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Fukuda Y, Kawada T, Kataoka Y, Peterson J, Saku K, Alexander J, Sunagawa K. Influence of angiotensin II and telmisartan on in vivo high-resolution renal arterial impedance in rats. Am J Physiol Regul Integr Comp Physiol 2024; 327:R349-R361. [PMID: 39005079 DOI: 10.1152/ajpregu.00009.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 06/18/2024] [Accepted: 07/03/2024] [Indexed: 07/16/2024]
Abstract
Angiotensin II (ANG II) is known to play an important role in regulating renal hemodynamics. We sought to quantify this effect in an in vivo rat model with high-resolution renal arterial (RA) impedance. This study examines the effects of ANG II and its type 1 receptor blocker telmisartan (TELM) on RA impedance. In baroreflex-deactivated rats, we measured RA pressure (Pr) and blood flow (Fr) during random ventricular pacing to induce pressure fluctuation at three different mean Pr (60, 80, and 100 mmHg). We then estimated RA impedance as the transfer function from Fr to Pr. The RA impedance was found to align with a three-element Windkessel model consisting of proximal (Rp) and distal (Rd) resistance and compliance (C). Our study showed Rd reflected the composite characteristics of afferent and efferent arterioles. Rd increased with increasing Pr under the baseline condition with a slope of 1.03 ± 0.21 (× 10-1) min·mL-1. ANG II significantly increased the slope by 0.72 ± 0.29 (× 10-1) min·mL-1 (P < 0.05) without affecting the intercept. TELM significantly reduced the intercept by 34.49 ± 4.86 (× 10-1) mmHg·min·mL-1 (P < 0.001) from the baseline value of 37.93 ± 13.36 (× 10-1) mmHg·min·mL-1, whereas it did not affect the slope. In contrast, Rp was less sensitive than Rd to ANG II or TELM, suggesting Rp may represent the characteristics of elastic large arteries. Our findings provide valuable insights into the influence of ANG II on the dynamics of the renal vasculature.NEW & NOTEWORTHY This present method of quantifying high-resolution renal arterial impedance could contribute to elucidating the characteristics of renal vasculature influenced by physiological mechanisms, renal diseases, or pharmacological effects. The present findings help construct a lumped-parameter renal hemodynamic model that reflects the influence of angiotensin II.
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Affiliation(s)
- Yukiko Fukuda
- Medical and Health Informatics Laboratories, NTT Research, Inc., Sunnyvale, California, United States
| | - Toru Kawada
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Yasuyuki Kataoka
- Medical and Health Informatics Laboratories, NTT Research, Inc., Sunnyvale, California, United States
| | - Jon Peterson
- Medical and Health Informatics Laboratories, NTT Research, Inc., Sunnyvale, California, United States
| | - Keita Saku
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
- Bio Digital Twin Center, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Joe Alexander
- Medical and Health Informatics Laboratories, NTT Research, Inc., Sunnyvale, California, United States
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Kuang SY, Ahmetaj B, Qu X. Fundamental equations and hypotheses governing glomerular hemodynamics. Front Physiol 2024; 15:1440627. [PMID: 39206387 PMCID: PMC11349631 DOI: 10.3389/fphys.2024.1440627] [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: 05/29/2024] [Accepted: 07/19/2024] [Indexed: 09/04/2024] Open
Abstract
The glomerular filtration rate (GFR) is the outcome of glomerular hemodynamics, influenced by a series of parameters: renal plasma flow, resistances of afferent arterioles and efferent arterioles (EAs), hydrostatic pressures in the glomerular capillary and Bowman's capsule, and plasma colloid osmotic pressure in the glomerular capillary. Although mathematical models have been proposed to predict the GFR at both the single-nephron level and the two-kidney system level using these parameters, mathematical equations governing glomerular filtration have not been well-established because of two major problems. First, the two-kidney system-level models are simply extended from the equations at the single-nephron level, which is inappropriate in epistemology and methodology. Second, the role of EAs in maintaining the normal GFR is underappreciated. In this article, these two problems are concretely elaborated, which collectively shows the need for a shift in epistemology toward a more holistic and evolving way of thinking, as reflected in the concept of the complex adaptive system (CAS). Then, we illustrate eight fundamental mathematical equations and four hypotheses governing glomerular hemodynamics at both the single-nephron and two-kidney levels as the theoretical foundation of glomerular hemodynamics. This illustration takes two steps. The first step is to modify the existing equations in the literature and establish a new equation within the conventional paradigm of epistemology. The second step is to formulate four hypotheses through logical reasoning from the perspective of the CAS (beyond the conventional paradigm). Finally, we apply the new equation and hypotheses to comprehensively analyze glomerular hemodynamics under different conditions and predict the GFR. By doing so, some concrete issues are eliminated. Unresolved issues are discussed from the perspective of the CAS and a desinger's view. In summary, this article advances the theoretical study of glomerular dynamics by 1) clarifying the necessity of shifting to the CAS paradigm; 2) adding new knowledge/insights into the significant role of EAs in maintaining the normal GFR; 3) bridging the significant gap between research findings and physiology education; and 4) establishing a new and advanced foundation for physiology education.
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Affiliation(s)
- Serena Y. Kuang
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Besjana Ahmetaj
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Xianggui Qu
- Department of Mathematics and Statistics, Oakland University, Rochester, MI, United States
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McDonald R, Watchorn J, Mehta R, Ostermann M, Hutchings S. The REPERFUSE study protocol: The effects of vasopressor therapy on renal perfusion in patients with septic shock-A mechanistically focused randomised control trial. PLoS One 2024; 19:e0304227. [PMID: 38870103 PMCID: PMC11175393 DOI: 10.1371/journal.pone.0304227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 05/06/2024] [Indexed: 06/15/2024] Open
Abstract
INTRODUCTION Acute kidney injury (AKI) is a common complication of septic shock and together these conditions carry a high mortality risk. In septic patients who develop severe AKI, renal cortical perfusion is deficient despite normal macrovascular organ blood flow. This intra-renal perfusion abnormality may be amenable to pharmacological manipulation, which may offer mechanistic insight into the pathophysiology of septic AKI. The aim of the current study is to investigate the effects of vasopressin and angiotensin II on renal microcirculatory perfusion in a cohort of patients with septic shock. METHODS AND ANALYSIS In this single centre, mechanistically focussed, randomised controlled study, 45 patients with septic shock will be randomly allocated to either of the study vasopressors (vasopressin or angiotensin II) or standard therapy (norepinephrine). Infusions will be titrated to maintain a mean arterial pressure (MAP) target set by the attending clinician. Renal microcirculatory assessment will be performed for the cortex and medulla using contrast-enhanced ultrasound (CEUS) and urinary oxygen tension (pO2), respectively. Renal macrovascular flow will be assessed via renal artery ultrasound. Measurement of systemic macrovascular flow will be performed through transthoracic echocardiography (TTE) and microvascular flow via sublingual incident dark field (IDF) video microscopy. Measures will be taken at baseline, +1 and +24hrs following infusion of the study drug commencing. Blood and urine samples will also be collected at the measurement time points. Longitudinal data will be compared between groups and over time. DISCUSSION Vasopressors are integral to the management of patients with septic shock. This study aims to further understanding of the relationship between this therapy, renal perfusion and the development of AKI. In addition, using CEUS and urinary pO2, we hope to build a more complete picture of renal perfusion in septic shock by interrogation of the constituent parts of the kidney. Results will be published in peer-reviewed journals and presented at academic meetings. TRIAL REGISTRATION The REPERFUSE study was registered on Clinical Trials.gov (NCT06234592) on the 30th Jan 24.
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Affiliation(s)
- Rory McDonald
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
- Academic Department of Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, United Kingdom
- Department of Critical Care, King’s College Hospital, London, United Kingdom
| | - James Watchorn
- Academic Department of Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, United Kingdom
| | - Reena Mehta
- Department of Critical Care, King’s College Hospital, London, United Kingdom
- Pharmacy Department, King’s College Hospital, London, United Kingdom
- School of Cancer and Pharmaceutical Sciences, King’s College London, London, United Kingdom
| | - Marlies Ostermann
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
- Department of Critical Care, Guy’s & St Thomas’ Hospital, London, United Kingdom
| | - Sam Hutchings
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
- Academic Department of Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, United Kingdom
- Department of Critical Care, King’s College Hospital, London, United Kingdom
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Picod A, Placier S, Genest M, Callebert J, Julian N, Zalc M, Assad N, Nordin H, Santos K, Gaudry S, Chatziantoniou C, Mebazaa A, Azibani F. Circulating Dipeptidyl Peptidase 3 Modulates Systemic and Renal Hemodynamics Through Cleavage of Angiotensin Peptides. Hypertension 2024; 81:927-935. [PMID: 38334001 PMCID: PMC10956665 DOI: 10.1161/hypertensionaha.123.21913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 01/25/2024] [Indexed: 02/10/2024]
Abstract
BACKGROUND High circulating DPP3 (dipeptidyl peptidase 3) has been associated with poor prognosis in critically ill patients with circulatory failure. In such situation, DPP3 could play a pathological role, putatively via an excessive angiotensin peptides cleavage. Our objective was to investigate the hemodynamics changes induced by DPP3 in mice and the relation between the observed effects and renin-angiotensin system modulation. METHODS Ten-week-old male C57Bl/6J mice were subjected to intravenous injection of purified human DPP3 or an anti-DPP3 antibody (procizumab). Invasive blood pressure and renal blood flow were monitored throughout the experiments. Circulating angiotensin peptides and catecholamines were measured and receptor blocking experiment performed to investigate the underlying mechanisms. RESULTS DPP3 administration significantly increased renal blood flow, while blood pressure was minimally affected. Conversely, procizumab led to significantly decreased renal blood flow. Angiotensin peptides measurement and an AT1R (angiotensin II receptor type 1) blockade experiment using valsartan demonstrated that the renovascular effect induced by DPP3 is due to reduced AT1R activation via decreased concentrations of circulating angiotensin II, III, and IV. Measurements of circulating catecholamines and an adrenergic receptor blockade by labetalol demonstrated a concomitant catecholamines release that explains blood pressure maintenance upon DPP3 administration. CONCLUSIONS High circulating DPP3 increases renal blood flow due to reduced AT1R activation via decreased concentrations of circulating angiotensin peptides while blood pressure is maintained by concomitant endogenous catecholamines release.
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Affiliation(s)
- Adrien Picod
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
| | - Sandrine Placier
- INSERM UMR-S 1155 CORAKID – Paris – Sorbonne University, France (S.P., S.G., C.C.)
| | - Magali Genest
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
| | - Jacques Callebert
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
- Department of Biochemistry and Molecular Biology, Lariboisière – Saint Louis Hospitals (J.C.), APHP, Paris, France
| | - Nathan Julian
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
- Department of Anesthesiology and Intensive Care, Lariboisière – Saint Louis Hospitals (N.J., A.M.), APHP, Paris, France
| | - Maxime Zalc
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
- Department of Anesthesiology and Intensive Care, Mondor Hospital (M.Z.), APHP, Paris, France
- Paris Est – Créteil University, France (M.Z.)
| | - Noma Assad
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
| | - Hugo Nordin
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
| | - Karine Santos
- 4TEEN4 Pharmaceuticals Gmbh, Hennigsdorf, Germany (K.S.)
| | - Stéphane Gaudry
- INSERM UMR-S 1155 CORAKID – Paris – Sorbonne University, France (S.P., S.G., C.C.)
- Sorbonne – Paris Nord University, France (S.G.)
