Short-term oral oleoyl-estrone decreases the expression of ghrelin in the rat stomach

Oleoyl-estrone (OE) mobilizes body fat and decreases food intake. The precise mechanism of its modulation of appetite is unknown. Since the effects of OE on food intake appear early, here we studied the effect of OE on the expression of gut peptides that affect short-term ingestive behavior: ghrelin, leptin, CCK, PYY, and GLP-1. Two hours after a single OE dose, adult male rats were killed and their stomach fundus and intestine sections were dissected and processed for real-time PCR amplification. Semi-quantitative estimation of gene mRNA tissue levels showed that OE markedly decreased ghrelin expression in the stomach; leptin mRNA was unchanged; CCK mRNA decreased in the proximal intestine while PYY and GLP-1 expression in the intestine was not altered. Our results indicate that the short-term decrease in food intake induced by OE may be essentially the consequence of a marked decrease in the expression of ghrelin in the stomach.     

Understory plant diversity is related to higher variability of vegetative mobility of coexisting species

Theoretical studies claim that if co-occurring species have very different mobilities this will result in greater small-scale species richness, but empirical evidence is still lacking. We measured horizontal vegetative mobility (VM) of 48 herbaceous understory species and estimated small-scale species richness in early and late successional boreonemoral herb-rich coniferous forests in central Estonia. VM of erosulate growth forms was significantly higher than that of hemi-rosette and rosette growth forms. Erosulate species exhibited higher mobility in young stands, but their relative and total cover was considerably higher in old stands. Local plant richness (in 1 × 1 m plots) correlated positively with the variability of VM of species in a plot—larger differences in VM resulted in a higher number of coexisting species. Our results thus suggest that species differences in VM can contribute to small-scale coexistence by providing different ways to colonise empty space. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

PLASTOCHRON3/GOLIATH encodes a glutamate carboxypeptidase required for proper development in rice

Most aerial parts of the plant body are products of the continuous activity of the shoot apical meristem (SAM). Leaves are the major component of the aerial plant body, and their temporal and spatial distribution mainly determines shoot architecture. Here we report the identification of the rice gene PLASTOCHRON3 ( PLA3 )/ GOLIATH ( GO ) that regulates various developmental processes including the rate of leaf initiation (the plastochron). PLA3 / GO encodes a glutamate carboxypeptidase, which is thought to catabolize small acidic peptides and produce small signaling molecules. pla3 exhibits similar phenotypes to pla1 and pla2 – a shortened plastochron, precocious leaf maturation and rachis branch-to-shoot conversion in the reproductive phase. However, in contrast to pla1 and pla2 , pla3 showed pleiotropic phenotypes including enlarged embryo, seed vivipary, defects in SAM maintenance and aberrant leaf morphology. Consistent with these pleiotropic phenotypes, PLA3 is expressed in the whole plant body, and is involved in plant hormone homeostasis. Double mutant analysis revealed that PLA1 , PLA2 and PLA3 are regulated independently but function redundantly. Our results suggest that PLA3 modulates various signaling pathways associated with a number of developmental processes.     

MHC class I A loci polymorphism and diversity in three Southeast Asian populations of cynomolgus macaque

Cynomolgus macaques (Macaca fascicularis, Mafa) have emerged as important animal models for biomedical research, necessitating a more extensive characterization of their major histocompatibility complex polymorphic regions. The current information on the polymorphism or diversity of the polygenetic Mafa class I A loci is limited in comparison to the more commonly studied rhesus macaque Mafa class I A loci. Therefore, in this paper, to better elucidate the degree and types of polymorphisms and genetic differences of Mafa-A1 among three native Southeast Asian populations (Indonesian, Vietnamese, and Filipino) and to investigate how the allele differences between macaques and humans might have evolved to affect their respective immune responses, we identified 83 Mafa-A loci-derived alleles by DNA sequencing of which 66 are newly described. Most alleles are unique to each population, but seven of the most frequent alleles were identical in sequence to some alleles in other macaque species. We also revealed (1) the large and dynamic genetic and structural differences and similarities in allelic variation by analyzing the population allele frequencies, Hardy-Weinberg’s equilibrium, heterozygosity, nucleotide diversity profiles, and phylogeny, (2) the difference in genetic structure of populations by Wright’s FST statistic and hierarchical analysis of molecular variance, and (3) the different demographic and selection pressures on the three populations by performing Tajima’s D test of neutrality. The large level of diversity and polymorphism at the Mafa-A1 was less evident in the Filipino than in the Vietnam or the Indonesian populations, which may have important implications in animal capture, selection, and breeding for medical research.     

