title: An ancient cytokine, astakine, mediates circadian regulation of invertebrate hematopoiesis.
abstract: Invertebrate circulating hemocytes are key players in the innate immune defense and their continuous renewal from hematopoietic tissues is tightly regulated in crustaceans by astakine, a new family of cytokines sharing a prokineticin (PROK) domain. In vertebrates, brain PROKs function as transmitters of circadian rhythms and we present evidence that hemocyte release from hematopoietic tissues in crayfish is under circadian regulation, a direct result of rhythmic expression of astakine. We demonstrate that the observed variation in astakine expression has an impact on innate immunity assessed as susceptibility to a pathogenic Pseudomonas species. These findings enlighten the importance of comparing immune responses at fixed times not to neglect circadian regulation of innate immunity. Moreover, our results entail an evolutionary conserved function for prokineticins as mediators of circadian rhythm, and for the first time show a role for this domain in circadian regulation of hematopoiesis that may have implications also in vertebrates.
authors.affiliation: Department of Comparative Physiology, Uppsala University, Sweden.
authors.forename: Apiruck
authors.initials: A
authors.lastname: Watthanasurorot
authors.forename: Kenneth
authors.initials: K
authors.lastname: Söderhäll
authors.forename: Pikul
authors.initials: P
authors.lastname: Jiravanichpaisal
authors.forename: Irene
authors.initials: I
authors.lastname: Söderhäll
mesh_terms: D000818:Animals; D003400:Astacoidea / Q000502:physiology; D002454:Cell Differentiation; D002940:Circadian Rhythm / Q000502:physiology; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D006410:Hematopoiesis / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000502:physiology; D006434:Hemocytes / Q000502:physiology; D007113:Immunity, Innate; D007448:Invertebrates / Q000502:physiology; D008297:Male; D011549:Pseudomonas; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived / Q000235:genetics / Q000378:metabolism
chemical_list: D016207:Cytokines; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived