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Liu M, Fan Y, Ni N, Yu T, Mao Z, Huang H, Zhang J, Tang Y, He H, Meng F, You Y, Zhou Q. TERT mediates the U-shape of glucocorticoids effects in modulation of hippocampal neural stem cells and associated brain function. CNS Neurosci Ther 2024; 30:e14577. [PMID: 38421107 PMCID: PMC10850922 DOI: 10.1111/cns.14577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 10/17/2023] [Accepted: 12/07/2023] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND Glucocorticoids (GCs) are steroidal hormones produced by the adrenal cortex. A physiological-level GCs have a crucial function in maintaining many cognitive processes, like cognition, memory, and mood, however, both insufficient and excessive GCs impair these functions. Although this phenomenon could be explained by the U-shape of GC effects, the underlying mechanisms are still not clear. Therefore, understanding the underlying mechanisms of GCs may provide insight into the treatments for cognitive and mood-related disorders. METHODS Consecutive administration of corticosterone (CORT, 10 mg/kg, i.g.) proceeded for 28 days to mimic excessive GCs condition. Adrenalectomy (ADX) surgery was performed to ablate endogenous GCs in mice. Microinjection of 1 μL of Ad-mTERT-GFP virus into mouse hippocampus dentate gyrus (DG) and behavioral alterations in mice were observed 4 weeks later. RESULTS Different concentrations of GCs were shown to affect the cell growth and development of neural stem cells (NSCs) in a U-shaped manner. The physiological level of GCs (0.01 μM) promoted NSC proliferation in vitro, while the stress level of GCs (10 μM) inhibited it. The glucocorticoid synthesis blocker metyrapone (100 mg/kg, i.p.) and ADX surgery both decreased the quantity and morphological development of doublecortin (DCX)-positive immature cells in the DG. The physiological level of GCs activated mineralocorticoid receptor and then promoted the production of telomerase reverse transcriptase (TERT); in contrast, the stress level of GCs activated glucocorticoid receptor and then reduced the expression of TERT. Overexpression of TERT by AD-mTERT-GFP reversed both chronic stresses- and ADX-induced deficiency of TERT and the proliferation and development of NSCs, chronic stresses-associated depressive symptoms, and ADX-associated learning and memory impairment. CONCLUSION The bidirectional regulation of TERT by different GCs concentrations is a key mechanism mediating the U-shape of GC effects in modulation of hippocampal NSCs and associated brain function. Replenishment of TERT could be a common treatment strategy for GC dysfunction-associated diseases.
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Affiliation(s)
- Meng‐Ying Liu
- Department of Pharmacy, Nanjing Drum Tower HospitalAffiliated Hospital of Medical School, Nanjing UniversityNanjingChina
- State Key Laboratory of Reproductive Medicine, Department of Clinical Pharmacology, School of PharmacyNanjing Medical UniversityNanjingChina
| | - Yixin Fan
- State Key Laboratory of Reproductive Medicine, Department of Clinical Pharmacology, School of PharmacyNanjing Medical UniversityNanjingChina
- Department of Pharmacy, Sir Run Run HospitalNanjing Medical UniversityNanjingChina
| | - Ningjie Ni
- State Key Laboratory of Reproductive Medicine, Department of Clinical Pharmacology, School of PharmacyNanjing Medical UniversityNanjingChina
- Department of NeurosurgeryThe First Affiliated Hospital of Nanjing Medical UniversityNanjingChina
| | - Tao Yu
- School of PharmacyNanjing Medical UniversityNanjingChina
| | - Zhiyuan Mao
- Key Laboratory for Aging & Disease, The State Key Laboratory of Reproductive Medicine, Department of Human Anatomy, Research Centre for Bone and Stem CellsNanjing Medical UniversityNanjingChina
| | - Hanyu Huang
- State Key Laboratory of Reproductive Medicine, Department of Clinical Pharmacology, School of PharmacyNanjing Medical UniversityNanjingChina
- Department of NeurosurgeryThe First Affiliated Hospital of Nanjing Medical UniversityNanjingChina
| | - Jing Zhang
- Department of Clinical Pharmacology, School of PharmacyNanjing Medical UniversityNanjingChina
| | - Yulin Tang
- Department of Pharmacy, Sir Run Run HospitalNanjing Medical UniversityNanjingChina
| | - Hongliang He
- Department of Pharmacy, Sir Run Run HospitalNanjing Medical UniversityNanjingChina
| | - Fan Meng
- Department of Clinical Pharmacology, School of PharmacyNanjing Medical UniversityNanjingChina
| | - Yongping You
- Department of NeurosurgeryThe First Affiliated Hospital of Nanjing Medical UniversityNanjingChina
| | - Qi‐Gang Zhou
- State Key Laboratory of Reproductive Medicine, Department of Clinical Pharmacology, School of PharmacyNanjing Medical UniversityNanjingChina
- Department of Pharmacy, Sir Run Run HospitalNanjing Medical UniversityNanjingChina
- Department of Clinical Pharmacology, School of PharmacyNanjing Medical UniversityNanjingChina
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Li J, Feng Y, Zhao J, Fang Z, Liu H. Telomerase reverse transcriptase promotes angiogenesis in neonatal rats after hypoxic-ischemic brain damage. PeerJ 2022; 10:e14220. [PMID: 36299510 PMCID: PMC9590416 DOI: 10.7717/peerj.14220] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/20/2022] [Indexed: 01/24/2023] Open
Abstract
Background Angiogenesis is an endogenous repair mechanism following hypoxic-ischemic brain damage (HIBD). Interestingly, recent studies have shown that angiogenesis can be regulated by telomerase reverse transcriptase (TERT), a critical component of telomerase. As telomerase reverse transcriptase can promote angiogenesis after stroke, we hypothesized that it could also promote angiogenesis after HIBD. To test this hypothesis, we developed in vivo and in vitro HIBD models in neonatal rats. Methods TERT was overexpressed by lentivirus and adenovirus infection, and levels were measured using quantitative real-time polymerase chain reaction. We used a cell counting kit to quantify the proliferation rate of brain microvascular endothelial cells (BMECs), and immunofluorescence staining to measure CD34 expression levels. A microvessel formation assay was used to evaluate angiogenesis. Blood-brain barrier (BBB) integrity was assessed using immunohistochemical staining for ZO-1 and Evans Blue staining. Lastly, the expression level of Notch-1 was measured by western blotting. Results Overexpression of TERT promoted the proliferation of BMECs after hypoxic-ischemic damage in vitro. TERT overexpression increased the formation of microvessels in the neonatal brain after HIBD both in vivo and in vitro. Overexpression of TERT improved BBB integrity in the brains of neonatal rats after HIBD. In addition, the expression level of Notch-1 was increased in BMECs following oxygen glucose deprivation, and overexpression of TERT further increased Notch-1 expression levels in BMECs following oxygen glucose deprivation. Discussion Our results reveal that telomerase reverse transcriptase promotes angiogenesis and maintains the integrity of the blood-brain barrier after neonatal hypoxic-ischemic brain damage. Furthermore, the Notch-1 signaling pathway appears to contribute to the angiogenic function of telomerase reverse transcriptase. This protective effect of telomerase reverse transcriptase opens new horizons for future investigations aimed at uncovering the full potential of telomerase reverse transcriptase as a promising new target for the treatment of hypoxic-ischemic encephalopathy.
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Affiliation(s)
- Jiao Li
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yi Feng
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Jing Zhao
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Zhi Fang
- Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Haiting Liu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
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3
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Ding H, Zhong Y, Liu N, Wu H, Xu H, Wu Y, Liu G, Yuan S, Zhou Q, Wang C. Panic disorder aging characteristics: The role of telomerase reverse transcriptase gene and brain function. Front Aging Neurosci 2022; 14:835963. [PMID: 35992589 PMCID: PMC9389410 DOI: 10.3389/fnagi.2022.835963] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 07/13/2022] [Indexed: 11/30/2022] Open
Abstract
Panic disorder (PD) causes serious functional damage and disability and accelerates the process of individual aging. The pathological basis of PD is the same as that of age-related diseases, which is proposed as a new viewpoint in recent years. Memory decline and social functional impairment are common manifestations of accelerated aging in PD. The function of telomerase reverse transcriptase (TERT) and telomere length (TL) is abnormal in patients with aging and PD. However, the molecular mechanism behind remains unclear. The purpose of this study was to explore the relationship between TERT gene expression (including DNA methylation) and the changes in PD aging characteristics (memory and social function). By TERT gene knockout mice, we found that loss of TERT attenuated the acquisition of recent fear memory during contextual fear conditioning. This study reported that a significantly lower methylation level of human TERT (hTERT) gene was detected in PD patients compared with healthy control and particularly decreased CpG methylation in the promoter region of hTERT was associated with the clinical characteristics in PD. Regional homogeneity (ReHo) analysis showed that the methylation of hTERT (cg1295648) influenced social function of PD patients through moderating the function of the left postcentral gyrus (PCG). This indicates that the hTERT gene may play an important role in the pathological basis of PD aging and may become a biological marker for evaluating PD aging. These findings provide multidimensional evidence for the underlying genetic and pathological mechanisms of PD.
