Genomic characterization of closely related species in the Rumoiensis clade infers ecogenomic signatures to non-marine environments

Members of the family Vibrionaceae are generally found in marine and brackish environments, playing important roles in nutrient cycling. The Rumoiensis clade is an unconventional group in the genus Vibrio, currently comprising six species from different origins including two species isolated from non-marine environments. In this study, we performed comparative genome analysis of all six species in the clade using their complete genome sequences. We found that two non-marine species, Vibrio casei and Vibrio gangliei, lacked the genes responsible for algal polysaccharide degradation, while a number of glycoside hydrolase genes were enriched in these two species. Expansion of insertion sequences was observed in V. casei and Vibrio rumoiensis, which suggests ongoing genomic changes associated with niche adaptations. The genes responsible for the metabolism of glucosylglycerate, a compound known to play a role as compatible solutes under nitrogen limitation, were conserved across the clade. These characteristics, along with genes encoding species-specific functions, may reflect the habit expansion which has led to the current distribution of Rumoiensis clade species. Genome analysis of all species in a single clade give us valuable insights into the genomic background of the Rumoiensis clade species and emphasize the genomic diversity and versatility of Vibrionaceae.     

Neuroprotective role of bradykinin because of the attenuation of pro-inflammatory cytokine release from activated microglia

Bradykinin (BK) has been reported to be a mediator of brain damage in acute insults. Receptors for BK have been identified on microglia, the pathologic sensors of the brain. Here, we report that BK attenuated lipopolysaccharide (LPS)-induced release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta from microglial cells, thus acting as an anti-inflammatory mediator in the brain. This effect was mimicked by raising intracellular cAMP or stimulating the prostanoid receptors EP2 and EP4, while it was abolished by a cAMP antagonist, a prostanoid receptor antagonist, or by an inhibitor of the inducible cyclooxygenase (cyclooxygenase-2). BK also enhanced formation of prostaglandin E(2) and expression of microsomal prostaglandin E synthase. Expression of BK receptors and EP2/EP4 receptors were also enhanced. Using physiological techniques, we identified functional BK receptors not only in culture, but also in microglia from acute brain slices. BK reduced LPS-induced neuronal death in neuron-microglia co-cultures. This was probably mediated via microglia as it did not affect TNF-alpha-induced neuronal death in pure neuronal cultures. Our data imply that BK has anti-inflammatory and neuroprotective effects in the central nervous system by modulating microglial function.     

Plastidic phosphatidic acid phosphatases identified in a distinct subfamily of lipid phosphate phosphatases with prokaryotic origin

Plastidic phosphatidic acid phosphatase (PAP) dephosphorylates phosphatidic acid to yield diacylglycerol, which is a precursor for galactolipids, a primary and indispensable component of photosynthetic membranes. Despite its functional importance, the molecular characteristics and phylogenetic origin of plastidic PAP were unknown because no potential homologs have been found. Here, we report the isolation and characterization of plastidic PAPs in Arabidopsis that belong to a distinct lipid phosphate phosphatase (LPP) subfamily with prokaryotic origin. Because no homolog of mammalian LPP was found in cyanobacteria, we sought an LPP ortholog in a more primitive organism, Chlorobium tepidum, and its homologs in cyanobacteria. Arabidopsis had five homologs of cyanobacterial LPP, three of which (LPP gamma, LPP epsilon 1, and LPP epsilon 2) localized to chloroplasts. Complementation of yeast Delta dpp1 Delta lpp1 Delta pah1 by plastidic LPPs rescued the relevant phenotype in vitro and in vivo, suggesting that they function as PAPs. Of the three LPPs, LPP gamma activity best resembled the native activity. The three plastidic LPPs were differentially expressed both in green and nongreen tissues, with LPP gamma expressed the highest in shoots. A knock-out mutant for LPP gamma could not be obtained, although a lpp epsilon 1 lpp epsilon 2 double knock-out showed no significant changes in lipid composition. However, lpp gamma homozygous mutant was isolated only under ectopic overexpression of LPP gamma, suggesting that loss of LPP gamma may cause lethal effect on plant viability. Thus, in Arabidopsis, there are three isoforms of plastidic PAP that belong to a distinct subfamily of LPP, and LPP gamma may be the primary plastidic PAP.     

