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Pegmatite is a coarse-grained intrusive igneous rock rich in rare elements such as uranium, tungsten, and tantalum with Ca, K, Mg, Fe, Se, Ge, and Ho. We tested in vitro and in vivo assays for the anti-inflammatory activity of pegmatites. We firstly evaluated the suppressive effects of pegmatite on macrophage cell line RAW 264.7 cells stimulated with proinflammatory stimuli lipopolysaccharide (LPS) to determine nitric oxide (NO) production and TNF-α and IL-6 release. The IC50 values of pegmatite exceeded 5,000 μg/mL. Treatment of RAW 264.7 cells with pegmatite significantly inhibited LPS-stimulated NO production and proinflammatory cytokines such as TNF-α and IL-6 secretion in a dose-dependent manner (P more...

Schwann cells provide a favorable microenvironment for successful regeneration of the injured peripheral nerve. Even though the roles of extracellular matrix proteins in the Schwann cell physiology have long been studied, the precise function of nidogen, a ubiquitous component of the basal lamina, in Schwann cells is unknown. In this study, we show that the protein and mRNA messages for nidogens are up-regulated in the sciatic nerve after sciatic nerve transection. We demonstrate that recombinant nidogen-1 increased the process formation of Schwann cells cultured from adult rat sciatic nerves and that nidogen-1 prevented Schwann cells from serum-deprivation-induced death. In addition, nidogen-1 promoted spontaneous migration of Schwann cells in two-independent migration assays. The Schwann cell responses to the recombinant nidogen-1 were specific because the nidogen-binding ectodomain of tumor endothelial marker 7 inhibited the nidogen responses without affecting Schwann cell response to laminin. Finally, we found that β1 subunit-containing integrins play a key role in the nidogen-induced process formation, survival, and migration of Schwann cells. Altogether, these results indicate that nidogen has a prosurvival and promigratory activity on Schwann cells in the peripheral nerve. more...

Among the various phenotypes seen in Down syndrome (DS), mental retardation is the most common and most debilitating condition suffered by individuals with DS. The DYRK1A gene on human chromosome 21q22.2 encodes a subfamily of protein kinases that displays dual substrate specificities and is known to play a critical role in neurodevelopment. To study DS mental retardation, we have generated transgenic mice that contain only one copy of the complete human DYRK1A gene in a bacterial artificial chromosome. The transgenic mice showed significant impairment in hippocampal-dependent memory tasks in a Morris water maze. Interestingly, we observed shifts in both long-term potentiation and long-term depression, which suggests a role for DYRK1A in bidirectional synaptic plasticity. These mice represent the most clinically relevant DYRK1A mouse model to date and provide us a valuable tool for the in vivo study of mechanisms that underlie the learning and memory deficit in DS. more...

The proteolytic activity of live Uronema marinum was analyzed by a fluorescence polarization (FP) technique. Protease activity was measured as a decrease in the FP value using fluorescein isothiocynate (FITC)-casein as a protein substrate. A time-dependent decrease in FP occurred in plate wells containing live U. marinum. Supplementation with the cysteine protease inhibitor E-64 had no significant inhibitory effect on the decrease in FP at any of the concentrations used. In contrast, supplementation with 1,10-phenanthroline resulted in complete inhibition of proteolysis for 30 min at 1 mM and for 1 h at 2 and 5 mM. Effective inhibition of the proteolytic activity of live U. marinum by 1,10-phenanthroline indicated that metalloproteases are the main proteases excreted by U. marinum. As U. marinum has a high potential for systemically invading and destroying fish tissues, the metalloproteases excreted by live U. marinum are likely to be involved in the invasion of host tissues and the pathogenicity of the parasite. more...

The effects of temperature and salinity on in vitro development of Perkinsus sp. prezoosporangia isolated from cultured Manila clams in Korea were investigated, and the difference in resistance to low temperature between prezoosporangia collected in winter and those collected in summer was compared. Temperature and salinity had significant effects on the development of prezoosporangia, and the developmental rates increased with increasing temperature and salinity. Prezoosporangia isolated in winter sporulated and released motile zoospores at 10 degrees C, although the rates were significantly lower than those at 20 and 30 degrees C. However, no prezoosporangia collected in summer sporulated at 10 degrees C. Low salinities (or = 10/1000) had a significant negative effect on the development of prezoosporangia. A small number of prezoosporangia sampled in summer did sporulate at 5/1000, but further developments including formation and release of zoospores were not observed. However, prezoosporangia sampled in winter and incubated at 5/1000 released motile zoospores, although the rates were significantly lower than those at higher salinities. more...

