Matrix metalloproteinases and their tissue inhibitors in hypertension-related pregnancy complications

Behind the Curtain of Abnormal Placentation in Pre-Eclampsia: From Molecular Mechanisms to Histological Hallmarks

Successful human pregnancy needs several highly controlled steps to guarantee an oocyte's fertilization, the embryo's pre-implantation development, and its subsequent implantation into the uterine wall. The subsequent placenta development ensures adequate fetal nutrition and oxygenation, with the trophoblast being the first cell lineage to differentiate during this process. The placenta sustains the growth of the fetus by providing it with oxygen and nutrients and removing waste products. It is not surprising that issues with the early development of the placenta can lead to common pregnancy disorders, such as recurrent miscarriage, fetal growth restriction, pre-eclampsia, and stillbirth. Understanding the normal development of the human placenta is essential for recognizing and contextualizing any pathological aberrations that may occur. The effects of these issues may not become apparent until later in pregnancy, during the mid or advanced stages. This review discusses the process of the embryo implantation phase, the molecular mechanisms involved, and the abnormalities in those mechanisms that are thought to contribute to the development of pre-eclampsia. The review also covers the histological hallmarks of pre-eclampsia as found during the examination of placental tissue from pre-eclampsia patients.

Circulating levels of tissue inhibitor of metalloproteinase 3, a protein with inhibitory effects on angiogenesis, are increased in pre-eclampsia

OBJECTIVE

To assess and compare circulating tissue inhibitor of metalloproteinase 3 (TIMP-3) concentrations between women with pre-eclampsia and healthy pregnant women. We also aimed to determine the relationships between circulating TIMP-3 and matrix metalloproteinase 2 (MMP-2), MMP-9, TIMP-1, and TIMP-2 concentrations in pre-eclampsia.

METHODS

A primary case-control study included patients with pre-eclampsia (n = 219) and gestational hypertension (n = 118), healthy pregnant women (n = 214), and non-pregnant women (n = 66), and a replication case-control study included patients with pre-eclampsia (n = 177) and healthy pregnant women (n = 124), all from southeastern Brazil. Plasma TIMP-3, MMP-2, MMP-9, TIMP-1, and TIMP-2 concentrations were assessed using commercially available enzyme-linked immunosorbent assay kits, and the relationships between them were analyzed using Spearman's correlation.

RESULTS

In our primary study, patients with pre-eclampsia and gestational hypertension exhibited increased TIMP-3 concentrations compared with healthy pregnant women (both P < 0.0001) and non-pregnant women (both P < 0.001). These findings were confirmed in the replication study, showing elevated TIMP-3 concentrations in women with pre-eclampsia versus healthy pregnant women (P < 0.001). We found no difference in TIMP-3 concentrations between early-onset and late-onset pre-eclampsia. Moreover, TIMP-3 concentrations were significantly correlated with plasma concentrations of TIMP-1 (r = 0.2333; P = 0.0086) and MMP-2 (r = 0.2159; P = 0.0156) in pre-eclampsia.

CONCLUSIONS

Circulating TIMP-3 concentration is increased in women with pre-eclampsia compared with healthy pregnant women, and it is positively correlated with plasma MMP-2 and TIMP-1 concentrations in pre-eclampsia.

Kisspeptin Is Upregulated at the Maternal-Fetal Interface of the Preeclamptic-like BPH/5 Mouse and Normalized after Synchronization of Sex Steroid Hormones

Insufficient invasion of conceptus-derived trophoblast cells in the maternal decidua is a key event in the development of early-onset preeclampsia (PE), a subtype of PE associated with high maternal and fetal morbidity and mortality. Kisspeptins, a family of peptides previously shown to inhibit trophoblast cell invasion, have been implicated in the pathogenesis of early-onset PE. However, a role of kisspeptin signaling during the genesis of this syndrome has not been elucidated. Herein, we used the preeclamptic-like BPH/5 mouse model to investigate kisspeptin expression and potential upstream regulatory mechanisms in a PE-like syndrome. Expression of the kisspeptin encoding gene, Kiss1, and the 10-amino-acid kisspeptide (Kp-10), are upregulated in the non-pregnant uterus of BPH/5 females during diestrus and in the maternal-fetal interface during embryonic implantation and decidualization. Correspondingly, the dysregulation of molecular pathways downstream to kisspeptins also occurs in this mouse model. BPH/5 females have abnormal sex steroid hormone profiles during early gestation. In this study, the normalization of circulating concentrations of 17β-estradiol (E2) and progesterone (P4) in pregnant BPH/5 females not only mitigated Kiss1 upregulation, but also rescued the expression of multiple molecules downstream to kisspeptin and ameliorated adverse fetoplacental outcomes. Those findings suggest that uterine Kiss1 upregulation occurs pre-pregnancy and persists during early gestation in a PE-like mouse model. Moreover, this study highlights the role of sex steroid hormones in uteroplacental Kiss1 dysregulation and the improvement of placentation by normalization of E2, P4 and Kiss1.

