1
|
Cheng R, Bai X, Guo J, Huang L, Zhao D, Liu Z, Zhang W. Hyperspectral discrimination of ginseng variety and age from Changbai Mountain area. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 307:123613. [PMID: 37976570 DOI: 10.1016/j.saa.2023.123613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/12/2023] [Accepted: 11/01/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND The efficacy and market value of Panax ginseng Meyer are significantly influenced by its diversity and age. Traditional identification methods are prone to subjective biases and necessitate the use of destructive sample processing, leading to the loss and wastage of ginseng. Consequently, non-destructive in-situ identification has emerged as a crucial subject of interest for both researchers and the ginseng industry. The advancement of technology and the expansion of research have introduced spectral technology and image processing technology as novel approaches and concepts for non-destructive in-situ identification. METHODS Hyperspectral imaging (HSI) is a methodology that combines conventional spectroscopy and imaging to acquire comprehensive spectral and spatial data from various samples. In this study, we investigated the use of Support Vector Machine (SVM) and Spectral Angle Mapper (SAM) classifier algorithms, in conjunction with HSI classification technology, for quasi-Artificial Intelligence (quasi-AI) ginseng identification. To enhance the hyperspectral images prior to SVM classification, we compared the efficacy of Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), and Independent Component Analysis (ICA). RESULTS The classification of ginseng based on age was accomplished through the utilization of Radial Basis Function (RBF) kernel SVM and SAM algorithm, which was trained on feature enhanced images. The classification of WMG, MCG, and GG is primarily based on age, with the endmember spectrum serving as the foundation for SAM and SVM. CONCLUSION The "endmember spectrum set" derived from the classification outcomes can serve as the "mutation point" for identifying ginseng of different ages.
Collapse
Affiliation(s)
- Ruiyang Cheng
- Northeast Asia Research Institute of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Xueyuan Bai
- Northeast Asia Research Institute of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Jianying Guo
- Northeast Asia Research Institute of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Luqi Huang
- Northeast Asia Research Institute of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Daqing Zhao
- Northeast Asia Research Institute of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Zhaojian Liu
- Department of Cell Biology, School of Basic Medical Science, Shandong University, Jinan, China.
| | - Wei Zhang
- Northeast Asia Research Institute of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China.
| |
Collapse
|
2
|
The hTERT-p50 homodimer inhibits PLEKHA7 expression to promote gastric cancer invasion and metastasis. Oncogene 2023; 42:1144-1156. [PMID: 36823376 PMCID: PMC10063444 DOI: 10.1038/s41388-023-02630-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 02/06/2023] [Accepted: 02/09/2023] [Indexed: 02/25/2023]
Abstract
Although accumulating evidence has highlighted the molecular mechanisms by which hTERT promotes tumour cell invasion and metastasis, the molecular mechanisms of the properties enabling hTERT to contribute to invasion and metastasis have not been clearly illustrated. Here, we report that hTERT promotes gastric cancer invasion and metastasis by recruiting p50 to synergistically inhibit PLEKHA7 expression. We observed that the expression of PLEKHA7 in gastric cancer was significantly negatively associated with the TNM stage and lymphatic metastasis and that decreased PLEKHA7 expression dramatically increased invasion and metastasis in gastric cancer cells. Further mechanistic research showed that hTERT directly regulates PLEKHA7 expression by binding p50 and recruiting the hTERT/p50 complex to the PLEKHA7 promoter. Increased hTERT dramatically decreased PLEKHA7 expression and promoted invasion and metastasis in gastric cancer cells. The hTERT-mediated invasion/metastasis properties at least partially depended on PLEKHA7. Our work uncovers a novel molecular mechanism underlying invasion/metastasis in gastric cancer orchestrated by hTERT and p50.
