Changnam Park

Immunohistochemical study of arginase 1 and 2 in various tissues of rats

Arginase 1 and arginase 2 catalyze the hydrolysis of arginine to ornithine and urea. The localization of these enzymes was studied in various tissues in Sprague-Dawley rats by immunohistochemistry and Western blotting. Western blot analysis showed that both arginase 1 and 2 were differentially expressed in the various organs examined. Arginase 1 was expressed at high levels in the liver, at moderate levels in the pancreas, and at low levels in the cerebrum, cerebellum, spinal cord, stomach, small and large intestines, kidneys, lungs, and spleen. The levels of arginase 2 immunoreactivity were high in the kidneys and pancreas, and moderate in the cerebrum, spinal cord, stomach, small intestine, large intestine, and lungs; the levels were very low in the liver and spleen compared with that in the cerebellum. Immunohistochemical analysis largely confirmed the results of the Western blot analysis. These findings indicate that the levels of arginase 1 and 2 varied among organs, suggesting that the arginase isoforms may play organ-specific roles in the urea cycle.

A morphological study of the vomeronasal organ and the accessory olfactory bulb in the Korean roe deer, Capreolus pygargus.

The vomeronasal organ (VNO) and accessory olfactory bulb (AOB) of the Korean roe deer (Capreolus pygargus) were studied histologically to evaluate their morphological characteristics. Grossly, the VNO, encased by cartilage, has a paired tubular structure with a caudal blind end and a rostral connection through incisive ducts on the hard palate. In the VNO, the vomeronasal sensory epithelium (VSE) consists of galectin-3-positive supporting cells, protein gene product (PGP) 9.5-positive receptor cells, and basal cells. The vomeronasal respiratory epithelium (VRE) consists of a pseudostratified epithelium. The AOB strata included a vomeronasal nerve layer (VNL), a glomerular layer (GL), a mitral/tufted cell layer, and a granular cell layer. All lectins used in this study, including Bandeiraea simplicifolia agglutinin isolectin B4 (BSI-B4), soybean agglutinin (SBA), Ulex europaeus agglutinin I (UEA-I), and Triticum vulgaris wheat germ agglutinin (WGA), labeled the VSE with varying intensity. In the AOB, both the VNL and the GL reacted with BSI-B4, SBA, and WGA with varying intensity, but not with UEA-I. This is the first morphological study of the VNO and AOB of the Korean roe deer, which are similar to those of goats.

Histological and lectin histochemical studies on the olfactory mucosae of the Korean roe deer, Capreolus pygargus.

The morphological features of the olfactory mucosae of Korean roe deer, Capreolus pygargus, were histologically studied using the ethmoid turbinates containing the olfactory mucosae from six roe deer (male, 2-3 years old). The ethmoid turbinates were embedded in paraffin, and histochemically evaluated in terms of the mucosal characteristics. Lectin histochemistry was performed to investigate the carbohydrate-binding specificity on the olfactory mucosa. Lectins, including Triticum vulgaris wheat germ agglutinin (WGA), Ulex europaeus agglutinin I (UEA-I), and soybean agglutinin (SBA) were used for the N-acetylglucosamine, fucose and N-acetylgalactosamine carbohydrate groups, respectively. Histologically, the olfactory mucosa, positioned mainly in the caudal roof of the nasal cavity, consisted of the olfactory epithelium and the lamina propria. The olfactory epithelium consisted of protein gene product (PGP) 9.5-positive olfactory receptor cells, galectin-3-positive supporting cells and basal cells. Bowmans glands in the lamina propria were stained by both the periodic acid Schiff reagent and alcian blue (pH 2.5). Two types of lectin, WGA and SBA, were labeled in free border, receptor cells, supporting cells and Bowmans glands, with the exception of basal cells, while UEA-I was labeled in free border, supporting cells and Bowmans glands, but not in receptor cells and basal cells, suggesting that carbohydrate terminals on the olfactory mucosae of roe deer vary depending on cell type. This is the first morphological study of the olfactory mucosa of the Korean roe deer to evaluate carbohydrate terminals in the olfactory mucosae.

