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Chuang MH, Wang HW, Huang YT, Jiang MY. Association between soluble α-klotho and mortality risk in middle-aged and older adults. Front Endocrinol (Lausanne) 2023; 14:1246590. [PMID: 37693344 PMCID: PMC10484398 DOI: 10.3389/fendo.2023.1246590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 08/11/2023] [Indexed: 09/12/2023] Open
Abstract
Introduction Studies on association of α-klotho levels with mortality risk in general population are relatively scarce and inconclusive. Therefore, we conducted a population-based cohort study to investigate the relationship between soluble α-klotho and all-cause mortality in a nationally representative sample of middle-aged and older adults in the United States (U.S.). Methods The study population was 2007-2016 National Health and Nutrition Examination Survey (NHANES) participants, totaling 13,583 adults aged 40-79 years. Participants were divided into 7 groups by septile of α-klotho levels. We linked the NHANES data to the National Death Index to determine participants' survival status. End of follow-up was participants' death date or December 31, 2019. Results We observed that males, current smokers, older age, higher body mass index, and lower estimated glomerular filtration rate correlated to lower α-klotho levels, while hepatitis C virus infection correlated to higher α-klotho. The population mortality rate was 11.8 per 10,000 person-months (1,490 deaths); group 1 (the first septile) had higher mortality risk compared with group 2 through group 7. By weighted Cox regression with adjustment for potential confounders, we found that group 2 through group 6, but not group 7, were associated with 25% to 35% lower risk of all-cause mortality compared with group 1. When compared with group 4, we observed that both group 1 (HR: 1.46, 95% CI 1.13-1.88) and group 7 (HR: 1.38, 95% CI 1.09-1.74) were associated with higher mortality risk. Conclusion In summary, among middle-aged and older U.S. adults, we observed a non-linear association between soluble α-klotho and all-cause mortality, with individuals at the two extremes at increased risk of death.
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Affiliation(s)
- Min-Hsiang Chuang
- Renal Division, Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan
| | - Hung-Wei Wang
- Renal Division, Department of Internal Medicine, Chi Mei Hospital Chiali, Tainan, Taiwan
| | - Yun-Ting Huang
- Renal Division, Department of Internal Medicine, Chi Mei Hospital Chiali, Tainan, Taiwan
| | - Ming-Yan Jiang
- Renal Division, Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan
- Department of Pharmacy, Chia Nan University of Pharmacy & Science, Tainan, Taiwan
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2
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Klotho Modulates Pro-Fibrotic Activities in Human Atrial Fibroblasts through Inhibition of Phospholipase C Signaling and Suppression of Store-Operated Calcium Entry. Biomedicines 2022; 10:biomedicines10071574. [PMID: 35884879 PMCID: PMC9312905 DOI: 10.3390/biomedicines10071574] [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: 05/30/2022] [Revised: 06/24/2022] [Accepted: 06/29/2022] [Indexed: 11/16/2022] Open
Abstract
Background: Atrial fibroblasts activation causes atrial fibrosis, which is one major pathophysiological contributor to atrial fibrillation (AF) genesis. Klotho is a pleiotropic protein with remarkable cardiovascular effects, including anti-inflammatory, anti-oxidative, and anti-apoptotic effects. This study investigated whether Klotho can modulate the activity of human atrial fibroblasts and provides an anti-fibrotic effect. Methods: Cell migration assay and proliferation assay were used to investigate fibrogenesis activities in single human atrial fibroblasts with or without treatment of Klotho (10 and 100 pM, 48 h). Calcium fluorescence imaging, the whole-cell patch-clamp, and Western blotting were performed in human atrial fibroblasts treated with and without Klotho (100 pM, 48 h) to evaluate the store-operated calcium entry (SOCE), transient receptor potential (TRP) currents, and downstream signaling. Results: High dose of Klotho (100 pM, 48 h) significantly reduced the migration of human atrial fibroblasts without alternating their proliferation; in addition, treatment of Klotho (100 pM, 48 h) also decreased SOCE and TRP currents. In the presence of BI-749327 (a selective canonical TRP 6 channel inhibitor, 1 μM, 48 h), Klotho (100 pM, 48 h) could not inhibit fibroblast migration nor suppress the TRP currents. Klotho-treated fibroblasts (100 pM, 48 h) had lower phosphorylated phospholipase C (PLC) (p-PLCβ3 Ser537) expression than the control. The PLC inhibitor, U73122 (1 μM, 48 h), reduced the migration, decreased SOCE and TRP currents, and lowered p-PLCβ3 in atrial fibroblasts, similar to Klotho. In the presence of the U73122 (1 μM, 48 h), Klotho (100 pM, 48 h) could not further modulate the migration and collagen synthesis nor suppress the TRP currents in human atrial fibroblasts. Conclusions: Klotho inhibited pro-fibrotic activities and SOCE by inhibiting the PLC signaling and suppressing the TRP currents, which may provide a novel insight into atrial fibrosis and arrhythmogenesis.
