Heparin/heparan sulfate/CD44-v3 enhances cell migration in term placenta-derived immortalized human trophoblast cells

Inhibition of LAMP3 mediates the protective effect of vitamin D against hypoxia/reoxygenation in trophoblast cells

Inadequate invasion and excessive apoptosis of trophoblast cells are associated with the development of preeclampsia. Vitamin D deficiency in pregnant women may lead to an increased risk of preeclampsia. However, the underlying mechanisms by which vitamin D is effective in preventing preeclampsia are not fully understood. The objectives of this study were to investigate the role of lysosome-associated membrane glycoprotein 3 (LAMP3) in the pathogenesis of preeclampsia and to evaluate whether vitamin D supplementation would protect against the development of preeclampsia by regulating LAMP3 expression. Firstly, the mRNA and protein levels of LAMP3 were significantly upregulated in the placentas of preeclampsia patients compared to normal placentas, especially in trophoblast cells (a key component of the human placenta). In the hypoxia/reoxygenation (H/R)-exposed HTR-8/Svneo trophoblast cells, LAMP3 expression was also upregulated. H/R exposure repressed cell viability and invasion and increased apoptosis of trophoblast cells. siRNA-mediated knockdown of LAMP3 increased cell viability and invasion and suppressed apoptosis of H/R-exposed trophoblast cells. We further found that 1,25(OH)2D3 (the hormonally active form of vitamin D) treatment reduced LAMP3 expression in H/R exposed trophoblast cells. In addition, 1,25(OH)2D3 treatment promoted cell viability and invasion and inhibited apoptosis of H/R-exposed trophoblast cells. Notably, overexpression of LAMP3 abrogated the protective effect of 1,25(OH)2D3 on H/R-exposed trophoblast cells. Collectively, we demonstrated trophoblast cytoprotection by vitamin D, a process mediated via LAMP3.

Syphilis vaccine: challenges, controversies and opportunities

Syphilis is a sexually or vertically (mother to fetus) transmitted disease caused by the infection of Treponema pallidum subspecie pallidum (TPA). The incidence of syphilis has increased over the past years despite the fact that this bacterium is an obligate human pathogen, the infection route is well known, and the disease can be successfully treated with penicillin. As complementary measures to preventive campaigns and early treatment of infected individuals, development of a syphilis vaccine may be crucial for controlling disease spread and/or severity, particularly in countries where the effectiveness of the aforementioned measures is limited. In the last century, several vaccine prototypes have been tested in preclinical studies, mainly in rabbits. While none of them provided protection against infection, some prototypes prevented bacteria from disseminating to distal organs, attenuated lesion development, and accelerated their healing. In spite of these promising results, there is still some controversy regarding the identification of vaccine candidates and the characteristics of a syphilis-protective immune response. In this review, we describe what is known about TPA immune response, and the main mechanisms used by this pathogen to evade it. Moreover, we emphasize the importance of integrating this knowledge, in conjunction with the characterization of outer membrane proteins (OMPs), to expedite the development of a syphilis vaccine that can protect against TPA infection.

HS, an Ancient Molecular Recognition and Information Storage Glycosaminoglycan, Equips HS-Proteoglycans with Diverse Matrix and Cell-Interactive Properties Operative in Tissue Development and Tissue Function in Health and Disease

Heparan sulfate is a ubiquitous, variably sulfated interactive glycosaminoglycan that consists of repeating disaccharides of glucuronic acid and glucosamine that are subject to a number of modifications (acetylation, de-acetylation, epimerization, sulfation). Variable heparan sulfate chain lengths and sequences within the heparan sulfate chains provide structural diversity generating interactive oligosaccharide binding motifs with a diverse range of extracellular ligands and cellular receptors providing instructional cues over cellular behaviour and tissue homeostasis through the regulation of essential physiological processes in development, health, and disease. heparan sulfate and heparan sulfate-PGs are integral components of the specialized glycocalyx surrounding cells. Heparan sulfate is the most heterogeneous glycosaminoglycan, in terms of its sequence and biosynthetic modifications making it a difficult molecule to fully characterize, multiple ligands also make an elucidation of heparan sulfate functional properties complicated. Spatio-temporal presentation of heparan sulfate sulfate groups is an important functional determinant in tissue development and in cellular control of wound healing and extracellular remodelling in pathological tissues. The regulatory properties of heparan sulfate are mediated via interactions with chemokines, chemokine receptors, growth factors and morphogens in cell proliferation, differentiation, development, tissue remodelling, wound healing, immune regulation, inflammation, and tumour development. A greater understanding of these HS interactive processes will improve therapeutic procedures and prognoses. Advances in glycosaminoglycan synthesis and sequencing, computational analytical carbohydrate algorithms and advanced software for the evaluation of molecular docking of heparan sulfate with its molecular partners are now available. These advanced analytic techniques and artificial intelligence offer predictive capability in the elucidation of heparan sulfate conformational effects on heparan sulfate-ligand interactions significantly aiding heparan sulfate therapeutics development.

