1
|
Chevalier RL. Why is chronic kidney disease progressive? Evolutionary adaptations and maladaptations. Am J Physiol Renal Physiol 2023; 325:F595-F617. [PMID: 37675460 DOI: 10.1152/ajprenal.00134.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/08/2023] [Accepted: 08/27/2023] [Indexed: 09/08/2023] Open
Abstract
Despite significant advances in renal physiology, the global prevalence of chronic kidney disease (CKD) continues to increase. The emergence of multicellular organisms gave rise to increasing complexity of life resulting in trade-offs reflecting ancestral adaptations to changing environments. Three evolutionary traits shape CKD over the lifespan: 1) variation in nephron number at birth, 2) progressive nephron loss with aging, and 3) adaptive kidney growth in response to decreased nephron number. Although providing plasticity in adaptation to changing environments, the cell cycle must function within constraints dictated by available energy. Prioritized allocation of energy available through the placenta can restrict fetal nephrogenesis, a risk factor for CKD. Moreover, nephron loss with aging is a consequence of cell senescence, a pathway accelerated by adaptive nephron hypertrophy that maintains metabolic homeostasis at the expense of increased vulnerability to stressors. Driven by reproductive fitness, natural selection operates in early life but diminishes thereafter, leading to an exponential increase in CKD with aging, a product of antagonistic pleiotropy. A deeper understanding of the evolutionary constraints on the cell cycle may lead to manipulation of the balance between progenitor cell renewal and differentiation, regulation of cell senescence, and modulation of the balance between cell proliferation and hypertrophy. Application of an evolutionary perspective may enhance understanding of adaptation and maladaptation by nephrons in the progression of CKD, leading to new therapeutic advances.
Collapse
Affiliation(s)
- Robert L Chevalier
- Department of Pediatrics, The University of Virginia, Charlottesville, Virginia, United States
| |
Collapse
|
2
|
Alp A, Saruhan E, Doğan E, Genek DG, Huddam B. Time to Change Our Viewpoints to Assess Renal Risks in Patients with Solitary Kidneys beyond Traditional Approaches? J Clin Med 2023; 12:6885. [PMID: 37959350 PMCID: PMC10649944 DOI: 10.3390/jcm12216885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/26/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023] Open
Abstract
Solitary functioning kidney (SFK) can be defined as the absence or hypofunction of a kidney due to acquired or congenital reasons. A congenital solitary functioning kidney (cSFK) is more common than is an acquired one (aSFK) and is characterized by the anatomical absence (agenesis) or hypofunction (hypoplasia; hypodysplasia) of one kidney from birth. Among the acquired causes, the most important is nephrectomy (Nx) (due to the donor, trauma or mass resection). Patients with SFK are at risk for the development of chronic kidney disease (CKD) in the long term. This risk potential is also significantly affected by hypertension. The relationship between hypertension and subclinical chronic inflammation is a connection that has not yet been fully clarified pathogenetically, but there are many studies highlighting this association. In recent years, studies examining different fibrosis and inflammation biomarkers in terms of the evaluation and prediction of renal risks have become increasingly popular in the literature. Oxidative stress is known to play an important role in homocysteine-induced endothelial dysfunction and has been associated with hypertension. In our study, we aimed to investigate the relationship between ambulatory blood pressure monitoring (ABPM) and urinary/serum fibrosis and inflammatory markers in patients with SFK. We prospectively investigated the relationship between ABPM results and soluble urokinase plasminogen activator receptor (suPAR), procollagen type III N-terminal peptide (PIIINP), homocysteine and other variables in 85 patients with SFK and compared them between cSFK and aSFK groups. In the etiology of SFK, a congenital or acquired origin may differ in terms of the significance of biomarkers. In particular, the serum homocysteine level may be associated with different clinical outcomes in patients with cSFK and aSFK.
Collapse
Affiliation(s)
- Alper Alp
- Department of Nephrology, Faculty of Medicine, Mugla Sıtkı Koçman University, 48000 Mugla, Turkey; (D.G.G.); (B.H.)
| | - Ercan Saruhan
- Department of Medical Biochemistry, Faculty of Medicine, Mugla Sıtkı Koçman University, 48000 Mugla, Turkey;
| | - Emrah Doğan
- Department of Radiology, Faculty of Medicine, Mugla Sıtkı Koçman University, 48000 Mugla, Turkey;
| | - Dilek Gibyeli Genek
- Department of Nephrology, Faculty of Medicine, Mugla Sıtkı Koçman University, 48000 Mugla, Turkey; (D.G.G.); (B.H.)
| | - Bülent Huddam
- Department of Nephrology, Faculty of Medicine, Mugla Sıtkı Koçman University, 48000 Mugla, Turkey; (D.G.G.); (B.H.)
| |
Collapse
|
3
|
Chen X, Hocher CF, Shen L, Krämer BK, Hocher B. Reno- and cardioprotective molecular mechanisms of SGLT2 inhibitors beyond glycemic control: from bedside to bench. Am J Physiol Cell Physiol 2023; 325:C661-C681. [PMID: 37519230 DOI: 10.1152/ajpcell.00177.2023] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 08/01/2023]
Abstract
Large placebo-controlled clinical trials have shown that sodium-glucose cotransporter-2 inhibitors (SGLT2i) delay the deterioration of renal function and reduce cardiovascular events in a glucose-independent manner, thereby ultimately reducing mortality in patients with chronic kidney disease (CKD) and/or heart failure. These existing clinical data stimulated preclinical studies aiming to understand the observed clinical effects. In animal models, it was shown that the beneficial effect of SGLT2i on the tubuloglomerular feedback (TGF) improves glomerular pressure and reduces tubular workload by improving renal hemodynamics, which appears to be dependent on salt intake. High salt intake might blunt the SGLT2i effects on the TGF. Beyond the salt-dependent effects of SGLT2i on renal hemodynamics, SGLT2i inhibited several key aspects of macrophage-mediated renal inflammation and fibrosis, including inhibiting the differentiation of monocytes to macrophages, promoting the polarization of macrophages from a proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype, and suppressing the activation of inflammasomes and major proinflammatory factors. As macrophages are also important cells mediating atherosclerosis and myocardial remodeling after injury, the inhibitory effects of SGLT2i on macrophage differentiation and inflammatory responses may also play a role in stabilizing atherosclerotic plaques and ameliorating myocardial inflammation and fibrosis. Recent studies suggest that SGLT2i may also act directly on the Na+/H+ exchanger and Late-INa in cardiomyocytes thus reducing Na+ and Ca2+ overload-mediated myocardial damage. In addition, the renal-cardioprotective mechanisms of SGLT2i include systemic effects on the sympathetic nervous system, blood volume, salt excretion, and energy metabolism.
Collapse
Affiliation(s)
- Xin Chen
- Department of Nephrology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Carl-Friedrich Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
- Klinik für Innere Medizin, Bundeswehrkrankenhaus Berlin, Berlin, Germany
| | - Linghong Shen
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bernhard K Krämer
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Berthold Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
- Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China
- Institute of Reproductive and Stem Cell Engineering, NHC Key Laboratory of Human Stem Cell and Reproductive Engineering, School of Basic Medical Science, Central South University, Changsha, China
- IMD Institut für Medizinische Diagnostik Berlin-Potsdam GbR, Berlin, Germany
| |
Collapse
|
4
|
Kourpa A, Schulz A, Mangelsen E, Kaiser-Graf D, Koppers N, Stoll M, Rothe M, Bader M, Purfürst B, Kunz S, Gladytz T, Niendorf T, Bachmann S, Mutig K, Bolbrinker J, Panáková D, Kreutz R. Studies in Zebrafish and Rat Models Support Dual Blockade of EP2 and EP4 (Prostaglandin E 2 Receptors Type 2 and 4) for Renoprotection in Glomerular Hyperfiltration and Albuminuria. Hypertension 2023; 80:771-782. [PMID: 36715011 DOI: 10.1161/hypertensionaha.122.20392] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Glomerular hyperfiltration (GH) is an important mechanism in the development of albuminuria in hypertension. Upregulation of COX2 (cyclooxygenase 2) and prostaglandin E2 (PGE2) was linked to podocyte damage in GH. We explored the potential renoprotective effects of either separate or combined pharmacological blockade of EP2 (PGE2 receptor type 2) and EP4 (PGE2 receptor type 4) in GH. METHODS We conducted in vivo studies in a transgenic zebrafish model (Tg[fabp10a:gc-EGFP]) suitable for analysis of glomerular filtration barrier function and a genetic rat model with GH, albuminuria, and upregulation of PGE2. Similar pharmacological interventions and primary outcome analysis on albuminuria phenotype development were conducted in both model systems. RESULTS Stimulation of zebrafish embryos with PGE2 induced an albuminuria-like phenotype, thus mimicking the suggested PGE2 effects on glomerular filtration barrier dysfunction. Both separate and combined blockade of EP2 and EP4 reduced albuminuria phenotypes in zebrafish and rat models. A significant correlation between albuminuria and podocyte damage in electron microscopy imaging was identified in the rat model. Dual blockade of both receptors showed a pronounced synergistic suppression of albuminuria. Importantly, this occurred without changes in arterial blood pressure, glomerular filtration rate, or tissue oxygenation in magnetic resonance imaging, while RNA sequencing analysis implicated a potential role of circadian clock genes. CONCLUSIONS Our findings confirm a role of PGE2 in the development of albuminuria in GH and support the renoprotective potential of combined pharmacological blockade of EP2 and EP4 receptors. These data support further translational research to explore this therapeutic option and a possible role of circadian clock genes.
