Yo Mori

Tumor necrosis factor bifunctionally regulates matrix metalloproteinases and tissue inhibitor of metalloproteinases (TIMP) production by human fibroblasts

The production of tissue inhibitor of metalloproteinases (TIMP) in human uterine cervical fibroblasts was increased by human recombinant tumor necrosis factor α (hrTNF) at a low concentration (0.005 ) but the elevated synthesis was suppressed in a dose‐dependent manner at higher concentrations (up to 50 ). In contrast, the production of collagenase (EC 3.4.24.7) and stromelysin was stimulated at all the corresponding concentrations. In contrast, human recombinant interleukin‐1α (hrIL‐1, 10 ) coordinately induced these enzymes and TIMP production. The reduction of the elevated TIMP production by TNF was not due to the inhibition of TIMP secretion. These results suggest that TNF modulates the extracellular matrix degradation in human fibroblasts bifunctionally by the suppression of TIMP production in addition to the acceleration of matrix metalloproteinases production. Furthermore, the fact that TNF and IL‐1 differently controlled the production of TIMP suggests that the signal pathway of TNF for TIMP production is different from that of IL‐1.

Hyaluronic acid is an endogenous inducer of interleukin-1 production by human monocytes and rabbit macrophages

When human peripheral monocytes and rabbit peritoneal macrophages were incubated with hyaluronic acid, the media were found to contain interleukin-1 (IL-1) activity and to stimulate collagenase production by rabbit fibroblasts. A digestion of hyaluronic acid by testicular hyaluronidase decreased the IL-1 inducing activity. Polymixin B, an inhibitor of endotoxin, did not exert any effect towards the action of hyaluronic acid. Hyaluronic acid also stimulated human polymorphonuclear leucocytes to produce IL-1 like activity. These results indicate that hyaluronic acid is an endogenous IL-1 inducer and may play important roles in the pathological and/or physiological changes of connective tissues.

Chlorovulones, new halogenated marine prostanoids with an antitumor activity from the stolonifer clavularia viridis Quoy and Gaimard

Abstract New halogenated marine prostanoids, chlorovulone I, II and III were isolated from the stolonifer Clavularia viridis Quoy and Gaimard. The structure elucidation and the antitumor activity of chlorovulones were described.

Cyclooxygenase inhibitors augment the production of pro-matrix metalloproteinase 9 (progelatinase B) in rabbit articular chondrocytes

Matrix metalloproteinase 9 (MMP‐9/gelatinase B) has recently been proposed to participate in the destruction of articular cartilage. Here, we report that interleukin 1 (IL‐1) enhances the production of the precursor of MMP‐9 in rabbit articular chondrocytes in primary culture, and this IL‐1‐mediated production of proMMP‐9 is greatly augmented by cyclooxygenase inhibitors such as diclofenac and indomethacin, whereas the constitutive production of proMMP‐2 (progelatinase A) is not modulated by IL‐1 and/or cyclooxygenase inhibitors. Exogenous prostaglandin (PG) E1 and PGE2 suppress the proMMP‐9 production in a dose‐dependent manner. Similar results are also obtained with cultured rabbit synoviocytes. These results provide the first evidence that PGE down‐regulates the production of proMMP‐9 in chondrocytes and synoviocytes. Thus, cyclooxygenase inhibitors probably exert undesirable catabolic actions on the maintenance of articular cartilage under inflammatory conditions.

The change in solubility of type I collagen in human uterine cervix in pregnancy at term.

Abstract Collagen changes in the human uterine cervix in pregnancy at term were investigated. Collagen concentration per dry tissue significantly decreased to about 50% of the control and more than 90% of cervical collagen was insoluble. The insoluble collagen was extracted by pepsin digestion, and about 52% of insoluble collagen in the control and 94% in pregnancy at term were solubilized. In pepsin-soluble fractions, genetically distinct types I and III collagens were isolated by different salt precipitation and identified by ion-exchange chromatography, SDS disc gel electrophoresis, and amino acid composition analysis. Although the rates of pepsin-soluble collagen fraction in control and in pregnancy at term were different, types I III ratios in the fraction were about 2 and 4.7, respectively. The BrCN collagen peptide analyses of pepsin-insoluble residues of control which was about 50% of whole collagen indicated that most of residual collagen was type I. Therefore the ratio of types I III collagen in control of whole collagen approaches the value of 4.7 in pregnancy at term, indicating that the solubility of type I collagen was significantly increased by pregnancy. Both decrease in collagen concentration and increased in type I collagen solubility are important factors to induce the cervical dilatation and effacement in pregnancy at term.

