Generation of a sensitive TNFR2-specific murine assays system.

Tumor necrosis factor (TNF)/TNF receptors (TNFR1/TNFR2) are considered to be potential drug targets to treat refractory diseases, including autoimmune diseases and malignant tumors. However, their specific functions, especially in the case of TNFR2, are poorly understood. In this study, we constructed a mouse TNFR2 (mTNFR2)-mediated biological assay system that shows no effects of mouse TNFR1 (mTNFR1) in order to screen mTNFR2-selective stimulating agents. Mouse TNFR1(-/-)R2(-/-) preadipocytes were transfected with the gene encoding the mTNFR2/mouse Fas (mFas) chimeric receptor in which the extracellular and transmembrane domains of mTNFR2 were fused to the intracellular domain of mFas. Our results demonstrated that this cell line exhibits highly sensitive mTNFR2-mediated cytotoxic effects. We propose that this mTNFR2-mediated biological assay system would be a useful tool to screen for mTNFR2-selective stimulating agents.

Ten-year incidences of self-reported non-vertebral fractures in Japanese patients with rheumatoid arthritis: discrepancy between disease activity control and the incidence of non-vertebral fracture.

UNLABELLED: Despite improvements in rheumatoid arthritis disease activity of in the past 10 years, the incidence of self-reported non-vertebral fractures did not decrease in our cohort of 9,987 patients. This study may indicate that osteoporosis treatment and non-vertebral fracture prevention remain important regardless of the rheumatoid arthritis disease activity. INTRODUCTION: Although rheumatoid arthritis (RA) is a risk factor for osteoporosis and fractures, few studies have described the association between disease activity and the fracture incidence in patients with RA. This study aimed to investigate changes in the non-vertebral fracture incidence between 2001 and 2010 in our Institute of Rheumatology Rheumatoid Arthritis (IORRA) cohort. METHODS: The IORRA is a prospective observational cohort study of Japanese RA patients. A total of 9,987 patients with RA were enrolled in this cohort from 2000 to 2010. The clinical parameter and non-vertebral fracture occurrence data were collected biannually through self-reported questionnaires. Incidences of self-reported non-vertebral fractures were also analyzed via standardization according to gender, age, and disease activity during each 2-year period. RESULTS: From 2001 to 2010, the percentage of patients with 28-joint disease activity score remission increased from 7.8 to 39.7%, prednisolone intake decreased from 51.4 to 41.3%, and bisphosphonate intake increased from 5.0 to 23.4%. The non-vertebral fracture incidence rates were 24.6/1,000 person-years in 2001 and 35.5/1,000 person-years in 2010, with no apparent change even after standardization. The overall non-vertebral fracture incidence was significantly higher in the autumn/winter than in the spring/summer (p = 0.02). CONCLUSION: Despite improvements in disease activity and functional disability, the non-vertebral fracture incidence exhibited no apparent change between 2001 and 2010 in our patients with RA. Osteoporosis treatment and non-vertebral fracture prevention remain important regardless of the disease control in patients with RA.

Risk factors associated with the occurrence of hip fracture in Japanese patients with rheumatoid arthritis: a prospective observational cohort study.

UNLABELLED: Risk factors associated with the occurrence of hip fracture in Japanese patients with rheumatoid arthritis (RA) were evaluated in a prospective, observational cohort study. Physical disability, advanced age, history of total knee replacement (TKR), and low body mass index (BMI) appear to be associated with the occurrence of hip fracture. INTRODUCTION: This study seeks to evaluate the association between potential risk factors and the occurrence of hip fractures in Japanese RA patients. METHODS: A total of 9,720 patients (82.1% female; mean age, 55.7 years) with RA were enrolled in a prospective observational study from 2000 to 2010. Self-reported hip fractures were verified using patient medical records. Cox proportional hazards models were used to analyze independent contributions of various risk factors to hip fracture occurrence. RESULTS: During a mean follow-up of 5.2 years, 152 patients reported 152 hip fractures. Among these patients, 97 hip fractures in 97 patients (15 males, 82 females) were verified with medical records. Japanese version of the Health Assessment Questionnaire (J-HAQ) disability score [per 1 score, hazard ratio (HR), 2.64; 95% confidence interval (CI), 1.94-3.58], age (per 10 years; HR, 1.53; 95% CI, 1.25-1.87), history of TKR (HR, 3.75; 95% CI, 1.57-8.96), and BMI (per 1 kg/m2, HR, 0.92; 95% CI, 0.86-0.99) were significantly associated with hip fractures. Among the scores on the eight domains of the J-HAQ, J-HAQ (arising) (HR, 1.74; 95% CI, 1.28-2.36) and J-HAQ (hygiene) (HR, 1.58; 95% CI, 1.11-2.24) were significantly correlated with the occurrence of hip fracture. CONCLUSIONS: High J-HAQ disability score, advanced age, history of TKR, and low BMI appear to be associated with the occurrence of hip fractures in Japanese RA patients. Among the eight domains of the J-HAQ, arising and hygiene disabilities appear to be correlated with the occurrence of hip fractures in this patient population.

