Mengzhou He

Upregulation of the Tim-3/Gal-9 pathway and correlation with the development of preeclampsia

OBJECTIVE It is well documented that an imbalance in immune tolerance at the maternal-fetal interface is likely to play an essential role in the etiology of preeclampsia. However, the mechanisms underlying immune tolerance during preeclampsia are still poorly understood. Tim-3, a Th1-specific cell surface molecule, is a relatively newly described molecule with important immunological functions. It can regulate Th1 responses with its ligand galectin-9 (Gal-9), and has become an attractive candidate for exploring the pathogenesis of preeclampsia. STUDY DESIGN Twenty normal pregnancies and 20 preeclamptic pregnancies were enrolled in the present study. We examined the expression and function of Tim-3/Gal-9 in decidual tissue at the RNA and protein levels. In order to analyze their correlation with the development of preeclampsia, we measured the expression of Tim-3 on peripheral blood leukocytes using flow cytometry. IFN-γ, IL-10, and IL-17 in the peripheral blood plasma were measured by ELISA. RESULTS Tim-3/Gal-9 was upregulated in decidual tissue of preeclamptic vs. normotensive pregnancies. There was a significantly increased Th1 and Th17 response in PE as demonstrated by the upregulated levels of IFN-γ/IL-17, whereas IL-10 secreted by Th2 cells was sharply reduced. CONCLUSIONS The present study showed that an abnormal Tim-3/Gal-9 pathway was able to facilitate the development of preeclampsia. Our data uncovered a novel mechanism by which the Tim-3/Gal-9 pathway regulates immune responses, and we now identify this pathway as a potential therapeutic target in preeclampsia.

Up-regulated expression of Tim-3/Gal-9 at maternal-fetal interface in pregnant woman with recurrent spontaneous abortion

SummaryThe relationship between T cell immunoglobulin domain and mucin domain protein 3 (Tim-3)/Galectin (Gal)-9 pathway and recurrent spontaneous abortion (RSA) was studied. Thirty-one pregnant women with RSA and 27 normal early gravidas were investigated to detect the levels of Tim-3 and Gal-9 in villi and deciduas by Western blotting. Meanwhile, the concentration of interleukin (IL)-4 and IL-12 in peripheral blood plasma was determined by ELISA in 25 healthy fertile non-pregnant controls, the normal early gravidas and pregnant women with RSA mentioned above, respectively. It was found that the relative expression levels of Tim-3 and Gal-9 in villi and deciduas were significantly increased in pregnant women with RSA as compared with those in the normal early gravidas. The concentration of IL-4 in peripheral blood plasma of pregnant women with RSA was lower than that of the normal early gravidas (P<0.05) and healthy fertile non-pregnant controls (P<0.05), but that of IL-2 in pregnant women with RSA was significantly higher than that of the normal early gravidas (P<0.05) and healthy fertile non-pregnant controls (P<0.05). It was suggested that the overexpression of Tim-3/Gal-9 pathway may be related to the pathogenesis of RSA.The relationship between T cell immunoglobulin domain and mucin domain protein 3 (Tim-3)/Galectin (Gal)-9 pathway and recurrent spontaneous abortion (RSA) was studied. Thirty-one pregnant women with RSA and 27 normal early gravidas were investigated to detect the levels of Tim-3 and Gal-9 in villi and deciduas by Western blotting. Meanwhile, the concentration of interleukin (IL)-4 and IL-12 in peripheral blood plasma was determined by ELISA in 25 healthy fertile non-pregnant controls, the normal early gravidas and pregnant women with RSA mentioned above, respectively. It was found that the relative expression levels of Tim-3 and Gal-9 in villi and deciduas were significantly increased in pregnant women with RSA as compared with those in the normal early gravidas. The concentration of IL-4 in peripheral blood plasma of pregnant women with RSA was lower than that of the normal early gravidas (P<0.05) and healthy fertile non-pregnant controls (P<0.05), but that of IL-2 in pregnant women with RSA was significantly higher than that of the normal early gravidas (P<0.05) and healthy fertile non-pregnant controls (P<0.05). It was suggested that the overexpression of Tim-3/Gal-9 pathway may be related to the pathogenesis of RSA.

