1
|
Panda DK, Bai X, Zhang Y, Stylianesis NA, Koromilas AE, Lipman ML, Karaplis AC. SCF-SKP2 E3 ubiquitin ligase links mTORC1/ER stress/ISR with YAP activation in murine renal cystogenesis. J Clin Invest 2022; 132:153943. [PMID: 36326820 PMCID: PMC9754004 DOI: 10.1172/jci153943] [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: 08/09/2021] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
The Hippo pathway nuclear effector Yes-associated protein (YAP) potentiates the progression of polycystic kidney disease (PKD) arising from ciliopathies. The mechanisms underlying the increase in YAP expression and transcriptional activity in PKD remain obscure. We observed that in kidneys from mice with juvenile cystic kidney (jck) ciliopathy, the aberrant hyperactivity of mechanistic target of rapamycin complex 1 (mTORC1), driven by ERK1/2 and PI3K/AKT cascades, induced ER proteotoxic stress. To reduce this stress by reprogramming translation, the protein kinase R-like ER kinase-eukaryotic initiation factor 2α (PERK/eIF2α) arm of the integrated stress response (ISR) was activated. PERK-mediated phosphorylation of eIF2α drove the selective translation of activating transcription factor 4 (ATF4), potentiating YAP expression. In parallel, YAP underwent K63-linked polyubiquitination by SCF S-phase kinase-associated protein 2 (SKP2) E3 ubiquitin ligase, a Hippo-independent, nonproteolytic ubiquitination that enhances YAP nuclear trafficking and transcriptional activity in cancer cells. Defective ISR cellular adaptation to ER stress in eIF2α phosphorylation-deficient jck mice further augmented YAP-mediated transcriptional activity and renal cyst growth. Conversely, pharmacological tuning down of ER stress/ISR activity and SKP2 expression in jck mice by administration of tauroursodeoxycholic acid (TUDCA) or tolvaptan impeded these processes. Restoring ER homeostasis and/or interfering with the SKP2-YAP interaction represent potential therapeutic avenues for stemming the progression of renal cystogenesis.
Collapse
Affiliation(s)
- Dibyendu K. Panda
- Division of Endocrinology and Metabolism, Department of Medicine, and Lady Davis Institute for Medical Research, Jewish General Hospital,,Division of Nephrology, Department of Medicine, and Lady Davis Institute for Medical Research, Jewish General Hospital
| | - Xiuying Bai
- Division of Endocrinology and Metabolism, Department of Medicine, and Lady Davis Institute for Medical Research, Jewish General Hospital
| | - Yan Zhang
- Division of Nephrology, Department of Medicine, and Lady Davis Institute for Medical Research, Jewish General Hospital
| | | | - Antonis E. Koromilas
- Gerald Bronfman Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.,Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Mark L. Lipman
- Division of Nephrology, Department of Medicine, and Lady Davis Institute for Medical Research, Jewish General Hospital
| | - Andrew C. Karaplis
- Division of Endocrinology and Metabolism, Department of Medicine, and Lady Davis Institute for Medical Research, Jewish General Hospital
| |
Collapse
|
2
|
Hadimeri H, Johansson AC, Haraldsson B, Nyberg G. Capd in Patients with Autosomal Dominant Polycystic Kidney Disease. Perit Dial Int 2020. [DOI: 10.1177/089686089801800414] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective To investigate whether there are specific complications to continuous ambulatory peritoneal dialysis (CAPD) in patients with autosomal dominant polycystic kidney disease (ADPKD) due to defects in various wall structures -causing hernia and diverticulitis -and to enlarged kidneys. Design The clinical experience of CAPD in 26 patients with ADPKD, treated for 11 ± 6 months, was studied in retrospect and compared with that of 26 contemporary controls. Medical records were reviewed with respect to survival in this treatment form and any complication. Peritoneal dialysis capacity (PDC), as measured in 21 ADPKD patients and 20 controls, was also evaluated. Setting University Hospital. Results Before initiation of CAPD, enlarged kidneys necessitated nephrectomy in 2 of 26 ADPKD patients; both cases were registered as preparation tor transplantation, not for CAPD. Survival in CAPD was similar in ADPKD patients and controls. Hernia was present in 4 ADPKD patients and 2 controls, and required transfer to hemodialysis in 1 patient from each group, temporarily. The incidence of peritonitis was 1 per 20 months in ADPKD patients versus 1 in 27 months in the controis, not significantly different. Peritonitis was caused by colonic bacteria in similar numbers. Residual renal function was 1.9 ± 2.1 mL/min per 1.73 m2 in ADPKD patients versus 1.9 ± 1.4 mL/min per 1.73 m2 in the controls. No difference was detected in any of the variables measured by PDC. Conclusion There were no specific problems related to ADPKD.
Collapse
|
3
|
Wang K, Zelnick LR, Chen Y, Hoofnagle AN, Watnick T, Seliger S, Kestenbaum B. Alterations of Proximal Tubular Secretion in Autosomal Dominant Polycystic Kidney Disease. Clin J Am Soc Nephrol 2019; 15:80-88. [PMID: 31628117 PMCID: PMC6946073 DOI: 10.2215/cjn.05610519] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 09/13/2019] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND OBJECTIVES In autosomal dominant polycystic kidney disease (ADPKD), the GFR often remains normal despite significant nephron loss. Proximal tubular secretory clearance may be reduced in ADPKD before detectable changes in GFR. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We used targeted mass spectrometry to quantify secretory solutes from blood and urine samples from 31 patients with ADPKD and preserved GFR (mean eGFR =111±11 ml/min per 1.73 m2) and 25 healthy control individuals as well as from 95 patients with ADPKD and reduced GFR (mean eGFR =53±21 ml/min per 1.73 m2) and 92 individuals with non-ADPKD CKD. We used linear regression to compare the fractional excretion of each solute between ADPKD and control groups. Among 112 patients with ADPKD, we used linear regression to determine associations of solute fractional excretion with height-adjusted total kidney volume. RESULTS After adjusting for demographics, clinical characteristics, and kidney function measures, the fractional excretions of three secretory solutes were lower in patients with ADPKD and preserved GFR compared with healthy individuals: 52% lower cinnamoylglycine excretion (95% confidence interval, 24% to 70%), 53% lower tiglylglycine excretion (95% confidence interval, 23% to 71%), and 91% lower xanthosine excretion (95% confidence interval, 83% to 95%). In addition to lower excretions of tiglylglycine and xanthosine, patients with ADPKD and reduced GFR also demonstrated 37% lower dimethyluric acid excretion (95% confidence interval, 21% to 50%), 58% lower hippurate excretion (95% confidence interval, 48% to 66%), 48% lower isovalerylglycine excretion (95% confidence interval, 37% to 56%), and 31% lower pyridoxic acid excretion (95% confidence interval, 16% to 42%) compared with patients with non-ADPKD CKD and comparable eGFR. Among patients with ADPKD, solute fractional excretions were not associated with differences in kidney volume. CONCLUSIONS Patients with ADPKD and preserved and reduced GFR demonstrate lower tubular secretory solute excretion compared with healthy controls and patients with non-ADPKD CKD. Our results suggest that tubular secretion is impaired in ADPKD independent of GFR.
