Calmodulin differentially modulates the interleukin 1-induced biosynthesis of tissue inhibitor of metalloproteinases and matrix metalloproteinases in human uterine cervical fibroblasts

Endocrine immune interactions in human parturition

Human parturition is an inflammatory event, modulated and influenced by a host of other environmental and physiological processes, including the endocrine hormones. Complex bidirectional communication occurs between the two systems to bring about some of the changes that are seen in labour, an event that is not yet fully understood. Preterm birth is a major problem in obstetrics and neonatology, with dysfunctional labour or prolonged pregnancy also making increasingly significant contributions to maternal morbidity. With better understanding of normal and abnormal parturition we may be able to develop novel ways of treating these complications of pregnancy and reduce maternal and neonatal morbidity and mortality. This review discusses the crucial role that endocrine-immune interaction plays in the process of labour and in the processes of abnormal and preterm labour. We propose that amongst these complex interactions it is the immune system that is the driving force behind human parturition.

MicroRNA expression profiling of the human uterine cervix after term labor and delivery

OBJECTIVE

MicroRNAs (miRNAs) are noncoding RNAs involved in posttranscriptional regulation of target genes. The objective of this study was to determine the miRNA expression profile of the human uterine cervix after spontaneous term labor (TL).

STUDY DESIGN

The miRNA expression pattern of cervical tissue was characterized using microarrays. Samples were collected at term from patients with (n = 8) and without (n = 9) TL. Moderated t tests and false discovery rate correction were applied. Results were confirmed using quantitative reverse transcriptase-polymerase chain reaction.

RESULTS

A total of 226 miRNAs were expressed in human cervical tissue. miR-223, miR-34b, and miR-34c were overexpressed in cervical tissue of patients with TL compared to those without. Quantitative reverse transcriptase-polymerase chain reaction assays confirmed these findings (miR-223 [fold change {FC} = 5.7], miR-34b [FC = 4.5], miR-34c [FC = 6.2]; P < .001).

CONCLUSION

This is the first report of miRNA expression in the human uterine cervix in pregnancy. Cervical remodeling after TL and delivery was associated with changes in miR-223, miR-34b, and miR-34c.

Different secretion patterns of matrix metalloproteinases and IL-8 and effect of corticotropin-releasing hormone in preterm and term cervical fibroblasts

The aims of the present study were to compare the levels of mRNA and protein expression of matrix metalloproteinase (MMP)-1, -3, -8 and -9 in human cervical tissue in preterm and term labor as well as not in labor and to determine if corticotropin-releasing hormone (CRH) has an effect on MMP-1, -3 and interleukin (IL)-8 secretion in both preterm and term cervical fibroblasts. Cervical biopsies were taken from 60 women: 18 at preterm labor, 7 at preterm not in labor, 18 at term labor and 17 at term not in labor. ELISA and Immulite were used for protein and real-time RT–PCR for mRNA analysis. Cervical fibroblast cultures were incubated for 18 h with different CRH concentrations (10⁻¹³–10⁻⁶ M). The mRNA expression of MMP-1, -3 and -9 was higher in laboring groups compared with term not in labor. Protein levels of MMP-8 and -9 were higher in term in labor group compared with non-laboring groups. There were no significant differences in mRNA and protein expression between the preterm and respective term control groups. CRH significantly increased secretion of IL-8 in preterm and term cervical fibroblasts compared with controls. The secretion of IL-8 and MMP-1 was significantly higher and MMP-3 secretion lower in preterm cervical fibroblasts. In conclusion, cervical ripening at preterm seems to be a similar inflammatory process as at term with CRH involved. However, preterm and term cervical fibroblasts might have different phenotypes based on different secretion patterns of IL-8, MMP-1 and MMP-3.

The matrix metalloproteinase system: changes, regulation, and impact throughout the ovarian and uterine reproductive cycle

The ovary and uterus undergo extensive tissue remodeling throughout each reproductive cycle. This remodeling of the extracellular environment is dependent upon the cyclic hormonal changes associated with each estrous or menstrual cycle. In the ovary, tissue remodeling is requisite for growth and expansion of the follicle, breakdown of the follicular wall during the ovulatory process, transformation of the postovulatory follicle into the corpus luteum, as well as the structural dissolution of the corpus luteum during luteal regression. In the uterus, there is extraordinary turnover of the endometrial connective tissue matrix during each menstrual cycle. This turnover encompasses the complete breakdown and loss of this layer, followed by its subsequent regrowth. With implantation, extensive remodeling of the uterus occurs to support placentation. These dynamic changes in the ovarian and uterine extracellular architecture are regulated, in part, by the matrix metalloproteinase (MMP) system. The MMP system acts to control connective tissue remodeling processes throughout the body and is comprised of both a proteolytic component, the MMPs, and a regulatory component, the associated tissue inhibitors of metalloproteinases. The current review will highlight the key features of the MMPs and tissue inhibitors of metalloproteinases, focus on the changes and regulation of the MMP system that take place throughout the estrous and menstrual cycles, and address the impact of the dynamic tissue remodeling processes on ovarian and uterine physiology.

