Medicine and Health Sciences Commons^™

Role Of Serum Biomarkers In Early Detection Of Non-Alcoholic Steatohepatitis And Fibrosis In West Virginian Children, Komal Sodhi, Lucas Bracero, Andrew S. Feyh, Alexandra Nichols, Krithika Srikanthan, Tariq M. Latif, Deborah L. Preston, Joseph I. Shapiro, Yoram Elitsur

Joseph I Shapiro MD

Background: Obesity, an epidemic among West Virginia children, as well as insulin resistance (IR), is wellestablished contributors to nonalcoholic steatohepatitis (NASH). Progression of NASH can lead to hepatic fibrosis and cirrhosis, making early detection imperative. The standard for diagnosing NASH is histologically via liver biopsy, which is highly invasive and generally contraindicated in children. By studying serum biomarkers associated with NASH, we aim to identify high risk children who can benefit from a less invasive, alternative approach to the early detection of NASH.

Methods: Seventy one children were prospectively recruited and divided into 3 groups: normal weight without IR …

Role Of Serum Biomarkers In Early Detection Of Non-Alcoholic Steatohepatitis And Fibrosis In West Virginian Children, Komal Sodhi, Lucas Bracero, Andrew S. Feyh, Alexandra Nichols, Krithika Srikanthan, Tariq M. Latif, Deborah L. Preston, Joseph I. Shapiro, Yoram Elitsur

Joseph I Shapiro MD

Background: Obesity, an epidemic among West Virginia children, as well as insulin resistance (IR), is wellestablished contributors to nonalcoholic steatohepatitis (NASH). Progression of NASH can lead to hepatic fibrosis and cirrhosis, making early detection imperative. The standard for diagnosing NASH is histologically via liver biopsy, which is highly invasive and generally contraindicated in children. By studying serum biomarkers associated with NASH, we aim to identify high risk children who can benefit from a less invasive, alternative approach to the early detection of NASH.

Methods: Seventy one children were prospectively recruited and divided into 3 groups: normal weight without IR …

Role Of Serum Biomarkers In Early Detection Of Diabetic Cardiomyopathy In The West Virginian Population, Adam Shaver, Alexandra Nichols, Ellen A. Thompson, Amrita Mallick, Nandini Manne, Shanmuga Sundaram, Joseph I. Shapiro Md, Komal Sodhi

Joseph I Shapiro MD

Objectives: Diabetic cardiomyopathy (DCM) is an established complication of diabetes mellitus. In West Virginia, the especially high incidence of diabetes and heart failure validate the necessity of developing new strategies for earlier detection of DCM. Since most DCM patients remain asymptomatic until the later stages of the disease when the fibrotic complications become irreversible, we aimed to explore biomarkers that can identify early-stage DCM.

Methods: The patients were grouped into 4 categories based on clinical diabetic and cardiac parameters: Control, Diabetes (DM), Diastolic dysfunction (DD), and Diabetes with diastolic dysfunction (DM+DD), the last group being the preclinical DCM group.

Results: …

Role Of Dietary Components In Modulating Hypertension, Andrew Feyh, Lucas Bracero, Hari Vishal Lakhani, Prasanna Santhanam, Joseph I. Shapiro Md, Zeid Khitan Md, Komal Sodhi

Joseph I Shapiro MD

Hypertension is a major health issue, particularly in medically underserved populations that may suffer from poor health literacy, poverty, and limited access to healthcare resources. Management of the disease reduces the risk of adverse outcomes, such as cardiovascular or cerebrovascular events, vision impairment due to retinal damage, and renal failure. In addition to pharmacological therapy, lifestyle modifications such as diet and exercise are effective in managing hypertension. Current diet guidelines include the DASH diet, a low-fat and low-sodium diet that encourages high consumption of fruits and vegetables. While the diet is effective in controlling hypertension, adherence to the diet is …

Attenuation Of Na/K-Atpase Mediated Oxidant Amplification With Pnaktide Ameliorates Experimental Uremic Cardiomyopathy, Jiang Liu, Jiang Tian, Muhammad Chaudhry, Kyle Maxwell, Yanling Yan, Xiaoliang Wang, Preeya T. Shah, Asad A. Khawaja, Rebecca Martin, Tylor J. Robinette, Adee El-Hamdani, Michael W. Dodrill, Komal Sodhi, Christopher A. Drummond, Steven T. Haller, David J. Keenedy, Nader G. Abraham, Zijian Xie, Joseph I. Shapiro Md

