长期饮用普萘洛尔对大鼠心脏和血淋巴细胞β肾上腺素受体效应及亚型的影响

采用放射配体结合实验，离体左心房收缩功能实验，逆转录聚合酶链反应及高效液相色谱等方法研究长期饮用普萘洛尔(70 mg·kg^-1·d^-1，8 wk)对大鼠心脏β肾上腺素受体(β-AR)及其亚型，外周血淋巴细胞β₂-AR和血浆儿茶酚胺水平的影响. 结果表明长期饮用普萘洛尔后：(1)心脏β- AR密度从对照组的41±8 pmol·g^-1蛋白上调到61±9 pmol·g^-1蛋白，CGP20712A竞争抑制曲线2位点分析结果显示为β₁和β₂-AR同等程度上调；(2)心脏β₁-AR mRNA水平不变而β₂-AR mRNA水平显著增加；(3)β-AR及其亚型介导的离体左心房正性变力效应增强，以β₂-AR的功能改变更为显著；(4)血淋巴细胞β₂-AR数目从对照组的19±7 pmol·g^-1蛋白上调至32±8 pmol·g^-1蛋白；(5)血浆去甲肾上腺素水平(0.21±0.12 μg·L^-1)明显低于对照组(0.38±0.15 μg·L^-1).     

阿魏酸钠对淀粉样β蛋白片段1～40引起的大鼠海马MAP激酶信号传导通路及凋亡蛋白表达的影响

目的观察阿魏酸钠(SF)是否对淀粉样β蛋白(Aβ)所致的海马损伤具有保护作用及其信号转导机制。方法大鼠灌胃给予SF(50,100和250mg.?-1),连续应用3周,左侧脑室内单次注射Aβ1-40(10μL,1.0mmol.L-1)制备大鼠痴呆动物模型,注射后6h,取海马CA1区。Western印迹观察有丝分裂原活化蛋白p38(p38MAP)激酶、丝裂原激活的蛋白激酶的激酶4(MKK4)、c-Jun氨基末端激酶(JNK1/2)、P53蛋白、FasL和半胱氨酸天冬氨酸蛋白酶-3(caspase3)蛋白表达。应用caspase3活性测定试剂盒分析caspase3活性变化。结果脑室内注射Aβ1-40可引起大鼠海马CA1区磷酸化p38MAP激酶表达明显增加,从正常0.127±0.018增加到0.95±0.12(n=4,P<0.01)。也可使磷酸化MKK4和JNK1/2表达明显增加。这些MAPK信号传导通路改变伴随有促凋亡蛋白P53和FasL表达明显增加,caspase3蛋白表达和活性均明显增加,P53从正常0.053±0.012增加到0.30±0.07(n=4,P<0.01),FasL从正常0.25±0.04增加到0.51±0.05(n=4,P<0.01),caspase3从正常0.036±0.007增加到0.63±0.041(n=4,P<0.01),caspase3活性从正常0.38±0.04增加到0.86±0.09(n=4,P<0.01)。SF(50、100和250mg.kg-1)连续应用3周,能明显抑制Aβ1-40引起的p38MAP激酶、磷酸化MKK4和JNK1/2表达明显增加,同时促凋亡蛋白p53和FasL表达明显增加,降低caspase3的活性。结论SF通过抑制Aβ1-40引起的p38MAP激酶和JNK1/2信号传导通路,产生抗凋亡作用,保护海马免除Aβ1-40引起的神经毒性。     

Biological activities contaminating preparations of phospholipase C ( -toxin) from Clostridium perfringens

Commercial preparations of phospholipase C from Clostridium perfringens (welchii) were found to contain the following biological activities: a second haemolytic protein probably theta-haemolysin, protease, deoxyribonuclease, α-glucosidase, endo-β-N-acetylglucosaminidase, hyaluronate lyase acid phosphatase, sulphatase and β-glucuronidase. Separation of phospholipase C in density gradient isoelectric focusing in an extremely shallow pH gradient resulted in two peaks and removed most of the contaminating activities. The isoelectric points (pI) of the phospholipase were 4·6 ± 0·05, and 5·7 ± 0·05, haemolysin pI 6·8, deoxyribonuclease pI 4·6, endo-β-N-acetylglucosaminidase pI 5·5, α-glucosidase pI 4·7, hyaluronate lyase pI 4·7, acid phosphatase pI 4·7, protease pI 4·5 and sulphatase, pI 4·5. The problem of interpreting previous biological studies on mammalian cell membranes by these rather crude preparations is discussed.     

