Effects of obesity on CC16 and their potential role in overweight/obese asthma.

INTRODUCTION: Club cell secretory protein-16 (CC16) is a major anti-inflammatory protein expressed in the airway; however, the potential role of CC16 on overweight/obese asthma has not been assessed. In this study, we examined whether obesity reduces airway/circulatory CC16 levels using experimental and epidemiological studies. Then, we explored the mediatory role of CC16 in the relationship of overweight/obesity with clinical asthma measures. METHODS: Circulating CC16 levels were assessed by ELISA in three independent human populations, including two groups of healthy and general populations and asthma patients. The percentage of cells expressing club markers in obese vs. non-obese mice and human airways was determined by immunohistochemistry. A causal mediation analysis was conducted to determine whether circulatory CC16 acted as a mediator between overweight/obesity and clinical asthma measures. RESULTS: BMI was significantly and monotonously associated with reduced circulating CC16 levels in all populations. The percentage of CC16-expressing cells was reduced in the small airways of both mice and humans with obesity. Finally, mediation analysis revealed significant contributions of circulatory CC16 in the association between BMI and clinical asthma measures; 21.8% of its total effect in BMI's association with airway hyperresponsiveness of healthy subjects (p = 0.09), 26.4% with asthma severity (p = 0.030), and 23% with the required dose of inhaled corticosteroid (p = 0.042). In logistic regression analysis, 1-SD decrease in serum CC16 levels of asthma patients was associated with 87% increased odds for high dose ICS requirement (p < 0.001). CONCLUSIONS: We demonstrate that airway/circulating CC16, which is inversely associated with BMI, may mediate development and severity in overweight/obese asthma.

Configuration of Materially Retained Carbon in Our Society: A WIO-MFA-Based Approach for Japan.

To achieve the goals of Paris Agreement, global society is directing much effort in substantially reducing greenhouse gas (GHG) emissions. In addition to energy-related efforts, prevention of carbon release into the atmosphere with carbon capture and storage (CCS) and/or utilization of biomass resources is considered indispensable to achieving the global objective. In this study, considering carbon-containing goods as carbon reservoirs in our society similar to forests and reservoirs enabling CCS, the flow of materially utilized carbon was quantified by input-output-based material flow analysis (IO-MFA). As a result, in 2011, 6.3 Mt-C of petroleum-derived carbon and 7.9 Mt-C of wood-derived carbon were introduced to the Japanese society as end-use products (e.g., automobiles and constructions) in various forms (e.g., plastics and synthetic rubbers). The total amount (14.2 Mt-C) corresponded to 4.1% (52.1 Mt-CO2) of annual CO2 emission in Japan in 2011. Subsequently, by referring to the technology that can treat carbon in the target forms in end-of-life products, the recoverability of carbon as a material has been discussed with respect to each form and end-use of carbon. By numerically showing the necessity and potential of implementing appropriate technologies, this study provides scientific direction for policymakers to establish a quality carbon cycle in our society.

Antibiotics Suppress Activation of Intestinal Mucosal Mast Cells and Reduce Dietary Lipid Absorption in Sprague-Dawley Rats.