A lipopolysaccharide (LPS)-binding protein/bactericidal permeability-increasing protein (LBP/BPI) homolog was isolated from peripheral blood leukocytes cDNA library of olive flounder Paralichthys olivaceus. The isolated LBP/BPI cDNA is 2806bp in length with a 1419bp open reading frame (ORF) that encodes a protein of 472 amino acid residues. The LPS-binding domain is well conserved in the N-terminal barrel, showing high sequence identities with other teleost LBP/BPI as well as those of mammals. RT-PCR analysis revealed that mRNA expression of LBP/BPI was significantly elevated in all tested tissues (liver, gill, intestine, head kidney, and spleen) after intraperitoneal injection of the gram-negative bacterium Edwardsiella tarda or the gram-positive bacterium Streptococcus iniae. This expression pattern profile corresponded to that of acute inflammatory cytokines, suggesting that it plays a role in the innate immune response, in particular, the acute phase response. more...

Schwann cells provide a favorable microenvironment for successful regeneration of the injured peripheral nerve. Even though the roles of extracellular matrix proteins in the Schwann cell physiology have long been studied, the precise function of nidogen, a ubiquitous component of the basal lamina, in Schwann cells is unknown. In this study, we show that the protein and mRNA messages for nidogens are up-regulated in the sciatic nerve after sciatic nerve transection. We demonstrate that recombinant nidogen-1 increased the process formation of Schwann cells cultured from adult rat sciatic nerves and that nidogen-1 prevented Schwann cells from serum-deprivation-induced death. In addition, nidogen-1 promoted spontaneous migration of Schwann cells in two-independent migration assays. The Schwann cell responses to the recombinant nidogen-1 were specific because the nidogen-binding ectodomain of tumor endothelial marker 7 inhibited the nidogen responses without affecting Schwann cell response to laminin. Finally, we found that beta1 subunit-containing integrins play a key role in the nidogen-induced process formation, survival, and migration of Schwann cells. Altogether, these results indicate that nidogen has a prosurvival and promigratory activity on Schwann cells in the peripheral nerve. more...

Previous studies have revealed that the immunoreactivities of basal lamina components in the central nervous system (CNS) vasculature change after lesions. The purpose of the present study was to determine the acute response of nidogen immunoreactivity (Nd-ir) in blood vessels of the spinal cord following a dorsal hemisection. Nd-ir immunoreactivity in the vascular basal lamina was dramatically increased within 24 h of injury, and returned to basal level after 1 week. This temporal profile of the Nd-ir change was almost the same as that of laminin. However, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis revealed that there was no significant increase in nidogen expression after the injury. These findings indicate that changes of antibody accessibility or epitope structure, but not a change in the expression of nidogen, may be responsible for the temporal change of Nd-ir in blood vessels following the spinal cord lesion. more...

UNC5A-D are transmembrane receptors for netrin that plays an important role in the development of the spinal cord. However, their function in the adult nervous system remains to be established. In the present study, the mRNA expression of UNC5 family was investigated in the adult rat spinal cord following a dorsal hemisection injury. Reverse transcription-polymerase chain reaction (RT-PCR) revealed that mRNA expression of rat UNC5 family was down-regulated in the spinal cord within 3 days after the dorsal hemisection. Unc5b-d mRNA expressions returned to near normal level after a week, whereas the down-regulation of Unc5a mRNA expression was maintained until 1 month after the injury. In situ hybridization and immunofluorescent showed that both neurons and non-neuronal cells express Unc5a and b mRNAs in the adult spinal cord, and the significant long lasting down-regulation of Unc5a mRNA expression was also noticed following the spinal cord injury. This result suggests netrin/UNC5 involvement in the injury response of the adult spinal cord of the rats. more...

Netrin is a neuronal guidance molecule implicated in the development of spinal commissural neurons and cortical neurons. The attractive function of netrin requires the receptor, Deleted in Colorectal Cancer (DCC), while the receptor Unc5h is involved in the repulsive action of netrin during embryonic development. Although the expression of netrin and its receptor has been demonstrated in the adult nervous system, the function of netrin in adult neurons has not yet been elucidated. Here, we show that netrin treatment inhibited neurite outgrowth of adult dorsal root ganglion (DRG) neurons in explant and dissociated cultures. In addition, unc5h1-3 mRNAs, but not the dcc mRNA, are abundantly expressed in the adult DRG. An in situ hybridization study demonstrated that unc5h mRNAs were expressed in DRG neurons. This finding indicates that netrin/Unc5h signaling may play a role in the neurite outgrowth of adult DRG neurons and that netrin may be involved in the regulation of peripheral nerve regeneration. more...