Pericyte perivascular cells, believed to originate mesenchymal stem cells (MSC), are characterized by their capability to differentiate into various phenotypes and participate in tissue reconstruction of different organs, including the brain. We show that these cells can be induced to differentiation into neural-like phenotypes. For these studies, pericytes were obtained from aorta ex-plants of Sprague-Dawley rats and differentiated into neural cells following induction with trans retinoic acid (RA) in serum-free defined media or differentiation media containing nerve growth and brain-derived neuronal factor, B27, N2, and IBMX. When induced to differentiation with RA, cells express the pluripotency marker protein stage-specific embryonic antigen-1, neural-specific proteins b3-tubulin, neurofilament-200, and glial fibrillary acidic protein, suggesting that pericytes undergo differentiation, similar to that of neuroectodermal cells. Differentiated cells respond with intracellular calcium transients to membrane depolarization by KCl indicating the presence of voltage-gated ion channels and express functional Nmethyl-D-aspartate receptors, characteristic for functional neurons. The study of neural differentiation of pericytes contributes to the understanding of induction of neuroectodermal differentiation as well as providing a new possible stem-cell source for cell regeneration therapy in the brain. ' 2011 International Society for Advancement of Cytometry

The in vitro and in vivo effect of prolactin (PRL) on kidney macrophages from Atlantic salmon (Salmo salar) was investigated under the assumption that PRL stimulates immune innate response in mammals. Kidney macrophages were treated two ways: first, cultured in RPMI 1640 medium containing 10, 25, 50 and 100 ng/mL of PRL and second, isolated from a fish with a PRL-injected dose of 100 ng/Kg. Reduced nitro blue tetrazolium (formazan) was used to produce intracellular superoxide anion. Phagocytic activity of PRL was determined in treated cells by optical microscopy observation of phagocytized Congo red-stained yeast. Kidney lysozyme activity was measured in PRL-injected fish. In vitro and in vivo macrophages treated with PRL presented an enhanced superoxide anion production, elevated phagocytic index and increased phagocytic activity. Treated fish showed higher levels of lysozyme activity in the head kidney compared to the control. These results indicate that PRL-stimulated innate immune response in Atlantic salmon and future studies will allow us to assess the possibility of using PRL as an immunostimulant in the Chilean salmon industry.

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MONTIEL-EULEFI SUMMARY:Poly (L-lactic acid) (PLA) nanoparticles have the approval of the main institutions for drugs administration and therapeutics. However, the use of lactic acid polymer is controversial because lactic acid has been proposed as an energy source for cancer cells. The aim of this study was to evaluate the cytotoxic, apoptotic and cell cycle properties of PLA and CuSO 4 -loaded PLA biodegradable nanoparticles on MKN-45 gastric adenocarcinoma cell line. PLA nanoparticles for the delivery of the anticancer active principle CuSO 4 were obtained using the double emulsion method. PLA and CuSO 4 loaded PLA nanoparticles were morphologically characterized and their size determined using transmission electron microscopy (TEM). The cytotoxicity of this drug delivery system was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay; apoptosis was evaluated using YO-PRO-1/Propidium Iodide and cell cycle analysis throughout flow cytometry. CuSO 4 -loaded PLA nanoparticles were effective inhibitors of MKN45 cancer cell growth. They increased cytotoxicity and apoptosis, and induced G1/Go cell cycle arrest; whereas the anticancer activity was increased using a 96 h treatment of a minimal (1mM) concentration of CuSO 4 loaded in 40 µM PLA nanoparticles. The treatment with 40 µM lactic acid and PLA (40 µM) did not increase the rate of cell survival assays related to the control, which indicate that PLA use as a polymer carrier not induce proliferation of MKN-45 cancer cells. Our research presents novel data about the effect of PLA nanoparticles and CuSO 4 on gastric cancer cell line MKN45.