Amount Of S-100 Protein Research Articles

The Dynamics of the Contents of Neurotrophic Factors in Early Ontogeny in the Brain Structures of Rats Subjected to Prenatal Hypoxia

We analyzed the contents of neurotrophic factors (BDNF and NGF) and the S-100 protein in the hippocampus, cortex, and cerebellum of the rat brain during early postnatal ontogeny. We found that the BDNF content in the cortex is significantly lower than in the hippocampus and cerebellum, which may indicate a different degree of maturity of the studied structures during the first month of life. The maximum BDNF and NGF content in the control group of animals was observed on the 10th day of life and by the first month it decreased in the cerebellum and remained at this level (in the hippocampus and cortex), while the amount of S-100 protein gradually increased during the entire first month of life. It was found that prenatal hypoxia is followed by a significant decrease in the contents of BDNF and NGF and the S-100 protein in early ontogeny; the change in their levels is maintained with age in comparison with control values, which may be one of the causes for a delay in the development of the nervous system and body as a whole.

Quantitative assay of S-100 protein in mouse brain cortex synaptosomes.

1. Data on the presence of S-100 protein in synaptic endings are revised, and evidence is given in favor of its localization inside mouse brain cortex synaptosomes and on the surface of their external membrane. 2. For identification of the S-100-specific polypeptide, proteins of external synaptosomal membranes were iodinated with lactoperoxidase fixed on cyanogen bromide (CNBr)-Sepharose, and after synaptosome lysis S-100-positive material was isolated by means of affinity chromatography antibodies to S-100 protein (a-S-100)-Sepharose. The molecular weight of the polypeptide obtained corresponded to that of S-100 subunits (10 kD), and iodine incorporation pointed to its localization on the surface of synaptosomal membranes. 3. With the help of antibodies labeled with horseradish peroxidase (a-S-100-HP) or 125I (a-S-100-125I), which do not penetrate into noninjured synaptosomes, the amount of S-100 protein on synaptosomal membranes was found to be 18.5 ng/mg total protein (as assayed with a-S-100-HP) or 95.33 ng/mg (as assayed with a-S-100-125I). 4. At the same time, the total S-100 protein content in synaptosomes measured by means of radioimmune analysis after their complete lysis turned out to be 284 +/- 0.84 ng/mg, i.e., a part of S-100 seemed to be inside synaptosomes. 5. Cosedimentation of water-soluble S-100 protein with the synaptosomal fraction during isolation was insignificant. Prefixation with glutaraldehyde or paraformaldehyde decreased the amount of material reacting with antibodies, possibly due to steric effects or denaturation of active centers. This could have influenced the earlier attempts to detect S-100 protein in synapses. Treatment of nonfixed synaptosomes with a conjugate of a-S-100 with colloidal gold made it possible to detect S-100-positive material on pre- and postsynaptic membranes, which confirms the biochemical data.

Effects of chronic n-hexane exposure on nervous system-specific and muscle-specific proteins.

Two kinds of nervous system-specific and muscle-specific proteins, enolase and S-100 protein, were quantitatively determined in peripheral nerves and skeletal muscles of rats chronically exposed to a neurotoxic solvent - n-hexane. Three groups of animals were exposed to n-hexane vapor at three different solvent concentrations (500 ppm, 1200 ppm, 3000 ppm) for 12 h/day, 7 days/week for 16 weeks. The body weight gain and motor nerve conduction velocity (MCV) in exposure groups show progressively concentration-dependent decreases compared to control values. Histopathological examination also demonstrates the degeneration of peripheral nerves in 3000 ppm- and 1200 ppm-exposed rats. The significant decrease in the amount of S-100 protein in peripheral nerves was observed not only in the high level exposure groups (3000 ppm and 1200 ppm), but also in the lowest level group (500 ppm), although the MCV and morphological examination remained unchanged at this level. In addition, the muscle-specific S-100 protein in 3000 ppm exposed rats' soleus also displayed a significant reduction. In contrast to this, however, enolase isozymes were not significantly changed by either dosage level in both nervous tissue and skeletal muscle. The experiment suggests that beta- and alpha-S-100 proteins which are specifically localized in nervous system and muscles, respectively, are more vulnerable than enolase isozymes under treatment with n-hexane, and may possibly serve as a specific indicator to evaluate the neurotoxic effects. Further research would be worthwhile to elucidate the role of the specific S-100 protein in evaluating the neurologic damage induced by various industrial chemicals.

