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Lewy body (LB), which mainly consists of abnormal α-synuclein (αS) aggregates, is a histological hallmark of Parkinson's disease (PD). αS aggregation and LB inclusions are induced by spreading αS fibrils to neurons; therefore, the formation and transmission of αS fibrils to neurons may play an essential role in initiating LB formation in neurons. αS expressed in neurons is released into the extracellular space and taken up by macrophages and microglia; therefore, we hypothesized that macrophages/microglia play a role in the formation and spread of αS fibrils. In this study, we aimed to investigate the involvement of macrophages/microglia in the formation and spread of αS fibrils using transgenic animals that express human αS in macrophages/microglia. Transgenic zebrafish expressing A53T mutated αS (αS_A53T) in macrophages/microglia revealed αS accumulation in neurons. Transcriptome analysis by RNA-seq of human αS and αS_A53T expressing zebrafish revealed that kinase genes and E3 ubiquitin protein ligase genes were significantly high, and neuronal activity and transport-related Gene Ontology terms were also isolated. Meanwhile, αS_A53T monomers were taken up by A-THP-1 cells; processed to larger molecules, which could be αS fibrils; and released from macrophage cells. Furthermore, the ubiquitin-proteasome system modulated αS fibrils in A-THP-1 cells. αS fibrils suggest being formed from monomers in macrophages and spread to neurons to induce αS aggregates. Therefore, macrophages may play an essential role in the formation of αS aggregates and the pathogenesis of PD.

The methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene is a strong predictor for the efficacy of temozolomide chemotherapy and survival periods. However, the correlation between the extent of methylation and the difference in survival times has not been fully clarified. Simple and quantitative evaluations of the methylation status in the promotor region of the MGMT gene are expected to be worldwide standardized diagnostics. We applied real-time semi-quantitative methylation-specific polymerase chain reaction (SQ-MSP) of the MGMT gene promoter region to 84 glioblastoma patients. The SQ-MSP result showed that the ΔCt value, which represents the difference between uCt and mCt (uCt value - mCt value), is inversely correlated with overall survival. With adequate cutoff setting, this assay showed that those patients suffering from a tumor with low ΔCt (methylated) survived significantly longer than those having tumors with high ΔCt (un-methylated). The most significant difference was observed when the cutoff was set at a ΔCt of 2. Using this cutoff point, the result of MGMT immunohistochemical analysis was also significantly correlated with the methylation status examined with real-time SQ-MSP. These results collectively show that MGMT promoter methylation status actually affects patients' survival and protein expression depending on its methylation level, and the extent of methylated CpGs would be better assessed with real-time SQ-MSP than with the standard gel-based MSP. This method is cost- and labor-saving compared with pyrosequencing, and significantly contributes to the accurate and objective prediction of patient survival.

The present study was planned to identify novel serum antibody markers for digestive organ cancers. We have used screening by phage expression cloning and identified novel fourteen antigens in this experiment. The presence of auto-antibodies against these antigens in serum specimens was confirmed by western blotting. As for auto-antibodies against fourteen antigens, AlphaLISA (amplified luminescence proximity homogeneous assay) assay was performed in the sera of gastrointestinal cancers patients to confirm the results. Serum antibody levels against these fourteen recombinant proteins as antigens between healthy donors (HD) and esophageal squamous cell carcinoma (ESCC) patients, gastric cancer (GC), or colon cancer (CC) were compared. The serum levels of all fourteen auto-antibodies were significantly higher in ESCC and GC than those of HD. Among those auto-antibodies, except ECSA2 and CCNL2, were also detected significantly higher levels in CC than those of HD. Receiver operating curve (ROC) revealed similar results except CCNL2 in CC. AUC values calculated by ROC were higher than 0.7 in auto-antibodies against TPI1, HOOK2, PUF60, PRDX4, HS3ST1, TUBA1B, TACSTD2, AKR1C3, BAMBI, DCAF15 in ESCC, auto-antibodies against TPI1, HOOK2, PUF60, PRDX4, TACSTD2, AKR1C3, BAMBI, DCAF15 in GC, and auto-antibodies against TPI1, HOOK2, PUF60 in CC. AUC of the combination of HOOK2 and anti-p53 antibodies in ESCC was observed to be as high as 0.8228. Higher serum antibody levels against ten antigens could be potential diagnostic tool for ESCC. Higher serum antibody levels against eight antigens could be potential diagnostic tool for GC, and serum antibody levels against three antigens could be potential diagnostic tool for CC.

Transient ischemic attack (TIA) is a predictor for cerebral infarction (CI), and early diagnosis of TIA is extremely important for the prevention of CI. We set out to identify novel antibody biomarkers for TIA and CI, and detected matrix metalloproteinase 1 (MMP1), chromobox homolog 1 (CBX1), and chromobox homolog 5 (CBX5) as candidate antigens using serological identification of antigens by recombinant cDNA expression cloning (SEREX) and Western blotting to confirm the presence of serum antibodies against the antigens. Amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) revealed that serum antibody levels were significantly higher in patients with TIA or acute-phase CI (aCI) compared with healthy donors (P < 0.01). Spearman’s correlation analysis and multivariate logistic regression analysis demonstrated that levels of anti-MMP1, anti-CBX1, and anti-CBX5 antibodies were associated with age, cigarette-smoking habits, and blood pressure. Thus, serum levels of antibodies against MMP1, CBX1, and CBX5 could potentially serve as useful tools for diagnosing TIA and predicting the onset of aCI.

