Plasma level of soluble c-Met is tightly associated with the clinical risk of preeclampsia

Influential Serum Kinases (Non-sFlt-1) and Phosphatases in Preeclampsia-Systemic Review and Metanalysis

The early identification of women with an increased risk of preeclampsia (PE) is desirable, but apart from soluble fms-like tyrosine kinase-1 (sFlt-1), few biomarkers have previously been identified as relevant for predicting preeclampsia. Since kinases and phosphatases regulate critical biological processes and previous evidence suggests a potential role of these molecules in preeclampsia, we performed this systematic review and metanalysis. The objective was to determine if there are kinases and phosphatases whose serum levels are different between women with and without PE, being relevant biomarkers of PE. We followed the recommendations of Cochrane and the Preferred Reported Items for Systematic Reviews and Metanalysis (PRISMA) to perform this study. The MESH terms preeclampsia, kinases, phosphatases, angiopoietins, soluble tyrosine protein kinase receptor (sTIE2), and cellular-mesenchymal-epithelial transition factor (c-MET) were combined to find relevant articles in the PubMed, PROSPERO, and Cochrane databases. Then, a qualitative and quantitative analysis was performed in R Studio software. From 580 abstracts identified, 37 were included in the final analysis, which comprised 24,211 pregnant women (2879 with PE and 21,332 women without PE [HP]. The pooled analysis showed that serum creatine kinase (CK) (SMD: 2.43, CI 95% 0.25-4.62) was significantly higher in PE, whereas sTIE2 and anti-angiogenic factor soluble c-Met (sMet)were significantly lower in PE than in HP (SMD: -0.23, CI95% -0.37 to -0.09; and SMD:0.24, CI95% 0.01-0.47, respectively). Adenosine monophosphate-activated protein kinase (AMPK), angiopoietin-1 (ANG-1), angiopoietin-2 (ANG-2), the ratio angiopoietin-1/angiopoietin-2, acid phosphatase, and alkaline phosphatase were not different between women with PE and HP. In summary CK, sTIE2, and c-MET are relevant biomarkers of PE. It is desirable to incorporate them into current models for PE prediction to evaluate their utility as biomarkers.

HGF/c-Met signaling regulates early differentiation of placental trophoblast cells

Depletion of hepatocyte growth factor (HGF) or mesenchymal-epithelial transition factor (c-Met) in mice leads to fetal lethality and placental maldevelopment. However, the dynamic change pattern of HGF/c-Met signaling during placental development and its involvement in the early differentiation of trophoblasts remain to be elucidated. In this study, using in situ hybridization assay, we elaborately demonstrated the spatial-temporal expression of Hgf and c-Met in mouse placenta from E5.5, the very early stage after embryonic implantation, to E12.5, when the placental structure is well developed. The concentration of the soluble form of c-Met (sMet) in maternal circulation peaked at E10.5. By utilizing the induced differentiation model of mouse trophoblast stem cells (mTSCs), we found that HGF significantly promoted mTSC differentiation into syncytiotrophoblasts (STBs) and invasive parietal trophoblast giant cells (PTGCs). Interestingly, sMet efficiently reversed the effect of HGF on mTSC differentiation. These findings indicate that HGF/c-Met signaling participates in regulating placental trophoblast cell fate at the early differentiation stage and that sMet acts as an endogenous antagonist in this aspect.

