姜黄素衍生物减缓大鼠糖尿病周围神经病变进展的作用及其机制研究

摘要 目的：探讨姜黄素衍生物减缓大鼠糖尿病周围神经病变（DPN）进展的作用及其机制。方法：30只健康成年雄性SD大鼠随机分为3组，每组10只；构建链脲佐菌素（STZ）诱导的DPN大鼠模型；研究组1按10 mg/kg体重喂养10 μM的姜黄素衍生物；研究组2按10 mg/kg体重喂养100 μM的姜黄素衍生物；对照组喂养同等量的生理盐水。利用Von Frey电子测痛仪检测各组大鼠痛觉机械戒断阈值（MWT）。采用实时定量聚合酶链反应（qRT-PCR）和蛋白免疫印迹试验检测AMPK、mTOR mRNA和蛋白表达水平。最后测定活化剂AICAR处理的RSC96细胞中mTOR的表达水平。结果：喂养姜黄素衍生物大鼠的痛觉机械戒断阈值（MWT）随时间推移逐渐降低，与对照组相比，研究组1大鼠的MWT显著降低，而研究组2大鼠的MWT也显著低于研究组1，差异均有统计学意义（P＜0.05）。与对照组相比，研究组1的AMPK mRNA和蛋白表达水平显著升高，mTOR mRNA和蛋白表达水平表达显著降低（P＜0.05）；而研究组2的AMPK mRNA和蛋白表达水平显著高于研究组1，mTOR mRNA和蛋白表达水平显著低于研究组1，差异均有统计学意义（P＜0.05）。使用活化剂AICAR处理RSC96细胞后，活化剂AICAR组的mTOR mRNA和mTOR蛋白表达水平明显低于非活化剂组，差异有统计学意义（P＜0.05）。结论：姜黄素衍生物可能通过AMPK调节mTOR信号通路改善DPN，其可能具有潜在的治疗DPN的能力。     

丁酸钠通过调节SIRT1/AMPK信号通路对慢性肾衰竭大鼠肾功能的影响

摘要 目的：探讨丁酸钠（NaB）通过调节沉默信息调节因子1（SIRT1）/单磷酸腺苷活化蛋白激酶（AMPK）信号通路对慢性肾衰竭（CRF）大鼠肾功能的影响。方法：选用SD大鼠72只,随机分为6组（12只/组）：control组、Model组、NaB低剂量组（100 mg/kg）、NaB中剂量组（200 mg/kg）、NaB高剂量组（400 mg/kg）、抑制剂组（400 mg/kg NaB+2 mg/kg SIRT1/AMPK通路抑制剂EX527）;采用饲喂0.5%腺嘌呤饲料以建立CRF大鼠模型,建模成功后,灌胃和腹腔注射相应药物。使用试剂盒检测大鼠24 h尿蛋白（24 h U-pro）、血清肌酐（SCr）、尿素氮（BUN）水平;采用苏木精-伊红（HE）及Masson染色法观察肾脏病理改变,并计算胶原容积分数（CVF）;采用茜素红染色法与主动脉钙含量测定评估主动脉钙化情况;采用酶联免疫吸附法（ELISA）检测各组大鼠肾脏组织白细胞介素（IL）-6、IL-β、肿瘤坏死因子（TNF）-α水平;采用过氧化氢酶（CAT）、丙二醛（MDA）、活性氧（ROS）检测试剂盒检测大鼠肾脏组织中CAT、MDA、ROS水平;采用蛋白免疫印迹法（WB）检测各组大鼠SIRT1/AMPK信号通路及骨形态发生蛋白2（BMP2）、Runt相关转录因子2（Runx2）蛋白的表达。结果：与control组比较,Model组大鼠肾脏组织损伤严重、胶原纤维沉积显著、主动脉钙化严重,CAT活性、SIRT1、p-AMPK/AMPK表达水平显著降低（P<0.05）,CVF、主动脉钙含量和SCr、BUN、24 h U-pro、IL-6、IL-β、TNF-α、MDA、ROS水平及BMP2、Runx2蛋白表达水平显著升高（P<0.05）;与Model组比较,NaB低、中、高剂量组大鼠肾脏组织损伤减轻、胶原纤维沉积面积明显减少、主动脉钙化程度减轻,CVF、主动脉钙含量和SCr、BUN、24 h U-pro、IL-6、IL-β、TNF-α、MDA、ROS水平及BMP2、Runx2蛋白表达水平显著降低（P<0.05）,CAT活性、SIRT1、p-AMPK/AMPK表达水平显著升高（P<0.05）;SIRT1/AMPK通路抑制剂EX527可降低高剂量NaB对CRF大鼠主动脉钙化和肾功能的改善作用（P<0.05）。结论：NaB可能通过激活SIRT1/AMPK信号通路,减轻肾脏组织炎症、氧化应激损伤、主动脉钙化和肾纤维化,从而起到改善CRF大鼠肾功能的作用。     

