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Chen J, Liu C, Sun C, Zeng J, Chi J, Che K, Wang Y. Association between Serum Phosphorus Levels and Diabetic Retinopathy: A Cross-Sectional Study. Int J Endocrinol 2024; 2024:3830246. [PMID: 38904033 PMCID: PMC11187971 DOI: 10.1155/2024/3830246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 05/27/2024] [Accepted: 05/30/2024] [Indexed: 06/22/2024] Open
Abstract
Background and Aims The aim of this study was to investigate the association between serum phosphate levels and diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM). Methods and Results The study sample consisted of 1657 T2DM patients hospitalized between 2017 and 2019. Patients were categorized into quartiles based on their serum phosphate levels (Q1-Q4). An increasing trend in the prevalence of DR was observed across these quartiles. Subsequently, logistic regression analysis was employed to adjust for potential confounders, such as gender, age, BMI, and duration of diabetes, and to evaluate the odds ratios (ORs) associated with these quartiles. The prevalence of DR showed an increasing trend with elevated serum phosphate levels. Logistic regression further confirmed that serum phosphate levels remain an independent risk factor for DR. Conclusion Elevated serum phosphate levels are closely associated with the prevalence of DR in hospitalized T2DM patients. Further studies are needed to establish causality. This trial is registered with chiCTR2000032374.
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Affiliation(s)
- Jintao Chen
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Chuanfeng Liu
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Cunwei Sun
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jia Zeng
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jingwei Chi
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Kui Che
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yangang Wang
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
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Wu CY, Song DF, Chen ZJ, Hu CS, Lin DPC, Chang HH. Absence of the Klotho Function Causes Cornea Degeneration with Specific Features Resembling Fuchs Endothelial Corneal Dystrophy and Bullous Keratopathy. BIOLOGY 2024; 13:133. [PMID: 38534403 DOI: 10.3390/biology13030133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/11/2024] [Accepted: 02/13/2024] [Indexed: 03/28/2024]
Abstract
The Klotho loss-of-function mutation is known to cause accelerated senescence in many organs, but its effects on the cornea have not been published. The present study aims to investigate the effects of the Klotho null mutation on cornea degeneration and to characterize the pathological features. Mouse corneas of Klotho homozygous, heterozygous, and wild-type mice at 8 weeks of age for both genders were subject to pathological and immunohistological examinations. The results show an irregular topography on the corneal surface with a Klotho null mutation. Histological examinations revealed a reduced corneal epithelial cell density, endothelial cell-shedding, and decreased cornea stromal layer thickness in the absence of the Klotho function. Furthermore, guttae formation and the desquamation of wing cells were significantly increased, which was comparable to the characteristics of Fuchs endothelial corneal dystrophy and bullous keratopathy. The mechanism analysis showed multi-fold abnormalities, including oxidative stress-induced cornea epithelium apoptosis and inflammation, extracellular matrix remodeling in the stroma, and a disruption of epithelial repair, presumably through the epithelial-mesenchymal transition. In conclusion, cornea degeneration was observed in the Klotho loss-of-function mutant mice. These pathological features support the use of Klotho mutant mice for investigating age-related cornea anomalies, including Fuchs endothelial corneal dystrophy, bullous keratopathy, and dry eye diseases.
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Affiliation(s)
- Chun-Yen Wu
- Department of Nutrition, Chung Shan Medical University, Taichung City 402, Taiwan
| | - Da-Fong Song
- Department of Nutrition, Chung Shan Medical University, Taichung City 402, Taiwan
| | - Zhi-Jia Chen
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung City 402, Taiwan
| | - Chao-Sheng Hu
- Department of Nutrition, Chung Shan Medical University, Taichung City 402, Taiwan
| | - David Pei-Cheng Lin
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung City 402, Taiwan
- Department of Ophthalmology, Chung Shan Medical University Hospital, Taichung City 402, Taiwan
| | - Han-Hsin Chang
- Department of Nutrition, Chung Shan Medical University, Taichung City 402, Taiwan
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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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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: 0] [Impact Index Per Article: 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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5
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Jang HY, Kim SJ, Park KS, Kim JH. Klotho prevents transforming growth factor-β2-induced senescent-like morphological changes in the retinal pigment epithelium. Cell Death Dis 2023; 14:334. [PMID: 37210384 DOI: 10.1038/s41419-023-05851-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 05/22/2023]
Abstract
Degenerative changes of the retinal pigment epithelium (RPE) triggered by transforming growth factor-β2 (TGF-β2) and oxidative stress play a critical role in the progression of age-related macular degeneration (AMD). The expression of α-klotho, an antiaging protein, declines with age, increasing the risk factors for age-related diseases. Here, we investigated the protective effects of soluble α-klotho on TGF-β2-induced RPE degeneration. The morphological changes induced by TGF-β2, including epithelial-mesenchymal transition (EMT), were attenuated in the mouse RPE by the intravitreal injection (IVT) of α-klotho. In ARPE19 cells, EMT and morphological alterations by TGF-β2 were attenuated by co-incubation with α-klotho. TGF-β2 decreased miR-200a accompanied by zinc finger e-box binding homeobox1 (ZEB1) upregulation and EMT, all of which were prevented by α-klotho co-treatment. Inhibitor of miR-200a mimicked TGF-β2-induced morphological changes, which were recovered by ZEP1 silencing, but not by α-klotho, implying the upstream regulation of α-klotho on miR-200a-ZEP1-EMT axis. α-Klotho inhibited receptor binding of TGF-β2, Smad2/3 phosphorylation, extracellular signal-regulated protein kinase 1/2 (ERK1/2)-a mechanistic target of rapamycin (mTOR) activation and oxidative stress via NADPH oxidase 4 (NOX4) upregulation. Furthermore, α-klotho recovered the TGF-β2-induced mitochondrial activation and superoxide generation. Interestingly, TGF-β2 upregulated α-klotho expression in the RPE cells, and genetic suppression of endogenous α-klotho aggravated TGF-β2-induced oxidative stress and EMT. Lastly, α-klotho abrogated senescence-associated signaling molecules and phenotypes induced by long-term incubation with TGF-β2. Hence, our findings indicate that the antiaging α-klotho plays a protective role against EMT and degeneration of the RPE, demonstrating the therapeutic potential for age-related retinal diseases, including the dry type of AMD.