Association of APOA1 and APOA5 polymorphisms and haplotypes with lipid parameters in a Brazilian elderly cohort.

Apolipoproteins have an important role in lipid metabolism and transport. Polymorphisms in the APOA1/C3/A4/A5 gene cluster have been associated with lipid alterations and cardiovascular diseases. We investigated APOA1 XmnI, APOA5 S19W, and APOA5 -1131T>C polymorphisms in 377 individuals from a cohort of a longitudinal Brazilian elderly study. Allele frequencies, genotype distribution, and association with major morbidities as well as with lipids, creatinine, albumin, urea, glycated hemoglobin, and fasting glucose serum levels were investigated. Linkage disequilibrium and haplotype associations were also analyzed. This is the first time that haplotypes involving these polymorphisms were evaluated. Genotyping was performed by PCR-RFLP. Minor allele frequencies were 0.119, 0.071, and 0.158 for XmnI, S19W, and -1131T>C polymorphisms, respectively. We found a significant association of the -1131C allele with low LDL-C levels. We also observed that XmnI and S19W polymorphisms were in linkage disequilibrium. The C/G haplotype, which is composed of the wild-type allele of XmnI and the minor allele of S19W, was associated with high total cholesterol serum levels in this elderly population. We conclude that the -1131T>C polymorphism and the C/G haplotype, including XmnI and S19W polymorphisms, are associated with alterations in lipid levels and may be risk factors for cardiovascular disease in the Brazilian elderly.

The effects of age on maintenance of intense neuromuscular block with rocuronium.

BACKGROUND: Increasing age is associated with a longer duration of action of neuromuscular block. The aim of this study was to determine the influence of ageing on the recovery of the post-tetanic count (PTC) from rocuronium-induced neuromuscular block. METHODS: Twenty-two younger (20-60 years) and 22 older (> 70 years) patients were enrolled in this study. After induction of anaesthesia with fentanyl and propofol, all patients initially received 1 mg/kg rocuronium and neuromuscular block were evaluated by contractions of the adductor pollicis muscle to ulnar nerve train-of-four stimulation using an acceleromyograph. Subsequently, intense rocuronium-induced block was determined every 6 min using the PTC during 1.0-1.5% sevoflurane and remifentanil anaesthesia. When the first response to the PTC stimulus was detected, 0.2 mg/kg rocuronium was additionally administered, and again, spontaneous recovery of neuromuscular function was monitored until the first response to the PTC reappeared. RESULTS: Median values (range) of the times from the administration of 1 mg/kg and 0.2 mg/kg rocuronium until recovery of the first detectable PTC were significantly longer in the older [51.0 (27-100) min, P < 0.0001 and 30.0 (12-66) min, P = 0.0036, respectively] than the younger patients [31.5 (21-45) min and 18.0 (12-36) min, respectively]. CONCLUSION: The times from rocuronium injection to reappearance of the first response to PTC stimulation are approximately twofold longer and more variable in older than younger patients. Hence, the dosing interval of rocuronium should be adjusted using neuromuscular monitoring when maintaining intense neuromuscular block, especially in older patients.

Correlation between cardiac output and reversibility of rocuronium-induced moderate neuromuscular block with sugammadex.