La autoantigen translocates to cytoplasm after cleavage during granzyme B-mediated cytotoxicity

Our recent report demonstrated that apoptosis-specific autoantibodies against granzyme B-induced cleavage fragments of SS-B (La) were found in the sera from patients with primary Sj?gren's syndrome. The objective of this study was identified by the intracellular redistribution of La autoantigen during granzyme B-induced apoptosis. We developed green fluorescence protein (GFP)-La and GFP-LaDelta220 (generation of granzyme B-specific cleavage of La protein) fusion proteins. GFP-La protein was localized in the nucleus, whereas the GFP-LaDelta220 protein predominantly existed in the cytoplasm in transformed A293T cells. Nuclear GFP-La protein was translocated to cytoplasm after granzyme B enriched YT cells incubation. La protein in human salivary grand HSG cells is cleaved and translocated from the nucleus to the cytoplasm after YT cell co-cultivation. These results suggest that La protein is cleaved by granzyme B and N-terminal La fragment (27 kD) translocated to the cytoplasm, thus leading to a novel autoantibody production during granzyme B-mediated cytotoxicity.     

Multifunctional effects of bradykinin on glial cells in relation to potential anti-inflammatory effects

Kinins have been reported to be produced and act at the site of injury and inflammation. Despite many reports that they are likely to initiate a particular cascade of inflammatory events, bradykinin (BK) has anti-inflammatory effects in the brain mediated by glial cells. In the present review, we have attempted to describe the complex responses and immediate reaction of glial cells to BK. Glial cells express BK receptors and induce Ca(2+)-dependent signal cascades. Among them, production of prostaglandin E(2) (PGE(2)), via B(1) receptors in primary cultured microglia, has a negative feedback effect on lipopolysaccharide (LPS)-induced release of tumor necrosis factor-alpha (TNF-alpha) via increasing intracellular cyclic adenosine monophosphate (cAMP). In addition, BK up-regulates the production of neurotrophic factors such as nerve growth factor (NGF) via B(2) receptors in astrocytes. These results suggest that BK may have anti-inflammatory and neuroprotective effects in the brain through multiple functions on glial cells. These observations may help to understand the paradox on the role of kinins in the central nervous system and may be useful for therapeutic strategy.     

Inter-group movement of females of the polygynous gobiid fish <Emphasis Type="Italic">Trimma okinawae</Emphasis> in relation to timing of protogynous sex change

Social conditions and function of inter-group movement of females of the polygynous goby, Trimma okinawae, have been studied at Akamizu Beach, Kagoshima, Japan. Some females moved from their original groups, where the male was still present, to other groups. Before the movement females sometimes temporarily visited the group into which they subsequently moved, suggesting they were able to assess social conditions during the visit. By moving, the females increased in size rank or escaped from similar-sized female competitors in their previous groups. Although the social ranks of the moving females in their original groups were lower than those of the resident females, the ratio of the number of females that changed sex to the number of females surviving at the end of the study did not differ for the two types of female. Inter-group movement of females may increase the probability of their changing sex to become a dominant male.     

Angiotensin II type 1 receptor signaling contributes to platelet-leukocyte-endothelial cell interactions in the cerebral microvasculature

