Hiroyuki Wakiguchi

Cysteine, histidine and glycine exhibit anti-inflammatory effects in human coronary arterial endothelial cells

The activation of nuclear factor‐kappa B (NF‐κB) in vascular endothelial cells may be involved in vascular pathogeneses such as vasculitis or atherosclerosis. Recently, it has been reported that some amino acids exhibit anti‐inflammatory effects. We investigated the inhibitory effects of a panel of amino acids on cytokine production or expression of adhesion molecules that are involved in inflammatory diseases in various cell types. The activation of NF‐κB was determined in human coronary arterial endothelial cells (HCAECs) because NF‐κB modulates the production of many cytokines and the expression of adhesion molecules. We examined the inhibitory effects of the amino acids cysteine, histidine and glycine on the induction of NF‐κB activation, expression of CD62E (E‐selectin) and the production of interleukin (IL)‐6 in HCAECs stimulated with tumour necrosis factor (TNF)‐α. Cysteine, histidine and glycine significantly reduced NF‐κB activation and inhibitor κBα (IκBα) degradation in HCAECs stimulated with TNF‐α. Additionally, all the amino acids inhibited the expression of E‐selectin and the production of IL‐6 in HCAECs, and the effects of cysteine were the most significant. Our results show that glycine, histidine and cysteine can inhibit NF‐κB activation, IκBα degradation, CD62E expression and IL‐6 production in HCAECs, suggesting that these amino acids may exhibit anti‐inflammatory effects during endothelial inflammation.

Molecular epidemiological study of human rhinovirus species A, B and C from patients with acute respiratory illnesses in Japan

Recent studies suggest that human rhinovirus species A, B and C (HRV-ABCs) may be associated with both the common cold and severe acute respiratory illnesses (ARIs) such as bronchiolitis, wheezy bronchiolitis and pneumonia. However, the state and molecular epidemiology of these viruses in Japan is not fully understood. This study detected the genomes of HRV-ABCs from Japanese patients (92 cases, 0-36 years old, mean±sd 3.5±5.0 years) with various ARIs including upper respiratory infection, bronchiolitis, wheezy bronchiolitis, croup and pneumonia between January and December 2010. HRV-ABCs were provisionally type assigned from the pairwise distances among the strains. On phylogenetic trees based on the nucleotide sequences of the VP4/VP2 coding region, HRV-A, -B and -C were provisionally assigned to 14, 2 and 12 types, respectively. The present HRV-A and -C strains had a wide genetic diversity (>30 % divergence). The interspecies distances were 0.230±0.063 (mean±sd, HRV-A), 0.218±0.048 (HRV-B) and 0.281±0.105 (HRV-C), based on nucleotide sequences, and 0.075±0.036 (HRV-A), 0.049±0.022 (HRV-B) and 0.141±0.064 (HRV-C) at the deduced amino acid level. Furthermore, HRV-A and -C were the predominant species and were detected throughout the seasons. The results suggested that HRV-A and -C strains have a wide genetic divergence and are associated with various ARIs in Japan.

1α,25-Dihydroxyvitamin D3 inhibits vascular cellular adhesion molecule-1 expression and interleukin-8 production in human coronary arterial endothelial cells

Kawasaki disease is an acute febrile vasculitis of childhood that is associated with elevated production of inflammatory cytokines, causing damage to the coronary arteries. The production of proinflammatory cytokines and expression of adhesion molecules in human coronary arterial endothelial cells (HCAECs) is regulated by nuclear transcription factor-κB (NF-κB) activation. We have previously reported that the active form of vitamin D, 1α,25-dihydroxyvitamin D(3) (1α,25-(OH)(2)D(3)), inhibits tumor necrosis factor-α (TNF-α)-induced NF-κB activation. In this study, we examined the anti-inflammatory effects of 1α,25-(OH)(2)D(3) on TNF-α-induced adhesion molecule expression (vascular cellular adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1)) and cytokine production (interleukin-6 (IL-6) and IL-8) in HCAECs. Pretreatment with 1α,25-(OH)(2)D(3) significantly inhibited TNF-α-induced VCAM-1 expression and IL-8 production in HCAECs. Our results suggest that adjunctive 1α,25-(OH)(2)D(3) therapy may modulate the inflammatory response during Kawasaki disease vasculitis.

