1
|
Hassan NH, Saleh D, Abo El-Khair SM, Almasry SM, Ibrahim A. The relation between autophagy modulation by intermittent fasting and aquaporin 2 expression in experimentally induced diabetic nephropathy in albino rat. Tissue Cell 2024; 88:102395. [PMID: 38692159 DOI: 10.1016/j.tice.2024.102395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 04/18/2024] [Accepted: 04/19/2024] [Indexed: 05/03/2024]
Abstract
Polyuria is an early sign of diabetic nephropathy (DN) that produces dehydration in diabetic patients. This could be caused by alteration of renal aquaporin 2 (AQP2) expression. This study aimed to describe the relation between autophagy modulation via intermittent fasting (IF) and renal AQP2 expression and polyuria in case of DN. We divided the rats into control, DN and IF groups. After 2 and 4 weeks of diabetes induction, blood glucose (BG), serum creatinine (Scr), urine volume, and 24 hours urine protein (UP) were examined. Diabetic nephropathy histopathological index (DNHI) was calculated to evaluate histopathological changes. Immunohistochemistry and real-time PCR were performed to measure the levels of AQP2 and the autophagy marker; LC3 in kidney tissue. DNHI was correlated to the PCR and immunoexpression of AQP2 and LC3. Intermittent fasting significantly decreased the BG, Scr, urine volume, 24 hours UP, and DNHI as compared diabetes. Diabetes significantly elevated the immunoreactivity and mRNA expression levels of AQP2 and LC3 as compared to the control. However, the IF decreased AQP2 and stimulated autophagy in cyclic fashion. Our data revealed significant positive correlations between AQP2 and LC3 at the level of immunoexpression and mRNA at 2nd weeks. Taken together, these data showed that autophagy stimulation didn't regulate AQP2 expression in case of diabetic nephropathy, however IF decreased polyuria through improvement of glycemic state.
Collapse
Affiliation(s)
- Nora Hisham Hassan
- Department of Anatomy and Embryology, Faculty of Medicine, Mansoura University, Egypt.
| | - Dalia Saleh
- Department of Anatomy and Embryology, Faculty of Medicine, Mansoura University, Egypt
| | - Salwa M Abo El-Khair
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Mansoura University, Egypt
| | - Shaima M Almasry
- Department of Anatomy and Embryology, Faculty of Medicine, Mansoura University, Egypt
| | - Amira Ibrahim
- Department of Anatomy and Embryology, Faculty of Medicine, Mansoura University, Egypt
| |
Collapse
|
2
|
Li S, Guo X, Wang H, Suo N, Mi X, Jiang S. Ectopic adrenocorticotropic hormone-secreting pheochromocytoma with severe metabolic disturbances: A case report. Int J Surg Case Rep 2024; 116:109341. [PMID: 38340623 PMCID: PMC10943668 DOI: 10.1016/j.ijscr.2024.109341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024] Open
Abstract
INTRODUCTION The occurrence of hypercortisolism resulting from adrenocorticotropic hormone (ACTH)-secreting pheochromocytoma is exceedingly uncommon, with limited documented instances thus far. PRESENTATION OF CASE We present a case of ectopic ACTH-secreting pheochromocytoma in a patient who suffered from severe metabolic disorders. Our clinical case outlines the diagnostic history, preoperative correction of the patient's metabolic disturbances and surgical strategy for management of a rare ectopic ACTH producing pheochromocytoma. DISCUSSION Ectopic adrenocorticotropic hormone-secreting pheochromocytoma displays multifaceted clinical features and requires prompt diagnosis and multidisciplinary management in order to overcome the related severe clinical derangements. CONCLUSION The combination of biochemical and hormonal testing and imaging procedures is mandatory for the diagnosis of ectopic ACTH secretion, and in the presence of an adrenal mass, the possibility of an ACTH-secreting pheochromocytoma should be taken into account.
Collapse
Affiliation(s)
- Shangjian Li
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, No. 9677, Jingshi Road, Lixia District, Jinan City, Shandong Province, China
| | - Xudong Guo
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, China
| | - Hanbo Wang
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, China
| | - Ni Suo
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, China
| | - Xiuqing Mi
- Guanxian People's Hospital, No.70 Guanyichun Road, Guan County, Liaocheng City, Shandong Province, China
| | - Shaobo Jiang
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, China.
| |
Collapse
|
3
|
Hoogstraten CA, Hoenderop JG, de Baaij JHF. Mitochondrial Dysfunction in Kidney Tubulopathies. Annu Rev Physiol 2024; 86:379-403. [PMID: 38012047 DOI: 10.1146/annurev-physiol-042222-025000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Mitochondria play a key role in kidney physiology and pathology. They produce ATP to fuel energy-demanding water and solute reabsorption processes along the nephron. Moreover, mitochondria contribute to cellular health by the regulation of autophagy, (oxidative) stress responses, and apoptosis. Mitochondrial abundance is particularly high in cortical segments, including proximal and distal convoluted tubules. Dysfunction of the mitochondria has been described for tubulopathies such as Fanconi, Gitelman, and Bartter-like syndromes and renal tubular acidosis. In addition, mitochondrial cytopathies often affect renal (tubular) tissues, such as in Kearns-Sayre and Leigh syndromes. Nevertheless, the mechanisms by which mitochondrial dysfunction results in renal tubular diseases are only scarcely being explored. This review provides an overview of mitochondrial dysfunction in the development and progression of kidney tubulopathies. Furthermore, it emphasizes the need for further mechanistic investigations to identify links between mitochondrial function and renal electrolyte reabsorption.
Collapse
Affiliation(s)
- Charlotte A Hoogstraten
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
| | - Joost G Hoenderop
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
| | - Jeroen H F de Baaij
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands;
| |
Collapse
|
4
|
Guida SJ, Bazzle L. Rebound hyperkalemia in a dog with albuterol toxicosis after cessation of potassium supplementation. J Vet Emerg Crit Care (San Antonio) 2023; 33:715-721. [PMID: 37943086 DOI: 10.1111/vec.13352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/03/2022] [Accepted: 09/23/2022] [Indexed: 11/10/2023]
Abstract
OBJECTIVE To describe the presentation of rebound hyperkalemia as a delayed side effect of albuterol toxicity in a dog. CASE SUMMARY A 3-year-old female neutered mixed-breed dog was presented for albuterol toxicosis that led to a severe hypokalemia, hyperlactatemia, and hyperglycemia. The dog also experienced sinus tachycardia and generalized weakness. Treatment was instituted with intravenous fluid therapy and potassium supplementation, and the dog was monitored with a continuous electrocardiogram. Resolution of hypokalemia was documented 12 hours after initial presentation, at which time fluid therapy and potassium supplementation were discontinued. There were no further periods of sinus tachycardia, but instead the dog developed ventricular ectopy with rapid couplets (instantaneous rates of 300/min). An echocardiogram revealed normal cardiac size and function. Twenty-four hours after presentation, the patient developed severe hyperkalemia, despite discontinuation of fluids and potassium supplementation for 12 hours. Serial venous and urinary electrolytes were performed for determination of the fractional excretion of electrolytes. These data confirmed rebound hyperkalemia (7.0 mmol/L), consistent with a markedly increased fractional excretion of potassium, and secondary to the release of potassium from inside the cells. Fluid therapy with dextrose supplementation was provided until 36 hours postpresentation. The hyperkalemia resolved, and the dog was discharged after 44 hours of hospitalization. NEW OR UNIQUE INFORMATION PROVIDED This case documents rebound hyperkalemia following treatment of albuterol toxicosis in a dog. This case highlights the importance of understanding the distribution of total body potassium when treating serum hypokalemia. Transcellular shifts of potassium, as in the case of albuterol toxicosis, can lead to rebound hyperkalemia even after discontinuation of potassium supplementation. This case further explores the utility of fractional excretion of electrolytes in elucidating the etiology and management of electrolyte disturbances.
Collapse
Affiliation(s)
- Samantha J Guida
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, Georgia, USA
| | - Lisa Bazzle
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, Georgia, USA
| |
Collapse
|
5
|
Guo X, Kong Y, Kwon TH, Li C, Wang W. Autophagy and regulation of aquaporins in the kidneys. Kidney Res Clin Pract 2023; 42:676-685. [PMID: 37098672 DOI: 10.23876/j.krcp.22.247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 12/20/2022] [Indexed: 04/27/2023] Open
Abstract
Aquaporins (AQPs) are water channel proteins that facilitate the transport of water molecules across cell membranes. To date, seven AQPs have been found to be expressed in mammal kidneys. The cellular localization and regulation of the transport properties of AQPs in the kidney have been widely investigated. Autophagy is known as a highly conserved lysosomal pathway, which degrades cytoplasmic components. Through basal autophagy, kidney cells maintain their functions and structure. As a part of the adaptive responses of the kidney, autophagy may be altered in response to stress conditions. Recent studies revealed that autophagic degradation of AQP2 in the kidney collecting ducts leads to impaired urine concentration in animal models with polyuria. Therefore, the modulation of autophagy could be a therapeutic approach to treat water balance disorders. However, as autophagy is either protective or deleterious, it is crucial to establish an optimal condition and therapeutic window where autophagy induction or inhibition could yield beneficial effects. Further studies are needed to understand both the regulation of autophagy and the interaction between AQPs and autophagy in the kidneys in renal diseases, including nephrogenic diabetes insipidus.
Collapse
Affiliation(s)
- Xiangdong Guo
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yonglun Kong
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Tae-Hwan Kwon
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Chunling Li
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Weidong Wang
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
6
|
Birtolo MF, Grossrubatscher EM, Antonini S, Loli P, Mazziotti G, Lania AG, Chiodini I. Preoperative management of patients with ectopic Cushing's syndrome caused by ACTH-secreting pheochromocytoma: a case series and review of the literature. J Endocrinol Invest 2023; 46:1983-1994. [PMID: 37195583 DOI: 10.1007/s40618-023-02105-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/26/2023] [Indexed: 05/18/2023]
Abstract
PURPOSE ACTH-secreting pheochromocytoma is a rare cause of ectopic Cushing's syndrome, posing a clinical challenge for the severity of its clinical presentation, the difficulty in the prevention and the management of surgical complications. Sparse data are currently available about the optimal preoperative management of the severe symptoms due to both hypercortisolism and catecholamine excess, especially regarding the role and timing of medical therapies. METHODS We present a series of three patients with ACTH-secreting pheochromocytoma. A brief review of the available literature evidence on the preoperative management of this rare clinical condition is also conducted. DISCUSSION Patients with ACTH-secreting pheochromocytoma show peculiarities as compared to other forms of ACTH-dependent Cushing's syndrome, in terms of clinical presentation, preoperative management, and peri- and post-surgical short-term outcome. Pheochromocytoma should be ruled out in patient with ectopic CS of unknown origin because of the high anesthesiologic risk of proceeding to surgery with an undiagnosed pheochromocytoma. Proper preoperative recognition of complications of both hypercortisolism and catecholamines excess is the key to prevent the morbidity and mortality of an ACTH-producing pheochromocytoma. In these patients the absolute priority is to control excessive cortisol secretion since the rapid correction of the hypercortisolism is the most effective treatment of all the related comorbidities and it is mandatory to prevent severe complications during surgery, opting if necessary for a "block-and-replace" regimen. CONCLUSION Our additional cases and this literature review could provide a better understanding of the complications to be evaluated at diagnosis and some suggestions on their management during the preoperative period.
Collapse
Affiliation(s)
- M F Birtolo
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4 Pieve Emanuele, 20090, Milan, Italy
- Endocrinology, Diabetology and Medical Andrology Unit, IRCCS Humanitas Research Hospital, Via Manzoni 56 Rozzano, 20089, Milan, Italy
| | - E M Grossrubatscher
- Endocrine Unit, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162, Milan, Italy
| | - S Antonini
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4 Pieve Emanuele, 20090, Milan, Italy
- Endocrinology, Diabetology and Medical Andrology Unit, IRCCS Humanitas Research Hospital, Via Manzoni 56 Rozzano, 20089, Milan, Italy
| | - P Loli
- Endocrinology, Clinica San Carlo, Via Ospedale 21, 20037 Paderno Dugnano, Milan, Italy
| | - G Mazziotti
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4 Pieve Emanuele, 20090, Milan, Italy
- Endocrinology, Diabetology and Medical Andrology Unit, IRCCS Humanitas Research Hospital, Via Manzoni 56 Rozzano, 20089, Milan, Italy
| | - A G Lania
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4 Pieve Emanuele, 20090, Milan, Italy.
