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Full-Text Articles in Medicine and Health Sciences
Identification Of Hydroxyxanthones As Na/K-Atpase Ligands, Zhongbing Zhang, Zhichuan Li, Jiang Tian, Wei Jiang, Yin Wang, Xiaojin Zhang, Zhuorong Li, Qidong You, Joseph Shapiro, Shuyi Si, Zijian Xie
Identification Of Hydroxyxanthones As Na/K-Atpase Ligands, Zhongbing Zhang, Zhichuan Li, Jiang Tian, Wei Jiang, Yin Wang, Xiaojin Zhang, Zhuorong Li, Qidong You, Joseph Shapiro, Shuyi Si, Zijian Xie
Zijian Xie
We have screened a chemical library and identified several novel structures of Na/K-ATPase inhibitors. One group of these inhibitors belongs to polyphenolic xanthone derivatives. Functional characterization reveals the following properties of this group of inhibitors. First, like ouabain, they are potent inhibitors of the purified Na/K-ATPase. Second, their effects on the Na/K-ATPase depend on the number and position of phenolic groups. Methylation of these phenolic groups reduces the inhibitory effect. Third, further characterization of the most potent xanthone derivative, MB7 (3,4,5,6-tetrahydroxyxanthone), reveals that it does not change either Na+ or ATP affinity of the enzyme. Finally, unlike that of …
Central Role For The Cardiotonic Steroid Marinobufagenin In The Pathogenesis Of Experimental Uremic Cardiomyopathy, David Kennedy, Sandeep Vetteth, Sankaridrug Periyasamy, Mohamed Kanj, Larisa Fedorova, Samer Khouri, M. Kahaleh, Zijian Xie, Deepak Malhotra, Nikolai Kolodkin, Edward Lakatta, Olga Fedorova, Alexei Bagrov, Joseph Shapiro
Central Role For The Cardiotonic Steroid Marinobufagenin In The Pathogenesis Of Experimental Uremic Cardiomyopathy, David Kennedy, Sandeep Vetteth, Sankaridrug Periyasamy, Mohamed Kanj, Larisa Fedorova, Samer Khouri, M. Kahaleh, Zijian Xie, Deepak Malhotra, Nikolai Kolodkin, Edward Lakatta, Olga Fedorova, Alexei Bagrov, Joseph Shapiro
Zijian Xie
Patients with chronic renal failure develop a “uremic” cardiomyopathy characterized by diastolic dysfunction, cardiac hypertrophy, and systemic oxidant stress. Patients with chronic renal failure are also known to have increases in the circulating concentrations of the cardiotonic steroid marinobufagenin (MBG). On this background, we hypothesized that elevations in circulating MBG may be involved in the cardiomyopathy. First, we observed that administration of MBG (10 g/kg per day) for 4 weeks caused comparable increases in plasma MBG as partial nephrectomy at 4 weeks. MBG infusion caused increases in conscious blood pressure, cardiac weight, and the time constant for left ventricular relaxation …
Marinobufagenin Stimulates Fibroblast Collagen Production And Causes Fibrosis In Experimental Uremic Cardiomyopathy, Jihad Elkareh, David Kennedy, Belvadi Yashaswi, Sandeep Vetteth, Amjad Shidyak, Eric Kim, Sleiman Smaili, Sankaridrug Periyasamy, Imad Hariri, Larisa Fedorova, Jiang Liu, Liang Wu, M. Kahaleh, Zijian Xie, Deepak Malhotra, Olga Fedorova, Vladimir Kashkin, Alexei Bagrov, Joseph Shapiro
Marinobufagenin Stimulates Fibroblast Collagen Production And Causes Fibrosis In Experimental Uremic Cardiomyopathy, Jihad Elkareh, David Kennedy, Belvadi Yashaswi, Sandeep Vetteth, Amjad Shidyak, Eric Kim, Sleiman Smaili, Sankaridrug Periyasamy, Imad Hariri, Larisa Fedorova, Jiang Liu, Liang Wu, M. Kahaleh, Zijian Xie, Deepak Malhotra, Olga Fedorova, Vladimir Kashkin, Alexei Bagrov, Joseph Shapiro
Zijian Xie
We have observed recently that experimental renal failure in the rat is accompanied by increases in circulating concentrations of the cardiotonic steroid, marinobufagenin (MBG), and substantial cardiac fibrosis. We performed the following studies to examine whether MBG might directly stimulate cardiac fibroblast collagen production. In vivo studies were performed using the 5/6th nephrectomy model of experimental renal failure (PNx), MBG infusion (MBG), PNx after immunization against MBG, and concomitant PNx and adrenalectomy. Physiological measurements with a Millar catheter and immunohistochemistry were performed. In vitro studies were then pursued with cultured isolated cardiac fibroblasts. We observed that PNx and MBG increased …