// Yoichi Yoshida 1,2,3 , Hao Wang 2,4 , Takaki Hiwasa 2 , Toshio Machida 5 , Eiichi Kobayashi 1,3 , Seiichiro Mine 5,6 , Go Tomiyoshi 2,7 , Rika Nakamura 2,7 , Natsuko Shinmen 2,7 , Hideyuki Kuroda 7 , Hirotaka Takizawa 8 , Koichi Kashiwado 9 , Ikuo Kamitsukasa 10,11 , Hideo Shin 12 , Takeshi Wada 13 , Akiyo Aotsuka 13 , Eiichiro Nishi 14 , Mikiko Ohno 14 , Minoru Takemoto 15 , Koutaro Yokote 15 , Sho Takahashi 16 , Jun Matsushima 17 , Xiao-Meng Zhang 2 , Masaki Takiguchi 2 and Yasuo Iwadate 1 1 Department of Neurological Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan 2 Department of Biochemistry and Genetics, Graduate School of Medicine, Chiba University, Chiba, Japan 3 Comprehensive Stroke Center, Chiba University Hospital, Chiba, Japan 4 Department of Anesthesia, The First Affiliated Hospital, Jinan University, Guangzhou, P. R. China 5 Department of Neurosurgery, Chiba Cerebral and Cardiovascular Center, Ichihara, Chiba, Japan 6 Department of Neurosurgery, Sawara Prefectural Hospital, Chiba, Japan 7 Medical Project Division, Research Development Center, Fujikura Kasei Co., Saitama, Japan 8 Port Square Kashiwado Clinic, Kashiwado Memorial Foundation, Chiba, Japan 9 Department of Neurology, Kashiwado Hospital, Chiba, Japan 10 Department of Neurology, Chiba Rosai Hospital, Chiba, Japan 11 Department of Neurology, Chibaken Saiseikai Narashino Hospital, Chiba, Japan 12 Department of Neurosurgery, Higashi Funabashi Hospital, Chiba, Japan 13 Department of Internal Medicine, Chiba Aoba Municipal Hospital, Chiba, Japan 14 Department of Pharmacology, Shiga University of Medical Science, Shiga, Japan 15 Department of Clinical Cell Biology and Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan 16 Clinical Research Center, Chiba University Hospital, Chiba, Japan 17 Department of Diagnostic Pathology, Graduate School of Medicine, Chiba University, Chiba, Japan Correspondence to: Takaki Hiwasa, email: // Keywords : TIA; PDCD11; cerebral infarction; autoantibody; biomarker; Gerotarget Received : August 08, 2017 Accepted : November 16, 2017 Published : December 24, 2017 Abstract Background: Disease specific autoantibodies have been detected in the sera of patients with atherosclerosis-related diseases, such as cerebral infarction, cardiovascular disease. In the present study, we aimed to identify novel autoantibodies responsible for transient ischemic attack (TIA), a prodromal condition for cerebral infarction. Methods: To identify candidate antigens, we screened a human aortic endothelial cell cDNA library using sera from 20 patients with TIA. Serum antibody levels were measured using amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) in 2 independent patient/healthy donor (HD) cohorts ( n = 192 and n = 906 in the second screening and validation cohort, respectively). Results: First screening identified 3 candidate antigens. Of these, programmed cell death 11 (PDCD11) was determined to be associated with stroke ( p < 0.0001), as evidenced from the second screening using AlphaLISA. The validation cohort revealed significantly higher antibody levels against PDCD11 (PDCD11-Ab levels) in patients with TIA than in HDs. Multivariate logistic regression analysis indicated that the predictive value of PDCD11-Ab levels for TIA [Odds ratio (OR): 2.44, 95% confidence interval (CI): 1.33-4.57, p = 0.0039] was not inferior to other known risk factors for ischemic stroke, including age (OR: 4.97, 95% CI: 2.67–9.48, p < 0.0001); hypertension (OR: 3.21, 95% CI: 1.76–5.86, p = 0.0001); and diabetes (OR: 4.31, 95% CI: 1.74–11.2, p = 0.0015). Conclusion: Serum PDCD11-Ab level may serve as a potential biomarker for TIA.

Gluconeogenesis is de novo glucose synthesis from substrates such as amino acids and is vital when glucose is lacking in the diurnal nutritional fluctuation. Accordingly, genes for hepatic gluconeogenic enzymes exhibit daily expression rhythms, whose detailed regulations under nutritional variations remain elusive. As a first step, we performed general systematic characterization of daily expression profiles of gluconeogenic enzyme genes for phosphoenolpyruvate carboxykinase (PEPCK), cytosolic form (Pck1), glucose-6-phosphatase (G6Pase), catalytic subunit (G6pc), and tyrosine aminotransferase (TAT) (Tat) in the mouse liver. On a standard diet fed ad libitum, mRNA levels of these genes showed robust daily rhythms with a peak or an elevation phase during the late sleep-fasting period in the diurnal feeding/fasting (wake/sleep) cycle. The rhythmicity was preserved in constant darkness, modulated with prolonged fasting, attenuated by Clock mutation, and entrained to varied photoperiods and time-restricted feedings. These results are concordant with the notion that gluconeogenic enzyme genes are under the control of the intrinsic circadian oscillator, which is entrained by the light/dark cycle, and which in turn entrains the feeding/fasting cycle and also drives systemic signaling pathways such as the hypothalamic-pituitary-adrenal axis. On the other hand, time-restricted feedings also showed that the ingestion schedule, when separated from the light/dark cycle, can serve as an independent entrainer to daily expression rhythms of gluconeogenic enzyme genes. Moreover, nutritional changes dramatically modified expression profiles of the genes. In addition to prolonged fasting, a high-fat diet and a high-carbohydrate (no-protein) diet caused modification of daily expression rhythms of the genes, with characteristic changes in profiles of glucoregulatory hormones such as corticosterone, glucagon, and insulin, as well as their modulators including ghrelin, leptin, resistin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide-1 (GLP-1). Remarkably, high-protein (60% casein or soy-protein) diets activated the gluconeogenic enzyme genes atypically during the wake-feeding period, with paradoxical up-regulation of glucagon, which frequently formed correlation networks with other humoral factors. Based on these results, we propose that daily expression rhythms of gluconeogenic enzyme genes are under the control of systemic oscillator-driven and nutrient-responsive hormones.

To identify autoantibodies using sera from ALS patients and elucidate their roles in disease pathology.An immunological screening was performed with a phage expression library SEREX method using sera from 3 ALS patients to identify ALS-related autoantibodies. Levels of antibodies identified by SEREX were measured in 33 ALS patients and 30 normal controls (NCs) by AlphaLISA using recombinant non-full-length proteins. The results were then validated by ELISA using full-length proteins in 71 ALS patients, 30 NCs and 34 disease controls (DCs). The relationship between the titres and clinical profiles of ALS patients were examined.Four autoantibodies identified by SEREX were proteasome subunit alpha type 7 (PSMA7), vimentin, hydroxymethylbilane synthase and TBC1 domain family member 2 (TBC1D2). AlphaLISA revealed that only the anti-PSMA7 and anti-TBC1D2 levels were significantly different between the ALS and NCs groups. ELISA showed that only the levels of antibody against PSMA7, involved in protein degradation by the ubiquitin-proteasome pathway (UPP), were higher in the ALS group than both the NC (P .01) and DC (P = .034) groups. Anti-PSMA7 levels tended to be negatively correlated with the logarithm of disease duration (P = .052) and were significantly positively correlated with the logarithm of creatine kinase levels (P = .011). The anti-PSMA7 antibody levels were different between patients with and without dysphagia (P .01).Serum anti-PSMA7 antibody might be a disease-promoting factor in early-stage ALS and might be a biomarker of ALS. Anti-PSMA7 autoantibody might contribute to the pathogenesis of ALS, possibly via its role in the UPP.

Recent clinical research has revealed a significant correlation between atherosclerosis, one of the primary etiologies of ischemic stroke, and the immune system. Assuming that "disease-specific autoantibodies are produced in the sera of patients with ischemic stroke," we investigated multiple arteriosclerosis-related antibodies using the serological identification of antigens by recombinant cDNA expression cloning (SEREX), an established method for identifying antigenic proteins. We either screened a human aortic endothelial cell cDNA library or conducted protein array screening using the sera from patients with ischemic stroke, such as carotid artery stenosis or transient ischemic attack (TIA). Next, we measured serum antibody levels using amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) in patient/healthy donor (HD) cohorts and identified several antigens, the antibody levels of which were significantly higher in patients with ischemic stroke than in HDs. This review introduced the method of identifying antigens by the SEREX and protein microarray and summarized antigenic proteins. In particular, it focused on anti-replication protein A2 antibody and anti-programmed cell death 11 antibody, which are significantly related to atherosclerotic plaque and ischemic brain tissue, respectively, and proposed the mechanism of elevated autoantibody levels against them. Furthermore, this review suggests a possibility of clinical application as an atherosclerotic disease diagnostic marker for TIA or cerebral infarction.

A novel method to reduce an acoustic noise and the vibration of a switched reluctance motor has been proposed. In this method, driving current is a sum of dc, fundamental, the second- and the third-harmonic components. This driving current is determined to eliminate the third harmonic component in the sum of radial forces of the stator teeth. Consequently, an acoustic noise and a vibration are reduced. The effectiveness of the proposed method is confirmed by means of finite-element method and test machine experiments.