Describing long-range patterns in leaf vasculature by metaphoric fields

Some patterns in dicotyledonous leaf vasculature depict rather precise, long-range structural features. This work identifies and quantifies these previously unrecognized features in terms of an empirically derived mathematical formalism that generates wave-like spatial patterns referred to as metaphoric fields. These patterns were used to specify regularities in the long-range structure of dicot leaf vasculature, and were found to account significantly for the predominant features of all 27 dicot species studied. The conserved features of these metaphoric fields are discussed in terms of existing models for leaf pattern formation based on efflux-protein mediated auxin transport in a developing cellular field. This work highlights the complex, regular, long-range structures existing in leaf vascular patterns, and provides a means for specifying and identifying the inherent global features of vascular patterns which must be accounted for in functional developmental models.     

Specific induction of a 72-kDa heat shock protein protects esophageal mucosa from reflux esophagitis

AimsThe aim of this study is to investigate the expression and cytoprotective function of a 72-kDa heat shock protein (HSP72) using a reflux esophagitis model in rats.Main methodsExpression of HSP60, HSP72, and HSP90 in rat esophageal mucosa was evaluated by Western blot analysis before and after hyperthermia (42.5 °C, 20 min). Rats received the operation to produce reflux esophagitis with or without pretreatment with hyperthermia to induce HSPs. The esophageal mucosal damage was evaluated 12 h after the operation.Key findingsExpression of HSP72 was significantly increased by hyperthermia in rat esophageal mucosa. Reflux esophagitis was dramatically prevented when HSP72 was preinduced by hyperthermia. Furthermore, activation of TNF-α and IL-1β in esophageal mucosa was also suppressed.SignificanceThese results suggested that hyperthermia protects the esophageal mucosa in reflux esophagitis model by inducing HSP72 and suppressing proinflammatory cytokine activation. These findings might suggest that HSP-inducing therapy could be a novel and unique therapy for reflux esophagitis.     