- Endocrinology, Diabetology and Medical Andrology Unit, IRCCS Humanitas Research Hospital, Via Manzoni 56 Rozzano, 20089, Milan, Italy.
| | - I Chiodini
- Endocrine Unit, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, University of Milan, 20122, Milan, Italy
| |
Collapse
|
7
|
Xu C, Yi X, Tang L, Wang H, Chu S, Yu J. Differential regulation of autophagy on urine-concentrating capability through modulating the renal AQP2 expression and renin-angiotensin system in mice. Am J Physiol Renal Physiol 2023; 325:F503-F518. [PMID: 37589054 DOI: 10.1152/ajprenal.00018.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 08/02/2023] [Accepted: 08/07/2023] [Indexed: 08/18/2023] Open
Abstract
Autophagy, a cellular process of "self-eating," plays an essential role in renal pathophysiology. However, the effect of autophagy on urine-concentrating ability in physiological conditions is still unknown. This study aimed to determine the relevance and mechanisms of autophagy for maintaining urine-concentrating capability during antidiuresis. The extent of the autophagic response to water deprivation (WD) was different between the renal cortex and medulla in mice. Autophagy activity levels in the renal cortex were initially suppressed and then stimulated by WD in a time-dependent manner. During 48 h WD, the urine-concentrating capability of mice was impaired by rapamycin (Rapa) but not by 3-methyladenine (3-MA), accompanied by suppressed renal aquaporin 2 (AQP2), V2 receptor (V2R), renin, and angiotensin-converting enzyme (ACE) expression, and levels of prorenin/renin, angiotensin II (ANG II), and aldosterone in the plasma and urine. In contrast, 3-MA and chloroquine (CQ) suppressed the urine-concentrating capability in WD72 mice, accompanied by downregulation of AQP2 and V2R expression in the renal cortex. 3-MA and CQ further increased AQP2 and V2R expression in the renal medulla of WD72 mice. Compared with 3-MA and CQ, Rapa administration yielded completely opposite results on the above parameters in WD72 mice. In addition, 3-MA and CQ abolished the upregulation of prorenin/renin, ANG II, and aldosterone levels in the plasma and urine in WD72 mice. Taken together, our study demonstrated that autophagy regulated urine-concentrating capability through differential regulation of renal AQP2/V2R and ACE/ANG II signaling during WD.NEW & NOTEWORTHY Autophagy exhibits a double-edged effect on cell survival and plays an essential role in renal pathophysiology. We for the first time reported a novel function of autophagy that controls the urine-concentrating capability in physiological conditions. We found that water deprivation (WD) differentially regulated autophagy in the kidneys of mice in a time-dependent manner and autophagy regulates the urine-concentrating capability mainly by regulating AQP2/V2R and ACE/ANG II signaling in the renal cortex in WD mice.
Collapse
Affiliation(s)
- Chuanming Xu
- Translational Medicine Centre, Jiangxi University of Chinese Medicine, Nanchang, People's Republic of China
| | - Xiaoli Yi
- Translational Medicine Centre, Jiangxi University of Chinese Medicine, Nanchang, People's Republic of China
| | - Le Tang
- Translational Medicine Centre, Jiangxi University of Chinese Medicine, Nanchang, People's Republic of China
| | - Hui Wang
- Translational Medicine Centre, Jiangxi University of Chinese Medicine, Nanchang, People's Republic of China
| | - Shuhan Chu
- Translational Medicine Centre, Jiangxi University of Chinese Medicine, Nanchang, People's Republic of China
| | - Jun Yu
- Center for Metabolic Disease Research and Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States
| |
Collapse
|
8
|
Mak A, Sung CC, Pisitkun T, Khositseth S, Knepper MA. 'Aquaporin-omics': mechanisms of aquaporin-2 loss in polyuric disorders. J Physiol 2023:10.1113/JP284634. [PMID: 37114282 PMCID: PMC10603215 DOI: 10.1113/jp284634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/21/2023] [Indexed: 04/29/2023] Open
Abstract
Animal models of a variety of acquired nephrogenic diabetes insipidus (NDI) disorders have identified a common feature: all such models are associated with the loss of aquaporin-2 (AQP2) from collecting duct principal cells, explaining the associated polyuria. To discover mechanisms of AQP2 loss, previous investigators have carried out either transcriptomics (lithium-induced NDI, unilateral ureteral obstruction, endotoxin-induced NDI) or proteomics (hypokalaemia-associated NDI, hypercalcaemia-associated NDI, bilateral ureteral obstruction), yielding contrasting views. Here, to address whether there may be common mechanisms underlying loss of AQP2 in acquired NDI disorders, we have used bioinformatic data integration techniques to combine information from all transcriptomic and proteomic data sets. The analysis reveals roles for autophagy/apoptosis, oxidative stress and inflammatory signalling as key elements of the mechanism that results in loss of AQP2. These processes can cause AQP2 loss through the combined effects of repression of Aqp2 gene transcription, generalized translational repression, and increased autophagic degradation of proteins including AQP2. Two possible types of stress-sensor proteins, namely death receptors and stress-sensitive protein kinases of the EIF2AK family, are discussed as potential triggers for signalling processes that result in loss of AQP2. KEY POINTS: Prior studies have shown in a variety of animal models of acquired nephrogenic diabetes insipidus (NDI) that loss of the aquaporin-2 (AQP2) protein is a common feature. Investigations of acquired NDI using transcriptomics (RNA-seq) and proteomics (protein mass spectrometry) have led to differing conclusions regarding mechanisms of AQP2 loss. Bioinformatic integration of transcriptomic and proteomic data from these prior studies now reveals that acquired NDI models map to three core processes: oxidative stress, apoptosis/autophagy and inflammatory signalling. These processes cause loss of AQP2 through translational repression, accelerated degradation of proteins, and transcriptional repression.
Collapse
Affiliation(s)
- Angela Mak
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Chih-Chien Sung
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Trairak Pisitkun
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
- Center of Excellence in Systems Biology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Sookkasem Khositseth
- Department of Pediatrics, Faculty of Medicine, Thammasat University, Bangkok,Thailand
| | - Mark A. Knepper
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
9
|
Little R, Murali SK, Poulsen SB, Grimm PR, Assmus A, Cheng L, Ivy JR, Hoorn EJ, Matchkov V, Welling PA, Fenton RA. Dissociation of sodium-chloride cotransporter expression and blood pressure during chronic high dietary potassium supplementation. JCI Insight 2023; 8:156437. [PMID: 36719746 PMCID: PMC10077486 DOI: 10.1172/jci.insight.156437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/25/2023] [Indexed: 02/01/2023] Open
Abstract
Dietary potassium (K+) supplementation is associated with a lowering effect in blood pressure (BP), but not all studies agree. Here, we examined the effects of short- and long-term K+ supplementation on BP in mice, whether differences depend on the accompanying anion or the sodium (Na+) intake and molecular alterations in the kidney that may underlie BP changes. Relative to the control diet, BP was higher in mice fed a high NaCl (1.57% Na+) diet for 7 weeks or fed a K+-free diet for 2 weeks. BP was highest on a K+-free/high NaCl diet. Commensurate with increased abundance and phosphorylation of the thiazide sensitive sodium-chloride-cotransporter (NCC) on the K+-free/high NaCl diet, BP returned to normal with thiazides. Three weeks of a high K+ diet (5% K+) increased BP (predominantly during the night) independently of dietary Na+ or anion intake. Conversely, 4 days of KCl feeding reduced BP. Both feeding periods resulted in lower NCC levels but in increased levels of cleaved (active) α and γ subunits of the epithelial Na+ channel ENaC. The elevated BP after chronic K+ feeding was reduced by amiloride but not thiazide. Our results suggest that dietary K+ has an optimal threshold where it may be most effective for cardiovascular health.
Collapse
Affiliation(s)
- Robert Little
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Søren B Poulsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Paul R Grimm
- Departments of Medicine, Nephrology and Physiology, Johns Hopkins School of Medicine, Baltimore, USA
| | - Adrienne Assmus
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Lei Cheng
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Jessica R Ivy
- University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ewout J Hoorn
- Department of Internal Medicine, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | | | - Paul A Welling
- Departments of Medicine, Nephrology and Physiology, Johns Hopkins School of Medicine, Baltimore, USA
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
10
|
Angelousi A, Alexandraki KI, Mytareli C, Grossman AB, Kaltsas G. New developments and concepts in the diagnosis and management of diabetes insipidus (AVP-deficiency and resistance). J Neuroendocrinol 2023; 35:e13233. [PMID: 36683321 DOI: 10.1111/jne.13233] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/10/2022] [Accepted: 12/29/2022] [Indexed: 01/04/2023]
Abstract
Diabetes insipidus (DI) is a disorder characterised by the excretion of large amounts of hypotonic urine, with a prevalence of 1 per 25,000 population. Central DI (CDI), better now referred to as arginine vasopressin (AVP)-deficiency, is the most common form of DI resulting from deficiency of the hormone AVP from the pituitary. The less common nephrogenic DI (NDI) or AVP-resistance develops secondary to AVP resistance in the kidneys. The majority of causes of DI are acquired, with CDI developing when more than 80% of AVP-secreting neurons are damaged. Inherited/familial CDI causes account for approximately 1% of cases. Although the pathogenesis of NDI is unclear, more than 280 disease-causing mutations affecting the AVP2 protein or AVP V2 receptor, as well as in aquaporin 2 (AQP2), have been described. Although the cAMP/protein kinase A pathway remains the major regulatory pathway of AVP/AQP2 action, in vitro data have also revealed additional cAMP independent pathways of NDI pathogenesis. Diagnosing partial forms of DI, and distinguishing them from primary polydipsia, can be challenging, previously necessitating the use of the water deprivation test. However, measurements of circulating copeptin levels, especially after stimulation, are increasingly replacing the classical tests in clinical practice because of their ease of use and high sensitivity and specificity. The treatment of CDI relies on desmopressin administration, whereas NDI requires the management of any underlying diseases, removal of offending drugs and, in some cases, administration of diuretics. A better understanding of the pathophysiology of DI has led to novel evolving therapeutic agents that are under clinical trial.