AMPK调控内质网应激抵抗COPD大鼠肺泡上皮细胞凋亡的实验研究

目的:初步探讨AMPK在内质网应激所致COPD大鼠肺泡上皮细胞凋亡中所起的作用及机制。方法:实验分三组:对照组,COPD模型组,AICAR干预组,以香烟烟雾烟熏加气管内滴注脂多糖方法构建COPD大鼠模型,取大鼠肺组织行HE染色病理观察,免疫组化,western blot检测p-AMPK/AMPK,ORP150,caspase-3及CHOP表达,TUNEL法检测各组凋亡情况。结果:病理HE染色提示模型组大量炎症细胞浸润,肺大疱形成,支气管壁发生狭窄;AICAR干预组炎症细胞较模型组减少。与正常对照组相比,免疫组化及western blot均提示模型组中p-AMPK和ORP150蛋白表达含量增强,差异有统计学意义(P0.05)。而AICAR干预组中p-AMPK/AMPK及ORP150蛋白表达较模型组明显上升,差异有统计学意义(P0.05)。内质网应激相关凋亡指标CHOP及caspase-3的表达在模型组明显增强,较正常组比较差异有显著性(P0.05),而AICAR组中凋亡指标较模型组明显下调。结论:AMPK可以保护肺泡上皮细胞免于香烟烟雾所致内质网应激凋亡,且有可能通过增加ORP150来实现其保护作用。     

银杏叶提取物对COPD大鼠p38MAPK/NF-κB信号通路的影响

摘要 目的：观察银杏叶提取物（Ginkgo biloba extract, GBE）对慢性阻塞性肺疾病( COPD) 大鼠肺p38丝裂原活化蛋白激酶（MAPK）/ 核转录因子-κB（NF-κB）信号通路的影响,探讨GBE对COPD抗炎作用的分子机制。方法：将90只雄性Wistar 大鼠随机分为空白对照组、COPD 模型组、GBE高剂量组、GBE中剂量组、GBE低剂量组、SB203580(p38MAPK抑制剂)组,共计6组,每组15只。采用香烟烟雾熏吸联合气道内注入脂多糖（LPS）的方法建立COPD大鼠模型。造模结束后分组给药,空白对照组与COPD 模型组给予生理盐水腹腔注射,GBE高、中、低剂量组 (14, 7, 3.5 mg?kg^-1?d^-1)分别给予不同浓度的GBE腹腔注射,SB203580组予5 mg?kg^-1?d^-1腹腔注射,每天给药1次,连续给药14 d。通过HE染色法观察大鼠肺泡和气道的病理变化,酶联免疫吸附法（ELISA）测定大鼠肺泡灌洗液（BALF）和血清中IL-6、IL-8与IL-10水平,蛋白免疫印迹法(Western blot) 检测大鼠肺组织p38MAPK、NF-κB p65、NF-κB抑制蛋白α（IκBα）蛋白含量,采取实时荧光定量聚合酶链式反应(Real-time qPCR) 法检测大鼠肺组织中p38MAPK、NF-κB p65、IκBα mRNA表达。结果：与COPD模型组相比,各用药组均能抑制肺泡破坏与气道重塑,减轻肺泡与支气管周围炎症浸润;与空白对照组相比,COPD 模型组BALF与血清中IL-6、IL-8含量明显升高（P<0.05）,IL-10含量明显降低（P<0.05）,肺组织中p38MAPK、NF-κB p65蛋白与p38MAPK、NF-κB p65 mRNA表达量明显升高（P<0.05）,IκBα蛋白与IκBα mRNA表达量明显下降（P<0.05）;与COPD模型组相比,各药物组均能明显降低大鼠BALF与血清中IL-8含量、提高IL-10含量（P<0.05）,而GBE高剂量组与SB203580组效果更明显;GBE高剂量组与SB203580组BALF中IL-6含量较GBE低剂量组与COPD模型组明显降低（P<0.05）;与COPD模型组相比,各药物组均能明显降低大鼠肺组织中p38MAPK、NF-κB p65蛋白与p38MAPK、NF-κB p65 mRNA表达量（P<0.05）,GBE高、中剂量组与SB203580组能明显提高IκBα蛋白与IκBα mRNA表达量（P<0.05）。结论：GBE能抑制COPD大鼠炎症反应与气道重塑,其机制可能与调控p38MAPK/NF-κB信号通路有关。     