[Abstract] In the pathogenesis of multiple sclerosis (MS), B cell/antibody-related mechanisms have recently received attention. To investigate the role of autoantibody in MS, we performed SEREX which can identify autoantibody cyclopedically. We identified serum antibodies against cytoskeletal protein talin1, and the levels of whom were remarkably higher in 39 MS than 43 normal controls (P < 0.01) and 35 disease controls (P = 0.06), and in MS patients without oligoclonal bands than ones with them. Moreover, we found negative-correlations between serum anti-talin1 antibody and IgG index in MS (P = 0.03). Anti-talin1 antibody exists in MS patients' sera, which may have some protective factor.

Stereotactic gamma knife surgery (GKS)-induced brain tumors are extremely rare, and no ependymal tumors induced by GKS have been reported. Therefore, little is known about their clinical, pathologic, and genetic features. In addition, a regimen of adjuvant chemotherapy for anaplastic ependymoma (AE) has not been established. A 77-year-old man presented with a gait disturbance and left-side cerebellar ataxia more than 19 years after GKS performed for a cerebellar arteriovenous malformation. Imaging studies demonstrated an enhancing mass in the irradiated field with signs of intraventricular dissemination. Surgical resection confirmed the diagnosis of AE. Temozolomide (TMZ) was administrated postoperatively because the methylated promoter region of O6-methylguanine-DNA methyltransferase (MGMT) and 1p36 deletion were observed. Surprisingly, images 16 days after TMZ initiation demonstrated a complete resolution of the residual tumor that was maintained after three cycles of TMZ. This first case report of GKS-induced AE emphasizes the importance of genetic evaluation of MGMT and chromosomal deletion of 1p36 that are not commonly performed in primary ependymal tumors. In addition, it is speculated that a GKS-induced tumor may have a different genetic background compared with the primary tumor because the pathogenesis of the tumors differed.

Sterol regulatory element-binding protein-1 (SREBP-1) plays a central role in transcriptional regulation of genes for hepatic lipid synthesis that utilizes diet-derived nutrients such as carbohydrates and amino acids, and expression of SREBP-1 exhibits daily rhythms with a peak in the nocturnal feeding period under standard housing conditions of mice. Here, we report that the Srebp-1 expression rhythm shows time cue-independent and Clock mutation-sensitive circadian nature, and is synchronized with varied photoperiods apparently through entrainment of locomotor activity and food intake. Fasting caused diminution of Srebp-1 expression, while diabetic db/db and ob/ob mice showed constantly high expression with loss of rhythmicity. Time-restricted feedings during mid-light and mid-dark periods exhibited differential effects, the latter causing more severe damping of the oscillation. Therefore, "when to eat in a day (the light/dark cycle)," rather than "whenever to eat in a day," is a critical determinant to shape the daily rhythm of Srebp-1 expression. We further found that a high-carbohydrate diet and a high-protein diet, as well as a high-fat diet, cause phase shifts of the oscillation peak into the light period, underlining the importance of "what to eat." Daily rhythms of SREBP-1 protein levels and Akt phosphorylation levels also exhibited nutrient-responsive changes. Taken together, these findings provide a model for mechanisms by which time of day and nutrients in feeding shape daily rhythms of the Srebp-1 expression and possibly a number of other physiological functions with interindividual and interdaily differences in human beings and wild animals subjected to day-by-day changes in dietary timing and nutrients.

Nicastrin (NCSTN), a component of the γ-secretase complex, is involved in the p53-dependent apoptosis of neurons, although its mechanism remains unclear. We analyzed the effects of NCSTN transfection on the transactivity of p53 in ras-NIH3T3 mouse fibroblasts with a luciferase assay. Luciferase activity was elevated after transfection, suggesting the stimulation of p53 transactivation ability. In addition, the protein levels of endogenous mouse p53 and transfected human p53 increased. The effects of NCSTN appeared to be independent of γ-secretase activity because it was not inhibited by the γ-secretase inhibitor DAPT. The functional domains of NCSTN were further examined with NCSTN deletion mutants. Activation of the p53-responsive promoter was completely diminished in a NCSTN mutant lacking the amino acid residues between 306 and 360. Since this domain is a γ-secretase-substrate-recognition site, the activation of p53 by NCSTN may be mediated by γ-secretase-substrate-like molecules.

Human cells derived from nevoid basal carcinoma syndrome (NBCCS) patients show increased levels of DNA synthesis activity after X-ray irradiation which is suggested to be casually related to reduction in cellular amounts of small ubiquitin-like protein modifier (SUMO-2/SMT-3A). In the present study, an increased level of DNA synthesis activity was found 8 h after X-ray irradiation in HeLa cells with reduction in SUMO-2 amounts by siRNA treatment for SUMO-2. When comparative proteomic analysis was performed between the siRNA and mimic control siRNA treated cells using two-dimensional (2D) electrophoresis and mass spectrometry, three proteins were identified as candidates. Our research focused on Nm23-H1, a nucleoside diphosphate kinase, whose amounts decreased after X-ray irradiation in HeLa cells treated with siRNA for SUMO-2. In the Nm23-H1 siRNA treated cells, induction of DNA synthesis was also detected. Furthermore, in synchronized HeLa cells, DNA synthesis was confirmed in the S phase. Moreover, increased expression of proliferating cell nuclear antigen (PCNA) was observed in Nm23-H1 siRNA treated HeLa cells after X-ray irradiation. In addition, Nm23-H1 was modified with SUMO-2 after X-ray irradiation. The present findings suggest that the reduction of Nm23-H1 is related to the decrease in sumoylation, which in turn, is involved in the induction of DNA synthesis via the regulation of PCNA expression after X-ray irradiation.

While lymph node metastasis is a major factor associated with poor prognosis in cancer, little is known of its molecular mechanisms. The aim of this study was to identify genes differentially expressed between non-cancerous and cancerous lung tissues, and to investigate the gene expression profiles of 41 primary lung adenocarcinomas to select sets of gene predictors for lymph node metastasis of lung cancer. Gene expression profiles were obtained using oligonucleotide microarrays, and predictor sets constructed by evaluating the statistical significance of expression levels of selected genes. Gene analysis revealed 15 predictor genes for lymph node metastasis of lung adenocarcinoma. Using the most suitable set of genes, it was possible to predict the lymph node metastasis of patients with lung cancer. The prediction scoring system yielded 71.4% accuracy for forecasting lymph node metastasis in 14 independent test cases. Survival was also significantly better in 18 cases that were pathologically LN negative and predicted to be LN negative according to molecular classification, compared with 23 cases that were pathologically LN positive or predicted to be LN positive according to molecular classification. Gene expression analysis combined with statistical analysis successfully distinguished lymph node metastasis. The findings of this study showed that pathological diagnosis combined with molecular classification clearly distinguished patients with good prognoses from patients with poor prognoses.

[Abstract] Phytoestrogens, including miroestrol and deoxymiroestrol, have the ability to act through competition with estrogen for binding to the estrogen receptor (ER). Here, we utilize manual ligand docking followed by molecular dynamics simulations and binding free energy calculations with the linear interaction energy method to predict the binding modes and the binding affinities of phytoestrogens on the ligand binding domain of ER (ERα-LBD). The calculations brought about the good correlation between the calculated binding free energy and the bioassays. Furthermore, consideration of Lennard?Jones and Coulomb interaction energies of miroestrol and deoxymiroestrol on ERα-LBD provided the information to develop the phytoestrogen derivatives as the preferred drug for ER positive breast cancer treatment.