Relationship between T-cell HLA-DR expression and intravenous immunoglobulin treatment response in Kawasaki disease

Background:Kawasaki disease (KD) is an acute febrile illness associated with the development of vasculitis. Administration of intravenous immunoglobulin (IVIG) is the standard treatment for KD. However, IVIG treatment is not effective in approximately 15% of children with KD. Some reports have presented evidence of immunological responses in IVIG-resistant KD patients. We assessed the possibility that T-cell activation is a contributing mechanism underlying this phenomenon.Methods:We analyzed human leukocyte antigen-DR (HLA-DR) expression on peripheral blood CD4+ and CD8+ T cells in 82 children with KD who were admitted to the hospital between October 2007 and February 2012. We compared the percentages of HLA-DR+ T cells among the CD4+ T-cell and CD8+ T-cell populations for the IVIG-effective and IVIG-resistant groups.Results:Among the 82 subjects, 51 had IVIG-effective KD and 31 children had IVIG-resistant KD. The percentages of HLA-DR+ T cells among the CD4+ T-cell and CD8+ T-cell populations in the IVIG-effective group were significantly lower than those in the IVIG-resistant group.Conclusion:Our results suggest that increased T-cell HLA-DR expression is associated with IVIG resistance in KD patients, indicating that HLA-DR expression would be a useful tool for predicting IVIG responsiveness during KD pathogenesis.

Coronary artery lesions and the increasing incidence of Kawasaki disease resistant to initial immunoglobulin

BACKGROUNDS Kawasaki disease (KD) is a systemic vasculitis of childhood involving coronary arteries. Treatment for intractable cases at a higher risk of cardiac sequelae remains controversial. METHODS Clinical outcomes of KD patients diagnosed in Yamaguchi prefecture, Japan between 2003 and 2014 were analyzed using the medical records from all 14 hospitals covering the prefecture. The study included 1487 patients (male:female, 873:614; median age at diagnosis, 24months). RESULTS The proportion of initial intravenous immunoglobulin (IVIG)-resistant patients increased from 7% to 23% during this decade, although no patients died. Twenty-four patients developed coronary artery lesions (CALs) over one month after the KD onset. The incidence of CAL in patients who received corticosteroid during the disease course (10/37; 27.0%) was higher than that in those who did not (14/1450; 0.97%, p=2.0×10(-35)). Nine patients who responded to initial IVIG plus corticosteroids had no CAL. Conversely, IVIG-resistant patients with alternate corticosteroid therapy more frequently developed CAL than those without it (10/28; 35.7% vs. 5/194; 2.6%, p=8.9×10(-10)). Multivariate analyses indicated corticosteroid therapy (p<0.0001), hyperbilirubinemia (p=0.0010), and a longer number of days before treatment (p=0.0005) as risk factors associated with CAL over a month after onset. The odds ratio of corticosteroid use increased from 18.3 to 43.5 if the cases were limited to initial IVIG non-responders and corticosteroid free-IVIG responders. CONCLUSIONS IVIG-failure has recently increased. The incidence of CAL increased in intractable cases with prolonged corticosteroid use. Corticosteroid may not be alternate choice for IVIG-failure to reduce the risk of cardiac sequelae.

Serum levels of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinases-1 in human herpesvirus-6-infected infants with or without febrile seizures.

Human herpesvirus-6 (HHV-6) is a cause of exanthema subitum and, sometimes, of febrile seizures. However, the pathogenesis of febrile seizures associated with HHV-6 infection remains unclear. We investigated serum matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) levels in infants with HHV-6 infection. Serum levels of both MMP-9 and TIMP-1 were significantly higher in infants with HHV-6 infection than in controls. Serum TIMP-1 levels were significantly higher in infants with febrile seizures than in infants without febrile seizures. Serum MMP-9/TIMP-1 ratios were significantly lower in infants with febrile seizures than in infants without febrile seizures. In infants with HHV-6 infection, positive correlations were found between serum MMP-9 concentrations and the white blood cells (WBC) count, and between serum TIMP-1 concentrations and the WBC count. Positive correlations were also found between the amounts of HHV-6 DNA and the ratios of MMP-9/TIMP-1 in infants with HHV-6 infection. In conclusion, we suggest that high serum levels of MMP-9 and TIMP-1 in infants with HHV-6 infection may induce dysfunction of the blood-brain barrier, eventually causing febrile seizures.

Cytokine profile of bronchoalveolar lavage fluid from a mouse model of bronchial asthma during seasonal H1N1 infection.

BACKGROUND Several studies support the role of viral infections in the pathogenesis of asthma exacerbation. However, several pediatricians believe that influenza virus infection does not exacerbate bronchial asthma, except for influenza A H1N1 2009 pandemic [A(H1N1)pdm09] virus infection. We previously reported that A(H1N1)pdm09 infection possibly induces severe pulmonary inflammation or severe asthmatic attack in a mouse model of bronchial asthma and in asthmatic children. However, the ability of seasonal H1N1 influenza (H1N1) infection to exacerbate asthmatic attacks in bronchial asthma patients has not been previously reported, and the differences in the pathogenicity profiles, such as cytokine profiles, remains unclear in bronchial asthma patients after A(H1N1)pdm09 and H1N1 infections. METHODS The cytokine levels and viral titers in the bronchoalveolar lavage (BAL) fluid from mice with and without asthma after H1N1 infection (A/Yamagata and A/Puerto Rico strains) were compared. RESULTS The interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, IL-5, interferon (IFN)-α, IFN-β, and IFN-γ levels were significantly higher in the BAL fluids from the control/H1N1 mice than from the asthmatic/H1N1 mice. The viral titers in the BAL fluid were also significantly higher in the control/H1N1mice than in the asthmatic/H1N1 mice infected with either A/Yamagata or A/Puerto Rico. CONCLUSIONS A(H1N1)pdm09 infection, but not H1N1 infection, can induce severe pulmonary inflammation through elevated cytokine levels in a mouse model of asthma.