BACKGROUND & AIMS: The gut microbiota affects intestinal permeability and mucosal mast cells (MMCs) responses. Activation of MMCs has been associated with absorption of dietary fat. We investigated whether the gut microbiota contributes to the fat-induced activation of MMCs in rats, and how antibiotics might affect this process. METHODS: Adult male Sprague-Dawley rats were given streptomycin and penicillin for 4 days (n = 6-8) to reduce the abundance of their gut flora, or normal drinking water (controls, n = 6-8). They underwent lymph fistula surgery and after an overnight recovery were given an intraduodenal bolus of intralipid. We collected intestinal tissues and lymph fluid and assessed activation of MMCs, intestinal permeability, and fat transport parameters. RESULTS: Compared with controls, intestinal lymph from rats given antibiotics had reduced levels of mucosal mast cell protease II (produced by MMCs) and decreased activity of diamine oxidase (produced by enterocytes) (P < .05). Rats given antibiotics had reduced intestinal permeability in response to dietary lipid compared with controls (P < .01). Unexpectedly, antibiotics also reduced lymphatic transport of triacylglycerol and phospholipid (P < .01), concomitant with decreased levels of mucosal apolipoproteins B, A-I, and A-IV (P < .01). No differences were found in intestinal motility or luminal pancreatic lipase activity between rats given antibiotics and controls. These effects were not seen with an acute dose of antibiotics or 4 weeks after the antibiotic regimen ended. CONCLUSIONS: The intestinal microbiota appears to activate MMCs after the ingestion of fat in rats; this contributes to fat-induced intestinal permeability. We found that the gut microbiome promotes absorption of lipid, probably by intestinal production of apolipoproteins and secretion of chylomicrons.

Uric acid ameliorates indomethacin-induced enteropathy in mice through its antioxidant activity.

BACKGROUND AND AIM: Uric acid is excreted from blood into the intestinal lumen, yet the roles of uric acid in intestinal diseases remain to be elucidated. The study aimed to determine whether uric acid could reduce end points associated with nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy. METHODS: A mouse model of NSAID-induced enteropathy was generated by administering indomethacin intraperitoneally to 8-week-old male C57BL/6 mice, and then vehicle or uric acid was administered orally. A group of mice treated with indomethacin was also concurrently administered inosinic acid, a uric acid precursor, and potassium oxonate, an inhibitor of uric acid metabolism, intraperitoneally. For in vitro analysis, Caco-2 cells treated with indomethacin were incubated in the presence or absence of uric acid. RESULTS: Oral administration of uric acid ameliorated NSAID-induced enteropathy in mice even though serum uric acid levels did not increase. Intraperitoneal administration of inosinic acid and potassium oxonate significantly elevated serum uric acid levels and ameliorated NSAID-induced enteropathy in mice. Both oral uric acid treatment and intraperitoneal treatment with inosinic acid and potassium oxonate significantly decreased lipid peroxidation in the ileum of mice with NSAID-induced enteropathy. Treatment with uric acid protected Caco-2 cells from indomethacin-induced oxidative stress, lipid peroxidation, and cytotoxicity. CONCLUSIONS: Uric acid within the intestinal lumen and in serum had a protective effect against NSAID-induced enteropathy in mice, through its antioxidant activity. Uric acid could be a promising therapeutic target for NSAID-induced enteropathy.

Current Status of Uterine Leiomyosarcoma in the Tohoku Region: Results of the Tohoku Translational Center Development Network Survey.

BACKGROUND: To prepare for a future clinical trial for improving the long-term prognosis of patients with uterine leiomyosarcoma (ULMS), we conducted a multi-institutional survey in the Tohoku region of Japan. METHODS: We conducted a retrospective cohort study between 2011 and 2014 in member institutions of the Tohoku Translational Research Center Development Network. RESULTS: A total of 53 patients with ULMS were registered in 31 institutions for the present survey. The median patient age was 56 years, 67.9% of the patients were postmenopausal, 88.7% had a performance status of 0 or 1, and only 6 patients (11.3%) showed preoperative evidence of malignancy. Although retroperitoneal lymphadenectomy was performed in only 26.4% of patients, 64.2% patients were identified as having FIGO stage 1 disease; 73.6% were eligible to undergo complete surgery. Among 36 patients who were treated with postoperative chemotherapy, 28 (77.8%) received docetaxel and gemcitabine combination therapy. The most frequent recurrence site was the lungs, and the median progression-free survival of all enrolled patients was 11.7 months. However, the median progression-free survival and the median overall survival in patients with stages III and IV disease were 3.4 and 11.4 months, respectively. CONCLUSION: Although ULMS was associated with a high rate of complete or optimal surgery, the long-term prognosis was poor. Effective postoperative therapy should be developed to improve the long-term prognosis of patients with ULMS.

