Biomedical subjects

F Vadillo-Ortega

Publications and source records attributed to F Vadillo-Ortega.

At least 19 recordsLinked to original sources

PubMed2006

Identification of a calcium-dependent matrix metalloproteinase complex in rat chorioallantoid membranes during labour.

The induction of the expression of matrix metalloproteinases (MMPs) and their extracellular activation are key processes in connective tissue degradation in the chorioallantoid membrane during rat labour. However, the regulatory mechanisms remain largely unknown. Here, we report the identification of a calcium-dependent high molecular weight complex composed of MMP-9, MMP-3, MMP-2, tissue inhibitor of metalloproteinase 1 (TIMP-1) and TIMP-2, identified by zymography and western blotting. Molecular sieve chromatography confirmed the presence of a complex of MMPs and TIMPs with an exclusion volume >670 kDa. Differential scanning calorimetry of the complex confirmed the existence of a macromolecular complex that unfolds with a broad transition; it is denatured over a wide range of temperatures and has a T(m) of 72 degrees C in the presence of Ca(2+). When denatured in the absence of Ca(2+), there were at least eight transitions with T(m)s that corresponded to pro-MMP-9, MMP-9, pro-MMP-3, MMP-3, pro-MMP-2, MMP-2, TIMP-1 and TIMP-2. Co-localization of the same molecular components was demonstrated by confocal microscopy using cell-depleted chorioallantoid membranes. The assembly and disassembly of the complex can be reproduced at physiological concentrations of Ca(2+). This complex provides a potential mechanism for the enzymatic regulation of MMPs, which may participate in connective tissue degradation leading to the rupture of the fetal membranes during labour.

Animals↗

PubMed2004

NF-kappaB translocation and endothelial cell activation is potentiated by macrophage-released signals co-secreted with TNF-alpha and IL-1beta.

OBJECTIVE AND METHODS: Over-expression of the immune response can lead to pathological conditions such as septic shock or chronic inflammation. Endothelial cell activation by pro-inflammatory products of activated macrophages plays a key role in these conditions. Here we examine the response of primary human endothelial cells (HUVEC) to conditioned media (CM) obtained from LPS-activated macrophages. We further characterized the translocation of NF-kappaB in the presence of CM by studying the degradation rate of individual IkappaB isoforms. RESULTS: We show that, as expected, CM induced NF-kappaB translocation, as well as adhesion capacity in HUVEC. We further show that this response is critically dependent on TNF-alpha and IL1beta naturally present in the CM. However, both the amplitude of NF-kappaB translocation and adhesiveness observed with CM were well beyond the saturation levels attained after the sole stimulation with recombinant TNF-alpha and IL-1beta, either separately or together. Our results show that CM induced a faster degradation of the IkappaB-beta and IkappaB-epsilon isoforms than the recombinant cytokines, leading to an enhanced recruitment of NF-kappaB activity. CONCLUSIONS: The above results suggest that the physiological context of factors co-secreted by LPS-activated macrophages enhances TNF-alpha mediated endothelial activation.

Animals↗

PubMed2003

Collagen synthesis during pregnancy, vitamin C availability, and risk of premature rupture of fetal membranes.

OBJECTIVE: To examine the relationship between plasma and leukocyte concentration of ascorbic acid and collagen type I propeptide C during pregnancy and subsequent premature rupture of membranes (PROM). METHODS: Fifteen women with PROM and 26 controls were compared for plasma and leukocyte concentration of vitamin C and for Pro-C during pregnancy. RESULTS: A statistically significant difference in maternal leukocyte ascorbic acid concentration was found between the two groups at week 28 of gestation (P50 was 16.90 for PROM group vs. 21.46 for control group; P>0.05). Increased risk for PROM (odds ratio, 10.99; 95% confidence interval, 2.40-49.91) was found with elevated concentrations of Pro-C at week 16 of gestation. CONCLUSIONS: A higher rate of collagen synthesis early in pregnancy was demonstrated in PROM cases. However, no correlation with ascorbic acid availability was found. This study supports the findings of others that collagen metabolism disturbances are associated with PROM.

