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1. chinaXiv:201605.01496 [pdf]

Relaxant Action of Plumula Nelumbinis Extract on Mouse Airway Smooth Muscle

Tan, Li; Chen, Weiwei; Wei, Ming-Yu; Shen, Jinhua; Yu, Meng-Fei; Liu, Qing-Hua; Tan, Li; Chen, Weiwei; Wei, Ming-Yu; Shen, Jinhua; Yu, Meng-Fei; Liu, Qing-Hua; Yang, Guangzhong; Guo, Donglin; Guo, Donglin; Qin, Gangjian; Ji, Guangju
Subjects: Biology >> Biophysics >> Integrative & Complementary Medicine

The traditional herb Plumula Nelumbinis is widely used in the world because it has many biological activities, such as anti-inflammation, antioxidant, antihypertension, and butyrylcholinesterase inhibition. However, the action of Plumula Nelumbinis on airway smooth muscle (ASM) relaxation has not been investigated. A chloroform extract of Plumula Nelumbinis (CEPN) was prepared, which completely inhibited precontraction induced by high K+ in a concentration-dependent manner in mouse tracheal rings, but it had no effect on resting tension. CEPN also blocked voltage-dependent L-type Ca2+ channel-(VDCC-) mediated currents. In addition, ACh-induced precontraction was also completely blocked by CEPN and partially inhibited by nifedipine or pyrazole 3. Besides, CEPN partially reduced ACh-activated nonselective cation channel (NSCC) currents. Taken together, our data demonstrate that CEPN blocked VDCC and NSCC to inhibit Ca2+ influx, resulting in relaxation of precontracted ASM. This finding indicates that CEPN would be a candidate of new potent bronchodilators.

submitted time 2016-05-12 Hits2082Downloads1309 Comment 0

2. chinaXiv:201605.01486 [pdf]

Involvement of Large-Conductance Ca2+-Activated K+ Channels in Chloroquine-Induced Force Alterations in Pre-Contracted Airway Smooth Muscle

Wei, Ming-Yu; Xue, Lu; Tan, Li; Sai, Wen-Bo; Liu, Xiao-Cao; Jiang, Qiu-Ju; Shen, Jinhua; Peng, Yong-Bo; Zhao, Ping; Yu, Meng-Fei; Chen, Weiwei; Ma, Li-Qun; Liu, Qing-Hua; Wei, Ming-Yu; Xue, Lu; Tan, Li; Sai, Wen-Bo; Liu, Xiao-Cao; Jiang, Qiu-Ju; Shen, Jinhua
Subjects: Biology >> Biophysics

The participation of large-conductance Ca2+ activated K+ channels (BKs) in chloroquine (chloro)-induced relaxation of precontracted airway smooth muscle (ASM) is currently undefined. In this study we found that iberiotoxin (IbTx, a selective inhibitor of BKs) and chloro both completely blocked spontaneous transient outward currents (STOCs) in single mouse tracheal smooth muscle cells, which suggests that chloro might block BKs. We further found that chloro inhibited Ca2+ sparks and caffeine-induced global Ca2+ increases. Moreover, chloro can directly block single BK currents completely from the intracellular side and partially from the extracellular side. All these data indicate that the chloro-induced inhibition of STOCs is due to the blockade of chloro on both BKs and ryanodine receptors (RyRs). We also found that low concentrations of chloro resulted in additional contractions in tracheal rings that were precontracted by acetylcholine (ACH). Increases in chloro concentration reversed the contractile actions to relaxations. In the presence of IbTx or paxilline (pax), BK blockers, chloro-induced contractions were inhibited, although the high concentrations of chloro-induced relaxations were not affected. Taken together, our results indicate that chloro blocks BKs and RyRs, resulting in abolishment of STOCs and occurrence of contraction, the latter will counteract the relaxations induced by high concentrations of chloro.

submitted time 2016-05-12 Hits1646Downloads962 Comment 0

3. chinaXiv:201605.01430 [pdf]