Urinary cMet as a prognostic marker in immunoglobulin A nephropathy

The prediction of prognosis in patients with immunoglobulin A nephropathy (IgAN) is challenging. We investigated the correlation between urinary cMet (ucMet) levels and clinical parameters and examined the effects of cMet agonistic antibody (cMet Ab) in an in vitro IgAN model. Patients diagnosed with IgAN (n = 194) were divided into three groups representing undetectable (Group 1), below‐median (Group 2) and above‐median (Group 3) levels of ucMet/creatinine (ucMet/Cr). Stained kidney biopsy samples were graded according to cMet intensity. Primary‐cultured human mesangial cells were stimulated with recombinant tumour necrosis factor (TNF)‐α and treated with cMet Ab. Our results showed that ucMet/Cr levels positively correlated with proteinuria (P < .001). During the follow‐up, patients in Group 3 showed a significantly lower probability of complete remission (CR; uPCr < 300 mg/g) than those in groups 1 and 2, after adjusting for blood pressure, estimated glomerular filtration rate, and proteinuria, which influence clinical prognosis (HR 0.60, P = .038); moreover, ucMet/Cr levels were also associated with glomerular cMet expression. After TNF‐α treatment, the proliferation of mesangial cells and increased interleukin‐8 and intercellular adhesion molecule‐1 expression were markedly reduced by cMet Ab in vitro. In conclusion, ucMet/Cr levels significantly correlated with proteinuria, glomerular cMet expression, and the probability of CR. Further, cMet Ab treatment alleviated the inflammation and proliferation of mesangial cells. Hence, ucMet could serve as a clinically significant marker for treating IgAN.

cMet agonistic antibody attenuates apoptosis in ischaemia-reperfusion-induced kidney injury

Acute kidney injury (AKI) is a very common complication with high morbidity and mortality rates and no fundamental treatment. In this study, we investigated whether the hepatocyte growth factor (HGF)/cMet pathway is associated with the development of AKI and how the administration of a cMet agonistic antibody (Ab) affects an AKI model. In the analysis using human blood samples, cMet and HGF levels were found to be significantly increased in the AKI group, regardless of underlying renal function. The administration of a cMet agonistic Ab improved the functional and histological changes after bilateral ischaemia‐reperfusion injury. TUNEL‐positive cells and Bax/Bcl‐2 ratio were also reduced by cMet agonistic Ab treatment. In addition, cMet agonistic Ab treatment significantly increased the levels of PI3K, Akt and mTOR. Furthermore, after 24 hours of hypoxia induction in human proximal tubular epithelial cells, treatment with the cMet agonistic Ab also showed dose‐dependent antiapoptotic effects similar to those of the recombinant HGF treatment. Even when the HGF axis was blocked with a HGF‐blocking Ab, the cMet agonistic Ab showed an independent dose‐dependent antiapoptotic effect. In conclusion, cMet expression is associated with the occurrence of AKI. cMet agonistic Ab treatment attenuates the severity of AKI through the PI3K/Akt/mTOR pathway and improves apoptosis. cMet agonistic Ab may have important significance for the treatment of AKI.

Circulating Levels of Bone and Inflammatory Markers in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) can cause short- and long-term complications to the mother and fetus. While the precise mechanisms in preserving glucose balance in a healthy pregnancy are unknown, various growth factors and hormones have been implicated or associated with GDM risk in humans or rodents, including prolactin, tumor necrosis factor alpha (TNFα), osteoprotegerin (OPG), hepatocyte growth factor (HGF), and receptor activator of nuclear factor-kappa B ligand (RANKL). We aimed to evaluate the relationship of these and other protein markers in women with GDM. In this cross-sectional study, blood samples were collected from pregnant women with GDM and with normal glucose tolerance (NGT) at the 24- to 32-week obstetrical visit, during the 1-h oral glucose challenge test or 3-h oral glucose tolerance test. Blood plasma was analyzed for RANKL, OPG, prolactin, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), HGF, plasminogen activator inhibitor type 1 (PAI-1), and TNFα. Forty-six women with NGT and 47 women with GDM were included (mean ± standard deviation maternal age 31.6 ± 5.7, mean ± standard deviation gestational age 28.1 ± 2.2 weeks). Groups were similar in terms of age, body mass index, gestational age, and race/ethnicity. Serum levels of OPG, prolactin, TRAIL, HGF, PAI-1, and TNFα were similar in both groups. RANKL was lower in GDM subjects (p = 0.019). Contrary to previous reports in the literature, we found a lower serum RANKL level in women with GDM. Further investigation is needed to determine whether there are suitable serum markers for diagnosing GDM or determining prognosis or severity.