BACKGROUND: The aim of this study was to evaluate the correlation between cardiac output (CO) and reversibility of rocuronium-induced moderate neuromuscular block with sugammadex in elderly patients. METHODS: Fifty elderly (≥ 65 years) patients were enrolled in this study. During 1.0-1.5% end-tidal sevoflurane and remifentanil anaesthesia, contraction of the adductor pollicis muscle in response to ulnar nerve stimulation was acceleromyographically quantified. All patients initially received 1 mg/kg rocuronium followed by 0.2 mg/kg whenever the second twitch T2 of the train-of-four (TOF) response reappeared. CO was measured throughout the study using a FloTrac™/Vigileo™ monitor. After completion of surgery and at the reappearance of T2, the time required for a bolus dose of 2 mg/kg sugammadex to facilitate recovery to a TOF ratio of 0.9 was recorded, and its correlation with CO was analysed. RESULTS: Adequate recovery of neuromuscular block was achieved after sugammadex in all patients. Mean CO at the time of reversal with sugammadex was 5.3 l/min (1.3), and recovery time to a TOF ratio of 0.9 was 173.4 s (54.8). A statistically significant inverse correlation was seen between the time to recovery to a TOF ratio of 0.9 and CO [reversal time (s) = -27.7·CO + 298.7, R(2) = 0.461, P < 0.0001]. CONCLUSIONS: The time to reach a TOF ratio of 0.9 following sugammadex is dependent on CO in elderly patients.

Comparison in effect of Heatsynch with heat detection aids and CIDR-Heatsynch in dairy heifers.

The objective of the present study was to determine whether oestrous detection with the help of oestrous detection aids during the Heatsynch without timed AI protocol is equally effective with the progesterone-combined protocol in dairy heifers. A total of 148 heifers were randomly assigned to one of the two groups. A group of heifers treated with Heatsynch with heat detection aids (n = 72) received GnRH on day 0, prostaglandin F(2alpha) (PGF(2alpha)) on day 7 and oestradiol benzoate (EB) on day 8, while in controlled internal drug release (CIDR)-Heatsynch group (n = 76), CIDR was included during a period from GnRH to PGF(2alpha). Heifers were checked for oestrus twice daily, i.e. from 09:00 to 10:00 hours and from 15:00 to 16:00 hours starting on day 2 for Heatsynch group and on day 8 in CIDR-Heatsynch group, and continued up to day 12. KAMAR heat mount detector (KAMAR Inc., Steamboat Springs, CO, USA) and ALL-WEATHER PAINTSTIK (LA-CO Industries Inc., Elk Grove Village, IL, USA) were used as heat detection aids. AI was conducted within 1 h after confirming oestrus in 72 heifers, while 19 animals were transferred with embryo 7 days after oestrus according to the request of the owners. Premature oestrus before PGF(2alpha) injection occurred in 18% of Heatsynch group. Of 13 heifers which showed premature oestrus, six were inseminated and two of them conceived. Oestrus detection rate within 12 days after initiation of the protocols did not differ between the two groups (94% vs 95%). There was no difference in the conception rate after first AI (including heifers that were inseminated before PGF(2alpha) injection) and embryo transfer between Heatsynch with heat detection aids and CIDR-Heatsynch groups (36% vs 44% and 70% vs 56%). It is concluded that the use of heat detection aids to monitor the occurrence of premature oestrus prior to PGF(2alpha) injection in Heatsynch protocol in dairy heifers was equally effective to the inclusion of CIDR.

Creation of an improved mutant TNF with TNFR1-selectivity and antagonistic activity by phage display technology.

Tumor necrosis factor-alpha (TNF), which binds two types of TNF receptors (TNFR1 and TNFR2), regulates the onset and exacerbation of autoimmune diseases such as rheumatoid arthritis and Crohn's disease. In particular, TNFR1-mediated signals are predominantly related to the induction of inflammatory responses. We have previously generated a TNFR1-selective antagonistic TNF-mutant (mutTNF) and shown that mutTNF efficiently inhibits TNFR1-mediated bioactivity in vitro and attenuates inflammatory conditions in vivo. In this study, we aimed to improve the TNFR1-selectivity of mutTNF This was achieved by constructing a phage library displaying mutTNF-based variants, in which the amino acid residues at the predicted receptor binding sites were substituted to other amino acids. From this mutant TNF library, 20 candidate TNFR1-selective antagonists were isolated. Like mutTNF, all 20 candidates were found to have an inhibitory effect on TNFR1-mediated bioactivity. However, one of the mutants, N7, displayed significantly more than 40-fold greater TNFR1-selectivty than mutTNF. Therefore, N7 could be a promising anti-autoimmune agent that does not interfere with TNFR2-mediated signaling pathways.