红景天苷调节AMPK/mTOR/ULK1信号通路对结肠癌SW480细胞裸鼠的肝脏损伤的影响

摘要 目的：探讨红景天苷（Sal）调节单磷酸腺苷活化蛋白激酶（AMPK）/哺乳动物雷帕霉素靶蛋白（mTOR）/Unc51样激酶1（ULK1）信号通路对结肠癌SW480细胞裸鼠肝脏损伤的影响。方法：通过皮下注射SW480细胞悬浮液建立肝转移裸鼠模型,将造模后的裸鼠随机分为模型组、Sal低剂量（Sal-L,50 mg/kg Sal）组、Sal中剂量（Sal-M,100 mg/kg Sal）组、Sal高剂量（Sal-H,200 mg/kg Sal）组,Sal-H+AMPK抑制剂（Compound C,200 mg/kg Sal+10 mg/kg Compound C）组,以未接种SW480细胞悬液的裸鼠作为对照组。腹部主动脉取血,检测裸鼠血清中丙氨酸氨基转移酶（AST）、天冬氨酸氨基转移酶（ALT）水平;处死裸鼠,检测肝转移瘤数目及肝脏重量;HE染色观察肝脏组织病理变化;qRT-PCR检测肝脏组织中AMPK、mTOR、ULK1 mRNA表达水平;Western blot检测肝脏组织中自噬（Beclin1、p62）蛋白及通路相关蛋白表达。结果：与对照组相比,模型组裸鼠组织中出现肝转移瘤,肝脏重量、AST、ALT水平、mTORmRNA、ULK1 mRNA、p62表达显著增加（P<0.05）;Beclin1、AMPK mRNA及蛋白表达显著降低（P<0.05）;与模型组相比,Sal-L、Sal-M、Sal-H组肝转移瘤数目、肝脏重量、AST、ALT水平、mTORmRNA、ULK1 mRNA、p62表达显著降低（P<0.05）;Beclin1、AMPK mRNA及蛋白表达显著增加（P<0.05）;与Sal-H组相比,Sal-H+Compound C组肝转移瘤数目、肝脏重量、AST、ALT水平、mTORmRNA、ULK1 mRNA、p62表达显著增加（P<0.05）;Beclin1、AMPK mRNA及蛋白表达显著降低（P<0.05）。结论：Sal可通过减少裸鼠肝转移瘤形成,保护裸鼠肝脏,其机制可能与激活AMPK/mTOR/ULK1信号通路,促进肝脏自噬有关。     

槲皮素调节AMPK/SIRT1/NF-κB通路对乙型肝炎大鼠肝组织损伤的影响

摘要 目的：探究槲皮素调节AMPK/SIRT1/NF-κB通路对乙型肝炎（HB）大鼠肝组织损伤的影响。方法：采用随机数字表法将65只Wistar大鼠分为Ctrl组、HB组、槲皮素低剂量组（槲皮素L组,50 mg/kg）、槲皮素高剂量组（槲皮素H组,200 mg/kg）及槲皮素H+AMPK抑制剂组（200 mg/kg槲皮素+10 mg/kg Compound C）,每组各13只,采用尾静脉注射携带1.3拷贝HBV基因组的重组8型腺相关病毒（rAAV8-1.3HBV）法建立HB大鼠模型（Ctrl组除外）;酶联免疫吸附实验（Elisa）检测血清中HB表面抗原（HBsAg）、HB e抗原（HBeAg）、肝功能指标[谷丙转氨酶（ALT）、谷草转氨酶（AST）、总胆红素（TBIL）]水平及肝组织中炎性因子[白介素-1β（IL-1β）、肿瘤坏死因子α（TNF-α）]水平;实时荧光定量PCR（qRT-PCR）检测血清中HBV-DNA水平;苏木素-伊红（HE）染色、曼森氏（Masson）染色观察肝组织病理改变;免疫印迹法（WB）检测肝组织中AMPK/SIRT1/NF-κB通路蛋白表达水平。结果：与Ctrl组比较,HB组血清中HBsAg、HBeAg、HBV-DNA、ALT、AST、TBIL水平均升高（P<0.05）;肝组织可见肝静脉扩张、充血,肝细胞排列紊乱、水肿、坏死,同时发生明显纤维化;肝组织中AMPK磷酸化、SIRT1蛋白水平均降低,IL-1β、TNF-α水平及核NF-κB蛋白水平均升高;经槲皮素L、槲皮素H干预后上述情况均得到改善,且槲皮素H干预改善更明显（P<0.05）;而增加AMPK抑制剂干预后,槲皮素H干预的改善作用被削弱（P<0.05）。结论：槲皮素能够减轻HB大鼠肝组织损伤,保护其肝功能,其机制可能与调节AMPK/SIRT1/NF-κB通路有关。     