Ascorbic Acid↗

PubMed2003

In-vitro secretion of proinflammatory cytokines by human amniochorion carrying hyper-responsive gene polymorphisms of tumour necrosis factor-alpha and interleukin-1beta.

The identification of polymorphisms in genes encoding proinflammatory cytokines that affect transcription or the secretion rate has opened new ways to understand the variation in responses to infection during pregnancy. In this study, human amniochorion carrying hyper-responsive alleles of tumour necrosis factor-alpha (TNF-alpha: TNF*2 at -308) and interleukin-1beta (IL-1beta: IL-1*2 at +3953) were stimulated in vitro with bacterial lipopolysaccharide (LPS) and compared with tissues carrying the common alleles (TNF*1 and IL-1*1). Fetal membranes carrying the TNF*1 allele displayed an identical dose-response pattern to tissues carrying a TNF*2 allele, except at the highest dose of LPS tested (50 ng/ml) there was a significantly greater production of TNF-alpha in the presence of a TNF*2 allele. Membranes carrying the IL-1*2 polymorphism secreted IL-1beta in a dose-response curve that was different from IL-1* tissues when challenged with 5, 10 and 50 ng/ml LPS. These observations support the hypothesis that reproductive tissues carrying hyper-responsive proinflammatory cytokine genes may over-respond to intrauterine infection secreting higher amounts of cytokines, which in turn, may lead to adverse pregnancy outcomes.

Amnion↗

PubMed2000

[Tumor necrosis factor-alpha and interleukin-1 beta in maternal, fetal and retroplacental intravascular compartments at term and preterm labor].

Neonato preterm birth (before 37 pregnancy weeks) account more than 80% perinatal deaths not attributable to congenital malformations. Preterm and term labor full mechanisms are unknown at present. Proinflammatory cytokinesis direct participation have been involved in the phenomena by several experimental evidence. The study's aim was to determine TNF-alpha and IL-1 beta concentration at maternal, fetal and fetal-maternal vascular compartments in women with term and preterm delivery and in women at term childbirth without labor. TNF-alpha and IL-1 beta concentration were determinated by commercial immunoassay. TNF-alpha concentration showed a tendency to be in more proportion at fetal and fetal-maternal compartments in preterm and term childbirth groups versus TNF-alpha concentration in term group without labor at same places. IL-1 beta concentration showed same tendency of increase than TNF-alpha in preterm and term childbirth groups, but alone at fetal-maternal compartment. Statistical difference were not documented at any compartment or group compared. Data allow to identify fetal-maternal compartments as target places where TNF-alpha and IL-1 beta were synthesized. Gradient concentration synthesis of cytokinesis allows to intend fetus as TNF-alpha initial producer.

Adult↗

PubMed1998

Assessment of the safety of intrauterine instillation of heated saline for endometrial ablation.

OBJECTIVE: To evaluate the safety of pressure, temperature-controlled, continuously circulating hot saline (EnAbl system, InnerDyne Medical, Sunnyvale, CA) for endometrial ablation using the in vivo human uterus. DESIGN: Clinical safety study. SETTING: An academic research environment. PATIENTS: Eleven women undergoing abdominal hysterectomy because of abnormal uterine bleeding. INTERVENTION: Before uterine removal, endometrial cavities were exposed to 15 minutes of recirculatory normal saline heated to 70-85 degrees C. MAIN OUTCOME MEASURE(S): The uteri were analyzed for extent of thermal damage using standard histopathological techniques and tissue viability histochemical staining. Intrauterine pressures and serosal and subserosal temperatures were continuously monitored by computer. RESULT(S): In each treated specimen, histochemical staining demonstrated a depth of necrosis that extended through the entire endometrium and approximately 1-2 mm into the myometrium. The control specimen showed no thermal or mechanical damage. There were no observed negative effects or related complications with this system. CONCLUSION(S): The computer-controlled system employing continuously circulating hot saline is an effective method to destroy the endometrium. In four cases with clearly patent tubes, no spill was observed. In all 11 patients, serosal and subserosal temperatures were within safe levels (mean temperature, 37 degrees C).