Comprehensive analyses of DNA methylation of the TIMP3 promoter in placentas from early-onset and late-onset preeclampsia

Preeclampsia (PE) is classified into late-onset (LOPE) or early-onset (EOPE) according to gestational age of onset (≥34 or <34 weeks, respectively), and into preterm and term (delivery at <37 or ≥37 weeks, respectively). An imbalanced expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) impairs proper placentation in PE, and DNA methylation (DNAm) may affect their expression. We performed comprehensive analyses of DNAm and TIMP3 expression in placentas from PE reclassified into EOPE, LOPE, and term PE. We identified significant differentially methylated probes at the TIMP3 promoter in PE (28), EOPE (38), LOPE (20), and term PE (4) compared to controls, and in EOPE vs. LOPE (8). Moreover, we found a hypomethylation >70% in all groups (except EOPE vs. LOPE) and an increased TIMP3 expression in corresponding placental samples from PE, EOPE and LOPE compared to controls (p<0.05). Our findings highlight the role of DNAm of the TIMP3 promoter region regarding an epigenetic mechanism in PE.

Role of Gelatinases MMP-2 and MMP-9 in Healthy and Complicated Pregnancy and Their Future Potential as Preeclampsia Biomarkers

Gelatinases (matrix metalloproteinase-2 and -9) are enzymes from the matrix metalloproteinases (MMPs) family, which are associated with collagen degradation. MMP-2 is capable of cleaving gelatine, types I and IV collagens, while MMP-9 is incapable of direct proteolysis of collagen I and digests collagen type IV. MMP-2 and -9 are both important regulators of vascular and uterine remodeling in a healthy pregnancy. Alterations in the collagen structure of the uterus and spiral arteries are observed in women with hypertensive disorders of pregnancy. Dysregulation of MMP-2 and MMP-9 has been implicated in abnormal vasodilation, placentation, and uterine expansion in preeclampsia. Early preeclampsia detection is paramount for risk stratification and prevention of further complications. Understanding the role of MMP-2 and-9 in uteroplacental and vascular remodeling could help design new approaches for prediction and management of preeclampsia. This review presents a general survey of MMP-2 and MMP-9 faulty regulation and impaired collagen types I and IV turnover in complicated pregnancies. Their potential role as circulating markers for diagnosis, prognosis, and monitoring of preeclampsia development is discussed as well.

The Roles of Matrix Metalloproteinases and Their Inhibitors in Human Diseases

Matrix metalloproteinases (MMPs) are a family of zinc-dependent extracellular matrix (ECM) remodeling endopeptidases that have the capacity to degrade almost every component of the ECM. The degradation of the ECM is of great importance, since it is related to embryonic development and angiogenesis. It is also involved in cell repair and the remodeling of tissues. When the expression of MMPs is altered, it can generate the abnormal degradation of the ECM. This is the initial cause of the development of chronic degenerative diseases and vascular complications generated by diabetes. In addition, this process has an association with neurodegeneration and cancer progression. Within the ECM, the tissue inhibitors of MMPs (TIMPs) inhibit the proteolytic activity of MMPs. TIMPs are important regulators of ECM turnover, tissue remodeling, and cellular behavior. Therefore, TIMPs (similar to MMPs) modulate angiogenesis, cell proliferation, and apoptosis. An interruption in the balance between MMPs and TIMPs has been implicated in the pathophysiology and progression of several diseases. This review focuses on the participation of both MMPs (e.g., MMP-2 and MMP-9) and TIMPs (e.g., TIMP-1 and TIMP-3) in physiological processes and on how their abnormal regulation is associated with human diseases. The inclusion of current strategies and mechanisms of MMP inhibition in the development of new therapies targeting MMPs was also considered.

