1
|
Shi Y, Duan H, Liu J, Shi X, Zhao M, Zhang Y. Association of triglyceride glucose index with the risk of acute kidney injury in patients with coronary revascularization: a cohort study. Diabetol Metab Syndr 2024; 16:117. [PMID: 38807249 PMCID: PMC11131318 DOI: 10.1186/s13098-024-01358-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024] Open
Abstract
BACKGROUND The triglyceride glucose (TyG) index is a novel and reliable alternative marker for insulin resistance. Previous studies have shown that TyG index is closely associated with cardiovascular outcomes in cardiovascular diseases and coronary revascularization. However, the relationship between TyG index and renal outcomes of coronary revascularization is unclear. The purpose of this study was to investigate the correlation between TyG index and the risk of acute kidney injury (AKI) in patients with coronary revascularization. METHODS A retrospective cohort study was conducted to select eligible patients with coronary revascularization admitted to ICU in the medical information mart for intensive care IV (MIMIC-IV). According to the TyG index quartile, these patients were divided into four groups (Q1-Q4). The primary endpoint was the incidence of AKI, and secondary endpoints included 28-day mortality and the rate of renal replacement therapy (RRT) use in the AKI population. Multivariate Cox regression analysis and restricted cubic splines (RCS) were used to analyze TyG index association with AKI risk. Kaplan-Meier survival analysis was performed to assess the incidence of endpoints in the four groups. RESULTS In this study, 790 patients who underwent coronary revascularization surgery were included, and the incidence of AKI was 30.13%. Kaplan-Meier analysis showed that patients with a high TyG index had a significantly increased incidence of AKI (Log-rank P = 0.0045). Multivariate Cox regression analysis showed that whether TyG index was a continuous variable (HR 1.42, 95% CI 1.06-1.92, P = 0.018) or a categorical variable (Q4: HR 1.89, 95% CI 1.12-3.17, P = 0.017), and there was an independent association between TyG index and AKI in patients with coronary revascularization. The RCS curve showed a linear relationship between higher TyG index and AKI in this particular population (P = 0.078). In addition, Kaplan-Meier analysis showed a significantly increased risk of RRT application in a subset of AKI patients based on quartiles of TyG index (P = 0.029). CONCLUSION TyG index was significantly associated with increased risk of AKI and adverse renal outcomes in patients with coronary revascularization. This finding suggests that the TyG index may be useful in identifying people at high risk for AKI and poor renal outcomes in patients with coronary revascularization.
Collapse
Affiliation(s)
- Yue Shi
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Hangyu Duan
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Jing Liu
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Xiujie Shi
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China
| | - Mingming Zhao
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China.
| | - Yu Zhang
- Department of Nephrology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, 100091, China.
| |
Collapse
|
2
|
Parwani K, Mandal P. Advanced glycation end products and insulin resistance in diabetic nephropathy. VITAMINS AND HORMONES 2024; 125:117-148. [PMID: 38997162 DOI: 10.1016/bs.vh.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2024]
Abstract
Insulin resistance is a central hallmark that connects the metabolic syndrome and diabetes to the resultant formation of advanced glycation end products (AGEs), which further results in the complications of diabetes, including diabetic nephropathy. Several factors play an important role as an inducer to diabetic nephropathy, and AGEs elicit their harmful effects via interacting with the receptor for AGEs Receptor for AGEs, by induction of pro-inflammatory cytokines, oxidative stress, endoplasmic reticulum stress and fibrosis in the kidney tissues leading to the loss of renal function. Insulin resistance results in the activation of other alternate pathways governed by insulin, which results in the hypertrophy of the renal cells and tissue remodeling. Apart from the glucose uptake and disposal, insulin dependent PI3K and Akt also upregulate the expression of endothelial nitric oxide synthase, that results in increasing the bioavailability of nitric oxide in the vascular endothelium, which further results in tissue fibrosis. Considering the global prevalence of diabetic nephropathy, and the impact of protein glycation, various inhibitors and treatment avenues are being developed, to prevent the progression of diabetic complications. In this chapter, we discuss the role of glycation in insulin resistance and further its impact on the kidney.
Collapse
Affiliation(s)
- Kirti Parwani
- Department of Biological Sciences, P. D. Patel Institute of Applied Sciences, Charotar University of Science & Technology, Gujarat, India
| | - Palash Mandal
- Department of Biological Sciences, P. D. Patel Institute of Applied Sciences, Charotar University of Science & Technology, Gujarat, India.
| |
Collapse
|
3
|
Xu C, Ha X, Yang S, Tian X, Jiang H. Advances in understanding and treating diabetic kidney disease: focus on tubulointerstitial inflammation mechanisms. Front Endocrinol (Lausanne) 2023; 14:1232790. [PMID: 37859992 PMCID: PMC10583558 DOI: 10.3389/fendo.2023.1232790] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 09/19/2023] [Indexed: 10/21/2023] Open
Abstract
Diabetic kidney disease (DKD) is a serious complication of diabetes that can lead to end-stage kidney disease. Despite its significant impact, most research has concentrated on the glomerulus, with little attention paid to the tubulointerstitial region, which accounts for the majority of the kidney volume. DKD's tubulointerstitial lesions are characterized by inflammation, fibrosis, and loss of kidney function, and recent studies indicate that these lesions may occur earlier than glomerular lesions. Evidence has shown that inflammatory mechanisms in the tubulointerstitium play a critical role in the development and progression of these lesions. Apart from the renin-angiotensin-aldosterone blockade, Sodium-Glucose Linked Transporter-2(SGLT-2) inhibitors and new types of mineralocorticoid receptor antagonists have emerged as effective ways to treat DKD. Moreover, researchers have proposed potential targeted therapies, such as inhibiting pro-inflammatory cytokines and modulating T cells and macrophages, among others. These therapies have demonstrated promising results in preclinical studies and clinical trials, suggesting their potential to treat DKD-induced tubulointerstitial lesions effectively. Understanding the immune-inflammatory mechanisms underlying DKD-induced tubulointerstitial lesions and developing targeted therapies could significantly improve the treatment and management of DKD. This review summarizes the latest advances in this field, highlighting the importance of focusing on tubulointerstitial inflammation mechanisms to improve DKD outcomes.
Collapse
Affiliation(s)
- Chengren Xu
- Division of Nephrology, Department of Internal Medicine, People’s Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Xiaowen Ha
- Division of Nephrology, Department of Internal Medicine, People’s Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Shufen Yang
- Division of Nephrology, Department of Internal Medicine, People’s Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Xuefei Tian
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Hong Jiang
- Division of Nephrology, Department of Internal Medicine, People’s Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| |
Collapse
|
4
|
Fan Y, Yuan Y, Xiong M, Jin M, Zhang D, Yang D, Liu C, Petersen RB, Huang K, Peng A, Zheng L. Tet1 deficiency exacerbates oxidative stress in acute kidney injury by regulating superoxide dismutase. Theranostics 2023; 13:5348-5364. [PMID: 37908721 PMCID: PMC10614682 DOI: 10.7150/thno.87416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 09/14/2023] [Indexed: 11/02/2023] Open
Abstract
Rationale: Increased methylation of key genes has been observed in kidney diseases, suggesting that the ten-eleven translocation (Tet) methyl-cytosine dioxygenase family as well as 5mC oxidation may play important roles. As a member of the Tet family, the role of Tet1 in acute kidney injury (AKI) remains unclear. Methods: Tet1 knockout mice, with or without tempol treatment, a scavenger of reactive oxygen species (ROS), were challenged with ischemia and reperfusion (I/R) injury or unilateral ureteral obstruction (UUO) injury. RNA-sequencing, Western blotting, qRT-PCR, bisulfite sequencing, chromatin immunoprecipitation, immunohistochemical staining, and dot blot assays were performed. Results: Tet1 expression was rapidly upregulated following I/R or UUO injury. Moreover, Tet1 knockout mice showed increased renal injury and renal cell death, increased ROS accumulation, G2/M cell cycle arrest, inflammation, and fibrosis. Severe renal damage in injured Tet1 knockout mice was alleviated by tempol treatment. Mechanistically, Tet1 reduced the 5mC levels in an enzymatic activity-dependent manner on the promoters of Sod1 and Sod2 to promote their expression, thus lowering injury-induced excessive ROS and reducing I/R or UUO injury. Conclusions: Tet1 plays an important role in the development of AKI by promoting SOD expression through a DNA demethylase-dependent mechanism.
