Expression of gastrin-releasing peptide (GRP) in the bovine uterus during the estrous cycle

Gastrin-releasing peptide (GRP) has been proposed as a novel regulatory peptide in the reproductive tract. We previously demonstrated that GRP immunoreactivities are found predominantly in the uterine gland epithelial cells of nonpregnant and pregnant cows. The present study focused on the distribution of GRP immunoreactivity and the expression of GRP mRNA in the bovine endometrium during the estrous cycle. Tissues were collected from 21 uterine horns and bodies during the estrous cycle. RT-PCR showed the expected GRP mRNA fragments (284 bp) in the tissues from all stages of the cycle. In situ hybridization results ascertained the expression of the GRP mRNA in the uterine gland epithelial cells and superficial epithelial cells of the endometrium. Positive staining of GRP immunoreactivity in the uterine gland epithelial cells was detected in both the uterine horn and body from all stages of the cycle. In metestrus and diestrus stages, GRP was also detected in the superficial epithelial cells of horn, but not in the body. The degrees of GRP mRNA expression and intensities of GRP immunoreactivity in the endometrium increased from proestrus to diestrus stages. These findings suggest that GRP may be important both in the endometrial remodeling during the estrous cycle and in the implantation and development of blastocysts.     

Increased circulating CD11b+CD11c+ dendritic cells (DC) in aged BWF1 mice which can be matured by TNF-alpha into BLC/CXCL13-producing DC

Dendritic cells (DC) play a pivotal role in regulating immune responses. We previously reported aberrant high production of B lymphocyte chemoattractant (BLC/CXCL13) by DC in aged BWF1 mice, amurine model for systemic lupus erythematosus (SLE). We describe here that CD11b+CD11c+ cells were markedly increased in the peripheral blood (PBL-DC) in aged BWF1, but not in similarly aged NZB or NZW mice. Part of PBL-DC showed a typical dendritic morphology and expressed MHC class II molecules, and had a weak, but significant antigen-presenting ability in mixed lymphocytereaction. PBL-DC were chemoattracted to several chemokines in vitro including secondary lymphoid tissue chemokine (SLC), liver and activation-regulated chemokine (LARC), RANTES, macrophage inflammatory protein-1alpha, whereas splenic mature DC from aged BWF1 mice were preferentially chemoattracted towards SLC. BLC production was induced when PBL-DC were cultured in the presence of TNF-alpha for 3 days. BLC expression was also induced in bone marrow-derived DC when they were differentiated into mature DC in the presence of TNF-alpha and IL-1beta, while both IFN-alpha and IFN-gamma failed to induce BLC expression in bone marrow-derived DC. Since TNF-alpha expression is increased in aged BWF1 mice, DC recruitment in the circulation and maturation into BLC-producing DC by TNF-alpha may play a pivotal role in the development of systemic autoimmune diseases.     

Identification of cryptochrome DASH from vertebrates

A new type of cryptochrome, CRY-DASH, has been recently identified. The CRY-DASH proteins constitute the fifth subfamily of the photolyase/cryptochrome family. CRY-DASHs have been identified from Synechocystis sp. PCC 6803, Vibrio cholerae, and Arabidopsis thaliana. The Synechocystis CRY-DASH was the first cryptochrome identified from bacteria, and its biochemical features and tertiary structure have been extensively investigated. To determine how broadly the subfamily is distributed within living organisms, we searched for new CRY-DASH candidates within several databases. We found five sequences as new CRY-DASH candidates, which are derived from four marine bacteria and Neurospora crassa. We also found many CRY-DASH candidates from the EST databases, which included sequences from fish and amphibians. We cloned and sequenced the cDNAs of the zebrafish and Xenopus laevis candidates, based on the EST sequences. The proteins encoded by the two genes were purified and characterized. Both proteins contained folate and flavin cofactors, and have a weak DNA photolyase activity. A phylogenetic analysis revealed that the seven candidates actually belong to the new type of cryptochrome subfamily. This is the first report of the CRY-DASH members from vertebrates and fungi.     

Comparative anatomical study of the m. retractor bulbi with special reference to the nerve innervations in rabbits and dogs

Detailed dissection was performed on eight head halves of four rabbits and six head halves of three dogs in order to investigate the nerve distributions to the m. retractor bulbi. Our observations indicated that the muscle was innervated by the branches of the abducens nerve in all sides which were examined in the present study. In addition, we observed that the ventral ramus of the oculomotor nerve gave rise to branches to the m. retractor bulbi in three sides of the rabbits, and in two sides of the dogs, which suggests that the innervation pattern of the muscle is variable even in the identical species. Considering these observations, we propose that the anlage of the m. retractor bulbi is mainly composed of the anlage innervated by the abducens nerve, and occasionally the anlage innervated by the ventral ramus of the oculomotor nerve is added to it, because the anlage of the m. retractor bulbi may be formed near the border region between the anlages innervated by the oculomotor and abducens nerves.     