HSP20 Exerts a Protective Effect on Preeclampsia by Regulating Function of Trophoblast Cells Via Akt Pathways

Preeclampsia (PE) remains the leading cause of maternal and fetal morbidity and mortality. Excessive apoptosis of the placenta and poor remodeling of spiral arteries caused by insufficient invasion of trophoblast cells into uterus have been implicated in the pathogenesis of PE. Accumulating evidence showed that heat shock protein 20 (HSP20) is closely associated with the proliferation, apoptosis, and metastasis of tumor cells. However, little is known about whether HSP20 plays a role in the development of PE. In this study, we detected the apoptosis index and the expressions of HSP20 and apoptosis-associated proteins in the placentas from PE and normal pregnancies. We found that HSP20 was reversely related to the apoptosis rate and the levels of proapoptotic proteins. Moreover, we identified that HSP20 could suppress the proliferation and apoptosis of trophoblast cells, turning them into a more invasive phenotype. Additionally, H2O2-induced oxidative stress was significantly alleviated, and several key proteins on the Akt signaling pathway were upregulated in HSP20-overexpressing trophoblast cells. These findings strongly suggested that HSP20 might play a role in the remodeling of spiral arteries through affecting the invasiveness of extravillous trophoblast cells via Akt signaling pathway, and the dysregulation of it might contribute to the pathophysiology of PE.

Impairment of BKca channels in human placental chorionic plate arteries is potentially relevant to the development of preeclampsia

Preeclampsia has known associations with insufficient placental perfusion. The large-conductance Ca2+-activated K+ (BKca) channels that have recently been found to play important roles in cellular growth and vasodilatation could potentially participate in the development of preeclampsia. However, the mechanisms by which downregulated BKca channels are involved in the development of preeclampsia remain unknown. In this study, we investigated the mechanism(s) underlying the impairment of vascular tone regulation by BKca channels in human placental chorionic plate arteries (CPAs) in preeclampsia. The levels of BKca channel α and β1 subunits were compared using immunohistochemistry, western blotting, and RT-PCR in CPAs of normal and preeclamptic pregnant women. To explore the role of BKca channels in the regulation of proliferation and apoptosis in human placental CPA smooth muscle cells (SMCs), a specific BKca opener, NS1619, was used to investigate proliferative reduction and apoptotic induction in human placental chorionic plate arterie smooth muscle cells (CPASMCs) collected from normal pregnancies. The vasodilator effects of BKca channels and their response to SNP (an NO donor) in both groups were also evaluated by wire myography. We found that BKca channel β1 subunits were less expressed in preeclamptic CPAs. After pretreatment with NS1619, cellular proliferation was significantly suppressed, and cellular apoptosis was dramatically promoted in cultured CPASMCs, demonstrating a relationship between increased Bax expression and decreased Bcl-2 expression in CPASMCs. Downregulated BKca is also associated with decreased vasodilatation and reduced susceptibility to NO donors. In conclusion, the decreased expression or activation of BKca channels may induce pathologic remodeling of human CPAs, weaken the vasodilation response, and decrease vascular sensitivity to vasoactive substances, thereby reducing fetal–placental blood flow and leading to the future development of preeclampsia.