miR-22-3p通过激活PTEN/PI3K/AKT/NF-κB信号通路加重慢性阻塞性肺疾病

摘要 目的：探索miR-22-3p对慢性阻塞性肺疾病（COPD）的影响及作用机制。方法：将7周龄（体重250~280 g）雄性SD大鼠随机分为5组（n=12）：对照组（Con组）、COPD组、COPD+NC-agomir组、COPD+miR-22-3p-agomir组、COPD+NC-antagomir组和COPD+miR-22-3p-antagomir组。Con组大鼠为正常饲养的大鼠,其他组大鼠均通过香烟烟雾（CS）和脂多糖（LPS）诱导COPD动物模型。在CS暴露当天,Con组和COPD组大鼠鼻腔内注射50 μL生理盐水,COPD+NC-agomir组、COPD+miR-22-3p-agomir组、COPD+NC-antagomir组和COPD+miR-22-3p-antagomir组大鼠分别鼻腔内注射50 μL 10 nmoL的NC-agomir、miR-22-3p-agomir、NC-antagomir和miR-22-3p-antagomir,每2周注射1次,共注射6次。CS暴露90 d后,检测各组大鼠的最大自主分钟通气量（MVV）、0.3 s用力呼气量（FEV0.3）、用力肺活量（FVC）和最大呼气峰流速（PEF）。通过ELISA法测定支气管肺泡灌洗液（BALF）中白细胞介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）和巨噬细胞炎性蛋白-2（MIP-2）水平。通过苏木精-伊红（HE）染色评价肺组织损伤。根据试剂盒说明检测肺组织丙二醛（MDA）和超氧化物歧化酶（SOD）水平。通过RT-PCR检测肺组织miR-22-3p、磷酸酶与张力蛋白同源物（PTEN）、诱导型一氧化氮合酶（iNOS）、CD86、CD206和精氨酸酶1（ARG1）mRNA水平。通过Western blot检测肺组织PTEN、磷脂酰肌醇3-激酶（PI3K）、p-PI3K、蛋白激酶B（AKT）、p-AKT、核因子-κB（NF-κB） p65和p-NF-κB p65的蛋白表达水平。结果：与COPD组和COPD+NC-antagomir组相比,COPD+miR-22-3p-antagomir组大鼠的MVV、FEV0.3/FVC和PEF均升高（P<0.05）;肺泡出血、肺泡壁断裂、肺泡间隔水肿和炎性细胞浸润等病变减轻;BALF中的IL-1β、TNF-α和MIP-2水平均降低（P<0.05）;肺组织SOD水平升高,MDA水平降低（P<0.05）;肺组织iNOS和CD86 mRNA相对表达量降低,CD206和ARG1 mRNA相对表达量升高（P<0.05）;肺组织miR-22-3p相对表达量降低,PTEN mRNA和蛋白相对表达量升高（P<0.05）;肺组织p-PI3K/PI3K、p-AKT/AKT和p-NF-κB p65/NF-κB p65的蛋白相对表达量降低（P<0.05）。结论：miR-22-3p在COPD大鼠肺组织中上调,可能通过激活PTEN/PI3K/AKT/NF-κB信号通路,促进肺组织炎症反应和氧化应激,加重大鼠肺功能障碍和肺组织结构损伤。     

