BACKGROUND & AIMS: :Studies of transcriptome profiles have provided new insights into mechanisms underlying the development of hypertension. Cell type heterogeneity in tissue samples, however, has been a significant hindrance in these studies. We performed a transcriptome analysis in medullary thick ascending limbs of the loop of Henle isolated from Dahl salt-sensitive rats. Genes differentially expressed between Dahl salt-sensitive rats and salt-insensitive consomic SS.13(BN) rats on either 0.4% or 7 days of 8.0% NaCl diet (n=4) were highly enriched for genes located on chromosome 13, the chromosome substituted in the SS.13(BN) rat. A pathway involving cell proliferation and cell cycle regulation was identified as one of the most highly ranked pathways based on differentially expressed genes and by a Bayesian model analysis. Immunofluorescent analysis indicated that just 1 week of a high-salt diet resulted in a severalfold increase in proliferative medullary thick ascending limb cells in both rat strains, and that Dahl salt-sensitive rats exhibited a significantly greater proportion of medullary thick ascending limb cells in a proliferative state than in SS.13(BN) rats (15.0±1.4% versus 10.1±0.6%; n=7-9; P<0.05). The total number of cells per medullary thick ascending limb section analyzed was not different between the 2 strains. The study revealed alterations in regulatory pathways in Dahl salt-sensitive rats in tissues highly enriched for a single cell type, leading to the unexpected finding of a greater increase in the number of proliferative medullary thick ascending limb cells in Dahl salt-sensitive rats on a high-salt diet.

背景与目标： : 转录组谱的研究为高血压发展的机制提供了新的见解。然而，在这些研究中，组织样本中的细胞类型异质性一直是一个重大障碍。我们对从达尔盐敏感大鼠中分离出的Henle环的髓质厚上升肢进行了转录组分析。在0.4% 或7天的8.0% NaCl饮食 (n = 4) 的Dahl盐敏感大鼠和盐不敏感的康体SS.13(BN) 大鼠之间差异表达的基因高度富集位于13号染色体上的基因，该染色体在SS.13(BN) 大鼠中被取代。基于差异表达基因和贝叶斯模型分析，涉及细胞增殖和细胞周期调控的途径被确定为排名最高的途径之一。免疫荧光分析表明，仅1周的高盐饮食就导致两种大鼠品系中增殖的髓质厚上升肢体细胞增加了几倍，并且Dahl盐敏感大鼠在增殖状态下表现出比SS.13(BN) 大鼠明显更大的髓质厚上升肢体细胞比例 (15.0 ± 1.4% 对10.1 ± 0.6%; n = 7-9; P<0.05)。分析的每个髓质厚上升肢切片的细胞总数在2个菌株之间没有差异。该研究揭示了Dahl盐敏感大鼠在单细胞类型高度富集的组织中调节途径的改变，导致意外发现Dahl盐敏感大鼠中增殖性髓质厚上升肢体细胞的数量增加高盐饮食。

BACKGROUND & AIMS: A study of three fluorescent anthroyl probes has been carried out using pure and mixed monomolecular films with dipalmitoylphosphatidylcholine. In addition, fluorescence depolarization and differential scanning calorimetry data were obtained from dipalmitoylphosphatidylcholine vesicles with incorporated anthroyl probes. The three probes used were 2-(9-anthroyl)palmitic acid. 12-(9-anthroyl)stearic acid, and 16-(9-anthroyl)palmitic acid. The latter probe was synthesized for these studies. In monolayers the probes shifted the onset of the liquid-condensed/liquid-expanded monolayer phase transition with the extent of the shift decreasing in the order2-(9-anthroyl)palmitic acid greater than 12-(9-anthroyl)stearic acid greater than 16-(9-anthroyl)stearic acid. A corresponding decrease in the gel-liquid crystalline bilayer transition temperature (Tc) showed the same order of perturbation in both the fluorescence depolarization and differential scanning calorimetry data. Locating the anthroyl entity in the center of the bilayer would appear to provide a minimum perturbation.

