胰岛中谷氨酸和γ-氨基丁酸受体的研究进展

谷氨酸和γ-氨基丁酸受体主要分布在中枢神经系统,在神经信号转导中发挥着重要作用.近年来在胰岛中也发现了这类受体,且胰岛中几乎含有这些受体的所有亚型.本文详细描述了胰岛中这些受体的各亚型,并着重讨论了它们的生理功能和相互作用关系,以及研究它们在胰岛中的生理功能的新技术方法.这些问题的探讨不但为研究胰岛功能机制提供了新思路,也将有助于从新的视角理解神经科学问题.     

Human umbilical cord blood-derived stromal cells prevent graft-versus-host disease in mice following haplo-identical stem cell transplantation

Background aimsHuman umbilical cord blood-derived stromal cells (hUCBDSC) comprise a novel population of CD34⁺ cells that has been isolated in our laboratory. They have been shown previously not only to be non-immunogenic but also to exert immunosuppressive effects on xenogenic T cells in vitro. This study investigated the role of hUCBDSC in immunomodulation in an acute graft-versus-host disease (GvHD) mouse model after haplo-identical stem cell transplantationMethodsAcute GvHD was induced in recipient (B6 × BALB/c)F₁ mice by irradiation (750 cGy) followed by infusion of bone marrow cells and splenocytes from donor C57BL/6 mice. hUCBDSC were co-transplanted in the experimental group. The survival time, body weight and clinical and histopathologic scores were recorded after transplantation. The expression of surface markers [major histocompatibility complex (MHC) I, MHC II, CD80 and CD86] on CD11c⁺ dendritic cells (DC), and the percentage of CD4⁺ regulatory T cells (Treg), in the spleens of recipient mice were examined by flow cytometryResultsThe survival time was significantly prolonged, and the clinical and histopathologic scores were reduced in mice co-transplanted with hUCBDSC. The expression levels of the surface markers on DC were significantly lower in mice transplanted with hUCBDSC compared with those without. The proportion of CD4⁺ Treg in the spleen was also increased in mice transplanted with hUCBDSCConclusionsThese results from a GvHD mouse model are in agreement with previous in vitro findings, suggesting that hUCBDSC possess immunosuppressive properties and may act via influencing DC and CD4⁺ Treg.     

Application of cross-linked beta-cyclodextrin polymer for adsorption of aromatic amino acids

Beta-cyclodextrin (beta-CyD) was cross-linked by hexamethylene diisocyanate and the polymer was investigated for adsorption of aromatic amino acids (AAA) from phosphate buffer. High adsorption rates were observed at the beginning and the adsorption equilibrium was then gradually achieved in about 45 min. The adsorption of AAA decreased with the increase of initial concentration and also temperature. Under the same conditions, the adsorption efficiencies of AAA were in the order of L-tryptophan (L-Trp) > L-phenylalanine (L-Phe) > L-tyrosine (L-Tyr). Much higher adsorption values, up to 52.4 and 43.0 mg/g for L-Trp and L-Phe, respectively, at 50 mmol/L and 3.2 mg/g for L-Tyr at 2 mmol/L, were obtained with the beta-CyD polymer at 37 degrees C. It was shown that the adsorption of AAA on the beta-CyD polymer was consistent with the Freundlich isotherm equation. The adsorption of mixed aromatic amino acids and branched-chain amino acids (BCAA) showed that AAA were preferentially adsorbed with adsorption efficiencies 10-24%, while those of BCAA were lower than 2%. It seems that the structure and hydrophobicity of amino acid molecules are responsible for the difference in adsorption, by influencing the strength of interactions between amino acid molecule and the polymer.     

RELATIONSHIP BETWEEN INCLUSION IN THE RAPE CROP-QINGYOU Ⅱ AND ALATE RATIO OF MYZUS PERSICAE

AlateratioofMyzuspersicaeSulzerwasgreatlycloserinrelationshiptocertaininclusionintherapecrop-QingyouⅡ,suchastryptophan,ratioofcontentsofsolublesugartoproteinandmeancrowdingnessunderconditionsofvariedmateproportionoffertilizers-N,P,K.Thefollowinginclusionintherapecropwerealsorelatedtotheratioofalatate:asperticacid,troeoninie,serine,glutancicacid,phenylalanine,lysine,histidine,valine,methionine,isoleucine,leucine,solublesugarandwater-solubleprotein.     

Origin and evolution of the RIG-I like RNA helicase gene family

Background  

The DExD/H domain containing RNA helicases such as retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) are key cytosolic pattern recognition receptors (PRRs) for detecting nucleotide pathogen associated molecular patterns (PAMPs) of invading viruses. The RIG-I and MDA5 proteins differentially recognise conserved PAMPs in double stranded or single stranded viral RNA molecules, leading to activation of the interferon system in vertebrates. They share three core protein domains including a RNA helicase domain near the C terminus (HELICc), one or more caspase activation and recruitment domains (CARDs) and an ATP dependent DExD/H domain. The RIG-I/MDA5 directed interferon response is negatively regulated by laboratory of genetics and physiology 2 (LGP2) and is believed to be controlled by the mitochondria antiviral signalling protein (MAVS), a CARD containing protein associated with mitochondria.     

Potential role of insulin on the pathogenesis of depression

The regulation of insulin on depression and depression‐like behaviour has been widely reported. Insulin and activation of its receptor can promote learning and memory, affect the hypothalamic‐pituitary‐adrenal axis (HPA) balance, regulate the secretion of neurotrophic factors and neurotransmitters, interact with gastrointestinal microbiome, exert neuroprotective effects and have an impact on depression. However, the role of insulin on depression remains largely unclear. Therefore, in this review, we summarized the potential role of insulin on depression. It may provide new insight for clarifying role of insulin on the pathogenesis of depression.     

OsSHOC1 and OsPTD1 are essential for crossover formation during rice meiosis

Meiosis is essential for eukaryotic sexual reproduction and plant fertility, and crossovers (COs) are essential for meiosis and the formation of new allelic combinations in gametes. In this study, we report the isolation of a meiotic gene, OsSHOC1, and the identification of its partner, OsPTD1. Osshoc1 was sterile both in male and female gametophytes, and it showed a striking reduction in the number of meiotic COs, indicating that OsSHOC1 was required for normal CO formation. Further investigations showed that OsSHOC1 physically interacted with OsPTD1 and that the latter was also required for normal CO formation and plant fertility. Additionally, the expression profiles of both genes were consistent with their functions. Our results suggest that OsSHOC1 and OsPTD1 are essential for rice fertility and CO formation, possibly by stabilizing the recombinant intermediates during meiosis.