Adult↗

PubMed1998

Modulation of 72-kilodalton type IV collagenase (Matrix metalloproteinase-2) by ascorbic acid in cultured human amnion-derived cells.

Extensive research has been done to investigate the effects of nutrients on placental and fetal development. It is now evident that environmental factors such as diet may exert a profound effect on gene expression during pregnancy. A low intake of vitamin C during pregnancy has been linked to a higher risk of premature rupture of the membranes (PROM) because of its well-known role in collagen biosynthesis. Here we report a new effect of ascorbic acid acting as a modulator of the 72-kDa type IV collagenase (matrix metalloproteinase-2; MMP-2). MMP-2 expression/activity is down-regulated by vitamin C in human amnion cultured cells. The regulatory effect is exerted at the transcriptional level and is specific for MMP-2. Matrix metalloproteinases are implicated in tissue remodeling, and our results allow us to suggest a molecular mechanism that relates poor availability of vitamin C during pregnancy and the development of PROM.

Amniotic Fluid↗

PubMed1998

Changes in matrix metalloproteinases during the evolution of interstitial renal fibrosis in a rat experimental model.

The aim of the present study was to analyze the matrix metalloproteinase (MMP) activity during the evolution of interstitial renal fibrosis in a rat experimental model of unilateral ureteral obstruction. The interstitial type I collagenase and the gelatinolytic activities were analyzed by radiolabeled substrate degradation. Interstitial collagenase activity was low at all times while gelatinolytic activity increased on day 6 of evolution, with a decrease in activity from this point. The use of organomercurials revealed the presence of latent enzyme in all cases. Normal kidney samples contained MMP-9 in both active and proenzyme forms as revealed by zymography. On day 3 MMP-9 dimers appeared, and increased activity was observed until day 6. A decrease in the gelatinolytic activity was detected from days 9-15 of evolution. This observation was confirmed by Western blot analysis that revealed the presence of proMMP-9 mainly from days 6-12. Tissue inhibitor of metalloproteinase-1 (TIMP-1) was also detected alone and in combination with proMMP-1 and MMP-1, particularly from days 6-15 of evolution. The presence of MMP-9 and MMP-1 was detected in the cytoplasm of cortical tubular cells by immunohistochemistry, with no difference between the experimental and the normal kidneys. There was also an increase in collagen concentration from day 3 after surgery that increased during the entire evolution of the experimental model. This work reveals that the decrease in the MMP-9 and MMP-1 enzymatic activity, due to their interaction with TIMP-1 and to the lack of activation of the latent forms, may participate in the excessive collagen deposit during the evolution of experimental interstitial renal fibrosis.

Animals↗

PubMed1997

[Endometrial ablation by liquid heat using the EnAbl system in patients after abdominal hysterectomy. Study of safety].

