Hyaluronan, CD44 and its variant exons in human trophoblast invasion and placental angiogenesis

Effect of Oral High Molecular Weight Hyaluronic Acid (HMWHA), Alpha Lipoic Acid (ALA), Magnesium, Vitamin B6 and Vitamin D Supplementation in Pregnant Women: A Retrospective Observational Pilot Study

Background-Pregnancy represents a nutritional challenge, since macro- and micronutrients intake can affect mother' health and influence negative outcomes. The aim of this retrospective pilot study is to evidence whether the oral supplementation with high molecular weight hyaluronic acid (HMWHA), in association with alpha lipoic acid (ALA), magnesium, vitamin B6 and vitamin D, in pregnant women, could reduce adverse effects, such as PTB, pelvic pain, contraction and hospitalization. Methods-Data were collected from n = 200 women treated daily with oral supplements of 200 mg HMWHA, 100 mg ALA, 450 mg magnesium, 2.6 mg vitamin B6 and 50 mcg vitamin D (treatment group) and from n = 50 women taking with oral supplements of 400 mg magnesium (control group). In both groups, supplementation started from the 7th gestational week until delivery. Results-Oral treatment with HMWHA, in association with ALA, magnesium, vitamin B6 and vitamin D in pregnant women, significantly reduced adverse events, such as PTB (p < 0.01), pelvic pain and contractions (p < 0.0001), miscarriages (p < 0.05) and admission to ER/hospitalization (p < 0.0001) compared with the control group. Conclusions-Despite HMWHA having been poorly used as a food supplement in pregnant women, our results open a reassuring scenario regarding its oral administration during pregnancy.

Global proteomic analyses of human cytotrophoblast differentiation/invasion

During human pregnancy, cytotrophoblasts (CTBs) from the placenta differentiate into specialized subpopulations that play crucial roles in proper fetal growth and development. A subset of these CTBs differentiate along an invasive pathway, penetrating the decidua and anchoring the placenta to the uterus. A crucial hurdle in pregnancy is the ability of these cells to migrate, invade and remodel spiral arteries, ensuring adequate blood flow to nourish the developing fetus. Although advances continue in describing the molecular features regulating the differentiation of these cells, assessment of their global proteomic changes at mid-gestation remain undefined. Here, using sequential window acquisition of all theoretical fragment-ion spectra (SWATH), which is a data-independent acquisition strategy, we characterized the protein repertoire of second trimester human CTBs during their differentiation towards an invasive phenotype. This mass spectrometry-based approach allowed identification of 3026 proteins across four culture time points corresponding to sequential stages of differentiation, confirming the expression dynamics of established molecules and offering new information into other pathways involved. The availability of a SWATH CTB global spectral library serves as a beneficial resource for hypothesis generation and as a foundation for further understanding CTB differentiation dynamics.

Absorption, distribution, metabolism and excretion of hyaluronic acid during pregnancy: a matter of molecular weight

INTRODUCTION

For many years hyaluronic acid (HA) was mainly used for its hydrating properties. However, new applications have recently arisen, considering the biological properties of HA and its molecular weight. Clinical application of low molecular weight HA (LMW-HA) initially was supported by specific absorption data. The identification of high molecular weight HA (HMW-HA) absorption pathways and the knowledge of its physiological role allowed to evaluate its clinical application. Based on the immunomodulatory properties of HMW-HA and its physiological involvement as signaling molecule, pregnancy represents an interesting context of application.

AREA COVERED

This expert opinion includes in-vitro, in-vivo, ex-vivo and clinical studies on gestational models. It provides an overview of the physiological and the therapeutic role of HMW-HA in pregnancy starting from its metabolism. Indeed, HMW-HA is widely involved in several physiological processes as implantation, immune response, uterine quiescence and cervical remodeling, and therefore is an essential molecule for a successful pregnancy.

EXPERT OPINION

Available evidence suggests that HMW-HA administration can support physiological pregnancy, favoring blastocyst adhesion and development, preventing miscarriage and pre-term birth. For this reason, supplementation in pregnancy should be evaluated.

Macrophage migration inhibitory factor in human early pregnancy events and association with placental pathologies

Macrophage migration inhibitory factor (MIF) is a versatile cytokine acting as an important regulator of innate and adaptive immunity and implicated in many physiological and pathological processes. It is abundantly expressed at the feto-maternal interface and proposed to have a role in establishing and maintaining a healthy pregnancy. This review presents the current literature data regarding the MIF role in early pregnancy events and its association with some of the placental pathological conditions, including infection, preeclampsia, gestational diabetes mellitus and choriocarcinoma. General information regarding MIF structure and function is followed by an overview of its expression in reproductive tissues and in pregnancy. Futher, we discuss MIF's involvement in the survival of decidual stromal cells, placenta of the first trimester of pregnancy, and in trophoblast cell functions studied in vitro. Current findings associating this cytokine to placental infection, preeclampsia, gestational diabetes mellitus and choriocarcinoma are presented in the final part.