Collapse
Affiliation(s)
- Anna Angelousi
- First Department of Internal Medicine, Unit of Endocrinology, Laikon Hospital, Athens, Greece
| | | | - Chrysoula Mytareli
- First Department of Internal Medicine, Unit of Endocrinology, Laikon Hospital, Athens, Greece
| | - Ashley B Grossman
- Green Templeton College, University of Oxford, Oxford, UK
- Centre for Endocrinology, Barts and the London School of Medicine, London, UK
- NET Unit, Royal Free Hospital, London, UK
| | - Gregory Kaltsas
- First Department of Propaedeutic Internal Medicine, Laikon Hospital, National & Kapodistrian University of Athens, Athens, Greece
| |
Collapse
|
11
|
Sandhya P, Akaishi T, Fujihara K, Aoki M. A novel association of osmotic demyelination in Sjögren's syndrome prompts revisiting role of aquaporins in CNS demyelinating diseases: A literature review. Mult Scler Relat Disord 2023; 69:104466. [PMID: 36584554 DOI: 10.1016/j.msard.2022.104466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/21/2022] [Accepted: 12/10/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Primary Sjögren's syndrome (SS) is a chronic systemic autoimmune disease with varied neurological manifestations. SS is associated with anti-aquaporin-4 antibody (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD), a demyelinating autoimmune disorder of the central nervous system (CNS). Intriguingly, there are reports of osmotic demyelinating syndrome (ODS), a supposedly non-inflammatory disorder, in the context of SS and renal tubular acidosis (RTA), both of which are not yet established risk factors for ODS. METHODS A literature search was undertaken to identify case reports of ODS in patients with SS. Details of the clinical and laboratory features of these patients were compiled. Additionally, we searched for NMOSD in patients with SS. We looked for co-existing RTA in patients with SS-ODS as well as SS-NMOSD. We also screened for reports of ODS in RTA without underlying SS. RESULTS & DISCUSSION We identified 15 patients (all women, median age 40 years) with ODS in SS, and all of these patients had comorbid RTA. There were only three reported cases of ODS in RTA without underlying SS. We identified a total of 67 patients with SS-NMOSD, of whom only 3 (4.5%) had RTA. Hence, unlike NMOSD, the development of ODS in SS requires a prolonged osmotic or electrolyte abnormality caused by the comorbid RTA. The 15 patients with ODS and SS -RTA, showed heterogeneous clinical manifestations and outcomes. The most common symptom was quadriparesis, seen in 14 of the 15 patients. Eleven of the 15 patients had one of the following features, either alone or in combination: worsening of the sensorium, extensor plantar response, dysphagia/dysarthria, and facial palsy. The latter four manifestations were present at the onset in 7 patients and later in the course of the illness in the remaining 4 patients. Ocular palsy was seen in only four of the 15 patients and was a late manifestation. One patient who had extensive long-segment myelitis and subsequent ODS died, but most patients recovered without significant sequelae. None had hyponatremia, while all patients had hypokalemia and/or hypernatremia. Hypokalemia causing nephrogenic diabetes insipidus (NDI) followed by rapid rise in sodium and the resultant osmotic stress could potentially explain the occurrence of ODS in SS-RTA. Aquaporin (AQP) in astrocytes is implicated in ODS, and renal AQP is downregulated in NDI. Antibodies against AQPs are present in some patients with SS. Defective AQP is therefore a common link underlying all the connected diseases, namely SS, NDI, and ODS, raising the possibility of immune-mediated AQP dysfunction in the pathogenesis. CONCLUSION The hitherto unreported association between SS-RTA and ODS may implicate SS and/or RTA in the development of ODS. In the setting of SS-RTA, ODS must be suspected when a patient with flaccid quadriparesis does not respond to the correction of potassium or develops additional neurological features along with a rise in sodium. Defective functions of AQPs may be a possible mechanism linking demyelinating CNS lesions, SS, and RTA. Studies evaluating AQP functions and serum antibodies against AQPs in these conditions are warranted.
Collapse
Affiliation(s)
- Pulukool Sandhya
- Department of Rheumatology, St Stephen's Hospital, Delhi-110054, India.
| | - Tetsuya Akaishi
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Kazuo Fujihara
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Masashi Aoki
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
| |
Collapse
|
12
|
Abstract
The kidneys, by equilibrating the outputs to the inputs, are essential for maintaining the constant volume, pH, and electrolyte composition of the internal milieu. Inability to do so, either because of internal kidney dysfunction (primary alteration) or because of some external factors (secondary alteration), leads to pathologies of varying severity, leading to modification of these parameters and affecting the functions of other organs. Alterations of the functions of the collecting duct (CD), the most distal part of the nephron, have been extensively studied and have led to a better diagnosis, better management of the related diseases, and the development of therapeutic tools. Thus, dysfunctions of principal cell-specific transporters such as ENaC or AQP2 or its receptors (mineralocorticoid or vasopressin receptors) caused by mutations or by compounds present in the environment (lithium, antibiotics, etc.) have been demonstrated in a variety of syndromes (Liddle, pseudohypoaldosteronism type-1, diabetes insipidus, etc.) affecting salt, potassium, and water balance. In parallel, studies on specific transporters (H+ -ATPase, anion exchanger 1) in intercalated cells have revealed the mechanisms of related tubulopathies like distal renal distal tubular acidosis or Sjögren syndrome. In this review, we will recapitulate the mechanisms of most of the primary and secondary alteration of the ion transport system of the CD to provide a better understanding of these diseases and highlight how a targeted perturbation may affect many different pathways due to the strong crosstalk and entanglements between the different actors (transporters, cell types).
Collapse
Affiliation(s)
- Nahid Tabibzadeh
- Laboratoire de Physiologie Rénale et Tubulopathies, Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France.,EMR 8228 Unité Métabolisme et Physiologie Rénale, CNRS, Paris, France.,Assistance Publique Hôpitaux de Paris, Hôpital Bichât, Paris, France
| | - Gilles Crambert
- Laboratoire de Physiologie Rénale et Tubulopathies, Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France.,EMR 8228 Unité Métabolisme et Physiologie Rénale, CNRS, Paris, France
| |
Collapse
|
13
|
Abstract
Hypernatremia occurs when the plasma sodium concentration is greater than 145 mmol/L. Depending on the duration, hypernatremia can be differentiated into acute and chronic. According to severity: mild, moderate and threatening hypernatremia. Finally, depending on pathogenesis, hypernatremia can be defined as hypervolemic, hypovolemic, and euvolemic. Acute hypervolemic hypernatremia is often secondary to increased sodium intake (hypertonic NaCl and NaHCO3 solutions). Instead, chronic hypervolemic hypernatremia may be an expression of primary hyperaldosteronism. Euvolemic hypernatremia occurs in diabetes insipidus: depending on the underlying pathogenesis, it can be classified into two basic types: neurogenic (or central) and nephrogenic. The neurogenic form may be triggered by traumatic, vascular or infectious events; the nephrogenic form may be due to pharmacological causes, such as lithium, or non-pharmacological ones, such as hypokalemia. For hypovolemic hypernatremia, possible explanations are renal or extrarenal losses. The main goal of treatment of hypernatremia is the restoration of plasma tonicity. In particular, if the imbalance has occurred acutely, rapid correction improves the prognosis by preventing the effects of cellular dehydration; if hypernatremia has developed slowly, over a period of days, a slow correction rate (no more than 0.4 mmol/L/h) is recommended.
Collapse
Affiliation(s)
- Alfonso Ilardi
- Department of Internal Medicine, Inmates ward, "Antonio Cardarelli" Hospital, Naples, Italy
| |
Collapse
|
14
|
Centrone M, Ranieri M, Di Mise A, D’agostino M, Venneri M, Ferrulli A, Valenti G, Tamma G. AQP2 trafficking in health and diseases: an updated overview. Int J Biochem Cell Biol 2022. [DOI: 10.1016/j.biocel.2022.106261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 05/25/2022] [Accepted: 06/30/2022] [Indexed: 11/23/2022]
|
15
|
Vaz de Castro PAS, Bitencourt L, de Oliveira Campos JL, Fischer BL, Soares de Brito SBC, Soares BS, Drummond JB, Simões E Silva AC. Nephrogenic diabetes insipidus: a comprehensive overview. J Pediatr Endocrinol Metab 2022; 35:421-434. [PMID: 35146976 DOI: 10.1515/jpem-2021-0566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 01/26/2022] [Indexed: 12/14/2022]
Abstract
Nephrogenic diabetes insipidus (NDI) is characterized by the inability to concentrate urine that results in polyuria and polydipsia, despite having normal or elevated plasma concentrations of arginine vasopressin (AVP). In this study, we review the clinical aspects and diagnosis of NDI, the various etiologies, current treatment options and potential future developments. NDI has different clinical manifestations and approaches according to the etiology. Hereditary forms of NDI are mainly caused by mutations in the genes that encode key proteins in the AVP signaling pathway, while acquired causes are normally associated with specific drug exposure, especially lithium, and hydroelectrolytic disorders. Clinical manifestations of the disease vary according to the degree of dehydration and hyperosmolality, being worse when renal water losses cannot be properly compensated by fluid intake. Regarding the diagnosis of NDI, it is important to consider the symptoms of the patient and the diagnostic tests, including the water deprivation test and the baseline plasma copeptin measurement, a stable surrogate biomarker of AVP release. Without proper treatment, patients may developcomplications leading to high morbidity and mortality, such as severe dehydration and hypernatremia. In that sense, the treatment of NDI consists in decreasing the urine output, while allowing appropriate fluid balance, normonatremia, and ensuring an acceptable quality of life. Therefore, therapeutic options include nonpharmacological interventions, including sufficient water intake and a low-sodium diet, and pharmacological treatment. The main medications used for NDI are thiazide diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), and amiloride, used isolated or in combination.
Collapse
Affiliation(s)
- Pedro Alves Soares Vaz de Castro
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Letícia Bitencourt
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Juliana Lacerda de Oliveira Campos
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Bruna Luisa Fischer
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Stephanie Bruna Camilo Soares de Brito
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Beatriz Santana Soares
- Division of Endocrinology, Department of Internal Medicine, Faculty of Medicine, UFMG, Belo Horizonte, Brazil
| | - Juliana Beaudette Drummond
- Division of Endocrinology, Department of Internal Medicine, Faculty of Medicine, UFMG, Belo Horizonte, Brazil
| | - Ana Cristina Simões E Silva
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| |
Collapse
|
16
|
Xu L, Xie H, Hu S, Zhao X, Han M, Liu Q, Feng P, Wang W, Li C. HDAC3 inhibition improves urinary-concentrating defect in hypokalaemia by promoting AQP2 transcription. Acta Physiol (Oxf) 2022; 234:e13802. [PMID: 35178888 DOI: 10.1111/apha.13802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 11/27/2022]
Abstract
AIM This study investigated whether enhanced histone acetylation, achieved by inhibiting histone deacetylases (HDACs), could prevent decreased aquaporin-2 (AQP2) expression during hypokalaemia. METHODS Male Wistar rats were fed a potassium-free diet with or without 4-phenylbutyric acid (4-PBA) or the selective HDAC3 inhibitor RGFP966 for 4 days. Primary renal inner medullary collecting duct (IMCD) cells and immortalized mouse cortical collecting duct (mpkCCD) cells were cultured in potassium-deprivation medium with or without HDAC inhibitors. RESULTS 4-PBA increased the levels of AQP2 mRNA and protein in the kidney inner medullae in hypokalaemic (HK) rats, which was associated with decreased urine output and increased urinary osmolality. The level of acetylated H3K27 (H3K27ac) protein was decreased in the inner medullae of HK rat kidneys; this decrease was mitigated by 4-PBA. The H3K27ac levels were decreased in IMCD and mpkCCD cells cultured in potassium-deprivation medium. Decreased H3K27ac in the Aqp2 promoter region was associated with reduced Aqp2 mRNA levels. HDAC3 protein expression was upregulated in mpkCCD and IMCD cells in response to potassium deprivation, and the binding of HDAC3 to the Aqp2 promoter was also increased. RGFP966 increased the levels of H3K27ac and AQP2 proteins and enhanced binding between H3K27ac and AQP2 in mpkCCD cells. Furthermore, RGFP966 reversed the hypokalaemia-induced downregulation of AQP2 and H3K27ac and alleviated polyuria in rats. RGFP966 increased interstitial osmolality in the kidney inner medullae of HK rats but did not affect urinary cAMP levels. CONCLUSION HDAC inhibitors prevented the downregulation of AQP2 induced by potassium deprivation, probably by enhancing H3K27 acetylation.
