HBs contributed to the discrepancies between the two assays. Cumulative anti-HBs positivity rates among discrepant cases were 12.7%, 17.2%, 38.8%, and 43.9% at baseline, 1 year, 3 years, and 5 years, respectively, whereas the corresponding rates among consistent cases were 50.8%, 56.0%, 61.7%, and 68.0%, respectively. Hepatitis B virus DNA negativity rates were 56.4% and 81.4% at baseline, 51.3% and 83.3% at 1 year, and 36.8% and 95.7% at 3 years, among discrepant and consistent cases, respectively. Hepatitis B surface antigen reversion was observed only in discrepant cases. CONCLUSIONS: Re-examination by high-sensitivity HBsAg assays revealed that HBsAg was positive in approximately 50% of cases. Cumulative anti-HBs seroconversion rates and HBV-DNA seroclearance rates were lower in these cases, suggesting a population at risk for HBsAg reversion.

Role of Supplementary Selenium on the Induction of Insulin Resistance and Oxidative Stress in NSY Mice Fed a High Fat Diet.

The role of supplementary selenium on the induction of insulin resistance and oxidative stress in a diabetic mouse model was investigated in NSY mice on a high fat diet (HFD) and administered seleno-L-methionine (SeMet)-containing water for 12 weeks. Significant increases in oral glucose tolerance-tested (OGTT), insulin tolerance-tested, and non-fasting blood glucose levels were observed in mice on a HFD, as well as the significant increases in OGTT and non-fasting plasma insulin levels. Mice on a HFD had decreased plasma adiponectin levels and increased free fatty acid (FFA) levels. Supplementary SeMet significantly augmented OGTT blood glucose levels in mice on a HFD and plasma FFA levels in mice on a normal diet. The mRNA levels of six selenoproteins were measured, and glutathione peroxidase (GPx) 1 and selenoprotein P (SelP) were selected as candidates that may be associated with insulin resistance or oxidative stress in the liver. Hepatic GPx1 expression was elevated in mice on a HFD and SeMet supplementation, and SelP expression increased in mice on a HFD. Histopathological observations in hepatic tissues showed hypertrophy of parenchymal cells and significant expression of 4-hydroxy-2-nonenal in mice on a HFD, indicating lipid accumulation and oxidative stress induction. Hepatic protein tyrosine phosphatase activity also increased by a HFD. These results suggest that hepatic lipid accumulation in NSY mice on a HFD promoted oxidative stress and hepatic SelP expression, and supplementary SeMet induced hepatic GPx1 expression.

Effects of Supplementary Seleno-L-methionine on Atopic Dermatitis-Like Skin Lesions in Mice.

Effects of selenium supplementation on atopic dermatitis (AD) were investigated by administering seleno-L-methionine (SeMet) using a mouse model of AD caused by repeated application of 2,4,6-trinitrochlorobenzene (TNCB). BALB/c mice were sensitized with TNCB to the abdomen on day -7; then, TNCB was applied repeatedly to each ear three times a week from days 0 to 23. SeMet was orally administered to the mice from days 0 to 23. The efficacy of SeMet on AD was assessed by measuring ear thickness, histologic evaluation, serum total immunoglobulin (Ig) E levels, and expression of interleukin (IL)-4 in the ear and superficial parotid lymph node. Ear thickness was remarkably increased by repeated application of TNCB, and SeMet significantly suppressed ear thickness in BALB/c mice. SeMet inhibited epidermal hyperplasia and dense infiltration of inflammatory cells. The number of TNCB-induced mast cells was significantly decreased by SeMet. Serum total IgE levels that increased by the repeated application of TNCB were significantly suppressed by SeMet. Repeated application of TNCB induced expression of IL-4, a T-helper (Th) 2 cytokine, in the ear and superficial parotid lymph node of BALB/c mice and its expression was significantly inhibited by SeMet. These results demonstrated that SeMet supplementation suppresses AD-like skin lesions in BALB/c mice and inhibits the expression of total IgE and IL-4.

Effect of Seleno-L-methionine on Oxidative Stress in the Pancreatic Islets of a Short-Term Induced Diabetic Mouse Model in Insufficient Selenium Status.

