Changes in cervical fibronectin levels during pregnancy, labor and in the postpartum period

The authors analysed the fibronectin content of the uterine cervix during pregnancy and delivery. The aim of their investigation was furnishing data to the biochemical changes during cervical maturation. The ripening of the uterine cervix during pregnancy is a result of complicated interactions between different macromolecules, where the fibronectin plays a key role. The quantitative determination of the extracellular matrix fibronectin is impossible because its extraction from tissues recently is not solved. Taking this fact in consideration the authors choose a semiquantitative method, being reliable indicator of changes in fibronectin content of uterine cervix. They took small pieces of materials from portio vaginalis uteri of 139 women being in postmenopause and premenopause, in different stages of pregnancy and parturition concerning directly after delivery. The slides were incubated, with rabbit-anti-human fibronectin-FITC. The evaluation of fluorescence happened with an Axiophot (Zeiss) microscope. Authors stated that the fibronectin content in the cervical extracellular matrix and in the cellular membrane of fibroblasts increases during the 1st trimester pregnancy. This increase can be shown in the 3rd trimester as well and it drops significantly during delivery. They could not found any relationship between the leucocyte invasion observed during delivery and the changes of cervical fibronectin content. These observations call our attention to the importance of fibronectin in cervical ripening respectively dilatation and the need of further examinations.     

Calmodulin antagonists increase the expression of membrane-type-1 matrix metalloproteinase in human uterine cervical fibroblasts

The treatment of human uterine cervical fibroblasts with concanavalin A (ConA), or a specific calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) or trifluoperazine resulted in accumulation of an active form of matrix metalloproteinase 2 (MMP-2, gelatinase A). In contrast, N-(6-aminohexyl)-1-naphthalenesulfonamide (W-5), a weaker antagonist of calmodulin, did not modulate the activation of proMMP-2. The activation of proMMP-2 was confirmed by the enhanced activity on gelatin and the conversion of proMMP-2 to a 62-kDa form by zymography and western blotting. The plasma membrane, but not the conditioned medium, of the W-7- or trifluoperazine-treated cells activated proMMP-2; this activation was blocked by membrane-type-1 MMP (MT1-MMP) antibody and EDTA. The plasma membrane from trifluoperazine- or ConA-treated cells contained MT1-MMP and tissue inhibitor of metalloproteinases 2. Both trifluoperazine treatment and ConA treatment increased the steady-state levels of MT1-MMP mRNA and proMMP-2 mRNA. These results, together with our previous observations on the production of proMMP-1 (interstitial procollagenase) and proMMP-3 (prostromelysin 1) [Ito, A., Sato, T., Ojima, Y., Chen, L.-C., Nagase, H. & Mori, Y. (1991) J. Biol. Chem. 266, 13598-13601], suggest that calmodulin negatively regulates the matrix turnover by suppressing the production of a number of proMMPs including proMMP-1, proMMP-3 and MT1-MMP, and the activation of proMMP-2 in human uterine cervical fibroblasts.     

Histological study of uterine cervix during termination of early pregnancy by mifepristone and prostaglandins

OBJECTIVE: To study the histological changes of uterine cervix during termination of early pregnancy by mifepristone and prostaglandins (PG). METHODS: A total of 24 women who requested medical abortion was recruited. For each woman, 3 cervical biopsies were taken: before mifepristone treatment; 48 hours after mifepristone 150 mg single dose treatment (i.e. immediately before PG administration); and 1 hour after gestational sac expulsion. Specimens were studied by optical and electron microscopy. RESULTS: Significant collagenolysis as demonstrated by marked reduction and irregularity of collagen fibers, abundant accumulation of an amorphorous material of ground substance, and infiltration of neutrophilic polymorphonuclear leukocytes were shown in stroma as well as in the deep portion of cervix after mifepristone as compared to the samples of early pregnant cervix before treatment. These changes presented to a further extent after the expulsion of gestational sac. CONCLUSION: The changes observed were similar to previous reports during cervical dilatation in term delivery. The present study confirmed the histological cervical ripening effect by mifepristone and suggested it may be used as cervical ripening agent before induction of labor as well.     