Angiotensin II type 1 (AT(1)) receptor signaling has been implicated in cerebral microvascular alterations associated with ischemia, diabetes mellitus, hypercholesterolemia, and atherosclerosis. Platelets, which express AT(1) receptors, also appear to contribute to the thrombogenic and inflammatory responses that are elicited by these pathological conditions. This study assesses the role of AT(1) receptor activation on platelet-leukocyte-endothelial cell interactions elicited in cerebral microvasculature by ischemia and reperfusion. Intravital microscopy was used to monitor the adhesion of platelets and leukocytes that were labeled with different fluorochromes, whereas dihydrorhodamine-123 was used to quantify oxygen radical production in cerebral surface of mice that were either treated with the AT(1) receptor agonist Val-angiotensin II (ANG II) or subjected to bilateral common carotid artery occlusion (BCCAO) followed by reperfusion. ANG II elicited a dose- and time- dependent increase in platelet-leukocyte-endothelial cell interactions in cerebral venules that included rolling platelets, adherent platelets on the leukocytes and the endothelial cells, rolling leukocytes, and adherent leukocytes. All of these interactions were attenuated by treatment with either P-selectin or P-selectin glycoprotein ligand 1 (PSGL-1) antibody. The AT(1) receptor antagonist candesartan and losartan as well as diphenyleneiodonium, an inhibitor of flavoproteins including NAD(P)H oxidase, significantly reduced the platelet-leukocyte-endothelial cell interactions elicited by either ANG II administration or BCCAO/reperfusion. The increased oxygen radical generation elicited by BCCAO/reperfusion was also attenuated by candesartan. These findings are consistent with an AT(1) receptor signaling mechanism, which involves oxygen radical production and ultimately results in P-selectin- and PSGL-1-mediated platelet-leukocyte-endothelial cell interactions in the cerebral microcirculation.     

Mamld1 knockdown reduces testosterone production and Cyp17a1 expression in mouse Leydig tumor cells

Background

MAMLD1 is known to be a causative gene for hypospadias. Although previous studies have indicated that MAMLD1 mutations result in hypospadias primarily because of compromised testosterone production around the critical period for fetal sex development, the underlying mechanism(s) remains to be clarified. Furthermore, although functional studies have indicated a transactivation function of MAMLD1 for the non-canonical Notch target Hes3, its relevance to testosterone production remains unknown. To examine these matters, we performed Mamld1 knockdown experiments.

Methodology/Principal Findings

Mamld1 knockdown was performed with two siRNAs, using mouse Leydig tumor cells (MLTCs). Mamld1 knockdown did not influence the concentrations of pregnenolone and progesterone but significantly reduced those of 17-OH pregnenolone, 17-OH progesterone, dehydroepiandrosterone, androstenedione, and testosterone in the culture media. Furthermore, Mamld1 knockdown significantly decreased Cyp17a1 expression, but did not affect expressions of other genes involved in testosterone biosynthesis as well as in insulin-like 3 production. Hes3 expression was not significantly altered. In addition, while 47 genes were significantly up-regulated (fold change >2.0×) and 38 genes were significantly down-regulated (fold change <0.5×), none of them was known to be involved in testosterone production. Cell proliferation analysis revealed no evidence for compromised proliferation of siRNA-transfected MLTCs.

Conclusions/Significance

The results, in conjunction with the previous data, imply that Mamld1 enhances Cyp17a1 expression primarily in Leydig cells and permit to produce a sufficient amount of testosterone for male sex development, independently of the Hes3-related non-canonical Notch signaling.     

Cloning and structural analysis of bglM gene coding for the fungal cell wall-lytic beta-1,3-glucan-hydrolase BglM of Bacillus circulans IAM1165

Bacillus circulans IAM1165 produces isoforms of beta-1,3-glucan-hydrolases. Of these enzymes, the 42-kDa enzyme BgIM degrades Aspergillus oryzae cell walls the most actively. A gene coding for a BgIM precursor consisting of 411 amino acid residues was cloned. The 27 N-terminal amino acid sequence of the precursor is a signal peptide. The 141 C-terminal amino acid sequence showed a motif of carbohydrate-binding module family 13. This domain bound to pachyman, lichenan, and A. oryzae cell walls. The central domain showed a bacterial beta-1,3-glucan-hydrolase motif belonging to glycosyl hydrolase family 16. By removal of the C-terminal domain in the IAM1165 culture, mature BglM was processed to several 27-kDa fragments that hydrolyze a soluble beta-1,3-glucan.