Simulated Microgravity Regulates Gene Transcript Profiles of 2T3 Preosteoblasts: Comparison of the Random Positioning Machine and the Rotating Wall Vessel Bioreactor

Microgravity of spaceflight induces bone loss due in part to decreased bone formation by osteoblasts. We have previously examined the microgravity-induced changes in gene expression profiles in 2T3 preosteoblasts using the Random Positioning Machine (RPM) to simulate microgravity conditions. Here, we hypothesized that exposure of preosteoblasts to an independent microgravity simulator, the Rotating Wall Vessel (RWV), induces similar changes in differentiation and gene transcript profiles, resulting in a more confined list of gravi-sensitive genes that may play a role in bone formation. In comparison to static 1g controls, exposure of 2T3 cells to RWV for 3 days inhibited alkaline phosphatase activity, a marker of differentiation, and downregulated 61 genes and upregulated 45 genes by more than two-fold as shown by microarray analysis. The microarray results were confirmed with real time PCR for downregulated genes osteomodulin, bone morphogenic protein 4 (BMP4), runx2, and parathyroid hormone receptor 1. Western blot analysis validated the expression of three downregulated genes, BMP4, peroxiredoxin IV, and osteoglycin, and one upregulated gene peroxiredoxin I. Comparison of the microarrays from the RPM and the RWV studies identified 14 gravi-sensitive genes that changed in the same direction in both systems. Further comparison of our results to a published database showing gene transcript profiles of mechanically loaded mouse tibiae revealed 16 genes upregulated by the loading that were shown to be downregulated by RWV and RPM. These mechanosensitive genes identified by the comparative studies may provide novel insights into understanding the mechanisms regulating bone formation and potential targets of countermeasure against decreased bone formation both in astronauts and in general patients with musculoskeletal disorders

Preliminary Results on Light Conditions Manipulation in Octopus vulgaris (Cuvier, 1797) Paralarval Rearing

High paralarvae mortality is a major bottleneck currently hindering the control over the lifecycle of common octopus (Octopus vulgaris Cuvier, 1797). It is believed that this problem might be related to either zoo-technical and/or nutritional aspects. The present paper is focused on the study of different zoo-technical aspects related to light conditions on the rearing of paralarvae, including the effects of polarization in prey ingestion, the use of a blue filter to simulate natural conditions, and the use of focused light to avoid reflections of the rearing tank’s walls. In the first experiment, O. vulgaris paralarvae ingestion of Artemia sp. and copepods (Tisbe sp.) was assessed under either normal or polarized light. In the second experiment, the effect of a blue filter with natural light or focused artificial light on growth and mortality was assessed over 15 days of rearing. Ingestion rate was not influenced by light polarization. Nonetheless, a significantly higher ingestion of Artemia sp. with respect to copepods was observed. The blue filter promoted the use of natural light conditions in Octopus paralarval culture, while focused light reduced the collision of the paralarvae against the walls. However, no significant differences were found in paralarval growth nor survivalEn prens

Meta‐analysis approach to the effects of live prey on the growth of Octopus vulgaris paralarvae under culture conditions

The common octopus (Octopus vulgaris, Cuvier 1797) is a promising species for aquaculture diversification, but the massive mortality during the first life stage is the main bottleneck for its commercial production. The aim of the present study was to compare the effects of different live preys (Artemia and crustacean zoeae) and/or Artemia enrichment protocols in the paralarval growth by using a meta‐analysis approach. A total of 26 independent assays were used, including data from the bibliography and from experiments carried out by our group. Three comparisons were established: (i) crustacean zoeae vs. Artemia, (ii) different crustacean zoeae species and (iii) Artemia enriched with marine lecithin (rich in polar lipids‐PL and docosahexaenoic acid‐DHA) vs. previously used Artemia enrichments. The meta‐analysis approach allowed a quantitative review of independent studies with reliable conclusions, avoiding the subjectivity inherent to classical reviews. The outputs provided statistical confirmation of the better suitability of crustacean zoeae with respect to Artemia. However, not all crustacean species showed the same results, given that the high variability on Grapsus zoeae hampered finding significant differences with respect to the control treatment (Artemia). Nutrient composition and biometry of the different types of prey are discussed as possible causes of the differences arising from the meta‐analysis. Finally, the present results suggest that marine lecithin has a beneficial effect on paralarval growth with respect to previously used enrichments, which could be related to the increase in DHA and PL in Artemia, given the essential role of these lipid components in octopus paralarval physiology.info:eu-repo/semantics/acceptedVersio

Un meta-análisis sobre el crecimiento de las paralarvas de pulpo común (Octopus vulgaris) alimentadas con diferentes presas vivas

