Transferrin and thyroid hormone converge in the control of myelinogenesis

L N Marziali; C I Garcia; J M Pasquini

doi:10.1016/j.expneurol.2014.12.021

Transferrin and thyroid hormone converge in the control of myelinogenesis

Exp Neurol. 2015 Mar:265:129-41. doi: 10.1016/j.expneurol.2014.12.021. Epub 2015 Jan 14.

Authors

L N Marziali¹, C I Garcia², J M Pasquini³

Affiliations

¹ Department of Biological Chemistry, Biological and Physical Chemistry Institute (IQUIFIB-CONICET), School of Pharmacy and Biochemistry, University of Buenos Aires, Argentina.
² Department of Pharmacology, School of Pharmacy and Biochemistry, University of Buenos Aires, Argentina.
³ Department of Biological Chemistry, Biological and Physical Chemistry Institute (IQUIFIB-CONICET), School of Pharmacy and Biochemistry, University of Buenos Aires, Argentina. Electronic address: jpasquin@qb.ffyb.uba.ar.

PMID: 25595122
DOI: 10.1016/j.expneurol.2014.12.021

Abstract

Myelination is a concerted mechanism tightly regulated in the brain. Although several factors are known to participate during this process, the complete sequence of events is far from being fully elucidated. Separate effects of apotransferrin (aTf) and thyroid hormone (TH) are well documented on rat myelin formation. TH promotes the maturation of oligodendrocyte progenitors (OPCs) into myelinating oligodendrocytes (OLGs), while aTf is able to induce the commitment of neural stem cells (NSCs) toward the oligodendroglial linage and favors OLG maturation. We have also demonstrated that Tf mRNA exhibited a seven-fold increase in hyperthyroid animals. These observations have led us to hypothesize that both factors may interplay during oligodendrogenesis. To assess the combined effects of aTf and TH on proper myelination in the rat brain, Tf expression and oligodendroglial maturation were evaluated at postnatal days 10 (P10) and 20 (P20) in several experimental groups. At P10, an up-regulation of both Tf mRNA and protein, as well as myelination, was found in hyperthyroid animals, while a decrease in Tf mRNA levels and myelin formation was detected in the hypothyroid group. At P20, no differences were found either in Tf mRNA or protein levels between hyperthyroid and control (Ctrol) rats, although differences in OLG differentiation remained. Also at P20, hypothyroid animals showed decreased Tf mRNA and protein levels accompanied with a less mature myelinating phenotype. Moreover, TH and aTf differentially regulate the expression of KLF9 transcription factor as well as TRα and TRβ at P10 and P20. Our results suggest that TH is necessary early in OLG development for aTf action, as exogenous aTf administration was unable to counteract the effect of low TH levels in the hypothyroid state in all the time points analyzed. Furthermore, the fact that hyperthyroidism induced an increase in Tf expression and aTf-dependent regulation of TRα strongly suggests that Tf could be involved in some of TH later effects on OLG maturation. Here we describe the possible relationship between TH and aTf and its implication in oligodendrogenesis.

Keywords: Myelin; Oligodendrocytes; Thyroid hormone; Transferrin.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Animals, Newborn
Apoproteins / biosynthesis*
Male
Mice
Myelin Sheath / metabolism*
Nerve Fibers, Myelinated / metabolism*
Oligodendroglia / metabolism*
Rats
Rats, Wistar
Thyroid Hormones / biosynthesis*
Transferrin / biosynthesis*

Substances

Apoproteins
Thyroid Hormones
Transferrin
apotransferrin