Peripheral distribution of nervous system-specific S-100 protein in rat

S-100 protein, a nervous system-specific protein, was determined in a soluble extract of various rat tissues with a sensitive enzyme immunoassay method, which consisted of a solid-phase with immobilized anti-S-100 antibody and the antibody labeled with beta-D-galactosidase from Escherichia coli. The minimum detectable amount of S-100 protein was 3 pg/assay. Central nervous tissues (cerebrum, cerebellum, and brain stem) contained 1.4 to 2.8 micrograms S-100 protein/mg protein, whereas most of the peripheral tissues contained less than 0.05 microgram/ml of the specific protein. However, the level of S-100 protein was high in adipose tissue (0.5--1.1 micrograms/mg) and in trachea (about 0.5 microgram/mg), which involves cartilage. The S-100 protein levels in several tissues were significantly higher in female rats than in males at ages of 5 to 6 weeks.     

Synthesis of a brain-specific protein (S100 protein) in a lectin-resistant mutant of a rat glial cell line (C6)

The synthesis of S100 protein increases toward the end of the exponential phase of growth of clonal rat glial cells C6 in monolayer culture. Moreover the synthesis of this protein can be increased by treatment of C6 cells with the lectin succinylated concanavalin A (succinyl ConA). In order to study the relationship between these two inductions of S100 protein we have isolated a cell line resistant to ConA from a population of C6 cells. The resistant cells (C6-ConAR) have less succinyl ConA receptors than C6 cells. In contrast to C6 cells, the synthesis of S100 protein does not increase in C6-ConAR cells after treatment with succinyl ConA. However in both cell types the synthesis of S100 protein increases toward the end of the exponential phase of growth. These results suggest firstly that the induction of S100 protein in C6 cells by succinyl ConA is mediated by an interaction of the lectin with its membrane receptors and secondly that the initial steps in the induction of S100 protein by the lectin are different from the initial steps in the induction of this protein which occurs toward the end of the exponential phase of growth in monolayer culture.     

Synthesis of a brain-specific protein (S100 protein) in a lectin-resistant mutant of a rat glial cell line (C6)

The synthesis of S100 protein increases toward the end of the exponential phase of growth of clonal rat glial cells C6 in monolayer culture. Moreover the synthesis of this protein can be increased by treatment of C6 cells with the lectin succinylated concanavalin A (succinyl ConA). In order to study the relationship between these two inductions of S100 protein we have isolated a cell line resistant to ConA from a population of C6 cells. The resistant cells (C6-ConAsuitr) have less succinyl ConA receptors than C6 cells.In contrast to C6 cells, the synthesis of S100 protein does not increase in C6-ConAsuitr cells after treatment with succinyl ConA. However in both cell types the synthesis of S100 protein increases toward the end of the exponential phase of growth.These results suggest firstly that the induction of S100 protein in C6 cells by succinyl ConA is mediated by an interaction of the lectin with its membrane receptors and secondly that the initial steps in the induction of S100 protein by the lectin are different from the initial steps in the induction of this protein which occurs toward the end of the exponential phase of growth in monolayer culture.     

Appearance of a brain-specific antigen (S-100 protein) in the developing rat brain

Abstract— Thelevel of the S-100 protein, a brain-specific antigen, wasdetermined by quantitative complement fixation in the brain stem and cerebrum of the rat during postnatal maturation. The content was minimal at birth in the brain stem and rose to its adult value by day 25. Although S-100 protein could not be detected in the cerebrum of the 2-day-old rat, adult values were also present by the 25th day of age. Neither single dose X-irradiation with 750 rd to the head at 2 days of age or single dose X-irradiation at 11 days of age affected the adult level of S-100 protein in the brain stem or cerebrum. Similarly, hypophysectomy at 20 days of age had no effect on the subsequent levels of S-100 protein.     

Synthesis by a clonal line of rat glial cells of a protein unique to the nervous system

The synthesis of a protein unique to the nervous system, the “S100-protein,” has been studied in a clonal line of rat glial cells. It has been shown that these cells do not begin to accumulate “S100-protein” until the cultures enter a phase of density-dependent inhibition of cell proliferation. Further experiments indicate that the regulation of “S100-protein” accumulation resides at least in part in an interaction involving the cell surface.     