Collapse
Affiliation(s)
- Ke Wang
- Division of Nephrology, Department of Medicine and .,Division of Nephrology, Kidney Research Institute, Kidney Research Institute, Seattle, Washington; and
| | - Leila R Zelnick
- Division of Nephrology, Department of Medicine and.,Division of Nephrology, Kidney Research Institute, Kidney Research Institute, Seattle, Washington; and
| | - Yan Chen
- Division of Nephrology, Kidney Research Institute, Kidney Research Institute, Seattle, Washington; and.,Departments of Epidemiology and
| | - Andrew N Hoofnagle
- Division of Nephrology, Kidney Research Institute, Kidney Research Institute, Seattle, Washington; and.,Laboratory Medicine, University of Washington, Seattle, Washington
| | - Terry Watnick
- Division of Nephrology, Department of Medicine, University of Maryland, Baltimore, Maryland
| | - Stephen Seliger
- Division of Nephrology, Department of Medicine, University of Maryland, Baltimore, Maryland
| | - Bryan Kestenbaum
- Division of Nephrology, Department of Medicine and.,Division of Nephrology, Kidney Research Institute, Kidney Research Institute, Seattle, Washington; and
| |
Collapse
|
4
|
Zacchia M, Di Iorio V, Trepiccione F, Caterino M, Capasso G. The Kidney in Bardet-Biedl Syndrome: Possible Pathogenesis of Urine Concentrating Defect. KIDNEY DISEASES 2017; 3:57-65. [PMID: 28868293 DOI: 10.1159/000475500] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/05/2017] [Indexed: 12/16/2022]
Abstract
BACKGROUND The ciliopathies are a growing number of disorders caused by mutations in genes involved in the function of the primary cilium. Bardet-Biedl syndrome (BBS) belongs to this group of disorders. In this setting, kidney dysfunction is highly variable, and urine concentrating defect, a common feature of multiple ciliopathies, has been described as the most frequent defect. Here we review the mechanism of urine concentration and describe the possible mechanism underling this defect in ciliopathies and especially BBS, based on the current body of literature. SUMMARY Active Na+ absorption along the thick ascending limb of the loop of Henle (TAL) is critical for generating the corticomedullary osmotic gradient, and the countercurrent anatomical arrangement of the 2 branches of the loop of Henle enhances this gradient. The vasa recta, paralleling the loop of Henle, operate into the countercurrent mechanism, minimizing washout of solutes from the interstitium. Final water reabsorption is mediated by the aquaporin 2 (AQP2) water channels along the distal nephron, and it is under hormonal control. Several studies demonstrated that hyposthenuria in BBS patients relies on kidney resistance to desmopressin, suggesting a renal origin. We recently showed that the majority of hyposthenuric BBS patients have also a defect regarding maximal urine dilution. Independent studies showed that BBS10 deficiency caused AQP2 mistrafficking in vitro; accordingly, we demonstrated impaired urinary AQP2 excretion in BBS patients with combined concentrating and diluting defect. Whether receptor signaling pathways or downstream events cause AQP2 deregulation is still unclear. In addition, reduced urinary uromodulin excretion in BBS patients opens the possibility that TAL dysfunction may also play a pathogenic role. KEY MESSAGE Impaired water handling in BBS is associated with AQP2 mistrafficking. The potential role of additional factors, such as the dissipation of the medullary osmotic gradient due to TAL dysfunction and/or structural anomalies, remains to be elucidated.
Collapse
Affiliation(s)
- Miriam Zacchia
- Division of Nephrology, Department of Cardiothoracic and Respiratory Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical, and Dental Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Francesco Trepiccione
- Division of Nephrology, Department of Cardiothoracic and Respiratory Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Marianna Caterino
- Department of Molecular Biology and Medical Biotechnologies, Università degli Studi di Napoli "Federico II," Naples, Italy
| | - Giovambattista Capasso
- Division of Nephrology, Department of Cardiothoracic and Respiratory Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| |
Collapse
|
5
|
Grantham JJ. Rationale for early treatment of polycystic kidney disease. Pediatr Nephrol 2015; 30:1053-62. [PMID: 25022529 DOI: 10.1007/s00467-014-2882-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/29/2014] [Accepted: 06/05/2014] [Indexed: 12/12/2022]
Abstract
In hereditary cystic disorders, renal injury begins with the formation of the first cyst. Renal injury may manifest as large kidneys, abdominal pain, hypertension and hematuria in children and young adults with autosomal dominant polycystic kidney disease (ADPKD). In autosomal recessive PKD (ARPKD) and ADPKD, cysts form primarily in collecting ducts and expand progressively. Collecting duct cysts that block urine flow have the potential to block urine formation in large numbers of upstream nephrons. In an ARPKD rat congenitally lacking vasopressin, only a few cysts developed until exogenous arginine vasopressin (AVP) was administered. AVP elevates cyclic AMP in vulnerable tubule cells to stimulate mitogenesis and fluid secretion, thereby causing cysts to form and enlarge indefinitely. The administration of an AVP-V2 receptor inhibitor or the consumption of sufficient water to persistently lower plasma AVP levels will ameliorate disease progression. Renal volume measurements provide the most reliable way to forecast long-term outcome in individual children and adult patients with ADPKD. Many drugs that have demonstrated efficacy in small clinical trials, preclinical trials and cell-based studies are in the treatment pipeline. Counseling, regular exercise, limitation of dietary calories, salt, protein and fat, increased fluid intake throughout the day and treatment of hypertension are components of a rational treatment program that can be offered at an early age to those with, or at risk for developing PKD.
Collapse
Affiliation(s)
- Jared J Grantham
- The Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS, 66160, USA,
| |
Collapse
|
6
|
Sas KM, Yin H, Fitzgibbon WR, Baicu CF, Zile MR, Steele SL, Amria M, Saigusa T, Funk J, Bunni MA, Siegal GP, Siroky BJ, Bissler JJ, Bell PD. Hyperglycemia in the absence of cilia accelerates cystogenesis and induces renal damage. Am J Physiol Renal Physiol 2015; 309:F79-87. [PMID: 25904703 DOI: 10.1152/ajprenal.00652.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/15/2015] [Indexed: 12/11/2022] Open
Abstract
In polycystic kidney disease (PKD), the rate of cyst formation and disease progression is highly variable. The lack of predictability in disease progression may be due to additional environmental factors or pathophysiological processes called "third hits." Diabetes is a growing epidemic, and recent studies suggest that PKD patients may be at an increased risk for this disease. We sought to determine if hyperglycemia enhances the initiation and rate of cystogenesis. Tamoxifen was administered to adult Ift88 conditional floxed allele mice to induce cilia loss in the presence of Cre. Subsequent administration of streptozotocin resulted in equivalent hyperglycemia in cilia(+) and cilia(-) mice. Hyperglycemia with loss of cilia increased the rate of cyst formation and cell proliferation. Structural and functional alterations in the kidney, including focal glomerular foot process effacement, interstitial inflammation, formation of primitive renal tubules, polyuria, and increased proteinuria, were also observed in hyperglycemic cilia(-) mice. Gene array analysis indicated enhanced Wnt and epithelial-to-mesenchymal transition signaling in the kidney of hyperglycemic cilia(-) mice. These data show that hyperglycemia, in the absence of cilia, results in renal structural and functional damage and accelerates cystogenesis, suggesting that diabetes is a risk factor in the progression of PKD.
Collapse
Affiliation(s)
- Kelli M Sas
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina;
| | - Hong Yin
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Wayne R Fitzgibbon
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Catalin F Baicu
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Michael R Zile
- Ralph H. Johnson Veterans Administration Medical Center, Charleston, South Carolina; Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stacy L Steele
- Ralph H. Johnson Veterans Administration Medical Center, Charleston, South Carolina; Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - May Amria
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Takamitsu Saigusa
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Jason Funk
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Marlene A Bunni
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Gene P Siegal
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama; and Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Brian J Siroky
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - John J Bissler
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - P Darwin Bell
- Ralph H. Johnson Veterans Administration Medical Center, Charleston, South Carolina; Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| |
Collapse
|
7
|
Bichet DG. A defect in vasopressin secretion in autosomal dominant polycystic kidney disease. Kidney Int 2014; 82:1051-3. [PMID: 23128116 DOI: 10.1038/ki.2012.271] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A nephrogenic defect in urine concentration is well established in patients with polycystic kidney disease, but Ho et al. report a defect in the increase of plasma vasopressin in response to dehydration. On a cellular level, transient receptor potential channels responsible for osmoperception could interact with TRPPs encoded by the polycystic genes PKD1 and PKD2.