CUG-BP1 regulates RyR1 ASI alternative splicing in skeletal muscle atrophy

Tang, Yinglong; Wang, Huiwen; Gu, Lei; Yang, Zhiguang; Wu, Yanyun; Yuan, Qi; Ji, Guangju; Wei, Bin; Tang, Yinglong; Guo, Yuting; Gu, Lei; Yang, Zhiguang; Zhao, Gang; Zhang, Qing
Subjects: Biology >> Biophysics

RNA binding protein is identified as an important mediator of aberrant alternative splicing in muscle atrophy. The altered splicing of calcium channels, such as ryanodine receptors (RyRs), plays an important role in impaired excitation-contraction (E-C) coupling in muscle atrophy; however, the regulatory mechanisms of ryanodine receptor 1 (RyR1) alternative splicing leading to skeletal muscle atrophy remains to be investigated. In this study we demonstrated that CUG binding protein 1 (CUG-BP1) was up-regulated and the alternative splicing of RyR1 ASI (exon70) was aberrant during the process of neurogenic muscle atrophy both in human patients and mouse models. The gain and loss of function experiments in vivo demonstrated that altered splicing pattern of RyR1 ASI was directly mediated by an up-regulated CUG-BP1 function. Furthermore, we found that CUG-BP1 affected the calcium release activity in single myofibers and the extent of atrophy was significantly reduced upon gene silencing of CUG-BP1 in atrophic muscle. These findings improve our understanding of calcium signaling related biological function of CUG-BP1 in muscle atrophy. Thus, we provide an intriguing perspective of involvement of mis-regulated RyR1 splicing in muscular disease.

submitted time 2016-05-12 Hits1535Downloads889 Comment 0

4. chinaXiv:201605.01283 [pdf]

Knockdown of ERp44 leads to apoptosis via activation of ER stress in HeLa cells

Chang, Yan; Wu, Yanyun; Ji, Guangju; Liu, Wei
Subjects: Biology >> Biophysics >> Biochemistry & Molecular Biology

ERp44, an endoplasmic reticulum (ER) resident protein, regulates intracellular Ca2+ release and involves in the maturation of many proteins in mammalian cells. In this study, we investigated the effects and mechanism of ERp44 on cell apoptosis by using ERp44 knockdown stable HeLa cell lines. We found that ERp44 knockdown resulted in increases in cell apoptosis rate more than one fold higher than that of control; using serum starvation, caspase-3 protein level was significantly up-regulated in ERp44 knockdown cells compared to the control cells. Furthermore, we demonstrated that in response to serum starvation, the protein levels of CHOP and GRP78 were also largely raised in ERp44 knockdown cells. Moreover, caspase-12 was activated, which suggested cell apoptosis was induced by ER stress. Taken together, our results indicate that knockdown of ERp44 leads to cell apoptosis through the activation of ER stress. (C) 2015 Elsevier Inc. All rights reserved.

submitted time 2016-05-11 Hits1748Downloads967 Comment 0

5. chinaXiv:201605.01237 [pdf]

Nitric oxide enhances extracellular ATP induced Ca2+ oscillation in He La cells

Tang, Yinglong; Miao, Lin; Zhai, Kui; Ji, Guangju; Yin, Yin; Wei, Bin; Tang, Yinglong
Subjects: Biology >> Biophysics >> Biochemistry & Molecular Biology

Calcium (Ca2+) oscillations play a central role in varieties of cellular processes including fertilization and immune response, but controversy over the regulation mechanisms still exists. It has been known that nitric oxide (NO) dependently regulates Ca2+ signaling in most physiopathological processes. Previous study indicated that eNOS translocation during some pathological process influences intracellular Ca2+ homeostasis. In this study, we investigated the role and mechanism of NO on Ca2+ release by overexpressing eNOS in cytoplasm (Cyto-eNOS) and endoplasmic reticulum (ER-eNOS) of HeLa cells. We found that the properties of Ca2+ release were altered by the overexpression of eNOS. The amplitude and frequency of extracellular ATP (eATP)-induced Ca2+ oscillation were enhanced in both Cyto-eNOS and ER-eNOS cells, respectively. Especially, the enhancement of the amplitude and frequency of the Ca2+ oscillation was much more significant in the ER-eNOS cells than that of Cyto-eNOS cells. Further study indicated that this effect was abrogated by NO inhibitor, 1..-NAME, suggesting it was not an artificial result induced by ER stress. Furthermore, an up-regulated phosphorylation of phospholamban (PLB) was observed and the sarco-endoplasmic reticulum Ca2tATPase (SERCA) function was activated followed by the significant increase in the ER Ca2+ load. Taken together, we revealed a novel regulatory mechanism of Ca2+ oscillation. (C) 2014 Elsevier Inc. All rights reserved.