Platelet interaction with lymphatics aggravates intestinal inflammation by suppressing lymphangiogenesis.

Lymphatic failure is a histopathological feature of inflammatory bowel disease (IBD). Recent studies show that interaction between platelets and podoplanin on lymphatic endothelial cells (LECs) suppresses lymphangiogenesis. We aimed to investigate the role of platelets in the inflammatory process of colitis, which is likely to be through modulation of lymphangiogenesis. Lymphangiogenesis in colonic mucosal specimens from patients with IBD was investigated by studying mRNA expression of lymphangiogenic factors and histologically by examining lymphatic vessel (LV) densities. Involvement of lymphangiogenesis in intestinal inflammation was studied by administering VEGF-receptor 3 (VEGF-R3) inhibitors to the mouse model of colitis using dextran sulfate sodium and evaluating platelet migration to LVs. The inhibitory effect of platelets on lymphangiogenesis was investigated in vivo by administering antiplatelet antibody to the colitis mouse model and in vitro by coculturing platelets with lymphatic endothelial cells. Although mRNA expressions of lymphangiogenic factors such as VEGF-R3 and podoplanin were significantly increased in the inflamed mucosa of patients with IBD compared with those with quiescent mucosa, there was no difference in LV density between them. In the colitis model, VEGF-R3 inhibition resulted in aggravated colitis, decreased lymphatic density, and increased platelet migration to LVs. Administration of an antiplatelet antibody increased LV densities and significantly ameliorated colitis. Coculture with platelets inhibited proliferation of LECs in vitro. Our data suggest that despite elevated lymphangiogenic factors during colonic inflammation, platelet migration to LVs resulted in suppressed lymphangiogenesis, leading to aggravation of colitis by blocking the clearance of inflammatory cells. Modulating the interaction between platelets and LVs could be a new therapeutic means for treating IBD.

Human serum albumin hydropersulfide is a potent reactive oxygen species scavenger in oxidative stress conditions such as chronic kidney disease.

Recently, hydropersulfide (RSSH) was found to exist in mammalian tissues and fluids. Cysteine hydropersulfide can be found in free cysteine residues as well as in proteins, and it has potent antioxidative activity. Human serum albumin (HSA) is the most abundant protein in mammalian serum. HSA possesses a free thiol group in Cys-34 that could be a site for hydropersulfide formation. HSA hydropersulfide of high purity as a positive control was prepared by treatment of HSA with Na2S. The presence of HSA hydropersulfide was confirmed by spectroscopy and ESI-TOFMS analysis where molecular weights of HSA hydropersulfide by increments of approximately 32 Da (Sulfur atom) were detected. The fluorescent probe results showed that Alexa Fluor 680 conjugated maleimide (Red-Mal) was a suitable assay and bromotrimethylammoniumbimane bromide appeared to be a selective reagent for hydropersulfide. The effect of oxidative stress related disease on the existence of albumin hydropersulfides was examined in rat 5/6 nephrectomy model of chronic kidney disease (CKD). Interestingly, the level of hydropersulfides in rat 5/6 nephrectomy model serum was decreased by a uremic toxin that increases oxidative stress in rat 5/6 nephrectomy model. Furthermore, we demonstrated that the levels of HSA hydropersulfide in human subjects were reduced in CKD but restored by hemodialysis using Red-Mal assay. We conclude that HSA hydropersulfide could potentially play an important role in biological anti-oxidative defense, and it is a promising diagnostic and therapeutic marker of oxidative diseases.

Differences between cardiac memory T wave changes after idiopathic left ventricular tachycardia and ischemic T wave inversion induced by acute coronary syndrome.