Successful control of juvenile dermatomyositis-associated macrophage activation syndrome and interstitial pneumonia: distinct kinetics of interleukin-6 and -18 levels

BackgroundMacrophage activation syndrome (MAS) is the secondary hemophagocytic lymphohistiocytosis associated with rheumatic diseases. Recently, the different cytokine profiles between systemic juvenile idiopathic arthritis (sJIA)-associated MAS (sJIA-MAS) and juvenile systemic lupus erythematosus (JSLE)-associated MAS (JSLE-MAS) were reported. However, there is little information about juvenile dermatomyositis (JDM)-associated MAS (JDM-MAS).Case presentationA 4-year-old girl with JDM was hospitalized because of fever, erythema, hepatosplenomegaly, cytopenia, liver dysfunction and coagulopathy. Bone marrow aspiration revealed appreciable numbers of activated and hemophagocytosing macrophages. She was diagnosed as having JDM–MAS complicated with interstitial pneumonia (IP) based on the findings of the elevation of serum Krebs von den Lungen-6 (KL-6) levels and chest computed tomography findings. We analyzed circulating levels of interleukin (IL)-2,4,6,10,18, tumor necrosis factor-α and interferon-γ in the patient. Hypercytokinemia occurred at the diagnosis of MAS and IP, showing with the prominent elevations of IL-6 and IL-18 levels. The cytokine profiles were distinct from those reported in patients with sJIA-MAS or JSLE-MAS. High-dose corticosteroid and cyclosporine therapy led to a drastic improvement of MAS with decreased IL-6 levels. Subsequent cyclophosphamide therapy successfully controlled IP, paralleled with the declining pattern of IL-18 and KL-6 levels.ConclusionThis is the first report to describe a successful treatment and the cytokine profile of JDM-MAS and IP. Serum IL-6 and IL-18 levels may be useful for predicting the disease activity of JDM-MAS and IP, respectively.

Treatable renal disease in children with silent lupus nephritis detected by baseline biopsy: association with serum C3 levels

Lupus nephritis is identified in up to 75% of patients with juvenile systemic lupus erythematosus and may present with abnormal urinary findings (overt lupus nephritis) or be apparent only upon renal biopsy (silent lupus nephritis). We investigated whether serum complement levels correlate with renal pathology in pediatric patients with silent lupus nephritis. We performed baseline renal biopsy in 45 children diagnosed with juvenile systemic lupus erythematosus who were admitted to Kagoshima University Hospital between January 2000 and June 2015. Patients were classified as having overt or silent lupus nephritis based on urinary findings at renal biopsy. Silent lupus nephritis was identified in 55.5% (25/45) of cases. Of these, 6 (13.3%) were classified as class III nephritis, according to the International Society of Nephrology/Renal Pathology Society criteria. Decreased serum C3 levels were associated with the renal pathology classification for patients with silent but not with overt lupus nephritis. No differences in serum C4 levels were identified between cases of silent and overt lupus nephritis. Baseline renal biopsy is a critical component of the work-up of juvenile systemic lupus erythematosus as treatable renal pathology may be present in the absence of urinary signs. Serum C3 may be an important marker of the progression of silent lupus nephritis.

Clinical utility of the liposteroid therapy: Potential effects on the macrophage activation.

Liposteroid, a lipid emulsion containing dexamethasone, was developed in Japan. This drug is effective against rheumatoid arthritis, and has fewer side effects than dexamethasone. Moreover, at high dosage, liposteroid has been effectively used for the treatment of macrophage activation syndrome, because the lipid emulsions are easily taken up by phagocytes, and are retained in macrophages. Its anti-inflammatory effect was found to be 2-5 times higher than that of dexamethasone in arthritis and granuloma rat models. Japanese researchers have reported the clinical efficacy and utility of liposteroid in the treatment of diseases with macrophage activation. These include hemophagocytic lymphohistiocytosis, graft-versus-host disease, and pulmonary hemosiderosis. Here, we describe the clinical effects of liposteroid on macrophage activation syndrome and the hypothalamus-pituitary-adrenal axis in patients.