Effectiveness, safety, and methotrexate dose-tapering pattern over two years of treatment with adalimumab and ≥12 mg/week methotrexate for early rheumatoid arthritis: Results of the HAWK postmarketing surveillance study in Japan

Objectives: To investigate the long-term effectiveness, safety, and methotrexate (MTX) dose-tapering patterns in patients with rheumatoid arthritis (RA) receiving adalimumab plus high-dose MTX.Methods: In this prospective, postmarketing study (2012-2017), conducted at 128 sites in Japan, biologic-naïve patients with RA (duration ≤2 years) previously treated with MTX for ≥3 months, initiated treatment with adalimumab and MTX (≥12 mg/week). Effectiveness by Disease Activity Score in 28 joints using C-reactive protein (DAS28-CRP), safety, and MTX dose-tapering were assessed from baseline to 104 weeks.Results: In the effectiveness analysis set (n = 292), DAS28-CRP remission (<2.6) was achieved in 92.3% (n = 120/130) of patients at week 104. The proportions of patients receiving MTX dose <10 mg/week increased to 32.3% (n = 50/155) and ≥12 mg/week reduced to 52.9% (n = 82/155) by week 104. Per univariate regression analysis, MTX dose tapering was associated with longer adalimumab drug survival. Of 70 patients with joint X-rays available, 59 (84.3%) achieved Δ modified total Sharp score ≤1.0 at 104 weeks. In the safety analysis set (n = 300), 143 adverse drug reactions were reported in 92 patients (30.7%, non-serious; 24.7%, serious 8.7%).Conclusion: The long-term effectiveness and safety of adalimumab with high-dose MTX was confirmed in biologic-naïve patients with early RA in a real-world setting in Japan.Clinical Trial Registration: This study is registered at ClinicalTrials.gov (identifier: NCT01736189; retrospectively registered 29 November 2012, due to administrative reasons).

Patient preference for biologic treatments of psoriasis in Japan

Psoriasis is a chronic autoimmune disease affecting skin which may also manifest in nails and joints. Several biologic treatments have been approved in Japan for psoriasis. Each biologic has a different profile for efficacy and safety, including different dosing regimens and co‐payment considerations which may complicate treatment decisions made by patients and physicians during short consultations. Elucidating patient preference is expected to contribute to shared decision‐making between patients and physicians to optimize treatment satisfaction and outcomes. However, the number of studies investigating this in Japan is very limited. The study used a discrete choice experiment methodology to elicit patient preferences for hypothetical options in an experimental framework. Participants were asked to choose their preferred treatment option from two hypothetical choices, defined by different levels of six attributes (i.e. early onset of efficacy, long‐term efficacy, sustained efficacy after drug withdrawal, dosing convenience, co‐payment and risk of serious infection). The survey included 16 treatment choice scenarios and was completed by 395 participants. Across all participants, the attribute regarded as most important was sustained efficacy after drug withdrawal, followed by dosing convenience, co‐payment, long‐term efficacy, early onset of efficacy and risk of serious infection. The study found that patients prefer treatments which have durable efficacy and lower treatment burden characterized as fewer injection frequency and lower co‐payment. These results may be helpful to understand patient preference for biologic treatments used for psoriasis in Japan and contribute to shared decision‐making between patients and physicians to improve patient satisfaction and treatment outcomes.

The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

Real-world effectiveness and safety of adalimumab for treatment of ankylosing spondylitis in Japan

Objective: To evaluate the real-world effectiveness and safety of adalimumab for the treatment of ankylosing spondylitis (AS) in Japan.Methods: All AS patients initiated on adalimumab from 27 October 2010 to 28 May 2015, were enrolled. Patient characteristics at baseline, changes in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores, and adverse drug reactions (ADRs) for 24 weeks from the first adalimumab treatment were evaluated.Results: Of 403 enrolled patients, 396 and 374 comprised the safety and effectiveness analysis sets, respectively. In the safety analysis set, 266/396 (67.2%) were males, with a mean ± standard deviation (SD) age of 46.3 ± 15.6 years and mean ± SD disease duration of 9.8 ± 9.8 years. Of 236 patients examined for human leukocyte antigen (HLA)-B27, 131 (55.5%) were HLA-B27-positive. In the effectiveness analysis set, the mean ± SD BASDAI score was 4.9 ± 2.3 at baseline (n = 292). Overall, 216 patients had BASDAI data pre- and post-baseline. At 24 weeks, 143 patients had BASDAI scores, and the mean ± SD decrease was -2.0 ± 2.6 (p < .0001). Fifteen serious ADRs occurred in 15 (3.79%) patients; 30 (7.58%) ADRs of infections were reported, of which, five (1.26%) were serious.Conclusion: Safety and effectiveness of adalimumab in this postmarketing observational study were similar to that in previous clinical trials.

Pre-Operative Planning Using Real-Time Virtual Sonography, an MRI/Ultrasound Image Fusion Technique, for Breast-Conserving Surgery in Patients with Non-Mass Enhancement on Breast MRI: A Preliminary Study

The purpose of this retrospective study was to evaluate the effect of pre-operative planning using real-time virtual sonography (RVS), a magnetic resonance imaging (MRI)/ultrasound (US) image fusion technique on breast-conserving surgery (BCS) in patients with non-mass enhancement (NME) on breast MRI. Between 2011 and 2015, we enrolled 12 consecutive patients who had lesions with NME that exceeded the US hypo-echoic area, in which it was particularly difficult to evaluate the tumor margin. During pre-operative planning before breast-conserving surgery, RVS was used to delineate the enhancing area on the breast surface after additional supine breast MRI was performed. We analyzed both the surgical margin positivity rate and the re-operation rate. All NME lesions corresponded to the index cancer. In all patients, the diameter of the NME lesion was greater than that of the hypo-echoic lesion. The median diameters of the NME and hypo-echoic lesions were 24 mm (range: 12-39 mm) and 8.0 mm (range: 4.9-18 mm), respectively (p = 0.0002). After RVS-derived skin marking was performed on the surface of the affected breast, lumpectomy and quadrantectomy were conducted in 7 and 5 patients, respectively. The surgical margins were negative in 10 (83%) patients. Two patients with positive margins were found to have ductal carcinoma in situ in 1 duct each, 2.4 and 3.2 mm from the resection margin, respectively. None of the patients required additional resection. Although further prospective studies are required, the findings of our preliminary study suggest that it is very well possible that the use of RVS-derived skin marking during pre-operative planning for BCS in patients with NME would have resulted in surgical outcomes similar to or better than those obtained without the use of such marking.

