cAMP induction by ouabain promotes endothelin-1 secretion via MAPK/ERK signaling in beating rabbit atria

Li-qun Peng,Ping Li,Qiu-li Zhang,Lan Hong,Li-ping Liu,Xun Cui,Bai-ri Cui 대한생리학회-대한약리학회 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.1

Adenosine 3 ,5 -cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the Na⁺-K⁺-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain (3.0 μmol/L) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabainincreased atrial dynamics was blocked by KB-R7943 (3.0 μmol/L), an inhibitor for reverse mode of Na⁺-Ca²⁺ exchangers (NCX), but did not by L-type Ca²⁺ channel blocker nifedipine (1.0 μmol/L) or protein kinase A (PKA) selective inhibitor H-89 (3.0 μmol/L). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline (100.0 μmol/L), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP (0.5 μmol/L) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 (30 μmol/L), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

Effects of metal-molecule interface conformations on the electron transport of single molecule

Ping Bai,Er Ping Li,Chee Ching Chong,Zhikuan Chen 한국물리학회 2006 Current Applied Physics Vol.6 No.3

The electron transport eects of molecule locations on the metal interface are investigated through metalmoleculemetal systemsusing the rst principles method, based on density functional theory with norm conserving non-local pseudopotentials and non-equilib-rium Green’s functions. Three kinds of moleculemetal interface conformations are studied. These include locating the molecule on thetop, at the hollow site and on the bridge of metal surface atoms. AumoleculeAu open systems are constructed and numerically exam-sion functions of constructed systems are calculated and analyzed. Simulated results show that the on-atom contact exhibits the bestmoleculemetal coupling when an external bias lower than 1.4 V is applied. The bridge contact has a similar coupling as the hollow con-tact with a small dierence at larger external bias. This may partially explain why experimental results have poor repeatability.

Short Communications : The Presence of the UGT2B17 gene is associated with Lung cancer in male Chinese Han smokers

( Shu Ping Bai ),( Yang Xu ),( Li Jie Wu ),( Xiao Hong Wang ),( Li Jing Li ) 한국유전학회 2010 Genes & Genomics Vol.32 No.1

cAMP induction by ouabain promotes endothelin-1 secretion via MAPK/ERK signaling in beating rabbit atria

Peng, Li-qun,Li, Ping,Zhang, Qiu-li,Hong, Lan,Liu, Li-ping,Cui, Xun,Cui, Bai-ri The Korean Society of Pharmacology 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.1

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

Clinical Significance of Quantitative Analysis of Plasma Epstein-Barr Virus DNA in Patients of Xinjiang Uygur Nationality with Hodgkin's Lymphoma

Li, Xun,Yang, Shun-E.,Guo, Yun-Quan,Shen, Ming-Xia,Gu, Li,Gulikezi, Gulikezi,Zhao, Bing,Liu, Wei,Tuerxun, Tuerxun,Bai, Jing-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Objective: To investigate the relationship between plasma EBV-DNA concentration and clinicopathologic features of Hodgkin's lymphoma cases. Methods: At first, the positive rate of plasma EBV-DNA was determined with a nested-PCR method using 45 specimens from Uygur HL patients, as well as 110 healthy people sampled as normal controls. Secondly, using fluorescent quantitative nested-PCR, EBV viral load was assessed in the EBV-DNA positive plasma samples. Then, relationships between plasma EBV viral load and clinicopathologic features of HL patients were analyzed. Results: The positive rate of plasma EBV-DNA of HL patients was significantly higher than that of normal controls (53.3% vs 26.4%, P=0.001). There was no significant difference about plasma EBV viral load between EBV-associated HL and EBV-DNA positive normal people (P=0.490). Looking at patients' characteristics, plasma EBV viral load in 10-20 years EBV-associated HL was higher than in EBV cases which were less than 10 years or more than 35 years (P=0.025). Furthermore, in EBV-associated HL, concentration of plasma EBV-DNA was significantly higher in advanced stage disease (stages III-IV; P=0.013), and with B-symptoms (P=0.020). Conclusion: EBV-DNA levels were associated with part of clinicopathologic features of cases. It was of practical use to screen HL. Further etiological studies appear warranted.