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3
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Xu JP, Zeng RX, He MH, Lin SS, Guo LH, Zhang MZ. Associations Between Serum Soluble α-Klotho and the Prevalence of Specific Cardiovascular Disease. Front Cardiovasc Med 2022; 9:899307. [PMID: 35795366 PMCID: PMC9251131 DOI: 10.3389/fcvm.2022.899307] [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: 03/21/2022] [Accepted: 05/20/2022] [Indexed: 12/03/2022] Open
Abstract
Objective Accumulating experimental evidence has identified the beneficial effects of the anti-aging protein, serum soluble α-Klotho, on longevity, and the cardiovascular system. Although a previous study has revealed the predictive value of α-Klotho on total cardiovascular disease (CVD), the associations between α-Klotho and specific CVDs, including congestive heart failure (CHF), coronary heart disease (CHD), myocardial infarction (MI), and stroke, remains to be fully elucidated in humans. Methods For 8,615 adults in the 2007 to 2016 National Health and Nutrition Examination Survey, stratified multivariable logistic regression models, restricted cubic spline curves, and subgroup analyses were used to evaluate the associations between α-Klotho and the four specific CVDs. Results In the quartile analyses, compared to those in the highest quartile, participants in the lowest level of α-Klotho were significantly associated with CHF [odds ratio (OR) = 1.46, 95% CI: 1.09–1.97] and MI (1.33, 1.02–1.74), which was not the case for CHD (1.12, 0.91–1.38) or stroke (0.96, 0.73–1.25). Each unit increment in the ln-transformed α-Klotho concentrations was only positively associated with a 38 and 24% reduction in the prevalence of CHF and MI, respectively. Restricted cubic spline curves indicated that the α-Klotho was correlated with CHF and MI in linear-inverse relationships. Conclusion The present findings suggested that the serum soluble α-Klotho is significantly associated with the prevalence of CHF and MI. To better determine whether α-Klotho is a specific biomarker of CVD, particularly for CHD and stroke, further research in humans is needed.
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Affiliation(s)
- Jun-Peng Xu
- The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Rui-Xiang Zeng
- The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Mu-Hua He
- School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, China
| | - Shan-Shan Lin
- The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Li-Heng Guo
- The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Min-Zhou Zhang
- The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
- *Correspondence: Min-Zhou Zhang
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4
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Higher Serum-Soluble α-Klotho Level Does Not Predict Longer Survival after Stroke. BIOMED RESEARCH INTERNATIONAL 2020; 2020:9283651. [PMID: 33376748 PMCID: PMC7738777 DOI: 10.1155/2020/9283651] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 10/10/2020] [Accepted: 11/04/2020] [Indexed: 01/01/2023]
Abstract
Results There were 5 recurrent strokes and 89 deaths during the 36-month follow-up. Even though no significant differences in OS and SFS between soluble α-Klotho level tertile groups were recorded, unexpectedly, OS and SFS were highest in patients with the lowest soluble α-Klotho concentrations. Moreover, the Cox proportional models adjusted for established risk factors, kidney function, and the severity of stroke revealed that each 100 pg/mL increase in soluble α-Klotho levels was associated with decreased OS (HR = 0.951 (0.908-0.995), p < 0.05) and SFS (HR = 0.949 (0.908-0.993), p < 0.05). In addition, the α-Klotho to iFGF23 index was predicting neither OS nor SFS. Conclusion Soluble α-Klotho levels in serum were not related to the severity of neurological deficits and long-term outcomes in patients with IS. No neuroprotective effect of soluble α-Klotho levels in patients with IS was demonstrated.
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5
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Xu F, Gao J, Munkhsaikhan U, Li N, Gu Q, Pierre JF, Starlard-Davenport A, Towbin JA, Cui Y, Purevjav E, Lu L. The Genetic Dissection of Ace2 Expression Variation in the Heart of Murine Genetic Reference Population. Front Cardiovasc Med 2020; 7:582949. [PMID: 33330645 PMCID: PMC7714829 DOI: 10.3389/fcvm.2020.582949] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022] Open
Abstract
Background: A high inflammatory and cytokine burden that induces vascular inflammation, myocarditis, cardiac arrhythmias, and myocardial injury is associated with a lethal outcome in COVID-19. The SARS-CoV-2 virus utilizes the ACE2 receptor for cell entry in a similar way to SARS-CoV. This study investigates the regulation, gene network, and associated pathways of ACE2 that may be involved in inflammatory and cardiovascular complications of COVID-19. Methods: Cardiovascular traits were determined in the one of the largest mouse genetic reference populations: BXD recombinant inbred strains using blood pressure, electrocardiography, and echocardiography measurements. Expression quantitative trait locus (eQTL) mapping, genetic correlation, and functional enrichment analysis were used to identify Ace2 regulation, gene pathway, and co-expression networks. Results: A wide range of variation was found in expression of Ace2 among the BXD strains. Levels of Ace2 expression are negatively correlated with cardiovascular traits, including systolic and diastolic blood pressure and P wave duration and amplitude. Ace2 co-expressed genes are significantly involved in cardiac- and inflammatory-related pathways. The eQTL mapping revealed that Cyld is a candidate upstream regulator for Ace2. Moreover, the protein–protein interaction (PPI) network analysis inferred several potential key regulators (Cul3, Atf2, Vcp, Jun, Ppp1cc, Npm1, Mapk8, Set, Dlg1, Mapk14, and Hspa1b) for Ace2 co-expressed genes in the heart. Conclusions:Ace2 is associated with blood pressure, atrial morphology, and sinoatrial conduction in BXD mice. Ace2 co-varies with Atf2, Cyld, Jun, Mapk8, and Mapk14 and is enriched in the RAS, TGFβ, TNFα, and p38α signaling pathways, involved in inflammation and cardiac damage. We suggest that all these novel Ace2-associated genes and pathways may be targeted for preventive, diagnostic, and therapeutic purposes in cardiovascular damage in patients with systemic inflammation, including COVID-19 patients.