The Stability of bFGF Against Thermal Denaturation

Abstract— The influence of sulphated ligand and pH on thermal denaturation of basic fibroblast growth factor (bFGF) was investigated by differential scanning calorimetry (DSC), and verified by fluorescence spectrophotometry. Purity of bFGF before and after heat denaturation was assessed by SDS-PAGE analysis. In DSC studies the samples were heated to 95°C. The midpoint of the temperature change in the thermogram was designated as T_m. Sulphated ligand experiments were undertaken in potassium phosphate (pH 6·5) and sodium acetate buffers. Control thermograms (with no ligand) showed a T_m at 59°C in potassium phosphate buffer. Higher T_m values were noted as sulphated ligand concentration was increased. Similarly when heparin was added, the T_m moved to a higher temperature. A ratio as low as 0·3:1 of heparin to bFGF, increased the T_m to 90°C, which is a 31°C shift in T_m. The effect of pH on thermal denaturation of bFGF was studied in a citrate-phosphate-borate buffer system. A shift in T_m from 46 to 65°C was observed as the pH is changed from 4 to 8. Changes in protein conformation as a function of pH were monitored by fluorescence spectroscopy. It was found that a pH range from 5 to 9 is optimal for the stability of bFGF formulations. In a stability study it was noted that heparin protected bFGF from thermal denaturation only at high temperature.     

染料木素促成骨样细胞增殖作用及其机制研究

目的观察染料木素(genistein)对成骨样细胞MC3T3-E1细胞增殖及骨形成蛋白-2(BMP-2)、β-连环素(β-catenin)表达的影响。方法培养成骨样细胞MC3T3-E1,加入不同浓度的染料木素(1×10-10、1×10-9、1×10-8、1×10-7、1×10-6和1×10-5mol·L-1),以1×10-9mol·L-1雌激素(β-estradiol,E2)作为阳性对照组,采用MTT比色试验法和碱性磷酸酶(ALP)活性检测法,观察染料木素作用后MC3T3-E1的增殖及分化情况,以Westernblot方法检测成骨样细胞中BMP-2和β-catenin蛋白的表达。结果染料木素可促进MC3T3-E1细胞增殖,染料木素作用后细胞的ALP值也明显升高,呈浓度依赖性;染料木素可增加BMP-2和β-catenin表达,且呈浓度依赖性。结论染料木素促进MC3T3-E1细胞增殖与分化,可通过调节BMP-2和Wnt/β-catenin信号通路而影响成骨样细胞的活性。     

Improvement of dissolution and absorption characteristics of phenytoin by a water-soluble β-cyclodextrin-epichlorohydrin polymer

Complexes of phenytoin with 3 water-soluble cyclodextrin-epichlorohydrin polymers (α-CyD · EP β-CyD · EP and γ-CyD · EP) in aqueous solution and in the solid phase were studied by a solubility method spectroscopic analyses and X-ray diffractometry. Binding to CyD polymers increased the solubility and dissolution rate of phenytoin in the order of $\text{β-}\text{CyD}\text{·}\text{EP}\text{> α-}\text{CyD}\text{·}\text{EP}\text{≧ γ-}\text{CyD}\text{·}\text{EP}$. The rapidly dissolving form of phenytoin-β-CyD · EP complex was found to significantly increase the plasma levels of the drug after oral administration to dogs. Data are presented suggesting that β-CyD · EP is particularly useful for improving the oral bioavailability of phenytoin.     