背景与目标： 已使用纯的和混合的单分子膜与二棕榈酰磷脂酰胆碱进行了对三种荧光拟人基探针的研究。此外，荧光去极化和差示扫描量热法数据是从结合了人角基探针的二棕榈酰磷脂酰胆碱囊泡获得的。使用的三种探针是2-(9-甘草酸) 棕榈酸。12-(9-甘草酸) 硬脂酸，和16-(9-人甘草酸) 棕榈酸。后一种探针是为这些研究合成的。在单层中，探针改变了液体冷凝/液体膨胀单层相变的开始，而这种转变的程度以2-(9-人甘草酸) 大于12-(9-人甘草酸) 的顺序减小硬脂酸大于16-(9-拟人酰) 硬脂酸。凝胶-液晶双分子层转变温度 (Tc) 的相应降低在荧光去极化和差示扫描量热法数据中显示出相同的扰动顺序。将拟人酰实体定位在双分子层的中心似乎提供了最小的摄动。

BACKGROUND & AIMS: :Purinergic stimulation of human airway epithelia results in a prolonged increase in ciliary beat frequency that depends on calcium-mediated cAMP production [Lieb, T., Wijkstrom Frei, C., Frohock, J.I., Bookman, R.J. and Salathe, M. (2002) Prolonged increase in ciliary beat frequency after short-term purinergic stimulation in human airway epithelial cells. J. Physiol. (Lond.) 538, 633-646]. Here, fully differentiated human airway epithelial cells in culture are shown to express calcium-stimulated transmembrane adenylyl cyclase (tmAC) isoforms (types 1, 3, and 8) by reverse transcription polymerase chain reaction. Immunohistochemistry of tracheal sections and fully differentiated airway epithelial cell cultures revealed polarized expression of these tmACs, with types 1 and 8 localized to the apical membrane and thus at the position required for ciliary regulation. Real-time, ciliated-cell specific cAMP production by tmACs upon apical, purinergic stimulation with UTP was confirmed using fluorescent energy resonance transfer between fluorescently tagged PKA subunits.

背景与目标： : 嘌呤能刺激人气道上皮细胞导致睫状搏动频率的延长增加，这取决于钙介导的cAMP产生 [Lieb，T.，Wijkstrom Frei，C.，Frohock，J.I.，Bookman，r.j.和salate，M. (2002) 人气道上皮细胞短期嘌呤能刺激后睫状搏动频率的延长增加。J. Physiol。(Lond。) 538，633-646]。在这里，通过逆转录聚合酶链反应显示培养物中完全分化的人气道上皮细胞表达钙刺激的跨膜腺苷酸环化酶 (tmAC) 亚型 (1、3和8型)。气管切片和完全分化的气道上皮细胞培养物的免疫组织化学显示这些tmac的极化表达，其中1型和8型位于根尖膜上，因此位于纤毛调节所需的位置。使用荧光标记的PKA亚基之间的荧光能量共振转移，证实了tmACs在UTP的顶端，嘌呤能刺激下实时，纤毛细胞特异性cAMP的产生。

BACKGROUND & AIMS: :The level of cyclic AMP in various fractions of rat skeletal tissue was measured after in vitro or in vivo administration of parathyroid hormone and calcitonin. Incubations of bone fractions prepared from young (5 weeks of age thyroparathyroidectomized rats revealed that both parathyroid hormone and calcitonin increased the cyclic AMP level in fractions of epiphysis, metaphysis and marrow cells. Cyclic AMP accumulation in incubated perisoteum and diaphysis were induced solely by parathyroid hormone. In in vivo experiments the cyclic AMP level in the tibia of the thyroparathyroidectomized rat was increased by infusion of either parathyroid hormone or calcitonin, and the simultaneous administration of each maximally effective dose of the two hormones exhibited an additive effect. Within 2 min, parathyroid hormone infusion caused an elevation of cyclic AMP content in periosteum and metaphysis. Rapid increase of cyclic AMP in the metaphysis was also induced by calcitonin, and the effect of the two hormones on cyclic AMP accumulation in this fraction was additive. Small but significant increase of cyclic AMP in the diaphysis was detected at 5 min after the administration of parathyroid hormone. Calcitonin infusion did not show any consistent effects on periosteum and diaphysis.

背景与目标： : 在体外或体内给予甲状旁腺激素和降钙素后，测量大鼠骨骼组织各部分中的环AMP水平。从年轻的 (5周龄甲状腺旁腺切除的大鼠) 制备的骨组分的孵育表明，甲状旁腺激素和降钙素均增加了骨骺组分中的环AMP水平，干phy端和骨髓细胞。仅由甲状旁腺激素诱导孵育的perisoteum和daphysis中的循环AMP积累。在体内实验中，甲状旁腺激素或降钙素的输注增加了甲状旁腺切除大鼠胫骨中的循环AMP水平，两种激素的最大有效剂量的同时给药均表现出累加作用。在2分钟内，甲状旁腺激素输注导致骨膜和干骺端循环AMP含量升高。降钙素也诱导了干骺端循环AMP的快速增加，两种激素对该级分中环AMP积累的影响是累加的。甲状旁腺激素给药后5分钟，检测到骨干中环AMP的少量但显着增加。降钙素输注对骨膜和骨干没有显示出任何一致的作用。