- Medical and Surgical Intensive Care Unit, Avicenne Hospital, APHP, Bobigny, France (S.G.)
| | | | - Alexandre Mebazaa
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
- Department of Anesthesiology and Intensive Care, Lariboisière – Saint Louis Hospitals (N.J., A.M.), APHP, Paris, France
| | - Feriel Azibani
- Institut National de la Santé et de la Recherche Médicale UMR-S 942 MASCOT – Paris – Cité University, Paris, France (A.P., M.G., J.C., N.J., M.Z., N.A., H.N., A.M., F.A.)
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Udzik J, Pacholewicz J, Biskupski A, Walerowicz P, Januszkiewicz K, Kwiatkowska E. Alterations to Kidney Physiology during Cardiopulmonary Bypass-A Narrative Review of the Literature and Practical Remarks. J Clin Med 2023; 12:6894. [PMID: 37959359 PMCID: PMC10647422 DOI: 10.3390/jcm12216894] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023] Open
Abstract
INTRODUCTION According to different authors, cardiac surgery-associated acute kidney injury (CSA-AKI) incidence can be as high as 20-50%. This complication increases postoperative morbidity and mortality and impairs long-term kidney function in some patients. This review aims to summarize current knowledge regarding alterations to renal physiology during cardiopulmonary bypass (CPB) and to discuss possible nephroprotective strategies for cardiac surgeries. Relevant sections: Systemic and renal circulation, Vasoactive drugs, Fluid balance and Osmotic regulation and Inflammatory response. CONCLUSIONS Considering the available scientific evidence, it is concluded that adequate kidney perfusion and fluid balance are the most critical factors determining postoperative kidney function. By adequate perfusion, one should understand perfusion with proper oxygen delivery and sufficient perfusion pressure. Maintaining the fluid balance is imperative for a normal kidney filtration process, which is essential for preserving the intra- and postoperative kidney function. FUTURE DIRECTIONS The review of the available literature regarding kidney function during cardiac surgery revealed a need for a more holistic approach to this subject.
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Affiliation(s)
- Jakub Udzik
- Department of Cardiac Surgery, Pomeranian Medical University, Powstancow Wielkopolskich 72, 70-111 Szczecin, Poland; (J.P.); (A.B.); (P.W.)
| | - Jerzy Pacholewicz
- Department of Cardiac Surgery, Pomeranian Medical University, Powstancow Wielkopolskich 72, 70-111 Szczecin, Poland; (J.P.); (A.B.); (P.W.)
| | - Andrzej Biskupski
- Department of Cardiac Surgery, Pomeranian Medical University, Powstancow Wielkopolskich 72, 70-111 Szczecin, Poland; (J.P.); (A.B.); (P.W.)
| | - Paweł Walerowicz
- Department of Cardiac Surgery, Pomeranian Medical University, Powstancow Wielkopolskich 72, 70-111 Szczecin, Poland; (J.P.); (A.B.); (P.W.)
| | - Kornelia Januszkiewicz
- Department of Anesthesiology, Intensive Care and Acute Intoxications, Pomeranian Medical University, Powstancow Wielkopolskich 72, 70-111 Szczecin, Poland;
| | - Ewa Kwiatkowska
- Clinical Department of Nephrology, Transplantology and Internal Medicine, Pomeranian Medical University, 70-111 Szczecin, Poland;
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Gleeson PJ, Crippa IA, Sannier A, Koopmansch C, Bienfait L, Allard J, Sexton DJ, Fontana V, Rorive S, Vincent JL, Creteur J, Taccone FS. Critically ill patients with acute kidney injury: clinical determinants and post-mortem histology. Clin Kidney J 2023; 16:1664-1673. [PMID: 37779855 PMCID: PMC10539222 DOI: 10.1093/ckj/sfad113] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Indexed: 10/03/2023] Open
Abstract
Background Acute kidney injury (AKI) requiring renal replacement therapy (RRT) in the intensive care unit (ICU) portends a poor prognosis. We aimed to better characterize predictors of survival and the mechanism of kidney failure in these patients. Methods This was a retrospective observational study using clinical and radiological electronic health records, analysed by univariable and multivariable binary logistic regression. Histopathological examination of post-mortem renal tissue was performed. Results Among 157 patients with AKI requiring RRT, higher serum creatinine at RRT initiation associated with increased ICU survival [odds ratio (OR) 0.33, 95% confidence interval (CI) 0.17-0.62, P = .001]; however, muscle mass (a marker of frailty) interacted with creatinine (P = .02) and superseded creatinine as a predictor of survival (OR 0.26, 95% CI 0.08-0.82; P = .02). Achieving lower cumulative fluid balance (mL/kg) predicted ICU survival (OR 1.01, 95% CI 1.00-1.01, P < .001), as supported by sensitivity analyses showing improved ICU survival with the use of furosemide (OR 0.40, 95% CI 0.18-0.87, P = .02) and increasing net ultrafiltration (OR 0.97, 95% CI 0.95-0.99, P = .02). A urine output of >500 mL/24 h strongly predicted successful liberation from RRT (OR 0.125, 95% CI 0.05-0.35, P < .001). Post-mortem reports were available for 32 patients; clinically unrecognized renal findings were described in 6 patients, 1 of whom had interstitial nephritis. Experimental staining of renal tissue from patients with sepsis-associated AKI (S-AKI) showed glomerular loss of synaptopodin (P = .02). Conclusions Confounding of creatinine by muscle mass undermines its use as a marker of AKI severity in clinical studies. Volume management and urine output are key determinants of outcome. Loss of synaptopodin implicates glomerular injury in the pathogenesis of S-AKI.
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Affiliation(s)
- Patrick James Gleeson
- Department of Intensive Care Medicine, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
- Université de Paris Cité, INSERM UMR1149 & CNRS EMR8252, Centre de Recherche sur l'Inflammation, Inflamex Laboratory of Excellence, Paris, France
- Department of Renal Medicine, Cork University Hospital, Cork, Ireland
| | - Ilaria Alice Crippa
- Department of Intensive Care Medicine, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
- Department of Anesthesiology, San Marco Hospital, San Donato Group, Zingonia, Bergame, Italy
| | - Aurélie Sannier
- AP-HP, Nord/Université de Paris, Hôpital Bichat-Claude Bernard, Service d'Anatomie-Pathologique, Paris, France
| | - Caroline Koopmansch
- Department of Pathology, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
- Institut de Pathologie et de Génétique, Avenue George Lemaître, Gosselies, Belgium
| | - Lucie Bienfait
- Department of Pathology, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - Justine Allard
- DIAPath, Center for Microscopy and Molecular Imaging, Université Libre de Bruxelles, Gosselies, Belgium
| | - Donal J Sexton
- Trinity Health Kidney Center, Trinity College Dublin, Dublin, Ireland
- Department of Nephrology, St James’ Hospital, Dublin, Ireland
| | - Vito Fontana
- Department of Intensive Care Medicine, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
- Department of Intensive Care Medicine, Clinique Saint-Jean, Brussels, Belgium
| | - Sandrine Rorive
- Department of Pathology, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean-Louis Vincent
- Department of Intensive Care Medicine, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - Jacques Creteur
- Department of Intensive Care Medicine, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - Fabio Silvio Taccone
- Department of Intensive Care Medicine, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
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Eleftheriadis T, Pissas G, Golfinopoulos S, Efthymiadi M, Poulianiti C, Polyzou Konsta MA, Liakopoulos V, Stefanidis I. Routes of Albumin Overload Toxicity in Renal Tubular Epithelial Cells. Int J Mol Sci 2023; 24:ijms24119640. [PMID: 37298591 DOI: 10.3390/ijms24119640] [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: 05/05/2023] [Revised: 05/29/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Besides being a marker of kidney disease severity, albuminuria exerts a toxic effect on renal proximal tubular epithelial cells (RPTECs). We evaluated whether an unfolded protein response (UPR) or DNA damage response (DDR) is elicited in RPTECs exposed to high albumin concentration. The deleterious outcomes of the above pathways, apoptosis, senescence, or epithelial-to-mesenchymal transition (EMT) were evaluated. Albumin caused reactive oxygen species (ROS) overproduction and protein modification, and a UPR assessed the level of crucial molecules involved in this pathway. ROS also induced a DDR evaluated by critical molecules involved in this pathway. Apoptosis ensued through the extrinsic pathway. Senescence also occurred, and the RPTECs acquired a senescence-associated secretory phenotype since they overproduced IL-1β and TGF-β1. The latter may contribute to the observed EMT. Agents against endoplasmic reticulum stress (ERS) only partially alleviated the above changes, while the inhibition of ROS upregulation prevented both UPR and DDR and all the subsequent harmful effects. Briefly, albumin overload causes cellular apoptosis, senescence, and EMT in RPTECs by triggering UPR and DDR. Promising anti-ERS factors are beneficial but cannot eliminate the albumin-induced deleterious effects because DDR also occurs. Factors that suppress ROS overproduction may be more effective since they could halt UPR and DDR.
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Affiliation(s)
- Theodoros Eleftheriadis
- Department of Nephrology, Faculty of Medicine, University of Thessaly, Biopolis, Mezourlo Hill, 41110 Larissa, Greece
| | - Georgios Pissas
- Department of Nephrology, Faculty of Medicine, University of Thessaly, Biopolis, Mezourlo Hill, 41110 Larissa, Greece
| | - Spyridon Golfinopoulos
- Department of Nephrology, Faculty of Medicine, University of Thessaly, Biopolis, Mezourlo Hill, 41110 Larissa, Greece
| | - Maria Efthymiadi
- Department of Nephrology, Faculty of Medicine, University of Thessaly, Biopolis, Mezourlo Hill, 41110 Larissa, Greece
| | - Christina Poulianiti
- Department of Nephrology, Faculty of Medicine, University of Thessaly, Biopolis, Mezourlo Hill, 41110 Larissa, Greece
| | - Maria Anna Polyzou Konsta
- Department of Nephrology, Faculty of Medicine, University of Thessaly, Biopolis, Mezourlo Hill, 41110 Larissa, Greece
| | - Vassilios Liakopoulos
- Department of Nephrology, Faculty of Medicine, University of Thessaly, Biopolis, Mezourlo Hill, 41110 Larissa, Greece
| | - Ioannis Stefanidis
- Department of Nephrology, Faculty of Medicine, University of Thessaly, Biopolis, Mezourlo Hill, 41110 Larissa, Greece
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Smith D, Layton A. The intrarenal renin-angiotensin system in hypertension: insights from mathematical modelling. J Math Biol 2023; 86:58. [PMID: 36952058 DOI: 10.1007/s00285-023-01891-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/14/2023] [Accepted: 02/21/2023] [Indexed: 03/24/2023]
Abstract
The renin-angiotensin system (RAS) plays a pivotal role in the maintenance of volume homeostasis and blood pressure. In addition to the well-studied systemic RAS, local RAS have been documented in various tissues, including the kidney. Given the role of the intrarenal RAS in the pathogenesis of hypertension, a role established via various pharmacologic and genetic studies, substantial efforts have been made to unravel the processes that govern intrarenal RAS activity. In particular, several mechanisms have been proposed to explain the rise in intrarenal angiotensin II (Ang II) that accompanies Ang II infusion, including increased angiotensin type 1 receptor (AT1R)-mediated uptake of Ang II and enhanced intrarenal Ang II production. However, experimentally isolating their contribution to the intrarenal accumulation of Ang II in Ang II-induced hypertension is challenging, given that they are fundamentally connected. Computational modelling is advantageous because the feedback underlying each mechanism can be removed and the effect on intrarenal Ang II can be studied. In this work, the mechanisms governing the intrarenal accumulation of Ang II during Ang II infusion experiments are delineated and the role of the intrarenal RAS in Ang II-induced hypertension is studied. To accomplish this, a compartmental ODE model of the systemic and intrarenal RAS is developed and Ang II infusion experiments are simulated. Simulations indicate that AT1R-mediated uptake of Ang II is the primary mechanism by which Ang II accumulates in the kidney during Ang II infusion. Enhanced local Ang II production is unnecessary. The results demonstrate the role of the intrarenal RAS in the pathogenesis of Ang II-induced hypertension and consequently, clinical hypertension associated with an overactive RAS.
