Interleukin-11 Gene Expression in Human Lymphoid Malignancy.

Interleukin-11 (IL-11) has diverse biological effects in hematopoiesis has been shown to share important functions with IL-6. However, unlike IL-6, there has been little information about the expression of IL-11 in lymphoid malignancy. Using reverse transcriptase polymerase chain reaction, IL-11 transcript was found in a number of lymphoid cell lines. A high level of expression was found in follicular lymphoma cell line FL18, and this was also detectable by Northern blotting. When TPA/A23187 were added to the culture of bone marrow stromal cell line KM102, IL-11 transcripts were rapidly upregulated. In contrast, levels of IL-11 transcripts were not increased in FL18 even upon the stimulation. The addition of actinomycin D to the cultures showed that the half life of the transcripts was similar in both FL18 and KM102. This suggests that posttran scriptional processes might not be involved in the constitutive expression of FL18. The results of IL-11 bioassay and enzymed-linked immunosorbent assay showed that FL18 did not secrete biologically active IL-11 into the medium. IL-11 transcript was also found in lymphoma cells in patient with malignant lymphoma, but not in B and T lymphocytes from reactive hyperplasia. Our results indicate that IL-11 transcripts can sometimes be produced in the neoplastic transformation of lymphoid cells.

12-O-tetradecanoylphorbol-13-acetate (TPA) downregulates expression of CD30 in erythroleukemia cell line K562.

CD30, a member of the tumour necrosis factor/nerve growth factor receptor superfamily, has been thought to have pleiotropic functions on immune response. However, there has been only a little information about the mechanism of CD30 expression. In this study, modulation of the CD30 molecule was investigated by the treatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). When cultures were supplemented with TPA, CD30 transcript was downregulated in a dose- and time-dependent manner in the erythroleukemia cell line K562. Half reduction of CD30 transcript, precursor protein and surface protein was at 3 h, 6 h, and 40 h, respectively, by Northern blot and Western blot analyses. This consecutive reduction of both the transcript and proteins suggests that TPA directly inhibits the transcriptional step of CD30, and subsequently CD30 molecules would decrease on the cell surface. To determine whether the protein kinase C (PKC) pathway is involved in this reduction, a PKC inhibitor, 10 microM H-7, was added to the K562 culture. The addition of H-7 recovered the inhibitory effect of TPA, indicating that PKC is involved in the transcription of CD30. When either 2 micrograms/ml actinomycin D or 20 micrograms/ml cycloheximide was added simultaneously with TPA to the culture, the repressive effect of TPA on CD30 was abolished. These results showed that the repression would also partly involve ongoing mRNA and protein synthesis under TPA treatment.

Incidence of ocular complications in rheumatoid arthritis and the relation of keratoconjunctivitis sicca with its systemic activity.

To investigate the incidence of ocular complications in patients with rheumatoid arthritis under modern modalities of treatment and find the relationship between its systemic activity and ocular complications, routine ophthalmological examinations were done as a prospective study in 111 consecutive patients including 89 inpatients and 22 outpatients with rheumatoid arthritis seen from April to May 1995, in a hospital with a special clinic for rheumatology. Keratoconjunctivitis sicca (secondary Sjögren's syndrome) was found in 19 patients (17.1%), scleritis in one patient (0.9%), central retinal vein occlusion in 2 patients (1.8%), and idiopathic retinal hemorrhage in 3 patients (2.7%). Patients with keratoconjunctivitis sicca had significantly higher titers of rheumatoid factor (Mann-Whitney's U-test, p = 0.0048), higher levels of IgM (p = 0.0484), and lower levels of HDL-cholesterol (p = 0.0191), compared to patients without it. The incidence of ocular complications was comparable to the previous studies and keratoconjunctivitis sicca should be considered in patients with high titers of rheumatoid factor.

Transcriptional down-regulation by epidermal growth factor of TRH receptor mRNA in rat pituitary cells.

To gain insight into the mechanism underlying the epidermal growth factor (EGF)-induced changes in responsiveness to TRH and in the numbers of TRH receptors (TRH-Rs) in the pituitary, we investigated the transcriptional regulation by EGF of the TRH-R gene in GH4C1 cells. Northern blot analyses and binding studies revealed that EGF reduced both TRH binding and TRH-R mRNA levels in a dose- and time-dependent manner, while no significant changes were observed in beta-actin mRNA levels. Addition of actinomycin D caused an acute increase in the basal TRH-R mRNA level, and the rate of decrease of the TRH-R mRNA was identical in control and EGF-treated groups, suggesting that the stability of the TRH-R mRNA was not significantly affected in EGF-treated cells. Incubation with cycloheximide also induced an increase in the basal TRH-R mRNA level and completely reversed the EGF-induced reduction of TRH-R mRNA levels. Furthermore, a nuclear run-on assay demonstrated that the rate of transcription of the TRH-R gene was significantly inhibited in cells treated with EGF. We conclude that (1) EGF decreases the expression of the TRH-R mRNA largely by reducing its rate of transcription, and this action requires the synthesis of new proteins, and (2) inhibitors of protein and RNA synthesis cause a significant increase in the basal TRH-R mRNA level, suggesting that there may be a short-lived protein suppressing the TRH-R mRNA level in the pituitary.

Reassessment of the two-site enzyme immunoassay for human epidermal growth factor (hEGF) and measurement of immunoreactive hEGF in human sera and urine.

We reassessed the enzyme immunoassay (EIA) system for hEGF previously developed by our laboratory (Clin Chim Acta 156:51-60, 1985), since it appeared that the reported EIA system detected not only hEGF but also pS2 protein owing to minor contamination by pS2 protein in the hEGF sample used for immunization. In this study, we purified the hEGF sample using Benzamidine-Sepharose 6B column chromatography as a critical step for purification and newly developed an EIA system with specificity for hEGF. We also measured the hEGF level in serum, plasma, and urine from normal subjects by our new EIA system and found that the values measured by the previous system were 1.2-5.8-fold higher than the new system values. These results suggest that the previous system detected "hEGF" in excess owing to the nonspecificity of the antibody used. We investigated the molecular nature of immunoreactive hEGF detected in serum using our new system and confirmed that considerable amounts of immunoreactive hEGF exist as a high molecular weight form through S-S linkage with some macromolecule(s) in human blood as reported previously (Biochem Int 12:677-683, 1986).

Serum and urinary ferritin levels in patients with rheumatoid arthritis.

The serum and urinary ferritin levels in 52 RA patients were measured by the 2-site immunoradiometric assay method. Serum ferritin levels in RA patients correlated with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) but not with serum iron levels and hemoglobin concentrations, although they were within the normal range. High serum ferritin levels were associated with sera with hyper gamma-globulin and rheumatoid factors. In sequential studies, serum ferritin changed in parallel with ESR, CRP and disease activity in a majority of the patients. The urinary ferritin levels and u/s ratios in some RA patients were higher than control values. Higher values were found particularly in the group of patients under gold therapy but not in groups under other treatments.

Low responsiveness of synovial and peripheral blood lymphocytes stimulated by either PHA-P or CON-A in patients with chronic rheumatoid arthritis.

Lymphocytes were highly purified from synovial fluid and peripheral blood of 10 rheumatoid arthritis patients and assessed for responsiveness to PHA-P and Con-A. In all cases, both synovial and blood lymphocytes showed a marked reduction in response to these mitogens compared with normal blood lymphocytes. The factors responsible for this low T cell responsiveness are discussed.