In order to enrich hepatocytes differentiated from embryonic stem cells, we developed a novel medium. Since only hepatocytes have the activity of ornithine transcarbamylase, phenylalanine hydroxylase, galactokinase, and glycerol kinase, we expected that hepatocytes would be enriched in a medium without arginine, tyrosine, glucose, and pyruvate, but supplemented with ornithine, phenylanaline, galactose, and glycerol (hepatocyte-selection medium, HSM). Embryoid bodies were transferred onto dishes coated with gelatin in HSM after 4 days of culture. At 18 days after embryoid body formation, a single type of polygonal cell survived with an enlarged intercellular space and micorvilli. These cells were positive for indocyanine green uptake and for mRNAs of albumin, transthyretin, and alpha-feto protein, but negative for mRNAs of tyrosine aminotransferase, alpha1-antitrypsin, glucose-6-phosphatase, and phosphoenol pyruvate carboxykinase. Since cells in HSM were positive for cytokeratin (CK)8 and CK18 (hepatocyte markers) and for CK19 (a marker of bile duct epithelial cells), we concluded that they were hepatoblasts. They showed weaker expression of CCAAT/enhancer-binding protein (C/EBP)alpha than fetal liver (18.5 days of gestation) and expression of C/EBPbeta at a similar level to that of fetal liver. These data support our conclusion that HSM allows the selection of hepatoblast-like cells.

Prostate-specific antigen (PSA) screening has led to a remarkable increase in prostate cancer cases undergoing operative therapy. Over half of patients with locally advanced cancer (>or=pT3) develop rising PSA levels (biochemical failure) within 10 years. It is very difficult to predict which patients will progress rapidly to advanced disease following biochemical failure (BF). Therefore, a more useful prognostic factor is needed to suggest the most appropriate therapies for each patient. To determine chromosomal aberrations, we examined 30 patients with stage pT2 or pT3 primary prostate adenocarcinomas and no metastases (pN0M0) by comparative genomic hybridization (CGH). Laser capture microdissection (LCM) was used to gather cancer cells from frozen prostate specimens. Common chromosomal alterations included losses on 2q23-24, 4q26-28, 6q14-22, 8p12-22 and 13q21-31, as well as gains on 1p32-36, 6p21 and 17q21-22. Losses at 8p12-22 and 13q21-31 were observed more frequently in pT3 than pT2 tumors (P

Spot14 is a putative transcriptional regulator for genes involved in fatty acid synthesis. The Spot14 gene is activated in response to lipogenic stimuli such as dietary carbohydrate and is also under circadian regulation. The authors investigated factors responsible for daily oscillation of Spot14 expression. If mice were kept under a 12-h light/12-h dark cycle with ad libitum feeding, Spot14 mRNA levels in the liver reached a peak at an early dark period when mice, as nocturnal animals, start feeding. Under fasting, while Spot14 mRNA levels were generally decreased, the rhythmicity was still maintained, suggesting contribution of both nutritional elements and circadian clock factors on robust rhythmicity of Spot14 expression. Effects of circadian clock factors were confirmed by the observations that the circadian rhythm of Spot14 expression was seen also under the constant darkness and that the rhythmicity was lost in Clock mutant mice. When mice were housed in short-photoperiod (6-h light/18-h dark) and long-photoperiod (18-h light/6-h dark) cycles, rhythms of Spot14 mRNA levels were phase advanced and phase delayed, respectively, being concordant with the notion that Spot14 expression is under the control of the light-entrainable oscillator. As for nutritional mediators, in the liver of db/ db mice exhibiting hyperinsulinemia-accompanied hyperglycemia, Spot14 mRNA levels were constantly high without apparent rhythmicity, consistent with previous observations for strong activation of the Spot14 gene by glucose and insulin. Restricted feeding during the 4-h mid-light period caused a phase advance of the Spot14 expression rhythm. On the other hand, restricted feeding during the 4-h mid-dark period led to damping of the rhythmicity, apparently resulting from the separation of phases between effects of the light/dark cycle and feeding on Spot14 expression. Thus, the daily rhythm of Spot14 expression in the liver is under the control of the light-entrainable oscillator, food-entrainable oscillator, and food-derived nutrients, in a separate or cooperative manner.

Background Hypomethylation of genomic DNA induces stem-cell properties in cancer cells and contributes to the treatment resistance of various malignancies. Objective To examine the correlation between the methylation status of stem-cell-related genes and the treatment outcomes in patients with glioblastoma (GBM). Methods The genome-wide DNA methylation status was determined using HumanMethylation450 BeadChips, and the methylation status was compared between a group of patients with good prognosis (survival > 4 yr) and a group with poor prognosis (survival < 1 yr). Immunohistochemistry for proteins translated from hypomethylated genes, including alkaline phosphatase (ALPL), CD133, and CD44, was performed in 70 GBMs and 60 oligodendroglial tumors. Results The genomic DNA in refractory GBM was more hypomethylated than in GBM from patients with relatively long survival (P = .0111). Stem-cell-related genes including ALPL, CD133, and CD44 were also significantly hypomethylated. A validation study using immunohistochemistry showed that DNA hypomethylation was strongly correlated with high protein expression of ALPL, CD133, and CD44. GBM patients with short survival showed high expression of these stem-cell markers. Multivariate analysis confirmed that co-expression of ALPL + CD133 or ALPL + CD44 was a strong predictor of short survival. Anaplastic oligodendroglial tumors without isocitrate dehydrogenase 1 mutation were significantly correlated with high ALPL expression and poor survival. Conclusion Accumulation of stem-cell properties due to aberrant DNA hypomethylation is associated with the refractory nature of GBM.

Cyclin L2 (CCNL2) (Acc. No.: NM_030937) was detected as a tumor antigen of esophageal squamous cell carcinoma (SCC) by serological identification of antigens by recombinant cDNA expression cloning (SEREX). Serum anti-CCNL2 antibodies were detected by enzyme-linked immunosorbent assay more frequent in patients with esophageal SCC than in healthy donors (32% and 15%, P

We have obtained some evidence that shows that the decorin gene is the target of p53 transactivation. Luciferase reporter plasmid, which contained the promoter region between positions -252 and -205, was activated by p53 dose- dependently up to 170-fold. The promoter region involved a sequence, 5’-AGGCAAGTAG-3’, similar to p53-binding consensus sequence, 5’-PuPuPuC(A/T)(A/T)GPyPyPy-3’. Chromatin immunoprecipitation assay using p53 antibodies revealed that the region between -413 and -232 of the promoter of the decorin gene was co-precipitated with p53. p53- binding to this region was further demonstrated by electrophoretic mobility shift assay, in which the complex between decorin promoter DNA and proteins decreased by pretreatment with anti-p53 antibodies. The mRNA expression levels of decorin increased after treatment with p53-activating nutlin-3 greatly and with genotoxic reagent, adriamycin, to some extent. Consequently, decorin promoter is useful to evaluate the p53 transactivation ability.

