β-Cell Specific Overexpression of GPR39 Protects against Streptozotocin-Induced Hyperglycemia

Mice deficient in the zinc-sensor GPR39, which has been demonstrated to protect cells against endoplasmatic stress and cell death in vitro, display moderate glucose intolerance and impaired glucose-induced insulin secretion. Here, we use the Tet-On system under the control of the proinsulin promoter to selectively overexpress GPR39 in the β cells in a double transgenic mouse strain and challenge them with multiple low doses of streptozotocin, which in the wild-type littermates leads to a gradual increase in nonfasting glucose levels and glucose intolerance observed during both food intake and OGTT. Although the overexpression of the constitutively active GPR39 receptor in animals not treated with streptozotocin appeared by itself to impair the glucose tolerance slightly and to decrease the β-cell mass, it nevertheless totally protected against the gradual hyperglycemia in the steptozotocin-treated animals. It is concluded that GPR39 functions in a β-cell protective manner and it is suggested that it is involved in some of the beneficial, β-cell protective effects observed for Zn(++) and that GPR39 may be a target for antidiabetic drug intervention.

Microcalorimetric assay on the antimicrobial property of five hydroxyanthraquinone derivatives in rhubarb (Rheum palmatum L.) to Bifidobacterium adolescentis

It was found that the intestinal bacteria balance would be deteriorated by rhubarb especially in long term treatment. Bifidobacteria is one of the most common species of probiotics in human intestine. The suppression of this particular probiotic, such as Bifidobacterium adolescentis, one of the dominant anaerobes in the intestines of humans, might lead to imbalance of intestinal flora and is considered to be potentially riskful for human health. Hence, the inhibitory effects of the five main components of hydroxyanthraquinones (HAQs) contained in rhubarb on B. adolescentis growth were investigated by microcalorimetry to discover the suppression potential of rhubarb and the structure-function relationship of such HAQs. The value of the maximum power- output (P(max)) and slope (k) of the thermogenic growth curves of B. adolescentis were found of decrease in the presence of the five HAQs, while the peak time (T(p)) of the thermogenic curves were found to be delayed. The sequence of antimicrobial activity of the five HAQs is rhein>emodin>aloe-emodin>chrysophanol>physicion. The functional groups carboxyl, hydroxyl and hydroxylmethyl on phenyl ring in HAQs could improve the antimicrobial activity. The influence of substituent groups on anti- B. adolescentis activity might be related with the polarity and the sequence was carboxyl>hydroxyl>hydroxylmethyl>methyl and methoxyl.

Case-control study of a HLA-G 14-bp insertion-deletion polymorphism in women with recurrent miscarriages

Human leucocyte antigen (HLA)-G is an important molecule for maintaining an immunotolerant foetal-maternal relationship. A 14-bp insertion (+14-bp)/deletion (-14-bp) polymorphism in exon 8 of the 3' untranslated region of the HLA-G gene has been proposed to be associated with HLA-G mRNA stability and the expression of HLA-G. This might play an immunomodulatory role in human pregnancy. In this study, a total of 526 Chinese women were genotyped for the +14-bp/-14-bp polymorphism, including 137 who had recurrent miscarriages (three miscarriages: 86, four or more miscarriages: 51), 138 women who had experienced two abortions and 251 women with normal fertility as controls. The +14-bp homozygote sequence was more prominent among those with recurrent miscarriages (three or more recurrent miscarriages) in contrast to fertile control women. Significant difference was observed in the distribution of +14-bp/+14-bp genotype between controls and the recurrent abortions group with four or more abortions. A 14-bp insertion/deletion polymorphism in exon 8 has a possible role in HLA-G expression in certain cases of recurrent miscarriage. However, additional studies are needed in this regard.

The psychological status of HIV-positive people and their psychosocial experiences in eastern China

OBJECTIVES

The aim of the study was to investigate the psychological status and the psychosocial experiences of HIV-positive people using Symptom Check List 90 (SCL-90) in eastern China.

METHODS

Two hundred and fourteen HIV-positive people and 200 controls were recruited to the study. Participants were given an anonymous questionnaire which included questions pertaining to demography, SCL-90 and psychosocial experiences.

