Embryonic Intermediate Filaments, Nestin and Vimentin, Expression in the Spinal Cords of Rats with Experimental Autoimmune Encephalomyelitis

Intermediate filaments, including nestin and vimentin, are found in specific cell types in central nervous system (CNS) tissues, particularly immature glial cells and multipotent progenitor cells. In the present study, the expression patterns of nestin and vimentin in the spinal cords of rats with experimental autoimmune encephalomyelitis (EAE) and the response of cells containing filaments against acute autoimmune injury were examined by immunohistochemistry. Nestin immunostaining was only weakly detected in vascular endothelial cells but not in any cell types in the spinal cord in normal and adjuvant-immunized rats. At the peak stage of EAE, nestin-immunoreativity was recognized in some astrocytes in the gray matter and white matter. Vimentin was immunopositive in some astrocytes and macrophages in EAE lesions, while vimentin was normally detected in ependymal cells of central canals in the rat spinal cords.We postulate that normal animals may contain multipotent progenitor cells in the spinal cord parenchyma as well as in the subpial lesion and ependyma. Multipotent progenitor cells may activate to transform into necessary cells, including neurons, astrocytes or oligodendrocytes, depending on CNS needs. Appropriate control of progenitor cells in the injured CNS is an alternative choice for CNS remodeling.

Histochemical Characterization of the Lectin-binding Sites in the Equine Vomeronasal Organ

The binding specificities of various lectins, such as the Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA), and the Bandeiraea simplicifolia BS-1 (Isolectin B4), Triticum vulgaris (WGA), Arachis hypogaea (PNA), and Ulex europaeus (UEA-I) lectins, were studied in the vomeronasal organ of the horse. The microvilli of the vomeronasal sensory epithelium were positive for DBA, SBA, Isolectin B4, WGA, PNA, and UEA-I. The receptor cells showed intense reactivity for DBA and WGA. Lectins were not detected in the supporting cells or basal cells. The Jacobson's glands were positive for WGA and UEA-I, but lectins were absent from the nerve bundles. From these results, we postulate that several lectin-binding carbohydrates on the microvilli and neurosensory cells are associated with chemoreception in the horse. In addition, the differential lectin-binding patterns in the horse suggest that the carbohydrates present in this particular sense organ are species-specific.

Histochemical Detection of Glycoconjugates in the Male Reproductive System of the Horse

Lectins are glycoproteins of plant and animal origin that have the ability to bind specific carbohydrate residues of cell glycoconjugates, particularly in terminal positions. In this study, the binding of lectins, Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA), Bandeiraea simplicifolia BS-1 (isolectin B4), Triticum vulgaris (WGA), Arachis hypogaea (PNA), and Ulex europaeus (UEA-I), was studied in the reproductive systems of male thoroughbred horses.DBA was detected in the stereocilia of the caput and corpus epididymis, and in the vas deferens. It was weakly detected in connective tissue of the corpus epididymis. Strong SBA staining was seen in epithelial cells in the testis, stereocilia of the corpus and cauda epididymis, and in the vas deferens. There were intense positive reactions for isolectin B4 in interstitial cells in all tissue and serosa of the vas deferens. PNA staining was seen only in stereocilia in the caput and corpus epididymis, and in the vas deferens. Strong WGA staining was seen throughout the testis, except in Sertoli cells, stereocilia, and connective tissue. UEA-I was detected in secondary spermatids, stereocilia, and epithelial cells of the cauda epididymis.These results show that degenerating cells in the testis, epididymal tubules, and vas deferens have differential affinities for lectins, and suggest that lectins play a role in the reproductive system of the horse. The heterogeneity of the lectin staining pattern in the reproductive tubules of adult horses suggests that the carbohydrate composition of each cell type is region specific.

Immunohistochemical Localization of Bcl-2 in the Spinal Cords of Rats with Experimental Autoimmune Encephalomyelitis

We examined the localization of the anti-apoptotic molecule Bcl-2 in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis (EAE). Western blot analysis showed that Bcl-2 was constitutively expressed in normal spinal cords, and weakly increased in response to complete Freund's adjuvant(CFA) immunization. In EAE, with infiltration of inflammatory cells into spinal cords, Bcl-2 declined during the peak stage and further decreased during the recovery stage. Immunohistochemically, some neurons and glial cells constitutively expressed Bcl-2 in normal rat spinal cords. In the spinal cords of rats with EAE, Bcl-2 was also immunoreacted in some perivascular inflammatory cells while some brain cells, such as neurons and GFAP (+) astrocytes showed less Bcl-2 immunoreaction.These findings suggest that in EAE, Bcl-2 expression in the CNS host cells decreases with CNS inflammation, possibly progressing to cell death in some cases, while the survival of host cells, including neurons, astrocytes, and some inflammatory cells, is associated with activation of the anti-apoptotic molecule Bcl-2. Taking all into considerations, its is postulated that Bcl-2 either beneficially or detrimentally functions in some host cells depending on the activation stage of each cell type.

Histochemistry of Six Lectins in the Tissues of the Flat Fish Paralichthys olivaceus

Lectins are glycoproteins that specifically bind carbohydrate structures and may participate in the biodefense mechanisms of fish. In this study, the binding of three lectins, Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA), Bandeiraea simplicifolia BS-1 (isolectin B4), Triticum vulgaris (WGA), Arachis hypogaea (PNA) and Ulex europaeus (UEA-I) were studied in the gill, liver, intestine, kidney, heart, and spleen of the flat fish Paralichthys olivaceus. DBA was detected in intestinal mucous cells, as well as in gill epithelial and mucous cells. It was weakly detected in renal tubule epithelial cells and in bile duct epithelial cells. The strong SBA staining was seen in the intestinal club cells, in bile duct epithelial cells and renal tubule epithelial cells. There were intense positive reactions for isolectin B4 in gill epithelial and mucous cells, and the strong isolectin B4 staining was seen in epithelial cells of the bile duct and intestine. The strong WGA staining was seen in the gill mucosal cells, sinusoid, renal tubule epithelial cells and mucosal cells of the intestine. UEA-I was detected in the gill epithelial and mucosal cells, bile duct epithelial cells and renal tubular epithelial cells. These results suggest that the six lectins examined were localized in the covering epithelia of the various organs of the flat fish and they may participate in the biodefense mechanism of the intra body surface in which is exposed to various antigens.