甲硫哒嗪损伤大鼠学习记忆伴随脑β-淀粉样蛋白的升高

目的观察甲硫哒嗪损伤大鼠学习记忆是否伴随脑内β-淀粉样蛋白(β-amyloid protein,Aβ)水平的升高,探讨甲硫哒嗪引起认知功能受损的机制。方法20只大鼠随机分为对照组和甲硫哒嗪组,连续2wk分别腹腔注射生理盐水和治疗剂量的甲硫哒嗪(10mg·kg-1)。用Morris水迷宫测定大鼠学习记忆能力,用放射免疫分析法测脑组织Aβ含量,用免疫组织化学染色检测β-淀粉样前体蛋白(β-amyloid precursor protein,APP)表达,用RT-PCR方法测定脑中3种APP、α及β-分泌酶mRNA表达。结果甲硫哒嗪组大鼠学习记忆能力下降,脑组织Aβ含量升高(P<0.05),是对照组的1.3倍;脑皮质和海马区APP蛋白表达增高(P<0.05);除APP695、α-分泌酶mRNA表达变化无统计学意义外,脑组织APP751和APP770 mRNA表达升高(P<0.05),相对表达量之和是对照组的2.5倍;β-分泌酶mRNA表达升高(P<0.05),是对照组的2.6倍。结论脑内Aβ水平的增加,可能是甲硫哒嗪引起认知功能损害的原因之一。     

Molecular docking and simulation studies to give insight of surfactin amyloid interaction for destabilizing Alzheimer’s Aβ42 protofibrils

Alzheimer’s disease is a neurodegenerative disorder. Aggregation of amyloid β-peptide (Aβ42) into fibrils is a key pathological process associated with Alzheimer’s disease. In this study, effect of surfactin against amyloid β-peptide was studied by using computational approaches. In the molecular docking, surfactin interacts with A chain of amyloid fibril and forms the hydrogen bonds with Ala 21 and Asp 23 with total energy of ?3.28 kcal/mol. Surfactin interacts with an amphiphilic pore amyloid β-peptide (Aβ42); binding of surfactin to amyloid fiber shows the decrease in salt bridge length (between Asp 23 and Lys 28) from 11.5 to 9.0 Å; and this may lead to displace the water molecules and so destabilize the amyloid β-peptide (Aβ42). 10-ns molecular dynamics simulation was performed for amyloid fibril and with surfactin amyloid fibril complex. RMSD, RMSF, Rg trajectories, and SASA plot further used to study the stability of complex and effect of surfactin. This is the novel in silico study of surfactin against the amyloid β-peptide (Aβ42) fiber responsible for Alzheimer’s disease, and these results may provide an insight role of surfactin in the drug design against Alzheimer’s disease.     

左甲状腺素对淀粉样β蛋白所致痴呆模型小鼠空间学习记忆的影响

目的探讨甲状腺激素对淀粉样β蛋白(Aβ)所致痴呆模型小鼠空间学习记忆的影响,并初步探讨其作用机制。方法小鼠海马内注射1.0μL的Aβ1-4210mmol·L-1制备阿尔茨海默病(AD)模型。小鼠一次性ip左甲状腺素(T4)5mg·kg-1后,Morris水迷宫实验测定对AD模型小鼠学习记忆的影响。分别采用比色法、黄嘌呤氧化酶法、碱性羟胺法和硫代巴比妥酸法检测小鼠海马胆碱乙酰转移酶(ChAT)和超氧化物歧化酶(SOD)活性,以及乙酰胆碱(ACh)和丙二醛(MDA)含量。结果与正常对照组比较,AD模型小鼠空间学习记忆能力受损。与AD模型组比较,T4治疗组小鼠在第3次到第6次训练中,在水迷宫中找到平台的时间明显缩短〔(105±9)vs(64±18)s;(90±11)vs(44±14)s;(71±14)vs(28±12)s;(65±11)vs(23±12)s〕;ChAT活性升高〔(21.9±6.7)vs(43.9±9.4)μmo.lg-1蛋白〕;SOD活性增高〔(2.40±0.12)vs(3.52±0.24)MU.g-1蛋白〕;ACh含量上升〔(4.74±0.60)vs(7.46±0.91)g.g-1蛋白〕;MDA减少〔(1.37±0.06)vs(0.74±0.09)μmol.g-1蛋白〕。结论T4可明显改善Aβ1-42所致痴呆模型小鼠空间学习记忆,其机制可能与增加脑内胆碱能神经功能,减少自由基损伤有关。     