BACKGROUND: Cardiac memory (CM) after idiopathic left ventricular tachycardia (ILVT) mimics ischemic T wave inversion (TWI) induced by acute coronary syndrome (ACS). We aimed to establish electrocardiography criteria for differentiating the CM from ischemic TWI. METHODS AND RESULTS: We evaluated 16 ILVT and 48 ACS patients. We identified TWI after ILVT in 9/16 patients (CM group), typically in leads II, III, aVF, aVR, and V4-6. The characteristics of CM were similar to TWI induced by ACS involving right coronary artery, but the CM group had more TWI in V4 and shorter QTc. The criteria of (1) positive T in aVL, (2) negative or isoelectric T in II, and (3) negative T in V4-6 or (4) QTc <430ms were 100% sensitive and 96% specific for the CM group. CONCLUSION: CM after ILVT can be differentiated in most cases from ischemic TWI by the distribution of TWI and the QTc.

Apolipoprotein A-V is present in bile and its secretion increases with lipid absorption in Sprague-Dawley rats.

Apolipoprotein (apo) A-V is a protein synthesized only in the liver that dramatically modulates plasma triglyceride levels. Recent studies suggest a novel role for hepatic apoA-V in regulating the absorption of dietary triglycerides, but its mode of action on the gut remains unknown. The aim of this study was to test for apoA-V in bile and to determine whether its secretion is regulated by dietary lipids. After an overnight recovery, adult male Sprague-Dawley bile fistula rats indeed secreted apoA-V into bile at a constant rate under fasting conditions. An intraduodenal bolus of intralipid (n = 12) increased the biliary secretion of apoA-V but not of other apolipoproteins, such as A-I, A-IV, B, and E. The lipid-induced increase of biliary apoA-V was abolished under conditions of poor lymphatic lipid transport, suggesting that the stimulation is regulated by the magnitude of lipids associated with chylomicrons transported into lymph. We also studied the secretion of apoA-V into bile immediately following bile duct cannulation. Biliary apoA-V increased over time (∼6-fold increase at hour 16, n = 8) but the secretions of other apolipoproteins remained constant. Replenishing luminal phosphatidylcholine and taurocholate (n = 9) only enhanced apoA-V secretion in bile, suggesting that the increase was not due to depletion of phospholipids or bile salts. This is the first study to demonstrate that apoA-V is secreted into bile, introducing a potential route of delivery of hepatic apoA-V to the gut lumen. Our study also reveals the uniqueness of apoA-V secretion into bile that is regulated by mechanisms different from other apolipoproteins.

Free cholesterol accumulation in hepatic stellate cells: mechanism of liver fibrosis aggravation in nonalcoholic steatohepatitis in mice.

UNLABELLED: Although nonalcoholic steatohepatitis (NASH) is associated with hypercholesterolemia, the underlying mechanisms of this association have not been clarified. We aimed to elucidate the precise role of cholesterol in the pathophysiology of NASH. C57BL/6 mice were fed a control, high-cholesterol (HC), methionine-choline-deficient (MCD), or MCD+HC diet for 12 weeks or a control, HC, high-fat (HF), or HF+HC diet for 24 weeks. Increased cholesterol intake accelerated liver fibrosis in both the mouse models without affecting the degree of hepatocellular injury or Kupffer cell activation. The major causes of the accelerated liver fibrosis involved free cholesterol (FC) accumulation in hepatic stellate cells (HSCs), which increased Toll-like receptor 4 protein (TLR4) levels through suppression of the endosomal-lysosomal degradation pathway of TLR4, and thereby sensitized the cells to transforming growth factor (TGF)ß-induced activation by down-regulating the expression of bone morphogenetic protein and activin membrane-bound inhibitor. Mammalian-cell cholesterol levels are regulated by way of a feedback mechanism mediated by sterol regulatory element-binding protein 2 (SREBP2), maintaining cellular cholesterol homeostasis. Nevertheless, HSCs were sensitive to FC accumulation because the high intracellular expression ratio of SREBP cleavage-activating protein (Scap) to insulin-induced gene (Insig) disrupted the SREBP2-mediated feedback regulation of cholesterol homeostasis in these cells. HSC activation subsequently enhanced the disruption of the feedback system by Insig-1 down-regulation. In addition, the suppression of peroxisome proliferator-activated receptor γ signaling accompanying HSC activation enhanced both SREBP2 and microRNA-33a signaling. Consequently, FC accumulation in HSCs increased and further sensitized these cells to TGFß-induced activation in a vicious cycle, leading to exaggerated liver fibrosis in NASH. CONCLUSION: These characteristic mechanisms of FC accumulation in HSCs are potential targets to treat liver fibrosis in liver diseases including NASH.

