Placental ADAMTS-12 Levels in the Pathogenesis of Preeclampsia and Intrahepatic Cholestasis of Pregnancy

Role of ADAM and ADAMTS Disintegrin and Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy (NP) involves intricate processes starting with egg fertilization, proceeding to embryo implantation, placentation and gestation, and culminating in parturition. These pregnancy-related processes require marked uteroplacental and vascular remodeling by proteolytic enzymes and metalloproteinases. A disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS) are members of the zinc-dependent family of proteinases with highly conserved protein structure and sequence homology, which include a pro-domain, and a metalloproteinase, disintegrin and cysteine-rich domain. In NP, ADAMs and ADAMTS regulate sperm-egg fusion, embryo implantation, trophoblast invasion, placental angiogenesis and spiral arteries remodeling through their ectodomain proteolysis of cell surface cytokines, cadherins and growth factors as well as their adhesion with integrins and cell-cell junction proteins. Preeclampsia (PE) is a serious complication of pregnancy characterized by new-onset hypertension (HTN) in pregnancy (HTN-Preg) at or after 20 weeks of gestation, with or without proteinuria. Insufficient trophoblast invasion of the uterine wall, inadequate expansive remodeling of the spiral arteries, reduced uteroplacental perfusion pressure, and placental ischemia/hypoxia are major initiating events in the pathogenesis of PE. Placental ischemia/hypoxia increase the release of reactive oxygen species (ROS), which lead to aberrant expression/activity of certain ADAMs and ADAMTS. In PE, abnormal expression/activity of specific ADAMs and ADAMTS that function as proteolytic sheddases could alter proangiogenic and growth factors, and promote the release of antiangiogenic factors and inflammatory cytokines into the placenta and maternal circulation leading to generalized inflammation, endothelial cell injury and HTN-Preg, renal injury and proteinuria, and further decreases in uteroplacental blood flow, exaggeration of placental ischemia, and consequently fetal growth restriction. Identifying the role of ADAMs and ADAMTS in NP and PE has led to a better understanding of the underlying molecular and vascular pathways, and advanced the potential for novel biomarkers for prediction and early detection, and new approaches for the management of PE.

miRNA and miRNA target genes in intervention effect of Zhuyu pill on cholestatic rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Zhuyu pill (ZYP), an effective prescription of traditional Chinese medicine, is composed of Coptis chinensis Franch. and Tetradium ruticarpum (A. Jussieu) T. G. Hartley and has shown potential anticholestatic effects. However, its mechanism of action in treating cholestasis remains unclear. Since post-transcriptional control of mRNA by micro-RNAs (miRNAs) represents an important mechanism of gene regulation, it is promising to explore this in relation to ZYP and cholestasis.

AIM OF THE STUDY

To confirm the anticholestatic effect of ZYP and to explore its potential biological mechanism.

MATERIALS AND METHODS

In this study, a cholestasis rat model was induced by α-naphthyl-isothiocyanate (ANIT, 50 mg/kg) and treated with ZYP (low dose: 0.6 g/kg, high dose: 1.2 g/kg). Serum biochemistry indices and liver histopathology were used to evaluate the model and efficacy, and miRNA sequencing was used to measure differences in miRNA expression in the liver between the control, model, low-dose ZYP, and high-dose ZYP groups. To verify the accuracy of sequencing results and explore the potential anti-cholestasis mechanism of ZYP, RT-PCR was used to identify differentially expressed miRNAs and their target genes.

RESULTS

Both high- and low-dose ZYP exhibited significant anticholestatic effects, with the high-dose showing better effects than low-dose ZYP. Additionally, four differentially expressed miRNAs, rno-miR-147, rno-miR-20b-5p, rno-miR-29b-3p, and rno-miR-3586-3p, were found to be upregulated in cholestasis and downregulated after ZYP intervention. Eight target genes of the above miRNAs, including ABCG8, CLOCK, PLEC, SLC4A2, NEB, ADAMTS12, TTN and FAM174B were inhibited in cholestatic rats, exhibiting up-regulated expression tendencies after ZYP intervention, and the expression tendencies were significant negatively correlated with serum biochemical indices.

CONCLUSIONS

ZYP can significantly reduce liver biochemical indices and improve liver tissue damage in cholestasis rats through the regulation of miRNA expression in the liver, producing a positive regulatory effect on bile excretion-related genes.

ADAMTS-12: Functions and Challenges for a Complex Metalloprotease

Nineteen members of the ADAMTS family of secreted zinc metalloproteinases are present in the human degradome. A wide range of different functions are being attributed to these enzymes and the number of their known substrates is considerably increasing in recent years. ADAMTSs can participate in processes such as fertility, inflammation, arthritis, neuronal and behavioral disorders, as well as cancer. Since its first annotation in 2001, ADAMTS-12 has been described to participate in different processes displayed by members of this family of proteinases. In this sense, ADAMTS-12 performs essential roles in modulation and recovery from inflammatory processes such as colitis, endotoxic sepsis and pancreatitis. ADAMTS-12 has also been involved in cancer development acting either as a tumor suppressor or as a pro-tumoral agent. Furthermore, participation of ADAMTS-12 in arthritis or in neuronal disorders has also been suggested through degradation of components of the extracellular matrix. In addition, ADAMTS-12 proteinase activity can also be modified by interaction with other proteins and thus, can be an alternative way of modulating ADAMTS-12 functions. In this review we revised the most relevant findings about ADAMTS-12 function on the 20th anniversary of its identification.