β淀粉样蛋白对衰老模型大鼠学习记忆及大脑皮层内脂褐素含量的影响

为探讨 β淀粉样蛋白 (βAP ,于d 2 8双侧海马内各注射 4 μg)对D 半乳糖 (D Gal ,ip ,5 0mg·kg- 1·d- 1连续 4 2d)致衰老大鼠学习记忆行为的影响 ,检测了大鼠学习记忆行为 ,包括开场行为 ,Y 迷宫分辨学习和一次性被动回避反应 ,并用荧光光度计测定大脑皮层内脂褐素含量 .结果表明D Gal和βAP使大鼠在新异环境中自发活动和探究行为减少 ,学习记忆能力减退 ;同时大脑皮层内脂褐素含量增加 .βAP与D Gal联用使上述作用进一步增强 ,说明 βAP与D Gal有一定协同作用     

黄芪提取物保护Aβ致海马神经元损伤

目的探讨黄芪提取物在Aβ所致海马神经元损伤中的作用。方法通过对孕18d胎鼠的海马神经细胞培养,观察Aβ对神经细胞的毒性及黄芪提取物的保护作用。采用LDH法和MTT法检测细胞活力,LSCM测胞质钙离子浓度的变化及TUNEL法测细胞凋亡。结果Aβ与细胞孵育后,细胞活力明显下降,并呈时间和剂量依赖性,同时细胞内钙显著上升,细胞出现凋亡的典型的形态学特征。20、40μg·L-1黄芪提取物能明显提高细胞活力、降低胞质钙离子浓度、减少凋亡的细胞数。结论黄芪提取物对Aβ所致海马神经元损伤具有一定的保护作用,可能与其降低海马神经元胞质钙离子有关。     

β-七叶皂苷钠治疗脑转移瘤引起脑水肿的疗效观察

目的:观察β-七叶皂苷钠治疗脑转移瘤引起脑水肿的疗效。方法:58例经病理学确诊的非颅内肿瘤,经临床表现、头颅CT和/或MRI证实有脑转移后,随机分为甘露醇组(甘露醇1g.kg-1.d-1)、β-七叶皂苷钠组(β-七叶皂苷钠20mg.d-1)和联合治疗组(甘露醇+β-七叶皂苷钠),各组7d为1个疗程,重者用药7~10d。结果:甘露醇组有效率(80%)与β-七叶皂苷钠组(75%)相似(P>0.05),均显著低于联合治疗组的91%(P<0.05)。结论:β-七叶皂苷钠治疗脑转移瘤引起的脑水肿有效,与甘露醇合用疗效更佳。     

Sulphate conjugation enhances reversible binding of drug to human serum albumin

Abstract— Reversible binding of model compounds, their conjugated metabolites (sulphates and glucuronides), and also derivatives of the compounds, to human serum albumin (HSA) has been examined using an ultrafiltration method. p-Nitrophenol (P-NP), α-naphthol (α-NA) and β-naphthol (β-NA) were used as model compounds. Reversible binding of 500 μm p-NP sulphate to 4% HSA (96·6 ± 0·35%, mean ± s.d. n = 3) was significantly higher (P < 0·001), whereas reversible binding of p-NP glucuronide to 4% HSA (33·3 ± 9·82%) was much lower (P < 0·001) than that of 500 μm p-NP (90·9 ± 0·60%). Reversible binding of 500 μm p-NP glucopyranoside to 4% HSA (25·8 ±2·82%) was comparable with that of the glucuronide, with which it is structurally similar. In contrast, reversible binding of 500 μm p-NP phosphate, an anionic compound like p-NP sulphate, to 4% HSA (61·4 ± 5·28%) was significantly lower than that of p-NP (P < 0·001). Similar results were observed in reversible binding of sulphates of α-NA and β-NA. Significant differences of dissociation constants for HSA binding were observed between the parent compound (α- or β-NA) and its sulphate conjugate (P < 0·005 for α-NA and α-NA sulphate, P < 0·001 for β-NA and β-NA sulphate), but the number of binding sites was the same. These results indicated that sulphate conjugation enhances reversible binding of a parent compound to HSA by increasing the binding affinity of the parent compound to HSA. This enhancement appeared to be advantageous for preventing random distribution of this metabolite to organs in the body.     