宣肺方对内毒素诱导大鼠急性肺损伤mTOR/S6K1信号通路的影响

目的观察宣肺方对内毒素诱导大鼠急性肺损伤mTOR/S6K1信号通路的影响,并探讨其作用机制。方法选取Wistar雄性大鼠30只,动物随机分为正常组、模型组、地塞米松组和宣肺方组(高、低剂量组),尾静脉注射LPS制备ALI模型。采用ELISA法测定支气管肺泡灌洗液(BALF)中炎症因子TNF-α、IL-1β和IL-6含量,免疫组化测mTOR蛋白表达,Western blot测肺组织p-mTOR蛋白表达,RT-PCR测肺泡灌洗液巨噬细胞RPS6KB1基因表达,并观察大鼠肺组织病理变化。结果与正常组比较,模型组TNF-α、IL-1β、IL-6、RPS6KB1均显著升高(P0.05),mTOR蛋白阳性面积率、p-mTOR蛋白表达显著降低(P0.01,P0.05);与模型组比较,地塞米松组TNF-α、IL-1β、IL-6均明显降低(P0.05);宣肺方高剂量组TNF-α、IL-6、RPS6KB1基因表达明显降低(P0.01,P0.05),mTOR蛋白阳性面积率、p-mTOR蛋白表达显著升高(P0.01,P0.05),宣肺方低剂量组TNF-α含量明显降低(P0.01)。HE染色示模型组肺组织内可见局部肺出血、坏死,肺小静脉扩张、血管内白细胞数显著增多,肺间质水肿、炎细胞浸润;与模型组比较,各治疗组呈轻度间质性肺炎。结论宣肺方对内毒素诱导大鼠急性肺损伤有保护作用,其机制可能与其能够下调TNF-α、IL-6含量、RPS6KB1基因表达和上调mTOR、p-mTOR蛋白表达有关。     

保护素DX对类风湿关节炎大鼠模型中PI3K/AKT/mTOR信号通路的影响

摘要 目的：研究保护素DX（PDX）对类风湿关节炎（RA）大鼠模型的治疗作用及机制,及其对PI3K/AKT/mTOR信号通路的影响。方法：通过皮下注射牛Ⅱ型胶原与弗氏完全佐剂诱导RA大鼠模型,建模后将SD大鼠随机分为4组：对照组（n=12）：正常SD大鼠;RA组（n=12）：RA模型大鼠;低剂量PDX处理组（n=12,L-PDX组）：接受10 μg/kg/d PDX治疗的RA模型大鼠;高剂量PDX处理组（n=12,H-PDX）：接受20 μg/kg/d PDX治疗的RA模型大鼠。各组大鼠治疗4周后,采用ELISA法检测血清中IgA、IgG、IgM、TNF-α、IFN-γ、IL-4和IL-10的水平。通过苏木精伊红（HE）染色评价大鼠踝关节病变。通过免疫组化染色或Western blot检测滑膜组织中PI3K、p-PI3K、AKT、p-AKT、mTOR、p-mTOR、Bcl-2、Bax、LC3-I、LC3-II和Becline-1的表达。结果：与RA组相比,L-PDX组和H-PDX组的关节炎指数（AI）评分均显著降低（P<0.05）,炎性细胞浸润、软骨破坏程度及滑膜上皮细胞增生减轻。与RA组相比,L-PDX组和H-PDX组的血清IgA、IgG和IgM含量均降低（P<0.05）。与RA组相比,L-PDX组和H-PDX组的血清TNF-α和IFN-γ水平均降低,IL-4和IL-10水平均升高（P<0.05）。与RA组相比,L-PDX组和H-PDX组大鼠踝关节滑膜组织中的p-PI3K/PI3K、p-AKT/AKT、p-mTOR/mTOR和Bcl-2的蛋白相对表达量均降低,而Bax、LC3-II/LC3-I和Becline-1的蛋白相对表达量均升高（P<0.05）。结论：本研究表明PDX可有效减轻RA大鼠症状,其机制与调节B淋巴细胞活化和体液免疫、纠正Th1/Th2失衡、抑制PI3K/Akt/mTOR信号通路有关。     