Joseph I Shapiro MD

We have previously reported that the sodium potassium adenosine triphosphatase (Na/K-ATPase) can effect the amplification of reactive oxygen species. In this study, we examined whether attenuation of oxidant stress by antagonism of Na/K-ATPase oxidant amplification might ameliorate experimental uremic cardiomyopathy induced by partial nephrectomy (PNx). PNx induced the development of cardiac morphological and biochemical changes consistent with human uremic cardiomyopathy. Both inhibition of Na/K-ATPase oxidant amplification with pNaKtide and induction of heme oxygenase-1 (HO-1) with cobalt protoporphyrin (CoPP) markedly attenuated the development of phenotypical features of uremic cardiomyopathy. In a reversal study, administration of pNaKtide after the induction of uremic …

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 …

Cigarette Smoking And Cardio-Renal Events In Patients With Atherosclerotic Renal Artery Stenosis, Christopher A. Drummond, Pamela S. Brewster, Wencan He, Kaili Ren, Yanmei Xie, Katherine R. Tuttle, Steven T. Haller, Kenneth Jamerson, Lance D. Dworkin, Donald E. Cutlip, Timothy P. Murphy, Ralph B. D'Agostino Sr., William L. Henrich, Jiang Tian, Joseph I. Shapiro Md, Christopher J. Cooper

Joseph I Shapiro MD

Cigarette smoking causes cardiovascular disease and is associated with poor kidney function in individuals with diabetes mellitus and primary kidney diseases. However, the association of smoking on patients with atherosclerotic renal artery stenosis has not been studied. The current study utilized data from the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL, NCT00081731) clinical trial to evaluate the effects of smoking on the risk of cardio-renal events and kidney function in this population. Baseline data showed that smokers (n = 277 out of 931) were significantly younger at enrollment than non-smokers (63.3±9.1 years vs 72.4±7.8 years; p<0.001). In addition, patients who smoke were also more likely to have bilateral renal artery stenoses and peripheral vascular disease (PVD). Longitudinal analysis showed that smokers experienced composite endpoint events (defined as first occurrence of: stroke; cardiovascular or renal death; myocardial infarction; hospitalization for congestive heart failure; permanent renal replacement; and progressive renal insufficiency defined as 30% reduction of GFR from baseline sustained for ≥ 60 days) at a substantially younger age compared to non-smokers (67.1±9.0 versus 76.1±7.9, p<0.001). Using linear regression and generalized linear modeling analysis controlled by age, sex, and ethnicity, smokers had significantly higher cystatin C levels (1.3±0.7 vs 1.2±0.9, p<0.01) whereas creatinine and estimated glomerular filtration rate (eGFR) were not different from non-smokers. From these data we conclude that smoking has a significant association with deleterious cardio-renal outcomes in patients with renovascular hypertension.

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.

Carbonylationmodificationregulatesna/K-Atpasesignalingandsaltsensitivity:Areviewandahypothesis, Preeya Shah Phd, Rebecca Martin, Yanling Yan, Joseph I. Shapiro Md, Jiang Liu

Joseph I Shapiro MD

Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions. Accumulating evidence indicates that oxidative stress not only regulates the Na/K-ATPase enzymatic activity, but also regulates its signaling and other functions. While cardiotonic steroids (CTS)-induced increase in reactive oxygen species (ROS) generation is an intermediate step in CTS-mediated Na/K-ATPase signaling, increase in ROS alone also stimulates Na/K-ATPase signaling. Based on literature and our observations, we hypothesize that ROS have biphasic effects on Na/K-ATPase signaling, transcellular sodium transport, and urinary sodium excretion. Oxidative modulation, in particular site specific carbonylation of the Na/K-ATPase α1 subunit, is a critical step in proximal …

Systematic Review Of Metabolic Syndrome Biomarkers: A Panel For Early Detection, Management, And Risk Stratification In The West Virginian Population, Krithika Srikanthan, Andrew Feyh, Haresh Visweshwar, Joseph I. Shapiro Md, Komal Sodhi

