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Aly R, Darwish S, Bala N, Ebrahim A, Shoemaker LR, McCray J, Garrett TJ, Alli AA. Functional and metabolomic analysis of urinary extracellular vesicles from juvenile mice with renal compensatory hypertrophy. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167096. [PMID: 38499276 DOI: 10.1016/j.bbadis.2024.167096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/14/2024] [Accepted: 02/20/2024] [Indexed: 03/20/2024]
Abstract
Unilateral nephrectomy, a procedure reducing kidney mass, triggers a compensatory response in the remaining kidney, increasing its size and function to maintain a normal glomerular filtration rate (GFR). Recent research has highlighted the role of extracellular vesicles (EVs) in renal physiology and disease, although their involvement in unilateral nephrectomy has been underexplored. In this study, unilateral nephrectomy was performed on young mice, and urinary extracellular vesicles (uEVs) characterization and cargo were analyzed. Kidney volume increased significantly post-nephrectomy, demonstrating compensatory hypertrophy. Serum creatinine, cystatin C, and urinary electrolytes concentrations were similar in both nephrectomized and control groups. Western blot analysis revealed upregulation of sodium-glucose cotransporter 2 (SGLT2) and sodium chloride cotransporter (NCC), and downregulation of sodium‑potassium-chloride co-transporter (NKCC2) and epithelial sodium channel (ENaC) in the nephrectomized group. Metabolomic analysis of uEVs showed an enrichment of certain metabolites, including citrate and stachydrine. Interestingly, uEVs from the nephrectomized group demonstrated a protective effect, downregulating signal transducer and activator of transcription 3 (STAT3) and reducing reactive oxygen species (ROS) in renal proximal cells, compared to uEVs from the control group. This study suggests that uEVs contain bioactive components capable of inducing protective, anti-inflammatory, anti-fibrinolytic, and antioxidative effects in renal cells. These findings contribute to our understanding of uEVs' role in renal compensatory mechanisms after unilateral nephrectomy and may hold promise for future therapeutic interventions in renal diseases.
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Affiliation(s)
- Rasha Aly
- Departement of Pediatrics, Division of Pediatric Nephrology, University of Florida, 32610, United States of America
| | - Sara Darwish
- Department of Physiology and Aging, College of Medicine, University of Florida, 32610, United States of America
| | - Niharika Bala
- Department of Physiology and Aging, College of Medicine, University of Florida, 32610, United States of America
| | - Areej Ebrahim
- Department of Physiology and Aging, College of Medicine, University of Florida, 32610, United States of America
| | - Lawrence R Shoemaker
- Departement of Pediatrics, Division of Pediatric Nephrology, University of Florida, 32610, United States of America
| | - Joel McCray
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, College of Medicine, Gainesville, FL 32610, United States of America
| | - Timothy J Garrett
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, College of Medicine, Gainesville, FL 32610, United States of America
| | - Abdel A Alli
- Department of Physiology and Aging, College of Medicine, University of Florida, 32610, United States of America; Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, College of Medicine, University of Florida, 32610, United States of America.
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Aly R, Dogan YE, Bala N, Lugo C, Darwish S, Shoemaker L, Alli AA. Dysregulation of kidney proteases in the pathogenesis of hypertension following unilateral nephrectomy in juvenile mice. Am J Transl Res 2024; 16:544-556. [PMID: 38463588 PMCID: PMC10918144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/12/2023] [Indexed: 03/12/2024]
Abstract
BACKGROUND Unliteral nephrectomy (UNX) results in the reduction of kidney mass. The remaining kidney undergoes compensatory renal growth via hypertrophy of the glomeruli and renal tubules to maintain a normal glomerular filtration rate (GFR). These compensatory mechanisms result in increased capillary pressure and glomerular hyperfiltration to increase single nephron GFR. Over time, hyperfiltration may lead to kidney scarring and the development of hypertension. OBJECTIVES The first objective of this study was to test the hypothesis that a 50% reduction in functioning nephrons in juvenile mice leads to increased blood pressure over a 24-hour phase. The second objective was to test the hypothesis that UNX leads to changes in the expression and activity of kidney proteases in juvenile mice. METHODS Eight male C57B6 juvenile wild-type mice were subject to UNX and an equal number of mice were subject to sham (SH) surgery. Metabolic cage studies were performed for 5 weeks to collect urine produced during the inactive and active phases. Blood pressure was measured using the tail cuff method twice weekly and tail blood was collected on different days during the inactive or active phase of each animal. The mice were euthanized at the age of 9 weeks. Western blotting and immunohistochemistry were performed to investigate changes in renal protein expression of various cathepsins and renal kallikrein 1 (KLK1) between the two groups. Protease activity assays were performed using kidney lysates and urine samples from each group. RESULTS Compared to the SH group, UNX mice showed a persistent increase in blood pressure at week 3 which progressed toward the end of the study at week 5 of age. Cathepsin B, D, and S expression and activity were up-regulated in kidney cortex lysates from UNX mice compared to the SH control group. KLK1 protein expression was down-regulated and urinary nitric oxide excretion was decreased in UNX mice compared to the SH control group. CONCLUSION UNX results in the development of persistent and progressive hypertension. Down-regulation of KLK1 and up-regulation of various cathepsins may contribute to the development of hypertension via multiple mechanisms including a decrease in nitric oxide (NO) production.
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Affiliation(s)
- Rasha Aly
- Department of Pediatrics, Division of Pediatric Nephrology, University of Florida College of MedicineGainesville, FL, USA
| | - Yunus E Dogan
- Department of Physiology and Aging, University of Florida College of MedicineGainesville, FL, USA
- Department of Pediatrics, Faculty of Medicine, Erciyes UniversityKayseri, Turkey
| | - Niharika Bala
- Department of Physiology and Aging, University of Florida College of MedicineGainesville, FL, USA
| | - Carlos Lugo
- Department of Physiology and Aging, University of Florida College of MedicineGainesville, FL, USA
| | - Seena Darwish
- Department of Physiology and Aging, University of Florida College of MedicineGainesville, FL, USA
| | - Lawrence Shoemaker
- Department of Pediatrics, Division of Pediatric Nephrology, University of Florida College of MedicineGainesville, FL, USA
| | - Abdel A Alli
- Department of Pediatrics, Division of Pediatric Nephrology, University of Florida College of MedicineGainesville, FL, USA
- Department of Physiology and Aging, University of Florida College of MedicineGainesville, FL, USA
- Department of Medicine, Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of MedicineGainesville, FL, USA
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Al-Humiari MA, Yu L, Liu LP, Nouri MZ, Tuna KM, Denslow ND, Alli AA. Extracellular vesicles from BALF of pediatric cystic fibrosis and asthma patients increase epithelial sodium channel activity in small airway epithelial cells. Biochim Biophys Acta Biomembr 2024; 1866:184219. [PMID: 37634857 DOI: 10.1016/j.bbamem.2023.184219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 08/20/2023] [Accepted: 08/23/2023] [Indexed: 08/29/2023]
Abstract
Extracellular Vesicles (EVs) are nanosized vesicles derived from all cell types. EV cargo allows for intercellular communication, intracellular signaling, and regulation of proteins in recipient cells. We tested the hypothesis that EVs isolated from the bronchoalveolar-lavage fluid (BALF) of pediatric cystic fibrosis (CF) or pediatric asthma patients increase epithelial sodium channel (ENaC) activity in normal human small airway epithelial cells (SAECs) and the mechanism involves specific EV lipids. We characterized EVs from BALF of pediatric CF and pediatric asthma patients by nanoparticle tracking analysis, transmission electron microscopy, and Western blotting. The CF and asthma pediatric groups were similar in BALF electrolytes concentration and cell count, except for neutrophils, which were higher in the CF group. Lipidomic analyses for each group of EVs were performed using targeted mass spectrometry. Phosphatidylethanolamine, sphingomyelins, and triacylglycerol were enriched in both groups, but phosphatidylcholine and phosphatidylinositol concentrations were greater in the CF group compared to the asthma group, and the opposite trend was found for phosphatidylserine. Endogenous ENaC activity, measured by the single-channel patch-clamp technique, increased in normal human SAECs after challenging SAEC with EVs from either the CF or asthma groups compared to control EVs. In conclusion, EVs isolated from BALF of pediatric patients with CF or asthma have unique lipid profiles. Despite the differences, both types of EVs increase ENaC activity in normal human SAECs compared to control EVs isolated from the conditioned media of these cells.
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Affiliation(s)
- Mohammed A Al-Humiari
- Department of Pediatrics, Pediatric Pulmonology, University of Florida, Gainesville, FL, United States of America
| | - Ling Yu
- Department of Physiology and Aging, University of Florida, Gainesville, FL, United States of America
| | - Lauren P Liu
- Department of Physiology and Aging, University of Florida, Gainesville, FL, United States of America
| | - Mohammad-Zaman Nouri
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, United States of America
| | - Kubra M Tuna
- Department of Endocrinology, University of Florida, Gainesville, FL, United States of America
| | - Nancy D Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, United States of America
| | - Abdel A Alli
- Department of Pediatrics, Pediatric Pulmonology, University of Florida, Gainesville, FL, United States of America; Department of Physiology and Aging, University of Florida, Gainesville, FL, United States of America; Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, United States of America.
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Dogan YE, Bala N, Chacko KM, Tuna KM, Alli AA. Tempol treatment normalizes membrane expression of epithelial transport proteins in the kidney of salt-loaded hypertensive diabetic db/db mice. Am J Transl Res 2023; 15:6690-6700. [PMID: 38186979 PMCID: PMC10767517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/14/2023] [Indexed: 01/09/2024]
Abstract
OBJECTIVE Hypertension exacerbates the progression and severity of diabetic kidney disease. In this study, we addressed the hypothesis that tempol acts at multiple segments of the nephron to normalize the abundance of sodium coupled epithelial transport proteins in the luminal plasma membrane to mitigate high blood pressure in salt-loaded hypertensive diabetic db/db mice. METHODS Soluble and membrane fractions from freshly homogenized kidney cortex tissue samples were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and probed for specific proteins by Western blotting. Western blotting for specific urinary extracellular vesicle (uEV) markers and nanoparticle tracking analysis was performed to characterize each uEV preparation from each group. A one-way ANOVA was performed to determine statistical significance between three groups (hypertensive diabetic db/db mice treated with vehicle, hypertensive diabetic db/db mice treated with tempol, and wild-type mice). RESULTS Tempol treatment reduced systolic blood pressure in hypertensive diabetic db/db mice compared to db/db mice that received vehicle. We observed attenuated membrane protein expression of the sodium hydrogen exchanger 3 (NHE3), sodium potassium chloride co-transporter (NKCC2), sodium chloride cotransporter (NCC), and epithelial sodium channel (ENaC) in the kidney of salt-loaded hypertensive diabetic db/db mice infused with tempol by osmotic minipump for 5 days compared to hypertensive diabetic db/db mice infused with vehicle. Also, the infusion of tempol in hypertensive diabetic db/db mice reduced the augmented protein expression of protein kinase c (PKC) epsilon observed in the vehicle treated hypertensive diabetic db/db kidney when compared to the healthy wild-type kidney. The amount of uEV and their size profiles were comparable between the three groups. CONCLUSIONS This study demonstrates that tempol down-regulates epithelial transport mechanisms in each segment of the nephron and normalizes salt-induced high blood pressure in diabetic animals presumably in a PKC dependent manner.
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Affiliation(s)
- Yunus E Dogan
- Department of Physiology and Aging, College of Medicine, University of FloridaGainesville Florida 32610, USA
- Department of Pediatrics, Faculty of Medicine, Erciyes UniversityKayseri, Turkey
| | - Niharika Bala
- Department of Physiology and Aging, College of Medicine, University of FloridaGainesville Florida 32610, USA
| | - Kevin M Chacko
- Department of Physiology and Aging, College of Medicine, University of FloridaGainesville Florida 32610, USA
| | - Kubra M Tuna
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, College of Medicine, University of FloridaGainesville Florida 32610, USA
| | - Abdel A Alli
- Department of Physiology and Aging, College of Medicine, University of FloridaGainesville Florida 32610, USA
- Department of Medicine, Division of Nephrology, Hypertension and Renal Transplantation, College of Medicine, University of FloridaGainesville Florida 32610, USA
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Crislip GR, Costello HM, Juffre A, Cheng KY, Lynch IJ, Johnston JG, Drucker CB, Bratanatawira P, Agarwal A, Mendez VM, Thelwell RS, Douma LG, Wingo CS, Alli AA, Scindia YM, Gumz ML. Male kidney-specific BMAL1 knockout mice are protected from K +-deficient, high-salt diet-induced blood pressure increases. Am J Physiol Renal Physiol 2023; 325:F656-F668. [PMID: 37706232 PMCID: PMC10874679 DOI: 10.1152/ajprenal.00126.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/22/2023] [Accepted: 09/07/2023] [Indexed: 09/15/2023] Open
Abstract
The circadian clock protein basic helix-loop-helix aryl hydrocarbon receptor nuclear translocator-like protein 1 (BMAL1) is a transcription factor that impacts kidney function, including blood pressure (BP) control. Previously, we have shown that male, but not female, kidney-specific cadherin Cre-positive BMAL1 knockout (KS-BMAL1 KO) mice exhibit lower BP compared with littermate controls. The goal of this study was to determine the BP phenotype and immune response in male KS-BMAL1 KO mice in response to a low-K+ high-salt (LKHS) diet. BP, renal inflammatory markers, and immune cells were measured in male mice following an LKHS diet. Male KS-BMAL1 KO mice had lower BP following the LKHS diet compared with control mice, yet their circadian rhythm in pressure remained unchanged. Additionally, KS-BMAL1 KO mice exhibited lower levels of renal proinflammatory cytokines and immune cells following the LKHS diet compared with control mice. KS-BMAL1 KO mice were protected from the salt-sensitive hypertension observed in control mice and displayed an attenuated immune response following the LKHS diet. These data suggest that BMAL1 plays a role in driving the BP increase and proinflammatory environment that occurs in response to an LKHS diet.NEW & NOTEWORTHY We show here, for the first time, that kidney-specific BMAL1 knockout mice are protected from blood pressure (BP) increases and immune responses to a salt-sensitive diet. Other kidney-specific BMAL1 knockout models exhibit lower BP phenotypes under basal conditions. A salt-sensitive diet exacerbates this genotype-specific BP response, leading to fewer proinflammatory cytokines and immune cells in knockout mice. These data demonstrate the importance of distal segment BMAL1 in BP and immune responses to a salt-sensitive environment.
