Toshiyuki Watanabe

Monitoring circadian time in rat plasma using a secreted Cypridina luciferase reporter.

A firefly luciferase reporter enabled us to monitor promoter activity in vivo as well as ex vivo; however, this requires a sufficient supply of the substrate luciferin and specific monitoring devices. To overcome these disadvantages, we developed transgenic rats carrying a secreted enzyme Cypridina luciferase (CLuc) reporter under the promoter of clock gene Per2 (Per2-CLuc). Per2-CLuc activity in serially sampled blood from freely moving rats exhibited robust circadian rhythms with a peak at early morning. The Per2-CLuc bioluminescence could be quantified even with approximately 100pl of plasma. Plasma Per2-CLuc rhythms were phase reversed, and the level was reduced by restricting food access for 2h during the light phase, suggesting that the plasma Per2-CLuc rhythms reflect the phase of peripheral clocks entrained to feeding cues as well as fuel metabolism. Fasting for 2days did not alter the circadian Per2-CLuc rhythms in rats, suggesting that feeding per se did not affect the circadian Per2-CLuc rhythms. Tissue-specific Per2-CLuc rhythms were observed in culture medium of peripheral tissues. The Per2-CLuc reporter is a powerful tool to access gene expression in vivo as well as ex vivo with ordinary laboratory equipment.

Multichannel perfusion culture bioluminescence reporter system for long-term detection in living cells

We constructed a multichannel perfusion culture system. Using this device, we developed a perfusion device to detect six samples at the same time and demonstrated the response to dexamethasone of the circadian-related promoter activity in Rat1 fibroblast cells. We could detect the sequential phase shifts of the circadian peaks that are dependent on the timing of the drug treatments. We also demonstrate a temporal dual reporter assay using two kinds of secreted luciferase in the perfusion culture. The combination of secreted luciferase and multiple perfusion culture assay system reveals the effects of transient drug treatment for the pharmacological assay.

Autoantibodies against a complement component 1 q subcomponent contribute to complement activation and recurrent thrombosis/pregnancy morbidity in anti-phospholipid syndrome

OBJECTIVE To investigate the prevalence and significance of the autoantibodies against complement component 1 q subcomponent (C1q) in patients with APS. METHODS In all, 40 consecutive primary APS patients, 42 patients with non-SLE CTDs and 20 SLE patients negative for aPL were enrolled in this retrospective analysis. Refractory APS was defined as a clinical status of recurring thrombosis or pregnancy morbidity during adequate secondary prophylaxis. An ELISA was used to measure serum levels of anti-C1q antibodies and anaphylatoxins (C3a, C4a). RESULTS Anti-C1q antibodies were found in 36% (15/42) and 2.5% (1/40) of primary APS patients and controls, respectively. Among primary APS patients, anti-C1q antibody titres were significantly correlated with serum C4a levels (P = 0.013). Neither the prevalence nor the titre of anti-C1q antibodies was associated with any specific clinical manifestations of APS, nor titres of aPL. Refractory APS patients (n = 10) had a higher prevalence of anti-C1q antibodies (9/10 vs 6/32, P = 0.01) than APS patients without recurrence (n = 32). CONCLUSION Anti-C1q antibodies are associated with complement activation in APS and may contribute to the pathogenesis, particularly in refractory cases.

(18)F-FDG and (18)F-NaF PET/CT demonstrate coupling of inflammation and accelerated bone turnover in rheumatoid arthritis.