Collapse
Affiliation(s)
- Yu Fan
- Hubei Key Laboratory of Cell Homeostasis, Frontier Science Center for Immunology and Metabolism, College of Life Sciences, Wuhan University, Wuhan, China, 430072
| | - Yangmian Yuan
- Hubei Key Laboratory of Cell Homeostasis, Frontier Science Center for Immunology and Metabolism, College of Life Sciences, Wuhan University, Wuhan, China, 430072
| | - Mingrui Xiong
- School of Pharmacy, Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Huazhong University of Science and Technology, Wuhan, China, 430030
| | - Muchuan Jin
- Hubei Key Laboratory of Cell Homeostasis, Frontier Science Center for Immunology and Metabolism, College of Life Sciences, Wuhan University, Wuhan, China, 430072
| | - Donge Zhang
- Department of Pharmacy, The Third Hospital of Wuhan and Tongren Hospital of Wuhan University, Wuhan, China, 430070
| | - Dong Yang
- School of Pharmacy, Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Huazhong University of Science and Technology, Wuhan, China, 430030
| | - Chengyu Liu
- Department of Transfusion Medicine, Wuhan Hospital of Traditional Chinese and Western Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, 430030
| | - Robert B. Petersen
- Foundational Sciences, Central Michigan University College of Medicine, Mount Pleasant, MI, USA, 48858
| | - Kun Huang
- School of Pharmacy, Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Huazhong University of Science and Technology, Wuhan, China, 430030
| | - Anlin Peng
- Department of Pharmacy, The Third Hospital of Wuhan and Tongren Hospital of Wuhan University, Wuhan, China, 430070
| | - Ling Zheng
- Hubei Key Laboratory of Cell Homeostasis, Frontier Science Center for Immunology and Metabolism, College of Life Sciences, Wuhan University, Wuhan, China, 430072
| |
Collapse
|
5
|
Sutovska H, Molcan L, Majzunova M, Sykora M, Kopkan L, Zeman M. Mineralocorticoid receptor blockade protects the kidneys but does not affect inverted blood pressure rhythm in hypertensive transgenic (mRen-2)27 rats. Mol Cell Endocrinol 2023; 572:111967. [PMID: 37210027 DOI: 10.1016/j.mce.2023.111967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/17/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023]
Abstract
Aldosterone regulates blood pressure (BP) through water and sodium balance. In our study, we studied if continuous treatment with a mineralocorticoid receptor antagonist, spironolactone (30 mg/kg/day) for 20 days can: 1) attenuate hypertension development and restore inverted 24-h BP rhythm in hypertensive transgenic (mRen-2)27 rats (TGR) measured by telemetry; 2) improve function of the kidneys and heart; 3) be protective against high salt load (1% in water) by mitigating oxidative injury and improving kidney function. Spironolactone decreased albuminuria and 8-isoprostane in normal and salt load conditions in BP-independent effects. Salt load increased BP, impaired autonomic balance, suppressed plasma aldosterone level and increased natriuresis, albuminuria and oxidative injury in TGR. Spironolactone did not restore the inverted 24-h rhythm of BP in TGR, therefore, mineralocorticoids are not crucial in regulation of BP daily profile. Spironolactone improved kidney function, decreased oxidative stress and was protective against high salt load in the BP-independent manner.
Collapse
Affiliation(s)
- Hana Sutovska
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
| | - Lubos Molcan
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
| | - Miroslava Majzunova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
| | - Matus Sykora
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic.
| | - Libor Kopkan
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
| | - Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovak Republic.
| |
Collapse
|
6
|
Huang J, Caliskan Guzelce E, Gholami SK, Gawelek KL, Mitchell RN, Pojoga LH, Romero JR, Williams GH, Adler GK. Effects of Mineralocorticoid Receptor Blockade and Statins on Kidney Injury Marker 1 (KIM-1) in Female Rats Receiving L-NAME and Angiotensin II. Int J Mol Sci 2023; 24:6500. [PMID: 37047470 PMCID: PMC10095483 DOI: 10.3390/ijms24076500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 03/31/2023] Open
Abstract
Kidney injury molecule-1 (KIM-1) is a biomarker of renal injury and a predictor of cardiovascular disease. Aldosterone, via activation of the mineralocorticoid receptor, is linked to cardiac and renal injury. However, the impact of mineralocorticoid receptor activation and blockade on KIM-1 is uncertain. We investigated whether renal KIM-1 is increased in a cardiorenal injury model induced by L-NAME/ANG II, and whether mineralocorticoid receptor blockade prevents the increase in KIM-1. Since statin use is associated with lower aldosterone, we also investigated whether administering eiSther a lipophilic statin (simvastatin) or a hydrophilic statin (pravastatin) prevents the increase in renal KIM-1. Female Wistar rats (8-10 week old), consuming a high salt diet (1.6% Na+), were randomized to the following conditions for 14 days: control; L-NAME (0.2 mg/mL in drinking water)/ANG II (225 ug/kg/day on days 12-14); L-NAME/ANG II + eplerenone (100 mg/kg/day p.o.); L-NAME/ANG II + pravastatin (20 mg/kg/day p.o.); L-NAME/ANG II + simvastatin (20 mg/kg/day p.o.). Groups treated with L-NAME/ANG II had significantly higher blood pressure, plasma and urine aldosterone, cardiac injury/stroke composite score, and renal KIM-1 than the control group. Both eplerenone and simvastatin reduced 24-h urinary KIM-1 (p = 0.0046, p = 0.031, respectively) and renal KIM-1 immunostaining (p = 0.004, p = 0.037, respectively). Eplerenone also reduced renal KIM-1 mRNA expression (p = 0.012) and cardiac injury/stroke composite score (p = 0.04). Pravastatin did not affect these damage markers. The 24-h urinary KIM-1, renal KIM-1 immunostaining, and renal KIM-1 mRNA expression correlated with cardiac injury/stroke composite score (p < 0.0001, Spearman ranked correlation = 0.69, 0.66, 0.59, respectively). In conclusion, L-NAME/ANG II increases renal KIM-1 and both eplerenone and simvastatin blunt this increase in renal KIM-1.
Collapse
Affiliation(s)
- Jiayan Huang
- Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ezgi Caliskan Guzelce
- Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Shadi K. Gholami
- Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Kara L. Gawelek
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - Richard N. Mitchell
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - Luminita H. Pojoga
- Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jose R. Romero
- Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Gordon H. Williams
- Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Gail K. Adler
- Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
7
|
Nutrient-derived modification of mineral corticoid receptors is relevant to diabetic kidney disease progression. Hypertens Res 2023; 46:261-263. [PMID: 36380204 DOI: 10.1038/s41440-022-01107-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022]
|
8
|
Elsakka EGE, Mokhtar MM, Hegazy M, Ismail A, Doghish AS. Megalin, a multi-ligand endocytic receptor, and its participation in renal function and diseases: A review. Life Sci 2022; 308:120923. [PMID: 36049529 DOI: 10.1016/j.lfs.2022.120923] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/13/2022] [Accepted: 08/26/2022] [Indexed: 11/16/2022]
Abstract
The endocytosis mechanism is a complicated system that is essential for cell signaling and survival. Megalin, a membrane-associated endocytic receptor, and its related proteins such as cubilin, the neonatal Fc receptor for IgG, and NaPi-IIa are important in receptors-mediated endocytosis. Physiologically, megalin uptakes plasma vitamins and proteins from primary urine, preventing their loss. It also facilitates tubular retrieval of solutes and endogenous components that may be involved in modulation and recovery from kidney injuries. Moreover, megalin is responsible for endocytosis of xenobiotics and drugs in renal tubules, increasing their half-life and/or their toxicity. Fluctuations in megalin expression and/or functionality due to changes in its regulatory mechanisms are associated with some sort of kidney injury. Also, it's an important component of several pathological conditions, including diabetic nephropathy and Dent disease. Thus, exploring the fundamental role of megalin in the kidney might help in the protection and/or treatment of multiple kidney-related diseases. Hence, this review aimed to explore the physiological roles of megalin in the kidney and their implications for kidney-related injuries.
