Expression of matrix metalloproteinase-3 in the rat cervix during pregnancy and in response to prostaglandin E2

Increasing cervical penetrability in sheep by long-acting treatments with oxytocin (Carbetocin) and/or prostaglandin E2 (Dinoprostone)

The aim was to study the effect of long-acting treatments with oxytocin (Carbetocin, Cb) and/or prostaglandin E2 (Dinoprostone, Dp) on cervical penetrability and collagenolysis in synchronized ewes (12 days MAP-eCG). At 42 h post eCG, ewes were treated with Cb (Group Cb, n = 6, 40 μg, i.m., Decomotón, Laboratorios Callier, Uruguay); Dp (Group Dp, n = 10, 10 mg, slow-release intravaginal device, Propess®, Ferring Pharmaceuticals Ltd., West Drayton, UK); combined Cb and Dp treatment (Group Cb+Dp, n = 8) and saline solution i.m. and a placebo intravaginal device (Group C, n = 10). Cervical penetrability increased from 0 h to 42 h post eCG (P < 0.003) in all groups, then decrease in Group C (P < 0.03) from 42 to 68 h post eCG, whereas remained unchanged in Groups Cb and Cb+Dp or increase at 54 h post eCG in Group Dp (P < 0.05). Thus, there was higher cervical penetrability in treated groups than Group C at the expected time of artificial insemination (54 h post eCG). At 54 h post eCG, collagen concentration was lower in Group Cb than in the others groups (P < 0.05), whereas the ratio between the activity of the activated and latent forms of MMP-2 was greater in Groups Cb and Cb+Dp than in Group C (P < 0.05). The increasing cervical penetrability induced by Cb, but not by Dp, could be explained by an increase in MMP-2-dependent collagen degradation. Furthermore, combined treatment with Cb and Dp did not enhance the effects induced by each hormone administered separately.

Matrix metalloproteinase-3 in preeclamptic and normotensive pregnancies complicated by foetal growth restriction

The aim of the present study was to assess the interrelationships between the level of matrix metalloproteinase-3 in the blood serum of pregnant women and the occurrence of pregnancy complications in the form of foetal growth restriction, idiopathic or in the course of preeclampsia.

Methods

A total of 245 patients were included in the study. 65 of them are normotensive patients with idiopathic foetal growth restriction (FGR group). 115 women were diagnosed with severe preeclampsia. In the group of women with preeclampsia, there were 51 patients with adequate for gestational age foetal growth and 64 patients with the foetal growth restriction in the course of severe preeclampsia. The control group consisted of 65 healthy patients with normal pregnancy course, with no cardiovascular disorders at the present and in the history, normal blood pressure and normal intrauterine foetal growth. Matrix metalloproteinase-3 (MMP-3) in maternal circulation were determined by ELISA method.

Results

In our studies, we observed elevated levels of matrix metalloproteinase-3 in preeclamptic women with pregnancies complicated by FGR and significantly lower in the group of normotensive women with idiopathic FGR. The mean values of MMP-3 were 33.50 ± 65.74 ng/mL [Median (min-max) 19.19 (2.05-454.53)] in the Control group, 21.22 ± 23.28 ng/mL [Median (min-max) 16.39 (3.45-156.29)] in the FGR group, 35.96 ± 46.14 ng/mL [Median (min-max) 25.21 (4.16-253.05)] in the P group and 52.81 ± 61.61 ng/mL [Median (min-max) 32.83 (5.06-314.14)] in preeclamptic women with FGR (group PI) respectively.The assessment of MMP-3 in the serum of women with pregnancies complicated by intrauterine foetal growth restriction with normal values of blood pressure and in the group of preeclamptic patients in relation to healthy pregnant women with uncomplicated pregnancies and in relation to preeclamptic patients with normal intrauterine foetal growth is the novelty of this study. Such a strict definition of each research group seems to allow for the assessment of each pregnancy complication separately.

