Distribution and ultrastructural localization of PACAP receptors in the rat pancreatic islets.
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Animals↗
Biomedical subjects
Y Nakai
Publications and source records attributed to Y Nakai.
Expression of the nicotinic acetylcholine receptor alpha4 subunit mRNA in the rat cerebellar cortex.
In order to compare the previous immunohistochemical and immunocytochemical data on the distribution of nicotinic acetylcholine receptor alpha4 subunit-like immunoreactivity with the expression of alpha4 mRNA in the rat cerebellar cortex, the present study determined the cellular distribution of alpha4 mRNA in the rat cerebellar cortex. Northern blot analysis revealed two alpha4 mRNA bands in the rat cerebellum and three in the cerebral cortex, hippocampus, hypothalamus and striatum. The total level of these transcripts was lower in the cerebellum than in the other four regions. The expression of alpha4 mRNA was high in Purkinje cells and granular cells, whereas low expression was detected in the molecular layer. These results suggest that the expression of alpha4 mRNA is closely related to the alpha4-like immunoreactivity in the molecular and Purkinje cell layers. In the granular layer, alpha4 mRNA was very highly and broadly expressed in comparison with the alpha4-like immunoreactivity.
Animals↗
Inhibition of nitric oxide formation and superoxide generation during reduction of LY83583 by neuronal nitric oxide synthase.
6-Anilino-5,8-quinolinedione (LY83583) has been widely used as an agent to reduce levels of nitric oxide (NO)-dependent cGMP in tissues. We report here that suppression of NO formation and production of superoxide during enzymatic reduction of LY83583 by neuronal NO synthase appeared to be potentially involved in the pharmacological action caused by LY83583. LY83583 suppressed neuronal NO synthase activity of 20,000 x g rat cerebellar supernatant preparation in a concentration-dependent manner (IC50 value = 12.9 microM). A kinetic study revealed that LY83583 is a competitive inhibitor with respect to NADPH, with a Ki value of 2.57 microM. With purified neuronal NO synthase it was found that LY83583 was a potent inhibitor of NO formation by the enzyme and served as efficient substrate for reduction with a specific activity of 173 nmol of NADPH oxidized per mg of protein per minute. The reductase activity was stimulated about 19.8-fold by addition of CaCl2/calmodulin, indicating that the presence of CaCl2/calmodulin is essential to express maximal activity of LY83583 reduction. Although LY83583 was a good substrate for both NADPH-cytochrome P450 reductase (P450 reductase) and DT-diaphorase, these flavin enzymes-catalyzed reductions of LY83583 were less than the neuronal NO synthase-mediated reduction in the presence of CaCl2/calmodulin. Enzymatic generation of superoxide during reduction of LY83583 by neuronal NO synthase, P450 reductase or DT-diaphorase was confirmed by electron spin resonance (ESR) experiments. Thus the present results indicate that a benzoquinone derivative LY83583 appears to interact with the P450 reductase domain on neuronal NO synthase, resulting in inhibition of NO formation and superoxide generation, which is involved in suppression of intracellular cGMP content.
Aminoquinolines↗
Type I interferon induces inhibitory 16-kD CCAAT/ enhancer binding protein (C/EBP)beta, repressing the HIV-1 long terminal repeat in macrophages: pulmonary tuberculosis alters C/EBP expression, enhancing HIV-1 replication.