Developmental changes in the translatable mRNA for β subunit of S-100 protein in rat brain

The presence of mRNA coding for β subunit of S-100 protein was demonstrated in polyadenylated RNA from the rat brain by in vitro translation in a reticulocyte lysate cell-free system. The products were identified with S-100 protein β subunit using the immunoprecipitation of the reaction products with the specific antisera, comigration of the isolated, labelled peptide with the purified S-100 protein in SDS-polyacrylamide gel electrophoresis and fluorography and the same retention time of the labelled S-100 protein β subunit with authentic S-100 β subunit by high performance liquid chromatography. The size determination of mRNA for S-100 protein on sucrose density gradient centrifugation gave 6–8 S. The assay gave a linear response with increasing amounts of polyadenylated RNA, allowing quantitation of mRNA level for S-100 protein in polyadenylated RNA. During the prenatal period and 10 postnatal days, only minute amounts of mRNA for β subunit of S-100 protein could be found, however a dramatic increase of mRNA for β subunit of S-100 was observed within the period of 10 to about 30 days and the mRNA level maintained a plateau from 40 days to adult age. These data indicate that the developmental changes in the amount of S-100 protein in the rat brain found by other authors is strongly correlated with the changes in the level of its translatable mRNA.

Alteration of water-soluble S-100 protein content in microembolized rat brain.

The amount of S-100 protein in rat brain embolized with carbon microspheres decreased in parallel with the development of cerebral edema as judged by water content, recovering to the normal range by 24h after embolization. These results suggest the participation of S-100 protein in the permeability characterisitics of nervous system capillaries known as the blood-brain barrier.

Detection of S-100 protein as an aid to the identification of melanocytic tumors.

We sought S-100 protein in sections prepared from formalin-fixed paraffin-embedded tumor and normal tissues by an immunoperoxidase technique with a rabbit anti-bovine S-100 protein antiserum as first antibody and aminoethyl carbazole as developer. S-100 protein was demonstrated in 56 of 56 cutaneous melanomas, regardless of their primary or metastatic status, and in 35 of 35 nevocytic nevi. The amount of S-100 protein was independent of the degree of melanization of the tumors. Only 1 of 51 non-neural non-melanocytic tumors tested contained S-100 protein. The technique is valuable in confirming the melanocytic nature of primary or metastatic tumors and in detecting small foci of metastatic melanoma in lymph nodes and other tissues. It also seems applicable to research on melanocytic anomalies.

Effects of thyroid state and undernutrition on S100 protein and astroglia development in rat cerebellum.

The developmental pattern of S100 protein, a specific marker of astroglia, was studied by radioimmunoassay in the cerebellum of thyroid-deficient, thyroxine-treated and undernourished rats during development. In the control animals, the S100 protein content of the cerebellum increased maximally after the 3rd postnatal week, i.e., after cell multiplication had stopped and when the cerebellum had acquired more than 70% of its adult weight and protein content. This developmental pattern of S100 protein reflected essentially the maturation of astroglia. In the thyroxine-treated rats the total amount and the concentration of S100 protein were higher than in controls during the first 3 weeks of postnatal life and returned to normal values thereafter. In the thyroid-deficient rats both the amount and concentration were lower than in controls throughout development. In the undernourished animals the amount of S100 protein per organ was also lower than in controls during the whole experimental period studied; the S100 protein concentration was higher during the first 2 postnatal weeks and became lower thereafter. These results are discussed taking into consideration previous histological and ultrastructural observations on the effects of altered thyroid state and undernutrition on the formation and maturation of cerebellar astrocytes.

培養グリオーマ細胞の形態学的分化に伴うDNAヒストグラム並びにS-100蛋白量の経時的変化に関する研究

培養グリオーマ細胞の形態学的分化に伴うDNAヒストグラム並びにS-100蛋白量の経時的変化に関する研究