Trophoblast invasion: Lessons from abnormally invasive placenta (placenta accreta)

The invasion of the uterine wall by extravillous trophoblast is acknowledged as a crucial component of the establishment of pregnancy however, the only part of this process that has been clearly identified is the differentiation of cytotrophoblast (CTB) into the invasive extravillous trophoblast (EVT). The control of invasion, both initiation and termination, have yet to be elucidated and even the mechanism of differentiation is unclear. This review describes our studies which are designed to characterize the intracellular mechanisms that drive differentiation. We have used the over-invasion observed in abnormally invasive placenta (AIP; placenta accreta) to further interrogate this mechanism. Our results show that first trimester CTB to EVT differentiation is accomplished via an epithelial-mesenchymal transition (EMT), with EVT displaying a metastable, mesenchymal phenotype. In the third trimester, while the invasiveness of the EVT is lost, these cells still demonstrate signs of the EMT, albeit diminished. EVT isolated from AIP pregnancies do not however, show the same degree of reduction in EMT shown by normal third trimester cells. They exhibit a more mesenchymal phenotype, consistent with a legacy of greater invasiveness. The master regulatory transcription factor controlling the EMT appears, from the observational data, to be ZEB2 (zinc finger E-box binding protein 2). We verified this by overexpressing ZEB2 in the BeWo and JEG3 trophoblast cell lines and showing that they became more stellate in shape, up-regulated the expression of EMT-associated genes and demonstrated a substantially increased degree of invasiveness. The identification of the differentiation mechanism will enable us to identify the factors controlling invasion and those aberrant processes which generate the abnormal invasion seen in pathologies such as AIP and preeclampsia.

Potential roles of metalloproteinases of endometrium-derived exosomes in embryo-maternal crosstalk during implantation

During embryo implantation, crosstalk between the endometrial epithelium and the blastocyst, especially the trophoblasts, is a prerequisite for successful implantation. During this crosstalk, various molecular and functional changes occur to promote synchrony between the embryo and the endometrium as well as the uterine cavity microenvironment. In the past few years, growing evidence has shown that endometrium-derived exosomes play pivotal roles in the embryonic-maternal crosstalk during implantation, although the exact mechanism of this crosstalk has yet to be determined. The presence of metalloproteinases has been reported in endometrium-derived exosomes, implying the importance of these enzymes in exosome-based crosstalk. Thus, in this review, we describe the potential roles of the metalloproteinases of endometrium-derived exosomes in promoting embryo attachment and implantation. This study could provide a better understanding of the potential roles of exosomal metalloproteinases in embryo implantation and pave the way for developing novel exosome-based regulatory agents to support early pregnancy.

Cytokines, growth factors and macromolecules as mediators of implantation in mammalian species

Implantation is one of the most critical steps in mammalian reproduction and implantation failure constitutes a major cause of infertility in both animals and humans. The mechanism of implantation is exclusively under the control of ovarian steroids progesterone and oestrogen whose actions are mediated in a complex phenomenon that involves a number of cytokines and growth factors. According to a plethora of literature on implantation in mammalian species, prominent of these cytokines and growth factor playing crucial roles in implantation include integrin, osteopontin, integrin, insulin-like growth factor and leukaemia inhibitory factor. Others are cluster domain 44, hyaluronan system and many non-adhesive molecules such as glycoprotein mucin 1. In this review, the specific roles played by these molecules are expatiated. Generally, they function as adhesive molecules that facilitate attachment of ligands/proteins on the trophectoderm to their respective receptors on endometrial luminal epithelia or vice versa. Sometimes, they also function as signalling molecules that enhance communication between implanting blastocyst and receptive endometrium. This is of particular importance in embryo culture and embryo transfer where in vitro derived blastocyst unlike the in vivo condition, is not exposed to these substances and hence, their absence may be partly responsible for the low implantation rate observed in the surrogate. Appreciation of the roles played by these cytokines, growth factors and molecules as revealed in this review will spur further research on these topics, facilitate their inclusion in embryo culture media (if positively required) and are considered as vital aspect while developing strategies to improve fertility.