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Affiliation(s)
- Huachen Ding
- Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China
- Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, China
| | - Yuan Zhong
- School of Psychology, Nanjing Normal University, Nanjing, China
| | - Na Liu
- Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China
- Cognitive Behavioral Therapy Institute of Nanjing Medical University, Nanjing, China
| | - Huiqin Wu
- Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China
- Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, China
| | - Huazhen Xu
- Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China
- Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, China
| | - Yun Wu
- Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China
- Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, China
- School of Psychology, Nanjing Normal University, Nanjing, China
- Cognitive Behavioral Therapy Institute of Nanjing Medical University, Nanjing, China
| | - Gang Liu
- Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China
- Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, China
- Cognitive Behavioral Therapy Institute of Nanjing Medical University, Nanjing, China
| | - Shiting Yuan
- Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China
- Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, China
| | - Qigang Zhou
- Department of Clinical Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing, China
- Qigang Zhou,
| | - Chun Wang
- Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China
- Functional Brain Imaging Institute of Nanjing Medical University, Nanjing, China
- School of Psychology, Nanjing Normal University, Nanjing, China
- Cognitive Behavioral Therapy Institute of Nanjing Medical University, Nanjing, China
- *Correspondence: Chun Wang,
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4
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Li J, Liu HT, Zhao J, Chen HJ. Telomerase reverse transcriptase (TERT) promotes neurogenesis after hypoxic-ischemic brain damage in neonatal rats. Neurol Res 2022; 44:819-829. [PMID: 35400306 DOI: 10.1080/01616412.2022.2056339] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Jiao Li
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Hai-Ting Liu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Jing Zhao
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Hong-Ju Chen
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, Sichuan, China
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Zhou Q, Lin L, Li H, Wang H, Jiang S, Huang P, Lin Q, Chen X, Deng Y. Melatonin Reduces Neuroinflammation and Improves Axonal Hypomyelination by Modulating M1/M2 Microglia Polarization via JAK2-STAT3-Telomerase Pathway in Postnatal Rats Exposed to Lipopolysaccharide. Mol Neurobiol 2021; 58:6552-6576. [PMID: 34585328 PMCID: PMC8639545 DOI: 10.1007/s12035-021-02568-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 09/12/2021] [Indexed: 02/05/2023]
Abstract
Microglia activation and associated inflammation are implicated in the periventricular white matter damage (PWMD) in septic postnatal rats. This study investigated whether melatonin would mitigate inflammation and alleviate the axonal hypomyelination in the corpus callosum in septic postnatal rats. We further explored if this might be related to the modulation of microglial polarization from M1 phenotype to M2 through the JAK2/STAT3/telomerase pathway. We reported here that indeed melatonin not only can it reduce the neurobehavioral disturbances in LPS-injected rats, but it can also dampen microglia-mediated inflammation. Thus, in LPS + melatonin group, the expression of proinflammatory mediators in M1 phenotype microglia was downregulated. As opposed to this, M2 microglia were increased which was accompanied by upregulated expression of anti-inflammatory mediators along with telomerase reverse transcriptase or melatonin receptor 1(MT1). In parallel to this was decreased NG2 expression but increased expression of myelin and neurofilament proteins. Melatonin can improve hypomyelination which was confirmed by electron microscopy. In vitro in primary microglia stimulated by LPS, melatonin decreased the expression of proinflammatory mediators significantly; but it increased the expression of anti-inflammatory mediators. Additionally, the expression levels of p-JAK2 and p-STAT3 were significantly elevated in microglia after melatonin treatment. Remarkably, the effect of melatonin on LPS-treated microglia was blocked by melatonin receptor, JAK2, STAT3 and telomerase reverse transcriptase inhibitors, respectively. Taken together, it is concluded that melatonin can attenuate PWMD through shifting M1 microglia towards M2 via MT1/JAK2/STAT3/telomerase pathway. The results suggest a new therapeutic strategy whereby melatonin may be adopted to convert microglial polarization from M1 to M2 phenotype that would ultimately contribute to the attenuation of PWMD.
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Affiliation(s)
- Qiuping Zhou
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
- School of Medicine, South China University of Technology, Guangzhou, 510006, China
| | - Lanfen Lin
- Department of Critical Care Medicine, Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China
| | - Haiyan Li
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Huifang Wang
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Shuqi Jiang
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
- School of Medicine, South China University of Technology, Guangzhou, 510006, China
| | - Peixian Huang
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
- School of Medicine, South China University of Technology, Guangzhou, 510006, China
| | - Qiongyu Lin
- Department of Critical Care Medicine, Jieyang People's Hospital, Jieyang, 522000, Guangdong, China
| | - Xuan Chen
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
- Shantou University Medical College (FCS), Shantou, 515063, China
| | - Yiyu Deng
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China.
- School of Medicine, South China University of Technology, Guangzhou, 510006, China.
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6
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Zhu L, Liu Z, Ren Y, Wu X, Liu Y, Wang T, Li Y, Cong Y, Guo Y. Neuroprotective effects of salidroside on ageing hippocampal neurons and naturally ageing mice via the PI3K/Akt/TERT pathway. Phytother Res 2021; 35:5767-5780. [PMID: 34374127 DOI: 10.1002/ptr.7235] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 06/22/2021] [Accepted: 07/17/2021] [Indexed: 12/23/2022]
Abstract
Studies have found that salidroside, isolated from Rhodiola rosea L, has various pharmacological activities, but there have been no studies on the effects of salidroside on brain hippocampal senescence. The purpose of this study was to investigate the mechanistic role of salidroside in hippocampal neuron senescence and injury. In this study, long-term cultured primary rat hippocampal neurons and naturally aged C57 mice were treated with salidroside. The results showed that salidroside increased the viability and MAP2 expression, reduced β-galactosidase (β-gal) levels of rat primary hippocampal neurons. Salidroside also improved cognition dysfunction in ageing mice and alleviated neuronal degeneration in the ageing mice CA1 region. Moreover, salidroside decreased the levels of oxidative stress and p21, p16 protein expressions of hippocampal neurons and ageing mice. Salidroside promoted telomerase reverse transcriptase (TERT) protein expression via the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) pathway. In conclusion, our findings suggest that salidroside has the potential to be used as a therapeutic strategy for anti-ageing and ageing-related disease treatment.
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Affiliation(s)
- Lin Zhu
- Institute of Cerebrovascular Diseases, Medical Research Center, The Affiliated Hospital of Qingdao University, Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Zhenchao Liu
- Institute of Cerebrovascular Diseases, Medical Research Center, The Affiliated Hospital of Qingdao University, Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Yuqian Ren
- Institute of Cerebrovascular Diseases, Medical Research Center, The Affiliated Hospital of Qingdao University, Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Xiaolin Wu
- Institute of Cerebrovascular Diseases, Medical Research Center, The Affiliated Hospital of Qingdao University, Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Yingjuan Liu
- Institute of Cerebrovascular Diseases, Medical Research Center, The Affiliated Hospital of Qingdao University, Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Tingting Wang
- Institute of Cerebrovascular Diseases, Medical Research Center, The Affiliated Hospital of Qingdao University, Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
| | - Yizhao Li
- Department of Neurology, Jinan Fanggan Rehabilitation Hospital, Jinan, China
| | - Yusheng Cong
- Institute of Aging Research, Hangzhou Normal University School of Medicine, Hangzhou, China
| | - Yunliang Guo
- Institute of Cerebrovascular Diseases, Medical Research Center, The Affiliated Hospital of Qingdao University, Taishan Scholars Construction Project Excellent Innovative Team of Shandong Province, Qingdao, China
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7
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Zhu L, Liu Y, Wu X, Ren Y, Zhang Q, Ren L, Guo Y. Cerebroprotein hydrolysate-I protects senescence-induced by D-galactose in PC12 cells and mice. Food Sci Nutr 2021; 9:3722-3731. [PMID: 34262731 PMCID: PMC8269606 DOI: 10.1002/fsn3.2333] [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] [Received: 01/20/2021] [Revised: 04/14/2021] [Accepted: 05/01/2021] [Indexed: 11/25/2022] Open
Abstract
Cerebroprotein hydrolysate-I (CH-I),a mixture of peptides extracted from porcine brain tissue,has shown a neuroprotective effect, but its role in brain senescence is unclear. In the present study, we established a senescence model of PC12 cells and mice to investigate the effect of CH-I on brain senescence via JAK2/STAT3 pathway. The results showed that CH-I could improve cell viability, inhibit the apoptosis of cells, and reduce the senescence-positive cells induced by D-galactose. In vivo, CH-I improved the learning ability and memory of aging mice, reduced neuronal damage in mice hippocampus. Mechanism studies showed that CH-I could adjust BDNF protein expressions, activate JAK2/STAT3 pathway, and finally enhance telomerase activity. All these findings indicated that CH-I showed a neuroprotective effect against brain senescence. These results might provide further reference and support for the application of CH-I in delaying aging.