Collapse
Affiliation(s)
- Long Xu
- Institute of Hypertension Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- Department of Physiology Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
| | - Haixia Xie
- Institute of Hypertension Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- Department of Physiology Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
| | - Shan Hu
- Institute of Hypertension Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- The School of Basic Medicine Guangzhou University of Chinese Medicine Guangzhou China
| | - Xiaoduo Zhao
- Institute of Hypertension Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- Department of Pathophysiology Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
| | - Mengke Han
- Institute of Hypertension Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- Department of Physiology Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
| | - Qiaojuan Liu
- Institute of Hypertension Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- Department of Physiology Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
| | - Pinning Feng
- Department of Clinical Laboratory The First Affiliated Hospital Sun Yat‐sen University Guangzhou China
| | - Weidong Wang
- Institute of Hypertension Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- Department of Pathophysiology Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- Department of Nephrology The Seventh Affiliated Hospital Sun Yat‐sen University Shenzhen China
| | - Chunling Li
- Institute of Hypertension Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
- Department of Physiology Zhongshan School of Medicine Sun Yat‐sen University Guangzhou China
| |
Collapse
|
17
|
Wu A, Wolley MJ, Wu Q, Cowley D, Palmfeldt J, Welling PA, Fenton RA, Stowasser M. Acute Intravenous NaCl and Volume Expansion Reduces Sodium-Chloride Cotransporter Abundance and Phosphorylation in Urinary Extracellular Vesicles. Kidney360 2022; 3:910-921. [PMID: 36128481 PMCID: PMC9438418 DOI: 10.34067/kid.0000362022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/28/2022] [Indexed: 01/12/2023]
Abstract
Background Sodium chloride (NaCl) loading and volume expansion suppress the renin-angiotensin-aldosterone system to reduce renal tubular reabsorption of NaCl and water, but effects on the sodium-chloride cotransporter (NCC) and relevant renal transmembrane proteins that are responsible for this modulation in humans are less well investigated. Methods We used urinary extracellular vesicles (uEVs) as an indirect readout to assess renal transmembrane proteins involved in NaCl and water homeostasis in 44 patients with hypertension who had repeatedly raised aldosterone/renin ratios undergoing infusion of 2 L of 0.9% saline over 4 hours. Results When measured by mass spectrometry in 13 patients, significant decreases were observed in NCC (median fold change [FC]=0.70); pendrin (FC=0.84); AQP2 (FC=0.62); and uEV markers, including ALIX (FC=0.65) and TSG101 (FC=0.66). Immunoblotting reproduced the reduction in NCC (FC=0.54), AQP2 (FC=0.42), ALIX (FC=0.52), and TSG101 (FC=0.55) in the remaining 31 patients, and demonstrated a significant decrease in phosphorylated NCC (pNCC; FC=0.49). However, after correction for ALIX, the reductions in NCC (FC=0.90) and pNCC (FC=1.00) were no longer apparent, whereas the significant decrease in AQP2 persisted (FC=0.62). Conclusion We conclude that (1) decreases in NCC and pNCC, induced by acute NaCl loading and volume expansion, may be due to diluted post-test urines; (2) the lack of change of NCC and pNCC when corrected for ALIX, despite a fall in plasma aldosterone, may be due to the lack of change in plasma K+; and (3) the decrease in AQP2 may be due to a decrease in vasopressin in response to volume expansion.
Collapse
Affiliation(s)
- Aihua Wu
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
| | - Martin J. Wolley
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia,Department of Nephrology, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Qi Wu
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Diane Cowley
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
| | - Johan Palmfeldt
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Paul A. Welling
- Department of Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland
| | | | - Michael Stowasser
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
| |
Collapse
|
18
|
Wieërs MLAJ, Mulder J, Rotmans JI, Hoorn EJ. Potassium and the kidney: a reciprocal relationship with clinical relevance. Pediatr Nephrol 2022; 37:2245-2254. [PMID: 35195759 PMCID: PMC9395506 DOI: 10.1007/s00467-022-05494-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/02/2022] [Accepted: 02/02/2022] [Indexed: 10/26/2022]
Abstract
By controlling urinary potassium excretion, the kidneys play a key role in maintaining whole-body potassium homeostasis. Conversely, low urinary potassium excretion (as a proxy for insufficient dietary intake) is increasingly recognized as a risk factor for the progression of kidney disease. Thus, there is a reciprocal relationship between potassium and the kidney: the kidney regulates potassium balance but potassium also affects kidney function. This review explores this relationship by discussing new insights into kidney potassium handling derived from recently characterized tubulopathies and studies on sexual dimorphism. These insights reveal a central but non-exclusive role for the distal convoluted tubule in sensing potassium and subsequently modifying the activity of the sodium-chloride cotransporter. This is another example of reciprocity: activation of the sodium-chloride cotransporter not only reduces distal sodium delivery and therefore potassium secretion but also increases salt sensitivity. This mechanism helps explain the well-known relationship between dietary potassium and blood pressure. Remarkably, in children, blood pressure is related to dietary potassium but not sodium intake. To explore how potassium deficiency can cause kidney injury, we review the mechanisms of hypokalemic nephropathy and discuss if these mechanisms may explain the association between low dietary potassium intake and adverse kidney outcomes. We discuss if potassium should be repleted in patients with kidney disease and what role dietary potassium plays in the risk of hyperkalemia. Supported by data and physiology, we reach the conclusion that we should view potassium not only as a potentially dangerous cation but also as a companion in the battle against kidney disease.
Collapse
Affiliation(s)
- Michiel L. A. J. Wieërs
- grid.5645.2000000040459992XDepartment of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Room Ns403, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Jaap Mulder
- grid.5645.2000000040459992XDepartment of Pediatrics, Division of Pediatric Nephrology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands ,grid.10419.3d0000000089452978Department of Pediatrics, Division of Pediatric Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Joris I. Rotmans
- grid.10419.3d0000000089452978Department of Internal Medicine, Division of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ewout J. Hoorn
- grid.5645.2000000040459992XDepartment of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Room Ns403, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| |
Collapse
|
19
|
Saha S, Mukherjee S, Guha G, Mukhopadhyay D. Dynamics of AQP4 upon exposure to seropositive patient serum before and after Rituximab therapy in Neuromyelitis Optica: A cell-based study. J Neuroimmunol 2021; 361:577752. [PMID: 34715591 DOI: 10.1016/j.jneuroim.2021.577752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 09/27/2021] [Accepted: 10/12/2021] [Indexed: 10/20/2022]
Abstract
Neuromyelitis Optica (NMO) is an autoimmune inflammatory disease that affects the optic nerves and spinal cord. The autoantibody is generated against the abundant water channel protein of the brain, Aquaporin 4 (AQP4). Of the two isoforms of AQP4, the shorter one (M23) often exists as a supramolecular assembly known as an orthogonal array of particles (OAPs). There have been debates about the fate of these AQP4 clusters upon binding to the antibody, the exact mechanism of its turnover, and the proteins associated with the process. Recently several clinical cases of NMO were reported delineating the effect of Rituximab (RTX) therapy. Extending these reports at the cell signaling level, we developed a glioma based cellular model that mimicked antibody binding and helped us track the subsequent events including a variation of AQP4 levels, alterations in cellular morphology, and the changes in downstream signaling cascades. Our results revealed the extent of perturbations in the signaling pathways related to stress involving ERK, JNK, and AKT1 together with markers for cell death. We could also decipher the possible routes of degradation of AQP4, post-exposure to antibody. We further investigated the effect of autoantibody on AQP4 transcriptional level and involvement of FOXO3a and miRNA-145 in the regulation of transcription. This study highlights the differential outcome at the cellular level when treated with the serum of the same patient pre and post RTX therapy and for the first time mechanistically describes the effect of RTX.
Collapse
Affiliation(s)
- Suparna Saha
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, HBNI.Sector - 1, Block - AF Bidhannagar, Kolkata 700064, India.
| | - Soumava Mukherjee
- Department of Neurology, Nil Ratan Sircar Medical College and Hospital, West Bengal University of Health Sciences, Kolkata, West Bengal, India
| | - Gautam Guha
- Department of Neurology, Nil Ratan Sircar Medical College and Hospital, West Bengal University of Health Sciences, Kolkata, West Bengal, India
| | - Debashis Mukhopadhyay
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, HBNI.Sector - 1, Block - AF Bidhannagar, Kolkata 700064, India.
| |
Collapse
|
20
|
Noda Y, Sasaki S. Updates and Perspectives on Aquaporin-2 and Water Balance Disorders. Int J Mol Sci 2021; 22:ijms222312950. [PMID: 34884753 PMCID: PMC8657825 DOI: 10.3390/ijms222312950] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/29/2021] [Accepted: 11/29/2021] [Indexed: 12/31/2022] Open
Abstract
Ensuring the proper amount of water inside the body is essential for survival. One of the key factors in the maintenance of body water balance is water reabsorption in the collecting ducts of the kidney, a process that is regulated by aquaporin-2 (AQP2). AQP2 is a channel that is exclusively selective for water molecules and impermeable to ions or other small molecules. Impairments of AQP2 result in various water balance disorders, including nephrogenic diabetes insipidus (NDI), which is a disease characterized by a massive loss of water through the kidney and consequent severe dehydration. Dysregulation of AQP2 is also a cause of water retention with hyponatremia in heart failure, hepatic cirrhosis, and syndrome of inappropriate antidiuretic hormone secretion (SIADH). Antidiuretic hormone vasopressin is an upstream regulator of AQP2. Its binding to the vasopressin V2 receptor promotes AQP2 targeting to the apical membrane and thus enables water reabsorption. Tolvaptan, a vasopressin V2 receptor antagonist, is effective and widely used for water retention with hyponatremia. However, there are no studies showing improvement in hard outcomes or long-term prognosis. A possible reason is that vasopressin receptors have many downstream effects other than AQP2 function. It is expected that the development of drugs that directly target AQP2 may result in increased treatment specificity and effectiveness for water balance disorders. This review summarizes recent progress in studies of AQP2 and drug development challenges for water balance disorders.
Collapse
Affiliation(s)
- Yumi Noda
- Department of Nephrology, Nitobe Memorial Nakano General Hospital, Tokyo 164-8607, Japan
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
- Correspondence: ; Tel.: +81-3-3382-1231; Fax: +81-3-3382-1588
| | - Sei Sasaki
- Department of Nephrology, Cellular and Structural Physiology Laboratory, Tokyo Medical and Dental University, Tokyo 113-8519, Japan;
| |
Collapse
|
21
|
Abstract
Central pontine myelinolysis (CPM) develops due to acute hypernatremia from a normal baseline serum sodium in the setting of electrolyte abnormalities induced by topiramate use. Topiramate is a commonly used medication with several indications including migraines, myoclonic jerks and seizures. It has been reported to cause renal tubular acidosis and severe electrolyte abnormalities, which in turn predispose patients to neuropathology via renal concentration defects and osmotic shifts. Our patient is a 55-year-old woman with a history of multiple sclerosis and myoclonus on topiramate for several years who presented with weakness and was found to be profoundly hypokalemic. She went on to develop changes in mental status, motor deficits and evidence of CPM on MRI during her hospitalisation. Surprisingly, the patient never had hyponatremia; however, she had an acute rise in serum sodium from a normal baseline after fluid resuscitation with normal saline for hypotension during her admission.
Collapse
Affiliation(s)
- Luba Muaddi
- Department of Medicine, Allegheny Health Network, Pittsburgh, Pennsylvania, USA .,Division of Nephrology and Hypertension, Medicine Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Omar Osman
- Department of Medicine, Allegheny Health Network, Pittsburgh, Pennsylvania, USA.,Division of Nephrology and Hypertension, Medicine Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Barbara Clark
- Department of Medicine, Allegheny Health Network, Pittsburgh, Pennsylvania, USA .,Division of Nephrology and Hypertension, Medicine Institute, Allegheny Health Network, Pittsburgh, PA, USA
| |
Collapse
|
22
|
Thomsen ML, Grønkjær C, Iervolino A, Rej S, Trepiccione F, Christensen BM. Atorvastatin does not ameliorate nephrogenic diabetes insipidus induced by lithium or potassium depletion in mice. Physiol Rep 2021; 9:e15111. [PMID: 34762363 PMCID: PMC8582289 DOI: 10.14814/phy2.15111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/15/2021] [Accepted: 10/15/2021] [Indexed: 11/30/2022] Open
Abstract
Acquired forms of nephrogenic diabetes insipidus (NDI) include lithium (Li)-induced and hypokalemia-induced NDI. Both forms are associated with AQP2 downregulation and collecting duct (CD) cellular remodeling. Statins are cholesterol-lowering drugs appearing to increase AQP2 membrane-translocation and improve urine concentration in other NDI models. We have investigated if statins are able to prevent or rescue the Li-induced changes in mice and in a mouse cortical CD cell line (mCCDc1l ). Biotinylation assays showed that acute (1hr) atorvastatin, simvastatin, or fluvastatin increased AQP2 membrane accumulation in mCCDc1l cells showing that the cell line responds to acute statin treatment. To see whether chronic statin treatment abolish the Li effects, mCCDc1l cells were treated with 48 h Li, combined Li/atorvastatin or combined Li/simvastatin. Li reduced AQP2, but combined Li/atorvastatin or Li/simvastatin did not prevent AQP2 downregulation. In mice, chronic (21 days) Li increased urine output and reduced urine osmolality, but combined Li/atorvastatin did not prevent these effects. In inner medulla (IM), Li reduced total AQP2 and increased pS261-AQP2. Combined Li/atorvastatin did not abolish these changes. Atorvastatin did not prevent a Li-induced increase in intercalated cells and proliferation in IM. In mice with already established NDI, atorvastatin had no effect on the Li-induced changes either. Mice subjected to 14 days of potassium-deficient diet developed polyuria and AQP2 downregulation in IM. Co-treatment with atorvastatin did not prevent this. In conclusion, atorvastatin does not appear to be able to prevent or rescue Li-NDI or to prevent hypokalemic-induced NDI.