Deciphering transcriptional regulation in human embryonic stem cells specified towards a trophoblast fate

Differentiated human embryonic stem cells (hESC) continue to provide a model for studying early trophoblast cells (TB), but many questions have been raised regarding their true identity. Therefore, we carried out a global and unbiased analysis on previously published transcriptomic profiles for hESC differentiated to TB by means of bone morphogenetic protein-4 and inhibitors of activin A and fibroblast growth factor-2 signaling (BAP treatment). Our results confirm that BAP treated hESC (ESCd) lack a mesoderm signature and are a subtype of placental cells unlike those present at term. ESCd display a high level of expression of genes implicated in migration and invasion compared to commonly used, immortalized TB cell lines and primary cells from term placenta. Co-expression network analysis also identified gene modules involved in cell migration and adhesion, processes that are likely critical during the beginning stages of placentation. Finally, protein-protein interaction analysis predicted several additional genes that may play important roles in early stages of placental development. Together, our analyses provide novel insights into the transcriptional programs that are active in ESCd.

Low molecular weight hyaluronan induces migration of human choriocarcinoma JEG-3 cells mediated by RHAMM as well as by PI3K and MAPK pathways

Hyaluronan (HA) is the major glycosaminoglycan present in the extracellular matrix. It is produced by some tumours and promotes proliferation, differentiation and migration among others cellular processes. Gestational trophoblastic disease (GTD) is composed by non-tumour entities, such as hydatidiform mole (HM), which is the most common type of GTD and also malignant entities such as choriocarcinoma (CC) and placental site trophoblastic tumour (PSTT), being CC the most aggressive tumour. Although there is a growing understanding of GTD biology, the role of HA in the pathogenesis of this group of diseases remains largely unknown. The aim of this work was to study the role of HA in the pathogenesis of GTD by defining the expression pattern of HA and its receptors CD44 and RHAMM, as well as to determine if HA can modulate proliferation, differentiation and migration of CC cells. Receptors and signalling pathways involved were also analyzed. We demonstrated that HA and RHAMM are differently expressed among GTD entities and even among trophoblast subtypes. We also showed that HA is able to enhance the expression of extravillous trophoblast markers and also to induce migration of JEG-3 cells, the latter mediated by RHAMM as well as PI3K and MAPK pathways. These findings indicate a novel regulatory mechanism for CC cell biology and also contribute to the understanding of GTD pathophysiology.

Regulation and roles of the hyaluronan system in mammalian reproduction

Hyaluronan (HA) is a non-sulphated glycosaminoglycan polymer naturally occurring in many tissues and fluids of mammals, including the reproductive system. Its biosynthesis by HA synthase (HAS1–3) and catabolism by hyaluronidases (HYALs) are affected by ovarian steroid hormones. Depending upon its molecular size, HA functions both as a structural component of tissues in the form of high-molecular-weight HA or as a signalling molecule in the form of small HA molecules or HA fragments with effects mediated through interaction with its specific cell-membrane receptors. HA is produced by oocytes and embryos and in various segments of the reproductive system. This review provides information about the expression and function of members of the HA system, including HAS, HYALs and HA receptors. We examine their role in various processes from folliculogenesis through oocyte maturation, fertilisation and early embryo development, to pregnancy and cervical dilation, as well as its application in assisted reproduction technologies. Particular emphasis has been placed upon the role of the HA system in pre-implantation embryo development and embryo implantation, for which we propose a hypothetical sequential model.

Catch bond interaction allows cells to attach to strongly hydrated interfaces

Hyaluronans are a class of glycosaminoglycans that are widespread in the mammalian body and serve a variety of functions. Their most striking characteristic is their pronounced hydrophilicity and their capability to inhibit unspecific adhesion when present at interfaces. Catch-bond interactions are used by the CD44 receptor to interact with this inert material and to roll on the surfaces coated with hyaluronans. In this minireview, the authors discuss the general properties of hyaluronans and the occurrence and relevance of the CD44 catch-bond interaction in the context of hematopoiesis, cancer development, and leukemia.

Pharmacological inhibition of MIF interferes with trophoblast cell migration and invasiveness

INTRODUCTION

Macrophage migration inhibitory factor (MIF) is expressed by villous and extravillous cytotrophoblast. This study was aimed to investigate functional relevance of MIF for human trophoblast.

METHODS

MIF mRNA and protein were documented in cytotrophoblast (CT) and extravillous trophoblast cell line HTR-8/SVneo by RT-PCR, Western blot (WB), and immunocytochemistry. Recombinant human MIF (rhMIF), or its specific inhibitor (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) were used in Wound healing migration and Matrigel invasion tests. Potential effectors, integrin subunits and matrix metalloproteinases (MMP) were studied using WB and gelatin zymography, respectively.