Collapse
Affiliation(s)
- Aikaterini Kourpa
- Institute of Clinical Pharmacology and Toxicology (A.K., A.S., E.M., D.K.-G., J.B., R.K.), Charité-Universitätsmedizin Berlin, Germany.,Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany (A.K., M.B., B.P., S.K., T.G., T.N., D.P.)
| | - Angela Schulz
- Institute of Clinical Pharmacology and Toxicology (A.K., A.S., E.M., D.K.-G., J.B., R.K.), Charité-Universitätsmedizin Berlin, Germany
| | - Eva Mangelsen
- Institute of Clinical Pharmacology and Toxicology (A.K., A.S., E.M., D.K.-G., J.B., R.K.), Charité-Universitätsmedizin Berlin, Germany
| | - Debora Kaiser-Graf
- Institute of Clinical Pharmacology and Toxicology (A.K., A.S., E.M., D.K.-G., J.B., R.K.), Charité-Universitätsmedizin Berlin, Germany
| | - Nils Koppers
- Genetic Epidemiology, Institute for Human Genetics, Westfälische Wilhelms University, Münster, Germany (N.K., M.S.)
| | - Monika Stoll
- Genetic Epidemiology, Institute for Human Genetics, Westfälische Wilhelms University, Münster, Germany (N.K., M.S.)
| | | | - Michael Bader
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany (A.K., M.B., B.P., S.K., T.G., T.N., D.P.).,German Center for Cardiovascular Research, Partner Site Berlin, Germany (M.B.).,Charité-Universitätsmedizin Berlin, Germany (M.B.).,Institute for Biology, University of Lübeck, Germany (M.B.)
| | - Bettina Purfürst
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany (A.K., M.B., B.P., S.K., T.G., T.N., D.P.)
| | - Severine Kunz
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany (A.K., M.B., B.P., S.K., T.G., T.N., D.P.)
| | - Thomas Gladytz
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany (A.K., M.B., B.P., S.K., T.G., T.N., D.P.)
| | - Thoralf Niendorf
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany (A.K., M.B., B.P., S.K., T.G., T.N., D.P.)
| | - Sebastian Bachmann
- Institute of Vegetative Anatomy (S.B.), Charité-Universitätsmedizin Berlin, Germany
| | - Kerim Mutig
- Institute of Translational Physiology (K.M.), Charité-Universitätsmedizin Berlin, Germany
| | - Juliane Bolbrinker
- Institute of Clinical Pharmacology and Toxicology (A.K., A.S., E.M., D.K.-G., J.B., R.K.), Charité-Universitätsmedizin Berlin, Germany
| | - Daniela Panáková
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany (A.K., M.B., B.P., S.K., T.G., T.N., D.P.)
| | - Reinhold Kreutz
- Institute of Clinical Pharmacology and Toxicology (A.K., A.S., E.M., D.K.-G., J.B., R.K.), Charité-Universitätsmedizin Berlin, Germany
| |
Collapse
|
5
|
Higashi Y, Homma J, Sekine H, Yago H, Kobayashi E, Shimizu T. External pressure dynamics promote kidney viability and perfusate filtration during ex vivo kidney perfusion. Sci Rep 2022; 12:21564. [PMID: 36513748 PMCID: PMC9747902 DOI: 10.1038/s41598-022-26147-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Normothermic machine perfusion (NMP) has not yet been established as a technique for preserving organs for a day. A key contributing factor to the same is that the perfusing solutions cannot circulate continuously and evenly in the organs. Here, we conceived a method of applying intermittent air pressure from outside the organ to assist its circulatory distribution during perfusion. We used a perfusion culture system while applying external pressure to culture rat kidneys and compared the circulatory distribution in the kidneys, changes in tissue morphology due to injury, and perfusate filtration. The intermittent pressurization (IMP) (-) group showed markedly poorer circulation on the upper side compared with that in the lower side, alongside histological damage. On the other hand, the IMP (+) group showed improved circulation in the upper side and had lesser histological damage. Furthermore, the IMP (+) group maintained the ability to filter perfusate for 24 h. In transplantation medicine and regenerative medicine research, this method has the potential to contribute to more efficient organ preservation and more functional tissue regeneration in the future.
Collapse
Affiliation(s)
- Yuhei Higashi
- grid.410818.40000 0001 0720 6587Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women’s Medical University, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo, 162-8666 Japan ,Tokaihit Co., Ltd., Shizuoka, Japan
| | - Jun Homma
- grid.410818.40000 0001 0720 6587Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women’s Medical University, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo, 162-8666 Japan
| | - Hidekazu Sekine
- grid.410818.40000 0001 0720 6587Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women’s Medical University, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo, 162-8666 Japan
| | - Hiroki Yago
- grid.410818.40000 0001 0720 6587Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women’s Medical University, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo, 162-8666 Japan
| | - Eiji Kobayashi
- grid.411898.d0000 0001 0661 2073Department of Kidney Regenerative Medicine, Industry-Academia Collaborative Department, The Jikei University School of Medicine, Tokyo, Japan
| | - Tatsuya Shimizu
- grid.410818.40000 0001 0720 6587Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women’s Medical University, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo, 162-8666 Japan
| |
Collapse
|
6
|
Srivastava T, Garola RE, Zhou J, Boinpelly VC, Priya L, Ali MF, Rezaiekhaligh MH, Heruth DP, Novak J, Alon US, Joshi T, Jiang Y, McCarthy ET, Savin VJ, Johnson ML, Sharma R, Sharma M. Prostanoid receptors in hyperfiltration-mediated glomerular injury: Novel agonists and antagonists reveal opposing roles for EP2 and EP4 receptors. FASEB J 2022; 36:e22559. [PMID: 36125047 DOI: 10.1096/fj.202200875r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/23/2022] [Accepted: 09/07/2022] [Indexed: 11/11/2022]
Abstract
Increased fluid-flow shear stress (FFSS) contributes to hyperfiltration-induced podocyte and glomerular injury resulting in progression of chronic kidney disease (CKD). We reported that increased FFSS in vitro and in vivo upregulates PGE2 receptor EP2 (but not EP4 expression), COX2-PGE2 -EP2 axis, and EP2-linked Akt-GSK3β-β-catenin signaling pathway in podocytes. To understand and use the disparities between PGE2 receptors, specific agonists, and antagonists of EP2 and EP4 were used to assess phosphorylation of Akt, GSK3β and β-catenin in podocytes using Western blotting, glomerular filtration barrier function using in vitro albumin permeability (Palb ) assay, and mitigation of hyperfiltration-induced injury in unilaterally nephrectomized (UNX) mice at 1 and 6 months. Results show an increase in Palb by PGE2 , EP2 agonist (EP2AGO ) and EP4 antagonist (EP4ANT ), but not by EP2 antagonist (EP2ANT ) or EP4 agonist (EP4AGO ). Pretreatment with EP2ANT blocked the effect of PGE2 or EP2AGO on Palb . Modulation of EP2 and EP4 also induced opposite effects on phosphorylation of Akt and β-Catenin. Individual agonists or antagonists of EP2 or EP4 did not induce significant improvement in albuminuria in UNX mice. However, treatment with a combination EP2ANT + EP4AGO for 1 or 6 months caused a robust decrease in albuminuria. EP2ANT + EP4AGO combination did not impact adaptive hypertrophy or increased serum creatinine. Observed differences between expression of EP2 and EP4 on the glomerular barrier highlight these receptors as potential targets for intervention. Safe and effective mitigating effect of EP2ANT + EP4AGO presents a novel opportunity to delay the progression of hyperfiltration-associated CKD as seen in transplant donors.
Collapse
Affiliation(s)
- Tarak Srivastava
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, Missouri, USA.,Midwest Veterans' Biomedical Research Foundation (MVBRF), Kansas City, Missouri, USA.,Department of Oral and Craniofacial Sciences, University of Missouri at Kansas City-School of Dentistry, Kansas City, Missouri, USA
| | - Robert E Garola
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, Missouri, USA
| | - Jianping Zhou
- Midwest Veterans' Biomedical Research Foundation (MVBRF), Kansas City, Missouri, USA.,Renal Research Laboratory, Kansas City VA Medical Center, Kansas City, Missouri, USA
| | - Varun C Boinpelly
- Midwest Veterans' Biomedical Research Foundation (MVBRF), Kansas City, Missouri, USA.,Renal Research Laboratory, Kansas City VA Medical Center, Kansas City, Missouri, USA
| | - Lakshmi Priya
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, Missouri, USA
| | - Mohammed Farhan Ali
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, Missouri, USA
| | - Mohammad H Rezaiekhaligh
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, Missouri, USA
| | - Daniel P Heruth
- Children's Mercy Research Institute, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, Missouri, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Uri S Alon
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, Missouri, USA
| | - Trupti Joshi
- Department of Health Management and Informatics, University of Missouri, Columbia, Missouri, USA.,Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, Missouri, USA.,Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, USA.,MU Institute for Data Science and Informatics, University of Missouri, Columbia, Missouri, USA
| | - Yuexu Jiang
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, Missouri, USA.,Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri, USA
| | - Ellen T McCarthy
- Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Virginia J Savin
- Renal Research Laboratory, Kansas City VA Medical Center, Kansas City, Missouri, USA.,Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Mark L Johnson
- Department of Oral and Craniofacial Sciences, University of Missouri at Kansas City-School of Dentistry, Kansas City, Missouri, USA
| | - Ram Sharma
- Renal Research Laboratory, Kansas City VA Medical Center, Kansas City, Missouri, USA
| | - Mukut Sharma
- Midwest Veterans' Biomedical Research Foundation (MVBRF), Kansas City, Missouri, USA.,Renal Research Laboratory, Kansas City VA Medical Center, Kansas City, Missouri, USA.,Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| |
Collapse
|
7
|
McArdle Z, Singh R, Bielefeldt-Ohmann H, Moritz K, Schreuder M, Denton K. Brief Early Life Angiotensin Converting Enzyme Inhibition Offers Reno-Protection in Sheep with a Solitary Functioning Kidney at 8 Months of Age. J Am Soc Nephrol 2022; 33:1341-1356. [PMID: 35351818 PMCID: PMC9257814 DOI: 10.1681/asn.2021111534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/18/2022] [Indexed: 11/03/2022] Open
Abstract
Background: Children born with a solitary functioning kidney (SFK) are predisposed to develop hypertension and kidney injury. Glomerular hyperfiltration and hypertrophy contribute to the pathophysiology of kidney injury. Angiotensin converting enzyme inhibitors (ACEi) can mitigate hyperfiltration and may be therapeutically beneficial in reducing progression of kidney injury in SFK. Methods: SFK was induced in male sheep fetuses at 100 days gestation (term=150 day). Between 4-8 weeks of age, SFK lambs received enalapril (SFK+ACEi; 0.5mg/kg/day, once daily, orally) or vehicle (SFK). At 8 months we examined whether SFK+ACEi reduced elevation in blood pressure (BP) and improved basal kidney function, renal functional reserve (RFR; glomerular filtration rate (GFR) response to combined amino acid and dopamine infusion), GFR response to nitric oxide synthase (NOS) inhibition and basal nitric oxide (NO) bioavailability (basal urinary total nitrate+nitrite (NOx)). Results: SFK+ACEi prevented albuminuria, resulted in lower basal GFR (16%), higher renal blood flow (~22%), and lower filtration fraction ( 35%), but similar BP compared to ~ vehicle-treated SFK sheep. Together with greater recruitment of RFR (~14%) in SFK+ACEi animals than SFK, this indicates reduction in glomerular hyperfiltration-mediated kidney dysfunction. During NOS inhibition, the decrease in GFR ( 14%) was greater among SFK+ACEi than among SFK animals. Increased ( 85%) basal urinary total NOx in SFK+ACEi animals compared to SFK indicates elevated NO bioavailability likely contributing to improvements in kidney function and prevention of albuminuria. Conclusions: Brief and early ACEi in SFK is associated with reduced glomerular hyperfiltration-mediated kidney disease up to 8 months of age in a sheep model.