MicroRNA‑491‑5p inhibits trophoblast cell migration and invasion through targeting matrix metalloproteinase‑9 in preeclampsia

Insufficient invasion of trophoblasts is correlated with the development of preeclampsia (PE). MicroRNA (miR)-491-5p has been reported to be implicated in human cancer cell invasion; however, whether miR-491-5p is involved in the development of PE remains largely unclear. The aim of the present study was to investigate the role of miR-491-5p in trophoblastic invasion in vitro and to determine its underlying mechanism of action. The expression levels of miR-491-5p were validated using reverse transcription-quantitative PCR. The effects of miR-491-5p on trophoblast cell invasion were evaluated in vitro. Then, the association between miR-491-5p and its downstream target was investigated in both cell lines and clinical specimens. miR-491-5p expression levels were observed to be significantly increased in the placental tissues from patients with PE. The invasive capacity of HTR-8/SVneo trophoblast cells was suppressed following the upregulation of miR-491-5p and increased following the inhibition of miR-491-5p. Matrix metalloproteinase-9 (MMP-9), a well-known regulator of trophoblast cell invasion, was discovered to be a direct target of miR-491-5p in HTR-8/SVneo trophoblast cells. Moreover, miR-491-5p expression levels were found to be inversely correlated with MMP-9 expression levels in placental tissues from patients with PE. The overexpression of MMP-9 partly attenuated the inhibitory effects of miR-491-5p on HTR-8/SVneo trophoblast cells invasion. Collectively, these findings suggested that the aberrant expression of miR-491-5p may contribute to PE through suppressing trophoblast invasion, thus highlighting the novel roles of miR-491-5p in the molecular pathogenesis of PE. The present study also showed that the miR-491-5p/MMP-9 axis may be an effective biomarker or a viable drug target for therapeutic intervention in PE.

Whole-Genome Uterine Artery Transcriptome Profiling and Alternative Splicing Analysis in Rat Pregnancy

During pregnancy, the uterine artery (UA) undergoes extensive remodeling to permit a 20–40 fold increase in blood flow with associated changes in the expression of a multitude of genes. This study used next-gen RNA sequencing technology to identify pathways and genes potentially involved in arterial adaptations in pregnant rat UA (gestation day 20) compared with non-pregnant rat UA (diestrus). A total of 2245 genes were differentially expressed, with 1257 up-regulated and 970 down-regulated in pregnant UA. Gene clustering analysis revealed a unique cluster of suppressed genes implicated in calcium signaling pathway and vascular smooth muscle contraction in pregnant UA. Transcription factor binding site motif scanning identified C2H2 ZF, AP-2 and CxxC as likely factors functional on the promoters of down-regulated genes involved in calcium signaling and vascular smooth muscle contraction. In addition, 1686 genes exhibited alternative splicing that were mainly implicated in microtubule organization and smooth muscle contraction. Cross-comparison analysis identified novel genes that were both differentially expressed and alternatively spliced; these were involved in leukocyte and B cell biology and lipid metabolism. In conclusion, this first comprehensive study provides a valuable resource for understanding the molecular mechanism underlying gestational uterine arterial adaptations during pregnancy.

Reductions of Circulating Nitric Oxide are Followed by Hypertension during Pregnancy and Increased Activity of Matrix Metalloproteinases-2 and -9 in Rats

Hypertensive pregnancy has been associated with reduced nitric oxide (NO), bioavailability, and increased activity of matrix metalloproteinases (MMPs). However, it is unclear if MMPs activation is regulated by NO during pregnancy. To this end, we examined activity of MMP-2 and MMP-9 in plasma, placenta, uterus and aorta, NO bioavailability, oxidative stress, systolic blood pressure (SBP), and fetal-placental development at the early, middle, and late pregnancy stages in normotensive and Nω-Nitro-L-arginine methyl-ester (L-NAME)-induced hypertensive pregnancy in rats. Reduced MMP-2 activity in uterus, placenta, and aorta and reduced MMP-9 activity in plasma and placenta with concomitant increased NO levels were found in normotensive pregnant rats. By contrast, increased MMP-2 activity in uterus, placenta, and aorta, and increased MMP-9 activity in plasma and placenta with concomitant reduced NO levels were observed in hypertensive pregnant rats. Also, elevated oxidative stress was displayed by hypertensive pregnant rats at the middle and late stages. These findings in the L-NAME-treated pregnant rats were also followed by increases in SBP and associated with fetal growth restrictions at the middle and late pregnancy stages. We concluded that NO bioavailability may regulate MMPs activation during normal and hypertensive pregnancy.