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Affiliation(s)
- Fuyi Xu
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Jun Gao
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Undral Munkhsaikhan
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - Ning Li
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN, United States.,Department of Cardiology, Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Qingqing Gu
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Cardiology, The Affiliated Hospital of Nantong University, Nantong, China
| | - Joseph F Pierre
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - Athena Starlard-Davenport
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Jeffrey A Towbin
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN, United States.,Pediatric Cardiology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Yan Cui
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Enkhsaikhan Purevjav
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - Lu Lu
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
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6
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South AM, Shaltout HA, Gwathmey TM, Jensen ET, Nixon PA, Diz DI, Chappell MC, Washburn LK. Lower urinary α-Klotho is associated with lower angiotensin-(1-7) and higher blood pressure in young adults born preterm with very low birthweight. J Clin Hypertens (Greenwich) 2020; 22:1033-1040. [PMID: 32475043 DOI: 10.1111/jch.13897] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/15/2020] [Accepted: 04/20/2020] [Indexed: 12/19/2022]
Abstract
Early-life factors including preterm birth and VLBW increase the risk of hypertension, but the mechanisms remain poorly understood. Reductions in the anti-aging protein α-klotho are associated with hypertension, possibly due to angiotensin (Ang) II activation, but the mechanisms are incompletely understood and clinical evidence is lacking. The association of α-klotho with the alternative Ang-(1-7) pathway, which counteracts Ang II to lower BP, is undescribed. We hypothesized that lower urinary α-klotho is associated with higher BP and lower urinary Ang-(1-7) in preterm-born VLBW young adults. In a cross-sectional analysis of data from a prospective cohort of 141 preterm-born VLBW young adults, we assessed the associations among urinary α-klotho/creatinine, Ang II/creatinine, Ang-(1-7)/creatinine, Ang II/Ang-(1-7), and BP using generalized linear models adjusted for age and hypertensive pregnancy and conducted a sensitivity analysis in 32 term-born young adults. Among those born preterm, lower α-klotho/creatinine was associated with higher systolic BP (adjusted β (aβ): -2.58 mm Hg, 95% CI -4.99 to -0.17), lower Ang-(1-7)/creatinine (ln aβ: 0.1, 0.04-0.16), and higher Ang II/Ang-(1-7) (ln aβ: -0.14, -0.21 to -0.07). In term-born participants, α-klotho/creatinine was inversely associated with Ang II/creatinine (ln aβ: -0.15, -0.27 to -0.03) and Ang II/Ang-(1-7) (ln aβ: -0.15, -0.27 to -0.03). In preterm-born young adults with VLBW, lower urinary α-klotho/creatinine was associated with higher SBP, lower urinary Ang-(1-7)/creatinine, and higher urinary Ang II/Ang-(1-7). Reduced renal α-klotho expression could lead to renal Ang-(1-7) suppression as a novel mechanism for the development of hypertension among individuals born preterm with VLBW.
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Affiliation(s)
- Andrew M South
- Department of Pediatrics, Wake Forest School of Medicine and Brenner Children's Hospital, Winston Salem, North Carolina, USA.,Cardiovascular Sciences Center, Wake Forest School of Medicine, Winston Salem, North Carolina, USA.,Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest School of Medicine, Winston Salem, North Carolina, USA.,Department of Surgery-Hypertension and Vascular Research, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
| | - Hossam A Shaltout
- Cardiovascular Sciences Center, Wake Forest School of Medicine, Winston Salem, North Carolina, USA.,Department of Obstetrics and Gynecology, Wake Forest School of Medicine, Winston Salem, North Carolina, USA.,Department of Pharmacology and Toxicology, School of Pharmacy, University of Alexandria, Alexandria, Egypt
| | - TanYa M Gwathmey
- Cardiovascular Sciences Center, Wake Forest School of Medicine, Winston Salem, North Carolina, USA.,Department of Surgery-Hypertension and Vascular Research, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
| | - Elizabeth T Jensen
- Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
| | - Patricia A Nixon
- Department of Pediatrics, Wake Forest School of Medicine and Brenner Children's Hospital, Winston Salem, North Carolina, USA.,Department of Health and Exercise Science, Wake Forest University, Winston Salem, North Carolina, USA
| | - Debra I Diz
- Cardiovascular Sciences Center, Wake Forest School of Medicine, Winston Salem, North Carolina, USA.,Department of Surgery-Hypertension and Vascular Research, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
| | - Mark C Chappell
- Cardiovascular Sciences Center, Wake Forest School of Medicine, Winston Salem, North Carolina, USA.,Department of Surgery-Hypertension and Vascular Research, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
| | - Lisa K Washburn
- Department of Pediatrics, Wake Forest School of Medicine and Brenner Children's Hospital, Winston Salem, North Carolina, USA.,Cardiovascular Sciences Center, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
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7
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Law JP, Price AM, Pickup L, Radhakrishnan A, Weston C, Jones AM, McGettrick HM, Chua W, Steeds RP, Fabritz L, Kirchhof P, Pavlovic D, Townend JN, Ferro CJ. Clinical Potential of Targeting Fibroblast Growth Factor-23 and αKlotho in the Treatment of Uremic Cardiomyopathy. J Am Heart Assoc 2020; 9:e016041. [PMID: 32212912 PMCID: PMC7428638 DOI: 10.1161/jaha.120.016041] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chronic kidney disease is highly prevalent, affecting 10% to 15% of the adult population worldwide and is associated with increased cardiovascular morbidity and mortality. As chronic kidney disease worsens, a unique cardiovascular phenotype develops characterized by heart muscle disease, increased arterial stiffness, atherosclerosis, and hypertension. Cardiovascular risk is multifaceted, but most cardiovascular deaths in patients with advanced chronic kidney disease are caused by heart failure and sudden cardiac death. While the exact drivers of these deaths are unknown, they are believed to be caused by uremic cardiomyopathy: a specific pattern of myocardial hypertrophy, fibrosis, with both diastolic and systolic dysfunction. Although the pathogenesis of uremic cardiomyopathy is likely to be multifactorial, accumulating evidence suggests increased production of fibroblast growth factor-23 and αKlotho deficiency as potential major drivers of cardiac remodeling in patients with uremic cardiomyopathy. In this article we review the increasing understanding of the physiology and clinical aspects of uremic cardiomyopathy and the rapidly increasing knowledge of the biology of both fibroblast growth factor-23 and αKlotho. Finally, we discuss how dissection of these pathological processes is aiding the development of therapeutic options, including small molecules and antibodies, directly aimed at improving the cardiovascular outcomes of patients with chronic kidney disease and end-stage renal disease.