Collapse
Affiliation(s)
- Zoe McArdle
- Z McArdle, Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Australia
| | - Reetu Singh
- R Singh, Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Australia
| | - Helle Bielefeldt-Ohmann
- H Bielefeldt-Ohmann, School of Veterinary Science, The University of Queensland, Gatton, Australia
| | - Karen Moritz
- K Moritz, Child Health Research Centre and School of Biomedical Sciences, The University of Queensland, Saint Lucia, Australia
| | - Michiel Schreuder
- M Schreuder, Department of Pediatric Nephrology , Amalia Children's Hospital, Nijmegen, Netherlands
| | - Kate Denton
- K Denton, Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Australia
| |
Collapse
|
8
|
Sharma M, Singh V, Sharma R, Koul A, McCarthy ET, Savin VJ, Joshi T, Srivastava T. Glomerular Biomechanical Stress and Lipid Mediators during Cellular Changes Leading to Chronic Kidney Disease. Biomedicines 2022; 10:biomedicines10020407. [PMID: 35203616 PMCID: PMC8962328 DOI: 10.3390/biomedicines10020407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 01/31/2022] [Accepted: 02/04/2022] [Indexed: 02/04/2023] Open
Abstract
Hyperfiltration is an important underlying cause of glomerular dysfunction associated with several systemic and intrinsic glomerular conditions leading to chronic kidney disease (CKD). These include obesity, diabetes, hypertension, focal segmental glomerulosclerosis (FSGS), congenital abnormalities and reduced renal mass (low nephron number). Hyperfiltration-associated biomechanical forces directly impact the cell membrane, generating tensile and fluid flow shear stresses in multiple segments of the nephron. Ongoing research suggests these biomechanical forces as the initial mediators of hyperfiltration-induced deterioration of podocyte structure and function leading to their detachment and irreplaceable loss from the glomerular filtration barrier. Membrane lipid-derived polyunsaturated fatty acids (PUFA) and their metabolites are potent transducers of biomechanical stress from the cell surface to intracellular compartments. Omega-6 and ω-3 long-chain PUFA from membrane phospholipids generate many versatile and autacoid oxylipins that modulate pro-inflammatory as well as anti-inflammatory autocrine and paracrine signaling. We advance the idea that lipid signaling molecules, related enzymes, metabolites and receptors are not just mediators of cellular stress but also potential targets for developing novel interventions. With the growing emphasis on lifestyle changes for wellness, dietary fatty acids are potential adjunct-therapeutics to minimize/treat hyperfiltration-induced progressive glomerular damage and CKD.
Collapse
Affiliation(s)
- Mukut Sharma
- Research and Development Service, Kansas City VA Medical Center, Kansas City, MO 64128, USA;
- Midwest Veterans’ Biomedical Research Foundation, Kansas City, MO 64128, USA; (A.K.); (V.J.S.); (T.S.)
- Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, MO 66160, USA;
- Correspondence: ; Tel.: +1-816-861-4700 (ext. 58222)
| | - Vikas Singh
- Neurology, Kansas City VA Medical Center, Kansas City, MO 64128, USA;
| | - Ram Sharma
- Research and Development Service, Kansas City VA Medical Center, Kansas City, MO 64128, USA;
| | - Arnav Koul
- Midwest Veterans’ Biomedical Research Foundation, Kansas City, MO 64128, USA; (A.K.); (V.J.S.); (T.S.)
| | - Ellen T. McCarthy
- Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, MO 66160, USA;
| | - Virginia J. Savin
- Midwest Veterans’ Biomedical Research Foundation, Kansas City, MO 64128, USA; (A.K.); (V.J.S.); (T.S.)
| | - Trupti Joshi
- Department of Health Management and Informatics, University of Missouri, Columbia, MO 65201, USA;
| | - Tarak Srivastava
- Midwest Veterans’ Biomedical Research Foundation, Kansas City, MO 64128, USA; (A.K.); (V.J.S.); (T.S.)
- Section of Nephrology, Children’s Mercy Hospital and University of Missouri, Kansas City, MO 64108, USA
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| |
Collapse
|
9
|
Arora S, Srinivasan A, Leung CM, Toh YC. Bio-mimicking Shear Stress Environments for Enhancing Mesenchymal Stem Cell Differentiation. Curr Stem Cell Res Ther 2021; 15:414-427. [PMID: 32268869 DOI: 10.2174/1574888x15666200408113630] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 09/03/2019] [Accepted: 02/19/2020] [Indexed: 12/12/2022]
Abstract
Mesenchymal stem cells (MSCs) are multipotent stromal cells, with the ability to differentiate into mesodermal (e.g., adipocyte, chondrocyte, hematopoietic, myocyte, osteoblast), ectodermal (e.g., epithelial, neural) and endodermal (e.g., hepatocyte, islet cell) lineages based on the type of induction cues provided. As compared to embryonic stem cells, MSCs hold a multitude of advantages from a clinical translation perspective, including ease of isolation, low immunogenicity and limited ethical concerns. Therefore, MSCs are a promising stem cell source for different regenerative medicine applications. The in vitro differentiation of MSCs into different lineages relies on effective mimicking of the in vivo milieu, including both biochemical and mechanical stimuli. As compared to other biophysical cues, such as substrate stiffness and topography, the role of fluid shear stress (SS) in regulating MSC differentiation has been investigated to a lesser extent although the role of interstitial fluid and vascular flow in regulating the normal physiology of bone, muscle and cardiovascular tissues is well-known. This review aims to summarise the current state-of-the-art regarding the role of SS in the differentiation of MSCs into osteogenic, cardiovascular, chondrogenic, adipogenic and neurogenic lineages. We will also highlight and discuss the potential of employing SS to augment the differentiation of MSCs to other lineages, where SS is known to play a role physiologically but has not yet been successfully harnessed for in vitro differentiation, including liver, kidney and corneal tissue lineage cells. The incorporation of SS, in combination with biochemical and biophysical cues during MSC differentiation, may provide a promising avenue to improve the functionality of the differentiated cells by more closely mimicking the in vivo milieu.
Collapse
Affiliation(s)
- Seep Arora
- Department of Biomedical Engineering, National University of Singapore, 21 Lower Kent Ridge Rd, 117583, Singapore
| | - Akshaya Srinivasan
- Department of Biomedical Engineering, National University of Singapore, 21 Lower Kent Ridge Rd, 117583, Singapore
| | - Chak Ming Leung
- Department of Biomedical Engineering, National University of Singapore, 21 Lower Kent Ridge Rd, 117583, Singapore
| | - Yi-Chin Toh
- Department of Biomedical Engineering, National University of Singapore, 21 Lower Kent Ridge Rd, 117583, Singapore
| |
Collapse
|
10
|
Srivastava T, Heruth DP, Duncan RS, Rezaiekhaligh MH, Garola RE, Priya L, Zhou J, Boinpelly VC, Novak J, Ali MF, Joshi T, Alon US, Jiang Y, McCarthy ET, Savin VJ, Sharma R, Johnson ML, Sharma M. Transcription Factor β-Catenin Plays a Key Role in Fluid Flow Shear Stress-Mediated Glomerular Injury in Solitary Kidney. Cells 2021; 10:cells10051253. [PMID: 34069476 PMCID: PMC8159099 DOI: 10.3390/cells10051253] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/06/2021] [Accepted: 05/14/2021] [Indexed: 01/21/2023] Open
Abstract
Increased fluid flow shear stress (FFSS) in solitary kidney alters podocyte function in vivo. FFSS-treated cultured podocytes show upregulated AKT-GSK3β-β-catenin signaling. The present study was undertaken to confirm (i) the activation of β-catenin signaling in podocytes in vivo using unilaterally nephrectomized (UNX) TOPGAL mice with the β-galactosidase reporter gene for β-catenin activation, (ii) β-catenin translocation in FFSS-treated mouse podocytes, and (iii) β-catenin signaling using publicly available data from UNX mice. The UNX of TOPGAL mice resulted in glomerular hypertrophy and increased the mesangial matrix consistent with hemodynamic adaptation. Uninephrectomized TOPGAL mice showed an increased β-galactosidase expression at 4 weeks but not at 12 weeks, as assessed using immunofluorescence microscopy (p < 0.001 at 4 weeks; p = 0.16 at 12 weeks) and X-gal staining (p = 0.008 at 4 weeks; p = 0.65 at 12 weeks). Immunofluorescence microscopy showed a significant increase in phospho-β-catenin (Ser552, p = 0.005) at 4 weeks but not at 12 weeks (p = 0.935) following UNX, and the levels of phospho-β-catenin (Ser675) did not change. In vitro FFSS caused a sustained increase in the nuclear translocation of phospho-β-catenin (Ser552) but not phospho-β-catenin (Ser675) in podocytes. The bioinformatic analysis of the GEO dataset, #GSE53996, also identified β-catenin as a key upstream regulator. We conclude that transcription factor β-catenin mediates FFSS-induced podocyte (glomerular) injury in solitary kidney.
Collapse
Affiliation(s)
- Tarak Srivastava
- Section of Nephrology, Children’s Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO 64108, USA; (M.H.R.); (L.P.); (M.F.A.); (U.S.A.)
- Midwest Veterans’ Biomedical Research Foundation (MVBRF), Kansas City, MO 64128, USA; (J.Z.); (V.C.B.); (M.S.)
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri at Kansas City, Kansas City, MO 64108, USA;
- Correspondence: ; Tel.: +1-816-234-3010; Fax: +1-816-302-9919
| | - Daniel P. Heruth
- Children’s Mercy Research Institute, Children’s Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO 64108, USA;
| | - R. Scott Duncan
- School of Biological Sciences, University of Missouri at Kansas City, Kansas City, MO 64108, USA;
| | - Mohammad H. Rezaiekhaligh
- Section of Nephrology, Children’s Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO 64108, USA; (M.H.R.); (L.P.); (M.F.A.); (U.S.A.)
| | - Robert E. Garola
- Department of Pathology and Laboratory Medicine, Children’s Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO 64108, USA;
| | - Lakshmi Priya
- Section of Nephrology, Children’s Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO 64108, USA; (M.H.R.); (L.P.); (M.F.A.); (U.S.A.)
| | - Jianping Zhou
- Midwest Veterans’ Biomedical Research Foundation (MVBRF), Kansas City, MO 64128, USA; (J.Z.); (V.C.B.); (M.S.)
- Kansas City VA Medical Center, Kansas City, MO 64128, USA; (V.J.S.); (R.S.)
| | - Varun C. Boinpelly
- Midwest Veterans’ Biomedical Research Foundation (MVBRF), Kansas City, MO 64128, USA; (J.Z.); (V.C.B.); (M.S.)
- Kansas City VA Medical Center, Kansas City, MO 64128, USA; (V.J.S.); (R.S.)
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35487, USA;
| | - Mohammed Farhan Ali
- Section of Nephrology, Children’s Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO 64108, USA; (M.H.R.); (L.P.); (M.F.A.); (U.S.A.)
| | - Trupti Joshi
- Department of Health Management and Informatics, University of Missouri, Columbia, MO 65211, USA;
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO 65211, USA;
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
- MU Data Science and Informatics Institute, University of Missouri, Columbia, MO 65211, USA
| | - Uri S. Alon
- Section of Nephrology, Children’s Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO 64108, USA; (M.H.R.); (L.P.); (M.F.A.); (U.S.A.)
| | - Yuexu Jiang
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO 65211, USA;
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Ellen T. McCarthy
- Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA;
| | - Virginia J. Savin
- Kansas City VA Medical Center, Kansas City, MO 64128, USA; (V.J.S.); (R.S.)
| | - Ram Sharma
- Kansas City VA Medical Center, Kansas City, MO 64128, USA; (V.J.S.); (R.S.)
| | - Mark L. Johnson
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri at Kansas City, Kansas City, MO 64108, USA;
| | - Mukut Sharma
- Midwest Veterans’ Biomedical Research Foundation (MVBRF), Kansas City, MO 64128, USA; (J.Z.); (V.C.B.); (M.S.)
