DAB2IP 基因的研究进展

Human DAB2 interaction protein (DAB2IP) is a novel member of Ras GTPase-activating protein family. It interacts directly with disabled-2 protein (DAB2/DOC2) which suppresses growth of cancers derived from different tissues, including mammary, prostate and ovarian cancers. DAB2IP was identified as an immediate downstream effector mediated by DAB2/DOC2. DAB2IP and DAB2/DOC2 form a unique protein complex that has a negative regulatory effect on the Ras-mediated signal pathway. It is demonstrated that DAB2IP is a tumor suppressor gene inactivated by methylation in several cancers. This article reviews the structure and biological functions of DAB2IP gene as well as its potential roles in carcinogenesis and evolution.     

Hydrogen peroxide increases GABAergic mIPSC through presynaptic release of calcium from IP3 receptor-sensitive stores in spinal cord substantia gelatinosa neurons

GABAergic interneurons of the spinal cord substantia gelatinosa regulate the transmission of nociceptive information. Hydrogen peroxide (H2O2) is likely a diffusible messenger contributing to the development of long-lasting pathological pain states after nerve injury. In this study, we examined the presynaptic effects of H2O2 on the inhibitory interneurons of mouse substantia gelatinosa (SG) using whole-cell patch-clamp recordings from spinal cord slices. H2O2 increased the frequency of GABAergic miniature inhibitory postsynaptic current (mIPSC) in a concentration-dependent (10-1000 microM) manner. The profound increase in mIPSC frequency was diminished by thapsigargin or cyclopiazonic acid suggesting that the intracellular stored pool was the source of presynaptic calcium. Further examination revealed the 2-aminoethoxydiphenil borate blockable inositol-(1,4,5) trisphosphate receptor (IP3R) regulated pool of stored calcium as the likely source. The phospholipase C (PLC) blocker, 1-(6-[([17beta]-3-methoxyestra-1,3,5[10]-trien-17-yl)-amino]hexyl)-1H-pyrrole-2,5-dione (U73122), did not block the frequency increase, which suggested that the site of action of H2O2 lies downstream in the IP3 signalling pathway, and nifedipine-sensitivity of the frequency increase indicated a possible role of calcium-induced calcium-release. However, a direct examination of L-type voltage-gated calcium channels (VGCC) demonstrated that H2O2 did not increase the calcium influx through these channels. The H2O2 effect on mIPSC frequency was markedly reduced in the opisthotonus (Opt) mutant mice with a known deletion in the IP3R1 gene. We demonstrated that H2O2 increased presynaptic activity in the GABAergic interneurons by the release of calcium from the IP3R-regulated intracellular pool. The presynaptic IP3R could emerge as a novel target for preventing H2O2-induced synaptic plasticity in substantia gelatinosa leading to pathological pain states.     

Alterations in the brain-gut axis underlying visceral chemosensitivity in Nippostrongylus brasiliensis-infected mice

BACKGROUND & AIMS: Visceral hypersensitivity, a hallmark of irritable bowel syndrome, is generally considered to be mechanosensitive in nature and mediated via spinal afferents. Both stress and inflammation are implicated in visceral hypersensitivity, but the underlying molecular mechanisms of visceral hypersensitivity are unknown. METHODS: Mice were infected with Nippostrongylus brasiliensis (Nb) larvae, exposed to environmental stress and the following separate studies performed 3-4 weeks later. Mesenteric afferent nerve activity was recorded in response to either ramp balloon distention (60 mm Hg), or to an intraluminal perfusion of hydrochloric acid (50 mmol/L), or to octreotide administration (2 micromol/L). Intraperitoneal injection of cholera toxin B-488 identified neurons projecting to the abdominal viscera. Fluorescent neurons in dorsal root and nodose ganglia were isolated using laser-capture microdissection. RNA was hybridized to Affymetrix Mouse whole genome arrays for analysis to evaluate the effects of stress and infection. RESULTS: In mice previously infected with Nb, there was no change in intestinal afferent mechanosensitivity, but there was an increase in chemosensitive responses to intraluminal hydrochloric acid when compared with control animals. Gene expression profiles in vagal but not spinal visceral sensory neurons were significantly altered in stressed Nb-infected mice. Decreased afferent responses to somatostatin receptor 2 stimulation correlated with lower expression of vagal somatostatin receptor 2 in stressed Nb-infected mice, confirming a link between molecular data and functional sequelae. CONCLUSIONS: Alterations in the intestinal brain-gut axis, in chemosensitivity but not mechanosensitivity, and through vagal rather than spinal pathways, are implicated in stress-induced postinflammatory visceral hypersensitivity.     

