Effect of genetic factors on the interindividual variability of warfarin dosage requirements in Japanese patients after adjusting for renal function.

Renal function significantly influences the appropriate warfarin dosage. However, studies investigating the impact of genetic factors on warfarin dosage, considering renal function, are limited. This study aimed to assess the role of genetic polymorphisms in VKORC1, CYP2C9, CYP2C19, CYP4F2, GGCX, and APOE in warfarin dosage adjustment considering renal function. A total of 108 outpatients receiving warfarin treatment with controlled prothrombin time-targeted international normalized ratio (1.5-3.0) were included. Patient data, warfarin dosage, and laboratory results were collected from electronic medical records. Each SNP [VKORC1 rs9923231, CYP2C9 rs1057910, CYP4F2 rs2108622, CYP2C19* 2 (rs4244285) and* 3 (rs4986893), GGCX rs699664 and rs12714145, and APOE rs7421] was analyzed. Multiple regression analysis revealed estimated glomerular filtration rate as the most significant factor influencing warfarin dose (p <0.001) (ß = -0.445). VKORC1 rs9923231 AA, CYP4F2 rs2108622 CT/TT, GGCX rs12714145 CT/TT, and CYP2C9 rs1057910 AC carriers were associated with warfarin dose (p <0.001, 0.015, 0.020, 0.038 and ß = -0.317, 0.191, -0.188, -0.162, respectively); however, other genes showed no significant association. In conclusion, after adjusting for renal function, genetic factors of VKORC1 rs9923231, CYP4F2 rs2108622, GGCX rs12714145, and CYP2C9 rs1057910 were found to contribute to warfarin dosage, having impact in that order. In contrast, the contribution of other genes to warfarin dosage was absent or negligible.

Morphological characterisation of glial and neuronal tau pathology in globular glial tauopathy (Types II and III).

AIMS: Globular glial tauopathy (GGT) is a new category within the 4-repeat tauopathies that is characterised neuropathologically by tau-positive globular glial inclusions (GGIs), namely, globular oligodendrocytic and astrocytic inclusions (GOIs and GAIs). Occurrence of tau-positive neuronal cytoplasmic inclusions (NCIs) is also a feature. GGT is classified into three pathological subtypes (Types I, II and III). We studied the tau pathology in 6 cases of GGT (Type II, n = 3; Type III, n = 3), with special reference to GAIs and NCIs. METHODS: Neuropathological examinations were conducted, along with immunohistochemistry, morphometry and three-dimensional imaging, and biochemical and genetic analysis of tau. RESULTS: The cortical GAIs in Type II and those in Type III were distinguishable from each other. In the motor cortex, GAIs were much more numerous in Type III than in Type II. Prominent occurrence of perikaryal globular structures was a feature of GAIs in Type III. By contrast, prominent occurrence of radiating process-like structures was a feature of GAIs in Type II. Overall, the GAIs were significantly smaller in Type III than in Type II. NCIs were divisible into three subgroups in terms of shape: diffuse granular, thick cord-like, and round/horseshoe-shaped structures. In all cases, NCIs were a feature of the upper and lower motor neurons. Interestingly, the round/horseshoe-shaped NCIs were observed only in Type III cases. CONCLUSIONS: These findings, which characterised GAIs and NCIs, indicated that Type II and Type III constitute two distinct pathological subtypes, and also further strengthen the concept of GGT as a distinct entity.

Genetic and phenotypic profile of 112 patients with X-linked Charcot-Marie-Tooth disease type 1.