[Intrahepatic cholestasis of pregnancy]

Intrahepatic cholestasis of pregnancy (ICP) is the most frequent pregnancy-specific liver disease. It is characterized by pruritus and an accompanying elevation of serum bile acid concentrations and/or alanine aminotransferase (ALT), which are the key parameters in the diagnosis. Despite good maternal prognosis, elevated bile acid concentration in maternal blood is an influencing factor to advers fetal outcome. The ICP is associated with increased rates of preterm birth, neonatal unit admission and stillbirth. This is the result of acute fetal asphyxia as opposed to a chronic uteroplacental insufficiency. Reliable monitoring or predictive tools (e.g. cardiotocography (CTG) or ultrasound) that help to prevent advers events are yet to be explored. Medicinal treatment with ursodeoxycholic acid (UDCA) does not demonstrably reduce adverse perinatal outcomes but does improve pruritus and liver function test results. Bile acid concentrations and gestational age should be used as indications to determine delivery. There is a high risk of recurrence in subsequent pregnancies.

Intrahepatic cholestasis of pregnancy as a risk factor for preeclampsia

PURPOSE

Intrahepatic cholestasis of pregnancy and preeclampsia are two major pregnancy complications. We aimed to investigate the association between intrahepatic cholestasis of pregnancy (ICP) and preeclampsia.

METHODS

Single-center retrospective study. Study group included 180 women (162 singletons and 18 twin gestations) who were diagnosed with ICP based on clinical presentation, elevated liver enzymes and bile acids. The reference group included 1618 women (1507 singletons and 111 twin gestations) who delivered during the study period, and were matched according to age, gravidity, parity and singleton or twin gestation.

RESULTS

The incidence of ICP was 0.36%. The incidence of preeclampsia was higher in women with ICP compared to reference group (7.78% vs 2.41%, aOR, 3.74 95% CI 12.0-7.02, p < 0.0001), for either without-(3.89% vs 1.61%, aOR 2.83, 95% CI 1.23-6.5, p = 0.145) or with severe features (3.89% vs 0.80%, aOR 5.17 95% CI 2.14-12.50, p = 0.0003). For both singleton and twin pregnancies, overall preeclampsia rates were higher in the ICP group (5.56% vs 2.19%, aOR 2.91 95% CI 1.39-6.07 p = 0.0045; and 27.78% vs 5.41%, aOR 10.9 95% CI 2.16-47.19, p = 0.0033, respectively). Earlier diagnosis of ICP was associated with higher incidence of preeclampsia (31.1 ± 3.8 vs 34.86 ± 6.2 gestational weeks, p = 0.0259). The average time between ICP diagnosis and to the onset of preeclampsia was 29.7 ± 24 days.

CONCLUSION

ICP is associated with an increased risk for preeclampsia. We suggest intensified follow-up for preeclampsia in women with ICP, especially among those with early ICP presentation and twins' gestations.

ADAMTS 1, 4, 12, and 13 levels in maternal blood, cord blood, and placenta in preeclampsia

The aim of this study is to compare ADAMTS (A Disintegrin and Metalloprotease Domains with Thrombospondins motifs) 1, 4, 12, and 13 levels in maternal and cord blood and placental tissue between preeclampsia and uncomplicated pregnancies. The enzyme-linked immunosorbent assay (ELISA) results showed that ADAMTS 1, 4, 12, and 13 levels in the maternal and cord blood were lower in the preeclampsia group than in the control group. Based on the immunohistochemistry (IHC) results, ADAMTS 1, 4, and 12 levels in placental tissues were higher in the preeclampsia group. According to the polymerase chain reaction (PCR) results, ADAMTS 1, 4, and 12 were higher, whereas ADAMTS 13 was lower in the preeclampsia group than in the control group.

Immunology of hepatic diseases during pregnancy

The mother's immune system has to adapt to pregnancy accepting the semi-allograft fetus and preventing harmful effects to the developing child. Aberrations in feto-maternal immune adaptation may result in disease of the mother, such as liver injury. Five pregnancy-associated liver disorders have been described so far, however, little is known concerning immune alterations promoting the respective disease. These liver disorders are pre-eclampsia, hemolysis, elevated liver enzymes, low platelet count (HELLP), acute fatty liver, hyperemesis gravidarum, and intrahepatic cholestasis of pregnancy. On the other hand, pre-existing autoimmune liver injury of the mother can be affected by pregnancy. This review intends to summarize current knowledge linking feto-maternal immunology and liver inflammation with a special emphasis on novel potential biomarkers.