Collapse
Affiliation(s)
- Daniel G Bichet
- Department of Physiology and Medicine, Hôpital du Sacré-Coeur, Université de Montréal, Montréal, Canada
| |
Collapse
|
8
|
Rinschen MM, Schermer B, Benzing T. Vasopressin-2 receptor signaling and autosomal dominant polycystic kidney disease: from bench to bedside and back again. J Am Soc Nephrol 2014; 25:1140-7. [PMID: 24556353 PMCID: PMC4033383 DOI: 10.1681/asn.2013101037] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Blockade of the vasopressin-2 receptor (V2R) in the kidney has recently emerged as a promising therapeutic strategy in autosomal dominant polycystic kidney disease. The pathophysiologic basis of V2R-dependent cyst proliferation and disease progression, however, is not fully understood. Recent evidence suggests that polycystic kidney disease is characterized by defects in urinary concentrating mechanisms and subsequent deregulation of vasopressin excretion by the neurohypophysis. On the cellular level, several recent studies revealed unexpected crosstalk of signaling pathways downstream of V2R activation in the kidney epithelium. This review summarizes some of the unexpected roles of V2R signaling and suggests that vasopressin signaling itself may contribute crucially to loss of polarity and enhanced proliferation in cystic kidney epithelium.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, and
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, and Systems Biology of Aging Cologne, University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, and Systems Biology of Aging Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
9
|
Higashihara E, Nutahara K, Tanbo M, Hara H, Miyazaki I, Kobayashi K, Nitatori T. Does increased water intake prevent disease progression in autosomal dominant polycystic kidney disease? Nephrol Dial Transplant 2014; 29:1710-9. [PMID: 24739484 PMCID: PMC4145867 DOI: 10.1093/ndt/gfu093] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The clinical effects of increased water intake on autosomal dominant polycystic kidney disease (ADPKD) progression are unknown. METHODS ADPKD patients with creatinine clearance ≧ 50 mL/min/1.73 m(2) were divided into high (H-, n = 18) and free (F-, n = 16) water-intake groups, mainly according to their preference. Prior to the study, 30 patients underwent annual evaluation of total kidney volume (TKV) and 24-h urine for an average of 33 months. During the 1-year study period, TKV and 24-h urine were analyzed at the beginning and end of the study and every 4 months, respectively. RESULTS During the pre-study period, urine volume (UV) in the H-group was higher (P = 0.034), but TKV and kidney function and their slopes were not significantly different between the two groups. After the study commenced, UV further increased (P < 0.001) in the H-group but not in the F-group. During the study period, TKV and kidney function slopes were not significantly different between the two groups (primary endpoint). Plasma copeptin was lower (P = 0.024) in the H-group than in the F-group. TKV and kidney function slopes became worse (P = 0.047 and 0.011, respectively) after high water intake (H-group) but not in the F-group. High UV was associated with increased urine sodium, and urine sodium positively correlated with the % TKV slope (P = 0.014). CONCLUSIONS Although the main endpoint was not significant, high water intake enhanced disease progression in the H-group when compared with the pre-study period. These findings necessitate a long-term randomized study before drawing a final conclusion.
Collapse
Affiliation(s)
- Eiji Higashihara
- Department of ADPKD Research, Kyorin University School of Medicine, Tokyo, Japan Department of Urology, Kyorin University School of Medicine, Tokyo, Japan
| | - Kikuo Nutahara
- Department of Urology, Kyorin University School of Medicine, Tokyo, Japan
| | - Mitsuhiro Tanbo
- Department of Urology, Kyorin University School of Medicine, Tokyo, Japan
| | - Hidehiko Hara
- Department of Urology, Kyorin University School of Medicine, Tokyo, Japan
| | - Isao Miyazaki
- Department of Radiology, Kyorin University School of Medicine, Tokyo, Japan
| | - Kuninori Kobayashi
- Department of Medical Radiological Technology, Faculty of Health Sciences, Kyorin University, Tokyo, Japan
| | - Toshiaki Nitatori
- Department of Radiology, Kyorin University School of Medicine, Tokyo, Japan
| |
Collapse
|
10
|
Fonseca JM, Bastos AP, Amaral AG, Sousa MF, Souza LE, Malheiros DM, Piontek K, Irigoyen MC, Watnick TJ, Onuchic LF. Renal cyst growth is the main determinant for hypertension and concentrating deficit in Pkd1-deficient mice. Kidney Int 2014; 85:1137-50. [PMID: 24429399 PMCID: PMC4510986 DOI: 10.1038/ki.2013.501] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 09/27/2013] [Accepted: 10/03/2013] [Indexed: 01/13/2023]
Abstract
We have bred a Pkd1 floxed allele with a nestin-Cre expressing line to generate cystic mice with preserved glomerular filtration rate to address the pathogenesis of complex autosomal dominant polycystic kidney disease (ADPKD) phenotypes. Hypertension affects about 60% of these patients before loss of renal function, leading to significant morbimortality. Cystic mice were hypertensive at 5 and 13 weeks of age, a phenotype not seen in noncystic controls and Pkd1-haploinsufficient animals that do not develop renal cysts. Fractional sodium excretion was reduced in cystic mice at these ages. Angiotensinogen gene expression was higher in cystic than noncystic kidneys at 18 weeks, while ACE and the AT1 receptor were expressed in renal cyst epithelia. Cystic animals displayed increased renal cAMP, cell proliferation, and apoptosis. At 24 weeks, mean arterial pressure and fractional sodium excretion did not significantly differ between the cystic and noncystic groups, whereas cardiac mass increased in cystic mice. Renal concentrating deficit is also an early finding in ADPKD. Maximum urine osmolality and urine nitrite excretion were reduced in 10-13- and 24-week-old cystic mice, deficits not found in haploinsufficient and noncystic controls. A trend of higher plasma vasopressin was observed in cystic mice. Thus, cyst growth most probably plays a central role in early-stage ADPKD-associated hypertension, with activation of the intrarenal renin-angiotensin system as a key mechanism. Cyst expansion is also likely essential for the development of the concentrating deficit in this disease. Our findings are consistent with areas of reduced perfusion in the kidneys of patients with ADPKD.
Collapse
Affiliation(s)
- Jonathan M Fonseca
- Divisions of Nephrology and Molecular Medicine, Department of Medicine, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Ana P Bastos
- Divisions of Nephrology and Molecular Medicine, Department of Medicine, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Andressa G Amaral
- Divisions of Nephrology and Molecular Medicine, Department of Medicine, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Mauri F Sousa
- Department of Medicine, Federal University of Goiás School of Medicine, Goiânia, Brazil
| | - Leandro E Souza
- Department of Cardiopneumology, Heart Institute, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Denise M Malheiros
- Department of Pathology, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Klaus Piontek
- Department of Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Maria C Irigoyen
- Department of Cardiopneumology, Heart Institute, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Terry J Watnick
- Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Luiz F Onuchic
- 1] Divisions of Nephrology and Molecular Medicine, Department of Medicine, University of São Paulo School of Medicine, São Paulo, Brazil [2] Center for Cellular and Molecular Studies and Therapy (NETCEM), University of São Paulo, São Paulo, Brazil
| |
Collapse
|
11
|
Autosomal dominant polycystic kidney disease is associated with central and nephrogenic defects in osmoregulation. Kidney Int 2012; 82:1121-9. [DOI: 10.1038/ki.2012.225] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
12
|
Zittema D, Boertien WE, van Beek AP, Dullaart RPF, Franssen CFM, de Jong PE, Meijer E, Gansevoort RT. Vasopressin, copeptin, and renal concentrating capacity in patients with autosomal dominant polycystic kidney disease without renal impairment. Clin J Am Soc Nephrol 2012; 7:906-13. [PMID: 22516290 DOI: 10.2215/cjn.11311111] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND OBJECTIVES Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent hereditary renal disease, characterized by cyst formation in the kidneys leading to end stage kidney failure. It is clinically acknowledged that ADPKD patients have impaired urine concentrating capacity, but the mechanism behind this observation is unknown. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Fifteen ADPKD patients (estimated GFR ≥60 ml/min per 1.73 m(2)) and 15 age- and sex-matched healthy controls underwent a standard prolonged water deprivation test in which urine and plasma osmolality, vasopressin, and copeptin were measured. The effect of a synthetic vasopressin analog (desmopressin) injected at the moment of maximal urine concentrating capacity was also studied. RESULTS After 14 hours of water deprivation, ADPKD patients tended to have higher plasma osmolality (P=0.07) and significantly higher vasopressin and copeptin levels (both P<0.05), whereas urine osmolality was similar in ADPKD patients and controls (710 versus 742 mOsmol/kg; P=0.61). Maximal urine concentrating capacity was lower in ADPKD patients (758 versus 915 mOsmol/kg in controls; P<0.001). At maximal urine concentrating capacity, plasma osmolality, vasopressin, and copeptin levels were significantly higher in ADPKD patients. The median increase in urine osmolality after desmopressin administration in ADPKD patients was less than in healthy controls. CONCLUSIONS Already early in their disease, ADPKD patients have impaired maximal urine concentrating capacity brought out upon dehydration, with no evidence of impaired hypothalamic response. To maintain fluid balance, vasopressin concentration increases, which is hypothesized to play a role in ADPKD disease progression.
