1
|
Han X, Akinseye L, Sun Z. KDM6A Demethylase Regulates Renal Sodium Excretion and Blood Pressure. Hypertension 2024; 81:541-551. [PMID: 38164755 PMCID: PMC10922853 DOI: 10.1161/hypertensionaha.123.22026] [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: 09/07/2023] [Accepted: 12/13/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND KDM6A (Lysine-Specific Demethylase 6A) is a specific demethylase for histone 3 lysine (K) 27 trimethylation (H3K27me3). The purpose of this study is to investigate whether KDM6A in renal tubule cells plays a role in the regulation of kidney function and blood pressure. METHODS We first crossed Ksp-Cre+/- and KDM6Aflox/flox mice for generating inducible kidney-specific deletion of KDM6A gene. RESULTS Notably, conditional knockout of KDM6A gene in renal tubule cells (KDM6A-cKO) increased H3K27me3 levels which leads to a decrease in Na excretion and elevation of blood pressure. Further analysis showed that the expression of NKCC2 (Na-K-2Cl cotransporter 2) and NCC (Na-Cl cotransporters) was upregulated which contributes to impaired Na excretion in KDM6A-cKO mice. The expression of AQP2 (aquaporin 2) was also increased in KDM6A-cKO mice, which may facilitate water reabsorption in KDM6A-cKO mice. The expression of Klotho was downregulated while expression of aging markers including p53, p21, and p16 was upregulated in kidneys of KDM6A-cKO mice, indicating that deletion of KDM6A in the renal tubule cells promotes kidney aging. Interestingly, KDM6A-cKO mice developed salt-sensitive hypertension which can be rescued by treatment with Klotho. KDM6A deficiency induced salt-sensitive hypertension likely through downregulation of the Klotho/ERK (extracellular signal-regulated kinase) signaling and upregulation of the WNK (with-no-lysine kinase) signaling. CONCLUSIONS This study provides the first evidence that KDM6A plays an essential role in maintaining normal tubular function and blood pressure. Renal tubule cell specific KDM6A deficiency causes hypertension due to increased H3K27me3 levels and the resultant downregulation of Klotho gene expression which disrupts the Klotho/ERK/NCC/NKCC2 signaling.
Collapse
Affiliation(s)
- Xiaobin Han
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Leah Akinseye
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Zhongjie Sun
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| |
Collapse
|
2
|
Li SS, Sheng MJ, Sun ZY, Liang Y, Yu LX, Liu QF. Upstream and downstream regulators of Klotho expression in chronic kidney disease. Metabolism 2023; 142:155530. [PMID: 36868370 DOI: 10.1016/j.metabol.2023.155530] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/05/2023]
Abstract
Klotho is a critical protein that protects the kidney. Klotho is severely downregulated in chronic kidney disease (CKD), and its deficiency is implicated in the pathogenesis and progression of CKD. Conversely, an increase in Klotho levels results in improved kidney function and delays CKD progression, supporting the notion that modulating Klotho levels could represent a possible therapeutic strategy for CKD treatment. Nevertheless, the regulatory mechanisms responsible for the loss of Klotho remain elusive. Previous studies have demonstrated that oxidative stress, inflammation, and epigenetic modifications can modulate Klotho levels. These mechanisms result in a decrease in Klotho mRNA transcript levels and reduced translation, thus can be grouped together as upstream regulatory mechanisms. However, therapeutic strategies that aim to rescue Klotho levels by targeting these upstream mechanisms do not always result in increased Klotho, indicating the involvement of other regulatory mechanisms. Emerging evidence has shown that endoplasmic reticulum (ER) stress, the unfolded protein response, and ER-associated degradation also affect the modification, translocation, and degradation of Klotho, and thus are proposed to be downstream regulatory mechanisms. Here, we discuss the current understanding of upstream and downstream regulatory mechanisms of Klotho and examine potential therapeutic strategies to upregulate Klotho expression for CKD treatment.