Angiogenic factor screening in women with mild preeclampsia - New and significant proteins in plasma

INTRODUCTION

The aim of this study was to analyse a panel of 60 angiogenic factors (pro-angiogenic and antiangiogenic) in the plasma of women with mild preeclampsia.

MATERIALS AND METHODS

We recruited 21 women between 25 and 40 weeks gestation with diagnosed mild preeclampsia into the study group and 27 healthy women with uncomplicated pregnancies of corresponding gestational age to that of the study to the control group. We used a quantitative protein macroarray method that allowed for analysis of 60 angiogenic proteins per sample simultaneously.

RESULTS

We showed a statistically significant increase in the concentration of 8 proteins, interferon gamma (IFN-γ), interleukin 6 (IL-6), leukaemia inhibitory factor (LIF), heparin-binding EGF-like growth factor (HB-EGF), hepatocyte growth factor (HGF), C-X-C motif chemokine 10 (IP-10), leptin and platelet-derived growth factor BB (PDGF-BB), as well as a significant decrease in the concentration of 3 proteins, vascular endothelial growth factor (VEGF), placental growth factor (PlGF) and follistatin, in the plasma of women with preeclampsia.

CONCLUSION

Based on our findings, it seems that protein factors may play an important role in the pathogenesis of preeclampsia, and there are many proteins that have not been studied in PE to date. There are no previous studies assessing the LIF, follistatin, HGF, HB-EGF and PDGF-BB concentrations in the plasma of women with PE; therefore, our obtained results indicate that these proteins are new factors that can play an important role in the pathomechanisms of PE.

Identification of key microRNAs and genes in preeclampsia by bioinformatics analysis

Preeclampsia is a leading cause of perinatal maternal–foetal mortality and morbidity. The aim of this study is to identify the key microRNAs and genes in preeclampsia and uncover their potential functions. We downloaded the miRNA expression profile of GSE84260 and the gene expression profile of GSE73374 from the Gene Expression Omnibus database. Differentially expressed miRNAs and genes were identified and compared to miRNA-target information from MiRWalk 2.0, and a total of 65 differentially expressed miRNAs (DEMIs), including 32 up-regulated miRNAs and 33 down-regulated miRNAs, and 91 differentially expressed genes (DEGs), including 83 up-regulated genes and 8 down-regulated genes, were identified. The pathway enrichment analyses of the DEMIs showed that the up-regulated DEMIs were enriched in the Hippo signalling pathway and MAPK signalling pathway, and the down-regulated DEMIs were enriched in HTLV-I infection and miRNAs in cancers. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses of the DEGs were performed using Multifaceted Analysis Tool for Human Transcriptome. The up-regulated DEGs were enriched in biological processes (BPs), including the response to cAMP, response to hydrogen peroxide and cell-cell adhesion mediated by integrin; no enrichment of down-regulated DEGs was identified. KEGG analysis showed that the up-regulated DEGs were enriched in the Hippo signalling pathway and pathways in cancer. A PPI network of the DEGs was constructed by using Cytoscape software, and FOS, STAT1, MMP14, ITGB1, VCAN, DUSP1, LDHA, MCL1, MET, and ZFP36 were identified as the hub genes. The current study illustrates a characteristic microRNA profile and gene profile in preeclampsia, which may contribute to the interpretation of the progression of preeclampsia and provide novel biomarkers and therapeutic targets for preeclampsia.

Genetic, immune and vasoactive factors in the vascular dysfunction associated with hypertension in pregnancy

INTRODUCTION

Preeclampsia (PE) is a major complication of pregnancy that could lead to maternal and fetal morbidity and mortality. The pathophysiological mechanisms of PE are not completely understood, but recent research has begun to unravel some of the potential mechanisms.