BACKGROUND & AIMS: :We reported previously that onset of oligodendrocyte precursor cell (OPC) differentiation is accompanied by an increase in intracellular pH (pH(i)). We show that OPC differentiation is dependent primarily on a permissive pH(i) value. The highest differentiation levels were observed for pH(i) values around 7.15 and inhibition of differentiation was observed at slightly more acidic or alkaline values. Clamping the pH(i) of OPCs at 7.15 caused a transient activation of ERK1/2 that was not observed at more acidic or alkaline values. Furthermore, inhibition of ERK activation with the UO126 compound totally prevented OPC differentiation in response to pH(i) shift. These results indicate that pH(i), acting through the ERK1/2 pathway, is a key determinant for oligodendrocyte differentiation. We also show that this pH(i) pathway is involved in the process of retinoic acid-induced OPC differentiation.

背景与目标： : 我们以前曾报道过少突胶质细胞前体细胞 (OPC) 分化的开始伴随着细胞内pH(i)) 的增加。我们表明OPC的分化主要取决于允许的pH(i) 值。对于7.15附近的pH(i) 值观察到最高的分化水平，并且在稍微更酸性或碱性值观察到分化的抑制。将OPCs的pH(i) 夹在7.15引起ERK1/2的瞬时活化，这在更酸性或碱性值下没有观察到。此外，用UO126化合物抑制ERK活化完全阻止了响应pH(i) 位移的OPC分化。这些结果表明，pH(i) 通过ERK1/2途径起作用，是少突胶质细胞分化的关键决定因素。我们还表明，该pH(i) 途径参与了视黄酸诱导的OPC分化过程。

BACKGROUND & AIMS: INTRODUCTION:The antiplatelet effects of low-dose aspirin (LDA) vary between individuals. Here, we investigated the relationship between the incidence of LDA-induced mucosal injury, antiplatelet effects of LDA, and intragastric pH. METHODS:We evaluated gastric injury severity and platelet function using the VerifyNow® System before and after administration of 100 mg aspirin for 7 days to 18 young healthy subjects (study 1). We investigated whether injury was correlated with platelet function and gastric juice pH in 45 patients with cardiovascular disease administered LDA daily (study 2). RESULTS:In study 1, platelet aggregation was attenuated by LDA to different degrees. Although 55.6% of subjects (10/18) developed gastric injury of modified Lanza score (MLS) ≥ 3, no significant difference in platelet function was detected between the mild (n = 8, MLS: 0-2) and severe injury groups (n = 10, MLS: 3-5). In study 2, the severity of LDA-induced injury was associated with gastric juice pH, but not with antiplatelet effects of LDA. DISCUSSION:In contrast to gastric juice pH, the antiplatelet effect had no correlation with the severity of gastric mucosal injury. Monitoring gastric acidity, rather than platelet function, may be useful for predicting the risk of gastric injury during LDA treatment.

背景与目标：

BACKGROUND & AIMS: :Multiple sclerosis (MS) is an autoimmune disease where myelin is incorrectly recognized as foreign and attacked by the adaptive immune system. Dendritic cells (DCs) direct adaptive immunity by presenting antigens to T cells, therefore serving as a target for autoimmune therapies. N-Phenyl-7-(hydroxyimino) cyclopropa[b]chromen-1a-carboxamide (PHCCC), a positive allosteric modulator of metabotropic glutamate receptor 4 (mGluR4), can promote regulatory T cells by altering cytokine secretion to bias T cell differentiation. The therapeutic potential of PHCCC, however, is hindered by dose-limiting toxicity, poor solubility, and the need for frequent dosing. We hypothesized liposomal delivery of PHCCC might enable safe, effective delivery of this hydrophobic drug to exploit metabolism as a means of controlling inflammation in self-reactive immune cells. PHCCC was readily encapsulated in liposomes modified with polyethylene glycol. Under sink conditions, controlled release resulted in 58% of drug released into media over 18 hours. Culture of primary DCs with PHCCC liposomes reduced pro-inflammatory cytokine secretion while reducing toxicity four-fold compared with soluble PHCCC. During co-culture of DCs with myelin-reactive T cells from transgenic mice, PHCCC liposomes reduced T cell proliferation and interferon gamma secretion. These results support the potential of using liposomes to promote tolerance through biocompatible delivery of metabolic modulators. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2977-2985, 2017.

