G蛋白β3亚单位基因825C/T多态性与中国人群原发性高血压相关性的Meta分析

目的系统评价G蛋白β3亚单位(GNB3)基因825C/T多态性与中国人群原发性高血压(EH)发病风险的关系。方法由两名评价者独立检索PubMed、EMbase、CNKI、CBM和WanFang数据库,收集探讨GNB3基因825C/T多态性与中国人EH相关性的病例-对照研究,检索时限均为建库至2013年9月30日。文献筛选及资料提取后,对纳入文献按NOS进行质量评价,然后采用Stata12.0软件行Meta分析。结果最终纳入30个病例-对照研究,包括EH患者5054例,对照人群5565例。Meta分析结果显示,与对照组相比,GNB3基因825C/T多态性与中国人EH发病风险间无统计学差异[TT vs.CC:(OR=1.13,95%CI:0.89~1.43,P=0.33);TT vs.CT+CC:(OR=1.04,95%CI:0.86~1.26,P=0.70);CT vs.CC:(OR=1.08,95%CI:0.98~1.19,P=0.11);TT+CT vs.CC:(OR=1.11,95%CI:0.96~1.29,P=0.15);T vs.C:(OR=1.06,95%CI:0.95~1.20,P=0.30)]。结论当前证据表明中国人群GNB3基因825C/T多态性与EH发病无关。     

Multiple self-splicing introns in the 16S rRNA genes of giant sulfur bacteria

The gene encoding the small subunit rRNA serves as a prominent tool for the phylogenetic analysis and classification of Bacteria and Archaea owing to its high degree of conservation and its fundamental function in living organisms. Here we show that the 16S rRNA genes of not-yet-cultivated large sulfur bacteria, among them the largest known bacterium Thiomargarita namibiensis, regularly contain numerous self-splicing introns of variable length. The 16S rRNA genes can thus be enlarged to up to 3.5 kb. Remarkably, introns have never been identified in bacterial 16S rRNA genes before, although they are the most frequently sequenced genes today. This may be caused in part by a bias during the PCR amplification step that discriminates against longer homologs, as we show experimentally. Such length heterogeneity of 16S rRNA genes has so far never been considered when constructing 16S rRNA-based clone libraries, even though an elongation of rRNA genes due to intervening sequences has been reported previously. The detection of elongated 16S rRNA genes has profound implications for common methods in molecular ecology and may cause systematic biases in several techniques. In this study, catalyzed reporter deposition-fluorescence in situ hybridization on both ribosomes and rRNA precursor molecules as well as in vitro splicing experiments were performed and confirmed self-splicing of the introns. Accordingly, the introns do not inhibit the formation of functional ribosomes.     

Early pregnancy induced expression of prostaglandin E2 receptors EP2 and EP4 in the ovine endometrium and regulated by interferon tau through multiple cell signaling pathways

Prostaglandin E2 (PGE₂) plays pleiotropic roles at fetal-maternal interface during establishment of pregnancy. The objectives of the study were to: (i) determine regulation of PGE2 receptors EP1, EP2, EP3, and EP4 in the endometrium during the estrous cycle and early pregnancy; and (ii) understand endometrial epithelial and stromal cell-specific hormonal regulation of EP2 and EP4 in sheep. Results indicate that: (i) early pregnancy induces expression of EP2 and EP4 but not EP1 and EP3 proteins in the endometrium on days 12-16 compared to that of estrous cycle; (ii) intrauterine infusion of interferon tau (IFNT) increases expression of EP2 and EP4 proteins in endometrium; and (iii) IFNT activates distinct epithelial and stromal cell-specific JAK, EGFR, ERK1/2, AKT, or JNK signaling module to regulate expression of EP2 and EP4 proteins in the ovine endometrium. Our results indicate a role for EP2 and EP4-mediated PGE₂ signaling in endometrial functions and establishment of pregnancy in ruminants.     

Somatostatin receptors: From signaling to clinical practice

Somatostatin is a peptide with a potent and broad antisecretory action, which makes it an invaluable drug target for the pharmacological management of pituitary adenomas and neuroendocrine tumors. Somatostatin receptors (SSTR1, 2A and B, 3, 4 and 5) belong to the G protein coupled receptor family and have a wide expression pattern in both normal tissues and solid tumors. Investigating the function of each SSTR in several tumor types has provided a wealth of information about the common but also distinct signaling cascades that suppress tumor cell proliferation, survival and angiogenesis. This provided the rationale for developing multireceptor-targeted somatostatin analogs and combination therapies with signaling-targeted agents such as inhibitors of the mammalian (or mechanistic) target of rapamycin (mTOR). The ability of SSTR to internalize and the development of rabiolabeled somatostatin analogs have improved the diagnosis and treatment of neuroendocrine tumors.     

