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211.
Jin Seok Woo Chung-Hyun Cho Do Han Kim Eun Hui Lee 《Experimental & molecular medicine》2010,42(9):614-627
During membrane depolarization associated with skeletal excitation-contraction (EC) coupling, dihydropyridine receptor [DHPR, a L-type Ca2+ channel in the transverse (t)-tubule membrane] undergoes conformational changes that are transmitted to ryanodine receptor 1 [RyR1, an internal Ca2+-release channel in the sarcoplasmic reticulum (SR) membrane] causing Ca2+ release from the SR. Canonical-type transient receptor potential cation channel 3 (TRPC3), an extracellular Ca2+-entry channel in the t-tubule and plasma membrane, is required for full-gain of skeletal EC coupling. To examine additional role(s) for TRPC3 in skeletal muscle other than mediation of EC coupling, in the present study, we created a stable myoblast line with reduced TRPC3 expression and without α1SDHPR (MDG/TRPC3 KD myoblast) by knock-down of TRPC3 in α1SDHPR-null muscular dysgenic (MDG) myoblasts using retrovirus-delivered small interference RNAs in order to eliminate any DHPR-associated EC coupling-related events. Unlike wild-type or α1SDHPR-null MDG myoblasts, MDG/TRPC3 KD myoblasts exhibited dramatic changes in cellular morphology (e.g., unusual expansion of both cell volume and the plasma membrane, and multi-nuclei) and failed to differentiate into myotubes possibly due to increased Ca2+ content in the SR. These results suggest that TRPC3 plays an important role in the maintenance of skeletal muscle myoblasts and myotubes. 相似文献
212.
Truong LX Nguyen Chung Kwon Kim Jun-Hee Cho Kyung-Hoon Lee Jee-Yin Ahn 《Experimental & molecular medicine》2010,42(8):583-595
Neurotrophins protect neurons against excitotoxicity; however the signaling mechanisms for this protection remain to be fully elucidated. Here we report that activation of the phosphatidyl inositol 3 kinase (PI3K)/Akt pathway is critical for protection of hippocampal cells from staurosporine (STS) induced apoptosis, characterized by nuclear condensation and activation of the caspase cascade. Both nerve growth factor (NGF) and brain-derived growth factor (BDNF) prevent STS-induced apoptotic morphology and caspase-3 activity by upregulating phosphorylation of the tropomyosin receptor kinase (Trk) receptor. Inhibition of Trk receptor by K252a altered the neuroprotective effect of both NGF and BDNF whereas inhibition of the p75 neurotrophin receptor (p75NTR) had no effect. Impairment of the PI3K/Akt pathway or overexpression of dominant negative (DN)-Akt abolished the protective effect of both neurotrophins, while active Akt prevented cell death. Moreover, knockdown of Akt by si-RNA was able to block the survival effect of both NGF and BDNF. Thus, the survival action of NGF and BDNF against STS-induced neurotoxicity was mediated by the activation of PI3K/Akt signaling through the Trk receptor. 相似文献
213.
A novel sensor for acetate containing thiourea and hydrazone structure has been synthesized. The anion recognition via hydrogen-bonding interactions could be monitored by anion complexation, which induced changes in UV-vis and fluorescence spectra. In particular, the recognition process could be easily detected by the ‘naked-eye’. Further insights to the nature of interactions between receptor 1 and AcO− were obtained by 1H NMR titration experiments. 相似文献
214.
采用密度泛函B3LYP(Becke, three-parameter, Lee-Yang-Parr)和HF(Hatree-Fock)方法, 从理论上探讨了1,3-双(1-苯基-1H-四唑-5-巯基)-乙酰苯腙(DAPHZ)钳形受体对卤素阴离子的识别机理,结果发现DAPHZ受体以其钳形结构中的-N-H基团与卤素阴离子间形成双侧红移氢键进行识别. 经BSSE校正后DAPHZ•••F-, DAPHZ•••Cl-和DAPHZ•••Br-体系的分子识别相互作用能ΔECP分别为-327.5,-163.5和-148.3 kJmol-1, 说明钳形DAPHZ受体对F-具有最好的识别能力. 此外, 采用自然键轨道(NBO)计算, 相关H原子化学位移计算及分子中原子(AIM)等理论分析了识别体系中红移氢键的电子结构和性质, 结果表明APHZ受体对卤素阴离子的识别能力的相对顺序为DAPHZ•••F- >> DAPHZ•••Cl- ≈ DAPHZ•••Br-. 相似文献
215.
