Plasma Biomarkers of Inflammation and Angiogenesis Predict Cerebral Cavernous Malformation Symptomatic Hemorrhage or Lesional Growth.

RATIONALE: The clinical course of cerebral cavernous malformations is highly unpredictable, with few cross-sectional studies correlating proinflammatory genotypes and plasma biomarkers with prior disease severity. OBJECTIVE: We hypothesize that a panel of 24 candidate plasma biomarkers, with a reported role in the physiopathology of cerebral cavernous malformations, may predict subsequent clinically relevant disease activity. METHODS AND RESULTS: Plasma biomarkers were assessed in nonfasting peripheral venous blood collected from consecutive cerebral cavernous malformation subjects followed for 1 year after initial sample collection. A first cohort (N=49) was used to define the best model of biomarker level combinations to predict a subsequent symptomatic lesional hemorrhagic expansion within a year after the blood sample. We generated the receiver operating characteristic curves and area under the curve for each biomarker individually and each weighted linear combination of relevant biomarkers. The best model to predict lesional activity was selected as that minimizing the Akaike information criterion. In this cohort, 11 subjects experienced symptomatic lesional hemorrhagic expansion (5 bleeds and 10 lesional growths) within a year after the blood draw. Subjects had lower soluble CD14 (cluster of differentiation 14; P=0.05), IL (interleukin)-6 (P=0.04), and VEGF (vascular endothelial growth factor; P=0.0003) levels along with higher plasma levels of IL-1ß (P=0.008) and soluble ROBO4 (roundabout guidance receptor 4; P=0.03). Among the 31 weighted linear combinations of these 5 biomarkers, the best model (with the lowest Akaike information criterion value, 25.3) was the weighted linear combination including soluble CD14, IL-1ß, VEGF, and soluble ROBO4, predicting a symptomatic hemorrhagic expansion with a sensitivity of 86% and specificity of 88% (area under the curve, 0.90; P<0.0001). We then validated our best model in the second sequential independent cohort (N=28). CONCLUSIONS: This is the first study reporting a predictive association between plasma biomarkers and subsequent cerebral cavernous malformation disease clinical activity. This may be applied in clinical prognostication and stratification of cases in clinical trials.

Evidence for the involvement of internal calcium stores during serotonin-induced meiosis reinitation in oocytes of the bivalve mollusc Ruditapes philippinarum.

In contrast to the situation found in the bivalves Barnea candida and Spisula solidissima, prophase-arrested oocytes of Ruditapes philippinarum cannot be fertilized when removed from the ovary. They must first undergo germinal vesicle breakdown under the influence of the neurohormone serotonin (5-HT), which drives them to a second block occurring in metaphase of the first maturation division. In the studies described in this paper, we investigate the possibility that calcium is involved as a second messenger in controlling this first step in the reinitiation of meiosis. Our data show that, in addition to 5-HT, ionophore, thapsigargin, and the weak bases ammonia and procaine can also induce prophase-arrested oocytes of Ruditapes to resume meiosis. 5-HT, thapsigargin, and ammonia all trigger a surge of intracellular Ca2+ and are effective even in the absence of external Ca2+. That such Ca2+ transients, which are enhanced in the presence of external Ca2+, actually play a key role in the process of meiosis reinitation is shown by the fact that loading the oocytes with BAPTA/AM or treating them with D-600 blocks maturation. In contrast, excess KCl, which has been shown to trigger meiosis reinitiation of prophase-arrested oocytes of Barnea and Spisula and to activate metaphase I-arrested oocytes of Ruditapes, does not produce any significant intracellular Ca2+ transient nor does it reinitiate meiosis, when added to Ruditapes prophase-arrested oocytes. These data suggest that such voltage-operated Ca2+ channels may only appear during the course of maturation and that both intracellular and extracellular Ca2+ are involved in triggering 5-HT-dependent release from the prophase block in this species.

Release from the metaphase I block in invertebrate oocytes: possible involvement of Ca2+/calmodulin-dependent kinase III.

Full grown mature oocytes of the prosobranch gastropod mollusc Patella or the bivalves Mytilus or Ruditapes provide an excellent model for studying the mechanisms which trigger cyclin degradation and exit from the M phase. They are naturally arrested in metaphase of the first maturation division and their fertilization or artificial activation rapidly results in destruction of the cyclins and completion of meiosis. In this paper, we establish the presence of Ca2+/calmodulin-dependent kinase III or eEF-2 kinase in these oocytes and describe how the protein synthesis inhibitor emetine is able to release them from the metaphase block. Using the fluorescent Ca2+ indicator dye, fluo-3, we demonstrate moreover that both fertilization or KCl-dependent activation of Ruditapes and Mytilus oocytes actually trigger a measurable transient increase in cytosolic free Ca2+ concentration. We also show that the activations triggered by these signals as well as by the ionophore A 23187 can be reversibly blocked by the calmodulin antagonists TFP (30 microM) and W7 (100 microM), while these drugs have no effect upon emetine-dependent activations. Finally, we report that the rate of protein synthesis, measured in pulse experiments, decreases at each meiotic and mitotic cleavage following fertilization of metaphase I-arrested oocytes of Mytilus. On the basis of these experiments and as a working hypothesis, we thus propose that the Ca2+ surge which activates the oocyte may inhibit protein synthesis by triggering a transient phosphorylation of eEF-2. This would result in disappearance of the putative short-lived proteins which protect cyclins from degradation during the metaphase block.

The relationship of gap junctions and compaction in the preimplantation mouse embryo.

In the mouse embryo, gap junctions first appear at the 8-cell stage as compaction is about to take place. Compaction of the embryo is important for the differentiation of the first two cell types; the inner cell mass and the trophectoderm. Our studies examine the contribution of gap junctional communication at this stage of development. We have characterised the normal sequence of appearance of gap junction protein and its distribution. The extent of communication as shown by the passage of dye between cells has been recorded in both normal embryos and embryos treated with drugs that influence gap junctional communication. Comparisons have been made with embryos that express a lethal gap junction defect and attempts were made to rescue such embryos by increasing their gap junction communication.