背景与目标： 多发性硬化症 (MS) 是一种自身免疫性疾病，其中髓磷脂被错误地识别为外来物质并受到适应性免疫系统的攻击。树突状细胞 (dc) 通过向T细胞呈递抗原来指导适应性免疫，因此可作为自身免疫疗法的靶标。N-Phenyl-7-(羟基亚氨基) 环丙 [b]chromen-1a-carboxamide (PHCCC) 是代谢型谷氨酸受体4 (mGluR4) 的正变构调节剂，可以通过改变细胞因子分泌来促进调节性T细胞分化。然而，PHCCC的治疗潜力受到剂量限制毒性，溶解度差以及需要频繁给药的阻碍。我们假设PHCCC的脂质体递送可能使这种疏水药物的安全，有效的递送能够利用代谢作为控制自我反应免疫细胞中炎症的手段。PHCCC很容易封装在用聚乙二醇修饰的脂质体中。在下沉条件下，受控释放导致药物在18小时内释放到培养基中的58%。与可溶性PHCCC相比，用PHCCC脂质体培养原代dc可减少促炎性细胞因子的分泌，同时降低毒性的四倍。在dc与转基因小鼠的髓磷脂反应性T细胞共培养期间，PHCCC脂质体降低了T细胞的增殖和干扰素 γ 的分泌。这些结果支持了使用脂质体通过代谢调节剂的生物相容性递送来促进耐受性的潜力。©2017威利期刊公司J生物材料Res部分A: 105A: 2977-2985，2017。

BACKGROUND & AIMS: :Inappropriate activation of the intrarenal renin-angiotensin system induces generation of reactive oxygen species and tubulointerstitial inflammation, which contribute to salt-sensitive hypertension (SSHT). Liver-type fatty acid-binding protein is expressed in proximal tubules in humans, but not in rodents, and may play an endogenous antioxidative role. The objective of the present study was to examine the antioxidative effect of liver-type fatty acid-binding protein on post-angiotensin II SSHT model in transgenic mice with selective overexpression of human liver-type fatty acid-binding protein in the proximal tubules. The transgenic mice showed marked protection against angiotensin II-induced SSHT. Overexpression of tubular liver-type fatty acid-binding protein prevented intrarenal T-cell infiltration and also reduced reactive oxygen species generation, intrarenal renin-angiotensin system activation, and monocyte chemotactic protein-1 expression. We also performed an in vitro study using the murine proximal tubular cell lines with or without recombinant liver-type fatty acid-binding protein and murine proximal tubular cell lines transfected with human liver-type fatty acid-binding protein, and found that gene transfection of liver-type fatty acid-binding protein and, in part, recombinant liver-type fatty acid-binding protein administration had significantly attenuated angiotensin II-induced reactive oxygen species generation and the expression of angiotensinogen and monocyte chemotactic protein-1 in murine proximal tubular cell lines. These findings indicated that liver-type fatty acid-binding protein in the proximal tubules may protect against angiotensin II-induced SSHT by attenuating activation of the intrarenal renin-angiotensin system and reducing oxidative stress and tubulointerstitial inflammation. Present data suggest that liver-type fatty acid-binding protein in the proximal tubules may be a novel therapeutic target for SSHT.

背景与目标： : 肾内肾素-血管紧张素系统的不适当激活会导致活性氧和肾小管间质炎症的产生，从而导致盐敏感性高血压 (SSHT)。肝型脂肪酸结合蛋白在人类近端小管中表达，但在啮齿动物中不表达，并且可能发挥内源性抗氧化作用。本研究的目的是研究肝型脂肪酸结合蛋白对血管紧张素II后SSHT模型的抗氧化作用，该模型在近端小管中选择性过表达人肝型脂肪酸结合蛋白。转基因小鼠对血管紧张素II诱导的SSHT具有明显的保护作用。肾小管型脂肪酸结合蛋白的过表达阻止了肾内T细胞的浸润，并减少了活性氧的产生，肾内肾素-血管紧张素系统的激活和单核细胞趋化蛋白-1的表达。我们还使用带有或不带有重组肝型脂肪酸结合蛋白的鼠近端肾小管细胞系和转染人肝型脂肪酸结合蛋白的鼠近端肾小管细胞系进行了体外研究，发现基因转染肝型脂肪酸结合蛋白，在某种程度上，重组肝型脂肪酸结合蛋白的施用显着减弱了血管紧张素II诱导的活性氧的产生以及鼠近端肾小管细胞系中血管紧张素原和单核细胞趋化蛋白-1的表达。这些发现表明，近端肾小管中的肝型脂肪酸结合蛋白可以通过减弱肾内肾素-血管紧张素系统的激活并减少氧化应激和肾小管间质炎症来预防血管紧张素II诱导的SSHT。目前的数据表明，近端小管中的肝型脂肪酸结合蛋白可能是SSHT的新治疗靶标。