AREAS COVERED

Genetic polymorphisms and altered maternal immune response may cause impaired remodeling of the spiral arteries; a potential early defect in PE. Inadequate invasion of cytotrophoblasts into the decidua leads to reduced uteroplacental perfusion pressure (RUPP) and placental ischemia/hypoxia. Placental ischemia causes the release of biologically active factors such as anti-angiogenic factors, inflammatory cytokines, reactive oxygen species, hypoxia-inducible factors, and angiotensin II receptor autoantibodies. These vasoactive factors could cause systemic vascular endotheliosis and consequent increase in vascular resistance and blood pressure, glomerular endotheliosis causing proteinuria, cerebrovascular endotheliosis causing cerebral edema, seizures and visual disturbances, and hepatic endotheliosis, which may contribute to the manifestations of HELLP syndrome. PE-associated vascular endotheliosis causes a decrease in vasodilator mediators such as nitric oxide, prostacyclin and endothelium-derived hyperpolarizing factor, an increase in vasoconstrictors such as endothelin-1, angiotensin II and thromboxane A2, and enhanced mechanisms of vascular smooth muscle contraction such as intracellular Ca(2+), protein kinase C and Rho-kinase. Changes in matrix metalloproteinase activity and extracellular matrix cause vascular remodeling and further vasoconstriction.

EXPERT OPINION

Some of the genetic, immune and vasoactive factors involved in vascular endotheliosis could be used as biomarkers for early detection, and as potential targets for prevention and treatment of PE.

Investigating the Relationship between Serum Level of s-Met (Soluble Hepatic Growth Factor Receptor) and Preeclampsia in the First and Second Trimesters of Pregnancy

Introduction. Preeclampsia (PE) is an important cause of mortality and morbidity for mothers, fetuses, and the newborns. Placenta plays a pivotal role in pathogenesis of PE. Hepatic growth factor (HGF) is a cytokine expressed by the mesenchymal stalk of placental villi during pregnancy and assumes a paracrine role in trophoblasts which express its receptor (c-MET). In the present study, we investigate the diagnostic value of s-Met (the soluble form of the receptor) in the first and second trimesters of pregnancy for early diagnosis of preeclampsia. Method and Materials. This is a case-control study conducted on 95 pregnant women. The serum level of s-Met was measured in the first and second trimesters, and the participants were followed until delivery. 44 individuals with preeclampsia (the case group) and 51 individuals without preeclampsia (the control group) were evaluated. Results. Serum level of s-Met in preeclamptic participants was lower than that of the control group in both the first and the second trimesters (P < 0.0001). In addition, serum levels of s-Met were significantly lower during the first and second trimesters in patients with early, severe preeclampsia compared to those with late, mild preeclampsia (P < 0.0001). The sensitivity and specificity of s-Met in the first and second trimesters were, respectively, (83%, 94%) and (77%, 94%) for early preeclampsia and (88%, 92%) and (86%, 98%) for severe preeclampsia. Conclusion. Considering our findings, serum level of s-Met may be used as a predictive factor for early detection of preeclampsia. Further research is required to corroborate the functional and therapeutic value of s-Met in preeclampsia.

Preeclampsia is associated with an elevation of plasma sMet concentrations in the second trimester

OBJECTIVE

The aim of this study was to investigate the association between anti-angiogenic factor soluble c-Met (sMet) concentrations in maternal plasma and the risk of preeclampsia.

METHODS

The pregnant women included in this study (1) had subsequent preeclampsia (n = 52) and were compared to normal controls (n = 104) at the time of amniocentesis (15-20 weeks); and (2) had preeclampsia (n = 63) and were compared to normal controls (n = 112) at the time of diagnosis of preeclampsia (29-40 weeks). sMet concentrations were measured by ELISA. Non-parametric statistics were used for analysis.

RESULTS

Maternal plasma sMet concentrations were significantly higher in both women with subsequent preeclampsia (median: 1372.7 ng/ml versus 1100.5 ng/ml; p = 0.036) and women with preeclampsia (median: 1651.9 ng/ml versus 1364.7 ng/ml; p < 0.001) than in the controls. After adjusting for potential confounding factors, the risks of developing preeclampsia were as follows: adjusted odds ratio 2.5 (95% confidence interval, 1.2-5.2; p = 0.016) for second trimester sMet concentration with a cut-off value of 1223.5 ng/ml and 4.4 (95% confidence interval, 2.2-9.1; p < 0.001) for third trimester sMet concentration with a cut-off value of 1460.3 ng/ml.