Electrons per atom ratio determination and Hume-Rothery electron concentration rule for P-based polar compounds studied by FLAPW-fourier calculations.

The extent to which reliable electrons per atom ratio, e/a, are determined and the validity of the Hume-Rothery stabilization mechanism are ensured upon increasing ionicity are studied by applying first-principles full potential linearized augmented plane wave (FLAPW)-Fourier band calculations to as many as 59 binary compounds formed by adding elements from periods 2-6 to phosphorus in group 15 of the Periodic Table. Van Arkel-Ketelaar triangle maps were constructed both by using the Allen electronegativity data and by using an energy difference between the center-of-gravity energies of FLAPW-derived s and p partial densities of states (DOSs) for the equiatomic compounds studied. The determination of e/a and the test of the interference condition, both of which play a key role in the Hume-Rothery stabilization mechanism, were reliably made for all intermetallic compounds, as long as the ionicity is less than 50%. In the A-P (A = Li, Na, K, Rb, and Cs) compounds with ionicity exceeding 50%, however, e/a determination becomes unstable, as reflected in its P concentration dependence. New Hume-Rothery electron concentration rules were theoretically found in two families of polar compounds: skutterudite compounds TMP(3), TMAs(3), and TMSb(3) (TM = Co, Ni, Rh, and Ir; cI32) with e/a = 4.34 and TM(3)P (TM = Cr, Mn, Fe, and Ni; tI32) with e/a = 2.20.

Pregnant woman with non-comatose autoimmune acute liver failure in the second trimester rescued using medical therapy: A case report.

We present the case of a 25-year-old woman at 16 weeks of gestation who presented with non-comatose autoimmune acute liver failure and was at high risk of developing fulminant hepatitis. Predictive formulas indicated a high probability of developing fulminant hepatitis. Unenhanced computed tomography showed marked hepatic atrophy and broadly heterogeneous hypoattenuating areas. The course of her illness was subacute, and the etiology of liver injury was unclear. Considering all of the above, we predicted a poor prognosis. Plasma exchange (PE) and continuous hemodiafiltration (CHDF) therapy were initiated just after admission. A few days after admission, a high titer (×80) of antinuclear antibody was noted. Because autoimmune hepatitis (AIH) was considered a cause of liver failure, treatment with moderate prednisolone (30 mg/day) doses was administrated, with careful consideration of her pregnancy. Thereafter, her laboratory findings and clinical course gradually improved without the need for liver transplantation. A liver biopsy at 18 days after admission indicated a diagnosis of AIH. She continued the pregnancy and delivered a healthy baby without any complications. Eventually, prednisolone doses were decreased to 10 mg, after which her liver function worsened. The second liver biopsy also indicated a diagnosis of AIH. Accordingly, low-dose prednisolone and azathioprine doses (50 mg/day) were administrated to recover her liver function, after which her liver function regained normalcy. This case illustrates that a pregnant woman with non-comatose autoimmune acute liver failure in the first or second trimester of pregnancy and her fetus can be rescued by PE/CHDF therapy and safe moderate doses of prednisolone.

Magnetic resonance enterocolonography in detecting erosion and redness in intestinal mucosa of patients with Crohn's disease.