We have previously observed that HIV-1 replication is suppressed in uninflamed lung and increased during tuberculosis. In vitro THP-1 cell-derived macrophages inhibited HIV-1 replication after infection with Mycobacterium tuberculosis. Suppression of HIV-1 replication was associated with inhibition of the HIV-1 long terminal repeat (LTR) and induction of ISGF-3, a type I interferon (IFN)-specific transcription factor. Repression of the HIV-1 LTR required intact CCAAT/enhancer binding protein (C/EBP) sites. THP-1 cell-derived macrophages infected with M. tuberculosis, lipopolysaccharide, or IFN-beta induced the 16-kD inhibitory C/EBPbeta isoform and coincidentally repressed HIV-1 LTR transcription. C/EBPbeta was the predominant C/EBP family member produced in THP-1 macrophages during HIV-1 LTR repression. In vivo, alveolar macrophages from uninflamed lung strongly expressed inhibitory 16-kD C/EBPbeta, but pulmonary tuberculosis abolished inhibitory C/EBPbeta expression and induced a novel C/EBP DNA binding protein. Therefore, in vitro, proinflammatory stimulation produces an IFN response inhibiting viral replication by induction of a C/EBPbeta transcriptional repressor. THP-1 cell-derived macrophages stimulated with type I IFN are similar to alveolar macrophages in the uninflamed lung in vivo. In contrast, the cellular immune response in active pulmonary tuberculosis disrupts this innate immunity, switching C/EBP expression and allowing high level viral replication.
Base Sequence↗
Beta-endorphinergic innervation of mu and delta receptor containing neurons in the dorsal raphe nucleus.
A pre-embedding double immunostaining technique was used to determine the role of beta-endorphin in synapse, particularly in neurons with a postsynaptic membrane containing micro-1 or delta-1 opioid receptors. A small number of beta-endorphin immunoreactive axon terminals in the dorsal raphe nucleus was found to make direct synapses on micro-1 or delta-1 opioid receptor-immunoreactive dendrites, some of which showed immunostaining of their postsynaptic membranes, although with low frequencies. These results suggest that beta-endorphin can play a direct role through the micro-1 or delta-1 opioid receptors at synapses, but the main route would be through other opioid receptor at the synapse or even not through the synapse.
Animals↗
cDNA cloning and characterization of mouse nifS-like protein, m-Nfs1: mitochondrial localization of eukaryotic NifS-like proteins.
We have isolated a mouse cDNA which shows significant sequence similarity to the yeast nifS-like gene (y-NFS1), and termed it m-Nfs1. The deduced protein sequence (459 amino acids long) has several characteristic features common to those of bacterial NifS proteins, but distinct from them by its amino-terminal extension which contains a typical mitochondrial targeting presequence. m-Nfs1 was found to be a soluble 47-kDa protein in the matrix fraction of mouse liver mitochondria. The m-Nfs1 gene was ubiquitously expressed in most tissues, suggesting its housekeeping function in vivo. We also found that the gamma-NFS1 protein was localized in the mitochondrial matrix in yeast cells. These results suggest that both eukaryotic NifS-like proteins may play some roles in mitochondrial functions.
Amino Acid Sequence↗
Crystal structures of Paracoccus denitrificans aromatic amino acid aminotransferase: a substrate recognition site constructed by rearrangement of hydrogen bond network.
Aminotransferase reversibly catalyzes the transamination reaction by a ping-pong bi-bi mechanism with pyridoxal 5'-phosphate (PLP) as a cofactor. Various kinds of aminotransferases developing into catalysts for particular substrates have been reported. Among the aminotransferases, aromatic amino acid aminotransferase (EC 2.6.1. 57) catalyzes the transamination reaction with both acidic substrates and aromatic substrates. To elucidate the multiple substrate recognition mechanism, we determined the crystal structures of aromatic amino acid aminotransferase from Paracoccus denitrificans (pdAroAT): unliganded pdAroAT, pdAroAT in a complex with maleate as an acidic substrate analog, and pdAroAT in a complex with 3-phenylpropionate as an aromatic substrate analog at 2.33 A, 2. 50 A and 2.30 A resolution, respectively. The pdAroAT molecule is a homo-dimer. Each subunit has 394 amino acids and one PLP and is divided into small and large domains. The overall structure of pdAroAT is essentially identical to that of aspartate aminotransferase (AspAT) which catalyzes the transamination reaction with only an acidic amino acid. On binding the acidic substrate analog, arginine 292 and 386 form end-on salt bridges with carboxylates of the analog. Furthermore, binding of the substrate induces the domain movement to close the active site. The recognition mechanism for the acidic substrate analog in pdAroAT is identical to that observed in AspAT. Binding of the aromatic substrate analog causes reorientation of the side-chain of the residues, lysine 16, asparagine 142, arginine 292* and serine 296*, and changes in the position of water molecules in the active site to form a new hydrogen bond network in contrast to the active site structure of pdAroAT in the complex with an acidic substrate analog. Consequently, the rearrangement of the hydrogen bond network can form recognition sites for both acidic and aromatic side-chains of the substrate without a conformational change in the backbone structure in pdAroAT.