Testing for risk of preterm delivery

Four discrete mechanisms for the pathogenesis of PTD have been described but they share a final common pathway. Moreover, although the mechanisms have distinct clinical characteristics, they are not mutually exclusive. As an example, triplet gestations are more likely to be associated with periconceptional intrauterine manipulations predisposing to infection, as well as fetal growth restriction, decidual hemorrhage, and pathologic uterine distention. An improved understanding of these pathologic pathways has led to the development of new tests to predict PTD. Use of multiple markers (eg, serum CRH, salivary E3, cervical IL-6, TAT, and fFN) holds promise for implementing targeted interventions to prevent PTD.

Differential regulation of the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases by cytokines and growth factors in bovine endometrial stromal cells and trophoblast cell line BT-1 in vitro

Degradation and reconstitution of extracellular matrix in uterine endometrium is a crucial event for embryonic implantation and is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). In the present study, we investigated the regulation of MMP and TIMP expression in cultured bovine endometrial stromal cells (BESCs) and a bovine trophoblast cell line BT-1 (BT-1 cells). The production of proMMP-9 was induced by transforming growth factor beta (TGFbeta) and 12-O-tetradecanoylphorbol 13-acetate in the stromal cells. The treatment of BESCs with TGFbeta, insulin-like growth factor-I, and hepatocyte growth factor (HGF) resulted in a significant increase in the level of TIMP-1 in the culture medium. In addition, a significant increase of TIMP-2 production was observed in interleukin (IL)-1alpha and HGF-treated BESCs. However, the expression of TIMP-1 and TIMP-2 mRNA was not augmented by these factors. The treatment of BESCs with 12-O-tetradecanoylphorbol 13-acetate resulted in a significant increase in the level of TIMP-1 but a significant decrease in the level of TIMP-2 in the stromal cells. Membrane type-1 MMP mRNA expression in the stromal cells was augmented by tumor necrosis factor alpha (TNFalpha), IL-6, HGF, and 12-O-tetradecanoylphorbol 13-acetate. On the other hand, BT-1 cells constitutively produced proMMP-9 and proMMP-2, and the treatment of BT-1 cells with TNFalpha, HGF, and 12-O-tetradecanoylphorbol 13-acetate resulted in a significant increase in the level of proMMP-9 but not in the level of proMMP-2. The production of TIMP-1 in BT-1 cells was also augmented by IL-1alpha, TNFalpha, and HGF at the level of translation and was transcriptionally increased by 12-O-tetradecanoylphorbol 13-acetate. However, the level of TIMP-2 mRNA in BT-1 cells was not affected by any of the treatments. These results suggest that the expression of MMPs and TIMPs is differentially regulated by cytokines and growth factors and that the production of TIMP-1 and TIMP-2 may not be accompanied by changes in their mRNA expression in bovine endometrium and trophoblasts. Furthermore, as in humans and rodents, MMPs and TIMPs may contribute to the control of degradation and reconstitution of extracellular matrix in bovine endometrium during embryonic implantation and early placentation.

Molecular epidemiology of preterm delivery: methodology and challenges

Preterm delivery (PTD) appears to be a complex trait determined by both genetic and environmental factors. Few studies have examined genetic influence on PTD. The overall goal of our study is to examine major candidate genes of PTD and to test gene-environment interactions. Our study includes 500 preterm trios, including 500 preterm babies and their parents and 500 maternal age-matched term controls. We will perform the transmission/disequilibrium test (TDT) on candidate genes thought to be important in each of the four biological pathways of PTD: (1) decidual chorioamionotic inflammation: interleukin 1 (IL-1), IL-6, and tumour necrosis factor (TNF); (2) maternal and fetal stress: corticotropin-releasing hormone (CRH); (3) uteroplacental vascular lesions: methylenetereahydrofolate reductase (MTHFR); and (4) susceptibility to environmental toxins: GSTM1, GSTT1, CYP1A1, CYP2D6, CYP2E1, NAT2, NQO1, ALDH2, and EPHX. We will also perform standard case-control analyses on the 500 preterm cases and 500 term controls to examine gene-environment interactions. The major environmental, nutritional and social factors as well as clinical variables known or suspected to be associated with PTD will be used to test for gene-environment interactions. This study integrates epidemiological and clinical data as well as genetic markers along major pathogenic pathways of PTD. The findings from this study should improve our understanding of genetic influences on PTD and gene-environment interactions.

