Fatty Acid Accumulation and Resulting PPARα Activation in Fibroblasts due to Trifunctional Protein Deficiency

To examine fatty acid accumulation and its toxic effects in cells, we analyzed skin fibroblasts from six patients with mitochondrial trifunctional protein deficiency, who had abnormalities in the second through fourth reactions in fatty acid β-oxidation system. We found free fatty acid accumulation, enhanced three acyl-CoA dehydrogenases, catalyzing the first reaction in the β-oxidation system and being assumed to have normal activities in these patients, and PPARα activation that was confirmed in the experiments using MK886, a PPARα specific antagonist and fenofibrate, a PPARα specific agonist. These novel findings suggest that the fatty acid accumulation and the resulting PPARα activation are major causes of the increase in the β-oxidation ability as probable compensation for fatty acid metabolism in the patients' fibroblasts, and that enhanced cell proliferation and increased oxidative stress due to the PPARα activation relate to the development of specific clinical features such as hypertrophic cardiomyopathy, slight hepatomegaly, and skeletal myopathy. Additionally, significant suppression of the PPARα activation by means of MK886 treatment is assumed to provide a new method of treating this deficiency

Softening and Salts Movement in the Ripening Process of Camembert Cheese

Experimental Camembert cheese softened from the surface to the center portion after 3-4 weeks of ripening.As ripening progressed,pH value rose from 4.5 to 7.8,lactic acid content decreased from 1.0% to 0.1%,ammonia content increased from 0.04g to 0.063g/100g,calcium content decreased from 0.3g to 0.048g/100g and phosphorus content decreased from 0.25g to 0.12g/100g in the center portion of cheese. The changes in these values were considered as criteria leading to softening of mold surface-ripened cheeses.Mold starter Penicillium candidum AM used the cheese manufacture possesses the abilities lactic acid,producing ammonia and lowering pH when supplemented with lactic acid and peptone Czapek Dox solution.However,normal softening was not observed by incubation of green cheese under ammonia atomsphere conditions.Also,lactic acid free cheese did not soften in spite of mold growth.It is proposed that the primary factor of softening in mold surface-ripened cheese is a rise of casein solubility caused by lowering of calcium crosslinking due to a decrease of calcium level in the cheese texture.The results suggested that the lactic acid metabolism and pH rise play a main part in inducement,and that insolble calcium phosphate accumulates in the cheese surface.本研究は、カマンベールチーズの熟成における軟化の主因と考えられているチーズ内でのpHや塩類の動態を追跡したものである。熟成開始前のグリーンチーズに比べて熟成が完了した4週目のチーズ中心部では、pHは4.5から7.8に上昇、乳酸は1.0% から0.1% で約1/10に低下、アンモニアは100g当たり0.04gから0.063gで約1.5倍に上昇、カルシウムは100g当たり0.3gから0.04gで約1/10のに減少、リンは100g当たり0.25gから0.12gで約1/2に減少した。これらの変化が本チーズの熟成軟化の要件と推察される。培養試験から、本チーズに使用したかびスターター　Pen. candidumに乳酸の代謝能とアンモニアの生成能を有すること、その結果pHが上昇することが確認された。しかし、未成熟のグリーンチーズをアンモニア蒸気にさらした場合も、乳酸を含まないチーズを熟成させた場合も正常な軟化は生じなかった。最も顕著な変化は、pH、乳酸、カルシウムに認められたが、これらのチーズ内での動態が主導的な役割を果たすものと推察された

Peroxisome proliferator-activated receptor alpha mediates enhancement of gene expression of cerebroside sulfotransferase in several murine organs