Collapse
Affiliation(s)
- Debbie Zittema
- Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Reif GA, Yamaguchi T, Nivens E, Fujiki H, Pinto CS, Wallace DP. Tolvaptan inhibits ERK-dependent cell proliferation, Cl⁻ secretion, and in vitro cyst growth of human ADPKD cells stimulated by vasopressin. Am J Physiol Renal Physiol 2011; 301:F1005-13. [PMID: 21816754 DOI: 10.1152/ajprenal.00243.2011] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In autosomal dominant polycystic kidney disease (ADPKD), arginine vasopressin (AVP) accelerates cyst growth by stimulating cAMP-dependent ERK activity and epithelial cell proliferation and by promoting Cl(-)-dependent fluid secretion. Tolvaptan, a V2 receptor antagonist, inhibits the renal effects of AVP and slows cyst growth in PKD animals. Here, we determined the effect of graded concentrations of tolvaptan on intracellular cAMP, ERK activity, cell proliferation, and transcellular Cl(-) secretion using human ADPKD cyst epithelial cells. Incubation of ADPKD cells with 10(-9) M AVP increased intracellular cAMP and stimulated ERK and cell proliferation. Tolvaptan caused a concentration-dependent inhibition of AVP-induced cAMP production with an apparent IC(50) of ∼10(-10) M. Correspondingly, tolvaptan inhibited AVP-induced ERK signaling and cell proliferation. Basolateral application of AVP to ADPKD cell monolayers grown on permeable supports caused a sustained increase in short-circuit current that was completely blocked by the Cl(-) channel blocker CFTR(inh-172), consistent with AVP-induced transepithelial Cl(-) secretion. Tolvaptan inhibited AVP-induced Cl(-) secretion and decreased in vitro cyst growth of ADPKD cells cultured within a three-dimensional collagen matrix. These data demonstrate that relatively low concentrations of tolvaptan inhibit AVP-stimulated cell proliferation and Cl(-)-dependent fluid secretion by human ADPKD cystic cells.
Collapse
Affiliation(s)
- Gail A Reif
- Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas 66160-3018, USA
| | | | | | | | | | | |
Collapse
|
14
|
Fluid transport and cystogenesis in autosomal dominant polycystic kidney disease. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1314-21. [PMID: 21255645 DOI: 10.1016/j.bbadis.2011.01.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Revised: 01/09/2011] [Accepted: 01/11/2011] [Indexed: 12/18/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent inherited nephropathy. The development and enlargement of cysts in ADPKD requires tubular cell proliferation, abnormalities in the extracellular matrix and transepithelial fluid secretion. Multiple studies have suggested that fluid secretion across ADPKD cyst-lining cells is driven by the transepithelial secretion of chloride, mediated by the apical CFTR channel and specific basolateral transporters. The whole secretory process is stimulated by increased levels of cAMP in the cells, probably reflecting modifications in the intracellular calcium homeostasis and abnormal stimulation of the vasopressin V2 receptor. This review will focus on the pathophysiology of fluid secretion in ADPKD cysts, starting with classic, morphological and physiological studies that were followed by investigations of the molecular mechanisms involved and therapeutic trials targeting these pathways in cellular and animal models and ADPKD patients. This article is part of a Special Issue entitled: Polycystic Kidney Disease.
Collapse
|
15
|
Flores D, Battini L, Gusella GL, Rohatgi R. Fluid shear stress induces renal epithelial gene expression through polycystin-2-dependent trafficking of extracellular regulated kinase. Nephron Clin Pract 2010; 117:p27-36. [PMID: 21109758 DOI: 10.1159/000321640] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 09/20/2010] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The cilium and cilial proteins have emerged as principal mechanosensors of renal epithelial cells responsible for translating mechanical forces into intracellular signals. Polycystin-2 (PC-2), a cilial protein, regulates flow/shear-induced changes in intracellular Ca(2+) ([Ca(2+)](i)) and recently has been implicated in the regulation of mitogen-activated protein (MAP) kinases. We hypothesize that fluid shear stress (FSS) activates PC-2 which regulates MAP kinase and, in turn, induces MAP kinase-dependent gene expression, specifically, monocyte chemoattractant protein-1 (MCP-1). METHODS To test this, PC-2 expression was constitutively reduced in a murine inner medullary collecting duct (IMCD3) cell line, and the expression of FSS-induced MCP-1 expression and MAP kinase signaling compared between the parental (PC-2-expressing) and PC-2-deficient IMCD3 cells. RESULTS FSS induces MAP kinase signaling and downstream MCP-1 mRNA expression in wild-type IMCD3 cells, while inhibitors of MAP kinase prevented the FSS-induced MCP-1 mRNA response. In contradistinction, FSS did not induce MCP-1 mRNA expression in PC-2-deficient cells, but did increase activation of the upstream MAP kinases. Wild-type cells exposed to FSS augmented the nuclear abundance of activated MAP kinase while PC-2-deficient cells did not. CONCLUSIONS PC-2 regulates FSS-induced MAP kinase trafficking into the nucleus of CD cells.
Collapse
Affiliation(s)
- Daniel Flores
- Department of Medicine, The Mount Sinai School of Medicine, New York, NY 10000209, USA
| | | | | | | |
Collapse
|
16
|
Torres VE, Bankir L, Grantham JJ. A case for water in the treatment of polycystic kidney disease. Clin J Am Soc Nephrol 2009; 4:1140-50. [PMID: 19443627 DOI: 10.2215/cjn.00790209] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Autosomal dominant polycystic disease (ADPKD) is an inherited disorder characterized by the development within renal tubules of innumerable cysts that progressively expand to cause renal insufficiency. Tubule cell proliferation and transepithelial fluid secretion combine to enlarge renal cysts, and 3'-5'-cyclic adenosine monophosphate (cAMP) stimulates that growth. The antidiuretic hormone, arginine vasopressin (AVP), operates continuously in ADPKD patients to stimulate the formation of cAMP, thereby contributing to cyst and kidney enlargement and renal dysfunction. Studies in animal models of ADPKD provide convincing evidence that blocking the action of AVP dramatically ameliorates the disease process. In the current analysis, the authors reason that increasing the amount of solute-free water drunk evenly throughout the day in patients with ADPKD and normal renal function will decrease plasma AVP concentrations and mitigate the action of cAMP on the renal cysts. Potential pitfalls of increasing fluid intake in ADPKD patients are considered, and suggestions for how physicians may prudently implement this therapy are offered.
Collapse
Affiliation(s)
- Vicente E Torres
- Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
| | | | | |
Collapse
|
17
|
Danielsen H, Nielsen AH, Pedersen EB, Herlevsen P, Kornerup HJ, Posborg V. Exaggerated natriuresis in adult polycystic kidney disease. ACTA MEDICA SCANDINAVICA 2009; 219:59-66. [PMID: 3953317 DOI: 10.1111/j.0954-6820.1986.tb03276.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Angiotensin II (AII), aldosterone (Aldo) arginine vasopressin (AVP) in plasma, serum osmolality (Sosm), and renal sodium excretion (UNaV) were studied before and after infusion of hypertonic sodium chloride solution in 20 patients with adult polycystic kidney disease (PKD) with normal or moderately reduced creatinine clearance (Ccr) and in 10 healthy control subjects. UNaV increased after sodium loading in all, significantly more in the PKD patients. AII and Aldo were normal before sodium loading and suppressed after saline in PKD patients and controls. The increase in VNaV correlated with Aldo in patients but not in controls. AVP before loading was increased in hypertensive PKD patients with reduced Ccr, but not in normotensive patients with normal Ccr. After hypertonic saline, Sosm increased to the same degree both in PKD and control subjects, but AVP increased more in those with PKD. The exaggerated natriuresis of PKD is probably not explained by a change in the activity of the renin-angiotensin-aldosterone system. The enhanced response of AVP to osmotic stimuli in PKD may be a compensatory reaction to a reduced renal tubular effect of AVP.
