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Autophagy and kidney aging. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 179:10-15. [PMID: 36849016 DOI: 10.1016/j.pbiomolbio.2023.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 01/02/2023] [Accepted: 02/23/2023] [Indexed: 02/27/2023]
Abstract
Autophagy is a highly conserved intracellular degradation system in eukaryotes that maintains cellular and tissue homeostasis. Upon autophagy induction, cytoplasmic components are engulfed by a double-membrane organelle called the autophagosome that fuses with a lysosome to degrade its contents. In recent years, it has become clear that autophagy becomes dysregulated with aging, which leads to age-related diseases. Kidney function is particularly prone to age-related decline, and aging is the most significant risk factor for chronic kidney disease. This review first discuss the relationship between autophagy and kidney aging. Second, we describe how age-related dysregulation of autophagy occurs. Finally, we discuss the potential of autophagy-targeting drugs to ameliorate human kidney aging and the approaches necessary to discover such agents.
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Shi M, Maique JO, Cleaver O, Moe OW, Hu MC. VEGFR2 insufficiency enhances phosphotoxicity and undermines Klotho's protection against peritubular capillary rarefaction and kidney fibrosis. Am J Physiol Renal Physiol 2023; 324:F106-F123. [PMID: 36395384 PMCID: PMC9799155 DOI: 10.1152/ajprenal.00149.2022] [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: 06/22/2022] [Revised: 10/17/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) and its cognate receptor (VEGFR2) system are crucial for cell functions associated with angiogenesis and vasculogenesis. Klotho contributes to vascular health maintenance in the kidney and other organs in mammals, but it is unknown whether renoprotection by Klotho is dependent on VEGF/VEGFR2 signaling. We used heterozygous VEGFR2-haploinsufficient (VEGFR2+/-) mice resulting from heterozygous knockin of green fluorescent protein in the locus of fetal liver kinase 1 encoding VEGFR2 to test the interplay of Klotho, phosphate, and VEGFR2 in kidney function, the vasculature, and fibrosis. VEGFR2+/- mice displayed downregulated VEGF/VEGFR2 signaling in the kidney, lower density of peritubular capillaries, and accelerated kidney fibrosis, all of which were also found in the homozygous Klotho hypomorphic mice. High dietary phosphate induced higher plasma phosphate, greater peritubular capillary rarefaction, and more kidney fibrosis in VEGFR2+/- mice compared with wild-type mice. Genetic overexpression of Klotho significantly attenuated the elevated plasma phosphate, kidney dysfunction, peritubular capillary rarefaction, and kidney fibrosis induced by a high-phosphate diet in wild-type mice but only modestly ameliorated these changes in the VEGFR2+/- background. In cultured endothelial cells, VEGFR2 inhibition reduced free VEGFR2 but enhanced its costaining of an endothelial marker (CD31) and exacerbated phosphotoxicity. Klotho protein maintained VEGFR2 expression and attenuated high phosphate-induced cell injury, which was reduced by VEGFR2 inhibition. In conclusion, normal VEGFR2 function is required for vascular integrity and for Klotho to exert vascular protective and antifibrotic actions in the kidney partially through the regulation of VEGFR2 function.NEW & NOTEWORTHY This research paper studied the interplay of vascular endothelial growth factor receptor type 2 (VEGFR2), high dietary phosphate, and Klotho, an antiaging protein, in peritubular structure and kidney fibrosis. Klotho protein was shown to maintain VEGFR2 expression in the kidney and reduce high phosphate-induced cell injury. However, Klotho cytoprotection was attenuated by VEGFR2 inhibition. Thus, normal VEGFR2 function is required for vascular integrity and Klotho to exert vascular protective and antifibrotic actions in the kidney.