BACKGROUND AND PURPOSE: X-linked Charcot-Marie-Tooth disease type 1 (CMTX1), caused by mutations in gap junction protein beta 1 (GJB1), is characterized by various central nervous system symptoms and gender differences of clinical severity. The aim of this study was to identify the frequency and mutation spectrum of CMTX1 patients in Japan and to demonstrate their phenotypic diversities. METHODS: Using three high-throughput sequencing systems, targeted gene panel sequencing on 1483 unrelated index patients with suspected Charcot-Marie-Tooth (CMT) disease was performed. The peripheral and central nervous system involvements of all patients with GJB1 variants were assessed retrospectively and a detailed gender comparison was conducted with the CMT examination score. RESULTS: Twenty-three novel and 36 described GJB1 variants were identified from 88 pedigrees, in which 34 female and 78 male patients were enrolled. Mean age at onset of the male patients was much younger than the females, 21.56 ± 17.63 years vs. 35.53 ± 23.72 years (P = 0.007). Male patients presented with more severe phenotypes in every examination item, but statistical differences were observed only in motor dysfunctions of the lower extremities and vibration sensation. No significant sensory difference was identified between genders, either clinically or electrophysiologically. Central nervous system dysfunctions were found in 15 patients from 12 pedigrees. Therein, six patients developed stroke-like phenotypes, with dysarthria as the leading symptom. CONCLUSIONS: A relatively lower frequency of CMTX1 (5.9%) was demonstrated and a broad mutation spectrum of GJB1 was described. Detailed clinical differences between genders and various central nervous system symptoms were also illustrated, even in the same pedigree.

Clinical and mutational spectrum of Japanese patients with Charcot-Marie-Tooth disease caused by GDAP1 variants.

BACKGROUND: Mutations in GDAP1 are responsible for heterogeneous clinical and electrophysiological phenotypes of Charcot-Marie-Tooth disease (CMT), with autosomal dominant or recessive inheritance pattern. The aim of this study is to identify the clinical and mutational spectrum of CMT patients with GDAP1 variants in Japan. MATERIALS AND METHODS: From April 2007 to October 2014, using three state-of-art technologies, we conducted gene panel sequencing in a cohort of 1,030 patients with inherited peripheral neuropathies (IPNs), and 398 mutation-negative cases were further analyzed with whole-exome sequencing. RESULTS: We identified GDAP1 variants from 10 patients clinically diagnosed with CMT. The most frequent recessive variant in our cohort (5/10), c.740C>T (p.A247V), was verified to be associated with a founder event. We also detected three novel likely pathogenic variants: c.928C>T (p.R310W) and c.546delA (p.E183Kfs*23) in Case 2 and c.376G>A (p.E126K) in Case 8. Nerve conduction study or sural nerve biopsy of all 10 patients indicated axonal type peripheral neuropathy. CONCLUSION: We identified GDAP1 variants in approximately 1% of our cohort with IPNs, and established a founder mutation in half of these patients. Our study originally described the mutational spectrum and clinical features of GDAP1-related CMT patients in Japan.

Clinical and mutational spectrum of Charcot-Marie-Tooth disease type 2Z caused by MORC2 variants in Japan.

BACKGROUND AND PURPOSE: The microrchidia family CW-type zinc finger 2 gene (MORC2) was newly identified as a causative gene of Charcot-Marie-Tooth disease (CMT) type 2Z in 2016. We aimed to describe the clinical and mutational spectrum of patients with CMT harboring MORC2 mutations in Japan. METHODS: We analyzed samples from 781 unrelated patients clinically diagnosed with CMT using deoxyribonucleic acid microarray or targeted resequencing by next-generation sequencing, and samples from 434 mutation-negative patients were subjected to whole-exome sequencing. We extracted MORC2 variants from these whole-exome sequencing data and classified them according to American College of Medical Genetics standards and guidelines. RESULTS: We identified MORC2 variants in 13 patients. As the second most common causative gene of CMT type 2 after MFN2, MORC2 variants were detected in 2.7% of patients with CMT type 2. The mean age of onset was 10.3 ± 8.7 years, and the inheritance pattern was mostly sporadic (11/13 patients, 84.6%). The clinical phenotype was typically length-dependent polyneuropathy, and electrophysiological studies revealed sensory-dominant axonal neuropathy. Mental retardation was identified in 4/13 patients (30.8%). p.Arg190Trp, as a mutational hotspot, was observed in eight unrelated families. We also identified two novel probably pathogenic variants, p.Cys345Tyr and p.Ala369Val, and one novel uncertain significance variant, p.Tyr332Cys. CONCLUSIONS: Our study is the largest report of patients harboring MORC2 variants. We revealed a clinical and mutational spectrum of Japanese patients with MORC2 variants. More attention should be paid to cognitive impairment, and the responsible mechanism requires further research for elucidation.

