title: Developmental patterns of Ki-67, Oct-4 and α-tubulin proteins expression in the human spinal cord.
abstract: The aim of this study was to analyze immunohistochemically the relationships between factors involved in processes of cell proliferation (Ki-67), differentiation (Oct-4) and primary cilia formation (α-tubulin) in the two parts of the developing human spinal cord (SC) of different origin in 11 human concepti (developmental weeks 5-10). Proliferation was highest in weeks 7-8 in the dorsal ventricular zones of the cranial (85.5%) and caudal (12.1%) SC. In the ventricular (VZ), intermediate (IZ) and marginal zones (MZ) of the cranial SC, α-tubulin and Oct-4 were moderately to strongly expressed. During weeks 5-6, moderate expression of α-tubulin and Oct-4 characterized the ventral part, with mild expression in the dorsal part of the caudal SC. In weeks 7-8, their expression increased in the VZ and IZ, and decreased in the MZ. In both parts of the SC Ki-67 and α-tubulin co-localized in the VZ. Oct-4 and Ki-67 co-localized only in the ependymal cells. In the cranial SC α-tubulin and Oct-4 co-localized (VZ and IZ), while the MZ expressed only α-tubulin. In the caudal SC, α-tubulin and Oct-4 co-localized in the VZ, while in the IZ some cells were only α-tubulin-positive. We suggest the importance of temporal-spatial expression of Ki-67 for the thickening of the cranial SC lateral wall. While in the cranial part of the SC, proliferation followed a ventral-dorsal direction, the caudal SC had a more irregular pattern. α-Tubulin was associated with cilia formation (ependymal cells) and axonic elongation of neuroblasts (MZ). Primary cilia signaling are important in control of SC proliferation and differentiation. Oct-4 expression in the SC coincided with presence of dividing neuroepithelial cells in the VZ and neuroblasts in the IZ, and could control the level of SC differentiation.
authors.affiliation: Department of Histology and Embryology, School of Medicine, University of Mostar, Bijeli Brijeg bb, 88000 Mostar, Bosnia and Herzegovina; Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, Soltanska 2, 21000 Split, Croatia. Electronic address: kvukojev@gmail.com.
authors.forename: Katarina
authors.initials: K
authors.lastname: Vukojevic
authors.affiliation: Department of Histology and Embryology, School of Medicine, University of Mostar, Bijeli Brijeg bb, 88000 Mostar, Bosnia and Herzegovina.
authors.forename: Tanja
authors.initials: T
authors.lastname: Janjic
authors.affiliation: Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, Soltanska 2, 21000 Split, Croatia.
authors.forename: Mirna
authors.initials: M
authors.lastname: Saraga-Babic
mesh_terms: D002454:Cell Differentiation; D049109:Cell Proliferation / Q000502:physiology; D004805:Ependyma / Q000378:metabolism; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D050814:Octamer Transcription Factor-3 / Q000378:metabolism*; D013116:Spinal Cord / Q000196:embryology / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism*
chemical_list: D019394:Ki-67 Antigen; D050814:Octamer Transcription Factor-3; D014404:Tubulin
keywords: Alpha-tubulin; Cilia; Differentiation; Human embryo; Ki-67; Oct-4