Security and efficacy of an EnABL, were evaluated; this system had been designed for endometrial ablation by liquid heat in uterine cavity. Eleven patients were included, from the Outpatient Department (INP), programmed for different causes that objectives of this study for abdominal hysterectomy due to abnormal uterine bleeding. The study was approved by Ethical and Scientific Committees. Each patient had preoperative studies, endometrial biopsy, PAP, and ultrasound, in series. The patients with uterus larger than 14 cm, possible cancer; younger than 18 year, or with active bleeding at the time of hysterectomy, were excluded. Each patient received a schema of standard endometrial suppression. The system was applied previously to TAH; 2271 measurements of temperature at one minute intervals were done during liquid heat application. Surgical pieces were sent to histology to analyze the thermic damage through macroscopic aspect, HE tinction and an immunohistochemical cellular viability of NADH test. The thermal damage by macroscopic appearance was 4.33 +/- 1.03 mm, with HE of 4.15 +/- 0.75 mm and with the tinction of NADH of 4.25 mm +/- 0.79. The maximal damage by macroscopic appearance was 4.33 +/- 1.03 mm, with HE of 4.15 +/- 0.75 mm, and with NADH it was 4.25 mm +/- 0.79. The maximal damage was by macroscopic appearance was 6.0 mm and the minimal one was 2.0 mm. In evaluation by H/E, maximal was 5.1 mm and the minimal one was 2.3 mm. In NADH tinction maximal was 4.25 and minimal 2.4 mm. Horizontal analysis showed eight patients with major thermal damage at 4 mm; and two patients with lesser damage at 4 mm. Sub-serous temperatures measured with thermopairs, were done 1504 times, in total. Average was 36.28 degrees C, ranging 35 to 37 degrees C. Maximal temperature was 45 degrees C, 1-2 mm, bellow from serous surface of uterus, and the last one was 28 degrees C. The serous temperatures measured by infrared radiation were done 767 times with an average temperature of 34.6 degrees C. Average was 34-35 C, with standard deviation of 1-2 degrees C. Maximal temperature was 40 degrees C and minimal 29 degrees C. There were no adverse effects. This study shows that EnAbl system is an efficacious method.

Catheter Ablation↗

PubMed1996

Increased matrix metalloproteinase activity and reduced tissue inhibitor of metalloproteinases-1 levels in amniotic fluids from pregnancies complicated by premature rupture of membranes.

OBJECTIVES: It has been suggested that increased matrix metalloproteinases activity promotes the weakening of the amniochorion during normal and premature rupture of membranes. This study was designed to determine whether levels of matrix metalloproteinases and the tissue inhibitor of metalloproteinases-1 in amniotic fluid change in a pattern consistent with this hypothesis. STUDY DESIGN: Gelatinolytic activity, measured by a soluble substrate assay and zymography, and the concentrations of tissue inhibitor of metalloproteinases-1 were estimated in amniotic fluid obtained from (1) normal early gestations, (2) normal term pregnancies with labor, (3) normal term pregnancies without labor, and (4) pregnancies complicated by premature rupture of membranes. The 92 kd type IV collagenase (matrix metalloproteinase-9) was also detected in amniotic fluid by Western blotting. RESULTS: Matrix metalloproteinase activities were higher in amniotic fluid from normal term pregnancies with labor and pregnancies complicated by premature rupture of membranes than from early pregnancies and term gestations without labor. The amniotic fluid from term pregnancies with labor or pregnancies with premature rupture of membranes contained several gelatinases, as revealed by zymography. The major amniotic fluid gelatinolytic activity in premature rupture of membranes and term pregnancies with labor corresponded to matrix metalloproteinase-9. Tissue inhibitor of metalloproteinases-1 concentrations were highest in early-pregnancy amniotic fluid, followed by term gestation with labor, term gestation without labor, and premature rupture of membranes. CONCLUSIONS: Normal labor and premature rupture of membranes are associated with increased levels of matrix metalloproteinases, particularly matrix metalloproteinase-9 in amniotic fluid. Premature rupture of membranes is associated with reduced levels of tissue inhibitor of metalloproteinases-1. The imbalance between matrix metalloproteinases and tissue inhibitor of metalloproteinases-1 in amniotic fluid may reflect a disorder that promotes premature rupture of membranes.