FoxO1 signaling plays a pivotal role in the cardiac telomere biology responses to calorie restriction.

This study examined whether the forkhead transcription factors of O group 1 (FoxO1) might be involved in telomere biology during calorie restriction (CR). We used FoxO1-knockout heterozygous mice (FoxO1(+/-)) and wild-type mice (WT) as a control. Both WT and FoxO1(+/-) were subjected to ad libitum (AL) feeding or 30% CR compared to AL for 20 weeks from 15 weeks of age. The heart-to-body weight ratio, blood glucose, and serum lipid profiles were not different among all groups of mice at the end of the study. Telomere size was significantly lower in the FoxO1(+/-)-AL than the WT-AL, and telomere attrition was not observed in either WT-CR or FoxO1(+/-)-CR. Telomerase activity was elevated in the heart and liver of WT-CR, but not in those of FoxO1(+/-)-CR. The phosphorylation of Akt was inhibited and Sirt 1 was activated in heart tissues of WT-CR and FoxO1(+/-)-CR. However, the ratio of conjugated to cytosolic light chain 3 increased and the level of p62 decreased in WT-CR, but not in FoxO1(+/-)-CR. A marker of oxidative DNA damage, 8-OhdG, was significantly lower in WT-CR only. The level of MnSOD and eNOS increased, and the level of cleaved caspase-3 decreased in WT-CR, but not FoxO1(+/-)-CR. Echocardiography showed that the left ventricular end-diastolic and systolic dimensions were significantly lower in WT-CR or FoxO1(+/-)-CR than WT-AL or FoxO1(+/-)-AL, respectively. The present studies suggest that FoxO1 plays beneficial roles by inducing genes involved in telomerase activity, as well as anti-oxidant, autophagic, and anti-apoptotic genes under conditions of CR, and suggest that FoxO1 signaling may be an important mediator of metabolic equilibrium during CR.

Identification and functional activity of a staphylocoagulase type XI variant originating from staphylococcal food poisoning isolates.

UNLABELLED: Staphylocoagulase, an extracellular protein secreted by Staphylococcus aureus, has been used as an epidemiological marker. At least 12 serotypes and 24 genotypes subdivided on the basis of nucleotide sequence have been reported to date. In this study, we identified a novel staphylocoagulase nucleotide sequence, coa310, from staphylococcal food poisoning isolates that had the ability to coagulate plasma, but could not be typed using the conventional method. The protein encoded by coa310 contained the six fundamental conserved domains of staphylocoagulase. The full-length nucleotide sequence of coa310 shared the highest similarity (77·5%) with that of staphylocoagulase-type (SCT) XIa. The sequence of the D1 region, which would be responsible for the determination of SCT, shared the highest similarity (91·8%) with that of SCT XIa. These results suggest that coa310 is a novel variant of SCT XI. Moreover, we demonstrated that coa310 encodes a functioning coagulase, by confirming the coagulating activity of the recombinant protein expressed from coa310. This is the first study to directly demonstrate that Coa310, a putative SCT XI, has coagulating activity. These findings may be useful for the improvement of the staphylocoagulase-typing method, including serotyping and genotyping. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to identify a novel variant of staphylocoagulase type XI based on its nucleotide sequence and to demonstrate coagulating activity in the variant using a recombinant protein. Elucidation of the variety of staphylocoagulases will provide suggestions for further improvement of the staphylocoagulase-typing method and contribute to our understanding of the epidemiologic characterization of Staphylococcus aureus.