Collapse
|
3
|
Passos JDC, Felisbino K, Laureano HA, Guiloski IC. Occupational exposure to pesticides and its association with telomere length - A systematic review and meta-analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 849:157715. [PMID: 35914599 DOI: 10.1016/j.scitotenv.2022.157715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/19/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Telomere length is a common biomarker for the cumulative effect of environmental factors on aging-related diseases, therefore an association has been hypothesized between occupational exposure to pesticides and shorter telomere length. OBJECTIVE This study is a systematic review and meta-analysis aiming to examine the association between telomere length and occupational exposure to pesticides. METHODS We systematically searched in SciELO, PubMed, Scopus, Embase, Cochrane, Lilacs, Science Direct, and Web of Science databases for all observational studies containing measurements of telomere length on groups occupationally exposed to pesticides. Data were synthesized through qualitative synthesis and meta-analysis. We estimated the associations between exposed and non-exposed groups by using the natural log of the response ratio (lnRR). Heterogeneity was quantified using the Cochran Q test and I2 statistics. RESULTS Six studies were included in the qualitative synthesis and meta-analysis, with a total of 480 participants exposed to pesticides. The time of exposure evaluated 391 participants that had a range of 5 to >30 years of occupational exposure. Most studies presented shorter telomere length in the occupationally exposed group. From the six studies included in the meta-analysis, three presented telomere length measurement as a single copy gene (T/S), and three presented telomere length measurement as base pairs (bp). The statistical analysis pooled estimates (log ratio of means) of the telomere length in both measurements (T/S and bp) showed a shortening of telomere length in the exposed group when compared with the non-exposed (control) group. Two of six studies reported longer telomere length in the group exposed to pesticides. DISCUSSION Our findings suggest an association between occupational exposure to pesticides and shorter telomere length. However, we found a small number of studies to include in our meta-analysis, being required more high-quality studies to strengthen our findings and conclusions.
Collapse
Affiliation(s)
- Jaqueline Dal Curtivo Passos
- Faculdades Pequeno Príncipe, Curitiba, Paraná, Brazil; Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Paraná, Brazil.
| | - Karoline Felisbino
- Faculdades Pequeno Príncipe, Curitiba, Paraná, Brazil; Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Paraná, Brazil
| | | | - Izonete Cristina Guiloski
- Faculdades Pequeno Príncipe, Curitiba, Paraná, Brazil; Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Paraná, Brazil
| |
Collapse
|
4
|
Hu Q, Xie N, Liao K, Huang J, Yang Q, Zhou Y, Liu Y, Deng K. An injectable thermosensitive Pluronic F127/hyaluronic acid hydrogel loaded with human umbilical cord mesenchymal stem cells and asiaticoside microspheres for uterine scar repair. Int J Biol Macromol 2022; 219:96-108. [PMID: 35902020 DOI: 10.1016/j.ijbiomac.2022.07.161] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 07/16/2022] [Accepted: 07/20/2022] [Indexed: 11/15/2022]
Abstract
Uterine scar was one of the long-term complications cesarean section. In this study, an thermo-responsive injectable hydrogel loaded with human umbilical cord mesenchymal stem cells (UCMSCs) and asiaticoside microspheres (AMs) was used for uterine scar repair, which was prepared by optimizing the mixed ratio of aldehyde-functionalized Pluronic F127 (F127-CHO) and adipic dihydrazide-modified hyaluronic acid (AHA). The asiaticoside was loaded in Poly (DL-lactide-co-gycolide) (PLGA) by emulsion- diffusion-evaporation method. The hydrogel had appropriate pore size, good mechanical property, and slow release ability of asiaticoside. In vitro cell experiments demonstrated that F127-CHO/AHA/AMs could effectively promote stem cell adhesion and proliferation, promote angiogenesis, and provide a suitable microenvironment for cell survival. The F127-CHO/AHA/AMs/UCMSCs hydrogel was further used to repair uterine scar in female SD rats. The results showed that the prepared hydrogel could promote the proliferation of rat endometrial cells, promote the regeneration of glands, reduce the degree of endometrial fibrosis and restore the morphology of uterine cavity. The hydrogel could upregulate expression of Ki67 and IGF-1, downregulate TGF-β1 expression and promote M1-M2 transition of macrophages. This study confirmed that the prepared hydrogel could be used as an effective transplantation strategy, which could be expected to achieve clinical transformation of uterine scar repair.