Objective. To compare the findings in rheumatoid arthritis (RA)-affected joints between 18F-fluorodeoxyglucose (FDG) and 18F-fluoride (NaF) positron emission tomography (PET)/computed tomography (CT). Methods. We enrolled twelve RA patients who started a new biologic agent (naïve 9 and switch 3). At entry, both hands were examined by 18F-FDG PET/CT, 18F-NaF PET/CT, and X-ray. Intensity of PET signals was determined by standardized uptake value max (SUVmax) in metacarpophalangeal (MCP), proximal interphalangeal (PIP), and ulnar, medial, and radial regions of the wrists. Hand X-rays were evaluated according to the Genant-modified Sharp score at baseline and 6 months. Results. Both 18F-FDG and 18F-NaF accumulated in RA-affected joints. The SUVmax of 18F-FDG correlated with that of 18F-NaF in individual joints (r = 0.65), though detail distribution was different between two tracers. 18F-NaF and 18F-FDG signals were mainly located in the bone and the surrounding soft tissues, respectively. The sum of SUVmax of 18F-NaF correlated with disease activity score in 28 joint (DAS28), modified health assessment questionnaire (MHAQ), and radiographic progression. 18F-FDG and 18F-NaF signals were associated with the presence of erosions, particularly progressive ones. Conclusion. Our data show that both 18F-FDG and 18F-NaF PET signals were associated with RA-affected joints, especially those with ongoing erosive changes.

Ultrasonography predicts achievement of Boolean remission after DAS28-based clinical remission of rheumatoid arthritis

Abstract Objectives. To determine whether ultrasonography (US) predicts Boolean remission in rheumatoid arthritis (RA) patients who had achieved disease activity score in 28 joints (DAS28)-based remission criteria. Methods. Thirty-one RA patients in DAS28-based clinical remission were recruited. US semiquantitatively determined Gray scale (GS) and power Doppler (PD) signal scores in the bilateral wrists and all metacarpophalangeals and proximal interphalangeals. Total GS score and total PD score were calculated as the sum of individual scores for each joint. Results. Among 22 RA patients, who maintained DAS28 remission for 2 years, 16 met Boolean remission criteria at the end of study. Both total GS and total PD scores at baseline were significantly lower in Boolean remission group than non-remission group. There was no significant difference in other baseline parameters, including duration of disease, duration of remission, mTSS, and disease activity composite parameters between the two groups. Among the factors for Boolean remission criteria at 2 years, patient global assessment score was associated with total GS score at the entry, while swollen joint count was related to total PD score. Conclusions. Null or low grade of GS and PD findings in US are associated with achieving Boolean remission. Thus, US is essential for assessment and prediction of “deeper remission” of RA.

Effectiveness of whole-body magnetic resonance imaging for the efficacy of biologic anti-rheumatic drugs in patients with rheumatoid arthritis: A retrospective pilot study

Abstract Objectives: To evaluate the scoring of whole-body magnetic resonance imaging (WBMRI) for efficacy assessment in rheumatoid arthritis (RA) patients receiving biological disease-modifying anti-rheumatic drugs (bDMARDs). Methods: Thirty consecutive RA patients receiving bDMARDs were included in this retrospective study. Contrast WBMRI was performed before and 1 year after bDMARDs initiation. Results: At baseline, mean age was 57.1 years and mean disease duration was 3.0 years. Median disease activity score in 28 joints improved from 5.1 to 2.1. Treatment with bDMARDs improved mean whole-body synovitis score from 31.2 to 23.2 and median whole-body bone-edema score from 11 to 3. Whole-body bone-erosion score improved in seven patients and deteriorated in 17 patients. Logistic regression analysis identified whole-body synovitis score as a poor prognostic factor for whole-body bone-erosion progression. Bone-edema score in individual bones was identified as a poor prognostic factor for the progression of bone-erosion. Changes in hand synovitis score correlated with those of other joints, but neither changes in bone-edema nor erosion score of hands correlated with those of other joints in WBMRI. Conclusions: WBMRI scoring may be a novel useful tool to evaluate the efficacy of anti-rheumatic drugs, as well as a potential predictor of joint prognosis, in patients with RA.