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Affiliation(s)
- Jonathan P. Law
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
- Department of NephrologyUniversity Hospitals Birmingham NHS Foundation TrustBirminghamUnited Kingdom
| | - Anna M. Price
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
- Department of NephrologyUniversity Hospitals Birmingham NHS Foundation TrustBirminghamUnited Kingdom
| | - Luke Pickup
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
| | - Ashwin Radhakrishnan
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
| | - Chris Weston
- Institute of Immunology and ImmunotherapyUniversity of BirminghamUnited Kingdom
- NIHR Birmingham Biomedical Research CentreUniversity Hospitals Birmingham NHS Foundation Trust and University of BirminghamUnited Kingdom
| | - Alan M. Jones
- School of PharmacyUniversity of BirminghamUnited Kingdom
| | | | - Winnie Chua
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
| | - Richard P. Steeds
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
- Department of CardiologyUniversity Hospitals Birmingham NHS Foundation TrustBirminghamUnited Kingdom
| | - Larissa Fabritz
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
- Department of CardiologyUniversity Hospitals Birmingham NHS Foundation TrustBirminghamUnited Kingdom
| | - Paulus Kirchhof
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
| | - Davor Pavlovic
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
| | - Jonathan N. Townend
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
- Department of CardiologyUniversity Hospitals Birmingham NHS Foundation TrustBirminghamUnited Kingdom
| | - Charles J. Ferro
- Birmingham Cardio‐Renal GroupUniversity Hospitals BirminghamUniversity of BirminghamUnited Kingdom
- Institute of Cardiovascular SciencesUniversity of BirminghamUnited Kingdom
- Department of NephrologyUniversity Hospitals Birmingham NHS Foundation TrustBirminghamUnited Kingdom
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8
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Xiao Z, King G, Mancarella S, Munkhsaikhan U, Cao L, Cai C, Quarles LD. FGF23 expression is stimulated in transgenic α-Klotho longevity mouse model. JCI Insight 2019; 4:132820. [PMID: 31801907 PMCID: PMC6962016 DOI: 10.1172/jci.insight.132820] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 10/23/2019] [Indexed: 12/21/2022] Open
Abstract
Observations in transgenic α-Klotho (Kl) mice (KlTg) defined the antiaging role of soluble Klotho (sKL130). A genetic translocation that elevates sKL levels in humans is paradoxically associated with increased circulating fibroblast growth factor 23 (FGF23) levels and the potential of both membrane KL (mKL135) and sKL130 to act as coreceptors for FGF23 activation of fibroblast growth factor receptors (FGFRs). Neither FGF23 expression nor the contributions of FGF23, mKL135, and sKL130 codependent and independent functions have been investigated in KlTg mice. In the current study, we examined the effects of Kl overexpression on FGF23 levels and functions in KlTg mice. We found that mKL135 but not sKL130 stimulated FGF23 expression in osteoblasts, leading to elevated Fgf23 bone expression and circulating levels in KlTg mice. Elevated FGF23 suppressed 1,25(OH)2D and parathyroid hormone levels but did not cause hypophosphatemic rickets in KlTg mice. KlTg mice developed low aldosterone-associated hypertension but not left ventricular hypertrophy. Mechanistically, we found that mKL135 and sKL130 are essential cofactors for FGF23-mediated ERK activation but that they inhibited FGF23 stimulation of PLC-γ and PI3K/AKT signaling. Thus, increased longevity in KlTg mice occurs in the presence of excess FGF23 that interacts with mKL and sKL to bias FGFR pathways.
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Affiliation(s)
- Zhousheng Xiao
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Gwendalyn King
- Department of Biology, Creighton University, Omaha, Nebraska, USA
| | | | - Undral Munkhsaikhan
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Li Cao
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Chun Cai
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Leigh Darryl Quarles
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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9
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Smith ER, Holt SG, Hewitson TD. αKlotho-FGF23 interactions and their role in kidney disease: a molecular insight. Cell Mol Life Sci 2019; 76:4705-4724. [PMID: 31350618 PMCID: PMC11105488 DOI: 10.1007/s00018-019-03241-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 07/09/2019] [Accepted: 07/22/2019] [Indexed: 12/16/2022]
Abstract
Following the serendipitous discovery of the ageing suppressor, αKlotho (αKl), several decades ago, a growing body of evidence has defined a pivotal role for its various forms in multiple aspects of vertebrate physiology and pathology. The transmembrane form of αKl serves as a co-receptor for the osteocyte-derived mineral regulator, fibroblast growth factor (FGF)23, principally in the renal tubules. However, compelling data also suggest that circulating soluble forms of αKl, derived from the same source, may have independent homeostatic functions either as a hormone, glycan-cleaving enzyme or lectin. Chronic kidney disease (CKD) is of particular interest as disruption of the FGF23-αKl axis is an early and common feature of disease manifesting in markedly deficient αKl expression, but FGF23 excess. Here we critically discuss recent findings in αKl biology that conflict with the view that soluble αKl has substantive functions independent of FGF23 signalling. Although the issue of whether soluble αKl can act without FGF23 has yet to be resolved, we explore the potential significance of these contrary findings in the context of CKD and highlight how this endocrine pathway represents a promising target for novel anti-ageing therapeutics.
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Affiliation(s)
- Edward R Smith
- Department of Nephrology, The Royal Melbourne Hospital, Melbourne, Australia.