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Affiliation(s)
- Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Dallas, Texas
| | - Jenny Omega Maique
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Dallas, Texas
| | - Ondine Cleaver
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Orson W Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Dallas, Texas
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Dallas, Texas
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
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3
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Tang A, Zhang Y, Wu L, Lin Y, Lv L, Zhao L, Xu B, Huang Y, Li M. Klotho's impact on diabetic nephropathy and its emerging connection to diabetic retinopathy. Front Endocrinol (Lausanne) 2023; 14:1180169. [PMID: 37143722 PMCID: PMC10151763 DOI: 10.3389/fendo.2023.1180169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 04/04/2023] [Indexed: 05/06/2023] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide and is a significant burden on healthcare systems. α-klotho (klotho) is a protein known for its anti-aging properties and has been shown to delay the onset of age-related diseases. Soluble klotho is produced by cleavage of the full-length transmembrane protein by a disintegrin and metalloproteases, and it exerts various physiological effects by circulating throughout the body. In type 2 diabetes and its complications DN, a significant decrease in klotho expression has been observed. This reduction in klotho levels may indicate the progression of DN and suggest that klotho may be involved in multiple pathological mechanisms that contribute to the onset and development of DN. This article examines the potential of soluble klotho as a therapeutic agent for DN, with a focus on its ability to impact multiple pathways. These pathways include anti-inflammatory and oxidative stress, anti-fibrotic, endothelial protection, prevention of vascular calcification, regulation of metabolism, maintenance of calcium and phosphate homeostasis, and regulation of cell fate through modulation of autophagy, apoptosis, and pyroptosis pathways. Diabetic retinopathy shares similar pathological mechanisms with DN, and targeting klotho may offer new insights into the prevention and treatment of both conditions. Finally, this review assesses the potential of various drugs used in clinical practice to modulate klotho levels through different mechanisms and their potential to improve DN by impacting klotho levels.
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Affiliation(s)
- Anqi Tang
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Yu Zhang
- Department of Nephrology, Shaanxi Provincial Hospital of Traditional Chinese Medicine, Xi’an, China
| | - Ling Wu
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Yong Lin
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Lizeyu Lv
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Liangbin Zhao
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Bojun Xu
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Youqun Huang
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Mingquan Li
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
- *Correspondence: Mingquan Li,
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4
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Morevati M, Fang EF, Mace ML, Kanbay M, Gravesen E, Nordholm A, Egstrand S, Hornum M. Roles of NAD + in Acute and Chronic Kidney Diseases. Int J Mol Sci 2022; 24:ijms24010137. [PMID: 36613582 PMCID: PMC9820289 DOI: 10.3390/ijms24010137] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/08/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Nicotinamide adenine dinucleotide (oxidized form, NAD+) is a critical coenzyme, with functions ranging from redox reactions and energy metabolism in mitochondrial respiration and oxidative phosphorylation to being a central player in multiple cellular signaling pathways, organ resilience, health, and longevity. Many of its cellular functions are executed via serving as a co-substrate for sirtuins (SIRTs), poly (ADP-ribose) polymerases (PARPs), and CD38. Kidney damage and diseases are common in the general population, especially in elderly persons and diabetic patients. While NAD+ is reduced in acute kidney injury (AKI) and chronic kidney disease (CKD), mounting evidence indicates that NAD+ augmentation is beneficial to AKI, although conflicting results exist for cases of CKD. Here, we review recent progress in the field of NAD+, mainly focusing on compromised NAD+ levels in AKI and its effect on essential cellular pathways, such as mitochondrial dysfunction, compromised autophagy, and low expression of the aging biomarker αKlotho (Klotho) in the kidney. We also review the compromised NAD+ levels in renal fibrosis and senescence cells in the case of CKD. As there is an urgent need for more effective treatments for patients with injured kidneys, further studies on NAD+ in relation to AKI/CKD may shed light on novel therapeutics.