[Abstract] Diabetic retinopathy is one of the most frequent complications of diabetes and is a leading cause of vision loss in adulthood. To better understand the molecular pathophysiology of diabetic retinopathy, we performed comprehensive gene expression analysis of the mouse retina under diabetic conditions with an in-house cDNA microarray system that was designed to be suitable for the small amount of RNA available from a single mouse retina. Diabetes was induced in male C57BL/6 mice by an intraperitoneal injection of streptozotocin, and the changes in retinal mRNA levels were examined in three pairs of diabetic and age-matched control mice at 1 and 3 months after the injection of streptozotocin. Northern blot analysis with amplified total cRNA confirmed the increase in mRNA levels of several selected genes. Most of the significantly up-regulated genes could be classified into two functional categories: oxidative phosphorylation and protein turnover. All mitochondrial DNA-encoded and most of the nuclear DNA-encoded genes for oxidative phosphorylation were up-regulated in the diabetic retina. This was in sharp contrast with a previous report of a down-regulation of these genes in skeletal muscles of streptozotocin-induced diabetic mice and type 2 diabetic humans. Genes for protein synthesis and ubiquitin were also up-regulated in the diabetic retina, suggesting the increase in turnover rates for at least a part of the protein population. Taken together, the diabetic retina appears to be in a state activated for intermediary metabolism, presumably because of an increase in insulin-independent glucose influx. These results provide insights into possible preventive and therapeutic intervention of diabetic retinopathy.

The extremely unfavorable prognosis of intrahepatic cholangiocarcinoma (ICC), even after surgical resection, is mainly attributed to a high rate of recurrence. The aim of this study was to identify the molecules associated with early recurrence of ICC following resection.Between December 1984 and July 2003, 46 patients with ICC underwent surgical resection. The clinical outcome of these patients was evaluated in view of the time of recurrence. Consequently, we categorized ICC patients into subgroups, based on the clinical results, and screened differentially expressed genes by DNA microarray analysis. Furthermore, the obtained results were validated in an independent sample set by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Immunohistochemistry was performed to assess the expressed genes at the protein level.The survival of patients with early recurrence, occurring within a year after surgical resection, was significantly poor after surgery and even after recurrence, as compared to that of patients whose recurrence occurred beyond a year after surgery. By the DNA microarray analysis, 13 differentially expressed genes were picked up, and quantitative RT-PCR reaction identified the pancreatic secretory trypsin inhibitor (PSTI) as a candidate gene associated with early recurrence of ICC after resection. This observation was confirmed through examination of an independent set of samples, in which the patients with higher levels of PSTI mRNA expression had significantly shorter recurrence-free survival. Immunohistochemically, PSTI was expressed in the cytoplasm of cancer cells.PSTI might be a potential marker for identifying ICC patients with an increased risk of early recurrence after surgical resection.

SEREX has been applied to esophageal SCC, and the TRIM21 gene was identified as a novel SEREX antigen of esophageal SCC. The presence of s-TRIM21-Abs was confirmed by Western blotting using bacterially expressed TRIM21 gene product and was evaluated for clinicopathological significance in patients with esophageal SCC. s-TRIM21-Abs were detected in 18 (20%) of 91 patients with esophageal SCC but not in 42 healthy donors. The presence of s-TRIM21-Abs was partly associated with tumor size (P = 0.063) and poor survival (P = 0.067). To measure serum antibody levels, ELISA using purified recombinant TRIM21 protein was developed. The levels of s-TRIM21-Abs were significantly higher in patients with esophageal SCC than in healthy donors (P = 0.013). s-TRIM21-Abs may be a useful tumor marker to diagnose and predict disease progression in patients with esophageal SCC.

Cathepsin D is an aspartyl protease involved in protein catabolism and tissue remodeling which can be secreted from cancer cells. To identify a potential serum marker for gliomas, we investigated the gene expression levels of cathepsin D in 87 tissue samples and measured the protein concentrations in sera of glioma patients. The tissue samples consisted of 43 glioblastomas, 13 anaplastic astrocytomas, 22 astrocytomas, and 9 normal brain tissues. The results of real-time quantitative reverse transcription-PCR analysis showed that cathepsin D transcript levels became significantly higher as the glioma grade advanced (P = 0.0466, glioblastoma and anaplastic astrocytoma; P = 0.0008, glioblastoma and astrocytoma; P = 0.0271, glioblastoma and normal brain tissue; unpaired t test). Immunohistochemical analysis with anti-cathepsin D antibody revealed dense and spotty staining in the tumor cells with high transcript levels. The low expression of cathepsin D significantly correlated with long survival of the glioma patients. Furthermore, the glioblastoma patients with high gene expression of cathepsin D lived significantly shorter than those with low expression (P = 0.0104, Cox-Mantel log-rank test) and frequently had leptomeningeal dissemination (P = 0.0016, χ2 test). The multivariate analysis confirmed that the cathepsin D expression level was an independent predictor for short survival (P = 0.0102, Cox proportional hazard regression model). Measurement of the serum cathepsin D concentrations by ELISA showed a significant increase in the patients with high-grade gliomas as compared with the low-grade tumors (P = 0.0081, χ2 test). These results collectively suggest that cathepsin D could be a potential serum marker for the prediction of aggressive nature of human gliomas.

We applied serological analysis of recombinant cDNA expression libraries (SEREX) to cases of esophageal squamous cell carcinoma (SCC) to identify tumor antigens. One of the clones identified was TROP2, which is known as calcium signal transducer. To evaluate the clinical significance of serum anti-TROP2 antibodies (s-TROP2-Abs) in patients with esophageal SCC, the presence of s-TROP2-Abs was analyzed by Western blotting using bacterially expressed TROP2 protein. We found that 23 of 75 (31%) patients were positive for s-TROP2-Abs. Positivity in terms of s-TROP2-Abs showed a significant association with tumor size but not with other clinicopathological features. The protein expression levels of TROP2 were much higher in esophageal SCC cell lines as compared to those in normal esophageal mucosa and its immortalized cells although the mRNA expression levels were not necessarily elevated in malignant cell lines and tissues. Immunohistochemical studies showed that the expression of TROP2 protein in esophageal SCC specimens was noticeably higher than that found in mild hyperplasia of esophageal mucosae. Thus, s-TROP2-Abs seemed useful in the diagnosis of SCC and may be a candidate for serum tumor markers.

Comprehensive analysis of the changes in gene expression during liver regeneration was carried out by using an in-house microarray composed of 2,304 distinct mouse liver cDNA clones. Mice were subjected to partial two-thirds hepatectomy, and changes in mRNA levels were monitored up to 48 h. Of the 2,304 genes analyzed, 496 genes showed expression levels measurable at all time points after the partial hepatectomy. 317 genes were up- or down-regulated 2-fold or more at least at one time point during liver regeneration and were classified into eight clusters based on their expression patterns. With a more stringent cut-off value of +/-2 S.D., 68 genes were listed and were classified into five clusters. In these two analyses with different clustering criteria, functionally categorized genes showed similar cluster distributions. Genes involved in protein synthesis and posttranslational processing were significantly enriched in the cluster characterized by rapid gene activation and subsequent persistence. This suggests the importance of modulating the efficiency of protein supply and/or altering the composition of protein population from the early phase of hepatocyte proliferation. Genes for two major liver functions, i.e. plasma protein secretion and intermediate metabolism were enriched in distinct clusters exhibiting the features of gradual gene activation and sustained repression, respectively. Therefore, these genes are differentially regulated during the regeneration, possibly leading to changes in the flow of amino acids and energy from enzyme proteins to plasma proteins in their synthesis. Thus, clustering analysis of expression patterns of functionally classified genes gave insights into mechanism and pathophysiology of liver regeneration.