Collapse
|
18
|
Sturfelt G, Truedsson L, Thysell H, Björck L. Serum level of complement factor D in systemic lupus erythematosus--an indicator of glomerular filtration rate. ACTA MEDICA SCANDINAVICA 2009; 216:171-7. [PMID: 6388250 DOI: 10.1111/j.0954-6820.1984.tb03789.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Serum levels of complement factor D, a low molecular weight (LMW) protein, were high and inversely correlated with glomerular filtration rate (GFR) determined in 19 patients with lupus glomerulonephritis (LGN). Factor D was significantly closer correlated with S-creatinine than were two other LMW proteins, beta 2-microglobulin and gamma-trace in 22 LGN patients. Close correlations between each of the LMW proteins and S-creatinine were found in patients with a non-inflammatory disorder, polycystic kidney disease. Slightly increased beta 2-microglobulin concentrations were found in 15 of 20 systemic lupus erythematosus (SLE) patients without renal involvement, while factor D and gamma-trace showed normal values in most of these patients. The findings imply that serum concentrations of complement factor D in SLE are mainly determined by the GFR.
Collapse
|
19
|
Danielsen H, Pedersen EB, Nielsen AH, Herlevsen P, Kornerup HJ, Posborg V. Expansion of extracellular volume in early polycystic kidney disease. ACTA MEDICA SCANDINAVICA 2009; 219:399-405. [PMID: 3716882 DOI: 10.1111/j.0954-6820.1986.tb03330.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Blood volume (BV), extracellular volume (ECV), blood pressure (BP), creatinine clearance (CCr), plasma levels of angiotensin II (AII), aldosterone (Aldo) and arginine vasopressin (AVP), and serum osmolality (Sosm) were determined in 18 patients with adult polycystic kidney disease, 8 normotensive (group I), 10 hypertensive (group II), and in 11 control subjects (group III). ECV but not BV was increased in group I compared with group III, whereas BV and ECV did not differ significantly between groups II and III. In group II, Aldo and AVP were increased and AII tended to be increased, while in group I the hormone levels did not differ significantly from those in group III. Sosm did not differ significantly between the groups. In the combined patient group, CCr correlated positively with BV and ECV and negatively with BP. In the patients, AII and AVP were positively correlated with BP but not with CCr. The results suggest that both the renin-angiotensin system and AVP might be involved in the BP elevation, whereas expansion of ECV can be found without an increase in BP.
Collapse
|
20
|
Eley L, Gabrielides C, Adams M, Johnson CA, Hildebrandt F, Sayer JA. Jouberin localizes to collecting ducts and interacts with nephrocystin-1. Kidney Int 2008; 74:1139-49. [PMID: 18633336 DOI: 10.1038/ki.2008.377] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Joubert syndrome and related disorders are autosomal recessive multisystem diseases characterized by cerebellar vermis aplasia/hypoplasia, retinal degeneration and cystic kidney disease. There are five known genes; mutations of which give rise to a spectrum of renal cystic diseases the most common of which is nephronophthisis, a disorder characterized by early loss of urinary concentrating ability, renal fibrosis, corticomedullary cyst formation and renal failure. Many of the proteins encoded by these genes interact with one another and are located at adherens junctions or the primary cilia and or basal bodies. Here we characterize Jouberin, a multi-domain protein encoded by the AHI1 gene. Immunohistochemistry with a novel antibody showed that endogenous Jouberin is expressed in brain, kidney and HEK293 cells. In the kidney, Jouberin co-localized with aquaporin-2 in the collecting ducts. We show that Jouberin interacts with nephrocystin-1 as determined by yeast-2-hybrid system and this was confirmed by exogenous and endogenous co-immunoprecipitation in HEK293 cells. Jouberin is expressed at cell-cell junctions, primary cilia and basal body of mIMCD3 cells while a Jouberin-GFP construct localized to centrosomes in subconfluent and dividing MDCK cells. Our results suggest that Jouberin is a protein whose expression pattern supports both the adherens junction and the ciliary hypotheses for abnormalities leading to nephronophthisis.
Collapse
Affiliation(s)
- Lorraine Eley
- Institute of Human Genetics, International Centre for Life, Newcastle University, Newcastle Upon Tyne, UK
| | | | | | | | | | | |
Collapse
|
21
|
Krishnan R, Eley L, Sayer JA. Urinary concentration defects and mechanisms underlying nephronophthisis. Kidney Blood Press Res 2008; 31:152-62. [PMID: 18460874 DOI: 10.1159/000129648] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The cystic kidney disease nephronophthisis (NPHP) is the commonest genetic cause of end-stage renal failure in young people and children. Histologically the disease is characterized by interstitial fibrosis, tubular atrophy with corticomedullary cyst development and disruption of the tubular basement membrane. Affected children present with polydipsia and polyuria, secondary to a urinary concentration defect, before these structural changes develop. Recently, molecular genetic advances have identified several genes mutated in NPHP, providing novel insights into its pathophysiology for the first time in decades. Here we review the normal physiological mechanisms of urinary concentration and explain, in the context of recent discoveries, the possible mechanisms underlying urinary concentration defects in patients with NPHP. The pattern of a ciliary and adherens junction subcellular localization of nephrocystin proteins is discussed. Recent animal models of cystic kidney disease and treatment with vasopressin V2 receptor antagonists are reviewed and a hypothesis regarding urinary concentration defects in NPHP is proposed. Understanding the cellular mechanisms underlying NPHP and other cystic kidney diseases will provide the rationale for therapeutic interventions in this disease. Early urinary concentration defects provide both a clue to clinical diagnosis of NPHP and potential therapeutic targets for pharmacological treatment of this condition.
Collapse
Affiliation(s)
- Rajesh Krishnan
- Royal Victoria Infirmary, International Centre for Life, Newcastle upon Tyne, UK
| | | | | |
Collapse
|
22
|
Masoumi A, Reed-Gitomer B, Kelleher C, Schrier RW. Potential pharmacological interventions in polycystic kidney disease. Drugs 2008; 67:2495-510. [PMID: 18034588 DOI: 10.2165/00003495-200767170-00004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Polycystic kidney diseases (autosomal dominant and autosomal recessive) are progressive renal tubular cystic diseases, which are characterised by cyst expansion and loss of normal kidney structure and function. Autosomal dominant polycystic kidney disease (ADPKD) is the most common life- threatening, hereditary disease. ADPKD is more prevalent than Huntington's disease, haemophilia, sickle cell disease, cystic fibrosis, myotonic dystrophy and Down's syndrome combined. Early diagnosis and treatment of hypertension with inhibitors of the renin-angiotensin-aldosterone system (RAAS) and its potential protective effect on left ventricular hypertrophy has been one of the major therapeutic goals to decrease cardiac complications and contribute to improved prognosis of the disease. Advances in the understanding of the genetics, molecular biology and pathophysiology of the disease are likely to facilitate the improvement of treatments for these diseases. Developments in describing the role of intracellular calcium ([Ca(2+)](i)) and its correlation with cellular signalling systems, Ras/Raf/mitogen extracellular kinase (MEK)/extracellular signal-regulated protein kinase (ERK), and interaction of these pathways with cyclic adenosine monophosphate (cAMP) levels, provide new insights on treatment strategies. Blocking the vasopressin V(2) receptor, a major adenylyl cyclase agonist, demonstrated significant improvements in inhibiting cytogenesis in animal models. Because of activation of the mammalian target of rapamycin (mTOR) pathway, the use of sirolimus (rapamycin) an mTOR inhibitor, markedly reduced cyst formation and decreased polycystic kidney size in several animal models. Caspase inhibitors have been shown to decrease cytogenesis and renal failure in rats with cystic disease. Cystic fluid secretion results in cyst enlargement and somatostatin analogues have been shown to decrease renal cyst progression in patients with ADPKD. The safety and efficacy of these classes of drugs provide potential interventions for experimental and clinical trials.
