Medicinal and Pharmaceutical Chemistry Commons^™

Lipopolysaccharide Induced Map Kinase Activation In Raw 264.7 Cells Attenuated By Cerium Oxide Nanoparticles, Vellaisamy Selvaraj, Niraj Nepa, Steven Rogers, Nandini D.P.K. Manne, Ravi K. Arvapalli, Kevin M. Rice, Shinichi Asano, Erin Fankenhanel, J. Y. Ma, Tolou Shokuhfar, Mani Maheshwari, Eric R. Blough

Mani Maheshwari

High mortality rates are associated with the life threatening disease of sepsis. Improvements in septic patient survivability have failed to materialize with currently available treatments. This article represents data regarding a study published in biomaterials (Vellaisamy et al., Biomaterials, 2015, in press). with the purpose of evaluating whether severe sepsis mortality and associated hepatic dysfunction induced by lipopolysaccharide (LPS) can be prevented by cerium oxide nanoparticles (CeO2NPs) treatment in male Sprague Dawley rats. Here we provide the information about the method and processing of raw data related to our study publish in Biomaterials and Data in Brief (Vellaisamy et al., …

Whole Genome Sequence Analysis Of The Tallyho/Jng Mouse, James Denvir, Goran Boskovic, Jun Fan, Donald A. Primerano, Jacaline K. Parkman, Jung Han Kim

Jung Han Kim

Background: The TALLYHO/Jng (TH) mouse is a polygenic model for obesity and type 2 diabetes first described in the literature in 2001. The origin of the TH strain is an outbred colony of the Theiler Original strain and mice derived from this source were selectively bred for male hyperglycemia establishing an inbred strain at The Jackson Laboratory. TH mice manifest many of the disease phenotypes observed in human obesity and type 2 diabetes.

Results: We sequenced the whole genome of TH mice maintained at Marshall University to a depth of approximately 64.8X coverage using data from three next generation sequencing …

Whole Genome Sequence Analysis Of The Tallyho/Jng Mouse, James Denvir, Goran Boskovic, Jun Fan, Donald A. Primerano, Jacaline K. Parkman, Jung Han Kim

Jun Fan

Background: The TALLYHO/Jng (TH) mouse is a polygenic model for obesity and type 2 diabetes first described in the literature in 2001. The origin of the TH strain is an outbred colony of the Theiler Original strain and mice derived from this source were selectively bred for male hyperglycemia establishing an inbred strain at The Jackson Laboratory. TH mice manifest many of the disease phenotypes observed in human obesity and type 2 diabetes. Results: We sequenced the whole genome of TH mice maintained at Marshall University to a depth of approximately 64.8X coverage using data from three next generation sequencing …

Whole Genome Sequence Analysis Of The Tallyho/Jng Mouse, James Denvir, Goran Boskovic, Jun Fan, Donald A. Primerano, Jacaline K. Parkman, Jung Han Kim

Goran Boskovic

Background: The TALLYHO/Jng (TH) mouse is a polygenic model for obesity and type 2 diabetes first described in the literature in 2001. The origin of the TH strain is an outbred colony of the Theiler Original strain and mice derived from this source were selectively bred for male hyperglycemia establishing an inbred strain at The Jackson Laboratory. TH mice manifest many of the disease phenotypes observed in human obesity and type 2 diabetes. Results: We sequenced the whole genome of TH mice maintained at Marshall University to a depth of approximately 64.8X coverage using data from three next generation sequencing …

Whole Genome Sequence Analysis Of The Tallyho/Jng Mouse, James Denvir, Goran Boskovic, Jun Fan, Donald A. Primerano, Jacaline K. Parkman, Jung Han Kim