Collapse
Affiliation(s)
- Elsayed G E Elsakka
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt.
| | - Mahmoud Mohamed Mokhtar
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt
| | - Maghawry Hegazy
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt
| | - Ahmed Ismail
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt
| | - Ahmed S Doghish
- Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt.
| |
Collapse
|
9
|
Cardiovascular and Renal Outcomes with Finerenone, a Selective Mineralocorticoid Receptor Antagonist. Cardiol Ther 2022; 11:337-354. [PMID: 35737275 PMCID: PMC9381668 DOI: 10.1007/s40119-022-00269-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/07/2022] [Indexed: 12/13/2022] Open
Abstract
Overactivation of the renin-angiotensin-aldosterone system (RAAS) has been shown to be pathologic in heart failure and albuminuric chronic kidney disease (CKD), triggering pro-inflammatory and pro-fibrotic cellular pathways. The standard of care in these disease states includes treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers. Mineralocorticoid receptor antagonists (MRAs) are also a mainstay in the treatment of heart failure with reduced ejection fraction; however, therapy is often limited by treatment-related hyperkalemia. In albuminuric CKD, the risk of hyperkalemia, acute kidney injury (AKI), and hypotension also remains significant. Finerenone is a novel non-steroidal MRA that may obviate some of these concerns and have therapeutic potential in additional patient populations. Finerenone was developed using the chemical structure of a dihydropyridine channel blocker but optimized to create a bulky MRA without any activity at the L-type calcium channel. It has several novel cellular mechanisms that may account for its ability to reduce cardiac hypertrophy and proteinuria more efficiently than an equinatriuretic dose of a steroidal MRA, while retaining anti-inflammatory and anti-fibrotic properties. Finerenone also has a lower rate of treatment-related hyperkalemia and AKI than steroidal MRAs with a smaller effect on systolic blood pressure, greatly expanding its therapeutic utility. The recently published FIGARO-DKD and FIDELIO-DKD trials demonstrate that treatment with finerenone in patients with type II diabetes and albuminuric CKD results in improved cardiovascular outcomes and a lower risk of CKD progression. Patients enrolled in these studies were already on maximally tolerated ACE inhibitor or angiotensin receptor blocker therapy. Trials investigating finerenone's therapeutic effect in patients with heart failure with preserved ejection fraction (HFpEF) and non-diabetic CKD, as well sodium-glucose cotransporter 2 (SGLT2) and finerenone combination therapy in patients with diabetic nephropathy, are ongoing.
Collapse
|
10
|
Molitoris BA, Sandoval RM, Yadav SPS, Wagner MC. Albumin Uptake and Processing by the Proximal Tubule: Physiologic, Pathologic and Therapeutic Implications. Physiol Rev 2022; 102:1625-1667. [PMID: 35378997 PMCID: PMC9255719 DOI: 10.1152/physrev.00014.2021] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
For nearly 50 years the proximal tubule (PT) has been known to reabsorb, process, and either catabolize or transcytose albumin from the glomerular filtrate. Innovative techniques and approaches have provided insights into these processes. Several genetic diseases, nonselective PT cell defects, chronic kidney disease (CKD), and acute PT injury lead to significant albuminuria, reaching nephrotic range. Albumin is also known to stimulate PT injury cascades. Thus, the mechanisms of albumin reabsorption, catabolism, and transcytosis are being reexamined with the use of techniques that allow for novel molecular and cellular discoveries. Megalin, a scavenger receptor, cubilin, amnionless, and Dab2 form a nonselective multireceptor complex that mediates albumin binding and uptake and directs proteins for lysosomal degradation after endocytosis. Albumin transcytosis is mediated by a pH-dependent binding affinity to the neonatal Fc receptor (FcRn) in the endosomal compartments. This reclamation pathway rescues albumin from urinary losses and cellular catabolism, extending its serum half-life. Albumin that has been altered by oxidation, glycation, or carbamylation or because of other bound ligands that do not bind to FcRn traffics to the lysosome. This molecular sorting mechanism reclaims physiological albumin and eliminates potentially toxic albumin. The clinical importance of PT albumin metabolism has also increased as albumin is now being used to bind therapeutic agents to extend their half-life and minimize filtration and kidney injury. The purpose of this review is to update and integrate evolving information regarding the reabsorption and processing of albumin by proximal tubule cells including discussion of genetic disorders and therapeutic considerations.
Collapse
Affiliation(s)
- Bruce A. Molitoris
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Dept.of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Ruben M. Sandoval
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Shiv Pratap S. Yadav
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Mark C. Wagner
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States
| |
Collapse
|
11
|
Mechanisms contributing to adverse outcomes of COVID-19 in obesity. Mol Cell Biochem 2022; 477:1155-1193. [PMID: 35084674 PMCID: PMC8793096 DOI: 10.1007/s11010-022-04356-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 01/07/2022] [Indexed: 01/08/2023]
Abstract
A growing amount of epidemiological data from multiple countries indicate an increased prevalence of obesity, more importantly central obesity, among hospitalized subjects with COVID-19. This suggests that obesity is a major factor contributing to adverse outcome of the disease. As it is a metabolic disorder with dysregulated immune and endocrine function, it is logical that dysfunctional metabolism contributes to the mechanisms behind obesity being a risk factor for adverse outcome in COVID-19. Emerging data suggest that in obese subjects, (a) the molecular mechanisms of viral entry and spread mediated through ACE2 receptor, a multifunctional host cell protein which links to cellular homeostasis mechanisms, are affected. This includes perturbation of the physiological renin-angiotensin system pathway causing pro-inflammatory and pro-thrombotic challenges (b) existent metabolic overload and ER stress-induced UPR pathway make obese subjects vulnerable to severe COVID-19, (c) host cell response is altered involving reprogramming of metabolism and epigenetic mechanisms involving microRNAs in line with changes in obesity, and (d) adiposopathy with altered endocrine, adipokine, and cytokine profile contributes to altered immune cell metabolism, systemic inflammation, and vascular endothelial dysfunction, exacerbating COVID-19 pathology. In this review, we have examined the available literature on the underlying mechanisms contributing to obesity being a risk for adverse outcome in COVID-19.