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Affiliation(s)
- Delaney Smith
- Department of Applied Mathematics, University of Waterloo, 200 University Ave, Waterloo, ON, N2L 3G1, Canada.
| | - Anita Layton
- Department of Applied Mathematics, University of Waterloo, 200 University Ave, Waterloo, ON, N2L 3G1, Canada
- Cheriton School of Computer Science, University of Waterloo, 200 University Ave, Waterloo, ON, N2L 3G1, Canada
- Department of Biology, University of Waterloo, 200 University Ave, Waterloo, ON, N2L 3G1, Canada
- School of Pharmacy, University of Waterloo, 200 University Ave, Waterloo, ON, N2L 3G1, Canada
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Savedchuk S, Phachu D, Shankar M, Sparks MA, Harrison-Bernard LM. Targeting Glomerular Hemodynamics for Kidney Protection. ADVANCES IN KIDNEY DISEASE AND HEALTH 2023; 30:71-84. [PMID: 36868736 DOI: 10.1053/j.akdh.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 12/14/2022] [Indexed: 03/05/2023]
Abstract
The kidney microcirculation is a unique structure as it is composed to 2 capillary beds in series: the glomerular and peritubular capillaries. The glomerular capillary bed is a high-pressure capillary bed, having a 60 mm Hg to 40 mm Hg pressure gradient, capable of producing an ultrafiltrate of plasma quantified as the glomerular filtration rate (GFR), thereby allowing for waste products to be removed and establishing sodium/volume homeostasis. Entering the glomerulus is the afferent arteriole, and the exiting one is the efferent arteriole. The concerted resistance of each of these arterioles is what is known as glomerular hemodynamics and is responsible for increasing or decreasing GFR and renal blood flow. Glomerular hemodynamics play an important role in how homeostasis is achieved. Minute-to-minute fluctuations in the GFR are achieved by constant sensing of distal delivery of sodium and chloride in the specialized cells called macula densa leading to upstream alternation in afferent arteriole resistance altering the pressure gradient for filtration. Specifically, 2 classes of medications (sodium glucose cotransporter-2 inhibitors and renin-angiotensin system blockers) have shown to be effective in long-term kidney health by altering glomerular hemodynamics. This review will discuss how tubuloglomerular feedback is achieved, and how different disease states and pharmacologic agents alter glomerular hemodynamics.
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Affiliation(s)
- Solomiia Savedchuk
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, NC
| | - Deep Phachu
- Division of Nephrology, University of Connecticut, Farmington, CT
| | - Mythri Shankar
- Department of Nephrology, Institute of Nephrourology, Bengaluru, India
| | - Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, NC; Renal Section, Durham VA Health Care System, Durham, NC
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10
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He FF, Wang YM, Chen YY, Huang W, Li ZQ, Zhang C. Sepsis-induced AKI: From pathogenesis to therapeutic approaches. Front Pharmacol 2022; 13:981578. [PMID: 36188562 PMCID: PMC9522319 DOI: 10.3389/fphar.2022.981578] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Sepsis is a heterogenous and highly complex clinical syndrome, which is caused by infectious or noninfectious factors. Acute kidney injury (AKI) is one of the most common and severe complication of sepsis, and it is associated with high mortality and poor outcomes. Recent evidence has identified that autophagy participates in the pathophysiology of sepsis-associated AKI. Despite the use of antibiotics, the mortality rate is still at an extremely high level in patients with sepsis. Besides traditional treatments, many natural products, including phytochemicals and their derivatives, are proved to exert protective effects through multiple mechanisms, such as regulation of autophagy, inhibition of inflammation, fibrosis, and apoptosis, etc. Accumulating evidence has also shown that many pharmacological inhibitors might have potential therapeutic effects in sepsis-induced AKI. Hence, understanding the pathophysiology of sepsis-induced AKI may help to develop novel therapeutics to attenuate the complications of sepsis and lower the mortality rate. This review updates the recent progress of underlying pathophysiological mechanisms of sepsis-associated AKI, focuses specifically on autophagy, and summarizes the potential therapeutic effects of phytochemicals and pharmacological inhibitors.
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11
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Edwards A, Kurtcuoglu V. Renal blood flow and oxygenation. Pflugers Arch 2022; 474:759-770. [PMID: 35438336 PMCID: PMC9338895 DOI: 10.1007/s00424-022-02690-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/19/2022] [Accepted: 03/21/2022] [Indexed: 02/07/2023]
Abstract
Our kidneys receive about one-fifth of the cardiac output at rest and have a low oxygen extraction ratio, but may sustain, under some conditions, hypoxic injuries that might lead to chronic kidney disease. This is due to large regional variations in renal blood flow and oxygenation, which are the prerequisite for some and the consequence of other kidney functions. The concurrent operation of these functions is reliant on a multitude of neuro-hormonal signaling cascades and feedback loops that also include the regulation of renal blood flow and tissue oxygenation. Starting with open questions on regulatory processes and disease mechanisms, we review herein the literature on renal blood flow and oxygenation. We assess the current understanding of renal blood flow regulation, reasons for disparities in oxygen delivery and consumption, and the consequences of disbalance between O2 delivery, consumption, and removal. We further consider methods for measuring and computing blood velocity, flow rate, oxygen partial pressure, and related parameters and point out how limitations of these methods constitute important hurdles in this area of research. We conclude that to obtain an integrated understanding of the relation between renal function and renal blood flow and oxygenation, combined experimental and computational modeling studies will be needed.
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Affiliation(s)
- Aurelie Edwards
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA, 02215, USA
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
- National Center of Competence in Research, Kidney.CH, University of Zurich, Zurich, Switzerland.
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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12
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Promsan S, Thongnak L, Pengrattanachot N, Phengpol N, Sutthasupha P, Lungkaphin A. Agomelatine, a structural analog of melatonin, improves kidney dysfunction through regulating the AMPK/mTOR signaling pathway to promote autophagy in obese rats. Food Chem Toxicol 2022; 165:113190. [DOI: 10.1016/j.fct.2022.113190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 05/20/2022] [Accepted: 05/25/2022] [Indexed: 12/20/2022]
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13
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Petitjeans F, Geloen A, Pichot C, Leroy S, Ghignone M, Quintin L. Is the Sympathetic System Detrimental in the Setting of Septic Shock, with Antihypertensive Agents as a Counterintuitive Approach? A Clinical Proposition. J Clin Med 2021; 10:4569. [PMID: 34640590 PMCID: PMC8509206 DOI: 10.3390/jcm10194569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/05/2021] [Accepted: 09/07/2021] [Indexed: 12/14/2022] Open
Abstract
Mortality in the setting of septic shock varies between 20% and 100%. Refractory septic shock leads to early circulatory failure and carries the worst prognosis. The pathophysiology is poorly understood despite studies of the microcirculatory defects and the immuno-paralysis. The acute circulatory distress is treated with volume expansion, administration of vasopressors (usually noradrenaline: NA), and inotropes. Ventilation and anti-infectious strategy shall not be discussed here. When circulation is considered, the literature is segregated between interventions directed to the systemic circulation vs. interventions directed to the micro-circulation. Our thesis is that, after stabilization of the acute cardioventilatory distress, the prolonged sympathetic hyperactivity is detrimental in the setting of septic shock. Our hypothesis is that the sympathetic hyperactivity observed in septic shock being normalized towards baseline activity will improve the microcirculation by recoupling the capillaries and the systemic circulation. Therefore, counterintuitively, antihypertensive agents such as beta-blockers or alpha-2 adrenergic agonists (clonidine, dexmedetomidine) are useful. They would reduce the noradrenaline requirements. Adjuncts (vitamins, steroids, NO donors/inhibitors, etc.) proposed to normalize the sepsis-evoked vasodilation are not reviewed. This itemized approach (systemic vs. microcirculation) requires physiological and epidemiological studies to look for reduced mortality.
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Affiliation(s)
- Fabrice Petitjeans
- Critical Care, Hôpital d’Instruction des Armées Desgenettes, 69003 Lyon, France;
| | - Alain Geloen
- UMR Ecologie Microbienne Lyon (LEM), University of Lyon, 69100 Villeurbanne, France;
| | - Cyrille Pichot
- Critical Care, Hôpital Louis Pasteur, 39108 Dole, France;
| | | | - Marco Ghignone
- Critical Care, JF Kennedy Hospital North Campus, West Palm Beach, FL 33407, USA;
| | - Luc Quintin
- Critical Care, Hôpital d’Instruction des Armées Desgenettes, 69003 Lyon, France;
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14
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Ning L, Rong J, Zhang Z, Xu Y. Therapeutic approaches targeting renin-angiotensin system in sepsis and its complications. Pharmacol Res 2021; 167:105409. [PMID: 33465472 DOI: 10.1016/j.phrs.2020.105409] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/28/2020] [Accepted: 12/22/2020] [Indexed: 01/08/2023]
Abstract
Sepsis, caused by the inappropriate host response to infection, is characterized by excessive inflammatory response and organ dysfunction, thus becomes a critical clinical problem. Commonly, sepsis may progress to septic shock and severe complications, including acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), sepsis-induced myocardial dysfunction (SIMD), liver dysfunction, cerebral dysfunction, and skeletal muscle atrophy, which predominantly contribute to high mortality. Additionally, the global pandemic of coronavirus disease 2019 (COVID-19) raised the concern of development of effectve therapeutic strategies for viral sepsis. Renin-angiotensin system (RAS) may represent as a potent therapeutic target for sepsis therapy. The emerging role of RAS in the pathogenesis of sepsis has been investigated and several preclinical and clinical trials targeting RAS for sepsis treatment revealed promising outcomes. Herein, we attempt to review the effects and mechanisms of RAS manipulation on sepsis and its complications and provide new insights into optimizing RAS interventions for sepsis treatment.
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Affiliation(s)
- Le Ning
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Jiabing Rong
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Zhaocai Zhang
- Department of Intensive Care Unit, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China.
| | - Yinchuan Xu
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China.
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15
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Plasma Renin Concentration is Associated With Hemodynamic Deficiency and Adverse Renal Outcome in Septic Shock. Shock 2020; 52:e22-e30. [PMID: 30407370 DOI: 10.1097/shk.0000000000001285] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND In septic shock, both systemic vasodilatation and glomerular arteriole dilatation are responsible for the drop in glomerular filtration observed in early acute kidney injury. Angiotensin II has been shown to act on both mechanisms. Our objective was to evaluate the impact of renin angiotensin system activation, on hemodynamic deficiency and renal outcome in patient with septic shock and to assess whether urinary sodium could be a reliable test for high plasma renin concentration screening. METHODS This was a prospective and observational study. Inclusion criteria were early septic shock (first episode), dose of norepinephrine ≥ 0.25 μg/kg/min, before the start of substitutive corticosteroids. Plasma renin concentration, plasma aldosterone concentration, and urinary sodium were measured at inclusion. Renal outcome, organ deficiency, and 28-day survival were followed. RESULTS Plasma renin concentration was associated with worse hemodynamic deficiency and adverse renal outcome. Natriuresis was associated with shock severity but was not associated with renal outcome. Low natriuresis (< 20 mM) was associated with higher renin concentration. Those two variables were only weakly correlated. CONCLUSION Plasma renin concentration is associated with adverse renal outcome, probably through shock severity and insufficient glomerular efferent arterioles vasoconstriction. An association was observed between low natriuresis and high plasma renin concentration.