Association of a Pre-miR-27a Polymorphism with Cancer Risk: an Updated Meta-analysis

Bai, Rong-Pan,Weng, Yu,Su, Li-Ling,Jin, Ming-Juan,Xu, Zheng-Ping,Lu, Li-Qin,Chen, Guang-Di Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

MicroRNA-27a is highly expressed in cancers and has been identified as an oncogenic microRNA. A genetic variant in pre-miR-27a (rs895819) with a transition of A to G has been demonstrated to be associated with cancer risk; however, the results of these studies remain conflicting rather than conclusive. Therefore, we performed a meta-analysis to derive a more precise estimation. Through searching PubMed or other databases up to March 2014 using the following MeSH terms and keywords, "miR-27a", "polymorphism" and "cancer", seventeen case-control studies were identified in this meta-analysis, including 7,813 cases and 9,602. Crude odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to investigate the association strength between rs895819 and the susceptibility of cancer. The results of the overall meta-analysis did not suggest any association between rs895819 polymorphism and cancer susceptibility, and this remained in Asians as a subgroup. In Caucasians, however, the rs895819 was associated with a reduced cancer risk in heterozygous (OR, 0.83; 95%CI, 0.75-0.93) and dominant models (OR, 0.84; 95%CI, 0.76-0.93), and the [G] allele of rs895819 showed a protective effect (OR, 0.90, 95%CI, 0.84-0.97). Further studies showed a significant association between the [G] allele of rs895819 and decreased risk of breast cancer (0.91; 95%CI, 0.85-0.98), and stratified analyses indicated a protective effect of the [G] allele in Caucasians (OR, 0.89; 95%CI, 0.82-0.98), younger breast cancer cases (OR, 0.87; 95%CI, 0.79-0.96), and in the group of unilateral breast cancer patients (OR, 0.90; 95%CI, 0.83-0.97). These findings suggest an association between pre-miR-27a polymorphism rs895819 and cancer risk in Caucasians. The protective effect of rs895819 [G] allele in younger breast cancer and in the group of unilateral breast cancer patients await further confirmation since the included studies in this meta-analysis were limited.

Lymph Node Ratio is More Predictive than Traditional Lymph Node Stratification in Lymph Node Positive Invasive Breast Cancer

Bai, Lian-Song,Chen, Chuang,Gong, Yi-Ping,Wei, Wen,Tu, Yi,Yao, Feng,Li, Juan-Juan,Wang, Li-Jun,Sun, Sheng-Rong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Objective: To evaluate the relationships between lymph node ratio (LNR, the ratio of positive lymph nodes in excised axillary lymph nodes) and disease-free survival (DFS) by comparing with traditional absolute positive lymph node number (pN classification) for prediction of breast cancer (BC) progrnosis. Methods and Patients: We retrospectively reviewed patients who received comprehensive therapy in Department of Breast Surgery, Hubei Cancer Hospital, China from Jan 2002 to Dec 2006 (Group A), and Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, China from Jun 2008 to May 2012 (Group B). Patients were allocated to low-risk (${\leq}0.20$), intermediate-risk (> 0.20 but ${\leq}0.65$), high-risk (>0.65) groups by LNR. The primary endpoint was 5-DFS. Results: A total of 294 patients were included in our study. LNR was verified as a negative prognostic factor for DFS (P=0.002 in Group A, P<0.0001 in Group B). Then we found the effects of pN and LNR delamination on disease-free survival (DFS) had statistical significance (P=0.012 for pN and P=0.031 for LNR stratification in Group A, both of them P<0.001 in Group B). Compared to pN staging, LNR staging displayed superior performance in prognosis, the adjusted hazard ratio of recurrence being 2.07 (95%CI, 1.07 to 4.0) for intermediate risk group (P=0.030) and 2.44 (95%CI, 1.21 to 4.92) for high risk group (P=0.013) in Group A. Conclusions: LNR stratification proved an adverse prognostic factor of DFS in lymph nodes positive invasive BC using cut-off values 0.20 and 0.65, and was more predictive than traditional pN classification for 5-DFS.