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Affiliation(s)
- Lin Zhu
- Institute of Cerebrovascular DiseasesTaishan Scholars Construction Project Excellent Innovative Team of Shandong ProvinceMedical Research CenterThe Affiliated Hospital of Qingdao UniversityQingdaoChina
| | - Yingjuan Liu
- Institute of Cerebrovascular DiseasesTaishan Scholars Construction Project Excellent Innovative Team of Shandong ProvinceMedical Research CenterThe Affiliated Hospital of Qingdao UniversityQingdaoChina
| | - Xiaolin Wu
- Institute of Cerebrovascular DiseasesTaishan Scholars Construction Project Excellent Innovative Team of Shandong ProvinceMedical Research CenterThe Affiliated Hospital of Qingdao UniversityQingdaoChina
| | - Yuqian Ren
- Institute of Cerebrovascular DiseasesTaishan Scholars Construction Project Excellent Innovative Team of Shandong ProvinceMedical Research CenterThe Affiliated Hospital of Qingdao UniversityQingdaoChina
| | - Qinghua Zhang
- Department of NeurologyShandong Second Provincial General HospitalJinanChina
| | - Leiming Ren
- Institute of Chinese Integrative MedicineHebei Medical UniversityShijiazhuangChina
| | - Yunliang Guo
- Institute of Cerebrovascular DiseasesTaishan Scholars Construction Project Excellent Innovative Team of Shandong ProvinceMedical Research CenterThe Affiliated Hospital of Qingdao UniversityQingdaoChina
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Subasri M, Shooshtari P, Watson AJ, Betts DH. Analysis of TERT Isoforms across TCGA, GTEx and CCLE Datasets. Cancers (Basel) 2021; 13:cancers13081853. [PMID: 33924498 PMCID: PMC8070023 DOI: 10.3390/cancers13081853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/01/2021] [Accepted: 04/08/2021] [Indexed: 12/14/2022] Open
Abstract
Reactivation of the multi-subunit ribonucleoprotein telomerase is the primary telomere maintenance mechanism in cancer, but it is rate-limited by the enzymatic component, telomerase reverse transcriptase (TERT). While regulatory in nature, TERT alternative splice variant/isoform regulation and functions are not fully elucidated and are further complicated by their highly diverse expression and nature. Our primary objective was to characterize TERT isoform expression across 7887 neoplastic and 2099 normal tissue samples using The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression Project (GTEx), respectively. We confirmed the global overexpression and splicing shift towards full-length TERT in neoplastic tissue. Stratifying by tissue type we found uncharacteristic TERT expression in normal brain tissue subtypes. Stratifying by tumor-specific subtypes, we detailed TERT expression differences potentially regulated by subtype-specific molecular characteristics. Focusing on β-deletion splicing regulation, we found the NOVA1 trans-acting factor to mediate alternative splicing in a cancer-dependent manner. Of relevance to future tissue-specific studies, we clustered cancer cell lines with tumors from related origin based on TERT isoform expression patterns. Taken together, our work has reinforced the need for tissue and tumour-specific TERT investigations, provided avenues to do so, and brought to light the current technical limitations of bioinformatic analyses of TERT isoform expression.
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Affiliation(s)
- Mathushan Subasri
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
| | - Parisa Shooshtari
- Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada;
- Department of Pathology and Laboratory Medicine, The University of Western Ontario, London, ON N6A 5C1, Canada
- Department of Computer Science, The University of Western Ontario, London, ON N6A 5C1, Canada
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
| | - Andrew J. Watson
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Dean H. Betts
- Department of Physiology and Pharmacology, The University of Western Ontario, London, ON N6A 5C1, Canada; (M.S.); (A.J.W.)
- The Children’s Health Research Institute—Lawson Health Research Institute, London, ON N6C 2R5, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, ON N6A 5C1, Canada
- Correspondence: ; Tel.: +1-519-661-2111 (ext. 83786)
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Human telomerase reverse transcriptase positively regulates mitophagy by inhibiting the processing and cytoplasmic release of mitochondrial PINK1. Cell Death Dis 2020; 11:425. [PMID: 32513926 PMCID: PMC7280311 DOI: 10.1038/s41419-020-2641-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 05/21/2020] [Accepted: 05/25/2020] [Indexed: 12/18/2022]
Abstract
Mutations in the phosphatase and tensin homologue-induced putative kinase 1 (PINK1) gene have been linked to an early-onset autosomal recessive form of familial Parkinson′s disease (PD). PINK1, a mitochondrial serine/threonine-protein kinase, plays an important role in clearing defective mitochondria by mitophagy – the selective removal of mitochondria through autophagy. Evidence suggests that alteration of the PINK1 pathway contributes to the pathogenesis of PD, but the mechanisms by which the PINK1 pathway regulates mitochondrial quality control through mitophagy remain unclear. Human telomerase reverse transcriptase (hTERT) is a catalytic subunit of telomerase that functions in telomere maintenance as well as several non-telomeric activities. For example, hTERT has been associated with cellular immortalization, cell growth control, and mitochondrial regulation. We determined that hTERT negatively regulates the cleavage and cytosolic processing of PINK1 and enhances its mitochondrial localization by inhibiting mitochondrial processing peptidase β (MPPβ). Consequently, hTERT promotes mitophagy following carbonyl cyanide m-chlorophenylhydrazone (CCCP)-induced mitochondrial dysfunction and improves the function of damaged mitochondria by modulating PINK1. These findings suggest that hTERT positively regulates PINK1 function, leading to increased mitophagy following mitochondrial damage.
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10
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Lv X, Wang X, Wang Y, Zhou D, Li W, Wilson JX, Chang H, Huang G. Folic acid delays age-related cognitive decline in senescence-accelerated mouse prone 8: alleviating telomere attrition as a potential mechanism. Aging (Albany NY) 2019; 11:10356-10373. [PMID: 31757935 PMCID: PMC6914419 DOI: 10.18632/aging.102461] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 11/08/2019] [Indexed: 02/06/2023]
Abstract
The occurrence of telomere attrition in brain may cause senescence and death of neurons, leading to cognitive decline. Folic acid (FA) has been reported to improve cognitive performance in mild cognitive impairment; however, its association with telomere remains unclear. The study aimed to investigate if alleviation of telomere attrition by FA supplementation could act as a potential mechanism to delay age-related cognitive decline in senescence-accelerated mouse prone 8 (SAMP8). Aged SAMP8 mice were assigned to four treatment groups: FAdeficient diet (FA-D) group, FA-normal diet (FA-N) group, low FA-supplemented diet (FA-L) group and high FAsupplemented diet (FA-H) group. There was also an age-matched senescence-accelerated mouse resistant 1 (SAMR1) control group (Con-R), and a young SAMP8 control group (Con-Y). The results demonstrated that FA supplementation delayed age-related cognitive decline and neurodegeneration in SAMP8 mice. Importantly, this effect could be attributed to the alleviated telomere attrition, which might be interpreted by the decreased levels of reactive oxygen species. Additionally, improved telomere integrity stimulated mitochondrial function via telomere-p53-mithondria pathway, consequently delayed neuronal degeneration. In conclusion, we demonstrate that FA supplementation delays age-related neurodegeneration and cognitive decline in SAMP8 mice, in which alleviated telomere attrition could serve as one influential factor in the process.
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Affiliation(s)
- Xin Lv
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin 300070, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on Environment, Nutrition and Public Health, Tianjin 300070, China
| | - Xinyan Wang
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin 300070, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on Environment, Nutrition and Public Health, Tianjin 300070, China
| | - Yalan Wang
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin 300070, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on Environment, Nutrition and Public Health, Tianjin 300070, China
| | - Dezheng Zhou
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin 300070, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on Environment, Nutrition and Public Health, Tianjin 300070, China
| | - Wen Li
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin 300070, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on Environment, Nutrition and Public Health, Tianjin 300070, China
| | - John X. Wilson
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY 14214, USA
| | - Hong Chang
- Department of Rehabilitation Medicine, Tianjin Medical University, Tianjin 300070, China
| | - Guowei Huang
- Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin 300070, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Center for International Collaborative Research on Environment, Nutrition and Public Health, Tianjin 300070, China
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11
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Anitha A, Thanseem I, Vasu MM, Viswambharan V, Poovathinal SA. Telomeres in neurological disorders. Adv Clin Chem 2019; 90:81-132. [PMID: 31122612 DOI: 10.1016/bs.acc.2019.01.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ever since their discovery, the telomeres and the telomerase have been topics of intensive research, first as a mechanism of cellular aging and later as an indicator of health and diseases in humans. By protecting the chromosome ends, the telomeres play a vital role in preserving the information in our genome. Telomeres shorten with age and the rate of telomere erosion provides insight into the proliferation history of cells. The pace of telomere attrition is known to increase at the onset of several pathological conditions. Telomere shortening has been emerging as a potential contributor in the pathogenesis of several neurological disorders including autism spectrum disorders (ASD), schizophrenia, Alzheimer's disease (AD), Parkinson's disease (PD) and depression. The rate of telomere attrition in the brain is slower than that of other tissues owing to the low rate of cell proliferation in brain. Telomere maintenance is crucial for the functioning of stem cells in brain. Taking together the studies on telomere attrition in various neurological disorders, an association between telomere shortening and disease status has been demonstrated in schizophrenia, AD and depression, in spite of a few negative reports. But, studies in ASD and PD have failed to produce conclusive results. The cause-effect relationship between TL and neurological disorders is yet to be elucidated. The factors responsible for telomere erosion, which have also been implicated in the pathogenesis of neurological disorders, need to be explored in detail. Telomerase activation is now being considered as a potential therapeutic strategy for neurological disorders.
