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Ralph DL, Ha D, Lei H, Priver TS, Smith SD, McFarlin BE, Schwindt S, Pandya D, Koepsell H, Pastor-Soler NM, Edwards A, McDonough AA. Potassium-Alkali-Enriched Diet, Hypertension, and Proteinuria following Uninephrectomy. J Am Soc Nephrol 2024; 35:1330-1350. [PMID: 38913441 PMCID: PMC11452139 DOI: 10.1681/asn.0000000000000420] [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: 01/12/2024] [Accepted: 06/10/2024] [Indexed: 06/26/2024] Open
Abstract
Key Points A K-alkali–enriched diet blunted post-uninephrectomy hypertension and facilitated acid clearance by suppressing Na+ reabsorption. Uninephrectomy-associated proteinuria could be attributed to elevated single-nephron GFR and downregulation of megalin, which reduced fractional protein endocytosis. Background Losing or donating a kidney is associated with risks of developing hypertension and albuminuria. Few studies address mechanisms or interventions. We investigate the potential benefits of a K+- alkali–enriched diet and the mechanisms underlying proteinuria. Methods Male Sprague Dawley rats were fed either a 2% NaCl+0.95% KCl diet (HNa-LK) or a 0.74% NaCl+3% K+-alkali diet (HK-alk) for 3 weeks before uninephrectomy and then maintained on respective diets for 12 weeks. BP (by tail-cuff), urine, blood, and kidney proteins were analyzed before and after uninephrectomy. Results Before uninephrectomy, HK-alk–fed versus HNa-LK–fed rats exhibited similar BPs and plasma [K+], [Na+], but lower proximal (NHE3, sodium bicarbonate cotransporter 1, NaPi2) and higher distal (NCC, ENaC, and pendrin) transporter abundance, a pattern facilitating K+ and HCO3− secretion. After uninephrectomy, single-nephron GFR increased 50% and Li+ clearance doubled with both diets; in HK-alk versus HNa-LK, the increase in BP was less and ammoniagenesis was lower, abundance of proximal tubule transporters remained lower, ENaC-α fell, and NCCp increased, consistent with K+ conservation. After uninephrectomy, independent of diet, albuminuria increased eight-fold and abundance of endocytic receptors was reduced (megalin by 44%, disabled homolog 2 by 25%–35%) and kidney injury molecule-1 was increased. Conclusions The K-alkali–enriched diet blunted post-uninephrectomy hypertension and facilitated acid clearance by suppressing proximal Na+ transporters and increasing K+-alkali secretion. Furthermore, uninephrectomy-associated proteinuria could be attributed, at least in part, to elevated single-nephron GFR coupled with downregulation of megalin, which reduced fractional protein endocytosis and Vmax. Podcast This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/JASN/2024_07_31_ASN0000000000000420.mp3
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Affiliation(s)
- Donna L. Ralph
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Darren Ha
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Hillmin Lei
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Taylor S. Priver
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Scotti D. Smith
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Brandon E. McFarlin
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Seth Schwindt
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Drishti Pandya
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Hermann Koepsell
- Institute for Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany
| | - Nuria M. Pastor-Soler
- Division of Nephrology, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Aurelie Edwards
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Alicia A. McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
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Boyd-Shiwarski CR, Rodan AR. Solitary Kidney Seeks Potassium Alkali to Lower the Pressure. J Am Soc Nephrol 2024; 35:1300-1302. [PMID: 39167444 PMCID: PMC11452165 DOI: 10.1681/asn.0000000000000476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024] Open
Affiliation(s)
- Cary R. Boyd-Shiwarski
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Pittsburgh Center for Kidney Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Aylin R. Rodan
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, Utah
- Molecular Medicine Program, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, Utah
- Department of Human Genetics, University of Utah Spencer Fox Eccles School of Medicine, Salt Lake City, Utah
- Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
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Bigot P, Bernhard JC, Khene ZE, Dariane C, Lebdai S, Doumerc N, Nouhaud FX, Ouzaid I, Saulnier P, Méjean A, Roupret M, Bensalah K. Nephrectomy for kidney tumour increases the risk of de novo arterial hypertension. BJU Int 2023; 132:575-580. [PMID: 37433580 DOI: 10.1111/bju.16124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
OBJECTIVE To evaluate prospectively the effects of surgical excision of renal tumours on blood pressure (BP). PATIENTS AND METHODS In a multicentre prospective study, we evaluated 200 patients who underwent nephrectomy for renal tumour between 2018 and 2020 at seven departments of the French Network for Kidney Cancer, the UroCCR. All patients had localized cancer without pre-existing hypertension (HTN). Blood pressure was measured the week before nephrectomy, and at 1 month and 6 months after nephrectomy, according to the recommendations for home BP monitoring. Plasma renin was measured 1 week before surgery and 6 months after surgery. The primary endpoint was the occurrence of de novo HTN. The secondary endpoint was clinically significant increase in BP at 6 months, defined by an increase in systolic and/or diastolic ambulatory BP ≥10 mmHg or requirement for medical antihypertensive treatment. RESULTS Blood pressure and renin measurements were available for 182 (91%) and 136 patients (68%), respectively. We excluded from the analysis 18 patients who had undeclared HTN detected on preoperative measurements. At 6 months, 31 patients (19.2%) had de novo HTN and 43 patients (26.3%) had a significant increase in their BP. Type of surgery was not associated with an increased risk of HTN (21.7% partial nephrectomy [PN] vs 15.7% radical nephrectomy [RN]; P = 0.59). There was no difference between plasmatic renin levels before and after surgery (18.5 vs 16; P = 0.46). In multivariable analysis, age (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.02-1.12; P = 0.03) and body mass index (OR 1.14, 95% CI 1.03-1.26; P = 0.01) were the only predictors of de novo HTN. CONCLUSION Surgical treatment of renal tumours is associated with significant changes in BP, with de novo HTN occurring in almost 20% of the patients. These changes are not impacted by the type of surgery (PN vs RN). Patients who are scheduled to undergo kidney cancer surgery should be informed of these findings and have their BP closely monitored after the operation.