BACKGROUND & AIMS: :We have established that 2,3-diphosphoglycerate (2,3-DPG) content and intracellular pH exert separate, but interdependent, effects on the equilibrium solubility (csat) of deoxyhemoglobin S (deoxy-Hb S) that act in concert to modulate intraerythrocytic polymer formation. In a nonphysiologic csat assay system, a steep dependence of csat on pH in the physiologic range 7.0 to 7.6 was shown for both stripped (Hb) and DPG-saturated deoxy-Hb S (Hb-DPG). The solubility-pH profile for Hb under near-physiologic buffer conditions also showed that csat increased steeply in the same pH range (6.8 to 7.6). The effect of 2,3-DPG on csat under near-physiologic conditions was evaluated separately. At pH 7.20, the pH of the human red blood cell, csat values for Hb and Hb-DPG were 19.56 +/- 0.14 and 17.95 +/- 0.45 g/dL, respectively, indicating that the solubility of Hb-DPG is lower than that of Hb by 8.2% +/- 2.3%. Thus, binding of 2,3-DPG in the beta-cleft promotes the polymerization of deoxy-Hb S, the ultimate determinant of cell sickling. Furthermore, because of the abnormal Bohr effect of sickle blood (approximately double that of normal blood), the intracellular pH of deoxygenated sickle erythrocytes should be approximately 0.28 pH unit higher than that of oxygenated cells (ie, 7.41 v 7.13). At the higher pH, the corresponding csat for Hb-DPG is 20.22 g/dL, which is the best estimate of the intrinsic solubility of T-state Hb S under conditions that approximate closely those of pH, temperature, ionic strength, and 2,3-DPG saturation in the fully desaturated sickle erythrocyte.

背景与目标： : 我们已经确定，2,3-二磷酸甘油酸 (2,3-dpg) 含量和细胞内pH对脱氧血红蛋白S (脱氧-Hb S) 的平衡溶解度 (csat) 产生独立但相互依存的影响，而脱氧血红蛋白S (脱氧-Hb S) 协同作用调节红细胞内聚合物的形成。在非生理性csat测定系统中，对于汽提 (Hb) 和DPG饱和脱氧-Hb S (hb-dpg)，显示出csat对7.0至7.6的生理范围内的pH的急剧依赖性。Hb在近生理缓冲条件下的溶解度-pH曲线也表明，在相同的pH范围内 (6.8至7.6)，csat急剧增加。分别评估了近生理条件下2,3-dpg对csat的影响。在pH 7.20时，人红细胞的pH、Hb和hb-dpg的csat值分别为19.56 +/- 0.14和17.95 +/- 0.45g/dL，表明hb-dpg的溶解度比Hb的溶解度低8.2% +/- 2.3%。因此，在 β-裂隙中结合2,3-dpg会促进脱氧-Hb S的聚合，脱氧-Hb S是细胞镰状的最终决定因素。此外，由于镰状血液的异常玻尔效应 (大约是正常血液的两倍)，脱氧镰状红细胞的细胞内pH应该比氧合细胞的pH高约0.28 pH单位 (即7.41 v 7.13)。在较高的pH下，hb-dpg的相应csat为20.22g/dL，这是在非常接近pH、温度、离子强度和完全去饱和镰刀红细胞中2,3-DPG饱和度的条件下，T-态Hb S固有溶解度的最佳估计值。

BACKGROUND & AIMS: :pH 5.9 is optimal for tobacco pollen tube growth in suspension culture. Little pH changes of sugar-mineral medium result from the release of surface-linked compounds from pollen grains. Germination and pollen tube growth bring about a progressive medium acidification resulting in total growth inhibition. An increase of the buffering capacity of the culture medium enhances pollen tube growth. When the pH was kept near the optimum by 25 mM MES-KOH buffer, pollen tubes grew for 4 days and in the presence of casein hydrolysate they reached a length of up to about 4 cm. The growth related acidification of the medium is independent of the presence of mineral cations and is not due to the hydration of respiratory CO(2). It is suggested that it is brought about by proton secretion from pollen tubes.