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16
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Promsan S, Lungkaphin A. The roles of melatonin on kidney injury in obese and diabetic conditions. Biofactors 2020; 46:531-549. [PMID: 32449276 DOI: 10.1002/biof.1637] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 04/24/2020] [Indexed: 01/07/2023]
Abstract
Obesity is a common and complex health problem worldwide and can induce the development of Type 2 diabetes. Chronic kidney disease (CKD) is a complication occurring as a result of obesity and diabetic conditions that lead to an increased mortality rate. There are several mechanisms and pathways contributing to kidney injury in obese and diabetic conditions. The expansion of adipocytes triggers proinflammatory cytokines release into blood circulation and bind with the receptors at the cell membranes of renal tissues leading to kidney injury. Obesity-mediated inflammation, oxidative stress, apoptosis, and mitochondrial dysfunction are the important causes and progression of CKD. Melatonin (N-acetyl-5-methoxytryptamine) is a neuronal hormone that is synthesized by the pineal gland and plays an essential role in regulating several physiological functions in the human body. Moreover, melatonin has pleiotropic effects such as antioxidant, anti-inflammation, antiapoptosis. In this review, the relationship between obesity, diabetic condition, and kidney injury and the renoprotective effect of melatonin in obese and diabetic conditions from in vitro and in vivo studies have been summarized and discussed.
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MESH Headings
- Adipocytes/drug effects
- Adipocytes/metabolism
- Adipocytes/pathology
- Adipose Tissue/drug effects
- Adipose Tissue/metabolism
- Adipose Tissue/pathology
- Animals
- Anti-Inflammatory Agents/metabolism
- Anti-Inflammatory Agents/pharmacology
- Antioxidants/metabolism
- Antioxidants/pharmacology
- Apoptosis/drug effects
- Cytokines/metabolism
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Epithelial Cells/drug effects
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Humans
- Kidney/drug effects
- Kidney/metabolism
- Kidney/pathology
- Melatonin/metabolism
- Melatonin/pharmacology
- Obesity/drug therapy
- Obesity/genetics
- Obesity/metabolism
- Obesity/pathology
- Oxidative Stress/drug effects
- Protective Agents/metabolism
- Protective Agents/pharmacology
- Receptors, Cytokine/genetics
- Receptors, Cytokine/metabolism
- Renal Insufficiency, Chronic/genetics
- Renal Insufficiency, Chronic/metabolism
- Renal Insufficiency, Chronic/pathology
- Renal Insufficiency, Chronic/prevention & control
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Affiliation(s)
- Sasivimon Promsan
- Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Anusorn Lungkaphin
- Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
- Center for Research and Development of Natural Products for Health, Chiang Mai University Chiang Mai, Thailand
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17
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Lankadeva YR, Okazaki N, Evans RG, Bellomo R, May CN. Renal Medullary Hypoxia: A New Therapeutic Target for Septic Acute Kidney Injury? Semin Nephrol 2019; 39:543-553. [DOI: 10.1016/j.semnephrol.2019.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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18
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Tang JM, Shi N, Dong K, Brown SA, Coleman AE, Boegehold MA, Chen SY. Response Gene to Complement 32 Maintains Blood Pressure Homeostasis by Regulating α-Adrenergic Receptor Expression. Circ Res 2019; 123:1080-1090. [PMID: 30355157 DOI: 10.1161/circresaha.118.313266] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
RATIONALE Hypertension prevalence is much higher among children and adolescents with low birth weight and greater postnatal weight gain than in individuals with normal birth weight. However, the cause and molecular mechanisms underlying this complication remain largely unknown. Our previous studies have shown that RGC-32 (response gene to complement 32)-deficient (RGC-32-/-) mice are born significantly smaller but grow faster than their WT (wild type) controls, which allows adult RGC-32-/- mice to attain body weights similar to those of control mice. OBJECTIVE The objective of this study is to determine whether RGC-32-/- mice develop hypertension, and if so, to elucidate the underlying mechanisms. METHODS AND RESULTS By using a radiotelemetry system, we found that RGC-32-/- mice exhibit higher mean arterial pressure than WT mice (101±4 versus 119±5 mm Hg), which enabled us to use RGC-32-/- mice to study the mechanisms underlying low birth weight-related hypertension. The increased blood pressure in RGC-32-/- mice was associated with increased vascular tone and decreased distensibility of small resistance arteries. The increased vascular tone was because of an increase in the relative contribution of sympathetic versus parasympathetic activity and was linked to increased expression of AT1R (angiotensin II type I receptor) and α1-AdR (α1-adrenergic receptor) in arterial smooth muscles. Mechanistically, RGC-32 regulated AT1R gene transcription by interacting with Sp1 (specificity protein 1) transcription factor and further blocking its binding to the AT1R promoter, leading to suppression of AT1R expression. The attenuation of AT1R leads to reduction in α1-AdR expression, which was critical for the balance of sympathetic versus parasympathetic control of vascular tone. Of importance, downregulation of RGC-32 in arterial smooth muscles was also associated with low birth weight and hypertension in humans. CONCLUSIONS Our results indicate that RGC-32 is a novel protein factor vital for maintaining blood pressure homeostasis, especially in individuals with low birth weight.
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Affiliation(s)
- Jun-Ming Tang
- From the Department of Physiology and Pharmacology (J.-M.T., N.S., K.D., S.A.B., M.A.B., S.-Y.C.), University of Georgia, Athens.,Institute of Clinical Medicine (J.-M.T.), Renmin Hospital, Hubei University of Medicine, Shiyan, China.,Department of Cardiology (J.-M.T.), Renmin Hospital, Hubei University of Medicine, Shiyan, China
| | - Ning Shi
- From the Department of Physiology and Pharmacology (J.-M.T., N.S., K.D., S.A.B., M.A.B., S.-Y.C.), University of Georgia, Athens
| | - Kun Dong
- From the Department of Physiology and Pharmacology (J.-M.T., N.S., K.D., S.A.B., M.A.B., S.-Y.C.), University of Georgia, Athens
| | - Scott A Brown
- From the Department of Physiology and Pharmacology (J.-M.T., N.S., K.D., S.A.B., M.A.B., S.-Y.C.), University of Georgia, Athens
| | - Amanda E Coleman
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine (A.E.C.), University of Georgia, Athens
| | - Matthew A Boegehold
- From the Department of Physiology and Pharmacology (J.-M.T., N.S., K.D., S.A.B., M.A.B., S.-Y.C.), University of Georgia, Athens
| | - Shi-You Chen
- From the Department of Physiology and Pharmacology (J.-M.T., N.S., K.D., S.A.B., M.A.B., S.-Y.C.), University of Georgia, Athens
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19
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Peerapornratana S, Manrique-Caballero CL, Gómez H, Kellum JA. Acute kidney injury from sepsis: current concepts, epidemiology, pathophysiology, prevention and treatment. Kidney Int 2019; 96:1083-1099. [PMID: 31443997 DOI: 10.1016/j.kint.2019.05.026] [Citation(s) in RCA: 721] [Impact Index Per Article: 144.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/19/2019] [Accepted: 05/08/2019] [Indexed: 12/16/2022]
Abstract
Sepsis-associated acute kidney injury (S-AKI) is a frequent complication of the critically ill patient and is associated with unacceptable morbidity and mortality. Prevention of S-AKI is difficult because by the time patients seek medical attention, most have already developed acute kidney injury. Thus, early recognition is crucial to provide supportive treatment and limit further insults. Current diagnostic criteria for acute kidney injury has limited early detection; however, novel biomarkers of kidney stress and damage have been recently validated for risk prediction and early diagnosis of acute kidney injury in the setting of sepsis. Recent evidence shows that microvascular dysfunction, inflammation, and metabolic reprogramming are 3 fundamental mechanisms that may play a role in the development of S-AKI. However, more mechanistic studies are needed to better understand the convoluted pathophysiology of S-AKI and to translate these findings into potential treatment strategies and add to the promising pharmacologic approaches being developed and tested in clinical trials.
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Affiliation(s)
- Sadudee Peerapornratana
- Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; The Clinical Research, Investigation and Systems Modeling of Acute Illness Center, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Excellence Center for Critical Care Nephrology, Division of Nephrology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Department of Laboratory Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Carlos L Manrique-Caballero
- Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; The Clinical Research, Investigation and Systems Modeling of Acute Illness Center, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Hernando Gómez
- Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; The Clinical Research, Investigation and Systems Modeling of Acute Illness Center, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - John A Kellum
- Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; The Clinical Research, Investigation and Systems Modeling of Acute Illness Center, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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20
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Gutsol AA, Blanco P, Samokhina SI, Afanasiev SA, Kennedy CRJ, Popov SV, Burns KD. A novel method for comparison of arterial remodeling in hypertension: Quantification of arterial trees and recognition of remodeling patterns on histological sections. PLoS One 2019; 14:e0216734. [PMID: 31112562 PMCID: PMC6529011 DOI: 10.1371/journal.pone.0216734] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 04/26/2019] [Indexed: 01/01/2023] Open
Abstract
Remodeling of spatially heterogeneous arterial trees is routinely quantified on tissue sections by averaging linear dimensions, with lack of comparison between different organs and models. The impact of experimental models or hypertension treatment modalities on organ-specific vascular remodeling remains undefined. A wide variety of arterial remodeling types has been demonstrated for hypertensive models, which include differences across organs. The purpose of this study was to reassess methods for measurement of arterial remodeling and to establish a morphometric algorithm for standard and comparable quantification of vascular remodeling in hypertension in different vascular beds. We performed a novel and comprehensive morphometric analysis of terminal arteries in the brain, heart, lung, liver, kidney, spleen, stomach, intestine, skin, skeletal muscle, and adrenal glands of control and Goldblatt hypertensive rats on routinely processed tissue sections. Mean dimensions were highly variable but grouping them into sequential 5 μm intervals permitted creation of reliable linear regression equations and complex profiles. Averaged arterial dimensions demonstrated seven remodeling patterns that were distinct from conventional inward-outward and hypertrophic-eutrophic definitions. Numerical modeling predicted at least nineteen variants of arterial spatial conformations. Recognition of remodeling variants was not possible using averaged dimensions, their ratios, or the remodeling and growth indices. To distinguish remodeling patterns, a three-dimensional modeling was established and tested. The proposed algorithm permits quantitative analysis of arterial remodeling in different organs and may be applicable for comparative studies between animal hypertensive models and human hypertension. Arterial wall tapering is the most important factor to consider in arterial morphometry, while perfusion fixation with vessel relaxation is not necessary. Terminal arteries in organs undergo the same remodeling pattern in Goldblatt rats, except for organs with hemodynamics affected by the arterial clip. The existing remodeling nomenclature should be replaced by a numerical classification applicable to any type of arterial remodeling.