- Kansas City VA Medical Center, Kansas City, MO 64128, USA; (V.J.S.); (R.S.)
- Department of Internal Medicine, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA;
| |
Collapse
|
11
|
Mima A. Sodium-Glucose Cotransporter 2 Inhibitors in Patients with Non-Diabetic Chronic Kidney Disease. Adv Ther 2021; 38:2201-2212. [PMID: 33860925 DOI: 10.1007/s12325-021-01735-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/27/2021] [Indexed: 01/08/2023]
Abstract
BACKGROUND Sodium-glucose cotransporter 2 (SGLT2) inhibitors can reduce cardiovascular morbidity and mortality in patients with type 2 diabetes. Furthermore, recent clinical studies have revealed that SGLT2 inhibitors decrease the risk of renal function impairment in patients with type 2 diabetes. However, the effects of SGLT2 inhibitors on non-diabetic chronic kidney disease (CKD) remains unclear. Regarding long-term clinical outcomes, the Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure (DAPA-HF) trial explicitly showed improvements in cardiovascular outcomes in patients presenting with heart failure, even in the absence of diabetes. The reduction in heart failure in patients without diabetes was confirmed following empagliflozin administration in the EMPagliflozin outcomE tRial in patients with chrOnic heart failure with Reduced ejection fraction (EMPEROR-Reduced) trial. A recent systematic review and meta-analysis of DAPA-HF and EMPEROR-Reduced showed improvements in the composite renal endpoint regardless of the presence of diabetes or baseline estimated glomerular filtration rate. The Dapagliflozin and Prevention of Adverse outcomes in Chronic Kidney Disease (DAPA-CKD) trial evaluated patients with CKD with or without type 2 diabetes, irrespective of whether SGLT2 inhibitor dapagliflozin was added for renin-angiotensin system blockade as background renoprotective therapy. In this trial, dapagliflozin reduced the hazard ratio for a composite renal and cardiovascular death endpoint in patients with CKD attributed to various causes, with or without type 2 diabetes.
Collapse
|
12
|
Mavrogeorgis E, Mischak H, Beige J, Latosinska A, Siwy J. Understanding glomerular diseases through proteomics. Expert Rev Proteomics 2021; 18:137-157. [PMID: 33779448 DOI: 10.1080/14789450.2021.1908893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Chronic kidney disease is avery common and complex chronic disease. Uncovering the pathological patterns of CKD on the molecular level of bio-fluids and tissue appears to be both vital and promising for a more favorable outcome. We reviewed recently discovered proteomics biomarkers for CKD to provide new insight into disease pathology. AREAS COVERED We review the application of proteome analysis in the context of CKD with various etiologies within the last 5 years. Proteins and peptides associated with CKD as derived from multiple sources (urine, blood and tissue) are reported along with their various biological pathways. EXPERT OPINION A systematic and theoretical comprehension of the CKD pathology is essential for its successful management. The underlying complexity of the disease further requires specific conditions for reliable and interpretable results. In this context, clinical proteomics has resulted in first encouraging findings in CKD. A more complete understanding of the biological pathways related to the disease, based on the scope of a holistic proteomic approach, could improve substantially the management of CKD, especially when in conjunction with the current trend of personalized medicine.
Collapse
Affiliation(s)
| | - H Mischak
- Mosaiques Diagnostics GmbH, Hannover, Germany.,Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - J Beige
- Division of Nephrology and KfH Renal Unit, Hospital St. Georg, Leipzig, Germany.,Department of Internal Medicine 2 (Nephrology, Rheumatology, Endocrinology), Martin-Luther-University Halle, Wittenberg, Germany
| | | | - J Siwy
- Mosaiques Diagnostics GmbH, Hannover, Germany
| |
Collapse
|
13
|
Singh RR, McArdle ZM, Booth LC, May CN, Head GA, Moritz KM, Schlaich MP, Denton KM. Increase in Bioavailability of Nitric Oxide After Renal Denervation Improves Kidney Function in Sheep With Hypertensive Kidney Disease. Hypertension 2021; 77:1299-1310. [PMID: 33641371 DOI: 10.1161/hypertensionaha.120.16718] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- Reetu R Singh
- From the Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia (R.R.S., Z.M.M., K.M.D.)
| | - Zoe M McArdle
- From the Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia (R.R.S., Z.M.M., K.M.D.)
| | - Lindsea C Booth
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia (L.C.B., C.N.M.)
| | - Clive N May
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia (L.C.B., C.N.M.)
| | - Geoff A Head
- Baker Heart and Diabetes Institute, Melbourne, Australia (G.A.H., M.P.S.)
| | - Karen M Moritz
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia (K.M.M.)
| | - Markus P Schlaich
- Baker Heart and Diabetes Institute, Melbourne, Australia (G.A.H., M.P.S.).,and Dobney Hypertension Centre, School of Medicine, Royal Perth Hospital Unit, University of Western Australia, Australia (M.P.S.)
| | - Kate M Denton
- From the Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia (R.R.S., Z.M.M., K.M.D.)
| |
Collapse
|
14
|
Repetti R, Majumder N, De Oliveira KC, Meth J, Yangchen T, Sharma M, Srivastava T, Rohatgi R. Unilateral Nephrectomy Stimulates ERK and Is Associated With Enhanced Na Transport. Front Physiol 2021; 12:583453. [PMID: 33633581 PMCID: PMC7901926 DOI: 10.3389/fphys.2021.583453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 01/14/2021] [Indexed: 11/13/2022] Open
Abstract
Nephron loss initiates compensatory hemodynamic and cellular effects on the remaining nephrons. Increases in single nephron glomerular filtration rate and tubular flow rate exert higher fluid shear stress (FSS) on tubules. In principal cell (PC) culture models FSS induces ERK, and ERK is implicated in the regulation of transepithelial sodium (Na) transport, as well as, proliferation. Thus, we hypothesize that high tubular flow and FSS mediate ERK activation in the cortical collecting duct (CCD) of solitary kidney which regulates amiloride sensitive Na transport and affects CCD cell number. Immunoblotting of whole kidney protein lysate was performed to determine phospho-ERK (pERK) expression. Next, sham and unilateral nephrectomized mice were stained with anti-pERK antibodies, and dolichos biflorus agglutinin (DBA) to identify PCs with pERK. Murine PCs (mpkCCD) were grown on semi-permeable supports under static, FSS, and FSS with U0126 (a MEK1/2 inhibitor) conditions to measure the effects of FSS and ERK inhibition on amiloride sensitive Na short circuit current (Isc). pERK abundance was greater in kidney lysate of unilateral vs. sham nephrectomies. The total number of cells in CCD and pERK positive PCs increased in nephrectomized mice (9.3 ± 0.4 vs. 6.1 ± 0.2 and 5.1 ± 0.5 vs. 3.6 ± 0.3 cell per CCD nephrectomy vs. sham, respectively, n > 6 per group, p < 0.05). However, Ki67, a marker of proliferation, did not differ by immunoblot or immunohistochemistry in nephrectomy samples at 1 month compared to sham. Next, amiloride sensitive Isc in static mpkCCD cells was 25.3 ± 1.7 μA/cm2 (n = 21), but after exposure to 24 h of FSS the Isc increased to 41.4 ± 2.8 μA/cm2 (n = 22; p < 0.01) and returned to 19.1 ± 2.1 μA/cm2 (n = 18, p < 0.01) upon treatment with U0126. Though FSS did not alter α- or γ-ENaC expression in mpkCCD cells, γ-ENaC was reduced in U0126 treated cells. In conclusion, pERK increases in whole kidney and, specifically, CCD cells after nephrectomy, but pERK was not associated with active proliferation at 1-month post-nephrectomy. In vitro studies suggest high tubular flow induces ERK dependent ENaC Na absorption and may play a critical role in Na balance post-nephrectomy.
Collapse
Affiliation(s)
- Robert Repetti
- Northport VA Medical Center, Northport, NY, United States.,School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Nomrota Majumder
- School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | | | - Jennifer Meth
- Northport VA Medical Center, Northport, NY, United States
| | - Tenzin Yangchen
- Program in Public Health, School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Mukut Sharma
- Kansas City VA Medical Center, Kansas City, MO, United States
| | | | - Rajeev Rohatgi
- Northport VA Medical Center, Northport, NY, United States.,School of Medicine, Stony Brook University, Stony Brook, NY, United States
| |
Collapse
|
15
|
Srivastava T, Joshi T, Jiang Y, Heruth DP, Rezaiekhaligh MH, Novak J, Staggs VS, Alon US, Garola RE, El-Meanawy A, McCarthy ET, Zhou J, Boinpelly VC, Sharma R, Savin VJ, Sharma M. Upregulated proteoglycan-related signaling pathways in fluid flow shear stress-treated podocytes. Am J Physiol Renal Physiol 2020; 319:F312-F322. [PMID: 32628542 DOI: 10.1152/ajprenal.00183.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The ultrafiltrate flow over the major processes and cell body generates fluid flow shear stress (FFSS) on podocytes. Hyperfiltration-associated increase in FFSS can lead to podocyte injury and detachment. Previously, we showed that FFSS-induced upregulation of the cyclooxygenase 2 (COX2)-PGE2-prostaglandin E receptor 2 (EP2) axis in podocytes activates Akt-glycogen synthase kinase-3β-β-catenin and MAPK/ERK signaling in response to FFSS. Integrative MultiOmics Pathway Resolution (IMPRes) is a new bioinformatic tool that enables simultaneous time-series analysis of more than two groups to identify pathways and molecular connections. In the present study, we used previously characterized COX2 [prostaglandin-endoperoxide synthase 2 (Ptgs2)], EP2 (Ptger2), and β1-catenin (Ctnnb1) as "seed genes" from an array data set of four groups analyzed over a time course. The 3 seed genes shared 7 pathways and 50 genes of 14 pathways and 89 genes identified by IMPRes. A composite of signaling pathways highlighted the temporal molecular connections during mechanotransduction signaling in FFSS-treated podocytes. We investigated the "proteoglycans in cancer" and "galactose metabolism" pathways predicted by IMPRes. A custom-designed PCR array validated 60.7% of the genes predicted by IMPRes analysis, including genes for the above-named pathways. Further validation using Western blot analysis showed increased expression of phosho-Erbb2, phospho-mammalian target of rapamycin (mTOR), CD44, and hexokinase II (Hk2); decreased total Erbb2, galactose mutarotase (Galm), and β-1,4-galactosyltransferase 1 (B4galt1); and unchanged total mTOR and AKT3. These findings corroborate our previously reported results. This study demonstrates the potential of the IMPRes method to identify novel pathways. Identifying the "proteoglycans in cancer" and "galactose metabolism" pathways has generated a lead to study the significance of FFSS-induced glycocalyx remodeling and possible detachment of podocytes from the glomerular matrix.