Platelet-activating factor induces an imbalance between matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases-1 expression in human uterine cervical fibroblasts

Platelet-activating factor (PAF) is involved in such reproductive processes as parturition. We investigated the effect of PAF on the expression of matrix metalloproteinase-1 (MMP-1) and that of tissue inhibitor of metalloproteinases-1 (TIMP-1) in human uterine cervical fibroblasts. Uterine cervical tissue was obtained from patients who underwent cesarean section at term. Collagenase-dispersed fibroblasts were cultured and used in the experiments. PAF receptor was identified in the uterine cervical fibroblasts by use of reverse transcription-polymerase chain reaction and Southern blot analysis. Northern blot analysis showed that PAF increased the expression of MMP-1 mRNA in a time-dependent manner, whereas expression of TIMP-1 mRNA was not affected by PAF. Concentration of MMP-1 protein in the PAF-treated culture media significantly exceeded that in control cultures. The PAF-induced production of MMP-1 protein was abolished by treatment with WEB 2170, a specific PAF receptor antagonist. Results suggest that PAF may accelerate collagenolysis in the human uterine cervix by inducing an imbalance in the activity between MMP-1 and TIMP-1, thus contributing to the cervical ripening during parturition.

Furin-independent pathway of membrane type 1-matrix metalloproteinase activation in rabbit dermal fibroblasts

We investigated the gene expression and intracellular activity of processing protease furin and its involvement in the process of membrane type 1-matrix metalloproteinase (MT1-MMP) activation in rabbit dermal fibroblasts. When the rabbit fibroblasts were treated with concanavalin A (ConA), pro-MMP-2 was converted to an active 62-kDa MMP-2 through the appearance of a 64-kDa intermediate MMP-2. The ConA-induced pro-MMP-2 activation resulted from increasing the gene expression and production of MT1-MMP in the rabbit fibroblasts. Reverse transcriptase-polymerase chain reaction demonstrated that in rabbit dermal fibroblasts furin mRNA was detected and, unlike MT1-MMP, was not increased by ConA. These findings are further supported by the fact that the intracellular furin activity also was constitutively detected and was unchanged by the ConA treatment. Very similar phenomena were also observed in human uterine cervical fibroblasts, which are known to produce MT1-MMP by ConA stimulation. These results suggest that the expression of the furin gene and the intracellular activity are not regulated by ConA. On the other hand, neither a synthetic furin inhibitor, decanoyl-RVKR-CH(2)Cl (25-100 microM) nor a furin antisense oligonucleotide (40 microM) inhibited the MT1-MMP-mediated pro-MMP-2 activation in ConA-treated rabbit dermal fibroblasts, whereas these compounds interfered with pro-MMP-2 activation in ConA-treated human uterine cervical fibroblasts. Nonetheless, the furin antisense oligonucleotide completely suppressed furin gene expression in both rabbit and human fibroblasts. These results suggest that furin does not participate in the process of MT1-MMP activation induced by ConA in rabbit dermal fibroblasts.

Heat shock suppresses membrane type 1-matrix metalloproteinase production and progelatinase A activation in human fibrosarcoma HT-1080 cells and thereby inhibits cellular invasion

Expression of membrane type-1 matrix metalloproteinase (MT1-MMP) is closely correlated with tumor invasiveness. We investigated the effect of hyperthermia on the production of MT1-MMP in human fibrosarcoma HT-1080 cells. Heat shock at 42 degrees C suppressed the production and gene expression of MT1-MMP in HT-1080 cells. Heat shock-induced suppression of MT1-MMP production resulted in the inhibition of progelatinase A (proMMP-2) activation and the increased release of tissue inhibitor of metalloproteinases 2 from cell surface. In addition, in vitro tumor invasion assay in a Matrigel model indicated that heat shock inhibited the invasive activity of HT-1080 cells. These results suggest that heat shock preferentially suppresses the production of MT1-MMP and thereby inhibits proMMP-2 activation, events which subsequently inhibit tumor invasion. Therefore, heat shock shows an anti-invasive effect along with the known mechanism of inhibiting tumor growth.

Markers of risk for preterm delivery

Clinical and experimental evidence indicate that PTD results from four primary pathogenic mechanisms: activation of the maternal or fetal HPA axis; amniochorionic-decidual or systemic inflammation; decidual hemorrhage; and, pathologic distention of the myometrium. Each of these four pathways has a distinct epidemiological and clinical profile, and unique biochemical and biophysical pathways initiating parturition, but shares a common final biochemical pathway involving myometrial activation and stimulation, and enhanced genital tract protease activity promoting PPROM and cervical change. Traditional methods of predicting women at risk relying on obstetrical history or symptoms and epidemiological risk factors are neither sensitive nor specific. Recent approaches to predicting PTD, including sonographic measurement of cervical length and biochemical assays for hCG, cytokines, fFN, MMPs, estrogens, and CRH, are more sensitive than traditional methods. Moreover, given the heterogeneous, interactive etiopathogeneses of PTD, multiple biochemical markers should not only increase sensitivity and specificity, but also permit the detection of the relative contribution of each pathogenesis to the overall risk of PTD.

Subtractive cloning identifies tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) increased gene expression following focal stroke

BACKGROUND AND PURPOSE

Differential gene expression has been reported following the onset of focal stroke. To identify de novo expression of ischemia-induced genes, we applied subtractive cDNA library strategy to identify the genes that are selectively upregulated by focal stroke.

METHODS

Spontaneously hypertensive rats were subjected to permanent occlusion of the middle cerebral artery (MCAO). mRNAs prepared from ischemic and nonischemic cortex 2 and 12 hours after MCAO were subtracted, and a subtractive cDNA library was constructed. A cDNA that encodes for tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) was identified in the subtractive cDNA library. The temporal expression of cortical TIMP-1 mRNA was further characterized in ischemic cortex subjected to permanent or temporary (160-minute) MCAO.

RESULTS

A panel of genes isolated from the subtractive cDNA library was subjected to Southern analysis to confirm ischemia-induced gene expression. TIMP-1 demonstrated robust induction after ischemic injury. Time-course studies revealed that TIMP-1 mRNA was induced threefold over controls at 12 hours (P<.001, n=4 animals) and reached a peak level at 2 days after permanent MCAO (sevenfold increase, P<.001). Similar induction profile of TIMP-1 mRNA was observed in the ischemic cortex after temporary MCAO followed by reperfusion.

CONCLUSIONS

This work demonstrated the utility of subtractive cDNA library strategy for discovery of genes differentially expressed in focal stroke. Furthermore, our data implicate TIMP-1 in ischemia-induced brain injury.

Elevated second trimester human chorionic gonadotropin level associated with adverse pregnancy outcome

OBJECTIVE

Our purpose was to determine whether unexplained elevations in maternal serum human chorionic gonadotropin in the second trimester may be associated with adverse pregnancy outcome.

METHOD

Between April 1992 and April 1995, 610 pregnant women undergoing second trimester triple marker screening for Down syndrome who delivered at our institution were evaluated. Eighty-one women with a hCG level greater than 2.0 multiples of the median (MoM) were included in the study group while 481 women with hCG levels < 2.0 MoM served as controls. Pregnancies with fetal chromosomal and structural anomalies and maternal serum alpha-fetoprotein levels greater than 2.0 MoM were excluded from the study. Pregnancy outcomes were obtained from hospital delivery records. Statistical analysis were performed by Student's t-test; odds ratios and 95% confidence intervals were also calculated.

RESULTS

Women with elevated human chorionic gonadotropin levels showed an increased risk for preeclampsia (odds ratio (OR): 5.93, 95% confidence interval (CI): 1.97-15.88), intrauterine growth retardation (OR: 5.34, 95% CI: 2.14-13.34), preterm delivery (OR: 5.66, 95% CI: 3.22-9.98), and preterm premature rupture of membranes (OR: 3.15, 95% CI: 1.23-8.07).

CONCLUSION

Unexplained elevation of human chorionic gonadotropin in the second trimester appears to be associated with adverse pregnancy outcome.