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Affiliation(s)
- Pierre Bigot
- Department of Urology, Angers University Hospital, Angers, France
| | | | | | - Charles Dariane
- Department of Urology, Hôpital Européen Georges-Pompidou, Paris, France
| | - Souhil Lebdai
- Department of Urology, Angers University Hospital, Angers, France
| | | | | | - Idir Ouzaid
- Department of Urology, Angers University Hospital, Paris, France
| | - Patrick Saulnier
- Department of Biostatistics, Angers University Hospital, Angers, France
| | - Arnaud Méjean
- Department of Urology, Hôpital Européen Georges-Pompidou, Paris, France
| | - Morgan Roupret
- Department of Urology, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris, France
| | - Karim Bensalah
- Department of Urology, Rennes University Hospital, Rennes, France
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Menendez-Castro C, Cordasic N, Fahlbusch FB, Woelfle J, Hilgers KF, Hartner A. Sex differences in long-term kidney fibrosis following neonatal nephron loss during ongoing nephrogenesis. Mol Cell Pediatr 2023; 10:8. [PMID: 37624430 PMCID: PMC10457250 DOI: 10.1186/s40348-023-00164-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 08/14/2023] [Indexed: 08/26/2023] Open
Abstract
BACKGROUND Clinical studies suggest that female sex plays a protective role in the development and progression of kidney disease. Recent experimental studies indicate that in male rats early nephron loss under ongoing nephrogenesis is accompanied by severe long-term sequelae. In humans, nephron formation occurs mainly in the third trimester, ceasing with 36 weeks of gestation. Due to perinatal complications, preterm infants delivered during this vulnerable period may undergo acute nephron loss. In rats nephrogenesis persists until postnatal day 10, reflecting the situation of human preterms with persisting nephrogenesis. In our animal model of neonatal uninephrectomy, female and male rats were uninephrectomized at day 1 of life. Hypothesizing sex-dependent differences, long-term renal outcome was assessed after 1 year. RESULTS In both sexes, neonatal uninephrectomy was not followed by arterial hypertension at 1 year of age. Compensatory weight gain and glomerular hypertrophy of the remaining kidney occurred in uninephrectomized female and male animals. Selected markers of interstitial inflammation and fibrosis were regulated sex-dependently. The expression of monocyte chemoattractant protein-1 was increased in females, while tubulointerstitial infiltration by M1 macrophages was significantly higher in males after neonatal uninephrectomy. Neonatally uninephrectomized male rats had more glomerulosclerosis and podocyte damage compared to females, which was assessed by a semiquantitative score and desmin staining. RT-PCR revealed that after neonatal uninephrectomy in the remaining contralateral kidney of female rats the expression of candidate genes of renal development and function, i.e., wt-1, nephrin, synaptopodin, gdnf, and itga8 was higher than in males. CONCLUSIONS Based on these observations we conclude that female sex is protective in the long-term response of the kidney to acute nephron loss under active nephrogenesis.
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Affiliation(s)
- Carlos Menendez-Castro
- Department of Pediatrics and Adolescent Medicine, University Hospital of Erlangen, Erlangen, Germany.
| | - Nada Cordasic
- Department of Nephrology and Hypertension, University Hospital of Erlangen, Erlangen, Germany
| | - Fabian B Fahlbusch
- Division of Neonatology and Pediatric Intensive Care Medicine, University Hospital of Erlangen, Erlangen, Germany
| | - Joachim Woelfle
- Department of Pediatrics and Adolescent Medicine, University Hospital of Erlangen, Erlangen, Germany
| | - Karl F Hilgers
- Department of Nephrology and Hypertension, University Hospital of Erlangen, Erlangen, Germany
| | - Andrea Hartner
- Department of Pediatrics and Adolescent Medicine, University Hospital of Erlangen, Erlangen, Germany
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Basta M, Yassin HA, Aly RG, El Sayed NS. Possible protective effect of zinc administration on renal and cognitive changes occurring in uninephrectomized adult male Wistar rats. Exp Physiol 2023; 108:253-267. [PMID: 36420617 PMCID: PMC10103884 DOI: 10.1113/ep090735] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/31/2022] [Indexed: 11/25/2022]
Abstract
NEW FINDINGS What is the central question of this study? Are renal changes occurring post-nephrectomy accompanied by cognitive changes, and does early administration of zinc supplements such as ZnSO4 to uninephrectomized rats ameliorate the renal and cognitive changes if present? What is the main finding and its importance? Uninephrectomy-induced renal changes were accompanied by species-atypical behaviour in rats in both Morris water maze and T maze tests, together with hypozincaemia and hippocampal inflammatory and oxidative changes. Early zinc administration to uninephrectomized rats ameliorated the renal, behavioural, hippocampal and serum zinc changes. ABSTRACT Cognitive impairment is increasingly recognized as an important consequence of kidney disease in humans. Kidney donation is a safe procedure but is known to increase the long-term risk of cardiovascular and kidney disease. Whether kidney donation impairs cognitive function is not known. In the present study, we examined whether the renal changes occurring post-nephrectomy were accompanied by cognitive changes as well, and whether early administration of zinc supplements such as ZnSO4 to uninephrectomized (UNX) rats could ameliorate the renal and cognitive changes if present. The present study included 30 adult male Wistar rats that were randomly assigned to three groups (n = 10 per group): sham-operated rats, UNX and UNX treated with ZnSO4 for 20 weeks. Before termination, rats were subjected to 24-h urine collection and behavioural testing with the Morris water maze and T maze tests. UNX induced significant proteinuria, renal functional, fibrotic and oxidative changes, as well as increased renal desmin expression. UNX rats also showed significant behavioural changes indicating spatial learning and memory affection, together with decreased hippocampal brain derived neurotrophic factor (BDNF) and antioxidant capacity, and increased glial fibrillary acidic protein (GFAP), nitric oxide and malondialdehyde. In addition, UNX induced significant hyperglycaemia and dyslipidaemia, as well as significant reduction in serum zinc, copper and selenium. Early administration of ZnSO4 starting 1 week post-nephrectomy significantly ameliorated renal and behavioural changes, as well as hippocampal oxidative, BDNF and GFAP changes. Additionally, Zn recovered serum changes of triglycerides, cholesterol, zinc and copper. Therefore, early administration of zinc to humans undergoing nephrectomy may be of benefit and should be considered in human trials.