Collapse
|
12
|
Epstein M. Aldosterone and Mineralocorticoid Receptor Signaling as Determinants of Cardiovascular and Renal Injury: From Hans Selye to the Present. Am J Nephrol 2021; 52:209-216. [PMID: 33857953 DOI: 10.1159/000515622] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/02/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND A full understanding of the mechanisms of action of aldosterone and its interaction with the mineralocorticoid receptor (MR) allows a theoretical framework to predict the therapeutic potential of MR antagonists (MRAs) in CKD, and heart failure with reduced ejection fraction. SUMMARY The initial focus on the mechanisms of action of aldosterone was directed primarily on its role in modulating renal excretory function. In contrast, many recent studies have demonstrated a wider and expanded role for aldosterone in modulating inflammation, collagen formation, fibrosis, and necrosis. Increasing evidence has accrued that implicates the pathophysiological overactivation of the MR as a major determinant of progression of CKD. By promoting inflammation and fibrosis, MR overactivation constitutes a pivotal determinant of CKD progression and its associated morbidity and mortality. In accord with this mechanism of action, blockade of the MR is currently being investigated as a novel treatment regimen to slow the progression of CKD. The recently reported FIDELIO-DKD (FInerenone in reducing kiDnEy faiLure and dIsease prOgression in Diabetic Kidney Disease) study demonstrated that patients with CKD and type 2 diabetes who were treated with finerenone (a novel nonsteroidal MRA) manifested a lower risk of a composite primary outcome event compared with patients in the placebo arm (defined as kidney failure, or a sustained decrease of ≥40% in the estimated glomerular filtration rate from baseline, or death from renal causes). In addition, patients in the finerenone group also manifested a lower risk of a key secondary outcome event (defined as death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure). Key Messages: Based on the success of the FIDELIO-DKD study, future studies should be implemented testing the hypothesis that a wide array of nondiabetic CKD is modulated by overactivation of the MR, and consequently may be amenable to treatment with novel nonsteroidal MRAs. Future studies are encouraged to elucidate the clinical implications of the interplay of nonsteroidal MRAs and the components of the renin-angiotensin cascade. The unique and recently reported interrelationship of fibroblast growth factor (FGF23) and aldosterone may also constitute a propitious subject for future investigation.
Collapse
Affiliation(s)
- Murray Epstein
- University of Miami School of Medicine, Miami, Florida, USA
| |
Collapse
|
13
|
Tsugawa-Shimizu Y, Fujishima Y, Kita S, Minami S, Sakaue TA, Nakamura Y, Okita T, Kawachi Y, Fukada S, Namba-Hamano T, Takabatake Y, Isaka Y, Nishizawa H, Ranscht B, Maeda N, Shimomura I. Increased vascular permeability and severe renal tubular damage after ischemia-reperfusion injury in mice lacking adiponectin or T-cadherin. Am J Physiol Endocrinol Metab 2021; 320:E179-E190. [PMID: 33284092 PMCID: PMC8260375 DOI: 10.1152/ajpendo.00393.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Adiponectin (APN) is a circulating protein specifically produced by adipocytes. Native APN specifically binds to T-cadherin, a glycosylphosphatidylinositol-anchored protein, mediating the exosome-stimulating effects of APN in endothelial, muscle, and mesenchymal stem cells. It was previously reported that APN has beneficial effects on kidney diseases, but the role of T-cadherin has not been clarified yet. Here, our immunofluorescence study indicated the existence of both T-cadherin and APN protein in pericytes, subsets of tissue-resident mesenchymal stem/progenitor cells positive for platelet-derived growth factor receptor β (PDGFRβ), surrounding peritubular capillaries. In an acute renal ischemia-reperfusion (I/R) model, T-cadherin-knockout (Tcad-KO) mice, similar to APN-KO mice, exhibited the more progressive phenotype of renal tubular damage and increased vascular permeability than wild-type mice. In addition, in response to I/R-injury, the renal PDGFRβ-positive cell area increased in wild-type mice, but opposingly decreased in both Tcad-KO and APN-KO mice, suggesting severe pericyte loss. Mouse primary pericytes also expressed T-cadherin. APN promoted exosome secretion in a T-cadherin-dependent manner. Such exosome production from pericytes may play an important role in maintaining the capillary network and APN-mediated inhibition of renal tubular injury. In summary, our study suggested that APN protected the kidney in an acute renal injury model by binding to T-cadherin.NEW & NOTEWORTHY In the kidney, T-cadherin-associated adiponectin protein existed on peritubular capillary pericytes. In an acute renal ischemia-reperfusion model, deficiency of adiponectin or T-cadherin exhibited the more progressive phenotype of renal tubular damage and increased vascular permeability, accompanied by severe pericyte loss. In vitro, adiponectin promoted exosome secretion from mouse primary pericytes in a T-cadherin-dependent manner. Adiponectin plays an important role in maintaining the capillary network and amelioration of renal tubular injury by binding to T-cadherin.
Collapse
Affiliation(s)
- Yuri Tsugawa-Shimizu
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Yuya Fujishima
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Shunbun Kita
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
- Department of Adipose Management, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Satoshi Minami
- Department of Nephrology, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Taka-Aki Sakaue
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Yuto Nakamura
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Tomonori Okita
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Yusuke Kawachi
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Shiro Fukada
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Tomoko Namba-Hamano
- Department of Nephrology, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Yoshitsugu Takabatake
- Department of Nephrology, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Yoshitaka Isaka
- Department of Nephrology, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Hitoshi Nishizawa
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Barbara Ranscht
- Development, Aging and Regeneration Program, NIH-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Norikazu Maeda
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
- Department of Metabolism and Atherosclerosis, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| | - Iichiro Shimomura
- Department of Metabolic Medicine, Graduate School of Medicine and Faculty of Medicine, Osaka University, Suita, Japan
| |
Collapse
|
14
|
Brooks DL, Garza AE, Caliskan Guzelce E, Gholami SK, Treesaranuwattana T, Maris S, Ranjit S, Tay CS, Lee JM, Romero JR, Adler GK, Pojoga LH, Williams GH. mTORC1 Deficiency Modifies Volume Homeostatic Responses to Dietary Sodium in a Sex-Specific Manner. Endocrinology 2020; 161:5802448. [PMID: 32154868 PMCID: PMC7391217 DOI: 10.1210/endocr/bqaa041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 03/06/2020] [Indexed: 12/21/2022]
Abstract
The mechanistic target of the rapamycin (mTOR) pathway plays a role in features common to both excess salt/aldosterone and cardiovascular/renal diseases. Dietary sodium can upregulate mTORC1 signaling in cardiac and renal tissue, and the inhibition of mTOR can prevent aldosterone-associated, salt-induced hypertension. The impact of sex and age on mTOR's role in volume homeostasis and the regulation of aldosterone secretion is largely unknown. We hypothesize that both age and sex modify mTOR's interaction with volume homeostatic mechanisms. The activity of 3 volume homeostatic mechanisms-cardiovascular, renal, and hormonal (aldosterone [sodium retaining] and brain natriuretic peptide [BNP; sodium losing])-were assessed in mTORC1 deficient (Raptor+/-) and wild-type male and female littermates at 2 different ages. The mice were volume stressed by being given a liberal salt (LibS) diet. Raptor+/-mice of both sexes when they aged: (1) reduced their blood pressure, (2) increased left ventricular internal diameter during diastole, (3) decreased renal blood flow, and (4) increased mineralocorticoid receptor expression. Aldosterone levels did not differ by sex in young Raptor+/- mice. However, as they aged, compared to their littermates, aldosterone decreased in males but increased in females. Finally, given the level of Na+ intake, BNP was inappropriately suppressed, but only in Raptor+/- males. These data indicate that Raptor+/- mice, when stressed with a LibS diet, display inappropriate volume homeostatic responses, particularly with aging, and the mechanisms altered, differing by sex.