Modulation of the functional binding sites for TGF-beta on the type II receptor leads to suppression of TGF-beta signaling.

Transforming growth factor-beta (TGF-beta) binds to two different types of serine/threonine kinase receptors termed type II (TbetaR-II) and type I (TbetaR-I). TGF-beta is unable to bind to TbetaR-I in the absence of TbetaR-II, and initiates receptor assembly by binding with high affinity to TbetaR-II. Previous structural analysis of the TGF-beta3-TbetaR-II complex has suggested that two charged amino acid residues, D55 and E142 of TbetaR-II, are binding sites of TGF-beta. In the present study, we have shown that mutations of the amino-acid residues, D55 and E142 of TbetaR-II, resulted in loss of TGF-beta binding and downstream signaling activity. Moreover, we found that 3,5,7,2',4'-pentahydroxyflavone (Morin) inhibits TGF-beta binding to TbetaR-II, and suppresses phosphorylation of Smad2 and expression of a TGF-beta target gene Smad7 induced by TGF-beta. Our findings may thus provide useful information for designing therapeutic agents for various diseases induced by TGF-beta, including advanced cancers.

Messenger ribonucleic acid expression profile in peripheral blood cells from RA patients following treatment with an anti-TNF-alpha monoclonal antibody, infliximab.

OBJECTIVES: We monitored the mRNA expression profiles of peripheral blood cells during treatment with a TNF-alpha inhibitor, infliximab, in patients with RA. Using a DNA microarray analysis, we demonstrated a unique set of genes, with distinct baseline and post-treatment changes in expression between responders and non-responders to infliximab treatment. METHODS: Using a customized low-density cDNA microarray with 747 genes and a reliable data collection system, we monitored the mRNA expression profiles of whole blood cells from 18 RA patients before and after the infusion of infliximab for up to 22 weeks. The clinical response to treatment with infliximab was determined using the ACR response criteria, the disease activity score of 28 joints (DAS28), and individual clinical parameters. The patients were classified as responders or non-responders based on their ACR50% response at 22 weeks. RESULTS: Approximately 15% of the total genes were found to exhibit a >1.5-fold change, compared with their reference values, at one or more time points during the 22 weeks of infliximab therapy. The expression of inflammatory genes, such as IFN-related genes, was strongly correlated with the serum level of CRP and the DAS28. The increased expression of inflammatory genes in responders was normalized within 2 weeks and then remained at a normal level during the treatment period. In contrast, in the non-responders, the elevated expression at baseline, although it was significantly decreased at 2 weeks, returned to the baseline level after 14 weeks. In addition to inflammatory genes, we identified several groups of genes with distinct differences in expression between the responders and non-responders. CONCLUSIONS: Our results suggest that a customized low-density microarray is useful for monitoring mRNA expression profiles in peripheral blood cells, enabling us to identify a unique set of genes with differentially regulated expressions in responders and non-responders to a TNF inhibitor among patients with RA.

Anti-glucose-6-phosphate isomerase, anti-cyclic citrullinated peptide antibodies and HLA-DRB1 genotypes in Japanese patients with early rheumatoid arthritis.