CAPS Activity in Priming Vesicle Exocytosis Requires CK2 Phosphorylation

CAPS (Ca²⁺-dependent activator protein for secretion) functions in priming Ca²⁺-dependent vesicle exocytosis, but the regulation of CAPS activity has not been characterized. Here we show that phosphorylation by protein kinase CK2 is required for CAPS activity. Dephosphorylation eliminated CAPS activity in reconstituting Ca²⁺-dependent vesicle exocytosis in permeable and intact PC12 cells. Ser-5, -6, and -7 and Ser-1281 were identified by mass spectrometry as the major phosphorylation sites in the 1289 residue protein. Ser-5, -6, and -7 but not Ser-1281 to Ala substitutions abolished CAPS activity. Protein kinase CK2 phosphorylated CAPS in vitro at these sites and restored the activity of dephosphorylated CAPS. CK2 is the likely in vivo CAPS protein kinase based on inhibition of phosphorylation by tetrabromo-2-benzotriazole in PC12 cells and by the identity of in vivo and in vitro phosphorylation sites. CAPS phosphorylation by CK2 was constitutive, but the elevation of Ca²⁺ in synaptosomes increased CAPS Ser-5 and -6 dephosphorylation, which terminates CAPS activity. These results identify a functionally important N-terminal phosphorylation site that regulates CAPS activity in priming vesicle exocytosis.Regulated neurotransmitter secretion is central to intercellular communication in the nervous system. Two types of secretory vesicles mediate neurotransmitter release; that is, synaptic vesicles that release transmitters such as glutamate at synapses and dense-core vesicles that release modulatory transmitters and neuropeptides at non-synaptic sites. Both types of secretory vesicles are recruited to docking sites on the plasma membrane where they are primed to a ready release state to undergo fusion in response to Ca²⁺ elevations. Many of the proteins that mediate the targeting, docking, priming, and Ca²⁺-dependent fusion of vesicles with the plasma membrane function in both synaptic vesicle and dense-core vesicle pathways (1). CAPS-1² (also known as Cadps1) is a 1289-residue protein that reconstitutes Ca²⁺-triggered dense-core vesicle exocytosis in permeable neuroendocrine cells at a priming step (2–4). CAPS is required for secretion of a subset of transmitters in Caenorhabditis elegans (5) and Drosophila melanogaster (6) and for priming dense-core vesicle exocytosis in neuroendocrine cells (7) and synaptic vesicle exocytosis in neurons (8). Vesicle priming reactions are extensively modulated during physiological demand (9), but mechanisms that regulate CAPS function remain to be identified.Reversible protein phosphorylation is a major mechanism for the regulation of cellular processes including vesicle exocytosis. Many proteins that function in evoked vesicle exocytosis are phosphoproteins (10, 11). The neuronal SNARE proteins syntaxin 1A, VAMP-2, and SNAP-25 are phosphorylated by several protein kinases in vitro (12–14). Protein kinase C and protein kinase A sites on SNAP-25 affect refilling rates and size, respectively, of the primed pool of vesicles in chromaffin cells (15, 16). Several SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)-binding proteins such as munc18, RIM1, and rabphilin undergo regulated phosphorylation, but it is not known whether phosphorylation affects function (10, 11, 17).Because the function of CAPS at a priming step in vesicle exocytosis may be regulated, we determined whether CAPS is phosphorylated. We show that CAPS is a phosphoprotein with functionally essential N-terminal phosphorylated Ser residues. Ser-5, -6, and -7 in CAPS were substrates for protein kinase CK2 in vitro and in vivo as well as for a Ca²⁺-dependent dephosphorylation mechanism. The results indicate that phosphorylation by protein kinase CK2 is necessary for CAPS activity in priming vesicle exocytosis and that regulated dephosphorylation may constitute a mechanism for terminating CAPS activity.     

Inhibitory effects of sesquiterpene lactones isolated from Eupatorium chinense L. on IgE-mediated degranulation in rat basophilic leukemia RBL-2H3 cells and passive cutaneous anaphylaxis reaction in mice

Sesquiterpene lactones (SQTLs) have been shown to suppress the degranulation as inferred by histamine release in rat basophilic leukemia RBL-2H3 cells. In this study, we isolated the 9 kinds of SQTLs from Eupatorium chinense L. and examined the effects of these SQTLs on the degranulation in RBL-2H3 cells. The chemical structures of two novel compounds (SQTL-3 and 8) were determined. All the SQTLs suppressed the degranulation from Ag-stimulated RBL-2H3 cells. To disclose the inhibitory mechanism of degranulation by SQTLs, we examined the activation of intracellular signaling molecules such as Lyn, Syk, and PLCγs and intracellular free Ca²⁺ concentration ([Ca²⁺]i). None of these SQTLs showed the activation of Syk and PLCγs. The intracellular free Ca²⁺ concentration ([Ca²⁺]i) was elevated by FcεRI activation, but SQTLs treatment reduced the elevation of [Ca²⁺]i by suppressing Ca²⁺ influx. Thus, it was suggested that the suppression of Ag-stimulated degranulation by these SQTLs is mainly due to the decreased Ca²⁺ influx.Furthermore, in order to clarify the in vivo effect of SQTL-rich extract, we administered SQTL-rich extract to the type I allergic model mice and measured the passive cutaneous anaphylaxis (PCA) reaction induced by IgE-antigen complex. The SQTLs remarkably suppressed PCA reaction in a dose-dependent manner. Thus, it was suggested that SQTLs would be a candidate as an anti-allergic agent.