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Affiliation(s)
- Marianne Basta
- Department of Medical PhysiologyFaculty of MedicineUniversity of AlexandriaAlexandriaEgypt
| | - Hend A. Yassin
- Department of Medical BiochemistryFaculty of MedicineUniversity of AlexandriaAlexandriaEgypt
| | - Rania G. Aly
- Department of Medical PathologyFaculty of MedicineUniversity of AlexandriaAlexandriaEgypt
| | - Norhan S. El Sayed
- Department of Medical PhysiologyFaculty of MedicineUniversity of AlexandriaAlexandriaEgypt
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Experimental uninephrectomy associates with less parasympathetic modulation of heart rate and facilitates sodium-dependent arterial hypertension. PLoS One 2022; 17:e0265086. [PMID: 35263383 PMCID: PMC8906640 DOI: 10.1371/journal.pone.0265086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 02/22/2022] [Indexed: 11/19/2022] Open
Abstract
Background Blood pressure is known to be increased in kidney donors following living-donor kidney transplantation. However, the physiological underpinnings of the blood-pressure increase following uninephrectomy remain unclear. We hypothesized that changes in sympathetic tone or in parasympathetic modulation of sinus node function are involved in the blood-pressure increase following experimental kidney-mass reduction. Methods C57BL6N mice (6 to 11 per group) subjected to sham surgery (controls) or uninephrectomy with or without a one-week course of sodium chloride-enriched, taurine-deficient diet were studied. Uninephrectomized mice treated with a subcutaneous infusion of angiotensin-II over a period of one week were positive controls. A transfemoral aortic catheter with telemetry unit was implanted, readings of heart-rate and blood-pressure were recorded. Powerspectral analysis of heart rate and systolic blood pressure was performed to gain surrogate parameters of sympathetictone and parasympathetic modulation of sinus node function. Baroreflex sensitivity of heart rate was determined from awake, unrestrained mice using spontaneous baroreflex gain technique. Results Systolic arterial blood pressure, heart rate and baroreflex sensitivity were not different in uninephrectomized mice when compared to controls. Parasympathetic modulation of sinus node function was less in uninephrectomized mice in comparison to controls. Uninephrectomized mice of the high-angiotensin-II model or of the high-salt and taurine-deficiency model had an increased systolic arterial blood pressure. Conclusions Uninephrectomy associated with less parasympathetic modulation of sinus node function. The combination of uninephrectomy, taurine-deficiency and high-salt intake led to arterial hypertension.
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Deoraj S, Moutzouris DA, Bellini MI. Prevalence, Mechanisms, Treatment, and Complications of Hypertension Postliving Kidney Donation. BIOMED RESEARCH INTERNATIONAL 2021; 2021:5460672. [PMID: 33628787 PMCID: PMC7884138 DOI: 10.1155/2021/5460672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 01/15/2021] [Accepted: 01/25/2021] [Indexed: 11/17/2022]
Abstract
Living kidney donors represent a unique population of patients. Potential donors are selected based on the belief that their preoperative fitness is likely to mitigate the risks of long- and short-term harm following uninephrectomy. Studies performed on postdonation outcomes have largely focused on mortality and the risk of end-stage renal failure, but have also investigated secondary outcomes such as cardiovascular morbidity and hypertension. It has been postulated that hypertension is a possible outcome of living kidney donation. A variety of studies have been conducted to investigate the prevalence, epidemiology, mechanisms, treatment strategies, and long-term ramifications of hypertension postdonation. These studies are heterogeneous in their population, design, methodology, and outcome measures and have presented contradicting outcomes. Additionally, the absence of a well-matched control group has made it challenging to interpret and generalise the reported findings. As such, it is not possible to definitively conclude that hypertension occurs at a higher rate among donors than the general population. This article will review the evidence of postdonation hypertension prevalence, mechanisms, treatment, and complications.