OBJECTIVE: Our goal was to evaluate the associations of antibodies (Abs) to glucose-6-phosphate isomerase (GPI) with Abs to cyclic citrullinated peptide (CCP) and HLA-DRB1 genotypes in Japanese patients with early rheumatoid arthritis (RA). METHODS: One hundred and eight patients with early RA (85 female, 23 male) who visited our clinic within 1 year of symptom onset were examined for anti-GPI and anti-CCP Ab levels, and HLA-DRB1 genotype. Anti-GPI and anti-CCP Ab levels, and HLA-DRB1 genotypes were also determined in 63 controls and 265 healthy controls, respectively. RESULTS: Of the 108 patients with early RA and the 63 controls, 20 (18.5%) and 3 (4.8%) were anti-GPI Ab-positive, respectively. Of the 20 patients with anti-GPI Abs, 17 (85%) were positive for anti-CCP Abs. HLA-DRB1*0405 and shared epitope (SE) carrier frequencies were significantly increased not only in anti-GPI Ab-positive patients (p=0.00057, odds ratio [OR] 4.6, 95% CI 1.8-11.8; p=0.0011, OR 5.0, 95% CI 1.7-14.0), but also in anti-GPI Ab-negative patients (p=0.0017, OR 2.2, 95% CI 1.3-3.7; p=0.00011, OR 2.6, 95% CI 1.6-4.3), when compared with controls. In addition, the carrier frequency of HLA-DRB1*1201 was significantly increased in anti-GPI Ab-positive patients compared with controls (p=0.0056, OR 4.3, 95% CI 1.4-13.2). CONCLUSIONS: The majority of anti-GPI Ab-positive RA patients constitute a subset of HLA-DRB1* SE-associated, anti-CCP Ab-positive RA patients.

Distribution of gene segments of the pandemic A(H1N1) 2009 virus lineage in pig populations.

Swine influenza viruses (SIVs) are important not only for pig farming, but also for public health. In fact, pandemic A(H1N1) 2009 viruses [A(H1N1)pdm09] were derived from SIVs. Therefore, timely characterization of locally circulating SIVs is necessary for understanding the global status of SIVs. To genetically characterize SIVs circulating in Japanese pig populations, we isolated 24 SIVs of three subtypes (17 H1N1, four H1N2 and three H3N2 strains) from 14 pig farms in Japan from 2013 to 2016. Genetic analyses revealed that the haemagglutinin (HA) and neuraminidase (NA) genes of the 17 H1N1 and the HA gene of one H1N2, A/swine/Aichi/02/2016 (H1N2), SIVs belonged to the A(H1N1)pdm09 lineage. More importantly, all of the remaining six gene segments (i.e., PB1, PB1, PA, NP, M and NS) of the 24 SIVs, regardless of the HA and NA subtype, were also classified as belonging to the A(H1N1)pdm09 lineage. These results indicate that gene segments of A(H1N1)pdm09 lineage are widely distributed in SIVs circulating in Japanese pig populations In addition, the NA gene of A/swine/Aichi/02/2016 (H1N2) shared less than 88.5% nucleotide identity with that of the closest relative A/swine/Miyagi/5/2003 (H1N2), which was isolated in Japan in 2003. These results indicate the sustained circulation of classical H1N2-derived SIVs with remarkable diversity in the NA genes in Japanese pig populations. These findings highlight the necessity of both intensive biosecurity systems and active SIV surveillance in pig populations worldwide for both animal and public health.

Differential association of HLA-DRB1 alleles in Japanese patients with early rheumatoid arthritis in relationship to autoantibodies to cyclic citrullinated peptide.

OBJECTIVE: To evaluate the role of HLA-DRB1 genotypes and antibodies to cyclic citrullinated peptides (anti-CCP antibodies) in the development and radiographic progression of Japanese patients with rheumatoid arthritis (RA). METHODS: One hundred and ten patients with early RA (88 female, 22 male) who visited our clinic within 1 year of symptom onset were examined for anti-CCP antibody levels and HLA-DRB1 genotypes. HLA-DRB1 genotypes were also determined in 265 healthy controls. Radiographic progression over a 2-year interval was evaluated using the Larsen's method in 66 patients. RESULTS: Among the 110 patients with early RA, 82 patients (74.5%) were anti-CCP positive. Carrier frequency of HLA-DRB1*0405 was significantly increased in RA patients with anti-CCP antibodies compared with controls and RA patients without anti-CCP antibodies (odds ratio [OR] 3.4, 95% confidence interval [95% CI] 2.0-5.7 and OR 3.3, 95% CI 1.3-8.6, respectively). Carriership of one or two SE alleles was significantly associated with production of anti-CCP antibodies (OR 2.7, 95% CI 1.1-6.7 and OR 9.3, 95% CI 1.1-78.2, respectively). On the other hand, allele frequency of HLA-DRB1*0901 was significantly increased in RA patients without anti-CCP antibodies compared with controls and RA patients with anti-CCP antibodies (OR 2.2, 95% CI 1.1-4.1 and OR 3.0, 95% CI 1.4-6.4, respectively). CONCLUSION: In Japanese patients with RA, HLA-DRB1 SE alleles are associated with production of anti-CCP antibodies and HLA-DRB1 alleles appear to be differently associated with early RA depending on anti-CCP positivity as in Caucasian patients with RA.