RBP4 regulates trophoblastic cell proliferation and invasion via the PI3K/AKT signaling pathway

Insufficient trophoblast invasion is associated with preeclampsia (PE) development. Retinol-binding protein 4 (RBP4) is important for regulating cell differentiation, migration and invasion. The aim of the present study was to determine RBP4 expression and function in the human placenta and to examine the underlying mechanisms. In the present study, RBP4 expression was determined in serum samples from 35 pregnant women with PE and 30 healthy pregnant women using enzyme-linked immunosorbent assays. Cell proliferation was assessed by Cell Counting Kit-8 assays, and cell invasion was examined with transwell assays. RBP4 concentrations were significantly lower in the PE group when compared with the control group. RBP4 overexpression enhanced HTR8/SVneo cell proliferation and invasion, and the levels of phosphorylated (p-) phosphoinositide 3-kinase (PI3K) and p-protein kinase B (AKT) in HTR8/SVneo cells. RBP4 knockdown significantly inhibited HTR8/SVneo cell proliferation and invasion, and repressed the expression of matrix metalloproteinases. In addition, RBP4 knockdown significantly reduced the levels of p-PI3K and p-AKT in HTR8/SVneo cells. Taken together, the results of the present study demonstrated that RBP4 overexpression increased HTR8/SVneo cell proliferation and invasion by suppressing PI3K/AKT signaling and RBP4 knockdown induced the opposite effects.

Celastrol attenuates symptoms of preeclampsia in rats by inhibiting matrix metalloproteinase-9

Preeclampsia is reported in pregnant women around the world and often causes maternal/fetal mortality and morbidity. In the current study, we assessed the efficacy of celastrol on a rat preeclampsia model induced by N^ω-nitro-L-arginine methyl ester hydrochloride (L-NAME). Pregnant rats were administered L-NAME to establish preeclampsia. A total of 48 animals were randomly assigned into 4 groups (n = 12 each): control, control plus celastrol treatment (control+celastrol), preeclampsia, and preeclampsia plus celastrol. Physiological parameters including total urine protein, urine volume and blood pressure were evaluated. Urinary messenger RNA (mRNA) levels of podocin and nephrin were determined using RT-PCR. Further, levels of serum placenta growth factor (PlGF), matrix metalloproteinase (MMP)-9 and renal renal soluble fms-like tyrosine kinase-1 (sFlt-1) were also measured. In rats with preeclampsia, there were robust increases in total urine protein, urine volume and blood pressure, which were significantly attenuated in rats treated with celastrol. Urinary mRNA levels of podocin and nephrin, as well as PlGF, MMP-9 and sFlt-1, were all reversed in preeclampsia plus celastrol group compared to rats in the preeclampsia group without celastrol treatments. MMP-9 overexpression in rats completely abolished the alleviating effect of celastrol. We hereby presented the first evidence that celastrol attenuated preeclampsia symptoms in an L-NAME-induced rat model of preeclampsia through inhibition of MMP-9 expression, supporting the potential therapeutic value of celastrol in the treatment of preeclampsia.

Tetrahydrobiopterin (BH4 ): Targeting endothelial nitric oxide synthase as a potential therapy for pulmonary hypertension

PURPOSE

Pulmonary Hypertension (PH) is complex disease which is associated with endothelial and cardiac dysfunction. Tetrahydrobiopterin (BH4 ) regulates endothelial nitric oxide synthase (eNOS) to produce nitric oxide rather than superoxide which maintains normal endothelial and cardiac function. This study explores the therapeutic potential of BH4 in experimental PH.