Effect of norepinephrine and dibutyryl cyclic AMP on S-100 protein level in C6 glioma cells

S-100 Protein level was determined in C6 glioma cells after treatments by norepinephrine. In growing cells norepinephrine induces an important increase of S-100 protein level continuing during the stationary phase to reach a level higher than in untreated quiescent cells. In quiescent, low density, thymidine blocked cells, S-100 protein level is also enhanced by norepinephrine. In high density, contact inhibited cells, S-100 protein level is not modified although cAMP level is much more stimulated by norepinephrine than is low density cells. Exogenous addition of dibutyryl cyclic AMP mimics the effects of norepinephrine.Our results suggest that cyclic AMP level can mudulate S-100 protein level in C6 cells but that in density inhibited cells, a subsequent step involved in the regulation is no more operative.     

Immunohistochemical localization of S-100 protein subunits (alpha and beta) in dorsal root ganglia of the rat

The distribution of S-100 protein and their subunits (alpha and beta) in lumbar dorsal root ganglia of adult rat was investigated immunohistochemically using monoclonal antibodies against the S-100 protein, alpha-subunit and beta-subunit of S-100 protein. The conventional S-100 protein antibody stained both neurons (large and intermediate in size; 20.3% and 41 +/- 3.2 microns of diameter) and glial cells (satellite cells and Schwann cells). The immunoreaction for the alpha-subunit was observed in the perikarya of some large and intermediate sized neurons (17.2%, 45.6 +/- 6.1 microns of diameter), satellite cells and Schwann cells, whereas the beta-subunit immunoreactivity was found principally in glial cells, and in a scarce number of large and intermediate sized neurons (2.8%, 43.3 +/- 5 microns of diameter) Our results demonstrate that a subpopulation of large and intermediate sized neurons of lumbar DRG contain alpha- and beta-subunits of S-100 protein, being alpha-subunit predominant. Furthermore, the satellite glial and Schwann cells contain also the two subunits but mainly beta-subunit. These data confirm previous studies about the presence of S-100 protein in neurons of the central and peripheral nervous system.     

Quantitative alterations of S-100 protein and neuron specific enolase in the rat nervous system after chronic 2,5-hexanedione exposure

The regional changes in quantities of the glial S-100 protein and the neuron specific enolase in the rat nervous system have been studied after long-term exposure to 2,5-hexanedione. The wet weights of most of the examined nervous tissues were found to be reduced, with an extensive effect seen in the brain stem. Using dot immunobinding assays, the concentrations of S-100 were found to be increased in most of the examined tissues, but unaffected in the brain stem. The total amount of S-100 per tissue was markedly reduced in the brain stem. The content of neuron specific enolase was reduced only in the brain stem. Thus the effects of 2,5-hexanedione on the nervous system varied regionally. The brain stem was severely atrophied with a reduction of neuronal as well as of glial marker proteins. Other brain regions contained increased glial cell marker proteins as signs of progressive astroglial reactions.     

Effect of parvalbumin and S-100 protein on protein synthesis in rabbit reticulocyte lysate.

The effect of two high affinity Ca+ binding acidic proteins, parvalbumin and S-100 protein on protein synthesis in rabbit reticulocyte lysates (RRL), was investigated. Nuclease-treated RRL, supplemented with yeast mRNA, and 3H-leucine were incubated at 37 degrees C, and incorporation of 3H-leucine into protein was determined for 24 min. At 20 micrograms/100 microliters lysate concentration, both parvalbumin and S-100 protein caused a marked inhibition of protein synthesis compared with the control lysate. At a lower concentration parvalbumin was less inhibitory than histone H1; the effect of S-100 protein was not significant. The combined inhibitory effect of parvalbumin and H1 was not additive probably due to strong interaction between them as was evidenced by the enhanced absorbance of parvalbumin-H1 mixture. Spectrophotometric profiles of parvalbumin-tRNA mixture indicated that, unlike H1, parvalbumin did not inhibit protein synthesis by binding with nucleic acids. These results suggest an important role for parvalbumin in translational regulation.     