Marinobufagenin Induces Increases In Procollagen Expression In A Process Involving Protein Kinase C And Fli-1: Implications For Uremic Cardiomyopathy, Jihad Elkareh, Sankaridrug Periyasamy, Amjad Shidyak, Sandeep Vetteth, Jeremy Schroeder, Vanamala Raju, Imad Hariri, Nasser El-Okdi, Shalini Gupta, Larisa Fedorova, Jiang Liu, Olga Fedorova, M. Kahaleh, Zijian Xie, Deepak Malhotra, Dennis Watson, Alexei Bagrov, Joseph Shapiro
Marinobufagenin Induces Increases In Procollagen Expression In A Process Involving Protein Kinase C And Fli-1: Implications For Uremic Cardiomyopathy, Jihad Elkareh, Sankaridrug Periyasamy, Amjad Shidyak, Sandeep Vetteth, Jeremy Schroeder, Vanamala Raju, Imad Hariri, Nasser El-Okdi, Shalini Gupta, Larisa Fedorova, Jiang Liu, Olga Fedorova, M. Kahaleh, Zijian Xie, Deepak Malhotra, Dennis Watson, Alexei Bagrov, Joseph Shapiro
Zijian Xie
The cardiotonic steroid marinobufagenin (MBG) has been implicated in the pathogenesis of experimental uremic cardiomyopathy, which is characterized by progressive cardiac fibrosis. We examined whether the transcription factor Friend leukemia integration-1 (Fli-1) might be involved in this process. Fli-1-knockdown mice demonstrated greater cardiac collagen-1 expression and fibrosis compared with wild-type mice; both developed increased cardiac collagen expression and fibrosis after 5/6 nephrectomy. There was a strong inverse relationship between the expressions of Fli-1 and procollagen in primary culture of rat cardiac and human dermal fibroblasts as well as a cell line derived from renal fibroblasts and MBG-induced decreases in nuclear …
Na/K-Atpase Mimetic Pnaktide Peptide Inhibits The Growth Of Human Cancer Cells, Zhichuan Li, Zhongbing Zhang, Joe X. Xie, Xin Li, Jiang Tian, Ting Cai, Hongaun Cui, Hanfei Ding, Joseph I. Shapiro Md, Zijian Xie
Na/K-Atpase Mimetic Pnaktide Peptide Inhibits The Growth Of Human Cancer Cells, Zhichuan Li, Zhongbing Zhang, Joe X. Xie, Xin Li, Jiang Tian, Ting Cai, Hongaun Cui, Hanfei Ding, Joseph I. Shapiro Md, Zijian Xie
Zijian Xie
Cells contain a large pool of non-pumping Na/K-ATPase that participates in signal transduction. Here, we show that the expression of α1 Na/K-ATPase is significantly reduced in human prostate carcinoma as well as in several human cancer cell lines. This down-regulation impairs the ability of Na/K-ATPase to regulate Src-related signaling processes. Supplement of pNaKtide, a peptide derived from α1 Na/K-ATPase, reduces activities of Src and Src effectors. Consequently, these treatments stimulate apoptosis and inhibit growth in cultures of human cancer cells. Moreover, administration of pNaKtide inhibits angiogenesis and growth of tumor xenograft. Thus, the new findings demonstrate the in vivo effectiveness …
Gender Differences In The Development Of Uremic Cardiomyopathy Following Partial Nephrectomy: Role Of Progesterone, Christopher Drummond, George Buddny, Steven Haller, Jiang Liu, Yanling Yan, Zijian Xie, Deepak Malhotra, Joseph Shapiro, Jiang Tian
Gender Differences In The Development Of Uremic Cardiomyopathy Following Partial Nephrectomy: Role Of Progesterone, Christopher Drummond, George Buddny, Steven Haller, Jiang Liu, Yanling Yan, Zijian Xie, Deepak Malhotra, Joseph Shapiro, Jiang Tian
Zijian Xie
Gender difference has been suggested as a risk factor for developing cardiovascular and renal diseases in humans and experimental animals. As a major sex hormone, progesterone was reported to compete with cardiotonic steroid binding to Na/K-ATPase. Our previous publication demonstrated that cardiotonic steroids (e.g., marinobufagenin) play an important role in the development of experimental uremic cardiomyopathy. We also observed that the putative mineralocorticoid antagonists, spironolactone and its major metabolite canrenone, antagonize binding of cardiotonic steroids to Na/K-ATPase in a competitive manner and also ameliorate experimental uremic cardiomyopathy induced by partial nephrectomy. In the following studies, we noted that progesterone displayed …