[Validation Study of Analytical Method for Determination of Amnesic Shellfish Poison in Bivalves]

Amnesic shellfish poison (ASP) is regarded as one of the shellfish poison groups in the EU, though it is not subject to regulation in Japan. We have developed an analytical method of ASP based on the report by Hatfield et al. and other methods. Validation studies were carried out with certified compositional reference materials (CRM). Performance parameters were estimated based on 17 analytical results. The estimate of trueness was 97.5%, and the estimate of intralaboratory reproducibility (RSD) was 1.5%. The HorRat(r) value was 0.16. These performance parameters meet the criteria in the Codex Procedural Manual. Furthermore, internal quality control was performed by using the CRM. The action limits were set based on the performance parameters of the method. Most of the results of the internal quality control were within the action limit range. The results confirmed that the quality of the analyses was well maintained. The purpose of the analytical method is to confirm that the level of ASP in scallop is less than 4.6 mg/kg. The applicability of the analytical method to scallops was confirmed by using spiked samples.

Second-look US Using Real-time Virtual Sonography, a Coordinated Breast US and MRI System with Electromagnetic Tracking Technology: A Pilot Study

Our aim was to retrospectively evaluate the utility of second-look ultrasound (US) using real-time virtual sonography (RVS) for detection of conventional B-mode (cB-mode) occult magnetic resonance imaging (MRI)-detected breast lesions. Between July 2011 and May 2015, 53 consecutive patients who underwent second-look US to identify lesions detected by prone MRI were enrolled in this study. Second-look US using RVS was performed for cB-mode occult MRI-detected breast lesions after an additional supine MRI. In the 53 patients, 59 lesions were initially detected by prone MRI, followed by second-look US. Of the 59 lesions, 20 (34%) were identified by second-look US using cB-mode. Of the 39 (66%) cB-mode occult lesions, 38 (97%) were detected in supine MRI and 33 (85%) were detected by second-look US using RVS. MRI morphology types of the 33 lesions were as follows: mass, 16; non-mass enhancement, 5; and focus, 12. US-guided biopsy under RVS or excisional biopsy demonstrated that of the 33 lesions, 8 (24%) were malignant and the remaining 25 (76%) were benign. A total of 53 (90%) MRI-detected lesions were sonographically identified using both cB-mode and RVS (p < 0.001). All five remaining US-occult lesions could be followed up under RVS after the enhancing area was marked on the breast surface using RVS. Although further prospective studies are required, the findings of our pilot study suggest that second-look US using RVS with additional supine MRI may improve the sonographic and histopathologic detection rate of cB-mode occult MRI-detected breast lesions.

Urinary Sodium-to-Potassium Ratio Tracks the Changes in Salt Intake during an Experimental Feeding Study Using Standardized Low-Salt and High-Salt Meals among Healthy Japanese Volunteers

The Na/K ratio is considered to be a useful index, the monitoring of which allows an effective Na reduction and K increase, because practical methods (self-monitoring devices and reliable individual estimates from spot urine) are available for assessing these levels in individuals. An intervention trial for lowering the Na/K ratio has demonstrated that a reduction of the Na/K ratio mainly involved Na reduction, with only a small change in K. The present study aimed to clarify the relationship between dietary Na intake and the urinary Na/K molar ratio, using standardized low- and high-salt diets, with an equal dietary K intake, to determine the corresponding Na/K ratio. Fourteen healthy young adult volunteers ingested low-salt (3 g salt per day) and high-salt (20 g salt per day) meals for seven days each. Using a portable urinary Na/K meter, participants measured their spot urine at each voiding, and 24-h urine was collected on the last day of each diet period. On the last day of the unrestricted, low-salt, and high-salt diet periods, the group averages of the 24-h urine Na/K ratio were 4.2, 1.0, and 6.9, while the group averages of the daily mean spot urine Na/K ratio were 4.2, 1.1, and 6.6, respectively. The urinary Na/K ratio tracked changes in dietary salt intake, and reached a plateau approximately three days after each change in diet. Frequent monitoring of the spot urine Na/K ratio may help individuals adhere to an appropriate dietary Na intake.

Low disease activity for up to 3 years after adalimumab discontinuation in patients with early rheumatoid arthritis: 2-year results of the HOPEFUL-3 Study

Background

This study was conducted to evaluate the feasibility of long-term adalimumab (ADA) discontinuation after achievement of low disease activity (LDA) in Japanese patients with early rheumatoid arthritis (RA) and to identify predictors of LDA maintenance.

Methods

In the HOPEFUL-1 study, patients received initial therapy with either ADA plus methotrexate (MTX; intensive therapy) or MTX alone (standard therapy) for 26 weeks, followed by ADA + MTX for 26 weeks. In the HOPEFUL-2 study, patients received ADA + MTX (ADA continuation) or MTX alone (ADA discontinuation) for 52 weeks. HOPEFUL-3 was an observational study that enrolled patients who had completed HOPEFUL-2; these patients were followed for an additional 104 weeks.

Results

Of the 172 patients enrolled in the HOPEFUL-3 study, 135 (ADA continuation, n = 61; ADA discontinuation, n = 74) with 28-joint Disease Activity Score using C-reactive protein (DAS28-CRP) values at both week 52 (start of HOPEFUL-2) and week 208 (end of HOPEFUL-3) were included in the effectiveness analysis. At week 208, 58 (95.1%) of 61 patients and 59 (79.7%) of 74 patients who continued or discontinued ADA, respectively, had LDA (DAS28-CRP <3.2). Initial intensive therapy was associated with a better outcome than standard therapy in terms of change in modified total Sharp score from week 0 to week 208, which was ≤0.5 (64% vs. 30%). The incidence of adverse events was significantly lower in the ADA discontinuation group than in the ADA continuation group (9.7% vs. 32.9%; p < 0.001).