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Affiliation(s)
- Marya Morevati
- Department of Nephrology, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
- Correspondence:
| | - Evandro Fei Fang
- Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, 1478 Lørenskog, Norway
| | - Maria L. Mace
- Department of Nephrology, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Mehmet Kanbay
- Division of Nephrology, Department of Medicine, Koç University School of Medicine, Istanbul 34010, Turkey
| | - Eva Gravesen
- Department of Pathology, Herlev Hospital, University of Copenhagen, 2730 Copenhagen, Denmark
| | - Anders Nordholm
- Department of Nephrology, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Søren Egstrand
- Department of Nephrology, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Mads Hornum
- Department of Nephrology, Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
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5
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He Y, Lu H, Zhao Y. Development of an autophagy activator from Class III PI3K complexes, Tat-BECN1 peptide: Mechanisms and applications. Front Cell Dev Biol 2022; 10:851166. [PMID: 36172279 PMCID: PMC9511052 DOI: 10.3389/fcell.2022.851166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
Impairment or dysregulation of autophagy has been implicated in many human pathologies ranging from neurodegenerative diseases, infectious diseases, cardiovascular diseases, metabolic diseases, to malignancies. Efforts have been made to explore the therapeutic potential of pharmacological autophagy activators, as beneficial health effects from caloric restriction or physical exercise are linked to autophagy activation. However, the lack of specificity remains the major challenge to the development and clinical use of autophagy activators. One candidate of specific autophagy activators is Tat-BECN1 peptide, derived from Beclin 1 subunit of Class III PI3K complexes. Here, we summarize the molecular mechanisms by which Tat-BECN1 peptide activates autophagy, the strategies for optimization and development, and the applications of Tat-BECN1 peptide in cellular and organismal models of physiology and pathology.
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An Z, Chiang WC, Fernández ÁF, Franco LH, He C, Huang SY, Lee E, Liu Y, Sebti S, Shoji-Kawata S, Sirasanagandla S, Wang RC, Wei Y, Zhao Y, Vega-Rubin-de-Celis S. Beth Levine’s Legacy: From the Discovery of BECN1 to Therapies. A Mentees’ Perspective. Front Cell Dev Biol 2022; 10:891332. [PMID: 35832792 PMCID: PMC9273008 DOI: 10.3389/fcell.2022.891332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
With great sadness, the scientific community received the news of the loss of Beth Levine on 15 June 2020. Dr. Levine was a pioneer in the autophagy field and work in her lab led not only to a better understanding of the molecular mechanisms regulating the pathway, but also its implications in multiple physiological and pathological conditions, including its role in development, host defense, tumorigenesis, aging or metabolism. This review does not aim to provide a comprehensive view of autophagy, but rather an outline of some of the discoveries made by the group of Beth Levine, from the perspective of some of her own mentees, hoping to honor her legacy in science.
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Affiliation(s)
- Zhenyi An
- Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Wei-Chung Chiang
- Institute of Biochemistry and Molecular Biology, College of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Álvaro F. Fernández
- Departamento de Bioquímica y Biología Molecular, Instituto Universitario de Oncología (IUOPA), Universidad de Oviedo, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Luis H. Franco
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - CongCong He
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Shu-Yi Huang
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Eunmyong Lee
- InnoCure Therapeutics Inc., Gyeonggi-do, South Korea
| | - Yang Liu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, United States
| | - Salwa Sebti
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | | | | | - Richard C. Wang
- Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Yongjie Wei
- Cancer Research Institute, Guangzhou Medical University, Guangzhou, China
| | - Yuting Zhao
- Institute of Future Agriculture, Northwest A&F University, Yangling, China
| | - Silvia Vega-Rubin-de-Celis
- Institute for Cell Biology (Cancer Research), Essen University Hospital, University of Duisburg-Essen, Essen, Germany
- *Correspondence: Silvia Vega-Rubin-de-Celis, ,
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7
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The biological clean-ups that could combat age-related disease. Nature 2022; 601:S15-S17. [PMID: 35046595 DOI: 10.1038/d41586-022-00075-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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8
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Therapeutic potential of Beclin1 for transition from AKI to CKD: autophagy-dependent and autophagy-independent functions. Kidney Int 2022; 101:13-15. [PMID: 34991802 DOI: 10.1016/j.kint.2021.10.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 10/18/2021] [Indexed: 12/28/2022]
Abstract
Acute kidney injury (AKI) increases the risk of chronic kidney disease (CKD), but the mechanisms of CKD development after AKI remain unclear. Recent studies have elucidated that autophagy protects against AKI, but the role of autophagy during the AKI-to-CKD transition is controversial. Beclin1 is a key molecule for autophagy as well as endocytosis and phagocytosis. Shi et al. demonstrate that Beclin1 activates autophagy and is a promising therapeutic target for AKI-to-CKD transition.
