title: JH modulates a cellular immunity of Tribolium castaneum in a Met-independent manner.
abstract: Juvenile hormone (JH) regulates diverse physiological processes in insects during entire developmental stages. Especially, the identification of Methoprene-tolerant (Met), a JH nuclear receptor, allows us to better understand molecular actions of JH to control gene expressions related with metamorphosis. However, several physiological processes including cellular immune response and some molecular actions of JH have been suspected to be mediated via its non-genomic actions. To prove its non-genomic action, JH nuclear signals were suppressed by RNA interference (RNAi) of Met or its downstream gene, Krüppel homolog 1 (Kr-h1), in the red flour beetle, Tribolium castaneum. These RNAi-treated larvae failed to undergo a normal development and suffered precocious metamorphosis. Hemocytes of T. castaneum exhibited their spreading behavior on extracellular matrix and nodule formation in response to bacterial challenge. When the larvae were treated with either RNAi of Met or Kr-h1, the hemocytes of the treated larvae were responsive to JH without any significant difference with those of control larvae. These results suggest that the response of hemocytes to JH is not mediated by its nuclear signal. On the other hand, the JH modulation of hemocyte behaviors of T. castaneum was significantly influenced by membrane and cytosolic protein activities, in which ethoxyzolamide (a specific inhibitor of carbonic anhydrase), calphostin C (a specific inhibitor of protein kinase C) or ouabain (a specific inhibitor of Na(+)-K(+) ATPase) significantly suppressed the responsiveness of hemocytes to JH.
authors.affiliation: Department of Bioresource Sciences, Andong National University, Andong 760-749, Republic of Korea.
authors.forename: Rahul
authors.initials: R
authors.lastname: Hepat
authors.affiliation: Department of Bioresource Sciences, Andong National University, Andong 760-749, Republic of Korea. Electronic address: hosanna@andong.ac.kr.
authors.forename: Yonggyun
authors.initials: Y
authors.lastname: Kim
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D006434:Hemocytes / Q000378:metabolism; D007111:Immunity, Cellular; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007605:Juvenile Hormones / Q000235:genetics* / Q000378:metabolism*; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008675:Metamorphosis, Biological; D008726:Methoprene / Q000378:metabolism; D011679:Pupa / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D014231:Tribolium / Q000235:genetics / Q000254:growth & development / Q000276:immunology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D019476:Insect Proteins; D007605:Juvenile Hormones; D051741:Kruppel-Like Transcription Factors; D008726:Methoprene
keywords: Hemocyte; Juvenile hormone; Non-genomic; RNA interference; Tribolium castaneum