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

We have examined the regulation of precursor of matrix metalloproteinase 9 (proMMP-9)/progelatinase B production by tumor necrosis factor alpha (TNFalpha) and interleukin 1alpha (IL-1alpha) using human uterine cervical fibroblasts. TNFalpha, but not IL-1alpha, induces the production of proMMP-9 in the cervical cells. IL-alpha, however, suppresses the TNFalpha-induced proMMP-9 production. 12-0-tetradecanoylphorbol 13-acetate (TPA) also stimulates the cervical cells to produce proMMP-9, and IL-1alpha synergistically enhances its production. TNFalpha-induced proMMP-9 production is not mediated by protein kinase C (PKC), whereas the effect of IL-1alpha is through PKC. By contrast, proMMP-3/prostromelysin 1 is up-regulated by TNFalpha or TPA in the presence of IL-1alpha, whose modulation is PKC-dependent. The suppressive effect of IL-1alpha on the TNFalpha-induced proMMP-9 production is a new biological effect of IL-1 on MMP production.

Degradation of interleukin 1beta by matrix metalloproteinases

Matrix metalloproteinases (MMPs) and interleukin 1 (IL-1) are implicated in inflammation and tissue destruction, where IL-1 is a potent stimulator of connective tissue cells to produce the extracellular matrix-degrading MMPs. Here, we report that IL-1beta, but not IL-1alpha, is degraded by MMP-1 (interstitial collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin 1), and MMP-9 (gelatinase B). This degradation was effectively blocked by tissue inhibitor of metalloproteinases (TIMP)-1. When IL-1beta was treated with MMPs it lost the ability to enhance the synthesis of prostaglandin E2 and pro-MMP-3 in human fibroblasts. The primary cleavage site of IL-1beta by MMP-2 was identified at the Glu25-Leu26 bond. These results suggest that IL-1beta stimulates connective tissue cells to produce MMPs, but activated MMPs in turn negatively regulate the activity of IL-1beta.

Biochemical changes in the cervical mucus after application of laminaria tent

BACKGROUND

This research was aimed to study the biochemical changes in cervical mucus after application of laminaria tent.

MATERIAL AND METHODS

Cervical mucus was collected before and after insertion of laminaria tent from 20 normal pregnant women in the first and second trimesters. Interleukin-1 beta, IL-8, collagenase activity, elastase activity, PGE2 and PGF2 alpha were measured in the collected samples. Laminaria tent was also inserted in one vaginal cervix of five non-pregnant rabbits and the clinical and histological changes were compared with five non-treated rabbits. Collagen contents were assessed histologically and Leukocyte number was counted.

RESULTS

IL-1 beta and IL-8 and elastase activity were significantly increased after insertion of laminaria (p<0.0001 and 0.001 respectively). Collagenase activity was not significantly changed. Whereas concentration of PGE2 and PGF2 alpha in the mucus were markedly increased (p<0.0001 and 0.001 respectively). Collagen contents were significantly decreased in laminaria and opposite side cervices (p<0.0001). No significant changes in leukocyte count could be observed in treated and non treated cervices.

CONCLUSIONS

Insertion of laminaria leads to increase concentration of IL-1 beta, IL-8, PGE2, PGF2 alpha and elastase activity. Mechanical stretching of the cervix and biochemical changes in cervical mucus may explain the mechanism of cervical ripening induced by laminaria.

Translational augmentation of pro-matrix metalloproteinase 3 (prostromelysin 1) and tissue inhibitor of metalloproteinases (TIMP)-1 mRNAs induced by epidermal growth factor in human uterine cervical fibroblasts

The mechanisms by which epidermal growth factor (EGF) enhances the production of pro-matrix metalloproteinase 3 (proMMP-3/prostromelysin 1) and tissue inhibitor of metalloproteinases (TIMP)-1 were investigated using human uterine cervical fibroblasts. The treatment of the cells with EGF for 24 h resulted in about 5-6-fold increase in the production of proMMP-3 and TIMP-1 compared with the untreated control cells. This increase was accompanied by an increase of proMMP-3 and TIMP-1 mRNAs. However, an about 3- and 2-fold increase in the production of proMMP-3 and TIMP-1, respectively, was observed as early as 1 h after the treatment of the cells with EGF, and it was not accompanied by any apparent increase in proMMP-3 and TIMP-1 mRNAs. This early effect of EGF on the enhanced production of proMMP-3 and TIMP-1 was not inhibited by actinomycin D, even though actinomycin D inhibited the synthesis of the total RNA in both the EGF-treated and untreated cells. These results indicate that EGF enhances the apparent production of proMMP-3 and TIMP-1 by two mechanisms: one by the accelerated translation of their mRNAs; and the other by the enhanced transcription of their genes. The former event takes place much earlier than the latter.