Collapse
Affiliation(s)
- Sha-Sha Li
- Clinical Research & Lab Centre, Affiliated Kunshan Hospital of Jiangsu University, 91 Qianjin West Road, Kunshan, Jiangsu 215300, China
| | - Ming-Jie Sheng
- Department of Nephrology, Affiliated Kunshan Hospital of Jiangsu University, 91 Qianjin West Road, Kunshan, Jiangsu 215300, China
| | - Zhuo-Yi Sun
- Department of Nephrology, Affiliated Kunshan Hospital of Jiangsu University, 91 Qianjin West Road, Kunshan, Jiangsu 215300, China
| | - Yan Liang
- Gusu School, Nanjing Medical University, The First People's Hospital of Kunshan, 91 Qianjin West Road, Kunshan, Jiangsu 215300, China
| | - Li-Xia Yu
- Department of Nephrology, Affiliated Kunshan Hospital of Jiangsu University, 91 Qianjin West Road, Kunshan, Jiangsu 215300, China.
| | - Qi-Feng Liu
- Department of Nephrology, Affiliated Kunshan Hospital of Jiangsu University, 91 Qianjin West Road, Kunshan, Jiangsu 215300, China; Gusu School, Nanjing Medical University, The First People's Hospital of Kunshan, 91 Qianjin West Road, Kunshan, Jiangsu 215300, China.
| |
Collapse
|
3
|
Idrees M, Kumar V, Khan AM, Joo MD, Lee KW, Sohn SH, Kong IK. Cycloastragenol activation of telomerase improves β-Klotho protein level and attenuates age-related malfunctioning in ovarian tissues. Mech Ageing Dev 2023; 209:111756. [PMID: 36462538 DOI: 10.1016/j.mad.2022.111756] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 12/02/2022]
Abstract
Age-related deterioration in the reproductive capacity of women is directly related to the poor developmental potential of ovarian follicles. Although telomerase plays a key role in female fertility, TERT-targeting therapeutic strategies for age-related female infertility have yet to be investigated. This study elucidated the effect of Telomerase activation on mice ovaries and more specifically on Klb (β-Klotho) gene expression, which is linked to ageing, female hormonal regulation, and cyclicity. The homology-based 3D model of hTERT was used to predict its binding mode of Cycloastragenol (CAG) using molecular docking and molecular dynamics simulations. Based on docking score, simulation behavior, and interaction with hTERT residues it was observed that CAG could bind with the hTERT model. CAG treatment to primary cultured mouse granulosa cells and activation of telomerase was examined via telomerase activity assay (Mouse TE (telomerase) ELISA Kit) and telomere length by quantitative fluorescence in situ hybridization. CAG mediated telomerase also significantly improved β-Klotho protein level in the aged granulosa cells. To demonstrate that β-Klotho is telomerase dependent, the TERT was knocked down via siRNA in granulosa cells and protein level of β-Klotho was examined. Furthermore, CAG-mediated telomerase activation significantly enhanced the level of Klb and recovered ovarian follicles in the D-galactose (D-gal)-induced ovarian ageing mouse model. Moreover, Doxorubicin-induced ovarian damage, which changes ovarian hormones, and inhibit follicular growth was successfully neutralized by CAG activated telomerase and its recovery of β-Klotho level. In conclusion, TERT dependent β-Klotho regulation in ovarian tissues is one of the mechanisms, which can overcome female infertility.
Collapse
Affiliation(s)
- Muhammad Idrees
- Division of Applied Life Science (BK21 Four), Gyeongsang National University, Jinju 52828, Gyeongnam Province, Republic of Korea.
| | - Vikas Kumar
- Division of Life Sciences, Department of Bio & Medical Big Data (BK21 Four), Research Institute of Natural Science (RINS), Gyeongsang National University (GNU), 501 Jinju-daero, Jinju 52828, Republic of Korea.
| | - Abdul Majid Khan
- Division of Applied Life Science (BK21 Four), Gyeongsang National University, Jinju 52828, Gyeongnam Province, Republic of Korea.
| | - Myeong-Don Joo
- Division of Applied Life Science (BK21 Four), Gyeongsang National University, Jinju 52828, Gyeongnam Province, Republic of Korea.
| | - Keun-Woo Lee
- Division of Life Sciences, Department of Bio & Medical Big Data (BK21 Four), Research Institute of Natural Science (RINS), Gyeongsang National University (GNU), 501 Jinju-daero, Jinju 52828, Republic of Korea.
| | - Sea-Hwan Sohn
- Department of Animal Science and Biotechnology, Gyeongsang National University, Jinju 52725, Gyeongnam Province, Republic of Korea.