背景与目标： : pH 5.9对于悬浮培养中的烟草花粉管生长是最佳的。糖矿物培养基的ph值变化很小，这是由于花粉粒中表面连接的化合物的释放所致。发芽和花粉管生长会导致培养基酸化，从而导致总生长抑制。培养基缓冲能力的增加可增强花粉管的生长。当通过25mmmes-KOH缓冲液将pH保持在最佳值附近时，花粉管生长4天，并且在酪蛋白水解产物存在下，它们达到高达约4厘米的长度。与生长相关的培养基酸化与矿物阳离子的存在无关，而不是由于呼吸CO(2) 的水合作用。建议它是由花粉管的质子分泌引起的。

BACKGROUND & AIMS: :Silymarin, a known standardized extract obtained from seeds of Silybum marianum is used in treatment of liver diseases of varying origins. Aiming at improving its poor bioavailability from oral products, silymarin hybrid liposomes are introduced in this work for buccal administration after investigating their stability and in vivo hepatoprotective efficiency. Silymarin loaded hybrid liposomes composed of lecithin (L), cholesterol (Ch), stearyl amine (SA) and Tween 20 (T20) in molar ratio of (9:1:1:0.5) were prepared. Their stability upon storage was studied at 4 degrees C and at ambient conditions. Stored samples were analyzed for percent encapsulation, drug release, particle size, turbidity measurement and visual changes. Characterization of the blend between phospholipid and silymarin was done using FT-IR and DSC which indicated a possible interaction. The stabilized formula of silymarin hybrid liposomes was evaluated upon buccal administration regarding its hepatoprotective activity against carbon tetrachloride-induced oxidative stress in albino rats. The degree of protection was measured using biochemical parameters like serum glutamic oxalacetate transaminase (SGOT) and serum glutamic pyruvate transaminase (SGPT). The introduced silymarin hybrid liposomes produced a significant decrease in both transaminase levels when challenged with CCl(4) (intraperitonially) in comparison with orally administered silymarin suspension. This improvement was also confirmed histopathologically.

背景与目标： 水飞蓟素，从水飞蓟素种子中获得的已知标准化提取物，用于治疗不同来源的肝脏疾病。为了改善口服产品的生物利用度，在研究其稳定性和体内保肝效率后，将水飞蓟素杂交脂质体引入口腔给药。制备了由卵磷脂 (L)，胆固醇 (Ch)，硬脂胺 (SA) 和吐温20 (T20) 组成的水飞蓟素杂化脂质体，摩尔比为 (9:1:1:0.5)。在4摄氏度和环境条件下研究了它们在储存时的稳定性。分析存储的样品的包封百分比，药物释放，粒径，浊度测量和视觉变化。使用ft-ir和DSC对磷脂和水飞蓟素之间的混合物进行表征，这表明可能存在相互作用。在颊给药后评估了水飞蓟素混合脂质体的稳定配方，以评估其对白化病大鼠四氯化碳诱导的氧化应激的保肝活性。使用生化参数 (例如血清谷草转氨酶 (SGOT) 和血清谷丙酮酸转氨酶 (SGPT)) 测量保护程度。与口服水飞蓟素混悬液相比，引入的水飞蓟素混合脂质体在用CCl(4) 攻击时 (腹膜内) 使两种转氨酶水平均显着降低。这种改善也在组织病理学上得到证实。

BACKGROUND & AIMS: :Despite intensive research, brain tumors remain among the most difficult type of malignancies to treat, due largely to their diffusely invasive nature and the associated difficulty of adequate surgical resection. To migrate through the brain parenchyma and to proliferate, glioma cells must be capable of significant changes in shape and volume. We have previously reported that glioma cells express an amiloride- and psalmotoxin-sensitive cation conductance that is not found in normal human astrocytes. In the present study, we investigated the potential role of this ion channel to mediate regulatory volume increase in glioma cells. We found that the ability of the cells to volume regulate subsequent to cell shrinkage by hyperosmolar solutions was abolished by both amiloride and psalmotoxin 1. This toxin is thought to be a specific peptide inhibitor of acid-sensing ion channel (ASIC1), a member of the Deg/ENaC superfamily of cation channels. We have previously shown this toxin to be an effective blocker of the glioma cation conductance. Our data suggest that one potential role for this conductance may be to restore cell volume during the cell's progression thorough the cell cycle and while the tumor cell migrates within the interstices of the brain.