建立了ICP-AES测定超导粉中痕量镍的新方法。优化了仪器工作参数,对超导前驱粉中痕量镍测定时的基体干扰及干扰消除方法进行了系统研究,结果表明:大量存在的基体元素产生严重基体效应,导致测定重现性及准确度变差,实验采用分离富集方法以提高测定结果的准确度和精密度。实验中首先用阴离子交换树脂,除去Bi3+及部分Pb2+,Sr2+,Ca2+,Cu2+等基体元素;在碱性条件下再通过甲苯萃取镍与丁二酮肟的络合物、稀盐酸反萃取富集镍;对分离富集条件进行了优化。对模拟标准样品进行测定,分析结果与理论值一致,相对标准偏差为1.9%,方法检出限为0.19μg.g-1。该方法已用于超导前驱粉样品中痕量镍的分析,结果令人满意。 相似文献
216.
K.C. Gowri SreedeviAjesh P. Thomas P.S. SaliniS. Ramakrishnan K.S. AnjuM.G. Derry Holaday M.L.P. Reddy 《Tetrahedron letters》2011,52(45):5995-5999
A two-step synthesis of 5,5-diaryldipyrromethanes in good yields is described. The adopted synthetic strategy can be used to tune the substituent at the meso-carbon very easily by choosing the Grignard reagent of interest. Further, the influence of the incorporation of various diaryl units at the meso-carbon atom in the inherent anion binding affinities of the dipyrromethanes through hydrogen bonding was discussed. 相似文献
217.
XIONG Zi-jun DU Peng LI Bian XU Li-li ZHEN Xue-chu FU Wei .Key Laboratory of Smart Drug Delivery Ministry of Education & PLA 《高等学校化学研究》2011,(4):655-660
The serotonin 2A(5-HT2A) receptor has been implicated in several neurological conditions and potent 5-HT2A antagonists have therapeutic effects in the treatment of schizo phrenia and depression.In this study,a potent novel 5-HT2A inhibitor 05245768 with a Ki value of (593.89±34.10) nmol/L was discovered by integrating a set of computational approaches and experiments(protein structure prediction,pharmacophore-based virtual screening,automated molecular docking and pharmacological bioassay).The 5-HT2A recept... 相似文献
218.
Shan-Yen Choir Paw-Hwa Yang Chia-Lin J. Wang Hsiao-Hwa Lu Yin Chen Jen-Mann Kao 《中国化学会会志》1999,46(1):53-62
A series of biphenylyltetrazole substituted triazinones and structure-related pyrimidinones are systhesized, and their binding affinities for angiotensin II receptor are reported. 相似文献
219.
Hydrazone-based receptors, containing fluorene-skeleton substituents, in a THF solution, in the presence of fluoride or cyanide, do not only form H-bond complexes, but mainly undergo deprotonation of the N–H fragments, an event, which is signaled by the color change, the ability of the deprotonation is associated with the fluorene skeleton. The deprotonation process is also reversible by the addition of metal ions, while cyanide from fluoride could be distinguished by the addition of copper (II). 相似文献
220.
Summary. Starting from 2-chloro-3-nitropyridine, 1H-pyrido[2,3-b][1,4]thiazin-2(3H)-one was synthesized. This compound was reacted with potassium tert-butoxide and diethyl chlorophosphate to give the intermediate 1H-pyrido[2,3-b][1,4]thiazin-2-ylphosphate derivative, which in turn afforded the 1,2,4-oxadiazolylimidazo[1,5-d]pyrido[2,3-b]pyrazine derivatives. The title compounds are potential ligands for the γ-aminobutyric acid A/benzodiazepine receptor complex.
Corresponding author. E-mail: thomas.erker@univie.ac.at
Received February 22, 2002. Accepted March 6, 2002 相似文献