Collapse
Affiliation(s)
- Amirali Masoumi
- Department of Medicine, Health Sciences Center, University of Colorado School of Medicine, Denver, Colorado, USA
| | | | | | | |
Collapse
|
23
|
Makita R, Uchijima Y, Nishiyama K, Amano T, Chen Q, Takeuchi T, Mitani A, Nagase T, Yatomi Y, Aburatani H, Nakagawa O, Small EV, Cobo-Stark P, Igarashi P, Murakami M, Tominaga J, Sato T, Asano T, Kurihara Y, Kurihara H. Multiple renal cysts, urinary concentration defects, and pulmonary emphysematous changes in mice lacking TAZ. Am J Physiol Renal Physiol 2008; 294:F542-53. [PMID: 18172001 DOI: 10.1152/ajprenal.00201.2007] [Citation(s) in RCA: 220] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
TAZ (transcriptional coactivator with PDZ-binding motif), also called WWTR1 (WW domain containing transcription regulator 1), is a 14-3-3-binding molecule homologous to Yes-associated protein. TAZ acts as a coactivator for several transcription factors as well as a modulator of membrane-associated PDZ domain-containing proteins, but its (patho)physiological roles remain unknown. Here we show that gene inactivation of TAZ in mice resulted in pathological changes in the kidney and lung that resemble the common human diseases polycystic kidney disease and pulmonary emphysema. Taz-null/lacZ knockin mutant homozygotes demonstrated renal cyst formation as early as embryonic day 15.5 with dilatation of Bowman's capsules and proximal tubules, followed by pelvic dilatation and hydronephrosis. After birth, only one-fifth of TAZ-deficient homozygotes grew to adulthood and demonstrated multicystic kidneys with severe urinary concentrating defects and polyuria. Furthermore, adult TAZ-deficient homozygotes exhibited diffuse emphysematous changes in the lung. Thus TAZ is essential for developmental mechanisms involved in kidney and lung organogenesis, whose disturbance may lead to the pathogenesis of common human diseases.
Collapse
Affiliation(s)
- Ryosuke Makita
- Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
|
25
|
|
26
|
Abstract
In autosomal dominant polycystic kidney disease (ADPKD), the genetic defect results in the slow growth of a multitude of epithelial cysts within the renal parenchyma. Cysts originate within the glomeruli and all tubular structures, and their growth is the result of proliferation of incompletely differentiated epithelial cells and the accumulation of fluid within the cysts. The majority of cysts disconnect from tubular structures as they grow but still accumulate fluid within the lumen. The fluid accumulation is the result of secretion of fluid driven by active transepithelial Cl- secretion. Proliferation of the cells and fluid secretion are activated by agonists of the cAMP signaling pathway. The transport mechanisms involved include the cystic fibrosis transmembrane conductance regulator (CFTR) present in the apical membrane of the cystic cells and a bumetanide-sensitive transporter located in the basolateral membrane. A lipid factor, called cyst activating factor, has been found in the cystic fluid. Cyst activating factor stimulates cAMP production, proliferation, and fluid secretion by cultured renal epithelial cells and also is a chemotactic agent. Cysts also appear in the intrahepatic biliary tree in ADPKD. Normal ductal cells secrete Cl- and HCO3-. The cystic ductal cell also secretes Cl-, but HCO3- secretion is diminished, probably as the result of a lower population of Cl-/HCO3- exchangers in the apical membrane as compared with the normal cells. Some segments of the normal renal tubule are also capable of utilizing CFTR to secrete Cl-, particularly the inner medullary collecting duct. The ability of Madin-Darby canine kidney cells and normal human kidney cortex cells to form cysts in culture and to secrete fluid and the functional similarities between these incompletely differentiated, proliferative cells and developing cells in the intestinal crypt and in the fetal lung have led us to suggest that Cl- and fluid secretion may be a common property of at least some renal epithelial cells in an intermediate stage of development. The genetic defect in ADPKD may not directly affect membrane transport mechanisms but rather may arrest the development of certain renal epithelial cells in an incompletely differentiated, proliferative stage.
Collapse
Affiliation(s)
- L P Sullivan
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City 66160, USA
| | | | | |
Collapse
|
27
|
Pabico RC, McKenna BA, Freeman RB. Renal tubular dysfunction in patients with cystic disease of the kidneys. Urology 1998; 51:156-60. [PMID: 9610573 DOI: 10.1016/s0090-4295(98)00081-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To define the renal tubular functional abnormalities in patients with cystic disease of the kidneys. METHODS Patients with autosomal dominant polycystic kidney disease (ADPKD) (n = 4) and medullary sponge kidneys (MSK) (n = 3) with normal glomerular filtration rate (GFR), determined by inulin clearance, and effective renal plasma flow (ERPF), measured by p-aminohippurate clearance, underwent measurement of proximal and distal tubular functions. Proximal tubular functions were determined by the maximum reabsorption of glucose (TmGlucose) and the maximum secretion of p-aminohippurate (TmPAH). Distal tubular functions were measured by the maximum urinary concentrating and diluting mechanisms, and the urinary acidification response to acid load. RESULTS TmGlucose was low in both groups (209 +/- 25 mg/min/1.73 m2 in the ADPKD group and 110 +/- 28 mg/min/1.73 m2 in the MSK, compared with 375 +/- 40 mg/min/1.73 m2 in healthy controls; P < 0.05). Likewise, TmPAH was significantly diminished in patients with ADPKD (72 +/- 6 mg/min/1.73 m2) and MSK (63 +/- 5 mg/min/1.73 m2) when compared with healthy controls (89 +/- 4 mg/min/1.73 m2; P < 0.05). Urinary maximum concentration after fluid deprivation was impaired in both ADPKD and MSK patients, but the diluting mechanism was intact. Finally, the ability to excrete urinary ammonium and titratable acids following an oral acid load was inadequate in both the ADPKD and MSK groups. CONCLUSIONS Proximal and distal tubular functions are impaired in patients with ADPKD and MSK when GFR and ERPF are normal, indicating tubular disruption by the cysts and the alteration of the tubulo-interstitial vascular relationship.
Collapse
Affiliation(s)
- R C Pabico
- Department of Medicine, University of Rochester Medical Center, New York 14642, USA
| | | | | |
Collapse
|
28
|
Abstract
Once viewed as hopelessly incurable disorders and the dustbin for careers in academic medicine, the polycystic kidney diseases have emerged as prime targets of pathophysiologic study and palliative and definitive treatment in the era of molecular medicine. Polycystic kidney disease (PKD) may be hereditary or acquired. The major inherited types are autosomal dominant (AD) and autosomal recessive (AR). ADPKD is caused by at least two (and possibly three) genes located on separate chromosomes, while ADPKD-1 is due to a 14 kb transcript in a duplicated region on the short arm of chromosome 16 very near the alpha-globin gene cluster and the gene for one form of tuberous sclerosis. ADPKD-2 has been assigned to the long arm of chromosome 4. ARPKD is due to a mutated gene on both copies of the long arm of chromosome 6. Cysts originate in renal tubules. Proliferation of tubule epithelial cells modulated by endocrine, paracrine, and autocrine factors is a major element in the pathogenesis of renal cystic diseases. In addition, fluid that is abnormally accumulated within the cysts is derived from glomerular filtrate and, to a greater extent, by transepithelial fluid secretion. Abnormal synthesis and degradation of matrix components associated with interstitial inflammation are additional features in the pathogenesis of renal cystic diseases. The ADPKD genotypes are characterized by bilateral kidney cysts, hypertension, hematuria, renal infection, stones, and renal insufficiency. ADPKD is a systemic disorder; cysts appear with decreasing frequency in the kidneys, liver, pancreas, brain, spleen, ovaries, and testis. Cardiac valvular disorders, abdominal and inguinal hernias, and aneurysms of cerebral and coronary arteries and aorta are also associated with ADPKD. Treatment is supportive: dietary regulation of salt and protein intake, control of hypertension and renal stones, and dialysis and transplantation at the end stage. ARPKD is a relatively rare disease that causes clinical symptoms at birth, with significant mortality in the first month of life. The cysts develop primarily in the collecting ducts because of a failure in the maturation process. Early complications include Potter's syndrome; excessive size of the kidneys, causing respiratory dysfunction; hypertension; and renal insufficiency. Hepatic fibrosis is an associated extrarenal problem that results in significant morbidity in young children and adolescents. Treatment includes supportive care, dialysis, and renal transplantation. Acquired cysts (solitary/simple) are commonplace in older persons. Multiple cysts may be seen in association with potassium deficiency, congenital disorders, metabolic diseases, and toxic renal injury.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- J R Martinez
- Department of Medicine, University of Kansas Medical Center, Kansas City, USA
| | | |
Collapse
|
29
|
Torres VE, Keith DS, Offord KP, Kon SP, Wilson DM. Renal ammonia in autosomal dominant polycystic kidney disease. Kidney Int 1994; 45:1745-53. [PMID: 7933822 DOI: 10.1038/ki.1994.227] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Recent studies have suggested that defective medullary trapping of ammonia underlies the acidosis associated with renal failure and sets in motion maladaptive compensatory mechanisms that contribute to the progression of renal disease. Since a renal concentrating defect is an early functional abnormality in autosomal dominant polycystic kidney disease (ADPKD), defective medullary trapping and urinary excretion of ammonia may also occur early and have important pathophysiological consequences. The urinary pH and excretions of ammonia, titratable acid, and bicarbonate, were measured during a 24-hour baseline period and following the administration of ammonium chloride (100 mg/kg body wt) in ADPKD patients with normal glomerular filtration rate and in age- and gender-matched healthy control subjects. The distal nephron hydrogen ion secretory capacity was assessed during a bicarbonate infusion. Ammonia, sodium, pH, C3dg, and C5b-9 were measured in cyst fluid samples. The excretion rates of ammonia during the 24-hour baseline period and following the administration of ammonium chloride were significantly lower, and the relationship of ammonia excretion to urinary pH was significantly shifted downward in ADPKD. No difference in the increment of urinary pCO2 (delta pCO2) or the peripheral blood-urine pCO2 gradient (U-B pCO2) between ADPKD patients and control subjects was detected during a sodium bicarbonate infusion. Calculated concentrations of free-base ammonia in cyst fluid samples exceeded those calculated from reported concentrations of ammonia in renal venous blood of normal subjects. C3dg and C5b-9 were detected in some cyst fluids. The urinary excretion of ammonia is reduced in ADPKD patients with normal glomerular filtration rate.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- V E Torres
- Department of Biostatistics, Mayo Clinic and Foundation, Rochester, Minnesota
| | | | | | | | | |
Collapse
|
30
|
Affiliation(s)
- P D Wilson
- Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School, Piscataway
| | | |
Collapse
|
31
|
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disease, affecting a half million Americans. The clinical phenotype can result from at least two different gene defects. One gene that can cause ADPKD has been located on the short arm of chromosome 16. This discovery has made possible new methods for diagnosing the disorder in gene carriers prior to the development of renal cysts. Although renal cysts are clearly an important manifestation of the gene defect, other systemic manifestations are both common and clinically important. Cardiac valvular lesions, intracranial aneurysms, hepatic cysts, and diverticula are included in the array of systemic manifestations. Moreover, renal cysts are only one of a myriad of renal manifestations. Although ADPKD was long considered an adult cystic disease, it is also a common cause of childhood cystic disease and must be considered in the differential diagnosis in that setting.