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Affiliation(s)
- Ayyappan Anitha
- Institute for Communicative and Cognitive Neurosciences (ICCONS), Palakkad, Kerala, India.
| | - Ismail Thanseem
- Institute for Communicative and Cognitive Neurosciences (ICCONS), Palakkad, Kerala, India
| | - Mahesh Mundalil Vasu
- Institute for Communicative and Cognitive Neurosciences (ICCONS), Palakkad, Kerala, India
| | - Vijitha Viswambharan
- Institute for Communicative and Cognitive Neurosciences (ICCONS), Palakkad, Kerala, India
| | - Suresh A Poovathinal
- Institute for Communicative and Cognitive Neurosciences (ICCONS), Palakkad, Kerala, India
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12
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Bhattacharyya J, Mihara K, Bhattacharjee D, Mukherjee M. Telomere length as a potential biomarker of coronary artery disease. Indian J Med Res 2018; 145:730-737. [PMID: 29067974 PMCID: PMC5674542 DOI: 10.4103/0971-5916.216974] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Coronary artery disease (CAD) is a multifactorial disease whose prevalence remains unabated especially in developing countries. Both lifestyle factors and genetic predisposition contribute to this disorder. Though notable achievements have been made in the medical, interventional and surgical management of CAD, the need for its prevention is more important. Among other modalities, this calls for defining evidence-based new biomarkers, which on their own or in combination with other known biomarkers may predict the risk of CAD to enable institution of appropriate preventive strategies. In the present communication, we have discussed the usefulness of shortening of telomeres as a potential biomarker of CAD. Clinical research evidence in favour of telomere shortening in CAD is well documented in different ethnic populations of the world. Establishing a well-standardized and accurate method of evaluating telomere length is essential before its routine use in preventive cardiology.
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Affiliation(s)
- Joyeeta Bhattacharyya
- Department of Cardiac Research, Cumballa Hill Hospital & Heart Institute, Mumbai, India
| | - Keichiro Mihara
- Department of Hematology & Oncology, Research Institute for Radiation Biology & Medicine, Hiroshima University, Hiroshima, Japan
| | | | - Manjarí Mukherjee
- Department of Cardiac Research, Cumballa Hill Hospital & Heart Institute, Mumbai, India
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13
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Liu MY, Nemes A, Zhou QG. The Emerging Roles for Telomerase in the Central Nervous System. Front Mol Neurosci 2018; 11:160. [PMID: 29867352 PMCID: PMC5964194 DOI: 10.3389/fnmol.2018.00160] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 04/26/2018] [Indexed: 12/11/2022] Open
Abstract
Telomerase, a specialized ribonucleoprotein enzyme complex, maintains telomere length at the 3′ end of chromosomes, and functions importantly in stem cells, cancer and aging. Telomerase exists in neural stem cells (NSCs) and neural progenitor cells (NPCs), at a high level in the developing and adult brains of humans and rodents. Increasing studies have demonstrated that telomerase in NSCs/NPCs plays important roles in cell proliferation, neuronal differentiation, neuronal survival and neuritogenesis. In addition, recent works have shown that telomerase reverse transcriptase (TERT) can protect newborn neurons from apoptosis and excitotoxicity. However, to date, the link between telomerase and diseases in the central nervous system (CNS) is not well reviewed. Here, we analyze the evidence and summarize the important roles of telomerase in the CNS. Understanding the roles of telomerase in the nervous system is not only important to gain further insight into the process of the neural cell life cycle but would also provide novel therapeutic applications in CNS diseases such as neurodegenerative condition, mood disorders, aging and other ailments.
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Affiliation(s)
- Meng-Ying Liu
- Department of Clinical Pharmacology, Pharmacy College, Nanjing Medical University, Nanjing, China.,The Affiliated Hospital of Nanjing University Medical School, Nanjing Drum Tower Hospital, Nanjing, China
| | - Ashley Nemes
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Qi-Gang Zhou
- Department of Clinical Pharmacology, Pharmacy College, Nanjing Medical University, Nanjing, China.,Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
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14
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Thanseem I, Viswambharan V, Poovathinal SA, Anitha A. Is telomere length a biomarker of neurological disorders? Biomark Med 2017; 11:799-810. [PMID: 30669856 DOI: 10.2217/bmm-2017-0032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Telomeres are DNA-protein complexes that form protective caps at the termini of chromosomes, maintaining genomic stability. In this review, we provide a comprehensive overview on the usefulness of telomere length (TL) as biomarkers of neurological disorders. The implications of TL in relation to cognitive ability, cognitive aging and cognitive decline in neurodegenerative disorders are also briefly discussed. Our review suggests that at present it is difficult to draw a reliable conclusion regarding the contribution of TL to neurological disorders. Further, it needs to be examined whether leukocyte TL, which is generally considered as a surrogate marker of TL in other tissues, serves as an indicator of central nervous system TL.
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Affiliation(s)
- Ismail Thanseem
- Department of Neurogenetics, Institute for Communicative & Cognitive Neurosciences (ICCONS), Shoranur, Palakkad 679 523, Kerala, India
| | - Vijitha Viswambharan
- Department of Neurogenetics, Institute for Communicative & Cognitive Neurosciences (ICCONS), Shoranur, Palakkad 679 523, Kerala, India
| | - Suresh A Poovathinal
- Department of Neurology, Institute for Communicative & Cognitive Neurosciences (ICCONS), Shoranur, Palakkad 679 523, Kerala, India
| | - Ayyappan Anitha
- Department of Neurogenetics, Institute for Communicative & Cognitive Neurosciences (ICCONS), Shoranur, Palakkad 679 523, Kerala, India
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15
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Lobanova A, She R, Pieraut S, Clapp C, Maximov A, Denchi EL. Different requirements of functional telomeres in neural stem cells and terminally differentiated neurons. Genes Dev 2017; 31:639-647. [PMID: 28428263 PMCID: PMC5411705 DOI: 10.1101/gad.295402.116] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/16/2017] [Indexed: 11/30/2022]
Abstract
Here, Lobanova et al. examine the roles of telomeres at distinct stages of murine brain development by using lineage-specific genetic ablation of TRF2, an essential component of the shelterin complex that protects chromosome ends from the DNA damage response machinery. These results suggest that telomeres are dispensable in terminally differentiated neurons and provide mechanistic insight into cognitive abnormalities associated with aberrant telomere length in humans. Telomeres have been studied extensively in peripheral tissues, but their relevance in the nervous system remains poorly understood. Here, we examine the roles of telomeres at distinct stages of murine brain development by using lineage-specific genetic ablation of TRF2, an essential component of the shelterin complex that protects chromosome ends from the DNA damage response machinery. We found that functional telomeres are required for embryonic and adult neurogenesis, but their uncapping has surprisingly no detectable consequences on terminally differentiated neurons. Conditional knockout of TRF2 in post-mitotic immature neurons had virtually no detectable effect on circuit assembly, neuronal gene expression, and the behavior of adult animals despite triggering massive end-to-end chromosome fusions across the brain. These results suggest that telomeres are dispensable in terminally differentiated neurons and provide mechanistic insight into cognitive abnormalities associated with aberrant telomere length in humans.
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Affiliation(s)
- Anastasia Lobanova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Robert She
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Simon Pieraut
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Charlie Clapp
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Anton Maximov
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Eros Lazzerini Denchi
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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16
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Zhao FY, Qu Y, Zhang L, Huang L, Liu HT, Li J, Mu DZ. [The neuroprotective role of exogenous TERT gene in neonatal rats with hypoxic-ischemic brain damage]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2016; 18:1296-1301. [PMID: 27974126 PMCID: PMC7403081 DOI: 10.7499/j.issn.1008-8830.2016.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/18/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To study the effect of telomerase reverse transcriptase (TERT) on cell apoptosis in neonatal rat brains after hypoxic-ischemic brain injury (HIBD). METHODS A total of 72 neonatal rats were divided into sham, vehicle, HIBD and TERT groups. HIBD was induced by Rice method in the later three groups. The neonatal rats in the vehicle and TERT groups were injected with plasmids containing mock or full length TERT by an intracerebroventricular injection 30 minutes after hypoxic-ischemic (HI) injury. Pathological changes of brain tissue were observed by hematoxylin and eosin (HE) staining. Western blot was used to detect the protein expression of TERT, apoptosis-inducing factor (AIF) and cleaved caspase 3 (CC3). Apoptotic cells were detected by TUNEL staining. RESULTS Western blot showed that TERT protein was dramatically increased in the vehicle, HIBD and TERT groups compared with the sham group. Compared with the vehicle and HIBD groups, TERT protein in the TERT group was significantly upregulated. Compared with the sham group, there was a significant increase in apoptotic index and expression of AIF and CC3 proteins in the vehicle and HIBD groups (p<0.01). The TERT group showed decreased expression of AIF and CC3 proteins and apoptotic index compared with the vehicle and HIBD groups (p<0.01). CONCLUSIONS TERT can inhibit cell apoptosis induced by HI and might have a neuroprotective role in developing brain with HIBD.