Collapse
Affiliation(s)
- Tarak Srivastava
- Section of Nephrology, Children's Mercy Hospital and University of Missouri, Kansas City, Missouri.,Midwest Veterans' Biomedical Research Foundation, Kansas City, Missouri.,Department of Oral and Craniofacial Sciences, University of Missouri School of Dentistry, Kansas City, Missouri
| | - Trupti Joshi
- Department of Health Management and Informatics and University of Missouri Informatics Institute, University of Missouri, Columbia, Missouri.,Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, Missouri.,Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri.,MU Data Science and Informatics Institute, University of Missouri, Columbia, Missouri
| | - Yuexu Jiang
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, Missouri.,Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri
| | - Daniel P Heruth
- Children's Mercy Research Institute, Children's Mercy Hospital and University of Missouri, Kansas City, Missouri
| | - Mohamed H Rezaiekhaligh
- Section of Nephrology, Children's Mercy Hospital and University of Missouri, Kansas City, Missouri
| | - Jan Novak
- Department of Microbiology, University of Alabama, Birmingham, Alabama
| | - Vincent S Staggs
- Biostatistics and Epidemiology Core, Children's Mercy Kansas City, Department of Pediatrics, University of Missouri, Kansas City, Missouri
| | - Uri S Alon
- Section of Nephrology, Children's Mercy Hospital and University of Missouri, Kansas City, Missouri
| | - Robert E Garola
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital and University of Missouri, Kansas City
| | - Ashraf El-Meanawy
- Division of Nephrology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ellen T McCarthy
- Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Jianping Zhou
- Midwest Veterans' Biomedical Research Foundation, Kansas City, Missouri.,Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| | - Varun C Boinpelly
- Midwest Veterans' Biomedical Research Foundation, Kansas City, Missouri.,Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| | - Ram Sharma
- Midwest Veterans' Biomedical Research Foundation, Kansas City, Missouri.,Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| | - Virginia J Savin
- Midwest Veterans' Biomedical Research Foundation, Kansas City, Missouri.,Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| | - Mukut Sharma
- Midwest Veterans' Biomedical Research Foundation, Kansas City, Missouri.,Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas.,Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| |
Collapse
|
16
|
Feng D, Kumar M, Muntel J, Gurley SB, Birrane G, Stillman IE, Ding L, Wang M, Ahmed S, Schlondorff J, Alper SL, Ferrante T, Marquez SL, Ng CF, Novak R, Ingber DE, Steen H, Pollak MR. Phosphorylation of ACTN4 Leads to Podocyte Vulnerability and Proteinuric Glomerulosclerosis. J Am Soc Nephrol 2020; 31:1479-1495. [PMID: 32540856 PMCID: PMC7351002 DOI: 10.1681/asn.2019101032] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/23/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Genetic mutations in α-actinin-4 (ACTN4)-an important actin crosslinking cytoskeletal protein that provides structural support for kidney podocytes-have been linked to proteinuric glomerulosclerosis in humans. However, the effect of post-translational modifications of ACTN4 on podocyte integrity and kidney function is not known. METHODS Using mass spectrometry, we found that ACTN4 is phosphorylated at serine (S) 159 in human podocytes. We used phosphomimetic and nonphosphorylatable ACTN4 to comprehensively study the effects of this phosphorylation in vitro and in vivo. We conducted x-ray crystallography, F-actin binding and bundling assays, and immunofluorescence staining to evaluate F-actin alignment. Microfluidic organ-on-a-chip technology was used to assess for detachment of podocytes simultaneously exposed to fluid flow and cyclic strain. We then used CRISPR/Cas9 to generate mouse models and assessed for renal injury by measuring albuminuria and examining kidney histology. We also performed targeted mass spectrometry to determine whether high extracellular glucose or TGF-β levels increase phosphorylation of ACTN4. RESULTS Compared with the wild type ACTN4, phosphomimetic ACTN4 demonstrated increased binding and bundling activity with F-actin in vitro. Phosphomimetic Actn4 mouse podocytes exhibited more spatially correlated F-actin alignment and a higher rate of detachment under mechanical stress. Phosphomimetic Actn4 mice developed proteinuria and glomerulosclerosis after subtotal nephrectomy. Moreover, we found that exposure to high extracellular glucose or TGF-β stimulates phosphorylation of ACTN4 at S159 in podocytes. CONCLUSIONS These findings suggest that increased phosphorylation of ACTN4 at S159 leads to biochemical, cellular, and renal pathology that is similar to pathology resulting from human disease-causing mutations in ACTN4. ACTN4 may mediate podocyte injury as a consequence of both genetic mutations and signaling events that modulate phosphorylation.
Collapse
Affiliation(s)
- Di Feng
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts,Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts
| | - Mukesh Kumar
- Department of Pathology, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts,F.M. Kirby Neurobiology Center, Department of Neurobiology, Boston Children’s Hospital, Boston, Massachusetts
| | | | - Susan B. Gurley
- Division of Nephrology and Hypertension, Oregon Health & Science University, Portland, Oregon
| | - Gabriel Birrane
- Division of Experimental Medicine, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Isaac E. Stillman
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts,Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Lai Ding
- NeuroTechnology Studio, Program for Interdisciplinary Neuroscience, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Minxian Wang
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Saima Ahmed
- Department of Pathology, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts
| | - Johannes Schlondorff
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Seth L. Alper
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Tom Ferrante
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts
| | - Susan L. Marquez
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts
| | - Carlos F. Ng
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts
| | - Richard Novak
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts
| | - Donald E. Ingber
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts,Vascular Biology Program, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts,Department of Surgery, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts,Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts
| | - Hanno Steen
- Department of Pathology, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts
| | - Martin R. Pollak
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts
| |
Collapse
|
17
|
McArdle Z, Schreuder MF, Moritz KM, Denton KM, Singh RR. Physiology and Pathophysiology of Compensatory Adaptations of a Solitary Functioning Kidney. Front Physiol 2020; 11:725. [PMID: 32670095 PMCID: PMC7332829 DOI: 10.3389/fphys.2020.00725] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/03/2020] [Indexed: 12/15/2022] Open
Abstract
Children born with a solitary functioning kidney (SFK) have an increased risk of hypertension and kidney disease from early in adulthood. In response to a reduction in kidney mass, the remaining kidney undergoes compensatory kidney growth. This is associated with both an increase in size of the kidney tubules and the glomeruli and an increase in single nephron glomerular filtration rate (SNGFR). The compensatory hypertrophy and increase in filtration at the level of the individual nephron results in normalization of total glomerular filtration rate (GFR). However, over time these same compensatory mechanisms may contribute to kidney injury and hypertension. Indeed, approximately 50% of children born with a SFK develop hypertension by the age of 18 and 20–40% require dialysis by the age of 30. The mechanisms that result in kidney injury are only partly understood, and early biomarkers that distinguish those at an elevated risk of kidney injury are needed. This review will outline the compensatory adaptations to a SFK, and outline how these adaptations may contribute to kidney injury and hypertension later in life. These will be based largely on the mechanisms we have identified from our studies in an ovine model of SFK, that implicate the renal nitric oxide system, the renin angiotensin system and the renal nerves to kidney disease and hypertension associated with SFK. This discussion will also evaluate current, and speculate on next generation, prognostic factors that may predict those children at a higher risk of future kidney disease and hypertension.
Collapse
Affiliation(s)
- Zoe McArdle
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Michiel F Schreuder
- Department of Pediatric Nephrology, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, Netherlands
| | - Karen M Moritz
- Child Health Research Centre and School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Kate M Denton
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Reetu R Singh
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| |
Collapse
|
18
|
Concerted EP2 and EP4 Receptor Signaling Stimulates Autocrine Prostaglandin E 2 Activation in Human Podocytes. Cells 2020; 9:cells9051256. [PMID: 32438662 PMCID: PMC7290667 DOI: 10.3390/cells9051256] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/29/2020] [Accepted: 05/14/2020] [Indexed: 12/14/2022] Open
Abstract
Glomerular hyperfiltration is an important mechanism in the development of albuminuria. During hyperfiltration, podocytes are exposed to increased fluid flow shear stress (FFSS) in Bowman’s space. Elevated Prostaglandin E2 (PGE2) synthesis and upregulated cyclooxygenase 2 (Cox2) are associated with podocyte injury by FFSS. We aimed to elucidate a PGE2 autocrine/paracrine pathway in human podocytes (hPC). We developed a modified liquid chromatography tandem mass spectrometry (LC/ESI-MS/MS) protocol to quantify cellular PGE2, 15-keto-PGE2, and 13,14-dihydro-15-keto-PGE2 levels. hPC were treated with PGE2 with or without separate or combined blockade of prostaglandin E receptors (EP), EP2, and EP4. Furthermore, the effect of FFSS on COX2, PTGER2, and PTGER4 expression in hPC was quantified. In hPC, stimulation with PGE2 led to an EP2- and EP4-dependent increase in cyclic adenosine monophosphate (cAMP) and COX2, and induced cellular PGE2. PTGER4 was downregulated after PGE2 stimulation in hPC. In the corresponding LC/ESI-MS/MS in vivo analysis at the tissue level, increased PGE2 and 15-keto-PGE2 levels were observed in isolated glomeruli obtained from a well-established rat model with glomerular hyperfiltration, the Munich Wistar Frömter rat. COX2 and PTGER2 were upregulated by FFSS. Our data thus support an autocrine/paracrine COX2/PGE2 pathway in hPC linked to concerted EP2 and EP4 signaling.
Collapse
|
19
|
MACROSCOPIC AND MICROSCOPIC CONDITIONS OF THE SINGLE KIDNEY AND URETEROPELVIC JUNCTION AFTER THE CONTRALATERAL NEPHRECTOMY. WORLD OF MEDICINE AND BIOLOGY 2020. [DOI: 10.26724/2079-8334-2020-1-71-201-205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
20
|
Srivastava T, Ju W, Milne GL, Rezaiekhaligh MH, Staggs VS, Alon US, Sharma R, Zhou J, El-Meanawy A, McCarthy ET, Savin VJ, Sharma M. Urinary prostaglandin E 2 is a biomarker of early adaptive hyperfiltration in solitary functioning kidney. Prostaglandins Other Lipid Mediat 2019; 146:106403. [PMID: 31838197 DOI: 10.1016/j.prostaglandins.2019.106403] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 11/20/2019] [Accepted: 12/10/2019] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Hyperfiltration is a major contributor to progression of chronic kidney disease (CKD) in diabetes, obesity and in individuals with solitary functioning kidney (SFK). We have proposed hyperfiltration-induced injury as a continuum of overlapping glomerular changes caused by increased biomechanical forces namely, fluid flow shear stress (FFSS) and tensile stress. We have shown that FFSS is elevated in animals with SFK and, it upregulates prostaglandin E2 (PGE2), cyclooxygenase-2 and PGE2 receptor EP2 in cultured podocytes and in uninephrectomized mice. We conceptualized urinary PGE2 as a biomarker of early effects of hyperfiltration-induced injury preceding microalbuminuria in individuals with SFK. We studied children with SFK to validate our hypothesis. METHODS Urine samples from children with SFK and controls were analyzed for PGE2, albumin (glomerular injury biomarker) and epidermal growth factor (EGF, tubular injury biomarker). Age, gender, and Z-scores for height, weight, BMI, and blood pressure were obtained. RESULTS Children with SFK were comparable to controls except for lower BMI Z-scores. The median values were elevated in SFK compared to control for urine PGE2 [9.1 (n = 57) vs. 5.7 (n = 72), p = 0.009] ng/mgCr and albumin [7.6 (n = 40) vs. 7.0 (n = 41), p = 0.085] μg/mgCr, but not for EGF [20098 (n = 44) vs. 18637 (n = 44), p = 0.746] pg/mgCr. Significant increase in urinary PGE2 (p = 0.024) and albumin (p = 0.019) but not EGF (p = 0.412) was observed using additional regression modeling. These three urinary analytes were independent of each other. CONCLUSION Increased urinary PGE2 from elevated SNGFR and consequently increased FFSS during early stage of CKD precedes overt microalbuminuria and is a biomarker for early hyperfiltration-induced injury in individuals with SFK.