Collapse
Affiliation(s)
- P A Gabow
- Denver General Hospital, University of Colorado Health Sciences Center
| |
Collapse
|
32
|
Gabow PA, Kaehny WD, Johnson AM, Duley IT, Manco-Johnson M, Lezotte DC, Schrier RW. The clinical utility of renal concentrating capacity in polycystic kidney disease. Kidney Int 1989; 35:675-80. [PMID: 2709672 DOI: 10.1038/ki.1989.38] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We studied 177 adult nonazotemic subjects with autosomal dominant polycystic kidney disease (ADPKD) and 123 unaffected family members (NADPKD). In order to assess the factors influencing renal concentrating capacity maximal urinary osmolality (UOsm) after overnight water deprivation and vasopressin was measured. UOsm was reduced in ADPKD (680 +/- 14) compared to NADPKD subjects (812 +/- 13 mOsm/kg). A greater severity of the architectural abnormality as assessed by cyst number and size and remaining volume of normal parenchyma was associated with a greater impairment of renal concentrating capacity. The concentrating defect was present in the youngest ADPKD subjects and the rate of decline of concentrating capacity with age in ADPKD paralleled that in NADPKD subjects. Based on the initial 135 subjects studied, we developed an algorithm for diagnostic screening for ADPKD utilizing blood pressure, serum creatinine and UOsm designed to maximize sensitivity. When applied to a subsequent population of 165 adults, 121 with ADPKD and 44 unaffected relatives, this algorithm would have spared 20% of unaffected subjects from the cost of ultrasound while failing to detect less than 2% of affected subjects. This simple protocol thus offers a rapid and inexpensive way to screen for ADPKD.
Collapse
Affiliation(s)
- P A Gabow
- Department of Medicine, University of Colorado School of Medicine, Denver
| | | | | | | | | | | | | |
Collapse
|
33
|
Savige JA, Patrikios V, Aldred P, Kincaid-Smith P. Use of a DNA probe in the diagnosis of adult polycystic kidney disease. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1988; 18:674-8. [PMID: 2907726 DOI: 10.1111/j.1445-5994.1988.tb00149.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Adult polycystic kidney disease (APKD) is one of the most common inherited diseases in man. A diagnosis based on the demonstration of renal cysts with ultrasonography or computerised tomography may be inconclusive in early adulthood, the crucial years before child-bearing is complete. Here we describe the improved diagnostic probability that is possible using genetic linkage studies. A 24-year-old woman, whose father and younger sister were affected by APKD, was demonstrated to have a single cyst in each kidney. These findings were insufficient for a diagnosis of APKD and for this reason genetic linkage studies were undertaken. DNA was extracted from peripheral blood leukocytes from the presenting individual, and her immediate and extended family; the DNA was cut with the restriction enzyme PvuII, electrophoresed in a 0.7% agarose gel and blotted onto nitrocellulose before probing with a 32P-labelled 4 kb fragment. This contained DNA from the hypervariable region (3' hypervariable region, 3'HVR) that is linked to the gene for APKD on the short arm of chromosome 16 and has been used in other family studies by Reeders et al. We correlated the findings on Southern blotting with ultrasound evidence of APKD and found that the disease segregated with a 7.0 kb fragment in the presenting individual's father and sister. She was shown to have inherited this allele also; the use of this technique thus increased the probability of her having APKD from 50% to 96.5%.
Collapse
Affiliation(s)
- J A Savige
- Department of Nephrology, Royal Melbourne Hospital, Vic, Australia
| | | | | | | |
Collapse
|
34
|
Kääriäinen H, Koskimies O, Norio R. Dominant and recessive polycystic kidney disease in children: evaluation of clinical features and laboratory data. Pediatr Nephrol 1988; 2:296-302. [PMID: 3153029 DOI: 10.1007/bf00858681] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The clinical features and laboratory data of 93 children with polycystic kidney disease were analysed. Family studies showed that the disease was dominant (DPKD) in 17 and recessive (RPKD) in 32 of them. Of the remaining 44 sporadic patients, 1 was classified by histological and/or imaging findings as having DPKD, 41 as having RPKD and 2 could not be classified. The symptoms tended to be more severe in RPKD than in DPKD, but there was much overlap. Death in early life was common in RPKD (55/73) and more rare in DPKD (4/18). If a child with DPKD had disease manifest during the neonatal period, then siblings were usually affected in the neonatal period. Survival to adulthood was seen in both diseases. In the patients who survived the neonatal period, hypertension was more common in RPKD (11/18) than in DPKD (4/14). Symptoms of portal hypertension were present in 2 patients with RPKD and none with DPKD. None of the laboratory investigations discriminated between the two entities. Glomerular filtration rate was diminished more often in RPKD (9/11) than in DPKD (2/8). Some difference was seen in the maximal urine concentrating ability; it was always reduced, often markedly, in RPKD but usually either normal or only moderately disturbed in DPKD. Studies on hepatic function and hepato-cellular damage were usually normal, but bacterial cholangitis was noted in some children with RPKD. The differential diagnosis between DPKD and RPKD needs to be based on the family history, family studies, radiological and/or histological features.
Collapse
Affiliation(s)
- H Kääriäinen
- Department of Medical Genetics, University of Helsinki, Finland
| | | | | |
Collapse
|
35
|
Talseth T, Fauchald P, Skrede S, Djøseland O, Berg KJ, Stenstrøm J, Heilo A, Brodwall EK, Flatmark A. Long-term blood pressure and renal function in kidney donors. Kidney Int 1986; 29:1072-6. [PMID: 3523003 DOI: 10.1038/ki.1986.109] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have reexamined 68 (92%) of 74 donors accepted at this center nine to 15 years ago. There was a moderate but significant increase in BP, and ten donors (15%) were hypertensive at the follow-up. Twenty-six donors (38%) had albumin excretion over 10 micrograms/min or excretion of total protein over 185 mg/24 hr. In four of 16 with increased excretion of total protein, this exceeded 400 mg/24 hr, and in three donors this could be due to an intercurrent disease. Ccr averaged 78.4% of preoperative values, and was less than 50% (range 32 to 49%) in eight donors. The compensatory increase (median 30.5 mliter/min/1.73m2) was inversely correlated with age and BP. Aspects of tubular function were assessed by the diluting capacity during water diuresis and by urinary excretion of beta 2-microglobulin and N-acetyl-beta-glucosaminidase. No consistent abnormalities were observed. A subgroup of donors (N = 32) was compared with a matched control group. Urinary albumin excretion among the donors was significantly higher compared to the controls, both in absolute terms (5.4 vs. 3.3 micrograms/min, P less than 0.002) and as percent of total protein excretion (7.6 vs. 5.7%, P less than 0.05). Otherwise no consistent differences were observed. The development of BP over time warrants further observations, but there is no evidence that uninephrectomy represents a long-term risk to the donors' health.