背景与目标： : 尽管进行了深入的研究，但脑肿瘤仍然是最难治疗的恶性肿瘤之一，这主要是由于其弥漫性侵袭性和相关的手术切除困难。为了通过脑实质迁移并增殖，神经胶质瘤细胞必须能够在形状和体积上发生重大变化。我们以前曾报道过，神经胶质瘤细胞表达对阿米洛利和海参毒素敏感的阳离子电导，这在正常人星形胶质细胞中找不到。在本研究中，我们研究了该离子通道在介导神经胶质瘤细胞中调节体积增加的潜在作用。我们发现，阿米洛利和psalmotoxin 1都消除了高渗溶液引起细胞收缩后细胞体积调节的能力。该毒素被认为是酸感应离子通道 (ASIC1) 的特定肽抑制剂，后者是Deg/ENaC阳离子通道超家族的成员。我们以前已经证明这种毒素是神经胶质瘤阳离子电导的有效阻滞剂。我们的数据表明，这种电导的一个潜在作用可能是在细胞整个细胞周期的进展过程中以及肿瘤细胞在大脑间隙内迁移时恢复细胞体积。

BACKGROUND & AIMS: :Troponin I isoforms play a key role in determining myofilament Ca2+ sensitivity in cardiac muscle. The goal here was to identify domain clusters and residues that confer troponin I isoform-specific myofilament Ca2+ and pH sensitivities of contraction. Key domains/residues that contribute to troponin I isoform-specific Ca2+ and pH sensitivity were studied using gene transfer of a slow skeletal troponin I (ssTnI) template, with targeted cardiac troponin I (cTnI) residue substitutions. Substitutions in ssTnI with cognate cTnI residues R125Q, H132A, and V134E, studied both independently and together (ssTnIQAE), resulted in efficient stoichiometric replacement of endogenous myofilament cTnI in adult cardiac myocytes. In permeabilized myocytes, the pCa50 of tension ([Ca2+] required for half maximal force), and the acidosis-induced rightward shift of pCa50 were converted to the cTnI phenotype in myocytes expressing ssTnIQAE or ssTnIH132A, and there was no functionally additive effect of ssTnIQAE versus ssTnIH132A. Interestingly, only the acidosis-induced shift in Ca2+ sensitivity was comparable to cTnI in myocytes expressing ssTnIV134E, while ssTnIR125Q fully retained the ssTnI phenotype. An additional ssTnIN141H substitution, which lies within the same structural region of TnI as V134, produced a shift in myofilament Ca2+ sensitivity comparable to cTnI at physiological pH, while the acidic pH response was similar to the effect of wild-type ssTnI. Analysis of sarcomere shortening in intact adult cardiac myocytes was consistent with the force measurements. Targeted substitutions in the carboxyl portion of TnI produced residue-specific influences on myofilament Ca2+ and pH sensitivity of force and give new molecular insights into the TnI isoform dependence of myofilament function.

背景与目标： : 肌钙蛋白I亚型在确定心肌肌丝Ca2敏感性中起关键作用。此处的目标是确定赋予肌钙蛋白I同工型特异性肌丝Ca2和收缩的pH敏感性的结构域簇和残基。使用缓慢的骨骼肌钙蛋白I (ssTnI) 模板的基因转移以及靶向的心肌肌钙蛋白I (cTnI) 残基取代，研究了有助于肌钙蛋白I亚型特异性Ca2和pH敏感性的关键域/残基。独立或共同研究的ssTnI中带有同源cTnI残基R125Q，H132A和V134E的取代 (ssTnIQAE) 导致成年心肌细胞内源性肌丝cTnI的有效化学计量替代。在透化的心肌细胞中，张力的pCa50 (最大力量一半所需的 [Ca2]) 和酸中毒诱导的pCa50的向右移位被转化为表达ssTnIQAE或ssTnIH132A的心肌细胞中的cTnI表型，并且没有ssTnIQAE与ssTnIH132A的功能累加作用。有趣的是，只有酸中毒诱导的Ca2敏感性的变化与表达ssTnIV134E的心肌细胞中的cTnI相当，而ssTnIR125Q完全保留了ssTnI表型。与V134位于TnI相同的结构区域内的另一个ssTnIN141H取代，在生理pH下产生了与cTnI相当的肌丝Ca2敏感性转变，而酸性pH响应类似于野生型ssTnI的作用。完整成年心肌细胞中肌节缩短的分析与力测量一致。TnI羧基部分中的靶向取代对肌丝Ca2和pH力敏感性产生了残基特异性影响，并为肌丝功能的TnI同工型依赖性提供了新的分子见解。