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8
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Veiras LC, McFarlin BE, Ralph DL, Buncha V, Prescott J, Shirvani BS, McDonough JC, Ha D, Giani J, Gurley SB, Mamenko M, McDonough AA. Electrolyte and transporter responses to angiotensin II induced hypertension in female and male rats and mice. Acta Physiol (Oxf) 2020; 229:e13448. [PMID: 31994810 DOI: 10.1111/apha.13448] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 12/15/2022]
Abstract
AIM Sexual dimorphisms are evident along the nephron: Females (F) exhibit higher ratios of renal distal to proximal Na+ transporters' abundance, greater lithium clearance (CLi ) more rapid natriuresis in response to saline infusion and lower plasma [K+ ] vs. males (M). During angiotensin II infusion hypertension (AngII-HTN) M exhibit distal Na+ transporter activation, lower proximal and medullary loop transporters, blunted natriuresis in response to saline load, and reduced plasma [K+ ]. This study aimed to determine whether responses of F to AngII-HTN mimicked those in M or were impacted by sexual dimorphisms evident at baseline. METHODS Sprague Dawley rats and C57BL/6 mice were AngII infused via osmotic minipumps 2 and 3 weeks, respectively, and assessed by metabolic cage collections, tail-cuff sphygmomanometer, semi-quantitative immunoblotting of kidney and patch-clamp electrophysiology. RESULTS In F rats, AngII-infusion increased BP to 190 mm Hg, increased phosphorylation of cortical NKCC2, NCC and cleavage of ENaC two to threefold, increased ENaC channel activity threefold and aldosterone 10-fold. K+ excretion increased and plasma [K+ ] decreased. Evidence of natriuresis in F included increased urine Na+ excretion and CLi , and decreased medullary NHE3, NKCC2 and Na,K-ATPase abundance. In C57BL/6 mice, AngII-HTN increased abundance of distal Na+ transporters, suppressed proximal-medullary transporters and reduced plasma [K+ ] in both F and M. CONCLUSION Despite baseline sexual dimorphisms, AngII-HTN provokes similar increases in BP, aldosterone, distal transporters, ENaC channel activation and K+ loss accompanied by similar suppression of proximal and loop Na+ transporters, natriuresis and diuresis in females and males.
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Affiliation(s)
- Luciana C. Veiras
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
- Department of Biomedical Sciences Cedars‐Sinai Medical Center Los Angeles CA USA
| | - Brandon E. McFarlin
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Donna L. Ralph
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Vadym Buncha
- Department of Physiology Medical College of Georgia at Augusta University Augusta GA USA
| | - Jessica Prescott
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Borna S. Shirvani
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Jillian C. McDonough
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Darren Ha
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
| | - Jorge Giani
- Department of Biomedical Sciences Cedars‐Sinai Medical Center Los Angeles CA USA
| | - Susan B. Gurley
- Division of Nephrology and Hypertension Oregon Health and Science University Portland OR USA
| | - Mykola Mamenko
- Department of Physiology Medical College of Georgia at Augusta University Augusta GA USA
| | - Alicia A. McDonough
- Department of Physiology and Neuroscience Keck School of Medicine of USC Los Angeles CA USA
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Kumar V, Yang C, Cowley AW. Temporal Expression and Cellular Localization of PAPPA2 in the Developing Kidney of Rat. J Histochem Cytochem 2020; 68:209-222. [PMID: 31989854 DOI: 10.1369/0022155420904478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PAPPA2 is a metalloproteinase which cleaves insulin-like growth factor binding protein (IGFBP)-3 and IGFBP-5, and its role in pregnancy and postnatal growth is primarily studied. Using exclusion mapping, we reported a subcongenic (26-P) rat where a 0.71-Mbp region containing the pregnancy-associated plasma protein a2 (Pappa2) allele of salt-insensitive Brown Norway (BN) was introgressed into Dahl saltsensitive (SS) genetic background, resulting in the reduction of salt sensitivity. Pappa2 was differentially expressed in the adult kidney of 26-P and SS rats. Here, the expression and cellular localization of Pappa2 in embryonic and postnatal kidneys of 26-P and SS rats were examined. Pappa2 mRNA expression was 5-fold higher in the embryonic kidney (day 20.5) of the 26-P rat compared with the SS rat. Pappa2 mRNA expression progressively increased with the development of kidney, reaching a peak at postnatal day 5 before trending downward in subsequent stages of development in both strains. At all tested time points, Pappa2 remained higher in the 26-P compared with the SS rat kidney. Immunohistochemistry studies localized PAPPA2 in the ureteric bud (UB) and distal part of S-shaped body. PAPPA2 was colocalized with IGFBP-5 in the UB and Na+/K+/2Cl- cotransporter-stained tubules, respectively. Future studies are needed to determine the role of Pappa2 in kidney development and mechanistic pathways involved in this process.
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Affiliation(s)
- Vikash Kumar
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Chun Yang
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Allen W Cowley
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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Holscher CM, Haugen CE, Jackson KR, Garonzik Wang JM, Waldram MM, Bae S, Locke JE, Reed RD, Lentine KL, Gupta G, Weir MR, Friedewald JJ, Verbesey J, Cooper M, Segev DL, Massie AB. Self-Reported Incident Hypertension and Long-Term Kidney Function in Living Kidney Donors Compared with Healthy Nondonors. Clin J Am Soc Nephrol 2019; 14:1493-1499. [PMID: 31537534 PMCID: PMC6777600 DOI: 10.2215/cjn.04020419] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/31/2019] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND OBJECTIVES The risk of hypertension attributable to living kidney donation remains unknown as does the effect of developing postdonation hypertension on subsequent eGFR. We sought to understand the association between living kidney donation, hypertension, and long-term eGFR by comparing donors with a cohort of healthy nondonors. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We compared 1295 living kidney donors with median 6 years of follow-up with a weighted cohort of 8233 healthy nondonors. We quantified the risk of self-reported hypertension using a parametric survival model. We examined the association of hypertension with yearly change in eGFR using multilevel linear regression and clustering by participant, with an interaction term for race. RESULTS Kidney donation was independently associated with a 19% higher risk of hypertension (adjusted hazard ratio, 1.19; 95% confidence interval, 1.01 to 1.41; P=0.04); this association did not vary by race (interaction P=0.60). For white and black nondonors, there was a mean decline in eGFR (-0.4 and -0.3 ml/min per year, respectively) that steepened after incident hypertension (-0.8 and -0.9 ml/min per year, respectively; both P<0.001). For white and black kidney donors, there was a mean increase in eGFR after donation (+0.4 and +0.6 ml/min per year, respectively) that plateaued after incident hypertension (0 and -0.2 ml/min per year, respectively; P=0.07 and P=0.01, respectively, after hypertension). CONCLUSIONS Kidney donors are at higher risk of hypertension than similar healthy nondonors, regardless of race. Donors who developed hypertension had a plateau in the usual postdonation increase of eGFR.