METHODS

Monocrotaline-induced PH in rats and Hph-1 deficiency in mice were used for animal experiments. Hemodynamic measurements using pressure transducers were conducted for pulmonary and cardiac pressures, and Langendorff apparatus was used for isolated heart experiments; preventive as well as rescue treatment protocols were conducted; tissues were collected for histological and biochemical studies.

RESULTS

In vivo acute BH4 administration reduced pulmonary artery pressure (PAP) only in the MCT rat. In a Langendorff preparation, BH4 increased right ventricular systolic pressure (RVSP) in right ventricular hypertrophy (RVH) but not in control. In "prevention" therapy, BH4 (10 and 100 mg/kg) attenuated the development of PH in rat MCT model. eNOS protein levels in lung homogenates were maintained and cGMP levels were increased. In "rescue" therapy, BH4 (10 and 100 mg/kg) ameliorated pulmonary vascular muscularization in a dose-dependent manner. RVSP was reduced in RVH and pulmonary vascular muscularization was attenuated. BH4 at 10 mg/kg reduced RV myocyte diameter while BH4 at 100 mg/kg reversed it to control level. BH4 restored normal levels of eNOS protein and in a dose of 100 mg/kg enhanced lung tissue levels of BH4 , cGMP, and NO compared to placebo.

CONCLUSION

The current study provides scientific evidence for a therapeutic potential of BH4 in PH and invites further investigation.

Celastrol attenuates pain and cartilage damage via SDF-1/CXCR4 signalling pathway in osteoarthritis rats

OBJECTIVES

Celastrol has attracted wide interests for its anticancer and anti-inflammation properties, and studies have demonstrated that celastrol negatively modulates the stromal cell-derived factor-1 (SDF-1) and receptor C-X-C chemokine receptor type 4 (CXCR4) signalling. We aim in this study to investigate the effects of celastrol in osteoarthritis (OA) in vivo and explored the underlying molecular mechanisms.

METHODS

We established a monoiodoacetate (MIA)-induced rat OA model and evaluated the joint pain and cartilage damage with or without celastrol treatments. We further assessed the alterations of the SDF-1/CXCR4 pathway and cartilage-specific genes, at both mRNA and protein levels.

KEY FINDINGS

Celastrol significantly attenuated the joint pain and cartilage damage induced by MIA in OA rats and suppressed the upregulation of SDF-1/CXCR4 and associated genes caused by MIA injections. Furthermore, MIA induced a decrease in cartilage-specific genes which was also prevented by celastrol treatments.

CONCLUSIONS

Celastrol ameliorate OA in vivo as evidenced by the attenuated joint pain and less cartilage damage in OA rats given celastrol treatments, an effect mediated via suppression of the SDF-1/CXCR4 pathway.

Longitudinal characterization of renal proximal tubular markers in normotensive and preeclamptic pregnancies

Glomerular damage is common in preeclampsia (PE), but the extent and etiology of tubular injury are not well understood. The aim of this study was to evaluate tubular injury in patients with PE and to assess whether it predates clinical disease. We performed a prospective cohort study of 315 pregnant women who provided urine samples at the end of the second trimester and at delivery. This analysis included women who developed PE ( n = 15), gestational hypertension (GH; n = 14), and normotensive controls (NC; n = 44). Urinary markers of tubular injury, α1-microglobulin (A1M), retinol-binding protein (RBP), kidney-injury molecule-1 (KIM1), complement C5b-9, tissue inhibitor metalloproteinase-2 (TIMP-2), and insulin-like growth factor binding protein-7 (IGFBP-7) were measured by enzyme-linked immunosorbent assay (ELISA) and reported in relation to urine creatinine concentration. Second-trimester concentrations of all markers were similar among groups. At delivery, A1M concentrations were higher in the PE group than in the GH and NC groups as an A1M/creatinine ratio >13 (66.7, 8.3, and 35%, respectively, P = 0.01). Concentrations of C5b-9 were higher in the PE group than in the GH and NC groups (medians 9.85, 0.05, and 0.28 ng/mg, respectively, P = 0.003). KIM1, RBP, TIMP-2, and IGFBP-7 concentrations did not differ among groups at delivery. In conclusion, proximal tubular dysfunction, as assessed by A1M and C5b-9, developed during the interval between the end of the second trimester and delivery in patients with PE. However, this was not matched by abnormalities in markers previously associated with tubular cell injury (KIM-1, IGFBP-7, and TIMP-2).