- Department of Medicine, University of Melbourne, Grattan Street, Parkville, VIC, 3050, Australia.
| | - Stephen G Holt
- Department of Nephrology, The Royal Melbourne Hospital, Melbourne, Australia
- Department of Medicine, University of Melbourne, Grattan Street, Parkville, VIC, 3050, Australia
| | - Tim D Hewitson
- Department of Nephrology, The Royal Melbourne Hospital, Melbourne, Australia
- Department of Medicine, University of Melbourne, Grattan Street, Parkville, VIC, 3050, Australia
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10
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Leifheit-Nestler M, Kirchhoff F, Nespor J, Richter B, Soetje B, Klintschar M, Heineke J, Haffner D. Fibroblast growth factor 23 is induced by an activated renin-angiotensin-aldosterone system in cardiac myocytes and promotes the pro-fibrotic crosstalk between cardiac myocytes and fibroblasts. Nephrol Dial Transplant 2019; 33:1722-1734. [PMID: 29425341 DOI: 10.1093/ndt/gfy006] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 12/18/2017] [Indexed: 12/18/2022] Open
Abstract
Background Fibroblast growth factor 23 (FGF23) is discussed as a new biomarker of cardiac hypertrophy and mortality in patients with and without chronic kidney disease (CKD). We previously demonstrated that FGF23 is expressed by cardiac myocytes, enhanced in CKD and induces cardiac hypertrophy via activation of FGF receptor 4 independent of its co-receptor klotho. The impact of FGF23 on cardiac fibrosis is largely unknown. Methods By conducting a retrospective case-control study including myocardial autopsy samples from 24 patients with end-stage CKD and in vitro studies in cardiac fibroblasts and myocytes, we investigated the pro-fibrotic properties of FGF23. Results The accumulation of fibrillar collagens I and III was increased in myocardial tissue of CKD patients and correlated with dialysis vintage, klotho deficiency and enhanced cardiac angiotensinogen (AGT) expression. Using human fibrosis RT2 Profiler PCR array analysis, transforming growth factor (TGF)-β and its related TGF-β receptor/Smad complexes, extracellular matrix remodeling enzymes and pro-fibrotic growth factors were upregulated in myocardial tissue of CKD patients. FGF23 stimulated cell proliferation, migration, pro-fibrotic TGF-β receptor/Smad complexes and collagen synthesis in cultured cardiac fibroblasts. In isolated cardiac myocytes, FGF23 enhanced collagen remodeling, expression of pro-inflammatory genes and pro-survival pathways and induced pro-hypertrophic genes. FGF23 stimulated AGT expression in cardiac myocytes and angiotensin II and aldosterone, as components of the renin-angiotensin-aldosterone system (RAAS), induced FGF23 in cardiac myocytes. Conclusions Our data demonstrate that activated RAAS induces FGF23 expression in cardiac myocytes and thereby stimulates a pro-fibrotic crosstalk between cardiac myocytes and fibroblasts, which may contribute to myocardial fibrosis in CKD.
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Affiliation(s)
- Maren Leifheit-Nestler
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
| | - Felix Kirchhoff
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
| | - Julia Nespor
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
| | - Beatrice Richter
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany.,Department of Medicine and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Birga Soetje
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
| | - Michael Klintschar
- Institute for Forensic Medicine, Hannover Medical School, Hannover, Germany
| | - Joerg Heineke
- Department of Cardiology and Angiology, Rebirth-Cluster of Excellence, Hannover Medical School, Hannover, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
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11
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Fibroblast growth factor 23 and α-Klotho co-dependent and independent functions. Curr Opin Nephrol Hypertens 2019; 28:16-25. [PMID: 30451736 DOI: 10.1097/mnh.0000000000000467] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE OF REVIEW The current review examines what is known about the FGF-23/α-Klotho co-dependent and independent pathophysiological effects, and whether FGF-23 and/or α-Klotho are potential therapeutic targets. RECENT FINDINGS FGF-23 is a hormone derived mainly from bone, and α-Klotho is a transmembrane protein. Together they form a trimeric signaling complex with FGFRs in target tissues to mediate the physiological functions of FGF-23. Local and systemic factors control FGF-23 release from osteoblast/osteocytes in bone, and circulating FGF-23 activates FGFR/α-Klotho complexes in kidney proximal and distal renal tubules to regulate renal phosphate excretion, 1,25 (OH)2D metabolism, sodium and calcium reabsorption, and ACE2 and α-Klotho expression. The resulting bone-renal-cardiac-immune networks provide a new understanding of bone and mineral homeostasis, as well as identify other biological effects FGF-23. Direct FGF-23 activation of FGFRs in the absence of α-Klotho is proposed to mediate cardiotoxic and adverse innate immune effects of excess FGF-23, particularly in chronic kidney disease, but this FGF-23, α-Klotho-independent signaling is controversial. In addition, circulating soluble Klotho (sKl) released from the distal tubule by ectodomain shedding is proposed to have beneficial health effects independent of FGF-23. SUMMARY Separation of FGF-23 and α-Klotho independent functions has been difficult in mammalian systems and understanding FGF-23/α-Klotho co-dependent and independent effects are incomplete. Antagonism of FGF-23 is important in treatment of hypophosphatemic disorders caused by excess FGF-23, but its role in chronic kidney disease is uncertain. Administration of recombinant sKl is an unproven therapeutic strategy that theoretically could improve the healt span and lifespan of patients with α-Klotho deficiency.
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12
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Olejnik A, Franczak A, Krzywonos-Zawadzka A, Kałużna-Oleksy M, Bil-Lula I. The Biological Role of Klotho Protein in the Development of Cardiovascular Diseases. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5171945. [PMID: 30671457 PMCID: PMC6323445 DOI: 10.1155/2018/5171945] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 11/09/2018] [Accepted: 11/28/2018] [Indexed: 12/22/2022]
Abstract
Klotho is a membrane-bound or soluble antiaging protein, whose protective activity is essential for a proper function of many organs. In 1997, an accidental insertion of a transgene led to creation of transgenic mice with several age-related disorders. In Klotho-deficient mice, the inherited phenotypes closely resemble human aging, while in an animal model of Klotho overexpression, the lifespan is extended. Klotho protein is detected mainly in the kidneys and brain. It is a coreceptor for fibroblast growth factor and hence is involved in maintaining endocrine system homeostasis. Furthermore, an inhibition of insulin/insulin-like growth factor-1 signaling pathway by Klotho regulates oxidative stress and reduces cell death. The association between serum Klotho and the classic risk factors, as well as the clinical history of cardiovascular disease, was also shown. There are a lot of evidences that Klotho deficiency correlates with the occurrence and development of coronary artery disease, atherosclerosis, myocardial infarction, and left ventricular hypertrophy. Therefore, an involvement of Klotho in the signaling pathways and in regulation of a proper cell metabolism could be a crucial factor in the cardiac and vascular protection. It is also well established that Klotho protein enhances the antioxidative response via augmented production of superoxide dismutase and reduced generation of reactive oxygen species. Recent studies have proven an expression of Klotho in cardiomyocytes and its increased expression in stress-related heart injury. Thus, the antioxidative and antiapoptotic activity of Klotho could be considered as the novel protective factor in cardiovascular disease and heart injury.