Donald A. Primerano

Background: The TALLYHO/Jng (TH) mouse is a polygenic model for obesity and type 2 diabetes first described in the literature in 2001. The origin of the TH strain is an outbred colony of the Theiler Original strain and mice derived from this source were selectively bred for male hyperglycemia establishing an inbred strain at The Jackson Laboratory. TH mice manifest many of the disease phenotypes observed in human obesity and type 2 diabetes. Results: We sequenced the whole genome of TH mice maintained at Marshall University to a depth of approximately 64.8X coverage using data from three next generation sequencing …

Whole Genome Sequence Analysis Of The Tallyho/Jng Mouse, James Denvir, Goran Boskovic, Jun Fan, Donald A. Primerano, Jacaline K. Parkman, Jung Han Kim

James Denvir

Background: The TALLYHO/Jng (TH) mouse is a polygenic model for obesity and type 2 diabetes first described in the literature in 2001. The origin of the TH strain is an outbred colony of the Theiler Original strain and mice derived from this source were selectively bred for male hyperglycemia establishing an inbred strain at The Jackson Laboratory. TH mice manifest many of the disease phenotypes observed in human obesity and type 2 diabetes.

Results: We sequenced the whole genome of TH mice maintained at Marshall University to a depth of approximately 64.8X coverage using data from three next generation sequencing …

Dengue Virus Ns2b/Ns3 Protease Inhibitors Exploiting The Prime Side, Kuan-Hung Lin, Akbar Ali, Linah Rusere, Djade I. Soumana, Nese Kurt Yilmaz, Celia A. Schiffer

Celia A. Schiffer

The mosquito-transmitted dengue virus (DENV) infects millions of people in tropical and subtropical regions. Maturation of DENV particles requires proper cleavage of the viral polyprotein, including processing of 8 of the 13 substrate cleavage sites by dengue virus NS2B/NS3 protease. With no available direct-acting antiviral targeting DENV, NS2/NS3 protease is a promising target for inhibitor design. Current design efforts focus on the nonprime side of the DENV protease active site, resulting in highly hydrophilic and nonspecific scaffolds. However, the prime side also significantly modulates DENV protease binding affinity, as revealed by engineering the binding loop of aprotinin, a small protein …

Interdependence Of Inhibitor Recognition In Hiv-1 Protease, Janet L. Paulsen, Florian Leidner, Debra A. Ragland, Nese Kurt Yilmaz, Celia A. Schiffer

Celia A. Schiffer

Molecular recognition is a highly interdependent process. Subsite couplings within the active site of proteases are most often revealed through conditional amino acid preferences in substrate recognition. However, the potential effect of these couplings on inhibition and thus inhibitor design is largely unexplored. The present study examines the interdependency of subsites in HIV-1 protease using a focused library of protease inhibitors, to aid in future inhibitor design. Previously a series of darunavir (DRV) analogs was designed to systematically probe the S1' and S2' subsites. Co-crystal structures of these analogs with HIV-1 protease provide the ideal opportunity to probe subsite interdependency. …

Effects Of Anandamide Administration On Components Of Reward Processing, Howard C. Cromwell

Howard Casey Cromwell

A Standardized Patient Counseling Rubric For A Pharmaceutical Care And Communications Course, Niambi Horton Pharmd, Kenna D. Payne Pharmd, Michelle Jernigan Pharmd, Jill Frost Pharmd, Stephen Wise Pharmd, Mary Klein Pharmd, Joel Epps Mba, H. Glenn Anderson Pharmd

H. Glenn Anderson

Objective. To restructure a required pharmaceutical care and communications course to place greater emphasis on communication skills and include a high-stakes assessment. Design. A standardized counseling rubric was developed for use throughout the pharmacy curriculum and the counseling laboratory practicals were changed to high-stakes assessments. Assessment. An annual mid-semester and end-of-semester high-stakes patient-counseling objective structured clinical examination (OSCE) conducted prior to and after revision of the course and counseling rubric documented improvements in students’ scores. Performance on the post-course annual assessment patient counseling OSCE improved compared to that on the pre-course (p,0.001). Conclusion. The 2010 course revision improved students’ medication …

Reactive Oxygen Species Modulation Of Na/K-Atpase Regulates Fibrosis And Renal Proximal Tubular Sodium Handling, Jiang Liu, David J. Kennedy, Yanling Yan, Joseph I. Shapiro Md

Yanling Yan

The Na/K-ATPase is the primary force regulating renal sodium handling and plays a key role in both ion homeostasis and blood pressure regulation. Recently, cardiotonic steroids (CTS)-mediated Na/K-ATPase signaling has been shown to regulate fibrosis, renal proximal tubule (RPT) sodium reabsorption, and experimental Dahl salt-sensitive hypertension in response to a high-salt diet. Reactive oxygen species (ROS) are an important modulator of nephron ion transport. As there is limited knowledge regarding the role of ROS-mediated fibrosis and RPT sodium reabsorption through the Na/K-ATPase, the focus of this review is to examine the possible role of ROS in the regulation of Na/K-ATPase …

Reactive Oxygen Species Modulation Of Na/K-Atpase Regulates Fibrosis And Renal Proximal Tubular Sodium Handling, Jiang Liu, David J. Kennedy, Yanling Yan, Joseph I. Shapiro Md

Jiang Liu

The Na/K-ATPase is the primary force regulating renal sodium handling and plays a key role in both ion homeostasis and blood pressure regulation. Recently, cardiotonic steroids (CTS)-mediated Na/K-ATPase signaling has been shown to regulate fibrosis, renal proximal tubule (RPT) sodium reabsorption, and experimental Dahl salt-sensitive hypertension in response to a high-salt diet. Reactive oxygen species (ROS) are an important modulator of nephron ion transport. As there is limited knowledge regarding the role of ROS-mediated fibrosis and RPT sodium reabsorption through the Na/K-ATPase, the focus of this review is to examine the possible role of ROS in the regulation of Na/K-ATPase …

Reactive Oxygen Species Modulation Of Na/K-Atpase Regulates Fibrosis And Renal Proximal Tubular Sodium Handling, Jiang Liu, David J. Kennedy, Yanling Yan, Joseph I. Shapiro Md

Joseph I Shapiro MD

The Na/K-ATPase is the primary force regulating renal sodium handling and plays a key role in both ion homeostasis and blood pressure regulation. Recently, cardiotonic steroids (CTS)-mediated Na/K-ATPase signaling has been shown to regulate fibrosis, renal proximal tubule (RPT) sodium reabsorption, and experimental Dahl salt-sensitive hypertension in response to a high-salt diet. Reactive oxygen species (ROS) are an important modulator of nephron ion transport. As there is limited knowledge regarding the role of ROS-mediated fibrosis and RPT sodium reabsorption through the Na/K-ATPase, the focus of this review is to examine the possible role of ROS in the regulation of Na/K-ATPase …

Ho-1 Upregulation Attenuates Adipocyte Dysfunction, Obesity, And Isoprostane Levels In Mice Fed High Fructose Diets, Zeid Khitan, Mohit Harsh, Komal Sodhi, Joseph Shapiro, Nader Abraham

Nader G. Abraham

Background. Fructose metabolism is an unregulated metabolic pathway and excessive fructose consumption is known to activate ROS.HO-1 is a potent antioxidant gene that plays a key role in decreasing ROS and isoprostanes.We examinedwhether the fructosemediated increase in adipocyte dysfunction involves an increase in isoprostanes and that pharmacological induction ofHO-1would decrease both isoprostane levels and adipogenesis. Methods and Results. We examined the effect of fructose, on adipogenesis in human MSCs in the presence and absence of CoPP, an inducer of HO-1. Fructose increased adipogenesis and the number of large lipid droplets while decreasing the number of small lipid droplets (𝑃 < 0.05). …

Ho-1 Upregulation Attenuates Adipocyte Dysfunction, Obesity, And Isoprostane Levels In Mice Fed High Fructose Diets, Zeid Khitan, Mohit Harsh, Komal Sodhi, Joseph I. Shapiro Md, Nader G. Abraham

Zeid J. Khitan

Background. Fructose metabolism is an unregulated metabolic pathway and excessive fructose consumption is known to activate ROS.HO-1 is a potent antioxidant gene that plays a key role in decreasing ROS and isoprostanes.We examinedwhether the fructosemediated increase in adipocyte dysfunction involves an increase in isoprostanes and that pharmacological induction ofHO-1would decrease both isoprostane levels and adipogenesis. Methods and Results. We examined the effect of fructose, on adipogenesis in human MSCs in the presence and absence of CoPP, an inducer of HO-1. Fructose increased adipogenesis and the number of large lipid droplets while decreasing the number of small lipid droplets (𝑃 < 0.05). …

Ho-1 Upregulation Attenuates Adipocyte Dysfunction, Obesity, And Isoprostane Levels In Mice Fed High Fructose Diets, Zeid Khitan, Mohit Harsh, Komal Sodhi, Joseph I. Shapiro Md, Nader G. Abraham

Komal Sodhi

Background. Fructose metabolism is an unregulated metabolic pathway and excessive fructose consumption is known to activate ROS.HO-1 is a potent antioxidant gene that plays a key role in decreasing ROS and isoprostanes.We examinedwhether the fructosemediated increase in adipocyte dysfunction involves an increase in isoprostanes and that pharmacological induction ofHO-1would decrease both isoprostane levels and adipogenesis. Methods and Results. We examined the effect of fructose, on adipogenesis in human MSCs in the presence and absence of CoPP, an inducer of HO-1. Fructose increased adipogenesis and the number of large lipid droplets while decreasing the number of small lipid droplets (𝑃 < 0.05). …

Ho-1 Upregulation Attenuates Adipocyte Dysfunction, Obesity, And Isoprostane Levels In Mice Fed High Fructose Diets, Zeid Khitan, Mohit Harsh, Komal Sodhi, Joseph I. Shapiro Md, Nader G. Abraham

Joseph I Shapiro MD

Background. Fructose metabolism is an unregulated metabolic pathway and excessive fructose consumption is known to activate ROS.HO-1 is a potent antioxidant gene that plays a key role in decreasing ROS and isoprostanes.We examinedwhether the fructosemediated increase in adipocyte dysfunction involves an increase in isoprostanes and that pharmacological induction ofHO-1would decrease both isoprostane levels and adipogenesis. Methods and Results. We examined the effect of fructose, on adipogenesis in human MSCs in the presence and absence of CoPP, an inducer of HO-1. Fructose increased adipogenesis and the number of large lipid droplets while decreasing the number of small lipid droplets (𝑃 < 0.05). …

Grp78/Bip Is Involved In Ouabain-Induced Endocytosis Of The Na/K-Atpase In Llc-Pk1 Cells, Riad Kesiry, Jiang Liu

Jiang Liu

We have demonstrated that ouabain causes dose- and time-dependent decreases both in 86Rb+ uptake and plasmalemmal Na/K-ATPase content of LLC-PK1 cells, which is related to ouabain-induced endocytosis of plasmalemmal Na/K-ATPase in LLC-PK1 cells through a clathrin-dependent mechanism. GRP78/BiP is a resident protein of the endoplasmic reticulum (ER) and acts as a molecular chaperone. Recently, several studies have shown that GRP78/BiP is also expressed on the cell surface and forms heterogeneous, high molecular weight complexes with other proteins. To identify the proteins that are possibly involved in ouabain-induced endocytosis of the Na/K-ATPase in LLC-PK1 cells, we separated and identified endosomal proteins …

Ouabain And Insulin Induce Sodium Pump Endocytosis In Renal Epithelium, Shalini Gupta, Yanling Yan, Deepak Malhotra, Jiang Liu, Zijian Xie, Sonia Najjar, Joseph Shapiro

Jiang Liu

Cardiotonic steroids signaling through the basolateral sodium pump (Na/K-ATPase) have been shown to alter renal salt handling in intact animals. Because the relationship between renal salt handling and blood pressure is a key determinant of hypertension, and patients with insulin resistance are frequently hypertensive, we chose to examine whether there might be competition for resources necessary for receptor-mediated endocytosis. In LLC-PK1 cells, the Na/K-ATPase-α1 and carcinoembryonic antigen cell adhesion molecule 1, a plasma membrane protein that promotes receptor-mediated endocytosis, colocalized in the plasma membranes and translocated to the intracellular region in response to ouabain. Either ouabain or insulin alone caused …

A Study Of 5-Aminolevulinic Acid And Its Methyl Ester Used In In Vitro And In Vivo Systems Of Human Bladder Cancer, Vanaja Manivasager, Paul Wan Sia Heng, Jinsong Hao, Wei Zheng, Khee Chee Soo, Malini Olivo

Jinsong Hao

The use of 5-aminolevulinic acid and its esters to induce endogenous porphyrins for the purpose of detection of epithelial cancers is being studied extensively in many centres around the world. The challenge is to prepare an efficacious formulation for the purpose of cancer detection. Photodynamic diagnosis of cancer using 5-aminolevulinic acid (ALA) and its ester derivatives is being actively investigated. In this study, we compared ALA with ALA methyl ester (AME) derivative in terms of PpIX fluorescence intensity in in vitro and in vivo systems of bladder carcinoma. For the in vivo system consisting of RT112 xenografts, the modes of …

Risperidone And Its Deconstructed Analogs: Functional Effects On The 5ht2ar, Sneha Shah

Sneha Shah

G protein-coupled receptors (GPCRs) are seven-transmembrane domain receptors that sense extracellular signal and activate intracellular signaling pathways. The serotonin 5HT2A receptor (or 2AR) is one of the GPCRs coupled to Gq proteins, activating PLC and hydrolyzing PIP2. This hydrolysis causes a diffusion of bound PIP2 away from the channel binding site resulting in G protein-gated inwardly rectifying K+ channel (GIRK) inhibition and a downstream stimulation of Ca2+ release from endoplasmic reticulum stores. Previous experiments have demonstrated that the serotonin 5HTA receptor is a target of serotonergic psychedelic drugs, such as LSD, and partially mediates the action of many atypical antipsychotic …

Effects Of Cardiac Glycosides On Sodium Pump Expression And Function In Llc-Pk1 And Mdck Cells, Jiang Liu, Sankaridrug Periyasamy, William Gunning, Olga Fedorova, Alexi Bagrov, Deepak Malhorta, Zijian Xie, Joseph Shapiro

Zijian Xie

Background: The decreases in proximal tubule sodium reabsorption seen with chronic renal failure and volume expansion have been ascribed to circulating digitalis-like substances (DLS). However, the circulating concentrations of DLS do not acutely inhibit the sodium pump to a degree consistent with the observed changes in proximal tubule sodium reabsorption.

Methods: We examined how cell lines that simulated proximal (LLC-PK1) and distal tubule (MDCK) cells responded to acute (30 min) and long-term (up to 12 hours) Na⁺,K⁺-ATPase inhibition with DLS.

Results: In LLC-PK1, but not MDCK cells, low concentrations of ouabain decreased ⁸⁶Rb uptake profoundly …

Ouabain Induces Endocytosis Of Plasmalemmal Na/K-Atpase In Llc-Pk1 Cells By A Clathrin-Dependent Mechanism, Jiang Liu, Riad Kesiry, Sankaridrug Periyasamy, Deppak Malhorta, Zijian Xie, Joseph Shapiro

Zijian Xie

Background: We have demonstrated that ouabain causes dose- and time-dependent decreases in ⁸⁶Rb uptake in porcine proximal tubular (LLC-PK1) cells. The present study addresses the molecular mechanisms involved in this process.