Forced expression of PDX-1 gene makes hepatoma cells to acquire glucose-responsive insulin secretion while maintaining hepatic characteristic.

Evidence shows that forced expression of the PDX1 gene converts hepatoma cells, mouse liver epithelial cells (MLECs) and HepaRG cells, into insulin—producing cells, β—cells, or islets of Langerhans. However, no reports have investigated the characteristics of mouse or human hepatocytes introduced with the PDX1 gene over prolonged observation periods. In this study, we immunohistologically and molecularly investigated the alternative processes induced by PDX1 gene introduction in mouse and human hepatocytes over prolonged observation periods using immunocytochemistry, immunofluorescence, polymerase chain reaction (PCR), Western blotting, and flow cytometry (FCM) analysis. Immunocytochemical and immunofluorescent observations showed that MLECs and HepaRG cells on 2 and 21 days after introduction of the PDX1 gene comprised cells double—positive for insulin and albumin. Additionally, they showed MAFA expression and glucose—responsive insulin secretion with glucokinase expression. However mouse embryonic fibroblasts introduced with PDX1—GFP could not acquire glucose—responsive insulin secretion and glucokinase expression. Subsequently, we hypothesized that the number of albumin—positive MLECs and HepaRG cells would decrease after introduction of PDX1 due to the conversion of MLECs and HepaRG cells into insulin—producing cells. However, FCM analysis indicated that the number of albumin—positive MLECs and HepaRG cells was not altered by the introduction of PDX1. We thought that MLECs and HepaRG cells introduced with the PDX1 gene could acquire a functional insulin secretory capacity without conversion to β—cells, or islets of Langerhans, and the acquisition could need glucokinase expression.

Associations between abdominal visceral fat and surrogate measures of obesity in Japanese men with spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: There are ethnic differences in the distribution of abdominal obesity associated with metabolic disorders. In Japan, the appropriate reference values for abdominal obesity have not been established in individuals with spinal cord injury (SCI), although there are a number of studies in Western countries. This study evaluates the associations between visceral fat area (VFA), waist circumference (WC) and body mass index (BMI), to examine cutoffs and estimate the error for WC and BMI equivalent to 100 cm(2) VFA in Japanese men with SCI. SETTING: National Rehabilitation Center for Persons with Disabilities, Japan. METHODS: Seventy-four men (aged 45.6 (s.d. 14.3) years) participated in the study. VFA was quantified using computed tomography at the level of the umbilicus, and associations were determined using nonlinear regression analysis. The error of the estimates from the regression equation was assessed using a Bland-Altman plot. RESULTS: The mean VFA was 101.2 (s.d. 53.0) cm(2) and 32 subjects had a VFA ⩾100 cm(2). The cutoffs for a VFA of 100 cm(2) were WC, 81.3 cm and BMI, 22.5 kg m(-2). The relationship between the estimated and actual values showed that the error increased as VFA increased, which resulted in a negative proportional bias. CONCLUSION: The suggested cutoff for Japanese men with SCI is a VFA of 100 cm(2), which is lower than that in the healthy able-bodied population for both WC and BMI. Further investigation is needed to determine the reference value for estimating SCI-specific VF accumulation.

Upregulation of mouse CD14 expression in Kupffer cells by lipopolysaccharide.