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Affiliation(s)
- G Ryan Crislip
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, Florida, United States
| | - Hannah M Costello
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, Florida, United States
| | - Alexandria Juffre
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, Florida, United States
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, United States
| | - Kit-Yan Cheng
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
| | - I Jeanette Lynch
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Department of Research, North Florida/South Georgia Veterans Health System, Gainesville, Florida, United States
| | - Jermaine G Johnston
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, Florida, United States
- Department of Research, North Florida/South Georgia Veterans Health System, Gainesville, Florida, United States
| | - Charles B Drucker
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
| | - Phillip Bratanatawira
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
| | - Annanya Agarwal
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, United States
| | - Victor M Mendez
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
| | - Ryanne S Thelwell
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
| | - Lauren G Douma
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, United States
| | - Charles S Wingo
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Department of Research, North Florida/South Georgia Veterans Health System, Gainesville, Florida, United States
| | - Abdel A Alli
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, Florida, United States
| | - Yogesh M Scindia
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, Florida, United States
| | - Michelle L Gumz
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, United States
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, United States
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, Florida, United States
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, United States
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Alli AA. Extracellular Vesicles: Investigating the Pathophysiology of Diabetes-Associated Hypertension and Diabetic Nephropathy. Biology (Basel) 2023; 12:1138. [PMID: 37627022 PMCID: PMC10452642 DOI: 10.3390/biology12081138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/03/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023]
Abstract
Extracellular vesicles (EVs) include exosomes, microvesicles, and apoptotic bodies. EVs are released by all cell types and are found in biological fluids including plasma and urine. Urinary extracellular vesicles (uEVs) are a mixed population of EVs that comprise small EVs that are filtered and excreted, EVs secreted by tubular epithelial cells, and EVs released from the bladder, urethra, and prostate. The packaged cargo within uEVs includes bioactive molecules such as metabolites, lipids, proteins, mRNAs, and miRNAs. These molecules are involved in intercellular communication, elicit changes in intracellular signaling pathways, and play a role in the pathogenesis of various diseases including diabetes-associated hypertension and diabetic nephropathy. uEVs represent a rich source of biomarkers, prognosis markers, and can be loaded with small-molecule drugs as a vehicle for delivery.
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Affiliation(s)
- Abdel A. Alli
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA; ; Tel.: +1-352-273-7877
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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Gholam MF, Bala N, Dogan YE, Alli AA. Augmentation of Cathepsin Isoforms in Diabetic db/db Mouse Kidneys Is Associated with an Increase in Renal MARCKS Expression and Proteolysis. Int J Mol Sci 2023; 24:12484. [PMID: 37569859 PMCID: PMC10419664 DOI: 10.3390/ijms241512484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 07/29/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023] Open
Abstract
The expression of the myristoylated alanine-rich C-kinase substrate (MARCKS) family of proteins in the kidneys plays an important role in the regulation of the renal epithelial sodium channel (ENaC) and hence overall blood pressure regulation. The function of MARCKS is regulated by post-translational modifications including myristoylation, phosphorylation, and proteolysis. Proteases known to cleave both ENaC and MARCKS have been shown to contribute to the development of high blood pressure, or hypertension. Here, we investigated protein expression and proteolysis of MARCKS, protein expression of multiple protein kinase C (PKC) isoforms, and protein expression and activity of several different proteases in the kidneys of diabetic db/db mice compared to wild-type littermate mice. In addition, MARCKS protein expression was assessed in cultured mouse cortical collecting duct (mpkCCD) cells treated with normal glucose and high glucose concentrations. Western blot and densitometric analysis showed less abundance of the unprocessed form of MARCKS and increased expression of a proteolytically cleaved form of MARCKS in the kidneys of diabetic db/db mice compared to wild-type mice. The protein expression levels of PKC delta and PKC epsilon were increased, while cathepsin B, cathepsin S, and cathepsin D were augmented in diabetic db/db kidneys compared to those of wild-type mice. An increase in the cleaved form of MARCKS was observed in mpkCCD cells cultured in high glucose compared to normal glucose concentrations. Taken together, these results suggest that high glucose may contribute to an increase in the proteolysis of renal MARCKS, while the upregulation of the cathepsin proteolytic pathway positively correlates with increased proteolysis of MARCKS in diabetic kidneys, where PKC expression is augmented.
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Affiliation(s)
- Mohammed F. Gholam
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah 22384, Saudi Arabia
| | - Niharika Bala
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Yunus E. Dogan
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Abdel A. Alli
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Medicine Division of Nephrology, Hypertension and Renal Transplantation, University of Florida College of Medicine, Gainesville, FL 32610, USA
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8
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Kawakibi T, Bala N, Liu LP, Searcy LA, Denslow ND, Alli AA. Decreased MARCKS Protein Expression in Kidney Cortex Membrane Fractions of Cathepsin B Knockout Mice Is Associated with Reduced Lysophosphatidylcholine and Protein Kinase C Activity. Biomedicines 2023; 11:1489. [PMID: 37239160 PMCID: PMC10216610 DOI: 10.3390/biomedicines11051489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/28/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
Cathpesin B is a multi-functional protease that plays numerous roles in physiology and pathophysiology. We hypothesized that actin cytoskeleton proteins that are substrates of cathepsin B, various lipids, and kinases that are regulated by lipids would be down-regulated in the kidney of cathepsin B knockout mice. Here, we show by Western blot and densitometric analysis that the expression and proteolysis of the actin cytoskeleton proteins myristoylated alanine-rich C-kinase substrate (MARCKS) and spectrin are significantly reduced in kidney cortex membrane fractions of cathepsin B knockout mice compared to C57B6 wild-type control mice. Lipidomic results show that specific lipids are increased while other lipids, including lysophosphatidylcholine (LPC) species LPC (16:0), LPC (18:0), LPC (18:1), and LPC (18:2), are significantly decreased in membrane fractions of the kidney cortex from Cathepsin B null mice. Protein Kinase C (PKC) activity is significantly lower in the kidney cortex of cathepsin B knockout mice compared to wild-type mice, while calcium/calmodulin-dependent protein kinase II (CaMKII) activity and phospholipase D (PLD) activity are comparable between the two groups. Together, these results provide the first evidence of altered actin cytoskeleton organization, membrane lipid composition, and PKC activity in the kidneys of mice lacking cathepsin B.
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Affiliation(s)
- Tamim Kawakibi
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Niharika Bala
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Lauren P. Liu
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Louis A. Searcy
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida College of Veterinary Medicine, Gainesville, FL 32610, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida College of Veterinary Medicine, Gainesville, FL 32610, USA
| | - Abdel A. Alli
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, FL 32610, USA
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Alli AA, Desai D, Elshika A, Conrad M, Proneth B, Clapp W, Atkinson C, Segal M, Searcy LA, Denslow ND, Bolisetty S, Mehrad B, Morel L, Scindia Y. Kidney tubular epithelial cell ferroptosis links glomerular injury to tubulointerstitial pathology in lupus nephritis. Clin Immunol 2023; 248:109213. [PMID: 36566913 PMCID: PMC10810556 DOI: 10.1016/j.clim.2022.109213] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022]
Abstract
Ferroptosis is a druggable, iron-dependent form of cell death that is characterized by lipid peroxidation but has received little attention in lupus nephritis. Kidneys of lupus nephritis patients and mice showed increased lipid peroxidation mainly in the tubular segments and an increase in Acyl-CoA synthetase long-chain family member 4, a pro-ferroptosis enzyme. Nephritic mice had an attenuated expression of SLC7A11, a cystine importer, an impaired glutathione synthesis pathway, and low expression of glutathione peroxidase 4, a ferroptosis inhibitor. Lipidomics of nephritic kidneys confirmed ferroptosis. Using nephrotoxic serum, we induced immune complex glomerulonephritis in congenic mice and demonstrate that impaired iron sequestration within the proximal tubules exacerbates ferroptosis. Lupus nephritis patient serum rendered human proximal tubular cells susceptibility to ferroptosis which was inhibited by Liproxstatin-2, a novel ferroptosis inhibitor. Collectively, our findings identify intra-renal ferroptosis as a pathological feature and contributor to tubular injury in human and murine lupus nephritis.
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Affiliation(s)
- Abdel A Alli
- Department of Physiology and Aging, University of Florida, Gainesville, USA
| | - Dhruv Desai
- Department of Medicine, University of Florida, Gainesville, USA
| | - Ahmed Elshika
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, USA
| | - Marcus Conrad
- Institute of Metabolism and Cell Death, Helmholtz Zentrum Munich, Germany
| | - Bettina Proneth
- Institute of Metabolism and Cell Death, Helmholtz Zentrum Munich, Germany
| | - William Clapp
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, USA
| | - Carl Atkinson
- Department of Medicine, University of Florida, Gainesville, USA
| | - Mark Segal
- Department of Medicine, University of Florida, Gainesville, USA
| | - Louis A Searcy
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, USA
| | - Nancy D Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, USA
| | | | - Borna Mehrad
- Department of Medicine, University of Florida, Gainesville, USA
| | - Laurence Morel
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, USA
| | - Yogesh Scindia
- Department of Medicine, University of Florida, Gainesville, USA; Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, USA.
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10
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Bala N, Yu L, Liu LP, Shelton L, Xu Y, Ghayee HK, Alli AA. Metabolic Characterization and Glyceraldehyde-3-Phosphate Dehydrogenase-Dependent Regulation of Epithelial Sodium Channels in hPheo1 Wild-type and SDHB Knockdown Cells. Endocrinology 2023; 164:7034155. [PMID: 36763043 DOI: 10.1210/endocr/bqad026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/11/2023]
Abstract
Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors with limited curative treatment options outside of surgical resection. Patients with mutations in succinate dehydrogenase subunit B (SDHB) are at an increased risk of malignant and aggressive disease. As cation channels are associated with tumorigenesis, we studied the expression and activity of cation channels from the Degenerin superfamily in a progenitor cell line derived from a human PCC. hPheo1 wild-type (WT) and SDHB knockdown (KD) cells were studied to investigate whether epithelial sodium channels (ENaC) and acid-sensing ion channels (ASIC) are regulated by the activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). First, we performed targeted metabolomic studies and quantified changes in glycolysis pathway intermediates and citric acid cycle intermediates using hPheo1 WT cells and SDHB KD cells. Next, we performed protein biochemistry and electrophysiology studies to characterize the protein expression and activity, respectively, of these ion channels. Our western blot experiments show both ENaC alpha and ASIC1/2 are expressed in both hPheo1 WT and SDHB KD cells, with lower levels of a cleaved 60 kDa form of ENaC in SDHB KD cells. Single-channel patch clamp studies corroborate these results and further indicate channel activity is decreased in SDHB KD cells. Additional experiments showed a more significant decreased membrane potential in SDHB KD cells, which were sensitive to amiloride compared to WT cells. We provide evidence for the differential expression and activity of ENaC and ASIC hybrid channels in hPheo1 WT and SDHB KD cells, providing an important area of investigation in understanding SDHB-related disease.
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Affiliation(s)
- Niharika Bala
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL, USA
| | - Ling Yu
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL, USA
| | - Lauren P Liu
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL, USA
| | | | - Yiling Xu
- Department of Medicine, Division of Endocrinology & Metabolism, University of Florida College of Medicine, Gainesville, FL, USA
| | - Hans K Ghayee
- Department of Medicine, Division of Endocrinology & Metabolism, University of Florida College of Medicine, Gainesville, FL, USA
- Malcom Randall VA Medical Center, Gainesville, FL, USA
| | - Abdel A Alli
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, FL, USA
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11
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Scindia YM, Gholam MF, Waleed A, Liu LP, Chacko KM, Desai D, Lopez JP, Malik Z, Schramm WC, Morales AG, Carson-Marino M, Alli AA. Metformin Alleviates Diabetes-Associated Hypertension by Attenuating the Renal Epithelial Sodium Channel. Biomedicines 2023; 11:305. [PMID: 36830842 PMCID: PMC9953274 DOI: 10.3390/biomedicines11020305] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/14/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023] Open
Abstract
Diabetic nephropathy is the primary cause of morbidity in type 2 diabetes mellitus (T2DM) patients. New data indicate that hypertension, a common comorbidity in T2DM, can worsen outcomes of diabetic nephropathy. While metformin is a commonly prescribed drug for treating type 2 diabetes, its blood pressure regulating ability is not well documented. The aim of this study was to investigate the effect of metformin on normalizing blood pressure in salt-loaded hypertensive diabetic db/db mice. Sixteen-week-old male and female diabetic db/db mice were individually placed in metabolic cages and then randomized to a control vehicle (saline) or metformin treatment group. We evaluated the blood pressure reducing ability of metformin in salt-induced hypertension and progression of nephropathy in db/db mice. We observed that metformin- normalized systolic blood pressure in hypertensive diabetic mice. Mechanistically, metformin treatment reduced renal cathepsin B expression. Low cathepsin B expression was associated with reduced expression and activity of the epithelial sodium channel (ENaC), sodium retention, and thus control of hypertension. In addition, we identified that urinary extracellular vesicles (EVs) from the diabetic mice are enriched in cathepsin B. Compared to treatment with urinary EVs of vehicle-treated hypertensive diabetic mice, the amiloride-sensitive transepithelial current was significantly attenuated upon exposure of renal collecting duct cells to urinary EVs isolated from metformin-treated db/db mice or cathepsin B knockout mice. Collectively, our study identifies a novel blood pressure reducing role of metformin in diabetic nephropathy by regulating the cathepsin B-ENaC axis.