木犀草素调节SIRT3/AMPK/mTOR信号通路对溃疡性结肠炎小鼠Th17/Treg免疫平衡的影响CSCD

探究木犀草素对溃疡性结肠炎(ulcerative colitis,UC)小鼠模型中辅助性T细胞17(Th17)/调节性T细胞(Treg)免疫平衡的影响,并分析其潜在机制。60只BALB/c雄性小鼠随机分为正常组、模型组、阳性对照组、木犀草素组、木犀草素+3-TYP组,每组12只。采用葡聚糖硫酸钠(DSS)诱导建立UC模型,观察并记录小鼠体重变化、大便稠度和大便潜血情况,计算疾病活动指数(DAI);HE染色观察结肠组织病理学变化;流式细胞术检测脾脏Th17、Treg细胞比例,计算Th17/Treg比值;ELISA检测结肠组织中IL-6、IL-10、IL-17和IL-23含量;RT-qPCR检测结肠组织RORγt和Foxp3的mRNA表达;Western blot检测结肠组织SIRT3、AMPK、p-AMPK、mTOR、p-mTOR蛋白表达。与正常组相比,模型组小鼠DAI评分、组织病理学评分、脾脏Th17/Treg比值、结肠组织IL-6、IL-17、IL-23、RORγt mRNA水平和p-mTOR/mTOR比值升高,IL-10、Foxp3 mRNA和SIRT3蛋白水平以及p-AMPK/AMPK比值降低(P<0.05)。经药物干预后,小鼠DAI评分、组织病理学评分、脾脏Th17/Treg比值、结肠组织IL-6、IL-17、IL-23、RORγt mRNA水平和p-mTOR/mTOR比值降低,IL-10、Foxp3 mRNA和SIRT3蛋白水平以及p-AMPK/AMPK比值升高(P<0.05);3-TYP可减弱木犀草素对UC小鼠Th17/Treg细胞分化平衡的影响(P<0.05)。木犀草素可改善DSS诱导的UC小鼠模型中Th17/Treg失衡,其机制可能与激活SIRT3/AMPK/mTOR通路有关。     

ATP/ADP exchange activity of gastric (H+ + K+)-ATPase

The ATP/ADP exchange is shown to be a partial reaction of the $\text{(}\text{H}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ by the absence of measurable nucleoside diphosphokinase activity and the insensitivity of the reaction to $\text{P}{}^1$, $\text{P}{}^5$ -di(adenosine-5′) pentaphosphate, a myokinase inhibitor. The exchange demonstrates an absolute requirement for Mg²⁺ and is optimal at an ADP/ATP ratio of 2. The high ATP concentration ($\text{K}{}_{0.5}\text{= 116 μ}\text{M}$) required for maximal exchange is interpreted as evidence for the involvement of a low affinity form of nucleotide site. The ATP/ADP exchange is regarded as evidence for an ADP-sensitive form of the phosphoenzyme. In native enzyme, pre-steady state kinetics show that the formation of the phosphoenzyme is partially sensitive to ADP while modification of the enzyme by pretreatment with 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) in the absence of Mg²⁺ results in a steady-state phosphoenzyme population, a component of which is ADP sensitive. The ATP/ADP exchange reaction can be either stimulated or inhibited by the presence of K⁺ as a function of pH and Mg²⁺.     

Characterization of cytochrome P-450SCC-containing liposomes

Purified cytochrome $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ from bovine adrenocortical mitochondria was incorporated into liposomes by the cholate-dilution method utilizing either dialysis or Sephadex gel filtration. Among synthetic phospholipids tested, dioleoylglycerophosphocholine showed the best stability during the incorporation of $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ into liposomes. A maximum amount of heme was incorporated into liposomes at a molar ratio of phospholipid to the cytochrome of approx. 200. When $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was incorporated into the dioleoylglycerophosphocholine liposomes by the cholate-filtration method, the $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}\text{-}\text{containing liposomes}$ showed two major populations on the elution pattern of the Sepharose 4B gel filtration, and were seen at a diameter of 200–600 Å and its aggregated forms. When the cytochrome was incorporated into dioleoylglycerophosphocholine liposomes or cholesterol-free adrenocortical mitochondrial liposomes, $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was less stable than $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ in aqueous solution. Cholesterol or adrenodoxin markedly stabilized the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. Liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ required cholesterol for its optimum reduction with adrenodoxin, adrenodoxin reductase, and NADPH in the presence of CO. About 70% of the total heme in the dioleoylglycerophosphocholine liposomes was reduced by the enzymatic reduction in the presence of cholesterol, indicating that 70% of the total molecules are exposed to the surface of the outer monolayer. In order to see the location of the heme in membrane, the dioleoylglycerophosphocholine-liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was subjected to $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ treatment. This reagent destroyed the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. These results suggest that the heme is located in the proximity of the $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ reacting sites which are exposed to the surface, or located on the vincinity of polar heads of the membrane.     

AutoFACT: AnAutomaticFunctionalAnnotation andClassificationTool

Background  

Assignment of function to new molecular sequence data is an essential step in genomics projects. The usual process involves similarity searches of a given sequence against one or more databases, an arduous process for large datasets.     