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9
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Hu MC, Moe OW. Phosphate and Cellular Senescence. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1362:55-72. [PMID: 35288873 PMCID: PMC10513121 DOI: 10.1007/978-3-030-91623-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cellular senescence is one type of permeant arrest of cell growth and one of increasingly recognized contributor to aging and age-associated disease. High phosphate and low Klotho individually and synergistically lead to age-related degeneration in multiple organs. Substantial evidence supports the causality of high phosphate in cellular senescence, and potential contribution to human aging, cancer, cardiovascular, kidney, neurodegenerative, and musculoskeletal diseases. Phosphate can induce cellular senescence both by direct phosphotoxicity, and indirectly through downregulation of Klotho and upregulation of plasminogen activator inhibitor-1. Restriction of dietary phosphate intake and blockage of intestinal absorption of phosphate help suppress cellular senescence. Supplementation of Klotho protein, cellular senescence inhibitor, and removal of senescent cells with senolytic agents are potential novel strategies to attenuate phosphate-induced cellular senescence, retard aging, and ameliorate age-associated, and phosphate-induced disorders.
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Affiliation(s)
- 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.
| | - 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
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10
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Shi M, Maique J, Shepard S, Li P, Seli O, Moe OW, Chang Hu M. In vivo evidence for therapeutic applications of beclin 1 to promote recovery and inhibit fibrosis after acute kidney injury. Kidney Int 2022; 101:63-78. [PMID: 34736972 PMCID: PMC8741729 DOI: 10.1016/j.kint.2021.09.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 09/09/2021] [Accepted: 09/16/2021] [Indexed: 01/18/2023]
Abstract
Autophagy regulator beclin 1 activity determines the severity of kidney damage induced by ischemia reperfusion injury, but its role in kidney recovery and fibrosis are unknown and its therapeutic potentials have not been tested. Here, we explored beclin 1 effects on kidney fibrosis in three models of acute kidney injury (AKI)-ischemia reperfusion injury, cisplatin kidney toxicity, and unilateral ureteric obstruction in mouse strains with three levels of beclin 1 function: normal (wild type), low (heterozygous global deletion of beclin 1, Becn1+/-), and high beclin 1 activity (knockin gain-of-function mutant Becn1, Becn1FA). Fourteen days after AKI induction, heterozygous mice had more, but knockin mice had less kidney fibrosis than wild-type mice did. One day after ischemia reperfusion injury, heterozygous pan-kidney tubular Becn1 null mice had more severe kidney damage than homozygous distal tubular Becn1 null mice did, which was similar to the wild-type mice, implying that proximal tubular beclin 1 protects the kidney against ischemia reperfusion injury. By 14 days, both pan-kidney heterozygous Becn1 null and distal tubular homozygous Becn1 null mice had poorer kidney recovery than wild-type mice did. Injection of beclin 1 peptides increased cell proliferation in kidney tubules in normal mice. Beclin 1 peptides injection either before or after (2-5 days) ischemia reperfusion injury protected the kidney from injury and suppressed kidney fibrosis. Thus, both endogenous beclin 1 protein expression in kidney tubules and exogenous beclin 1 peptides are kidney protective via attenuation of acute kidney damage, promotion of cell proliferation, and inhibition of kidney fibrosis, consequently improving kidney recovery post-AKI. Hence, exogenous beclin 1 peptide may be a potential new therapy for AKI.