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Affiliation(s)
- Courtenay M Holscher
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Christine E Haugen
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Kyle R Jackson
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Madeleine M Waldram
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sunjae Bae
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Jayme E Locke
- Comprehensive Transplant Institute, University of Alabama at Birmingham, Birmingham, Alabama
| | - Rhiannon D Reed
- Comprehensive Transplant Institute, University of Alabama at Birmingham, Birmingham, Alabama
| | - Krista L Lentine
- Saint Louis University Center for Abdominal Transplantation, St. Louis, Missouri
| | - Gaurav Gupta
- Department of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Matthew R Weir
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - John J Friedewald
- Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; and
| | - Jennifer Verbesey
- MedStar Georgetown Transplant Institute, MedStar Georgetown University Hospital, Washington, DC
| | - Matthew Cooper
- MedStar Georgetown Transplant Institute, MedStar Georgetown University Hospital, Washington, DC
| | - Dorry L Segev
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland; .,Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Allan B Massie
- Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland
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Basta M, Dief AE, Ghareeb DA, Saleh SR, Elshorbagy A, El Eter E. Resveratrol ameliorates long-term structural, functional and metabolic perturbations in a rat model of donor nephrectomy: Implication of SIRT1. J Funct Foods 2019. [DOI: 10.1016/j.jff.2019.04.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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12
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Resveratrol ameliorates long-term structural, functional and metabolic perturbations in a rat model of donor nephrectomy: Implication of SIRT1. J Funct Foods 2019. [DOI: 10.1016/j.jff.2019.04.043\] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Renal injury after uninephrectomy in male and female intrauterine growth-restricted aged rats. PLoS One 2019; 14:e0213404. [PMID: 30845173 PMCID: PMC6405063 DOI: 10.1371/journal.pone.0213404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 02/20/2019] [Indexed: 12/24/2022] Open
Abstract
Epidemiological studies report an inverse association between birth weight and risk for kidney disease that may differ between males and females, but studies investigating this association are limited. This study tested the hypothesis that male intrauterine growth-restricted offspring in a model of low birth weight induced by placental insufficiency in the rat exhibit enhanced renal injury in response to a persistent secondary renal insult while female growth-restricted offspring are protected. For this study, control offspring from sham-operated dams and growth-restricted offspring from reduced uterine perfusion dams underwent uninephrectomy or a sham procedure at 18 months of age. One month later, urinary markers of renal injury, renal function, and histological damage were measured. Results were analyzed using 2-way ANOVA. Male and female offspring were assessed separately. Proteinuria and urinary neutrophil gelatinase-associated lipocalin were significantly elevated in male growth-restricted offspring exposed to uninephrectomy when compared to male uninephrectomized control. Urinary kidney injury marker-1 was elevated in male uninephrectomized growth-restricted offspring relative to male sham growth-restricted but not to male uninephrectomized controls. Likewise, urinary neutrophil gelatinase-associated lipocalin was elevated in female uninephrectomized growth-restricted offspring but only when compared to female sham growth-restricted offspring. Markers of renal function including glomerular filtration rate and serum creatinine were impaired after uninephrectomy in female offspring regardless of birth weight. Histological parameters did not differ between control and growth-restricted offspring. Collectively, these studies suggest that both male and female growth-restricted offspring demonstrate susceptibility to renal injury following uninephrectomy; however, only male growth-restricted offspring exhibited an increase in renal markers of injury in response to uninephrectomy relative to same-sex control counterparts. These findings further suggest that urinary excretion of protein, kidney injury marker-1, and neutrophil gelatinase-associated lipocalin may be early markers of kidney injury in growth-restricted offspring exposed to a secondary renal insult such as reduction in renal mass.