Amniotic Fluid↗

PubMed1996

Endometrial Ablation with the EnAbl System

We assessed the safety of a new method of endometrial ablation using heated saline in 11 patients who were undergoing elective hysterectomy. The EnAbl system consists of a controller, computer, and disposable, flexible probe that provides in situ heating and circulation of the saline while maintaining a tight seal at the internal os. The system's low pressure precluded ligation of the oviducts. Temperatures of the saline, uterine serosa, subserosa, and oviducts were monitored throughout the 15-minute procedure in all 10 treatments and 1 control. Histology revealed an average depth of treatment of 4 mm, including necrosis of the surface myometrium. Average depth of necrosis was consistent throughout the cavity regardless of the presence of insignificant myomas. Serosal, subserosal, and oviduct temperatures remained low (&lte;45° C) during the 10 treatments of 70 to 85° C. We believe that this method provides an efficacious depth of treatment while maintaining safe serosal temperatures.

Journal Article↗

PubMed1996

[Peritoneal immune response in endometriosis].

The systematic analysis of immunity status in the peritoneum of women with endometriosis, is presented. Twenty five patients were studied, distributed as follows: A. Endometriosis, B. Sterility of non identified cause. In all the patients, peritoneal fluid was obtained (PF) during diagnostic laparoscopy, and a sample of peripheral blood was taken simultaneously. Both samples were processed analysis of lymphocytes subpopulations (ALS) by flux cytometry using monoclonal antibodies with reactivity to lymphocytes T total (CD+), lymphocytes B (CD19+), auxiliatory/inductory (CD3+CD4+), suppressor/cytotoxic (CD3+CD8+) and NK (CD3+CD16+ + 56+). The peritoneal ALS of both groups were characterized by a clear lymphocyte B diminution, moderate diminution of activators; a considerable increase of suppressors; altered CD4+/CD8+ relation in favour of suppression and NK diminution when comparing with its own blood compartment. All of these values were identical for both groups, and the only significant difference was found when comparing activated lymphocytes T subpopulation that was lesser in PF of women with endometriosis. This is the only fact that backs up the existence of altered immunity in the peritoneum of these patients, that affects the expression of activated lymphocytes. However, taking as a criterium the rest of subpopulations, in endometriosis as well as in ECNI the microenvironment goes for suppression and they are not distinguishable among them. On other side, it started signal characterization that conditions suppression induction for lymphocytes activation in peritoneal environment of women with endometriosis. Ten samples of PF of patients using peripheral purified lymphocytes by density gradient of voluntary donnors, normal, fertile, were analyzed. Cells were cultivated and stimulated in vitro with concanavaline A in presence of timidine 3H. In experimental holes PF was added at dose-response concentration, and it was evaluated as the difference in synthesis of radioactive ADN against the incubated cells in absence of PF. It was possible to demonstrate the presence of associated factors in PF of patients with endometriosis that inhibit proliferation of lymphocytes stimulated by Con A, and not so in samples of ECNI. With these factors one supposes the presence of soluble signals that condition local immunological suppression.

Adult↗

PubMed1995

Collagen metabolism in human aqueous humor from primary open-angle glaucoma. Decreased degradation and increased biosynthesis play a role in its pathogenesis.

OBJECTIVE: To explore the influence of aqueous humor from patients with glaucoma on collagen turnover. METHODS: The aqueous humor of patients with primary open-angle glaucoma (POAG), chronic angle-closure glaucoma, congenital glaucoma, neovascular glaucoma, and senile cataract (control group) was analyzed for its capacity to induce fibroblast proliferation, collagen synthesis, collagenolytic activity, and production of tissue inhibitor of metalloproteinase-1. All data were analyzed using the Mann-Whitney U test. RESULTS: Aqueous humor derived from patients with POAG induced a significant decrease of functional collagenase activity (mean +/- SE, 9.12 +/- 1.33 microgram of degraded collagen per milligram of incubated protein vs 20.94 +/- 4.14 micrograms from the control group, P < .05). The enzymatic activity in the other types of glaucoma was similar to that of controls. The POAG samples had a significantly higher concentration of tissue inhibitor of metalloproteinase-1 (mean +/- SE, 3.11 +/- 0.58 vs 0.91 +/- 0.13 micrograms/mL from controls; P < .05). The amount of immunoreactive tissue inhibitor of metalloproteinase-1 found in the other three groups was not significantly different from the control. Aqueous humor stimulated fibroblast proliferation in all cases, but significant differences were not observed between the POAG samples (mean +/- SE, 20,285 +/- 4642 cpm/mg of incubated protein) and the control group samples (26,550 +/- 3688 cpm/mg of incubated protein). Primary open-angle glaucoma fluids increased collagen synthesis significantly compared with the control group (mean +/- SD, 3352 +/- 630 vs 985 +/- 285, P < .05), and the other groups. CONCLUSIONS: An increase of collagen synthesis and a decrease of collagen degradation may contribute to an excessive deposit of collagen with loss of the trabecular cells during the development of POAG, and aqueous humor must be considered as a microenvironment that affects the metabolism or function of the trabecular meshwork or both.