Conclusions

Approximately 80% of patients who discontinued ADA for 3 years after achieving LDA with ADA + MTX were still in LDA, with a lower incidence of adverse events than patients who continued ADA.

Trial registration

ClinicalTrials.gov identifier: NCT01346501. Registered 29 April 2011.

Mechanisms of Impaired Neutrophil Migration by MicroRNAs in Myelodysplastic Syndromes

In myelodysplastic syndromes (MDS), functional defects of neutrophils result in high mortality because of infections; however, the molecular basis remains unclear. We recently found that miR-34a and miR-155 were significantly increased in MDS neutrophils. To clarify the effects of the aberrant microRNA expression on neutrophil functions, we introduced miR-34a, miR-155, or control microRNA into neutrophil-like differentiated HL60 cells. Ectopically introduced miR-34a and miR-155 significantly attenuated migration toward chemoattractants fMLF and IL-8, but enhanced degranulation. To clarify the mechanisms for inhibition of migration, we studied the effects of miR-34a and miR-155 on the migration-regulating Rho family members, Cdc42 and Rac1. The introduced miR-34a and miR-155 decreased the fMLF-induced active form of Cdc42 to 29.0 ± 15.9 and 39.7 ± 4.8% of that in the control cells, respectively, although Cdc42 protein levels were not altered. miR-34a decreased a Cdc42-specific guanine nucleotide exchange factor (GEF), dedicator of cytokinesis (DOCK) 8, whereas miR-155 reduced another Cdc42-specific GEF, FYVE, RhoGEF, and PH domain-containing (FGD) 4. The knockdown of DOCK8 and FGD4 by small interfering RNA suppressed Cdc42 activation and fMLF/IL-8-induced migration. miR-155, but not miR-34a, decreased Rac1 protein, and introduction of Rac1 small interfering RNA attenuated Rac1 activation and migration. Neutrophils from patients showed significant attenuation in migration compared with healthy cells, and protein levels of DOCK8, FGD4, and Rac1 were well correlated with migration toward fMLF (r = 0.642, 0.686, and 0.436, respectively) and IL-8 (r = 0.778, 0.659, and 0.606, respectively). Our results indicated that reduction of DOCK8, FGD4, and Rac1 contributes to impaired neutrophil migration in MDS.

Evaluation of the Glasgow Prognostic Score in patients receiving chemoradiotherapy for stage III and IV esophageal cancer

High Glasgow Prognostic scores (GPSs) have been associated with poor outcomes in various tumors, but the values of GPS and modified GPS (mGPS) in patients with advanced esophageal cancer receiving chemoradiotherapy (CRT) has not yet been reported. We have evaluated these with respect to predicting responsiveness to CRT and long-term survival. Between January 2002 and December 2011, tumor responses in 142 esophageal cancer patients (131 men and 11 women) with stage III (A, B and C) and IV receiving CRT were assessed. We assessed the value of the GPS as a predictor of a response to definitive CRT and also as a prognostic indicator in patients with esophageal cancer receiving CRT. We found that independent predictors of CRT responsiveness were Eastern Cooperative Oncology Group (ECOG) performance status, GPS and cTNM stage. Independent prognostic factors were ECOG performance status and GPS for progression-free survival and ECOG performance status, GPS and cTNM stage IV for disease-specific survival. GPS may be a novel predictor of CRT responsiveness and a prognostic indicator for progression-free and disease-specific survival in patients with advanced esophageal cancer. However, a multicenter study as same regime with large number of patients will be needed to confirm these outcomes.

Reduction of c-Fos via Overexpression of miR-34a Results in Enhancement of TNF- Production by LPS in Neutrophils from Myelodysplastic Syndrome Patients

Although increased TNF-α has been considered to cause ineffective hematopoiesis in myelodysplastic syndromes (MDS), the mechanisms of TNF-α elevation are not known. We recently found that c-Fos mRNA stabilization under translation-inhibiting stimuli was impaired in MDS-derived neutrophilic granulocytes. In the current study, we identified overexpression of c-Fos-targeting miR-34a and miR-155 as the cause of impairment. Expression levels of miR-34a but not miR-155 inversely correlated with ratios of c-Fos-positive cells in MDS-derived CD16⁺ neutrophils (r = -0.618, P<0.05), which were analyzed by flow cytometry. Among the seventeen patients, c-Fos was detectable in less than 60% of CD16⁺ cells in eight patients (Group A), while five (Group B) expressed c-Fos in more than 80% of CD16⁺ cells, which was consistent with the controls (88.6 ± 7.8%). Group A-derived granulocytes secreted more TNF-α in response to 1 μM LPS for 3 hours (735.4 ± 237.5 pg/mL) than Group B (143.5 ± 65.7 pg/mL, P<0.05) and healthy controls (150.8 ± 91.5 pg/mL, P<0.05). Knockdown of c-Fos in neutrophil-like differentiated HL60 increased the binding of NF-κB p65 to the promoter region of TNF-α DNA. Thus, c-Fos reduction via overexpression of miR-34a contributes to TNF-α overproduction under inflammatory stimuli in MDS.

Inhibitory effect of YM-244769, a novel Na+/Ca2+ exchanger inhibitor on Na+/Ca2+ exchange current in guinea pig cardiac ventricular myocytes

