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Rapamycin Attenuates Cardiac Fibrosis In Experimental Uremic Cardiomyopathy By Reducing Marinobufagenin Levels And Inhibiting Downstream Pro-Fibrotic Signaling, Steven T. Haller Phd, Yanling Yan Phd, Christopher A. Drummond Phd, Joe Xie Md, Jiang Tian Phd, David J. Kennedy Phd, Victoria Y. Shilova Phd, Zijian Xie Phd, Jiang Liu Phd, Christopher J. Cooper Md, Deepak Malhotra Md, Phd, Joseph I. Shapiro Md, Olga V. Fedorova Phd, Alexei Y. Bagrov Md, Phd

Jiang Liu

Background: Experimental uremic cardiomyopathy causes cardiac fibrosis and is causally related to the increased circulating levels of the cardiotonic steroid, marinobufagenin (MBG), which signals through Na/K‐ATPase. Rapamycin is an inhibitor of the serine/threonine kinase mammalian target of rapamycin (mTOR) implicated in the progression of many different forms of renal disease. Given that Na/K‐ATPase signaling is known to stimulate the mTOR system, we speculated that the ameliorative effects of rapamycin might influence this pathway.

Methods and Results: Biosynthesis of MBG by cultured human JEG‐3 cells is initiated by CYP27A1, which is also a target for rapamycin. It was demonstrated that 1 …

Rapamycin Attenuates Cardiac Fibrosis In Experimental Uremic Cardiomyopathy By Reducing Marinobufagenin Levels And Inhibiting Downstream Pro-Fibrotic Signaling, Steven T. Haller Phd, Yanling Yan Phd, Christopher A. Drummond Phd, Joe Xie Md, Jiang Tian Phd, David J. Kennedy Phd, Victoria Y. Shilova Phd, Zijian Xie Phd, Jiang Liu Phd, Christopher J. Cooper Md, Deepak Malhotra Md, Phd, Joseph I. Shapiro Md, Olga V. Fedorova Phd, Alexei Y. Bagrov Md, Phd

Zijian Xie

Background: Experimental uremic cardiomyopathy causes cardiac fibrosis and is causally related to the increased circulating levels of the cardiotonic steroid, marinobufagenin (MBG), which signals through Na/K‐ATPase. Rapamycin is an inhibitor of the serine/threonine kinase mammalian target of rapamycin (mTOR) implicated in the progression of many different forms of renal disease. Given that Na/K‐ATPase signaling is known to stimulate the mTOR system, we speculated that the ameliorative effects of rapamycin might influence this pathway.

Methods and Results: Biosynthesis of MBG by cultured human JEG‐3 cells is initiated by CYP27A1, which is also a target for rapamycin. It was demonstrated that 1 …

Rapamycin Attenuates Cardiac Fibrosis In Experimental Uremic Cardiomyopathy By Reducing Marinobufagenin Levels And Inhibiting Downstream Pro-Fibrotic Signaling, Steven T. Haller Phd, Yanling Yan Phd, Christopher A. Drummond Phd, Joe Xie Md, Jiang Tian Phd, David J. Kennedy Phd, Victoria Y. Shilova Phd, Zijian Xie Phd, Jiang Liu Phd, Christopher J. Cooper Md, Deepak Malhotra Md, Phd, Joseph I. Shapiro Md, Olga V. Fedorova Phd, Alexei Y. Bagrov Md, Phd

Yanling Yan

Background: Experimental uremic cardiomyopathy causes cardiac fibrosis and is causally related to the increased circulating levels of the cardiotonic steroid, marinobufagenin (MBG), which signals through Na/K‐ATPase. Rapamycin is an inhibitor of the serine/threonine kinase mammalian target of rapamycin (mTOR) implicated in the progression of many different forms of renal disease. Given that Na/K‐ATPase signaling is known to stimulate the mTOR system, we speculated that the ameliorative effects of rapamycin might influence this pathway.

Methods and Results: Biosynthesis of MBG by cultured human JEG‐3 cells is initiated by CYP27A1, which is also a target for rapamycin. It was demonstrated that 1 …

Rapamycin Attenuates Cardiac Fibrosis In Experimental Uremic Cardiomyopathy By Reducing Marinobufagenin Levels And Inhibiting Downstream Pro-Fibrotic Signaling, Steven T. Haller Phd, Yanling Yan Phd, Christopher A. Drummond Phd, Joe Xie Md, Jiang Tian Phd, David J. Kennedy Phd, Victoria Y. Shilova Phd, Zijian Xie Phd, Jiang Liu Phd, Christopher J. Cooper Md, Deepak Malhotra Md, Phd, Joseph I. Shapiro Md, Olga V. Fedorova Phd, Alexei Y. Bagrov Md, Phd

Joseph I Shapiro MD

Background: Experimental uremic cardiomyopathy causes cardiac fibrosis and is causally related to the increased circulating levels of the cardiotonic steroid, marinobufagenin (MBG), which signals through Na/K‐ATPase. Rapamycin is an inhibitor of the serine/threonine kinase mammalian target of rapamycin (mTOR) implicated in the progression of many different forms of renal disease. Given that Na/K‐ATPase signaling is known to stimulate the mTOR system, we speculated that the ameliorative effects of rapamycin might influence this pathway.

Methods and Results: Biosynthesis of MBG by cultured human JEG‐3 cells is initiated by CYP27A1, which is also a target for rapamycin. It was demonstrated that 1 …

The Trade-Off Between Dietary Salt And Cardiovascular Disease; A Role For Na/K-Atpase Signaling?, Joe X. Xie, Anna Pearl Shapiro, Joseph I. Shapiro Md

Joseph I Shapiro MD

It has been postulated for some time that endogenous digitalis-like substances, also called cardiotonic steroids (CTS), exist, and that these substances are involved in sodium handling. Within the past 20 years, these substances have been unequivocally identified and measurements of circulating and tissue concentrations have been made. More recently, it has been identified that CTS also mediate signal transduction through the Na/K-ATPase, and consequently been implicated in profibrotic pathways. This review will discuss the mechanism of CTS in renal sodium handling and a potential “trade-off” effect from their role in inducing tissue fibrosis.