RESULTS

The mean subscale scores for SCL-90 in the HIV-positive group were all higher than those of the control group (P<0.001), especially for depression, anxiety, obsessive-compulsive disorder and hostility. Female HIV-positive individuals had significantly higher depression and anxiety scores (P<0.05) and more scores higher than 2.0 than male HIV-positive individuals. The average number of subscales with mean scores higher than 2.0 was 4.1 for female HIV-positive individuals and 3.7 for male HIV-positive individuals. The most common psychosocial experiences related to HIV infection were fear (36.9%) and helplessness (31.8%). 90.2% of HIV-positive people would not tell others about their disease because of fear of discrimination against family members (42.2%), exclusion by community members (26.9%) and abandonment (23.3%). Discrimination from acquaintances (38.8%) was a main stressor in the HIV-positive individuals' daily life. Most members of HIV-positive individuals' communities expressed negative attitudes: alienation, coldness, aversion and fear. 38.3% of the HIV-positive participants reported that their family members had been discriminated against.

CONCLUSIONS

The results demonstrate that HIV-positive people in eastern China live in a negative psychosocial environment and suffer from psychological distress. It is necessary to provide psychological interventions for people living with AIDS and to educate community members in order to improve the psychosocial environment.

Pulsed laser deposition of antimicrobial silver coating on Ormocer microneedles

One promising option for transdermal delivery of protein- and nucleic acid-based pharmacologic agents involves the use of microneedles. However, microneedle-generated pores may allow microorganisms to penetrate the stratum corneum layer of the epidermis and cause local or systemic infection. In this study, microneedles with antimicrobial functionality were fabricated using two-photon polymerization-micromolding and pulsed laser deposition.The antibacterial activity of the silver-coated organically modified ceramic (Ormocer)microneedles was demonstrated using an agar diffusion assay. Human epidermal keratinocyte viability on the Ormocer surfaces coated with silver was similar to that on uncoated Ormocer surfaces. This study indicates that coating microneedles with silver thin films using pulsed laser deposition is a useful and novel approach for creating microneedles with antimicrobial functionality.

In vivo characterization of high Basal signaling from the ghrelin receptor

The receptor for the orexigenic peptide, ghrelin, is one of the most constitutively active 7TM receptors known, as demonstrated under in vitro conditions. Change in expression of a constitutively active receptor is associated with change in signaling independent of the endogenous ligand. In the following study, we found that the expression of the ghrelin receptor in the hypothalamus was up-regulated approximately 2-fold in rats both during 48-h fasting and by streptozotocin-induced hyperphagia. In a separate experiment, to probe for the effect of the high basal signaling of the ghrelin receptor in vivo, we used intracerebroventricular administration by osmotic pumps of a peptide [D-Arg(1), D-Phe(5), D-Trp(7,9), Leu(11)]-substance P. This peptide selectively displays inverse agonism at the ghrelin receptor as compared with an inactive control peptide with just a single amino acid substitution. Food intake and body weight were significantly decreased in the group of rats treated with the inverse agonist, as compared with the groups treated with the control peptide or the vehicle. In the hypothalamus, the expression of neuropeptide Y and uncoupling protein 2 was decreased by the inverse agonist. In a hypothalamic cell line that endogenously expresses the ghrelin receptor, we observed high basal activity of the cAMP response element binding protein, an important signaling transduction pathway for appetite regulation. The activation was further increased by ghrelin administration and decreased by administration of the inverse agonist. It is suggested that the high constitutive signaling activity is important for the in vivo function of the ghrelin receptor in the control of food intake and body weight.

Positron annihilation in hydrogen-doped alkali-metal fullerides

Hydrogen-doped alkali-metal fullerides were studied by means of mass-analyzed thermal desorption and positron annihilation. The hydrogen desorption spectra reveal the inclusion of hydrogen in the fullerides as two types of components; one weakly adsorbed and the other strongly bound, probably as hydride ion. The positron lifetime spectra demonstrate that hydrogen-doping to alkali-metal fullerides increases a concentration of higher-order vacancy-type defects, through which more than 50% injected positrons decay with a lifetime of 0.42–0.71 ns.