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Affiliation(s)
- Agnieszka Olejnik
- Department of Medical Laboratory Diagnostics, Division of Clinical Chemistry, Wroclaw Medical University, 50-556 Wroclaw, Poland
| | - Aleksandra Franczak
- Department of Medical Laboratory Diagnostics, Division of Clinical Chemistry, Wroclaw Medical University, 50-556 Wroclaw, Poland
| | - Anna Krzywonos-Zawadzka
- Department of Medical Laboratory Diagnostics, Division of Clinical Chemistry, Wroclaw Medical University, 50-556 Wroclaw, Poland
| | - Marta Kałużna-Oleksy
- Department of Cardiology, University Hospital of Lord's Transfiguration, Poznan University of Medical Sciences, 61-848 Poznan, Poland
| | - Iwona Bil-Lula
- Department of Medical Laboratory Diagnostics, Division of Clinical Chemistry, Wroclaw Medical University, 50-556 Wroclaw, Poland
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13
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Cardiovascular Interactions between Fibroblast Growth Factor-23 and Angiotensin II. Sci Rep 2018; 8:12398. [PMID: 30120363 PMCID: PMC6098163 DOI: 10.1038/s41598-018-30098-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 07/14/2018] [Indexed: 12/12/2022] Open
Abstract
Both the activation of the renin angiotensin aldosterone system (RAAS) and elevations of circulating Fibroblast Growth Factor-23 (FGF-23) have been implicated in the pathogenesis of left ventricular hypertrophy (LVH) in chronic kidney disease. To investigate potential cross-talk between RAAS and FGF-23, we administered angiotensin II (Ang II) to wild-type rodents and the Hyp mouse model of excess FGF-23. Ang II administration for four weeks to wild-type rodents resulted in significant increases in systolic blood pressure and LVH. Unexpectedly, FGF-23 circulating levels were increased by 1.5-1.7 fold in Ang II treated animals. In addition, Ang II treatment increased expression of FGF-23 message levels in bone, the predominant tissue for FGF-23 production, and induced expression of FGF-23 and its co-receptor α-Klotho in the heart, which normally does not express FGF-23 or α-Klotho in physiologically relevant levels. Hyp mice with elevated FGF-23 exhibited increased blood pressure and LVH at baseline. Ang II administration to Hyp mice resulted further increments in blood pressure and left ventricular hypertrophy, consistent with additive cardiovascular effects. These findings suggest that FGF-23 may participate in unexpected systemic and paracrine networks regulating hemodynamic and myocardial responses.
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14
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Han X, Ross J, Kolumam G, Pi M, Sonoda J, King G, Quarles LD. Cardiovascular Effects of Renal Distal Tubule Deletion of the FGF Receptor 1 Gene. J Am Soc Nephrol 2018; 29:69-80. [PMID: 28993502 PMCID: PMC5748915 DOI: 10.1681/asn.2017040412] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/03/2017] [Indexed: 01/11/2023] Open
Abstract
The bone-derived hormone fibroblast growth factor-23 (FGF-23) activates complexes composed of FGF receptors (FGFRs), including FGFR1, and α-Klotho in the kidney distal tubule (DT), leading to increased sodium retention and hypertension. However, the role of FGFR1 in regulating renal processes linked to hypertension is unclear. Here, we investigated the effects of selective FGFR1 loss in the DT. Conditional knockout (cKO) of FGFR1 in the DT (FGFR1DT-cKO mice) resulted in left ventricular hypertrophy (LVH) and decreased kidney expression of α-Klotho in association with enhanced BP, decreased expression of angiotensin converting enzyme 2, and increased expression of the Na+-K+-2Cl- cotransporter. Notably, recombinant FGF-23 administration similarly decreased the kidney expression of α-Klotho and induced LVH in mice. Pharmacologic activation of FGFR1 with a monoclonal anti-FGFR1 antibody (R1MAb1) normalized BP and significantly attenuated LVH in the Hyp mouse model of excess FGF-23, but did not induce a response in FGFR1DT-cKO mice. The hearts of FGFR1DT-cKO mice showed increased expression of the transient receptor potential cation channel, subfamily C, member 6 (TRPC6), consistent with cardiac effects of soluble Klotho deficiency. Moreover, administration of recombinant soluble Klotho lowered BP in the Hyp mice. Thus, FGFR1 in the DT regulates systemic hemodynamic responses opposite to those predicted by the actions of FGF-23. These cardiovascular effects appear to be mediated by paracrine FGF control of kidney FGFR1 and subsequent regulation of soluble Klotho and TRPC6. FGFR1 in the kidney may provide a new molecular target for treating hypertension.