RESULTS

Blocking endogenous MIF by ISO-1 decreased HTR-8/SVneo cell migration dose dependently, most significantly with 200 μg/ml to 65% of control. Supplementation with rhMIF induced a significant stimulation to 129% of control with 200 ng/ml. In CT cell invasion test, ISO-1 at 200 μg/ml reduced invasion to 59% of control, while rhMIF (200 ng/ml) induced stimulation to 159% of control. In HTR-8/SVneo cells, invasion was significantly inhibited by ISO-1 to 40%, and increased to 150% of control by rhMIF (200 ng/ml). Integrin α1 was reduced by ISO-1 in both cell types, while integrins α5 and β1 were not changed. Addition of rhMIF increased integrin α1. In the presence of ISO-1, levels of MMP-2 and MMP-9 were reduced in CT and HTR-8/SVneo, while rhMIF stimulated MMP-2 in CT and MMP-9 in HTR-8/SVneo cells.

CONCLUSION

Reported findings provide the first insight into the cellular effects of MIF in human trophoblast, which acts to promote cell migration and invasion.

The placental specific gene, PLAC1, is induced by the Epstein-Barr virus and is expressed in human tumor cells

BACKGROUND

The Epstein-Barr virus (EBV) is a causal agent in a number of malignancies in humans including hematopoietic tumors and non-hematopoietic tumors. Burkitt's lymphoma cell lines containing the Epstein-Barr virus have been shown to form tumors in nude mice while clonal derivatives of such cell lines in which the viral genome has been lost do not (JID 177: 1194-1201, 1998; JV 72: 9150-9156, 1998; JV 68: 6069-6073, 1994). The re-introduction of EBV into these EBV negative BLs reconstitutes the tumor phenotype. Thus, EBV-induced cellular genes play critical role in EBV-related tumors.

METHODS AND RESULTS

In an attempt to identify cellular genes regulated by EBV that may contribute to its tumorigenic properties, we have enforced genome loss in the Burkitt's lymphoma (BL) line, MutuI, by introducing a dominant negative form of the episomal replication factor, EBNA1 and carried out gene array analysis. One of the genes identified by this analysis is PLAC1, a gene originally identified as being expressed exclusively in placental tissue. Real time RT-PCR analysis verified higher expression in EBV positive vs. EBV negative Mutu clones. Analysis of a panel of RNAs from 20 normal tissues demonstrated the highest level of expression in placenta but significant expression was also observed in testis and brain cerebellum. PLAC1 expression was also observed in non-BL tumor cell lines derived from breast, ovary, and prostate. Lastly, expression of PLAC1 was found to be higher in some primary breast tumors compared to normal adjacent tissues.

CONCLUSION

This data suggests that the EBV-induced PLAC1 is a member of the cancer/testis group of tumor antigens.

Hyaluronan-CD44 interaction promotes growth of decidual stromal cells in human first-trimester pregnancy

Hyaluronan (HA) and its receptor CD44 are expressed at the maternal-fetal interface, but its role in early pregnancy remains unclear. Here, we found that primary decidual stromal cells (DSCs) continuously secreted HA and expressed its receptor CD44. Pregnancy-associated hormones up-regulated HA synthetase (HAS) 2 transcription and HA release from DSCs. High molecular weight-HA (HMW-HA), but not medium molecular weight (MMW-HA) or low molecular weight (LMW-HA), promoted proliferation and inhibited apoptosis of DSCs in a CD44-dependent manner. The in-cell Western analysis revealed HMW-HA activated PI3K/AKT and mitogen-activated protein kinase (MAPK)/ERK1/2 signaling pathways time-dependently. Blocking these pathways by specific inhibitor LY294002 or U0126 abrogated HMW-HA-regulated DSc proliferation and apoptosis. Finally, we have found that HA content, HA molecular weight, HAS2 mRNA level, and CD44 expression were significantly decreased in DSCs from unexplained miscarriage compared with the normal pregnancy. Collectively, our results indicate that higher level and greater molecular mass of HA at maternal-fetal interface contributes to DSc growth and maintenance of DSCs in human early pregnancy.

Hyaluronan up-regulates growth and invasion of trophoblasts in an autocrine manner via PI3K/AKT and MAPK/ERK1/2 pathways in early human pregnancy

INTRODUCTION

As one of the key molecules in the extracellular matrix in human conceptus, hyaluronan (HA) has been receiving particular attention. Here, we have investigated the expression and regulation of different molecular weight HA on the biological behaviors of primary human trophoblasts during the first trimester of pregnancy.