Aluminum trichloride impairs bone and downregulates Wnt/β-catenin signaling pathway in young growing rats

Aluminum (Al) can accumulate in bone and cause bone diseases. Few studies have investigated molecular mechanism of Al-induced bone diseases. Thus, in this study, rats were orally exposed to 0 (control group) and 0.4 g/L aluminum trichloride (AlCl₃) (treatment group) for 30, 60, 90 or 120 days, respectively. The Al content of femora and serum, bone histological structure, bone mineral density (BMD) of the distal and proximal femoral metaphysis and Wnt/β-catenin signaling pathway (the mRNA expressions of Wnt3a, Fzd2, LRP-5, β-catenin, Tcf4, cyclin D1 and c-Myc, the protein levels of Wnt3a and β-catenin, the activities of Fzd2 and LRP-5) in rat femora were determined on day 30, 60, 90 or 120, respectively. The results showed that the Al contents of femora and serum were increased, the BMD of the distal and proximal femoral metaphysis were decreased, the femora histological structure were disrupted, the mRNA expressions of Wnt3a, Fzd2, LRP-5, β-catenin, Tcf4, cyclin D1 and c-Myc, the protein levels of Wnt3a and β-catenin, the activities of Fzd2 and LRP-5 were all decreased in the treatment group compared with the control group with time prolonged. These results indicated that AlCl₃ impaired femora by inhibiting the Wnt/β-catenin signaling pathway in young growing rats.     

Intestinal bacterial hydrolysis is indispensable to absorption of 18β-glycyrrhetic acid after oral administration of glycyrrhizin in rats

Abstract— Gnotobiote rats were prepared by infecting germ-free rats with Eubaclerium sp. strain GLH, a human intestinal bacterium capable of hydrolysing glycyrrhizin to 18β-glycyrrhetic acid. Their faeces and caecal contents showed glycyrrhizin-hydrolysing activities (31·7 and 31·3 pmol min^?1 (mg protein)^?1, respectively) similar to those (81·0 and 39·9 pmol min^?1 (mg protein)^?1, respectively) of conventional rats, although there was no detectable activity in germ-free rats. When glycyrrhizin (100 mg kg^?1) was orally administered to conventional, germ-free and gnotobiote rats, no glycyrrhizin could be detected in plasma 4 or 17 h after the administration, using EIA and HPLC assays. Plasma 18β-glycyrrhetic acid was not detected 4 or 17 h after the administration of glycyrrhizin to germ-free rats nor could this compound be detected in caecal contents or in the faeces. However, 18β-glycyrrhetic acid (0·6–2·6 nmol mL^?1) was detected in plasma of the conventional and the gnotobiote rats 4 and 17 h after the administration, and the caecal contents after 4 h and the cumulative faeces up to 17 h of the conventional and the gnotobiote rats contained considerable amounts of 18β-glycyrrhetic acid. These findings indicate that orally administered glycyrrhizin is poorly absorbed from the gut, but is hydrolysed to 18β-glycyrrhetic acid by intestinal bacteria such as E. sp. strain GLH, and the resulting 18β-glycyrrhetic acid is absorbed.     