The protective effects of seleno-L-methionine (SeMet) on oxidative stress in pancreatic islets were investigated with a short-term nicotinamide (NA) and streptozotocin (STZ)-induced diabetic mouse model. ICR mice were intraperitoneally injected twice with 100 mg/kg STZ and 120 mg/kg NA at a 1-d interval and were then orally administered 158 µg Se/kg SeMet with free access to a selenium-deficient diet for 5 weeks. Administration of SeMet significantly improved the levels of glycated hemoglobin (HbA1c), non-fasting and oral glucose tolerance-tested (OGTT) blood glucose, plasma adiponectin and hepatic glycogen that deteriorated by NA/STZ treatment. However, supplementary SeMet did not restore non-fasting plasma insulin levels in NA/STZ treatment group and significantly suppressed OGTT plasma insulin levels in the control group. Although SeMet significantly suppressed 8-hydroxy-2'-deoxyguanosine density in pancreatic islets, SeMet did not restore insulin density. The hepatic and pancreatic mRNA levels of glutathione peroxidase 1 (GPX1) increased by NA/STZ treatment or SeMet administration. These results suggest that although a physiological level of SeMet improves glucose tolerance by exhibiting insulin-mimetic activity in a short-term induced diabetic mouse model under insufficient Se status, the suppression of pancreatic oxidative stress with the induction GPX1 by SeMet supplementation is unlikely to restore insulin storage and secretion.

Successful achievement of sustained virological response to triple combination therapy containing simeprevir in two patients with chronic hepatitis C who had failed asunaprevir:Daclatasvir combination therapy.

Patients 1 and 2 were treatment-naive women who had genotype 1b chronic hepatitis C. Both had IL-28B genotype TT, and amino acid substitutions of core 70 and 91 were both wild type. Search for the presence of resistance-associated variants (RAV) in non-structural (NS)3 and NS5A regions confirmed wild-type D168 and L31, along with Y93H, in both patients. These patients participated in a Japanese phase III clinical study of asunaprevir and daclatasvir at the age of 52 and 67 years, respectively, and were treated with the combination regimen for 24 weeks. However, both experienced post-treatment relapse, and then treated with triple combination therapy with simeprevir, pegylated interferon (IFN) and ribavirin at the age of 53 and 68 years, respectively, and achieved sustained virological response. A search for RAV prior to simeprevir treatment identified multiple resistance including D168E, Y93H and L31V in both patients. It has been demonstrated that, in many cases, a treatment failure with a combination of asunaprevir and daclatasvir results in acquisition of RAV in NS3 and NS5A regions and that drug-resistant mutants, particularly those in the NS5A region, survive for a long time. In these cases, direct-acting antivirals targeted towards the NS5A region may have a limited efficacy. The present case report is based on an idea that a regimen containing IFN with simeprevir could be a therapeutic option particularly for those who are likely to be highly sensitive and tolerable to IFN.

Oxidized dietary oils enhance immediate- and/or delayed-type allergic reactions in BALB/c mice.

BACKGROUND: The consumption of cooking oils may exacerbate some allergic diseases. In the present study, the effects of naturally oxidized olive oil on immediate- and/or delayed-type allergic reactions were investigated in BALB/c mice. METHODS: Mouse models of 3 types of allergic reactions: contact hypersensitivity (CHS), active cutaneous anaphylaxis (ACA), and DNFB-induced hypersensitivity, were orally administered naturally oxidized olive oil that was obtained by keeping the oil at room temperature for more than 3 years. The effects of ultraviolet ray (UV)-irradiated olive oil and other dietary oils as well as their possible oxidation products on CHS were also investigated. RESULTS: Naturally oxidized olive oil had a high peroxide value (POV) and exacerbated CHS, ACA, and DNFB-induced hypersensitivity in a POV-dependent manner. UV-irradiated olive oil, corn oil, sesame oil and triolein had high POVs, but almost the same acid value (AV) and thiobarbituric acid-reactive substance (TBARS) level as fresh oils. Fresh olive oil and the representative oxidation product with a high AV or TBARS level had no effect on CHS, whereas all UV-irradiated oils and naturally oxidized olive oil exacerbated it. CONCLUSIONS: Oxidized dietary oils that have high POVs exacerbated immediate- and/or delayed-type allergic reactions regardless of the different oil constituents or oxidation processes.

Glutathione-dependent cell cycle G1 arrest and apoptosis induction in human lung cancer A549 cells caused by methylseleninic acid: comparison with sodium selenite.