Nitric oxide donors induce ripening of the human uterine cervix: a randomised controlled trial

OBJECTIVE: To determine whether nitric oxide donors can induce cervical ripening before surgical termination of pregnancy in the first trimester. DESIGN: Prospective, randomised controlled trial. SETTING: Department of Obstetrics and Gynaecology, Royal Infirmary, Glasgow. PARTICIPANTS: Forty-eight primigravid women undergoing surgical termination of pregnancy before 12 weeks of gestation. METHODS: The women were randomised to receive per vaginam before surgery either the nitric oxide donor isosorbide mononitrate, the nitric oxide donor glyceryl trinitrate, the prostaglandin analogue gemeprost, or no treatment. MAIN OUTCOME MEASURES: The cumulative force required to dilate the cervix to 8 mm was measured objectively and the cervical diameter before surgical dilatation was recorded. RESULTS: Following isosorbide mononitrate or gemeprost, a lower cumulative force was required to dilate the cervix to 8 mm and a higher cervical diameter before dilatation was recorded. Pretreatment with glyceryl trinitrate reduced the cumulative force required to dilate the cervix but had no effect on cervical diameter. CONCLUSIONS: Like the prostaglandin analogue gemeprost, the nitric oxide donors isosorbide mononitrate and glyceryl trinitrate can effect cervical ripening. Nitric oxide donors may provide an alternative to prostaglandins for cervical ripening before surgical procedures in the first trimester.     

Cyclooxygenase inhibitors enhance the production of tissue inhibitor-1 of metalloproteinases (TIMP-1) and pro-matrix metalloproteinase 1 (proMMP-1) in human rheumatoid synovial fibroblasts

OBJECTIVE AND DESIGN: We investigated the influence of cyclooxygenase inhibitors against the production of tissue inhibitor-1 of metalloproteinases (TIMP-1) and pro-matrix metalloproteinase 1 (proMMP-1) in rheumatoid arthritis (RA) synoviocytes. MATERIAL: Synovial fibroblasts from RA patients were used. TREATMENT: The cells were treated with recombinant human interleukin 1 beta (rhIL-1 beta) (100 ng/ml) and/or indomethacin (0.1, 1, 10 microM) and diclofenac (0.1, 1, 10 microM) and/or prostaglandin E2 (PGE2) (1, 10 microM) for 72 h. METHODS: The amounts of TIMP-1, proMMP-1 and PGE2 was measured by enzyme linked immunosorbent assay (ELISA). Statistical significance was tested with Student's t-test and Dunnett test. RESULTS: RhIL-1 beta augments the production of TIMP-1 and proMMP-1 in synovial fibroblasts from RA patients, and this IL-1-induced production of TIMP-1 and proMMP-1 was further enhanced by treatment with the cyclooxygenase inhibitors, indomethacin and diclofenac. Exogenous PGE2 significantly suppresses indomethacin- and diclofenacenhanced TIMP-1 and proMMP-1 production. CONCLUSION: PGE2 down-regulates the production of TIMP-1 and proMMP-1 in RA synoviocytes, and cyclooxygenase inhibitors regulate the production of TIMP-1 and proMMP-1 through the inhibition of PGE2 production in inflammation.     

Clinical study on uterine cervix ripening with hyaluronidase and animal experimentation on mechanism of action

The clinical course of labor in 53 cases with cervical injection of hyaluronidase (HD) and 51 cases with intravenous infusion of oxytocin to ripen the cervix was studied. The success rate of HD group (92.5%) was significantly higher than that of control group (62.8%). HD was without adverse side effects, and did not induce uterine contraction and therefore was preferable for high risk pregnancy cases. This method needed less time for cervical priming than others. The drug is easily available, not expensive and the method is simple. The animal experiments showed the mechanism of action of cervical ripening by HD was probably as follows: (1) the dissociation of ground substance in cervical connective tissue; (2) The destruction of blood vessels permit the migrating of leucocytes to surrounding tissue and resolve collagen; (3) stimulation of cervical fibroblasts to release prostaglandin.     