Bacterial Proteins↗
Pituitary adenylate cyclase-activating polypeptide: a key player in male reproduction?
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Animals↗
Vasopressin neuron activation and Fos expression by stimulation of the caudal ventrolateral medulla.
The present study demonstrates that projections ascending from the caudal ventrolateral medulla have direct effects on the expression of the immediate early gene c-fos and of the arginine-vasopressin gene in neurosecretory cells of the hypothalamic supraoptic nucleus. Intense Fos-like immunoreactivity (Fos-LI) was observed in many magnocellular neurons of the supraoptic nucleus after electrical stimulation of the caudal ventrolateral medulla. In sham-operated rats, Fos-LI was absent or present in very few magnocellular neurons in the supraoptic nucleus. Fos-LI was visible in neurons expressing arginine-vasopressin, and was seen rarely in oxytocin neurons by double-immunostaining method. This study showed that 76% of all Fos-positive cells were arginine-vasopressin immunoreactive, whereas only 4% of them showed oxytocin immunoreactivity in the supraoptic nucleus. With in situ hybridization, a high level of arginine-vasopressin mRNA was noted in the supraoptic nucleus 3 h after stimulation of the caudal ventrolateral medulla; the expression was highest 6 h after the stimulation compared with the same region in sham-operated animals. These findings suggest that noradrenaline, released from the axon terminals originating from the caudal ventrolateral medulla, may participate in the regulation of gene transcription of arginine-vasopressin in response to physiological stimuli.
Afferent Pathways↗
Immunohistochemical localization of leptin receptor in the rat brain.
The distribution of leptin receptor in the rat brain was determined by immunocytochemistry and Western blotting. Strong leptin receptor immunoreactivity was detected in the arcuate, paraventricular and ventromedial nuclei of the hypothalamus, and lateral hypothalamic area. The olfactory bulb, neocortex, cerebellar cortex, dorsal raphe nucleus, inferior olive nucleus, nucleus of the solitary tract, dorsal motor nucleus of the vagus nerve also showed intense immunoreactivity. Western blotting analysis yielded a 120-kDa major band.
Animals↗
Glutamate-stimulated proliferation of rat retinal pigment epithelial cells.
We investigated the effects of glutamate on cell proliferation and the expression of basic fibroblast growth factor (bFGF) and its receptor (FGF-R1) mRNA in cultured rat retinal pigment epithelial (RPE) cells. The number of primary RPE cells was significantly higher after treatment with 0.2 to 1.0 mM glutamate (maximum at 1.0 mM) for 7 days than in controls. Glutamate-stimulated cell proliferation was abolished by (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801), but not by 6,7-dinitroquinoxaline-2,3-dione or L(+)-2-amino-3-phosphonopropionic acid. Proliferation was increased to a similar extent by N-methyl-D-aspartate (NMDA), but not by kainate, alpha-amino-3-hydroxy-3-methyl-4-isoxazolepropionic acid or trans-(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid. NMDA-receptor-like immunoreactivity was detected in most cells cultured. Treatment of cells with glutamate increased the level of bFGF mRNA and, to a lesser extent, that of FGF-R1 mRNA, which peaked 2 and 4 days, respectively, after glutamate was added. The increase in bFGF mRNA induced by glutamate was inhibited by MK-801. These findings suggest that glutamate might stimulate proliferation of RPE cells through activation of NMDA receptors and expression of bFGF and further suggest that glutamate may be involved in the proliferative changes of RPE cells in retinal wound healing.
Animals↗
Clinical role of soluble adhesion molecules during immunotherapy for perennial allergic rhinitis.