Joseph I Shapiro MD

Introduction: Metabolic syndrome represents a cluster of related metabolic abnormalities, including central obesity, hypertension, dyslipidemia, hyperglycemia, and insulin resistance, with central obesity and insulin resistance in particular recognized as causative factors. These metabolic derangements present significant risk factors for cardiovascular disease, which is commonly recognized as the primary clinical outcome, although other outcomes are possible. Metabolic syndrome is a progressive condition that encompasses a wide array of disorders with specific metabolic abnormalities presenting at different times. These abnormalities can be detected and monitored via serum biomarkers. This review will compile a list of promising biomarkers that are associated with metabolic …

Management Of Severe Hyponatremia: Infusion Of Hypertonic Saline And Desmopressin Or Infusion Of Vasopressin Inhibitors?, Antonios H. Tzamaloukas Md, Joseph I. Shapiro Md, Dominic S. Raj Md, Glen H. Murata Md, Deepak Malhotra Md, Phd, Robert H. Glew Phd

Joseph I Shapiro MD

Rapid correction of severe hyponatremia carries the risk of osmotic demyelination. Two recently introduced methods of correction of hyponatremia have diametrically opposite effects on aquaresis. inhibitors of vasopressin V2 receptor (vaptans) lead to the production of dilute urine, whereas infusion of desmopressin causes urinary concentration. Identification of the category of hyponatremia that will benefit from one or the other treatment is critical. In general, vaptans are effective in hyponatremias presenting with concentrated urine and, with the exception of hypovolemic hyponatremia, can be used as their primary treatment. Desmopressin is effective in hyponatremias presenting with dilute urine or developing urinary dilution …

Adiposity Predicts Pulse Pressure In Subjects With Chronic Kidney Disease: Data From The Modification Of Diet In Renal Disease, Preeya T. Shah Phd, Rebecca Martin, Juan R. Sanabria, Zeid Khitan Md, Prasanna Santhanam, Komal Sodhi, Nader G. Abraham, Joseph I. Shapiro Md

Joseph I Shapiro MD

Obesity is a known risk factor for hypertension, but the mechanisms by which this occurs are still unclear. As the body mass index (BMI) is frequently used to define obesity, but the BMI does not distinguish between adipose and other tissues, we sought to develop another index of obesity. We decided to look at the ratio of BMI to urinary creatinine excretion as the latter measurement is believed to be an index of muscle mass. We used data from the modification of diet in renal disease (MDRD) study as urinary creatinine collections and blood pressure measurements were readily available in …

Why Does Obesity Lead To Hypertension? Further Lessons From The Intersalt Study., Preeya T. Shah, Anna P. Shapiro, Zeid Khitan Md, Prasanna Santhanam Md, Joseph I. Shapiro Md

Joseph I Shapiro MD

Objectives To analyze correlations between major determinants of blood pressure (BP), in efforts to generate and compare predictive models that explain for variance in systolic, diastolic, and mean BP amongst participants of the Intersalt study. Methods Data from the Intersalt study, consisting of nearly 10,000 subjects from 32 different countries, were reviewed and analyzed. Published mean values of 24 hour urinary electrolyte excretion (Na+, K+), 24 hour urine creatinine excretion, body mass index (BMI, kg/m^2), and blood pressure data were extracted and imported into Matlab™ for stepwise linear regression analysis. Results As shown earlier, strong correlations between urinary sodium excretion …

Fructose Mediated Non-Alcoholic Fatty Liver Is Attenuated By Ho-1-Sirt1 Module In Murine Hepatocytes And Mice Fed A High Fructose Diet, Komal Sodhi, Nitin Puri, Gaia Favero, Sarah Stevens, Charles Meadows, Nader G. Abraham, Rita Rezzani, Hayden A. Ansinelli, Edward Lebovics, Joseph I. Shapiro

Joseph I Shapiro MD

Background Oxidative stress underlies the etiopathogenesis of nonalcoholic fatty liver disease (NAFLD), obesity and cardiovascular disease (CVD). Heme Oxygenase-1 (HO-1) is a potent endogenous antioxidant gene that plays a key role in decreasing oxidative stress. Sirtuin1 (SIRT1) belongs to the family of NAD-dependent de-acyetylases and is modulated by cellular redox. Hypothesis We hypothesize that fructose-induced obesity creates an inflammatory and oxidative environment conducive to the development of NAFLD and metabolic syndrome. The aim of this study is to determine whether HO-1 acts through SIRT1 to form a functional module within hepatocytes to attenuate steatohepatitis, hepatic fibrosis and cardiovascular dysfunction. Methods …