Collapse
|
36
|
Conte G, Dal Canton A, Fuiano G, Terribile M, Sabbatini M, Balletta M, Stanziale P, Andreucci VE. Mechanism of impaired urinary concentration in chronic primary glomerulonephritis. Kidney Int 1985; 27:792-8. [PMID: 4021313 DOI: 10.1038/ki.1985.82] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
To define the role of medullary damage and the influence of solute load and blood pressure (BP) in impairing urinary concentration, patients with chronic glomerulonephritis were investigated by histological and functional studies. In 59 biopsy specimens, the degree of medullary fibrosis was correlated inversely with urinary specific gravity and was significantly greater in hypertensive than in normotensive subjects. The following clearance studies were carried out in patients with a GFR of 15 to 40 ml/min in maximal antidiuresis: (1) Eight patients were studied while receiving a high sodium and protein diet and then after 1 week of low sodium, low protein diet; (2) ten patients were loaded with hypertonic saline (3%) to increase urine volume up to 25 to 30% of GFR; (3) the concentrating ability was compared in 15 normotensives and 15 hypertensives with comparable GFR; (4) the concentrating ability was studied in nine hypertensive patients before and after drug-induced normalization of BP. In (1) no change occurred in maximal urine osmolality (UOsm) even if fractional sodium excretion and filtered load of urea were reduced. In (2), values of UOsm fell below those of plasma osmolality. In (3), UOsm and negative free-water generation were lower in hypertensive than in normotensive subjects. In (4), normalization of BP was not associated with any change in UOsm. These results indicate that osmotic diuresis does not play a critical role in reducing urinary concentration. This defect is better accounted for by an intrinsic medullary damage, enhanced in hypertensive patients, which may impair the permeability of collecting ducts to water.
Collapse
|
37
|
Bear JC, McManamon P, Morgan J, Payne RH, Lewis H, Gault MH, Churchill DN. Age at clinical onset and at ultrasonographic detection of adult polycystic kidney disease: data for genetic counselling. AMERICAN JOURNAL OF MEDICAL GENETICS 1984; 18:45-53. [PMID: 6741995 DOI: 10.1002/ajmg.1320180108] [Citation(s) in RCA: 129] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Few reports are available on the age-related risk of relatives of affected persons to manifest adult polycystic kidney disease (APKD). For 371 persons in 17 kindreds, at risk for APKD by virtue of having an affected first degree relative, we calculated the estimated probability of clinical diagnosis of APKD to be 0.011 by age 20, 0.041 by age 30, 0.115 by age 40, 0.299 by age 50, and 0.404 by age 60 years (expected = 0.50). Ultrasonographic examination of 172 asymptomatic persons at risk showed definite APKD in 60. The probability of ultrasonographic detection of asymptomatic APKD is estimated as 0.222, 0.657, and 0.855 at age 5, 15, and 25 years, respectively. The probability of having APKD following normal ultrasonogram results (conservatively assuming 90% specificity) is estimated as 0.46, 0.28, and 0.14 for persons at 50% risk in their first, second, or third decade. The marginal benefit of ultrasound as a diagnostic test for APKD for persons in the second or third decade is estimated as 0.37 and 0.41, respectively for a "positive" test and 0.22 and 0.37 for a "negative" test.
Collapse
|
38
|
|
39
|
Batlle D, Gaviria M, Grupp M, Arruda JA, Wynn J, Kurtzman NA. Distal nephron function in patients receiving chronic lithium therapy. Kidney Int 1982; 21:477-85. [PMID: 6283233 DOI: 10.1038/ki.1982.49] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Renal tubular function was studied in 14 patients chronically treated with lithium for affective disorders. Patients were separated into two groups according to the duration of lithium therapy: long-term (35 +/- 7.0 months) and short-term (4.8 +/- 0.8 months). At comparable urine lithium concentrations, patients on long-term therapy had a lower maximal urine osmolality (Umax) and free water reabsorption (TcH2O) than did patients on short-term therapy. The latter group achieved a Umax above 800 mOsm kg H2O. In contrast, both groups of patients failed to increase the urine-blood (U-B) Pco2 gradient normally during acute sodium bicarbonate loading. This low U-B Pco2 was observed at comparable urine bicarbonate concentrations between both groups of patients and controls, and thus was associated with a higher urine pH in patients. These findings indicate that the inability of these patients to achieve a normal U-B Pco2 in a maximally alkaline urine was the result of decreased distal hydrogen ion secretion rather than inability to raise urine bicarbonate concentrations as a result of a concentrating defect. Bicarbonate reabsorptive capacity was normal in our lithium-treated subjects. Both groups of patients achieved a normal U-B Pco2 gradient in response to sodium phosphate loading. They also were able to achieve a minimal urine pH and a maximal acid excretion similar to those of controls in response to a 3-day ammonium chloride loading test. Our data demonstrate that chronic lithium therapy is associated with a mild distal acidification defect disclosed only by the finding of a low U-B Pco2 gradient during sodium bicarbonate loading. This peculiar defect can be found in short-term lithium-treated patients in whom the concentrating capacity is relatively well preserved.
Collapse
|
40
|
|
41
|
Abstract
A case is presented of a twenty-eight-year-old man in whom renal failure developed at age twenty-four from polycystic kidney disease known to be present since childhood. He also had cutaneous manifestations of the tuberous sclerosis complex. Intrarenal hemorrhage led to bilateral nephrectomy. Microscopic examination disclosed typical polycystic disease and multiple angiomyolipomas in each kidney. In addition several renal cell carcinomas of oncocytic, papillary, and clear cell type were found. Review of the literature disclosed the uncommon coexistence of any two of these lesions and did not uncover any reported case of the simultaneous existence of all three.
Collapse
|
42
|
Abstract
A 28 year old woman, with diabetes since age 18, had the nephrotic syndrome, hypertension and renal insufficiency. The initial renal biopsy specimen revealed diffuse glomerulosclerosis with early nodular changes. After an initial decline in renal function, her creatinine clearance progressively improved and has remained normal. Within 2 years she had a spontaneous remission of the nephrotic syndrome despite the presence of more pronounced nodular glomerular lesions. Although the renal hemodynamic functions were normal, certain tubular functions were impaired. Since we found no etiology for the nephrotic syndrome other than diabetic glomerulopathy, the complete remission of the nephrotic syndrome and improvement in renal function were very unusual events.
Collapse
|
43
|
Pabico RC, McKenna BA, Freeman RB. Renal function before and after unilateral nephrectomy in renal donors. Kidney Int 1975; 8:166-75. [PMID: 1177376 DOI: 10.1038/ki.1975.96] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Measurements of glomerular filtration rate (GFR), effective renal plasma flow (ERPF), tubular maximum reabsorption of glucose (Tmglucose) and secretion of para-aminohippurate (Tmpah), clearance of inorganic phosphate (Cphosphate) and uric acid (Curic acid), urine diluting capacity (CH2O) and urinary net acid excretion (UH + V) were made before and 10 to 14 days after unilateral nephrectomy in seven healthy renal donors. Comparisons were made between the functions of the remaining kidney and 50% of pre-uninephrectomy values. Mean post-uninephrectomy GFR increased by 36%, and mean ERPF, 55%. Tmglucose, Tmpah, Cphosphate, uric acid, CH2O, UH + V increased significantly, after uninephrectomy. The increase in Tmpah, Tmglucose and CH2O is proportional to the rise in GFR while the increase in Cphosphate, Curic acid and UH + V is proportionally greater than the increase in GFR. The changes in post-uninephrectomy renal handling of phosphate are not due to an increase in parathyroid hormone secretion.
Collapse
|