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Affiliation(s)
- Yogesh M. Scindia
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Pathology, University of Florida, Gainesville, FL 32610, USA
| | - Mohammed F. Gholam
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia
| | - Alina Waleed
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Lauren P. Liu
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Kevin M. Chacko
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Dhruv Desai
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Juliana Pena Lopez
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Zeeshan Malik
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Whitney C. Schramm
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Angelica G. Morales
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Morgan Carson-Marino
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA
| | - Abdel A. Alli
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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12
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Lugo CI, Liu LP, Bala N, Morales AG, Gholam MF, Abchee JC, Elmoujahid N, Elshikha AS, Avdiaj R, Searcy LA, Denslow ND, Song S, Alli AA. Human Alpha-1 Antitrypsin Attenuates ENaC and MARCKS and Lowers Blood Pressure in Hypertensive Diabetic db/db Mice. Biomolecules 2022; 13:66. [PMID: 36671451 PMCID: PMC9856210 DOI: 10.3390/biom13010066] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/17/2022] [Accepted: 12/22/2022] [Indexed: 12/31/2022] Open
Abstract
Hypertension may develop before or after the onset of diabetes and it is known to increase the risk of developing diabetic nephropathy. Alpha-1 antitrypsin (AAT) is a multi-functional protein with beneficial effects in various diseases but its role in reducing blood pressure in the diabetic kidney has not been thoroughly studied. Like blood pressure, epithelial sodium channels (ENaC) and its adaptor protein myristoylated alanine-rich C-kinase substrate (MARCKS) are regulated by circadian rhythms. Our hypothesis is that administration of human AAT (hAAT) reduces blood pressure in hypertensive diabetic mice by attenuating membrane expression of ENaC and its association with the actin cytoskeleton. First, we show hAAT administration results in reduced blood pressure in diabetic db/db mice compared to vehicle treatment in both the inactive and active cycles. Western blotting and immunohistochemistry analyses showed a reduction of ENaC and the actin cytoskeleton protein, MARCKS in the kidneys of diabetic db/db mice treated with hAAT compared to vehicle. hAAT treatment resulted in elevated amounts of extracellular vesicles present in the urine of diabetic db/db mice compared to vehicle treatment both in the inactive and active cycles. Multiple hexosylceramides, among other lipid classes increased in urinary EVs released from hAAT treated hypertensive diabetic mice compared to vehicle treated mice. Taken together, these data suggest hAAT treatment could normalize blood pressure in the diabetic kidney in a mechanism involving attenuation of renal ENaC and MARCKS protein expression and possibly ceramide metabolism to hexosylceramide in kidney cells.
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Affiliation(s)
- Carlos I. Lugo
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Lauren P. Liu
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Niharika Bala
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Angelica G. Morales
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Mohammed F. Gholam
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia
| | - Julia C. Abchee
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Nasseem Elmoujahid
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Ahmed Samir Elshikha
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Pharmaceutics, University of Florida College of Pharmacy, Gainesville, FL 32610, USA
| | - Rigena Avdiaj
- Department of Pharmaceutics, University of Florida College of Pharmacy, Gainesville, FL 32610, USA
| | - Louis A. Searcy
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida College of Veterinary Medicine, Gainesville, FL 32610, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida College of Veterinary Medicine, Gainesville, FL 32610, USA
| | - Sihong Song
- Department of Pharmaceutics, University of Florida College of Pharmacy, Gainesville, FL 32610, USA
| | - Abdel A. Alli
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, FL 32610, USA
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13
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Lopez JP, Nouri MZ, Ebrahim A, Chacko KM, Schramm WC, Gholam MF, Ozrazgat-Baslanti T, Denslow ND, Alli AA. Lipid Profiles of Urinary Extracellular Vesicles Released during the Inactive and Active Phases of Aged Male Mice with Spontaneous Hypertension. Int J Mol Sci 2022; 23:ijms232315397. [PMID: 36499728 PMCID: PMC9739303 DOI: 10.3390/ijms232315397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Hypertension remains a major problem, especially in the elderly, as it increases the risk for cardiovascular, coronary artery, cerebrovascular, and kidney diseases. Extracellular vesicles (EVs) play a role in the aging process and contribute to pathophysiology. Our goal was to examine differences in lipid profiles of urinary EVs (uEVs) collected during the inactive and active phases of aged mice and investigate whether these EVs regulate the density of lipid rafts in mouse cortical collecting duct (mpkCCD) principal cells. Here, we demonstrate the epithelial sodium channel (ENaC) inhibitor benzyl amiloride reduced systolic blood pressure in aged male mice during the inactive and active phases. Lipidomics data demonstrate differential enrichment of lipids between the two groups. For example, there are more phosphatidylethanolamine plasmalogens, particularly in the form of alkyl phosphatidylethanolamines, that are enriched in active phase uEVs compared to inactive phase uEVs from the same mice. Amiloride-sensitive transepithelial current increased more in mpkCCD cells challenged with uEVs from the active phase group. Moreover, more ENaC alpha protein was distributed to lipid raft fractions of mpkCCD cells challenged with active phase uEVs. Taken together, the identification of bioactive lipids associated with lipid rafts that are enriched in EVs released during the active phase of aged mice may offer clues to help understand lipid raft organization in recipient principal cells after EV uptake and increased renal ENaC activity, leading to a time-of-day dependent regulation of blood pressure in an aging model.
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Affiliation(s)
- Juliana Pena Lopez
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mohammad-Zaman Nouri
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA
| | - Areej Ebrahim
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Kevin M. Chacko
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Whitney C. Schramm
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mohammed F. Gholam
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Basic Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia
| | - Tezcan Ozrazgat-Baslanti
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA
| | - Abdel A. Alli
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Correspondence: ; Tel.: +1-352-273-7877
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14
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Yu L, Nouri MZ, Liu LP, Bala N, Denslow ND, LaDisa JF, Alli AA. C Type Natriuretic Peptide Receptor Activation Inhibits Sodium Channel Activity in Human Aortic Endothelial Cells by Activating the Diacylglycerol-Protein Kinase C Pathway. Int J Mol Sci 2022; 23:13959. [PMID: 36430437 PMCID: PMC9698807 DOI: 10.3390/ijms232213959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/04/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
The C-type natriuretic peptide receptor (NPRC) is expressed in many cell types and binds all natriuretic peptides with high affinity. Ligand binding results in the activation or inhibition of various intracellular signaling pathways. Although NPRC ligand binding has been shown to regulate various ion channels, the regulation of endothelial sodium channel (EnNaC) activity by NPRC activation has not been studied. The objective of this study was to investigate mechanisms of EnNaC regulation associated with NPRC activation in human aortic endothelial cells (hAoEC). EnNaC protein expression and activity was attenuated after treating hAoEC with the NPRC agonist cANF compared to vehicle, as demonstrated by Western blotting and patch clamping studies, respectively. NPRC knockdown studies using siRNA's corroborated the specificity of EnNaC regulation by NPRC activation mediated by ligand binding. The concentration of multiple diacylglycerols (DAG) and the activity of protein kinase C (PKC) was augmented after treating hAoEC with cANF compared to vehicle, suggesting EnNaC activity is down-regulated upon NPRC ligand binding in a DAG-PKC dependent manner. The reciprocal cross-talk between NPRC activation and EnNaC inhibition represents a feedback mechanism that presumably is involved in the regulation of endothelial function and aortic stiffness.
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Affiliation(s)
- Ling Yu
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mohammad-Zaman Nouri
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32610, USA
| | - Lauren P. Liu
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Niharika Bala
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32610, USA
| | - John F. LaDisa
- Department of Pediatrics, Section of Cardiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- The Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA
- Department of Biomedical Engineering, Marquette University and the Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Abdel A. Alli
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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15
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Carson‐Marino MW, Ramsay HG, Alli AA. Sphingomyelin‐enriched extracellular vesicles from hypertensive diabetic mice regulate calcium mobilization and amiloride‐sensitive transepithelial current in mouse cortical collecting duct cells. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.l8082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Hunter G. Ramsay
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Abdel A. Alli
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
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16
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Glover SC, Scindia Y, Liu LP, Dhaliwal N, Williams H, Pride Y, Owings AH, Robinson T, Alli AA. Circulating extracellular vesicles from patients with severe COVID-19 upregulate Cathepsin B and activate STAT3 in normal human mesangial cells. The Journal of Immunology 2022. [DOI: 10.4049/jimmunol.208.supp.161.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Severe COVID-19 disease is associated with acute kidney injury in up to 57% of infected patients. The etiology of this is likely multifactorial. Extracellular vesicles (EVs) contain unique molecular cargo that contributes to health and disease in many different organ systems and can contain useful surrogate biomarkers. To gain insight into SARS-CoV2’s impact on the human kidney, we prospectively collected blood and urine from individuals hospitalized with severe COVID-19 infection and isolated EVs. Using these EVs, we investigated the impact of circulating EVs released during COVID-19 infection on healthy human glomerular mesangial cells. Nanoparticle tracking analysis and electron microscopy showed that EVs isolated from the plasma of COVID-19 patients were larger in size compared to those isolated from the plasma of non-COVID-19 patients, suggesting the presence of unique cargo within circulating EVs in the setting of COVID-19. The plasma derived EV’s from COVID-19 patients also increased glomerular cell proliferation, STAT3 activation, and cathepsin B protein expression in normal human glomerular cells when compared to EVs isolated from the plasma of non-COVID-19 patients. These data suggest systemic EVs during COVID-19 infection alter normal human mesangial cell function. and provide insight into the effects of SARS-CoV2 on the kidney.
This work was supported by the University of Florida College of Medicine and the University of Mississippi Medical Center.
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Affiliation(s)
- Sarah C Glover
- 1Medicine/Digestive Diseases, University of Mississippi Medical Center
- 2Microbiology and Immunology, University of Mississippi Medical Center
| | | | - Lauren P Liu
- 4Physiology and Functional Genomics, University of Florida
| | - Neha Dhaliwal
- 1Medicine/Digestive Diseases, University of Mississippi Medical Center
| | - Haley Williams
- 1Medicine/Digestive Diseases, University of Mississippi Medical Center
| | - Yilianys Pride
- 1Medicine/Digestive Diseases, University of Mississippi Medical Center
| | | | - Tanya Robinson
- 1Medicine/Digestive Diseases, University of Mississippi Medical Center
| | - Abdel A Alli
- 4Physiology and Functional Genomics, University of Florida
- 6Nephrology, Hypertension, and Renal Transplantation, University of Florida
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17
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Vallera RD, Ding Y, Hatanpaa KJ, Bishop JA, Mirfakhraee S, Alli AA, Tevosian SG, Tabebi M, Gimm O, Söderkvist P, Estrada-Zuniga C, Dahia PLM, Ghayee HK. Case report: Two sisters with a germline CHEK2 variant and distinct endocrine neoplasias. Front Endocrinol (Lausanne) 2022; 13:1024108. [PMID: 36440216 PMCID: PMC9682564 DOI: 10.3389/fendo.2022.1024108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 09/23/2022] [Indexed: 11/09/2022] Open
Abstract
Genetic testing has become the standard of care for many disease states. As a result, physicians treating patients who have tumors often rely on germline genetic testing results for making clinical decisions. Cases of two sisters carrying a germline CHEK2 variant are highlighted whereby possible other genetic drivers were discovered on tumor analysis. CHEK2 (also referred to as CHK2) loss of function has been firmly associated with breast cancer development. In this case report, two siblings with a germline CHEK2 mutation also had distinct endocrine tumors. Pituitary adenoma and pancreatic neuroendocrine tumor (PNET) was found in the first sibling and pheochromocytoma (PCC) discovered in the second sibling. Although pituitary adenomas, PNETs, and PCC have been associated with NF1 gene mutations, the second sister with a PCC did have proven germline CHEK2 with a pathogenic somatic NF1 mutation. We highlight the clinical point that unless the tumor is sequenced, the real driver mutation that is causing the patient's tumor may remain unknown.