BACKGROUND AND AIM: In Crohn's disease (CD), assessment of disease activity and extension is important for clinical management. Endoscopy is the most reliable tool for evaluating disease activity in these patients and it distinguishes between lesions based on ulcer, erosion, and redness. Magnetic resonance imaging (MRI) is less invasive than endoscopy; however, the sensitivity of MRI in detecting lesions is believed to be lower, and whether MRI can detect milder lesions has not been studied. The aim of this study was to compare the detection ability of magnetic resonance enterocolonography (MREC) with ileocolonic endoscopy in patients with CD. METHODS: A total of 27 patients with CD underwent both MREC and ileocolonoscopy. There were 55 lesions (18 ileum and 37 colon) endoscopically detected, and the findings of MREC were compared with each ileocolonoscopic finding to determine sensitivity and specificity. RESULTS: For a positive lesion defined as having at least one of the following: wall thickness, edema, diffusion-weighted imaging (DWI) high intensity and relative contrast enhancement (RCE) on MREC, the sensitivities were 100% for ulcer, 84.6% for erosion, and 52.9% for redness, suggesting an ability to detect milder lesions such as erosion or redness. Moreover, RCE values were well correlated with the severity of endoscopically identified active lesions. CONCLUSION: MREC findings may be useful not only for evaluation of ulcers, but also for detection of endoscopically identified milder lesions in CD, suggesting a clinical usefulness of MREC for disease detection and monitoring.

Toll-like receptor (TLR) 2 agonists ameliorate indomethacin-induced murine ileitis by suppressing the TLR4 signaling.

BACKGROUND AND AIM: Few drugs have been found satisfactory in the treatment of nonsteroidal anti-inflammatory drugs (NSAIDs)-induced enteropathy. Toll-like receptor (TLR) 4 and aberrant leukocyte migration to the intestinal mucosa are reported to be involved in the pathology of intestinal enteropathy and TLR2 agonists have been found to evoke hyposensitivity to TLR4 stimulation in vitro. In this study, we investigated whether and how lipoarabinomannan (LAM) or lipoteichoic acid (LTA), TLR2 agonists, attenuated indomethacin (IND)-induced intestinal damage. METHODS: LAM (0.5 mg/kg) or LTA (15 mg/kg) was administered intraperitoneally to mice before IND (10 mg/kg) administration. Disease activity was evaluated macroscopically and histologically. In the migration analysis, fluorescence-labeled leukocyte movement in the intestinal microvessels was observed by intravital microscopy. Expression of P-selectin, MAdCAM-1, TLR2, TLR4, and F4/80 was observed immunohistochemically. In the in vitro analysis, RAW264.7 macrophage cells were preincubated with LAM and stimulated with lipopolysaccharide (LPS), and the mRNA expression levels of TLR4, tumor necrosis factor-α, and interleukin-12p40 were measured. RESULTS: Pretreatment with LAM or LTA significantly decreased IND-induced injury as well as decreased leukocyte infiltration. Pretreatment with LAM decreased IND-induced TLR4 expression on F4/80(+) macrophages, the level of P-selectin expression, and leukocyte migration in the small intestinal vessels. In the in vitro study, a single administration of LAM decreased TLR4 mRNA expression and inhibited the increase in mRNA expression of inflammatory cytokines by LPS in a dose-dependent manner. CONCLUSION: TLR2 agonists attenuated IND-induced small intestinal lesions and leukocyte infiltration probably by suppressing the TLR4 signaling pathway in tissue macrophages.

Quantitative trait loci for whiteness of cooked rice detected in improved rice cultivars in Hokkaido.