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14
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Pathogenic role of angiotensin II and the NF-κB system in a model of malignant hypertensive nephrosclerosis. Hypertens Res 2019; 42:779-789. [PMID: 30809002 DOI: 10.1038/s41440-019-0226-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/24/2018] [Accepted: 10/22/2018] [Indexed: 11/08/2022]
Abstract
We previously reported that rats treated with an NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), during lactation developed hypertension in adult life, without apparent functional or structural damage to kidneys, providing a new model of essential hypertension. Here, we investigated whether uninephrectomy associated with salt overload would unveil a latent renal dysfunction in this model, aggravating arterial hypertension and promoting renal injury. Male Munich-Wistar rat pups received PDTC from maternal milk (PDTCLact) from 0 to 20 days after birth. Another group received no treatment during lactation. All offspring underwent uninephrectomy (UNx) at 10 weeks of age and then were subdivided into NS, receiving a normal salt (0.5% Na+) diet, PDTCLact + NS, HS, receiving a high-salt diet (2% Na+ chow + 0.5% saline to drink), and PDTCLact+HS. Twelve weeks later, HS rats were moderately hypertensive with mild albuminuria and renal injury. In contrast, severe hypertension, glomerulosclerosis, and cortical collagen deposition were prominent in PDTCLact + HS animals, along with "onion-skin" arteriolar lesions, evidence of oxidative stress and intense renal infiltration by macrophages, and lymphocytes and angiotensin II-positive cells, contrasting with low circulating renin. The NF-κB pathway was also activated. In a separate set of PDTCLact+HS rats, Losartan treatment prevented NF-κB activation and strongly attenuated glomerular injury, cortical fibrosis, and renal inflammation. NF-κB activity during late nephrogenesis is essential for the kidneys to properly maintain sodium homeostasis in adult life. Paradoxically, this same system contributed to renal injury resembling that caused by malignant hypertension when renal dysfunction caused by its inhibition during lactation was unmasked by uninephrectomy associated with HS.
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15
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Pillai SM, Seebeck P, Fingerhut R, Huang J, Ming XF, Yang Z, Verrey F. Kidney Mass Reduction Leads to l-Arginine Metabolism-Dependent Blood Pressure Increase in Mice. J Am Heart Assoc 2018; 7:JAHA.117.008025. [PMID: 29478971 PMCID: PMC5866334 DOI: 10.1161/jaha.117.008025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background Uninephrectomy (UNX) is performed for various reasons, including kidney cancer or donation. Kidneys being the main site of l‐arginine production in the body, we tested whether UNX mediated kidney mass reduction impacts l‐arginine metabolism and thereby nitric oxide production and blood pressure regulation in mice. Methods and Results In a first series of experiments, we observed a significant increase in arterial blood pressure 8 days post‐UNX in female and not in male mice. Further experimental series were performed in female mice, and the blood pressure increase was confirmed by telemetry. l‐citrulline, that is used in the kidney to produce l‐arginine, was elevated post‐UNX as was also asymmetric dimethylarginine, an inhibitor of nitric oxide synthase that competes with l‐arginine and is a marker for renal failure. Interestingly, the UNX‐induced blood pressure increase was prevented by supplementation of the diet with 5% of the l‐arginine precursor, l‐citrulline. Because l‐arginine is metabolized in the kidney and other peripheral tissues by arginase‐2, we tested whether the lack of this metabolic pathway also compensates for decreased l‐arginine production in the kidney and/or for local nitric oxide synthase inhibition and consecutive blood pressure increase. Indeed, upon uninephrectomy, arginase‐2 knockout mice (Arg‐2−/−) neither displayed an increase in asymmetric dimethylarginine and l‐citrulline plasma levels nor a significant increase in blood pressure. Conclusions UNX leads to a small increase in blood pressure that is prevented by l‐citrulline supplementation or arginase deficiency, 2 measures that appear to compensate for the impact of kidney mass reduction on l‐arginine metabolism.
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Affiliation(s)
- Samyuktha Muralidharan Pillai
- Institute of Physiology, Zurich Center for Integrative Human Physiology (ZIHP) and NCCR Kidney.CH, University of Zurich, Switzerland
| | - Petra Seebeck
- Zurich Integrative Rodent Physiology (ZIRP), University of Zurich, Switzerland
| | - Ralph Fingerhut
- Swiss Newborn Screening Laboratory, Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Ji Huang
- Division of Physiology, Department of Medicine, Faculty of Science and NCCR Kidney.CH, University of Fribourg, Switzerland
| | - Xiu-Fen Ming
- Division of Physiology, Department of Medicine, Faculty of Science and NCCR Kidney.CH, University of Fribourg, Switzerland
| | - Zhihong Yang
- Division of Physiology, Department of Medicine, Faculty of Science and NCCR Kidney.CH, University of Fribourg, Switzerland
| | - François Verrey
- Institute of Physiology, Zurich Center for Integrative Human Physiology (ZIHP) and NCCR Kidney.CH, University of Zurich, Switzerland
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16
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Veiras LC, Girardi ACC, Curry J, Pei L, Ralph DL, Tran A, Castelo-Branco RC, Pastor-Soler N, Arranz CT, Yu ASL, McDonough AA. Sexual Dimorphic Pattern of Renal Transporters and Electrolyte Homeostasis. J Am Soc Nephrol 2017; 28:3504-3517. [PMID: 28774999 PMCID: PMC5698077 DOI: 10.1681/asn.2017030295] [Citation(s) in RCA: 186] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/20/2017] [Indexed: 12/30/2022] Open
Abstract
Compared with males, females have lower BP before age 60, blunted hypertensive response to angiotensin II, and a leftward shift in pressure natriuresis. This study tested the concept that this female advantage associates with a distinct sexual dimorphic pattern of transporters along the nephron. We applied quantitative immunoblotting to generate profiles of transporters, channels, claudins, and selected regulators in both sexes and assessed the physiologic consequences of the differences. In rats, females excreted a saline load more rapidly than males did. Compared with the proximal tubule of males, the proximal tubule of females had greater phosphorylation of Na+/H+ exchanger isoform 3 (NHE3), distribution of NHE3 at the base of the microvilli, and less abundant expression of Na+/Pi cotransporter 2, claudin-2, and aquaporin 1. These changes associated with less bicarbonate reabsorption and higher lithium clearance in females. The distal nephrons of females had a higher abundance of total and phosphorylated Na+/Cl- cotransporter (NCC), claudin-7, and cleaved forms of epithelial Na+ channel (ENaC) α and γ subunits, which associated with a lower baseline plasma K+ concentration. A K+-rich meal increased the urinary K+ concentration and decreased the level of renal phosphorylated NCC in females. Notably, we observed similar abundance profiles in female versus male C57BL/6 mice. These results define sexual dimorphic phenotypes along the nephron and suggest that lower proximal reabsorption in female rats expedites excretion of a saline load and enhances NCC and ENaC abundance and activation, which may facilitate K+ secretion and set plasma K+ at a lower level.
