Yasuhiro Deguchi

Age-related changes of heat shock protein gene transcription in human peripheral blood mononuclear cells.

In this study, we show the age-related retardation of heat shock 70 kD protein (hsp 70) gene transcription in peripheral blood mononuclear cells (PBMC). The amount of maximum transcription of the hsp 70 gene is decreased in PBMC from aged subjects, compared with PBMC from young control subjects. It might mean that the ability for homeostasis against heat shock stress decreases in PBMC from aged subjects. Our observation might be at least correlative and consistent with the age-related change of a possible essential function in PBMC.

Enhanced expression of the tumour necrosis factor/cachectin gene in peripheral blood mononuclear cells from patients with systemic vasculitis.

The expression of tumour necrosis factor‐alpha (TNF‐α) gene in peripheral blood mononuclear cells from patients with systemic vasculitis. periarteritis nodosa and Wegeners granulomatosis, has been studied by RNA dot blot and Northern blot assays. We further examined the transcriptional level of TNF‐α gene in peripheral blood mononuclear cells from these patients by performing nuclear run on transcription assay. We demonstrate enhanced TNF‐α gene expression in mononuclear cells from these patients compared with healthy subjects and patients with bronchial asthma. These findings suggest that the enhanced transcription of TNF‐α gene in peripheral blood mononuclear cells from patients with systemic vasculitis may be involved in the pathophysiology/pathogenesis of these diseases by cylokine dysregulation.

Tumour necrosis factor/cachectin plays a key role in autoimmune pulmonary inflammation in lupus‐prone mice

The role of tumour necrosis factor‐alpha (TNF‐α) in the development of autoimmune pulmonary inflammation has been investigated in lupus‐prone mice. An increase in TNF‐α mRNA level from whole lung preparation of lupus‐prone mice was evident, from 3 weeks to 12 weeks during growing process, as shown by Northern blot analysis, but not in control mice. Furthermore, it is also found that the major source of this increase in TNF‐α mRNA was attributed to infiltrating mononuclear cells found within the lung. Treatment of lupus‐prone mice with rabbit anti‐mouse TNF‐α IgG prevented the development of pulmonary inflammation lesions such as lung fibrosis and alveolitis. These results suggest that an increased TNF‐α production by infiltrating mononuclear cells in the lungs of lupus‐prone mice may play a role in the development of autoimmune pulmonary inflammation and in significant changes of cytokines and the immune responses in pulmonary inflammation lesions of lupus‐prone mice.

Age-related changes of expression of IL-2 receptor subunits and kinetics of IL-2 internalization in T cells after mitogenic stimulation

The age-associated changes of the expression of IL-2 binding molecules p55/Tac(alpha chain) and p70/75(beta chain) were examined after phytohemagglutinin (PHA) stimulation. The expressions of both p55/Tac molecules and p70/75 molecules were significantly reduced in the aged compared with those in the young persons. The amounts of p55/Tac and p70/75 molecules on T cells from the aged were 55% and 59% of those on young ones, respectively. The ratio of the amount of p70/75 to that of p55/Tac in aged T cells was 0.28 and that in young ones was 0.26. The ratio was somewhat higher in the aged but not significantly. We also examined the kinetics of IL-2 internalization mediated by its receptor. The calculated t1/2 of receptor-mediated IL-2 internalization was 17 min in the aged and 16 min in the young, respectively. There was no kinetic difference between the 2 groups. The percentage of the internalized IL-2 to the sum total was 58.2% in the aged and 73.4% in the young (P less than 0.02). the amount of internalized IL-2 in T cells from the aged was 48.6% of that from the young (P less than 0.01).

Heat-shock protein synthesis by human peripheral mononuclear cells from sle patients

Peripheral blood mononuclear cells (PBMC) from systemic lupus erythematosus (SLE) patients have heat shock protein (hsp) 70 and hsp 85 as well as the response to various temperatures of normal PBMC and are inducible for these proteins over about 5-8 levels with heat exposure in short-term culture. Synthesis of hsp 70 and hsp 85 as well as the response to various temperatures and the time course of induction were typical for mammalian cell systems. This enhancement with heat-shock treatment was blocked by actinomycin D added before heat exposure. This demonstration that hsp genes are activated in PBMC from active SLE patients without heat exposure supports the hypothesis that gene activation can serve some roles in these cells and be related to the PBMC function in SLE patients. These observations are at least correlative and consistent with a possible homeostatic function for hsps in this system.