| | - Il-Keun Kong
- Division of Applied Life Science (BK21 Four), Gyeongsang National University, Jinju 52828, Gyeongnam Province, Republic of Korea; Institute of Agriculture and Life Science, Gyeongsang National University, Gyeongnam Province, Republic of Korea; The King Kong Corp. Ltd., Gyeongsang National University, Jinju 52828, Gyeongnam Province, Republic of Korea.
| |
Collapse
|
4
|
Han X, Sun Z. Adult Mouse Kidney Stem Cells Orchestrate the De Novo Assembly of a Nephron via Sirt2-Modulated Canonical Wnt/β-Catenin Signaling. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104034. [PMID: 35315252 PMCID: PMC9130916 DOI: 10.1002/advs.202104034] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Generation of kidney organoids using autologous kidney stem cells represents an attractive strategy for treating and potentially replacing the failing kidneys. However, whether adult mammalian kidney stem cells have regenerative capacity remains unknown. Here, previously unidentified adult kidney Sca1+ Oct4+ stem/progenitor cells are isolated. Interestingly, culturing these cells leads to generation of kidney-like structures. First, the assembly of self-organizing 3D kidney-like structures is observed. These kidney organoids contain podocytes, proximal tubules, and endothelial cells that form networks of capillary loop-like structures. Second, the differentiation of kidney stem cells into functionally mature tubules and self-organizing kidney-shaped structures in monolayer culture that selectively endocytoses dextran, is shown. Finally, the de novo generation of an entire self-organizing nephron from monolayer cultures is observed. Mechanistically, it is demonstrated that Sirt2-mediated canonical Wnt/β-catenin signaling is critical for the development of kidney organoids. Thus, the first evidence is provided that the adult mouse kidney stem cells are capable of de novo generating kidney organoids.
Collapse
Affiliation(s)
- Xiaobin Han
- Department of PhysiologyUniversity of Tennessee Health Science CenterMemphisTN38163USA
| | - Zhongjie Sun
- Department of PhysiologyUniversity of Tennessee Health Science CenterMemphisTN38163USA
| |
Collapse
|
5
|
Ostojic SM, Engeset D. Improving Brain Creatine Uptake by Klotho Protein Stimulation: Can Diet Hit the Big Time? Front Nutr 2022; 8:795599. [PMID: 35004821 PMCID: PMC8732999 DOI: 10.3389/fnut.2021.795599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/08/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sergej M Ostojic
- Department of Nutrition and Public Health, University of Agder, Kristiansand, Norway
| | - Dagrun Engeset
- Department of Nutrition and Public Health, University of Agder, Kristiansand, Norway
| |
Collapse
|
6
|
Xia J, Cao W. Epigenetic modifications of Klotho expression in kidney diseases. J Mol Med (Berl) 2021; 99:581-592. [PMID: 33547909 DOI: 10.1007/s00109-021-02044-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/10/2020] [Accepted: 01/20/2021] [Indexed: 12/21/2022]
Abstract
Developments of many renal diseases are substantially influenced by epigenetic modifications of numerous genes, mainly mediated by DNA methylations, histone modifications, and microRNA interference; however, not all gene modifications causally affect the disease onset or progression. Klotho is a critical gene whose repressions in various pathological conditions reportedly involve epigenetic regulatory mechanisms. Klotho is almost unexceptionally repressed early after acute or chronic renal injuries and its levels inversely correlated with the disease progression and severity. Moreover, the strategies of Klotho derepression via epigenetic modulations beneficially change the pathological courses both in vitro and in vivo. Hence, Klotho is not only considered a biomarker of the renal disease but also a potential or even an ideal target of therapeutic epigenetic intervention. Here, we summarize and discuss studies that investigate the Klotho repression and intervention in renal diseases from an epigenetic point of view. These information might shed new sights into the effective therapeutic strategies to prevent and treat various renal disorders.
