The mRNA of transferrin is expressed in Schwann cells during their maturation and after nerve injury.
Transferrin, the iron carrier protein, has been shown to be involved in oligodendroglial cell differentiation in the central nervous system but little is known about its role in the peripheral nervous system. In the present work, we have studied the presence of transferrin and of its mRNA in rat sciatic nerves and in Schwann cells isolated at embryonic and adult ages as well as during the regeneration process that follows nerve crush. We have also studied the correlation between the expression of the mRNAs of transferrin and the expression of mature myelin markers in the PNS. We show that transferrin is present in whole sciatic nerves at late stages of embryonic life as well as at postnatal day 4 and in adult rats. We demonstrate for the first time, that in normal conditions, the transferrin mRNA is expressed in Schwann cells isolated from sciatic nerves between embryonic days 14 and 18, being absent at later stages of development and in adult animals. In adult rats, 3 days after sciatic nerve crushing, the mRNA of transferrin is expressed in the injured nerve, but 7 days after injury its expression disappears. Transferrin protein in the sciatic nerve closely follows the expression of its mRNA indicating that under these circumstances, it appears to be locally synthesized. Transferrin in the PNS could have a dual role. During late embryonic ages it could be locally synthesized by differentiating Schwann cells, acting as a pro-differentiating factor. A similar situation would occur during the regeneration that follows Wallerian degeneration. In the adult animals on the other hand, Schwann cells could pick up transferrin from the circulation or/and from the axons, sub serving possible trophic actions closely related to myelin maintenance.
Salis
C
C
Instituto de Química y Fisicoquímica Biológica (IQUIFIB), UBA-CONICET and Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junin 956, Buenos Aires C1113AAD, Argentina.
Setton
C P
CP
Soto
E F
EF
Pasquini
J M
JM
D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D016922:Cellular Senescence; D004622:Embryo, Mammalian / Q000378:metabolism; D005260:Female; D009409:Nerve Crush; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012583:Schwann Cells / Q000378:metabolism* / Q000473:pathology; D012584:Sciatic Nerve / Q000196:embryology / Q000293:injuries* / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D014168:Transferrin / Q000235:genetics* / Q000378:metabolism; D014947:Wounds and Injuries / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology
D012333:RNA, Messenger; D014168:Transferrin