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Affiliation(s)
- Alex A. Gutsol
- Kidney Research Centre, Ottawa Hospital Research Institute, ON, Canada
| | - Paula Blanco
- Department of Pathology and Laboratory Medicine, University of Ottawa, ON, Canada
| | | | | | | | | | - Kevin D. Burns
- Kidney Research Centre, Ottawa Hospital Research Institute, ON, Canada
- Division of Nephrology, Department of Medicine, University of Ottawa, ON, Canada
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21
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Jadhav AP, Sadaka FG. Angiotensin II in septic shock. Am J Emerg Med 2019; 37:1169-1174. [PMID: 30935784 DOI: 10.1016/j.ajem.2019.03.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 03/13/2019] [Accepted: 03/18/2019] [Indexed: 01/21/2023] Open
Abstract
Septic shock is a life threatening condition and a medical emergency. It is associated with organ dysfunction and hypotension despite optimal volume resuscitation. Refractory septic shock carries a very high rate of mortality and is associated with ischemic and arrhythmogenic complications from high dose vasopressors. Angiotensin II (AT-II) is a product of the renin-angiotensin-aldosterone system. It is a vasopressor agent that has been recently approved by FDA to be used in conjunction with other vasopressors (catecholamines) in refractory shock and to reduce catecholamine requirements. We have reviewed the physiology and current literature on AT-II in refractory septic/vasodilatory shock. Larger trials with longer duration of follow-up are warranted to address the questions which are unanswered by the ATHOS-3 trial, especially pertaining to its effects on lungs, brain, microcirculation, inflammation, and venous thromboembolism risk.
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Affiliation(s)
- Amar P Jadhav
- Intensivist, SSM St. Mary's Hospital, Richmond Heights, St. Louis, United States of America..
| | - Farid G Sadaka
- Clinical Associate Professor, Critical care/Neurocritical care, Mercy Hospital St.Louis, St. Louis University School of Medicine Program, United States of America
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22
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Ahmed M, Habis S, Mahmoud A, Rutland C, Saeed R. Angiotensin II Use in Refractory Multisystem Shock: A Case Report. Cureus 2018; 10:e3665. [PMID: 30740284 PMCID: PMC6355300 DOI: 10.7759/cureus.3665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Distributive (vasodilatory) shock is common in patients admitted to the intensive care unit (ICU). Treating distributive shock presents a challenge, especially if a patient is tachyphylactic to commonly used vasopressors. This case report illustrates the use of a newly approved vasopressor in a patient with vasodilatory shock resulting from a motor vehicle injury. A 56-year-old man was brought to our emergency department (ED) hemodynamically unstable requiring aggressive resuscitation. The results of his evaluation were consistent with multisystem trauma for which he required intubation on arrival, and he received multiple units of blood and blood product via transfusion. The patient’s condition declined despite receiving multiple vasopressors in the ICU. A few days after admission, the patient developed ischemic bowel requiring surgical resection. While his chance of survival was believed to be dismal, the use of angiotensin II (ATII) as a last resort proved to be helpful.
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Affiliation(s)
- Mohamed Ahmed
- Surgery, Riverside Community Hospital / Envision Healthcare, Riverside, USA
| | - Saba Habis
- Internal Medicine, Riverside Community Hospital / Hospital Corporation of America, Riverside, USA
| | - Ahmed Mahmoud
- Surgery, Riverside Community Hospital / Envision Healthcare, Riverside, USA
| | - Cedric Rutland
- Internal Medicine, Riverside Community Hospital, Riverside, USA
| | - Rasha Saeed
- Surgery, Riverside Community Hospital / University of California, Riverside, USA
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23
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Ma S, Evans RG, Iguchi N, Tare M, Parkington HC, Bellomo R, May CN, Lankadeva YR. Sepsis-induced acute kidney injury: A disease of the microcirculation. Microcirculation 2018; 26:e12483. [PMID: 29908046 DOI: 10.1111/micc.12483] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 06/12/2018] [Indexed: 12/13/2022]
Abstract
AKI is a common complication of sepsis and is significantly associated with mortality. Sepsis accounts for more than 50% of the cases of AKI, with a mortality rate of up to 40%. The pathogenesis of septic AKI is complex, but there is emerging evidence that, at least in the first 48 hours, the defects may be functional rather than structural in nature. For example, septic AKI is associated with an absence of histopathological changes, but with microvascular abnormalities and tubular stress. In this context, renal medullary hypoxia due to redistribution of intra-renal perfusion is emerging as a critical mediator of septic AKI. Clinically, vasopressor drugs remain the cornerstone of therapy for maintenance of blood pressure and organ perfusion. However, in septic AKI, there is insensitivity to vasopressors such as norepinephrine, leading to persistent hypotension and organ failure. Vasopressin, angiotensin II, and, paradoxically, α2 -adrenergic receptor agonists (clonidine and dexmedetomidine) may be feasible adjunct therapies for catecholamine-resistant vasodilatory shock. In this review, we outline the recent progress made in understanding how these drugs may influence the renal microcirculation, which represents a crucial step toward developing better approaches for the circulatory management of patients with septic AKI.
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Affiliation(s)
- Shuai Ma
- Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia.,Division of Nephrology & Unit of Critical Nephrology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Roger G Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Naoya Iguchi
- Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia.,Department of Anesthesiology and Intensive Care Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Marianne Tare
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia.,Monash Rural Health, Monash University, Melbourne, VIC, Australia
| | - Helena C Parkington
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Rinaldo Bellomo
- School of Medicine, University of Melbourne, Melbourne, VIC, Australia
| | - Clive N May
- Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
| | - Yugeesh R Lankadeva
- Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
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Markovič R, Peltan J, Gosak M, Horvat D, Žalik B, Seguy B, Chauvel R, Malandain G, Couffinhal T, Duplàa C, Marhl M, Roux E. Planar cell polarity genes frizzled4 and frizzled6 exert patterning influence on arterial vessel morphogenesis. PLoS One 2017; 12:e0171033. [PMID: 28253274 PMCID: PMC5333836 DOI: 10.1371/journal.pone.0171033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/14/2017] [Indexed: 11/19/2022] Open
Abstract
Quantitative analysis of the vascular network anatomy is critical for the understanding of the vasculature structure and function. In this study, we have combined microcomputed tomography (microCT) and computational analysis to provide quantitative three-dimensional geometrical and topological characterization of the normal kidney vasculature, and to investigate how 2 core genes of the Wnt/planar cell polarity, Frizzled4 and Frizzled6, affect vascular network morphogenesis. Experiments were performed on frizzled4 (Fzd4-/-) and frizzled6 (Fzd6-/-) deleted mice and littermate controls (WT) perfused with a contrast medium after euthanasia and exsanguination. The kidneys were scanned with a high-resolution (16 μm) microCT imaging system, followed by 3D reconstruction of the arterial vasculature. Computational treatment includes decomposition of 3D networks based on Diameter-Defined Strahler Order (DDSO). We have calculated quantitative (i) Global scale parameters, such as the volume of the vasculature and its fractal dimension (ii) Structural parameters depending on the DDSO hierarchical levels such as hierarchical ordering, diameter, length and branching angles of the vessel segments, and (iii) Functional parameters such as estimated resistance to blood flow alongside the vascular tree and average density of terminal arterioles. In normal kidneys, fractal dimension was 2.07±0.11 (n = 7), and was significantly lower in Fzd4-/- (1.71±0.04; n = 4), and Fzd6-/- (1.54±0.09; n = 3) kidneys. The DDSO number was 5 in WT and Fzd4-/-, and only 4 in Fzd6-/-. Scaling characteristics such as diameter and length of vessel segments were altered in mutants, whereas bifurcation angles were not different from WT. Fzd4 and Fzd6 deletion increased vessel resistance, calculated using the Hagen-Poiseuille equation, for each DDSO, and decreased the density and the homogeneity of the distal vessel segments. Our results show that our methodology is suitable for 3D quantitative characterization of vascular networks, and that Fzd4 and Fzd6 genes have a deep patterning effect on arterial vessel morphogenesis that may determine its functional efficiency.
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Affiliation(s)
- Rene Markovič
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Faculty of Education, University of Maribor, Maribor, Slovenia
| | - Julien Peltan
- INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France
- Université de Bordeaux, Biology of Cardiovascular Diseases U1034, Pessac, France
- Service des Maladies Cardiaques et Vasculaires, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Marko Gosak
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Denis Horvat
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia
| | - Borut Žalik
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia
| | - Benjamin Seguy
- INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France
- Service des Maladies Cardiaques et Vasculaires, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Remi Chauvel
- INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France
- Université de Bordeaux, Biology of Cardiovascular Diseases U1034, Pessac, France
- Service des Maladies Cardiaques et Vasculaires, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | | | - Thierry Couffinhal
- INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France
- Université de Bordeaux, Biology of Cardiovascular Diseases U1034, Pessac, France
- Service des Maladies Cardiaques et Vasculaires, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Cécile Duplàa
- INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France
| | - Marko Marhl
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Faculty of Education, University of Maribor, Maribor, Slovenia
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Etienne Roux
- INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France
- Université de Bordeaux, Biology of Cardiovascular Diseases U1034, Pessac, France
- * E-mail:
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Hering D, Winklewski PJ. R1 autonomic nervous system in acute kidney injury. Clin Exp Pharmacol Physiol 2017; 44:162-171. [DOI: 10.1111/1440-1681.12694] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 10/17/2016] [Accepted: 10/29/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Dagmara Hering
- Dobney Hypertension Centre; School of Medicine and Pharmacology; Royal Perth Hospital Unit; The University of Western Australia; Perth WA Australia
| | - Pawel J Winklewski
- Institute of Human Physiology; Medical University of Gdansk; Gdansk Poland
- Department of Clinical Sciences; Institute of Health Sciences; Pomeranian University of Slupsk; Slupsk Poland
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Niles DJ, Artz NS, Djamali A, Sadowski EA, Grist TM, Fain SB. Longitudinal Assessment of Renal Perfusion and Oxygenation in Transplant Donor-Recipient Pairs Using Arterial Spin Labeling and Blood Oxygen Level-Dependent Magnetic Resonance Imaging. Invest Radiol 2016; 51:113-20. [PMID: 26561047 DOI: 10.1097/rli.0000000000000210] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVES The aims of this study were to assess renal function in kidney transplant recipients and their respective donors over 2 years using arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) and to prospectively evaluate the effect of losartan on functional MRI measures in recipients. MATERIALS AND METHODS The study included 15 matched pairs of renal transplant donors and recipients. Arterial spin labeling and BOLD MRI of the kidneys were performed on donors before transplant surgery (baseline) and on both donors and recipients at 3 months, 1 year, and 2 years after transplant. After 3 months, 7 of the 15 recipients were prescribed 25 to 50 mg/d losartan for the remainder of the study. A linear mixed-effects model was used to evaluate perfusion, R2*, estimated glomerular filtration rate, and fractional excretion of sodium for changes across time or associated with losartan treatment. RESULTS In donors, cortical perfusion in the remaining kidney decreased by 50 ± 19 mL/min per 100 g (11.8%) between baseline and 2 years (P < 0.05), while cortical R2* declined modestly by 0.7 ± 0.3 s-1 (5.6%; P < 0.05). In transplanted kidneys, cortical perfusion decreased markedly by 141 ± 21 mL/min per 100 g (34.2%) between baseline and 2 years (P < 0.001), while medullary R2* declined by 1.5 ± 0.8 s-1 (8.3%; P = 0.06). Single-kidney estimated glomerular filtration rate increased between baseline and 2 years by 17.7 ± 2.7 mL/min per 1.73 m (40.3%; P < 0.0001) in donors and to 14.6 ± 4.3 mL/min per 1.73 m (33.3%; P < 0.01) in recipients. Cortical perfusion at 1 and 2 years in recipients receiving 25 to 50 mg/d losartan was 62 ± 24 mL/min per 100 g higher than recipients not receiving the drug (P < 0.05). No significant effects of losartan were observed for any other markers of renal function. CONCLUSIONS The results suggest an important role for noninvasive functional monitoring with ASL and BOLD MRI in kidney transplant recipients and donors, and they indicate a potentially beneficial effect of losartan in recipients.