Ratio of matrix metalloproteinase-2 to -9 is a more accurate predictive biomarker in women with suspected pre-eclampsia

Pre-eclampsia (PE) is a condition unique to pregnancy, and abnormal expression of matrix metalloproteinases (MMPs) has been implicated in its pathogenesis. We aimed to evaluate the reliability of plasma levels of MMP-2, MMP-9 and their relative ratio in predicting PE. A total of 318 women with suspected PE were recruited for the study, who were subsequently either cleared or diagnosed of PE and grouped accordingly. Their baseline characteristics were compared. Blood samples were also collected from all participants, to determine the plasma levels of MMP-2 and MMP-9. The predictive values of levels of MMP-2 and MMP-9, as well as their ratio, were analyzed using the receiver operating characteristic (ROC) curve. Either MMP-2 or MMP-9 alone did not exhibit any obvious differences between normal and PE pregnancies. However the ratio of MMP-2/MMP-9 was significantly higher in PE-affected pregnancy than normal control group. ROC curve analysis also indicated that the MMP-2/MMP-9 ratio provided better compromise between specificity and sensitivity in distinguishing PE from normal pregnancies, than either of the two MMPs alone. MMP-2/MMP-9 ratio is a more accurate biomarker to predict PE than either MMP-2 or MMP-9 alone.

ECM-Regulator timp Is Required for Stem Cell Niche Organization and Cyst Production in the Drosophila Ovary

The extracellular matrix (ECM) is a pivotal component adult tissues and of many tissue-specific stem cell niches. It provides structural support and regulates niche signaling during tissue maintenance and regeneration. In many tissues, ECM remodeling depends on the regulation of MMP (matrix metalloproteinase) activity by inhibitory TIMP (tissue inhibitors of metalloproteinases) proteins. Here, we report that the only Drosophila timp gene is required for maintaining the normal organization and function of the germline stem cell niche in adult females. timp mutant ovaries show reduced levels of both Drosophila Collagen IV α chains. In addition, tissue stiffness and the cellular organization of the ovarian niche are affected in timp mutants. Finally, loss of timp impairs the ability of the germline stem cell niche to generate new cysts. Our results demonstrating a crucial role for timp in tissue organization and gamete production thus provide a link between the regulation of ECM metabolism and tissue homeostasis.

The extracellular matrix (ECM) offers signals and support to stem cell niches, local microenvironments that provide these cells with necessary factors for their survival. The ECM also helps shaping and maintaining tissues and organs in adult animals. Because the repair of damaged tissue or the replenishment of cell lineages in functional organs requires significant cellular rearrangements, ECM remodeling has to be tightly coordinated with stem cell niche activity. By studying Timp, a regulator of ECM remodeling, we have discovered that the Drosophila timp gene is required to maintain ECM composition and biophysical properties and the organization of the female germline stem cell niche. Because loss of timp prevents proper gamete production in experimental ovaries, our results thus link ECM metabolism and tissue homeostasis.

Maternal plasma TIMP-4 levels combined with clinical risk factors for the early prediction of pregnancy-induced hypertension

OBJECTIVE

The objective of this study was to create a model for early predicting pregnancy-induced hypertension (PIH) using plasma markers and clinical risk factors.

METHODS

A nested case-control study was performed at the Laboratory Department of Guangzhou Women and Children's Medical Center. From a prospective cohort of tens of thousands of unselected women with singleton pregnancies at 8-20 weeks gestation, maternal plasma samples were obtained from 73 women who subsequently developed PIH (PIH group) and 146 gestational age- and maternal age-matched women with normotensive pregnancies (control group). Proteins extracted from the plasma samples were screened by microchip and verified by ELISA. Clinical risk factor data were analyzed retrospectively.

RESULTS

Compared to the control group, high concentrations of tissue inhibitor of metalloproteinase-4 (TIMP-4) were found in women with PIH (P = 0.000). Univariate risk factor analysis identified three variables with significant differences between the groups: family history of PIH (P = 0.031), body mass index (BMI; P < 0.001), and non-glucose-6-phosphate dehydrogenase deficiency-induced anemia (P < 0.027). Multiple regression analyses revealed a significant relationship of PIH with TIMP-4 levels, BMI, and family history (combined area under the receiver operating characteristic curve = 0.820).