Recently, YM-244769 (N-(3-aminobenzyl)-6-{4-[(3-fluorobenzyl)oxy]phenoxy} nicotinamide) has been reported as a new potent and selective Na⁺/Ca²⁺ exchange (NCX) inhibitor by using various cells transfected with NCX using the ⁴⁵Ca²⁺ fluorescent technique. However, the electrophysiological study of YM-244769 on NCX had not been performed in the mammalian heart. We examined the effects of YM-244769 on NCX current (I_NCX) in single cardiac ventricular myocytes of guinea pigs by using the whole-cell voltage clamp technique. YM-244769 suppressed the bidirectional I_NCX in a concentration-dependent manner. The IC₅₀ values of YM-244769 for the bidirectional outward and inward I_NCX were both about 0.1 μM. YM-244769 suppressed the unidirectional outward I_NCX (Ca²⁺ entry mode) with an IC₅₀ value of 0.05 μM. The effect on the unidirectional inward I_NCX (Ca²⁺ exit mode) was less potent, with 10 μM of YM-244769 resulting in the inhibition of only about 50 %. At 5 mM intracellular Na⁺ concentration, YM-244769 suppressed I_NCX more potently than it did at 0 mM [Na⁺]_i. Intracellular application of trypsin via the pipette solution did not change the blocking effect of YM-244769. In conclusion, YM-244769 inhibits the Ca²⁺ entry mode of NCX more potently than the Ca²⁺ exit mode, and inhibition by YM-244769 is [Na⁺]_i-dependent and trypsin-insensitive. These characteristics are similar to those of other benzyloxyphenyl derivative NCX inhibitors such as KB-R7943, SEA0400, and SN-6. The potency of YM-244769 as an NCX1 inhibitor is higher than those of KB-R7943 and SN-6 and is similar to that of SEA0400.

DEC2 is a negative regulator for the proliferation and differentiation of chondrocyte lineage-committed mesenchymal stem cells

Differentiated embryo chondrocyte 2 (DEC2) is a basic helix-loop-helix-Orange transcription factor that regulates cell differentiation in various mammalian tissues. DEC2 has been shown to suppress the differentiation of mesenchymal stem cells (MSCs) into myocytes and adipocytes. In the present study, we examined the role of DEC2 in the chondrogenic differentiation of human MSCs. The overexpression of DEC2 exerted minimal effects on the proliferation of MSCs in monolayer cultures with the growth medium under undifferentiating conditions, whereas it suppressed increases in DNA content, glycosaminoglycan content, and the expression of several chondrocyte-related genes, including aggrecan and type X collagen alpha 1, in MSC pellets in centrifuge tubes under chondrogenic conditions. In the pellets exposed to chondrogenesis induction medium, DEC2 overexpression downregulated the mRNA expression of fibroblast growth factor 18, which is involved in the proliferation and differentiation of chondrocytes, and upregulated the expression of p16INK4, which is a cell cycle inhibitor. These findings suggest that DEC2 is a negative regulator of the proliferation and differentiation of chondrocyte lineage-committed mesenchymal cells.

Dual Roles of 5-Hydroxytryptamine in Ischemia-Reperfusion Injury in Isolated Rat Hearts

Background: 5-Hydroxytryptamine (5-HT) has been shown to be involved in exacerbating cardiac ischemia-reperfusion injury; however, the role of 5-HT in the injury has yet to be established. This study demonstrates that 5-HT has dual roles in ischemia-reperfusion injury.

Methods and Results: The role of 5-HT in cardiac ischemia-reperfusion injury was examined in isolated rat hearts perfused with oxygenated Krebs-Henseleit solution. A 30-minute global ischemia and 30-minute reperfusion exacerbated functional cardiac parameters such as left ventricular end-diastolic pressure, coronary flow, heart rate, and total lactate dehydrogenase release. The 5-HT2A receptor antagonist sarpogrelate (0.3-1.0 μM) improved cardiac function during ischemia-reperfusion. High-performance liquid chromatography analysis revealed an elevation in the level of 5-HT in the coronary effluent immediately after ischemia, suggesting that 5-HT is released from the ischemic heart and that sarpogrelate protects the heart from ischemia-reperfusion injury by blocking 5-HT2A receptors. However, 5-HT (0.3-1.0,μM) applied exogenously unexpectedly improved the cardiac mechanical parameters during ischemia-reperfusion, increased coronary flow, and increased the level of NO in the effluent, which was inhibited by L-NG-nitro-arginine methyl ester, a NO synthase blocker.

Conclusions: Present results suggest dual roles of 5-HT in ischemia-reperfusion injury. During ischemia, 5HT is released endogenously, constricts coronary smooth muscles via 5-HT2A receptors, and aggravates cardiac function. In contrast, 5-HT applied exogenously affects predominantly non-5HT2A receptors on the endothelium and induces coronary vasodilatation via endothelial NO production, which is protective against ischemia-reperfusion injury.

When Does the Culturally Dominant Mode of Attention Appear or Disappear? Comparing Patterns of Eye Movement During the Visual Flicker Task Between European Canadians and Japanese

Previous findings in culture and attention reported mixed results. While some studies demonstrated systematic cultural variations in patterns of eye movement, other studies reported that the magnitude of the effects is minor. To further scrutinize when cultural variations in attention are attenuated or enhanced, we conducted a new series of visual flicker tasks while making changes in focal figures more salient than those in the background. European Canadian and Japanese participants searched for a change in a pair of quickly alternating still images. The task consisted of two parts: In the majority of trials, we set a change in part of either the focal object or the background (change trials), while in some trials, a pair of identical images was presented unbeknownst to participants (no-change trials), which resulted in forcing participants to search for a nonexistent change for 1 min. We then measured patterns of eye movement during each type of trial. The results of the change trials indicated that there were no cultural variations in change detection styles, nor were there cultural variations in eye movement patterns except for the total fixation duration, suggesting in general that both groups exhibited similar bottom-up patterns of attention. However, in the no-change trials, there were substantial cultural variations in eye movement patterns: European Canadians substantially attended to the focal figures longer and more frequently than to the backgrounds, whereas Japanese equally allocated their attention to both the focal figures and the backgrounds, suggesting that culturally unique top-down patterns were more evident.

Swelling-activated and arachidonic acid-induced currents are TREK-1 in rat bladder smooth muscle cells

Using the perforated patch voltage clamp, we investigated swelling-activated ionic channels (SACs) in rat urinary bladder smooth muscle cells.　Hypo-osmotic (60%) bath solution increased a membrane current which was inhibited by the SAC inhibitor, gadolinium.　The reversal potential of the hypotonicity-induced current shifted in the positive direction by increasing external K(+) concentration.　The hypotonicity-induced current was inhibited by extracellular acidic pH, phorbol ester and forskolin.　These pharmacological properties are identical to those of arachidonic acid-induced current present in these cells, suggesting the presence of TREK-1, a four-transmembrane two pore domain K(+) channel.　Using RT-PCR we screened rat bladder smooth muscles and cerebellum for expression of TREK-1, TREK-2 and TRAAK mRNAs.　Only TREK-1 mRNA was expressed in the bladder, while all three were expressed in the cerebellum.　We conclude that a mechanosensitive K(+) channel is present in rat bladder myocytes, which is activated by arachidonic acid and most likely is TREK-1.　This K(+) channel may have an important role in the regulation of bladder smooth muscle tone during urine storage.

