Stathmin: Cellular localization of a major phosphoprotein in the adult rat and human CNS

Abstract

Stathmin is a ubiquitous, 19 kDa cytoplasmic protein the phosphorylation of which is associated with many cellular signaling pathways. It is particularly abundant in neurons and reaches a peak of expression in the neonatal period, although it remains highly expressed in the adult brain. In order to determine whether this abundant expression is associated with discrete cellular populations that are still at an immature stage during adulthood, as suggested by others, the cellular localization of stathmin was investigated in the adult rat and human central nervous system. Western blotting with a specific antiserum indicated that stathmin was ubiquitous in the brain and spinal cord but that its relative concentration varied up to 2.6 times between regions. To characterize the distribution of stathmin within the brain, its cellular localization was analyzed by immunocytochemistry. Highly immunoreactive neurons and oligodendrocytes were observed, and stathmin immunoreactivity was localized to the perikaryon and all processes, but not the nucleus. Most brain and spinal cord cell groups showed stathmin immunoreactivity, although the extent and intensity of labeling differed largely from one place to another. Particularly numerous stathmin-immunoreactive neuronal cell bodies were found in the pyriform, cingulate, and neocortex, as well as in many cholinergic nuclei of the basal forebrain and brainstem, in the medial thalamus, in various brainstem nuclei, in the dorsalmost layers of the spinal cord, and in brain areas lacking a blood-brain barrier to macromolecules. In addition to neuronal populations, stathmin-antibodies intensely labeled choroid plexuses. Many other brain regions exhibited moderate neuronal immunostaining. The distribution of stathmin-immunoreactive processes was in some areas relatively heterogeneous. Intense immunoreactivity was observed in some fiber tracts (corpus callosum, anterior commissure, inferior cerebellar peduncle, etc.) but was missing in others (internal capsule, posterior commissure, etc.). Some brain areas rich in immunoreactive neurons also displayed an intense immunoreactivity of the neuropile, whereas others contained either immunoreactive cells or fibers. In the human brain, stathmin immunostaining occurred in many areas, corresponding to those identified in the rat, with the exception of the cerebral cortex, the hippocampal fascia dentata, and the substantia nigra. The present results support our suggestion that, in addition to its involvement in cell proliferation and differentiation, stathmin may also be related to regulation of differentiated cell functions, as it appears to be a major signaling protein in widespread areas of the adult brain in both rat and human.

Lipocalin-2-induced renal regeneration depends on cytokines

“…Slides were examined in a blinded manner, and proliferation was quantified by counting the number of stathmin-and PCNA-positive cells/100 cells counted in an average of five highpower fields (ϫ40) in each section. Stathmin is a ubiquitously expressed cytosolic phosphoprotein (25,28) that has been identified as a marker of cell proliferation in the recovery phase of acute ischemic renal failure (36). Increased expression of stathmin is associated with the reentry of cells into the cell cycle and the onset of cell proliferation (7), whereas PCNA labels proliferating nuclei.…”

Identification of stathmin as a novel marker of cell proliferation in the recovery phase of acute ischemic renal failure

“…Western blot analyses were performed as previously described by Peschanski et al (42). Briefly, 50 g of protein from each extract were loaded onto an SDS-12% polyacrylamide gel.…”

“…After two 10-min washes in 2.5% dry milk in TTBS and two 10-min washes in TBS, the membrane was developed by using peroxidase detection reagents (ECL kit; Amersham, Piscataway, NJ) and exposed for 5-30 s to an X-ray film. The stathmin antibody is highly specific and detects the stathmin as an ϳ19-kDa band (42).…”

Expression of Stathmin, a Developmentally Controlled Cytoskeleton-Regulating Molecule, in Demyelinating Disorders

“…It was originally identified as a cytosolic phosphoprotein in neuroendocrine cells (Sobel and Tashjian, 1983;Schubart, 1988), also called Op18 (Hailat et al, 1990) and p19 (Pasmantier et al, 1986), and then identified in high abundance in the developing brain (Schubart et al, 1989;Koppel et al, 1990;Amat et al, 1991). In the adult brain, stathmin has been detected in germinal areas with neurogenic and gliogenic potential (Amat et al, 1991) and in specific subpopulations of neurons (Peschanski et al, 1993;Camoletto et al, 1997;Ozon et al, 1999), although its expression in neurons is much lower than SCG10 (Himi et al, 1994).…”