Adult↗

PubMed1995

Progesterone induces human sperm chemotaxis.

OBJECTIVE: To characterize the molecular nature of the chemotactic signal for sperm contained in human follicular fluid (FF). DESIGN: Follicular fluid was fractionated and several procedures were followed to the physicochemical initial characterization of sperm chemotactic compound(s). MAIN OUTCOME MEASURE: Relative chemotactic activity of each fraction was measured in a double chamber device. RESULTS: Sperm chemotaxis was found to be associated with a lipid-like molecule extracted from FF. Several steroids were assayed individually and only P showed sperm chemotactic properties in dose-response curves. CONCLUSIONS: In this paper we present experimental evidence to support the hypothesis that P, the main steroid component of FF, is a mediator of sperm chemoattraction in human beings.

Chemotactic Factors↗

PubMed1995

Influence on collagen metabolism of vitreous from eyes with proliferative vitreoretinopathy.

PURPOSE: Proliferative vitreoretinopathy (PVR) is characterized by cell proliferation and membrane formation on the vitreoretinal cavity of the eye. The membranes are composed of extracellular matrix, mainly collagen type I. To explore the possible mechanisms involved in PVR membrane formation, the authors analyzed the role of vitreous humor on collagen turnover. METHODS: The authors studied vitreous samples from ten patients with PVR and from five donor eyes (keratoplasty) as the control group. Human lung fibroblasts were used to study the influence of vitreous on collagen synthesis and cell proliferation. Neutralizing antibodies against transforming growth factor-beta 2 (TGF-beta 2) were used to inhibit the fibroblast collagen synthesis induced by the vitreous samples. Collagenolytic activity was analyzed in vitreous fluid using 3H-labeled collagen. RESULTS: The authors found that samples obtained from patients with PVR significantly increased collagen synthesis (2979 +/- 963.26 versus 800 +/- 232 dpm of 3H-proline incorporated per milligram of vitreous-incubated protein; P < 0.00043), without affecting fibroblast replication. The collagen synthesis induced by the vitreous samples was inhibited by anti-TGF-beta 2 antibodies in both groups (0 and 481 +/- 59 dpm of 3H-proline incorporated per milligram of vitreous-incubated protein for control and PVR samples, respectively). Collagenolytic activity was considerably lower in vitreous derived from PVR samples compared with the control group (19.9 +/- 20.3 versus 234.1 +/- 19.1 micrograms of degraded collagen per milligram of vitreous-incubated protein; P < 0.0032). CONCLUSION: These results suggest that a combined mechanism, including an increase of collagen synthesis mediated at least in part by TGF-beta 2 and a decrease of collagen degradation, may contribute to the exaggerated deposition of collagen observed in PVR membranes, and that vitreous should be considered as a part of the microenvironment that is participating actively in the pathogenesis of this vitreoretinal disorder.

Cell Division↗

PubMed1995

92-kDa gelatinase (matrix metalloproteinase-9) is induced in rat amnion immediately prior to parturition.