Differential effects of lysophosphatidylcholine and ACh on muscarinic K(+),non-selective cation and Ca(2+) currents in guinea-pig atrial cells

We compared the effects of lysophosphatidylcholine (LPC) and acetylcholine (ACh) on IK(ACh), ICa and a non-selective cation current (INSC) in guinea-pig atrial myocytes to clarify whether LPC and ACh activate similar Gi/o-coupled effector systems.　IK(ACh), ICa and INSC were analyzed in single atrial myocytes by the whole cell patch-clamp.　LPC induced INSC in a concentration-dependent manner in atrial cells.　ACh activated IK(ACh), but failed to evoke INSC.　LPC also activated IK(ACh) but with significantly less potency than ACh.　The effects of both ligands on IK(ACh) were inhibited by intracellular loading of pre-activated PTX.　This treatment also inhibited LPC-induced INSC, indicating that IK(ACh) and INSC induced by LPC are both mediated by Gi/o.　LPC and ACh had similar potencies in inhibiting ICa, which was pre-augmented by forskolin, indicating that LPC and ACh activate similar amounts of α-subunits of Gi/o.　The different effects of LPC and ACh on IK(ACh) and INSC may suggest that LPC and ACh activate Gi/o having different types of βγ subunits, and that LPC-induced INSC may be mediated by βγ subunits of Gi/o, which are less effective in inducing IK(ACh).

Nerve growth factor enhances the CRE-dependent transcriptional activity activated by nobiletin in PC12 cells

Prevention and treatment of Alzheimer disease are urgent problems for elderly people in developed countries. We previously reported that nobiletin, a poly-methoxylated flavone from the citrus peel, improved the symptoms in various types of animal models of memory loss and activated the cAMP responsive element (CRE)-dependent transcription in PC12 cells. Nobiletin activated the cAMP/PKA/MEK/Erk/MAPK signaling pathway without using the TrkA signaling activated by nerve growth factor (NGF). Here, we examined the effect of combination of nobiletin and NGF on the CRE-dependent transcription in PC12 cells. Although NGF alone had little effect on the CRE-dependent transcription, NGF markedly enhanced the CRE-dependent transcription induced by nobiletin. The NGF-induced enhancement was neutralized by a TrkA antagonist, K252a. This effect of NGF was effective on the early signaling event elicited by nobiletin. These results suggested that there was crosstalk between NGF and nobiletin signaling in activating the CRE-dependent transcription in PC12 cells.

THE INHIBITORY EFFECT OF PACLITAXEL ON (Kv2.1) K+ CURRENT IN H9c2 CELLS

Using the whole-cell voltage clamp technique, we investigated the effect of paclitaxel, an anticancer agent which promotes microtubule formation, on K(+) current in H9c2 cells originated from rat embryonic cardiac myocytes. Paclitaxel inhibited Kv2.1 voltage-dependent K(+) current (IKur) with ultra-rapidly activating and slowly inactivating kinetics in a concentration-dependent manner. The inhibitory effect of paclitaxel on IKur was time-dependent and more marked at 200 ms after the onset than at the beginning of the depolarizing pulse. The IC50 value of paclitaxel was 1.1 µM at 200 ms. The time-dependent inhibition suggests that paclitaxel might be an open channel blocker of Kv2.1. This inhibition of Kv2.1 may be involved in the adverse effects of paclitaxel on cardiac and neuronal cells.

Characteristic expressions of GABA receptors and GABA producing/transporting molecules in rat kidney

Gamma-aminobutyric acid (GABA) is an important neurotransmitter, but recent reports have revealed the expression of GABAergic components in peripheral, non-neural tissues. GABA administration induces natriuresis and lowers blood pressure, suggesting renal GABA targets. However, systematic evaluation of renal GABAergic components has not been reported. In this study, kidney cortices of Wistar-Kyoto rats (WKY) were used to assay for messenger RNAs of GABA-related molecules using RT-PCR. In WKY kidney cortex, GABA_A receptor subunits, α1, β3, δ, ε and π, in addition to both types of GABA_B receptors, R1 and R2, and GABA_C receptor ρ1 and ρ2 subunit mRNAs were detected. Kidney cortex also expressed mRNAs of glutamate decarboxylase (GAD) 65, GAD67, 4-aminobutyrate aminotransferase and GABA transporter, GAT2. Western blot and/or immunohistochemistry were performed for those molecules detected by RT-PCR. By immunofluorescent observation, co-staining of α1, β3, and π subunits was observed mainly on the apical side of cortical tubules, and immunoblot of kidney protein precipitated with π subunit antibody revealed α1 and β3 subunit co-assembly. This is the first report of GABA_A receptor π subunit in the kidney. In summary, unique set of GABA receptor subunits and subtypes were found in rat kidney cortex. As GABA producing enzymes, transporters and degrading enzyme were also detected, a possible existence of local renal GABAergic system with an autocrine/paracrine mechanism is suggested.

Abstract 072: Newly Developed Personal Device can Detect Changes and Variations of Urinary Na/K Ratio with Standardized Low- and High-salt Meals in Healthy Volunteers

Background: A low-sodium (Na), high-potassium (K) diet is recommended to suppress blood pressure elevation, but determining the absolute amounts of Na and K in a diet is difficult. A novel portable device was developed to allow easy measurement of urinary Na/K ratio on the spot. In this study, our aims were 1): to observe the changes of urinary Na/K ratio in subjects on low- and high-Na diet and 2): to determine if there are differences in urinary Na/K ratio between subjects with and without salt sensitivity.