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Affiliation(s)
- Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Jenny Maique
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Sierra Shepard
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Peng Li
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Olivia Seli
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research
| | - Orson W. Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA,Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA,Address for reprint request and other correspondence: Ming Chang Hu, MD, PhD, Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390 USA, or Orson W. Moe, MD, Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390 USA,
| | - Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA,Address for reprint request and other correspondence: Ming Chang Hu, MD, PhD, Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390 USA, or Orson W. Moe, MD, Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390 USA,
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11
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Gagan JM, Cao K, Zhang YA, Zhang J, Davidson TL, Pastor JV, Moe OW, Hsia CCW. Constitutive transgenic alpha-Klotho overexpression enhances resilience to and recovery from murine acute lung injury. Am J Physiol Lung Cell Mol Physiol 2021; 321:L736-L749. [PMID: 34346778 DOI: 10.1152/ajplung.00629.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
AIMS Normal lungs do not express alpha-Klotho (Klotho) protein but derive cytoprotection from circulating soluble Klotho. It is unclear whether chronic supranormal Klotho levels confer additional benefit. To address this, we tested the age-related effects of Klotho overexpression on acute lung injury (ALI) and recovery. METHODS Transgenic Klotho-overexpressing (Tg-Kl) and wild-type (WT) mice (2 and 6 months old) were exposed to hyperoxia (95% O2; 72 h) then returned to normoxia (21% O2; 24 h) (Hx-R). Control mice were kept in normoxia. Renal and serum Klotho, lung histology, and bronchoalveolar lavage fluid oxidative damage markers were assessed. Effects of hyperoxia were tested in human embryonic kidney cells stably expressing Klotho. A549 lung epithelial cells transfected with Klotho cDNA or vector were exposed to cigarette smoke; lactate dehydrogenase and double-strand DNA breaks were measured. RESULTS Serum Klotho decreased with age. Hyperoxia suppressed renal Klotho at both ages and serum Klotho at 2-months of age. Tg-Kl mice at both ages and 2-months-old WT mice survived Hx-R; 6-months-old Tg-Kl mice showed lower lung damage than age-matched WT mice. Hyperoxia directly inhibited Klotho expression and release in vitro; Klotho transfection attenuated cigarette smoke-induced cytotoxicity and DNA double-strand breaks in lung epithelial cells. CONCLUSIONS Young animals with chronic high baseline Klotho expression are more resistant to ALI. Chronic constitutive Klotho overexpression in older Tg-Kl animals attenuates hyperoxia-induced lung damage and improves survival and short-term recovery despite an acute reduction in serum Klotho level during injury. We conclude that chronic enhancement of Klotho expression increases resilience to ALI.
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Affiliation(s)
- Joshuah M Gagan
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Khoa Cao
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Yu-An Zhang
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Jianning Zhang
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Taylor L Davidson
- Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Johanne V Pastor
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Orson W Moe
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Connie C W Hsia
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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12
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Morevati M, Mace ML, Egstrand S, Nordholm A, Doganli C, Strand J, Rukov JL, Torsetnes SB, Gorbunova V, Olgaard K, Lewin E. Extrarenal expression of α-klotho, the kidney related longevity gene, in Heterocephalus glaber, the long living Naked Mole Rat. Sci Rep 2021; 11:15375. [PMID: 34321565 PMCID: PMC8319335 DOI: 10.1038/s41598-021-94972-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/16/2021] [Indexed: 11/19/2022] Open
Abstract
The Naked Mole Rat (NMR), Heterocephalus glaber, provides an interesting model for studying biomarkers of longevity due to its long lifespan of more than 30 years, almost ten times longer than that of mice and rats. α-Klotho (klotho) is an aging-suppressor gene, and overexpression of klotho is associated with extended lifespan in mice. Klotho is predominantly expressed in the kidney. The expression profile of klotho in the NMR has not previously been reported. The present investigation studied the expression of klotho in the kidney of NMR with that of Rattus Norvegicus (RN) and demonstrated that klotho was expressed in the kidney of NMR at the same level as found in RN. Besides, a significant expression of Kl mRNA was found in the liver of NMR, in contrast to RN, where no hepatic expression was detected. The Klotho expression was further confirmed at the protein level. Thus, the results of the present comparative study indicate a differential tissue expression of klotho between different species. Besides its important function in the kidney, Klotho might also be of significance in the liver of NMR. It is suggested that the hepatic extrarenal expression of klotho may function as a further longevity-related factor in supplement to the Klotho in the kidney.