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MESH Headings
- Angiotensin-Converting Enzyme 2
- Animals
- Antibodies, Monoclonal/pharmacology
- Blood Pressure/drug effects
- Blood Pressure/genetics
- Female
- Fibroblast Growth Factor-23
- Fibroblast Growth Factors/pharmacology
- Glucuronidase/genetics
- Glucuronidase/metabolism
- Hypertension/genetics
- Hypertrophy, Left Ventricular/genetics
- Immunologic Factors/pharmacology
- Kidney Tubules, Distal
- Klotho Proteins
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Myocardium/metabolism
- Peptidyl-Dipeptidase A/genetics
- Peptidyl-Dipeptidase A/metabolism
- RNA, Messenger/metabolism
- Receptor, Fibroblast Growth Factor, Type 1/genetics
- Receptor, Fibroblast Growth Factor, Type 1/immunology
- Recombinant Proteins/pharmacology
- Sodium-Potassium-Chloride Symporters/genetics
- Sodium-Potassium-Chloride Symporters/metabolism
- TRPC Cation Channels/genetics
- TRPC Cation Channels/metabolism
- TRPC6 Cation Channel
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Affiliation(s)
- Xiaobin Han
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Jed Ross
- Department of Molecular Biology and Biomedical Imaging, Genentech, South San Francisco, California; and
| | - Ganesh Kolumam
- Department of Molecular Biology and Biomedical Imaging, Genentech, South San Francisco, California; and
| | - Min Pi
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Junichiro Sonoda
- Department of Molecular Biology and Biomedical Imaging, Genentech, South San Francisco, California; and
| | - Gwendalyn King
- Department of Neurobiology, University of Alabama in Birmingham, Birmingham, Alabama
| | - L Darryl Quarles
- Department of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee;
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15
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Leifheit-Nestler M, Richter B, Basaran M, Nespor J, Vogt I, Alesutan I, Voelkl J, Lang F, Heineke J, Krick S, Haffner D. Impact of Altered Mineral Metabolism on Pathological Cardiac Remodeling in Elevated Fibroblast Growth Factor 23. Front Endocrinol (Lausanne) 2018; 9:333. [PMID: 29977226 PMCID: PMC6021503 DOI: 10.3389/fendo.2018.00333] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 05/31/2018] [Indexed: 12/11/2022] Open
Abstract
Clinical and experimental studies indicate a possible link between high serum levels of fibroblast growth factor 23 (FGF23), phosphate, and parathyroid hormone (PTH), deficiency of active vitamin D (1,25D) and klotho with the development of pathological cardiac remodeling, i.e., left ventricular hypertrophy and myocardial fibrosis, but a causal link has not been established so far. Here, we investigated the cardiac phenotype in klotho hypomorphic (kl/kl) mice and Hyp mice, two mouse models of elevated FGF23 levels and klotho deficiency, but differing in parameters of mineral metabolism, by using histology, quantitative real-time PCR, immunoblot analysis, and serum and urine biochemistry. Additionally, the specific impact of calcium, phosphate, PTH, and 1,25D on hypertrophic growth of isolated neonatal rat cardiac myocytes was investigated in vitro. Kl/kl mice displayed high serum Fgf23 levels, increased relative heart weight, enhanced cross-sectional area of individual cardiac myocytes, activated cardiac Fgf23/Fgf receptor (Fgfr) 4/calcineurin/nuclear factor of activated T cell (NFAT) signaling, and induction of pro-hypertrophic NFAT target genes including Rcan1, bMHC, brain natriuretic peptide (BNP), and atrial natriuretic peptide (ANP) as compared to corresponding wild-type (WT) mice. Investigation of fibrosis-related molecules characteristic for pathological cardiac remodeling processes demonstrated ERK1/2 activation and enhanced expression of Tgf-β1, collagen I, and Mmp2 in kl/kl mice than in WT mice. In contrast, despite significantly elevation of serum and cardiac Fgf23, and reduced renal klotho expression, Hyp mice showed no signs of pathological cardiac remodeling. Kl/kl mice showed enhanced serum calcium and phosphate levels, while Hyp mice showed unchanged serum calcium levels, lower serum phosphate, and elevated serum iPTH concentrations compared to corresponding WT mice. In cultured cardiac myocytes, treatment with both calcium or phosphate significantly upregulated endogenous Fgf23 mRNA expression and stimulated hypertrophic cell growth and expression of pro-hypertrophic genes. The treatment with PTH induced hypertrophic cell growth only, and stimulation with 1,25D had no significant effects. In conclusion, our data indicate that Hyp mice, in contrast to kl/kl mice appear to be protected from pathological cardiac remodeling during conditions of high FGF23 levels and klotho deficiency, which may be due, at least in part, to differences in mineral metabolism alterations, i.e., hypophosphatemia and lack of hypercalcemia.
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Affiliation(s)
- Maren Leifheit-Nestler
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
- *Correspondence: Maren Leifheit-Nestler,
| | - Beatrice Richter
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Melis Basaran
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
| | - Julia Nespor
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
| | - Isabel Vogt
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
| | - Ioana Alesutan
- Department of Internal Medicine and Cardiology, Center for Cardiovascular Research, Charité University Medicine, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
| | - Jakob Voelkl
- Department of Internal Medicine and Cardiology, Center for Cardiovascular Research, Charité University Medicine, Berlin, Germany
| | - Florian Lang
- Department of Physiology I, University of Tuebingen, Tuebingen, Germany
| | - Joerg Heineke
- Department of Cardiology and Angiology, Experimental Cardiology, Rebirth-Cluster of Excellence, Hannover Medical School, Hannover, Germany
| | - Stefanie Krick
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
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16
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Zhao W, Zhao T, Chen Y, Bhattacharya SK, Lu L, Sun Y. Differential Expression of Hypertensive Phenotypes in BXD Mouse Strains in Response to Angiotensin II. Am J Hypertens 2017; 31:108-114. [PMID: 29036574 DOI: 10.1093/ajh/hpx144] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 09/12/2017] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Besides environmental risk factors, genetic factors play a crucial role in the pathogenesis of primary hypertension. The current study is to unravel whether hypertensive phenotypes vary in mice with different genetic background. METHODS Hypertension was induced in C57BL/6J (B6), DBA/2J (D2), and 25 BXD strains by administrating angiotensin (Ang)II (2.5 mg/kg/day infused by osmotic minipump) for 4 weeks. Systolic blood pressure was monitored before (baseline) and after 4 weeks of AngII treatment by tail cuff. Cardiac and renal fibrosis was evaluated by picrosirius red staining and collagen volume fraction (CVF) was quantitated using imaging analyzing system; cardiac transforming growth factor (TGF)-β gene expression was monitored by RT-PCR, and inflammatory response was detected by immunohistochemical ED-1 staining. RESULTS AngII infusion caused hypertension in all strains. However, blood pressure elevation was more evident in the D2 strain than the B6 group, while it was widely variable among BXD strains. Furthermore, chronic AngII treatment lead to development of hypertensive cardiac and renal diseases. Cardiac and renal CVF levels in the D2 strain was significantly higher than the B6 cohort, whereas these varied vastly across BXD strains. Moreover, cardiac TGF-β mRNA levels were markedly diverse among various mouse strains. CONCLUSION Our study unequivocally demonstrates that in response to AngII, BXDs with different genetic background expressed hypertension phenotypes with varied degree in severity. It implicates that genomics contribute to pathogenesis of primary hypertension. Building upon the genotype and hypertensive phenotypes, the BXD cohort can be further exploited experimentally to identify genes that influence blood pressure.