Inhibition of interleukin 1-induced biosynthesis of stromelysin by the calcium antagonist TMB-8 (8-(N, N-diethylamino)octyl-3,4,5-trimethoxybenzoate HCl)

This study was done to identify agents that can inhibit interleukin 1 (IL1)-induced stromelysin biosynthesis and to gain insight into the mechanism of IL1 action. For this purpose, various agents known to modulate calcium-dependent signal transduction pathway were evaluated in rabbit synovial fibroblast (RSF) cultures. Only the conditioned medium from RSF treated with the intracellular calcium antagonist TMB-8 (8-(N,N-diethylamino)-octyl 3,4,5-trimethoxybenzoate hydrochloride) had significantly lower proteoglycan-degrading metalloproteinase activity than controls. Biosynthetic labeling, immunoprecipitation and immunohistochemical studies, using a polyclonal antibody against rabbit stromelysin, demonstrated that TMB-8 inhibited synthesis stromelysin, the proteoglycan-degrading matrix metalloproteinase. Further evaluation of the TMB-8 effect revealed that the compound had no effect on secretion and that it was not acting by preventing activation of the proenzyme or by inhibiting the enzyme activity. These results suggest that TMB-8 may be inhibiting stromelysin synthesis by limiting intracellular calcium levels.

Interleukin-1 beta induces differential gene expression in aortic smooth muscle cells

PURPOSE

Abdominal aortic aneurysms are characterized by an accelerated turnover of extracellular matrix proteins and by an inflammatory infiltrate that releases the cytokines interleukin-1 beta and tumor necrosis factor-alpha. We examined the gene expression of human aneurysmal aortic smooth muscle cells and normal aortic smooth muscle cells after treatment with interleukin-1 beta and tumor necrosis factor-alpha by measuring the changes in smooth muscle cell collagen, elastin, collagenase, and tissue inhibitor of metalloproteinase messenger ribonucleic acid levels in response to these cytokines.

METHODS

Biopsy of aneurysmal aorta (n = 6) and donor normal aorta (n = 3) was obtained at operation. Medial smooth muscle cells were cultured, passaged (P2 to P4), and incubated with 0, 10, 100, or 1000 pg/ml interleukin-1 beta, tumor necrosis factor-alpha, or platelet-derived growth factor for 24 hours. Total ribonucleic acid was harvested. Percentage changes in messenger ribonucleic acid from control levels for type I and type III procollagen, elastin, collagenase, 72 kDa type IV collagenase, tissue inhibitor of metalloproteinase-1, and tissue inhibitor of metalloproteinase-2 were measured by Northern hybridization. Analyses were performed with analysis of variance (p < 0.05). All comparisons between aneurysmal aortic smooth muscle cells and normal aortic smooth muscle cells represent comparisons between one aneurysmal aorta and one normal aorta.

RESULTS

Added interleukin-1 beta resulted in significant, dose-dependent increases in the collagenase messenger ribonucleic acid level at all concentrations tested in both aneurysmal aorta and normal aorta. The increase in the collagenase messenger ribonucleic acid level ranged from a minimum increase of 123% for 10 pg/ml interleukin-1 beta in aneurysmal aortic smooth muscle cells to a maximum of 450% for 1000 pg/ml interleukin-1 beta in normal aortic smooth muscle cells. Interleukin-1 beta caused a significant decrease in the steady-state messenger ribonucleic acid levels for type 1 procollagen in both aneurysmal and normal aorta. The greatest reduction in type 1 procollagen messenger ribonucleic acid levels occurred at 100 pg/ml interleukin-1 beta in both aneurysmal aortic smooth muscle cells (-39%) and normal aortic smooth muscle cells (-48%). The only observed qualitative difference between aneurysmal aortic smooth muscle cells and normal aortic smooth muscle cells was the change in tissue inhibitor of metalloproteinase-1 messenger ribonucleic acid levels in response to added interleukin-1 beta. In aneurysmal aortic smooth muscle cells interleukin-1 beta at 1000 pg/ml significantly increased messenger ribonucleic acid levels by 82%, whereas levels of tissue inhibitor of metalloproteinase-1 messenger ribonucleic acid in normal aortic smooth muscle cells did not change in response to added interleukin-1 beta. Interleukin-1 beta did not alter messenger ribonucleic acid levels for type III procollagen, elastin, type IV collagenase, or tissue inhibitor of metalloproteinase-2 in aneurysmal aorta or normal aorta. When tumor necrosis factor-alpha or platelet-derived growth factor were added, this did not significantly change aneurysmal aortic smooth muscle cells messenger ribonucleic acid levels for collagenase, type IV collagenase, tissue inhibitor of metalloproteinase-1, tissue inhibitor of metalloproteinase-2, and type I and type III procollagen.