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Affiliation(s)
- David J Niles
- From the Departments of *Medical Physics, †Medicine, ‡Surgery, §Radiology, ∥Obstetrics and Gynecology, and ¶Biomedical Engineering, University of Wisconsin, Madison, WI
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Zhou M, Zhang X, Wen X, Wu T, Wang W, Yang M, Wang J, Fang M, Lin B, Lin H. Development of a Functional Glomerulus at the Organ Level on a Chip to Mimic Hypertensive Nephropathy. Sci Rep 2016; 6:31771. [PMID: 27558173 PMCID: PMC4997336 DOI: 10.1038/srep31771] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/26/2016] [Indexed: 01/15/2023] Open
Abstract
Glomerular hypertension is an important factor exacerbating glomerular diseases to end-stage renal diseases because, ultimately, it results in glomerular sclerosis (especially in hypertensive and diabetic nephropathy). The precise mechanism of glomerular sclerosis caused by glomerular hypertension is unclear, due partly to the absence of suitable in vitro or in vivo models capable of mimicking and regulating the complex mechanical forces and/or organ-level disease processes. We developed a “glomerulus-on-a-chip” (GC) microfluidic device. This device reconstitutes the glomerulus with organ-level glomerular functions to create a disease model-on-a chip that mimics hypertensive nephropathy in humans. It comprises two channels lined by closely opposed layers of glomerular endothelial cells and podocytes that experience fluid flow of physiological conditions to mimic the glomerular microenvironment in vivo. Our results revealed that glomerular mechanical forces have a crucial role in cellular cytoskeletal rearrangement as well as the damage to cells and their junctions that leads to increased glomerular leakage observed in hypertensive nephropathy. Results also showed that the GC could readily and flexibly meet the demands of a renal-disease model. The GC could provide drug screening and toxicology testing, and create potential new personalized and accurate therapeutic platforms for glomerular disease.
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Affiliation(s)
- Mengying Zhou
- Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, Key Laboratory of Kidney Disease of Liaoning Province, The Center for the Transformation Medicine of Kidney Disease of Liaoning Province, No. 222 Zhongshan Road, Dalian 116011, China
| | - Xulang Zhang
- Department of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023, China
| | - Xinyu Wen
- Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, Key Laboratory of Kidney Disease of Liaoning Province, The Center for the Transformation Medicine of Kidney Disease of Liaoning Province, No. 222 Zhongshan Road, Dalian 116011, China
| | - Taihua Wu
- Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, Key Laboratory of Kidney Disease of Liaoning Province, The Center for the Transformation Medicine of Kidney Disease of Liaoning Province, No. 222 Zhongshan Road, Dalian 116011, China
| | - Weidong Wang
- Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, Key Laboratory of Kidney Disease of Liaoning Province, The Center for the Transformation Medicine of Kidney Disease of Liaoning Province, No. 222 Zhongshan Road, Dalian 116011, China
| | - Mingzhou Yang
- Department of Urology, Dalian Friendship Hospital, No. 8 Sanba Square, Dalian, 116001, China
| | - Jing Wang
- Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, Key Laboratory of Kidney Disease of Liaoning Province, The Center for the Transformation Medicine of Kidney Disease of Liaoning Province, No. 222 Zhongshan Road, Dalian 116011, China
| | - Ming Fang
- Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, Key Laboratory of Kidney Disease of Liaoning Province, The Center for the Transformation Medicine of Kidney Disease of Liaoning Province, No. 222 Zhongshan Road, Dalian 116011, China
| | - Bingcheng Lin
- Department of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023, China
| | - Hongli Lin
- Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, Key Laboratory of Kidney Disease of Liaoning Province, The Center for the Transformation Medicine of Kidney Disease of Liaoning Province, No. 222 Zhongshan Road, Dalian 116011, China
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Strategies to optimize kidney recovery and preservation in transplantation: specific aspects in pediatric transplantation. Pediatr Nephrol 2015; 30:1243-54. [PMID: 25185880 DOI: 10.1007/s00467-014-2924-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 07/09/2014] [Accepted: 07/21/2014] [Indexed: 01/08/2023]
Abstract
In renal transplantation, live donor kidney grafts are associated with optimum success rates due to the shorter period of ischemia during the surgical procedure. The current shortage of donor organs for adult patients has caused a shift towards deceased donors, often with co-morbidity factors, whose organs are more sensitive to ischemia-reperfusion injury, which is unavoidable during transplantation. Donor management is pivotal to kidney graft survival through the control of the ischemia-reperfusion sequence, which is known to stimulate numerous deleterious or regenerative pathways. Although the key role of endothelial cells has been established, the complexity of the injury, associated with stimulation of different cell signaling pathways, such as unfolded protein response and cell death, prevents the definition of a unique therapeutic target. Preclinical transplant models in large animals are necessary to establish relationships and kinetics and have already contributed to the improvement of organ preservation. Therapeutic strategies using mesenchymal stem cells to induce allograft tolerance are promising advances in the treatment of the pediatric recipient in terms of reducing/withdrawing immunosuppressive therapy. In this review we focus on the different donor management strategies in kidney graft conditioning and on graft preservation consequences by highlighting the role of endothelial cells. We also propose strategies for preventing ischemia-reperfusion, such as cell therapy.
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Angiotensin-II: more than just another vasoconstrictor to treat septic shock-induced hypotension?*. Crit Care Med 2015; 42:1961-3. [PMID: 25029144 DOI: 10.1097/ccm.0000000000000436] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Corrêa TD, Takala J, Jakob SM. Angiotensin II in septic shock. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:98. [PMID: 25886853 PMCID: PMC4360936 DOI: 10.1186/s13054-015-0802-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2015 and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/annualupdate2015. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.
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Affiliation(s)
- Thiago D Corrêa
- Hospital Israelita Albert Einstein, Intensive Care Unit, São Paulo, Brazil.
| | - Jukka Takala
- Department of Intensive Care Medicine, Bern University Hospital, Inselspital, Bern, Switzerland. .,University of Bern, Bern, Switzerland.
| | - Stephan M Jakob
- Department of Intensive Care Medicine, Bern University Hospital, Inselspital, Bern, Switzerland. .,University of Bern, Bern, Switzerland.
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Sparks MA, Crowley SD, Gurley SB, Mirotsou M, Coffman TM. Classical Renin-Angiotensin system in kidney physiology. Compr Physiol 2015; 4:1201-28. [PMID: 24944035 DOI: 10.1002/cphy.c130040] [Citation(s) in RCA: 353] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The renin-angiotensin system has powerful effects in control of the blood pressure and sodium homeostasis. These actions are coordinated through integrated actions in the kidney, cardiovascular system and the central nervous system. Along with its impact on blood pressure, the renin-angiotensin system also influences a range of processes from inflammation and immune responses to longevity. Here, we review the actions of the "classical" renin-angiotensin system, whereby the substrate protein angiotensinogen is processed in a two-step reaction by renin and angiotensin converting enzyme, resulting in the sequential generation of angiotensin I and angiotensin II, the major biologically active renin-angiotensin system peptide, which exerts its actions via type 1 and type 2 angiotensin receptors. In recent years, several new enzymes, peptides, and receptors related to the renin-angiotensin system have been identified, manifesting a complexity that was previously unappreciated. While the functions of these alternative pathways will be reviewed elsewhere in this journal, our focus here is on the physiological role of components of the "classical" renin-angiotensin system, with an emphasis on new developments and modern concepts.
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Affiliation(s)
- Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
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Polichnowski AJ, Griffin KA, Picken MM, Licea-Vargas H, Long J, Williamson GA, Bidani AK. Hemodynamic basis for the limited renal injury in rats with angiotensin II-induced hypertension. Am J Physiol Renal Physiol 2014; 308:F252-60. [PMID: 25477472 DOI: 10.1152/ajprenal.00596.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ANG II is thought to increase the susceptibility to hypertension-induced renal disease (HIRD) via blood pressure (BP)-dependent and BP-independent pathways; however, the quantitative relationships between BP and HIRD have not been examined in ANG II-infused hypertensive rats. We compared the relationship between radiotelemetrically measured BP and HIRD in Sprague-Dawley rats (Harlan) chronically administered ANG II (300-500 ng·kg(-1)·min(-1), n = 19) for 4 wk versus another commonly employed pharmacological model of hypertension induced by the chronic administration of N(ω)-nitro-l-arginine methyl ester (l-NAME, 50 mg·kg(-1)·day(-1), n = 23). [DOSAGE ERROR CORRECTED]. Despite the significantly higher average systolic BP associated with ANG II (191.1 ± 3.2 mmHg) versus l-NAME (179.9 ± 2.5 mmHg) administration, the level of HIRD was very modest in the ANG II versus l-NAME model as evidenced by significantly less glomerular injury (6.6 ± 1.3% vs. 11.3 ± 1.5%, respectively), tubulointerstitial injury (0.3 ± 0.1 vs. 0.7 ± 0.1 injury score, respectively), proteinuria (66.3 ± 10.0 vs. 117.5 ± 10.1 mg/day, respectively), and serum creatinine levels (0.5 ± 0.04 vs. 0.9 ± 0.07 mg/dl, respectively). Given that HIRD severity is expected to be a function of renal microvascular BP transmission, BP-renal blood flow (RBF) relationships were examined in additional conscious rats administered ANG II (n = 7) or l-NAME (n = 8). Greater renal vasoconstriction was observed during ANG II versus l-NAME administration (41% vs. 23% decrease in RBF from baseline). Moreover, administration of ANG II, but not l-NAME, led to a unique BP-RBF pattern in which the most substantial decreases in RBF were observed during spontaneous increases in BP. We conclude that the hemodynamic effects of ANG II may mediate the strikingly low susceptibility to HIRD in the ANG II-infused model of hypertension in rats.
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Affiliation(s)
- Aaron J Polichnowski
- Hines Veterans Affairs Hospital and Department of Medicine Loyola University, Maywood, Illinois;
| | - Karen A Griffin
- Hines Veterans Affairs Hospital and Department of Medicine Loyola University, Maywood, Illinois
| | - Maria M Picken
- Department of Pathology Loyola University, Maywood, Illinois
| | - Hector Licea-Vargas
- Hines Veterans Affairs Hospital and Department of Medicine Loyola University, Maywood, Illinois
| | - Jianrui Long
- Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Geoffrey A Williamson
- Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Anil K Bidani
- Hines Veterans Affairs Hospital and Department of Medicine Loyola University, Maywood, Illinois
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Calzavacca P, May CN, Bellomo R. Glomerular haemodynamics, the renal sympathetic nervous system and sepsis-induced acute kidney injury. Nephrol Dial Transplant 2014; 29:2178-2184. [DOI: 10.1093/ndt/gfu052] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Ferreira JP, Santos M, Almeida S, Marques I, Bettencourt P, Carvalho H. The role of albuminuria as a non-invasive marker for congestive acutely decompensated chronic heart failure and the spironolactone effect in elderly Portuguese: a non-randomized trial. Nephrology (Carlton) 2014; 19:149-56. [PMID: 24533733 DOI: 10.1111/nep.12188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2013] [Indexed: 01/09/2023]
Abstract
BACKGROUND/OBJECTIVES Albuminuria is a robust, validated cardiovascular risk factor. It is a simple and widely available test that was shown to be a powerful and independent predictor of prognosis in chronic heart failure. Mineralocorticoid receptor antagonists may reduce the acute and chronic harmful effects of mineralocorticoid receptor activation on the kidney. The objectives of the trial were to compare the effect of spironolactone versus standard acutely decompensated heart failure (ADHF) therapy on albuminuria and to investigate the role of albuminuria as a prognostic marker in patients with ADHF. METHODS Secondary analysis of a prospective, interventional study including 100 patients with ADHF. Fifty patients were non-randomly assigned to spironolactone 100 mg/day plus standard ADHF therapy (intervention group) or standard ADHF therapy alone (control group). RESULTS Patients in control group were older, had higher creatinine and urea levels, and had higher proportion of microalbuminuria (all, P < 0.05). Paired comparison of baseline and day 3 log albuminuria within each group, showed a more pronounced decrease in the intervention group (1.79 ± 0.75 to 1.59 ± 0.67, P = 0.003 vs 1.89 ± 0.70 to 1.79 ± 0.74, P = 0.096). In addition, the proportion of patients with normoalbuminuria increased from baseline to day 3 in spironolactone group (20 (40%) to 27 (54%), P < 001), accordingly the number of patients in the micro and macroalbuminuria groups was reduced. Day 1 albuminuria was positively correlated with day 1 N-terminal pro-brain natriuretic peptide (0.260 [0.105-0.758], P = 0.009). CONCLUSIONS High-dose spironolactone added to standard ADHF therapy is likely to induce a more pronounced albuminuria decrease and a significant reduction in the proportion of micro and macroalbuminuria.