Western blot analysis showed that a monoclonal antibody against recombinant mouse CD14 (mCD14), designated rmC5-3, specifically reacted with mouse macrophage cell line J774, but not myeloma cell line NS1. Fluorographic and immunocytochemical analysis demonstrated specific binding of rmC5-3 with mouse resident macrophages, inflammatory monocytes and neutrophils, and macrophage cell lines. Immunohistochemical staining using rmC5-3 showed that CD14-positive Kupffer cells (KC) were small in number in the liver in nonstimulated mice. The number of stained KC, which were rich in the midzonal and periportal regions, gradually increased with time after intraperitoneal injection of lipopolysaccharide (LPS), peaked 6 h after injection, and returned to normal by 20 h after injection. Staining intensity over time was proportional to the number of KC. A slight increase in mCD14 expression was observed in peritoneal macrophages 2 h after LPS administration in vivo using flow cytometric analysis. mCD14 mRNA became detectable at 1 h after the intraperitoneal injection of LPS (20 micrograms/mice), and the level dramatically increased with time, peaking at 3 h, and sharply dropped at 6 h. The resident peritoneal macrophages demonstrated a constitutively high mCD14 mRNA expression, which slightly increased 2 h after LPS (100 ng/ml) stimulation in vitro. The level of mCD14 expression in macrophages did not increase after intraperitoneal injection of LPS (20 micrograms/mice).

Expression of a tumor necrosis factor alpha transgene in murine pancreatic beta cells results in severe and permanent insulitis without evolution towards diabetes.

Mice bearing a tumor necrosis factor (TNF) alpha transgene controlled by an insulin promoter developed an increasingly severe lymphocytic insulitis, apparently resulting from the induction of endothelial changes with features similar to those observed in other places of intense lymphocytic traffic. This was accompanied by dissociation of the endocrine tissue (without marked decrease in its total mass), islet fibrosis, and the development of intraislet ductules containing, by places, beta cells in their walls, suggesting a regenerative capacity. Islet disorganization and fibrosis did not result from lymphocytic infiltration, since they were also observed in SCID mice bearing the transgene. Diabetes never developed, even though a number of potentially inducing conditions were used, including the prolonged perfusion of interferon gamma and the permanent expression of a nontolerogenic viral protein on beta cells (obtained by using mice bearing two transgenes). It is concluded that (a) a slow process of TNF release in pancreatic islets induces insulitis, and may be instrumental in the insulitis resulting from local cell-mediated immune reactions, but (b) that insulitis per se is not diabetogenic, lymphocyte stimulation by cells other than beta cells being necessary to trigger extensive beta cell damage. This provides an explanation for the discrepancy between the occurrence of insulitis and that of clinical disease in autoimmune diabetes.

Transcription factor ERG variants and functional diversification of chondrocytes during limb long bone development.

During limb development, chondrocytes located at the epiphyseal tip of long bone models give rise to articular tissue, whereas the more numerous chondrocytes in the shaft undergo maturation, hypertrophy, and mineralization and are replaced by bone cells. It is not understood how chondrocytes follow these alternative pathways to distinct fates and functions. In this study we describe the cloning of C-1-1, a novel variant of the ets transcription factor ch-ERG. C-1-1 lacks a short 27-amino acid segment located approximately 80 amino acids upstream of the ets DNA binding domain. We found that in chick embryo long bone anlagen, C-1-1 expression characterizes developing articular chondrocytes, whereas ch-ERG expression is particularly prominent in prehypertrophic chondrocytes in the growth plate. To analyze the function of C-1-1 and ch-ERG, viral vectors were used to constitutively express each factor in developing chick leg buds and cultured chondrocytes. We found that virally driven expression of C-1-1 maintained chondrocytes in a stable and immature phenotype, blocked their maturation into hypertrophic cells, and prevented the replacement of cartilage with bone. It also induced synthesis of tenascin-C, an extracellular matrix protein that is a unique product of developing articular chondrocytes. In contrast, virally driven expression of ch-ERG significantly stimulated chondrocyte maturation in culture, as indicated by increases in alkaline phosphatase activity and deposition of a mineralized matrix; however, it had modest effects in vivo. The data show that C-1-1 and ch-ERG have diverse biological properties and distinct expression patterns during skeletogenesis, and are part of molecular mechanisms by which limb chondrocytes follow alternative developmental pathways. C-1-1 is the first transcription factor identified to date that appears to be instrumental in the genesis and function of epiphyseal articular chondrocytes.

