Transient induction of cytochromes P450 1A1 and 1B1 in MCF-7 human breast cancer cells by indirubin

The aryl hydrocarbon receptor (AhR), when activated by exogenous ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), regulates expression of several phase I and phase II enzymes and is also involved in the regulation of cell proliferation. Several studies suggest that endogenous AhR ligand(s) may exist. One putative endogenous ligand is indirubin, which was recently identified in human urine and bovine serum. We determined the effect of indirubin in MCF-7 breast cancer cells on induction of the activities of cytochromes P450 (CYP) 1A1 and 1B1, as measured by estradiol and ethoxyresorufin metabolism, and on induction of the CYP1A1 and CYP1B1 mRNAs. With 4-hr exposure, the effects of indirubin and TCDD at 10nM on CYP activity were comparable, but the effects of indirubin, unlike those of TCDD, were transitory. Indirubin-induced ethoxyresorufin-O-deethylase activity was maximal by 6-9 hr post-exposure and had disappeared by 24 hr, whereas TCDD-induced activities remained elevated for at least 72 hr. The effects of indirubin on CYP mRNA induction were maximal at 3 hr. Indirubin was metabolized by microsomes containing cDNA-expressed human CYP1A1 or CYP1B1. The potency of indirubin was comparable to that of TCDD in a CYP1B1-promoter-driven luciferase assay, when MCF-7 cells were co-exposed to the AhR ligands together with the CYP inhibitor, ellipticine. Thus, if indirubin is an endogenous AhR ligand, then AhR-mediated signaling by indirubin is likely to be transient and tightly controlled by the ability of indirubin to induce CYP1A1 and CYP1B1, and hence its own metabolism.     

Aldosteronism revisited: perspectives on less well-recognized actions of aldosterone

Aldosterone is a mineralocorticoid with protean actions in both epithelial and nonepithelial cells. These include endocrine properties of circulating aldosterone that promote Na(+) resorption at the expense of well-recognized K(+) excretion and less well-recognized Mg(2+) excretion in classic target tissues: kidneys, colon, and sweat and salivary glands. The regulation of adrenal aldosterone secretion by [Mg(2+)](o) is also less well appreciated. More recently recognized endocrine actions of aldosterone include induction of Mg(2+) efflux in exchange for Na(+) in such nonepithelial cells as peripheral-blood mononuclear cells and influence on epithelial cells of the choroid plexus, where aldosterone alters the composition of cerebrospinal fluid that contributes to blood-pressure regulation. An association between primary aldosteronism and idiopathic intracranial hypertension has recently been reported. Extraadrenal steroidogenesis with de novo aldosterone production by the cardiovasculature, where its auto-/paracrine properties may contribute to tissue repair at sites of injury, has been observed. These less well-recognized actions of aldosterone have led to a revival of interest in how this steroid molecule contributes to the pathophysiology of various clinical disorders.     

Nitric oxide synthase-positive neurons in the rat superior colliculus: colocalization of NOS with NMDAR1 glutamate receptor, GABA, and parvalbumin

We analyzed the potential input and output components of nitric oxide synthase (NOS)-containing neurons in the rat superior colliculus (SC). To identify whether NOS-positive neurons receive glutamatergic input we investigated the colocalization of NOS with NMDA receptor subunit R1 (NMDAR1). In addition, to examine whether putative nitric oxide synthesizing neurons represent a neurochemically specific or distinct subpopulation of cells in the SC we studied the colocalization of NOS with the neurotransmitter GABA, the calcium-binding proteins parvalbumin, calbindin and calretinin and with neuropeptides such as somatostatin, substance P and neuropeptide Y. We found that 90% of NOS-positive neurons in the superficial layers of the rat SC express NMDAR1. Nearly 20% of the population of nitridergic neurons also expresses GABA and 15% of them express parvalbumin. NOS-positive neurons in the superior colliculus did not contain calretinin, calbindin or either of the neuropeptides tested. The results of this study show that the capacity for synthesizing NO in the SC is largely restricted to neurons that receive glutamatergic inputs and that some of these neurons express GABA or parvalbumin.     