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Affiliation(s)
- Feng-Yan Zhao
- Department of Pediatrics, West China Second Hospital, Sichuan University/Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Chengdu 610041, China.
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17
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Miwa S, Czapiewski R, Wan T, Bell A, Hill KN, von Zglinicki T, Saretzki G. Decreased mTOR signalling reduces mitochondrial ROS in brain via accumulation of the telomerase protein TERT within mitochondria. Aging (Albany NY) 2016; 8:2551-2567. [PMID: 27777385 PMCID: PMC5115906 DOI: 10.18632/aging.101089] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/02/2016] [Indexed: 01/11/2023]
Abstract
Telomerase in its canonical function maintains telomeres in dividing cells. In addition, the telomerase protein TERT has non-telomeric functions such as shuttling to mitochondria resulting in a decreased oxidative stress, DNA damage and apoptosis. TERT protein persists in adult neurons and can co-localise to mitochondria under various stress conditions. We show here that TERT expression decreased in mouse brain during aging while release of reactive oxygen species (ROS) from the mitochondrial electron transport chain increased. Dietary restriction (DR) caused accumulation of TERT protein in mouse brain mitochondria correlating to decreased ROS release and improved learning and spatial short-term memory. Decreased mTOR signalling is a mediator of DR. Accordingly, feeding mice with rapamycin increased brain mitochondrial TERT and reduced ROS release. Importantly, the beneficial effects of rapamycin on mitochondrial function were absent in brains and fibroblasts from first generation TERT -/- mice, and when TERT shuttling was inhibited by the Src kinase inhibitor bosutinib. Taken together, our data suggests that the mTOR signalling pathway impinges on the mitochondrial localisation of TERT protein, which might in turn contribute to the protection of the brain by DR or rapamycin against age-associated mitochondrial ROS increase and cognitive decline.
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Affiliation(s)
- Satomi Miwa
- Institute for Cell and Molecular Biosciences, Newcastle Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
| | - Rafal Czapiewski
- Institute for Cell and Molecular Biosciences, Newcastle Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
| | - Tengfei Wan
- Institute for Cell and Molecular Biosciences, Newcastle Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
| | - Amy Bell
- Institute for Cell and Molecular Biosciences, Newcastle Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
| | - Kirsten N. Hill
- Institute for Cell and Molecular Biosciences, Newcastle Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
| | - Thomas von Zglinicki
- Institute for Cell and Molecular Biosciences, Newcastle Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
| | - Gabriele Saretzki
- Institute for Cell and Molecular Biosciences, Newcastle Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
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18
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Reactivation of Tert in the medial prefrontal cortex and hippocampus rescues aggression and depression of Tert(-/-) mice. Transl Psychiatry 2016; 6:e836. [PMID: 27300262 PMCID: PMC4931604 DOI: 10.1038/tp.2016.106] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 04/19/2016] [Accepted: 04/24/2016] [Indexed: 12/25/2022] Open
Abstract
The role of telomerase reverse transcriptase (TERT) has been extensively investigated in the contexts of aging and cancer. Interestingly, Tert(-/-) mice exhibit additional but unexpected aggressive and depressive behaviors, implying the potential involvement of TERT function in mood control. Our conditional rescue experiments revealed that the depressive and aggressive behaviors of Tert(-/-) mice originate from Tert deficiency in two distinct brain structures. Reactivation of Tert in the hippocampus was sufficient to normalize the depressive but not the aggressive behaviors of Tert(-/-) mice. Conversely, re-expression of Tert in the medial prefrontal cortex (mPFC) reversed the aggressive but not the depressive behavior of Tert(-/-) mice. Mechanistically, decreased serotonergic signaling and increased nitric oxide (NO) transmission in the hippocampus transduced Tert deficiency into depression as evidenced by our observation that the infusion of a pharmacological agonist for serotonin receptor 1a (5-HTR1A) and a selective antagonist for neuronal NO synthase into the hippocampus successfully normalized the depressive behavior of Tert(-/-) mice. In addition, increased serotonergic transmission by the 5-HTR1A agonist in the mPFC was sufficient to rescue the aggressive behavior of Tert(-/-) mice. Thus, our studies revealed a novel function of TERT in the pathology of depression and aggression in a brain structure-specific manner, providing direct evidence for the contribution of TERT to emotional control.
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19
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Zhang J, Rane G, Dai X, Shanmugam MK, Arfuso F, Samy RP, Lai MKP, Kappei D, Kumar AP, Sethi G. Ageing and the telomere connection: An intimate relationship with inflammation. Ageing Res Rev 2016; 25:55-69. [PMID: 26616852 DOI: 10.1016/j.arr.2015.11.006] [Citation(s) in RCA: 251] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 12/19/2022]
Abstract
Telomeres are the heterochromatic repeat regions at the ends of eukaryotic chromosomes, whose length is considered to be a determinant of biological ageing. Normal ageing itself is associated with telomere shortening. Here, critically short telomeres trigger senescence and eventually cell death. This shortening rate may be further increased by inflammation and oxidative stress and thus affect the ageing process. Apart from shortened or dysfunctional telomeres, cells undergoing senescence are also associated with hyperactivity of the transcription factor NF-κB and overexpression of inflammatory cytokines such as TNF-α, IL-6, and IFN-γ in circulating macrophages. Interestingly, telomerase, a reverse transcriptase that elongates telomeres, is involved in modulating NF-κB activity. Furthermore, inflammation and oxidative stress are implicated as pre-disease mechanisms for chronic diseases of ageing such as neurodegenerative diseases, cardiovascular disease, and cancer. To date, inflammation and telomere shortening have mostly been studied individually in terms of ageing and the associated disease phenotype. However, the interdependent nature of the two demands a more synergistic approach in understanding the ageing process itself and for developing new therapeutic approaches. In this review, we aim to summarize the intricate association between the various inflammatory molecules and telomeres that together contribute to the ageing process and related diseases.
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20
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A prospective study of leukocyte telomere length and risk of phobic anxiety among women. Psychiatry Res 2015; 230:545-52. [PMID: 26603336 PMCID: PMC4767547 DOI: 10.1016/j.psychres.2015.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 08/14/2015] [Accepted: 10/01/2015] [Indexed: 12/24/2022]
Abstract
We prospectively examined the relation of relative telomere lengths (RTLs), a marker of biological aging, to phobic anxiety in later-life. RTLs in peripheral blood leukocytes were measured among 3194 women in the Nurses' Health Study who provided blood samples in 1989/90. The Crown-Crisp Phobic Index (CCI, range=0–16) was assessed in 1988 and 2004. Only participants with CCI≤3 (consistent with no meaningful anxiety symptoms) in 1988 were included. We related baseline RTLs to odds ratios (ORs) of incident high phobic anxiety symptoms (CCI≥6). To enhance clinical relevance, we used finite mixture modeling (FMM) to relate baseline RTLs to latent classes of CCI in 2004. RTLs were not significantly associated with high phobic anxiety symptoms after 16 years of follow-up. However, FMM identified 3 groups of phobic symptoms in later-life: severe, minimal/intermediate, and non-anxious. The severe group had non-significantly shorter multivariable-adjusted mean RTLs than the minimal/intermediate and non-anxious groups. Women with shorter telomeres vs. longest telomeres had non-significantly higher likelihood of being in the severe vs. non-anxious group. Overall, there was no significant association between RTLs and incident phobic anxiety symptoms. Further work is required to explore potential connections of telomere length and emergence of severe phobic anxiety symptoms during later-life.
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21
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Abstract
DNA damage is correlated with and may drive the ageing process. Neurons in the brain are postmitotic and are excluded from many forms of DNA repair; therefore, neurons are vulnerable to various neurodegenerative diseases. The challenges facing the field are to understand how and when neuronal DNA damage accumulates, how this loss of genomic integrity might serve as a 'time keeper' of nerve cell ageing and why this process manifests itself as different diseases in different individuals.
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Affiliation(s)
- Hei-man Chow
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.,Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Karl Herrup
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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22
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Boccardi V, Pelini L, Ercolani S, Ruggiero C, Mecocci P. From cellular senescence to Alzheimer's disease: The role of telomere shortening. Ageing Res Rev 2015; 22:1-8. [PMID: 25896211 DOI: 10.1016/j.arr.2015.04.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 11/17/2022]
Abstract
The old age population is increasing worldwide as well as age related diseases, including neurodegenerative disorders, such as Alzheimer's disease (AD), which negatively impacts on the health care systems. Aging represents per se a risk factor for AD. Thus, the study and identification of pathways within the biology of aging represent an important end point for the development of novel and effective disease-modifying drugs to treat, delay, or prevent AD. Cellular senescence and telomere shortening represent suitable and promising targets. Several studies show that cellular senescence is tightly interconnected to aging and AD, while the role of telomere dynamic and stability in AD pathogenesis is still unclear. This review will focus on the linking mechanisms between cellular senescence, telomere shortening, and AD.