The effect of taurine on age-related immune decline in mice: the effect of taurine on T cell and B cell proliferative response under costimulation with ionomycin and phorbol myristate acetate.

Proliferative responses to the costimulation with phorbol-12-myristate-13-acetate (PMA) and suboptimal doses of ionomycin in the purified T and B cells from old mice were lower than those from young mice. The degree of the age-related decline was more significant in T cells than in B cells. Taurine, a sulfur containing amino acid, augmented the proliferative responses of T cells from both young and old mice. The augmentation of the proliferative response by taurine was more marked in old T cells than in young ones. The concentration of intracellular free calcium ion ([Ca2+]i) was significantly lower in the old T cells under the stimulation with PMA and ionomycin than that in the young ones. In the presence of taurine, the concentration of [Ca2+]i in the old T cell significantly increased under the stimulation. The results indicate that taurine improved the proliferative response of old T cells by the restoration of the increment of the concentration of [Ca2+]i under the stimulation.

Age-related changes of proliferative response, kinetics of expression of protooncogenes after the mitogenic stimulation and methylation level of the pr purified human lymphocyte subsets ☆

Abstract Proliferative responses of highly purified T and B cells from aged persons to the combined stimulation with ionomycin and PMA were more significantly reduced than that from young ones although the degree of the age-related reduction was more significant in T cells than in B cells. In B cells, the levels and kinetics of c-myc gene expression after the stimulation were comparable between aged and young groups. In T cells, the maximum level of c-myc gene expression after the stimulation was comparable between the two age groups but the rate of reduction of c-myc mRNA was significantly retarded in the aged. The results of nuclear run on transcription assay showed the reduction of the rate of c-myc mRNA degradation seemed to be the cause. The levels and kinetics of c-myb gene expression in either T or B cells were comparable between the two age groups. We further examined the level of methylation of Xho I site of c-myc gene. The level of the methylation was significantly lower in the aged T cells and more significant in aged CD 8 positive T cells although that in aged B cells was comparable to that in young ones. The relation between a reduced proliferation, a retarded rate of c-myc mRNA degradation and reduction of methylation level of c-myc gene was discussed.

Cellular oncogene expression in the idiopathic cardiomyopathic hamster heart during the growing process

The expression of various proto-oncogenes was evaluated in the Syrian hamster with hereditary idiopathic cardiomyopathy. mRNA from the heart and aorta of controls (BIO-RB) and cardiomyopathic hamsters (UM-X7.1 strain, BIO 14.6 line) was tested using RNA hybridization techniques. Of the 19 different v-oncogene probes used in the study, only the v-myc probe revealed a substantially greater expression of oncogene in the 30th day of cardiomyopathic hamster heart than in control hamster heart. The amplified expression of c-myc was also observed in the heart of 1-year-old, but not of 7-day-old cardiomyopathic hamster. Overexpression of c-myc, otherwise associated with the regulation of cell differentiation or rapid growth, may relate to the pathological state or pathogenesis of the hereditary cardiomyopathy.

Elevated transcription of heat shock protein gene in scleroderma fibroblasts

Scleroderma is a systemic disorder characterized by fibrosis, which affects skin, lung, kidney and other organs. Heat shock protein (hsp) (70 kD) has been implicated as an essential element of cell function in cell growth and differentiation. To study the molecular basis of intracellular events in scleroderma fibroblasts, we compared the expression of hsp 70 gene in scleroderma and normal control fibroblasts by nuclear run on transcription assay and Northern blot assay. We show that scleroderma fibroblasts express more than eight times higher level of hsp 70 transcription in normal control fibroblasts at quiescent conditions in the absence of serum. After stimulation with serum, the transcription level of the hsp 70 gene is similar in scleroderma and normal control fibroblasts. Therefore, our results indicate an alteration/activation of intracellular events in scleroderma fibroblasts.

Autoantibody to human c-myc oncogene product in autoimmune patient's sera

Sera from autoimmune diseases including systemic lupus erythematosus, dermatomyositis, progressive systemic sclerosis and Sjögrens disease, were examined for reactivity against human c-myc oncogene product. We first found the presence of the autoantibody to human c-myc oncogene product in sera from autoimmune diseases. No significant correlation between the presence of the anti-c-myc product antibody and disease activity, clinical disease types and other autoantibodies such as antinuclear factor, anti-DNA antibody, anti-RNP antibody and anti-Sm antibody were shown in this study.