Collapse
Affiliation(s)
- Danielle L Brooks
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Amanda E Garza
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Ezgi Caliskan Guzelce
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Shadi K Gholami
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | | | - Stephen Maris
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Sanjay Ranjit
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Chee Sin Tay
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Jessica M Lee
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Jose R Romero
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Gail K Adler
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Luminita H Pojoga
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
| | - Gordon H Williams
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA
- Correspondence: Gordon H. Williams, MD, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, 221 Longwood Avenue, Boston Massachusetts 02115. E-mail:
| |
Collapse
|
15
|
Brooks DL, Garza AE, Katayama IA, Romero JR, Adler GK, Pojoga LH, Williams GH. Aldosterone Modulates the Mechanistic Target of Rapamycin Signaling in Male Mice. Endocrinology 2019; 160:716-728. [PMID: 30726893 PMCID: PMC6397424 DOI: 10.1210/en.2018-00989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 01/31/2019] [Indexed: 12/12/2022]
Abstract
Both mechanistic target of rapamycin (mTOR) pathway and aldosterone are implicated in the development of cardiovascular and renal disease. However, the interaction between aldosterone and the mTOR pathway is unknown. We hypothesized the following: that (i) increased aldosterone will modulate the activity of the mTORC1 and mTORC2 molecular pathways in the heart and kidney; (ii) a physiologic increase in aldosterone will affect these pathways differently than a pathophysiologic one; and (iii) the changes in the mTOR level/activity will differ between the heart and kidney. In both kidney and heart tissues, phosphorylation of mTOR is significantly decreased when aldosterone levels are physiologically increased (by dietary sodium restriction), followed by a decrease in phosphorylated p70S6K1 in cardiac, but not renal, tissue. Sirtuin 1, an epigenetic modulator, is decreased in the heart but increased in the kidney. Conversely, pathophysiologic aldosterone levels (an infusion for 3 weeks) had divergent effects on phosphorylated mTOR and the downstream substrates of mTORC1 and mTORC2 in cardiac and renal tissues. Increased aldosterone levels significantly alter mTOR activity in the heart and kidney. In the kidney, substantial differences were noted if the increase was produced physiologically vs pathophysiologically, suggesting that mTOR activity, in part, may mediate aldosterone-induced renal damage. Thus, modulating mTOR activity may reduce aldosterone-dependent renal damage similar to mineralocorticoid receptor blockade but potentially with less adverse side effects.
Collapse
Affiliation(s)
- Danielle L Brooks
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
- Correspondence: Danielle L. Brooks, PhD, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, 221 Longwood Avenue, Boston, Massachusetts 02115. E-mail:
| | - Amanda E Garza
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Isis A Katayama
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Jose R Romero
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Gail K Adler
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Luminita H Pojoga
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Gordon H Williams
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| |
Collapse
|
16
|
Ming Y, Stefano GB, Kream RM, Zhuang Q. Anti-Diabetogenic Properties of Mineralocorticoid Receptor Antagonists: Implications for Enhanced Safety and Efficacy of Post-Transplantation Pharmacotherapies. Med Sci Monit 2019; 25:1102-1104. [PMID: 30739121 PMCID: PMC6378856 DOI: 10.12659/msm.914340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Widespread usage of the calcineurin inhibitors tacrolimus and cyclosporine A as post-transplantation immunosuppressive agents is fraught with severe nephrotoxic and diabetogenic side effects. More recently, tapering of calcineurin inhibitor-based immunotherapies with concurrent administration of the mammalian target of rapamycin (mTOR) inhibitors sirolimus and everolimus has been employed within pharmacological regimens designed to achieve better safety and efficacy for preservation of allograft kidney function. Collected preclinical data and recent clinical study, however, indicate that usage of calcineurin inhibitors and/or mTOR blockers as immunosuppressive agents promotes equivalent diabetogenic side effects. Based on a wealth of validating preclinical studies, we contend that the favorable metabolic effects of mineralocorticoid receptor antagonists, such as spironolactone, support their inclusion in novel immunosuppressive strategies to inhibit new onset type II diabetic symptoms in post-transplantation patient populations.
Collapse
Affiliation(s)
- Yingzi Ming
- Transplantation Center, Third Xiangya Hospital of Central South University, Engineering and Technology Research Center for Transplantation Medicine of National Ministry of Health, Changsha, Hunan, China (mainland)
| | - George B Stefano
- Transplantation Center, Third Xiangya Hospital of Central South University, Engineering and Technology Research Center for Transplantation Medicine of National Ministry of Health, Changsha, Hunan, China (mainland)
| | - Richard M Kream
- Transplantation Center, Third Xiangya Hospital of Central South University, Engineering and Technology Research Center for Transplantation Medicine of National Ministry of Health, Changsha, Hunan, China (mainland)
| | - Quan Zhuang
- Transplantation Center, Third Xiangya Hospital of Central South University, Engineering and Technology Research Center for Transplantation Medicine of National Ministry of Health, Changsha, Hunan, China (mainland)
| |
Collapse
|
17
|
New insights on the renal protective effects of mineralocorticoid receptor antagonists. J Hypertens 2019; 37:9-10. [DOI: 10.1097/hjh.0000000000001917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
18
|
Renal miR-148b is associated with megalin down-regulation in IgA nephropathy. Biosci Rep 2018; 38:BSR20181578. [PMID: 30355654 PMCID: PMC6239259 DOI: 10.1042/bsr20181578] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/06/2018] [Accepted: 10/16/2018] [Indexed: 12/13/2022] Open
Abstract
Megalin is essential for proximal tubule reabsorption of filtered proteins, hormones, and vitamins, and its dysfunction has been reported in IgA nephropathy (IgAN). miR-148b has been shown to regulate renal megalin expression in vitro and in animal models of kidney disease. We examined a potential role of miR-148b and other miRNAs in regulating megalin expression in IgAN by analyzing the association between megalin and miR-148b, miR-21, miR-146a, and miR-192 expression. Quantitative PCR (qPCR) analysis identified a marked increase in renal levels of several miRNAs, including miR-148b, miR-21, miR-146a, and a significant decrease in megalin mRNA levels in IgAN patients when compared with normal controls. By multiple linear regression analysis, however, only renal miR-148b was independently associated with megalin mRNA levels in IgAN. Proximal tubule megalin expression was further evaluated by immunofluorescence labeling of biopsies from the patients. The megalin expression was significantly lower in patients with highest levels of renal miR-148b compared with patients with lowest levels. To examine the direct effects of the miRNAs on megalin and other membrane proteins expression, proximal tubule LLC-PK1 cells were transfected with miR-148b, miR-21, miR-146a, or miR-192 mimics. Transfection with miR-148b mimic, but not the other three miRNA mimics inhibited endogenous megalin mRNA expression. No significant effect of any of the four miRNA mimics was observed on cubilin or aquaporin 1 (AQP1) mRNA expression. The findings suggest that miR-148b negatively regulates megalin expression in IgAN, which may affect renal uptake and metabolism of essential substances.
Collapse
|
19
|
Wang B, Lin L, Wang H, Guo H, Gu Y, Ding W. Overexpressed cyclophilin B suppresses aldosterone-induced proximal tubular cell injury both in vitro and in vivo. Oncotarget 2018; 7:69309-69320. [PMID: 27732567 PMCID: PMC5342479 DOI: 10.18632/oncotarget.12503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/28/2016] [Indexed: 11/25/2022] Open
Abstract
The renin-angiotensin-aldosterone system (RAAS) is overactivated in patients with chronic kidney disease. Oxidative stress and endoplasmic reticulum stress (ERS) are two major mechanisms responsible for aldosterone-induced kidney injury. Cyclophilin (CYP) B is a chaperone protein that accelerates the rate of protein folding through its peptidyl-prolyl cis-trans isomerase (PPIase) activity. We report that overexpression of wild-type CYPB attenuated aldosterone-induced oxidative stress (evidenced by reduced production of reactive oxygen species and improved mitochondrial dysfunction), ERS (indicated by reduced expression of the ERS markers glucose-regulated protein 78 [GRP78] and C/-EBP homologous protein [CHOP]), and tubular cell apoptosis in comparison with aldosterone-induced human kidney-2 (HK-2) cells. The in vivo study also yielded similar results. Hence, CYPB performs a crucial function in protecting cells against aldosterone-induced oxidative stress, ERS, and tubular cell injury via its PPIase activity.