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Affiliation(s)
- Virginia Boccardi
- Institute of Gerontology and Geriatrics, Department of Medicine, University of Perugia, Perugia, Italy.
| | - Luca Pelini
- Institute of Gerontology and Geriatrics, Department of Medicine, University of Perugia, Perugia, Italy
| | - Sara Ercolani
- Institute of Gerontology and Geriatrics, Department of Medicine, University of Perugia, Perugia, Italy
| | - Carmelinda Ruggiero
- Institute of Gerontology and Geriatrics, Department of Medicine, University of Perugia, Perugia, Italy
| | - Patrizia Mecocci
- Institute of Gerontology and Geriatrics, Department of Medicine, University of Perugia, Perugia, Italy
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23
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SPECK-HERNÁNDEZ CÉSARA, OJEDA DIEGOA, CASTRO-VEGA LUISJ, FORERO DIEGOA. Relative telomere length is associated with a functional polymorphism in the monoamine oxidase A gene in a South American sample. J Genet 2015; 94:305-8. [DOI: 10.1007/s12041-015-0513-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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Wolkowitz OM, Mellon SH, Lindqvist D, Epel ES, Blackburn EH, Lin J, Reus VI, Burke H, Rosser R, Mahan L, Mackin S, Yang T, Weiner M, Mueller S. PBMC telomerase activity, but not leukocyte telomere length, correlates with hippocampal volume in major depression. Psychiatry Res 2015; 232:58-64. [PMID: 25773002 PMCID: PMC4404215 DOI: 10.1016/j.pscychresns.2015.01.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 12/02/2014] [Accepted: 01/09/2015] [Indexed: 11/29/2022]
Abstract
Accelerated cell aging, indexed in peripheral leukocytes by telomere shortness and in peripheral blood mononuclear cells (PBMCs) by telomerase activity, has been reported in several studies of major depressive disorder (MDD). However, the relevance of these peripheral measures for brain indices that are presumably more directly related to MDD pathophysiology is unknown. In this study, we explored the relationship between PBMC telomerase activity and leukocyte telomere length and magnetic resonance imaging-estimated hippocampal volume in un-medicated depressed individuals and healthy controls. We predicted that, to the extent peripheral and central telomerase activity are directly related, PBMC telomerase activity would be positively correlated with hippocampal volume, perhaps due to hippocampal telomerase-associated neurogenesis, neuroprotection or neurotrophic facilitation, and that this effect would be clearer in individuals with increased PBMC telomerase activity, as previously reported in un-medicated MDD. We did not have specific hypotheses regarding the relationship between leukocyte telomere length and hippocampal volume, due to conflicting reports in the published literature. We found, in 25 un-medicated MDD subjects, that PBMC telomerase activity was significantly positively correlated with hippocampal volume; this relationship was not observed in 18 healthy controls. Leukocyte telomere length was not significantly related to hippocampal volume in either group (19 unmedicated MDD subjects and 17 healthy controls). Although the nature of the relationship between peripheral telomerase activity and telomere length and the hippocampus is unclear, these preliminary data are consistent with the possibility that PBMC telomerase activity indexes, and may provide a novel window into, hippocampal neuroprotection and/or neurogenesis in MDD.
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Affiliation(s)
- Owen M. Wolkowitz
- Department of Psychiatry, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
,Corresponding author: Dept. of Psychiatry, UCSF School of Medicine, 401 Parnassus Ave., San Francisco, CA 94143-0983, USA. Tel.: +1 (415) 476-7433; Fax: +1 (415) 502-2661;
| | - Synthia H. Mellon
- Department of OBGYN and Reproductive Endocrinology, UCSF School of Medicine, San Francisco, CA, USA
| | - Daniel Lindqvist
- Department of Clinical Sciences, Section for Psychiatry, Lund University, Lund, Sweden
| | - Elissa S. Epel
- Department of Psychiatry, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Elizabeth H. Blackburn
- Department of Physiology and Biochemistry, UCSF School of Medicine, San Francisco, CA, USA
| | - Jue Lin
- Department of Physiology and Biochemistry, UCSF School of Medicine, San Francisco, CA, USA
| | - Victor I. Reus
- Department of Psychiatry, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Heather Burke
- Department of Psychiatry, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Rebecca Rosser
- Department of Psychiatry, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Laura Mahan
- Department of Psychiatry, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Scott Mackin
- Department of Psychiatry, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Tony Yang
- Department of Psychiatry, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Michael Weiner
- Department of Radiology, UCSF School of Medicine, and San Francisco Veterans Administration Medical Center, San Francisco, CA, USA
| | - Susanne Mueller
- Department of Radiology, UCSF School of Medicine, and San Francisco Veterans Administration Medical Center, San Francisco, CA, USA
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The role of telomerase protein TERT in Alzheimer's disease and in tau-related pathology in vitro. J Neurosci 2015; 35:1659-74. [PMID: 25632141 DOI: 10.1523/jneurosci.2925-14.2015] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The telomerase reverse transcriptase protein TERT has recently been demonstrated to have a variety of functions both in vitro and in vivo, which are distinct from its canonical role in telomere extension. In different cellular systems, TERT protein has been shown to be protective through its interaction with mitochondria. TERT has previously been found in rodent neurons, and we hypothesize that it might have a protective function in adult human brain. Here, we investigated the expression of TERT at different stages of Alzheimer's disease pathology (Braak Stages I-VI) in situ and the ability of TERT to protect against oxidative damage in an in vitro model of tau pathology. Our data reveal that TERT is expressed in vitro in mouse neurons and microglia, and in vivo in the cytoplasm of mature human hippocampal neurons and activated microglia, but is absent from astrocytes. Intriguingly, hippocampal neurons expressing TERT did not contain hyperphosphorylated tau. Vice versa, neurons that expressed high levels of pathological tau did not appear to express TERT protein. TERT protein colocalized with mitochondria in the hippocampus of Alzheimer's disease brains (Braak Stage VI), as well as in cultured neurons under conditions of oxidative stress. Our in vitro data suggest that the absence of TERT increases ROS generation and oxidative damage in neurons induced by pathological tau. Together, our findings suggest that TERT protein persists in neurons of the adult human brain, where it may have a protective role against tau pathology.
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26
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Zhao F, Qu Y, Liu H, Du B, Mu D. Umbilical cord blood mesenchymal stem cells co-modified by TERT and BDNF: a novel neuroprotective therapy for neonatal hypoxic-ischemic brain damage. Int J Dev Neurosci 2014; 38:147-54. [PMID: 24999119 DOI: 10.1016/j.ijdevneu.2014.06.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 06/18/2014] [Accepted: 06/25/2014] [Indexed: 01/01/2023] Open
Abstract
Hypoxic-ischemic brain damage (HIBD), a leading cause of perinatal disability and death, has limited therapeutic options. Stem cell therapy has been demonstrated as a potential novel therapy for neurological disorders. Compared with other types of stem cells, umbilical cord blood mesenchymal stem cells (UCB-MSCs) have several unique characteristics, such as a higher rate of cell proliferation and clonality. However, the limited life span of UCB-MSCs hinders their clinical application. Therefore, efforts are urgently needed to circumvent this disadvantage. Telomerase reverse transcriptase (TERT), which promotes cell proliferation and survival, plays a protective role in hypoxic-ischemic (HI) brain injury. Thus, it is reasonable to propose that UCB-MSCs modified by exogenous TERT expression might have a longer lifespan and increased viability. Moreover, brain-derived neurotrophic factor (BDNF), a neurotrophin that regulates development, regeneration, survival and maintenance of neurons, facilitates post-injury recovery when administered by infusion or virus-mediated delivery. Therefore, TERT- and BDNF-modified UCB-MSCs may have a longer lifespan and also maintain neural differentiation, thus promoting the recovery of neurological function following hypoxic-ischemic brain damage (HIBD) and thereby representing a new effective strategy for HIBD in neonates.
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Affiliation(s)
- Fengyan Zhao
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China; Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Yi Qu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China; Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Haiting Liu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China; Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Baowen Du
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Dezhi Mu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China; Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu 610041, China; Department of Pediatrics and Neurology, University of California, San Francisco, CA 94143, USA.
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27
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Eitan E, Hutchison ER, Mattson MP. Telomere shortening in neurological disorders: an abundance of unanswered questions. Trends Neurosci 2014; 37:256-63. [PMID: 24698125 PMCID: PMC4008659 DOI: 10.1016/j.tins.2014.02.010] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 02/24/2014] [Accepted: 02/25/2014] [Indexed: 11/24/2022]
Abstract
Telomeres, ribonucleoprotein complexes that cap eukaryotic chromosomes, typically shorten in leukocytes with aging. Aging is a primary risk factor for neurodegenerative disease (ND), and a common assumption has arisen that leukocyte telomere length (LTL) can serve as a predictor of neurological disease. However, the evidence for shorter LTL in Alzheimer's and Parkinson's patients is inconsistent. The diverse causes of telomere shortening may explain variability in LTL between studies and individuals. Additional research is needed to determine whether neuronal and glial telomeres shorten during aging and in neurodegenerative disorders, if and how LTL is related to brain cell telomere shortening, and whether telomere shortening plays a causal role in or exacerbates neurological disorders.