Improving the eating quality of cooked rice has been one of the most important objectives in rice breeding programs. Eating quality of cooked rice is a complex trait including several components, such as external appearance, taste, aroma, and texture. Therefore, dissection of these components followed by marker-assisted selection of detected QTL(s) may be a useful approach for achieving desirable eating quality in rice breeding. Whiteness of cooked rice (WCR) is an important factor related to the external appearance of cooked rice. WCR is known to be associated with the amylose and protein contents of the endosperm. However, the genetic basis of WCR remains unclear. In this study, we evaluated phenotypic variation in WCR among recently developed rice cultivars from Hokkaido, Japan. Then, we developed doubled haploid lines (DHLs) derived from a cross between two cultivars from Hokkaido, Joiku No. 462 (high WCR) and Jokei06214 (low WCR). Using the DHLs, we detected two QTLs for WCR, qWCR3 and qWCR11, on chromosomes 3 and 11, respectively. We also examined the dosage effect of the two QTLs based on both the categorized segregants in the DHLs and the relationship between the WCR phenotype and inheritance around the QTL regions in cultivars from Hokkaido.

Quantitative trait loci for rice blast resistance detected in a local rice breeding population by genome-wide association mapping.

Plant breeding programs aim to develop cultivars with high adaptability to the specific conditions in a local region. As a result, unique genes and gene combinations have been accumulated in local elite breeding populations during the long history of plant breeding. Genetic analyses on such genes and combinations may be useful for developing new cultivars with more-desirable agronomic traits. Here, we attempted to detect quantitative trait loci (QTL) for rice blast resistance (BR) using a local breeding rice population from Hokkaido, Japan. Using genotyping data on single nucleotide polymorphisms and simple sequence repeat markers distributed throughout the whole genomic region, we detected genetic regions associated with phenotypic variation in BR by a genome-wide association mapping study (GWAS). An additional association analysis using other breeding cultivars verified the effect and inheritance of the associated region. Furthermore, the existence of a gene for BR in the associated region was confirmed by QTL mapping. The results from these studies enabled us to estimate potential of the Hokkaido rice population as a gene pool for improving BR. The results of this study could be useful for developing novel cultivars with vigorous BR in rice breeding programs.

Acyl-CoA:cholesterol acyltransferase 1 mediates liver fibrosis by regulating free cholesterol accumulation in hepatic stellate cells.

BACKGROUND & AIMS: Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes the conversion of free cholesterol (FC) to cholesterol ester, which prevents excess accumulation of FC. We recently found that FC accumulation in hepatic stellate cells (HSCs) plays a role in progression of liver fibrosis, but the effect of ACAT1 on liver fibrosis has not been clarified. In this study, we aimed to define the role of ACAT1 in the pathogenesis of liver fibrosis. METHODS: ACAT1-deficient and wild-type mice, or Toll-like receptor 4 (TLR4)(-/-)ACAT1(+/+) and TLR4(-/-)ACAT1(-/-) mice were subjected to bile duct ligation (BDL) for 3 weeks or were given carbon tetrachloride (CCl4) for 4 weeks to induce liver fibrosis. RESULTS: ACAT1 was the major isozyme in mice and human primary HSCs, and ACAT2 was the major isozyme in mouse primary hepatocytes and Kupffer cells. ACAT1 deficiency significantly exaggerated liver fibrosis in the mouse models of liver fibrosis, without affecting the degree of hepatocellular injury or liver inflammation, including hepatocyte apoptosis or Kupffer cell activation. ACAT1 deficiency significantly increased FC levels in HSCs, augmenting TLR4 protein and downregulating expression of transforming growth factor-ß (TGFß) pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor), leading to sensitization of HSCs to TGFß activation. Exacerbation of liver fibrosis by ACAT1 deficiency was dependent on FC accumulation-induced enhancement of TLR4 signaling. CONCLUSIONS: ACAT1 deficiency exaggerates liver fibrosis mainly through enhanced FC accumulation in HSCs. Regulation of ACAT1 activities in HSCs could be a target for treatment of liver fibrosis.

Phlebosclerotic colitis that was difficult to distinguish from collagenous colitis.