Ligand-dependent reactivity of (Na+ + K+)-ATPase with showdomycin

Showdomycin inhibited pig brain ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ with pseudo first-order kinetics. The rate of inhibition by showdomycin was examined in the presence of 16 combinations of four ligands, i.e., Na⁺, K⁺, Mg²⁺ and ATP, and was found to depend on the ligands added. Combinations of ligands were divided into five groups in terms of the magnitude of the rate constant; in the order of decreasing rate constants these were: (1)$\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$, (2) $\text{Mg}{}^{\mathrm{2+}}$, $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}$ and none, (3) $\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{,}\text{Na}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}$ and $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}$, (4) $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}\text{,}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}$ and $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}\text{, (5)}\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$ and ATP. The highest rate was obtained in the presence of Na⁺, Mg²⁺ and ATP. The apparent concentrations of Na⁺, Mg²⁺ and ATP for half-maximum stimulation of inhibition ($\text{K}{}_{0.5}{}^{\mathrm{<mtext>s</mtext>}}$) were 3 mM, 0.13 mM and 4μM, respectively. The rate was unchanged upon further increase in Na⁺ concentration from 140 to 1000 mM. The rates of inhibition could be explained on the basis of the enzyme forms present, including E₁, E₂, ES, E₁-P and E₂-P, i.e., E₂ has higher reactivity with showdomycin than E₁, while E₂-P has almost the same reactivity as E₁-P. We conclude that the reaction of ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ proceeds via at least four kinds of enzyme form (E₁, E₂, E₁ · nucleotide and EP), which all have different conformations.     

A/California/7/2009与A/California/4/2009病毒感染力比较

目的甲型H1N1流感病毒A/California/7/2009与A/California/4/2009病毒序列比较同源性在99%以上,本实验旨在比较两株病毒感染BALB/c小鼠研究感染力强弱。方法分别将A/California/7/2009（CA7）与A/California/4/2009（CA4）两株病毒分别连续10倍稀释后,对4~6周龄雌性BALB/c小鼠经乙醚麻醉后进行滴鼻攻毒,每个稀释度接种10只实验小鼠,测定CA7 MLD50为101.24/0.05 mL,检测小鼠感染、致病的多项指标,观察期为14 d。结果相同TCID50的CA7和CA4病毒感染小鼠,CA4感染小鼠后14 d内死亡率为20%,而CA7感染小鼠后8 d内死亡率为100%。CA7 106TCID50感染的小鼠病理表现为重度弥漫性间质性肺炎,CA4 106TCID50感染的小鼠病理表现为中度-重度间质性肺炎。结论在相同条件下,CA7感染力明显强于CA4。     

Characterization of partially purified (Na+ + K+)-ATPase from porcine lens

The partial purification of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ from pig lens has been achieved by treatment with deoxycholate followed by density gradient centrifugation. The specific activity of the final preparation, ranging from 300 to 500 nmol/h per mg protein, is increased approx. 100-fold compared to the homogenate. A parallel increase in $\text{p-}\text{nitrophenylphosphatase}$ activity is also observed. Sodium dodecyl sulfate (SDS) gel electrophoresis reveals six major protein bands, one of which is the 93 kDa α subunit of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ which can be phosphorylated by reaction with [γ-³²P]ATP. A second band contains a glycoprotein which displays an apparent molecular weight of 51 000 and thus appears to be the β subunit of the enzyme. The enzyme is sensitive to ouabain with the $\text{I}{}_{50}$ for $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ and $\text{p-}\text{nitrophenylphosphatase}$ inhibition being 1.2 and 1.3 μM, respectively. Several agents which inhibit $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ from other tissues such as oligomycin, Ca²⁺, vanadate, $\text{N-}\text{ethylmaleimide}$, $\text{p-}\text{chloromercuribenzenesulfonic acid}$ (PCMBS) and 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) also inhibit the lens enzyme. Monovalent cations other than K⁺ are partially effective in activating the ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}$)-ATPase and $\text{p-}\text{nitrophenylphosphatase}$ activities. The K⁺ congeners were relatively more effective in supporting $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ compared to $\text{p-}\text{nitrophenylphosphatase}$ activity. Other kinetic properties of the lens enzyme are also comparable to those of the enzyme from other tissues. Utilizing the partially purified membrane bound enzyme, discontinuities in Arrhenius plots of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ activity, $\text{p-}\text{nitrophenylphosphatase}$ activity and fluoresence polarization of the fluidity probe, 1,6-diphenyl-1,3,5-hexatriene (DPH), are observed near the physiological temperature of lens. The possible significance of these observations for the mechanism of cataract formation are discussed.     