Members of the CCAAT/enhancer-binding protein (C/EBP) family of transcription factors are pivotal regulators of liver functions such as nutrient metabolism and its control by hormones, acute-phase response and liver regeneration. Recent progress in clarification of regulatory mechanisms for the C/EBP family members gives insight into understanding the liver functions at the molecular level.

Background Because circulating antibodies against a variety of antigens have been detected in patients with coronary heart disease, carotid atherosclerosis and those who have suffered a stroke, it is suspected that immune response may be one of the mechanisms of atherogenesis The objective of this study is to identify novel antibodies in ischemic stroke patients by screening the expressed recombinant proteins using a human cDNA library (SEREX). Methods To identify the candidate antigens, cDNA library was screened by SEREX using plasma from ten patients with ischemic stroke. Subsequently, via ELISA using recombinant proteins and synthetic peptides, the serum antibody levels were measured in two independent patient/healthy donor (HD) cohorts (142 and 78 in the 2nd screening and a validation cohort, respectively). Results The initial screening resulted in the identification of six candidate antigens. Of these antigens, replication protein A2 (RPA2) was determined to be the antigen associated with stroke (P

The lung-specific surfactant proteins (SP) are essential for normal respiratory function. Transcription factors may play an important role in the regulation of surfactant proteins. The CCAAT/enhancer-binding protein (C/EBP) family consists of transcription factors that can stimulate expression of genes in lipid-metabolizing epithelial cells. C/EBPalpha-deficient mice have been shown to exhibit abnormal pulmonary histopathology. Recently, we demonstrated that C/EBP family members are differentially expressed in alveolar type II cell proliferation and in pulmonary fibrosis. In the present study, to investigate whether the C/EBP family would be involved in the regulation of surfactant proteins, we examined the protein expression of SP-A, and SP-C, and mRNA expression of SP-A, SP-B, and SP-C in the lungs from newborn C/EBPalpha-deficient mice. Using immunohistochemistry, we demonstrated that positive cells for SP-C, specific to alveolar type II cells, in the lungs were more abundant in the newborn C/EBPalpha-deficient mice than in control mice, which suggests the hyperproliferation of alveolar type II cells in the lungs of the C/EBPalpha-deficient mice. In situ hybridization analysis revealed that expression of SP-A, SP-B, and SP-C mRNAs were increased in the lungs of newborn C/EBPalpha-deficient mice. Northern blot analysis revealed that surfactant protein mRNAs were also increased. Thus, these results suggest that C/EBPalpha may play a key role in the proliferation of alveolar type II cells and the regulation of genes of surfactant protein.

The gene for a transcription factor hepatocyte nuclear factor-4alpha (HNF-4alpha) is responsible for maturity-onset diabetes of the young, type 1. We examined hormonal regulation of the HNF-4alpha gene in the liver. Stimulation of primary-cultured rat hepatocytes with dexamethasone or glucagon led to induction of HNF-4alpha mRNA, being antagonized by insulin. In the liver of streptozotocin-induced diabetic rat, mRNA and protein levels for HNF-4alpha were elevated, and were normalized by insulin treatment. Therefore, HNF-4alpha in the liver is likely to be involved in the regulation of glucose metabolism in response to these hormones.

Nitric oxide (NO) is involved in many physiological and pathological processes in the brain. NO is synthesized from arginine by nitric oxide synthase (NOS), with citrulline generated as a by-product of the reaction. Thus, citrulline can by recycled to arginine by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL) via the citrulline-NO cycle. Rat astroglioma C6 cells were treated with bacterial lipopolysaccharide (LPS), interferon-gamma (IFNgamma) and tumor necrosis factor-alpha, and the expression of the enzymes of the citrulline-NO cycle was investigated by RNA blot and immunoblot analyses. NO production from arginine and citrulline was also assessed. iNOS mRNA and protein were induced 6-12 h after stimulation with LPS and cytokines and decreased at 24 h. AS mRNA increased up to 12 h and decreased at 24 h. AS protein increased gradually up to 48 h. On the other hand, AL mRNA remained unchanged by stimulation. NO production from arginine was enhanced by the treatment with LPS and cytokines. NO production was also observed when arginine was replaced by citrulline. These results indicate that NO production is enhanced in LPS- and cytokine-stimulated C6 cells due to induction of iNOS and that the citrulline-arginine recycling is important for NO production.

We previously identified various upstream and downstream regulatory elements and factors important for hepatic expression of the human angiotensinogen (ANG) gene, the precursor of vasoactive octapeptide angiotensin II. In the present study, to further investigate the molecular mechanism of human ANG transcriptional regulation, we generated transgenic mice carrying the fusion gene composed of the 1. 3-kilobase promoter of the human ANG gene, its downstream enhancer, and the chloramphenicol acetyltransferase reporter gene. Because expression of the chloramphenicol acetyltransferase gene was observed strongly in the liver and weakly in the kidney, we suspected that hepatocyte nuclear factor (HNF) 4 with a tissue expression pattern similar to that of the reporter gene would regulate ANG transcription. In vitro assays indicated that HNF4 bound to the promoter elements and strongly activated the ANG transcription, but that chicken ovalbumin upstream promoter transcription factor (COUP-TF), a transcriptional repressor, dramatically repressed human ANG transcription through the promoter elements and the downstream enhancer core elements. Furthermore, COUP-TF dramatically decreased the human ANG transcription in the mouse liver by the Helios Gene Gun system in vivo. These results suggest that an interplay between HNF4 and COUP-TF could be important in hepatic human ANG transcription.

Hyperammonemia in the brain leads to poorly understood alterations of nitric oxide (NO) synthesis. Arginine, the substrate of nitric oxide synthases, might be recycled from the citrulline produced with NO by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL). The regulation of AS and AL genes during hyperammonemia is unknown in the brain. We used brain cell aggregates cultured from dissociated telencephalic cortex of rat embryos to analyze the regulation of AS and AL genes in hyperammonemia. Using RNase protection assay and non-radioactive in situ hybridization on aggregate cryosections, we show that both AS and AL genes are induced in astrocytes but not in neurons of aggregates exposed to 5 mM NH4Cl. Our work suggests that the hyperammonemic brain might increase its recycling of citrulline to arginine.

Ammonia produced by amino acid metabolism is detoxified through conversion into urea by the ornithine cycle in the liver, whereas carbon skeletons of amino acids are converted to glucose by gluconeogenic enzymes. Promoter and enhancer sequences of several genes for ornithine cycle enzymes interact with members of the CCAAT/enhancer-binding protein (C/EBP) transcription factor family. Disruption of the C/EBPalpha gene in mice causes hypoglycemia associated with the impaired expression of gluconeogenic enzymes. Here we examined the expression of ornithine cycle enzyme genes in the livers of C/EBPalpha-deficient mice. mRNA levels for the first, third, fourth, and fifth enzymes of five enzymes in the cycle were decreased in C/EBPalpha-deficient mice. Protein levels for the first, second, fourth, and fifth enzymes were also decreased. In situ hybridization analysis revealed that the enzyme mRNAs were distributed normally in the periportal region but were disordered in C/EBPalpha-deficient mice with relatively higher mRNA levels in the midlobular region. Blood ammonia concentrations in the mutant mice were severalfold higher than in wild-type mice. Thus, C/EBPalpha is crucial for ammonia detoxification by ornithine cycle enzymes and for coordination of gluconeogenesis and urea synthesis.