Na/K-Atpase Amplification Of Oxidant Stress; A Universal But Unrecognized Clinical Target?, Zijian Xie, Phd, Joseph I. Shapiro, Md

Joseph I Shapiro MD

The Na/K-ATPase has a signaling function which appears to be separate from its ion pumping function. This signaling function refers to the transduction of conformational changes in the Na/K-ATPase alpha1 subunit into activating Src’s tyrosine kinase activity, triggering a cascade which generates reactive oxygen species (ROS), modulates other signaling pathways, and causes many physiological and pathophysiological effects. We have recently observed that ROS themselves as well as cardiotonic steroids can actually initiate the signal by directly inducing conformational changes in alpha1. It therefore appears that the Na/K-ATPase signal cascade can serve as a feed forward amplification for ROS with circulating …

Management Of Severe Hyponatremia: Infusion Of Hypertonic Saline And Desmopressin Or Infusion Of Vasopressin Inhibitors?, Antonios H. Tzamaloukas Md, Joseph I. Shapiro Md, Dominic S. Raj Md, Glen H. Murata Md, Robert H. Glew Phd, Deepak Malhotra Md, Phd

Joseph I Shapiro MD

Rapid correction of severe hyponatremia carries the risk of osmotic demyelination. Two recently introduced methods of correction of hyponatremia have diametrically opposite effects on aquaresis. Inhibitors of vasopressin V2 receptor (vaptans) lead to the production of dilute urine, whereas infusion of desmopressin causes urinary concentration. Identification of the category of hyponatremia that will benefit from one or the other treatment is critical. In general, vaptans are effective in hyponatremias presenting with concentrated urine and, with the exception of hypovolemic hyponatremia, can be used as their primary treatment. Desmopressin is effective in hyponatremias presenting with dilute urine or developing urinary dilution …

Prieurianin Causes Weight Loss In Diet-Induced Obese Mice And Inhibits Adipogenesis In Cultured Preadipocytes, Ahmed Kablan, Rudel A. Saunders, Maria Szkudlarek-Mikho, Andrew J.B. Chin, Raul M. Bosio, Kazuyuki Fujii, Joseph I. Shapiro M.D., Khew-Voon Chin

Joseph I Shapiro MD

The global increase in the incidence of obesity has emerged as one of the most serious public health risks in recent years. Despite the enormity of the obesity pandemic, there are currently only two FDA-approved therapies for its treatment and these drugs exhibit modest effi cacy and have limiting side effects. Prieurianin is a plant limonoid product that deters feeding in insect larvae. We investigated in this study the effects of prieurianin on weight loss and adipogenesis. Our results showed that prieurianin causes weight loss by reducing energy intake in obese mice on highcalorie diet. We also found that prieurianin …

Down-Regulation Of The Transcription Factor Snail In The Placentas Of Patients With Preeclampsia And In A Rat Model Of Preeclampsia, Larissa Federova, Cara Gatto-Weis, Sleiman Smaili, Nauman Khurshid, Joseph I. Shapiro M.D., Deepak Malhorta, Terrence Horrigan

Joseph I Shapiro MD

Background: Placental malfunction in preeclampsia is believed to be a consequence of aberrant differentiation of trophoblast lineages and changes in utero-placental oxygenation. The transcription factor Snail, a master regulator molecule of epithelial-mesenchymal transition in embryonic development and in cancer, is shown to be involved in trophoblast differentiation as well. Moreover, Snail can be controlled by oxidative stress and hypoxia. Therefore, we examined the expression of Snail and its downstream target, e-cadherin, in human normal term, preterm and preeclamptic placentas, and in pregnant rats that developed preeclampsia-like symptoms in the response to a 20- fold increase in sodium intake. Methods: Western …

Stem Cell Transplantation Increases Antioxidant Effects In Diabetic Mice, Ming Li, Luca Vanella, Yuming Zhang, Ming Shi, Takashi Takaki, Joseph I. Shapiro M.D., Susuma Ikehera