METHODS

The expression of HA and HA synthetase (HAS) by human first trimester trophoblasts was analyzed in placentae from normal pregnancy or miscarriage by immunochemistry and real-time RT-PCR, respectively. ELISA was used to measure the secretion of HA by primary trophoblasts. The effects of HA on the proliferation, apoptosis and invasiveness of trophoblasts were examined. We also investigated the signaling pathways involved in HA activation in human trophoblasts.

RESULTS

The higher HAS2 expression and HA secretion were observed in normal villi than that of miscarriage, and the primary trophoblasts secreted HA continuously. High molecular weight HA (HMW-HA) and medium molecular weight HA (MMW-HA) promoted proliferation and invasiveness while inhibited apoptosis of trophoblasts. However, low molecular weight HA (LMW-HA) had no obvious effect on the growth or invasiveness of human trophoblasts. In addition, HMW-HA showed more efficiently than MMW-HA on the growth while MMW-HA displayed a more obvious effect on the invasiveness of trophoblasts than HMW-HA. HMW-HA activated PI3K/AKT and MAPK/ERK1/2 signaling pathways in trophoblasts. Blocking PI3K/AKT or MAPK/ERK1/2 signaling inhibited the HA-upregulated growth and invasiveness of human trophoblasts.

CONCLUSION

Our results suggest that higher level and greater molecular mass of HA can promote trophoblast growth and invasion in an autocrine manner, which was beneficial to placentation and maintenance of human early pregnancy.

Anesthetic management of patients with placenta accreta and resuscitation strategies for associated massive hemorrhage

PURPOSE OF REVIEW

Placenta accreta is one of the leading causes of peripartum hemorrhage. The goal of this article is to review anesthetic management of parturients with placenta accreta and to examine a modern approach to massive peripartum hemorrhage.

RECENT FINDINGS

The incidence of placenta accreta is rising in parallel with the increased rate of cesarean delivery. If accreta is diagnosed or suspected preoperatively, anesthetic management can be optimized. Even with the best possible management, the blood loss associated with placenta accreta can resemble that of a major trauma. The use of Damage Control Resuscitation strategies to guide transfusion may improve morbidity and mortality.

SUMMARY

Careful planning and close communication are essential between anesthesiology, obstetric, interventional radiology, gynecologic oncology, blood bank, and specialized surgical teams when taking care of a patient with placenta accreta.

Expression of CD44 adhesion molecules on human placentae

OBJECTIVE

This study was performed to characterize CD44 expression in human placentae.

STUDY DESIGN

We conducted reverse transcriptase polymerase chain reaction (RT-PCR) analyses of CD44H (hematopoietic form, also called CD44s) and CD44R1 (epithelial form) in 14 normal term placentae, and immunohistochemical analysis of CD44H and CD44v6 in 31 placentae (25 term and 6 first-trimester).

RESULTS

All 14 term placentae expressed CD44H (double bands) suggesting expression of alternative isoforms on the placentae. CD44R1 was expressed on 3 of 14 (21.4%) term placentae. Immunohistochemical analysis revealed expression of CD44H in all the placentae examined. However, positive staining for CD44v6 was observed in 3 of 6 (50%) first-trimester and only 6 of 25 (24%) term placentae showing decreased expression on term placentae. Positive staining for CD44v6 was observed on the trophoblast surface of immature villi especially in the sub-chorionic area where hypoxic conditions prevail.

CONCLUSION

These results suggest that CD44 splicing variants might play a role in the invasion of trophoblast into maternal tissue in early pregnancy.

CD44 in cancer progression: adhesion, migration and growth regulation

It is well established that the large array of functions that a tumour cell has to fulfil to settle as a metastasis in a distant organ requires cooperative activities between the tumour and the surrounding tissue and that several classes of molecules are involved, such as cell-cell and cell-matrix adhesion molecules and matrix degrading enzymes, to name only a few. Furthermore, metastasis formation requires concerted activities between tumour cells and surrounding cells as well as matrix elements and possibly concerted activities between individual molecules of the tumour cell itself. Adhesion molecules have originally been thought to be essential for the formation of multicellular organisms and to tether cells to the extracellular matrix or to neighbouring cells. CD44 transmembrane glycoproteins belong to the families of adhesion molecules and have originally been described to mediate lymphocyte homing to peripheral lymphoid tissues. It was soon recognized that the molecules, under selective conditions, may suffice to initiate metastatic spread of tumour cells. The question remained as to how a single adhesion molecule can fulfil that task. This review outlines that adhesion is by no means a passive task. Rather, ligand binding, as exemplified for CD44 and other similar adhesion molecules, initiates a cascade of events that can be started by adherence to the extracellular matrix. This leads to activation of the molecule itself, binding to additional ligands, such as growth factors and matrix degrading enzymes, complex formation with additional transmembrane molecules and association with cytoskeletal elements and signal transducing molecules. Thus, through the interplay of CD44 with its ligands and associating molecules CD44 modulates adhesiveness, motility, matrix degradation, proliferation and cell survival, features that together may well allow a tumour cell to proceed through all steps of the metastatic cascade.