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Affiliation(s)
- Raphaelle D. Vallera
- Department of Medicine, Division of Endocrinology, Baylor Scott & White Health, Dallas, TX, United States
| | - Yanli Ding
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Kimmo J. Hatanpaa
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Justin A. Bishop
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Sasan Mirfakhraee
- Department of Medicine, Division of Endocrinology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Abdel A. Alli
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Sergei G. Tevosian
- Department of Physiological Sciences, University of Florida, Gainesville, FL, United States
| | - Mouna Tabebi
- Department of Surgery and Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
- Division of Cell Biology, Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
| | - Oliver Gimm
- Department of Surgery and Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
| | - Peter Söderkvist
- Division of Cell Biology, Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
- Clinical Genomics Linköping, Science for Life Laboratory, Linköping University, Linköping, Sweden
| | - Cynthia Estrada-Zuniga
- Department of Medicine, Division of Hematology and Medical Oncology, Mays Cancer Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Patricia L. M. Dahia
- Department of Medicine, Division of Hematology and Medical Oncology, Mays Cancer Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Hans K. Ghayee
- Department of Medicine, Division of Endocrinology & Metabolism, University of Florida, Malcom Randall VA Medical Center, Gainesville, FL, United States
- *Correspondence: Hans K. Ghayee,
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18
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Chacko KM, Nouri MZ, Schramm WC, Malik Z, Liu LP, Denslow ND, Alli AA. Tempol Alters Urinary Extracellular Vesicle Lipid Content and Release While Reducing Blood Pressure during the Development of Salt-Sensitive Hypertension. Biomolecules 2021; 11:biom11121804. [PMID: 34944449 PMCID: PMC8699083 DOI: 10.3390/biom11121804] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 11/27/2021] [Indexed: 12/11/2022] Open
Abstract
Salt-sensitive hypertension resulting from an increase in blood pressure after high dietary salt intake is associated with an increase in the production of reactive oxygen species (ROS). ROS are known to increase the activity of the epithelial sodium channel (ENaC), and therefore, they have an indirect effect on sodium retention and increasing blood pressure. Extracellular vesicles (EVs) carry various molecules including proteins, microRNAs, and lipids and play a role in intercellular communication and intracellular signaling in health and disease. We investigated changes in EV lipids, urinary electrolytes, osmolality, blood pressure, and expression of renal ENaC and its adaptor protein, MARCKS/MARCKS Like Protein 1 (MLP1) after administration of the antioxidant Tempol in salt-sensitive hypertensive 129Sv mice. Our results show Tempol infusion reduces systolic blood pressure and protein expression of the alpha subunit of ENaC and MARCKS in the kidney cortex of hypertensive 129Sv mice. Our lipidomic data show an enrichment of diacylglycerols and monoacylglycerols and reduction in ceramides, dihydroceramides, and triacylglycerols in urinary EVs from these mice after Tempol treatment. These data will provide insight into our understanding of mechanisms involving strategies aimed to inhibit ROS to alleviate salt-sensitive hypertension.
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Affiliation(s)
- Kevin M. Chacko
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL 32610, USA; (K.M.C.); (W.C.S.); (Z.M.); (L.P.L.)
| | - Mohammad-Zaman Nouri
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32610, USA; (M.-Z.N.); (N.D.D.)
| | - Whitney C. Schramm
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL 32610, USA; (K.M.C.); (W.C.S.); (Z.M.); (L.P.L.)
| | - Zeeshan Malik
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL 32610, USA; (K.M.C.); (W.C.S.); (Z.M.); (L.P.L.)
| | - Lauren P. Liu
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL 32610, USA; (K.M.C.); (W.C.S.); (Z.M.); (L.P.L.)
| | - Nancy D. Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32610, USA; (M.-Z.N.); (N.D.D.)
| | - Abdel A. Alli
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL 32610, USA; (K.M.C.); (W.C.S.); (Z.M.); (L.P.L.)
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL 32610, USA
- Correspondence: ; Tel.: +1-(352)-273-7877
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Liu LP, Gholam MF, Elshikha AS, Kawakibi T, Elmoujahid N, Moussa HH, Song S, Alli AA. Transgenic Mice Overexpressing Human Alpha-1 Antitrypsin Exhibit Low Blood Pressure and Altered Epithelial Transport Mechanisms in the Inactive and Active Cycles. Front Physiol 2021; 12:710313. [PMID: 34630137 PMCID: PMC8493122 DOI: 10.3389/fphys.2021.710313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Human alpha-1 antitrypsin (hAAT) is a versatile protease inhibitor, but little is known about its targets in the aldosterone-sensitive distal nephron and its role in electrolyte balance and blood pressure control. We analyzed urinary electrolytes, osmolality, and blood pressure from hAAT transgenic (hAAT-Tg) mice and C57B/6 wild-type control mice maintained on either a normal salt or high salt diet. Urinary sodium, potassium, and chloride concentrations as well as urinary osmolality were lower in hAAT-Tg mice maintained on a high salt diet during both the active and inactive cycles. hAAT-Tg mice showed a lower systolic blood pressure compared to C57B6 mice when maintained on a normal salt diet but this was not observed when they were maintained on a high salt diet. Cathepsin B protein activity was less in hAAT-Tg mice compared to wild-type controls. Protein expression of the alpha subunit of the sodium epithelial channel (ENaC) alpha was also reduced in the hAAT-Tg mice. Natriuretic peptide receptor C (NPRC) protein expression in membrane fractions of the kidney cortex was reduced while circulating levels of atrial natriuretic peptide (ANP) were greater in hAAT-Tg mice compared to wild-type controls. This study characterizes the electrolyte and blood pressure phenotype of hAAT-Tg mice during the inactive and active cycles and investigates the mechanism by which ENaC activation is inhibited in part by a mechanism involving decreased cathepsin B activity and increased ANP levels in the systemic circulation.
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Affiliation(s)
- Lauren P Liu
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Mohammed F Gholam
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Ahmed Samir Elshikha
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, United States
| | - Tamim Kawakibi
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Nasseem Elmoujahid
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Hassan H Moussa
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Sihong Song
- Department of Pharmaceutics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States.,Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida College of Medicine, Gainesville, FL, United States
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20
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Nouri MZ, Yu L, Liu L, Chacko KM, Denslow ND, LaDisa JF, Alli AA. Increased endothelial sodium channel activity by extracellular vesicles in human aortic endothelial cells: Putative role of MLP1 and bioactive lipids. Am J Physiol Cell Physiol 2021; 321:C535-C548. [PMID: 34288724 DOI: 10.1152/ajpcell.00092.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Extracellular vesicles (EVs) contain biological molecules and are secreted by cells into the extracellular milieu. The endothelial sodium channel (EnNaC) plays an important role in modulating endothelial cell stiffness. We hypothesized EVs secreted from human aortic endothelial cells (hAoEC) positively regulate EnNaC in an autocrine dependent manner. A comprehensive lipidomic analysis using targeted mass spectrometry was performed on multiple preparations of EVs isolated from the conditioned media of hAoEC or complete growth media of these cells. Cultured hAoEC challenged with EVs isolated from the conditioned media of these cells resulted in an increase in EnNaC activity when compared to the same concentration of media derived EVs or vehicle alone. EVs isolated from the conditioned media of hAoEC but not human fibroblast cells were enriched in MARCKS Like Protein 1 (MLP1). The pharmacological inhibition of the negative regulator of MLP1, protein kinase C, in cultured hAoEC resulted in an increase in EV size and release compared to vehicle or pharmacological inhibition of protein kinase D. The MLP1 enriched EVs increased the density of actin filaments in cultured hAoEC compared to EVs isolated from human fibroblast cells lacking MLP1. We quantified 141 lipids from glycerolipids, glycerophospholipids, and sphingolipids in conditioned media EVs that represented twice the number found in control media EVs. The concentrations of sphingomyelin, lysophosphatidylcholine and phosphatidylethanolamine were higher in conditioned media EVs. These results provide the first evidence for EnNaC regulation in hAoEC by EVs and provide insight into a possible mechanism involving MLP1, unsaturated lipids, and bioactive lipids.
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Affiliation(s)
- Mohammad-Zaman Nouri
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, United States
| | - Ling Yu
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Lauren Liu
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Kevin M Chacko
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Nancy D Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, United States
| | - John F LaDisa
- Department of Biomedical Engineering, Marquette University and the Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States.,Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, United States
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21
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Ghayee HK, Patel S, Tuna KM, Liu L, Xu Y, Alli AA. Extracellular Vesicles From SDHB Deficient hPheo1 Cells Activate STAT3 in Wild-Type Cells. J Endocr Soc 2021. [PMCID: PMC8265752 DOI: 10.1210/jendso/bvab048.138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors that originate from the adrenal medulla and extra-adrenal paraganglia, respectively. Inactivating mutations in succinate dehydrogenase (SDHx) genes leads to succinate accumulation, increased HIF1-α levels, and uncontrollable growth of PPGLs. We hypothesized that small extracellular vesicles (EVs) released from progenitor cells derived from pheochromocytoma (hPheo1) with a shRNA mediated knockdown of SDHB are enriched in succinate metabolites that play a key role in the activation of various tyrosine dependent signaling pathways that are involved in turmorigenesis and proliferation. We isolated EVs from the conditioned media of human wild-type hPheo1 cells and hPheo1 cells with shRNA SDHB knockdown. The EVs from three separate preparations of each group were characterized by nanoparticle tracking analysis, transmission electron microscopy, and Western blotting using antibodies against different types of EV and one non-EV marker. Our results show small EVs from the SDHB knockdown hPheo1 cells increased the activation of phosphotyrosine residues in wild-type cells compared to cells treated with control EVs from the same cell type. Additionally, our data show these EVs increase phospho-STAT3 compared to the control EVs (3843.10 +/- 1138.89 vs. 213.65+/- 40.75; p<0.05; n=3) in cultured wild-type hPheo1 cells. Protein tyrosine kinases (PTKs) control various cellular processes including growth, differentiation, and metabolism by activating various signaling pathways including STAT3. The significance of these findings is that in some cancers, elevated succinate from a SDHx mutation has been shown to activate STAT3 which may explain a possible pathway for tumorigenesis. Studies from other investigators have shown that STAT3 expression is elevated in malignant PPGL tissues. Through enriched EV analysis our findings have confirmed the role of STAT3 in SDHB deficient cells. Additional studies are needed to identify other metabolites that are enriched in EVs that regulate phosphorylation of tyrosine residues and STAT3 activation.
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Affiliation(s)
- Hans K Ghayee
- University of Florida and Malcom Randall VA Medical Center, Gainesville, FL, USA
| | | | | | - Lauren Liu
- University of Florida, Gainesville, FL, USA
| | - Yiling Xu
- University of Florida, Gainesville, FL, USA
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22
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Conrad KP, Tuna KM, Mestre CT, Banwatt ES, Alli AA. Activation of multiple receptors stimulates extracellular vesicle release from trophoblast cells. Physiol Rep 2020; 8:e14592. [PMID: 33080118 PMCID: PMC7575225 DOI: 10.14814/phy2.14592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 12/19/2022] Open
Abstract
Reports of the stimulated release of extracellular vesicles (EVs) are few, and the mechanisms incompletely understood. To our knowledge, the possibility that the activation of any one of the multitudes of G-protein-coupled receptors (GPCRs) expressed by a single cell-type might increase EV release has not been explored. Recently, we identified the expression of cholecystokinin (CCK), gastrin, gastrin/cholecystokinin types A and/or B receptors (CCKAR and/or -BR), and the bitter taste receptor, TAS2R14 in the human and mouse placenta. specifically, trophoblast. These GPCR(s) were also expressed in four different human trophoblast cell lines. The current objective was to employ two of these cell lines-JAR choriocarcinoma cells and HTR-8/SVneo cells derived from first-trimester human villous trophoblast-to investigate whether CCK, TAS2R14 agonists, and other GPCR ligands would each augment EV release. EVs were isolated from the cell-culture medium by filtration and ultracentrifugation. The preparations were enriched in small EVs (<200 nm) as determined by syntenin western blot before and after sucrose gradient purification, phycoerythrin (PE)-ADAM10 antibody labeling, and electron microscopy. Activation of TAS2R14, CCKBR, cholinergic muscarinic 1 & 3, and angiotensin II receptors, each increased EV release by 4.91-, 2.79-, 1.87-, and 3.11-fold, respectively (all p < .05 versus vehicle controls), without significantly changing EV diameter. A progressive increase of EV concentration in conditioned medium was observed over 24 hr consistent with the release of preformed EVs and de novo biogenesis. Compared to receptor-mediated stimulation, EV release by the calcium ionophore, A23187, was less robust (1.63-fold, p = .08). Diphenhydramine, a TAS2R14 agonist, enhanced EV release in JAR cells at a concentration 10-fold below that required to increase intracellular calcium. CCK activation of HTR-8/SVneo cells, which did not raise intracellular calcium, increased EV release by 2.06-fold (p < .05). Taken together, these results suggested that other signaling pathways may underlie receptor-stimulated EV release besides, or in addition to, calcium. To our knowledge, the finding that the activation of multiple GPCRs can stimulate EV release from a single cell-type is unprecedented and engenders a novel thesis that each receptor may orchestrate intercellular communication through the release of EVs containing a subset of unique cargo, thus mobilizing a specific integrated physiological response by a network of neighboring and distant cells.