Joseph I Shapiro MD

Intra bone marrow-bone marrow transplantation (IBM- BMT) + thymus transplantation (TT) has been shown to reduce the incidence of graft versus host disease (GVHD) and restore donor-derived T cell function. In addition, an increase in insulin sensitivity occurred in db/db mice after IBM-BMT+TT treatment. Heme oxygenase (HO)-1 is a stress inducible enzyme which exert antioxidant, antiapoptotic, and immune-modulating properties. We examined whether IBM-BMT+TT could modulate the expression of HO-1 in the kidneys of db/db mice. Six-week-old db/db mice with blood glucose levels higher than 250 mg/dl were treated with IBM-BMT+TT. Six weeks later, the db/db mice showed decreased body weight, …

Principles Of Management Of Severe Hyponatremia, Antonios H. Tzamaloukas Md, Deepak Malhorta Md, Phd, Bradley H. Rosen Do, Dominic S. C. Raj S. C. Raj Md, Glen H. Murata Md, Joseph I. Shapiro Md

Joseph I Shapiro MD

Hyponatremia represents a serious health hazard.1 Hospitalized patients,2 nursing home residents,3 women,4,5 and children6 exhibit high frequency and/or severity of hyponatremia. Hyponatremia developing during the course of other morbid conditions increases their severity.7–10 Estimates of direct costs for treating hyponatremia in the United States ranged between $1.61 and $3.6 billion.11 Clinical manifestations of hyponatremia are universal12,13 and range from subtle (disturbances of balance, problems in cognition detected only during specific testing) to life-threatening manifestations of increased intracranial pressure with life-threatening hypoxia14–16 and noncardiac pulmonary edema.17 Although the treating physicians must make an accurate diagnosis based on well-established and described clinical …

Cyclooxygenase-2 Dependent Metabolism Of 20-Hete Increases Adiposity And Adipocyte Enlargement In Mesenchymal Stem Cell-Derived Adipocytes, Dong Hyun Kim, Nitin Puri, Komal Sodhi, John R. Falck, Nader G. Abraham, Joseph I. Shapiro M.D., Michal L. Schwartzman

Joseph I Shapiro MD

Abstract 20-Hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE), a product of the cytochrome P450 (CYP)-catalyzed [1] -hydroxylation of arachidonic acid, induces oxidative stress and, in clinical studies, is associated with increased body mass index (BMI) and the metabolic syndrome. This study was designed to examine the effects of exogenous 20- HETE on mesenchymal stem cell (MSC)-derived adipocytes. The expression levels of CYP4A11 and CYP4F2 (major 20-HETE synthases in humans) in MSCs decreased during adipocyte differentiation; however, exogenous administration of 20-HETE (0.1–1 M) increased adipogenesis in a dose dependent manner in these cells ( P < 0.05). The inability of a 20-HETE analog to reproduce these …

Increased Heme-Oxygenase 1 Expression In Mesenchymal Stem Cell-Derived Adipocytes Decreases Differentiation And Lipid Accumulation Via Upregulation Of The Canonical Wnt Signaling Cascade, Luca Vanella, Komal Sodhi, Dong Hyun Kim, Nitin Puri, Mani Maheshwari, Terry D . Hinds, Lars Bellner, Dov Goldstein, Stephen J . Peterson, Joseph I. Shapiro M.D., Nader G. Abraham

Joseph I Shapiro MD

Introduction: Heme oxygenase (HO), a major cytoprotective enzyme, attenuates oxidative stress and obesity. The canonical Wnt signaling cascade plays a pivotal role in the regulation of adipogenesis. The present study examined the interplay between HO-1and the Wnt canonical pathway in the modulation of adipogenesis in mesenchymal stem cell (MSC)-derived adipocytes. Methods: To verify the role of HO-1 in generating small healthy adipocytes, cobalt protoporphyrin (CoPP), inducer of HO-1, was used during adipocyte differentiation. Lipid accumulation was measured by Oil red O staining and lipid droplet size was measured by BODIPY staining. Results: During adipogenesis in vitro, differentiating pre-adipocytes display transient …

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

Joseph I Shapiro MD

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 …

Principles Of Quantitative Fluid And Cation Replacement In Extreme Hyperglycemia, Antonios H. Tzamaloukas, Yijuan Sun, Nikifor K. Konstantinov, Richard I. Dorin, Todd S. Ing, Deepak Malhorta, Glenn H. Murata, Joseph I. Shapiro M.D.