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Affiliation(s)
- Ha Young Jang
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Soo-Jin Kim
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
| | - Jeong Hun Kim
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea.
- Department of Ophthalmology, College of Medicine, Seoul National University, Seoul, Republic of Korea.
- Institute of Reproductive Medicine and Population, Seoul National University College of Medicine, Seoul, Republic of Korea.
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The Anti-Aging Hormone Klotho Promotes Retinal Pigment Epithelium Cell Viability and Metabolism by Activating the AMPK/PGC-1α Pathway. Antioxidants (Basel) 2023; 12:antiox12020385. [PMID: 36829944 PMCID: PMC9952846 DOI: 10.3390/antiox12020385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/30/2023] [Accepted: 01/30/2023] [Indexed: 02/08/2023] Open
Abstract
Initially discovered by Makuto Kuro-o in 1997, Klotho is a putative aging-suppressor gene when overexpressed and accelerates aging when deleted in mice. Previously, we showed that α-Klotho regulates retinal pigment epithelium (RPE) functions and protects against oxidative stress. However, the mechanisms by which Klotho influences RPE and retinal homeostasis remain elusive. Here, by performing a series of in vitro and in vivo experiments, we demonstrate that Klotho regulates cell viability under oxidative stress, mitochondrial gene expression and activity by inducing the phosphorylation of AMPK and p38MAPK, which in turn phosphorylate and activate CREB and ATF2, respectively, triggering PGC-1α transcription. The inhibition of Klotho in human RPE cells using CRISPR-Cas9 gene editing confirmed that a lack of Klotho negatively affects RPE functions, including mitochondrial activity and cell viability. Proteomic analyses showed that myelin sheath and mitochondrial-related proteins are downregulated in the RPE/retina of Kl-/- compared to WT mice, further supporting our biochemical observations. We conclude that Klotho acts upstream of the AMPK/PGC-1α pathway and regulates RPE/retinal resistance to oxidative stress, mitochondrial function, and gene and protein expressions. Thus, KL decline during aging could negatively impact retinal health, inducing age-related retinal degeneration.
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Tang A, Zhang Y, Wu L, Lin Y, Lv L, Zhao L, Xu B, Huang Y, Li M. Klotho's impact on diabetic nephropathy and its emerging connection to diabetic retinopathy. Front Endocrinol (Lausanne) 2023; 14:1180169. [PMID: 37143722 PMCID: PMC10151763 DOI: 10.3389/fendo.2023.1180169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 04/04/2023] [Indexed: 05/06/2023] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide and is a significant burden on healthcare systems. α-klotho (klotho) is a protein known for its anti-aging properties and has been shown to delay the onset of age-related diseases. Soluble klotho is produced by cleavage of the full-length transmembrane protein by a disintegrin and metalloproteases, and it exerts various physiological effects by circulating throughout the body. In type 2 diabetes and its complications DN, a significant decrease in klotho expression has been observed. This reduction in klotho levels may indicate the progression of DN and suggest that klotho may be involved in multiple pathological mechanisms that contribute to the onset and development of DN. This article examines the potential of soluble klotho as a therapeutic agent for DN, with a focus on its ability to impact multiple pathways. These pathways include anti-inflammatory and oxidative stress, anti-fibrotic, endothelial protection, prevention of vascular calcification, regulation of metabolism, maintenance of calcium and phosphate homeostasis, and regulation of cell fate through modulation of autophagy, apoptosis, and pyroptosis pathways. Diabetic retinopathy shares similar pathological mechanisms with DN, and targeting klotho may offer new insights into the prevention and treatment of both conditions. Finally, this review assesses the potential of various drugs used in clinical practice to modulate klotho levels through different mechanisms and their potential to improve DN by impacting klotho levels.