G protein-coupled receptor 39 deficiency is associated with pancreatic islet dysfunction

G protein-coupled receptor (GPR)-39 is a seven-transmembrane receptor expressed mainly in endocrine and metabolic tissues that acts as a Zn(++) sensor signaling mainly through the G(q) and G(12/13) pathways. The expression of GPR39 is regulated by hepatocyte nuclear factor (HNF)-1alpha and HNF-4alpha, and in the present study, we addressed the importance of GPR39 for glucose homeostasis and pancreatic islets function. The expression and localization of GPR39 were characterized in the endocrine pancreas and pancreatic cell lines. Gpr39(-/-) mice were studied in vivo, especially in respect of glucose tolerance and insulin sensitivity, and in vitro in respect of islet architecture, gene expression, and insulin secretion. Gpr39 was down-regulated on differentiation of the pluripotent pancreatic cell line AR42J cells toward the exocrine phenotype but was along with Pdx-1 strongly up-regulated on differentiation toward the endocrine phenotype. Immunohistochemistry demonstrated that GRP39 is localized selectively in the insulin-storing cells of the pancreatic islets as well as in the duct cells of the exocrine pancreas. Gpr39(-/-) mice displayed normal insulin sensitivity but moderately impaired glucose tolerance both during oral and iv glucose tolerance tests, and Gpr39(-/-) mice had decreased plasma insulin response to oral glucose. Islet architecture was normal in the Gpr39 null mice, but expression of Pdx-1 and Hnf-1alpha was reduced. Isolated, perifused islets from Gpr39 null mice secreted less insulin in response to glucose stimulation than islets from wild-type littermates. It is concluded that GPR39 is involved in the control of endocrine pancreatic function, and it is suggested that this receptor could be a novel potential target for the treatment of diabetes.

Developmental systems biology flourishing on new technologies

Organism development is a systems level process. It has benefited greatly from the recent technological advances in the field of systems biology. DNA microarray, phenome, interactome and transcriptome mapping, the new generation of deep sequencing technologies, and faster and better computational and modeling approaches have opened new frontiers for both systems biologists and developmental biologists to reexamine the old developmental biology questions, such as pattern formation, and to tackle new problems, such as stem cell reprogramming. As showcased in the International Developmental Systems Biology Symposium organized by Chinese Academy of Sciences, developmental systems biology is flourishing in many perspectives, from the evolution of developmental systems, to the underlying genetic and molecular pathways and networks, to the genomic, epigenomic and noncoding levels, to the computational analysis and modeling. We believe that the field will continue to reap rewards into the future with these new approaches.

[Involvement of the amygdala on place aversion induced by naloxone in single-dose morphine-treated rats]

Signs characteristic of opiate withdrawal symptoms can be precipitated by an opiate antagonist after short-term infusion or even a single dose of an opiate both in humans and in animals. This phenomenon has been referred to as acute dependence. In contrast to extensive studies on chronic dependence, less is known about the neural mechanisms mediating acute dependence. It will benefit the development of appropriate therapies to facilitate opiate abstinence and reduced craving to better understand the mechanisms underlying acute opiate dependence and to determine whether there are dissociation and similarity between the early and fully developed stages of dependence. In the present study, we examined the influence of c-Fos expression in the amygdala in acquisition of conditioned place aversion (CPA) induced by naloxone-precipitated withdrawal from a single morphine exposure 24 h earlier. The effect of microinjection into the central amygdaloid nucleus (CeA) of various kinds of glutamatergic neurotransmission inhibitors was also investigated. Findings showed that CeA displayed significant increase in c-Fos expression in the acquisition of CPA. Furthermore, CPA was attenuated significantly and dose-dependently by microinjection into CeA of all glutamatergic neurotransmission inhibitors (NMDA receptor antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclo-hepten-5,10-imine maleate (MK-801), AMPA receptor antagonist 1-(4-aminophenyl)4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine hydrochloride (GYKI52466), metabotropic glutamate receptor antagonist (+/-)-alpha-methyl-4-carboxyphenylglycine (MCPG), and glutamate release inhibitor riluzole). These findings suggest that CeA involves the acquisition of CPA induced by naloxone-precipitated withdrawal from a single morphine exposure, and the function of the glutamatergic system projected from the amygdala to nucleus accumbens plays a facilitative role in formation of morphine dependence.