CONCLUSION

Upregulation of plasma TIMP-4 might contribute to PIH processes. Potential risk factors of this disease may include a family history of PIH and BMI. The combination of TIMP-4 levels and these risk factors may have some predictive values for PIH. Future multicenter studies including greater numbers of samples, analyzed proteins, and risk factors are needed to obtain a higher predictive value of the model for the clinical diagnosis of PIH.

Contribution of TIMP3 polymorphisms to the development of preeclampsia in Han Chinese women

PURPOSE

The aim of this study was to investigate whether polymorphisms in the tissue inhibitor of metalloproteinase 3 gene (TIMP3) are associated with the risk of preeclampsia (PE) in Han Chinese women.

METHODS

Nine single TIMP3 tag-single nucleotide polymorphisms were selected by Haploview and genotyped using the Sequenom method in 181 preeclamptic and 203 healthy pregnant women from eastern China.

RESULTS

The allele frequencies of the tag-single nucleotide polymorphisms were not significantly different between groups (P > 0.05). However, the genotype distribution of rs135025 was shown to differ between the multigravidity PE subgroup (>3) and controls under additive (P = 0.018) and recessive models (P = 0.008), while the genotype distribution of rs80272 differed significantly between the severe PE subgroup and controls under additive (P = 0.014) and dominant models (P = 0.041). Moreover, the H2 haplotype (A-C-G-T-A-A-G-C-G) was found to be associated with the risk of PE (P = 0.035).

CONCLUSIONS

Genotypes of rs135025 and rs80272 in TIMP3 may therefore influence susceptibility to PE, and pregnant women carrying the H2 haplotype might be more prone to developing PE.

Association of parity with carotid diameter and distensibility: multi-ethnic study of atherosclerosis

Pregnancy and childbirth are associated with hemodynamic changes and vascular remodeling. It is not known whether parity is associated with later adverse vascular properties such as larger arterial diameter, wall thickness, and lower distensibility. We used baseline data from 3283 women free of cardiovascular disease aged 45 to 84 years enrolled in the population-based Multi-Ethnic Study of Atherosclerosis. Participants self-reported parity status. Ultrasound-derived carotid artery lumen diameters and brachial artery blood pressures were measured at peak-systole and end-diastole. Common carotid intima-media thickness was also measured. Regression models to determine the association of carotid distensibility coefficient, lumen diameter, and carotid intima-media thickness with parity were adjusted for age, race, height, weight, diabetes mellitus, current smoking, blood pressure medication use, and total and high-density lipoprotein cholesterol levels. The prevalence of nulliparity was 18%. In adjusted models, carotid distensibility coefficient was 0.09×10−5 Pa−1 lower (P=0.009) in parous versus nulliparous women. Among parous women, there was a nonlinear association with the greatest carotid distensibility coefficient seen in women with 2 live births and significantly lower distensibility seen in primiparas (P=0.04) or with higher parity >2 (P=0.005). No such pattern of association with parity was found for lumen diameter or carotid intima-media thickness. Parity is associated with lower carotid artery distensibility, suggesting arterial remodeling that lasts beyond childbirth. These long-term effects on the vasculature may explain the association of parity with cardiovascular events later in life.

Tissue inhibitor of matrix metalloproteinase-1 polymorphism, plasma TIMP-1 levels, and antihypertensive therapy responsiveness in hypertensive disorders of pregnancy

Tissue inhibitor of metalloproteinase (TIMP)-1 is a major endogenous inhibitor of matrix metalloproteinase (MMP)-9, which may affect the responsiveness to therapy in hypertensive disorders of pregnancy. We examined whether TIMP-1 polymorphism (g.-9830T>G, rs2070584) modifies plasma MMP-9 and TIMP-1 levels and the response to antihypertensive therapy in 596 pregnant: 206 patients with preeclampsia (PE), 183 patients with gestational hypertension (GH) and 207 healthy pregnant controls. We also studied the TIMP-3 polymorphism (g.-1296T>C, rs9619311). Plasma MMP-9 and TIMP-1 levels were measured by ELISA. GH patients with the GG genotype for the TIMP-1 polymorphism had lower MMP-9 levels and MMP-9/TIMP-1 ratios than those with the TT genotype. PE patients with the TG genotype had higher TIMP-1 levels. The G allele and the GG genotype were associated with PE and responsiveness to antihypertensive therapy in PE, but not in GH. Our results suggest that the TIMP-1 g.-9830T>G polymorphism not only promotes PE but also decreases the responses to antihypertensive therapy.