The opposite roles of nNOS in cardiac ischemia–reperfusion-induced injury and in ischemia preconditioning-induced cardioprotection in mice

The role of neuronal nitric oxide synthase (nNOS) in cardiac ischemia–reperfusion (IR) and ischemia preconditioning (IP) is still controversial. Here, we focused on the possible roles of nNOS in cardiac IR and IP. Wild type C57BL/6 (WT) mice were subjected to coronary artery occlusion for 30 min followed by 24-h reperfusion (IR). Cardiac injury (infarct size and apoptotic cell number) was increased, associated with elevation of oxidative stress (lipid peroxidation) and nitrative stress (nitrotyrosine formation). A potent nNOS inhibitor, L-VNIO, and a superoxide dismutase mimetic and peroxynitrite scavenger, MnTBAP, significantly reduced IR-induced increases of oxidative/nitrative stress and cardiac injury. IR-induced cardiac injury in nNOS^−/− (KO) mice was significantly lower than that in WT mice. MnTBAP markedly reduced IR-induced cardiac injury by suppression of oxidative/nitrative stress in KO mice. Cardiac IP was performed by three cycles of 5-min IR before 30-min ischemia followed by 24-h reperfusion. IP attenuated IR-induced cardiac injury in WT mice associated with reductions of oxidative/nitrative stress. IP-induced reduction of cardiac injury and oxidative/nitrative stress were eliminated by pretreatment with L-VNIO. In contrast with WT mice, IP had no protective effects in nNOS KO mice. In conclusion, nNOS played a dual role during cardiac IR and IP; nNOS exacerbated IR-induced injury by increasing oxidative/nitrative stress and contributed to IP-induced protection by inhibition of oxidative/nitrative stress.     

Oral osmotically driven systems: 30 years of development and clinical use

The number of marketed oral osmotically driven systems (OODS) has doubled in the last 10 years. The main clinical benefits of OODS are their ability to improve treatment tolerability and patient compliance. These advantages are mainly driven by the capacity to deliver drugs in a sustained manner, independent of the drug chemical properties, of the patient’s physiological factors or concomitant food intake. However, access to these technologies has been restricted by the crowded patent landscape and manufacturing challenges. In this review article, we intend to give an overview of the OODS development in the last 30 years, detailing the technologies, specific products and their clinical use. General guidance on technology selection is described in light of the recent advances in the field. The clinical performance of these technologies is also discussed, with a focus on food effects and the in vivo-in vitro correlation. Special attention is paid to safety given the controversial case study of Osmosin^®. Overall, oral osmotically driven systems appear to be a promising technology for product life-cycle strategies.     

Effects of carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone on the growth inhibition in human pulmonary adenocarcinoma Calu-6 cells

Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) is an uncoupler of mitochondrial oxidative phosphorylation in eukaryotic cells. Here, we evaluated the in vitro effects of FCCP on the growth of Calu-6 lung cancer cells. FCCP inhibited the growth of Calu-6 cells with an IC₅₀ of approximately 6.64 ± 1.84 μM at 72 h, as shown by MTT. DNA flow cytometric analysis indicated that FCCP induced G1 phase arrest below 20 μM of FCCP. Treatment with FCCP decreased the level of CDKs and cyclines in relation to G1 phase. In addition, FCCP not only increased the p27 level but also enhanced its binding with CDK4, which was associated with hypophosphorylation of Rb protein. While transfection of p27 siRNA inhibited G1 phase arrest in FCCP-treated cells, it did not enhance Rb phosphorylation. FCCP also efficiently induced apoptosis. The apoptotic process was accompanied with an increase in sub-G1 cells, annexin V staining cells, mitochondria membrane potential (MMP) loss and cleavage of PARP protein. All of the caspase inhibitors (caspase-3, -8, -9 and pan-caspase inhibitor) markedly rescued the Calu-6 cells from FCCP-induced cell death. However, knock down of p27 protein intensified FCCP-induced cell death. Moreover, FCCP induced the depletion of GSH content in Calu-6 cells, which was prevented by all of the caspase inhibitors. In summary, our results demonstrated that FCCP inhibits the growth of Calu-6 cells in vitro. The growth inhibitory effect of FCCP might be mediated by cell cycle arrest and apoptosis via decrease of CDKs and caspase activation, respectively. These findings now provide a better elucidation of the mechanisms involved in FCCP-induced growth inhibition in lung cancer.     