Iron Cycles Link with Arsenic Availability in Rice for Food Safety from South China

Fang Bai Li,Chuan-Ping Liu,Min Hu 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Verification of the Correlation between Progression-free Survival and Overall Survival Considering Magnitudes of Survival Post-progression in the Treatment of Four Types of Cancer

Liu, Li-Ya,Yu, Hao,Bai, Jian-Ling,Zeng, Ping,Miao, Dan-Dan,Chen, Feng Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.3

Background: With development and application of new and effective anti-cancer drugs, the median survival post-progression (SPP) is often prolonged, and the role of the median SPP on surrogacy performance should be considered. To evaluate the impact of the median SPP on the correlation between progression-free survival (PFS) and overall survival (OS), we performed simulations for treatment of four types of cancer, advanced gastric cancer (AGC), metastatic colorectal cancer (MCC), glioblastoma (GBM), and advanced non-small-cell lung cancer (ANSCLC). Materials and Methods: The effects of the median SPP on the statistical properties of OS and the correlation between PFS and OS were assessed. Further, comparisons were made between the surrogacy performance based on real data from meta-analyses and simulation results with similar scenarios. Results: The probability of a significant gain in OS and HR for OS was decreased by an increase of the SPP/OS ratio or by a decrease of observed treatment benefit for PFS. Similarly, for each of the four types of cancer, the correlation between PFS and OS was reduced as the median SPP increased from 2 to 12 months. Except for ANSCLC, for which the median SPP was equal to the true value, the simulated correlation between PFS and OS was consistent with the values derived from meta-analyses for the other three kinds of cancer. Further, for these three types of cancer, when the median SPP was controlled at a designated level (i.e., < 4 months for AGC, < 12 months for MCC, and <6 months for GBM), the correlation between PFS and OS was strong; and the power of OS reached 34.9% at the minimum. Conclusions: PFS is an acceptable surrogate endpoint for OS under the condition of controlling SPPs for AGC, MCC, and GBM at their limit levels; a similar conclusion cannot be made for ANSCLC.

Cough Inhibition Activity of Schisandra chinensis in Guinea Pigs

Shan Zhong,Li-Ping Bai,Xiao-Dong Liu,Die-Yi Cai,Lee-Fong Yau,Chu-Qin Huang,Jia-Qi Zhang,Ke-Fang Lai,Nan-Shan Zhong 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.4

Chronic cough is very common in respiratory clinics, and no effective drugs are available. Schisandra chinensis (Turcz.) Baill. (S. chinensis), an important traditional Chinese medicine, has been extensively prescribed for patients with a persistent cough. Preliminary research indicated that 95% ethanol extracts (EE) of S. chinensis showed remarkable antitussive activity in guinea pigs exposed to cigarette smoke (CS). To find out the antitussive ingredients of S. chinensis, EE was divided into four fractions according to the polarity: petroleum ether extract (PEE), ethyl acetate extract (ECE), n-butyl alcohol extract, and residue extract. The antitussive, antioxidant, and anti-inflammatory effects of the four fractions were evaluated in a guinea pig model of cough hypersensitivity induced by CS exposure. Eighteen main constituents of the two effective fractions, PEE and ECE, were identified using ultra-high-pressure liquid chromatography electronic spray ion time-of-flight mass spectrometry. The cough inhibition activities of compound 1, 3, 9, 10, 17 were evaluated on citric acid induced acute cough guinea pigs. The results showed that the antitussive activity of EE was almost all contained in PEE and ECE. The 16 major peaks in PEE were identified as 15 lignans (1–12 and 14–16) and 1 triterpene (compound 13), and 3 major peaks (1, 17, and 18) in ECE were also identified as lignans. Three doses of five compounds brought about a significant decrease in number of cough efforts (P < .01), and the cough inhibition rates were between 40.9% and 85.1%. Therefore, lignans are the antitussive ingredients of S. chinensis.