Development and regional expression of beta nerve growth factor messenger RNA and protein in the rat central nervous system.

Abstract

The presence of nerve growth factor (NGF) mRNA and protein in the rat central nervous system is documented. Blot-hybridization analysis showed an abundance of NGF mRNA in the hippocampus, cerebral cortex, and olfactory bulb. Enzyme immunoassay confirmed significant levels of a NGF-like protein in the hippocampus and cerebral cortex. Bioassay of a NGF-like immunoaffinity-purified protein from these regions was physiologically indistinguishable from NGF. Immunohistochemistry revealed a widespread distribution of NGF-like reactivity in the adult brain, preferentially in fiber tracts. NGF mRNA accumulation began at birth, with adult levels reached 3 weeks postnatally. Enzyme immunoassay detected the presence of a NGF-like protein in the embryonic rat brain. Postnatally, the level of NGF-like protein reached a maximum at 3 weeks. Additionally, a distinct fetal form of NGF may exist.,B nerve growth factor (NGF) is essential for the development and maintenance of sensory and sympathetic neurons in the peripheral nervous system (PNS) (1, 2). However, both the presence and potential physiological function of NGF in the central nervous system (CNS) has remained elusive (3). The characteristic responses of peripheral adrenergic neurons following NGF or anti-NGF antibody injection have not been observed after similar application into the CNS (4-11).In the PNS, NGF is taken up by adrenergic terminals and also retrogradely transported to the cell body (2). In the CNS, injected NGF was specifically retrogradely transported from the hippocampus to the medial septum and the diagonal band of Broca (9) and also from the neocortex to the nucleus basalis (12), presumably in cholinergic neurons. NGF induced choline acetyltransferase in neonatal rat cortex, hippocampus, septum (10), and striatum (11), but not in adult hippocampus (13).Thus, NGF may have a physiological function in the CNS, and affect cholinergic neurons. Initial indication of endogenous NGF in the CNS was obtained by immunohistochemistry in the fetal rat (14, 15). NGF cDNA clones have been isolated from male mouse submaxillary glands (16,17), and Shelton and Reichardt (18) recently detected NGF mRNA in the rat brain. Subsequently, NGF mRNA and an NGF-like protein have been described in some regions of the adult rat brain (19).In the present study, we demonstrate the developmental time course as well as the adult regional distribution of both NGF mRNA and protein in the adult rat brain. Finally, using a bioassay, we show that the adult brain contains nerve growth-stimulating activity typical of purified NGF. Our results demonstrate that NGF is expressed in the adult rat CNS with regional specificity and suggests the existence of a fetal form of NGF. MATERIALS AND METHODSPreparation of RNA and Blot-Hybridization Analysis. Total RNA from the brains of Sprague-Dawley rats (Alab, Stockholm, Sweden) was prepared (20), and poly(A)+ RNA, isolated by oligo(dT) chromatography (21), was separated on 1% agarose gels containing 0.7% formaldehyde and transferred to nitrocel...

Expression of β‐nerve growth factor mRNA in rat glioma cells and astrocytes from rat brain

“…In addition to the major 1.3 kb mRNA transcript, hybridization to a more slowly migrating band was also observed. These results were in agreement with data previously reported [5][6][7], which indicates that the probe specifically cross-hybridizes to the transcript of rat NGF gene. Therefore genomic DNA digested with the restriction enzymes, EcoRI, HindIII and PstI was carried out.…”

“…Further, a recent report [7] has shown that in adult rat brain, cortex and hippocampus have the highest NGF mRNA, while NGF mRNA is undetectable in the hypothalamus, striatum and septum. Therefore, we cultured cells from the region of newborn rat brain including cortex and hippocampus.…”

“…Recently, several researchers have reported the presence of NGF mRNA and a NGF-like protein in the rat central nervous system (CNS) as well as in the PNS, and suggested that NGF may function as a retrograde trophic factor for magnocellular cholinergic neurons in basal forebrain nuclei [4][5][6][7]. However, we have no information on the cell type(s) producing NGF protein in the brain and on the molecular mechanism that controls the expression of the NGF gene in the CNS.…”

Rescue of lesioned septal cholinergic neurons by nerve growth factor: specificity and requirement for chronic treatment

“…Furthermore, injections of NGF into the brain of newborn rats elevate ChAT activity in the target areas of the forebrain cholinergic neurons (Gnahn et al, 1983;Mobley et al, 1985Mobley et al, , 1986. Levels of NGF and its mRNA (mRNANGF) develop parallel to the growth of cholinergic axons of the rat basal forebrain (Large et al, 1986;Whittemore et al, 1986;Auburger et al, 1987). Lesions of the septohippocampal pathway in neonatal rats result in increases of both mRNANGF and NGF in the hippocampus (Whittemore et al, 1987).…”

Cloning and expression of a cDNA encoding a novel human neurotrophic factor

“…NGF is a neurotrophic factor essential for the survival and development of sensory and sympathetic neurons and cholinergic neurons of the basal forebrain, and it is distributed in many peripheral tissues and in brain [17,18]. In rat brain NGF mRNA begins to accumulate after birth [19]. BDNF supports the survival of sensory neurons and is distributed mainly in brain [7].…”