Thyroid hormones promote differentiation of oligodendrocyte progenitor cells and improve remyelination after cuprizone-induced demyelination.
In the present work we analyzed the capacity of thyroid hormones (THs) to improve remyelination using a rat model of cuprizone-induced demyelination previously described in our laboratories. Twenty one days old Wistar rats were fed a diet containing 0.6% cuprizone for two weeks to induce demyelination. After cuprizone withdrawal, rats were injected with triiodothyronine (T3). Histological studies carried out in these animals revealed that remyelination in the corpus callosum (CC) of T3-treated rats improved markedly when compared to saline treated animals. The cellular events occurring in the CC and in the subventricular zone (SVZ) during the first week of remyelination were analyzed using specific oligodendroglial cell (OLGc) markers. In the CC of saline treated demyelinated animals, mature OLGcs decreased and oligodendroglial precursor cells (OPCs) increased after one week of spontaneous remyelination. Furthermore, the SVZ of these animals showed an increase in early progenitor cell numbers, dispersion of OPCs and inhibition of Olig and Shh expression compared to non-demyelinated animals. The changes triggered by demyelination were reverted after T3 administration, suggesting that THs could be regulating the emergence of remyelinating oligodendrocytes from the pool of proliferating cells residing in the SVZ. Our results also suggest that THs receptor beta mediates T3 effects on remyelination. These results support a potential role for THs in the remyelination process that could be used to develop new therapeutic approaches for demyelinating diseases.
Departamento de Química Biológica, IQUIFIB and IIMHNO, Facultad de Farmacia y Bioquímica, UBA-CONICET, Junín 956, Buenos Aires C1113AAD, Argentina.
P G
PG
Franco
L
L
Silvestroff
E F
EF
Soto
J M
JM
Pasquini
D000818:Animals; D000831:Animals, Newborn; D000941:Antigens / Q000378:metabolism; D001779:Blood Coagulation Factors / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D003471:Cuprizone; D003711:Demyelinating Diseases / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D005732:Gangliosides / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D053823:Hedgehog Proteins / Q000378:metabolism; D004676:Myelin Basic Protein / Q000378:metabolism; D019081:O Antigens / Q000378:metabolism; D009836:Oligodendroglia / Q000187:drug effects*; D011509:Proteoglycans / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D013234:Stem Cells / Q000187:drug effects*; D013963:Thyroid Hormones / Q000494:pharmacology*; D013997:Time Factors; D014284:Triiodothyronine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000099216:Chondroitin Sulfate Proteoglycan 4
D000941:Antigens; D001779:Blood Coagulation Factors; D003471:Cuprizone; D005732:Gangliosides; D005904:Glial Fibrillary Acidic Protein; D053823:Hedgehog Proteins; D004676:Myelin Basic Protein; D019081:O Antigens; D011509:Proteoglycans; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; D011956:Receptors, Cell Surface; D013963:Thyroid Hormones; D014284:Triiodothyronine; D000099216:Chondroitin Sulfate Proteoglycan 4; C091963:activated protein C receptor; C062875:ganglioside A2B5; C040407:3,3',5-triiodothyronamine