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Affiliation(s)
- Kirk P. Conrad
- Department of Physiology and Functional GenomicsUniversity of Florida College of MedicineGainesvilleFLUSA
- Department of Obstetrics and GynecologyUniversity of Florida College of MedicineGainesvilleFLUSA
- D. H. Barron Reproductive and Perinatal Biology Research ProgramUniversity of FloridaGainesvilleFLUSA
| | - Kubra M. Tuna
- Department of Physiology and Functional GenomicsUniversity of Florida College of MedicineGainesvilleFLUSA
| | - Cathleen T. Mestre
- Department of Physiology and Functional GenomicsUniversity of Florida College of MedicineGainesvilleFLUSA
| | - Esha S. Banwatt
- Department of Physiology and Functional GenomicsUniversity of Florida College of MedicineGainesvilleFLUSA
| | - Abdel A. Alli
- Department of Physiology and Functional GenomicsUniversity of Florida College of MedicineGainesvilleFLUSA
- Department of Medicine, Division of Nephrology, Hypertension and Renal TransplantationUniversity of Florida College of MedicineGainesvilleFLUSA
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23
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Gholam MF, Waleed A, Tuna KM, Carson-Marino M, Chacko KM, Malik ZS, Schramm WC, Lopez JVP, Alli AA. SAT-LB126 Metformin Attenuates Sodium Retention and Blood Pressure in Hypertensive Diabetic Mice by Reducing the Phosphorylation of Renal NCC and Its Association With the Actin Cytoskeleton. J Endocr Soc 2020. [PMCID: PMC7209095 DOI: 10.1210/jendso/bvaa046.2201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Metformin is the first-line drug in the treatment of type 2 diabetes mellitus. The aim of this work was to evaluate the efficacy of metformin treatment in reducing blood pressure and investigate the molecular mechanism using a preclinical animal model. Adult male and female diabetic db/db mice with a blood glucose of greater than 300 mg/dl were salt-loaded (8% NaCl) for 10 days to induce hypertension. The mice were subject to metabolic cage studies for 24 hour urine collections in order to measure urinary electrolytes, albumin, and creatinine. Blood pressure was measured weekly by the tail-cuff method to assess the effect of metformin or vehicle given by oral gavage (dose of 60 mg/kg of body weight per day). At the end of the study the mice was euthanized and the left kidney was formalin-fixed and paraffin-embedded for immunohistochemistry while the right kidney was homogenized for Western blotting. Western blotting showed attenuation of total NCC and phospho-NCC in diabetic db/db mice given an oral gavage of metformin (Pearson correlation coefficient: 0.9470 +/- 2.52e-3) compared to vehicle (Pearson correlation coefficient: 0.9800 +/- 2.86e-3). Immunohistochemical analysis showed less co-localization of the actin cytoskeleton protein filamin and phosphorylated NCC in the metformin treated group compared to the control group. Taken together, we show metformin decreases sodium retention and blood pressure by reducing the density of renal NCC at the luminal membrane and the association between NCC and the actin cytoskeleton.
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Affiliation(s)
- Mohammed F Gholam
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, USA
| | - Alina Waleed
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, USA
| | - Kubra M Tuna
- Graduate Medical Education, University of Central Florida, College of Medicine and Internal Medicine Residency Program, Ocala Regional Medical Center, Ocala, FL, USA
| | - Morgan Carson-Marino
- Department of Pharmaceutics, University of Florida, College of Pharmacy, Gainesville, FL, USA
| | - Kevin M Chacko
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, USA
| | - Zeeshan S Malik
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, USA
| | - Whitney C Schramm
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, USA
| | - Juliana V Pena Lopez
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, USA
| | - Abdel A Alli
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL, USA
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Tuna KM, Ramsay HG, Nouri MZ, Denslow ND, Alli AA. SAT-LB127 Regulation of ENaC by Exosomal Lipids in the Diabetic Kidney. J Endocr Soc 2020. [PMCID: PMC7208333 DOI: 10.1210/jendso/bvaa046.2202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Effective treatment of hypertension (HTN) in patients with diabetes may help to significantly reduce the risk of those patients developing additional complications including vascular disease and diabetic nephropathy. Blockers of the renin-angiotensin system including angiotensin converting enzyme inhibitors and angiotensin receptor blockers are not always effective in treating HTN in diabetic patients. Therefore, the aim of this study was to use an animal model of type 2 diabetes to investigate a novel mechanism of diabetes associated HTN involving exosomal lipids in the upregulation of epithelial sodium channel (ENaC) activity in the kidney. We performed metabolic cages studies using male and female hypertensive (salt-loaded induced) diabetic db/db mice and healthy age-matched wild-type control mice in order to isolate and characterize urinary exosomes from each group by nanoparticle tracking analysis, Western blotting, and transmission electron microscopy. Our mass spectrometry based lipidomic studies identified key lipids that were differentially expressed in the kidney derived exosomes from the hypertensive diabetic mice compared to control mice. Sphingomyelin quantification assays showed total sphingomyelin content was elevated in the exosomes from the hypertensive diabetic mice compared to the control group. Single channel patch clamp studies showed urinary exosomes enriched in sphingomyelins from hypertensive diabetic mice compared to controls increase ENaC activity (at the level of channel density and open probability) in cultured distal tubule renal epithelial cells. Moreover, exogenous application of sphinomyelin-6 to cultured mouse cortical collecting duct (mpkCCD) cells resulted in an increase in amiloride-sensitive transepithelial current. Taken together, our data show various lipids are enriched in exosomes from hypertensive diabetic mice compared to controls and these exosomes positively regulate ENaC activity in distal tubule and collecting duct cells.
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Affiliation(s)
- Kubra M Tuna
- Graduate Medical Education, University of Central Florida, College of Medicine and Internal Medicine Residency Program, Ocala Regional Medical Center, Ocala, FL, USA
| | - Hunter G Ramsay
- Department of Physiology and Functional Genomics, University of Florida, College of Medicine, Gainesville, FL, USA
| | - Mohammad-Zaman Nouri
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, USA
| | - Nancy D Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, USA
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida, College of Medicine, Gainesville, FL, USA
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25
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Tuna KM, Liu BC, Yue Q, Ghazi ZM, Ma HP, Eaton DC, Alli AA. Mal protein stabilizes luminal membrane PLC-β3 and negatively regulates ENaC in mouse cortical collecting duct cells. Am J Physiol Renal Physiol 2019; 317:F986-F995. [PMID: 31364376 PMCID: PMC6843038 DOI: 10.1152/ajprenal.00446.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 07/18/2019] [Accepted: 07/18/2019] [Indexed: 01/15/2023] Open
Abstract
Abnormally high epithelial Na+ channel (ENaC) activity in the aldosterone-sensitive distal nephron and collecting duct leads to hypertension. Myelin and lymphocyte (Mal) is a lipid raft-associated protein that has been previously shown to regulate Na+-K-2Cl- cotransporter and aquaporin-2 in the kidney, but it is not known whether it regulates renal ENaC. ENaC activity is positively regulated by the anionic phospholipid phosphate phosphatidylinositol 4,5-bisphosphate (PIP2). Members of the myristoylated alanine-rich C-kinase substrate (MARCKS) family increase PIP2 concentrations at the plasma membrane, whereas hydrolysis of PIP2 by phospholipase C (PLC) reduces PIP2 abundance. Our hypothesis was that Mal protein negatively regulates renal ENaC activity by stabilizing PLC protein expression at the luminal plasma membrane. We investigated the association between Mal, MARCKS-like protein, and ENaC. We showed Mal colocalizes with PLC-β3 in lipid rafts and positively regulates its protein expression, thereby reducing PIP2 availability at the plasma membrane. Kidneys of 129Sv mice injected with MAL shRNA lentivirus resulted in increased ENaC open probability in split-open renal tubules. Overexpression of Mal protein in mouse cortical collecting duct (mpkCCD) cells resulted in an increase in PLC-β3 protein expression at the plasma membrane. siRNA-mediated knockdown of MAL in mpkCCD cells resulted in a decrease in PLC-β3 protein expression and an increase in PIP2 abundance. Moreover, kidneys from salt-loaded mice showed less Mal membrane protein expression compared with non-salt-loaded mice. Taken together, Mal protein may play an essential role in the negative feedback of ENaC gating in principal cells of the collecting duct.
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Affiliation(s)
- Kubra M Tuna
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Bing-Chen Liu
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Qiang Yue
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Zinah M Ghazi
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
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26
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Glover SC, Nouri MZ, Tuna KM, Mendoza Alvarez LB, Ryan LK, Shirley JF, Tang Y, Denslow ND, Alli AA. Lipidomic analysis of urinary exosomes from hereditary α-tryptasemia patients and healthy volunteers. FASEB Bioadv 2019; 1:624-638. [PMID: 31803861 PMCID: PMC6892164 DOI: 10.1096/fba.2019-00030] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Exosomes are nano‐sized vesicles that are involved in various biological processes including cell differentiation, proliferation, signaling, and intercellular communication. Urinary exosomes were isolated from a cohort of hereditary α‐tryptasemia (HαT) patients and from healthy volunteers. There was a greater number of exosomes isolated from the urine in the HαT group compared to the control volunteers. Here, we investigated the differences in both lipid classes and lipid species within urinary exosomes of the two groups. Lipids were extracted from urinary exosomes and subjected to liquid chromatography mass spectrometry using a targeted approach. Various molecular species of glycerophospholipids, glycerolipids, and sterols were significantly reduced in HαT patients. Out of a possible 1127 lipids, 521 lipid species were detected, and relative quantities were calculated. Sixty‐four lipids were significantly reduced in urinary exosomes of HαT patients compared to controls. All significantly reduced sphingolipids and most of the phospholipids were saturated or mono‐unsaturated lipids. These results suggest exosome secretion is augmented in HαT patients and the lipids within these exosomes may be involved in various biological processes. The unique lipid composition of urinary exosomes from HαT patients will contribute to our understanding of the biochemistry of this disease.
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Affiliation(s)
- Sarah C Glover
- Division of Gastroenterology, Hepatology and Nutrition, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | - Mohammad-Zaman Nouri
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL
| | - Kubra M Tuna
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, College of Medicine, Gainesville, FL
| | - Lybil B Mendoza Alvarez
- Department of Pediatrics, Pediatric Gastroenterology, University of Florida, Gainesville, FL
| | - Lisa K Ryan
- Division of Gastroenterology, Hepatology and Nutrition, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | - James F Shirley
- Division of Gastroenterology, Hepatology and Nutrition, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | - Ying Tang
- Division of Gastroenterology, Hepatology and Nutrition, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | - Nancy D Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL
| | - Abdel A Alli
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida, College of Medicine, Gainesville, FL
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27
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Larionov A, Dahlke E, Kunke M, Zanon Rodriguez L, Schiessl IM, Magnin JL, Kern U, Alli AA, Mollet G, Schilling O, Castrop H, Theilig F. Cathepsin B increases ENaC activity leading to hypertension early in nephrotic syndrome. J Cell Mol Med 2019; 23:6543-6553. [PMID: 31368174 PMCID: PMC6787568 DOI: 10.1111/jcmm.14387] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/04/2019] [Accepted: 05/06/2019] [Indexed: 11/28/2022] Open
Abstract
The NPHS2 gene, encoding the slit diaphragm protein podocin, accounts for genetic and sporadic forms of nephrotic syndrome (NS). Patients with NS often present symptoms of volume retention, such as oedema formation or hypertension. The primary dysregulation in sodium handling involves an inappropriate activation of the epithelial sodium channel, ENaC. Plasma proteases in a proteinuria‐dependent fashion have been made responsible; however, referring to the timeline of symptoms occurring and underlying mechanisms, contradictory results have been published. Characterizing the mouse model of podocyte inactivation of NPHS2 (Nphs2∆pod) with respect to volume handling and proteinuria revealed that sodium retention, hypertension and gross proteinuria appeared sequentially in a chronological order. Detailed analysis of Nphs2∆pod during early sodium retention, revealed increased expression of full‐length ENaC subunits and αENaC cleavage product with concomitant increase in ENaC activity as tested by amiloride application, and augmented collecting duct Na+/K+‐ATPase expression. Urinary proteolytic activity was increased and several proteases were identified by mass spectrometry including cathepsin B, which was found to process αENaC. Renal expression levels of precursor and active cathepsin B were increased and could be localized to glomeruli and intercalated cells. Inhibition of cathepsin B prevented hypertension. With the appearance of gross proteinuria, plasmin occurs in the urine and additional cleavage of γENaC is encountered. In conclusion, characterizing the volume handling of Nphs2∆pod revealed early sodium retention occurring independent to aberrantly filtered plasma proteases. As an underlying mechanism cathepsin B induced αENaC processing leading to augmented channel activity and hypertension was identified.
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Affiliation(s)
- Alexey Larionov
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Eileen Dahlke
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
| | - Madlen Kunke
- Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
| | | | - Ina M Schiessl
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | | | - Ursula Kern
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Geraldine Mollet
- Laboratory of Hereditary Kidney Diseases, INSERM UMR 1163, Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Oliver Schilling
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Center for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Hayo Castrop
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Franziska Theilig
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland.,Institute of Anatomy, Christian Albrechts-University Kiel, Kiel, Germany
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28
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LaDisa JF, Tomita-Mitchell A, Stamm K, Bazan K, Mahnke DK, Goetsch MA, Wegter BJ, Gerringer JW, Repp K, Palygin O, Zietara AP, Krolikowski MM, Eddinger TJ, Alli AA, Mitchell ME. Human genotyping and an experimental model reveal NPR-C as a possible contributor to morbidity in coarctation of the aorta. Physiol Genomics 2019; 51:177-185. [PMID: 31002586 DOI: 10.1152/physiolgenomics.00049.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Coarctation of the aorta (CoA) is a common congenital cardiovascular (CV) defect characterized by a stenosis of the descending thoracic aorta. Treatment exists, but many patients develop hypertension (HTN). Identifying the cause of HTN is challenging because of patient variability (e.g., age, follow-up duration, severity) and concurrent CV abnormalities. Our objective was to conduct RNA sequencing of aortic tissue from humans with CoA to identify a candidate gene for mechanistic studies of arterial dysfunction in a rabbit model of CoA devoid of the variability seen with humans. We present the first known evidence of natriuretic peptide receptor C (NPR-C; aka NPR3) downregulation in human aortic sections subjected to high blood pressure (BP) from CoA versus normal BP regions (validated to PCR). These changes in NPR-C, a gene associated with BP and proliferation, were replicated in the rabbit model of CoA. Artery segments from this model were used with human aortic endothelial cells to reveal the functional relevance of altered NPR-C activity. Results showed decreased intracellular calcium ([Ca2+]i) activity to C-type natriuretic peptide (CNP). Normal relaxation induced by CNP and atrial natriuretic peptide was impaired for aortic segments exposed to elevated BP from CoA. Inhibition of NPR-C (M372049) also impaired aortic relaxation and [Ca2+]i activity. Genotyping of NPR-C variants predicted to be damaging revealed that rs146301345 was enriched in our CoA patients, but sample size limited association with HTN. These results may ultimately be used to tailor treatment for CoA based on mechanical stimuli, genotyping, and/or changes in arterial function.