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Affiliation(s)
- Anqi Tang
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Yu Zhang
- Department of Nephrology, Shaanxi Provincial Hospital of Traditional Chinese Medicine, Xi’an, China
| | - Ling Wu
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Yong Lin
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Lizeyu Lv
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Liangbin Zhao
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Bojun Xu
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Youqun Huang
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Mingquan Li
- Department of Nephrology, Hospital of Chengdu University of Traditional Chinese Medicine, Sichuan, China
- *Correspondence: Mingquan Li,
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8
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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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Guo JC, Yang YJ, Guo M, Zhang JQ, Zheng JF, Liu Z. Involvement of CDK11B-mediated SPDEF ubiquitination and SPDEF-mediated microRNA-448 activation in the oncogenicity and self-renewal of hepatocellular carcinoma stem cells. Cancer Gene Ther 2020; 28:1136-1149. [PMID: 33328586 DOI: 10.1038/s41417-020-00261-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/25/2020] [Accepted: 11/10/2020] [Indexed: 11/09/2022]
Abstract
Increasing evidence has suggested the crucial role cyclin-dependent kinases (CDKs) in the biology of hepatocellular carcinoma (HCC), a lethal malignancy with high morbidity and mortality. Hence, this study explored the modulatory effect of the putative cyclin-dependent kinase 11B (CDK11B)-mediated ubiquitination on HCC stem cells. The expression of CDK11B, SAM pointed domain-containing ETS transcription factor (SPDEF) and DOT1-like histone lysine methyltransferase (DOT1L) was determined by RT-qPCR and western blot analysis in HCC tissues and cells. The interaction among CDK11B, SPDEF, miR-448, and DOT1L was analyzed by Co-IP, ubiquitination-IP and ChIP assays, whereas their effects on the biological characteristics of HCC stem cells were assessed by sphere formation and colony formation assays. An in vivo xenograft tumor model was developed for validating the regulation of CDK11B in oncogenicity of HCC stem cells. We characterized the aberrant upregulation of CDK11B and downregulation SPDEF in HCC tissues and cells. CDK11B degraded SPDEF through ubiquitin-proteasome pathway, whereas SPDEF could bind to the miR-448 promoter and inhibit the expression of DOT1L by activating miR-448, whereby promoting self-renewal of HCC stem cells. Knockdown of CDK11B attenuated the self-renewal capability of HCC stem cells and their oncogenicity in vivo. These findings highlighted that blocking the CDK11B-induced degradation of SPDEF and enhancing miR-448-dependent inhibition of DOT1L may delay the progression of HCC by restraining self-renewal capability of HCC stem cells, representing novel targets for HCC management.
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Affiliation(s)
- Jun-Cheng Guo
- Department of Hepatobiliary Surgery, Central South University Xiangya School of Medicine Affiliated Haikou Hospital, Haikou, 570208, P. R. China
| | - Yi-Jun Yang
- Department of Hepatobiliary Surgery, Central South University Xiangya School of Medicine Affiliated Haikou Hospital, Haikou, 570208, P. R. China.
| | - Min Guo
- Psychological Research Center, Hainan General Hospital, Haikou, 570311, P. R. China
| | - Jian-Quan Zhang
- Department of Hepatobiliary Surgery, Central South University Xiangya School of Medicine Affiliated Haikou Hospital, Haikou, 570208, P. R. China.
| | - Jin-Fang Zheng
- Department of Hepatobiliary Surgery, Hainan General Hospital, Haikou, 570311, P. R. China
| | - Zhuo Liu
- School of Public Health, Hainan Medical University, Haikou, 571199, P. R. China
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Ma Z, Liu J, Li J, Jiang H, Kong J. Klotho Levels are Decreased and Associated with Enhanced Oxidative Stress and Inflammation in the Aqueous Humor in Patients with Exudative Age-related Macular Degeneration. Ocul Immunol Inflamm 2020; 30:630-637. [PMID: 33048602 DOI: 10.1080/09273948.2020.1828488] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE To evaluate anti-aging protein klotho levels in the aqueous humor and its association with oxidative stress and inflammation in patients with age-related macular degeneration (AMD). METHODS Levels of klotho, oxidative, and antioxidative stress markers, and proinflammatory and anti-inflammatory markers in the aqueous humor from 28 patients with exudative AMD and 35 age-matched controls were measured. RESULTS Patients with AMD had lower levels of klotho, which were negatively correlated with macular lesion size. Patients with AMD also exhibited increased levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and interleukin (IL)-6 but not tumor necrosis factor‑α, and decreased levels of total antioxidant status (TAS) and IL-10. Moreover, levels of klotho were negatively correlated with levels of 8-OHdG and IL-6, but positively correlated with levels of TSA and IL-10. CONCLUSION Klotho levels in the aqueous humor are decreased and associated with oxidative stress and inflammation in patients with exudative AMD.