Two Japanese cases with MAGIC syndrome (mouth and genital ulcers with inflamed cartilage).

We describe two cases, a 28-year-old woman and a 46-year-old man, with mouth and genital ulcers with inflamed cartilage (chondritis of the nose and ears) (MAGIC syndrome). The conditions of both patients were resolved by treatment with corticosteroid and colchicine. We also review the English literature related to this rare syndrome.

Induction of hepatic tumors in rats by senkirkine and symphytine.

The carcinogenicity of the pyrrolizidine alkaloids senkirkine and symphytine was studied in male inbred ACI rats. Animals were divided into 3 groups: Group I received ip injections of freshly prepared senkirkine at a dose of 10% of the median lethal dose (LD50) twice weekly for 4 weeks and then once a week for 52 weeks. Group II received ip injections of symphytine at a dose of 10% of the LD50 by the same injection schedule as in group I. The control group was given ip injections of a 0.9% NaCl solution following the same injection schedule as in experimental groups. All group I rats survived for more than 290 days after the start of injections, and 9 of 20 rats developed liver cell adenoma. All group II animals survived for more than 330 days after the start of injections. Of 20 rats, 4 had liver tumors, 3 had hemangioendothelial sarcomas, and 1 had liver cell adenoma. The hemangioendothelial sarcomas showed metastasis in the lungs of 2 rats. The control group had no liver tumors.

The relationship of DNA ploidy to chromosomal instability in primary human colorectal cancers.

The aim of this investigation was to corroborate the relationship between DNA ploidy and chromosomal variation in surgically removed colorectal cancers. For 101 specimens from 21 advanced colorectal cancers, the numerical variations in chromosomes 7, 17, and 18 among cells were measured by fluorescence in situ hybridization using DNA probes specific for centromere of each chromosome, and DNA ploidy was determined by laser scanning cytometry or flow cytometry. DNA diploidy (DNA index = 1.0) was linked with minor variation in copy number of chromosomes 7, 17 and 18, whereas DNA aneuploidy (DNA index > or = 1.2) was found exclusively in tumors with large variations in centromere copy number for all chromosomes. There was a significant difference in the degree of intercellular variations in chromosome copy number between diploid and aneuploid clones for all chromosomes examined (P < 0.001). In near-diploid clones (1.0 < DNA index < 1.2), the numerical variation of chromosome 18 was significantly different from that in diploid clones (P < 0.002), but it was not different from that in aneuploid clones. These observations support the hypothesis that chromosomal instability is associated with DNA aneuploidy in colorectal cancers. Additionally, they suggest that near-diploid tumors are also unstable at a lower level than classic aneuploid tumors and that all chromosomes are not affected equally in near-diploid cases.

Genotoxicity of a variety of pyrrolizidine alkaloids in the hepatocyte primary culture-DNA repair test using rat, mouse, and hamster hepatocytes.

Seventeen pyrrolizidine alkaloids were studied with the hepatocyte primary culture-DNA repair test using rat hepatocytes. DNA repair synthesis was elicited by 15 alkaloids, including 11 of unknown carcinogenicity, i.e., senecionine, seneciphylline, jacobine, epoxyseneciphylline, senecicannabine, acetylfukinotoxin, syneilesine, dihydroclivorine, ligularidine, neoligularidine, and ligularizine. The positive results with these alkaloids of unknown carcinogenicity suggest that they are possibly genotoxic carcinogens. The two pyrrolizidine alkaloids that did not elicit DNA repair were retronecine which lacks a necic acid component and ligularinine which lacks the unsaturated double bond at the 1,2-position of the pyrrolizidine ring. Five pyrrolizidine alkaloids, retronecine, monocrotaline, seneciphylline, senkirkine, and clivorine, were also tested in the DNA repair test with hamster or mouse hepatocytes. These alkaloids, except retronecine, showed a positive response in the test with hamster hepatocytes, but in the test with mouse hepatocytes clivorine in addition to retronecine was also negative. The results indicate a species difference in liver bioactivation of pyrrolizidine alkaloids, implying that there could be species differences in their carcinogenic activities.