Collapse
Affiliation(s)
- Tarak Srivastava
- Division of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO, United States; Research and Development, Nephrology, Kansas City VA Medical Center, Kansas City, MO, United States.
| | - Wenjun Ju
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States
| | - Ginger L Milne
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Mohamed H Rezaiekhaligh
- Division of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO, United States
| | - Vincent S Staggs
- Biostatistics & Epidemiology Core, Children's Mercy Kansas City, Department of Pediatrics, University of Missouri, Kansas City, United States
| | - Uri S Alon
- Division of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO, United States
| | - Ram Sharma
- Research and Development, Nephrology, Kansas City VA Medical Center, Kansas City, MO, United States
| | - Jianping Zhou
- Research and Development, Nephrology, Kansas City VA Medical Center, Kansas City, MO, United States; Midwest Biomedical Research Foundation (MBRF), KCVA Medical Center, Kansas City, MO, United States
| | - Ashraf El-Meanawy
- Division of Nephrology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Ellen T McCarthy
- Kidney Institute, Kansas University Medical Center, Kansas City, KS, United States
| | - Virginia J Savin
- Research and Development, Nephrology, Kansas City VA Medical Center, Kansas City, MO, United States; Kidney Institute, Kansas University Medical Center, Kansas City, KS, United States
| | - Mukut Sharma
- Research and Development, Nephrology, Kansas City VA Medical Center, Kansas City, MO, United States; Midwest Biomedical Research Foundation (MBRF), KCVA Medical Center, Kansas City, MO, United States; Kidney Institute, Kansas University Medical Center, Kansas City, KS, United States
| |
Collapse
|
21
|
Abstract
Kidney donors face a small but definite risk of end-stage renal disease 15 to 30 years postdonation. The development of proteinuria, hypertension with gradual decrease in kidney function in the donor after surgical resection of 1 kidney, has been attributed to hyperfiltration. Genetic variations, physiological adaptations, and comorbidities exacerbate the hyperfiltration-induced loss of kidney function in the years after donation. A focus on glomerular hemodynamics and capillary pressure has led to the development of drugs that target the renin-angiotensin-aldosterone system (RAAS), but these agents yield mixed results in transplant recipients and donors. Recent work on glomerular biomechanical forces highlights the differential effects of tensile stress and fluid flow shear stress (FFSS) from hyperfiltration. Capillary wall stretch due to glomerular capillary pressure increases tensile stress on podocyte foot processes that cover the capillary. In parallel, increased flow of the ultrafiltrate due to single-nephron glomerular filtration rate elevates FFSS on the podocyte cell body. Although tensile stress invokes the RAAS, FFSS predominantly activates the cyclooxygenase 2-prostaglandin E2-EP2 receptor axis. Distinguishing these 2 mechanisms is critical, as current therapeutic approaches focus on the RAAS system. A better understanding of the biomechanical forces can lead to novel therapeutic agents to target FFSS through the cyclooxygenase 2-prostaglandin E2-EP2 receptor axis in hyperfiltration-mediated injury. We present an overview of several aspects of the risk to transplant donors and discuss the relevance of FFSS in podocyte injury, loss of glomerular barrier function leading to albuminuria and gradual loss of renal function, and potential therapeutic strategies to mitigate hyperfiltration-mediated injury to the remaining kidney.
Collapse
|
22
|
Comparative transcriptomics of shear stress treated Pkd1−/− cells and pre-cystic kidneys reveals pathways involved in early polycystic kidney disease. Biomed Pharmacother 2018; 108:1123-1134. [DOI: 10.1016/j.biopha.2018.07.178] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/30/2018] [Accepted: 07/31/2018] [Indexed: 02/08/2023] Open
|
23
|
Kriz W, Lemley KV. Potential relevance of shear stress for slit diaphragm and podocyte function. Kidney Int 2018; 91:1283-1286. [PMID: 28501303 DOI: 10.1016/j.kint.2017.02.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/07/2017] [Accepted: 02/24/2017] [Indexed: 11/30/2022]
Abstract
Filtrate flow through the glomerular barrier produces shear stresses that tend to disconnect podocytes from the glomerular basement membrane. Forces are highest within the filtration slits. The slit diaphragm mechanically balances the lateral components of the shear stresses on opposing foot processes, preventing widening of the slit.
Collapse
Affiliation(s)
- Wilhelm Kriz
- Department of Neuroanatomy, Medical Faculty Mannheim, Germany.
| | - Kevin V Lemley
- Division of Nephrology, Children's Hospital Los Angeles, California, USA
| |
Collapse
|
24
|
Feng D, DuMontier C, Pollak MR. Mechanical challenges and cytoskeletal impairments in focal segmental glomerulosclerosis. Am J Physiol Renal Physiol 2018; 314:F921-F925. [PMID: 29363327 DOI: 10.1152/ajprenal.00641.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is a histologically defined form of kidney injury typically mediated by podocyte dysfunction. Podocytes rely on their intricate actin-based cytoskeleton to maintain the glomerular filtration barrier in the face of mechanical challenges resulting from pulsatile blood flow and filtration of this blood flow. This review summarizes the mechanical challenges faced by podocytes in the form of stretch and shear stress, both of which may play a role in the progression of podocyte dysfunction and detachment. It also reviews how podocytes respond to these mechanical challenges in dynamic fashion through rearranging their cytoskeleton, triggering various biochemical pathways, and, in some disease states, altering their morphology in the form of foot process effacement. Furthermore, this review highlights the growing body of evidence identifying several mutations of important cytoskeleton proteins as causes of FSGS. Lastly, it synthesizes the above evidence to show that a better understanding of how these mutations leave podocytes vulnerable to the mechanical challenges they face is essential to better understanding the mechanisms by which they lead to disease. The review concludes with future research directions to fill this gap and some novel techniques with which to pursue these directions.
Collapse
Affiliation(s)
- Di Feng
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center , Boston, Massachusetts.,Harvard Medical School , Boston, Massachusetts
| | - Clark DuMontier
- Harvard Medical School , Boston, Massachusetts.,Division of Gerontology, Department of Medicine, Beth Israel Deaconess Medical Center , Boston, Massachusetts
| | - Martin R Pollak
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center , Boston, Massachusetts.,Harvard Medical School , Boston, Massachusetts
| |
Collapse
|
25
|
Srivastava T, Thiagarajan G, Alon US, Sharma R, El-Meanawy A, McCarthy ET, Savin VJ, Sharma M. Role of biomechanical forces in hyperfiltration-mediated glomerular injury in congenital anomalies of the kidney and urinary tract. Nephrol Dial Transplant 2018; 32:759-765. [PMID: 28339567 DOI: 10.1093/ndt/gfw430] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/15/2016] [Indexed: 11/13/2022] Open
Abstract
Congenital anomalies of the kidney and urinary tract (CAKUT) including solitary kidney constitute the main cause of progressive chronic kidney disease (CKD) in children. Children born with CAKUT develop signs of CKD only during adolescence and do not respond to renin-angiotensin-aldosterone system blockers. Early cellular changes underlying CKD progression to end-stage renal disease by early adulthood are not well understood. The mechanism of maladaptive hyperfiltration that occurs from loss of functional nephrons, including solitary kidney, is not clear. We re-examine the phenomenon of hyperfiltration in the context of biomechanical forces with special reference to glomerular podocytes. Capillary stretch exerts tensile stress on podocytes through the glomerular basement membrane. The flow of ultrafiltrate over the cell surface directly causes fluid flow shear stress (FFSS) on podocytes. FFSS on the podocyte surface increases 1.5- to 2-fold in animal models of solitary kidney and its effect on podocytes is a subject of ongoing research. Podocytes (i) are mechanosensitive to tensile and shear forces, (ii) use prostaglandin E2, angiotensin-II or nitric oxide for mechanoperception and (iii) use specific signaling pathways for mechanotransduction. We discuss (i) the nature of and differences in cellular responses to biomechanical forces, (ii) methods to study biomechanical forces and (iii) effects of biomechanical forces on podocytes and glomeruli. Future studies on FFSS will likely identify novel targets for strategies for early intervention to complement and strengthen the current regimen for treating children with CAKUT.
Collapse
Affiliation(s)
- Tarak Srivastava
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO, USA.,Renal Research Laboratory, Research and Development, Kansas City VA Medical Center, Kansas City, MO, USA
| | - Ganesh Thiagarajan
- School of Computing and Engineering, University of Missouri at Kansas City, MO, USA
| | - Uri S Alon
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO, USA
| | - Ram Sharma
- Renal Research Laboratory, Research and Development, Kansas City VA Medical Center, Kansas City, MO, USA
| | - Ashraf El-Meanawy
- Division of Nephrology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ellen T McCarthy
- Kidney Institute, Kansas University Medical Center, Kansas City, KS, USA
| | - Virginia J Savin
- Renal Research Laboratory, Research and Development, Kansas City VA Medical Center, Kansas City, MO, USA
| | - Mukut Sharma
- Renal Research Laboratory, Research and Development, Kansas City VA Medical Center, Kansas City, MO, USA
| |
Collapse
|
26
|
Abstract
Life with a solitary functioning kidney (SFK) may be different from that when born with two kidneys. Based on the hyperfiltration hypothesis, a SFK may lead to glomerular damage with hypertension, albuminuria and progression towards end-stage renal disease. As the prognosis of kidney donors was considered to be very good, having a SFK has been considered to be a benign condition. In contrast, our research group has demonstrated that being born with or acquiring a SFK in childhood results in renal injury before adulthood in over 50% of those affected. Most congenital cases will be detected during antenatal ultrasound screening, but up to 38% of cases of unilateral renal agenesis are missed. In about 25-50% of cases of antenatally detected SFK there will be signs of hypertrophy, which could indicate additional nephron formation and is associated with a somewhat reduced risk of renal injury. Additional renal and extrarenal anomalies are frequently detected and may denote a genetic cause for the SFK, even though for the majority of cases no explanation can (yet) be found. The ongoing glomerular hyperfiltration results in renal injury, for which early markers are lacking. Individuals with SFK should avoid obesity and excessive salt intake to limit additional hyperfiltration. As conditions like hypertension, albuminuria and a mildly reduced glomerular filtration rate generally do not result in specific complaints but may pose a threat to long-term health, screening for renal injury in any individual with a SFK would appear to be imperative, starting from infancy. With early treatment, secondary consequences may be diminished, thereby providing the optimal life for anyone born with a SFK.