Detection of the Hyaluronan Receptor CD44 in the Bovine Oviductal Epithelium

Hyaluronan is involved in fundamental reproductive events such as sperm storage in the female reproductive tract, fertilization, and early embryo development, these functions are presumably mediated by its major cell surface receptor, CD44. The present study was conducted to investigate the presence and localization of CD44 in the bovine oviductal epithelium, using immunohistochemical and Western blot methods on tissue sections and epithelial cell extracts collected from the uterotubal junction (UTJ), isthmus, and ampulla of animals in the oestrus or luteal phase of the oestrous cycle. While positive immunolabelling for CD44 was found on the ad-luminal surface and supra-nuclear region of epithelial cells in all tubal segments investigated, in the UTJ, there were epithelial cells in which the entire cytoplasm positively stained. We found no differences in terms of CD44-positive staining between the different stages of the oestrous cycle. Presence of CD44 was detected by Western blotting in the tubal epithelium as a single band at 200 kDa. Although it appeared in all tubal segments, the expression of CD44 protein was more accentuated in the sperm reservoir (UTJ) than in the other segments. This is the first time CD44 has been detected in the epithelium of the tubal sperm reservoir in cattle, suggesting a pathway for the action of hyaluronan in this segment.

Enhanced expression of CD44 variants in human atheroma and abdominal aortic aneurysm: possible role for a feedback loop in endothelial cells

CD44, a polymorphic hyaluronate receptor, may participate in chronic inflammation. We hypothesized that CD44 variants contribute to the development of arterial diseases. CD44 levels vary in normal and diseased arterial tissues in the following order: unaffected arteries < fibrous plaques < or = abdominal aortic aneurysm < atheromatous plaques; and correlate with macrophage content. Furthermore, plaque microvessels express CD44, and anti-CD44v3 or anti-CD44v6 treatment reduces endothelial cell proliferation but not apoptosis in vitro, suggesting functionality of these receptors. Endothelial cells express CD44H and CD44v6 after exposure to interleukin-1beta and tumor necrosis factor-alpha. Macrophages, a major source of abundant CD44 in vitro, express not only CD44H but also variants CD44v4/5, CD44v6, and CD44v7/8, isoforms distinctively regulated by proinflammatory cytokines. Several proinflammatory cytokines induce shedding of CD44 from the surface of macrophages and endothelial cells. Soluble CD44 stimulates the expression and release of interleukin-1beta from endothelial cells, suggesting a positive feedback loop of this cytokine. By demonstrating augmented expression of CD44 and variants within human atheroma and in abdominal aortic aneurysm as well as the vascular cell release of sCD44, a process regulated by proinflammatory cytokines, this study provides new insights on the functions of CD44 in arterial diseases.

Adhesion-related proteins E-cadherin, P-cadherin, CD44, and CD44v6, and antimetastatic protein nm23H1 in complete hydatidiform moles in relation to invasion potential

Cell adhesion has an essential role in regulating metastasis, and loss of cell adhesion is a classic feature of invasion. There is currently a great deal of interest in the role of adhesion proteins and the antimetastatic protein nm23H1 in the progression of cancer. However, reports on the expression of these proteins in complete hydatidiform moles (CHMs) are limited. In the present study, expression of the adhesion molecules E-cadherin, P-cadherin, CD44, and CD44v6, and the antimetastatic protein nm23H1 was assessed in relation to the invasive potential of CHMs. This is the first report on the expression of these proteins in CHMs. Immunohistochemical assessment was carried out in CHMs (105 cases including 15 cases of invasive moles) and compared with that of gestational age-matched normal placentae (95 cases). The expression of the adhesion proteins ranged from mild to moderate intensity with a general down-regulation in the molar trophoblasts, the down-regulation in CD44 and CD44V6 being highly significant. No relation was, however, noticed with the invasiveness or the persistence of the disease. nm23H1 protein, on the other hand, was significantly down-regulated in the molar trophoblasts with none of the invasive lesions showing intense expression. The study thus suggests down-regulation of adhesion proteins, especially that of CD44 and CD44v6, to be an early step in the transformation to molar placenta with reduced expression of nm23H1 conferring an invasive potential to the trophoblasts.