Collapse
Affiliation(s)
| | | | - Anna Iervolino
- Department of Translational Medical SciencesUniversity of Campania “L. Vanvitelli”NaplesItaly
- Biogem Institute of Molecular Biology and GeneticsAriano IrpinoItaly
| | - Soham Rej
- Jewish General Hospital/Lady Davis Institute/Department of PsychiatryMcGill UniversityMontrealQuebecCanada
| | - Francesco Trepiccione
- Department of Translational Medical SciencesUniversity of Campania “L. Vanvitelli”NaplesItaly
- Biogem Institute of Molecular Biology and GeneticsAriano IrpinoItaly
| | | |
Collapse
|
23
|
Matchimakul P, Pongkan W, Kongtung P, Mektrirat R. Comparative quantitation of aquaporin-2 and arginine vasopressin receptor-2 localizations among chronic kidney disease and healthy kidney in dogs. Vet World 2021; 14:2773-2781. [PMID: 34903939 PMCID: PMC8654747 DOI: 10.14202/vetworld.2021.2773-2781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/09/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND AND AIM Aquaporin-2 (AQP2) and arginine vasopressin receptor-2 (AVPR2) are proteins that control water homeostasis in principal cells. Chronic kidney disease (CKD) is defined as the impairment and irreversible loss of kidney function and/or structure, which causes water imbalances and polyuria. The study aimed to know the expression of AQPs and AVPR2 in the kidneys of a canine with CKD. MATERIALS AND METHODS The kidneys were collected from two dog carcasses from Small Animal Teaching Hospital, Faculty of Veterinary Medicine, Chiang Mai University. The kidney tissue was prepared for immunohistochemistry and investigated the expression and localization of tissue's AQP2 and AVPR2. For statistical analysis, the Mann-Whitney U-test was applied to the data. RESULTS By immunohistochemistry, AQP2 was expressed strongly in the basolateral and apical membranes of the principal cells, whereas AVPR2 was localized in the principal cell's basolateral membrane in both renal cortex and renal medulla. In the normal kidney, the semi-quantitative immunohistochemistry for the percentage of protein expression of AQP2 and AVPR2 was 5.062±0.4587 and 4.306±0.7695, respectively. In contrast, protein expression of AQP2 and AVPR2 in CKD was found to be 1.218±0.1719 and 0.8536±0.1396, respectively. The data shows that the percentage of AQP2 and AVPR2 expression was decreased, corresponding to a 4-fold and 5-fold in CKD (p<0.001). CONCLUSION Our findings revealed that CKD was a marked decrease in AQP2 and AVPR2 expression. The central role of specific AQP2 and AVPR2 in regulating water homeostasis will provide correlations in case of CKD with polyuria.
Collapse
Affiliation(s)
- Pitchaya Matchimakul
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
- Integrative Research Center for Veterinary Circulatory Sciences, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
| | - Wanpitak Pongkan
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
- Integrative Research Center for Veterinary Circulatory Sciences, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
| | - Piyamat Kongtung
- Central Laboratory, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
| | - Raktham Mektrirat
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
- Integrative Research Center for Veterinary Circulatory Sciences, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
| |
Collapse
|
24
|
Liu Q, Kong Y, Guo X, Liang B, Xie H, Hu S, Han M, Zhao X, Feng P, Lyu Q, Dong W, Liang X, Wang W, Li C. GSK-3β inhibitor TDZD-8 prevents reduction of aquaporin-1 expression via activating autophagy under renal ischemia reperfusion injury. FASEB J 2021; 35:e21809. [PMID: 34314052 DOI: 10.1096/fj.202100549r] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/12/2021] [Accepted: 07/06/2021] [Indexed: 11/11/2022]
Abstract
Renal ischemia/reperfusion (I/R) injury is a main cause of acute kidney injury (AKI). Aquaporin (AQP)-1 water channel in the kidney is critical for the maintenance of water homeostasis and the urinary concentrating ability. Increasing evidence supports an important role of autophagy in the pathogenesis of AKI induced by renal I/R. The purpose of the present study is to investigate whether activation of autophagy prevents downregulation of AQP1 protein induced by renal I/R and potential molecular mechanisms. Renal I/R induced consistently reduced protein expression of AQP1, 2, and 3, as well as sodium cotransporters Na+ -K+ -2Cl- cotransporter and α-Na,K-ATPase, which was associated with increased urine output and decreased creatinine clearance in rats. Renal I/R also suppressed autophagy and increased inflammatory responses in the kidney. 4-Benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), the glycogen synthase kinase-3β inhibitor, ameliorated renal injury under I/R, activated autophagy and markedly increased expression of AQPs and sodium transporters in the kidney, which was associated with improved urine output and creatinine clearance in rats. Hypoxia/reoxygenation (H/R) induced suppression of autophagy and downregulation of AQP1 in murine inner medullary collecting duct 3 (IMCD3) cells, which was fully prevented by TDZD-8 treatment. Inhibition of autophagy by 3-methyladenine or Atg5 gene knockdown attenuated recovery of AQP1 protein expression induced by TDZD-8 in IMCD3 cells with H/R. Interleukin-1 beta (IL-1β) decreased the abundance of AQP1 protein in IMCD3 cells. H/R induced increases in protein expression of nod-like receptor pyrin domain-containing 3 and IL-1β, which was reversed by TDZD-8. In conclusion, TDZD-8 treatment prevented downregulation of AQP1 expression under renal I/R injury, likely via activating autophagy and decreasing IL-1β production.
Collapse
Affiliation(s)
- Qiaojuan Liu
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yonglun Kong
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Xiangdong Guo
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Baien Liang
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Haixia Xie
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Shan Hu
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Mengke Han
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Xiaoduo Zhao
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Pinning Feng
- Department of Clinical Laboratory, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Qianqian Lyu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Wei Dong
- Division of Nephrology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xinling Liang
- Division of Nephrology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Weidong Wang
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Department of Nephrology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Chunling Li
- Institute of Hypertension, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
25
|
Sangey E, Chudasama K, Mwinyi A. The combined effect of hypomagnesemia and hypokalemia inducing nephrogenic diabetes insipidus in a patient with type 1 diabetes mellitus. Clin Case Rep 2021; 9:e04564. [PMID: 34322271 PMCID: PMC8301578 DOI: 10.1002/ccr3.4564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 11/29/2022] Open
Abstract
Nephrogenic diabetes insipidus (NDI) is rarely considered against more common differentials such as diabetes mellitus in patients presenting with polydipsia and polyuria. Hypokalemia and hypercalcemia are known to induce NDI, but not much is known about hypomagnesemia. Hypokalemia refractory to therapy should prompt consideration of hypomagnesemia.
Collapse
Affiliation(s)
- Esmail Sangey
- Emergency & ICU DepartmentShree Hindu Mandal HospitalDar es SalaamTanzania
| | - Kishan Chudasama
- Emergency & ICU DepartmentShree Hindu Mandal HospitalDar es SalaamTanzania
| | - Ahmad Mwinyi
- Emergency & ICU DepartmentShree Hindu Mandal HospitalDar es SalaamTanzania
| |
Collapse
|
26
|
Al-Qusairi L, Grimm PR, Zapf AM, Welling PA. Rapid development of vasopressin resistance in dietary K + deficiency. Am J Physiol Renal Physiol 2021; 320:F748-F760. [PMID: 33749322 PMCID: PMC8174811 DOI: 10.1152/ajprenal.00655.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/15/2021] [Accepted: 03/15/2021] [Indexed: 12/27/2022] Open
Abstract
The association between diabetes insipidus (DI) and chronic dietary K+ deprivation is well known, but it remains uncertain how the disorder develops and whether it is influenced by the sexual dimorphism in K+ handling. Here, we determined the plasma K+ (PK) threshold for DI in male and female mice and ascertained if DI is initiated by polydipsia or by a central or nephrogenic defect. C57BL6J mice were randomized to a control diet or to graded reductions in dietary K+ for 8 days, and kidney function and transporters involved in water balance were characterized. We found that male and female mice develop polyuria and secondary polydipsia. Altered water balance coincided with a decrease in aquaporin-2 (AQP2) phosphorylation and apical localization despite increased levels of the vasopressin surrogate marker copeptin. No change in the protein abundance of urea transporter-A1 was observed. The Na+-K+-2Cl- cotransporter decreased only in males. Desmopressin treatment failed to reverse water diuresis in K+-restricted mice. These findings indicate that even a small fall in PK is associated with nephrogenic DI (NDI), coincident with the development of altered AQP2 regulation, implicating low PK as a causal trigger of NDI. We found that PK decreased more in females, and, consequently, females were more prone to develop NDI. Together, these data indicate that AQP2 regulation is disrupted by a small decrease in PK and that the response is influenced by sexual dimorphism in K+ handling. These findings provide new insights into the mechanisms linking water and K+ balances and support defining the disorder as "potassium-dependent NDI."NEW & NOTEWORTHY This study shows that aquaporin-2 regulation is disrupted by a small fall in plasma potassium levels and the response is influenced by sexual dimorphism in renal potassium handling. The findings provided new insights into the mechanisms by which water balance is altered in dietary potassium deficiency and support defining the disorder as "potassium-dependent nephrogenic diabetes insipidus."
Collapse
Affiliation(s)
- Lama Al-Qusairi
- Departments of Medicine, Nephrology, and Physiology, Johns Hopkins University Medical School, Baltimore, Maryland
| | - P Richard Grimm
- Departments of Medicine, Nephrology, and Physiology, Johns Hopkins University Medical School, Baltimore, Maryland
| | - Ava M Zapf
- Graduate Program in Life Sciences, University of Maryland, Baltimore, Maryland
| | - Paul A Welling
- Departments of Medicine, Nephrology, and Physiology, Johns Hopkins University Medical School, Baltimore, Maryland
| |
Collapse
|
27
|
Kuo C, Foon D, Waters K, Cheung C, Margol AS. Central diabetes insipidus: A rare unreported side effect of temozolomide in pediatrics. Pediatr Blood Cancer 2020; 67:e28516. [PMID: 32573959 DOI: 10.1002/pbc.28516] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/30/2020] [Accepted: 06/02/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Christopher Kuo
- Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, California
| | - Dione Foon
- Cancer and Blood Disease Institute and Division of Hematology Oncology, Children's Hospital Los Angeles, Los Angeles, California
| | - Kaaren Waters
- Cancer and Blood Disease Institute and Division of Hematology Oncology, Children's Hospital Los Angeles, Los Angeles, California
| | - Clement Cheung
- Division of Endocrinology, Diabetes, and Metabolism, Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, California.,Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Ashley S Margol
- Cancer and Blood Disease Institute and Division of Hematology Oncology, Children's Hospital Los Angeles, Los Angeles, California.,Keck School of Medicine, University of Southern California, Los Angeles, California
| |
Collapse
|
28
|
Fenton RA, Murali SK, Moeller HB. Advances in Aquaporin-2 trafficking mechanisms and their implications for treatment of water balance disorders. Am J Physiol Cell Physiol 2020; 319:C1-C10. [PMID: 32432927 DOI: 10.1152/ajpcell.00150.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In mammals, conservation of body water is critical for survival and is dependent on the kidneys ability to minimize water loss in the urine during periods of water deprivation. The collecting duct water channel aquaporin-2 (AQP2) plays an essential role in this homeostatic response by facilitating water reabsorption along osmotic gradients. The ability to increase the levels of AQP2 in the apical plasma membrane following an increase in plasma osmolality is a rate-limiting step in water reabsorption, a process that is tightly regulated by the antidiuretic hormone arginine vasopressin (AVP). In this review, the focus is on the role of the carboxyl-terminus of AQP2 as a key regulatory point for AQP2 trafficking. We provide an overview of AQP2 structure, disease-causing mutations in the AQP2 carboxyl-terminus, the role of post-translational modifications such as phosphorylation and ubiquitylation in the tail domain, and their implications for balanced trafficking of AQP2. Finally, we discuss how various modifications of the AQP2 tail facilitate selective protein:protein interactions that modulate the AQP2 trafficking mechanism.