黄芪总皂苷对缺氧性肺动脉高压作用探讨

目的　探讨黄芪总皂苷（AST）对缺氧性肺动脉高压（HPH）病理进展的抑制作用及相关机制。方法　28只SPF级雄性SD大鼠随机分为对照组、HPH组、HPH+AST15［15 mg/（kg·d）］组、HPH+AST45［45 mg/（kg·d）］组,每组7只。采用间断式常压低氧建立大鼠HPH模型。实验28 d后,检测大鼠右心室收缩压力（RVSP）;计算右心室（RV）和左心室+室间隔（LV+S）的比值RV/（LV+S）;HE染色及免疫荧光染色观察大鼠肺动脉结构重建,计算肺动脉厚度百分比（WT）、面积百分比（WA）,并测量肺动脉α-平滑肌肌动蛋白（α-SMA）的光密度（OD）值;分光光度法检测大鼠肺组织及血清中的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）及丙二醛（MDA）水平;Western blot法检测大鼠肺组织中还原型烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶Nox2和Nox4蛋白表达情况。结果　与对照组比较,HPH组大鼠RVSP、RV/（LV+S）、WT、WA、α-SMA均增高（P＜0.05）,肺组织及血清中的SOD、CAT水平明显降低,而MDA水平增高（P＜0.05）,肺组织中Nox2和Nox4蛋白表达水平升高（P＜0.05）。与HPH组比较,HPH+AST15组和HPH+AST45组大鼠RVSP、RV/（LV+S）、WT、WA、α-SMA均降低（P＜0.05）,肺组织及血清中的SOD、CAT水平升高,MDA水平降低（P＜0.05）,肺组织中Nox2和Nox4蛋白表达水平均降低（P＜0.05）,其中HPH+AST45组WT、WA、α-SMA及肺组织MDA水平、Nox2和Nox4蛋白表达水平均较HPH+AST15组更低（P＜0.05）。结论　黄芪总皂苷可抑制大鼠HPH的病理进展,其机制可能与提高大鼠体内SOD和CAT水平并抑制Nox2和Nox4表达有关。     

酶促微粒体脂质过氧化模型的建立

运用体外实验，对ＮＡＤＰＨ／ＦｅＳＯ４诱发的微粒体脂质过氧化发生条件及反应历程进行了探讨。结果表明：在３７℃水浴，微粒体蛋白浓度为１．０ｍｇ／ｍｌ，ｐＨ值７．４的０．４ｍｏｌ／ＬＴｒｉｓ－ＨＣｌ缓冲液的条件，１５０μｍｏｌ／Ｌ ＮＡＤＰＨ和４．４５μｍｏｌ／Ｌ ＦｅＳＯ４可使微粒体中丙二醛含量高于反应１５分钟内迅速上升，３０分钟时达到高峰，以后趋于平稳。     

福辛普利对糖尿病大鼠肾脏NADPH氧化酶p22phox亚基mRNA表达的影响

目的 观察福辛普利对链脲佐菌素(STZ)诱导的糖尿病大鼠肾脏还原型辅酶Ⅱ(NADPH)氧化酶p22phox 亚基mRNA表达及细胞外基质（ECM）聚积的影响，并探讨其可能机制。 方法 STZ诱导的糖尿病大鼠模型，随机分为糖尿病非治疗组（DM组）和福辛普利治疗组（DM+Fosin组，福辛普利10 mg·kg-1·d-1），疗程12周。RT-PCR法检测肾脏NADPH氧化酶p22phox mRNA的表达；免疫组织化学方法检测肾脏纤连蛋白（FN）表达；白明胶酶谱法检测肾脏基质金属蛋白酶9（MMP-9）的活性；并检测Scr、尿蛋白排泄量和肾质量指数等指标。 结果 实验第4 周，DM+Fosin组大鼠肾脏NADPH氧化酶p22phox mRNA表达较DM组减少45％（P ＜ 0.05）。第8周时，DM+Fosin组的肾小球和肾小管间质FN表达较DM组分别降低52.5％和42.9％（均P ＜ 0.05）；肾脏MMP-9的活性升高29.6％（P ＜ 0.05）。实验第12周时，DM+Fosin组大鼠Scr水平、尿蛋白量（24 h）和肾质量指数较DM组分别降低35.9％、50.2％和17.2％（均P ＜ 0.05）。DM+Fosin组和DM组血糖的差异无统计学意义（P ＞ 0.05）。 结论 福辛普利可延缓糖尿病肾病的发生和发展，其机制可能与通过抑制NADPH氧化酶p22phox亚基mRNA的表达有关。     