Use of an on-farm progesterone test in the clinical management of parturient disorders in three cows

Measurement of blood progesterone concentrations with a rapid, on-farm test was used to guide the clinical management of 3 cows with parturient disorders. An 8-year-old cow in the third trimester of pregnancy had chronic vaginocervical prolapse with partially dilated (4 cm) necrotic cervix. Blood progesterone concentration estimated with the test kit was low (< 2 ng/ml), and the cervical dilatation was attributed to stage-1 parturition. Vaginal delivery of the calf occurred 7 hours later. A 2-year-old cow examined for dystocia had a uterine torsion. Eighteen hours after apparent correction of the torsion, the cervix had failed to dilate. Blood progesterone concentration was 2 to 5 ng/ml, suggesting parturition had not yet been initiated. Parturition was induced with dexamethasone and prostaglandin, and calving occurred 32 hours later. A pregnant, 16-month-old heifer was believed to be about to calve and was admitted because of potential need cesarean section. Examination revealed the cervix to be closed. Blood progesterone concentration was low, and calving was predicted to occur within 24 hours. The heifer was monitored, and stage-2 labor was observed 8 hours later. The calf was delivered with minor assistance. In each case, the test provided diagnostic information that was useful in making therapeutic management decisions.     

Inhibition and augmentation of progesterone production during pregnancy: effects on parturition in rhesus monkeys

OBJECTIVES: Uterine quiescence during mammalian pregnancy is attributed to progesterone. However. systemic progesterone levels remain elevated in primates before parturition. Epostane, a selective 3beta-hydroxysteroid dehydrogenase inhibitor, and progesterone (with or without epostane) were administered to late pregnant rhesus monkeys to clarify the role of progesterone in primate parturition. STUDY DESIGN: On days 122 to 132 of gestation (term 167 days), 11 rhesus monkeys (Macaca mulatta) with timed pregnancies were divided into three treatment groups: (1) epostane alone (10 mg/kg subcutaneously), (2) epostane with progesterone subcutaneously in Silastic silicone rubber capsules, and (3) progesterone implants only with no surgical instrumentation. Maternal and fetal blood and amniotic fluid were sampled for progesterone, estrone, estradiol, cortisol, testosterone, androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate, and amniotic fluid was sampled for prostaglandins E2 and F2alpha. Uterine activity was monitored continuously by electromyography and intraamniotic pressure. Cervical status was assessed by a modified Bishop's score. Production of prostaglandins E2 and F2alpha by amnion was determined by tissue superfusion. The group of three noninstrumented monkeys, which received only progesterone Silastic silicone rubber implants subcutaneously at 146 to 148 days, were observed until spontaneous vaginal delivery. RESULTS: Epostane reduced maternal and fetal progesterone levels by 75% and 50%, respectively, followed by increased uterine activity and cervical ripening within 24 hours and vaginal delivery within 48 hours. Amniotic fluid progesterone decreased to undetectable levels. Progesterone implants prevented the epostane-induced decrease in maternal and fetal progesterone levels and the associated myometrial and cervical changes until the implants were removed. Alterations in other steroid hormones were consistent with inhibition of 3beta-hydroxysteroid dehydrogenase. Amniotic prostaglandin E2 production was increased sixfold by epostane (p < 0.05) but did not reach the high levels normally seen at spontaneous parturition. Animals that received progesterone implants alone had markedly elevated circulating progesterone concentrations yet were delivered spontaneously at term (range 163 to 167 days). CONCLUSIONS: Progesterone withdrawal induces preterm labor and delivery (which can be blocked by progesterone substitution) but exogenous progesterone, even in substantial quantities, does not prevent parturition at term.     