Collapse
Affiliation(s)
- Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus DK-8000, Denmark
| | - Sathish K Murali
- Department of Biomedicine, Aarhus University, Aarhus DK-8000, Denmark
| | - Hanne B Moeller
- Department of Biomedicine, Aarhus University, Aarhus DK-8000, Denmark
| |
Collapse
|
29
|
Choi HJ, Jang HJ, Park E, Tingskov SJ, Nørregaard R, Jung HJ, Kwon TH. Sorting Nexin 27 Regulates the Lysosomal Degradation of Aquaporin-2 Protein in the Kidney Collecting Duct. Cells 2020; 9:E1208. [PMID: 32413996 DOI: 10.3390/cells9051208] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/01/2020] [Accepted: 05/11/2020] [Indexed: 12/16/2022] Open
Abstract
Sorting nexin 27 (SNX27), a PDZ (Postsynaptic density-95/Discs large/Zonula occludens 1) domain-containing protein, cooperates with a retromer complex, which regulates intracellular trafficking and the abundance of membrane proteins. Since the carboxyl terminus of aquaporin-2 (AQP2c) has a class I PDZ-interacting motif (X-T/S-X-Φ), the role of SNX27 in the regulation of AQP2 was studied. Co-immunoprecipitation assay of the rat kidney demonstrated an interaction of SNX27 with AQP2. Glutathione S-transferase (GST) pull-down assays revealed an interaction of the PDZ domain of SNX27 with AQP2c. Immunocytochemistry of HeLa cells co-transfected with FLAG-SNX27 and hemagglutinin (HA)-AQP2 also revealed co-localization throughout the cytoplasm. When the PDZ domain was deleted, punctate HA-AQP2 labeling was localized in the perinuclear region. The labeling was intensively overlaid by Lysotracker staining but not by GM130 labeling, a cis-Golgi marker. In rat kidneys and primary cultured inner medullary collecting duct cells, the subcellular redistribution of SNX27 was similar to AQP2 under 1-deamino-8-D-arginine vasopressin (dDAVP) stimulation/withdrawal. Cell surface biotinylation assay showed that dDAVP-induced AQP2 translocation to the apical plasma membrane was unaffected after SNX27 knockdown in mpkCCD cells. In contrast, the dDAVP-induced AQP2 protein abundance was significantly attenuated without changes in AQP2 mRNA expression. Moreover, the AQP2 protein abundance was markedly declined during the dDAVP withdrawal period after stimulation under SNX27 knockdown, which was inhibited by lysosome inhibitors. Autophagy was induced after SNX27 knockdown in mpkCCD cells. Lithium-induced nephrogenic diabetes insipidus in rats revealed a significant downregulation of SNX27 in the kidney inner medulla. Taken together, the PDZ domain-containing SNX27 interacts with AQP2 and depletion of SNX27 contributes to the autophagy-lysosomal degradation of AQP2.
Collapse
|
30
|
Du Y, Qian Y, Tang X, Guo Y, Chen S, Jiang M, Yang B, Cao W, Huang S, Zhang A, Jia Z, Zhang Y. Chloroquine attenuates lithium-induced NDI and proliferation of renal collecting duct cells. Am J Physiol Renal Physiol 2020; 318:F1199-F1209. [PMID: 32249612 DOI: 10.1152/ajprenal.00478.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Lithium is widely used in psychiatry as the golden standard for more than 60 yr due to its effectiveness. However, its adverse effect has been limiting its long-term use in clinic. About 40% of patients taking lithium develop nephrogenic diabetes insipidus (NDI). Lithium can also induce proliferation of collecting duct cells, leading to microcyst formation in the kidney. Lithium was considered an autophagy inducer that might contribute to the therapeutic benefit of neuropsychiatric disorders. Thus, we hypothesized that autophagy may play a role in lithium-induced kidney nephrotoxicity. To address our hypothesis, we fed mice with a lithium-containing diet with chloroquine (CQ), an autophagy inhibitor, concurrently. Lithium-treated mice presented enhanced autophagy activity in the kidney cortex and medulla. CQ treatment significantly ameliorated lithium-induced polyuria, polydipsia, natriuresis, and kaliuresis accompanied with attenuated downregulation of aquaporin-2 and Na+-K+-2Cl- cotransporter protein. The protective effect of CQ on aquaporin-2 protein abundance was confirmed in cultured cortical collecting duct cells. In addition, we found that lithium-induced proliferation of collecting duct cells was also suppressed by CQ as detected by proliferating cell nuclear antigen staining. Moreover, both phosphorylated mammalian target of rapamycin and β-catenin expression, which have been reported to be increased by lithium and associated with cell proliferation, were reduced by CQ. Taken together, our study demonstrated that CQ protected against lithium-induced NDI and collecting duct cell proliferation possibly through inhibiting autophagy.
Collapse
Affiliation(s)
- Yang Du
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yun Qian
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaomei Tang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yan Guo
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Shuang Chen
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Mingzhu Jiang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Bingyu Yang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Weidong Cao
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Songming Huang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Aihua Zhang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zhanjun Jia
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yue Zhang
- Department of Nephrology, Children's Hospital of Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.,Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| |
Collapse
|
31
|
Shi M, Maique J, Shaffer J, Davidson T, Sebti S, Fernández ÁF, Zou Z, Yan S, Levine B, Moe OW, Hu MC. The tripartite interaction of phosphate, autophagy, and αKlotho in health maintenance. FASEB J 2020; 34:3129-3150. [PMID: 31908069 DOI: 10.1096/fj.201902127r] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/19/2019] [Accepted: 12/19/2019] [Indexed: 12/11/2022]
Abstract
Aging-related organ degeneration is driven by multiple factors including the cell maintenance mechanisms of autophagy, the cytoprotective protein αKlotho, and the lesser known effects of excess phosphate (Pi), or phosphotoxicity. To examine the interplay between Pi, autophagy, and αKlotho, we used the BK/BK mouse (homozygous for mutant Becn1F121A ) with increased autophagic flux, and αKlotho-hypomorphic mouse (kl/kl) with impaired urinary Pi excretion, low autophagy, and premature organ dysfunction. BK/BK mice live longer than WT littermates, and have heightened phosphaturia from downregulation of two key NaPi cotransporters in the kidney. The multi-organ failure in kl/kl mice was rescued in the double-mutant BK/BK;kl/kl mice exhibiting lower plasma Pi, improved weight gain, restored plasma and renal αKlotho levels, decreased pathology of multiple organs, and improved fertility compared to kl/kl mice. The beneficial effects of heightened autophagy from Becn1F121A was abolished by chronic high-Pi diet which also shortened life span in the BK/BK;kl/kl mice. Pi promoted beclin 1 binding to its negative regulator BCL2, which impairs autophagy flux. Pi downregulated αKlotho, which also independently impaired autophagy. In conclusion, Pi, αKlotho, and autophagy interact intricately to affect each other. Both autophagy and αKlotho antagonizes phosphotoxicity. In concert, this tripartite system jointly determines longevity and life span.
Collapse
Affiliation(s)
- Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jenny Maique
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joy Shaffer
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Taylor Davidson
- Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Salwa Sebti
- Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Center for Autophagy Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Álvaro F Fernández
- Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Center for Autophagy Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Zhongju Zou
- Center for Autophagy Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Shirley Yan
- Departments of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Beth Levine
- Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Center for Autophagy Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Departments of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Orson W Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Departments of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
32
|
Somparn P, Boonkrai C, Charngkaew K, Chomanee N, Hodge KG, Fenton RA, Pisitkun T, Khositseth S. Bilateral ureteral obstruction is rapidly accompanied by ER stress and activation of autophagic degradation of IMCD proteins, including AQP2. Am J Physiol Renal Physiol 2020; 318:F135-F147. [PMID: 31736351 PMCID: PMC7054639 DOI: 10.1152/ajprenal.00113.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
After the release of bilateral ureteral obstruction (BUO), postobstructive diuresis from an impaired urine concentration mechanism is associated with reduced aquaporin 2 (AQP2) abundance in the inner medullary collecting duct (IMCD). However, the underlying molecular mechanism of this AQP2 reduction is incompletely understood. To elucidate the mechanisms responsible for this phenomenon, we studied molecular changes in IMCDs isolated from rats with 4-h BUO or sham operation at the early onset of AQP2 downregulation using mass spectrometry-based proteomic analysis. Two-hundred fifteen proteins had significant changes in abundances, with 65% of them downregulated in the IMCD of 4-h BUO rats compared with sham rats. Bioinformatic analysis revealed that significantly changed proteins were associated with functional Gene Ontology terms, including “cell-cell adhesion,” “cell-cell adherens junction,” “mitochondrial inner membrane,” “endoplasmic reticulum chaperone complex,” and the KEGG pathway of glycolysis/gluconeogenesis. Targeted liquid chromatography-tandem mass spectrometry or immunoblot analysis confirmed the changes in 19 proteins representative of each predominant cluster, including AQP2. Electron microscopy demonstrated disrupted tight junctions, disorganized adherens junctions, swollen mitochondria, enlargement of the endoplasmic reticulum lumen, and numerous autophagosomes/lysosomes in the IMCD of rats with 4-h BUO. AQP2 and seven proteins chosen as representative of the significantly altered clusters had a significant increase in immunofluorescence-based colocalization with autophagosomes/lysosomes. Immunogold electron microscopy confirmed colocalization of AQP2 with the autophagosome marker microtubule-associated protein 1A/1B-light chain 3 and the lysosomal marker cathepsin D in IMCD cells of rats with 4-h BUO. We conclude that enhanced autophagic degradation of AQP2 and other critical proteins, as well as endoplasmic reticulum stress in the IMCD, are initiated shortly after BUO.
Collapse
Affiliation(s)
- Poorichaya Somparn
- Center of Excellent in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Translational Research in Inflammation and Immunology Research Unit, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Chatikorn Boonkrai
- Center of Excellent in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Komgrid Charngkaew
- Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand
| | - Nusara Chomanee
- Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand
| | - Kenneth G Hodge
- Center of Excellent in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Robert A Fenton
- Department of Biomedicine and Center for Interactions of Proteins in Epithelial Transport, Aarhus University, Aarhus, Denmark
| | - Trairak Pisitkun
- Center of Excellent in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Sookkasem Khositseth
- Department of Pediatrics, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
| |
Collapse
|
33
|
|
34
|
Keppner A, Maric D, Sergi C, Ansermet C, De Bellis D, Kratschmar DV, Canonica J, Klusonova P, Fenton RA, Odermatt A, Crambert G, Hoogewijs D, Hummler E. Deletion of the serine protease CAP2/Tmprss4 leads to dysregulated renal water handling upon dietary potassium depletion. Sci Rep 2019; 9:19540. [PMID: 31863073 PMCID: PMC6925205 DOI: 10.1038/s41598-019-55995-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 12/04/2019] [Indexed: 01/09/2023] Open
Abstract
The kidney needs to adapt daily to variable dietary K+ contents via various mechanisms including diuretic, acid-base and hormonal changes that are still not fully understood. In this study, we demonstrate that following a K+-deficient diet in wildtype mice, the serine protease CAP2/Tmprss4 is upregulated in connecting tubule and cortical collecting duct and also localizes to the medulla and transitional epithelium of the papilla and minor calyx. Male CAP2/Tmprss4 knockout mice display altered water handling and urine osmolality, enhanced vasopressin response leading to upregulated adenylate cyclase 6 expression and cAMP overproduction, and subsequently greater aquaporin 2 (AQP2) and Na+-K+-2Cl− cotransporter 2 (NKCC2) expression following K+-deficient diet. Urinary acidification coincides with significantly increased H+,K+-ATPase type 2 (HKA2) mRNA and protein expression, and decreased calcium and phosphate excretion. This is accompanied by increased glucocorticoid receptor (GR) protein levels and reduced 11β-hydroxysteroid dehydrogenase 2 activity in knockout mice. Strikingly, genetic nephron-specific deletion of GR leads to the mirrored phenotype of CAP2/Tmprss4 knockouts, including increased water intake and urine output, urinary alkalinisation, downregulation of HKA2, AQP2 and NKCC2. Collectively, our data unveil a novel role of the serine protease CAP2/Tmprss4 and GR on renal water handling upon dietary K+ depletion.