Methods: Healthy volunteers (14 subjects) ingested standardized low- (3 g NaCl /day) and high-Na (20 g NaCl/day) meals for 7 days each. Urinary Na/K ratio was measured at each voiding using a prototype device (Omron Healthcare). Collection of blood and 24-hour urine was conducted at the end of each diet period (unrestricted (NS), low-salt (LS), and high-salt (HS)). Those with mean blood pressure difference (LS vs. HS) ≥ 5% were determined as salt-sensitive (SS) and others salt-resistant (SR).

Results: Urinary Na/K ratio reached a plateau approximately 3 days after each change in the Na level of the diet. Urinary Na/K ratio of spot urine correlated well with Na/K ratio of 24-hour urine. Average urinary Na/K ratio was 3.9 ± 1.9 on the last day of NS, 0.8 ± 0.3 on LS, and 6.9 ± 2.1 on HS. The variation of urinary Na/K ratio was small during the LS diet period. The change in urinary Na/K ratio of SS group tended to be slower than that of SR. This device may also be useful in diabetic and proteinuric patients as Na/K ratio was affected minimally by experimental glucose and protein addition.

Conclusion: Using an easy-to-use device, measurements of urinary Na/K ratio keenly reflected the sodium level of the diet.

Upregulation of N-methyl-D-aspartate receptor subunits and c-Fos expressing genes in PC12D cells by nobiletin

The N-methyl-D-aspartate (NMDA) receptor plays a key role in learning and memory. Our recent studies have shown that nobiletin from citrus peels activates the cAMP response element-binding protein (CREB) signaling pathway and ameliorates NMDA receptor antagonist-induced learning impairment by activating extracellular signal-regulated kinase. For the first time, we have shown that nobiletin significantly upregulated mRNA expression of the NMDA receptor subunits NR1, NR2A, and NR2B in PC12D cells. Furthermore, c-Fos mRNA expression also increased due to the action of nobiletin. Our results indicate that nobiletin modulates the expression of essential genes for learning and memory by activating the CREB signaling pathway, and suggest that this action mechanism of nobiletin plays a crucial role in improving NMDA receptor antagonist-induced learning impairment in model animals with dementia.

Studies of Successive Phase Transitions and Molecular Motions in [Mg(H2O)6][SiF6] by 1,2H and 19F NMR

The successive phase transitions of [Mg(H2O)6][SiF6] were studied by measuring 2H NMR spectra. The quadrupole coupling constant e2Qq/h and asymmetry parameter η changed drastically at each transition temperature. 1,2H and 19F NMR Tl were measured for this compound to study the relation between the molecular motions and the successive phase transitions. The activation energy Ea and the pre-exponential factor τ0 for the reorientation of [SiF6]2- were estimated as 28 kJmol-1 and 6.0 x 10-14 s, and those of the 180° flip of H2O as 33 kJmol-1 and 4.0x 10-14 s. These two motions occur rapidly even in phase V. For the reorientation of [Mg(H2O)6]2+ , Ea = 62 kJmol-1 and τ0 = 1.1 x 10-16 s were obtained from the simulation of 2H NMR spectra. The jump rate of this motion is of the order of 104 -106 s-1 in phase II. These results suggest that the successive phase transitions are closely related to the motion of [Mg(H2O)6]2+ .

Palmdelphin, a novel target of p53 with Ser46 phosphorylation, controls cell death in response to DNA damage

The tumor suppressor gene p53 regulates apoptosis in response to DNA damage. Promoter selectivity of p53 depends on mainly its phosphorylation. Particularly, the phosphorylation at serine-46 of p53 is indispensable in promoting pro-apoptotic genes that are, however, poorly determined. In the current study, we identified palmdelphin as a pro-apoptotic gene induced by p53 in a phosphorylated serine-46-specific manner. Upregulation of palmdelphin was observed in wild-type p53-transfected cells, but not in serine-46-mutated cells. Expression of palmdelphin was induced by p53 in response to DNA damage. In turn, palmdelphin induced apoptosis. Intriguingly, downregulation of palmdelphin resulted in necroptosis-like cell death via ATP depletion. Upon DNA damage, palmdelphin dominantly accumulated in the nucleus to induce apoptosis. These findings define palmdelphin as a target of serine-46-phosphorylated p53 that controls cell death in response to DNA damage.

The inhibitory effect of shakuyakukanzoto on K+ current in H9c2 cells

Shakuyakukanzoto (shao-yao-gan-cao-tang) is a commonly used Chinese traditional herbal medicine for the treatment of acute pain with muscle cramp. However, its mechanism of action is unclear. We previously reported that a low concentration of Kanzo (licorice) and isoliquiritigenin, a component of licorice, inhibited the potassium (K(+)) current in H9c2 cells. Therefore, in the present study, we examined the effects of Shakuyakukanzoto, Shakuyaku or Kanzo on the K(+) current (IKur) in H9c2 cells. Shakuyakukanzoto inhibited IKur in a concentration-dependent manner. The half-maximal concentration of Shakuyakukanzoto was approximately 1.3 mg/mL and the Hill coefficient was 1.2. The order of potency of inhibiting IKur was Kanzo>Shakuyakukanzoto>Shakuyaku. Glycyrrhizin, a major component of licorice, had no inhibitory effect on IKur. A small interfering RNA experiment indicated that IKur was most likely to be Kv2.1 in H9c2 cells. Our results suggest that Shakuyakukanzoto may normalize intracellular and extracellular K(+) balance by inhibiting IKur and reducing K(+) efflux, while the Na(+)-K(+) pump promotes K(+) influx into myofibers. Consequently, excess K(+) may be reduced from external space of myofibers. This may be a part of the Shakuyakukanzoto mechanism for improving muscle pain.