Conclusion

It seems that higher levels of MMP-3 in preeclamptic women may suggest the need for observation towards the risk of lower birth weight of newborns. This necessitates further research and a better integration in the clinical practice.

Investigation of Murine Vaginal Creep Response to Altered Mechanical Loads

The vagina is a viscoelastic fibromuscular organ that provides support to the pelvic organs. The viscoelastic properties of the vagina are understudied but may be critical for pelvic stability. Most studies evaluate vaginal viscoelasticity under a single uniaxial load; however, the vagina is subjected to dynamic multiaxial loading in the body. It is unknown how varied multiaxial loading conditions affect vaginal viscoelastic behavior and which microstructural processes dictate the viscoelastic response. Therefore, the objective was to develop methods using extension-inflation protocols to quantify vaginal viscoelastic creep under various circumferential and axial loads. Then, the protocol was applied to quantify vaginal creep and collagen microstructure in the fibulin-5 wildtype and haploinsufficient vaginas. To evaluate pressure-dependent creep, the fibulin-5 wildtype and haploinsufficient vaginas (n = 7/genotype) were subjected to various constant pressures at the physiologic length for 100 s. For axial length-dependent creep, the vaginas (n = 7/genotype) were extended to various fixed axial lengths then subjected to the mean in vivo pressure for 100 s. Second-harmonic generation imaging was performed to quantify collagen fiber organization and undulation (n = 3/genotype). Increased pressure significantly increased creep strain in the wildtype, but not the haploinsufficient vagina. The axial length did not significantly affect the creep rate or strain in both genotypes. Collagen undulation varied through the depth of the subepithelium but not between genotypes. These findings suggest that the creep response to loading may vary with biological processes and pathologies, therefore, evaluating vaginal creep under various circumferential loads may be important to understand vaginal function.

[Factors predicting unsuccessful labor induction with dinoprostone in post-term pregnancy with unfavorable cervix]

OBJECTIVE

To identify predictive factors for unsuccessful induction of labor within 24hours after dinoprostone insertion in post-term pregnancy with unfavorable cervix.

MATERIAL AND METHODS

We retrospectively reviewed 325 singleton pregnancies with a diagnosis of post-term pregnancy and unfavorable cervix (Bishop score<6) during the period January 2012-Decembre 2012. Patients were classified into 2 groups: successful labor, defined as cervical ripening, within 24hours after dinoprostone insertion (Group R; n=248; 76.3 %) or failure group (Group E; n=77; 23.7 %). Antepartum and perpartum characteristics of women were compared.

RESULTS

Nulliparity (74.0 versus 56.0 %; OR=2.23; 95 % CI: 1.27-4.00; P=0.005), gestational age ≤41 SA+4 (53.2 versus 33.9 %; OR=2.22; 95 % CI: 1.32-3.74; P=0.003) and history of dilatation and curettage (27.3 versus 10.5 %; OR=3.19; 95 % CI: 1.66-6.11; P=0.0005) were significantly associated with unsuccessful induction of labor. Bishop score was significantly higher in Group R (3.6 versus 1.9; P=0.001). Also, consistency (74.0 versus 44.4 %; OR=3.57; 95 % CI: 2.04-6.40; P<10(-5)) and absence of dilatation of the cervix (59.7 versus 23.0 %; OR=4.97; 95 % CI: 2.89-8.56; P<10(-6)) were identified as significant predictive factors for unsuccessful induction of labor.

CONCLUSION

Nulliparity, gestational age ≤41 SA+4, history of dilatation and curettage and Bishop score, in particular consistency and dilatation, are correlated with failure of cervical ripening in post-term pregnancy with unfavorable cervix.

