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The kinins bradykinin and des-arg9-bradykinin cleaved from kininogen precursors by kallikreins exert their biological actions by stimulating kinin-B2 and B1 receptors, respectively. In vitro models of neural differentiation such as P19 embryonal carcinoma cells and neural progenitor cells have suggested the involvement of B2 receptors in neural differentiation and phenotype determination; however, the involvement of B1 receptors in these processes has not been established. Here, we show that B1 and B2 receptors are differentially expressed in mouse embryonic E14Tg2A stem cells undergoing neural differentiation. Proliferation and differentiation assays, performed in the presence of receptor subtype-selective agonists and antagonists, revealed that B1 receptor activity is required for the proliferation of embryonic and differentiating cells as well as for neuronal maturation at later stages of differentiation, while the B2 receptor acts on neural phenotype choice, promoting neurogenesis over gliogenesis. Besides the elucidation of bradykinin functions in an in vitro model reflecting early embryogenesis and neurogenesis, this study contributes to the understanding of B1 receptor functions in this process. © 2015 International Society for Advancement of Cytometry [ABSTRACT FROM AUTHOR]

(-)-Carvone is an antinociceptive monoterpene found as the main active constituent of essential oils obtained from plants of the genus Mentha. Here, we have investigated the pharmacology of this monoterpene in dorsal root ganglia (DRG) neurons and TRPV1-expressing HEK293 cells. (-)-carvone at pharmacological active concentrations did not reveal significant cytotoxicity to the cells used in this study, as investigated by neutral red and propidium iodide flow cytometry assays. In calcium imaging experiments 1 mM (-)-carvone increased the cytosolic calcium levels in DRG neurons from 120.6 ± 5.0 nM (basal) to 310.7 ± 23.1 nM ( P < 0.05). These effects were completely abolished when neurons were preincubated with calcium-free bath solution or ruthenium-red (5 µM) and capsazepine (10 µM), suggesting the possibility of TRPV1 channel-activation by (-)-carvone. Activity of (-)-carvone on TRPV1 channels was further investigated in HEK293 cells expressing recombinant human TRPV1 channels revealing dose-dependent calcium transients with an EC50 of 1.3 ± 0.2 mM (Hill coefficient = 2.5). In conclusion, we show for the first time the ability of (-)-carvone to induce increases in cytosolic calcium concentration through TRPV1 activation. © 2013 International Society for Advancement of Cytometry [ABSTRACT FROM AUTHOR]

Modern medicine will unequivocally include regenerative medicine as a major breakthrough in the re-establishment of damaged or lost tissues due to degenerative diseases or injury. In this scenario, millions of patients worldwide can have their quality of life improved by stem cell implantation coupled with endogenous secretion or administration of survival and differentiation promoting factors. Large efforts, relying mostly on flow cytometry and imaging techniques, have been put into cell isolation, immunophenotyping, and studies of differentiation properties of stem cells of diverse origins. Mesenchymal stem cells (MSCs) are particularly relevant for therapy due to their simplicity of isolation. A minimal phenotypic pattern for the identification of MSCs cells requires them to be immunopositive for CD73, CD90, and CD105 expression, while being negative for CD34, CD45, and HLA-DR and other surface markers. MSCs identified by their cell surface marker expression pattern can be readily purified from patient's bone marrow and adipose tissues. Following expansion and/or predifferentiation into a desired tissue type, stem cells can be reimplanted for tissue repair in the same patient, virtually eliminating rejection problems. Transplantation of MSCs is subject of almost 200 clinical trials to cure and treat a very broad range of conditions, including bone, heart, and neurodegenerative diseases. Immediate or medium term improvements of clinical symptoms have been reported as results of many clinical studies. © 2012 International Society for Advancement of Cytometry [ABSTRACT FROM AUTHOR]

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 β3-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 N-methyl- 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 [ABSTRACT FROM AUTHOR]

Melatonin and its derivatives modulate the Plasmodium falciparum and Plasmodium chabaudi cell cycle. Flow cytometry was employed together with the nucleic acid dye YOYO-1 allowing precise discrimination between mono- and multinucleated forms of P. falciparum-infected red blood cell. The use of YOYO-1 permitted excellent discrimination between uninfected and infected red blood cells as well as between early and late parasite stages. Fluorescence intensities of schizont-stage parasites were about 10-fold greater than those of ring-trophozoite form parasites. Melatonin and related indolic compounds including serotonin, N-acetyl-serotonin and tryptamine induced an increase in the percentage of multinucleated forms compared to non-treated control cultures. YOYO-1 staining of infected erythrocyte and subsequent flow cytometry analysis provides a powerful tool in malaria research for screening of bioactive compounds. © 2011 International Society for Advancement of Cytometry [ABSTRACT FROM AUTHOR]