Collapse
Affiliation(s)
- Jinkun Xia
- Center for Organ Fibrosis and Remodeling Research, Jiangsu Key Lab of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China
| | - Wangsen Cao
- Center for Organ Fibrosis and Remodeling Research, Jiangsu Key Lab of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China.
| |
Collapse
|
7
|
Yang L, Wu Y, He H, Hu F, Li M, Mo L, Xiao Y, Wang X, Xie B. Delivery of BR2‐SOX17 fusion protein can inhibit cell survival, proliferation, and invasion in gastric cancer cells through regulating Klotho gene expression. Cell Biol Int 2020; 44:2011-2020. [PMID: 32544287 DOI: 10.1002/cbin.11407] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/30/2020] [Accepted: 06/13/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Lixia Yang
- Department of Cancer The First Affiliated Hospital of Changsha Medical School Changsha Hunan China
| | - Yue Wu
- Department of Cancer The First Affiliated Hospital of Changsha Medical School Changsha Hunan China
| | - Heli He
- Department of Cancer The First Affiliated Hospital of Changsha Medical School Changsha Hunan China
| | - Fan Hu
- Department One of Anorectal Surgery The Second Affiliated Hospital of Hunan University of Chinese Medicine Changsha Hunan China
| | - Mei Li
- Department One of Anorectal Surgery The Second Affiliated Hospital of Hunan University of Chinese Medicine Changsha Hunan China
| | - Li Mo
- Department One of Anorectal Surgery The Second Affiliated Hospital of Hunan University of Chinese Medicine Changsha Hunan China
| | - You Xiao
- Department One of Anorectal Surgery The Second Affiliated Hospital of Hunan University of Chinese Medicine Changsha Hunan China
| | - Xiaoyan Wang
- Department One of Anorectal Surgery The Second Affiliated Hospital of Hunan University of Chinese Medicine Changsha Hunan China
| | - Biao Xie
- Department of Cancer The First Affiliated Hospital of Changsha Medical School Changsha Hunan China
- Department One of Anorectal Surgery The Second Affiliated Hospital of Hunan University of Chinese Medicine Changsha Hunan China
| |
Collapse
|
8
|
Lau WL, Liang C, Liu H, Singh K, Mukherjee J. Development of zirconium-89 PET for in vivo imaging of alpha-klotho. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2020; 10:95-105. [PMID: 32419978 PMCID: PMC7218695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Alpha-klotho is a single-pass membrane protein primarily expressed by the kidneys. Klotho deficiency in chronic kidney disease contributes to an accelerated aging phenotype. We report here development of [89Zr]DFO-anti-klotho positron emission tomography (PET) imaging as a novel non-invasive method for assessing whole-body alpha-klotho distribution. Rat monoclonal anti-mouse klotho antibody was reacted with SCN-Bn-deferoxamine (DFO) and was radiolabeled using Zirconium-89. In vitro testing of [89Zr]DFO-anti-mKlotho was done in a distal convoluted tubule kidney cell line and with 40-micron whole kidney sections from C57BL/6J mice. Competitive binding was assessed in co-incubation studies with unlabeled anti-mKlotho antibody. For in vivo testing, C57BL/6J mice were injected retro-orbitally with [89Zr]DFO-anti-mKlotho and were scanned using Inveon PET/CT. Autoradiographs of kidney sections were obtained post-imaging on select animals. Radiochemical yield of [89Zr]DFO-anti-mKlotho was >70% and radiochemical purity was confirmed by iTLC. Specific binding in the kidney cell line was reduced by 60% in the presence of unlabeled anti-mKlotho. In the PET/CT scans, initial uptake of [89Zr]DFO-anti-mKlotho was observed in the intestines and liver. Selective retention of radioactivity was observed in the kidneys in the subsequent 24, 48, and 72 hrs scans with cortical binding of [89Zr]DFO-anti-mKlotho clearly visualized. Sites of lower alpha-klotho expression were not visualized. In summary, we have successfully synthesized [89Zr]DFO-anti-mKlotho and our initial in vitro and in vivo studies in mice demonstrate selective binding in the kidney cortex, which is known to express high levels of alpha-klotho. PET imaging promises to be a novel tool for in vivo evaluation of alpha-klotho distribution.