Sulfatides, 3-O-sulfogalactosylceramides, are known to have multifunctional properties. These molecules are distributed in various tissues of mammals, where they are synthesized from galactosylceramides by sulfation at C3 of the galactosyl residue. Although this reaction is specifically catalyzed by cerebroside sulfotransferase (CST), the mechanisms underlying the transcriptional regulation of this enzyme are not understood. With respect to this issue, we previously found potential sequences of peroxisome proliferator-activated receptor (PPAR) response element on upstream regions of the mouse CST gene and presumed the possible regulation by the nuclear receptor PPAR alpha. To confirm this hypothesis, we treated wild-type and Ppara-null mice with the specific PPAR alpha agonist fenofibrate and examined the amounts of sulfatides and CST gene expression in various tissues. Fenofibrate treatment increased sulfatides and CST mRNA levels in the kidney, heart, liver, and small intestine in a PPAR alpha-dependent manner. However, these effects of fenofibrate were absent in the brain or colon. Fenofibrate treatment did not affect the mRNA level of arylsulfatase A, which is the key enzyme for catalyzing desulfation of sulfatides, in any of these six tissues. Analyses of the DNA-binding activity and conventional gene expression targets of PPAR alpha has demonstrated that fenofibrate treatment activated PPAR alpha in the kidney, heart, liver, and small intestine but did not affect the brain or colon. These findings suggest that PPAR alpha activation induces CST gene expression and enhances sulfatide synthesis in mice, which suggests that PPAR alpha is a possible transcriptional regulator for the mouse CST gene.ArticleGLYCOCONJUGATE JOURNAL. 30(6):553-560 (2013)journal articl

Early detection of interstitial pneumonia by monitoring KL-6 in a chronic hepatitis C patient undergoing pegylated interferon and ribavirin therapy

A 58-year-old woman with chronic hepatitis C developed interstitial pneumonia (IP) while undergoing pegylated interferon (PEG IFN)-alpha-2a and ribavirin (RBV) therapy. Serum levels of sialylated carbohydrate antigen KL-6 (KL-6), a known marker of disease activity in fibrosing lung disorders, had been regularly measured once a month for early detection of IP, and had begun rising noticeably from 12 weeks to 540 U/mL at 33 weeks of treatment. On examination, remarkable fine crackles were detected by dorsal auscultation and bilateral ground-glass opacities and reticular shadows were depicted by computed tomography. The patient successfully recovered from her early-stage pneumonia by immediate discontinuation of therapy, which indicates that regular monitoring of serum KL-6 may be effective for avoidance of IP progression induced by PEG IFN and RBV therapy.ArticleHEPATOLOGY RESEARCH. 41(9):904-909 (2011)journal articl

Association analysis of toll-like receptor 4 polymorphisms in Japanese primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is characterized by portal inflammation and immune-mediated destruction of intrahepatic bile ducts that often result in liver failure. Toll-like receptor (TLR) 4 recognizes lipopolysaccharides of Gram-negative bacteria. Infectious agents have been suspected to play a crucial role in PBC pathogenesis since TLR4 expression was found in bile duct epithelial cells and periportal hepatocytes in liver tissues of PBC. To assess the potential contribution of TLR4 SNPs to the development of this disease, we genotyped five SNPs in TLR4 in 261 PBC patients and 359 controls using a TaqMan assay. No significant positive associations with either PBC susceptibility or progression were uncovered. These results indicate that TLR4 polymorphisms do not play a prominent role in the development of PBC in Japanese patients. (C) 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.ArticleHUMAN IMMUNOLOGY. 74(2):219-222 (2013)journal articl

Association of IL28B gene polymorphism with development of hepatocellular carcinoma in Japanese patients with chronic hepatitis C virus infection

IL28B single nucleotide polymorphisms (SNPs) are associated with spontaneous and treatment-induced elimination of hepatitis C virus (HCV). To assess whether the IL28B rs8099917 SNP also affects the progression of chronic HCV infection, we genotyped 511 Japanese HCV patients, including 69 with hepatocellular carcinoma (HCC). The T/T genotype of rs8099917 was not associated with the development of HCC (p = 0.623), although stepwise logistic regression analysis showed that liver cirrhosis, age greater than 68 years, and serum albumin <4.2 mg/dl were associated with HCC onset. It appears that the IL28B SNP does not directly influence hepatocarcinogenesis in chronic HCV infection.ArticleHUMAN IMMUNOLOGY. 73(3):298-300 (2012)journal articl

Serum Autotaxin Is a Useful Disease Progression Marker in Patients with Primary Biliary Cholangitis