Collapse
|
27
|
Srivastava T, Dai H, Heruth DP, Alon US, Garola RE, Zhou J, Duncan RS, El-Meanawy A, McCarthy ET, Sharma R, Johnson ML, Savin VJ, Sharma M. Mechanotransduction signaling in podocytes from fluid flow shear stress. Am J Physiol Renal Physiol 2018; 314:F22-F34. [PMID: 28877882 PMCID: PMC5866353 DOI: 10.1152/ajprenal.00325.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/21/2017] [Accepted: 08/28/2017] [Indexed: 12/28/2022] Open
Abstract
Recently, we and others have found that hyperfiltration-associated increase in biomechanical forces, namely, tensile stress and fluid flow shear stress (FFSS), can directly and distinctly alter podocyte structure and function. The ultrafiltrate flow over the major processes and cell body generates FFSS to podocytes. Our previous work suggests that the cyclooxygenase-2 (COX-2)-PGE2-PGE2 receptor 2 (EP2) axis plays an important role in mechanoperception of FFSS in podocytes. To address mechanotransduction of the perceived stimulus through EP2, cultured podocytes were exposed to FFSS (2 dyn/cm2) for 2 h. Total RNA from cells at the end of FFSS treatment, 2-h post-FFSS, and 24-h post-FFSS was used for whole exon array analysis. Differentially regulated genes ( P < 0.01) were analyzed using bioinformatics tools Enrichr and Ingenuity Pathway Analysis to predict pathways/molecules. Candidate pathways were validated using Western blot analysis and then further confirmed to be resulting from a direct effect of PGE2 on podocytes. Results show that FFSS-induced mechanotransduction as well as exogenous PGE2 activate the Akt-GSK3β-β-catenin (Ser552) and MAPK/ERK but not the cAMP-PKA signal transduction cascades. These pathways are reportedly associated with FFSS-induced and EP2-mediated signaling in other epithelial cells as well. The current regimen for treating hyperfiltration-mediated injury largely depends on targeting the renin-angiotensin-aldosterone system. The present study identifies specific transduction mechanisms and provides novel information on the direct effect of FFSS on podocytes. These results suggest that targeting EP2-mediated signaling pathways holds therapeutic significance for delaying progression of chronic kidney disease secondary to hyperfiltration.
Collapse
Affiliation(s)
- Tarak Srivastava
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City , Kansas City, Missouri
- Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center , Kansas City, Missouri
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri at Kansas City , Kansas City, Missouri
| | - Hongying Dai
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City , Kansas City, Missouri
| | - Daniel P Heruth
- Department of Experimental and Translational Genetics Research, Children's Mercy Hospital and University of Missouri at Kansas City , Kansas City, Missouri
| | - Uri S Alon
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City , Kansas City, Missouri
| | - Robert E Garola
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital and University of Missouri at Kansas City , Kansas City, Missouri
| | - Jianping Zhou
- Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center , Kansas City, Missouri
| | - R Scott Duncan
- Department of Ophthalmology, University of Missouri at Kansas City , Kansas City, Missouri
| | - Ashraf El-Meanawy
- Division of Nephrology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Ellen T McCarthy
- Kidney Institute, University of Kansas Medical Center , Kansas City, Kansas
| | - Ram Sharma
- Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center , Kansas City, Missouri
| | - Mark L Johnson
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri at Kansas City , Kansas City, Missouri
| | - Virginia J Savin
- Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center , Kansas City, Missouri
- Kidney Institute, University of Kansas Medical Center , Kansas City, Kansas
| | - Mukut Sharma
- Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center , Kansas City, Missouri
- Kidney Institute, University of Kansas Medical Center , Kansas City, Kansas
| |
Collapse
|
28
|
Endlich K, Kliewe F, Endlich N. Stressed podocytes-mechanical forces, sensors, signaling and response. Pflugers Arch 2017; 469:937-949. [PMID: 28687864 DOI: 10.1007/s00424-017-2025-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 06/22/2017] [Indexed: 02/07/2023]
Abstract
Increased glomerular capillary pressure (glomerular hypertension) and increased glomerular filtration rate (glomerular hyperfiltration) have been proven to cause glomerulosclerosis in animal models and are likely to be operative in patients. Since podocytes cover the glomerular basement membrane, they are exposed to tensile stress due to circumferential wall tension and to fluid shear stress arising from filtrate flow through the narrow filtration slits and through Bowman's space. In vitro evidence documents that podocytes respond to tensile stress as well as to fluid shear stress. Several proteins are discussed in this review that are expressed in podocytes and could act as mechanosensors converting mechanical force via a conformational change into a biochemical signal. The cation channels P2X4 and TRPC6 were shown to be involved in mechanosignaling in podocytes. P2X4 is activated by stretch-induced ATP release, while TRPC6 might be inherently mechanosensitive. Membrane, slit diaphragm and cell-matrix contact proteins are connected to the sublemmal actin network in podocytes via various linker proteins. Therefore, actin-associated proteins, like the proven mechanosensor filamin, are ideal candidates to sense forces in the podocyte cytoskeleton. Furthermore, podocytes express talin, p130Cas, and fibronectin that are known to undergo a conformational change in response to mechanical force exposing cryptic binding sites. Downstream of mechanosensors, experimental evidence suggests the involvement of MAP kinases, Ca2+ and COX2 in mechanosignaling and an emerging role of YAP/TAZ. In summary, our understanding of mechanotransduction in podocytes is still sketchy, but future progress holds promise to identify targets to alleviate conditions of increased mechanical load.
Collapse
Affiliation(s)
- Karlhans Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489, Greifswald, Germany.
- Institut für Anatomie and Zellbiologie, Universitätsmedizin Greifswald, Friedrich-Loeffler-Str. 23c, 17489, Greifswald, Germany.
| | - Felix Kliewe
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489, Greifswald, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489, Greifswald, Germany
| |
Collapse
|
29
|
Kriz W, Lemley KV. Mechanical challenges to the glomerular filtration barrier: adaptations and pathway to sclerosis. Pediatr Nephrol 2017; 32:405-417. [PMID: 27008645 DOI: 10.1007/s00467-016-3358-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 11/30/2022]
Abstract
Podocytes are lost as viable cells by detachment from the glomerular basement membrane (GBM), possibly due to factors such as pressure and filtrate flow. Distension of glomerular capillaries in response to increased pressure is limited by the elastic resistance of the GBM. The endothelium and podocytes adapt to changes in GBM area. The slit diaphragm (SD) seems to adjust by shuttling SD components between the SD and the adjacent foot processes (FPs), resulting in changes in SD area that parallel those in perfusion pressure.Filtrate flow tends to drag podocytes towards the urinary orifice by shear forces, which are highest within the filtration slits. The SD represents an atypical adherens junction, mechanically interconnecting the cytoskeleton of opposing FPs and tending to balance the shear forces.If under pathological conditions, increased filtrate flows locally overtax the attachment of FPs, the SDs are replaced by occluding junctions that seal the slits and the attachment of podocytes to the GBM is reinforced by FP effacement. Failure of these temporary adaptive mechanisms results in a steady process of podocyte detachment due to uncontrolled filtrate flows through bare areas of the GBM and, subsequently, the labyrinthine subpodocyte spaces, presenting as pseudocysts. In our view, shear stress due to filtrate flow-not capillary hydrostatic pressure-is the major challenge to the attachment of podocytes to the GBM.
Collapse
Affiliation(s)
- Wilhelm Kriz
- Department of Neuroanatomy, Medical Faculty Mannheim, University of Heidelberg, Ludolf-Krehl-Str. 13-17, 68167, Mannheim, Germany.
| | - Kevin V Lemley
- Division of Nephrology, Children's Hospital Los Angeles, Los Angeles, CA, USA
- Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| |
Collapse
|
30
|
Hyperfiltration-associated biomechanical forces in glomerular injury and response: Potential role for eicosanoids. Prostaglandins Other Lipid Mediat 2017; 132:59-68. [PMID: 28108282 DOI: 10.1016/j.prostaglandins.2017.01.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 12/22/2016] [Accepted: 01/10/2017] [Indexed: 12/29/2022]
Abstract
Hyperfiltration is a well-known risk factor in progressive loss of renal function in chronic kidney disease (CKD) secondary to various diseases. A reduced number of functional nephrons due to congenital or acquired cause(s) results in hyperfiltration in the remnant kidney. Hyperfiltration-associated increase in biomechanical forces, namely pressure-induced tensile stress and fluid flow-induced shear stress (FFSS) determine cellular injury and response. We believe the current treatment of CKD yields limited success because it largely attenuates pressure-induced tensile stress changes but not the effect of FFSS on podocytes. Studies on glomerular podocytes, tubular epithelial cells and bone osteocytes provide evidence for a significant role of COX-2 generated PGE2 and its receptors in response to tensile stress and FFSS. Preliminary observations show increased urinary PGE2 in children born with a solitary kidney. FFSS-induced COX2-PGE2-EP2 signaling provides an opportunity to identify targets and, for developing novel agents to complement currently available treatment.
Collapse
|
31
|
Melsom T, Stefansson V, Schei J, Solbu M, Jenssen T, Wilsgaard T, Eriksen BO. Association of Increasing GFR with Change in Albuminuria in the General Population. Clin J Am Soc Nephrol 2016; 11:2186-2194. [PMID: 27683625 PMCID: PMC5142069 DOI: 10.2215/cjn.04940516] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/02/2016] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND OBJECTIVES Hyperfiltration at the single-nephron level has been proposed as an early stage of kidney dysfunction of different origins. Evidence supporting this hypothesis in humans is lacking, because there is no method of measuring single-nephron GFR in humans. However, increased whole-kidney GFR in the same individual implies an increased single-nephron GFR, because the number of nephrons does not increase with age. We hypothesized that an increase in GFR would be associated with an increased albumin-to-creatinine ratio in a cohort of the general population. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We measured GFR by iohexol clearance at baseline in 2007-2009 and follow-up after 5.6 years in a representative sample of 1246 persons (aged 50-62 years) who were nondiabetic from the general population of Tromso, northern Norway. Participants were without cardiovascular disease, kidney disease, or diabetes at baseline. We investigated the association between change in GFR and change in albumin-to-creatinine ratio. Increased GFR was defined as a positive change in GFR (change in GFR>0 ml/min) from baseline to follow-up. An albumin-to-creatinine ratio >30 mg/g was classified as albuminuria. RESULTS Change in GFR was positively associated with a change in albumin-to-creatinine ratio in the entire cohort in the multiple linear regression. The albumin-to-creatinine ratiofollow-up-to-albumin-to-creatinine ratiobaseline ratio increased by 8.0% (95% confidence interval, 1.4 to 15.0) per SD increase in change in GFR. When participants with increased GFR (n=343) were compared with those with a reduced GFR (n=903), the ratio increased by 16.3% (95% confidence interval, 1.1 to 33.7). The multivariable adjusted odds ratio for incident albuminuria (n=14) was 4.98 (95% confidence interval, 1.49 to 16.13) for those with an increased GFR (yes/no). CONCLUSIONS Increasing GFR is associated with an increase in albumin-to-creatinine ratio and incident albuminuria in the general nondiabetic population. These findings support single-nephron hyperfiltration as a risk factor for albuminuria in the general population.