Nobiletin, a flavone from Citrus depressa, induces gene expression and increases the protein level and activity of neprilysin in SK-N-SH cells

Neprilysin (NEP) is one of the candidate amyloid β protein (Aβ) degrading enzymes affecting brain Aβ clearance. This enzyme declines in the brain with age, which leads to the increased Aβ deposition in Alzheimer's disease (AD). Pharmacological activation of NEP during the aging process, therefore, represents a potential strategy to prevent the development of AD. To examine the influence of nobiletin on neprilysin activity, we measured cellular NEP activity in SK-N-SH cells. Moreover, NEP expression was examined by using reverse transcription - polymerase chain reaction and Western blotting. Measurement of cellular NEP activity showed that nobiletin stimulated this in a dose- and time-dependent manner in SK-N-SH cells. Moreover, nobiletin increased the expression of NEP mRNA, and then the levels of NEP protein, also in a dose- and time-dependent manner. Our findings showed that nobiletin promoted NEP gene and protein expression, resulting in enhancement of cellular NEP activity in SK-N-SH cells. This compound could be a novel Aβ-degrading compound for use in the development of disease-modifying drugs to prevent and (or) cure AD.

BXSB-type genome causes murine autoimmune glomerulonephritis: pathological correlation between telomeric region of chromosome 1 and Yaa

The autoimmune-prone BXSB/MpJ-Yaa mouse is a model of membranous proliferative glomerulonephritis (MPGN). Severe MPGN has been reported only in male BXSB/MpJ-Yaa mice because of the Y-linked autoimmune accelerator (Yaa) locus. However, we show that female BXSB/MpJ mice develop age-related MPGN without Yaa. Female BXSB/MpJ mice clearly developed MPGN characterized by increased mesangial cells, thickening of the glomerular basement membrane (GBM), double contouring and spike formation of GBM with T-cell infiltrations and podocyte injuries corresponding with increased autoantibody production and albuminuria. Analysis of the renal levels of the Fc gamma receptor (Fcgr) and interferon-activated gene 200 (Ifi200) family genes, which are MPGN candidate genes localized to the telomeric region of chromosome 1 (Chr.1), showed that Fcgr2b levels decreased, whereas Fcgr3 and Ifi202b levels increased in female BXSB/MpJ mice compared with healthy C57BL/6 mice. Furthermore, in isolated glomeruli, microarray analysis revealed that Fcgr3, Fcgr4 and Ifi202b expression was higher in male BXSB/MpJ-Yaa mice than in male BXSB/MpJ mice. These findings indicate that the BXSB/MpJ-type genome causes age-related MPGN with significant contribution from the telomeric region of Chr.1, and Yaa enhances the expression of genes localizing to this locus, thereby leading to severe MPGN in male mice.

A new method for maturity-dependent fractionation of neutrophil progenitors applicable for the study of myelodysplastic syndromes

We applied our new method, maturity-dependent fractionation of bone marrow-derived neutrophil progenitors, to a study of gene expression profiles during granulopoiesis in myelodysplastic syndromes. CD34+ cells with low density [F1], CD11b-/CD16- [F2], CD11b+/CD16- [F3] and CD11b+/CD16low [F4] with intermediate density, CD11b+/CD16int [F5] and CD11b+/CD16high [F6] with high density were isolated from six patients. Although AML1 and C/EBP-ϵ mRNA peaked at F1 and F4, respectively, in healthy individuals, C/EBP-ϵ was maximized at F2/F3 in all patients, two of whom showed simultaneous peaks of AML1 at F2. Thus, this fractionation is useful to detect mistimed induction of granulopoiesis-regulating genes in myelodysplastic syndromes.

Green tea ingestion greatly reduces plasma concentrations of nadolol in healthy subjects

This study aimed to evaluate the effects of green tea on the pharmacokinetics and pharmacodynamics of the β-blocker nadolol. Ten healthy volunteers received a single oral dose of 30 mg nadolol with green tea or water after repeated consumption of green tea (700 ml/day) or water for 14 days. Catechin concentrations in green tea and plasma were determined. Green tea markedly decreased the maximum plasma concentration (C(max)) and area under the plasma concentration-time curve (AUC(0-48)) of nadolol by 85.3% and 85.0%, respectively (P < 0.01), without altering renal clearance of nadolol. The effects of nadolol on systolic blood pressure were significantly reduced by green tea. [(3)H]-Nadolol uptake assays in human embryonic kidney 293 cells stably expressing the organic anion-transporting polypeptides OATP1A2 and OATP2B1 revealed that nadolol is a substrate of OATP1A2 (Michaelis constant (K(m)) = 84.3 μmol/l) but not of OATP2B1. Moreover, green tea significantly inhibited OATP1A2-mediated nadolol uptake (half-maximal inhibitory concentration, IC(50) = 1.36%). These results suggest that green tea reduces plasma concentrations of nadolol possibly in part by inhibition of OATP1A2-mediated uptake of nadolol in the intestine.

Mechanism of statin-induced rhabdomyolysis

Statins, a group of drugs used for the treatment of hypercholesterolemia, have adverse effects on skeletal muscle. The symptoms of these effects range from slight myalgia to severe rhabdomyolysis. The number of patients currently taking statins is estimated to be several millions worldwide. However, the mechanism of statins' myotoxic effects is unclear. Statins inhibit biosynthesis of mevalonate, a rate-limiting step of cholesterol synthesis, by inhibiting HMG-CoA reductase. Mevalonate is also an essential precursor for producing isoprenoids such as farnesylpyrophosphate and geranylgeranylpyrophosphate. These isoprenoids are especially important for anchoring small GTPases to the membrane before they function; e.g., Ras GTPases modulate proliferation and apoptosis, Rho GTPases control cytoskeleton formation, and Rab GTPases are essential for intracellular vesicle trafficking. Inactivation of these small GTPases alters cellular functions. Recently, we successfully reproduced statin-induced myotoxicity in culture dishes using in vitro skeletal muscle systems (e.g., skeletal myotubes and myofibers). This review summarizes our findings that statins induce depletion of isoprenoids and inactivation of small GTPases, especially Rab, which are critical for statin-induced myotoxicity. Although further study is required, our findings may contribute to the prevention and treatment of statins' adverse effects on skeletal muscle and development of safer anti-hypercholesterolemia drugs.