A comprehensive immunohistochemistry of prostaglandins F2α and E2 synthetic enzymes in rat ovary and uterus around parturition

A comprehensive immunohistochemistry with the isoform-distinguishable antibodies against prostaglandin (PG) F2α and PGE2 biosynthetic enzymes was undertaken to identify the cellular types and enzyme isoforms in rat ovary and uterus around parturition. In general ovarian and uterine cells showed positive immunoreactions for phospholipase A2 groups 4A and 6A, but not group 2A, and cyclooxygenase (COX)-1 rather than COX-2. Their immunoreactions for PGF2α synthase and PGE2 synthase were cell type-dependently variable. The putative PGF2α and PGE2 producing cell types included, as expected, ovarian luteal cells, uterine endometrial epithelium and myometrium, and cervical connective tissue and, unexpectedly, ovarian stromal cells and basal lamina of cervical endometrium. Obtained data indicate the generation of PGF2α and PGE2 by multiple sites, which are entirely the same as established sites of actions, in parturition processes and tissue-dependent differential usage of PG biosynthetic pathway.

Temporal changes in circulating levels of plasma interleukin-8 during peripartum period in Murrah buffaloes (Bubalus bubalis) under subtropical climate

The objective of this study was to elucidate the changes in circulating levels of plasma interleukin-8 (IL-8) during peripartum period in Murrah buffaloes (Bubalus bubalis). IL-8 was estimated in blood plasma of healthy peripartum Murrah buffaloes (n=6) on days ± 30, ± 15, ± 5, ± 3, ± 1 and 0 pre- and postpartum with respect to the day of parturition (day 0) in each of the two different seasons (hot-humid and spring). The mean microclimate Temperature-Humidity Index (THI) during spring season was significantly lower (p<0.01) than the corresponding THI in hot-humid season. In both the seasons, plasma IL-8 remained lower in prepartum period (≤ 46.56 ± 14.08 pg/ml during spring and ≤ 73.18 ± 18.56 pg/ml during hot-humid season) than in the postpartum period (≥ 51.41 ± 13.82 pg/ml during spring and ≥ 84.13 ± 16.97 pg/ml in hot humid season). During spring, the IL-8 levels were significantly higher (P<0.05) on days+5 and +15 postpartum in comparison to the IL-8 levels on days -30, -5, and -3 prepartum. During hot-humid season, IL-8 level was significantly higher (P<0.05) on day +30 as compared to the IL-8 levels on days -30 and -5 prepartum. The correlation between IL-8 and mean microclimate THI was significant (r=0.25, P<0.01). From the results, it is concluded that peripartum period in buffaloes is associated with an inflammatory response leading to significantly higher plasma IL-8 during parturition and postpartum period than in the pre-partum period.

The role of transforming growth factor beta in cervical remodeling within the rat cervix

OBJECTIVE

Transforming growth factor beta (TGFbeta) plays a central role in extracellular matrix remodeling. We hypothesized that TGFbeta signaling is involved in cervical remodeling. This study evaluated patterns within this signaling pathway.

STUDY DESIGN

The cervices of nonpregnant and timed pregnant rats were obtained. Messenger ribonucleic acid (mRNA) expression of TGFbeta1, TGFbeta receptor 1 (TbetaR1), TbetaR2, and TbetaR3 was evaluated. Four animals were euthanized for each time point. Western blotting was performed for protein expression. Phosphorylated mothers against decapentaplegic (Smad)-2 and -3 phosphorylation was assessed to evaluate TGFbeta activation.

RESULTS

TGFbeta1 mRNA increased through day 21 and declined on day 22 (analysis of variance, P = .001). TbetaR1 expression was unchanged. TbetaR2 and TbetaR3 mRNA expression was similar to TGFbeta1. TbetaR3 protein expression was similar to mRNA. Smad2 phosphorylation paralleled changes in TbetaR3.

CONCLUSION

Components of the TGFbeta signaling pathway increase during pregnancy along with Smad2 activation. The decline on day 22 correlates with a transition to the ripening phase supporting a role in cervical remodeling.

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.