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Affiliation(s)
- Wenyuan Zhao
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science Center, USA
| | - Tieqiang Zhao
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science Center, USA
| | - Yuanjian Chen
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science Center, USA
| | - Syamal K Bhattacharya
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science Center, USA
| | - Lu Lu
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science Center, USA
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, USA
| | - Yao Sun
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science Center, USA
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17
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Mencke R, Olauson H, Hillebrands JL. Effects of Klotho on fibrosis and cancer: A renal focus on mechanisms and therapeutic strategies. Adv Drug Deliv Rev 2017; 121:85-100. [PMID: 28709936 DOI: 10.1016/j.addr.2017.07.009] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 06/28/2017] [Accepted: 07/07/2017] [Indexed: 12/21/2022]
Abstract
Klotho is a membrane-bound protein predominantly expressed in the kidney, where it acts as a permissive co-receptor for Fibroblast Growth Factor 23. In its shed form, Klotho exerts anti-fibrotic effects in several tissues. Klotho-deficient mice spontaneously develop fibrosis and Klotho deficiency exacerbates the disease progression in fibrotic animal models. Furthermore, Klotho overexpression or supplementation protects against fibrosis in various models of renal and cardiac fibrotic disease. These effects are mediated at least partially by the direct inhibitory effects of soluble Klotho on TGFβ1 signaling, Wnt signaling, and FGF2 signaling. Soluble Klotho, as present in the circulation, appears to be the primary mediator of anti-fibrotic effects. Similarly, through inhibition of the TGFβ1, Wnt, FGF2, and IGF1 signaling pathways, Klotho also inhibits tumorigenesis. The Klotho promoter gene is generally hypermethylated in cancer, and overexpression or supplementation of Klotho has been found to inhibit tumor growth in various animal models. This review focuses on the protective effects of soluble Klotho in inhibiting renal fibrosis and fibrosis in distant organs secondary to renal Klotho deficiency. We also discuss the structure-function relationships of Klotho domains and biological effects in the context of potential targeted treatment strategies.
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Affiliation(s)
- Rik Mencke
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Hannes Olauson
- Department of Clinical Science, Intervention and Technology (Division of Renal Medicine), Karolinska Institutet, Stockholm, Sweden
| | - Jan-Luuk Hillebrands
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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18
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Mencke R, Harms G, Moser J, van Meurs M, Diepstra A, Leuvenink HG, Hillebrands JL. Human alternative Klotho mRNA is a nonsense-mediated mRNA decay target inefficiently spliced in renal disease. JCI Insight 2017; 2:94375. [PMID: 29046474 DOI: 10.1172/jci.insight.94375] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 09/14/2017] [Indexed: 12/11/2022] Open
Abstract
Klotho is a renal protein involved in phosphate homeostasis, which is downregulated in renal disease. It has long been considered an antiaging factor. Two Klotho gene transcripts are thought to encode membrane-bound and secreted Klotho. Indeed, soluble Klotho is detectable in bodily fluids, but the relative contributions of Klotho secretion and of membrane-bound Klotho shedding are unknown. Recent advances in RNA surveillance reveal that premature termination codons, as present in alternative Klotho mRNA (for secreted Klotho), prime mRNAs for degradation by nonsense-mediated mRNA decay (NMD). Disruption of NMD led to accumulation of alternative Klotho mRNA, indicative of normally continuous degradation. RNA IP for NMD core factor UPF1 resulted in enrichment for alternative Klotho mRNA, which was also not associated with polysomes, indicating no active protein translation. Alternative Klotho mRNA transcripts colocalized with some P bodies, where NMD transcripts are degraded. Moreover, we could not detect secreted Klotho in vitro. These results suggest that soluble Klotho is likely cleaved membrane-bound Klotho only. Furthermore, we found that, especially in acute kidney injury, splicing of the 2 mRNA transcripts is dysregulated, which was recapitulated by various noxious stimuli in vitro. This likely constitutes a novel mechanism resulting in the downregulation of membrane-bound Klotho.
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Affiliation(s)
- Rik Mencke
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands.,The NIGRAM consortium detailed in the Supplemental Acknowledgments
| | - Geert Harms
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands.,The NIGRAM consortium detailed in the Supplemental Acknowledgments
| | - Jill Moser
- Department of Intensive Care Medicine.,Department of Pathology and Medical Biology (Division of Medical Biology), and
| | - Matijs van Meurs
- Department of Intensive Care Medicine.,Department of Pathology and Medical Biology (Division of Medical Biology), and
| | - Arjan Diepstra
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands
| | - Henri G Leuvenink
- Department of Surgery (Division of Experimental Surgery), University of Groningen, UMCG, Groningen, The Netherlands
| | - Jan-Luuk Hillebrands
- Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands.,The NIGRAM consortium detailed in the Supplemental Acknowledgments
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