Collapse
Affiliation(s)
- Bin Wang
- Division of Nephrology, Huashan Hospital and Institute of Nephrology, Fudan University, Xuhui, Shanghai, P.R. China
| | - Lilu Lin
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, P.R. China
| | - Haidong Wang
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, P.R. China
| | - Honglei Guo
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, P.R. China
| | - Yong Gu
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, P.R. China
| | - Wei Ding
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, P.R. China
| |
Collapse
|
20
|
Whaley-Connell A, Sowers JR. Insulin Resistance in Kidney Disease: Is There a Distinct Role Separate from That of Diabetes or Obesity? Cardiorenal Med 2017; 8:41-49. [PMID: 29344025 DOI: 10.1159/000479801] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Insulin resistance is a central component of the metabolic dysregulation observed in obesity, which puts one at risk for the development of type 2 diabetes and complications related to diabetes such as chronic kidney disease. Insulin resistance and compensatory hyperinsulinemia place one at risk for other risk factors such as dyslipidemia, hypertension, and proteinuria, e.g., development of kidney disease. Our traditional view of insulin actions focuses on insulin-sensitive tissues such as skeletal muscle, liver, adipose tissue, and the pancreas. However, insulin also has distinct actions in kidney tissue that regulate growth, hypertrophy, as well as microcirculatory and fibrotic pathways which, in turn, impact glomerular filtration, including that governed by tubuloglomerular feedback. However, it is often difficult to discern the distinct effects of excess circulating insulin and impaired insulin actions, as exist in the insulin resistance individual, from the associated effects of obesity or elevated systolic blood pressure on the development and progression of kidney disease over time. Therefore, we review the experimental and clinical evidence for the distinct impact of insulin resistance on kidney function and disease.
Collapse
Affiliation(s)
- Adam Whaley-Connell
- Research Service, Harry S. Truman Memorial Veterans' Hospital, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA.,Diabetes and Cardiovascular Center, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA.,Division of Nephrology and Hypertension, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA.,Division of Endocrinology and Metabolism, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA.,Department of Medicine, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA
| | - James R Sowers
- Research Service, Harry S. Truman Memorial Veterans' Hospital, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA.,Diabetes and Cardiovascular Center, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA.,Division of Endocrinology and Metabolism, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA.,Department of Medicine, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA.,Department of Medical Pharmacology and Physiology, University of Missouri-Columbia School of Medicine, Columbia, Missouri, USA
| |
Collapse
|
21
|
Wen L, Andersen PK, Husum DMU, Nørregaard R, Zhao Z, Liu Z, Birn H. MicroRNA-148b regulates megalin expression and is associated with receptor downregulation in mice with unilateral ureteral obstruction. Am J Physiol Renal Physiol 2017; 313:F210-F217. [PMID: 28331063 DOI: 10.1152/ajprenal.00585.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/02/2017] [Accepted: 03/16/2017] [Indexed: 11/22/2022] Open
Abstract
Megalin is a multiligand, endocytic receptor that is important for the normal, proximal tubule reabsorption of filtered proteins, hormones, enzymes, essential nutrients, and nephrotoxins. Megalin dysfunction has been associated with acute, as well as chronic kidney diseases. Tubular proteinuria has been observed following unilateral ureteral obstruction (UUO), suggesting megalin dysfunction; however, the pathophysiological mechanism has not been determined. To identify potential regulators of megalin expression, we examined renal microRNAs (miRNAs) expression and observed an upregulation of microRNA-148b (miR-148b) in obstructed mouse kidneys 7 days after UUO, which was associated with a significant reduction in proximal tubule megalin expression and accumulation of megalin ligands. By in silico miRNA target prediction analysis, we identified megalin messenger RNA (mRNA) as a potential target of miR-148b and confirmed using a dual-luciferase reporter assay that miR-148b targeted the 3'-untranslated region of the megalin gene. Transfection of LLC-PK1 cells with miR-148b mimic reduced endogenous megalin mRNA and protein levels in a concentration-dependent manner, while transfection with miR-148b inhibitor resulted in an increase. Our findings suggest that miR-148b directly downregulates megalin expression and that miR-148b negatively regulates megalin expression in UUO-induced kidney injury. Furthermore, the identification of a miRNA regulating megalin expression may allow for targeted interventions to modulate megalin function and proximal tubule uptake of proteins, as well as other ligands.
Collapse
Affiliation(s)
- Lu Wen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Nephrology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Pia K Andersen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Dina M U Husum
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; and
| | - Rikke Nørregaard
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; and
| | - Zhanzheng Zhao
- Department of Nephrology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhangsuo Liu
- Department of Nephrology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Henrik Birn
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; .,Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| |
Collapse
|
22
|
Nielsen R, Christensen EI, Birn H. Megalin and cubilin in proximal tubule protein reabsorption: from experimental models to human disease. Kidney Int 2017; 89:58-67. [PMID: 26759048 DOI: 10.1016/j.kint.2015.11.007] [Citation(s) in RCA: 298] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/17/2015] [Accepted: 08/19/2015] [Indexed: 01/19/2023]
Abstract
Proximal tubule protein uptake is mediated by 2 receptors, megalin and cubilin. These receptors rescue a variety of filtered ligands, including biomarkers, essential vitamins, and hormones. Receptor gene knockout animal models have identified important functions of the receptors and have established their essential role in modulating urinary protein excretion. Rare genetic syndromes associated with dysfunction of these receptors have been identified and characterized, providing additional information on the importance of these receptors in humans. Using various disease models in combination with receptor gene knockout, the implications of receptor dysfunction in acute and chronic kidney injury have been explored and have pointed to potential new roles of these receptors. Based on data from animal models, this paper will review current knowledge on proximal tubule endocytic receptor function and regulation, and their role in renal development, protein reabsorption, albumin uptake, and normal renal physiology. These findings have implications for the pathophysiology and diagnosis of proteinuric renal diseases. We will examine the limitations of the different models and compare the findings to phenotypic observations in inherited human disorders associated with receptor dysfunction. Furthermore, evidence from receptor knockout mouse models as well as human observations suggesting a role of protein receptors for renal disease will be discussed in light of conditions such as chronic kidney disease, diabetes, and hypertension.
Collapse
Affiliation(s)
- Rikke Nielsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Henrik Birn
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark.
| |
Collapse
|
23
|
Dieterlen MT, John K, Haase S, Garbade J, Tarnok A, Mohr FW, Bittner HB, Barten MJ. Effect of confounding factors on a phospho-flow assay of ribosomal S6 protein for therapeutic drug monitoring of the mTOR-inhibitor everolimus in heart transplanted patients. Biomarkers 2016; 22:86-92. [DOI: 10.1080/1354750x.2016.1210676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
24
|
Epstein M. Reduction of cardiovascular risk in chronic kidney disease by mineralocorticoid receptor antagonism. Lancet Diabetes Endocrinol 2015; 3:993-1003. [PMID: 26429402 DOI: 10.1016/s2213-8587(15)00289-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/24/2015] [Accepted: 07/30/2015] [Indexed: 12/24/2022]
Abstract
Cardiovascular disease is the leading cause of death and morbidity in people with chronic kidney disease, but there are few evidence-based treatments for reducing cardiovascular events in these patients. The failure of novel drug candidates to delay progression to end-stage renal disease and limit or abrogate cardiovascular morbidity and mortality has led to increased interest in a mineralocorticoid receptor (MR) antagonist-based treatment model to reduce cardiovascular risk in patients with chronic kidney disease and end-stage renal disease. Aldosterone concentrations and MR signalling are associated with an enhanced risk of cardiovascular injury and the incidence of sudden death, and MR blockade decreases the risk of cardiovascular events and sudden death in patients with reduced glomerular filtration rate. Since evidence from clinical trials shows that treatment with MR antagonists confers a morbidity and mortality advantage for patients with cardiovascular disorders, similar benefits might also accrue in patients with chronic kidney disease. Large prospective trials are urgently needed to answer this question. In this Review, I argue that despite differences in the pathophysiology and clinical features of cardiovascular disease in patients with and without chronic kidney disease, MR antagonists could provide cardiovascular benefit in patients with chronic kidney disease.