CONCLUSIONS

These findings suggest that interleukin-1 beta, through its effect on smooth muscle cell collagenase and collagen gene expression, mediates the increased matrix turnover observed in aneurysms. Macrophages may induce changes in aortic smooth muscle cell gene expression in a paracrine manner that could lead to aneurysm formation.

Progesterone increases the production of tissue inhibitor of metalloproteinases-2 in rabbit uterine cervical fibroblasts

Rabbit uterine cervical fibroblasts in culture produces tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2. When cells were treated with physiological concentrations of progesterone, the production of two TIMPs increased, and essentially all TIMP-2 was found to be complexed with promatrix metalloproteinase 2 (proMMP-2)/progelatinase A. Progesterone did not modulate the production of proMMP-2 and resulted in the increased total amount of proMMP-2-TIMP-2 complex. These observations provide the first evidence that progesterone participates in maintaining the homeostasis of connective tissue matrix in uterine cervix by augmenting both TIMP-1 and TIMP-2 production along with the known suppressive effects on the proMMP-1 and proMMP-3 production.

Involvement of protein kinase C in the interleukin 1 alpha-induced gene expression of matrix metalloproteinases and tissue inhibitor-1 of metalloproteinases (TIMP-1) in human uterine cervical fibroblasts

The role of protein kinase C in the interleukin 1 (IL-1)-mediated production of pro-matrix metalloproteinases (proMMPs) and tissue inhibitor-1 of metalloproteinases (TIMP-1) in human uterine cervical fibro-blasts has been investigated. IL-1 and a protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA) augmented the production of proMMP-1 (interstitial procollagenase), proMMP-3 (prostromelysin-1) and TIMP-1, but their effects were inhibited by the protein kinase C inhibitors 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) and staurosporine in a dose-dependent manner. The suppressive effect of H-7 and staurosporine on the IL-1-induced production of proMMPs-1 and -3 and TIMP-1 resulted from the decrease in the steady-state levels of their mRNAs. When protein kinase C was down-regulated by treating the cells with a high level of TPA, the inductive effect of IL-1 upon proMMP-3 production was reduced considerably. These results indicate that protein kinase C mediates the IL-1-induced production of proMMPs-1 and -3 and TIMP-1 at the pretranslational level in human uterine cervical fibroblasts. On the other hand, neither IL-1 nor TPA modulated the production of proMMP-2 (progelatinase A). Both IL-1 and TPA also accelerated the production of prostaglandin E2 (PGE2) by cervical fibroblasts. However, the treatment of the cells with staurosporine in the presence of IL-1 or TPA further augmented PGE2 synthesis, suggesting that the increased synthesis of PGE2 by IL-1 treatment is mediated via signalling pathways distinct from those of proMMPs-1 and -3 and TIMP-1.

Cytokine regulation of metalloproteinase gene expression

Matrix metalloproteinases belong to a family of zinc-dependent enzymes capable of degrading extracellular matrix and basement membrane components. Their expression is greatly modulated by cytokines and growth factors and involves the gene products of the Fos and Jun families of oncogenes. After extra(peri)cellular activation, their activity can be further controlled by specific tissue inhibitors of metalloproteinases. A correct balance between these regulatory mechanisms is necessary to ensure matrix remodeling in normal physiological processes such as embryonic development, but the overexpression of these enzymes may initiate or contribute to pathological situations such as cartilage degradation in rheumatoid arthritis or to tumor progression and metastasis. Delineation of the mechanisms of metalloproteinase and metalloproteinase inhibitors gene expression, understanding of their mode of interactions, and characterization of their patterns of expression in various tissues in normal and pathological states will lead to new therapeutic strategies to counteract the deleterious effects of matrix metalloproteinases in human disease.

The presence of cervical and vaginal fetal fibronectin predicts preterm delivery in an inner-city obstetric population

OBJECTIVE

It has previously been shown that fibronectin bearing a specific oncofetal domain is present at the chorionic-decidual interface and that its release into cervical and vaginal secretions accurately predicts preterm delivery in patients with uterine contractions. This study examines whether serial assessment of cervical and vaginal fetal fibronectin allows for the prediction of preterm delivery in symptom-free patients derived from an inner-city, general obstetric population.