Knockdown of JARID2 inhibits the viability and migration of placenta trophoblast cells in preeclampsia

Protein Jumonji (JARID2) is a member of the Jumonji family of proteins and has been demonstrated to regulate cell proliferation and invasion. However, little is known about the role of JARID2 in the metastasis of placenta trophoblast cells. In the present study, the effect and the underlying molecular mechanism of JARID2 on trophoblast cell viability and invasion was investigated. The expression of JARID2 in placental tissues was analyzed by reverse transcription‑quantitative polymerase chain reaction and western blotting. HTR8/SVneo cells were transfected with si‑JARID2 or scramble for 24 h. Cell viability, migration and invasion in HTR8/SVneo cells were then evaluated. The expression levels of matrix metallopeptidase 2 (MMP2), MMP9, phosphorylated phosphatidylinositol 3‑kinase (p‑PI3K), PI3K, phosphorylated AKT serine/threonine kinase 1 (p‑Akt) and Akt in HTR8/SVneo cells were also detected using western blotting. The results of the present study demonstrated that JARID2 is underexpressed in human preeclamptic placentas. The knockdown of JARID2 significantly inhibited the viability, migration and invasion of HTR8/SVneo cells. In addition, the knockdown of JARID2 significantly decreased the levels of phosphorylated PI3K and Akt in HTR8/SVneo cells. The results of the present study demonstrated that JARID2 may serve a role in the progression of preeclampsia. The knockdown of JARID2 inhibited the viability and invasion of trophoblast cells in preeclampsia by suppressing the PI3K/Akt signaling pathway. Therefore, JARID2 may serve as a novel potential target for treating preeclampsia.

Chymotrypsin Enhances Soluble Fms-Like Tyrosine Kinase 1 Production Through Protease-Activated Receptor 2 in Placenta-Derived Immortalized Human Trophoblast Cells

The production of soluble fms-like tyrosine kinase 1 (sFLT1) by exogenous chymotrypsin in trophoblast cells through protease-activated receptor (PAR) 2 was investigated to identify the role of a chymotrypsin-like serine protease in preeclampsia (PE) pathogenesis. We evaluated the expression of chymotrypsin, FLT1, and sFLT1 in monolayers of immortalized human trophoblast cells derived from placenta (TCL-1 cells). To investigate whether chymotrypsin enhances the production and release of sFLT1 through PAR-2, we examined changes in sFLT1 protein levels in conditioned medium by enzyme-linked immunosorbent assay and sFLT1 messenger RNA (mRNA) levels by real-time polymerase chain reaction in TCL-1 cells treated with exogenous chymotrypsin in the presence or absence of a PAR-2 antagonist or a chymotrypsin inhibitor (TPCK). We also examined changes in PAR-2 expression in TCL-1 cells treated with tumor necrosis factor (TNF) α in the presence or absence of a polyclonal anti-TNF-α antibody. Western blot analysis showed that TCL-1 trophoblast cells expressed chymotrypsin, FLT1, and sFLT1. Compared with the control cells, the sFLT1 level in the conditioned medium and sFLT1 mRNA level in cells were both significantly enhanced when treated with a PAR-2 agonist or chymotrypsin for 6 hours. In contrast, the sFLT1 level in the medium and sFLT1 mRNA level in cells treated with a PAR-2 agonist or chymotrypsin were suppressed in the presence of a PAR-2 antagonist or a chymotrypsin inhibitor. The PAR-2 expression was upregulated by TNF-α, which was suppressed in the presence of TNF-α antibodies. These results indicate that chymotrypsin-like serine protease enhances sFLT1 production through PAR-2 in trophoblast cells and thus plays an important additional role in PE pathogenesis.

Quantifying trophoblast migration: In vitro approaches to address in vivo situations

When trophoblasts migrate and invade in vivo, they do so by interacting with a range of other cell types, extracellular matrix proteins, chemotactic factors and physical forces such as fluid shear stress. These factors combine to influence overall trophoblast migration and invasion into the decidua, which in turn determines the success of spiral artery remodelling, and pregnancy itself. Our understanding of these important but complex processes is limited by the simplified conditions in which we often study cell migration in vitro, and many discrepancies are observed between different in vitro models in the literature. On top of these experimental considerations, the migration of individual trophoblasts can vary widely. While time-lapse microscopy provides a wealth of information on trophoblast migration, manual tracking of individual cell migration is a time consuming task that ultimately restricts the numbers of cells quantified, and thus the ability to extract meaningful information from the data. However, the development of automated imaging algorithms is likely to aid our ability to accurately interpret trophoblast migration in vitro, and better allow us to relate these observations to in vivo scenarios. This commentary discusses the advantages and disadvantages of techniques commonly used to quantify trophoblast migration and invasion, both from a cell biology and a mathematical perspective, and examines how such techniques could be improved to help us relate trophoblast migration more accurately to in vivo function in the future.