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Karaaslan F, Denizhan Y, Hester R. A mathematical model of long-term renal sympathetic nerve activity inhibition during an increase in sodium intake. Am J Physiol Regul Integr Comp Physiol 2013; 306:R234-47. [PMID: 24285363 DOI: 10.1152/ajpregu.00302.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is well known that renal nerves directly affect renal vascular resistance, tubular sodium reabsorption, and renin secretion. Inhibition of renal sympathetic nerve activity (RSNA) decreases renal vascular resistance, tubular sodium reabsorption, and renin secretion, leading to an increase in sodium excretion. Although several studies show that inhibition of RSNA promotes sodium excretion during an acute blood volume expansion, there is limited research relating to the importance of RSNA inhibition that contributes to sodium homeostasis during a long-term increase in sodium intake. Therefore, to dissect the underlying mechanisms of sodium excretion, a mathematical model of a cardiovascular system consisting of two kidneys, each with an independent RSNA, was developed. Simulations were performed to determine the responses of RSNA and sodium excretion to an increased sodium intake. In these simulations, RSNA in the left kidney was fixed at its normal steady-state value, while RSNA in the contralateral kidney was allowed to change normally in response to the increased sodium intake. The results demonstrate that the fixed-RSNA kidney excretes less sodium than the intact-RSNA collateral kidney. Because each kidney is exposed to the same arterial pressure and circulatory hormones, the impaired sodium excretion in the absence of RSNA inhibition supports the hypothesis that RSNA inhibition contributes to natriuresis in response to a long-term increase in sodium intake.
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Affiliation(s)
- Fatih Karaaslan
- Department of Physiology and Biophysics, Center for Computational Medicine, University of Mississippi Medical Center, Jackson, Mississippi; and
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Abstract
An intact microcirculation is vital for diffusion of oxygen and nutrients and for removal of toxins of every organ and system in the human body. The functional and/or anatomical loss of microvessels is known as rarefaction, which can compromise the normal organ function and have been suggested as a possible starting point of several diseases. The purpose of this overview is to discuss the potential underlying mechanisms leading to renal microvascular rarefaction, and the potential consequences on renal function and on the progression of renal damage. Although the kidney is a special organ that receives much more blood than its metabolic needs, experimental and clinical evidence indicates that renal microvascular rarefaction is associated to prevalent cardiovascular diseases such as diabetes, hypertension, and atherosclerosis, either as cause or consequence. On the other hand, emerging experimental evidence using progenitor cells or angiogenic cytokines supports the feasibility of therapeutic interventions capable of modifying the progressive nature of microvascular rarefaction in the kidney. This overview will also attempt to discuss the potential renoprotective mechanisms of the therapeutic targeting of the renal microcirculation.
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Affiliation(s)
- Alejandro R Chade
- The Department of Physiology and Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, Mississippi, USA.
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Beierwaltes WH, Harrison-Bernard LM, Sullivan JC, Mattson DL. Assessment of renal function; clearance, the renal microcirculation, renal blood flow, and metabolic balance. Compr Physiol 2013; 3:165-200. [PMID: 23720284 DOI: 10.1002/cphy.c120008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Historically, tools to assess renal function have been developed to investigate the physiology of the kidney in an experimental setting, and certain of these techniques have utility in evaluating renal function in the clinical setting. The following work will survey a spectrum of these tools, their applications and limitations in four general sections. The first is clearance, including evaluation of exogenous and endogenous markers for determining glomerular filtration rate, the adaptation of estimated glomerular filtration rate in the clinical arena, and additional clearance techniques to assess various other parameters of renal function. The second section deals with in vivo and in vitro approaches to the study of the renal microvasculature. This section surveys a number of experimental techniques including corticotomy, the hydronephrotic kidney, vascular casting, intravital charge coupled device videomicroscopy, multiphoton fluorescent microscopy, synchrotron-based angiography, laser speckle contrast imaging, isolated renal microvessels, and the perfused juxtamedullary nephron microvasculature. The third section addresses in vivo and in vitro approaches to the study of renal blood flow. These include ultrasonic flowmetry, laser-Doppler flowmetry, magnetic resonance imaging (MRI), phase contrast MRI, cine phase contrast MRI, dynamic contrast-enhanced MRI, blood oxygen level dependent MRI, arterial spin labeling MRI, x-ray computed tomography, and positron emission tomography. The final section addresses the methodologies of metabolic balance studies. These are described for humans, large experimental animals as well as for rodents. Overall, the various in vitro and in vivo topics and applications to evaluate renal function should provide a guide for the investigator or physician to understand and to implement the techniques in the laboratory or clinic setting.
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Affiliation(s)
- William H Beierwaltes
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, and Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, USA.
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Moss R, Thomas SR. Hormonal regulation of salt and water excretion: a mathematical model of whole kidney function and pressure natriuresis. Am J Physiol Renal Physiol 2013; 306:F224-48. [PMID: 24107423 DOI: 10.1152/ajprenal.00089.2013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
We present a lumped-nephron model that explicitly represents the main features of the underlying physiology, incorporating the major hormonal regulatory effects on both tubular and vascular function, and that accurately simulates hormonal regulation of renal salt and water excretion. This is the first model to explicitly couple glomerulovascular and medullary dynamics, and it is much more detailed in structure than existing whole organ models and renal portions of multiorgan models. In contrast to previous medullary models, which have only considered the antidiuretic state, our model is able to regulate water and sodium excretion over a variety of experimental conditions in good agreement with data from experimental studies of the rat. Since the properties of the vasculature and epithelia are explicitly represented, they can be altered to simulate pathophysiological conditions and pharmacological interventions. The model serves as an appropriate starting point for simulations of physiological, pathophysiological, and pharmacological renal conditions and for exploring the relationship between the extrarenal environment and renal excretory function in physiological and pathophysiological contexts.
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Affiliation(s)
- Robert Moss
- Mathematics Dept., Duke Univ., Box 90320, Durham, NC 27708-0320.
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Ahmeda AF, Rae MG, Johns EJ. Effect of reactive oxygen species and nitric oxide in the neural control of intrarenal haemodynamics in anaesthetized normotensive rats. Acta Physiol (Oxf) 2013; 209:156-66. [PMID: 23910436 DOI: 10.1111/apha.12150] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/15/2013] [Accepted: 07/24/2013] [Indexed: 12/13/2022]
Abstract
AIMS This study examined the interaction between reactive oxygen species and nitric oxide (NO) in mediating the decrease in renal blood flow (RBF) evoked by sympathetic renal nerve stimulation (RNS). METHODS Groups of male Wistar rats were subjected to RNS at different frequencies prior to, and following, an infusion of: (i) tempol, the superoxide dismutase (SOD) mimetic, (ii) tempol plus the hydrogen peroxide-degrading enzyme catalase (tem + cat), (iii) diethyldithiocarbamic acid (DETC), a SOD inhibitor, (iv) the nitric oxide synthase (NOS) inhibitor, L-nitro-arginine methyl ester (L-NAME) alone, or (v) L-NAME followed by tempol, into the kidney cortico-medullary border (CMB). Blood perfusion within the cortical (CBP) and medullary (MBP) regions of the kidney was measured using Laser-Doppler flowmetry. RESULTS Infusion of tempol CMB significantly attenuated RNS-evoked reductions in CBP (by 22% at 8 Hz; P < 0.05), but not MBP. When tempol and catalase were co-infused to reduce both ROS and hydrogen peroxide (H2 O2 ), respectively, there was a significantly greater attenuation of the RNS-evoked reduction in CBP compared with that of tempol alone. Infusion of either DETC or L-NAME alone did not significantly affect the CBP or MBP responses to RNS. Similarly, RNS following tempol infusion with L-NAME also had no effect on CBP and MBP over and above the group that received tempol alone. CONCLUSION These results suggest that reactive oxygen species such as superoxide and H2 O2 have a direct role in reducing renal vascular compliance in response to RNS, rather than indirectly through scavenging NO.
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Affiliation(s)
- A. F. Ahmeda
- Department of Physiology; University College Cork; Cork; Ireland
| | - M. G. Rae
- Department of Physiology; University College Cork; Cork; Ireland
| | - E. J. Johns
- Department of Physiology; University College Cork; Cork; Ireland
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Koyama S, Sato Y, Tanada Y, Fujiwara H, Takatsu Y. Early evolution and correlates of urine albumin excretion in patients presenting with acutely decompensated heart failure. Circ Heart Fail 2013; 6:227-32. [PMID: 23395932 DOI: 10.1161/circheartfailure.112.000152] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Urine albumin excretion is an important predictor of adverse cardiovascular events in various populations. Its correlation in patients with acute heart failure has not been described. METHODS AND RESULTS This prospective, observational study included 115 patients presenting with acute heart failure. The urine albumin/creatinine ratio (UACR) was measured from spot urine samples collected on days 1 and 7 of hospitalization. Median UACR decreased from 83 to 22 mg/gCr on days 1 and 7, respectively (P<0.0001). The proportion of patients with normoalbuminuria (UACR <30 mg/gCr) increased from 31% on day 1 to 60% on day 7, whereas the proportion with microalbuminuria (UACR between 30 and 299 mg/gCr) and macroalbuminuria (UACR ≥300 mg/gCr) decreased, respectively, from 42% and 27% on day 1 to 30% and 10% on day 7 (P<0.0001). These changes in UACR were correlated with changes in serum bilirubin and N-terminal pro b-type natriuretic peptide concentrations (correlation coefficients 1.087 and 0.384, respectively; 95% confidence interval, 0.394-1.781 and 0.087-0.680, respectively; and P=0.003 and 0.013, respectively), although they were not correlated with change in estimated glomerular filtration rate. CONCLUSIONS In this sample of patients presenting with acute heart failure, urine albumin excretion was often increased at admission to the hospital and decreased significantly within 7 days of treatment. The decrease was correlated with serum N-terminal pro b-type natriuretic peptide and bilirubin concentrations, although neither with baseline nor with changes in indices of renal function.
