Elevated miR‐200a and miR‐141 inhibit endocrine gland‐derived vascular endothelial growth factor expression and ciliogenesis in preeclampsia

Over half a million women die each year from pregnancy related causes, 99% in low and middle income countries. In many low income countries, complications of pregnancy and childbirth are the leading cause of death amongst women of reproductive years. The Millennium Development Goals have placed maternal health at the core of the struggle against poverty and inequality, as a matter of human rights. Ten percent of women have high blood pressure during pregnancy, and preeclampsia complicates 2% to 8% of pregnancies. Preeclampsia can lead to problems in the liver, kidneys, brain and the clotting system. Risks for the baby include poor growth and prematurity. Although outcome is often good, preeclampsia can be devastating and life threatening. Overall, 10% to 15% of direct maternal deaths are associated with preeclampsia and eclampsia. Where maternal mortality is high, most of deaths are attributable to eclampsia, rather than preeclampsia. Perinatal mortality is high following preeclampsia, and even higher following eclampsia. In low and middle income countries many public hospitals have limited access to neonatal intensive care, and so the mortality and morbidity is likely to be considerably higher than in settings where such facilities are available. The only interventions shown to prevent preeclampsia are antiplatelet agents, primarily low dose aspirin, and calcium supplementation. Treatment is largely symptomatic. Antihypertensive drugs are mandatory for very high blood pressure. Plasma volume expansion, corticosteroids and antioxidant agents have been suggested for severe preeclampsia, but trials to date have not shown benefit. Optimal timing for delivery of women with severe preeclampsia before 32 to 34 weeks' gestation remains a dilemma. Magnesium sulfate can prevent and control eclamptic seizures. For preeclampsia, it more than halves the risk of eclampsia (number needed to treat 100, 95% confidence interval 50 to 100) and probably reduces the risk of maternal death. A quarter of women have side effects, primarily flushing. With clinical monitoring serious adverse effects are rare. Magnesium sulfate is the anticonvulsant of choice for treating eclampsia; more effective than diazepam, phenytoin, or lytic cocktail. Although it is a low cost effective treatment, magnesium sulfate is not available in all low and middle income countries; scaling up its use for eclampsia and severe preeclampsia will contribute to achieving the Millennium Development Goals.

Microtubule-dependent motor, murine KIF3B, was disrupted by gene targeting. The null mutants did not survive beyond midgestation, exhibiting growth retardation, pericardial sac ballooning, and neural tube disorganization. Prominently, the left-right asymmetry was randomized in the heart loop and the direction of embryonic turning. lefty-2 expression was either bilateral or absent. Furthermore, the node lacked monocilia while the basal bodies were present. Immunocytochemistry revealed KIF3B localization in wild-type nodal cilia. Video microscopy showed that these cilia were motile and generated a leftward flow. These data suggest that KIF3B is essential for the left-right determination through intraciliary transportation of materials for ciliogenesis of motile primary cilia that could produce a gradient of putative morphogen along the left-right axis in the node.

Primary cilia project in a single copy from the surface of most vertebrate cell types; they detect and transmit extracellular cues to regulate diverse cellular processes during development and to maintain tissue homeostasis. The sensory capacity of primary cilia relies on the coordinated trafficking and temporal localization of specific receptors and associated signal transduction modules in the cilium. The canonical hedgehog (HH) pathway, for example, is a bona fide ciliary signalling system that regulates cell fate and self-renewal in development and tissue homeostasis. Specific receptors and associated signal transduction proteins can also localize to primary cilia in a cell type-dependent manner; available evidence suggests that the ciliary constellation of these proteins can temporally change to allow the cell to adapt to specific developmental and homeostatic cues. Consistent with important roles for primary cilia in signalling, mutations that lead to their dysfunction underlie a pleiotropic group of diseases and syndromic disorders termed ciliopathies, which affect many different tissues and organs of the body. In this review we highlight central mechanisms by which primary cilia coordinate HH, G-protein-coupled receptor, WNT, receptor tyrosine kinase and TGFβ/BMP signalling, and illustrate how defects in the balanced output of ciliary signalling events are coupled to developmental disorders and disease progression.