Effects of green tea extract and (-)-epigallocatechin-3-gallate on pharmacokinetics of nadolol in rats

Green tea catechins have been shown to affect the activities of drug transporters in vitro, including P-glycoprotein and organic anion transporting polypeptides. However, it remains unclear whether catechins influence the in vivo disposition of substrate drugs for these transporters. In the present study, we investigated effects of green tea extract (GTE) and (-)-epigallocatechin-3-gallate (EGCG) on pharmacokinetics of a non-selective hydrophilic β-blocker nadolol, which is reported to be a substrate for several drug transporters and is not metabolized by cytochrome P450 enzymes. Male Sprague-Dawley rats received GTE (400 mg/kg), EGCG (150 mg/kg) or saline (control) by oral gavage, 30 min before a single intragastric administration of 10 mg/kg nadolol. Plasma and urinary concentrations of nadolol were determined using high performance liquid chromatography. Pharmacokinetic parameters were estimated by a noncompartmental analysis. Pretreatment with GTE resulted in marked reductions in the maximum concentration (Cmax) and area under the time-plasma concentration curve (AUC) of nadolol by 85% and 74%, respectively, as compared with control. In addition, EGCG alone significantly reduced Cmax and AUC of nadolol. Amounts of nadolol excreted into the urine were decreased by pretreatments with GTE and EGCG, while the terminal half-life of nadolol was not different among groups. These results suggest that the coadministration with green tea catechins, particularly EGCG, causes a significant alteration in the pharmacokinetics of nadolol, possibly through the inhibition of its intestinal absorption mediated by uptake transporters.

6-demethoxynobiletin, a nobiletin-analog citrus flavonoid, enhances extracellular signal-regulated kinase phosphorylation in PC12D cells

We previously demonstrated that nobiletin, a polymethoxylated flavone isolated from citrus peels, has the potential to improve cognitive dysfunction in patients with Alzheimer's disease (AD). Recent studies suggest that the generation of intraneuronal amyloid-beta (Aβ) oligomers is an early event in the pathogenesis of AD. Aβ oligomers cause deficits in the regulation of the extracellular signal-regulated kinase (ERK) signaling which is critical for consolidation of the memory. Our previous studies revealed that nobiletin activated ERK signaling and subsequent cyclic AMP response element-dependent transcription. In this study, the effects of five nobiletin analogs, 6-demethoxynobiletin, tangeretin, 5-demethylnobiletin, sinensetin, and 6-demethoxytangeretin, isolated from citrus peels were assessed on ERK phosphorylation in PC12D cells, and the structure-activity relationships were examined. PC12D cells were treated with nobiletin or its analogs, and the cell extracts were analyzed by Western blotting using an antibody specific to phosphorylated ERK. 6-Demethoxynobiletin markedly enhanced ERK phosphorylation in a concentration-dependent manner. These results may be useful in developing drugs and functional foods using citrus peels for the treatment of dementia including AD.

Loss of ectonucleotidases from the coronary vascular bed after ischemia-reperfusion in isolated rat heart

Background

Ectonucleotidase plays an important role in the regulation of cardiac function by controlling extracellular levels of adenine nucleotides and adenosine. To determine the influence of ischemia-reperfusion injury on ectonucleotidase activity in coronary vascular bed, we compared the metabolic profile of adenine nucleotides during the coronary circulation in pre- and post-ischemic heart.

Methods

Langendorff-perfused rat hearts were used to assess the intracoronary metabolism of adenine nucleotides. The effects of ischemia on the adenine nucleotide metabolism were examined after 30 min of ischemia and 30 min of reperfusion. Adenine nucleotide metabolites were measured by high performance liquid chromatography.

Results

ATP, ADP and AMP were rapidly metabolized to adenosine and inosine during the coronary circulation. After ischemia, ectonucleotidase activity of the coronary vascular bed was significantly decreased. In addition, the perfusate from the ischemic heart contained a considerable amount of enzymes degrading ATP, AMP and adenosine. Immunoblot analysis revealed that the perfusate from the ischemic heart dominantly contained ectonucleoside triphosphate diphosphohydrolase 1, and, to a lesser extent, ecto-5’-nucleotidase. The leakage of nucleotide metabolizing enzymes from the coronary vascular bed by ischemia-reperfusion was more remarkable in aged rats, in which post-ischemic cardiac dysfunction was more serious.

Conclusion

Ectonucleotidases were liberated from the coronary vascular bed by ischemia-reperfusion, resulting in an overall decrease in ectonucleotidase activity in the post-ischemic coronary vascular bed. These results suggest that decreased ectonucleotidase activity by ischemia may exacerbate subsequent reperfusion injury, and that levels of circulating ectonucleotidase may reflect the severity of ischemic vascular injury.

Effect of oral L-arginine administration on exhaled nitric oxide (NO) concentration in healthy volunteers

We previously reported a case of pulmonary hypertension, where the symptoms were improved by oral L-arginine (arginine) administration. Arginine may increase nitric oxide (NO) production in the pulmonary artery. Exhaled NO may reflect pulmonary artery NO production. It has been demonstrated that exhaled NO concentration is higher in patients with allergic diseases, but whether oral arginine administration alters exhaled NO is unknown. Therefore, in this study, we investigated whether oral arginine administration increases exhaled NO among healthy volunteers with and without a history of allergy. Eleven subjects were given a single oral dose (200 mg/kg) of arginine, and their plasma arginine concentrations and exhaled NO were measured up to 150 minutes. Baseline values of exhaled NO concentration were significantly higher in those with a history of allergy (56.4±20.3 ppb, n=5, P< 0.05) than those without (16.8±4.0 ppb, n=6). Oral arginine increased exhaled NO, which peaked at 60 minutes after the administration in those with a history of allergy (85.2±44.8 ppb, n=5). However, the increase in exhaled NO was not significant compared to the baseline values. In contrast, plasma arginine concentration was increased significantly by arginine administration (P< 0.01), regardless of an allergy history. These results suggested that the difference in exhaled NO concentration was not due to a difference in arginine absorption. Serum IgE level was significantly higher in the group with a history of allergy. Eosinophils and white blood cells were within normal range in all subjects. We conclude that oral arginine administration does not significantly increase exhaled NO, regardless of allergy history. However, as arginine administration has been reported to be effective in patients with pulmonary hypertension, it will be necessary to test exhaled NO in subjects with pulmonary hypertension in the future.