CONCLUSION

Elevated maternal plasma sMet concentrations were independently associated with the increased risk of preeclampsia.

Soluble c-Met in serum of patients with multiple myeloma: correlation with clinical parameters

OBJECTIVES

The receptor tyrosine kinase c-Met and its ligand, hepatocyte growth factor (HGF), play key roles in tumour genesis and metastasis and contribute in multiple myeloma pathogenesis. Substantial data support that a soluble extracellular fragment of c-Met may function as a decoy receptor that downregulates the biological effects of HGF and c-Met. We examined serum levels of soluble c-Met in patients with myeloma and healthy individuals and investigated a possible relationship with clinical disease parameters and survival.

METHODS

The concentration of c-Met and HGF was measured by enzyme-linked immunosorbent assay in serum (n=49) and bone marrow plasma (n=16) from patients with multiple myeloma and in serum from healthy controls (n=26).

RESULTS

The median serum concentration of soluble c-Met was 186 ng/mL (range 22-562) in patients with multiple myeloma and 189 ng/mL (range 124-397) in healthy individuals. There was a significant negative correlation between serum c-Met levels and disease stage, bone marrow plasma cell percentage and serum concentration of M-protein.

CONCLUSION

We have for the first time examined the concentration of soluble c-Met in serum from patients with myeloma and found equal median levels in patients with myeloma as a group and healthy individuals. Still, serum levels of soluble c-Met correlated negatively with parameters of disease burden in patients with myeloma. We suggest that a possible role for the c-Met ectodomain as a negative regulator of HGF/c-Met activity should be examined in multiple myeloma.

Molecular and vascular targets in the pathogenesis and management of the hypertension associated with preeclampsia

Normal pregnancy is associated with significant hemodynamic changes and vasodilation of the uterine and systemic circulation in order to meet the metabolic demands of the mother and developing fetus. Preeclampsia (PE) is one of the foremost complications of pregnancy and a major cause of maternal and fetal mortality. The pathophysiological mechanisms of PE have been elusive, but some parts of the puzzle have begun to unravel. Genetic factors such as leptin gene polymorphism, environmental and dietary factors such as Ca(2+) and vitamin D deficiency, and co-morbidities such as obesity and diabetes may increase the susceptibility of pregnant women to develop PE. An altered maternal immune response may also play a role in the development of PE. Although the pathophysiology of PE is unclear, most studies have implicated inadequate invasion of cytotrophoblasts into the uterine artery, leading to reduced uteroplacental perfusion pressure (RUPP) and placental ischemia/hypoxia. Placental ischemia induces the release of biologically active factors such as growth factor inhibitors, anti-angiogenic factors, inflammatory cytokines, reactive oxygen species, hypoxia-inducible factors, and antibodies to vascular angiotensin II (AngII) receptor. These bioactive factors could cause vascular endotheliosis and consequent increase in vascular resistance and blood pressure, as well as glomerular endotheliosis with consequent proteinuria. The PE-associated vascular endotheliosis could be manifested as decreased vasodilator mediators such as nitric oxide, prostacyclin and hyperpolarizing factor and increased vasoconstrictor mediators such as endothelin-1, AngII and thromboxane A₂. PE could also involve enhanced mechanisms of vascular smooth muscle contraction including intracellular Ca(2+), and Ca(2+) sensitization pathways such as protein kinase C and Rho-kinase. PE-associated changes in the extracellular matrix composition and matrix metalloproteinases activity also promote vascular remodeling and further vasoconstriction in the uterine and systemic circulation. Some of these biologically active factors and vascular mediators have been proposed as biomarkers for early prediction or diagnosis of PE, and as potential targets for prevention or treatment of the disease.