Nobuhiko Saito

Modulation by proinflammatory cytokines of Fas/Fas ligand-mediated apoptotic cell death of synovial cells in patients with rheumatoid arthritis (RA)

Synovial cell hyperplasia is a characteristic of patients with RA. Excessive proliferation of RA synovial cells is, in part, responsible for the synovial cell hyperplasia. In addition, synovial cell death that would reduce synovial cell number may be defective, leading to the hyperplasia. Thus, the defective control of cell death as well as cell proliferation may be of central importance in the pathogenesis of RA. In this study we analysed effects of proinflammatory cytokines on Fas/Fas ligand (FasL)‐induced synovial cell apoptosis, and evaluated apoptosis‐associated protein expression in the synovial cells in patients with RA. RA synovial cells expressed Fas antigen and lymphocytes infiltrating into RA synovium expressed FasL. Apoptotic synovial cells were detected within the sublining layer of RA synovium. Anti‐Fas MoAb induced apoptosis of RA synovial cells in vitro, and proinflammatory cytokines tumour necrosis factor‐alpha (TNF‐α) and IL‐1β, but not IL‐6 or IL‐8, inhibited the anti‐Fas‐induced apoptosis accompanying up‐regulation of Bcl‐2 protein expression and reduced expression of CPP32 and ICH‐1L. Immunohistochemical study revealed that CPP32 and ICH‐1L were expressed weakly in the RA synovial lining cells compared with osteoarthritis (OA) synovial lining cells. Thus, we found that although RA synovial cells could die via apoptosis through Fas/FasL pathway, apoptosis of synovial cells was inhibited by proinflammatory cytokines present within the synovium. Inhibition of apoptosis by the proinflammatory cytokines may contribute outgrowth of synovial cells that leads to pannus formation and the destruction of joints in patients with RA.

Possible correction of abnormal rheumatoid arthritis synovial cell function by jun D transfection in vitro

OBJECTIVE Rheumatoid arthritis (RA) is a chronic inflammatory disorder of joints, and excessive proliferation of and proinflammatory cytokine and collagenase production by synovial cells are a principal cause of joint destruction. Recent studies have revealed that c-jun and jun B promote growth of fibroblasts, whereas jun D suppresses fibroblast proliferation and even antagonizes Ras-mediated transformation of the fibroblasts. We analyzed effects of gene transfer-mediated jun D overexpression of synovial fibroblast-like cells in patients with RA. METHODS RA synovial fibroblast-like cells were transiently transfected with jun D expression vector. The transfectants were stimulated with tumor necrosis factor alpha, and their subsequent proliferative responses and proinflammatory cytokine and matrix metalloproteinase (MMP) production at the messenger RNA and protein levels were measured. RESULTS Transfection with jun D inhibited the proliferation of, and proinflammatory cytokine and MMP production by, RA synovial cells, mainly due to inhibiting their transcription via down-modulation of AP-1 transcription factor. CONCLUSION Localized jun D transfection into the synovial cells of affected joints may inhibit aberrant synovial cell function in patients with RA by down-regulating gene transcription. This function suggests a possible clinical application of this gene therapy.

Involvement of simultaneous multiple transcription factor expression, including cAMP responsive element binding protein and OCT-1, for synovial cell outgrowth in patients with rheumatoid arthritis

OBJECTIVE To elucidate possible roles of several transcription factors in the pathogenesis of rheumatoid arthritis (RA), the transcription factor expression in RA synovial tissue and their contribution to RA synovial cell functions were studied. METHODS Single cell suspension of dissociated synovial tissue was cultured to induce in vitro tissue outgrowth of RA synovial cells. Transcription factors were immunohistochemically identified in RA synovial tissue obtained by joint surgery and in the in vitro tissue outgrowth, and confirmed by western blotting and gel shift assays. RESULTS Immunohistochemical examination of RA synovial tissue revealed simultaneous expression of various transcription factors (NF-κB, c-Jun (a component of AP-1), cAMP responsive element binding protein (CREB), and OCT-1). The same set of transcription factors was expressed in the in vitro tissue outgrowth of RA patients. The early passage RA synovial cells were treated with interleukin 1β (IL1β) and confirmed translocation of transcription factors into the nucleus by western blotting, and their DNA binding activity by gel shift assays. CONCLUSION This study emphasises the importance of the simultaneous expression of several transcription factors for the hyperactivity of RA synovial cells that leads to tissue outgrowth.

13C-UBT using an infrared spectrometer for detection of Helicobacter pylori and for monitoring the effects of lansoprazole.

The stable isotope [13C]-labeled urea breath test (13C-UBT) is very useful for detecting Helicobacter pylori. Conventionally, a mass spectrometer is used to measure the presence of 13CO2 in breath. However, this technique is complex and expensive. Therefore, we carried out the 13C-UBT using an easy-to-operate infrared spectrometer, and we studied its usefulness. The 95 subjects included 35 patients with gastric ulcers, 32 with duodenal ulcers, 13 with gastroduodenal ulcers, some patients with nonulcer gastroduodenal disease, and normal controls. The 13C-UBT was negative in normal controls and positive in 86 of 91 (95%) patients with illness. Peaks appeared 15 to 30 min after [13C]urea administration. The 33 patients who were 13C-UBT-positive were then given lansoprazole 30 mg/day and the 13C-UBT was repeated after 8 to 16 weeks. Lansoprazole was found to be effective in patients who exhibited peak 13CO2 values that were at least two-thirds less than the pretreatment values. This effect was seen in 16 patients (48%), 13 of whom (81%) had gastric ulcers. Thirteen of the 17 patients (76%) who exhibited no effect had duodenal ulcers, and there were clear treatment response differences between the two types of ulcers.

Acceleration of pentosidine formation by medication

Abstract The possibility that oxidative stress caused by chemotherapy would accelerate formation of pentosidine was investigated. The pentosidine levels of erythrocyte membrane protein, plasma, and urine of pulmonary cancer in patients who had been administered cisplatin were higher than those of unadministered patients. Injection of cisplatin to SD mice resulted in a gradual increase in pentosidine levels. These results suggest that oxidative stress caused by cisplatin accelerates pentosidine formation in vivo.

Obesity and life style of middle aged Japanese women: An experience of a health promotion seminar at a public health center

Takastu Health Center, Kawasaki City near Tokyo, has been holding a Health Promotion Seminar since April 1978, to prevent various adult diseases. Obesity is the representative of adult diseases, and is accompanied by various diseases such as diabetes mellitus, hypertension, hyperlipemia, arteriosclerosis etc. In this study, obese women participating in this seminar were analyzed from various aspects.