The aim of the present study was to clarify the mechanism underlying the inhibition of cell proliferation in human lung cancer A549 cells by selenium (Se) compounds. Methylseleninic acid (CH3SeO2H, abbreviated as MSA), a synthetic Se compound, is a direct precursor of active methylselenol (CH3SeH) and is considered to be one of beneficial agents for cancer prevention and therapy. Sodium selenite (Na2SeO3), an inorganic Se form, is utilized in clinical Se supplementation. MSA markedly inhibited the growth of A549 cells at a concentration of 2.5×10(-6) mol/L for 1 d. On Day 1, Na2SeO3 also inhibited A549 cell growth at the concentration of 7.5×10(-6) mol/L. These compounds induced cell cycle arrest at the G1 phase and apoptosis under the inhibitory condition. Reduced glutathione (GSH) is critical to MSA or Na2SeO3 metabolism. The depletion of intracellular GSH suppressed Na2SeO3-induced G1 arrest, but promoted Na2SeO3-induced apoptosis. Therefore, Na2SeO3 appears to have directly induced apoptosis. In contrast, the MSA-induced G1 arrest was ameliorated by a marked decrease in GSH content. Additionally, the depletion of GSH slightly suppressed MSA-induced apoptosis. The difference in inhibitory effects between MSA and Na2SeO3 may be due to this variation in GSH-related metabolism. After exposure of A549 cells to MSA, the GSH content was significantly decreased. These results indicate that because MSA-induced G1 arrest and apoptosis induction are enhanced by GSH, the maintenance of GSH is essential for the effective anticancer action of MSA in A549 cells.

Effects of administering sodium selenite, methylseleninic acid, and seleno-L-methionine on glucose tolerance in a streptozotocin/nicotinamide-induced diabetic mouse model.

The effects of administering the selenocompounds, sodium selenite, methylseleninic acid (MSA), and seleno-L-methionine (SeMet) on glucose tolerance were compared in the nicotinamide (NA) and streptozotocin (STZ)-induced diabetic mouse model. ICR mice were intraperitoneally treated twice with STZ (100 mg/kg) 15 min after an injection of NA (120 mg/kg) at a 1-d interval. Non-fasting blood glucose levels were then monitored weekly while orally administering the selenocompounds at 158 µg Se/kg body weight with free access to a selenium-deficient diet for 5 weeks. The mean body weights of NA/STZ-induced diabetic mice were partly restored by the administration of selenocompounds, while SeMet led to a higher selenium content and glutathione peroxidase 1 activity in the pancreas. Non-fasting and oral glucose tolerance-tested blood glucose levels, which were elevated by NA/STZ, were significantly suppressed by the administration of SeMet. These results suggest that SeMet may improve glucose tolerance in a NA/STZ-induced mild diabetic mouse model by increasing bioavailability in the pancreas.

Effect of selenite on T-cell mitogenesis: contribution of ROS production and apoptosis signal-regulating kinase 1.

Although supplementation with the selenocompound, sodium selenite has been shown to stimulate the concanavalin A-induced T-cell mitogenic response, the mechanisms responsible remain unclear. This study was conducted to evaluate the relationships between the induction of apoptosis, formation of tumor necrosis factor (TNF)-alpha and reactive oxygen species (ROS), activation of apoptosis signal-regulating kinase (ASK) 1 and the thioredoxin (Trx) system when mitogenesis was stimulated by selenite. TNF-alpha was dose-dependently released by mouse splenocytes treated with selenite, and apoptosis was induced when TNF-alpha was added at the indicated concentrations. However, supplementation with selenite at low concentrations inhibited the accumulation of ROS with the increased expression of Trx reductase 1 and induction of apoptosis in wild-type splenocytes, and also at high concentrations in Trx-1-transgenic mouse splenocytes. The suppression of apoptosis was accompanied by a decrease in the expression of phospho-ASK1. These results suggest that the stimulation of T-cell mitogenesis by selenite may be partly attributed to the inhibited accumulation of ROS due to a reduced Trx-1/TR1 system, the inactivation of ASK1, and the suppression of apoptosis.

Supplementary seleno-L-methionine suppresses active cutaneous anaphylaxis reaction.