Effect of protein S-100 on phosphorylation of nuclear proteins of cells of rat brain and liver

The effect of acidic neurospecific protein S-100 on the phosphorylation of brain and liver nuclear proteins with 1 and 10 microM ATP was investigated. It was shown that protein S-100 increases the phosphorylation of brain nuclear proteins, while antigen D, another acidic neurospecific protein half-identical to 14-3-2 protein, inhibits this process. Ca2+ and cAMP at concentration of 10(-6) M do not affect the phosphorylation of brain nuclear proteins. In control assays the tracer 32P is presumably incorporated into high molecular weight nuclear protein fractions (Mr greater than 40000). After addition of protein S-100 the tracer is mainly incorporated into these proteins as well independently of ATP concentration (1 or 10 microM). The phosphorylation of nuclear proteins with molecular weights above 100000 is mostly increased in this case. At ATP concentration of 1 microM protein S-100 decreases histone phosphorylation 2.3 times but does not affect that of non-histone proteins. However, at 10 microM ATP the inhibitory action of this protein on histone phosphorylation is absent. The possible mechanisms of protein S-100 action on nuclear proteins phosphorylation are discussed.     

Appearance of a brain specific antigen (th S-100 protein) during human foetal development

—The concentration of a protein specific to brain, the S-100 protein, was measured in various regions of the human foetal brain at gestational ages ranging from 10 weeks until term. The relative increase in concentrations of the S-100 protein during development of the human foetal brain proceeded in a caudal-rostral fashion. This observation is emphasized by the delayed appearance of the S-100 protein in the frontal cerebral cortex until the 30th week of gestation.     

Filiform papillae as a sensory apparatus in the tongue: An immunohistochemical study of nervous elements by use of neurofilamcnt protein (NFP) and S-100 protein antibodies

Summary Nervous elements supplying the filiform papillae of the tongue of cattle and rats were investigated using immunohistochemistry against neurofilament protein (NFP) and glia-specific S-100 protein. The rod-shaped bovine filiform papillae were heavily keratinized along their entire length and lacked the connective tissue core that occurs in other mammals. Instead, the core was located posterior to the filiform papilla. The base of the bovine filiform papillae was invaded vertically by laminar connective tissue papillae. The core contained a large number of NFP-positive nerve fibers, most of them terminating as free endings in its anterior margin. NFP-positive nerves gathered around the anterior ridge of the epithelium at the base of the core and occasionally penetrated into the epithelium. The laminar connective tissue papillae at the base of the filiform papilla also contained NFP-positive nerve fibers. The core contained S-100-immunoreactive lamellated corpuscles, which were identified as simple corpuscles in electron micrographs. The structure and innervation of the bovine filiform papilla suggest that they represent a specialized sensory apparatus. The pyramidal filiform papillae of the rat were smaller, each containing a simple connective tissue core. Few NFP-positive nerve fibers from the nerve plexus entered the core. Filiform papillae are thus less specialized in rats than in cattle.     

Effect of dicarboxylic (C6 and C9) acids on a human squamous carcinoma cell line in culture

In tissue culture, azelaic acid (C9) has been shown to have an anti-proliferative and cytotoxic effect on human and murine malignant melanocytes, with inhibition of mitochondrial oxido-reductase enzymes and DNA synthesis, and damage to mitochondria. Recent reports of effects on differentiation of normal keratocytes have led to the present study of its effects on a squamous carcinoma cell line. Cells were exposed to single doses of disodium salts of azelaic (C9(2)Na) and adipic (C6(2)Na) acids at concentrations of 10(-2)M and 5 x 10(-2)M for 48 hrs. Only C9(2)Na at 5 x 10(-2) M for 4 hrs., and longer, significantly affected proliferation, and the cells exhibited massive swelling of mitochondria with loss of cristae. The results further confirm the probable value of azelaic acid as a general anti-tumoral agent rather than a specifically melanocytotoxic one. They could justify clinical studies on the effect of topical azelaic acid therapy on squamous cell carcinoma in vivo.