Control of feeding rhythm in the terrestrial slug Incilaria bilineata

A modulatory neuron of feeding rhythm was newly identified in the buccal ganglia of the isolated central nervous system (CNS) of the terrestrial slug Incilaria bilineata. This neuron was termed the “feeding rhythm modulator” (FRM). Its morphological and electrical properties were compared with those of the MGC (metacerebral giant cell, a cerebral modulatory neuron of feeding rhythm). There was no direct connection between FRM and MGC. In order to investigate the control mechanism of the buccal central pattern generator, feeding rhythm was observed by varying the activities of MGC and FRM simultaneously. At a lower level of activity of MGC, feeding rhythm was not only sensitive to the activity of MGC but also to that of FRM. As the level of activity of MGC increased, feeding rhythm was exclusively controlled by the activity of MGC, and became unaffected by the activity of FRM. This indicates that cerebral neurons such as MGC primarily control feeding rhythm and modulate the contribution of FRM in a hierarchical manner.     

Endocannabinoid system modulates relapse to methamphetamine seeking: possible mediation by the arachidonic acid cascade.

We clarified the modulating action of the endocannabinoid system, and its possible mediation by the arachidonic acid cascade, on the reinstatement of methamphetamine (METH)-seeking behavior, using the intravenous self-administration paradigm in rats. Following 12 days of self-administration of METH, the replacement of METH with saline resulted in a gradual decrease in lever press responses (extinction). Under extinction conditions, METH-priming or re-exposure to cues previously paired with METH infusion markedly increased the responses (reinstatement of drug-seeking). The cannabinoid CB1 receptor antagonist, SR141716A, blocked this behavior. Although the cannabinoid agonist, Delta8-tetrahydrocannabinol (THC), had no effects by itself, coadministration of the agonist and METH at small doses reinstated the drug-seeking behavior. THC attenuated the effects of the reinstatement-inducing dose of METH, but enhanced the effect of cues. Either given repeatedly during the extinction or singly, 24 h before the first METH-priming or cues challenge, THC suppressed the reinstatement. In another set of experiments, we found that diclofenac, a cyclooxygenase inhibitor, also attenuated the reinstatement induced by exposure to cues or drug-priming. These results suggest that the endocannabinoid system, through possible mediation by the arachidonic acid cascade, serves as a modulator of the reinstating effects of METH-priming and cues. Extending the current view on the treatment of drug dependence, these results indicate that endocannabinoid-activating substances as well as cyclooxygenase inhibitors may be promising as antirelapse agents.     

Stress sensitization induced by stressor and methamphetamine]

Repetitive or acute treatment of methamphetamine (MAP) or amphetamine (AMP) induces sensitization to both subsequent challenge treatment of the drugs, and exposure to emotional and physiological stress. In addition, chronic treatment of AMP enhanced DA utilization/release in striatum. Similarly, repetitive exposure to footshock or tail shock stress induces sensitization of noradrenaline or 3-methoxy-4-hydroxyphenylglycol (MHPG) to subsequent mild stress and to small amounts of AMP or MAP injection. Striatum, nucleus accumbens and prefrontal dopaminergic systems have an important role in the development of this sensitization. Immediate early gene (IEG) expression in the hypothalamus, nucleus accumbens and striatum may be involved in this process. Neurobiological vulnerability to schizophrenia may be induced by the interaction of multiple gene disposition and environmental insult, and schizophrenia onset and/or relapse in response to mild, non-specific stress. Stress-sensitive systems therefore are postulated in the pathophysiology of schizophrenia. In this regard, mesolimbic DA systems may be involved in the pathophysiology of schizophrenia. In contrast to MAP- or AMP- and stress-induced sensitization, haloperidol and clozapine induce IEG expression in the caudate-putamen and amygdala. Collectively, MAP- or AMP-induced sensitization may, in part, share an early functional process of neurobiological mechanisms.     

Expression of GPIV and Naka antigen on monocytes in Naka-negative subjects whose platelets lack GPIV

Summary. The platelet antigen Nak^a was once considered to be a platelet-specific alloantigen and is carried on platelet membrane glycoprotein (GP) IV. Recent studies suggest that Nak^a-negative subjects lack platelet GPIV. GPIV is an important adhesive receptor and expressed on the surface of monocytes as well as of platelets. In the present study, flow cytometry was used to detect GPIV and Nak^a antigen on the surface of monocytes. Nak^a antigen was expressed on monocytes as well as on platelets in Nak^a-positive subjects ( n = 6) (P-GPIV-positive subjects). To our surprise, monocytes of Nak^a-negative subjects ( n = 7) (P-GPIV-negative subjects) having no anti-Nak^a antibody in their serum expressed GPIV and Nak^a antigen to almost the same degree as did the monocytes of P-GPIV-positive subjects. Competitive experiments using OKM5 (a monoclonal antibody against GPIV) and anti-Nak^a antibody showed that the epitope of anti-Nak^a antibody on monocytes was very close to that of OKM5. In two P-GPIV-negative subjects having anti-Nak^a antibody in their serum, GPIV and Nak^a antigen were not expressed on the surface of either monocytes or platelets. These results indicate that the GPIV molecules and Nak^a antigen are expressed on the surface of monocytes in the majority of P-GPIV-negative subjects, but that in a very few P-GPIV-negative subjects neither GPIV nor Nak^a antigen is expressed on the surface of their monocytes. We hypothesize that P-GPIV-negative subjects who carry neither GPIV nor Nak^a antigen on their monocytes produce anti-Nak^a antibody as a result of transfusion or pregnancy.