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Affiliation(s)
- M Morevati
- Nephrological Department P 2131, Rigshospitalet, University of Copenhagen, 9 Blegdamsvej, 2100, Copenhagen, Denmark.
| | - M L Mace
- Nephrological Department P 2131, Rigshospitalet, University of Copenhagen, 9 Blegdamsvej, 2100, Copenhagen, Denmark
| | - S Egstrand
- Nephrological Department P 2131, Rigshospitalet, University of Copenhagen, 9 Blegdamsvej, 2100, Copenhagen, Denmark.,Nephrological Department B, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
| | - A Nordholm
- Nephrological Department P 2131, Rigshospitalet, University of Copenhagen, 9 Blegdamsvej, 2100, Copenhagen, Denmark.,Nephrological Department B, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
| | - C Doganli
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - J Strand
- Randers Regnskov, Randers, Denmark
| | - J L Rukov
- Nephrological Department P 2131, Rigshospitalet, University of Copenhagen, 9 Blegdamsvej, 2100, Copenhagen, Denmark
| | - S B Torsetnes
- Department of Neurology, Akershus University Hospital, Oslo, Norway
| | - V Gorbunova
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - K Olgaard
- Nephrological Department P 2131, Rigshospitalet, University of Copenhagen, 9 Blegdamsvej, 2100, Copenhagen, Denmark
| | - E Lewin
- Nephrological Department P 2131, Rigshospitalet, University of Copenhagen, 9 Blegdamsvej, 2100, Copenhagen, Denmark.,Nephrological Department B, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
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13
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Bird RP, Eskin NAM. The emerging role of phosphorus in human health. ADVANCES IN FOOD AND NUTRITION RESEARCH 2021; 96:27-88. [PMID: 34112356 DOI: 10.1016/bs.afnr.2021.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Phosphorus, an essential nutrient, performs vital functions in skeletal and non-skeletal tissues and is pivotal for energy production. The last two decades of research on the physiological importance of phosphorus have provided several novel insights about its dynamic nature as a nutrient performing functions as a phosphate ion. Phosphorous also acts as a signaling molecule and induces complex physiological responses. It is recognized that phosphorus homeostasis is critical for health. The intake of phosphorus by the general population world-wide is almost double the amount required to maintain health. This increase is attributed to the incorporation of phosphate containing food additives in processed foods purchased by consumers. Research findings assessed the impact of excessive phosphorus intake on cells' and organs' responses, and highlighted the potential pathogenic consequences. Research also identified a new class of bioactive phosphates composed of polymers of phosphate molecules varying in chain length. These polymers are involved in metabolic responses including hemostasis, brain and bone health, via complex mechanism(s) with positive or negative health effects, depending on their chain length. It is amazing, that phosphorus, a simple element, is capable of exerting multiple and powerful effects. The role of phosphorus and its polymers in the renal and cardiovascular system as well as on brain health appear to be important and promising future research directions.