Activation of c-Jun N-terminal kinase by Akabane virus is required for apoptosis.

Akabane virus (AKAV) belongs to the Simbu serogroup of the genus Orthobunyavirus in the family Bunyaviridae. It has been shown that AKAV induces apoptosis in mammalian cells. It is necessary to understand the signaling pathways involved in AKAV-induced apoptosis to further elucidate the molecular virology of AKAV. c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) are mediators of apoptosis; therefore, we investigated the roles of JNK and p38 MAPK cascades in AKAV-infected cells. We found that JNK and p38 MAPK as well as their downstream substrates, c-Jun and heat shock protein 27 (HSP27), were phosphorylated in response to AKAV infection. A JNK inhibitor (SP600125) inhibited AKAV-mediated apoptosis whereas a p38 MAPK inhibitor (SB203580) did not. We conclude that AKAV infection activates the JNK and p38 MAPK signaling pathways, and the JNK cascade plays a crucial role in AKAV-induced apoptosis in vitro.

Solution structure of calmodulin-W-7 complex: the basis of diversity in molecular recognition.

The solution structure of calcium-bound calmodulin (CaM) complexed with an antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), has been determined by multidimensional NMR spectroscopy. The structure consists of one molecule of W-7 binding to each of the two domains of CaM. In each domain, the W-7 chloronaphthalene ring interacts with four methionine methyl groups and other aliphatic or aromatic side-chains in a deep hydrophobic pocket, the site responsible for CaM binding to CaM-dependent enzymes such as myosin light chain kinases (MLCKs) and CaM kinase II. This competitive binding at the same site between W-7 and CaM-dependent enzymes suggests the mechanism by which W-7 inhibits CaM to activate the enzymes. The orientation of the W-7 naphthalene ring in the N-terminal pocket is rotated approximately 40 degrees with respect to that in the C-terminal pocket. The W-7 ring orientation differs significantly from the Trp800 indole ring of smooth muscle MLCK bound to the C-terminal pocket and the phenothiazine ring of trifluoperazine bound to the N or C-terminal pocket. These comparative structural analyses demonstrate that the two hydrophobic pockets of CaM can accommodate a variety of bulky aromatic rings, which provides a plausible structural basis for the diversity in CaM-mediated molecular recognition.

Licodione Synthase, a Cytochrome P450 Monooxygenase Catalyzing 2-Hydroxylation of 5-Deoxyflavanone, in Cultured Glycyrrhiza echinata L. Cells.

Cultured Glycyrrhiza echinata L. (Leguminosae) cells produce a retrochalcone echinatin (4,4[prime]-dihydroxy-2-methoxychalcone) and its biosynthetic intermediate licodione [1-(2,4-dihydroxyphenyl)-3-(4-hydroxyphenyl)-1,3-propanedione, a dibenzoylmethane (keto form) or its enol tautomer ([beta]-hydroxychalcone)], when treated with elicitor-active substances, e.g. yeast extract. A microsomal fraction (160,000g pellet) prepared from yeast extract-induced suspension cultures of G. echinata catalyzed the formation of licodione from (2S)-liquiritigenin (7,4[prime]-dihydroxyflavanone) in the presence of NADPH and air. This licodione synthase activity was shown to be dependent on cytochrome P450 by its microsomal localization, requirement of NAD(P)H and O2 for activity, and inhibition by typical cytochrome P450 inhibitors. Licodione synthase activity transiently increased in the cells after treatment with yeast extract. When (2S)-naringenin (5,7,4[prime]-trihydroxyflavanone) and NADPH were incubated with the same microsomal preparation, a polar compound, which further converted into apigenin (5,7,4[prime]-trihydroxyflavone) when treated with acid, was produced. The reaction mechanism of licodione synthase is likely to be 2-hydroxylation of the flavanone molecule and subsequent hemiacetal opening and is possibly the same as the previously suggested mechanism of flavone synthase II from soybean and, furthermore, closely related to isoflavone synthase from Pueraria lobata.