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Affiliation(s)
- Erez Eitan
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, USA
| | - Emmette R Hutchison
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, USA
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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28
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Dreesen O, Ong PF, Chojnowski A, Colman A. The contrasting roles of lamin B1 in cellular aging and human disease. Nucleus 2013; 4:283-90. [PMID: 23873483 PMCID: PMC3810336 DOI: 10.4161/nucl.25808] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/16/2013] [Accepted: 07/18/2013] [Indexed: 12/17/2022] Open
Abstract
The nuclear lamina underlies the inner nuclear membrane and consists of a proteinaceous meshwork of intermediate filaments: the A- and B-type lamins. Mutations in LMNA (encoding lamin A and C) give rise to a variety of human diseases including muscular dystrophies, cardiomyopathies and the premature aging syndrome progeria (HGPS). Duplication of the LMNB1 locus, leading to elevated levels of lamin B1, causes adult-onset autosomal dominant leukodystrophy (ADLD), a rare genetic disease that leads to demyelination in the central nervous system (CNS). Conversely, reduced levels of lamin B1 have been observed in HGPS patient derived fibroblasts, as well as fibroblasts and keratinocytes undergoing replicative senescence, suggesting that the regulation of lamin B1 is important for cellular physiology and disease. However, the causal relationship between low levels of lamin B1 and cellular senescence and its relevance in vivo remain unclear. How do elevated levels of lamin B1 cause disease and why is the CNS particularly susceptible to lamin B1 fluctuations? Here we summarize recent findings as to how perturbations of lamin B1 affect cellular physiology and discuss the implications this has on senescence, HGPS and ADLD.
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Affiliation(s)
- Oliver Dreesen
- Stem Cell Disease Models; Institute of Medical Biology; Singapore, Singapore
| | - Peh Fern Ong
- Stem Cell Disease Models; Institute of Medical Biology; Singapore, Singapore
| | - Alexandre Chojnowski
- Developmental and Regenerative Biology; Institute of Medical Biology; Singapore, Singapore
| | - Alan Colman
- Stem Cell Disease Models; Institute of Medical Biology; Singapore, Singapore
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29
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Limpert AS, Mattmann ME, Cosford NDP. Recent progress in the discovery of small molecules for the treatment of amyotrophic lateral sclerosis (ALS). Beilstein J Org Chem 2013; 9:717-32. [PMID: 23766784 PMCID: PMC3678841 DOI: 10.3762/bjoc.9.82] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/07/2013] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with few therapeutic options. While several gene mutations have been implicated in ALS, the exact cause of neuronal dysfunction is unknown and motor neurons of affected individuals display numerous cellular abnormalities. Ongoing efforts to develop novel ALS treatments involve the identification of small molecules targeting specific mechanisms of neuronal pathology, including glutamate excitotoxicity, mutant protein aggregation, endoplasmic reticulum (ER) stress, loss of trophic factors, oxidative stress, or neuroinflammation. Herein, we review recent advances in the discovery and preclinical characterization of lead compounds that may ultimately provide novel drugs to treat patients suffering from ALS.
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Affiliation(s)
- Allison S Limpert
- Apoptosis and Cell Death Research Program, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Road, La Jolla, California 92037, United States
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30
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Smith JA, Park S, Krause JS, Banik NL. Oxidative stress, DNA damage, and the telomeric complex as therapeutic targets in acute neurodegeneration. Neurochem Int 2013; 62:764-75. [PMID: 23422879 DOI: 10.1016/j.neuint.2013.02.013] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 02/04/2013] [Accepted: 02/08/2013] [Indexed: 01/19/2023]
Abstract
Oxidative stress has been identified as an important contributor to neurodegeneration associated with acute CNS injuries and diseases such as spinal cord injury (SCI), traumatic brain injury (TBI), and ischemic stroke. In this review, we briefly detail the damaging effects of oxidative stress (lipid peroxidation, protein oxidation, etc.) with a particular emphasis on DNA damage. Evidence for DNA damage in acute CNS injuries is presented along with its downstream effects on neuronal viability. In particular, unchecked oxidative DNA damage initiates a series of signaling events (e.g. activation of p53 and PARP-1, cell cycle re-activation) which have been shown to promote neuronal loss following CNS injury. These findings suggest that preventing DNA damage might be an effective way to promote neuronal survival and enhance neurological recovery in these conditions. Finally, we identify the telomere and telomere-associated proteins (e.g. telomerase) as novel therapeutic targets in the treatment of neurodegeneration due to their ability to modulate the neuronal response to both oxidative stress and DNA damage.
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Affiliation(s)
- Joshua A Smith
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, 96 Jonathan Lucas St., Clinical Sciences Building Room 309, Charleston, SC 29425, USA.
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31
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Eitan E, Tichon A, Daniel G, Priel E. Telomerase expression in adult and old mouse Purkinje neurons. Rejuvenation Res 2012; 15:206-9. [PMID: 22533433 DOI: 10.1089/rej.2011.1285] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Telomerase promotes tissue regeneration by delaying the entrance of cells into senescence. Studies performed on cells or animals overexpressing telomerase reverse transcriptase (TERT), the catalytic subunit of telomerase, have revealed that TERT exhibits antiapoptotic effects in neurons. However, it is not clear whether endogenous TERT possesses these functions as well. Here we demonstrate the presence of active telomerase in the cytoplasm and nucleus of cerebellar Purkinje neurons of adult and old mice. TERT protein levels are reduced with age, whereas in the nucleus TERT activity is increased. These findings suggest that telomerase plays a role in the aging of nondividing cells.
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Affiliation(s)
- Erez Eitan
- Shraga Segal Department of Microbiology & Immunology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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32
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Alternatively spliced telomerase reverse transcriptase variants lacking telomerase activity stimulate cell proliferation. Mol Cell Biol 2012; 32:4283-96. [PMID: 22907755 DOI: 10.1128/mcb.00550-12] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eight human and six chicken novel alternatively spliced (AS) variants of telomerase reverse transcriptase (TERT) were identified, including a human variant (Δ4-13) containing an in-frame deletion which removed exons 4 through 13, encoding the catalytic domain of telomerase. This variant was expressed in telomerase-negative normal cells and tissues as well as in transformed telomerase-positive cell lines and cells which employ an alternative method to maintain telomere length. The overexpression of the Δ4-13 variant significantly elevated the proliferation rates of several cell types without enhancing telomerase activity, while decreasing the endogenous expression of this variant by use of small interfering RNA (siRNA) technology reduced cell proliferation. The expression of the Δ4-13 variant stimulated Wnt signaling. In chicken cells, AS TERT variants containing internal deletions or insertions that eliminated or reduced telomerase activity also enhanced cell proliferation. This is the first report that naturally occurring AS TERT variants which lack telomerase activity stimulate cell proliferation.
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33
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Eitan E, Tichon A, Gazit A, Gitler D, Slavin S, Priel E. Novel telomerase-increasing compound in mouse brain delays the onset of amyotrophic lateral sclerosis. EMBO Mol Med 2012; 4:313-29. [PMID: 22351600 PMCID: PMC3376858 DOI: 10.1002/emmm.201200212] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 12/22/2011] [Accepted: 01/03/2012] [Indexed: 01/12/2023] Open
Abstract
Telomerase is expressed in the neonatal brain, in distinct regions of adult brain, and was shown to protect developing neurons from apoptosis. Telomerase reactivation by gene manipulation reverses neurodegeneration in aged telomerase-deficient mice. Hence, we and others hypothesized that increasing telomerase expression by pharmaceutical compounds may protect brain cells from death caused by damaging agents. In this study, we demonstrate for the first time that the novel compound AGS-499 increases telomerase activity and expression in the mouse brain and spinal cord (SC). It exerts neuroprotective effects in NMDA-injected CD-1 mice, delays the onset and progression of the amyotrophic lateral sclerosis (ALS) disease in SOD1 transgenic mice, and, after the onset of ALS, it increases the survival of motor neurons in the SC by 60%. The survival of telomerase-expressing cells (i.e. motor neurons), but not telomerase-deficient cells, exposed to oxidative stress was increased by AGS-499 treatment, suggesting that the AGS-499 effects are telomerase-mediated. Therefore, a controlled and transient increase in telomerase expression and activity in the brain by AGS-499 may exert neuroprotective effects.