BACKGROUND & AIMS: :Lys-gingipain (Kgp) is a major cysteine proteinase produced by the oral anaerobic bacterium Porphyromonas gingivalis, and has been implicated as a major pathogen in the development and progression of advanced adult periodontitis. This enzyme is believed to act as a major virulence factor of the disease, yet there exist no convenient and sensitive substrates for analyzing its biological activity. For a better understanding of the importance of this enzyme in the organism, there is an urgent need for specific substrates. Here we designed and synthesized two peptide 4-methyl-coumaryl-7-amides (MCA), carbobenzoxy (Z)-His-Glu-Lys-MCA, and Z-Glu-Lys-MCA, and tested their possible use as sensitive substrates for Kgp with limited specificity. Both substrates exhibited greater k(cat)/K(m) values than the best known Kgp substrates described so far. Both substrates were resistant to Arg-gingipain, another pathogenic cysteine proteinase from P. gingivalis, as well as trypsin and cathepsins B, L, and H. The levels of Kgp in various microorganisms and human cells were determined with Z-His-Glu-Lys-MCA. Little or no Kgp-like activity was detected in either other microorganisms or human cells tested. These results indicate that the present substrates are a valuable and fast tool for routine assays and for mechanistic studies on Kgp.

背景与目标： : Lys-gingipain (Kgp) 是由口腔厌氧菌牙龈卟啉单胞菌产生的主要半胱氨酸蛋白酶，已被认为是晚期成人牙周炎的发生和发展的主要病原体。该酶被认为是该疾病的主要毒力因子，但没有方便而敏感的底物来分析其生物活性。为了更好地了解这种酶在生物体中的重要性，迫切需要特定的底物。在这里，我们设计并合成了两种肽4-甲基-香豆基-7-酰胺 (MCA)，即碳苯氧基 (Z)-His-Glu-Lys-MCA和Z-Glu-Lys-MCA，并测试了它们作为敏感底物的可能用途Kgp的特异性有限。与迄今为止描述的最著名的Kgp衬底相比，两种衬底均显示出更大的k(cat)/K(m) 值。两种底物均对牙龈卟啉单胞菌的另一种致病性半胱氨酸蛋白酶，以及胰蛋白酶和组织蛋白酶B，L和H具有抗性。用Z-His-Glu-Lys-MCA测定各种微生物和人类细胞中Kgp的水平。在其他测试的微生物或人类细胞中几乎没有或没有检测到Kgp样活性。这些结果表明，本发明的底物是常规测定和Kgp机理研究的有价值且快速的工具。

BACKGROUND & AIMS: :Internalization by cells of radiolabeled protein ligands bound to the cell surface is frequently analyzed by extraction of the cells with low pH buffers. This treatment supposedly strips the ligands from the cell surface, and remaining molecules are considered to be internalized. However, we show herein that: (1) low molecular weight catabolic products that are trapped within lysosomes (residualizing radiolabels) are efficiently extracted by low pH buffers, under the same conditions used to remove cell surface-bound material, and (2) low pH treatment lyses the majority of the cells, as shown with both a nonadherent and an adherent cell line, with the release of most of a (51)Cr label. Still, low pH extraction was effective at demonstrating Ab internalization, as has been demonstrated many times. These effects of low pH treatment may be attributed to the fixative properties of these buffers. Regardless of the mechanism, these data must be taken into consideration in interpreting the results of such experiments.

背景与目标： : 通过细胞内化结合到细胞表面的放射性标记蛋白配体经常通过用低pH缓冲液提取细胞来分析。据推测，这种处理将配体从细胞表面剥离，剩余的分子被认为是内在化的。然而，我们在本文中显示 :( 1) 在用于去除细胞表面结合材料的相同条件下，通过低pH缓冲液有效地提取了溶酶体中捕获的低分子量分解代谢产物 (残留放射性标记)，以及 (2) 低pH处理裂解大多数细胞，如非粘附细胞系和粘附细胞系所示，大部分 (51)Cr标记的释放。尽管如此，低pH萃取仍可有效证明Ab内化，正如多次证明的那样。低pH处理的这些影响可能归因于这些缓冲液的固定性。无论机制如何，在解释此类实验结果时必须考虑这些数据。