Histological and lectin histochemical studies of the vomeronasal organ of horses

The morphological characteristics and glycoconjugate composition of the vomeronasal organ (VNO) of the horse was investigated using histological, immunohistochemical, and lectin histochemical methods. The VNO is bilaterally located at the base of the nasal septum, has a tubular structure surrounded by cartilage, and consists of sensory and non-sensory epithelia. Immunohistochemical examination showed that the vomeronasal sensory epithelium (VSE) consisted of receptor cells positive for both olfactory marker protein (OMP) and protein gene product 9.5 (PGP 9.5), supporting cells, and basal cells. VNO receptor cells were positive for G protein Gαi2 (vomeronasal receptor type 1 marker), but not Gαo (vomeronasal receptor type 2 marker). Lectin histochemical studies using 21 biotinylated lectins showed that the free border of the VSE was positive for 20 lectins. The receptor and supporting cells reacted with 16 lectins while the basal cells reacted with 15 lectins, with varying intensities. In the vomeronasal non-sensory epithelium, the free border was positive for 19 lectins. The cilated cells were positive for 17 lectins and the basal cells were positive for 15 lectins. The vomeronasal glands, positioned in the lamina propria, were stained with both periodic acid Schiff (PAS) and alcian blue (pH 2.5). Eighteen lectins stained the acinar cells of the vomeronasal glands with various binding patterns. These findings suggest that horse VNO receptor cells express vomeronasal receptor type 1, and the VNO glands have mucous to seromucous characteristics. Moreover, each lectin differentially binds each cell type in both the VNO sensory and non-sensory epithelia.

Galectin-3 immunohistochemistry in the vomeronasal organ of the domestic pig, Sus scrofa

The immunohistochemical localization of galectin-3, a β-galactoside-binding protein, was studied in the vomeronasal organ (VNO) of fetal, 1-day-old, and 6-month-old pigs. In all age groups, the porcine VNO consisted of vomeronasal sensory epithelium (VSE) located medially and non-sensory vomeronasal respiratory epithelium (VRE) located laterally. In the pig, the VNO epithelium increased in height with postnatal development from fetus to adult. In the VSE of all stages examined, galectin-3 immunostaining was seen in the supporting cells and free border, but not in receptor or basal cells. Galectin-3 immunostaining was seen in all layers of the VRE, and the intensity increased with postnatal development. In the lamina propria, galectin-3 was detected in some ductal epithelial cells and the vomeronasal nerve sheath, but not in the acini of the Jacobson glands in all age groups. In view of these observations, we postulate that galectin-3 plays a role in cell survival and cell adhesion in both the VSE and VRE of porcine VNO in all age groups.

Histochemical study of the olfactory mucosae of the horse

The olfactory mucosae of the horse were examined by using histology and lectin histochemistry to characterize the carbohydrate sugar residues therein. Histological findings revealed that olfactory epithelium (OE) consisted of both olfactory marker protein (OMP)- and protein gene product (PGP) 9.5-positive receptor cells, supporting cells and basal cells with intervening secretory ducts from Bowmans glands. Mucus histochemistry showed that Bowmans gland acini contain periodic acid-Schiff (PAS) reagent-positive neutral mucins and alcian blue pH 2.5-positive mucosubstances. Lectin histochemistry revealed that a variety of carbohydrate sugar residues, including N-acetylglucosamine, mannose, galactose, N-acetylgalactosamine, fucose and complex type N-glycan groups, are present in the various cell types in the olfactory mucosa at varying levels. Collectively, this is the first descriptive study of horse olfactory mucosa to characterize carbohydrate sugar residues in the OE and Bowmans glands.

Potential involvement of glycogen synthase kinase (GSK)-3β in a rat model of multiple sclerosis: evidenced by lithium treatment

Glycogen synthase kinase (GSK)-3β has been known as a pro-inflammatory molecule in neuroinflammation. The involvement of GSK-3β remains unsolved in acute monophasic rat experimental autoimmune encephalomyelitis (EAE). The aim of this study was to evaluate a potential role of GSK-3β in central nervous system (CNS) autoimmunity through its inhibition by lithium. Lithium treatment significantly delayed the onset of EAE paralysis and ameliorated its severity. Lithium treatment reduced the serum level of pro-inflammatory tumor necrosis factor a but not that of interleukin 10. Western blot analysis showed that the phosphorylation of GSK-3β (p-GSK-3β) and its upstream factor Akt was significantly increased in the lithium-treated group. Immunohistochemical examination revealed that lithium treatment also suppressed the activation of ionized calcium binding protein-1-positive microglial cells and vascular cell adhesion molecule-1 expression in the spinal cords of lithium-treated EAE rats. These results demonstrate that lithium ameliorates clinical symptom of acute monophasic rat EAE, and GSK-3 is a target for the suppression of acute neuroinflammation as far as rat model of human CNS disease is involved.

