title: Inflammation severely alters thyroid hormone signaling in the central nervous system during experimental allergic encephalomyelitis in rat: Direct impact on OPCs differentiation failure.
abstract: Differentiation of oligodendrocyte precursor cells (OPCs) into myelinating oligodendrocytes is severely impaired by inflammatory cytokines and this could lead to remyelination failure in inflammatory/demyelinating diseases. Due to the role of thyroid hormone in the maturation of OPCs and developmental myelination, in this study we investigated (i) the possible occurrence of dysregulation of thyroid hormone signaling in the CNS tissue during experimental neuroinflammation; (ii) the possible impact of inflammatory cytokines on thyroid hormone signaling and OPCs differentiation in vitro. The disease model is the experimental allergic encephalomyelitis in female Dark-Agouti rats, whereas in vitro experiments were carried out in OPCs derived from neural stem cells. The main results are the following: (i) a strong upregulation of cytokine mRNA expression level was found in the spinal cord during experimental allergic encephalomyelitis; (ii) thyroid hormone signaling in the spinal cord (thyroid hormone receptors; deiodinase; thyroid hormone membrane transporter) is substantially downregulated, due to the upregulation of the thyroid hormone inactivating enzyme deiodinase 3 and the downregulation of thyroid hormone receptors, as investigated at mRNA expression level; (iii) when exposed to inflammatory cytokines, deiodinase 3 is upregulated in OPCs as well, and OPCs differentiation is blocked; (iv) deiodinase 3 inhibition by iopanoic acid recovers OPCs differentiation in the presence on inflammatory cytokines. These data suggest that cellular hypothyroidism occurs during experimental allergic encephalomyelitis, possibly impacting on thyroid hormone-dependent cellular processes, including maturation of OPCs into myelinating oligodendrocytes. GLIA 2016;64:1573-1589.
authors.affiliation: Health Science and Technology Interdepartmental Center for Industrial Research, University of Bologna, Bologna, Italy.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Fernández
authors.affiliation: Health Science and Technology Interdepartmental Center for Industrial Research, University of Bologna, Bologna, Italy.|Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
authors.forename: Vito A
authors.initials: VA
authors.lastname: Baldassarro
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
authors.forename: Sandra
authors.initials: S
authors.lastname: Sivilia
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.|IRET Foundation, Ozzano Emilia, Bologna, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Giardino
authors.affiliation: Health Science and Technology Interdepartmental Center for Industrial Research, University of Bologna, Bologna, Italy.|Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.|IRET Foundation, Ozzano Emilia, Bologna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Calzà
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000378:metabolism*; D005260:Female; D007249:Inflammation / Q000378:metabolism; D009186:Myelin Sheath / Q000378:metabolism* / Q000473:pathology; D058953:Neural Stem Cells / Q000378:metabolism; D000073637:Oligodendrocyte Precursor Cells / Q000378:metabolism; D009836:Oligodendroglia / Q000166:cytology*; D051381:Rats
keywords: deiodinases; inflammatory cytokines; iopanoic acid; rat; remyelination