Collapse
Affiliation(s)
- Murray Epstein
- Division of Nephrology and Hypertension, University of Miami, Leonard M Miller School of Medicine, Miami, FL, USA.
| |
Collapse
|
25
|
de Cavanagh EMV, Inserra F, Ferder L. Angiotensin II blockade: how its molecular targets may signal to mitochondria and slow aging. Coincidences with calorie restriction and mTOR inhibition. Am J Physiol Heart Circ Physiol 2015; 309:H15-44. [PMID: 25934099 DOI: 10.1152/ajpheart.00459.2014] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 04/30/2015] [Indexed: 02/07/2023]
Abstract
Caloric restriction (CR), renin angiotensin system blockade (RAS-bl), and rapamycin-mediated mechanistic target of rapamycin (mTOR) inhibition increase survival and retard aging across species. Previously, we have summarized CR and RAS-bl's converging effects, and the mitochondrial function changes associated with their physiological benefits. mTOR inhibition and enhanced sirtuin and KLOTHO signaling contribute to the benefits of CR in aging. mTORC1/mTORC2 complexes contribute to cell growth and metabolic regulation. Prolonged mTORC1 activation may lead to age-related disease progression; thus, rapamycin-mediated mTOR inhibition and CR may extend lifespan and retard aging through mTORC1 interference. Sirtuins by deacetylating histone and transcription-related proteins modulate signaling and survival pathways and mitochondrial functioning. CR regulates several mammalian sirtuins favoring their role in aging regulation. KLOTHO/fibroblast growth factor 23 (FGF23) contribute to control Ca(2+), phosphate, and vitamin D metabolism, and their dysregulation may participate in age-related disease. Here we review how mTOR inhibition extends lifespan, how KLOTHO functions as an aging suppressor, how sirtuins mediate longevity, how vitamin D loss may contribute to age-related disease, and how they relate to mitochondrial function. Also, we discuss how RAS-bl downregulates mTOR and upregulates KLOTHO, sirtuin, and vitamin D receptor expression, suggesting that at least some of RAS-bl benefits in aging are mediated through the modulation of mTOR, KLOTHO, and sirtuin expression and vitamin D signaling, paralleling CR actions in age retardation. Concluding, the available evidence endorses the idea that RAS-bl is among the interventions that may turn out to provide relief to the spreading issue of age-associated chronic disease.
Collapse
Affiliation(s)
- Elena M V de Cavanagh
- Center of Hypertension, Cardiology Department, Austral University Hospital, Derqui, Argentina; School of Biomedical Sciences, Austral University, Buenos Aires, Argentina; and
| | - Felipe Inserra
- Center of Hypertension, Cardiology Department, Austral University Hospital, Derqui, Argentina; School of Biomedical Sciences, Austral University, Buenos Aires, Argentina; and
| | - León Ferder
- Department of Physiology and Pharmacology, Ponce School of Medicine, Ponce, Puerto Rico
| |
Collapse
|
26
|
Della Penna SL, Rosón MI, Toblli JE, Fernández BE. Role of angiotensin II and oxidative stress in renal inflammation by hypernatremia: Benefits of atrial natriuretic peptide, losartan, and tempol. Free Radic Res 2015; 49:383-96. [DOI: 10.3109/10715762.2015.1006216] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
27
|
Ichikawa D, Kamijo-Ikemori A, Sugaya T, Shibagaki Y, Yasuda T, Hoshino S, Katayama K, Igarashi-Migitaka J, Hirata K, Kimura K. Human liver-type fatty acid–binding protein protects against tubulointerstitial injury in aldosterone-induced renal injury. Am J Physiol Renal Physiol 2015; 308:F114-21. [DOI: 10.1152/ajprenal.00469.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
To demonstrate the renoprotective function of human liver-type fatty acid–binding protein (hL-FABP) expressed in proximal tubules in aldosterone (Aldo)-induced renal injury, hL-FABP chromosomal transgenic (Tg) and wild-type (WT) mice received systemic Aldo infusions (Tg-Aldo and WT-Aldo, respectively) were given 1% NaCl water for 28 days. In this model, elevation of systolic blood pressure, monocyte chemoattractant protein-1 expression, macrophage infiltration in the interstitium, tubulointerstitial damage, and depositions of type I and III collagens were observed. Elevation of systolic blood pressure did not differ in WT-Aldo vs. Tg-Aldo animals, however, renal injury was suppressed in Tg-Aldo compared with WT-Aldo mice. Dihydroethidium fluorescence was used to evaluate reactive oxidative stress, which was suppressed in Tg-Aldo compared with WT-Aldo mice. Gene expression of angiotensinogen in the kidney was upregulated, and excretion of urinary angiotensinogen was increased in WT-Aldo mice. This exacerbation was suppressed in Tg-Aldo mice. Expression of hL-FABP was upregulated in proximal tubules of Tg-Aldo mice. Urinary excretion of hL-FABP was significantly greater in Tg-Aldo than in Tg-control mice. In conclusion, hL-FABP ameliorated the tubulointerstitial damage in Aldo-induced renal injury via reducing oxidative stress and suppressing activation of the intrarenal renin-angiotensin system.
Collapse
Affiliation(s)
- Daisuke Ichikawa
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan; and
| | - Atsuko Kamijo-Ikemori
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan; and
- Department of Anatomy, St. Marianna University School of Medicine, Kanagawa, Japan
| | - Takeshi Sugaya
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan; and
| | - Yugo Shibagaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan; and
| | - Takashi Yasuda
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan; and
| | - Seiko Hoshino
- Department of Anatomy, St. Marianna University School of Medicine, Kanagawa, Japan
| | - Kimie Katayama
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan; and
| | | | - Kazuaki Hirata
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan; and
- Department of Anatomy, St. Marianna University School of Medicine, Kanagawa, Japan
| | - Kenjiro Kimura
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan; and
| |
Collapse
|
28
|
Sun QL, Li M, Rui HL, Chen YP. Inhibition of local aldosterone by eplerenone reduces renal structural damage in a novel model of chronic cyclosporine A nephrotoxicity. J Renin Angiotensin Aldosterone Syst 2014; 16:301-10. [PMID: 25500744 DOI: 10.1177/1470320314561248] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 10/14/2014] [Indexed: 11/16/2022] Open
Affiliation(s)
- Qiao-Ling Sun
- Department of Nephrology, Qilu Hospital, Shandong University, China
| | - Meng Li
- Department of Neurosurgery, Qianfoshan Hospital, Shandong University, China
| | - Hong-Liang Rui
- Department of Nephrology, Beijing An Zhen Hospital, Capital Medical University, China
| | - Yi-Pu Chen
- Department of Nephrology, Beijing An Zhen Hospital, Capital Medical University, China
| |
Collapse
|
29
|
Gomez-Sanchez EP. Brain mineralocorticoid receptors in cognition and cardiovascular homeostasis. Steroids 2014; 91:20-31. [PMID: 25173821 PMCID: PMC4302001 DOI: 10.1016/j.steroids.2014.08.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/10/2014] [Accepted: 08/04/2014] [Indexed: 12/20/2022]
Abstract
Mineralocorticoid receptors (MR) mediate diverse functions supporting osmotic and hemodynamic homeostasis, response to injury and inflammation, and neuronal changes required for learning and memory. Inappropriate MR activation in kidneys, heart, vessels, and brain hemodynamic control centers results in cardiovascular and renal pathology and hypertension. MR binds aldosterone, cortisol and corticosterone with similar affinity, while the glucocorticoid receptor (GR) has less affinity for cortisol and corticosterone. As glucocorticoids are more abundant than aldosterone, aldosterone activates MR in cells co-expressing enzymes with 11β-hydroxydehydrogenase activity to inactivate them. MR and GR co-expressed in the same cell interact at the molecular and functional level and these functions may be complementary or opposing depending on the cell type. Thus the balance between MR and GR expression and activation is crucial for normal function. Where 11β-hydroxydehydrogenase 2 (11β-HSD2) that inactivates cortisol and corticosterone in aldosterone target cells of the kidney and nucleus tractus solitarius (NTS) is not expressed, as in most neurons, MR are activated at basal glucocorticoid concentrations, GR at stress concentrations. An exception may be pre-autonomic neurons of the PVN which express MR and 11β-HSD1 in the absence of hexose-6-phosphate dehydrogenase required to generate the requisite cofactor for reductase activity, thus it acts as a dehydrogenase. MR antagonists, valuable adjuncts to the treatment of cardiovascular disease, also inhibit MR in the brain that are crucial for memory formation and exacerbate detrimental effects of excessive GR activation on cognition and mood. 11β-HSD1 inhibitors combat metabolic and cognitive diseases related to glucocorticoid excess, but may exacerbate MR action where 11β-HSD1 acts as a dehydrogenase, while non-selective 11β-HSD1&2 inhibitors cause injurious disruption of MR hemodynamic control. MR functions in the brain are multifaceted and optimal MR:GR activity is crucial. Therefore selectively targeting down-stream effectors of MR specific actions may be a better therapeutic goal.