Immunohistochemical study of Krüppel-like factor 4 in the spinal cords of rats with experimental autoimmune encephalomyelitis.

The expression and localization of Krüppel-like factor (KLF) 4, a class of zinc-finger transcription factors, was investigated in the spinal cords of rats with experimental autoimmune encephalomyelitis (EAE) using western blotting and immunohistochemistry. KLF4 expression was increased significantly in EAE-affected spinal cords compared with normal rat spinal cords. The elevated levels of KLF4 in the spinal cords of rats with EAE remained significant, even during the recovery stage of EAE. The cellular phenotype of KLF4 in EAE lesions consisted of some T cells, macrophages, and reactive astrocytes, whereas it was expressed constitutively in resting astrocytes and neurons, but not in ramified microglial cells in normal spinal cords. Collectively, we postulate that autoimmune T cells and macrophages activate KLF4 and subsequently do not proliferate or exhibit phenotypic switching from M1 to M2 macrophages, respectively. In addition, we hypothesize that the increased and sustained expression of KLF4 in reactive astrocytes during EAE was associated with suppressed CNS inflammation, as well as reduced numbers of pro-inflammatory T cells and M1 macrophages.

Immunohistochemical localization of GABAergic key molecules in the main olfactory bulb of the Korean roe deer, Capreolus pygargus.

Gamma-amino butyric acid (GABA) negatively regulates the excitatory activity of neurons and is a predominant neurotransmitter in the nervous system. The olfactory bulb, the main center in the olfactory system, is modulated by inhibitory interneurons that use GABA as their main neurotransmitter. The present study aimed to evaluate GABAergic transmission in the main olfactory bulb (MOB) of the Korean roe deer (Capreolus pygargus) by examining the immunohistochemical localization of GABAergic key molecules, including glutamic acid decarboxylase (GAD), vesicular GABA transporter (VGAT), GABA transporters (GATs; GAT-1 and GAT-3), and potassium sodium chloride co-transporter 2 (KCC2). GAD, VGAT, and KCC2 were expressed in the glomerular layer (GL), external plexiform layer (ePL), mitral cell layer (ML), and granule cell layer (GrL). Intense GAT-1 expression was observed in the GL; GAT-1 expression was discernible in the ePL, ML, and GrL. However, intense GAT-3 expression was extensively observed in all layers of the MOB. These results suggest that substantial GABAergic synapses are present in the GL, ePL, ML, and GrL. Furthermore, the released GABA may be removed by GAT-1 and GAT-3 in the GL, and the majority of GABA, which is present in the ePL to GrL, may undergo reuptake by GAT-3. This is the first morphological and descriptive study of GABAergic transmission in the MOB of Korean roe deer.

Unilaminar follicular cells transiently express galectin-3 during ovarian folliculogenesis in pigs

The localization of galectin-3, a β-galactoside-binding animal lectin, was immunohistochemically studied in the ovaries of pigs to determine its expression in ovarian folliculogenesis. Various stages of ovarian follicles were identified in the ovaries of adult pigs. Galectin-3 was immunostained in the squamous follicular cells surrounding oocytes in primordial follicles and in the unilaminar granulosa cells of primary follicles, but not in oocytes of multilaminar follicles (including primary, secondary, and tertiary Graafian follicles). As in adult ovaries, galectin-3 immunoreactivity was prominent in the unilaminar follicles in neonatal ovaries. Galectin-3 was also immunolocalized in the luteal cells in the corpus luteum and granulosa cells of atretic follicles as well as in interstitial macrophages in porcine ovaries. Collectively, these results suggest that galectin-3 is transiently expressed in follicular cells in the unilaminar ovarian follicles (primordial and primary) but not in multilaminar ovarian follicles (primary to tertiary), implying that galectin-3 is embryologically involved in ovum generation.