MADPH氧化酶抑制剂对晚期氧化蛋白产物诱导内皮细胞高通透性的影响及机制

目的:探讨NADPH氧化酶(Nox)抑制剂对晚期氧化蛋白产物(AOPP)刺激下血管内皮的保护作用。方法:体外培养人脐静脉内皮细胞进行实验,人血清白蛋白(HSA)作为阴性对照,用不同浓度(50、100和200mg/L)AOPP-HSA共同孵育8 h后,利用5-氯甲基二乙酸荧光素标记人急性单核细胞白血病细胞株THP-1的细胞渗出数量反映内皮细胞的通透性,研究不同浓度AOPP-HSA对单层细胞通透性的影响。此外,另将细胞分为HSA组、AOPP-HSA组和AOPP-HSA+二联苯碘(DPI)组,进而探讨AOPP-HSA对Nox活化水平的影响以及DPI对内皮细胞骨架重构和细胞通透性改变的作用。结果:AOPP-HSA可使血管内皮细胞通透性明显增加(P0.05)。AOPP-HSA可导致Nox磷酸化水平上升,并呈剂量依赖性。Nox抑制剂DPI预处理组可抑制AOPP-HSA刺激下Nox磷酸化水平的上升,从而抑制血管内皮细胞通透性增加及细胞骨架重构。结论:AOPP-HSA可通过激活Nox导致血管内皮细胞通透性受损,Nox抑制剂DPI可以降低其通透性及细胞骨架重构,起到一定的保护作用。     

NADPH oxidase inhibition rescues keratinocytes from elevated oxidative stress in a 2D atopic dermatitis and psoriasis model

Emerging evidence suggests oxidative stress plays a role in the pathophysiology of both atopic dermatitis (AD) and psoriasis (PSO). We established in vitro models of AD and PSO skin, and characterized these models in regard to their oxidative stress state. Both AD and PSO model keratinocytes exhibited elevated reactive oxygen species (ROS) levels and accumulated more DNA damage than control cells after oxidative stress induced by 250 µmol/L H₂O₂. Elevated ROS levels and DNA damage accumulation could be inhibited by the NADPH oxidase (NOX) inhibitor diphenyleneiodonium (DPI). Further, immunofluorescence analysis revealed the presence of both NOX1 and NOX4 in keratinocytes. By inhibiting NOX1, stress-related signalling cascades and elevated ROS levels could be abrogated, and survival of AD and PSO cells improved. Taken together, this study reveals that inhibition of NOX inhibition could abrogate elevated oxidative stress in a 2D model of AD and PSO.     

NADPH氧化酶与男性勃起功能障碍

勃起功能障碍是男性的常见病和多发病。目前认为氧化应激是引起阴茎勃起功能障碍的重要机制之一。NADPH氧化酶广泛存在于机体多个系统(包括阴茎组织),发挥重要的生理功能。在多种病理情况下,NADPH氧化酶可以在阴茎组织中催化合成大量活性氧,导致过度氧化应激,从而影响阴茎勃起功能。本文就NADPH氧化酶的组成、同源物、活性调节、生理功能、在勃起功能障碍中的作用以及在勃起功能障碍治疗中的应用作一综述。     

The Nitric Oxide/Cyclic GMP Messenger System in Olfactory Pathways of the Locust Brain

Nitric oxide is generated by a Ca²⁺/calmodulin-stimulated nitric oxide synthase and activates soluble guanylyl cyclase. Using NADPH diaphorase (NADPHd) staining as a marker for the enzyme nitric oxide synthase and an antiserum against cGMP, we investigated the cellular organization of nitric oxide donor and target cells in olfactory pathways of the brain of the locust ( Schistocerca gregaria ). A small subset of neuronal and glial cells expressed cGMP immunoreactivity after incubation of tissue in a nitric oxide donor. Nitric oxide-induced increases in cGMP immunoreactivity were quantified in a tissue preparation of the antennal lobe and in primary mushroom body cell cultures. The mushroom body neuropil is a potential target of a transcellular nitric oxide/ cGMP messenger system since it is innervated by extrinsic NADPHd-positive neurons. The mushroom body-intrinsic Kenyon cells do not stain for NADPHd but can be induced to express cGMP immunoreactivity. The colocalization of NADPHd and cGMP immunoreactivity in a cluster of interneurons of the antennal lobe, the principal olfactory neuropil of the insect brain, suggests a role of the nitric oxide/cGMP system in olfactory sensory processing. Colocalization of NADPHd staining and cGMP immunoreactivity was also found in certain glial cells. The cellular organization of the nitric oxide/cGMP system in neurons and glia raises the possibility that nitric oxide acts not only as an intercellular but also as an intracellular messenger molecule in the insect brain.