BACKGROUND: Soluble forms of intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) have recently been identified in serum samples from atopic patients, but their clinical significance in the treatment of allergic diseases remains to be established. OBJECTIVE: To study the clinical roles of serum sICAM-1 and sVCAM-1 during immunotherapy for perennial allergic rhinitis. DESIGN: Our study included 30 nonatopic volunteers and 60 patients with perennial allergic rhinitis due to Dermatophagoides farinae. The 60 patients had been treated for variable periods (7.3+/-3.0 years [mean+/-SD]) with immunotherapy using a standardized D. farinae antigen. Serum samples were collected from each patient before and after immunotherapy to determine sICAM-1 and sVCAM-1 with sandwich enzyme-linked immunosorbent assays. RESULTS: Serum levels of sICAM-1 in the patients before immunotherapy were higher than those in the nonatopic volunteers (P<.001). The levels of sICAM-1 in the patients' serum samples were decreased significantly after immunotherapy (P<.001), and the percentage of the decrease in the sICAM-1 levels was significantly correlated with the duration of immunotherapy (P=.04) and with the percentage of the decrease in symptom scores (P<.001). The levels of sVCAM-1 in the serum samples from the patients with severe symptoms were significantly higher before immunotherapy than those in the nonatopic volunteers (P=.002) and were significantly decreased after immunotherapy (P=.05). However, the percentage of the decrease in the sVCAM-1 levels was not correlated with the duration of immunotherapy (P=.89) or with the percentage of the decrease in symptom scores (P=.89). CONCLUSION: Decrease in serum sICAM-1 levels during immunotherapy is probably involved in the working mechanisms of immunotherapy, but modulation of serum sVCAM-1 levels is not likely related to the clinical effect of immunotherapy.
Adult↗
Serologic study of the working mechanisms of immunotherapy for children with perennial allergic rhinitis.
BACKGROUND: Recent double-blind placebo-controlled trials have clearly shown the efficacy of immunotherapy for perennial allergic rhinitis. However, the exact working mechanisms related to the clinical effect of immunotherapy remain unclear. OBJECTIVES: To monitor the changes over time in immunologic parameters in children who received immunotherapy for perennial allergic rhinitis, and to elucidate the working mechanisms of immunotherapy related to its clinical efficacy. DESIGN: Nineteen children with perennial allergic rhinitis due to Dermatophagoides farinae enrolled in this prospective open study. Venous blood was collected to determine levels of specific IgE, specific IgG4, soluble interleukin 2 receptor, interleukin 4, soluble intercellular adhesion molecule 1, and soluble vascular cell adhesion molecule 1 at enrollment and 1, 2, 3, 5, and 10 years after enrollment. RESULTS: Immunotherapy affected serum levels of specific IgE, specific IgG4, soluble interleukin 2 receptor, interleukin 4, and soluble intercellular adhesion molecule 1, but not soluble vascular cell adhesion molecule 1. The rates of increase of levels of specific IgG4 and the rates of decrease of levels of soluble interleukin 2 receptor were correlated with the rates of decrease of symptom scores during the first 3 years of treatment, but not after 5 years. The rates of decrease in levels of soluble intercellular adhesion molecule 1 were correlated with the rates of decrease in symptom scores at 3 and 5 years after the beginning of the course of immunotherapy. The rates of decrease in levels of specific IgE and interleukin 4 were correlated with the rates of decrease in symptom scores after 5 and 10 years of treatment, but not during the first 3 years. CONCLUSION: Each modulation in levels of specific IgE, specific IgG4, soluble interleukin 2 receptor, interleukin 4, and soluble intercellular adhesion molecule 1 contributed to the clinical effect of immunotherapy in particular phases of treatment for children with perennial allergic rhinitis.
Anti-Asthmatic Agents↗
Ultrastructural localization of mu-1 opioid receptor in the dorsal raphe nucleus of the rat.