蛇床子素对体外培养骨髓基质干细胞增殖与成骨性分化的影响

目的研究蛇床子素对体外培养大鼠骨髓基质干细胞(bone marrow stromal stem cells,BMSCs)增殖与成骨性分化的影响。方法取大鼠股骨及胫骨全骨髓,利用全骨髓培养法培养单核层细胞,培养于含10%FBS的DMEM-F12培养液中,3d后首次换液,9d后传代培养。培养基中蛇床子素终浓度分别为1×10-4、1×10-5、1×10-6、1×10-7mol·L-1。增殖分析采用MTT法,于成骨性诱导培养d4、8、12、16测碱性磷酸酶(alkaline phosphatase,ALP)活性、钙盐沉积量、骨钙素分泌量,d15进行钙化结节组织化学染色及计数。成骨性诱导后不同时间点提取Total RNA,RTReal-Time PCR法检测bFGF、IGF-1、Osterix与Runx-2的基因表达情况。结果蛇床子素剂量依赖性抑制BMSCs增殖,但能明显促进其向成骨性分化,表现为提高BMSCs的ALP活性、促进骨钙素分泌、钙盐沉积量、增加钙化结节数量、提高bFGF、IGF-1、Osterix和Runx-2的mRNA表达水平。结论终浓度为1×10-5mol·L-1蛇床子素能明显促进BMSCs的成骨性分化,证明蛇床子素是中药蛇床子抗骨质疏松的有效成分。     

8-异戊烯基柑橘素促进体外骨髓基质干细胞成骨性分化的研究

目的研究8-异戊烯基柑橘素对体外培养大鼠骨髓基质干细胞(bone marrow stromal cells,BMSCs)的增殖与成骨性分化的影响。方法取大鼠股骨及胫骨全骨髓,利用全骨髓培养法培养于含体积分数为10%FBS的DMEM-F12培养液中。以碱性磷酸酶(alkaline phosphatase,ALP)为指标,96孔板梯度筛选作用最佳浓度。增殖分析采用MTT法。以1×10-6 mol.L-1的最佳浓度作用并成骨性诱导(1×10-7mmol.L-1地塞米松、10 mmol.L-1β-甘油磷酸钠和50 mg.L-1抗坏血酸)培养的d 4、8、12、16测ALP活性、钙盐沉积量,d 16进行ALP和钙化结节组织化学染色及计数。成骨性诱导后不同时间点提取Total RNA,RT Real-Time PCR法检测bFGF、IGF-1、Osterix、Runx-2、BMP-2及COL-Ⅰ的基因表达情况。结果 8-异戊烯基柑橘素不能促进BMSCs增殖,但8-异戊烯基柑橘素在1×10-6 mol.L-1时能促进其向成骨性分化,表现为提高BMSCs的ALP活性、促进钙盐沉积、增加钙化结节数量、提高bFGF、IGF-1、Osterix、Runx-2、BMP-2及COL-Ⅰ的mRNA表达水平。结论 8-异戊烯基柑橘素可诱导骨髓间充质干细胞向成骨细胞分化,作为促进骨修复和抗骨质疏松的有效成分具有较大的药用价值。     

虎杖苷对LPS作用下心肌细胞β-肾上腺素能受体的调节作用

目的　探讨LPS对心肌细胞 β肾上腺素能受体 (β AR)功能的影响以及虎杖苷 (PD)的防治效果。方法　体外培养心肌细胞 ,利用放射配体竞争结合法检测 β AR数量和亲和力 ,同时应用流式细胞术检测 β AR数量。 结果　正常心肌细胞膜上的 β AR最大结合容量 (Bmax)为 (4 14± 1 4 1)fmol·1× 10 5cells-1,解离常数Kd 值为 (4 0 2± 0 5 9)nmol·L-1;LPS刺激后 ,受体Bmax减小为 1 78± 0 12fmol·(1×10 5cells) -1,亲和力下降为 (2 3 88± 2 34)nmol·L-1;当用PD处理后 ,最大结合容量和亲和常数都恢复至接近正常 ,分别为 (3 37± 0 36 )fmol·(1× 10 5cells) -1和 (3 4 4± 0 4 4 )nmol·L-1;单纯用PD处理细胞Bmax和Kd 都与正常组差异无显著性 ,分别为 (2 76± 0 32 )fmol· 1× 10 5cells) -1和(4 6 3± 1 5 4 )nmol·L-1。流式细胞术检测 β AR数量变化与放射配体结合法检测结果一致。结论　LPS可直接引起心肌细胞β AR数量下调、亲和力降低 ,虎杖苷可调节 β AR的功能 ,使其维持正常水平。     