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Affiliation(s)
- Ranjana P Bird
- School of Health Sciences, University of Northern British Columbia, Prince George, BC, Canada.
| | - N A Michael Eskin
- Department of Food and Human Nutritional Sciences, Faculty of Agricultural and Food Sciences, University of Manitoba, Winnipeg, MB, Canada
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Shi M, Shepard S, Zhou Z, Maique J, Seli O, Moe OW, Hu MC. High Dietary Phosphate Exacerbates and Acts Independently of Low Autophagy Activity in Pathological Cardiac Remodeling and Dysfunction. Cells 2021; 10:777. [PMID: 33915953 PMCID: PMC8065663 DOI: 10.3390/cells10040777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 11/21/2022] Open
Abstract
High phosphate contributes to uremic cardiomyopathy. Abnormal autophagy is associated with the development and progression of heart disease. What is unknown is the effects of phosphate on autophagy and whether the ill effects of phosphate on cardiomyocytes are mediated by low autophagy. High (2.0% w/w)-phosphate diet reduced LC3 puncta in cardiomyocytes and ratio of LC3 II/I and increased p62 protein, indicating that autophagy activity was suppressed. Mice with cardiomyocyte-specific deletion of autophagy-related protein 5 (H-atg5-/-) had reduced autophagy only in the heart, developed cardiac dysfunction with hypertrophy and fibrosis, and had a short lifespan. When H-atg5-/- mice were fed a high-phosphate diet, they developed more apoptosis in cardiomyocytes, more severe cardiac remodeling, and shorter lifespan than normal phosphate-fed H-atg5-/- mice, indicating that cardiac phosphotoxicity is imparted independently of atg5. In conclusion, although high phosphate suppresses autophagy, high phosphate and low autophagy independently trigger and additionally amplify cardiac remodeling and dysfunction.
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Affiliation(s)
- Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (M.S.); (S.S.); (Z.Z.); (J.M.); (O.S.)
| | - Sierra Shepard
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (M.S.); (S.S.); (Z.Z.); (J.M.); (O.S.)
| | - Zhiyong Zhou
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (M.S.); (S.S.); (Z.Z.); (J.M.); (O.S.)
| | - Jenny Maique
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (M.S.); (S.S.); (Z.Z.); (J.M.); (O.S.)
| | - Olivia Seli
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (M.S.); (S.S.); (Z.Z.); (J.M.); (O.S.)
| | - Orson W. Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (M.S.); (S.S.); (Z.Z.); (J.M.); (O.S.)
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (M.S.); (S.S.); (Z.Z.); (J.M.); (O.S.)
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Neutel CHG, Hendrickx JO, Martinet W, De Meyer GRY, Guns PJ. The Protective Effects of the Autophagic and Lysosomal Machinery in Vascular and Valvular Calcification: A Systematic Review. Int J Mol Sci 2020; 21:ijms21238933. [PMID: 33255685 PMCID: PMC7728070 DOI: 10.3390/ijms21238933] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 11/19/2020] [Accepted: 11/21/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Autophagy is a highly conserved catabolic homeostatic process, crucial for cell survival. It has been shown that autophagy can modulate different cardiovascular pathologies, including vascular calcification (VCN). OBJECTIVE To assess how modulation of autophagy, either through induction or inhibition, affects vascular and valvular calcification and to determine the therapeutic applicability of inducing autophagy. DATA SOURCES A systematic review of English language articles using MEDLINE/PubMed, Web of Science (WoS) and the Cochrane library. The search terms included autophagy, autolysosome, mitophagy, endoplasmic reticulum (ER)-phagy, lysosomal, calcification and calcinosis. Study characteristics: Thirty-seven articles were selected based on pre-defined eligibility criteria. Thirty-three studies (89%) studied vascular smooth muscle cell (VSMC) calcification of which 27 (82%) studies investigated autophagy and six (18%) studies lysosomal function in VCN. Four studies (11%) studied aortic valve calcification (AVCN). Thirty-four studies were published in the time period 2015-2020 (92%). CONCLUSION There is compelling evidence that both autophagy and lysosomal function are critical regulators of VCN, which opens new perspectives for treatment strategies. However, there are still challenges to overcome, such as the development of more selective pharmacological agents and standardization of methods to measure autophagic flux.