Perinatal Outcome of Pregnancies Complicated by Placenta Accreta

OBJECTIVE

The purpose of the study was to characterize the perinatal outcome of pregnancies complicated by placenta accreta.

METHODS

We conducted a case-control analysis of all deliveries between the years 1990 and 2000 that were complicated by placenta accreta. Perinatal variables included in the analysis were gestational age at delivery, birth weight, Apgar scores, and perinatal mortality. Statistical analysis was performed using both the unpaired and paired approach. P <.05 was considered significant.

RESULTS

The study encompassed 34,450 deliveries, from which 310 cases of placenta accreta were diagnosed (0.9%) and compared with 310 matched controls. In the pregnancies complicated by placenta accreta, we found a statistically significant increase in preterm deliveries (10.7% versus 1%, P <.001, odds ratio 12.1, 95% confidence interval 3.7-39.9) and small-for-gestational-age babies (27.3% versus 14%, P <.001, odds ratio 5.05, 95% confidence interval 1.46-3.28).

CONCLUSION

Pregnancies complicated by placenta accreta are at increased risk for perinatal adverse outcome. We speculate that these findings may arise from pathological implantation of the placenta, resulting in interference with normal fetal growth.

Expression of hyaluronan synthases and corresponding hyaluronan receptors is differentially regulated during oocyte maturation in cattle

In response to the gonadotropin surge, the compact cumulus-oocyte complex (COC) undergoes expansion by synthesis of the mucopolysaccharide hyaluronan (HA) accompanying oocyte maturation. The objective of the present study was to quantify mRNA transcripts of the HA synthase (HAS) 1, HAS2, and HAS3 and the HA-receptors CD44 and RHAMM (receptor for HA-mediated motility). Additionally, we determined the histological localization of HA and its receptor, CD44, in maturing bovine COCs and cultured granulosa cells (GCs). Full-length transcript of bovine HAS2 and a part of the bovine RHAMM sequence has been made available. Real-time reverse transcriptase-polymerase chain reaction was used for individual mRNA expressions of bovine COCs in comparison to follicular GC gonadotropin treatment. Localization of CD44 and HA were done by immunohistochemistry and biotinylated HA-binding protein, respectively. Gonadotropins caused a rapid, 120-fold increase of HAS2 mRNA, whereas a delayed, 2-fold up-regulation of HAS3 mRNA was observed. The HAS1 transcripts were barely detected. Expression of CD44 mRNA greatly increased during in vitro maturation of COCs, indicating an important role when compared to an unchanged, steady-state RHAMM expression. As a consequence, HA was locally enriched after COC expansion, but only limited change was observed in the GCs. In cultured GCs, HAS2 expression was stimulated through FSH application, followed by the effective treatments of FSH+LH and LH. Treatment with LH induced the highest increase of the CD44 receptor, followed by FSH and FSH+LH treatments. These results suggest that HAS2 is mainly responsible for rapid HA synthesis in bovine COCs and GCs. In bovine COCs, the transcriptional up-regulation of both HAS2 and the receptor CD44 appear to be important prerequisites for initiating HA-mediated effects during final oocyte development and sperm-egg interaction.

Placenta accreta--summary of 10 years: a survey of 310 cases

The objective was to study the incidence, risk factors, and outcome of pregnancies complicated by placenta accreta in our population. Retrospective analysis of all deliveries between the years 1990-2000, and identification of all cases of placenta accreta, defined by clinical or histological criteria. For comparison purposes we defined two sub-groups: (i) all cases that ended with severe outcome and (ii) all patients who had a previous event of placenta accreta in one or more of their previous deliveries. We evaluated the potential risk factors leading to these conditions. The SPSS software package was used for statistical analysis. Univariate and multivariate analyses were performed by stepwise logistic regression. The study covered 34 450 deliveries from which 310 cases of placenta accreta were diagnosed (0.9 per cent). The risk factors associated with placenta accreta were previous cesarean delivery (12 per cent), advanced maternal age, high gravidity, multiparity, previous curettage and placenta previa (10 per cent). Hysterectomy was performed in 11 patients (3.5 per cent) with one case of maternal death, whereas 21 per cent of the patients required postpartum blood products transfusion. Antenatal diagnosis of placenta accreta or percreta by ultrasound or MRI, was achieved only in eight of the cases. In the sub-group of 15 patients (4.8 per cent) with severe outcome, the only significant risk factors were increased parity (O.R.=1.29, 95 per cent CI 1.056-1.585), anteriorly low placenta (O.R.=6.1, 95 per cent CI 1.4-25.3) and repeated cases of caesarean sections (O.R.=3.3, 95 per cent CI 0.9-12.5), whereas in the 49 (16 per cent) patients with repeated cases of placenta accreta the only significant risk factor was the number of deliveries (O.R.=1.5, 95 per cent CI 1.0-2.2). Repeated cesarean delivery, high parity, and anteriorly low placental location are associated with severe outcome in case of placenta accreta. Women with repeated events of placenta accreta may have better outcome and a genetic factor may serve as a cause for this condition.