Respiratory distress in newborn: treated with ventilation in a level II nursery

The ClearView Uterine Manipulator was compared with the Cohen acorn-tipped cannula for efficacy and safety in patients undergoing laparoscopy at the University of Utah Medical Center. Fifty consecutive patients were randomized by computer to have either the ClearView instrument or the Cohen cannula used as a uterine manipulator (25 patients each). The ClearView manipulator was statistically superior to the Cohen cannula for range of motion in the anterior and posterior sagittal plane (p <0.0001). The Cohen cannula was consistently inserted in less time (p <0.02). There was no statistically significant difference between the instruments in ease of uterine manipulation, ease of dye instillation, percentage of dye leakage from the cervix, overall ease of use, ease of device insertion, and ease of device removal. Two cervical perforations occurred during cervical dilatation in the ClearView manipulator group in patients with cervical stenosis requiring dilatation with metal dilators (os <2 mm). No patients in the Cohen cannula group had cervical stenosis. In that group two cervical lacerations occurred requiring suture ligation. The ClearView instrument provides a greater range of motion, does not require an assistant to maintain uterine position, and allows manipulation without a cervical tenaculum. Its insertion occasionally (36%) required tenaculum placement, uterine sounding, and cervical dilatation, increasing the time of insertion compared with placement of the Cohen cannula. In patients with cervical stenosis, use of a uterine sound and cervical dilatation increase the risk of perforation.     

Fibronectin-mediated cell adhesion is required for induction of 92-kDa type IV collagenase/gelatinase (MMP-9) gene expression during macrophage differentiation. The signaling role of protein kinase C-beta

Induction of the 92-kDa gelatinase (MMP-9) gene expression is associated with macrophage differentiation. In this study, we explored the regulatory mechanisms underlying this differentiation-associated MMP-9 gene expression in human HL-60 myeloid leukemia cells and human peripheral blood monocytes. Phorbol 12-myristate 13-acetate (PMA) markedly induced MMP-9 gene expression in HL-60 cells; the induction closely paralleled the timing and extent of PMA-induced cell adhesion and spreading, a hallmark of macrophage differentiation. Similarly, treatment with PMA or macrophage-colony stimulating factor stimulated adherence and spreading of blood monocytes with a concurrent 7- or 5-fold increase in MMP-9 production, respectively. In protein kinase C (PKC)-beta-deficient HL-60 variant cells (HL-525), PMA failed to induce cell adhesion and MMP-9 gene expression. Transfecting HL-525 cells with a PKC-beta expression plasmid restored PKC-beta levels and PMA inducibility of cell adhesion and spreading as well as MMP-9 gene expression. Induction of cell adhesion and MMP-9 gene expression in HL-60 cells and blood monocytes was strongly inhibited by neutralizing monoclonal antibodies to fibronectin (FN) and its receptor alpha5 beta1 integrin. HL-525 cells, which constitutively display high levels of surface alpha5 beta1 integrin, adhered and spread on immobilized FN with concomitant induction of MMP-9 gene expression. Cytochalasins B and D were each a potent inhibitor of MMP-9 production. Our results suggest that alpha5 beta1 integrin-mediated interaction of immature hematopoietic cells with FN plays a critical role in modulating matrix-degrading activities during macrophage differentiation.     

Expression of nerve growth factor and its high-affinity receptor Trk-A in the rat pancreas during embryonic and fetal life

We recently reported that nitric oxide (NO), which is produced by chondrocytes treated with interleukin-1beta (IL-1), releases basic fibroblast growth factor (bFGF) stored in the matrix of articular chondrocytes. To clarify the mechanism of the IL-1-induced bFGF release, we investigated the production and gene expression of bFGF, matrix metalloproteinases (MMPs), syndecan 3, and inducible NO synthase (iNOS) by IL-1-treated rabbit articular chondrocytes. IL-1 stimulated not only the release of bFGF but also the production of it. Gelatin and casein zymography revealed that IL-1 stimulated the production of not only MMP-9 but also MMP-3. The increase in the production of these MMPs preceded the IL-1-stimulated bFGF release. An MMP inhibitor partially suppressed the release of bFGF, indicating that matrix degradation is at least partially involved in the IL-1-stimulated bFGF release even if increased production of bFGF is related to the release. IL-1 sequentially stimulated mRNA expression of iNOS, membrane type 1-MMP, MMP-9 and -3, and bFGF, in that order. NG-Monomethyl-L-arginine, an inhibitor of NO production, inhibited gene expression of MMP-9 and bFGF. These findings suggest that elevation of the NO level via iNOS mRNA expression stimulated by IL-1 mediates gene expression and production of MMPs and bFGF, resulting in the release of bFGF, and also reveal molecular mechanisms implicating the degradation of articular cartilage followed by angiogenesis in the synovium in arthritic joints.     

