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Li Q, Wang P, Gong Y, Xu M, Wang M, Luan R, Liu J, Li X, Shao Y. α-Klotho prevents diabetic retinopathy by reversing the senescence of macrophages. Cell Commun Signal 2024; 22:449. [PMID: 39327553 PMCID: PMC11426092 DOI: 10.1186/s12964-024-01838-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Accepted: 09/18/2024] [Indexed: 09/28/2024] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus (DM) and a significant cause of acquired blindness in the working-age population worldwide. Aging is considered as an important risk factor for DR development. Macrophages in aged mice bear typical M2 marker proteins but simultaneously express a pro-inflammatory factor profile. This may explain why the level of intraocular inflammation does not decrease during proliferative diabetic retinopathy (PDR) despite the occurrence of neovascularization and fibrosis (M2 activation). α-Klotho (KL) was originally discovered as a soluble anti-aging factor, which is mainly expressed in kidney tubular epithelium, choroid plexus in the brain and secreted in the blood. However, the role of KL in DR pathophysiology has not been previously reported. METHODS Type 1 (streptozotocin [STZ]-induced) and type 2 (a high-fat diet along with a low dose of STZ) diabetic mouse models were established and injected with or without KL adenovirus via the tail vein for 12 weeks. Vldlr-/- mice were injected intravitreally with or without soluble KL protein from P8 to P15. The retinal structure and function were analyzed by electroretinogram and optical coherence tomography. The neovascular lesions were analyzed by retinal flat mount and RPE flat mount. The senescence markers, macrophage morphology, and KL expression levels were detected by immunofluorescence staining. A cell model was constructed using RAW264.7 cells stimulated by 4-hydroxynonenal (4HNE) and transfected with or without KL adenovirus. The senescence-associated secretory phenotypes were detected by qRT-PCR. Senescence was detected by SA-β-Gal staining. Serum, aqueous humor, and vitreous humor KL levels of proliferative diabetic retinopathy (PDR) patients were measured by enzyme-linked immunosorbent assay. Quantitative proteomics and bioinformatics were applied to predict the change of proteins and biological function after overexpression of KL in macrophages. The effects of KL on the HECTD1 binding to IRS1 were analyzed by bioinformatics, molecular docking, and Western Blot. RESULTS Serum, aqueous humor, and vitreous humor KL levels were lower in patients with PDR than in those with cataracts. KL relieved the retinal structure damage, improved retina function, and inhibited retinal senescence in diabetic mice. KL administration attenuated the neovascular lesions in VLDLR-/- mice by decreasing the secretion of VEGFA and FGF2 from macrophages. KL also protected RAW264.7 cells from 4HNE-induced senescence. Additionally, it inhibited E3 ubiquitin ligase HECTD1 expression in both diabetic mouse peripheral blood mononuclear cells and 4HNE-treated RAW264.7 cells. KL inhibited HECTD1 binding to IRS1 and reduced the ubiquitination of IRS1. CONCLUSIONS Macrophage aging is involved in DM-induced retinopathy. KL alleviates DM-induced retinal macrophage senescence by downregulating HECTD1 and decreasing IRS1 ubiquitination and degradation. Meanwhile, KL administration attenuated the neovascular lesions by altering the activation state of macrophages and decreasing the expression of VEGFA and FGF2.
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Affiliation(s)
- Qingbo Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
| | - Peiyu Wang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
| | - Yi Gong
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
| | - Manhong Xu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
| | - Manqiao Wang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
| | - Rong Luan
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China
| | - Juping Liu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
| | - Xiaorong Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
| | - Yan Shao
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute & School of Optometry and Ophthalmology, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
- Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Nankai District, No. 251, Fukang Road, Tianjin, 300384, China.
- University of Tibetan Medicine, Lhasa, 850000, China.