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Affiliation(s)
| | | | - Joshua Curry
- Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | - Lei Pei
- Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
| | | | - An Tran
- Department of Integrative Anatomical Sciences and
| | - Regiane C Castelo-Branco
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil; and
| | - Nuria Pastor-Soler
- Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Cristina T Arranz
- University of Buenos Aires, National Council of Science and Technology, Buenos Aires, Argentina
| | - Alan S L Yu
- Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas
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17
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Altmann U, Böger CA, Farkas S, Mack M, Luchner A, Hamer OW, Zeman F, Debl K, Fellner C, Jungbauer C, Banas B, Buchner S. Effects of Reduced Kidney Function Because of Living Kidney Donation on Left Ventricular Mass. Hypertension 2017; 69:297-303. [DOI: 10.1161/hypertensionaha.116.08175] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 07/29/2016] [Accepted: 12/05/2016] [Indexed: 11/16/2022]
Abstract
Living kidney donation is associated with a small but significant increase in cardiovascular mortality. In addition, mildly decreased kidney function is associated with an increase of left ventricular mass and with cardiovascular disease in patients with chronic kidney disease. To investigate this association, we evaluated the impact of mildly decreased kidney function after living kidney donation on subclinical cardiac structural and functional changes. In this prospective cohort study, cardiac and renal magnetic resonance imaging and laboratory analyses were performed in 23 living kidney donors (mean age 54±10 years, 52% male) before donation and at 4 and 12 months after nephrectomy. Mean estimated glomerular filtration rate was 102±15 mL min
−1
1.73 m
−2
before donation and 70±13 mL min
−1
1.73 m
−2
at 12 months (
P
<0.001). Left ventricular mass increased from 112±22 to 115±23 g (
P
<0.001). In addition, heart rate was significantly increased (65±7 to 74±14;
P
=0.04). Concurrently, kidney and adrenal gland volume increased from 163±33 to 195±34 mL (
P
<0.001) and from 7.6±2.2 to 8.4±2.4 mL (
P
=0.032), respectively, as did procollagen type III (Δ0.11 ng/mL,
P
<0.001) and not N-terminal probrain natriuretic peptide (Δ14 pg/mL,
P
=0.25). The mild decrease in kidney function after living kidney donation leads to a significant but clinically negligible increase in left ventricular mass 12 months after living kidney donation. This study of a longitudinal analysis of living kidney donors provides direct evidence of a kidney–heart link.
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Affiliation(s)
- Ursula Altmann
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Carsten A. Böger
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Stefan Farkas
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Matthias Mack
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Andreas Luchner
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Okka W. Hamer
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Florian Zeman
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Kurt Debl
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Claudia Fellner
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Carsten Jungbauer
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Bernhard Banas
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
| | - Stefan Buchner
- From the Klinik und Poliklinik für Innere Medizin II (U.A., A.L., K.D., C.J., S.B.), Abteilung für Nephrologie (C.A.B., M.M., B.B.), Klinik und Poliklinik für Chirurgie (S.F.), Institut für Röntgendiagnostik (O.W.H., C.F.), and Zentrum für klinische Studien, Biostatistics (F.Z.), Universitätsklinikum Regensburg, Germany
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18
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Wang X, Garrett MR. Nephron number, hypertension, and CKD: physiological and genetic insight from humans and animal models. Physiol Genomics 2017; 49:180-192. [PMID: 28130427 DOI: 10.1152/physiolgenomics.00098.2016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The kidneys play a vital role in the excretion of waste products and the regulation of electrolytes, maintenance of acid-base balance, regulation of blood pressure, and production of several hormones. Any alteration in the structure of the nephron (basic functional unit of the kidney) can have a major impact on the kidney's ability to work efficiently. Progressive decline in kidney function can lead to serious illness and ultimately death if not treated by dialysis or transplantation. While there have been numerous studies that implicate lower nephron numbers as being an important factor in influencing susceptibility to developing hypertension and chronic kidney disease, a direct association has been difficult to establish because of three main limitations: 1) the large variation in nephron number observed in the human population; 2) no established reliable noninvasive methods to determine nephron complement; and 3) to date, nephron measurements have been done after death, which doesn't adequately account for potential loss of nephrons with age or disease. In this review, we will provide an overview of kidney structure/function, discuss the current literature for both humans and other species linking nephron deficiency and cardio-renal complications, as well as describe the major molecular signaling factors involved in nephrogenesis that modulate variation in nephron number. As more detailed knowledge about the molecular determinants of nephron development and the role of nephron endowment in the cardio-renal system is obtained, it will hopefully provide clinicians the ability to accurately identify people at risk to develop CKD/hypertension and lead to a shift in patient care from disease treatment to prevention.
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Affiliation(s)
- Xuexiang Wang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Michael R Garrett
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and .,Department of Medicine (Nephrology) and Pediatrics (Genetics), University of Mississippi Medical Center, Jackson, Mississippi
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19
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Compensatory renal hypertrophy and the handling of an acute nephrotoxicant in a model of aging. Exp Gerontol 2016; 75:16-23. [PMID: 26768998 DOI: 10.1016/j.exger.2016.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/17/2015] [Accepted: 01/02/2016] [Indexed: 11/21/2022]
Abstract
Aging often results in progressive losses of functioning nephrons, which can lead to a significant reduction in overall renal function. Because of age-related pathological changes, the remaining functional nephrons within aged kidneys may be unable to fully counteract physiological and/or toxicological challenges. We hypothesized that when the total functional renal mass of aged rats is reduced by 50%, the nephrons within the remnant kidney do not fully undergo the functional and physiological changes that are necessary to maintain normal fluid and solute homeostasis. We also tested the hypothesis that the disposition and handling of a nephrotoxicant are altered significantly in aged kidneys following an acute, 50% reduction in functional renal mass. To test these hypotheses, we examined molecular indices of renal cellular hypertrophy and the disposition of inorganic mercury (Hg(2+)), a model nephrotoxicant, in young control, young uninephrectomized (NPX), aged control and aged NPX Wistar rats. We found that the process of aging reduces the ability of the remnant kidney to undergo compensatory renal growth. In addition, we found that an additional reduction in renal mass in aged animals alters the disposition of Hg(2+) and potentially alters the risk of renal intoxication by this nephrotoxicant. To our knowledge, this study represents the first report of the handling of a nephrotoxicant in an aged animal following a 50% reduction in functional renal mass.
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20
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Lankadeva YR, Singh RR, Tare M, Moritz KM, Denton KM. Loss of a kidney during fetal life: long-term consequences and lessons learned. Am J Physiol Renal Physiol 2014; 306:F791-800. [PMID: 24500691 DOI: 10.1152/ajprenal.00666.2013] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Epidemiological studies reveal that children born with a solitary functioning kidney (SFK) have a greater predisposition to develop renal insufficiency and hypertension in early adulthood. A congenital SFK is present in patients with unilateral renal agenesis or unilateral multicystic kidney dysplasia, leading to both structural and functional adaptations in the remaining kidney, which act to mitigate the reductions in glomerular filtration rate and sodium excretion that would otherwise ensue. To understand the mechanisms underlying the early development of renal insufficiency in children born with a SFK, we established a model of fetal uninephrectomy (uni-x) in sheep, a species that similar to humans complete nephrogenesis before birth. This model results in a 30% reduction in nephron number rather than 50%, due to compensatory nephrogenesis in the remaining kidney. Similar to children with a congenital SFK, uni-x sheep demonstrate a progressive increase in arterial pressure and a loss of renal function with aging. This review summarizes the compensatory changes in renal hemodynamics and tubular sodium handling that drive impairments in renal function and highlights the existence of sex differences in the functional adaptations following the loss of a kidney during fetal life.
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21
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Tsukamoto Y, Mano T, Sakata Y, Ohtani T, Takeda Y, Tamaki S, Omori Y, Ikeya Y, Saito Y, Ishii R, Higashimori M, Kaneko M, Miwa T, Yamamoto K, Komuro I. A novel heart failure mice model of hypertensive heart disease by angiotensin II infusion, nephrectomy, and salt loading. Am J Physiol Heart Circ Physiol 2013; 305:H1658-67. [DOI: 10.1152/ajpheart.00349.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Although the mouse heart failure (HF) model of hypertensive heart disease (HHD) is useful to investigate the pathophysiology and new therapeutic targets for HHD, the model using simple experimental procedures and stable phenotypes has not been established. This study aimed to develop a novel mouse HF model of HHD by combining salt loading and uninephrectomy with ANG II infusion. Eight-week-old C57BL/6 male mice were treated with ANG II infusion (AT), ANG II infusion and uninephrectomy (AN), ANG II infusion and salt loading (AS), or ANG II infusion, uninephrectomy, and salt loading (ANS). Systolic blood pressure was significantly elevated and left ventricular (LV) hypertrophy was found in AT, AN, AS, and ANS mice, and there were no significant differences in those parameters between the four groups. At 6 wk after the procedures, only ANS mice showed significant decreases in LV fractional shortening and increases in lung weight with a high incidence. This phenotype was reproducible, and there were few perioperative or early deaths in the experimental procedures. Severe LV fibrosis was found in ANS mice. Oxidative stress was enhanced and small GTPase Rac1 activity was upregulated in the hearts of ANS mice. After the addition of salt loading and uninephrectomy to the ANG II infusion mouse model, cardiac function was significantly impaired, and mice developed HF. This might be a novel and useful mouse HF model to study the transition from compensated LV hypertrophy to HF in HHD.
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Affiliation(s)
- Yasumasa Tsukamoto
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
- Genome Information Research Center, Osaka University, Suita, Japan
| | - Toshiaki Mano
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
- Genome Information Research Center, Osaka University, Suita, Japan
| | - Yasushi Sakata
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Tomohito Ohtani
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yasuharu Takeda
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Shunsuke Tamaki
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
- Genome Information Research Center, Osaka University, Suita, Japan
| | - Yosuke Omori
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
- Genome Information Research Center, Osaka University, Suita, Japan
| | - Yukitoshi Ikeya
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
- Division of Cardiology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Yuki Saito
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
- Division of Cardiology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Ryohei Ishii
- Department of Mechanical Engineering, Osaka University, Suita, Japan; and
| | | | - Makoto Kaneko
- Department of Mechanical Engineering, Osaka University, Suita, Japan; and
| | - Takeshi Miwa
- Genome Information Research Center, Osaka University, Suita, Japan
| | - Kazuhiro Yamamoto
- Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Issei Komuro
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
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23
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