Methods: Studies were performed with cultured LLC-PK1 and Src family kinase deficient (SYF) cells.

Results: We found that 50 nmol/L ouabain applied to the basal, but not apical, aspect for 12 hours caused decreases in the plasmalemmal Na/K-ATPase. This loss of plasmalemmal Na/K-ATPase reverses completely within 12 to 24 hours after removal of ouabain. Ouabain also increased the Na/K-ATPase content in both early and late endosomes, activated phosphatidylinositol …

Regulation Of Apical Nhe3 Trafficking By Ouabain-Induced Activation Of Basolateral Na/K-Atpase Receptor Complex, Haiping Cai, Liang Wu, Weikai Qu, Deepak Malhotra, Zijian Xie, Joseph I. Shapiro, Jiang Liu

Zijian Xie

The long-term effects of ouabain on transepithelial Na+ transport involve transcriptional downregulation of apical Na+/H+ exchanger isoform 3 (NHE3). The aim of this study was to determine whether ouabain could acutely regulate NHE3 via a posttranscriptional mechanism in LLC-PK1 cells. We observed that the basolateral, but not apical, application of ouabain for 1 h significantly reduced transepithelial Na+ transport. This effect was not due to changes in the integrity of tight junctions or increases in the intracellular Na+ concentration. Ouabain regulated the trafficking of NHE3 and subsequently inhibited its activity, a process independent of intracellular Na+ concentration. Ouabain-induced NHE3 trafficking …

Cardiac Glycoside Downregulates Nhe3 Activity And Expression In Llc-Pk1 Cells, Shadi Oweis, Liang Wu, Pawel Kiela, Deepak Malhotra, Fayez Ghishan, Zijian Xie, Joseph Shapiro, Jiang Liu

Zijian Xie

Ouabain, a cardiotonic steroid and a specific inhibitor of the Na+-K+-ATPase, has been shown to significantly inhibit transcellular Na+ transport without altering the intracellular Na+ concentration ([Na+]i) in the epithelial cells derived from the renal proximal tubules. We therefore studied whether ouabain affects the activity and expression of Na_/H_ exchanger isoform 3 (NHE3) representing the major route of apical Na_ reabsorption in LLC-PK1 cells. Chronic basolateral, but not apical, exposure to low-concentration ouabain (50 and 100 nM) did not change [Na+]i but significantly reduced NHE3 activity, NHE3 protein, and mRNA wxpression. Inhibition of c-Src or phosphoinositide 3-kinase (PI3K) with PP2 …

Ouabain-Induced Endocytosis Of The Plasmalemmal Na/K-Atpase In Llc-Pk1 Cells Requires Caveolin-1, Jiang Liu, Man Liang, Lijun Liu, Deepak Malhotra, Zijian Xie, Joseph Shapiro

Zijian Xie

Background: We have demonstrated that ouabain causes dose- and time-dependent decreases in 86Rb uptake in pig renal proximal tubule cell line (LLC-PK1) cells; and ouabain induces endocytosis of plasmalemmal Na/K-ATPase in LLC-PK1 cells in a clathrin-dependent pathway. Our data also suggest a role of endocytosis in both ouabain-induced signal transduction and proximal tubule sodium handling. The present study addresses the molecular mechanisms involved in this process. Methods: Studies were performed with cultured LLC-PK1 and a stable-expressed caveolin-1 knockdown LLC-PK1 cell line by SiRNA method. Results: In wild-type LLC-PK1 cells, depletion of cholesterol by methyl -cyclodextrin reduced ouabain-induced accumulation of Na/K-ATPase …

Intracellular Reactive Oxygen Species Mediate The Linkage Of Na+/K+-Atpase To Hypertrophy And Its Marker Genes In Cardiac Myocytes, Joseph I. Shapiro, Amir Askari, Zijian Xie, Peter Kometiani, Jie Li, Jiang Liu