Stimulation of prostanoid IP and EP(2) receptors dilates retinal arterioles and increases retinal and choroidal blood flow in rats

We examined the effects of vasodilatory prostaglandins (prostacyclin and prostaglandin E₂) and selective agonists for prostanoid EP₂ and EP₄ receptor on the diameters of retinal blood vessels and fundus (retinal/choroidal) blood flow in rats. Male Wistar rats (8- to 10-week-old) were treated with tetrodotoxin (50 μg/kg, i.v.) to eliminate any nerve activity and prevent movement of the eye and infused with a mixture solution of norepinephrine and epinephrine (1:9) to maintain adequate systemic circulation under artificial ventilation. Fundus images were captured with a digital camera that was equipped with the special objective lens for small animals, and the diameters of retinal arterioles and venules were measured on a personal computer. Fundus blood flow was estimated using a laser Doppler flowmetry. Intravenous infusions of prostacyclin and prostaglandin E₂ dilated retinal blood vessels, increased fundus blood flow and decreased systemic blood pressure in a dose-dependent manner. The effects of vasodilatory prostaglandins on retinal arterioles were greater than those on retinal venules. Similarly, a prostanoid EP₂ receptor agonist (ONO-AE1-259-01) dilated retinal blood vessels, and increased fundus blood flow and decreased systemic blood pressure. However, a prostanoid EP₄ receptor agonist (ONO-AE1-329) failed to increase fundus blood flow, despite its comparable depressor response with those to vasodilatory prostaglandins and the prostanoid EP₂ receptor agonist. The responses to forskolin, an activator of adenylyl cyclase, were very similar to those to prostacyclin and the prostanoid EP₂ receptor agonist.

These results suggest that prostacyclin and prostaglandin E₂ act as vasodilators in retinal and choroidal circulation, and prostanoid IP and EP₂ receptors play an important role in the regulation of ocular hemodynamics in rats.     

气相色谱－质谱联用法测定7－甲基鸟嘌呤

利用气相色谱－质谱联用仪测定ＤＮＡ烷基化产物７－甲基鸟嘌呤，在本文所介绍的测定条件下，用Ｎ－甲基－Ｎ－（三甲基硅烷基）三氟乙酰胺使７－甲基鸟嘌呤形成稳定的硅烷化衍生物，该衍生物可电离成（Ｍ－ＣＨ３）＋碎片离子，特征峰明显，有利于定量及结构分析，测定灵敏度可达ｎｇ级。     

Acting via A_2 receptors，adenosine inhibits H_2O_2 production and elastase releaseon FMLP一stimulated

ＡｃｔｉｎｇｖｉａＡ２ｒｅｃｅｐｔｏｒｓ，ａｄｅｎｏｓｉｎｅｉｎｈｉｂｉｔｓＨ２Ｏ２ｐｒｏｄｕｃｔｉｏｎａｎｄｅｌａｓｔａｓｅｒｅｌｅａｓｅｏｎＦＭＬＰ一ｓｔｉｍｕｌａｔｅｄｎｅｕｔｒｏｐｈｉｌｓＺｈａｎｇＹｕ，ＢａＴｕ（ＤｅｐａｒｔｍｅｎｔｏｆＣａ...     

反相离子对高效液相色谱法测定盐酸黄酮哌酯片的含量

目的:建立一种采用反相离子对高效液相色谱法测定盐酸黄酮哌酯片含量的方法。方法:用Shim-Pack vp-ODS柱(4.6mm×150mm,5μm),以0.05mol·L~(-1)磷酸二氢钾(含1％三乙胺,用磷酸调pH3.8)-0.0025mol·L~(-1)庚烷磷酸钠甲醇溶液(1:1.2)为流动相,流速1mL·min~(-1),UV检测波长241nm。柱温:室温,进样量20μL。结果:盐酸黄酮哌酯和前体杂质3-甲基黄酮-8-羧酸的保留时间分别为7.0min和5.0min,分离度为6.0,最低检测浓度分别为1.20μg·mL~(-1)和0.55μg·mL~(-1)。盐酸黄酮哌酯在0.119～0.834mg·mL~(-1)范围内呈良好的线性关系,r=0.9999。平均回收率(n=5)分别为99.04％(RSD=0.66％),99.36％(RSD=0.87％),99.64％(RSD=0.62％)。结论:本方法简便、快速、专属,结果准确可靠,能有效控制产品质量。