Bone morphogenetic protein signaling is required for maintenance of differentiated phenotype, control of proliferation, and hypertrophy in chondrocytes.

To examine the role of bone morphogenetic protein (BMP) signaling in chondrocytes during endochondral ossification, the dominant negative (DN) forms of BMP receptors were introduced into immature and mature chondrocytes isolated from lower and upper portions of chick embryo sternum, respectively. We found that control sternal chondrocyte populations expressed type IA, IB, and II BMP receptors as well as BMP-4 and -7. Expression of a DN-type II BMP receptor (termed DN-BMPR-II) in immature lower sternal (LS) chondrocytes led to a loss of differentiated functions; compared with control cells, the DN-BMPR- II-expressing LS chondrocytes proliferated more rapidly, acquired a fibroblastic morphology, showed little expression of type II collagen and aggrecan genes, and upregulated type I collagen gene expression. Expression of DN-BMPR-II in mature hypertrophic upper sternal (US) chondrocytes caused similar effects. In addition, the DN-BMPR-II-expressing US cells exhibited little alkaline phosphatase activity and type X collagen gene expression, while the control US cells produced both alkaline phosphatase and type X collagen. Both DN-BMPR-II-expressing US and LS chondrocytes failed to respond to treatment with BMP-2 . When we examined the effects of DN forms of types IA and IB BMP receptors, we found that DN-BMPR-IA had little effect, while DN-BMPR-IB had similar but weaker effects compared with those of DN-BMPR-II. We conclude that BMP signaling, particularly that mediated by the type II BMP receptor, is required for maintenance of the differentiated phenotype, control of cell proliferation, and expression of hypertrophic phenotype.

Insertional activation of N-myc by endogenous Moloney-like murine retrovirus sequences in macrophage cell lines derived from myeloma cell line-macrophage hybrids.

Hybrids formed from a myeloma cell line, NS1, and macrophages initially show myeloma properties but later, after loss of the parental macrophage genome and consequent loss of myeloma characteristics, express macrophage properties. Molecular studies demonstrated that macrophage properties in the hybridomas originate from the NS1 parental cells (M. Setoguchi, S. Yoshida, Y. Higuchi, S. Akizuki, and S. Yamamoto, Somatic Cell Mol. Genet. 14:427-438, 1988). In such hybrids, N-myc was activated by insertion of endogenous Moloney-like retrovirus sequences into mouse N-myc exon 3 when the hybrids gained macrophage properties. Interestingly, expression of N-myc took place in all aged hybrids. These results suggest that such unique insertional mutagenesis occurs in a regionally specific manner and that expression of N-myc may play a role in hematopoietic lineage conversion.

Immunosuppression Modification by Everolimus With Minimization of Calcineurin Inhibitors Recovers Kidney Graft Function Even in Patients With Very Late Conversion and Also With Poor Graft Function.

BACKGROUND: Although kidney graft survival within 5 years after transplantation is now achieved in >95% of recipients, chronic graft deterioration remains a factor limiting long-term survival. Chronic nephrotoxicity induced by calcineurin inhibitors (CNIs) is one of the major causes of chronic graft injury; thus, minimization of CNIs by administration of everolimus (EVR) is expected to relieve their toxic effects. METHODS: Fifty-six kidney transplant recipients receiving CNI-based immunosuppression (tacrolimus, n = 34; cyclosporine, n = 22) were analyzed. The average posttransplant period at conversion was 7.4 years and no less than 3 years. Conversion of immunosuppression was accomplished by reducing CNI by 40% in dose and beginning EVR at 1 or 1.5 mg. Changes in graft function were examined, and adverse effects were evaluated. RESULTS: Significant improvement in graft function was observed quickly after EVR administration, and it had persisted for 1 year after conversion as a 7% increase in estimated glomerular filtration rate. No obvious acute rejection was observed. Further analyses concerning "timing of EVR conversion" and "graft function at conversion" were performed. Graft function was significantly improved even in patients with late conversion at 2 to 10 years. The estimated glomerular filtration rate was significantly improved even in patients with poor function. CONCLUSIONS: We concluded that this modification to the immunosuppressive regimen, as expected, reduced CNI nephrotoxicity. Our results showed that even patients with very late conversion or poor graft function also benefited from EVR conversion with CNI minimization.