Matrix metalloproteinases in autism spectrum disorders

Autism Spectrum Disorders (ASD) are group of developmental disabilities with a complex neurobiological basis including putative changes in the immune system. They are characterized by pervasive qualitative abnormalities in social interactions, communication, and stereotyped behaviour. Matrix metalloproteinases (MMPs) represent a group of proteases which play an important role in neuroinflammation and neurodevelopment. Therefore, they possibly have a crucial function in the etiopathology of ASD. In this review, we summarize the plausibility of the hypothesis that MMPs are involved in the neuropathology of ASD. Possible pathways through which MMPs can contribute to the pathogenesis of ASD are discussed including neuroinflammatory mechanisms inclusive of mediating neuropathological effects of infections, the associations between MMPs and other biomarkers such as cytokines, chemokines and neurotrophic factors. Despite sufficient evidence for such an involvement of MMPs in the neuropathology of ASD, they have not yet been extensively studied in this context. Thus, further research in this field is not only urgently needed but also very promising and may also lead to new therapeutic approaches.

Matrix metalloproteinases as drug targets in preeclampsia

Preeclampsia is an important syndrome complicating pregnancy. While the pathogenesis of preeclampsia is not entirely known, poor placental perfusion leading to widespread maternal endothelial dysfunction is accepted as a major mechanism. It has been suggested that altered placental expression of matrix metalloproteinases (MMPs) may cause shallow cytotrophoblastic invasion and incomplete remodeling of the spiral arteries. MMPs are also thought to link placental ischemia to the cardiovascular alterations of preeclampsia. In fact, MMPs may promote vasoconstriction and surface receptors cleavage affecting the vasculature. Therefore, the overall goal of this review article is to provide an overview of the pathophisiology of preeclampsia, more specifically regarding the role of MMPs in the pathogenesis of preeclampsia and the potential of MMP inhibitors as therapeutic options.

ECM-dependent HIF induction directs trophoblast stem cell fate via LIMK1-mediated cytoskeletal rearrangement

The Hypoxia-inducible Factor (HIF) family of transcriptional regulators coordinates the expression of dozens of genes in response to oxygen deprivation. Mammalian development occurs in a hypoxic environment and HIF-null mice therefore die in utero due to multiple embryonic and placental defects. Mouse embryonic stem cells do not differentiate into placental cells; therefore, trophoblast stem cells (TSCs) are used to study mouse placental development. Consistent with a requirement for HIF activity during placental development in utero, TSCs derived from HIF-null mice exhibit severe differentiation defects and fail to form trophoblast giant cells (TGCs) in vitro. Interestingly, differentiating TSCs induce HIF activity independent of oxygen tension via unclear mechanisms. Here, we show that altering the extracellular matrix (ECM) composition upon which TSCs are cultured changes their differentiation potential from TGCs to multinucleated syncytiotropholasts (SynTs) and blocks oxygen-independent HIF induction. We further find that modulation of Mitogen Activated Protein Kinase Kinase-1/2 (MAP2K1/2, MEK-1/2) signaling by ECM composition is responsible for this effect. In the absence of ECM-dependent cues, hypoxia-signaling pathways activate this MAPK cascade to drive HIF induction and redirect TSC fate along the TGC lineage. In addition, we show that integrity of the microtubule and actin cytoskeleton is critical for TGC fate determination. HIF-2α ensures TSC cytoskeletal integrity and promotes invasive TGC formation by interacting with c-MYC to induce non-canonical expression of Lim domain kinase 1-an enzyme that regulates microtubule and actin stability, as well as cell invasion. Thus, we find that HIF can integrate positional and metabolic cues from within the TSC niche to regulate placental development by modulating the cellular cytoskeleton via non-canonical gene expression.