Collapse
Affiliation(s)
- Wei Ling Lau
- Nephrology, Department of Medicine, University of California-IrvineIrvine, CA 92697, USA
| | - Christopher Liang
- Preclinical Imaging, Radiological Sciences, University of California-IrvineIrvine, CA 92697, USA
| | - Han Liu
- Nephrology, Department of Medicine, University of California-IrvineIrvine, CA 92697, USA
| | - Karanveer Singh
- Preclinical Imaging, Radiological Sciences, University of California-IrvineIrvine, CA 92697, USA
| | - Jogeshwar Mukherjee
- Preclinical Imaging, Radiological Sciences, University of California-IrvineIrvine, CA 92697, USA
| |
Collapse
|
9
|
Han X, Sun Z. Epigenetic Regulation of KL (Klotho) via H3K27me3 (Histone 3 Lysine [K] 27 Trimethylation) in Renal Tubule Cells. Hypertension 2020; 75:1233-1241. [PMID: 32223380 DOI: 10.1161/hypertensionaha.120.14642] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
KL (klotho) levels decline with age, which is an important mechanistic driver of aging. KL gene deficiency is associated with hypertension. The purpose of this study is to investigate the potential role of H3K27me3 (histone 3 lysine [K] 27 trimethylation) in the regulation of KL gene expression and examine the related molecular pathways that may drive kidney cell aging. Kidneys were collected from 6-month-old WT (wild type; young WT), 30-month-old WT (aged WT), and 6- (young) and 20-month-old (aged) KL mutant mice, respectively. We demonstrated that the H3K27me3 level was increased in kidneys of aged WT and KL mutant mice versus young WT mice. Elevation of H3K27me3 levels was likely due to downregulation of the H3K27 (histone H3 Lys 27)-specific demethylase JMJD3 (the Jumonji domain containing-3) in the aged kidneys. Inhibition of PRC2 (polycomb repressive complex C2; histone trimethyltransferase) decreased the H3K27me3 levels leading to an increase in the expression of KL in cultured primary renal tubule cells assessed by Western blot and KL promoter activity assays. The chromatin immunoprecipitation qPCR assay revealed that H3K27me3 was physically associated with the KL promoter region. Furthermore, aging impaired the SGK1 (serum- and glucocorticoid-induced protein kinase 1)/FOXO3a (the forkhead box class O 3a) signaling leading to upregulation of p53 and p16 (aging markers) in the kidney of aged WT mice. KL may regulate the SGK1/FOXO3 signaling, which was decreased due to KL deficiency. Thus, aging-associated downregulation of KL gene expression may be partly attributed to upregulation of H3K27me3 levels. Downregulation of KL may impair the SGK1/FOXO3 signaling contributing to kidney cell aging.
Collapse
Affiliation(s)
- Xiaobin Han
- From the Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis
| | - Zhongjie Sun
- From the Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis
| |
Collapse
|
10
|
Vervloet M. Modifying Phosphate Toxicity in Chronic Kidney Disease. Toxins (Basel) 2019; 11:E522. [PMID: 31505780 PMCID: PMC6784221 DOI: 10.3390/toxins11090522] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 08/29/2019] [Accepted: 09/05/2019] [Indexed: 02/06/2023] Open
Abstract
Phosphate toxicity is a well-established phenomenon, especially in chronic kidney disease (CKD), where hyperphosphatemia is a frequent occurrence when CKD is advanced. Many therapeutic efforts are targeted at phosphate, and comprise dietary intervention, modifying dialysis schemes, treating uncontrolled hyperparathyroidism and importantly, phosphate binder therapy. Despite all these interventions, hyperphosphatemia persists in many, and its pathological influence is ongoing. In nephrological care, a somewhat neglected aspect of treatment-when attempts fail to lower exposure to a toxin like phosphate-is to explore the possibility of "anti-dotes". Indeed, quite a long list of factors modify, or are mediators of phosphate toxicity. Addressing these, especially when phosphate itself cannot be sufficiently controlled, may provide additional protection. In this narrative overview, several factors are discussed that may qualify as either such a modifier or mediator, that can be influenced by other means than simply lowering phosphate exposure. A wider scope when targeting phosphate-induced comorbidity in CKD, in particular cardiovascular disease, may alleviate the burden of disease that is the consequence of this potentially toxic mineral in CKD.