CD44v10 in hematopoiesis and stem cell mobilization

Transplantation of hematopoietic progenitor cells provides in many instances of malignant tumors an ultimate chance of curative therapy, whereby the transfer of peripheral blood stem cells (PBSC) may even be advantageous as compared to bone marrow cells. Yet, the transfer of PBSC requires mobilization of stem cells into the periphery, which is mostly achieved via hematopoietic growth factors like G-CSF. Although G-CSF has been found to efficiently mobilize stem cells in most instances, some patients do not or insufficiently respond to G-CSF treatment In addition, G-CSF treatment may by accompanied by maturation of the most primitive progenitors and this may have an impact on stem cell homing and recovery of hemopoiesis. Therefore, additional approaches for stem cell mobilization have been searched for, in particular mobilization via a blockade of an adhesion molecule expressed by CD34-positive cells, like VLA-4 (CD49d) and the hematopoietic isoform of CD44 (CD44s). We recently described that in the mouse one of the CD44 variant isoforms, CD44v10, is expressed on a subpopulation of bone marrow cells, whereas a CD44v10 receptor-globulin only binds to stromal elements. These features appeared promising for anti-CD44v10 as a means of stem cell mobilization. Indeed, treatment with anti-CD44v10 revealed promising results concerning the recovery of multilineage colony forming units in the spleen and the peripheral blood. We here summarize features of expression and function of CD44 in hematopoiesis an provide further evidence for anti-CD44v10 as a means to mobilize hematopoietic progenitor cells.

Expression of syndecan-1 in human placenta and decidua

Syndecan-1 is a cell surface heparan sulphate proteoglycan, which binds to the extracellular matrix (ECM), growth factors and antithrombin III. The early expression of syndecan-1 during mouse embryonic development suggests a potential role in the communication between the embryo and the ECM of decidua. Using immunohistochemical methods, the present study showed that the expression of syndecan-1 in the trophoblast cells changes along trophoblast differentiation. The syncytiotrophoblasts in the chorionic villi exhibited an apical expression of syndecan-1. This suggests that the expression is restricted to non-migrating, non-proliferating trophoblasts. The mode of syndecan-1 expression by human placental trophoblasts is independent of gestational age. The expression is not changed in miscarriages. In pre-eclampsia, the staining for syndecan-1 on the villous syncytiotrophoblast is weaker compared to normal pregnancy, but in placental bed the expression is similar. The unique apical localization of syndecan-1 in chorionic villi, not detected in any other tissues, suggests a potential role in fetomaternal communication probably via growth factor binding and in anticoagulation of intervillous circulation.

Isolation and characterization by electrospray-ionization mass spectrometry and high-performance anion-exchange chromatography of oligosaccharides derived from hyaluronic acid by hyaluronate lyase digestion: observation of some heretofore unobserved oligosaccharides that contain an odd number of units

Hyaluronic acid was degraded with hyaluronate lyase (E.C. 4.2.2.1, from Streptomyces hyalurolyticus), and the resulting oligosaccharides up to dp 16 were characterized by electrospray-ionization mass spectrometry (ESIMS) and high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD). In accordance with the known regiospecificity of the enzyme, the products included even-numbered oligosaccharides of structure beta-D-4en-thrHexpA-(1-->3)-[beta-D-GlcpNAc-(1-->4)-beta-D- GlcpA]n-(1-->3)-D-GlcpNAc. Minor amounts of novel and unexpected odd-numbered oligomers, having the structure beta-D-4en-thrHexpA-(1-->3)-[beta-D-GlcpNAc-(1-->4)-D-Glc pA]n, were also isolated and characterized. This study, in addition to others beginning to appear in the literature, demonstrates the usefulness of ESIMS and HPAEC-PAD in the analysis and characterization of anionic glycosaminoglycan-type oligosaccharides.