Phlebosclerotic colitis is a rare and recently known disease entity and its etiology is still to be elucidated. Some phlebosclerotic colitis cases are difficult to distinguish from collagenous colitis because of the similarity of pathological findings. In all Japanese case reports of phlebosclerotic colitis in which an association with the use of Chinese herbal medicine is suspected, sansisi (gardenia fruit) was included, suggesting pathogenesis of this disease. We report a case of phlebosclerotic colitis that wasdifficult to be distinguished from collagenous colitis, and an association with the use of Chinese herbal medicine was suspected as the cause of the disease.

Introduction of a tryptophan side chain into subsite +1 enhances transglycosylation activity of a GH-18 chitinase from Arabidopsis thaliana, AtChiC.

A tryptophan side chain was introduced into subsite +1 of family GH-18 (class V) chitinases from Nicotiana tabacum and Arabidopsis thaliana (NtChiV and AtChiC, respectively) by the mutation of a glycine residue to tryptophan (G74W-NtChiV and G75W-AtChiC). The specific activity toward glycol chitin of the two mutant enzymes was 70-71% of that of the wild type. Using chitin oligosaccharides, (GlcNAc)(n) (n = 4, 5 and 6), as the substrates, we found the transglycosylation reaction to be significantly enhanced in G74W-NtChiV and G75W-AtChiC when compared with the corresponding wild-type enzymes. The introduced tryptophan side chain might protect the oxazolinium ion intermediate from attack by a nucleophilic water molecule. The enhancement of transglycosylation activity was much more distinct in G75W-AtChiC than in G74W-NtChiV. Nuclear magnetic resonance titration experiments using the inactive double mutants, E115Q/G74W-NtChiV and E116Q/G75W-AtChiC revealed that the association constant of (GlcNAc)(5) was considerably larger for the latter. Amino acid substitutions at the acceptor binding site might have resulted in the larger association constant for G75W-AtChiC, giving rise to the higher transglycosylation activity of G75W-AtChiC.

Involvement of autotaxin/lysophospholipase D expression in intestinal vessels in aggravation of intestinal damage through lymphocyte migration.

Lysophosphatidic acid (LPA) has a critical role in lymphocyte migration to secondary lymphoid organs. Autotaxin (ATX)/lysophospholipase D, in the vascular endothelium, is the main enzyme involved in LPA production. Whether ATX is involved in pathological lymphocyte migration to the inflamed mucosa has not been studied. We investigated the involvement of ATX in inflammatory bowel disease patients and two murine models of colitis. Tissue samples were obtained by intestinal biopsies from patients with Crohn's disease and those with ulcerative colitis with informed consent. ATX immunoreactivity was colocalized with MAdCAM-1-positive high-endothelial-like vessels, close to sites of lymphocyte infiltration. Enhanced expression of ATX mRNA was observed in the inflamed mucosa from Crohn's disease and ulcerative colitis patients. ATX mRNA expression level was remarkably higher in the actively inflamed mucosa than in the quiescent mucosa in the same patient. In the T-cell-transferred mouse model, ATX mRNA expression level gradually increased as colitis developed. In the dextran sodium sulfate mouse model, the expression level was considerably higher in colonic mucosa of chronically developed colitis than in colonic mucosa of acute colitis. Administration of an ATX inhibitor, bithionol, remarkably decreased lymphocyte migration to the intestine and ameliorated both dextran sodium sulfate-induced colitis and CD4-induced ileocolitis. In transwell assays, administration of bithionol or 1-bromo-3(s)-hydroxy-4-(palmitoyloxy) butylphosphonate (BrP-LPA) significantly decreased transmigration of splenocytes through high-endothelial-like vessels induced by TNF-α. We conclude that enhanced expression of ATX in the active mucosa has been implicated in the pathophysiology of inflammatory bowel disease through enhancing aberrant lymphocyte migration to the inflamed mucosa.