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Affiliation(s)
- John F LaDisa
- Department of Biomedical Engineering, Marquette University and the Medical College of Wisconsin , Milwaukee, Wisconsin.,Department of Medicine, Division of Cardiovascular Medicine; Medical College of Wisconsin , Milwaukee, Wisconsin.,Department of Physiology; Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Aoy Tomita-Mitchell
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Karl Stamm
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Kathleen Bazan
- Department of Physiology; Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Donna K Mahnke
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Mary A Goetsch
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Brandon J Wegter
- Department of Biomedical Engineering, Marquette University and the Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Jesse W Gerringer
- Department of Biomedical Engineering, Marquette University and the Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Kathryn Repp
- Department of Biomedical Engineering, Marquette University and the Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Oleg Palygin
- Department of Physiology; Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Adrian P Zietara
- Department of Physiology; Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Mary M Krolikowski
- Department of Pediatrics; Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Thomas J Eddinger
- Department of Biological Sciences; Marquette University , Milwaukee, Wisconsin
| | - Abdel A Alli
- Department of Physiology and Functional Genomics and Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida College of Medicine , Gainesville, Florida
| | - Michael E Mitchell
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin , Milwaukee, Wisconsin.,Children's Hospital of Wisconsin , Milwaukee, Wisconsin
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29
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Schramm WC, Malik ZS, Liu LP, Chacko KM, Alli AA. Salt Loading Effects on ENaC and Blood Pressure in Aged 129Sv Mice. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.751.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Whitney C. Schramm
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Zeeshan S. Malik
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Lauren P. Liu
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Kevin M. Chacko
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Abdel A. Alli
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
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30
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Affiliation(s)
- Kevin M. Chacko
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Lauren P. Liu
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Whitney C. Schramm
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Zeeshan S. Malik
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Abdel A. Alli
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
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31
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Malik ZS, Schramm WC, Liu LP, Chacko KM, Alli AA. MARCKS Expression and Localization in the Aged Kidney of Hypertensive 129Sv Mice. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.751.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zeeshan S. Malik
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Whitney C. Schramm
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Lauren P. Liu
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Kevin M. Chacko
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Abdel A. Alli
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
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32
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Bauza JM, Carson‐Marino MW, DeMars KM, Tuna KM, Montgomery DS, Sanz BD, Candelario‐Jalil E, Alli AA. Quantification of Protein Expression Changes in the PKC‐epsilon/Ca2+/CaMKII‐alpha Pathway after Early and Late Onset of Ischemic‐reperfusion Injury in Adult Male Rats. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.551.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- John M. Bauza
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | | | - Kelly M. DeMars
- Department of NeuroscienceUniversity of FloridaGainesvilleFL
| | - Kubra M. Tuna
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | | | - Brian D. Sanz
- Department of NeuroscienceUniversity of FloridaGainesvilleFL
| | | | - Abdel A. Alli
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
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33
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Liu LP, Chacko KM, Schramm WC, Malik ZS, Alli AA. Sex Differences in Aged Hypertensive 129Sv Mice. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.751.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lauren P. Liu
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Kevin M. Chacko
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Whitney C. Schramm
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Zeeshan S. Malik
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
| | - Abdel A. Alli
- Department of Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
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34
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Khodayari N, Oshins R, Alli AA, Tuna KM, Holliday LS, Krotova K, Brantly M. Modulation of calreticulin expression reveals a novel exosome-mediated mechanism of Z variant α 1-antitrypsin disposal. J Biol Chem 2019; 294:6240-6252. [PMID: 30833329 DOI: 10.1074/jbc.ra118.006142] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 02/26/2019] [Indexed: 01/08/2023] Open
Abstract
α1-Antitrypsin deficiency (AATD) is an inherited disease characterized by emphysema and liver disease. AATD is most often caused by a single amino acid substitution at position 342 in the mature protein, resulting in the Z mutation of the AAT gene (ZAAT). This substitution is associated with misfolding and accumulation of ZAAT in the endoplasmic reticulum (ER) of hepatocytes, causing a toxic gain of function. ERdj3 is an ER luminal DnaJ homologue, which, along with calreticulin, directly interacts with misfolded ZAAT. We hypothesize that depletion of each of these chaperones will change the fate of ZAAT polymers. Our study demonstrates that calreticulin modulation reveals a novel ZAAT degradation mechanism mediated by exosomes. Using human PiZZ hepatocytes and K42, a mouse calreticulin-deficient fibroblast cell line, our results show ERdj3 and calreticulin directly interact with ZAAT in PiZZ hepatocytes. Silencing calreticulin induces calcium independent ZAAT-ERdj3 secretion through the exosome pathway. This co-secretion decreases ZAAT aggregates within the ER of hepatocytes. We demonstrate that calreticulin has an inhibitory effect on exosome-mediated ZAAT-ERdj3 secretion. This is a novel ZAAT degradation process that involves a DnaJ homologue chaperone bound to ZAAT. In this context, calreticulin modulation may eliminate the toxic gain of function associated with aggregation of ZAAT in lung and liver, thus providing a potential new therapeutic approach to the treatment of AATD-related liver disease.
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Affiliation(s)
- Nazli Khodayari
- From the Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - Regina Oshins
- From the Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine
| | - Abdel A Alli
- the Department of Physiology and Functional Genomics, College of Medicine, and
| | - Kubra M Tuna
- the Department of Physiology and Functional Genomics, College of Medicine, and
| | - L Shannon Holliday
- the Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, Florida 32610 and
| | - Karina Krotova
- the Hormel Institute, University of Minnesota, Austin, Minnesota 55912
| | - Mark Brantly
- From the Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine,
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35
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Rodrigues TA, Tuna KM, Alli AA, Tribulo P, Hansen PJ, Koh J, Paula-Lopes FF. Follicular fluid exosomes act on the bovine oocyte to improve oocyte competence to support development and survival to heat shock. Reprod Fertil Dev 2019; 31:888-897. [DOI: 10.1071/rd18450] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 12/05/2018] [Indexed: 12/12/2022] Open
Abstract
Addition of follicular fluid to oocyte maturation medium can affect cumulus cell function, increase competence of the oocytes to be fertilised and develop to the blastocyst stage and protect the oocyte from heat shock. Here, it was tested whether exosomes in follicular fluid are responsible for the effects of follicular fluid on the function of the cumulus–oocyte complex (COC). This was accomplished by culturing COCs during oocyte maturation at 38.5°C (body temperature of the cow) or 41°C (heat shock) with follicular fluid or exosomes derived from follicular fluid and evaluating various aspects of function of the oocyte and the embryo derived from it. Negative effects of heat shock on cleavage and blastocyst development, but not cumulus expansion, were reduced by follicular fluid and exosomes. The results support the idea that exosomes in follicular fluid play important roles during oocyte maturation to enhance oocyte function and protect it from stress.
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36
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Downs CA, Dang VD, Johnson NM, Denslow ND, Alli AA. Hydrogen Peroxide Stimulates Exosomal Cathepsin B Regulation of the Receptor for Advanced Glycation End-Products (RAGE). J Cell Biochem 2017; 119:599-606. [PMID: 28618037 DOI: 10.1002/jcb.26219] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 06/14/2017] [Indexed: 01/03/2023]
Abstract
Exosomes are nano-sized vesicles that are secreted into the extracellular environment. These vesicles contain various biological effector molecules that can regulate intracellular signaling pathways in recipient cells. The aim of this study was to examine a correlation between exosomal cathepsin B activity and the receptor for advanced glycation end-products (RAGE). Type 1 alveolar epithelial (R3/1) cells were treated with or without hydrogen peroxide and exosomes isolated from the cell conditioned media were characterized by NanoSight analysis. Lipidomic and proteomic analysis showed exosomes released from R3/1 cells exposed to oxidative stress induced by hydrogen peroxide or vehicle differ in their lipid and protein content, respectively. Cathepsin B activity was detected in exosomes isolated from hydrogen peroxide treated cells. The mRNA and protein expression of RAGE increased in cultured R3/1 cells treated with exosomes containing active cathepsin B while depletion of exosomal cathepsin B attenuated RAGE mRNA and protein expression. These results suggest exosomal cathepsin B regulates RAGE in type 1 alveolar cells under conditions of oxidative stress. J. Cell. Biochem. 119: 599-606, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Charles A Downs
- College of Nursing, Biobehavioral Healthscience Division & College of Medicine, Department of Medicine Division of Translational & Regenerative Medicine, The University of Arizona, Tucson, Arizona
| | - Viet D Dang
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, Florida
| | - Nicholle M Johnson
- College of Nursing, Biobehavioral Healthscience Division & College of Medicine, Department of Medicine Division of Translational & Regenerative Medicine, The University of Arizona, Tucson, Arizona
| | - Nancy D Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, Florida
| | - Abdel A Alli
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
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37
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Dang VD, Jella KK, Ragheb RRT, Denslow ND, Alli AA. Lipidomic and proteomic analysis of exosomes from mouse cortical collecting duct cells. FASEB J 2017; 31:5399-5408. [PMID: 28821634 DOI: 10.1096/fj.201700417r] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 07/25/2017] [Indexed: 12/13/2022]
Abstract
Exosomes are endosome-derived nanovesicles that are involved in cellular communication and signaling. Exosomes are produced by epithelial cells and are found in biologic fluids including blood and urine. The packaged material within exosomes includes proteins and lipids, but the molecular comparison within exosome subtypes is largely unknown. The purpose of this study was to investigate differences between exosomes derived from the apical plasma membrane and basolateral plasma membrane of polarized murine cortical collecting duct principal cells. Nanoparticle tracking analysis showed that the size and concentration of apical and basolateral exosomes remained relatively stable across 3 different temperatures (23, 37, and 42°C). Liquid chromatography-tandem mass spectrometry analysis revealed marked differences between the proteins packaged within the two types of exosomes from the same cells. Several proteins expressed at the inner leaflet of the plasma membrane, including α-actinin-1, moesin, 14-3-3 protein ζ/δ, annexin A1/A3/A4/A5/A6, clathrin heavy chain 1, glyceraldehyde-3-phosphate dehydrogenase, α-enolase, filamin-A, and heat shock protein 90, were identified in samples of apical plasma membrane-derived exosomes, but not in basolateral plasma membrane exosomes from mouse cortical collecting duct cells. In addition to differences at the protein level, mass spectrometry-based shotgun lipidomics analysis showed significant differences in the lipid classes and fatty acid composition of the two types of exosomes. We found higher levels of sphingomyelin and lower levels of cardiolipin, among other phospholipids in the apical plasma membrane compared to the basolateral plasma membrane exosomes. The molecular analyses of exosome subtypes presented herein will contribute to our understanding of exosome biogenesis, and the results may have potential implications for biomarker discovery.-Dang, V. D., Jella, K. K., Ragheb, R. R. T., Denslow, N. D., Alli, A. A. Lipidomic and proteomic analysis of exosomes from mouse cortical collecting duct cells.
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Affiliation(s)
- Viet D Dang
- Department of Physiological Sciences, University of Florida, Gainesville, Florida, USA.,Center for Environmental and Human Toxicology, University of Florida, Gainesville, Florida, USA.,Department of Veterinary Diagnostic and Production Animal Production, Iowa State University, Ames, Iowa, USA
| | - Kishore Kumar Jella
- Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Nancy D Denslow
- Department of Physiological Sciences, University of Florida, Gainesville, Florida, USA.,Center for Environmental and Human Toxicology, University of Florida, Gainesville, Florida, USA
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida, USA; .,Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida College of Medicine, Gainesville, Florida, USA
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38
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Czikora I, Alli AA, Sridhar S, Matthay MA, Pillich H, Hudel M, Berisha B, Gorshkov B, Romero MJ, Gonzales J, Wu G, Huo Y, Su Y, Verin AD, Fulton D, Chakraborty T, Eaton DC, Lucas R. Epithelial Sodium Channel-α Mediates the Protective Effect of the TNF-Derived TIP Peptide in Pneumolysin-Induced Endothelial Barrier Dysfunction. Front Immunol 2017; 8:842. [PMID: 28785264 PMCID: PMC5519615 DOI: 10.3389/fimmu.2017.00842] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/04/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is a major etiologic agent of bacterial pneumonia. Autolysis and antibiotic-mediated lysis of pneumococci induce release of the pore-forming toxin, pneumolysin (PLY), their major virulence factor, which is a prominent cause of acute lung injury. PLY inhibits alveolar liquid clearance and severely compromises alveolar-capillary barrier function, leading to permeability edema associated with pneumonia. As a consequence, alveolar flooding occurs, which can precipitate lethal hypoxemia by impairing gas exchange. The α subunit of the epithelial sodium channel (ENaC) is crucial for promoting Na+ reabsorption across Na+-transporting epithelia. However, it is not known if human lung microvascular endothelial cells (HL-MVEC) also express ENaC-α and whether this subunit is involved in the regulation of their barrier function. METHODS The presence of α, β, and γ subunits of ENaC and protein phosphorylation status in HL-MVEC were assessed in western blotting. The role of ENaC-α in monolayer resistance of HL-MVEC was examined by depletion of this subunit by specific siRNA and by employing the TNF-derived TIP peptide, a specific activator that directly binds to ENaC-α. RESULTS HL-MVEC express all three subunits of ENaC, as well as acid-sensing ion channel 1a (ASIC1a), which has the capacity to form hybrid non-selective cation channels with ENaC-α. Both TIP peptide, which specifically binds to ENaC-α, and the specific ASIC1a activator MitTx significantly strengthened barrier function in PLY-treated HL-MVEC. ENaC-α depletion significantly increased sensitivity to PLY-induced hyperpermeability and in addition, blunted the protective effect of both the TIP peptide and MitTx, indicating an important role for ENaC-α and for hybrid NSC channels in barrier function of HL-MVEC. TIP peptide blunted PLY-induced phosphorylation of both calmodulin-dependent kinase II (CaMKII) and of its substrate, the actin-binding protein filamin A (FLN-A), requiring the expression of both ENaC-α and ASIC1a. Since non-phosphorylated FLN-A promotes ENaC channel open probability and blunts stress fiber formation, modulation of this activity represents an attractive target for the protective actions of ENaC-α in both barrier function and liquid clearance. CONCLUSION Our results in cultured endothelial cells demonstrate a previously unrecognized role for ENaC-α in strengthening capillary barrier function that may apply to the human lung. Strategies aiming to activate endothelial NSC channels that contain ENaC-α should be further investigated as a novel approach to improve barrier function in the capillary endothelium during pneumonia.
