title: Carbonic anhydrase inhibition blocks skeletogenesis and echinochrome production in Paracentrotus lividus and Heliocidaris tuberculata embryos and larvae.
abstract: Carbonic anhydrases (CAs) are a family of widely distributed metalloenzymes, involved in diverse physiological processes. These enzymes catalyse the reversible conversion of carbon dioxide to protons and bicarbonate. At least 19 genes encoding for CAs have been identified in the sea urchin genome, with one of these localized to the skeletogenic mesoderm (primary mesenchyme cells, PMCs). We investigated the effects of a specific inhibitor of CA, acetazolamide (AZ), on development of two sea urchin species with contrasting investment in skeleton production, Paracentrotus lividus and Heliocidaris tuberculata, to determine the role of CA on PMC differentiation, skeletogenesis and on non-skeletogenic mesodermal (NSM) cells. Embryos were cultured in the presence of AZ from the blastula stage prior to skeleton formation and development to the larval stage was monitored. At the dose of 8 mmol/L AZ, 98% and 90% of P. lividus and H. tuberculata embryos lacked skeleton, respectively. Nevertheless, an almost normal PMC differentiation was indicated by the expression of msp130, a PMC-specific marker. Strikingly, the AZ-treated embryos also lacked the echinochrome pigment produced by the pigment cells, a subpopulation of NSM cells with immune activities within the larva. Conversely, all ectoderm and endoderm derivatives and other subpopulations of mesoderm developed normally. The inhibitory effects of AZ were completely reversed after removal of the inhibitor from the medium. Our data, together with new information concerning the involvement of CA on skeleton formation, provide evidence for the first time of a possible role of the CAs in larval immune pigment cells.
authors.affiliation: Institute of Biomedicine and Molecular Immunology "A. Monroy", National Research Council, Via Ugo La Malfa, Palermo, 153 - 90146, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Zito
authors.affiliation: Schools of Medical and Biological Sciences, University of Sydney, Sydney, New South Wales, 2006, Australia.
authors.forename: Demian
authors.initials: D
authors.lastname: Koop
authors.affiliation: Schools of Medical and Biological Sciences, University of Sydney, Sydney, New South Wales, 2006, Australia.
authors.forename: Maria
authors.initials: M
authors.lastname: Byrne
authors.affiliation: Institute of Biomedicine and Molecular Immunology "A. Monroy", National Research Council, Via Ugo La Malfa, Palermo, 153 - 90146, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Matranga
mesh_terms: D000086:Acetazolamide / Q000494:pharmacology; D000818:Animals; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology*; D002256:Carbonic Anhydrases / Q000378:metabolism; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000201:enzymology; D047328:Paracentrotus / Q000187:drug effects* / Q000196:embryology* / Q000378:metabolism; D010860:Pigments, Biological / Q000096:biosynthesis*; D012617:Sea Urchins / Q000187:drug effects* / Q000196:embryology* / Q000378:metabolism
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D010860:Pigments, Biological; D002256:Carbonic Anhydrases; D000086:Acetazolamide
keywords: acetazolamide; biomineralization; larval immune pigment cells; primary mesenchyme cells; sea urchin