El objetivo del presente estudio fue comparar el efecto de la alimentación con diferentes presas vivas (Artemia y zoeas de crustáceos) y/o Artemia enriquecida, sobre el crecimiento de paralarvas de pulpo común (Octopus vulgaris) a través de un meta-análisis. Se usaron un total de 26 ensayos independientes para analizar las diferencias en crecimiento entre: (i) zoeas de crustáceos vs Artemia, (ii) diferentes especies de crustáceos y (iii) Artemia enriquecida con fosfolípidos marinos vs otros enriquecedores de Artemia. Se observó un mejor crecimiento de las paralarvas alimentadas con zoeas de crustáceos vs Artemia. Sin embargo, no todas las zoeas mostraron los mismos resultados, dada la alta variabilidad observada con el género Grapsus que impidió que se pudieran apreciar diferencias respecto a la Artemia usada como control. Finalmente, el enriquecimiento de Artemia con fosfolípidos marinos mejoró el crecimiento de las paralarvas, lo cual podría estar relacionado con el incremento en los niveles del ácido docosahexaenoico ((DHA, 22:6n-3) y de los lípidos polares en Artemia

Niche-Based Screening in Multiple Myeloma Identifies a Kinesin-5 Inhibitor with Improved Selectivity over Hematopoietic Progenitors

SummaryNovel therapeutic approaches are urgently required for multiple myeloma (MM). We used a phenotypic screening approach using co-cultures of MM cells with bone marrow stromal cells to identify compounds that overcome stromal resistance. One such compound, BRD9876, displayed selectivity over normal hematopoietic progenitors and was discovered to be an unusual ATP non-competitive kinesin-5 (Eg5) inhibitor. A novel mutation caused resistance, suggesting a binding site distinct from known Eg5 inhibitors, and BRD9876 inhibited only microtubule-bound Eg5. Eg5 phosphorylation, which increases microtubule binding, uniquely enhanced BRD9876 activity. MM cells have greater phosphorylated Eg5 than hematopoietic cells, consistent with increased vulnerability specifically to BRD9876’s mode of action. Thus, differences in Eg5-microtubule binding between malignant and normal blood cells may be exploited to treat multiple myeloma. Additional steps are required for further therapeutic development, but our results indicate that unbiased chemical biology approaches can identify therapeutic strategies unanticipated by prior knowledge of protein targets

Un meta-análisis sobre el crecimiento de las paralarvas de pulpo común (Octopus vulgaris) alimentadas con diferentes presas vivas

El objetivo del presente estudio fue comparar el efecto de la alimentación con diferentes presas vivas (Artemia y zoeas de crustáceos) y/o Artemia enriquecida, sobre el crecimiento de paralarvas de pulpo común (Octopus vulgaris) a través de un meta-análisis. Se usaron un total de 26 ensayos independientes para analizar las diferencias en crecimiento entre: (i) zoeas de crustáceos vs Artemia, (ii) diferentes especies de crustáceos y (iii) Artemia enriquecida con fosfolípidos marinos vs otros enriquecedores de Artemia. Se observó un mejor crecimiento de las paralarvas alimentadas con zoeas de crustáceos vs Artemia. Sin embargo, no todas las zoeas mostraron los mismos resultados, dada la alta variabilidad observada con el género Grapsus que impidió que se pudieran apreciar diferencias respecto a la Artemia usada como control. Finalmente, el enriquecimiento de Artemia con fosfolípidos marinos mejoró el crecimiento de las paralarvas, lo cual podría estar relacionado con el incremento en los niveles del ácido docosahexaenoico ((DHA, 22:6n-3) y de los lípidos polares en Artemia

The Relevance of Marine Chemical Ecology to Plankton and Ecosystem Function: An Emerging Field

Marine chemical ecology comprises the study of the production and interaction of bioactive molecules affecting organism behavior and function. Here we focus on bioactive compounds and interactions associated with phytoplankton, particularly bloom-forming diatoms, prymnesiophytes and dinoflagellates. Planktonic bioactive metabolites are structurally and functionally diverse and some may have multiple simultaneous functions including roles in chemical defense (antipredator, allelopathic and antibacterial compounds), and/or cell-to-cell signaling (e.g., polyunsaturated aldehydes (PUAs) of diatoms). Among inducible chemical defenses in response to grazing, there is high species-specific variability in the effects on grazers, ranging from severe physical incapacitation and/or death to no apparent physiological response, depending on predator susceptibility and detoxification capability. Most bioactive compounds are present in very low concentrations, in both the producing organism and the surrounding aqueous medium. Furthermore, bioactivity may be subject to synergistic interactions with other natural and anthropogenic environmental toxicants. Most, if not all phycotoxins are classic secondary metabolites, but many other bioactive metabolites are simple molecules derived from primary metabolism (e.g., PUAs in diatoms, dimethylsulfoniopropionate (DMSP) in prymnesiophytes). Producing cells do not seem to suffer physiological impact due to their synthesis. Functional genome sequence data and gene expression analysis will provide insights into regulatory and metabolic pathways in producer organisms, as well as identification of mechanisms of action in target organisms. Understanding chemical ecological responses to environmental triggers and chemically-mediated species interactions will help define crucial chemical and molecular processes that help maintain biodiversity and ecosystem functionality