Collapse
Affiliation(s)
- Elise P Gomez-Sanchez
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| |
Collapse
|
30
|
Bauersachs J, Jaisser F, Toto R. Mineralocorticoid receptor activation and mineralocorticoid receptor antagonist treatment in cardiac and renal diseases. Hypertension 2014; 65:257-63. [PMID: 25368026 DOI: 10.1161/hypertensionaha.114.04488] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Johann Bauersachs
- From the Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany (J.B.); Centre de Recherche des Cordeliers, Inserm U1138, Université Pierre et Marie Curie, Paris, France (F.J.); and Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas (R.T.).
| | - Frédéric Jaisser
- From the Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany (J.B.); Centre de Recherche des Cordeliers, Inserm U1138, Université Pierre et Marie Curie, Paris, France (F.J.); and Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas (R.T.)
| | - Robert Toto
- From the Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany (J.B.); Centre de Recherche des Cordeliers, Inserm U1138, Université Pierre et Marie Curie, Paris, France (F.J.); and Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas (R.T.)
| |
Collapse
|
31
|
Jia G, Aroor AR, Martinez-Lemus LA, Sowers JR. Overnutrition, mTOR signaling, and cardiovascular diseases. Am J Physiol Regul Integr Comp Physiol 2014; 307:R1198-206. [PMID: 25253086 DOI: 10.1152/ajpregu.00262.2014] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The prevalence of obesity and associated medical disorders has increased dramatically in the United States and throughout much of the world in the past decade. Obesity, induced by excess intake of carbohydrates and fats, is a major cause of Type 2 diabetes, hypertension, and the cardiorenal metabolic syndrome. There is emerging evidence that excessive nutrient intake promotes signaling through the mammalian target of rapamycin (mTOR), which, in turn, may lead to alterations of cellular metabolic signaling leading to insulin resistance and obesity-related diseases, such as diabetes, cardiovascular and kidney disease, as well as cancer. While the pivotal role of mTOR signaling in regulating metabolic stress, autophagy, and adaptive immune responses has received increasing attention, there remain many gaps in our knowledge regarding this important nutrient sensor. For example, the precise cellular signaling mechanisms linking excessive nutrient intake and enhanced mTOR signaling with increased cardiovascular and kidney disease, as well as cancer, are not well understood. In this review, we focus on the effects that the interaction between excess intake of nutrients and enhanced mTOR signaling have on the promotion of obesity-associated diseases and potential therapeutic strategies involving targeting mTOR signaling.
Collapse
Affiliation(s)
- Guanghong Jia
- Divisions of Endocrinology, Diabetes, Hypertension and Metabolism, Diabetes Cardiovascular Center, University of Missouri School of Medicine, Columbia, Missouri; Harry S. Truman Memorial Veterans Hospital, University of Missouri School of Medicine, Columbia, Missouri; and
| | - Annayya R Aroor
- Divisions of Endocrinology, Diabetes, Hypertension and Metabolism, Diabetes Cardiovascular Center, University of Missouri School of Medicine, Columbia, Missouri; Harry S. Truman Memorial Veterans Hospital, University of Missouri School of Medicine, Columbia, Missouri; and
| | - Luis A Martinez-Lemus
- Departments of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri; Harry S. Truman Memorial Veterans Hospital, University of Missouri School of Medicine, Columbia, Missouri; and Dalton Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, Missouri
| | - James R Sowers
- Divisions of Endocrinology, Diabetes, Hypertension and Metabolism, Diabetes Cardiovascular Center, University of Missouri School of Medicine, Columbia, Missouri; Departments of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri; Harry S. Truman Memorial Veterans Hospital, University of Missouri School of Medicine, Columbia, Missouri; and Dalton Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, Missouri
| |
Collapse
|
32
|
Nichols LA, Grunz-Borgmann EA, Wang X, Parrish AR. A role for the age-dependent loss of α(E)-catenin in regulation of N-cadherin expression and cell migration. Physiol Rep 2014; 2:2/6/e12039. [PMID: 24920123 PMCID: PMC4208646 DOI: 10.14814/phy2.12039] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The aging kidney has a decreased ability to repair following acute kidney injury. Previous studies from our laboratory have demonstrated a loss in α‐catenin expression in the aging rat kidney. We hypothesize that loss of α‐catenin expression in tubular epithelial cells may induce changes that result in a decreased repair capacity. In these studies, we demonstrate that decreased α‐catenin protein expression is detectable as early as 20 months of age in male Fischer 344 rats. Protein loss is also observed in aged nonhuman primate kidneys, suggesting that this is not a species‐specific response. In an effort to elucidate alterations due to the loss of α‐catenin, we generated NRK‐52E cell lines with stable knockdown of α(E)‐catenin (C2 cells). Interestingly, C2 cells had decreased expression of N‐cadherin, decreased cell–cell adhesion, and increased monolayer permeability. C2 had deficits in wound repair, due to alterations in cell migration. Analysis of gene expression in the migrating control cells indicated that expression of N‐cadherin and N‐CAM was increased during repair. In migrating C2 cells, expression of N‐CAM was also increased, but the expression of N‐cadherin was not upregulated. Importantly, a blocking antibody against N‐cadherin inhibited repair in NRK‐52E cells, suggesting an important role in repair. Taken together, these data suggest that loss of α‐catenin, and the subsequent downregulation of N‐cadherin expression, is a mechanism underlying the decreased migration of tubular epithelial cells that contributes to the inability of the aging kidney to repair following injury. Aging is associated with loss of α‐catenin and N‐cadherin expression in the kidney. In these studies, we demonstrate that α‐catenin regulates, in part, N‐cadherin expression and migration in tubular epithelial cells.
Collapse
Affiliation(s)
- LaNita A Nichols
- Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri
| | | | - Xinhui Wang
- Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri
| | - Alan R Parrish
- Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri
| |
Collapse
|
33
|
Nistala R, Whaley-Connell A. Resistance to insulin and kidney disease in the cardiorenal metabolic syndrome; role for angiotensin II. Mol Cell Endocrinol 2013; 378:53-8. [PMID: 23416840 PMCID: PMC3711952 DOI: 10.1016/j.mce.2013.02.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 01/03/2013] [Accepted: 02/06/2013] [Indexed: 12/14/2022]
Abstract
The presence of insulin resistance is increasingly recognized as an important contributor to early stage kidney disease independent of the contribution of diabetes. Important in this relationship is the strong correlation between hyperinsulinemia and low levels of albuminuria (e.g. microalbuminuria). Recent work highlight mechanisms for glomerular/tubulointerstitial injury with excess insulin and emerging evidence identifies a unique role for insulin metabolic signaling and altered handling of salt reabsorption at the level of the proximal tubule. Evidence is also emerging for the role of insulin signaling in the glomerulus both epithelial and endothelial. Central to the mechanism of injury is inappropriate activation of the RAAS.
Collapse
Affiliation(s)
- Ravi Nistala
- University of Missouri School of Medicine, Diabetes and Cardiovascular Center, Departments of Internal Medicine, Divisions of Nephrology and Hypertension, United States; Dialysis Clinics Inc., Lemone Industrial Blvd., Columbia MO, United States.
| | | |
Collapse
|