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Affiliation(s)
- Satoshi Koyama
- Department of Cardiovascular Medicine, Hyogo Prefectural Amagasaki Hospital, Amagasaki, Hyogo, Japan
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May CN, Calzavacca P, Ishikawa K, Langenberg C, Wan L, Ramchandra R, Bellomo R. Novel targets for sepsis-induced kidney injury: the glomerular arterioles and the sympathetic nervous system. Exp Physiol 2012; 97:1168-77. [DOI: 10.1113/expphysiol.2011.061804] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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In vivo, label-free, three-dimensional quantitative imaging of kidney microcirculation using Doppler optical coherence tomography. J Transl Med 2011; 91:1596-604. [PMID: 21808233 PMCID: PMC3312876 DOI: 10.1038/labinvest.2011.112] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Doppler optical coherence tomography (DOCT) is a functional extension of optical coherence tomography (OCT) and is currently being employed in several clinical arenas to quantify blood flow in vivo. In this study, the objective was to investigate the feasibility of DOCT to image kidney microcirculation, specifically, glomerular blood flow. DOCT is able to capture three-dimensional (3D) data sets consisting of a series of cross-sectional images in real time, which enables label-free and non-destructive quantification of glomerular blood flow. The kidneys of adult, male Munich-Wistar rats were exposed through laparotomy procedure after being anesthetized. Following exposure of the kidney beneath the DOCT microscope, glomerular blood flow was observed. The effects of acute mannitol and angiotensin II infusion were also observed. Glomerular blood flow was quantified for the induced physiological states and compared with baseline measurements. Glomerular volume, cumulative Doppler volume, and Doppler flow range parameters were computed from 3D OCT/DOCT data sets. Glomerular size was determined from OCT, and DOCT readily revealed glomerular blood flow. After infusion of mannitol, a significant increase in blood flow was observed and quantified, and following infusion of angiontensin II, a significant decrease in blood flow was observed and quantified. Also, blood flow histograms were produced to illustrate differences in blood flow rate and blood volume among the induced physiological states. We demonstrated 3D DOCT imaging of rat kidney microcirculation in the glomerulus in vivo. Dynamic changes in blood flow were detected under altered physiological conditions demonstrating the real-time imaging capability of DOCT. This method holds promise to allow non-invasive imaging of kidney blood flow for transplant graft evaluation or monitoring of altered-renal hemodynamics related to disease progression.
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Benigni A, Morigi M, Rizzo P, Gagliardini E, Rota C, Abbate M, Ghezzi S, Remuzzi A, Remuzzi G. Inhibiting angiotensin-converting enzyme promotes renal repair by limiting progenitor cell proliferation and restoring the glomerular architecture. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:628-38. [PMID: 21718676 DOI: 10.1016/j.ajpath.2011.04.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 03/16/2011] [Accepted: 04/22/2011] [Indexed: 11/18/2022]
Abstract
We previously reported that angiotensin-converting enzyme inhibitor (ACEi) renoprotection in Munich Wistar Frömter (MWF) rats, which develop progressive glomerular injury, was associated with podocyte repopulation and preservation of glomerular architecture. Here, we studied the time course of the lesions, their cellular components, and the effect of ACEi. Early glomerular lesions were synechiae, followed by extracapillary crescents and glomerulosclerosis. The majority of cells forming crescents were claudin1(+) parietal epithelial cells and, to a lesser extent, WT1(+) podocytes, both in active proliferation. In crescents, cells expressing the metanephric mesenchyme marker NCAM were also found. Three distinct populations of parietal epithelial cells were identified in the rat Bowman's capsule: NCAM(+)WT1(-) cells, also expressing progenitor cell marker CD24, and NCAM(+)WT1(+) and NCAM(-)WT1(+) cells, the latter population representing parietal podocytes. After exposure to inductive medium, cultured parietal epithelial cells that were obtained by capsulated glomeruli generated podocytes, documenting their progenitor nature. Mitotic activity of cultured renal progenitors was induced by angiotensin II through the down-regulation of cell cycle inhibitor C/EBPδ expression. Treatment with ACEi reduced number and extension of crescents and glomerulosclerosis in MWF rats. Renoprotection was accomplished through the limitation of NCAM(+) progenitor proliferation via the modulation of C/EBPδ. Thus, chaotic migration and proliferation of the Bowman's capsule progenitor cells pave the way to crescent formation and subsequent sclerosis. ACEi, by moderating progenitor cell activation, restores glomerular architecture and prevents renal disease progression.
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Affiliation(s)
- Ariela Benigni
- Mario Negri Institute for Pharmacological Research, Centro Anna Maria Astori, Bergamo, Italy
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The impact of intrarenal nitric oxide synthase inhibition on renal blood flow and function in mild and severe hyperdynamic sepsis*. Crit Care Med 2011; 39:770-6. [DOI: 10.1097/ccm.0b013e318206c1fb] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Rao RP, Jain AK, Srinivasan BP. Dual therapy versus monotherapy of trandolapril and telmisartan on diabetic nephropathy in experimentally induced type 2 diabetes mellitus rats. J Renin Angiotensin Aldosterone Syst 2011; 12:169-75. [DOI: 10.1177/1470320310392097] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective: To investigate the combination of telmisartan with trandolapril therapy versus monotherapy of trandolapril and telmisartan on diabetic nephropathy in type 2 diabetes mellitus rats. Material and methods: Neonatal rats (2 days old) were used for inducing type 2 diabetes mellitus. Streptozotocin at a dose of 90 mg/kg, in freshly prepared citrate buffer (0.1M, pH 4.5), was injected intraperitoneally. There were five groups: (1) normal control, (2) diabetic control, (3) diabetic treated with telmisartan, (4) diabetic treated with trandolapril and (5) diabetic treated with telmisartan and trandolapril. Albumin excretion rate, total protein excretion rate, plasma fibronectin, transforming growth factor beta 1(TGF-β1), tumour necrosis factor-α (TNF-α) concentration and renal structural changes were measured. Results: Albumin excretion rate, total protein excretion rate, plasma fibronectin, TGF-β1, TNF-α concentration and renal structural changes increased significantly in untreated diabetic rats compared with normal control rats. Administration of telmisartan, trandolapril, or both decreased these changes. Conclusions: Addition of the telmisartan to trandolapril was more effective in reducing renal structural changes and improvement of renal function than monotherapy with either drug, possibly due to dual inhibitory effect on the renin— angiotensin system, and thus suppression of TGF-β1, TNF-α.
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Affiliation(s)
- Ravi P Rao
- Department of Pharmacology, Delhi Institute of Pharmaceutical Sciences and Research, University of Delhi, New Delhi, India,
| | - AK Jain
- Institute of Pathology-ICMR, Safdarjung Hospital Campus, New Delhi, India
| | - BP Srinivasan
- Department of Pharmacology, Delhi Institute of Pharmaceutical Sciences and Research, University of Delhi, New Delhi, India
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van der Meer IM, Cravedi P, Remuzzi G. The role of renin angiotensin system inhibition in kidney repair. FIBROGENESIS & TISSUE REPAIR 2010; 3:7. [PMID: 20441574 PMCID: PMC2888753 DOI: 10.1186/1755-1536-3-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Accepted: 05/04/2010] [Indexed: 01/08/2023]
Abstract
Chronic kidney diseases share common pathogenic mechanisms that, independently from the initial injury, lead to glomerular hyperfiltration, proteinuria, and progressive renal scarring and function loss. Inhibition of the renin angiotensin system (RAS) has been consistently found to reduce or halt the progressive deterioration of renal function through reduction of blood pressure and proteinuria, the two main determinants of renal function decline. In few instances, RAS inhibition may even promote amelioration of the glomerular filtration rate. Animal data suggest that chronic therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor type I blockers promotes regression of glomerulosclerosis, even in later phases of the disease. In humans, studies investigating the effect of angiotensin II inhibition on renal structural changes have shown inconsistent results, possibly due to small numbers and/or short duration of follow-up. Whether regression of glomerulosclerosis relies on a direct regenerative effect of RAS inhibition or on spontaneous kidney self-repair after the injury has been removed is still unknown. Improved understanding of mechanisms that promote renal regeneration may help in designing specific therapies to prevent the development of end-stage renal disease. This is a desirable goal, considering the economic burden of chronic kidney diseases and their effect on morbidity and mortality.
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Cho BS, Kim SD, Park JK, Chung JH, Hong MS, Lee BC, Ihm CG. Effects of Bupleurum falcatum and its combination with an angiotensin II receptor blocker on cytokine and chemokine expression in human mesangial cells. Phytother Res 2010; 24:339-43. [PMID: 19610027 DOI: 10.1002/ptr.2936] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study aimed to investigate the inhibitory effect of Bupleurum falcatum and its combination with angiotensin II receptor blocker (ARB) on cytokine and chemokine production in cultured human mesangial cells. Human mesangial cells were isolated and cultured in Dulbecco's modified Eagle's medium culture medium. Bupleurum falcatum, ARB, and the combination of the two were added to human mesangial cells. Cytokine and chemokine levels were analysed using an enzyme-linked immunosorbent assay. There were no significant differences in the expression of IL-1ss, IL-2 or TNF-a between controls and the experimental groups. However, IL-11 and monocyte chemoattractant protein-1 (MCP-1) levels were significantly reduced in response to ARB, Bupleurum falcatum, or their combination when compared with controls. IL-8 expression was reduced significantly only in cells treated with ARB. Both Bupleurum falcatum and ARB treatments alone reduced the cytokine concentration, but there was not a stronger reduction when the two drugs were combined. It was shown that Bupleurum falcatum inhibited cytokine production in human mesangial cells. However, there were no additive effects on the suppression of cytokine production when Bupleurum falcatum was combined with ARB. Further studies are needed to elucidate the renoprotective effects of Bupleurum falcatum.
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Affiliation(s)
- Byoung-Soo Cho
- Department of Pediatrics, East West Kidney Diseases Research Institute, Kyung Hee University, Seoul, Korea
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Evans RG, Eppel GA, Michaels S, Burke SL, Nematbakhsh M, Head GA, Carroll JF, O'Connor PM. Multiple mechanisms act to maintain kidney oxygenation during renal ischemia in anesthetized rabbits. Am J Physiol Renal Physiol 2010; 298:F1235-43. [PMID: 20200093 DOI: 10.1152/ajprenal.00647.2009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We examined the mechanisms that maintain stable renal tissue PO(2) during moderate renal ischemia, when changes in renal oxygen delivery (DO(2)) and consumption (VO(2)) are mismatched. When renal artery pressure (RAP) was reduced progressively from 80 to 40 mmHg, VO(2) (-38 ± 7%) was reduced more than DO(2) (-26 ± 4%). Electrical stimulation of the renal nerves (RNS) reduced DO(2) (-49 ± 4% at 2 Hz) more than VO(2) (-30 ± 7% at 2 Hz). Renal arterial infusion of angiotensin II reduced DO(2) (-38 ± 3%) but not VO(2) (+10 ± 10%). Despite mismatched changes in DO(2) and VO(2), renal tissue PO(2) remained remarkably stable at ≥40 mmHg RAP, during RNS at ≤2 Hz, and during angiotensin II infusion. The ratio of sodium reabsorption to VO(2) was reduced by all three ischemic stimuli. None of the stimuli significantly altered the gradients in PCO(2) or pH across the kidney. Fractional oxygen extraction increased and renal venous PO(2) fell during 2-Hz RNS and angiotensin II infusion, but not when RAP was reduced to 40 mmHg. Thus reduced renal VO(2) can help prevent tissue hypoxia during mild renal ischemia, but when renal VO(2) is reduced less than DO(2), other mechanisms prevent a fall in renal PO(2). These mechanisms do not include increased efficiency of renal oxygen utilization for sodium reabsorption or reduced washout of carbon dioxide from the kidney, leading to increased oxygen extraction. However, increased oxygen extraction could be driven by altered countercurrent exchange of carbon dioxide and/or oxygen between renal arteries and veins.
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Affiliation(s)
- Roger G Evans
- Dept. of Physiology, PO Box 13F, Monash Univ., Victoria 3800, Australia.
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Evans RG, Head GA, Eppel GA, Burke SL, Rajapakse NW. Angiotensin II and neurohumoral control of the renal medullary circulation. Clin Exp Pharmacol Physiol 2010; 37:e58-69. [DOI: 10.1111/j.1440-1681.2009.05233.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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