Collapse
Affiliation(s)
- Marc Vervloet
- Department of Nephrology and Amsterdam Cardiovascular Sciences, Amsterdam University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
| |
Collapse
|
11
|
Chen K, Sun Z. Activation of DNA demethylases attenuates aging-associated arterial stiffening and hypertension. Aging Cell 2018; 17:e12762. [PMID: 29659128 PMCID: PMC6052484 DOI: 10.1111/acel.12762] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2018] [Indexed: 11/26/2022] Open
Abstract
DNA methylation increases with age. The objective of this study was to investigate whether compound H, a potential activator of DNA demethylases, attenuates aging‐related arterial stiffness and hypertension. Aged mice (24–27 months) and adult mice (12 months) were used. Pulse wave velocity (PWV), a direct measure of arterial stiffness, and blood pressure (BP) were increased significantly in aged mice. Notably, daily treatments with compound H (15 mg/kg, IP) for 2 weeks significantly attenuated the aging‐related increases in PWV and BP. Compound H abolished aging‐associated downregulation of secreted Klotho (SKL) levels in both kidneys and serum likely by enhancing DNA demethylase activity and decreasing DNA methylation. Aging‐related arterial stiffness was associated with accumulation of stiffer collagen and degradation of compliant elastin which are accompanied by increased expression of MMP2, MMP9, TGF‐β1, and TGF‐β3. These changes were effectively attenuated by compound H, suggesting rejuvenation of aged arteries. Compound H also rescued downregulation of Sirt1 deacetylase, AMPKα, and eNOS activities in aortas of aged mice. In cultured smooth muscle cells (SMCc) Klotho‐deficient serum upregulated expression of MMPs and TGFβ which, however, was not affected by compound H. In conclusion, compound H attenuates aging‐associated arterial stiffness and hypertension by activation of DNA demethylase which increases renal SKL expression and consequently circulating SKL levels leading to activation of the Sirt1‐AMPK‐eNOS pathway in aortas of aged mice.
Collapse
Affiliation(s)
- Kai Chen
- Department of Physiology; College of Medicine; University of Oklahoma Health Sciences Center; Oklahoma City OK USA
| | - Zhongjie Sun
- Department of Physiology; College of Medicine; University of Oklahoma Health Sciences Center; Oklahoma City OK USA
| |
Collapse
|
12
|
Chen J, Fan J, Wang S, Sun Z. Secreted Klotho Attenuates Inflammation-Associated Aortic Valve Fibrosis in Senescence-Accelerated Mice P1. Hypertension 2018; 71:877-885. [PMID: 29581213 DOI: 10.1161/hypertensionaha.117.10560] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/09/2017] [Accepted: 03/01/2018] [Indexed: 01/04/2023]
Abstract
Senescence-accelerated mice P1 (SAMP1) is an aging model characterized by shortened lifespan and early signs of senescence. Klotho is an aging-suppressor gene. The purpose of this study is to investigate whether in vivo expression of secreted klotho (Skl) gene attenuates aortic valve fibrosis in SAMP1 mice. SAMP1 mice and age-matched (AKR/J) control mice were used. SAMP1 mice developed obvious fibrosis in aortic valves, namely fibrotic aortic valve disease. Serum level of Skl was decreased drastically in SAMP1 mice. Expression of MCP-1 (monocyte chemoattractant protein 1), ICAM-1 (intercellular adhesion molecule 1), F4/80, and CD68 was increased in aortic valves of SAMP1 mice, indicating inflammation. An increase in expression of α-smooth muscle actin (myofibroblast marker), transforming growth factorβ-1, and scleraxis (a transcription factor of collagen synthesis) was also found in aortic valves of SAMP1 mice, suggesting that accelerated aging is associated with myofibroblast transition and collagen gene activation. We constructed adeno-associated virus 2 carrying mouse Skl cDNA for in vivo expression of Skl. Skl gene delivery effectively increased serum Skl of SAMP1 mice to the control level. Skl gene delivery inhibited inflammation and myofibroblastic transition in aortic valves and attenuated fibrotic aortic valve disease in SAMP1 mice. It is concluded that senescence-related fibrotic aortic valve disease in SAMP1 mice is associated with a decrease in serum klotho leading to inflammation, including macrophage infiltration and transforming growth factorβ-1/scleraxis-driven myofibroblast differentiation in aortic valves. Restoration of serum Skl levels by adeno-associated virus 2 carrying mouse Skl cDNA effectively suppresses inflammation and myofibroblastic transition and attenuates aortic valve fibrosis. Skl may be a potential therapeutic target for fibrotic aortic valve disease.
Collapse
Affiliation(s)
- Jianglei Chen
- From the Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City
| | - Jun Fan
- From the Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City
| | - Shirley Wang
- From the Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City
| | - Zhongjie Sun
- From the Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City.
| |
Collapse
|