Lysophosphatidic acid-induced membrane ruffling and brain-derived neurotrophic factor gene expression are mediated by ATP release in primary microglia

We examined the effects of lysophosphatidic acid (LPA) on microglia, which may play an important role in the development and maintenance of neuropathic pain. LPA caused membrane ruffling as detected by scanning electron microscopy, and increased the expression of brain-derived neurotrophic factor (BDNF) in a primary culture of rat microglia, which express LPA(3), but not LPA(1) or LPA(2) receptors. These actions were inhibited by a Galpha(q/11)-antisense oligodeoxynucleotide (AS-ODN), U73122, an inhibitor of phospholipase C (PLC), and apyrase, which specifically degrades ATP and ADP. When ATP release was measured using a luciferin-luciferase bioluminescence assay, LPA was shown to increase it in an LPA(3) and PLC inhibitor-reversible manner. However, LPA-induced ATP release was also blocked by the Galpha(q/11) AS-ODN, but not by pertussis toxin. These results suggest that LPA induces the release of ATP from rat primary cultured microglia via the LPA(3) receptor, Galpha(q/11) and PLC, and that the released ATP or ectopically converted ADP may in turn cause membrane ruffling via P2Y(12) receptors and Galpha(i/o) activation, and BDNF expression via activation of P2X(4) receptors.     

Angiotensin III as well as angiotensin II regulates water flow through aquaporins in a clam worm

Angiotensin III has been reported to exist in various animals and tissues. The physiological role, however, is still unclear except that brain angiotensin III is a central regulator of vasopressin release. In this study, angiotensin III as well as angiotensin II enhanced an increase in body weight of clam worms of Perinereis sp. under a hypo-osmotic condition and suppressed a decrease in body weight under a hyper-osmotic condition. When clam worms were treated with tetrachloroaurate (III) after angiotensin-treatment, these enhancing and suppressive effects of the angiotensins under hypo- and hyper-osmotic conditions were inhibited. In contrast, when clam worms were pretreated with tetrachloroaurate (III) before angiotensin-treatment, these effects of angiotensins were not inhibited. Since tetrachloroaurate (III) is a representative blocker of aquaporins, these results indicate that angiotensin III as well as angiotensin II regulates water flow through aquaporins in clam worms.     

Expression of the urokinase receptor regulates focal adhesion assembly and cell migration in adenoid cystic carcinoma cells

Adenoid cystic carcinoma (AdCC) cell lines (ACCS and ACCT) showed higher migration responses and adhesion to the extracellular matrix (ECM), especially types I and IV collagen, than did the oral squamous cell carcinoma (SCC) lines (NA and TF). The response to collagens was largely and exclusively inhibited by anti-alpha(2) integrin antibody. Moreover, AdCC cell lines expressed higher surface levels of urokinase-type plasminogen activator receptor (uPAR) than did SCC cell lines. When AdCC cells were plated on collagen, the surface level of uPAR was increased, and numerous focal adhesions consisting of uPAR, vinculin, and paxillin were assembled; whereas collagen-stimulated SCC cell counterparts or AdCC cells plated on other types of ECM, such as fibronectin, failed to assemble such definite focal adhesions. In order to elucidate the association of uPAR with collagen-induced events, an ACCS-AS cell line transfected with a vector expressing antisense uPAR RNA was established and shown to have reduced uPAR (about 10% that of parental ACCS at both the protein and mRNA levels). ACCS-AS showed a strong reduction of collagen-stimulated migration and focal adhesion assembly of alpha(2) integrin, vinculin, and paxillin. These findings suggest that AdCC has a proclivity for migrating to types I and IV collagens due to the overexpression of uPAR, which plays a key role in focal adhesion assembly and migration.     

ADRP is dissociated from lipid droplets by ARF1-dependent mechanism

Adipocyte differentiation-related protein (ADRP) is a member of PAT proteins existing in lipid droplets (LDs). By yeast two-hybrid screening, we identified ADP-ribosylation factor 1 (ARF1) as a binding partner of ADRP. The interaction of ADRP and ARF1 was verified by GST pull-down and co-immunoprecipitation experiments. Interestingly, ADRP precipitated the GDP-bound ARF1 preferentially to the GTP-bound ARF1. Consistent with this, either brefeldin A (BFA), a fungal metabolite to inhibit ARF-GEF, or a dominant-negative mutant of ARF1 caused dissociation of ADRP from LD. On the other hand, overexpression of wild-type ARF1 did not promote the ADRP dissociation or new LD formation. By using deletion mutants, a central domain of ADRP, which is dispensable for LD binding, was shown to bind to ARF1. The present study showed that the GDP-bound ARF1 induces dissociation of ADRP from the LD surface, and that LD is a target of BFA action.     

(−)1-(Benzofuran-2-yl)-2-propylaminopentane Shows Survival Effect on Cortical Neurons Under Serum-Free Condition Through Sigma Receptors

SUMMARY 1. The rapid cell death of cortical neurons in serum-free culture was rescued by the condition medium from the high-density culture, but not by brain-derived neurotrophic factor or basic fibroblast growth factor.2. Similar rescue was observed by the addition of (–)BPAP, an impulse enhancer, and (+)-pentazocine, a sigma receptor agonist. These actions were blocked by BD1063, a sigma receptor antagonist.3. (–)BPAP showed a weak displacement activity in the [³H]pentazocine binding to synaptic membranes from rat cerebral cortex.4. These findings suggest that (–)BPAP and (+)-pentazocine have unique survival activity on cortical neurons through sigma receptors.     

Are individuals with lower neutrophil oxidative burst activity more prone to Helicobacter pylori infection?

Helicobacter pylori infection has been reported to cause enhanced reactive oxygen species in the gastric mucosa. We examined the relationship between H. pylori infection and neutrophil function of peripheral blood. The subjects were 904 volunteers who participated in the Iwaki Health Promotion Project in 2005. 158 subjects who were infected with H. pylori in 2005 also participated in this project in 2006 and were categorized into two groups: the eradication group, in which H. pylori was successfully eradicated during the 12 month period, and the non‐eradication group, in which eradication was unsuccessful or the subjects did not receive eradication therapy. The laboratory assays performed were: a titre of H. pylori antibody; neutrophil counts; and oxidative burst activity (OBA) of neutrophils. Logistic regression analysis was executed, with H. pylori infection as the dependent variable and other items as the independent variables. OBA showed an inverse association with H. pylori infection in 2005. Additionally, when comparing the eradication and non‐eradication groups, the change rates of OBA between 2005 and 2006 did not show any significant difference. It was concluded that H. pylori infection does not lower OBA, but those individuals in whom OBA was lower were more prone to H. pylori infection. Copyright © 2008 John Wiley & Sons, Ltd.     

Presentation of two patients with malignant granulosa cell tumors, with a review of the literature

ABSTRACT: Granulosa cell tumors (GCTs) of the ovary account for 2 to 5 of ovarian malignancies. We present two patients with malignant ovarian adult GCT. In one patient, a combination of bleomycin, etoposide, and cisplatin was effective after initial surgery for malignant GCT. In the other, an aromatase inhibitor was effective for recurrent malignant GCT. We also review the literature for further management of this tumor. Because GCT of the ovary is rare, it will be necessary to elucidate the clinical phenotype and establish treatment protocols by accumulating and analyzing more patients.