大麻素受体2激动剂AM1241对TGF-β1诱导的HSC-T6增殖、活化及凋亡的影响

目的 探究大麻素受体2激动剂AM1241对转化生长因子（TGF）-β1诱导的大鼠肝星状细胞（HSC-T6）增 殖、活化与凋亡的影响及其作用机制。方法 体外培养HSC-T6,采用CCK-8法检测AM1241对空白对照组（空白培 养基）、阴性对照组（未加药品）、TGF-β1 组（5 μg/L TGF-β1）及 20、40、80、160 μmol/L AM1241 组（5 μg/L TGF-β1+ 20、40、80、160 μmol/L AM1241）HSC-T6增殖的影响,计算半数抑制浓度（IC50）。采用流式细胞术检测阴性对照组、 TGF-β1组、30 μmol/L AM1241组、60 μmol/L AM1241组HSC-T6凋亡情况;采用Western blot检测阴性对照组、TGF- β1 组、27 μmol/L AM1241 组 α-平滑肌肌动蛋白（α-SMA）、碱性成纤维细胞生长因子（bFGF）、凋亡相关蛋白 Bax、 cleaved caspase-3、JNK及磷酸化c-Jun氨基末端激酶（p-JNK）蛋白表达水平。结果 与TGF-β1组比较,AM1241可 抑制HSC-T6增殖能力,且呈剂量依赖性（P＜0.05）。AM1241的IC50为27 μmol/L。30、60 μmol/L AM1241组HSC-T6 凋亡率较TGF-β1组明显上升,且60 μmol/L AM1241组高于30 μmol/L AM1241组（P＜0.05）。27 μmol/L AM1241组 α-SMA 和 bFGF 蛋白表达水平较 TGF-β1 组降低,Bax、cleaved caspase-3、p-JNK 蛋白表达水平较 TGF-β1 组升高 （P＜0.05）。结论 大麻素受体2激动剂AM1241能抑制TGF-β1诱导的HSC-T6的增殖与活化,并促进其凋亡,其作 用机制可能与JNK通路有关。     

知母皂苷对Aβ_(25-35)引起的巨噬细胞炎症介质释放的抑制作用及信号转导机制

目的观察知母皂苷(SAaB)是否能对抗淀粉样β蛋白片段25-35(Aβ25-35)引起的巨噬细胞炎症介质释放并探讨其信号转导通路的影响。方法小鼠腹腔巨噬细胞培养24 h,加入不同浓度SAaB(10、30和100μmol·L-1)或加入不同的阻断剂(诱导性一氧化氮合酶阻断剂SMT、MEK1的特异性阻断剂PD98059、p38MAPK特异性阻断剂SB203580和PI3K特异性阻断剂LY294002),之后加入Aβ25-35(20μmol·L-1)继续培养。Aβ25-35作用2 h后,采用Westernblot观察巨噬细胞磷酸化Akt/PKB蛋白表达水平的改变。Aβ25-35作用48 h后,取巨噬细胞培养上清液分别测定肿瘤坏死因子-α(TNF-α)和一氧化氮(NO)的含量变化。结果 PD98059和LY294002均可明显抑制Aβ25-35引起的巨噬细胞TNF-α产生增加和磷酸化Akt/PKB表达明显增加。SMT可完全对抗Aβ25-35引起的NO释放增加。SAaB可明显抑制Aβ25-35引起的TNF-a和NO的产生增加,并呈明显的浓度依赖性。SAaB也可明显抑制Aβ25-35引起磷酸化Akt/PKB表达增加。结论 SAaB能够明显的抑制Aβ25-35引起的巨噬细胞炎症因子释放,这种抑制作用部分通过SAaB抑制Akt/PKB信号转导通路产生。