Changes in the human uterine cervical collagenase with special reference to cervical ripening

Abstract Changes in the human cervical collagenase activity of three different types, free active enzyme, a complex with α 2 -macroglobulin, and inactive form activated by 4-aminophenylmercuric acetate, were examined by using fluorescein-labeled collagen and 2,4-dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln- d -Arg. Both active collagenase and the complex of collagenase with α 2 -macroglobulin were found to increase more significantly in pregnancy at term than those in nonpregnant control group. This tendency was also observed in chromatographic profiles on Sephadex G-150. However, the inactive enzyme estimated by activation did not change during the course of pregnancy.

Chemotactic factor in the pregnant rabbit uterine cervix

OBJECTIVE Neutrophil accumulation is one of the characteristic changes observed in uterine cervical stroma at term pregnancy, but chemotactic activity in the tissue is obscure. Our study examined the existence and production of chemotactic factor in the rabbit uterine cervix. STUDY DESIGN Uterine cervical explants of rabbits at term pregnancy and nonpregnant rabbits were cultured with and without interleukin-1 alpha. Rat neutrophilic chemotaxis in culture media was evaluated with a Boyden chamber. RESULTS Tissue extract from the pregnant rabbit uterine cervix at term pregnancy contained more chemoattractive activity than the nonpregnant cervix. Production of chemoattractant from cultured rabbit cervical explants at term pregnancy was also higher than that from nonpregnant explants. The addition of interleukin-1 alpha to the culture system promoted its production. This chemoattractant was characterized as a true chemotactic factor and heat-stable and trypsin-sensitive protein with an apparent relative molecular mass of 16,200. So far, these properties are very similar to those of the interleukin-8 family. Rabbit uterine cervical fibroblast is characterized as a chemotactic factor-producing cell in the rabbit uterine cervix. CONCLUSION These results indicate that interleukin-8-like chemotactic factor participates in the cervical ripening at term pregnancy and that the production of this factor is controlled effectively by interleukin-1.

Enhancement of Prostaglandin E2 Production by Epidermal Growth Factor Requires the Coordinate Activation of Cytosolic Phospholipase A2 and Cyclooxygenase 2 in Human Squamous Carcinoma A431 Cells

We demonstrated the effect of epidermal growth factor (EGF) on the production of PGE2 in human squamous carcinoma A431 cells. The production of PGE2 was increased by stimulating the cells with EGF for 2 h and reached a maximum for 10 h. EGF was also found to augment the release of arachidonic acid (AA) following the increase in phospholipase A2 (PLA2) activity (1.7-fold). The induced PLA2 activity was diminished by 4-bromophenacyl bromide, but not by dithiothreitol, indicating that the EGF-induced release of AA was due to the increase in the activity of cytosolic PLA2 (cPLA2). On the other hand, cyclooxygenase (COX) activity was increased (1.6-fold) within 2 h after the EGF-treatment and the induced activity was inhibited by cycloheximide. In addition, Northern blot analysis showed that the level of COX-2 mRNA was increased by the EGF-treatment, whereas no COX-2 mRNA was detected in the untreated cells, indicating that the EGF-induced COX activity was resulted from the increase in the production of COX-2. These results suggest that EGF augments the production of PGE2 by increasing not only the activity of cPLA2 but also the production of COX-2 in A431 cells.

Spontaneous production of interleukin-1—like factors from pregnant rabbit uterine cervix

Uterine cervical explants in culture from pregnant rabbits at term spontaneously synthesized and secreted three species of interleukin-1-like factors in culture medium. The addition of the exogenous mitogen lipopolysaccharide to the culture system induced further release of these factors. However, these phenomena were not observed with explants from nonpregnant cervices. The molecular weights of these factors estimated by gel filtration were approximately 49, 22, and 12 kDa, respectively, and were identical to those of interleukin-1 from rabbit macrophages and polymorphonuclear leukocytes. These results indicate that interleukin-1-like factors are involved in cervical ripening and dilatation, especially in the acceleration of collagenase production, at term.

Tumor necrosis factor α (TNFα) induces pro‐matrix metalloproteinase 9 production in human uterine cervical fibroblasts but interleukin 1 α antagonizes the inductive effect of TNFα

We have examined the regulation of precursor of matrix metalloproteinase 9 (proMMP‐9)/progelatinase B production by tumor necrosis factor α (TNFα) and interleukin 1α (IL‐1α) using human uterine cervical fibroblasts. TNFα, but not IL‐1α, induces the production of proMMP‐9 in the cervical cells. IL‐1α, however, suppresses the TNFα‐induced proMMP‐9 production. 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) also stimulates the cervical cells to produce proMMP‐9, and IL‐1α synergistically enhances its production. TNFα‐induced proMMP‐9 production is not mediated by protein kinase C (PKC), whereas the effect of IL‐1α is through PKC. By contrast, proMMP‐3/prostromelysin 1 is up‐regulated by TNFα or TPA in the presence of IL‐1α, whose modulation is PKC‐dependent. The suppressive effect of IL‐1α on the TNFα‐induced proMMP‐9 production is a new biological effect of IL‐1 on MMP production.