Relaxin increases the accumulation of new epithelial and stromal cells in the rat cervix during the second half of pregnancy

Both cervical and vaginal growth are relaxin dependent during rat pregnancy. We recently reported a relaxin-dependent 1.5-fold increase in cervical and vaginal DNA content from midpregnancy until term. This finding indicated that relaxin probably promotes cervical and vaginal growth at least in part by promoting cellular proliferation. The objective of this study was to identify and quantify cells in the cervix and vagina that proliferate during the second half of rat pregnancy in response to relaxin. Primiparous pregnant rats were ovariectomized or sham ovariectomized (group C; n = 8) on day 9 of pregnancy (D9). Ovariectomized rats were then treated with physiological doses of progesterone plus estrogen (n = 7) or progesterone, estrogen, and porcine relaxin (n = 7). Cellular proliferation was determined by continuously administering a low dose of 5-bromo-2'-deoxyuridine (BrdU) via miniature osmotic pump from D9-D22. On D22, cervices and vaginas were collected, fixed in formalin, paraffin embedded, and serially sectioned (4 microm). Adjacent serial sections were either immunostained for BrdU to assess cell proliferation or stained with hematoxylin to determine total cell number. Cell proliferation was evaluated by counting BrdU-positive nuclei and total nuclei in the same area on adjacent sections. Cell counts were determined using computerized digital morphometric analysis at x575. In control rats, nearly 75% of the epithelial cells and 55% of the stromal cells within the cervix at term had proliferated during the second half of pregnancy. The accumulation of approximately half of the new cells was relaxin dependent. Within the cervical stroma, relaxin increased the accumulation of cells associated with blood vessels and also the number of isolated cells (probably fibroblasts). Relaxin did not appear to affect smooth muscle cell proliferation in the cervix. In contrast to the cervix, a minority of vaginal epithelial cells (45%) and stromal cells (20%) proliferated during the second half of pregnancy. Although relaxin appeared to have a tendency to increase the accumulation of new vaginal epithelial and stromal cells, morphometric analysis did not provide support for such an effect. In conclusion, this study demonstrates that relaxin promotes a marked increase in the accumulation of new epithelial cells and stromal cells within the cervix. The relaxin-induced increase in new epithelial and stromal cells probably contributes to relaxin's effects on growth and remodeling of the cervix that are required for rapid and safe delivery.     

Elevated production of interleukin-1-beta from alveolar macrophages isolated from newborn rabbits

Alveolar macrophage (AM) production of pro-inflammatory cytokines has been associated with the development of acute and chronic lung injury. However, the role of AM-derived IL-1 beta in the development of bronchopulmonary dysplasia has not been extensively examined. To determine if in vitro production of IL-1 beta by AM is influenced by maturity, cells were isolated by lung lavage from litters of newborn rabbits and from adults. After overnight incubation in serum-supplemented medium, newborn AM produced more IL-1 beta than cells from adults. When these AM were then exposed for 2 h to endotoxin in serum-free medium, adult cells increased their IL-1 beta secretion while the newborn cells did not. Newborn AM IL-1 beta response to LPS returned by 24 h. AM from newborn rabbits also demonstrated increased spontaneous production and increased LPS-induced production of IL-1 beta during overnight incubation in serum-free medium. The newborn rabbit AM appears to be up-regulated in its IL-1 beta production compared to the adult.     