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Jiang Y, Zhang W, Xu Y, Zeng X, Sun X. Relationship of fibroblast growth factor 21, Klotho, and diabetic retinopathy: a meta-analysis. Front Endocrinol (Lausanne) 2024; 15:1390035. [PMID: 39257905 PMCID: PMC11384578 DOI: 10.3389/fendo.2024.1390035] [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: 02/22/2024] [Accepted: 08/08/2024] [Indexed: 09/12/2024] Open
Abstract
Background Diabetic retinopathy (DR) is a serious microvascular complication of diabetes mellitus. Research has identified a close relationship between fibroblast growth factor 21 (FGF21) and DR. FGF21 is a member of the FGF subfamily, which is activated by the Klotho coenzyme involved in the occurrence of DR. However, the association between FGF21, Klotho, and DR remains controversial. Aim To assess FGF21 and Klotho levels in patients with DR. Methods A literature search of the Web of Science, Wiley Online Library, PubMed, China National Knowledge Infrastructure and Wanfang databases was performed. The title or abstract search terms "diabetic retinopathy" and "DR" were used in combination with "fibroblast growth factor 21", "FGF21", and "Klotho". Meta-analysis results are presented as standardized mean difference (SMD) with corresponding 95% confidence interval (CI). Results Fifteen studies were included in this meta-analysis. FGF21 levels in patients with DR were significantly higher than in non-DR patients with diabetes (SMD: 2.12, 95% CI [1.40, 2.84]). Klotho levels in patients with DR were significantly lower than in non-DR patients with diabetes (SMD: -0.63, 95% CI [-1.22, - 0.04]). Conclusions This systematic review is the first to evaluate the relationship between FGF21, Klotho levels, and DR. FGF21 levels were significantly higher in patients with DR. Fully elucidating the role of FGF21 will significantly contribute to the treatment of DR.
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Affiliation(s)
- Yanhua Jiang
- Department of Ophthalmology, Fourth People’s Hospital of Shenyang, Shenyang, China
| | - Weilai Zhang
- Department of Ophthalmology, Fourth People’s Hospital of Shenyang, Shenyang, China
| | - Yao Xu
- Department of Ophthalmology, Fourth Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiandong Zeng
- Department of Ophthalmology, Fourth People’s Hospital of Shenyang, Shenyang, China
| | - Xin Sun
- Department of Endocrinology, First Affiliated Hospital of Soochow University, Suzhou, China
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Oner C, Dogan B, Tuzun S, Ekinci A, Feyizoglu G, Basok BI. Serum α-Klotho and fibroblast growth factor 23 levels are not associated with non-proliferative diabetic retinopathy in type 1 diabetes mellitus. Sci Rep 2024; 14:4054. [PMID: 38374169 PMCID: PMC10876523 DOI: 10.1038/s41598-024-54788-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 02/16/2024] [Indexed: 02/21/2024] Open
Abstract
Diabetic retinopathy is a commonly observed cause of blindness and is a common problem in individuals with diabetes. Recent investigations have showed the capability of serum α-Klotho and FGF 23 in mitigating the effects of diabetic retinopathy. This study aimed to discover the correlation between FGF 23, α-Klotho, and diabetic retinopathy in type 1 diabetics. This case-control study included 63 diabetic patients and 66 healthy controls. Following an overnight duration of fasting, morning blood samples were taken from both the patient and the control groups. The serum concentrations of α-Klotho and FGF 23 were quantified. An experienced ophthalmologist inspected the retinopathy. All participants in this study have moderate non-proliferative retinopathy. A p value under 0.05 was considered statistically significant. The mean α-Klotho level for retinopathic diabetic patients was 501.7 ± 172.2 pg/mL and 579.6 ± 312.1 pg/mL for non-retinopathic diabetic patients. In comparison, α-Klotho level of the control group was 523.2 ± 265.4 pg/mL (p = 0.531). The mean of FGF 23 level did not demonstrate a significant difference (p = 0.259). The mean FGF 23 level were 75.7 ± 14.0 pg/mL, 74.0 ± 14.8 pg/mL and 79.3 ± 14.4 pg/mL in groups, respectively. In conclusion, there was no significant difference in FGF 23 and α-Klotho levels between type 1 diabetics with and without retinopathy when compared to the control group.
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Affiliation(s)
- Can Oner
- Department of Family Medicine, Health Sciences University Kartal Dr Lutfi Kirdar City Hospital, Istanbul, Turkey.
| | - Burcu Dogan
- Department of Family Medicine, Health Sciences University Gulhane Training and Research Hospital, Ankara, Turkey
| | - Sabah Tuzun
- Department of Family Medicine, Health Sciences University Haseki Sultangazi Training and Research Hospital, Istanbul, Turkey
| | - Asiye Ekinci
- Department of Ophtalmology, Health Sciences University Bursa Yuksek Ihtisas Training and Research Hospital, Bursa, Turkey
| | - Gunes Feyizoglu
- Department of Internal Medicine, Goztepe Prof Dr Suleyman Yalcın City Hospital, Istanbul, Turkey
| | - Banu Isbilen Basok
- Department of Medical Biochemistry, Health Sciences University Tepecik Training and Research Hospital, Izmir, Turkey
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Liu Y, Chen M. Emerging role of α-Klotho in energy metabolism and cardiometabolic diseases. Diabetes Metab Syndr 2023; 17:102854. [PMID: 37722166 DOI: 10.1016/j.dsx.2023.102854] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/16/2023] [Accepted: 09/08/2023] [Indexed: 09/20/2023]
Abstract
BACKGROUND AND AIM Klotho was first identified as a gene associated with aging and longevity in 1997. α-Klotho is an anti-aging protein and its role in energy metabolism, various cardiovascular diseases (CVDs), and metabolic disorders is increasingly being recognized. In this review, we aimed to outline the potential protective role and therapeutic prospects of α-Klotho in energy metabolism and cardiometabolic diseases (CMDs). METHODS We comprehensively reviewed the relevant literature in PubMed using the keywords 'Klotho', 'metabolism', 'cardiovascular', 'diabetes', 'obesity', 'metabolic syndrome', and 'nonalcoholic fatty liver disease'. RESULTS α-Klotho can be divided into membrane-bound Klotho, secreted Klotho, and the most studied circulating soluble Klotho that can act as a hormone. Klotho gene polymorphisms have been implicated in energy metabolism and CMDs. α-Klotho can inhibit insulin/insulin growth factor-1 signaling and its overexpression can lead to a 'healthy insulin resistance' and may exert beneficial effects on the regulation of glycolipid metabolism and central energy homeostasis. α-Klotho, mainly serum Klotho, has been revealed to be protective against CVDs, diabetes and its complications, obesity, and nonalcoholic fatty liver disease. Human recombinant Klotho protein/Klotho gene delivery, multiple drugs, or natural products, and exercise can increase α-Klotho expression. CONCLUSION Overall, α-Klotho has demonstrated its potential as a promising target for modulating energy metabolism and CMDs, and further research is needed to explore its utilization in clinical practice in the future.
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Affiliation(s)
- Yuanbin Liu
- Department of Gastroenterology, Renmin Hospital of Wuhan University, No. 99 Zhang Zhidong Road, Wuhan, Hubei, 430000, PR China
| | - Mingkai Chen
- Department of Gastroenterology, Renmin Hospital of Wuhan University, No. 99 Zhang Zhidong Road, Wuhan, Hubei, 430000, PR China.
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Puddu A, Maggi DC. Klotho: A new therapeutic target in diabetic retinopathy? World J Diabetes 2023; 14:1027-1036. [PMID: 37547589 PMCID: PMC10401458 DOI: 10.4239/wjd.v14.i7.1027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/12/2023] [Accepted: 05/22/2023] [Indexed: 07/12/2023] Open
Abstract
Klotho (Kl) is considered an antiaging gene, mainly for the inhibition of the insulin-like growth factor-1 signaling. Kl exists as full-length transmembrane, which acts as co-receptor for fibroblast growth factor receptor, and in soluble forms (sKl). The sKl may exert pleiotropic effects on organs and tissues by regulating several pathways involved in the pathogenesis of diseases associated with oxidative and inflammatory state. In diabetic Patients, serum levels of Kl are significantly decreased compared to healthy subjects, and are related to duration of diabetes. In diabetic retinopathy (DR), one of the most common microvascular complications of type 2 diabetes, serum Kl levels are negatively correlated with progression of the disease. A lot of evidences showed that Kl regulates several mechanisms involved in maintaining homeostasis and functions of retinal cells, including phagocytosis, calcium signaling, secretion of vascular endothelial growth factor A (VEGF-A), maintenance of redox status, and melanin biosynthesis. Experimental data have been shown that Kl exerts positive effects on several mechanisms involved in onset and progression of DR. In particular, treatment with Kl: (1) Prevents apoptosis induced by oxidative stress in human retinal endothelial cells and in retinal pigment epithelium (RPE) cells; (2) reduces secretion of VEGF-A by RPE cells; and (3) decreases subretinal fibrosis and preserves autophagic activity. Therefore, Kl may become a novel biomarker and a good candidate for the treatment of DR.
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Affiliation(s)
- Alessandra Puddu
- Department of Internal Medicine and Medical Specialties, University of Genova, Genova 16132, Italy
| | - Davide Carlo Maggi
- Department of Internal Medicine and Medical Specialties, University of Genova, Genova 16132, Italy
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Mohhamed SA, Khadir F, Rahimi Z, Kohsari M. Klotho G395A variants are associated with T2DM and diabetic nephropathy and influence on the levels of biochemical parameters. GENE REPORTS 2023. [DOI: 10.1016/j.genrep.2022.101733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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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: 4] [Impact Index Per Article: 4.0] [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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Wen X, Li S, Zhang Y, Zhu L, Xi X, Zhang S, Li Y. Recombinant human klotho protects against hydrogen peroxide-mediated injury in human retinal pigment epithelial cells via the PI3K/Akt-Nrf2/HO-1 signaling pathway. Bioengineered 2022; 13:11767-11781. [PMID: 35543385 PMCID: PMC9275962 DOI: 10.1080/21655979.2022.2071023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Globally, age-related macular degeneration (AMD) is a common irreversible ophthalmopathy. Oxidative stress of retinal pigment epithelial cells is involved in AMD occurrence and development. Klotho is an anti-aging protein with antioxidant properties. We investigated the protective properties of Klotho on hydrogen peroxide (H2O2)-induced injury of retinal pigment epithelial cells (ARPE-19 cells) and its associated pathomechanisms. We found that Klotho pretreatment for 24 h could up-regulate Bcl-2 levels, decrease the cleaved-caspase-3 and Bax levels, inhibit H2O2-induced ARPE-19 cell apoptosis, and promote cell proliferation. Klotho pretreatment inhibited the H2O2-mediated elevations of reactive oxygen species (ROS) in ARPE-19 cells. It enhanced antioxidant activities of the cells and restored the glutathione peroxidase (GPX), superoxide dismutase (SOD2), catalase (CAT), as well as malondialdehyde (MDA) levels to close to the normal level. N-acetylcysteine (NAC), a reactive oxygen scavenger, could reverse the harmful effects of H2O2 on proliferation, apoptosis, and oxidative stress of ARPE-19 cells. Further, Klotho pretreatment enhanced Akt phosphorylation and expression as well as nuclear translocation of Nrf2 in H2O2-treated ARPE-19 cells. This indicates that Klotho protects cells from oxidative stress by activating phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)-nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) signaling pathway. Klotho is, therefore, a potential preventive or treatment option for AMD.
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Affiliation(s)
- Xuewei Wen
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Song Li
- Department of Sport Medicine, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Yanfei Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Liang Zhu
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Xiaoting Xi
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Shuyuan Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Yan Li
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
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Landry T, Shookster D, Huang H. Circulating α-klotho regulates metabolism via distinct central and peripheral mechanisms. Metabolism 2021; 121:154819. [PMID: 34153302 PMCID: PMC8277751 DOI: 10.1016/j.metabol.2021.154819] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 06/08/2021] [Accepted: 06/16/2021] [Indexed: 12/24/2022]
Abstract
Emerging evidence implicates the circulating α-klotho protein as a prominent regulator of energy balance and substrate metabolism, with diverse, tissue-specific functions. Despite its well-documented ubiquitous role inhibiting insulin signaling, α-klotho elicits potent antidiabetic and anti-obesogenic effects. α-Klotho facilitates insulin release and promotes β cell health in the pancreas, stimulates lipid oxidation in liver and adipose tissue, attenuates hepatic gluconeogenesis, and increases whole-body energy expenditure. The mechanisms underlying α-klotho's peripheral functions are multifaceted, including hydrolyzing transient receptor potential channels, stimulating integrin β1➔focal adhesion kinase signaling, and activating PPARα via inhibition of insulin-like growth factor receptor 1. Moreover, until recently, potential metabolic roles of α-klotho in the central nervous system remained unexplored; however, a novel α-klotho➔fibroblast growth factor receptor➔PI3kinase signaling axis in the arcuate nucleus of the hypothalamus has been identified as a critical regulator of energy balance and glucose metabolism. Overall, the role of circulating α-klotho in the regulation of metabolism is a new focus of research, but accumulating evidence identifies this protein as an encouraging therapeutic target for Type 1 and 2 Diabetes and obesity. This review analyzes the new literature investigating α-klotho-mediated regulation of metabolism and proposes impactful future directions to progress our understanding of this complex metabolic protein.
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Affiliation(s)
- Taylor Landry
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Daniel Shookster
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Hu Huang
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA; Department of Physiology, East Carolina University, Greenville, NC, USA.
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Zubkiewicz-Kucharska A, Wikiera B, Noczyńska A. Soluble Klotho Is Decreased in Children With Type 1 Diabetes and Correlated With Metabolic Control. Front Endocrinol (Lausanne) 2021; 12:709564. [PMID: 34603200 PMCID: PMC8484787 DOI: 10.3389/fendo.2021.709564] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/25/2021] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Klotho concentration may be considered as a prognostic factor in the development of chronic complications of diabetes. Moreover, decrease in sKlotho concentration may contribute to beta cell apoptosis and type 1 diabetes development. The aim of this study was to evaluate if sKlotho protein concentration in children with type 1 diabetes (T1D) and its correlation with classical risk factors of chronic complications of diabetes: dysglycemia and endothelial dysfunction. MATERIAL AND METHODS In a cross-section single center study the levels of soluble Klotho protein in 80 T1D (37 boys) and 34 healthy children (controls, 15 boys). Micro- and macroangiopathy were excluded and renal function was normal in all participants. Serum sKlotho, sICAM-1, sVCAM-1 and E-selectin levels were measured. RESULTS The concentration of sKlotho was lower in T1D than in the controls (2041.9 ± 1017.6 pg/mL vs. 2790.3 ± 1423.9 pg/mL, p=0.0113). sICAM-1, sVCAM-1 and E-selectin concentrations were comparable in patients and controls. In T1D, sKlotho was not correlated with the duration of diabetes. Klotho and E-selectin were correlated with HbA1c (r=-0.31, P=0.0066 and r=0.25, P=0.0351, respectively), but not with AVBG and blood glucose SD. Correlations of sKlotho with total cholesterol (r=0.31, P=0.0129), HDL-cholesterol (r=0.43, P=0.0011) and LDL-cholesterol (r=0.28, P=0.0412), but not with triglycerides, were found. Likewise, Klotho was not correlated with sICAM-1, sVCAM-1, and E-selectin concentrations. CONCLUSIONS This study reports the significantly lower level of s-Klotho in children with type 1 diabetes, correlated with HbA1c and HDL cholesterol, but not with the adhesion molecules concentrations nor the duration of the disease. Negative correlation between the levels of HbA1c and soluble Klotho may suggest its possible involvement in the development of chronic diabetes complications.
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Landry T, Li P, Shookster D, Jiang Z, Li H, Laing BT, Bunner W, Langton T, Tong Q, Huang H. Centrally circulating α-klotho inversely correlates with human obesity and modulates arcuate cell populations in mice. Mol Metab 2020; 44:101136. [PMID: 33301986 PMCID: PMC7777546 DOI: 10.1016/j.molmet.2020.101136] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/20/2022] Open
Abstract
Objective Our laboratory recently identified the centrally circulating α-klotho protein as a novel hypothalamic regulator of food intake and glucose metabolism in mice. The current study aimed to investigate novel molecular effectors of central α-klotho in the arcuate nucleus of the hypothalamus (ARC), while further deciphering its role regulating energy balance in both humans and mice. Methods Cerebrospinal fluid (CSF) was collected from 22 adults undergoing lower limb orthopedic surgeries, and correlations between body weight and α-klotho were determined using an α-klotho enzyme-linked immunosorbent assay (ELISA) kit. To investigate the effects of α-klotho on energy expenditure (EE), 2-day intracerebroventricular (ICV) treatment was performed in diet-induced obesity (DIO) mice housed in TSE Phenomaster indirect calorimetry metabolic cages. Immunohistochemical staining for cFOS and patch clamp electrophysiology were used to determine the effects of central α-klotho on proopiomelanocortin (POMC) and tyrosine hydroxylase (TH) neurons. Additional stainings were performed to determine novel roles for central α-klotho to regulate non-neuronal cell populations in the ARC. Lastly, ICV pretreatment with fibroblast growth factor receptor (FGFR) or PI3kinase inhibitors was performed to determine the intracellular signaling involved in α-klotho-mediated regulation of ARC nuclei. Results Obese/overweight human subjects had significantly lower CSF α-klotho concentrations compared to lean counterparts (1,044 ± 251 vs. 1616 ± 218 pmol/L, respectively). Additionally, 2 days of ICV α-klotho treatment increased EE in DIO mice. α-Klotho had no effects on TH neuron activity but elicited varied responses in POMC neurons, with 44% experiencing excitatory and 56% experiencing inhibitory effects. Inhibitor experiments identified an α-klotho→FGFR→PI3kinase signaling mechanism in the regulation of ARC POMC and NPY/AgRP neurons. Acute ICV α-klotho treatment also increased phosphorylated ERK in ARC astrocytes via FGFR signaling. Conclusion Our human CSF data provide the first evidence that impaired central α-klotho function may be involved in the pathophysiology of obesity. Furthermore, results in mouse models identify ARC POMC neurons and astrocytes as novel molecular effectors of central α-klotho. Overall, the current study highlights prominent roles of α-klotho→FGFR→PI3kinase signaling in the homeostatic regulation of ARC neurons and whole-body energy balance. Human CSF α-klotho concentrations exhibit a strong, inverse correlation with body weight and BMI. ICV α-klotho treatment increases energy expenditure in DIO mice. α-Klotho.→FGFR→PI3kinase signaling modulates ARC NPY/AgRP and POMC neurons. α-Klotho.→FGFR→ERK signaling regulates ARC astrocytes.
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Affiliation(s)
- Taylor Landry
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Peixin Li
- Department of Comprehensive Surgery, Medical and Health Center, Beijing Friendship Hospital, Capital Medical University, Beijing, PR China
| | - Daniel Shookster
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Zhiying Jiang
- Brown Foundation Institute of Molecular Medicine of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Hongli Li
- Brown Foundation Institute of Molecular Medicine of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Brenton Thomas Laing
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Wyatt Bunner
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Theodore Langton
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine of McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Hu Huang
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Human Performance Laboratory, College of Human Performance and Health, East Carolina University, Greenville, NC, USA; Department of Physiology, East Carolina University, Greenville, NC, USA.
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Corcillo A, Fountoulakis N, Sohal A, Farrow F, Ayis S, Karalliedde J. Low levels of circulating anti-ageing hormone Klotho predict the onset and progression of diabetic retinopathy. Diab Vasc Dis Res 2020; 17:1479164120970901. [PMID: 33225726 PMCID: PMC7919202 DOI: 10.1177/1479164120970901] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Klotho is a circulating anti-ageing hormone that predicts progression of cardiovascular and renal disease. The role of Klotho in diabetic retinopathy is unknown. METHODS We performed a single-centre observational study of 81 people (males 62%) with type 2 diabetes followed for a median of 44 months. Circulating levels of Klotho and other markers, were measured from stored samples. The primary outcome was progression of retinopathy defined as new onset retinopathy or step change in retinopathy grading. RESULTS During follow-up, 46 (57%) people reached the primary outcome. People with progression of retinopathy had lower levels of serum Klotho as compared to those without (median (interquartile range) 226.9 (171.1-394.0) vs 484.5 (221.8-709.9) pg/ml, p = 0.001). In multivariable logistic regression analyses, baseline Klotho level was the only variable independently associated with reduced risk of progression of retinopathy. Our results suggest that a halving of circulating Klotho levels increases the risk of retinopathy progression by 44%. CONCLUSION In people with type 2 diabetes, lower circulating levels of the vascular protective hormone Klotho are associated with increased risk of progression of diabetic retinopathy. Klotho may be a novel biomarker and potential treatment target for diabetic eye disease.