Clinical significance of plasma presepsin levels in patients with systemic lupus erythematosus

Abstract Objectives: Presepsin (PSEP: soluble CD14 subtype) is produced from bacteria-stimulated monocytes or neutrophils, thus recognized as a biomarker of sepsis. Aberrant functions in monocyte or neutrophils are increasingly recognized in systemic lupus erythematosus (SLE). We investigated whether plasma PSEP reflects disease activity in patients with SLE. Methods: This retrospective study comprised 35 patients with SLE and 72 with non-SLE autoimmune diseases who visited our facility during the period from August 2012 to September 2015. Plasma PSEP levels and laboratory data were compared between SLE and non-SLE. Clinical markers of SLE disease activity, including SLE disease activity index 2000 (SLEDAI-2K), serum complement concentrations and serum anti-ds-DNA antibodies were assessed in correlation with plasma PSEP levels. Results: Plasma PSEP levels in SLE were higher than those in non-SLE. This phenomenon holds true when comparing SLE and non-SLE patients in the absence of infection (p = .0008). Plasma PSEP levels in SLE patients negatively correlated with C3 (r = –0.4454, p = .0430), CH50 (r = –0.4502, p = .0406) and positively with SLEDAI-2K (r = 0.4801, p = .0237). Conclusion: Elevated plasma PSEP levels were correlated with disease activity of SLE, suggesting inappropriate monocyte or neutrophil activation in the pathophysiology of SLE exacerbation.

Genome-wide Association Study of Idiopathic Osteonecrosis of the Femoral Head

Idiopathic osteonecrosis of the femoral head (IONFH) is an ischemic disorder that causes bone necrosis of the femoral head, resulting in hip joint dysfunction. IONFH is a polygenic disease and steroid and alcohol have already known to increase its risk; however, the mechanism of IONFH remains to be elucidated. We performed a genome-wide association study using ~60,000 subjects and found two novel loci on chromosome 20q12 and 12q24. Big data analyses identified LINC01370 as a candidate susceptibility gene in the 20q12 locus. Stratified analysis by IONFH risk factors suggested that the 12q24 locus was associated with IONFH through drinking capacity. Our findings would shed new light on pathophysiology of IONFH.

Thermal Conductivities of β-SiAlONs by Mechanically Activated Combustion Synthesis

–sialons (Si6-zAlzOzN8-z, z=3) synthesized by mechanically activated combustion synthesis (MA-CS) at a low N2 pressure of 1 MPa, were sintered by Spark Plasma Sintering (SPS) and thermal conductivity was measured at room temperatures. Specimens were fully densified at 1600oC for 10 mins. and showed only –sialon phases confirmed by x-ray diffraction patterns though un-reacted Si was present as impurities after MA-CS. Thermal conductivities increased with sintering temperature and had a maximum value 5.49 W m-1 K-1 for specimens sintered at 1700oC.

Intracranial vasculitis in eosinophilic granulomatosis with polyangiitis

A 59-year-old man with allergic asthma and sinusitis was admitted to the referring hospital with complaints of high fever, paraesthesia in the left foot and disturbance of consciousness. Laboratory tests demonstrated eosinophilia, positivity for MPO-ANCA, haematuria and proteinuria. Brain MRI, performed 2 days before admission to our hospital, revealed abnormal high-signal-intensity lesions indicating multiple cerebral infarctions, whereas brain magnetic resonance angiography (MRA) revealed no abnormal findings (Fig. 1A). Renal biopsy showed pauci-immune necrotizing glomerulonephritis. After admission, the disturbance of consciousness worsened, with new-onset disorientation. Therefore, brain MRI and MRA were repeated on hospital day 5, exhibiting cerebral infarction deterioration and multiple stenoses of the intracranial arteries with decreased intensity levels, respectively (Fig. 1B). The patient was diagnosed with eosinophilic granulomatosis with polyangiitis involving rapidly progressive intracranial arteritis. He was treated using glucocorticoid, CYC and cilostazol. Subsequently, brain MRI and MRA examinations were repeated on hospital day 18; the former showed no additional cerebral infarctions and the latter revealed intracranial vasculitis improvement (Fig. 1C). For eosinophilic granulomatosis with polyangiitis, angiographic imaging is usually ineffective for identifying blood vessels that cause CNS involvement [1, 2]. In our case, the rapid progression of intracranial arteritis could be detected using brain MRA.