Granule major basic protein (MBP) is expressed exclusively in eosinophils, basophils, and placental trophoblasts. To identify thecis-elements and transcription factors involved in regulating MBP expression, we subcloned 3.2 kb of sequence upstream of the exon 9 transcriptional start site (P2 promoter) and serial 5′ deletions into the pXP2 luciferase reporter vector. An 80% decrement in promoter activity was obtained when MBP sequences between bp −117 to −67 were deleted. To identify transcription factors that bind to and transactivate through the bp −117 to −67 region, we first compared the upstream genomic sequences of human and murine MBP; a potential GATA binding consensus site was conserved in the 50-bp region between the two genes. To determine which GATA proteins bind this consensus site, we performed electrophoretic mobility shift assays (EMSAs), which showed that both GATA-1 and GATA-2 can bind to this consensus site. To determine the functionality of this site, we tested whether GATA-1 and GATA-2, either individually or in combination, can transactivate the MBP promoter in the Jurkat T cell line. Cotransfection with a GATA-1 expression vector produced 20-fold augmentation of MBP promoter activity, whereas GATA-2 had no activity. In contrast, combined cotransfection of GATA-1 and GATA-2 decreased the ability of GATA-1 to transactivate the MBP promoter by approximately 50%. Our results provide the first evidence for a GATA-1 target gene in eosinophils, a negative regulatory role for GATA-2 in MBP expression, and possibly eosinophil gene transcription in general during myelopoiesis.

Arginine is a precursor for the synthesis of urea, polyamines, creatine phosphate, nitric oxide and proteins. It is synthesized from ornithine by argininosuccinate synthetase and argininosuccinate lyase and is degraded by arginase, which consists of a liver-type (arginase I) and a non-hepatic type (arginase II). Recently, cDNAs for human and rat arginase II have been isolated. In this study, immunocytochemical analysis showed that human arginase II expressed in COS-7 cells was localized in the mitochondria. Arginase II mRNA was abundant in the rat small intestine and kidney. In the kidney, argininosuccinate synthetase and lyase were immunostained in the cortex, intensely in proximal tubules and much less intensely in distal tubules. In contrast, arginase II was stained intensely in the outer stripes of the outer medulla, presumably in the proximal straight tubules, and in a subpopulation of the proximal tubules in the cortex. Immunostaining of serial sections of the kidney showed that argininosuccinate synthetase and arginase II were collocalized in a subpopulation of proximal tubules in the cortex, whereas only the synthetase, but not arginase II, was present in another subpopulation of proximal tubules. In the liver, all the enzymes of the urea cycle, i.e. carbamylphosphate synthetase I, ornithine transcarbamylase, argininosuccinate synthetase and lyase and arginase I, showed similar zonation patterns with staining more intense in periportal hepatocytes than in pericentral hepatocytes, although zonation of ornithine transcarbamylase was much less prominent. The implications of these results are discussed.

Nitric oxide is synthesized by nitric-oxide synthase from arginine, a common substrate of arginase. Rat peritoneal macrophages were cultured in the presence of bacterial lipopolysaccharide (LPS), and expression of the inducible isoform of nitric-oxide synthase (iNOS) and liver-type arginase (arginase I) was analyzed. mRNAs for iNOS and arginase I were induced by LPS in a dose-dependent manner. iNOS mRNA appeared 2 h after LPS treatment and increased to a near maximum at 8-12 h. On the other hand, arginase I mRNA that was undetectable prior to the treatment began to increase after 4 h with a lag time and reached a maximum at 12 h. Immunoblot analysis showed that iNOS and arginase I proteins were also induced. mRNA for arginase II, an arginase isozyme, was not detected in the LPS-activated peritoneal cells. mRNA for CCAAT/enhancer-binding protein beta (C/EBPbeta), a transactivator of the arginase I gene, was also induced, and the induction was more rapid than that of arginase I mRNA. Changes in iNOS and arginase I mRNAs were also examined in LPS-injected rats in vivo. iNOS mRNA increased rapidly in the lung and spleen, reached a maximum 2-6 h after the LPS treatment, and decreased thereafter. Arginase I mRNA was induced markedly and more slowly in both tissues, reaching a maximum in 12 h. Thus, arginase I appears to have an important role in down-regulating nitric oxide synthesis in murine macrophages by decreasing the availability of arginine, and the induction of arginase I is mediated by C/EBPbeta.

The gene for liver-type arginase, an ornithine cycle enzyme, is induced by glucocorticoids in a delayed secondary manner. An enhancer element located around intron 7 of the rat arginase gene shows delayed glucocorticoid responsiveness, and it harbors two sites binding with members of the CCAAT/enhancer binding protein (C/EBP) family. Here, we investigate the role of these C/EBP binding sites in glucocorticoid response of the arginase gene. When inserted in front of the herpes simplex virus thymidine kinase promoter, these C/EBP sites exhibited glucocorticoid responsiveness in reporter transfection assay using rat hepatoma H4IIE cells. In footprint analysis using nuclear extracts of H4IIE cells, profiles of the protected areas of the two C/EBP sites changed when cells were treated with dexamethasone. In gel shift analysis, the complex formation for the two C/EBP sites was augmented in response to dexamethasone. Antibody supershift/inhibition analysis demonstrated that a major portion of the binding proteins induced by dexamethasone is C/EBPβ. Induction of arginase mRNA by dexamethasone was preceded by augmentation of the C/EBP site-binding activities, which followed increase in C/EBPβ mRNA. These results were consistent with the notion that the glucocorticoid response of the arginase gene is mediated by C/EBPβ.

Systemic carnitine-deficient juvenile visceral steatosis (JVS) mice exhibit decreased expression of some liver-selective genes including those for the urea cycle enzymes during the infantile period. At 25 days, carbamoylphosphate synthetase (CPS) mRNA level was remarkably low in the liver of JVS mice, and the HNF-4 and C/EBP-alpha mRNA contents were also reduced. HNF-3 alpha and C/EBP-beta mRNAs were slightly higher in the liver of JVS mice, and HNF-1 mRNA remained normal. These results, together with the developmental changes of these transcription factor mRNA levels, suggest that HNF-4 and C/EBP-alpha are involved in the suppression of CPS expression. If JVS mice survived the crisis at 4-5 weeks, their body weight caught up with that of control mice around 7 weeks. The steady-state levels of CPS and argininosuccinate synthetase (ASS) mRNAs in the liver of JVS mice were normalized by no later than 8 weeks. Starvation for 48 h caused an increase of about twofold in CPS and ASS mRNA levels in the liver of control mice, while the same treatment failed to increase their levels in the liver of JVS mice. The starvation similarly caused increases in HNF-4 and C/EBP-beta mRNA levels in the liver of both control and JVS mice, but the increases were significantly less in JVS mice than in control mice. Thus, the lack of induction of CPS and ASS mRNAs during development and under starvation in JVS mice correlated with the lower induction of HNF-4 and C/EBP-alpha mRNAs, and of HNF-4 and C/ EBP-beta mRNAs, respectively. Furthermore, all these changes seemed to correlate with the presence of fatty liver and the high serum free fatty acid levels, suggesting that disturbance of fatty acid metabolism affects nitrogen metabolism at least in part via altered gene expression of transcription factors such as HNF-4, C/EBP-alpha, and C/EBP-beta.