Pseudocystic metastases of carcinoma of the uterine cervix mimicking polycystic liver disease

Pseudocystic liver metastases are rare and mainly described in neuroendocrine or ovarian tumors. We report the case of a 46-year-old woman who presented with multiple hepatic metastases mimicking polycystic liver disease. Carcinoma of the uterine cervix had been diagnosed 9 years earlier, and initially treated by radiumtherapy and surgery. Although histological post mortem examination of the pseudocystic liver metastases was not characteristic, they were related to the uterine cervix carcinoma for the following reasons: no other primary tumor was discovered, especially carcinoid or ovarian tumors: immunostains were positive for epithelial cells and negative for the neuroendocrine panel: the cystic cerebellum metastasis had a typical histologic aspect. Uterine cervical carcinoma must thus be included in the list of tumors which may form cystic hepatic metastases.     

Identification of prometalloproteinase-3 as a major protein secreted by human endometrial fibroblasts and inhibited by coculture with trophoblast cells

To assess endometrial fibroblast-cytotrophoblast interactions, we used a coculture system allowing analysis of the potential cell morphology modifications and protein secretion variations possibly involved in endometrial invasion arrest. Stromal cells and cytotrophoblasts were isolated from endometrial biopsies and first-trimester placental villi, respectively. In our culture conditions, a 57-kDa protein that was secreted by cultured fibroblasts but was absent in the 4-day coculture medium was found to be identical to prometalloproteinase-3 (proMMP-3) through determination of amino acid sequences of NH2-terminal and internal peptides. Northern blotting analysis of endometrial fibroblast total RNA showed a 38.6% metalloproteinase-3 (MMP-3) mRNA inhibition by 4-day 10(-6) M R5020 treatment. Inhibition of proMMP-3 secretion was weak when cytotrophoblasts were cultured for 4 days in a polycarbonate membrane insert over cultured fibroblasts without possible cell contact in spite of high levels of progesterone produced by cytotrophoblasts. Furthermore, cytotrophoblasts cultured on a monolayer of endometrial fibroblasts became syncytia, and most of the fibroblasts were decidualized. The closeness of the two cell types allowed paracrine relationships that might facilitate the progesterone action. Since MMP-3 is known to activate collagenases, inhibition of its secretion by cell contact might be a mechanism of invasion arrest for trophoblast cell migration.     

Conceptus, progesterone, and breed effects on uterine protein secretion in swine

This experiment consisted of the following treatment-breed groups: 1) White crossbred gilts, 2) White crossbred gilts treated with progesterone (200 mg/d in corn oil given on d 2 and 3 after estrus), and 3) Chinese Meishan gilts. Pregnant and nonpregnant gilts (n=3 to 6) from each treatment-breed combination were assigned to be slaughtered on d 10, 11, 12, 13, and 15. At slaughter each uterine horn was flushed with 20 mL of minimal essential medium. Uterine flushings were assayed for total protein, acid phosphatase, uteroferrin, retinol-binding protein, and oxytocin. Uterine flush total protein was increased by progesterone treatment, was unaffected by pregnancy status, and was less in Meishans. Similar patterns were found for retinol binding protein and uteroferrin, except that uteroferrin was greater in pregnant than in nonpregnant gilts. Oxytocin was greater in pregnant than in nonpregnant gilts, was not influenced by progesterone treatment, and was similar in Meishan and in White crossbred gilts. These results indicate that the conceptus does not influence secretion of either total protein or retinol binding protein during pregnancy and that the onset of secretion of these uterine proteins may be controlled by progesterone. The presence of the conceptus is associated with increased uteroferrin and oxytocin production. The decreased secretion of uterine proteins in Meishan gilts may partially explain the slower embryonic development that has been reported for this breed.     