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Affiliation(s)
- Istvan Czikora
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States.,Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida College of Medicine, Gainesville, FL, United States
| | - Supriya Sridhar
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Michael A Matthay
- Cardiovascular Research Institute, UCSF, San Francisco, CA, United States
| | - Helena Pillich
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Martina Hudel
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Besim Berisha
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Maritza J Romero
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Joyce Gonzales
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Yuqing Huo
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Alexander D Verin
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - David Fulton
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
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39
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Montgomery DS, Yu L, Ghazi ZM, Thai TL, Al-Khalili O, Ma HP, Eaton DC, Alli AA. ENaC activity is regulated by calpain-2 proteolysis of MARCKS proteins. Am J Physiol Cell Physiol 2017; 313:C42-C53. [PMID: 28468944 PMCID: PMC5538800 DOI: 10.1152/ajpcell.00244.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 04/13/2017] [Accepted: 04/15/2017] [Indexed: 12/27/2022]
Abstract
We previously demonstrated a role for the myristoylated alanine-rich C kinase substrate (MARCKS) to serve as an adaptor protein in the anionic phospholipid phosphate-dependent regulation of the epithelial sodium channel (ENaC). Both MARCKS and ENaC are regulated by proteolysis. Calpains are a family of ubiquitously expressed intracellular Ca2+-dependent cysteine proteases involved in signal transduction. Here we examine the role of calpain-2 in regulating MARCKS and ENaC in cultured renal epithelial cells and in the mouse kidney. Using recombinant fusion proteins, we show that MARCKS, but not the ENaC subunits, are a substrate of calpain-2 in the presence of Ca2+ Pharmacological inhibition of calpain-2 alters MARCKS protein expression in light-density sucrose gradient fractions from cell lysates of mouse cortical collecting duct cells. Calpain-dependent cleaved products of MARCKS are detectable in cultured renal cells. Ca2+ mobilization and calpain-2 inhibition decrease the association between ENaC and MARCKS. The inhibition of calpain-2 reduces ENaC activity as demonstrated by single-channel patch-clamp recordings and transepithelial current measurements. These results suggest that calpain-2 proteolysis of MARCKS promotes its interaction with lipids and ENaC at the plasma membrane to allow for the phosphatidylinositol 4,5-bisphosphate (PIP2)-dependent regulation of ENaC activity in the kidney.
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Affiliation(s)
- Darrice S Montgomery
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida
| | - Ling Yu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China; and
| | - Zinah M Ghazi
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Tiffany L Thai
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Otor Al-Khalili
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Abdel A Alli
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida;
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Trac PT, Thai TL, Linck V, Zou L, Greenlee M, Yue Q, Al-Khalili O, Alli AA, Eaton AF, Eaton DC. Alveolar nonselective channels are ASIC1a/α-ENaC channels and contribute to AFC. Am J Physiol Lung Cell Mol Physiol 2017; 312:L797-L811. [PMID: 28283476 DOI: 10.1152/ajplung.00379.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/01/2017] [Accepted: 03/02/2017] [Indexed: 12/13/2022] Open
Abstract
A thin fluid layer in alveoli is normal and results from a balance of fluid entry and fluid uptake by transepithelial salt and water reabsorption. Conventional wisdom suggests the reabsorption is via epithelial Na+ channels (ENaC), but if all Na+ reabsorption were via ENaC, then amiloride, an ENaC inhibitor, should block alveolar fluid clearance (AFC). However, amiloride blocks only half of AFC. The reason for failure to block is clear from single-channel measurements from alveolar epithelial cells: ENaC channels are observed, but another channel is present at the same frequency that is nonselective for Na+ over K+, has a larger conductance, and has shorter open and closed times. These two channel types are known as highly selective channels (HSC) and nonselective cation channels (NSC). HSC channels are made up of three ENaC subunits since knocking down any of the subunits reduces HSC number. NSC channels contain α-ENaC since knocking down α-ENaC reduces the number of NSC (knocking down β- or γ-ENaC has no effect on NSC, but the molecular composition of NSC channels remains unclear). We show that NSC channels consist of at least one α-ENaC and one or more acid-sensing ion channel 1a (ASIC1a) proteins. Knocking down either α-ENaC or ASIC1a reduces both NSC and HSC number, and no NSC channels are observable in single-channel patches on lung slices from ASIC1a knockout mice. AFC is reduced in knockout mice, and wet wt-to-dry wt ratio is increased, but the percentage increase in wet wt-to-dry wt ratio is larger than expected based on the reduction in AFC.
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Affiliation(s)
- Phi T Trac
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Tiffany L Thai
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Valerie Linck
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Li Zou
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Megan Greenlee
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Qiang Yue
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Otor Al-Khalili
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Amity F Eaton
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Douglas C Eaton
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
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Wu MM, Zhai YJ, Li YX, Hu QQ, Wang ZR, Wei SP, Zou L, Alli AA, Thai TL, Zhang ZR, Ma HP. Hydrogen peroxide suppresses TRPM4 trafficking to the apical membrane in mouse cortical collecting duct principal cells. Am J Physiol Renal Physiol 2016; 311:F1360-F1368. [PMID: 27956381 DOI: 10.1152/ajprenal.00439.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/31/2016] [Accepted: 10/31/2016] [Indexed: 01/14/2023] Open
Abstract
A Ca2+-activated nonselective cation channel (NSCCa) is found in principal cells of the mouse cortical collecting duct (CCD). However, the molecular identity of this channel remains unclear. We used mpkCCDc14 cells, a mouse CCD principal cell line, to determine whether NSCCa represents the transient receptor potential (TRP) channel, the melastatin subfamily 4 (TRPM4). A Ca2+-sensitive single-channel current was observed in inside-out patches excised from the apical membrane of mpkCCDc14 cells. Like TRPM4 channels found in other cell types, this channel has an equal permeability for Na+ and K+ and has a linear current-voltage relationship with a slope conductance of ~23 pS. The channel was inhibited by a specific TRPM4 inhibitor, 9-phenanthrol. Moreover, the frequency of observing this channel was dramatically decreased in TRPM4 knockdown mpkCCDc14 cells. Unlike those previously reported in other cell types, the TRPM4 in mpkCCDc14 cells was unable to be activated by hydrogen peroxide (H2O2). Conversely, after treatment with H2O2, TRPM4 density in the apical membrane of mpkCCDc14 cells was significantly decreased. The channel in intact cell-attached patches was activated by ionomycin (a Ca2+ ionophore), but not by ATP (a purinergic P2 receptor agonist). These data suggest that the NSCCa current previously described in CCD principal cells is actually carried through TRPM4 channels. However, the physiological role of this channel in the CCD remains to be further determined.
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Affiliation(s)
- Ming-Ming Wu
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and.,Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Yu-Jia Zhai
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Yu-Xia Li
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and
| | - Qing-Qing Hu
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and
| | - Zhi-Rui Wang
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and
| | - Shi-Peng Wei
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Li Zou
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Abdel A Alli
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Tiffany L Thai
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Zhi-Ren Zhang
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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Abstract
Exosomes are nanometer-scale, cell-derived vesicles that contain various molecules including nucleic acids, proteins, and lipids. These vesicles can release their cargo into adjacent or distant cells and mediate intercellular communication and cellular function. Here we examined the regulation of epithelial sodium channels in mpkCCD cells and distal tubule Xenopus 2F3 cells by exosomes isolated from proximal tubule LLC-PK1 cells. Cultured mpkCCD cells were stained with CTX coupled to a green fluorophore in order to label the cell membranes and freshly isolated exosomes from LLC-PK1 cells were labeled with the red lipophilic dye PKH26 in order to visualize uptake of exosomes into the cells. Single-channel patch clamp recordings showed the open probability of ENaC in Xenopus 2F3 cells and in freshly isolated split-open tubules decreased in response to exogenous application of exosomes derived from LLC-PK1 proximal tubule cells. Active GAPDH was identified within exosomes derived from proximal tubule LLC-PK1 cells. The effect on ENaC activity in Xenopus 2F3 cells was blunted after application of exosomes transfected with the GAPDH inhibitor heptelidic acid. Also, we show GAPDH and ENaC subunits associate in mpkCCD cells. These studies examine a potential role for exosomes in the regulation of ENaC activity and examine a possible mechanism for communication from proximal tubule cells to distal tubule and collecting duct cells.
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Affiliation(s)
- Kishore Kumar Jella
- Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia
| | - Ling Yu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
| | - Qiang Yue
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Daniel Friedman
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Billie J. Duke
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Abdel A. Alli
- Department of Physiology and Functional Genomics and Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, Florida, United States of America
- * E-mail:
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A. Downs C, A. Alli A, M. Johnson N, N. Helms M. Cigarette smoke extract is a Nox agonist and regulates ENaC in alveolar type 2 cells. AIMS Molecular Science 2016. [DOI: 10.3934/molsci.2016.3.439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Qian X, Li X, Ilori TO, Klein JD, Hughey RP, Li CJ, Alli AA, Guo Z, Yu P, Song X, Chen G. RNA-seq analysis of glycosylation related gene expression in STZ-induced diabetic rat kidney inner medulla. Front Physiol 2015; 6:274. [PMID: 26483702 PMCID: PMC4590316 DOI: 10.3389/fphys.2015.00274] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 09/17/2015] [Indexed: 12/30/2022] Open
Abstract
The UT-A1 urea transporter is crucial to the kidney's ability to generate concentrated urine. Native UT-A1 from kidney inner medulla (IM) is a heavily glycosylated protein with two glycosylation forms of 97 and 117 kDa. In diabetes, UT-A1 protein abundance, particularly the 117 kD isoform, is significantly increased corresponding to an increased urea permeability in perfused IM collecting ducts, which plays an important role in preventing the osmotic diuresis caused by glucosuria. However, how the glycan carbohydrate structure change and the glycan related enzymes regulate kidney urea transport activity, particularly under diabetic condition, is largely unknown. In this study, using sugar-specific binding lectins, we found that the carbohydrate structure of UT-A1 is changed with increased amounts of sialic acid, fucose, and increased glycan branching under diabetic conditions. These changes were accompanied by altered UT-A1 association with the galectin proteins, β-galactoside glycan binding proteins. To explore the molecular basis of the alterations of glycan structures, the highly sensitive next generation sequencing (NGS) technology, Illumina RNA-seq, was employed to analyze genes involved in the process of UT-A1 glycosylation using streptozotocin (STZ)—induced diabetic rat kidney. Differential gene expression analysis combining with quantitative PCR revealed that expression of a number of important glycosylation related genes were changed under diabetic conditions. These genes include the glycosyltransferase genes Mgat4a, the sialylation enzymes St3gal1 and St3gal4 and glycan binding protein galectin-3, -5, -8, and -9. In contrast, although highly expressed in kidney IM, the glycosyltransferase genes Mgat1, Mgat2, and fucosyltransferase Fut8, did not show any changes. Conclusions: In diabetes, not only is UT-A1 protein abundance increased but the protein's glycan structure is also significantly changed. UT-A1 protein becomes highly sialylated, fucosylated and branched. Consistently, a number of crucial glycosylation related genes are changed under diabetic conditions. The alteration of these genes may contribute to changes in the UT-A1 glycan structure and therefore modulate kidney urea transport activity and alleviate osmotic diuresis caused by glucosuria in diabetes.