Zijian Xie

We showed before that in cardiac myocytes partial inhibition of Na+/K+-ATPase by nontoxic concentrations of ouabain causes hypertrophy and transcriptional regulations of growth-related marker genes through multiple Ca2+-dependent signal pathways many of which involve Ras and p42/44 mitogen-activated protein kinases. The aim of this work was to explore the roles of intracellular reactive oxygen species (ROS) in these ouabain-initiated pathways. Ouabain caused a rapid generation of ROS within the myocytes that was prevented by preexposure of cells to N-acetylcysteine (NAC) or vitamin E. These antioxidants also blocked or attenuated the following actions of ouabain: inductions of the genes of skeletal …

Ouabain And Insulin Induce Sodium Pump Endocytosis In Renal Epithelium, Shalini Gupta, Yanling Yan, Deepak Malhotra, Jiang Liu, Zijian Xie, Sonia Najjar, Joseph Shapiro

Zijian Xie

Cardiotonic steroids signaling through the basolateral sodium pump (Na/K-ATPase) have been shown to alter renal salt handling in intact animals. Because the relationship between renal salt handling and blood pressure is a key determinant of hypertension, and patients with insulin resistance are frequently hypertensive, we chose to examine whether there might be competition for resources necessary for receptor-mediated endocytosis. In LLC-PK1 cells, the Na/K-ATPase-α1 and carcinoembryonic antigen cell adhesion molecule 1, a plasma membrane protein that promotes receptor-mediated endocytosis, colocalized in the plasma membranes and translocated to the intracellular region in response to ouabain. Either ouabain or insulin alone caused …

Ouabain-Stimulated Trafficking Regulation Of The Na/K-Atpase And Nhe3 In Renal Proximal Tubule Cells, Yanling Yan, Steven Haller, Anna Shapiro, Nathan Malhotra, Jiang Tian, Zijian Xie, Deepak Malhotra, Joseph Shapiro, Jiang Liu

Zijian Xie

We have demonstrated that ouabain regulates protein trafficking of the Na/K-ATPase a1 subunit and NHE3 (Na/H exchanger, isoform 3) via ouabain-activated Na/K-ATPase signaling in porcine LLC-PK1 cells. To investigate whether this mechanism is species-specific, ouabain-induced regulation of the a1 subunit and NHE3 as well as transcellular 22Na? transport were compared in three renal proximal tubular cell lines (human HK-2, porcine LLC-PK1, and AAC-19 originated from LLC-PK1 in which the pig a1 was replaced by ouabain-resistant rat a1). Ouabain-induced inhibition of transcellular 22Na? transport is due to an ouabain-induced redistribution of the a1 subunit and NHE3. In LLC-PK1 cells, ouabain also …

Salt Loading Induces Redistribution Of The Plasmalemmal Na/K-Atpase In Proximal Tubule Cells, Sankaridrug Periyasamy, Jiang Liu, Feras Tanta, Besher Kabak, Brent Wakefield, Deepak Malhorta, David Kennedy, Alaa Nodoor, Olga Fedorova, William Gunning, Zijian Xie, Alexi Bagrov, Joseph Shapiro

Zijian Xie

Background: We have reported that digitalis-like substances (cardiotonic steroids), including marinobufagenin (MBG), induce endocytosis of the plasmalemmal Na/K-ATPase in LLCPK1 cells. The current report addresses the potential relevance of plasmalemmal Na/K-ATPase redistribution to in vivo salt handling. Methods: Male Sprague-Dawley rats were given 1 week of a high salt (4.0% NaCl) or normal salt (0.4% NaCl) diet. Urinary sodium excretion, as well as MBG excretion, was monitored, and proximal tubules were isolated using a Percoll gradient method. Tubular 86Rb uptake, Na/K-ATPase enzymatic activity, and Na/K-ATPase a1 subunit density were determined. Results: The high salt diet increased urinary sodium (17.8 ± …