Collapse
Affiliation(s)
- Toralf Melsom
- Metabolic and Renal Research Group and
- Section of Nephrology, University Hospital of North Norway, Tromso, Norway; and
| | | | - Jørgen Schei
- Metabolic and Renal Research Group and
- Section of Nephrology, University Hospital of North Norway, Tromso, Norway; and
| | - Marit Solbu
- Metabolic and Renal Research Group and
- Section of Nephrology, University Hospital of North Norway, Tromso, Norway; and
| | - Trond Jenssen
- Metabolic and Renal Research Group and
- Section of Nephrology, Department of Organ Transplantation, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Tom Wilsgaard
- Department of Community Medicine, UiT The Arctic University of Norway, Tromso, Norway
| | - Bjørn O. Eriksen
- Metabolic and Renal Research Group and
- Section of Nephrology, University Hospital of North Norway, Tromso, Norway; and
| |
Collapse
|
32
|
Mahboub P, Ottens P, Seelen M, t Hart N, Van Goor H, Ploeg R, Martins P, Leuvenink H. Gradual Rewarming with Gradual Increase in Pressure during Machine Perfusion after Cold Static Preservation Reduces Kidney Ischemia Reperfusion Injury. PLoS One 2015; 10:e0143859. [PMID: 26630031 PMCID: PMC4667888 DOI: 10.1371/journal.pone.0143859] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 11/09/2015] [Indexed: 01/09/2023] Open
Abstract
In this study we evaluated whether gradual rewarming after the period of cold ischemia would improve organ quality in an Isolated Perfused Kidney Model. Left rat kidneys were statically cold stored in University of Wisconsin solution for 24 hours at 4°C. After cold storage kidneys were rewarmed in one of three ways: perfusion at body temperature (38°C), or rewarmed gradually from 10°C to 38°C with stabilization at 10°C for 30 min and rewarmed gradually from 10°C to 38°C with stabilization at 25°C for 30 min. In the gradual rewarming groups the pressure was increased stepwise to 40 mmHg at 10°C and 70 mmHg at 25°C to counteract for vasodilatation leading to low perfusate flows. Renal function parameters and injury biomarkers were measured in perfusate and urine samples. Increases in injury biomarkers such as aspartate transaminase and lactate dehydrogenase in the perfusate were lower in the gradual rewarming groups versus the control group. Sodium re-absorption was improved in the gradual rewarming groups and reached significance in the 25°C group after ninety minutes of perfusion. HSP-70, ICAM-1, VCAM-1 mRNA expressions were decreased in the 10°C and 25°C groups. Based on the data kidneys that underwent gradual rewarming suffered less renal parenchymal, tubular injury and showed better endothelial preservation. Renal function improved in the gradual rewarming groups versus the control group.
Collapse
Affiliation(s)
- Paria Mahboub
- Dept of Surgery, Groningen Transplant Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Dept. of Surgery, Division of Transplantation, University of Massachusetts, Worcester, MA, United States of America
| | - Petra Ottens
- Dept of Surgery, Groningen Transplant Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Marc Seelen
- Dept of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Nails t Hart
- Dept of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Harry Van Goor
- Dept of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Rutger Ploeg
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Paulo Martins
- Dept. of Surgery, Division of Transplantation, University of Massachusetts, Worcester, MA, United States of America
| | - Henri Leuvenink
- Dept of Surgery, Groningen Transplant Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- * E-mail:
| |
Collapse
|
33
|
Matsell DG, Cojocaru D, Matsell EW, Eddy AA. The impact of small kidneys. Pediatr Nephrol 2015; 30:1501-9. [PMID: 25794549 DOI: 10.1007/s00467-015-3079-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 02/03/2015] [Accepted: 02/20/2015] [Indexed: 12/20/2022]
Abstract
BACKGROUND Small kidneys due to renal hypodysplasia (RHD) result from a decrease in nephron number. The objectives of this study were to identify clinical variables that determine long-term renal outcome in children with RHD and to define the role of kidney size as a predictor of developing end-stage renal disease (ESRD). METHODS This was a single-center retrospective cohort analysis. The primary outcome was development of ESRD. We identified 202 RHD cases, with 25 (12%) reaching ESRD at mean age of 8.9 (±6.6) years. RESULTS Children with RHD with a known genetic syndrome had the smallest kidneys while those with posterior urethral valves (PUV) had the largest kidneys at diagnosis. Cases with bilateral RHD were most likely to develop ESRD. Younger gestational age (OR 0.8, CI 0.69-0.99, p = 0.05), smaller kidney size at diagnosis (OR 0.13, CI 0.03-0.47, p = 0.002), lower best-estimated glomerular filtration rate (eGFR) (OR 0.74, CI 0.58-0.93, p = 0.01), proteinuria (OR 1.03, CI 1.01-1.05, p < 0.001) and high blood pressure (OR 1.02, CI 1.01-1.04, p = 0.01) were associated with development of ESRD, while kidney size at diagnosis was independently associated with ESRD (HR 0.03, CI 0.01-0.72, p = 0.043). CONCLUSIONS In children with RHD, kidney size at diagnosis predicts the likelihood of developing ESRD.
Collapse
Affiliation(s)
- Douglas G Matsell
- Department of Pediatrics, British Columbia Children's Hospital, Vancouver, BC, Canada,
| | | | | | | |
Collapse
|
34
|
Srivastava T, Alon US, Cudmore PA, Tarakji B, Kats A, Garola RE, Duncan RS, McCarthy ET, Sharma R, Johnson ML, Bonewald LF, El-Meanawy A, Savin VJ, Sharma M. Cyclooxygenase-2, prostaglandin E2, and prostanoid receptor EP2 in fluid flow shear stress-mediated injury in the solitary kidney. Am J Physiol Renal Physiol 2014; 307:F1323-33. [PMID: 25234310 DOI: 10.1152/ajprenal.00335.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Hyperfiltration subjects podocytes to increased tensile stress and fluid flow shear stress (FFSS). We showed a 1.5- to 2.0-fold increase in FFSS in uninephrectomized animals and altered podocyte actin cytoskeleton and increased synthesis of prostaglandin E2 (PGE2) following in vitro application of FFSS. We hypothesized that increased FFSS mediates cellular changes through specific receptors of PGE2. Presently, we studied the effect of FFSS on cultured podocytes and decapsulated isolated glomeruli in vitro, and on solitary kidney in uninephrectomized sv129 mice. In cultured podocytes, FFSS resulted in increased gene and protein expression of cyclooxygenase (COX)-2 but not COX-1, prostanoid receptor EP2 but not EP4, and increased synthesis and secretion of PGE2, which were effectively blocked by indomethacin. Next, we developed a special flow chamber for applying FFSS to isolated glomeruli to determine its effect on an intact glomerular filtration barrier by measuring change in albumin permeability (Palb) in vitro. FFSS caused an increase in Palb that was blocked by indomethacin (P < 0.001). Finally, we show that unilateral nephrectomy in sv129 mice resulted in glomerular hypertrophy (P = 0.006), increased glomerular expression of COX-2 (P < 0.001) and EP2 (P = 0.039), and increased urinary albumin excretion (P = 0.001). Activation of the COX-2-PGE2-EP2 axis appears to be a specific response to FFSS in podocytes and provides a mechanistic basis for alteration in podocyte structure and the glomerular filtration barrier, leading to albuminuria in hyperfiltration-mediated kidney injury. The COX-2-PGE2-EP2 axis is a potential target for developing specific interventions to ameliorate the effects of hyperfiltration-mediated kidney injury in the progression of chronic kidney disease.
Collapse
Affiliation(s)
- Tarak Srivastava
- Section of Nephrology, Children's Mercy Hospital and University of Missouri-Kansas City, Kansas City, Missouri; Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center, Kansas City, Missouri;
| | - Uri S Alon
- Section of Nephrology, Children's Mercy Hospital and University of Missouri-Kansas City, Kansas City, Missouri
| | - Patricia A Cudmore
- Section of Nephrology, Children's Mercy Hospital and University of Missouri-Kansas City, Kansas City, Missouri
| | - Belal Tarakji
- Section of Nephrology, Children's Mercy Hospital and University of Missouri-Kansas City, Kansas City, Missouri
| | - Alexander Kats
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital and University of Missouri-Kansas City, Kansas City, Missouri
| | - Robert E Garola
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital and University of Missouri-Kansas City, Kansas City, Missouri
| | - R Scott Duncan
- Section of Infectious Diseases, Children's Mercy Hospital and University of Missouri-Kansas City, Kansas City, Missouri
| | - Ellen T McCarthy
- Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Ram Sharma
- Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| | - Mark L Johnson
- Department of Oral Biology, University of Missouri-Kansas City School of Dentistry, Kansas City, Missouri; and
| | - Lynda F Bonewald
- Department of Oral Biology, University of Missouri-Kansas City School of Dentistry, Kansas City, Missouri; and
| | - Ashraf El-Meanawy
- Division of Nephrology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Virginia J Savin
- Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas; Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| | - Mukut Sharma
- Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas; Renal Research Laboratory, Research and Development, Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
| |
Collapse
|
35
|
Kriz W, Lemley KV. A potential role for mechanical forces in the detachment of podocytes and the progression of CKD. J Am Soc Nephrol 2014; 26:258-69. [PMID: 25060060 DOI: 10.1681/asn.2014030278] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Loss of podocytes underlies progression of CKD. Detachment of podocytes from the glomerular basement membrane (GBM) rather than apoptosis or necrosis seems to be the major mechanism of podocyte loss. Such detachment of viable podocytes may be caused by increased mechanical distending and shear forces and/or impaired adhesion to the GBM. This review considers the mechanical challenges that may lead to podocyte loss by detachment from the GBM under physiologic and pathophysiologic conditions, including glomerular hypertension, hyperfiltration, hypertrophy, and outflow of filtrate from subpodocyte spaces. Furthermore, we detail the cellular mechanisms by which podocytes respond to these challenges, discuss the protective effects of angiotensin blockade, and note the questions that must be addressed to better understand the relationship between podocyte detachment and progression of CKD.
Collapse
Affiliation(s)
- Wilhelm Kriz
- Institutes of Transfusion Medicine and Immunology and Neuroanatomy, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; and
| | - Kevin V Lemley
- Division of Nephrology, Children's Hospital Los Angeles, Los Angeles, California; and Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California
| |
Collapse
|