Joseph I Shapiro MD

Hyperglycemia may cause profound deficits of water, sodium and potassium through osmotic diuresis, which continues during treatment as long as there is glucosuria. Replacement fluids should cover both the deficits at presentation and the ongoing losses during treatment. At presentation with hyperglycemia, quantitative estimates of the deficits in water, sodium and potassium are based on rapid body weight changes, which indicate changes in body water, and on the serum sodium concentration corrected to a normal serum glucose level. The corrected serum sodium concentration provides a measure of the water deficit relative to the cation deficit (sodium, plus potassium) that is …

Gender Differences In The Development Of Uremic Cardiomyopathy Following Partial Nephrectomy: Role Of Progesterone, Christopher A. Drummond, George Buddny, Steven T. Haller, Jiang Liu, Yanling Yan, Zijian Xie, Deepak Malhotra, Joseph I. Shapiro Md, Jiang Tian

Joseph I Shapiro MD

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 …

Involvement Of Reactive Oxygen Species In A Feed-Forward Mechanism Of Na/K-Atpase Mediated Signaling, Yanling Yan, Anna P. Shapiro, Steven Haller, Vinal Katragadda, Lijun Liu, Jiang Tian, Venkatesha Basrur, Deepak Malhotra, Zi-Jian Xie, Nader G. Abraham, Joseph I. Shapiro Md, Jiang Liu

Joseph I Shapiro MD

Cardiotonic steroids (such as ouabain) signaling through Na/K-ATPase regulate sodium reabsorption in the renal proximal tubule. We report here that reactive oxygen species are required to initiate ouabain-stimulated Na/K-ATPase·c-Src signaling. Pretreatment with the antioxidant N-acetyl-L-cysteine prevented ouabain-stimulated Na/K-ATPase·c-Src signaling, protein carbonylation, redistribution of Na/K-ATPase and sodium/proton exchanger isoform 3, and inhibition of active transepithelial 22Na+ transport. Disruption of the Na/K-ATPase·c-Src signaling complex attenuated ouabain-stimulated protein carbonylation. Ouabain-stimulated protein carbonylation is reversed after removal of ouabain, and this reversibility is largely independent of de novo protein synthesis and degradation by either the lysosome or the proteasome pathways. Furthermore, ouabain stimulated direct …

Reduction Of Na/K-Atpase Potentiates Marinobufagenin-Induced Cardiac Dysfunction And Myocyte Apoptosis, Changxuan Liu, Yan Bai, Yiliang Chen, Yu Wang, Yoann Sottejeau, Lijun Liu, Xiaomei Li, Jerry B. Lingrel, Deepak Malhorta, Christopher Cooper, Joseph I. Shapiro M.D., Zi-Jian Xie, Jiang Tian

Joseph I Shapiro MD

Background: Na/K-ATPase decrease has been reported in patients with heart failure and is related to cardiac dysfunction. Results: Reducing Na/K-ATPase activates caspase 9 and induces cardiac dilation when treated with marinobufagenin. Conclusion: Reduction of Na/K-ATPase potentiates marinobufagenin-induced cardiac myocyte apoptosis. Significance: Decreased Na/K-ATPase content together with increased cardiotonic steroids levels is a novel mechanism that may account for cardiac dysfunction.

Pparδ Binding To Heme Oxygenase 1 Promoter Prevents Angiotensin Ii-Induced Adipocyte Dysfunction In Goldblatt Hypertensive Rats, Komal Sodhi, Nitin Puri, Dong Hyun Kim, Terry D. Hinds Jr., Lance A. Stechschulte, Gaia Favero, Luigi Rodella, Joseph I. Shapiro M.D., David C. Jude, Nader X. Abraham

Joseph I Shapiro MD

Abstract: OBJECTIVE: Renin–angiotensin system (RAS) regulates adipogenic response with adipocyte hypertrophy by increasing oxidative stress. Recent studies have shown the role of peroxisome proliferator-activated receptor-d (PPARδ) agonist in attenuation of angiotensin II-induced oxidative stress. The aim of this study was to explore a potential mechanistic link between PPARδ and the cytoprotective enzyme heme oxygenase-1 (HO-1) and to elucidate the contribution of HO-1 to the adipocyte regulatory effects of PPARδ agonism in an animal model of enhanced RAS, the Goldblatt 2 kidney 1 clip (2K1C) model. METHOD: We first established a direct stimulatory effect of the PPARδ agonist (GW 501516) on …