STUDY DESIGN

Cervical and vaginal samples were obtained from 429 consenting patients who received routine prenatal care between 24 and 37 weeks' gestation. A sensitive immunoassay was used to quantitate cervical and vaginal fetal fibronectin levels, and clinicians were blinded to fetal fibronectin results. Post hoc receiver operating characteristic curve analysis was used to determine which sample site (cervical or vaginal), fetal fibronectin concentration, and number of consecutive positive samples optimized screening efficacy. Logistic regression was employed to determine whether fetal fibronectin was an independent predictor of preterm delivery.

RESULTS

The spontaneous preterm delivery rate was 11% (49/429). Among the 326 patients sampled within 28 days of delivery, receiver operating characteristic curve analysis indicated that the presence of a single cervical fetal fibronectin value > 60 ng/ml between 24 and 36 weeks' gestation predicted preterm delivery with a sensitivity of 73%, a specificity of 72%, and positive and negative predictive values of 25% and 95%, respectively. A vaginal fetal fibronectin value > 50 ng/ml predicted preterm delivery with a sensitivity of 68%, a specificity of 80%, and positive and negative predictive values of 30% and 95%, respectively. Cervical and vaginal fetal fibronectin predicted preterm deliveries resulting from both membrane rupture and preterm labor with intact membranes. A positive fetal fibronectin result preceded preterm delivery by 3.4 (+/- 3.2) weeks. Stepwise logistic regression demonstrated that cervical and vaginal fetal fibronectin levels were independent predictors of preterm delivery with adjusted odds ratios of 8.9 (95% confidence interval 3.6 to 22.1) and 6.0 (95% confidence interval 2.6 to 13.7), respectively.

CONCLUSIONS

Among patients undergoing monthly cervical and vaginal sampling between 24 and 36 weeks' gestation, the presence of fetal fibronectin is a sensitive and specific predictor of preterm delivery.

Double-blind; placebo-controlled trial of piperacillin prophylaxis in preterm membrane rupture

OBJECTIVE

We attempted to test whether antibiotic therapy prolongs pregnancy in preterm premature rupture of membranes, because preterm premature rupture of membranes is frequently associated with chorionic-decidual infection.

STUDY DESIGN

Women with preterm premature rupture of membranes and a singleton gestation at 24 to 34 completed weeks were randomized to receive either piperacillin 3 gm or placebo intravenously every 6 hours for 72 hours and were managed conservatively until spontaneous delivery, chorioamnionitis, or fetal distress.

RESULTS

Between January 1987 and January 1992, a total of 75 patients were randomized to receive piperacillin (n = 38) or placebo (n = 37). There were no differences between the piperacillin group and the placebo group in mean gestational age at randomization (30.2 +/- 3 vs 30.3 +/- 2.9 weeks). However, a greater number of patients had pregnancy prolonged beyond 7 days (42.1% vs 10.8% p = 0.005) and the mean latency period was significantly prolonged (11.4 +/- 18.8 vs 6.1 +/- 13.6 days, p = 0.001) in the piperacillin group compared with the control groups.

CONCLUSIONS

Use of intravenous piperacillin for 72 hours in preterm premature rupture of membranes significantly prolongs the latency period between membrane rupture and delivery.

Effects of interleukin-6 on the metabolism of connective tissue components in rheumatoid synovial fibroblasts

OBJECTIVE

High levels of interleukin-6 (IL-6) have been found in the synovial fluid of patients with rheumatoid arthritis (RA). We undertook the present study to investigate the role of IL-6 in this disease.

METHODS

We examined the effects of IL-6, in comparison with IL-1, on the biosynthesis of extracellular matrix macromolecules and of matrix-degrading proteinases in rheumatoid synovial fibroblasts.

RESULTS

In rheumatoid synovial fibroblasts, IL-6 by itself enhanced the production of plasminogen activator, its inhibitor, and tissue inhibitor of metalloproteinases, whereas it did not modulate the biosynthesis of precursor of matrix metalloproteinase 1 (proMMP-1) (tissue collagenase), proMMP-3 (stromelysin), or connective tissue components. However, IL-1-induced production of proMMP-1 and proMMP-3 was preferentially augmented by IL-6.

CONCLUSION

These results suggest that in RA, IL-6 may participate along with IL-1 in fine tuning of the catabolism of connective tissue components, by modulating the balance between connective tissue-degrading enzymes and their inhibitors.