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Maique J, Flores B, Shi M, Shepard S, Zhou Z, Yan S, Moe OW, Hu MC. High Phosphate Induces and Klotho Attenuates Kidney Epithelial Senescence and Fibrosis. Front Pharmacol 2020; 11:1273. [PMID: 32973510 PMCID: PMC7468469 DOI: 10.3389/fphar.2020.01273] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 07/31/2020] [Indexed: 12/18/2022] Open
Abstract
Cellular senescence is an irreversible cell growth arrest and is associated with aging and age-related diseases. High plasma phosphate (Pi) and deficiency of Klotho contribute to aging and kidney fibrosis, a pathological feature in the aging kidney and chronic kidney disease. This study examined the interactive role of Pi and Klotho in kidney senescence and fibrosis. Homozygous Klotho hypomorphic mice had high plasma Pi, undetectable Klotho in plasma and kidney, high senescence with massive collagen accumulation in kidney tubules, and fibrin deposits in peritubular capillaries. To examine the Pi effect on kidney senescence, a high (2%) Pi diet was given to wild-type mice. One week of high dietary Pi mildly increased plasma Pi, and upregulated kidney p16/p21 expression, but did not significantly decrease Klotho. Two weeks of high Pi intake led to increase in plasminogen activator inhibitor (PAI)-1, and decrease in kidney Klotho, but still without detectable increase in kidney fibrosis. More prolonged dietary Pi for 12 weeks exacerbated kidney senescence and fibrosis; more so in heterozygous Klotho hypomorphic mice compared to wild-type mice, and in mice with chronic kidney disease (CKD) on high Pi diet compared to CKD mice fed a normal Pi diet. In cultured kidney tubular cells, high Pi directly induced cellular senescence, injury and epithelial-mesenchymal transition, and enhanced H2O2-induced cellular senescence and injury, which were abrogated by Klotho. Fucoidan, a bioactive molecule with multiple biologic functions including senescence inhibition, blunted Pi-induced cellular senescence, oxidation, injury, epithelial-mesenchymal transition, and senescence-associated secretary phenotype. In conclusion, high Pi activates senescence through distinct but interconnected mechanisms: upregulating p16/p21 (early), and elevating plasminogen activator inhibitor-1 and downregulating Klotho (late). Klotho may be a promising agent to attenuate senescence and ameliorate age-associated, and Pi-induced kidney degeneration such as kidney fibrosis.
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Affiliation(s)
- Jenny Maique
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Brianna Flores
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Sierra Shepard
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Zhiyong Zhou
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Shirely Yan
- Departments of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Orson W Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
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Li Y, Liu R, Wu J, Li X. Self-eating: friend or foe? The emerging role of autophagy in fibrotic diseases. Am J Cancer Res 2020; 10:7993-8017. [PMID: 32724454 PMCID: PMC7381749 DOI: 10.7150/thno.47826] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/16/2020] [Indexed: 01/18/2023] Open
Abstract
Fibrosis occurs in most human organs including the liver, lung, heart and kidney, and is crucial for the progression of most chronic diseases. As an indispensable catabolic process for intracellular quality control and homeostasis, autophagy occurs in most mammalian cells and is implicated in many biological processes including fibrogenesis. Although advances have been made in understanding autophagy process, the potential role of autophagy in fibrotic diseases remains controversial and has recently attracted a great deal of attention. In the current review, we summarize the commonalities of autophagy affecting different types of fibrosis in different organs, including the liver, lung, heart, and kidney as well as in cystic fibrosis, systematically outline the contradictory results and highlight the distinct role of autophagy during the various stages of fibrosis. In summary, the exact role autophagy plays in fibrogenesis depends on specific cell types and different stimuli, and identifying and evaluating the pathogenic contribution of autophagy in fibrogenesis will promote the discovery of novel therapeutic strategies for the clinical management of these fibrotic diseases.
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