Autotaxin (ATX) is a secreted enzyme metabolized by liver sinusoidal endothelial cells that has been associated with liver fibrosis. We evaluated serum ATX values in 128 treatment-naive, histologically assessed primary biliary cholangitis (PBC) patients and 80 healthy controls for comparisons of clinical parameters in a case-control study. The median ATX concentrations in controls and PBC patients of Nakanuma's stage I, II, III, and IV were 0.70, 0.80, 0.87, 1.03, and 1.70 mg/L, respectively, which increased significantly with disease stage (r = 0.53, P < 0.0001) as confirmed by Scheuer's classification (r = 0.43, P < 0.0001). ATX correlated with Wisteria floribunda agglutinin-positive Mac-2 binding protein (M2BPGi) (r = 0.51, P < 0.0001) and fibrosis index based on four factors (FIB-4) index (r = 0.51, P < 0.0001). While ALP and M2BPGi levels had decreased significantly (both P < 0.001) by 12 months of ursodeoxycholic acid treatment, ATX had not (0.95 to 0.96 mg/L) (P = 0.07). We observed in a longitudinal study that ATX increased significantly (P < 0.00001) over 18 years in an independent group of 29 patients. Patients succumbing to disease-related death showed a significantly higher ATX increase rate (0.05 mg/L/year) than did survivors (0.02 mg/L/year) (P < 0.01). ATX therefore appears useful for assessing disease stage and prognosis in PBC.ArticleSCIENTIFIC REPORTS.8:8159(2018)journal articl

Cutaneous sarcoidosis in a chronic hepatitis C patient receiving pegylated interferon and ribavirin therapy

A 61-year-old Japanese woman suffered from a small, painful, subcutaneous nodule on the sole of her foot that was 10mm across in diameter during pegylated interferon (PEG IFN) and ribavirin (RBV) combination therapy for chronic hepatitis C. Skin biopsy revealed multiple non-caseating granulomas composed of epithelioid histiocytes with multinucleate giant cells, which was consistent with sarcoidosis. Ophthalmologic examination revealed uveitis. Thoracic computed tomography (CT) showed multiple bilateral hilar lymphadenopathies and a diffuse micronodular interstitial pattern of the lungs. Genetic analysis indicated a probable homozygous haplotype of A*02:01-C*15:02-B*51:01-DRB1*16:02-DQB1*05:02 in human leukocyte antigen regions. The patient was observed carefully without any additional medication because no significant systemic symptoms were noted. Combination therapy was continued for 2months afterwards. She was asymptomatic for over 3years of follow up, and repeated hematological and biological investigations and chest CT showed improvement. In conclusion, clinicians should bear sarcoidosis in mind as a complication during PEG IFN and RBV combination therapy. They should also be aware of the usually good prognosis of PEG IFN-induced cutaneous sarcoidosis in order not to prematurely discontinue a treatment necessary for liver disease; maintenance of PEG IFN treatment may be advised with careful follow up.ArticleHEPATOLOGY RESEARCH. 43(7):801-807 (2013)journal articl

Steatogenesis in adult-onset type II citrullinemia is associated with down-regulation of PPARα

AbstractSLC25A13 (citrin or aspartate–glutamate carrier 2) is located in the mitochondrial membrane in the liver and its genetic deficiency causes adult-onset type II citrullinemia (CTLN2). CTLN2 is one of the urea cycle disorders characterized by sudden-onset hyperammonemia due to reduced argininosuccinate synthase activity. This disorder is frequently accompanied with hepatosteatosis in the absence of obesity and ethanol consumption. However, the precise mechanism of steatogenesis remains unclear. The expression of genes associated with fatty acid (FA) and triglyceride (TG) metabolism was examined using liver samples obtained from 16 CTLN2 patients and compared with 7 healthy individuals. Although expression of hepatic genes associated with lipogenesis and TG hydrolysis was not changed, the mRNAs encoding enzymes/proteins involved in FA oxidation (carnitine palmitoyl-CoA transferase 1α, medium- and very-long-chain acyl-CoA dehydrogenases, and acyl-CoA oxidase 1), very-low-density lipoprotein secretion (microsomal TG transfer protein), and FA transport (CD36 and FA-binding protein 1), were markedly suppressed in CTLN2 patients. Serum concentrations of ketone bodies were also decreased in these patients, suggesting reduced mitochondrial β-oxidation activity. Consistent with these findings, the expression of peroxisome proliferator-activated receptor α (PPARα), a master regulator of hepatic lipid metabolism, was significantly down-regulated. Hepatic PPARα expression was inversely correlated with severity of steatosis and circulating ammonia and citrulline levels. Additionally, phosphorylation of c-Jun-N-terminal kinase was enhanced in CTLN2 livers, which was likely associated with lower hepatic PPARα. Collectively, down-regulation of PPARα is associated with steatogenesis in CTLN2 patients. These findings provide a novel link between urea cycle disorder, lipid metabolism, and PPARα