Imbalance between interstitial collagenase and tissue inhibitor of metalloproteinases 1 in synoviocytes and fibroblasts upon direct contact with stimulated T lymphocytes: involvement of membrane-associated cytokines

OBJECTIVE: To determine whether direct cell-cell contact with stimulated T lymphocytes (a) differentially modulates the production of interstitial collagenase (matrix metalloproteinase 1 [MMP-1]) and tissue inhibitor of metalloproteinases 1 (TIMP-1) on human synoviocytes and dermal fibroblasts, and (b) induces the production of prostaglandin E2 (PGE2); and to identify the membrane-associated factors on T cell surfaces involved in these mechanisms. METHODS: Dermal fibroblasts and fibroblast-like synovial cells (synoviocytes) were cultured with fixed T cells, isolated plasma membranes from T cells, interleukin-1beta (IL-1beta; 250 pg/ml), or transforming growth factor beta (TGFbeta; 5 ng/ml). Culture supernatants were assayed for the production of MMP-1, TIMP-1, and PGE2. The expression of MMP-1 and TIMP-1 messenger RNA was analyzed by Northern blot of total fibroblast RNA. RESULTS: Membranes of stimulated T cells, i.e., human peripheral blood T lymphocytes (PBTL) and the human T cell line HUT-78, induced the production of PGE2 and MMP-1 on both synoviocytes and dermal fibroblasts. TIMP-1 production was enhanced upon contact with PBTL stimulated for short periods of time (2-4 hours) but not for longer periods. Similar results were obtained with CD4+ and CD8+ synovial tissue T cell clones (TCCs), which induced the production of TIMP-1 by fibroblasts when stimulated for short (2-4 hours), but not long, periods of time. This time dependency was not observed with HUT-78 cells. The production of MMP-1 by fibroblasts and synoviocytes upon cellular contact with stimulated T cells was higher than that induced by an optimum concentration of IL-1beta, whereas the production of PGE2 was equivalent or slightly lower. Cell membrane-associated IL-1alpha and tumor necrosis factor a, but not CD69, CD40 ligand, or CD11b, were involved in the induction of MMP-1 and PGE2 production, as shown by blockade experiments using monoclonal antibodies and cytokine antagonists. CONCLUSION: Synovial tissue TCCs and PBTL stimulated for long periods of time trigger the production of PGE2 and MMP-1, but not TIMP-1, in synoviocytes and dermal fibroblasts, thus inducing an imbalance between the metalloenzyme and its inhibitor. These results demonstrate that T cells may affect fibroblast and synoviocyte functions directly (i.e., by contact activation) and indirectly (i.e., by activation of cytokine production in monocyte/macrophages, which in turn, trigger stromal cell functions). Since the production of MMPs in monocyte/macrophages is also induced upon contact with stimulated T cells, our results strongly suggest that contact of synovial cells with chronically stimulated T lymphocytes favors matrix catabolism. By analogy, this mechanism may trigger tissue destruction in vivo and, thus, may potentiate tissue destruction in chronic inflammatory diseases such as RA.     

Decreased interleukin-2 production by rat uterine artery, aorta and uterine tissues during pregnancy

Changes in size and function during pregnancy are unique to the uterine artery. The aim of this study was to determine the interleukin (IL)-6 activity of the uterine artery wall tissue in pregnant rats. A total of 18 Charles River white rats (nine virgin and nine in midpregnancy) were used for the study. Bilateral uterine arteries were obtained, together with reference tissues from aorta and uterus. IL-6 production was measured as optical density (OD)/mg protein, in control culture media, and in the presence of stimulants including IL-1, tumour necrosis factor alpha and lipopolysaccharide. Polyclonal rabbit anti-human IL-6 antibodies were used to assess IL-6 activity. In control culture medium, uterine artery tissue samples from virgin rats produced significantly higher concentrations of IL-6 than samples obtained from pregnancy animals (1.8 +/- 0.3 versus 0.9 +/- 0.25 OD/mg protein respectively (mean +/- SE, P = 0.001). Stimulation by lipopolysaccharide increased IL-6 activity of the uterine artery wall. In comparison with the uterine artery, the aorta produced higher activities of IL-6, and its production in virgin animal samples was higher than during pregnancy. Stimulants increased IL-6 production by both aorta and uterus tissues. Neutralization of IL-6 activity was obtained in a range of 77-93% in all samples. The lower level of IL-6 activity during pregnancy in the uterine artery and in reference tissues including aorta and uterus, may be related to acceptance of pregnancy by maternal tissues.