The fetal membranes undergo striking changes in structure before delivery that involve catabolism of the extracellular matrix. To investigate the role of specific enzymes in this process, we examined gelatinase activities in rat amnion, visceral yolk sac placenta, and placenta and amniotic fluid between Days 18-21 of pregnancy. Matrix metalloproteinase (MMP)-2 was present in amnion on all days, and its activity increased slightly on Day 21. The 92-kDa gelatinase, MMP-9, was not detected on Days 18-20 but appeared by the morning of Day 21. There was a marked increase in MMP-9 mRNA in the amnion on Day 20, preceding the appearance of MMP-9 activity. Western blotting confirmed an increase in MMP-9 protein in amnion on Day 21. MMP-2 and MMP-9 activities were detected in extracts of whole yolk sac placenta, placenta, and amniotic fluid, but there were no striking changes in these gelatinases between Days 18 and 21. However, the capsular regions of the visceral yolk sac placentae, which thin and rupture during labor, did show higher MMP-9 activity on Day 21 than on Days 18 and 20. We suggest that the striking increase in MMP-9 expression in amnion and possibly the capsular region of the visceral yolk sac placenta approximately 12 h prior to delivery is responsible, in part, for the alterations in the structure of these fetal membranes before parturition.

Amnion↗

PubMed1995

92-kd type IV collagenase (matrix metalloproteinase-9) activity in human amniochorion increases with labor.

To determine whether specific collagenolytic enzymes are expressed in human fetal membranes with labor, we examined gelatinase activity in extracts of amniochorion by zymography. The 92-kd gelatinase (MMP-9) was barely detectable in extracts of fetal membranes before the onset of labor but was readily demonstrable in extracts prepared from membranes isolated from laboring women or membranes collected immediately after delivery. In contrast, the 72-kd gelatinase (MMP-2) was detectable in extracts from pre- and post-labor membranes. Ethylenediaminetetracetic acid and the tissue inhibitor of metalloproteinases, TIMP-1, inhibited the gelatinase activities detected by zymography, confirming that the enzymes are metalloproteinase. Assay of amniochorion gelatinase activity using a radiolabeled denatured collagen substrate revealed a more than twofold increase in activity comparing pre-labor with post-labor fetal membrane extracts. A function-blocking anti-MMP-9 monoclonal antibody inhibited pre-labor membrane gelatinase activity by approximately 11.5%, which was only slightly greater inhibition than observed with irrelevant monoclonal antibodies. However, post-labor membrane gelatinase activity was reduced by 53% by the function-blocking antibody, indicating that MMP-9 is a major contributor to the increased gelatinase activity extractable from post-labor membranes. Western blot analyses demonstrated increased MMP-9 protein in amniochorion extracts after onset of labor. MMP-9 protein and mRNA were co-localized in amnion epithelium, underlying macrophages and chorion laeve trophoblast and decidual cells after labor. We conclude that 1) MMP-9 activity and protein in human amniochorion increases with labor and 2) MMP-9 is expressed by amnion epithelium, macrophages and chorion laeve trophoblast and decidual cells. The increased expression of MMP-9 may result in degradation of the extracellular matrix of the fetal membranes and facilitate their rupture under both physiological and pathological conditions.

Amino Acid Sequence↗

PubMed1995

Extraction and partial characterization of a low molecular weight collagenase from normal rat kidney.

A matrix metalloproteinase with selective affinity for collagen was identified and partially purified from normal rat kidney. A two-step purification procedure consisting of gel filtration and affinity chromatography on Sepharose 4B-collagen resulted in an increase in specific activity of more than 3,000 times. The partially purified collagenase cleaved type I collagen and also showed low gelatinolytic activity. The enzyme required Ca2+ and revealed a neutral pH optimum; it was not inhibited by thiol or serineprotease inhibitors. Its activity was fully blocked using recombinant tissue inhibitor of metalloproteinases-1. Using SDS-PAGE and zymography, the estimated Mr of the collagenase was 16.5 x 10(3).

Animals↗