To clarify the relationship between selenium supplementation and type I allergic reaction, we investigated the effect of seleno-L-methionine (SeMet) supplementation on the active cutaneous anaphylaxis (ACA) reaction and cytokine production in splenocytes. Female BALB/c mice were sensitized by intraperitoneal injection of ovalbumin (OVA), and SeMet was administered orally for 2 weeks followed by a challenge with OVA to induce an ACA reaction. SeMet supplementation suppressed the ACA reaction in a dose-dependent manner. Plasma OVA-specific immunoglobulin E (IgE) level was strongly inhibited in SeMet-supplemented mice compared with control mice. The mRNA expression levels of the T helper 2 (Th2) cytokines interleukin (IL)-4 and IL-13 in the spleen of SeMet-supplemented mice were lower than those in control mice. The mRNA expression level of a Th1 cytokine, interferon (IFN)-γ, in the spleen of SeMet-supplemented mice was higher than that in control mice. Splenocytes restimulated with OVA in vitro from SeMet-supplemented mice produced lower amounts of IL-4 and IL-13 than those of control mice and higher amounts of IFN-γ than those from the control mice. These results suggest that oral SeMet supplementation suppresses OVA-induced ACA reaction by lowered Th2 cytokine production and augmenting Th1 cytokine production.

Inhibition of plasminogen suppresses fibrosis and macrophage foaming in a nonalcoholic steatohepatitis mouse model.

Nonalcoholic steatohepatitis is a clinically important liver disease. Its symptoms are exacerbated by macrophage foaming, which is promoted by plasminogen in vitro. However, the influence of plasminogen on nonalcoholic steatohepatitis has not been reported. In this study, we evaluated the influence of plasminogen in a mouse model of nonalcoholic steatohepatitis with macrophage foaming. L-/- /A-/- mice, characterized by hypercholesterolemia, were injected with streptozotocin and fed a high-fat diet to develop nonalcoholic steatohepatitis with macrophage foaming. To confirm the influence of plasminogen, we used the well-known plasminogen inhibitor tranexamic acid and L-/- /A-/- /Plg-/- mice, which are deficient in plasminogen and investigated the influence on nonalcoholic steatohepatitis. The influence of plasminogen on the expression levels of proinflammatory cytokines involved in foaming in macrophages was also assessed. The formation of nonalcoholic steatohepatitis lesions with macrophage foaming was confirmed in the L-/- /A-/- mouse model. Tranexamic acid attenuated foaming and fibrosis in the L-/- /A-/- mice. Similarly, foaming and liver fibrosis were also attenuated in the L-/- /A-/- /Plg-/- mice. The mRNA expression levels of TGF-ß1 and IL-1ß in liver and peritoneal macrophages were reduced upon plasminogen inhibition. We show that inhibition of plasminogen suppressed macrophage foaming, cytokine expression, and consequently fibrosis in nonalcoholic steatohepatitis. Our results provide a clue toward various processes leading to fibrosis and may contribute to new therapeutic strategies for nonalcoholic steatohepatitis.

Plasminogen Deficiency Significantly Reduces Vascular Wall Disease in a Murine Model of Type IIa Hypercholesterolemia.

The fibrinolytic system has been implicated in the genesis and progression of atherosclerosis. It has been reported that a plasminogen (Pg) deficiency (Plg-/-) exacerbates the progression of atherosclerosis in Apoe-/- mice. However, the manner in which Plg functions in a low-density lipoprotein-cholesterol (LDL-C)-driven model has not been evaluated. To characterize the effect of Pg in an LDL-C-driven model, mice with a triple deficiency of the LDL-receptor (LDLr), along with the active component (apobec1) of the apolipoprotein B editosome complex, and Pg (L-/-/A-/-/Plg-/-), were generated. Atherosclerotic plaque formation was severely retarded in the absence of Pg. In vitro studies demonstrated that LDL uptake by macrophages was enhanced by plasmin (Pm), whereas circulating levels of LDL were enhanced, relative to L-/-/A-/- mice, and VLDL synthesis was suppressed. These results indicated that clearance of lipoproteins in the absence of LDLr may be regulated by Pg/Pm. Conclusions: The results from this study indicate that Pg exacerbates atherosclerosis in an LDL-C model of atherosclerosis and also plays a role in lipoprotein modification and clearance. Therefore, controlling the Pg system on macrophages to prevent foam cell formation would be a novel therapeutic approach.