NR2B subunit blockade does not affect motor symptoms induced by 3-nitropropionic acid

Abstract

Broad-spectrum N-methyl D-aspartate (NMDA) antagonists, although proposed in therapies for several pathologies including Huntington’s disease (HD), can produce dramatic side-effects. Thus, the therapeutic potential of subunit selective NMDA receptor antagonists warrants investigation. Overactivation of NMDA receptors containing the NR2B subunit plays a pathogenic role in HD, suggesting a neuroprotective potential of selective NR2B blockade. In the present study, we investigated whether the selective NR2B receptor antagonist, R-(R*,S*)-alpha-(4-hydroxyphenyl)-beta-methyl-4-(phenylmethyl)-1-piperidinepropanol, could also affect motor symptoms in mice intoxicated with 3-nitropropionic acid (3-NP), a phenotypic model of HD. NR2B subunit acute blockade had no effect on spontaneous activity, HD-like symptoms (clinical scale), and sensorimotor performances (beam task) in 3-NP intoxicated mice. These results suggest that selective NR2B antagonism has no acute symptomatic effect on motor and sensorimotor impairments due to 3-NP-induced striatal injury.     

Direct binding of GABAA receptor β2 and β3 subunits to gephyrin

GABAergic transmission is essential to brain function, and a large repertoire of GABA type A receptor (GABA_AR) subunits is at a neuron's disposition to serve this function. The glycine receptor (GlyR)‐associated protein gephyrin has been shown to be essential for the clustering of a subset of GABA_AR. Despite recent progress in the field of gephyrin‐dependent mechanisms of postsynaptic GABA_AR stabilisation, the role of gephyrin in synaptic GABA_AR localisation has remained a complex matter with many open questions. Here, we analysed comparatively the interaction of purified rat gephyrin and mouse brain gephyrin with the large cytoplasmic loops of GABA_AR α1, α2, β2 and β3 subunits. Binding affinities were determined using surface plasmon resonance spectroscopy, and showed an ~ 20‐fold lower affinity of the β2 loop to gephyrin as compared to the GlyR β loop–gephyrin interaction. We also probed in vivo binding in primary cortical neurons by the well‐established use of chimaeras of GlyR α1 that harbour respective gephyrin‐binding motifs derived from the different GABA_AR subunits. These studies identify a novel gephyrin‐binding motif in GABA_AR β2 and β3 large cytoplasmic loops.     

艾司洛尔联合右美托咪定对重型颅脑创伤患者去骨瓣 减压术后脑代谢及预后的影响

目的　探讨艾司洛尔联合右美托咪定对重型颅脑创伤去骨瓣减压术患者脑脊液（CSF）中乳酸、S100B表达,颅内压（ICP）以及预后的影响。方法　选取2015年1月—2018年12月行单侧去骨瓣减压的重型颅脑创伤患者60例为观察对象,采用随机信封法分为艾司洛尔联合右美托咪定治疗组（联合治疗组,30例）与单用右美托咪定治疗组（对照组,30例）。记录治疗前和治疗后1、3、7 d颅内压变化及CSF中乳酸和S100B蛋白水平,比较2组患者治疗后14 d格拉斯哥昏迷（GCS）评分和美国国立卫生研究院卒中量表（NIHSS）评分及不良反应发生情况。出院后共随访6个月,采用Glasgow预后分级（GOS）评价2组患者的预后。结果　联合治疗组患者治疗后1、3、7 d其CSF乳酸含量、S100B水平和ICP均低于对照组（P＜0.05）;联合治疗组治疗后14 d GCS评分及NIHSS评分高于对照组（P＜0.01）;出院后6个月随访时2组患者GOS评分差异无统计学意义（P＞0.05）。结论　艾司洛尔联合右美托咪定联合治疗可降低重型颅脑创伤去骨瓣术患者CSF乳酸水平和S100B蛋白表达,改善患者的短期预后,但并未改善长期预后。     

Endometrial microbiome at the time of embryo transfer: next-generation sequencing of the 16S ribosomal subunit

Purpose

Characterization of the human microbiome has become more precise with the application of powerful molecular tools utilizing the unique 16S ribosomal subunit’s hypervariable regions to greatly increase sensitivity. The microbiome of the lower genital tract can prognosticate obstetrical outcome while the upper reproductive tract remains poorly characterized. Here, the endometrial microbiome at the time of single embryo transfer (SET) is characterized by reproductive outcome.

Methods

Consecutive patients undergoing euploid, SET was included in the analysis. After embryo transfer, performed as per routine, the most distal 5-mm portion of the transfer catheter was sterilely placed in a DNA free PCR tube. Next-generation sequencing of the bacteria specific 16S ribosome gene was performed, allowing genus and species calls for microorganisms.

Results

Taxonomy assignments were made on 35 samples from 33 patients and 2 Escherichia coli controls. Of the 33 patients, 18 had ongoing pregnancies and 15 did not. There were a total of 278 different genus calls present across patient samples. The microbiome at time of transfer for those patients with ongoing pregnancy vs. those without ongoing pregnancy was characterized by top genera by sum fraction. Lactobacillus was the top species call for both outcomes.

Conclusions

The data presented here show the microbiome at the time of embryo transfer can successfully be characterized without altering standard clinical practice. This novel approach, both in specimen collection and analysis, is the first step toward the goal of determining physiologic from pathophysiologic microbiota. Further studies will help delineate if differences in the microbiome at the time of embryo transfer have a reliable impact on pregnancy outcome.