Mouse embryonic stem cells can differentiate into various cell types within cell aggregates called embryoid bodies (EBs). This structure consists of ectodermal, mesodermal, and endodermal tissues, which resemble the embryo of egg-cylinder stage. After 8-10 days in culture, about half of the EBs expand into large cystic structures homologous to visceral yolk sac of postimplantation embryos. To study endoderm differentiation at molecular level, we examined expression of endoderm marker genes during the processes of EB development. alpha-Fetoprotein (AFP) and transthyretin (TTR) transcripts increased at the stage when embryoid bodies began to form yolk-sac-like structures and were expressed strongly thereafter. Expression of hepatocyte nuclear factor (HNF) 4, a variant form of HNF1 (also called HNF1beta), and HNF3beta started before the onset of AFP and TTR expression. HNF1 (also called HNF1alpha) expression began a few days after the onset of the expression of the transcription factors described above. Serum albumin (ALB) transcript was only found in late large cystic EBs. Also, AFP gene expression preceded ALB gene expression. These results suggest that the patterns of endoderm gene expression during EB development reflect the order found during mouse development in vivo, and EB formation may serve as an in vitro system to study the differentiation process.

The synthetic glucocorticoid, dexamethasone, and glucagon cooperatively elevated the level of mRNA for the transcription factor CCAAT/enhancer binding protein beta (C/EBP beta) in primary-cultured rat hepatocytes. In response to dexamethasone and/or glucagon, C/EBP beta mRNA started to increase as early as 30 min, reached a maximum within 2 h, and then gradually decreased. The administration of cycloheximide, a protein synthesis inhibitor, led rather to an increase in C/EBP beta mRNA, which suggested that a labile negative protein factor(s) is involved in regulation of the C/EBP beta mRNA level. Cycloheximide further augmented the increases in C/EBP beta mRNA by dexamethasone and/or glucagon. Therefore, C/EBP beta mRNA accumulation in response to these hormones is apparently independent of ongoing protein synthesis. The elevation of the C/EBP beta mRNA level by these hormones was accounted for by increases in the rate of transcription of the C/EBP beta gene, as deduced on nuclear run-on analysis. Gel mobility shift analysis revealed that the DNA-binding activity of C/EBP beta was increased cooperatively by dexamethasone and glucagon. These results suggest that the C/EBP beta gene is primarily induced by glucocorticoids and/or glucagon and that the accumulated C/EBP beta protein is then involved in secondary activation of target genes in response to these hormones in the liver.

In an attempt to elucidate the mechanism governing liver-specific transcription of the arginase gene, we previously detected two protein-binding sites designated footprint areas A and B at positions around--90 and --55 bp, respectively, relative to the transcription start site of the rat arginase gene. Based on the finding that area A was bound by a liver-selective factor(s) related to CCAAT/enhancer-binding protein (C/EBP), we performed cotransfection assay and showed that C/EBP family members and a related factor, albumin D-element-binding protein (DBP) stimulate transcription from the arginase promoter. In addition to area A, a recombinant C/EBP beta protein bound to area B, which appeared to be primarily responsible for activation by C/EBPs. We unexpectedly found that the arginase promoter activity stimulated by C/EBPs and DBP was repressed by another liver-enriched transcription factor, hepatocyte nuclear factor-4 (HNF-4). Analysis of chimeras formed between the arginase promoter and the herpes simplex virus thymidine kinase promoter allowed us to delimit the negative HNF-4-responsive element into the region overlapping with footprint area B. However, no apparent binding of HNF-4 was observed in this negative element. We speculate that HNF-4 is involved in fine regulation of the arginase gene in the liver or shutdown of the gene in nonhepatic tissues without direct binding to the promoter region.

Nitric oxide (NO) is synthesized from arginine by nitric oxide synthase (NOS), and citrulline which is generated can be recycled to arginine by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL). Rats were injected with bacterial lipopolysaccharide (LPS), and expression of the inducible isoform of NOS (iNOS), AS, and AL was analyzed. In RNA blot analysis, iNOS mRNA was undetectable before the LPS treatment but was induced by LPS in the lung, heart, liver, and spleen, and less strongly in the skeletal muscle and testis. AS mRNA was induced in the lung and spleen, and AL mRNA was weakly induced in these tissues. AS and AL mRNAs were abundant in the control liver and remained unchanged after the treatment. Kinetic studies showed that iNOS mRNA increased rapidly in both spleen and lung, reached a maximum 2-5 h after the treatment, and decreased thereafter. On the other hand, AS mRNA increased more slowly and reached a maximum in 6-12 h (by about 10-fold in the spleen and 2-fold in the lung). AL mRNA in the spleen and lung increased slowly and remained high up to 24 h. In immunoblot analysis, increase of iNOS protein was evident in the lung, liver, and spleen, and there was an increase of AS protein in the lung and spleen. In immunohistochemical analysis, macrophages in the spleen that were negative for iNOS and AS before LPS treatment were strongly positive for both iNOS and AS after this treatment. As iNOS, AS, and AL were coinduced in rat tissues and cells, citrulline-arginine recycling seems to be important in NO synthesis under the conditions of stimulation.

Nitric oxide (NO) is synthesized from arginine by nitric oxide synthase, generating citrulline as another product, which can be recycled to arginine by argininosuccinate synthetase and argininosuccinate lyase. Rat argininosuccinate synthetase was expressed in Escherichia coli as a fusion protein with maltose binding protein, cleaved from binding protein, and purified. The purified synthetase had no enzyme activity. Rat argininosuccinate lyase was expressed in E. coli using pET-3a as a vector, and purified. The purified enzyme had a specific enzyme activity of arginine formation of 2.6 mumol/min/mg protein at 37 degrees C, the value being somewhat lower than those of the enzyme purified from various tissues. Antibodies against these enzymes were produced in rabbits. Immunoblot analyses showed that the two enzymes are most abundant in the liver, followed by kidney and testis. Smaller amounts of the enzyme proteins were present in other tissues. RNA blot analysis showed that the argininosuccinate synthetase mRNA was most abundant in the liver and kidney, followed by testis and other tissues. On the other hand, argininosuccinate lyase mRNA was most abundant in the testis, followed by kidney and liver, and by other tissues. These results show that argininosuccinate synthetase and argininosuccinate lyase are expressed both tissue-specifically and ubiquitously, and that practically all tissues have activities to convert citrulline to arginine.

The gene for rat argininosuccinate lyase (AL), which catalyzes the last step of arginine biosynthesis, is expressed in many tissues, though its expression is much higher in the liver where the enzyme is involved in the ornithine cycle (urea cycle), and moderately higher in the kidney. In transient transfection analysis using various cell lines, the AL promoter exhibited considerable levels of activity in all tested cell lines, with no apparent liver cell specificity, presumably reflecting the ubiquitous expression of this gene. Analysis of 5'-deletion mutants of the promoter region revealed several cis-regulatory elements, whose contribution to the promoter activity seemed to vary according to cell type. The most prominent positive regulatory region was detected around the position -80 base pairs, and it overlapped with a dyad-symmetric CCAAT box sequence CCAATTGG. A factor(s) interacting with this sequence element was found to be present ubiquitously. Gel shift competition analysis and antibody double shift analysis showed that this factor was identical or highly similar to a transcription factor, nuclear factor-Y (NF-Y), which consists of two different subunits and recognizes CCAAT motifs in various promoters. Point mutagenesis at each half site of the palindrome CCAATTGG and the introduction of a space between the half-site motifs abolished the binding with NF-Y. Thus, it seems that NF-Y recognizes the correctly spaced dyad-symmetric CCAAT box.