An electron spin probe study of (Na+ + K+)-ATPase-Containing membranes

The modulating effect of membrane lipids on enzyme function has been described by several investigators. We have used the spin probe $\text{N-}\text{oxyl}\text{-4′,4′-}\text{dimethyloxazolidine}\text{-12-}\text{keto}$ methyl stearate (M 12-NSE) to study this interaction in ox brain membranes enriched with $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$. This methyl ester of stearic acid is practically insoluble in aqueous media, and consequently spectra of M 12-NSE-labelled preparations are free of “liquid lines”.At least two types of spectra may be obtained when ox brain microsomes are spin labelled with M 12-NSE, indicating the presence of two distinct binding sites. At one site the spin label is relatively unrestricted and gives rise to an isotropic spectrum. A second spectrum, which is obtained from spin label at another site, is similar to that which is observed after incorporation of M 12-NSE into phospholipid bilayers. This suggests that this latter site is within the core of the microsomal membrane.The two binding sites differ in their affinity for the spin probe. The low affinity site is both more abundant in crude preparations and is more easily removed by detergent treatment; spin labels at this site produce isotropic spectra. The high affinity sites are fewer in number and produce broad spectra. In addition these high affinity sites increase in concentration as the enzyme undergoes purification.The two sites are quite distinct in their sensitivity to ascorbic acid, the low affinity site showing a considerably greater rate of reduction by this agent.This study also demonstrates that the delipidation effects of sodium dodecyl sulfate and sodium deoxycholate on $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase-enriched}$ microsomes from ox brain are not identical.It is suggested that the two spin probe binding sites represent two different lipid domains, one of which is very closely associated with the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ enzyme and may reflect a protein-directed phospholipid specificity for this enzyme.     

Annular and non-annular binding sites on the (Ca2+ + Mg2+)-ATPase

Quenching of the fluorescence of the $\text{(}\text{Ca}{}^{\mathrm{2+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{)-}\text{ATPase}$ purified from muscle sarcoplasmic reticulum can be used to measure relative binding constants of hydrophobic compounds to the phospholipid-protein interface. We show that the binding constant for cholesterol is considerably less than that for phosphatidylcholine, so that cholesterol is effectively excluded from the phospholipid annulus around the ATPase. However, dibromocholestan-3β-ol causes quenching of the fluorescence of the ATPase, and so has access to other, non-annular sites. We suggest that these non-annular sites could be at protein/protein interfaces in ATPase oligomers. Oleic acid can bind at the phospholipid/protein interface, although its binding constant is less than that for a phosphatidylcholine, and it can also bind at the postulated non-annular sites. The effects of these compounds on the activity of the ATPase depend on the structure of the phospholipid present in the systems.     

Comparison of parameters estimated from A/Ci and A/Cc curve analysis

The parameters estimated from traditional A/C _i curve analysis are dependent upon some underlying assumptions that substomatal CO₂ concentration (C _i) equals the chloroplast CO₂ concentration (C _c) and the C _i value at which the A/C _i curve switches between Rubisco- and electron transport-limited portions of the curve (C _i-t) is set to a constant. However, the assumptions reduced the accuracy of parameter estimation significantly without taking the influence of C _i-t value and mesophyll conductance (g _m) on parameters into account. Based on the analysis of Larix gmelinii’s A/C _i curves, it showed the C _i-t value varied significantly, ranging from 24 Pa to 72 Pa and averaging 38 Pa. t-test demonstrated there were significant differences in parameters respectively estimated from A/C _i and A/C _c curve analysis (p<0.01). Compared with the maximum ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (V_cmax), the maximum electron transport rate (J_max) and J_max/V_cmax estimated from A/C _c curve analysis which considers the effects of g _m limit and simultaneously fits parameters with the whole A/C _c curve, mean V_cmax estimated from A/C _i curve analysis (V_cmax-C _i) was underestimated by 37.49%; mean Jmax estimated from A/C _i curve analysis (J_max-C _i) was overestimated by 17.8% and (J_max-C _i)/(V_cmax-C _i) was overestimated by 24.2%. However, there was a significant linear relationship between V_cmax estimated from A/C _i curve analysis and V_cmax estimated from A/C _c curve analysis, so was it J_max (p<0.05).     

Comparative study of Bifidobacteriumanimalis, Escherichiacoli, Lactobacilluscasei and Saccharomycesboulardii probiotic properties

The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.