Structural basis of the redox switches in the NAD+-reducing soluble [NiFe]-hydrogenase.

NAD+ (oxidized form of NAD:nicotinamide adenine dinucleotide)-reducing soluble [NiFe]-hydrogenase (SH) is phylogenetically related to NADH (reduced form of NAD+):quinone oxidoreductase (complex I), but the geometrical arrangements of the subunits and Fe-S clusters are unclear. Here, we describe the crystal structures of SH in the oxidized and reduced states. The cluster arrangement is similar to that of complex I, but the subunits orientation is not, which supports the hypothesis that subunits evolved as prebuilt modules. The oxidized active site includes a six-coordinate Ni, which is unprecedented for hydrogenases, whose coordination geometry would prevent O2 from approaching. In the reduced state showing the normal active site structure without a physiological electron acceptor, the flavin mononucleotide cofactor is dissociated, which may be caused by the oxidation state change of nearby Fe-S clusters and may suppress production of reactive oxygen species.

Unusual ligand structure in Ni-Fe active center and an additional Mg site in hydrogenase revealed by high resolution X-ray structure analysis.

BACKGROUND: The hydrogenase of Desulfovibrio sp. catalyzes the reversible oxidoreduction of molecular hydrogen, in conjunction with a specific electron acceptor, cytochrome c3. The Ni-Fe active center of Desulfovibrio hydrogenase has an unusual ligand structure with non-protein ligands. An atomic model at high resolution is required to make concrete assignment of the ligands which coordinate the Ni-Fe center. These in turn will provide insight into the mechanism of electron transfer, during the reaction catalysed by hydrogenase. RESULTS: The X-ray structure of the hydrogenase from Desulfovibrio vulgaris Miyazaki has been solved at 1.8 A resolution and refined to a crystallographic R factor of 0.229. The overall folding pattern and the spatial arrangement of the metal centers are very similar to those found in Desulfovibrio gigas hydrogenase. This high resolution crystal structure enabled us to assign the non-protein ligands to the Fe atom in the Ni-Fe site and revealed the presence of a Mg center, located approximately 13 A from the Ni-Fe active center. CONCLUSIONS: From the nature of the electron-density map, stereochemical geometry and atomic parameters of the refined structure, the most probable candidates for the four ligands, coordinating the Ni-Fe center, have been proposed to be diatomic S=O, C triple bond O and C triple bond N molecules and one sulfur atom. The assignment was supported by pyrolysis mass spectrometry measurements. These ligands may have a role as an electron sink during the electron transfer reaction between the hydrogenase and its biological counterparts, and they could stabilize the redox state of Fe(II), which may not change during the catalytic cycle and is independent of the redox transition of the Ni. The hydrogen-bonding system between the Ni-Fe and the Mg centers suggests the possible.

Removal of the bridging ligand atom at the Ni-Fe active site of [NiFe] hydrogenase upon reduction with H2, as revealed by X-ray structure analysis at 1.4 A resolution.

