title: Loss of parafollicular cells during gravitational changes (microgravity, hypergravity) and the secret effect of pleiotrophin.
abstract: It is generally known that bone loss is one of the most important complications for astronauts who are exposed to long-term microgravity in space. Changes in blood flow, systemic hormones, and locally produced factors were indicated as important elements contributing to the response of osteoblastic cells to loading, but research in this field still has many questions. Here, the possible biological involvement of thyroid C cells is being investigated. The paper is a comparison between a case of a wild type single mouse and a over-expressing pleiotrophin single mouse exposed to hypogravity conditions during the first animal experiment of long stay in International Space Station (91 days) and three similar mice exposed to hypergravity (2Gs) conditions. We provide evidence that both microgravity and hypergravity induce similar loss of C cells with reduction of calcitonin production. Pleiotrophin over-expression result in some protection against negative effects of gravity change. Potential implication of the gravity mechanic forces in the regulation of bone homeostasis via thyroid equilibrium is discussed.
authors.affiliation: Laboratory of Nuclear Lipid BioPathology, Centro Ricerche Analisi Biochimico Specialistiche, Perugia, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Albi
authors.forename: Francesco
authors.initials: F
authors.lastname: Curcio
authors.forename: Renza
authors.initials: R
authors.lastname: Spelat
authors.forename: Andrea
authors.initials: A
authors.lastname: Lazzarini
authors.forename: Remo
authors.initials: R
authors.lastname: Lazzarini
authors.forename: Samuela
authors.initials: S
authors.lastname: Cataldi
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Loreti
authors.forename: Ivana
authors.initials: I
authors.lastname: Ferri
authors.forename: Francesco Saverio
authors.initials: FS
authors.lastname: Ambesi-Impiombato
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002452:Cell Count; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D018471:Hypergravity / Q000009:adverse effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D055099:Neuroendocrine Cells / Q000166:cytology*; D013026:Space Flight; D018531:Spacecraft; D013961:Thyroid Gland / Q000166:cytology*; D014893:Weightlessness / Q000009:adverse effects*
chemical_list: D002352:Carrier Proteins; D016207:Cytokines; C066845:pleiotrophin