submitted time 2016-05-11 Hits1542Downloads941 Comment 0

6. chinaXiv:201605.01189 [pdf]

Adamantane-Resistant Influenza A Viruses in the World (1902-2013): Frequency and Distribution of M2 Gene Mutations

Dong, Guoying; Peng, Chao; Han, Le; Dong, Guoying; Luo, Jing; Wang, Chengmin; Wu, Bin; He, Hongxuan; Dong, Guoying; Ji, Guangju
Subjects: Biology >> Biophysics

Adamantanes (amantadine and rimantadine) have been used to prevent and treat influenza A virus infections for many years; however, resistance to these drugs has been widely reported in the world. To investigate the frequency and distribution of M2 gene mutations in adamantane-resistant influenza variants circulated in the world between 1902 and 2013, 31251 available M2 protein sequences from different HA-subtype influenza A viruses (H1-H17) were analyzed and adamantane resistance-associated mutations were compared (L26F, V27A, A30T, A30V, S31N, G34E, and L38F). We find that 45.2% (n = 14132) of influenza A (H1-H17) viruses circulating globally were resistant to adamantanes, and the vast majority of resistant viruses (95%) bear S31N mutations. Whereas, only about 1% have V27A mutations and other mutations (L26F, A30T, G34E, and L38F) were extremely rare (their prevalence appeared to be < 0.2%). Our results confirm that H1, H3, H5, H7, H9, and H17 subtype influenza A viruses exhibit high-level resistance to adamantanes. In contrast, the appearance of adamantane-resistant mutants in H2, H4, H6, H10, and H11 subtypes was rare. However, no adamantane resistance viruses were identified among other HA subtypes (H8, H12-H16). Our findings indicate that the frequency and distribution of adamantane- resistant influenza variants varied among different HA subtypes, host species, years of isolation, and geographical areas. This comprehensive study raises concerns about the increasing prevalence of adamantane-resistant influenza A viruses and highlights the importance of monitoring the emergence and worldwide spread of adamantaneresistant variants.

submitted time 2016-05-11 Hits1380Downloads814 Comment 0

7. chinaXiv:201605.00713 [pdf]

Calstabin 2: An important regulator for learning and memory in mice

Yuan, Qi; Chi, Shaopeng; Yang, Zhiguang; Wang, Jun; Ji, Guangju; Yuan, Qi; Deng, Ke-Yu; Xin, Hong-Bo; Sun, Le; Wang, Xiaoqun; Chi, Shaopeng;
Subjects: Biology >> Biophysics

Calstabin2, also named FK506 binding protein 12.6 (FKBP12.6), is a subunit of ryanodine receptor subtype 2 (RyR2) macromolecular complex, which is an intracellular calcium channel and abundant in the brain. Previous studies identified a role of leaky neuronal RyR2 in posttraumatic stress disorder (PTSD). However, the functional role of Calstabin2 in the cognitive function remains unclear. Herein, we used a mouse model of genetic deletion of Calstabin2 to investigate the function of Calstabin2 in cognitive dysfunction. We found that Calstabin2 knockout (KO) mice showed significantly reduced performance in Morris Water Maze (MWM), long-term memory (LTM) contextual fear testing, and rotarod test when compared to wild type (WT) littermates. Indeed, genetic deletion of Calstabin2 reduced long-term potentiation (LTP) at the hippocampal CA3-CA1 connection, increased membrane excitability, and induced RyR2 leak. Finally, we demonstrated that the increase in cytoplasmic calcium activated Ca2+ dependent potassium currents and led to neuronal apoptosis in KO hippocampal neurons. Thus, these results suggest that neuronal RyR2 Ca2+ leak due to Calstabin2 deletion contributes to learning deficiency and memory impairment.

submitted time 2016-05-05 Hits1579Downloads859 Comment 0

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