Alteration of heat shock protein 20 expression in preeclamptic patients and its effect in vascular and coagulation function

Preeclampsia (PE) is a pregnancy-specific, multi-system disorder and the leading cause of maternal and perinatal morbidity and mortality in obstetrics worldwide. Excessive vasoconstriction and dysregulated coagulation function are closely associated with PE. Heat shock protein 20 (HSP20) is ubiquitously expressed under normal physiological conditions and has important roles in vascular dilatation and suppression of platelet aggregation. However, the role of HSP20 in the pathogenesis of PE remains unclear. In this study, we collected chorionic plate resistance arteries (CPAs) and serum from 118 healthy pregnant women and 80 women with PE and detected the levels of HSP20 and its phosphorylated form. Both HSP20 and phosphorylated HSP20 were downregulated in CPAs from women with PE. Comparison of the vasodilative ability of CPAs from the two groups showed impaired relaxation responses to acetyl choline in preeclamptic vessels. In addition to the reduced HSP20 in serum from women with PE, the platelet distribution width and mean platelet volume were also decreased, and the activated partial thromboplastin time and thromboplastin time were elevated.With regard to the vital roles of HSP20 in mediating vasorelaxation and coagulation function, the decreased HSP20 might contribute to the pathogenesis of PE.

Impaired Gal-9 Dysregulates the PBMC-Induced Th1/Th2 Imbalance in Abortion-Prone Matings

Recurrent miscarriage is defined as the loss of 3 or more consecutive pregnancies; however, the underlying immunologic mechanisms that trigger pregnancy loss remain largely unelucidated. Galectin-9 (Gal-9) may modulate a variety of biologic functions and play an important role in Th1/Th2 immune deviation. To analyze the mechanism of Gal-9 in abortion, we used the classical abortion-prone mouse model (DBA/2-mated CBA/J mice) to detect the expression of Gal-9 at the maternal-fetal interface. We also mimicked the immune environment of pregnancy by culturing trophoblast cells with peripheral blood mononuclear cells (PBMCs) to explore how Gal-9 might be involved in the pathogenesis of abortion. We found that the expression levels of Gal-9 in abortion-prone matings were lower than that for controls. Using a coculture system, we detected a Th1 preponderance in the coculture from abortion-prone matings. Furthermore, Gal-9 blockade augmented the imbalance of Th1/Th2 immunity in abortion-prone matings by promoting the secretion of Th1-derived cytokines in coculture, while there was a Th2 preponderance when we administered recombinant Gal-9. In conclusion, our results suggest that the Gal-9 signal is important for the regulation of PBMC function toward a Th2 bias at the maternal-fetal interface, which is beneficial for the maintenance of a normal pregnancy.

Upregulation of Tim-3 expression at feto-maternal interface may explain embryo survival in the CBAxDBA/2 model of abortion

To understand the mechanisms of action of Tim‐3 at the maternal‐fetal interface and explore how Tim‐3 might be involved in the pathogenesis of abortion by constructing an in vitro trophoblast‐lymphocyte system.

Increased Toll-Like Receptor-Myeloid Differentiation Factor 88 Expression at the Maternal-Fetal Interface Is Associated with Spontaneous Abortion.

Aims: Toll-like receptors (TLRs) form a group of pattern recognition receptors that play a major role in maintaining innate host immunity. Myeloid differentiation factor 88 (MyD88) is an adaptor molecule that is essential for signaling via the TLR family. To analyze the mechanism of the imbalance in the innate immune system mediated by TLRs-MyD88 in spontaneous abortion, we detected the expression of TLR-2, TLR-4, TLR-7, and MyD88 in placentae and deciduas. Methods: The expression of TLR-2, TLR-4, TLR-7, and MyD88 in the placentae and deciduas of abortion-prone mice (n = 10) and normal pregnant mice (n = 10) were analyzed by immunochemistry, western blot, and real-time polymerase chain reaction. Results: There were higher protein expression levels of TLR-2, TLR-4, TLR-7, and MyD88 in the placentae and deciduas in the abortion-prone group than in the normal pregnant group. However, TLR-2, TLR-4, and TLR-7 showed lower gene expression, while MyD88 manifested higher gene expression in placentae and deciduas of abortion-prone mice matings. Conclusions: TLR-2, TLR-4, TLR-7, and MyD88 were expressed in the placenta and decidua of both the abortion-prone pregnant and normal pregnant mice. The overexpression of TLRs may excessively activate the innate immune system mediated by MyD88, which is considered to be related to the pathogenesis of spontaneous abortion.