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Affiliation(s)
- Antonella Corcillo
- School of Cardiovascular Medicine & Sciences, King’s College London, London, UK
- Guy’s and St Thomas NHS Foundation Trust, Guy’s Hospital, London UK
- Antonella Corcillo and Janaka Karalliedde, Diabetes and Endocrine Day, London, SE1 9RT, UK. Emails: ;
| | | | - Angela Sohal
- School of Cardiovascular Medicine & Sciences, King’s College London, London, UK
| | - Frederick Farrow
- School of Cardiovascular Medicine & Sciences, King’s College London, London, UK
| | - Salma Ayis
- School of Cardiovascular Medicine & Sciences, King’s College London, London, UK
| | - Janaka Karalliedde
- School of Cardiovascular Medicine & Sciences, King’s College London, London, UK
- Guy’s and St Thomas NHS Foundation Trust, Guy’s Hospital, London UK
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Moos WH, Faller DV, Glavas IP, Harpp DN, Kanara I, Mavrakis AN, Pernokas J, Pernokas M, Pinkert CA, Powers WR, Sampani K, Steliou K, Vavvas DG, Zamboni RJ, Kodukula K, Chen X. Klotho Pathways, Myelination Disorders, Neurodegenerative Diseases, and Epigenetic Drugs. Biores Open Access 2020; 9:94-105. [PMID: 32257625 PMCID: PMC7133426 DOI: 10.1089/biores.2020.0004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this review we outline a rationale for identifying neuroprotectants aimed at inducing endogenous Klotho activity and expression, which is epigenetic action, by definition. Such an approach should promote remyelination and/or stimulate myelin repair by acting on mitochondrial function, thereby heralding a life-saving path forward for patients suffering from neuroinflammatory diseases. Disorders of myelin in the nervous system damage the transmission of signals, resulting in loss of vision, motion, sensation, and other functions depending on the affected nerves, currently with no effective treatment. Klotho genes and their single-pass transmembrane Klotho proteins are powerful governors of the threads of life and death, true to the origin of their name, Fates, in Greek mythology. Among its many important functions, Klotho is an obligatory co-receptor that binds, activates, and/or potentiates critical fibroblast growth factor activity. Since the discovery of Klotho a little over two decades ago, it has become ever more apparent that when Klotho pathways go awry, oxidative stress and mitochondrial dysfunction take over, and age-related chronic disorders are likely to follow. The physiological consequences can be wide ranging, potentially wreaking havoc on the brain, eye, kidney, muscle, and more. Central nervous system disorders, neurodegenerative in nature, and especially those affecting the myelin sheath, represent worthy targets for advancing therapies that act upon Klotho pathways. Current drugs for these diseases, even therapeutics that are disease modifying rather than treating only the symptoms, leave much room for improvement. It is thus no wonder that this topic has caught the attention of biomedical researchers around the world.
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Affiliation(s)
- Walter H. Moos
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, San Francisco, San Francisco, California
- ShangPharma Innovation, Inc., South San Francisco, California
| | - Douglas V. Faller
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts
| | - Ioannis P. Glavas
- Department of Ophthalmology, New York University School of Medicine, New York, New York
| | - David N. Harpp
- Department of Chemistry, McGill University, Montreal, Canada
| | | | - Anastasios N. Mavrakis
- Department of Medicine, Tufts University School of Medicine, St. Elizabeth's Medical Center, Boston, Massachusetts
| | - Julie Pernokas
- Advanced Dental Associates of New England, Woburn, Massachusetts
| | - Mark Pernokas
- Advanced Dental Associates of New England, Woburn, Massachusetts
| | - Carl A. Pinkert
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama
| | - Whitney R. Powers
- Department of Health Sciences, Boston University, Boston, Massachusetts
- Department of Anatomy, Boston University School of Medicine, Boston, Massachusetts
| | - Konstantina Sampani
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts
| | - Kosta Steliou
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts
- PhenoMatriX, Inc., Natick, Massachusetts
| | - Demetrios G. Vavvas
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
| | | | | | - Xiaohong Chen
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
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