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Affiliation(s)
- Erez Eitan
- The Shraga Segal Department of Immunology and Microbiology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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34
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Encinas JM, Sierra A. Neural stem cell deforestation as the main force driving the age-related decline in adult hippocampal neurogenesis. Behav Brain Res 2012; 227:433-9. [DOI: 10.1016/j.bbr.2011.10.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Revised: 09/28/2011] [Accepted: 10/07/2011] [Indexed: 10/16/2022]
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Abstract
Telomere and telomerase alterations have been reported in mood disorders. However, the role of telomerase in depression remains unclear. Here we show that chronic mild stress (CMS) led to a significant decrease in telomerase reverse transcriptase (TERT) level and telomerase activity in the hippocampus. Treatment with antidepressant fluoxetine reversed the CMS-induced TERT and telomerase activity changes. Inhibiting telomerase by systemic administration (100 mg · kg(-1) · d(-1), i.p., for 14 d), intrahippocampal microinjection (0.7 μmol, 2 μl), or infusion (using an osmotic minipump, 0.134 μg/μl, 0.25 μl/h) of 3'-azido-deoxythymidine (AZT) resulted in depression-like behaviors and impaired hippocampal neurogenesis in mice. In contrast, overexpressing telomerase by intrahippocampal infusion of recombinant adenovirus vector expressing mouse TERT (Ad-mTERT-GFP) led to neurogenesis upregulation, produced antidepressant-like behaviors, and prevented the CMS-induced behavioral modifications. Disrupting neurogenesis in the dentate gyrus by X-irradiation (15 Gy) of a restricted region of mouse brain containing the hippocampus abolished the antidepressant-like effect of Ad-mTERT-GFP. Additionally, AZT had no effect on DNA polymerase activity and did not cause cell damage in vitro and in vivo. Microinjection of AZT into the subventricular zone of lateral ventricle (0.7 μmol, 2 μl) inhibited local neurogenesis but had no behavioral effect. These results suggest that hippocampal telomerase is involved in the modulation of depression-related behaviors, possibly by regulating adult neurogenesis.
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36
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Kaliman P, Párrizas M, Lalanza JF, Camins A, Escorihuela RM, Pallàs M. Neurophysiological and epigenetic effects of physical exercise on the aging process. Ageing Res Rev 2011; 10:475-86. [PMID: 21624506 DOI: 10.1016/j.arr.2011.05.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 04/29/2011] [Accepted: 05/13/2011] [Indexed: 10/18/2022]
Abstract
Aging is a gradual process during which molecular and cellular processes deteriorate progressively, often leading to such pathological conditions as vascular and metabolic disorders and cognitive decline. Although the mechanisms of aging are not yet fully understood, inflammation, oxidative damage, mitochondrial dysfunction, functional alterations in specific neuronal circuits and a restricted degree of apoptosis are involved. Physical exercise improves the efficiency of the capillary system and increases the oxygen supply to the brain, thus enhancing metabolic activity and oxygen intake in neurons, and increases neurotrophin levels and resistance to stress. Regular exercise and an active lifestyle during adulthood have been associated with reduced risk and protective effects for mild cognitive impairment and Alzheimer's disease. Similarly, studies in animal models show that physical activity has positive physiological and cognitive effects that correlate with changes in transcriptional profiles. According to numerous studies, epigenetic events that include changes in DNA methylation patterns, histone modification and alterations in microRNA profiles seem to be a signature of aging. Hence, insight into the epigenetic mechanisms involved in the aging process and their modulation through lifestyle interventions such as physical exercise might open new avenues for the development of preventive and therapeutic strategies to treat aging-related diseases.
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37
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Li J, Tang B, Qu Y, Mu D. Telomerase reverse transcriptase: A novel neuroprotective mechanism involved in neonatal hypoxic‐ischemic brain injury. Int J Dev Neurosci 2011; 29:867-72. [DOI: 10.1016/j.ijdevneu.2011.07.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2011] [Revised: 07/26/2011] [Accepted: 07/26/2011] [Indexed: 01/16/2023] Open
Affiliation(s)
- Jiao Li
- Department of PediatricsWest China Second University HospitalSichuan UniversityChengduSichuan ProvinceChina
| | - Binzhi Tang
- Department of PediatricsWest China Second University HospitalSichuan UniversityChengduSichuan ProvinceChina
| | - Yi Qu
- Department of PediatricsWest China Second University HospitalSichuan UniversityChengduSichuan ProvinceChina
| | - Dezhi Mu
- Department of PediatricsWest China Second University HospitalSichuan UniversityChengduSichuan ProvinceChina
- Department of NeurologyUniversity of CaliforniaSan FranciscoCA94143USA
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38
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Physical exercise increases adult neurogenesis and telomerase activity, and improves behavioral deficits in a mouse model of schizophrenia. Brain Behav Immun 2011; 25:971-80. [PMID: 20970493 DOI: 10.1016/j.bbi.2010.10.014] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 10/07/2010] [Accepted: 10/18/2010] [Indexed: 12/13/2022] Open
Abstract
Epidemiological studies indicate that among other early life challenges, maternal infection with influenza during pregnancy increased the risk of developing schizophrenia in the child. One morphological manifestation of schizophrenia is hippocampal atrophy. In the hippocampus, playing a key role in learning and memory formation, new granule cell neurons are produced throughout life from resident precursor cells. We hypothesize that individuals exposed to a maternal anti-viral immune response would presumably enter life with a challenged neural precursor cell pool and might later be susceptible to psychiatric pathologies due to reduced adult neurogenesis. We used the injection of double-stranded RNA (polyriboinosinicpolyribocytidylic acid - PolyI:C) in pregnant C57Bl/6 and nestin-GFP reporter mice to induce a maternal viral-like infection and schizophrenia-like behavior in the offspring. In the progeny we found impairments in the open field test and in sensorimotor gating as measured by pre-pulse inhibition of the startle response. The behavioral deficits were accompanied by reduced baseline adult hippocampal neurogenesis. Telomerase activity in neural precursor cells was reduced from birth on and telomere shortening was found in the same cell type in adult life. When we subjected the progeny of viral-like infected dams to voluntary exercise, a known stimulus of adult hippocampal neurogenesis, we could rescue the phenotype in behavior, adult neurogenesis, and cellular senescence. In summary, maternal viral-like immune response reduced telomerase activity and resulted in telomere shortening in neural precursor cells. Further we demonstrate that beneficial behavioral and cellular effects induced by exercise can be studied in a rodent model of schizophrenia.
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39
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Majerská J, Sýkorová E, Fajkus J. Non-telomeric activities of telomerase. MOLECULAR BIOSYSTEMS 2011; 7:1013-23. [DOI: 10.1039/c0mb00268b] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Jaskelioff M, Muller FL, Paik JH, Thomas E, Jiang S, Adams AC, Sahin E, Kost-Alimova M, Protopopov A, Cadiñanos J, Horner JW, Maratos-Flier E, Depinho RA. Telomerase reactivation reverses tissue degeneration in aged telomerase-deficient mice. Nature 2010; 469:102-6. [PMID: 21113150 PMCID: PMC3057569 DOI: 10.1038/nature09603] [Citation(s) in RCA: 546] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Accepted: 10/26/2010] [Indexed: 12/15/2022]
Abstract
An ageing world population has fuelled interest in regenerative remedies that may stem declining organ function and maintain fitness. Unanswered is whether elimination of intrinsic instigators driving age-associated degeneration can reverse, as opposed to simply arrest, various afflictions of the aged. Such instigators include progressively damaged genomes. Telomerase-deficient mice have served as a model system to study the adverse cellular and organismal consequences of wide-spread endogenous DNA damage signalling activation in vivo. Telomere loss and uncapping provokes progressive tissue atrophy, stem cell depletion, organ system failure and impaired tissue injury responses. Here, we sought to determine whether entrenched multi-system degeneration in adult mice with severe telomere dysfunction can be halted or possibly reversed by reactivation of endogenous telomerase activity. To this end, we engineered a knock-in allele encoding a 4-hydroxytamoxifen (4-OHT)-inducible telomerase reverse transcriptase-oestrogen receptor (TERT-ER) under transcriptional control of the endogenous TERT promoter. Homozygous TERT-ER mice have short dysfunctional telomeres and sustain increased DNA damage signalling and classical degenerative phenotypes upon successive generational matings and advancing age. Telomerase reactivation in such late generation TERT-ER mice extends telomeres, reduces DNA damage signalling and associated cellular checkpoint responses, allows resumption of proliferation in quiescent cultures, and eliminates degenerative phenotypes across multiple organs including testes, spleens and intestines. Notably, somatic telomerase reactivation reversed neurodegeneration with restoration of proliferating Sox2(+) neural progenitors, Dcx(+) newborn neurons, and Olig2(+) oligodendrocyte populations. Consistent with the integral role of subventricular zone neural progenitors in generation and maintenance of olfactory bulb interneurons, this wave of telomerase-dependent neurogenesis resulted in alleviation of hyposmia and recovery of innate olfactory avoidance responses. Accumulating evidence implicating telomere damage as a driver of age-associated organ decline and disease risk and the marked reversal of systemic degenerative phenotypes in adult mice observed here support the development of regenerative strategies designed to restore telomere integrity.
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Affiliation(s)
- Mariela Jaskelioff
- Belfer Institute for Applied Cancer Science and Departments of Medical Oncology, Medicine and Genetics, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
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