Prostaglandin E2-regulated cervical ripening: analysis of proteoglycan expression in the rat cervix

OBJECTIVE

Prostaglandins reduce cervical resistance by reorganizing collagen fibrils. Proteoglycans are involved in collagen fibril organization and structure. We evaluated the changes in proteoglycan composition induced by prostaglandin E(2) (PGE(2)).

STUDY DESIGN

Prostaglandins were administered intravaginally to induce cervical ripening in timed pregnant Sprague-Dawley rats. Changes in proteoglycan messenger ribonucleic acid (mRNA) expression were measured using reverse transcription (RT-PCR) for core protein. Fluorophore assisted carbohydrate gel electrophoresis (FACE) was used to evaluate proteoglycan glycosaminoglycan composition along with size exclusion high-performance liquid chromatography (HPLC).

RESULTS

No change in core protein mRNA expression was detected after PGE(2) treatment. Total glycosaminoglycan (GAG) decreased more than 20% after PGE(2) (P = .02). FACE demonstrated a shift in disaccharide subunit composition after PGE(2), with a decrease in 4-sulfated disaccharides (P = .02). HPLC confirmed a decrease in total GAG (P = .04).

CONCLUSION

Although there was no change in core protein mRNA expression, alterations in GAG composition was detected after PGE(2). The decrease in sulfated GAG could decrease electrostatic interactions that would weaken interfibrillar interactions. These findings would be consistent with a decline in cervical resistance.

Relaxation of the mouse pubic symphysis during late pregnancy is not accompanied by the influx of granulocytes

In some animals, such as mice and guinea pigs, a hormonally controlled mechanism increases the flexibility of the pubic symphysis and enhances the cervical remodeling necessary for safe delivery. Cervical ripening during pregnancy is associated with a paradoxical influx of leukocytes. However, the changes in cell metabolism during relaxation of the mouse pubic symphysis for delivery have not been extensively studied. In this work, we used light microscopy and transmission and scanning electron microcopy, as well as immunohistochemistry and Western blotting for MMP-8, to investigate the involvement of granulocytes or resident stromal cells in the relaxation of the virgin pubic symphysis during late pregnancy (days 18 and 19, before delivery) in vivo and in explanted joints. MMP-8 was studied because this collagenase is a hallmark for cervical ripening associated with the influx of granulocytes during late pregnancy. Extensive dissolution and disorganization of the extracellular matrix was seen around fibroblastic-like cells in late pregnancy. In contrast to the cervix (positive control), morphological and immunohistochemical analyses revealed that there was no characteristic cellular inflammatory response in the interpubic tissue. Staining for MMP-8 was observed in chondroid and fibroblastic-like cells of virgin and relaxed interpubic ligament, respectively. However, no granulocytes were seen during the extensive remodeling of the pubic joint in late pregnancy. These results indicate that constitutive stromal cells may have an important role in tissue relaxation during remodeling of the pubic symphysis in pregnancy.

Mifepristone-induced cervical ripening: structural, biomechanical, and molecular events

OBJECTIVE

The purpose of this study was to assess the structural, biomechanical, and biochemical effects of mifepristone-induced progesterone withdrawal on the rat cervix to identify possible mechanisms by which mifepristone incites cervical ripening.

STUDY DESIGN

After the administration of mifepristone, cervical tensile strength was determined by the cervical creep method. With polarized light microscopy and transmission electron microscopy, collagen organization and microstructure were quantified. Matrix metalloproteinase expression was assessed by Western Blot and Real-time reverse transcriptase-polymerase chain reaction.

RESULTS

Mifepristone induced a decrease in cervical tensile strength at mid gestation that was associated with a decrease in collagen organization. Additionally, mifepristone led to collagen fragmentation with a significant decrease in fibril length and diameter, although fibril bundling remained unaffected. Matrix metalloproteinase-2 expression increased after the administration of mifepristone.

CONCLUSION

Mifepristone-induced cervical ripening is associated with collagen degradation, and the collagenase activity of matrix metalloproteinase-2 may play a role in this process.