Collapse
Affiliation(s)
- Anna Keppner
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,Department of Medicine/Physiology, University of Fribourg, Fribourg, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Lausanne, Lausanne, Switzerland
| | - Darko Maric
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,Department of Medicine/Physiology, University of Fribourg, Fribourg, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Lausanne, Lausanne, Switzerland
| | - Chloé Sergi
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Camille Ansermet
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Damien De Bellis
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,Electron Microscopy Facility, University of Lausanne, Lausanne, Switzerland.,Department of Plant Molecular Biology, University of Lausanne, Lausanne, Switzerland
| | - Denise V Kratschmar
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Lausanne, Lausanne, Switzerland
| | - Jérémie Canonica
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Lausanne, Lausanne, Switzerland.,Ophthalmic Hospital Jules Gonin, University of Lausanne, Lausanne, Switzerland
| | - Petra Klusonova
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Lausanne, Lausanne, Switzerland
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Alex Odermatt
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Lausanne, Lausanne, Switzerland
| | | | - David Hoogewijs
- Department of Medicine/Physiology, University of Fribourg, Fribourg, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Lausanne, Lausanne, Switzerland
| | - Edith Hummler
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland. .,National Center of Competence in Research Kidney Control of Homeostasis (NCCR Kidney.CH), University of Lausanne, Lausanne, Switzerland.
| |
Collapse
|
35
|
Abstract
Diabetes insipidus (DI) is a disorder characterized by excretion of large amounts of hypotonic urine. Central DI results from a deficiency of the hormone arginine vasopressin (AVP) in the pituitary gland or the hypothalamus, whereas nephrogenic DI results from resistance to AVP in the kidneys. Central and nephrogenic DI are usually acquired, but genetic causes must be evaluated, especially if symptoms occur in early childhood. Central or nephrogenic DI must be differentiated from primary polydipsia, which involves excessive intake of large amounts of water despite normal AVP secretion and action. Primary polydipsia is most common in psychiatric patients and health enthusiasts but the polydipsia in a small subgroup of patients seems to be due to an abnormally low thirst threshold, a condition termed dipsogenic DI. Distinguishing between the different types of DI can be challenging and is done either by a water deprivation test or by hypertonic saline stimulation together with copeptin (or AVP) measurement. Furthermore, a detailed medical history, physical examination and imaging studies are needed to ensure an accurate DI diagnosis. Treatment of DI or primary polydipsia depends on the underlying aetiology and differs in central DI, nephrogenic DI and primary polydipsia.
Collapse
|
36
|
|
37
|
Murali SK, Aroankins TS, Moeller HB, Fenton RA. The Deubiquitylase USP4 Interacts with the Water Channel AQP2 to Modulate Its Apical Membrane Accumulation and Cellular Abundance. Cells 2019; 8:E265. [PMID: 30901874 DOI: 10.3390/cells8030265] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 01/26/2023] Open
Abstract
Aquaporin 2 (AQP2) mediates the osmotic water permeability of the kidney collecting duct in response to arginine vasopressin (VP) and is essential for body water homeostasis. VP effects on AQP2 occur via long-term alterations in AQP2 abundance and short-term changes in AQP2 localization. Several of the effects of VP on AQP2 are dependent on AQP2 phosphorylation and ubiquitylation; post-translational modifications (PTM) that modulate AQP2 subcellular distribution and function. Although several protein kinases, phosphatases, and ubiquitin E3 ligases have been implicated in AQP2 PTM, how AQP2 is deubiquitylated or the role of deubiquitylases (DUBS) in AQP2 function is unknown. Here, we report a novel role of the ubiquitin-specific protease USP4 in modulating AQP2 function. USP4 co-localized with AQP2 in the mouse kidney, and in mpkCCD14 cells USP4 and AQP2 abundance are increased by VP. AQP2 and USP4 co-immunoprecipitated from mpkCCD14 cells and mouse kidney, and in vitro, USP4 can deubiquitylate AQP2. In mpkCCD14 cells, shRNA mediated knockdown of USP4 decreased AQP2 protein abundance, whereas no changes in AQP2 mRNA levels or VP-induced cAMP production were detected. VP-induced AQP2 membrane accumulation in knockdown cells was significantly reduced, which was associated with higher levels of ubiquitylated AQP2. AQP2 protein half-life was also significantly reduced in USP4 knockdown cells. Taken together, the data suggest that USP4 is a key regulator of AQP2 deubiquitylation and that loss of USP4 leads to increased AQP2 ubiquitylation, decreased AQP2 levels, and decreased cell surface AQP2 accumulation upon VP treatment. These studies have implications for understanding body water homeostasis.
Collapse
|
38
|
Kim WY, Nam SA, Choi A, Kim YM, Park SH, Kim HL, Kim H, Han KH, Yang CW, Lee MS, Kim YK, Kim J. Atg7-dependent canonical autophagy regulates the degradation of aquaporin 2 in prolonged hypokalemia. Sci Rep 2019; 9:3021. [PMID: 30816234 PMCID: PMC6395725 DOI: 10.1038/s41598-019-39702-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 11/23/2018] [Indexed: 01/31/2023] Open
Abstract
Prolonged hypokalemia induces a decrease of urinary concentrating ability via down-regulation of aquaporin 2 (AQP2); however, the precise mechanisms remain unknown. To investigate the role of autophagy in the degradation of AQP2, we generated the principal cell-specific Atg7 deletion (Atg7Δpc) mice. In hypokalemic Atg7-floxed (Atg7f/f) mice, huge irregular shaped LC3-positive autophagic vacuoles accumulated mainly in inner medullary collecting duct (IMCD) cells. Total- and pS261-AQP2 were redistributed from apical and subapical domains into these vacuoles, which were not co-localized with RAB9. However, in the IMCD cells of hypokalemic Atg7Δpc mice, these canonical autophagic vacuoles were markedly reduced, whereas numerous small regular shaped LC3-negative/RAB9-positive non-canonical autophagic vacuoles were observed along with diffusely distributed total- and pS261-AQP2 in the cytoplasm. The immunoreactivity of pS256-AQP2 in the apical membrane of IMCD cells was markedly decreased, and no redistribution was observed in both hypokalemic Atg7f/f and Atg7Δpc mice. These findings suggest that AQP2 down regulation in hypokalemia was induced by reduced phosphorylation of AQP2, resulting in a reduction of apical plasma labeling of pS256-AQP2 and degradation of total- and pS261-AQP2 via an LC3/ATG7-dependent canonical autophagy pathway.
Collapse
Affiliation(s)
- Wan-Young Kim
- Department of Anatomy and Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sun Ah Nam
- Department of Anatomy and Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Arum Choi
- Department of Anatomy and Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yu-Mi Kim
- Department of Anatomy and Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sang Hee Park
- Institute of Clinical Medicine Research of Bucheon St. Mary's Hospital, Bucheon, Korea
| | - Hong Lim Kim
- Integrative Research Support Center, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Hyang Kim
- Division of Nephrology, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | - Ki-Hwan Han
- Department of Anatomy, Ewha Womans University School of Medicine, Seoul, Korea
| | - Chul Woo Yang
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Myung-Shik Lee
- Severance Biomedical Science Institute, College of Medicine, Yonsei University, Seoul, Korea
| | - Yong Kyun Kim
- Department of Anatomy and Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea. .,Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
| | - Jin Kim
- Department of Anatomy and Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
| |
Collapse
|
39
|
Abstract
Aquaporins (AQPs) are a family of highly selective transmembrane channels that mainly transport water across the cell and some facilitate low-molecular-weight solutes. Eight AQPs, including AQP1, AQP2, AQP3, AQP4, AQP5, AQP6, AQP7, and AQP11, are expressed in different segments and various cells in the kidney to maintain normal urine concentration function. AQP2 is critical in regulating urine concentrating ability. The expression and function of AQP2 are regulated by a series of transcriptional factors and post-transcriptional phosphorylation, ubiquitination, and glycosylation. Mutation or functional deficiency of AQP2 leads to severe nephrogenic diabetes insipidus. Studies with animal models show AQPs are related to acute kidney injury and various chronic kidney diseases, such as diabetic nephropathy, polycystic kidney disease, and renal cell carcinoma. Experimental data suggest ideal prospects for AQPs as biomarkers and therapeutic targets in clinic. This review article mainly focuses on recent advances in studying AQPs in renal diseases.
Collapse
|
40
|
Rinschen MM, Limbutara K, Knepper MA, Payne DM, Pisitkun T. From Molecules to Mechanisms: Functional Proteomics and Its Application to Renal Tubule Physiology. Physiol Rev 2019; 98:2571-2606. [PMID: 30182799 DOI: 10.1152/physrev.00057.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Classical physiological studies using electrophysiological, biophysical, biochemical, and molecular techniques have created a detailed picture of molecular transport, bioenergetics, contractility and movement, and growth, as well as the regulation of these processes by external stimuli in cells and organisms. Newer systems biology approaches are beginning to provide deeper and broader understanding of these complex biological processes and their dynamic responses to a variety of environmental cues. In the past decade, advances in mass spectrometry-based proteomic technologies have provided invaluable tools to further elucidate these complex cellular processes, thereby confirming, complementing, and advancing common views of physiology. As one notable example, the application of proteomics to study the regulation of kidney function has yielded novel insights into the chemical and physical processes that tightly control body fluids, electrolytes, and metabolites to provide optimal microenvironments for various cellular and organ functions. Here, we systematically review, summarize, and discuss the most significant key findings from functional proteomic studies in renal epithelial physiology. We also identify further improvements in technological and bioinformatics methods that will be essential to advance precision medicine in nephrology.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| | - Kavee Limbutara
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| | - Mark A Knepper
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| | - D Michael Payne
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| | - Trairak Pisitkun
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| |
Collapse
|
41
|
Kanwar A. Alcohol withdrawal & Diabetes Insipidus – A rare but clinically important association. Indian Journal of Medical Specialities 2018. [DOI: 10.1016/j.injms.2018.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
42
|
|
43
|
Li D, Liu Q, Feng Z, Zhang Q, Feng S. Nephrogenic diabetes insipidus in initial stage of acute lymphoblastic leukemia and relapse after haploidentical hematopoietic stem-cell transplantation: A case report. Medicine (Baltimore) 2018; 97:e11157. [PMID: 29901649 PMCID: PMC6024069 DOI: 10.1097/md.0000000000011157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
RATIONALE Nephrogenic diabetes insipidus (NDI) rarely presents in the initial stage of acute lymphoblastic leukemia (ALL) and relapse due to renal infiltration is also rare. PATIENT CONCERNS A 19-year-old man presented with weakness, polydipsia, and polyuria for 1 month. DIAGNOSES NDI was diagnosed with insignificant response to a water deprivation test after stimulation with vasopressin injection. Bone marrow examination combined with immunophenotypic analysis, cerebrospinal cytology, and abdominal ultrasonography confirmed the diagnoses of precursor B cell ALL with renal infiltration. INTERVENTIONS The patient accepted standardized combination chemotherapy and ultimately had sustained remission, and his polydipsia and polyuria disappeared after 3 days of treatment. The ALL relapsed 1 year later and he received haploidentical stem cell transplantation (haplo-SCT) from his father. OUTCOMES One year later, he again developed NDI, with bilateral renal enlargement because of extramedullary relapse, leading to subsequent death. LESSONS This case demonstrates unusual early renal involvement in ALL presenting with initial NDI. Interestingly, the NDI returned with the relapse of renal infiltration 1 year after haplo-SCT. This case suggests that NDI was probably secondary to renal leukemic infiltration.