A simple pre-embedding avidin-biotin-peroxidase complex technique was used to study the ultrastructural localization of mu-1 opioid receptor in the rat dorsal raphe nucleus. Using low concentrations of the first antiserum for incubation with a short reaction time to 3,3'-diaminobenzidine, the immunostaining was faint at the light microscopic level. However, at the electron microscopic level strong immunoreaction was observed. Mu-1 opioid receptors were found to be localized on the postsynaptic membrane of dendrites, extra-synaptic plasma membrane, and the surface of the small, clear vesicles in axon terminals. Of the total 407 immunopositive profiles observed, 76.4% (311/407) were dendrites and 18.9% (77/407) were axon terminals. The immunostained myelinated axons and perikarya were relatively rare, with frequencies of 1.0% (4/407) and 3.7% (15/407), respectively. About 50.8% of the immunopositive dendrites (158/311) were immunostained having their MOR-LI results beneath the postsynaptic membrane, although about 19.6% of them (31/158) also exhibited MOR-LI on other components, including the extrasynaptic plasma membrane. Other immunopositive dendrites showed staining in some other contents, including extrasynaptic plasma membrane (82/311, 26.4%) or not on the plasma membranes (71/311, 22.8%). Less than half of the immunopositive axon terminals (35/77, 45.5%) were found to make synapses with nonimmunoreactive dendrites (31/77, 40.3%) or immunopositive dendrites (4/77, 5.2%); none were found to make synapses with immunoreactive perikarya. The present study shows that mu-1 opioid receptor in the dorsal raphe nucleus plays a role at both synapse or not.
Animals↗
Distribution of PNP 14 (beta-synuclein) in neuroendocrine tissues: localization in Sertoli cells.
Phosphoneuroprotein (PNP 14) is abundant in the central nervous system and is localized at nerve endings but not in synaptic vesicles. In this study, we examined the presence of PNP 14 in various endocrine tissues of the rat. PNP 14 was not detected in the endocrine cells of the intestine, testes, or adrenal gland, but it was present in axon terminals in both the medulla of the adrenal gland and the anterior pituitary gland. When testes were stained with PNP 14-specific antibodies by an indirect immunofluorescence method, PNP 14 was found in Sertoli cells of the testes, associated with fibrillar structures. PNP 14 was also detected in cultured Sertoli cells with a fibrillar pattern in the cytoplasm and around the nuclei. The fibrillar structure did not resemble actin stress fibers, microtubules, or intermediate filaments. The amount of PNP 14 in the testis changed with development. It increased markedly during the first 4 weeks after birth and then decreased. During the first 4 weeks after birth, spermatogonia undergo two rounds of meiosis. It is possible, therefore, that PNP 14 might be a factor related to meiosis.
Animals↗
Apoptosis of guinea pig cochlear hair cells following chronic aminoglycoside treatment.
Although aminoglycosides have been investigated for their cochleotoxicity, it has still not been determined whether apoptosis or necrosis results in cochlear hair cell death following aminoglycoside treatment. To study possible mechanisms of cell death, we used in situ DNA break-labeling to examine guinea pig cochleae affected by Kanamycin ototoxicity. Chronic kanamycin treatment induced DNA fragmentation that was detectable in both outer and inner hair cells, suggesting the occurrence of apoptosis. These findings suggest that apoptosis achieves deletion of affected hair cells without disrupting tissue architecture in the organ of Corti.
Animals↗
Osteolipoma in the parapharyngeal space.
We report our experience in managing a 58-year-old Japanese woman with a rare parapharyngeal interstitial cell tumor. Her main complaint was that of a submandibular swelling, which was diagnosed as osteolipoma histologically after resection.
Adipose Tissue↗
Synovial sarcoma of the esophagus: report of a case.
Synovial sarcomas are exceedingly rare neoplasms of the digestive tract. We herein report a case of a synovial sarcoma occurring in the esophagus of a 20-year-old man. He had a history of acute lymphocytic leukemia and had undergone aggressive chemotherapy between the ages of 4 and 8 years. The tumor, which was large and extended into the upper mediastinum, was successfully resected without an esophagectomy via the cervical approach. After postoperative radiation and chemotherapy, the patient remained healthy, without any evidence of disease 20 months after the operation.
Adult↗