BACKGROUND: The active site of [NiFe] hydrogenase, a heterodimeric protein, is suggested to be a binuclear Ni-Fe complex having three diatomic ligands to the Fe atom and three bridging ligands between the Fe and Ni atoms in the oxidized form of the enzyme. Two of the bridging ligands are thiolate sidechains of cysteinyl residues of the large subunit, but the third bridging ligand was assigned as a non-protein monatomic sulfur species in Desulfovibrio vulgaris Miyazaki F hydrogenase. RESULTS: The X-ray crystal structure of the reduced form of D. vulgaris Miyazaki F [NiFe] hydrogenase has been solved at 1.4 A resolution and refined to a crystallographic R factor of 21.8%. The overall structure is very similar to that of the oxidized form, with the exception that the third monatomic bridge observed at the Ni-Fe site in the oxidized enzyme is absent, leaving this site unoccupied in the reduced form. CONCLUSIONS: The unusual ligand structure found in the oxidized form of D. vulgaris Miyazaki F [NiFe] hydrogenase was confirmed in the reduced form of the enzyme, with the exception that the electron density assigned to the monatomic sulfur bridge had almost disappeared. On the basis of this finding, as well as the observation that H2S is liberated from the oxidized enzyme under an atmosphere of H2 in the presence of its electron carrier, it was postulated that the monatomic sulfur bridge must be removed for the enzyme to be activated. A possible mechanism for the catalytic action of the hydrogenase is proposed.

Suppression of TNFalpha production in LPS induced liver failure in mice after intravenous injection of cationic liposomes/NFkappaB decoy complex.

NFkappaB decoy, double stranded oligonucleotides containing NFkappaB binding sequences, inhibits NFkappaB-mediated production of inflammatory cytokines, and therefore NFkappaB decoy has been applied to several diseases. However, naked NFkappaB decoy, which is quickly cleared from the circulation in mice after intravenous injection, is readily absorbed into the systemic circulation. In order to deliver enough NFkappaB decoy for a therapeutic effect, it is necessary to develop a carrier, which enables much more NFkappaKB decoy to transfer to the target cells. In this study, using N-[1-(2,3-dioleyloxy)propyl]-n,n,n-trimethylammonium chloride (DOTMA)/cholesterol (1 :1) liposomes, the therapeutic effect of NFkappaB decoy was investigated in an LPS induced acute hepatitis model mice. The mean diameter of the cationic liposomes/NFkappaB decoy complex was about 70.9 nm and the zeta potential of complex was about 37.4 mV. Tissue distribution was determined by measuring the radioactivity of a cationic liposomes/ [32P] NFkappaB decoy complex after intravenous injection. The cationic liposomes/[32P] NFkappaB decoy complex was rapidly accumulated in the lung and gradually moved to the liver. The therapeutic effect was determined by the serum concentration of TNFalpha in LPS treated mice. The production of TNFalpha was significantly inhibited by cationic liposomes/NFkappaB decoy complex but not by cationic liposomes/random decoy complex or naked NFkappaB decoy. These results suggested that NFkappaB decoy therapy could be achieved using cationic liposomes. This information is of great value for the design of NFkappaB decoy carrier systems.

Enhancement of c-fos expression is associated with activated macrophages.

Unique hybrids (HINS and CANS lines) between macrophages and a myeloma cell line, NS1 initially expressed myeloma functions but later expressed active macrophage functions together with constitutive expression of c-fos gene. Enhancement of c-fos transcription was also observed in activated mouse peritoneal macrophages, and a range of macrophage-stimulating substance was found to induce c-fos transcription kinetic unique to each stimulator including immediate, delayed and prolonged responses in aged HINS-B3 cells, which displayed low levels of steady-state c-fos transcription. It was also found that a significant enhancement of c-fos transcription followed restimulation with either interferon gamma (IFN gamma) or lipopolysaccharide (LPS) after an initial IFN gamma stimulation. Thus it appeared that enhanced c-fos expression was closely connected with macrophage activation. On the other hand, macrophage stimulators suppressed [3H]thymidine incorporation into aged HINS-B3 cells. These results may simply suggest that c-fos expression contributes to macrophase activation but not to cell proliferation. However, it is also possible to speculate that c-fos expression contributes to cell proliferation as a salvage system operating to overcome the suppression during the macrophage activation.