Collapse
Affiliation(s)
- Dezhi Li
- Department of Respiratory Medicine, Shandong Provincial Hospital Affiliated to Shandong University
| | - Qian Liu
- Department of Hematology, Shandong Provincial Qianfoshan Hospital, Jinan City
| | - Zhifang Feng
- Department of Endocrinology, Zhucheng Traditional Chinese Medicine Hospital, Zhucheng City, China
| | - Qi Zhang
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC
| | - Saran Feng
- Department of Hematology, Shandong Provincial Qianfoshan Hospital, Jinan City
| |
Collapse
|
44
|
Madonna R, Pieragostino D, Balistreri CR, Rossi C, Geng YJ, Del Boccio P, De Caterina R. Diabetic macroangiopathy: Pathogenetic insights and novel therapeutic approaches with focus on high glucose-mediated vascular damage. Vascul Pharmacol 2018; 107:S1537-1891(17)30322-1. [PMID: 29425894 DOI: 10.1016/j.vph.2018.01.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/22/2017] [Accepted: 01/31/2018] [Indexed: 12/11/2022]
Abstract
Diabetic macroangiopathy - a specific form of accelerated atherosclerosis - is characterized by intra-plaque new vessel formation due to excessive/abnormal neovasculogenesis and angiogenesis, increased vascular permeability of the capillary vessels, and tissue edema, resulting in frequent atherosclerotic plaque hemorrhage and plaque rupture. Mechanisms that may explain the premature and rapidly progressive nature of atherosclerosis in diabetes are multiple, and to a large extent still unclear. However, mechanisms related to hyperglycemia certainly play an important role. These include a dysregulated vascular regeneration. In addition, oxidative and hyperosmolar stresses, as well as the activation of inflammatory pathways triggered by a dysregulated activation of membrane channel proteins aquaporins, have been recognized as key events. Here, we review recent knowledge of cellular and molecular pathways of macrovascular disease related to hyperglycemia in diabetes. We also here highlight how new insights into pathogenic mechanisms of vascular damage in diabetes may indicate new targets for prevention and treatment.
Collapse
Affiliation(s)
- Rosalinda Madonna
- Center of Aging Sciences and Translational Medicine - CESI-MeT, Institute of Cardiology, Department of Neurosciences, Imaging and Clinical Sciences, "G. d'Annunzio" University, Chieti, Italy; Center for Cardiovascular Biology and Atherosclerosis Research, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Damiana Pieragostino
- Analitical Biochemistry and Proteomics Unit Center of Aging Sciences and Translational Medicine - CESI-MeT, "G. d'Annunzio" University, Chieti, Italy
| | - Carmela Rita Balistreri
- Department of Patho-biology and Medical Biotechnologies, University of Palermo, Palermo, Italy
| | - Claudia Rossi
- Analitical Biochemistry and Proteomics Unit Center of Aging Sciences and Translational Medicine - CESI-MeT, "G. d'Annunzio" University, Chieti, Italy
| | - Yong-Jian Geng
- Center for Cardiovascular Biology and Atherosclerosis Research, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Piero Del Boccio
- Analitical Biochemistry and Proteomics Unit Center of Aging Sciences and Translational Medicine - CESI-MeT, "G. d'Annunzio" University, Chieti, Italy
| | - Raffaele De Caterina
- Center of Aging Sciences and Translational Medicine - CESI-MeT, Institute of Cardiology, Department of Neurosciences, Imaging and Clinical Sciences, "G. d'Annunzio" University, Chieti, Italy.
| |
Collapse
|
45
|
Abstract
Autophagy is an adaptive cellular response to "stress" in which proteins are targeted for lysosomal degradation. Using a combined proteomics and microscopy approach, Khositseth et al. show that autophagy contributes to the downregulation of the water channel aquaporin-2 in response to hypercalcemia. This commentary discusses the role of autophagy in renal epithelial transport, and explores whether autophagy may also contribute to chronic kidney disease once it becomes dysfunctional.
Collapse
Affiliation(s)
- Ewout J Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, Netherlands.
| | - David Severs
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, Netherlands
| |
Collapse
|
46
|
Rosner MH. Polyuria in a Patient with Aspergillus Infection. Clin J Am Soc Nephrol 2017; 12:1343-1346. [PMID: 28289066 PMCID: PMC5544519 DOI: 10.2215/cjn.12791216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/14/2023]
Affiliation(s)
- Mitchell H Rosner
- Division of Nephrology, University of Virginia Health System, Charlottesville, Virginia
| |
Collapse
|
47
|
Khositseth S, Charngkaew K, Boonkrai C, Somparn P, Uawithya P, Chomanee N, Payne DM, Fenton RA, Pisitkun T. Hypercalcemia induces targeted autophagic degradation of aquaporin-2 at the onset of nephrogenic diabetes insipidus. Kidney Int 2017; 91:1070-1087. [PMID: 28139295 DOI: 10.1016/j.kint.2016.12.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 11/16/2016] [Accepted: 12/01/2016] [Indexed: 12/22/2022]
Abstract
Hypercalcemia can cause renal dysfunction such as nephrogenic diabetes insipidus (NDI), but the mechanisms underlying hypercalcemia-induced NDI are not well understood. To elucidate the early molecular changes responsible for this disorder, we employed mass spectrometry-based proteomic analysis of inner medullary collecting ducts (IMCD) isolated from parathyroid hormone-treated rats at onset of hypercalcemia-induced NDI. Forty-one proteins, including the water channel aquaporin-2, exhibited significant changes in abundance, most of which were decreased. Bioinformatic analysis revealed that many of the downregulated proteins were associated with cytoskeletal protein binding, regulation of actin filament polymerization, and cell-cell junctions. Targeted LC-MS/MS and immunoblot studies confirmed the downregulation of 16 proteins identified in the initial proteomic analysis and in additional experiments using a vitamin D treatment model of hypercalcemia-induced NDI. Evaluation of transcript levels and estimated half-life of the downregulated proteins suggested enhanced protein degradation as the possible regulatory mechanism. Electron microscopy showed defective intercellular junctions and autophagy in the IMCD cells from both vitamin D- and parathyroid hormone-treated rats. A significant increase in the number of autophagosomes was confirmed by immunofluorescence labeling of LC3. Colocalization of LC3 and Lamp1 with aquaporin-2 and other downregulated proteins was found in both models. Immunogold electron microscopy revealed aquaporin-2 in autophagosomes in IMCD cells from both hypercalcemia models. Finally, parathyroid hormone withdrawal reversed the NDI phenotype, accompanied by termination of aquaporin-2 autophagic degradation and normalization of both nonphoshorylated and S256-phosphorylated aquaporin-2 levels. Thus, enhanced autophagic degradation of proteins plays an important role in the initial mechanism of hypercalcemic-induced NDI.
Collapse
Affiliation(s)
- Sookkasem Khositseth
- Department of Pediatrics, Faculty of Medicine, Thammasat University, Pathumthani, Thailand.
| | - Komgrid Charngkaew
- Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chatikorn Boonkrai
- Systems Biology Center, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Poorichaya Somparn
- Systems Biology Center, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Panapat Uawithya
- Department of Physiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nusara Chomanee
- Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - D Michael Payne
- Systems Biology Center, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Robert A Fenton
- Department of Biomedicine and Center for Interactions of Proteins in Epithelial Transport, Aarhus University, Aarhus, Denmark
| | - Trairak Pisitkun
- Systems Biology Center, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA.
| |
Collapse
|
48
|
Al-Qusairi L, Basquin D, Roy A, Rajaram RD, Maillard MP, Subramanya AR, Staub O. Renal Tubular Ubiquitin-Protein Ligase NEDD4-2 Is Required for Renal Adaptation during Long-Term Potassium Depletion. J Am Soc Nephrol 2017; 28:2431-2442. [PMID: 28289184 DOI: 10.1681/asn.2016070732] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 02/01/2017] [Indexed: 11/03/2022] Open
Abstract
Adaptation of the organism to potassium (K+) deficiency requires precise coordination among organs involved in K+ homeostasis, including muscle, liver, and kidney. How the latter performs functional and molecular changes to ensure K+ retention is not well understood. Here, we investigated the role of ubiquitin-protein ligase NEDD4-2, which negatively regulates the epithelial sodium channel (ENaC), Na+/Cl- cotransporter (NCC), and with no-lysine-kinase 1 (WNK1). After dietary K+ restriction for 2 weeks, compared with control littermates, inducible renal tubular NEDD4-2 knockout (Nedd4LPax8/LC1 ) mice exhibited severe hypokalemia and urinary K+ wasting. Notably, expression of the ROMK K+ channel did not change in the distal convoluted tubule and decreased slightly in the cortical/medullary collecting duct, whereas BK channel abundance increased in principal cells of the connecting tubule/collecting ducts. However, K+ restriction also enhanced ENaC expression in Nedd4LPax8/LC1 mice, and treatment with the ENaC inhibitor, benzamil, reversed excessive K+ wasting. Moreover, K+ restriction increased WNK1 and WNK4 expression and enhanced SPAK-mediated NCC phosphorylation in Nedd4LPax8/LC1 mice, with no change in total NCC. We propose a mechanism in which NEDD4-2 deficiency exacerbates hypokalemia during dietary K+ restriction primarily through direct upregulation of ENaC, whereas increased BK channel expression has a less significant role. These changes outweigh the compensatory antikaliuretic effects of diminished ROMK expression, increased NCC phosphorylation, and enhanced WNK pathway activity in the distal convoluted tubule. Thus, NEDD4-2 has a crucial role in K+ conservation through direct and indirect effects on ENaC, distal nephron K+ channels, and WNK signaling.
Collapse
Affiliation(s)
- Lama Al-Qusairi
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,National Centre of Competence in Research "Kidney.ch", Zurich, Switzerland
| | - Denis Basquin
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,National Centre of Competence in Research "Kidney.ch", Zurich, Switzerland
| | - Ankita Roy
- Department of Medicine, University of Pittsburgh School of Medicine and VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania; and
| | - Renuga Devi Rajaram
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,National Centre of Competence in Research "Kidney.ch", Zurich, Switzerland
| | - Marc P Maillard
- Service of Nephrology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Arohan R Subramanya
- Department of Medicine, University of Pittsburgh School of Medicine and VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania; and
| | - Olivier Staub
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland; .,National Centre of Competence in Research "Kidney.ch", Zurich, Switzerland
| |
Collapse
|
49
|
George JC, Vedamurthy D, Bermudez M, Kennedy JW. Quiz Page October 2016. Am J Kidney Dis 2016; 68:A17-A19. [DOI: 10.1053/j.ajkd.2016.06.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/17/2016] [Indexed: 11/11/2022]
|
50
|
Abstract
Hypernatremia (serum sodium concentration >145 mEq/L) is a common electrolyte disorder with increased morbidity and mortality especially in the elderly and critically ill patients. The review presents the main pathogenetic mechanisms of hypernatremia, provides specific directions for the evaluation of patients with increased sodium levels and describes a detailed algorithm for the proper correction of hypernatremia. Furthermore, two representative cases of hypovolemic and hypervolemic hypernatremia are presented along with practical clues for their proper evaluation and treatment. Accurate diagnosis and appropriate treatment is crucial since undercorrection or overcorrection of hypernatremia are both associated with poor patients' prognosis.
Collapse
Affiliation(s)
- George Liamis
- a Department of Internal Medicine , School of Medicine, University of Ioannina , Ioannina , Greece
| | - Theodosios D Filippatos
- a Department of Internal Medicine , School of Medicine, University of Ioannina , Ioannina , Greece
| | - Moses S Elisaf
- a Department of Internal Medicine , School of Medicine, University of Ioannina , Ioannina , Greece
| |
Collapse
|