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Affiliation(s)
- Zhongxu Ma
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Jingjing Liu
- Provincial Key Laboratory of Lens Research, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
| | - Jing Li
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Hao Jiang
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Jun Kong
- Provincial Key Laboratory of Lens Research, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
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Bales KL, Bentley MR, Croyle MJ, Kesterson RA, Yoder BK, Gross AK. BBSome Component BBS5 Is Required for Cone Photoreceptor Protein Trafficking and Outer Segment Maintenance. Invest Ophthalmol Vis Sci 2020; 61:17. [PMID: 32776140 PMCID: PMC7441369 DOI: 10.1167/iovs.61.10.17] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/15/2020] [Indexed: 01/07/2023] Open
Abstract
Purpose To identify the role of the BBSome protein Bardet-Biedl syndrome 5 (BBS5) in photoreceptor function, protein trafficking, and structure using a congenital mutant mouse model. Methods Bbs5-/- mice (2 and 9 months old) were used to assess retinal function and morphology. Hematoxylin and eosin staining of retinal sections was performed to visualize histology. Electroretinography was used to analyze rod and cone photoreceptor function. Retinal protein localization was visualized using immunofluorescence (IF) within retinal cryosections. TUNEL staining was used to quantify cell death. Transmission electron microscopy (TEM) was used to examine retinal ultrastructure. Results In the Bbs5-/- retina, there was a significant loss of nuclei in the outer nuclear layer accompanied by an increase in cell death. Through electroretinography, Bbs5-/- mice showed complete loss of cone photoreceptor function. IF revealed mislocalization of the cone-specific proteins M- and S-opsins, arrestin-4, CNGA3, and GNAT2, as well as a light-dependent arrestin-1 mislocalization, although perpherin-2 was properly localized. TEM revealed abnormal outer segment disk orientation in Bbs5-/-. Conclusions Collectively, these data suggest that, although BBS5 is a core BBSome component expressed in all ciliated cells, its role within the retina mediates specific photoreceptor protein cargo transport. In the absence of BBS5, cone-specific protein mislocalization and a loss of cone photoreceptor function occur.
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Affiliation(s)
- Katie L. Bales
- Department of Optometry and Vision Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Melissa R. Bentley
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Mandy J. Croyle
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Robert A. Kesterson
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Bradley K. Yoder
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Alecia K. Gross
- Department of Optometry and Vision Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, United States
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Yan F, Feng Y, Chen J, Yan J. Klotho downregulation contributes to myocardial damage of cardiorenal syndrome in sepsis. Mol Med Rep 2020; 22:1035-1043. [PMID: 32468073 PMCID: PMC7339823 DOI: 10.3892/mmr.2020.11178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 05/01/2020] [Indexed: 02/06/2023] Open
Abstract
Klotho is a type of single-pass transmembrane protein that is important for the proper function of numerous organs. The aim of the present study was to investigate the role of Klotho in sepsis-associated myocardial damage. In the present study, reverse transcription-quantitative PCR, western blotting and ELISA were conducted to examine the expression levels of function genes, and flow cytometry was performed to detect cell apoptosis and reactive oxygen species. The present study demonstrated that Klotho expression was significantly downregulated in septic mice and that the myocardial function of septic mice improved after treatment with exogenous Klotho protein. It further demonstrated that indoxyl sulfate inhibited the expression of Klotho protein. In addition, decreased Klotho protein further led to activation of the reactive oxygen species-p38 mitogen-activated protein kinase signaling pathway, finally resulting in myocardial damage. In conclusion, Klotho protein may be a key regulator in the myocardial damage of cardiorenal syndrome in sepsis. It also has a potential to be a therapeutic target for sepsis-associated myocardial damage in the future.
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Affiliation(s)
- Fei Yan
- Department of General Practice, Zhejiang Hospital, Hangzhou, Zhejiang 310013, P.R. China
| | - Yue Feng
- Department of Radiology, Zhejiang Hospital, Hangzhou, Zhejiang 310013, P.R. China
| | - Jin Chen
- Department of General Practice, Zhejiang Hospital, Hangzhou, Zhejiang 310013, P.R. China
| | - Jing Yan
- Department of Critical Care Medicine, Zhejiang Hospital, Hangzhou, Zhejiang 310013, P.R. China
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13
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A comparison of the mitochondrial proteome and lipidome in the mouse and long-lived Pipistrelle bats. Aging (Albany NY) 2020; 11:1664-1685. [PMID: 30892277 PMCID: PMC6461166 DOI: 10.18632/aging.101861] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/06/2019] [Indexed: 02/06/2023]
Abstract
It is accepted that smaller mammals with higher metabolic rates have shorter lifespans. The very few species that do not follow these rules can give insights into interesting differences. The recorded maximum lifespans of bats are exceptional - over 40 years, compared with the laboratory mouse of 4 years. We investigated the differences in the biochemical composition of mitochondria between bat and mouse species. We used proteomics and ultra-high-performance liquid chromatography coupled with high resolution mass spectrometry lipidomics, to interrogate mitochondrial fractions prepared from Mus musculus and Pipistrellus pipistrellus brain and skeletal muscle. Fatty acid binding protein 3 was found at different levels in mouse and bat muscle mitochondria and its orthologues were investigated in Caenorhabditis elegans knock-downs for LBP 4, 5 and 6. In the bat, high levels of free fatty acids and N-acylethanolamine lipid species together with a significantly greater abundance of fatty acid binding protein 3 in muscle (1.8-fold, p=0.037) were found. Manipulation of fatty acid binding protein orthologues in C. elegans suggest these proteins and their role in lipid regulation are important for mitochondrial function.
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14
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Cheikhi A, Barchowsky A, Sahu A, Shinde SN, Pius A, Clemens ZJ, Li H, Kennedy CA, Hoeck JD, Franti M, Ambrosio F. Klotho: An Elephant in Aging Research. J Gerontol A Biol Sci Med Sci 2020; 74:1031-1042. [PMID: 30843026 DOI: 10.1093/gerona/glz061] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Indexed: 12/12/2022] Open
Abstract
The year 2017 marked the 20th anniversary of the first publication describing Klotho. This single protein was and is remarkable in that its absence in mice conferred an accelerated aging, or progeroid, phenotype with a dramatically shortened life span. On the other hand, genetic overexpression extended both health span and life span by an impressive 30%. Not only has Klotho deficiency been linked to a number of debilitating age-related illnesses but many subsequent reports have lent credence to the idea that Klotho can compress the period of morbidity and extend the life span of both model organisms and humans. This suggests that Klotho functions as an integrator of organ systems, making it both a promising tool for advancing our understanding of the biology of aging and an intriguing target for interventional studies. In this review, we highlight advances in our understanding of Klotho as well as key challenges that have somewhat limited our view, and thus translational potential, of this potent protein.
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Affiliation(s)
- Amin Cheikhi
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh.,Division of Geriatric Medicine, Department of Medicine, University of Pittsburgh
| | - Aaron Barchowsky
- Department of Environmental and Occupational Health, University of Pittsburgh.,Department of Pharmacology and Chemical Biology, University of Pittsburgh
| | - Amrita Sahu
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh.,Department of Environmental and Occupational Health, University of Pittsburgh
| | - Sunita N Shinde
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh
| | - Abish Pius
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh
| | - Zachary J Clemens
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh
| | - Hua Li
- Department of Biotherapeutics Discovery, Research Division, Boehringer Ingelheim Pharmaceuticals, Inc. Ridgefield, Connecticut
| | - Charles A Kennedy
- Department of Research Beyond Borders, Regenerative Medicine, Boehringer Ingelheim Pharmaceuticals, Inc. Ridgefield, Connecticut
| | - Joerg D Hoeck
- Department of Research Beyond Borders, Regenerative Medicine, Boehringer Ingelheim Pharmaceuticals, Inc. Ridgefield, Connecticut
| | - Michael Franti
- Department of Research Beyond Borders, Regenerative Medicine, Boehringer Ingelheim Pharmaceuticals, Inc. Ridgefield, Connecticut
| | - Fabrisia Ambrosio
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh.,Department of Environmental and Occupational Health, University of Pittsburgh.,Department of Bioengineering, University of Pittsburgh, Pennsylvania.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pennsylvania
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15
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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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16
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Ji B, Wei H, Ding Y, Liang H, Yao L, Wang H, Qu H, Deng H. Protective potential of klotho protein on diabetic retinopathy: Evidence from clinical and in vitro studies. J Diabetes Investig 2020; 11:162-169. [PMID: 31197979 PMCID: PMC6944830 DOI: 10.1111/jdi.13100] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/18/2019] [Accepted: 06/11/2019] [Indexed: 01/14/2023] Open
Abstract
AIMS/INTRODUCTION The purpose of the present study was to observe the relationship between serum α-klotho (KL) protein level and diabetic retinopathy (DR), and to further examine the effects of KL protein on apoptosis induced by palmitic acid (PA) in human retinal endothelial cells. MATERIALS AND METHODS A total of 17 healthy people and 60 type 2 diabetes patients were included. According to the results from fundus fluorescein angiography, the diabetes patients were divided into three subgroups: without DR, non-proliferative DR and proliferative DR. Serum KL level was measured by enzyme-linked immunosorbent assay. In vitro, human retinal endothelial cells were exposed to PA with or without KL protein. Apoptosis rates were analyzed by flow cytometry analysis. Apoptotic-related protein expressions were detected by western blotting analysis. RESULTS Serum KL level was lower in diabetes patients than that in healthy participants (P = 0.007), and was gradually decreased among the without DR, non-proliferative DR and proliferative DR subgroups (P = 0.045). A logistic regression analysis showed that after adjusting for the other confounding factors, serum KL level was independently and negatively related with DR (P = 0.049). Furthermore, the increased apoptosis rates induced by PA were inhibited with the addition of KL protein. Consistently, KL protein reversed the expression levels of the increased pro-apoptotic protein Bax and the decreased anti-apoptotic protein Bcl-2 induced by PA. However, the anti-apoptotic effect of KL protein was attenuated by LY294002 through the phosphatidylinositol 3 kinase-serine∕threonine kinase pathway. CONCLUSIONS The data suggested that KL protein was probably a potential protective factor against retinopathy in type 2 diabetes patients.
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Affiliation(s)
- Baolan Ji
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Huili Wei
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Yao Ding
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Huimin Liang
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Lu Yao
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Hang Wang
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Hua Qu
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Huacong Deng
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
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17
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Brown RB. Diabetes, Diabetic Complications, and Phosphate Toxicity: A Scoping Review. Curr Diabetes Rev 2020; 16:674-689. [PMID: 31686640 DOI: 10.2174/1573399815666191104113236] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/09/2019] [Accepted: 10/28/2019] [Indexed: 02/06/2023]
Abstract
This article presents a scoping review and synthesis of research findings investigating the toxic cellular accumulation of dysregulated inorganic phosphate-phosphate toxicity-as a pathophysiological determinant of diabetes and diabetic complications. Phosphorus, an essential micronutrient, is closely linked to the cellular metabolism of glucose for energy production, and serum inorganic phosphate is often transported into cells along with glucose during insulin therapy. Mitochondrial dysfunction and apoptosis, endoplasmic reticulum stress, neuronal degeneration, and pancreatic cancer are associated with dysregulated levels of phosphate in diabetes. Ectopic calcification involving deposition of calcium-phosphate crystals is prevalent throughout diabetic complications, including vascular calcification, nephropathy, retinopathy, and bone disorders. A low-glycemic, low-phosphate dietary intervention is proposed for further investigations in the treatment and prevention of diabetes and related diabetic pathologies.
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Affiliation(s)
- Ronald B Brown
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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18
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Lewis WR, Bales KL, Revell DZ, Croyle MJ, Engle SE, Song CJ, Malarkey EB, Uytingco CR, Shan D, Antonellis PJ, Nagy TR, Kesterson RA, Mrug MM, Martens JR, Berbari NF, Gross AK, Yoder BK. Mks6 mutations reveal tissue- and cell type-specific roles for the cilia transition zone. FASEB J 2018; 33:1440-1455. [PMID: 30133325 PMCID: PMC6355093 DOI: 10.1096/fj.201801149r] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The transition zone (TZ) is a domain at the base of the cilium that is involved in maintaining ciliary compartment-specific sensory and signaling activity by regulating cilia protein composition. Mutations in TZ proteins result in cilia dysfunction, often causing pleiotropic effects observed in a group of human diseases classified as ciliopathies. The purpose of this study is to describe the importance of the TZ component Meckel-Grüber syndrome 6 ( Mks6) in several organ systems and tissues regarding ciliogenesis and cilia maintenance using congenital and conditional mutant mouse models. Similar to MKS, congenital loss of Mks6 is embryonic lethal, displaying cilia loss and altered cytoskeletal microtubule modifications but only in specific cell types. Conditional Mks6 mutants have a variable cystic kidney phenotype along with severe retinal degeneration with mislocalization of phototransduction cascade proteins. However, other phenotypes, such as anosmia and obesity, which are typically associated with cilia and TZ dysfunction, were not evident. These data indicate that despite Mks6 being a core TZ component, it has tissue- or cell type-specific functions important for cilia formation and cilia sensory and signaling activities. Lewis, W. R., Bales, K. L., Revell, D. Z., Croyle, M. J., Engle, S. E., Song, C. J., Malarkey, E. B., Uytingco, C. R., Shan, D., Antonellis, P. J., Nagy, T. R., Kesterson, R. A., Mrug, M. M., Martens, J. R., Berbari, N. F., Gross, A. K., Yoder, B. K. Mks6 mutations reveal tissue- and cell type-specific roles for the cilia transition zone.
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Affiliation(s)
- Wesley R Lewis
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Katie L Bales
- Department of Optometry and Vision Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Dustin Z Revell
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Mandy J Croyle
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Staci E Engle
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
| | - Cheng Jack Song
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Erik B Malarkey
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Cedric R Uytingco
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Dan Shan
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Patrick J Antonellis
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
| | - Tim R Nagy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA; and
| | - Robert A Kesterson
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Michal M Mrug
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jeffrey R Martens
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA
| | - Alecia K Gross
- Department of Optometry and Vision Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Bradley K Yoder
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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19
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Słomiński B, Ryba-Stanisławowska M, Skrzypkowska M, Myśliwska J, Myśliwiec M. The KL-VS polymorphism of KLOTHO gene is protective against retinopathy incidence in patients with type 1 diabetes. Biochim Biophys Acta Mol Basis Dis 2017; 1864:758-763. [PMID: 29247834 DOI: 10.1016/j.bbadis.2017.12.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 12/04/2017] [Accepted: 12/11/2017] [Indexed: 02/01/2023]
Abstract
BACKGROUND AND AIMS KLOTHO is an anti-ageing circulating hormone involved in insulin signaling, inflammation and vascular homeostasis through its protective effects on the endothelium and antioxidant actions. The common functional "KL-VS" variant of the KLOTHO gene is reproducibly associated with longevity in humans. Large number of studies have evaluated close relationship between KLOTHO protein and diabetes but the association between KL-VS variant and retinopathy in type 1 diabetes mellitus (T1D) is unknown. Therefore, in the present study we examined the association between the KL-VS polymorphism and the risk of diabetic retinopathy (DR) in patients with T1D. METHODS We examined 400 patients with T1D and 350 healthy age-matched controls. The analysis concerned KL-VS polymorphism along with the levels of serum inflammatory (CRP, TNF-α) and anti-inflammatory (IL-10) markers, pro-angiogenic (angiogenin) and anti-angiogenic interferon gamma-induced protein 10 (IP-10) factors as well as adhesion molecules (ICAM-1, ICAM-3). RESULTS We did not find significant association between T1D and KL-VS alleles. However, we observed that the incidence of KL-VS genotype is lower in a group with retinopathy in comparison to diabetic patients without this complication. Moreover, we established that KL-VS carriers had the lowest levels of inflammatory markers, pro-angiogenic factors and adhesion molecules. Simultaneously, the KL-VS carriers had increased serum levels of anti-inflammatory and anti-angiogenic cytokines than holders bearing wild type genotype. CONCLUSIONS In conclusion, the findings of our studies suggest that the functional KL-VS variant of the KLOTHO gene protects against the development of retinopathy in patients with T1D.
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Affiliation(s)
- Bartosz Słomiński
- Department of Immunology, Medical University of Gdańsk, Dębinki 1, 80-211 Gdańsk, Poland.
| | | | - Maria Skrzypkowska
- Department of Immunology, Medical University of Gdańsk, Dębinki 1, 80-211 Gdańsk, Poland
| | - Jolanta Myśliwska
- Department of Immunology, Medical University of Gdańsk, Dębinki 1, 80-211 Gdańsk, Poland
| | - Małgorzata Myśliwiec
- Chair & Clinics of Paediatrics, Diabetology and Endocrinology, Medical University of Gdańsk, Dębinki 7, 80-211 Gdańsk, Poland
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20
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Olauson H, Mencke R, Hillebrands JL, Larsson TE. Tissue expression and source of circulating αKlotho. Bone 2017; 100:19-35. [PMID: 28323144 DOI: 10.1016/j.bone.2017.03.043] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 03/15/2017] [Accepted: 03/16/2017] [Indexed: 12/16/2022]
Abstract
αKlotho (Klotho), a type I transmembrane protein and a coreceptor for Fibroblast Growth Factor-23, was initially thought to be expressed only in a limited number of tissues, most importantly the kidney, parathyroid gland and choroid plexus. Emerging data may suggest a more ubiquitous Klotho expression pattern which has prompted reevaluation of the restricted Klotho paradigm. Herein we systematically review the evidence for Klotho expression in various tissues and cell types in humans and other mammals, and discuss potential reasons behind existing conflicting data. Based on current literature and tissue expression atlases, we propose a classification of tissues into high, intermediate and low/absent Klotho expression. The functional relevance of Klotho in organs with low expression levels remain uncertain and there is currently limited data on a role for membrane-bound Klotho outside the kidney. Finally, we review the evidence for the tissue source of soluble Klotho, and conclude that the kidney is likely to be the principal source of circulating Klotho in physiology.
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Affiliation(s)
- Hannes Olauson
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
| | - Rik Mencke
- Division of Pathology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan-Luuk Hillebrands
- Division of Pathology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Tobias E Larsson
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
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21
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Zhang Y, Wang L, Wu Z, Yu X, Du X, Li X. The Expressions of Klotho Family Genes in Human Ocular Tissues and in Anterior Lens Capsules of Age-Related Cataract. Curr Eye Res 2017; 42:871-875. [PMID: 28095050 DOI: 10.1080/02713683.2016.1259421] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yu Zhang
- Department of Laboratory, Henan Eye Institute, Henan Eye Hospital, Zhengzhou, China
| | - Liya Wang
- Department of Keratopathy, Henan Eye Institute, Henan Eye Hospital, Zhengzhou, China
| | - Zhong Wu
- Department of Cataract, Henan Eye Institute, Henan Eye Hospital, Zhengzhou, China
| | - Xiaolin Yu
- Department of Cataract, Henan Eye Institute, Henan Eye Hospital, Zhengzhou, China
| | - Xiaofeng Du
- Eye Bank, Henan Eye Institute, Henan Eye Hospital, Zhengzhou, China
| | - Xiaohua Li
- Department of Laboratory, Henan Eye Institute, Henan Eye Hospital, Zhengzhou, China
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22
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Abraham CR, Mullen PC, Tucker-Zhou T, Chen CD, Zeldich E. Klotho Is a Neuroprotective and Cognition-Enhancing Protein. VITAMINS AND HORMONES 2016; 101:215-38. [PMID: 27125744 DOI: 10.1016/bs.vh.2016.02.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this chapter, we will describe what has been learned about Klotho and its potential functions in the brain. Klotho is localized in the choroid plexus and, to a lesser extent, in hippocampal neurons. Cognitive decline is a common issue in human aging affecting over 50% of the population. This cognitive decline can also be seen in animal models such as the Rhesus monkey. A long-term study undertaken by our lab demonstrated that normal brain aging in rhesus monkeys and other animal models is associated with a significant downregulation of Klotho expression. This observation substantiates data from other laboratories that have reported that loss of Klotho accelerates the development of aging-like phenotypes, including cognitive deficits, whereas Klotho overexpression extends life span and enhances cognition in mice and humans. Klotho is a type 1 transmembrane pleiotropic protein predominantly expressed in kidney and brain and shed by ADAM 10 and 17 into the blood and cerebral spinal fluid, respectively. While the renal functions of Klotho are well known, its roles in the brain remain to be fully elucidated. We recently demonstrated that Klotho protects hippocampal neurons from amyloid and glutamate toxicity via the activation of an antioxidant enzymatic system suggesting Klotho is a neuroprotective protein. Furthermore, Klotho is necessary for oligodendrocyte maturation and myelin integrity. Through its diverse roles in the brain, Klotho has become a new therapeutic target for neurodegenerative diseases such as Alzheimer's disease and demyelinating diseases like multiple sclerosis. Discovery of small molecule Klotho enhancers may lead to novel treatments for these incurable disorders.
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Affiliation(s)
- C R Abraham
- Boston University School of Medicine, Boston, MA, United States.
| | - P C Mullen
- Boston University School of Medicine, Boston, MA, United States
| | - T Tucker-Zhou
- Boston University School of Medicine, Boston, MA, United States
| | - C D Chen
- Boston University School of Medicine, Boston, MA, United States
| | - E Zeldich
- Boston University School of Medicine, Boston, MA, United States
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23
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Deming JD, Pak JS, Brown BM, Kim MK, Aung MH, Eom YS, Shin JA, Lee EJ, Pardue MT, Craft CM. Visual Cone Arrestin 4 Contributes to Visual Function and Cone Health. Invest Ophthalmol Vis Sci 2015; 56:5407-16. [PMID: 26284544 DOI: 10.1167/iovs.15-16647] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
PURPOSE Visual arrestins (ARR) play a critical role in shutoff of rod and cone phototransduction. When electrophysiological responses are measured for a single mouse cone photoreceptor, ARR1 expression can substitute for ARR4 in cone pigment desensitization; however, each arrestin may also contribute its own, unique role to modulate other cellular functions. METHODS A combination of ERG, optokinetic tracking, immunohistochemistry, and immunoblot analysis was used to investigate the retinal phenotypes of Arr4 null mice (Arr4-/-) compared with age-matched control, wild-type mice. RESULTS When 2-month-old Arr4-/- mice were compared with wild-type mice, they had diminished visual acuity and contrast sensitivity, yet enhanced ERG flicker response and higher photopic ERG b-wave amplitudes. In contrast, in older Arr4-/- mice, all ERG amplitudes were significantly reduced in magnitude compared with age-matched controls. Furthermore, in older Arr4-/- mice, the total cone numbers decreased and cone opsin protein immunoreactive expression levels were significantly reduced, while overall photoreceptor outer nuclear layer thickness was unchanged. CONCLUSIONS Our study demonstrates that Arr4-/- mice display distinct phenotypic differences when compared to controls, suggesting that ARR4 modulates essential functions in high acuity vision and downstream cellular signaling pathways that are not fulfilled or substituted by the coexpression of ARR1, despite its high expression levels in all mouse cones. Without normal ARR4 expression levels, cones slowly degenerate with increasing age, making this a new model to study age-related cone dystrophy.
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Affiliation(s)
- Janise D Deming
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - Joseph S Pak
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - Bruce M Brown
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - Moon K Kim
- Rehabilitation Research & Development Center of Excellence, Atlanta VA Medical Center, Decatur, Georgia, United States
| | - Moe H Aung
- Neuroscience/Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Yun Sung Eom
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States 4Dornsife College of Letters, Arts and Sciences, Univers
| | - Jung-A Shin
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States 5Department of Anatomy, School of Medicine, Ewha Womans
| | - Eun-Jin Lee
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States 6Department of Biomedical Engineering, University of Sou
| | - Machelle T Pardue
- Rehabilitation Research & Development Center of Excellence, Atlanta VA Medical Center, Decatur, Georgia, United States 3Neuroscience/Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Cheryl Mae Craft
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States 7Department of Cell & Neurobiology, Keck School of Medic
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