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Affiliation(s)
- Xiaoqian Qian
- Department of Physiology, Emory University School of Medicine Atlanta, GA, USA ; Department of Cardiology, The Fourth Affiliated Hospital of Harbin Medical University Harbin, China
| | - Xuechen Li
- Department of Physiology, Emory University School of Medicine Atlanta, GA, USA
| | - Titilayo O Ilori
- Renal Division, Department of Medicine, Emory University School of Medicine Atlanta, GA, USA
| | - Janet D Klein
- Department of Physiology, Emory University School of Medicine Atlanta, GA, USA ; Renal Division, Department of Medicine, Emory University School of Medicine Atlanta, GA, USA
| | - Rebecca P Hughey
- Renal-Electrolyte Division and Department of Cell Biology and Physiology, Department of Medicine, University of Pittsburgh School of Medicine Pittsburgh, PA, USA
| | - Cong-Jun Li
- Bovine Functional Genomics Laboratory, United States Department of Agriculture - Agricultural Research Service Beltsville, MD, USA
| | - Abdel A Alli
- Department of Physiology, Emory University School of Medicine Atlanta, GA, USA
| | - Zhengyu Guo
- Department of Electrical and Computer Engineering, TEES-AgriLife Center for Bioinformatics and Genomic Systems Engineering, Texas A&M University College Station, TX, USA
| | - Peng Yu
- Department of Electrical and Computer Engineering, TEES-AgriLife Center for Bioinformatics and Genomic Systems Engineering, Texas A&M University College Station, TX, USA
| | - Xiang Song
- Department of Cardiology, The Fourth Affiliated Hospital of Harbin Medical University Harbin, China
| | - Guangping Chen
- Department of Physiology, Emory University School of Medicine Atlanta, GA, USA ; Renal Division, Department of Medicine, Emory University School of Medicine Atlanta, GA, USA
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Alli AA, Bao HF, Liu BC, Yu L, Aldrugh S, Montgomery DS, Ma HP, Eaton DC. Calmodulin and CaMKII modulate ENaC activity by regulating the association of MARCKS and the cytoskeleton with the apical membrane. Am J Physiol Renal Physiol 2015; 309:F456-63. [PMID: 26136560 DOI: 10.1152/ajprenal.00631.2014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 06/24/2015] [Indexed: 11/22/2022] Open
Abstract
Phosphatidylinositol bisphosphate (PIP2) regulates epithelial sodium channel (ENaC) open probability. In turn, myristoylated alanine-rich C kinase substrate (MARCKS) protein or MARCKS-like protein 1 (MLP-1) at the plasma membrane regulates the delivery of PIP2 to ENaC. MARCKS and MLP-1 are regulated by changes in cytosolic calcium; increasing calcium promotes dissociation of MARCKS from the membrane, but the calcium-regulatory mechanisms are unclear. However, it is known that increased intracellular calcium can activate calmodulin and we show that inhibition of calmodulin with calmidazolium increases ENaC activity presumably by regulating MARCKS and MLP-1. Activated calmodulin can regulate MARCKS and MLP-1 in two ways. Calmodulin can bind to the effector domain of MARCKS or MLP-1, inactivating both proteins by causing their dissociation from the membrane. Mutations in MARCKS that prevent calmodulin association prevent dissociation of MARCKS from the membrane. Calmodulin also activates CaM kinase II (CaMKII). An inhibitor of CaMKII (KN93) increases ENaC activity, MARCKS association with ENaC, and promotes MARCKS movement to a membrane fraction. CaMKII phosphorylates filamin. Filamin is an essential component of the cytoskeleton and promotes association of ENaC, MARCKS, and MLP-1. Disruption of the cytoskeleton with cytochalasin E reduces ENaC activity. CaMKII phosphorylation of filamin disrupts the cytoskeleton and the association of MARCKS, MLP-1, and ENaC, thereby reducing ENaC open probability. Taken together, these findings suggest calmodulin and CaMKII modulate ENaC activity by destabilizing the association between the actin cytoskeleton, ENaC, and MARCKS, or MLP-1 at the apical membrane.
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Affiliation(s)
- Abdel A Alli
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Hui-Fang Bao
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Bing-Chen Liu
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Ling Yu
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Summer Aldrugh
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Darrice S Montgomery
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - He-Ping Ma
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Douglas C Eaton
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
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Lu XY, Liu BC, Wang LH, Yang LL, Bao Q, Zhai YJ, Alli AA, Thai TL, Eaton DC, Wang WZ, Ma HP. Acute ethanol induces apoptosis by stimulating TRPC6 via elevation of superoxide in oxygenated podocytes. Biochim Biophys Acta 2015; 1853:965-74. [PMID: 25601712 DOI: 10.1016/j.bbamcr.2015.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 01/07/2015] [Accepted: 01/09/2015] [Indexed: 01/06/2023]
Abstract
Our recent studies indicate that hydrogen peroxide (H2O2) only at high concentrations can cause oxidative stress in renal epithelial cells and induce apoptosis of podocytes. Consistently, the present study shows that H2O2, even at 1 mM, failed to induce intracellular oxidative stress and apoptosis of the podocytes due to efficient activity of catalase, an enzyme which degrades H2O2 to produce water and oxygen (O2). However, H2O2 acted as a source of O2 to allow acute ethanol to induce superoxide production and cause apoptosis of the podocytes. In contrast, acute ethanol alone did not elevate intracellular superoxide, even though it stimulates expression and translocation of p47phox to the plasma membrane. Inhibition of catalase abolished not only O2 production from H2O2 degradation, but also NOX2-dependent superoxide production in the podocytes challenged by both H2O2 and acute ethanol. In parallel, acute ethanol in the presence of H2O2, but neither ethanol nor H2O2 alone, stimulated transient receptor potential canonical 6 (TRPC6) channels and caused TRPC6-dependent elevation of intracellular Ca2+. These data suggest that exogenous H2O2 does not induce oxidative stress due to rapid degradation to produce O2 in the podocytes, but the oxygenated podocytes become sensitive to acute ethanol challenge and undergo apoptosis via a TRPC6-dependent elevation of intracellular Ca2+. Since cultured podocytes are considered in hypoxic conditions, H2O2 may be used as a source of O2 to establish an ischemia-reperfusion model in some type of cultured cells in which H2O2 does not directly induce intracellular oxidative stress.
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Affiliation(s)
- Xiao-Yu Lu
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Bing-Chen Liu
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Radiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Li-Hua Wang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Li-Li Yang
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Radiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Qing Bao
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Yu-Jia Zhai
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Radiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Abdel A Alli
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Tiffany L Thai
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Wei-Zhi Wang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States.
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Reifenberger MS, Yu L, Bao HF, Duke BJ, Liu BC, Ma HP, Alli AA, Eaton DC, Alli AA. Cytochalasin E alters the cytoskeleton and decreases ENaC activity in Xenopus 2F3 cells. Am J Physiol Renal Physiol 2014; 307:F86-95. [PMID: 24829507 DOI: 10.1152/ajprenal.00251.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Numerous reports have linked cytoskeleton-associated proteins with the regulation of epithelial Na(+) channel (ENaC) activity. The purpose of the present study was to determine the effect of actin cytoskeleton disruption by cytochalasin E on ENaC activity in Xenopus 2F3 cells. Here, we show that cytochalasin E treatment for 60 min can disrupt the integrity of the actin cytoskeleton in cultured Xenopus 2F3 cells. We show using single channel patch-clamp experiments and measurements of short-circuit current that ENaC activity, but not its density, is altered by cytochalasin E-induced disruption of the cytoskeleton. In nontreated cells, 8 of 33 patches (24%) had no measurable ENaC activity, whereas in cytochalasin E-treated cells, 17 of 32 patches (53%) had no activity. Analysis of those patches that did contain ENaC activity showed channel open probability significantly decreased from 0.081 ± 0.01 in nontreated cells to 0.043 ± 0.01 in cells treated with cytochalasin E. Transepithelial current from mpkCCD cells treated with cytochalasin E, cytochalasin D, or latrunculin B for 60 min was decreased compared with vehicle-treated cells. The subcellular expression of fodrin changed significantly, and several protein elements of the cytoskeleton decreased at least twofold after 60 min of cytochalasin E treatment. Cytochalasin E treatment disrupted the association between ENaC and myristoylated alanine-rich C-kinase substrate. The results presented here suggest disruption of the actin cytoskeleton by different compounds can attenuate ENaC activity through a mechanism involving changes in the subcellular expression of fodrin, several elements of the cytoskeleton, and destabilization of the ENaC-myristoylated alanine-rich C-kinase substrate complex.
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Affiliation(s)
- Matthew S Reifenberger
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
| | - Ling Yu
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
| | - Hui-Fang Bao
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
| | - Billie Jeanne Duke
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
| | - Bing-Chen Liu
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
| | - He-Ping Ma
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
| | - Ahmed A Alli
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
| | - Douglas C Eaton
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
| | - Abdel A Alli
- Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia
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Alli AA, Brewer EM, Montgomery DS, Ghant MS, Eaton DC, Brown LA, Helms MN. Chronic ethanol exposure alters the lung proteome and leads to mitochondrial dysfunction in alveolar type 2 cells. Am J Physiol Lung Cell Mol Physiol 2014; 306:L1026-35. [PMID: 24682449 DOI: 10.1152/ajplung.00287.2013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The lungs can undergo irreversible damage from chronic alcohol consumption. Herein, we developed an animal model predisposed for edematous lung injury following chronic ingestion of alcohol to better understand the etiology of alcohol-related disorders. Using animal modeling, alongside high-throughput proteomic and microarray assays, we identified changes in lung protein and transcript in mice and rats, respectively, following chronic alcohol ingestion or a caloric control diet. Liquid chromatography-mass spectrometry identified several mitochondrial-related proteins in which the expression was upregulated following long-term alcohol ingestion in mice. Consistent with these observations, rat gene chip microarray analysis of alveolar cells obtained from animals maintained on a Lieber-DeCarli liquid alcohol diet confirmed significant changes in mitochondrial-related transcripts in the alcohol lung. Transmission electron microscopy revealed significant changes in the mitochondrial architecture in alcohol mice, particularly following lipopolysaccharide exposure. Chronic alcohol ingestion was also shown to worsen mitochondrial respiration, mitochondrial membrane polarization, and NAD(+)-to-NADH ratios in alveolar type 2 cells. In summary, our studies show causal connection between chronic alcohol ingestion and mitochondrial dysfunction, albeit the specific role of each of the mitochondrial-related proteins and transcripts identified in our study requires additional study.
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Affiliation(s)
- Abdel A Alli
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Elizabeth M Brewer
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia; and
| | | | - Marcus S Ghant
- Department of Biological Sciences, Clark Atlanta University, Atlanta, Georgia
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia; Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia; and
| | - Lou Ann Brown
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia; and
| | - My N Helms
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia; Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia; and
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Liu BC, Song X, Lu XY, Fang CZ, Wei SP, Alli AA, Eaton DC, Shen BZ, Li XQ, Ma HP. Lovastatin attenuates effects of cyclosporine A on tight junctions and apoptosis in cultured cortical collecting duct principal cells. Am J Physiol Renal Physiol 2013; 305:F304-13. [PMID: 23720343 DOI: 10.1152/ajprenal.00074.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We used mouse cortical collecting duct principal cells (mpkCCDc14 cell line) as a model to determine whether statins reduce the harmful effects of cyclosporine A (CsA) on the distal nephron. The data showed that treatment of cells with CsA increased transepithelial resistance and that the effect of CsA was abolished by lovastatin. Scanning ion conductance microscopy showed that CsA significantly increased the height of cellular protrusions near tight junctions. In contrast, lovastatin eliminated the protrusions and even caused a modest depression between cells. Western blot analysis and confocal microscopy showed that lovastatin also abolished CsA-induced elevation of both zonula occludens-1 and cholesterol in tight junctions. In contrast, a high concentration of CsA induced apoptosis, which was also attenuated by lovastatin, elevated intracellular ROS via activation of NADPH oxidase, and increased the expression of p47phox. Sustained treatment of cells with lovastatin also induced significant apoptosis, which was attenuated by CsA, but did not elevate intracellular ROS. These results indicate that both CsA and lovastatin are harmful to principal cells of the distal tubule, but via ROS-dependent and ROS-independent apoptotic pathways, respectively, and that they counteract probably via mobilization of cellular cholesterol levels.
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Affiliation(s)
- Bing-Chen Liu
- Department of Cardiology, The Fourth Affiliated Hospital, Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
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Yu L, Cai H, Yue Q, Alli AA, Wang D, Al-Khalili O, Bao HF, Eaton DC. WNK4 inhibition of ENaC is independent of Nedd4-2-mediated ENaC ubiquitination. Am J Physiol Renal Physiol 2013; 305:F31-41. [PMID: 23594824 DOI: 10.1152/ajprenal.00652.2012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
A serine-threonine protein kinase, WNK4, reduces Na⁺ reabsorption and K⁺ secretion in the distal convoluted tubule by reducing trafficking of the thiazide-sensitive Na-Cl cotransporter to and enhancing renal outer medullary potassium channel retrieval from the apical membrane. Epithelial sodium channels (ENaC) in the distal nephron also play a role in regulating Na⁺ reabsorption and are also regulated by WNK4, but the mechanism is unclear. In A6 distal nephron cells, transepithelial current measurement and single channel recording show that WNK4 inhibits ENaC activity. Analysis of the number of channel per patch shows that WNK4 reduces channel number but has no effect on channel open probability. Western blots of apical and total ENaC provide additional evidence that WNK4 reduces apical as well as total ENaC expression. WNK4 enhances ENaC internalization independent of Nedd4-2-mediated ENaC ubiquitination. WNK4 also reduced the amount of ENaC available for recycling but has no effect on the rate of transepithelial current increase to forskolin. In contrast, Nedd4-2 not only reduced ENaC in the recycling pool but also decreased the rate of increase of current after forskolin. WNK4 associates with wild-type as well as Liddle's mutated ENaC, and WNK4 reduces both wild-type and mutated ENaC expressed in HEK293 cells.
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Affiliation(s)
- Ling Yu
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA.
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