Collapse
Affiliation(s)
- Qinqin Hu
- Department of Gynecology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, Guangdong 528308, China
| | - Ning Xie
- Department of Gynecology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, Guangdong 528308, China
| | - Kedan Liao
- Department of Gynecology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, Guangdong 528308, China
| | - Jinfa Huang
- Department of Gynecology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, Guangdong 528308, China
| | - Qian Yang
- Department of Gynecology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, Guangdong 528308, China
| | - Yuan Zhou
- Department of Gynecology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, Guangdong 528308, China
| | - Yixuan Liu
- Department of Gynecology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, Guangdong 528308, China
| | - Kaixian Deng
- Department of Gynecology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), Foshan, Guangdong 528308, China.
| |
Collapse
|
5
|
Bazaz MR, Balasubramanian R, Monroy-Jaramillo N, Dandekar MP. Linking the Triad of Telomere Length, Inflammation, and Gut Dysbiosis in the Manifestation of Depression. ACS Chem Neurosci 2021; 12:3516-3526. [PMID: 34547897 DOI: 10.1021/acschemneuro.1c00457] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Telomere length is an indispensable marker for cellular and biological aging, and it also represents an individual's physical and mental health status. Telomere shortening has been observed in chronic inflammatory conditions, which in turn accelerates aging and risk for psychiatric disorders, including depression. Considering the influence of inflammation and telomere shortening on the gut-brain axis, herein we describe a plausible interplay between telomere attrition, inflammation, and gut dysbiosis in the neurobiology of depression. Telomere shortening and hyperinflammation are well reported in depression. A negative impact of augmented inflammation has been noted on the intestinal permeability and microbial consortia and their byproducts in depressive patients. Moreover, gut dysbiosis provokes host-immune responses. As the gut microbiome is gaining importance in the manifestation and management of depression, herein we discuss whether telomere attrition is connected with the perturbation of commensal microflora. We also describe a pathological connection of cortisol with hyperinflammation, telomere shortening, and gut dysbiosis occurring in depression. This review summarizes how the triad of telomere attrition, inflammation, and gut dysbiosis is interconnected and modulates the risk for depression by regulating the systemic cortisol levels.
Collapse
Affiliation(s)
- Mohd Rabi Bazaz
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, India, 500037
| | - Ramya Balasubramanian
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, India, 500037
| | - Nancy Monroy-Jaramillo
- Department of Genetics, National Institute of Neurology and Neurosurgery Manuel Velasco Suárez (NINN), Mexico City, Mexico, 14269
| | - Manoj P. Dandekar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, India, 500037
| |
Collapse
|
6
|
Hooshmand-Moghadam B, Eskandari M, Golestani F, Rezae S, Mahmoudi N, Gaeini AA. The effect of 12-week resistance exercise training on serum levels of cellular aging process parameters in elderly men. Exp Gerontol 2020; 141:111090. [PMID: 32919015 DOI: 10.1016/j.exger.2020.111090] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/04/2020] [Accepted: 09/04/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Regular physical activity has a positive effect on the prevention of cellular aging. The present study investigated the effect of 12-week resistance training (RT) on serum levels of Sirtuin-1 (SIRT1), Sirtuin-3 (SIRT3), Sirtuin-6 (SIRT6), Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α), and telomerase enzyme in elderly men. METHODS For this purpose, 30 elderly men (age 66.23 ± 0.57 years) were randomly divided into two groups: resistance training group (RET, n = 15) and control group (CTR, n = 15). Participants in RET performed RT protocols with intensity of 60% one-repetition maximum (3×/week, 4 sets of the six exercise circuits). Body composition, physical functioning and, blood samples were assessed before (pre-test) and after (post-test) a 12-week intervention. RESULTS The results showed that there was a significant increase in serum levels of SIRT1 (P = 0.001), SIRT3 (P = 0.001), SIRT6 (P = 0.02), PGC1-α (P = 0.001), and telomerase enzyme (P = 0.001) in RET. Also, we found a significant difference between the RET and CTR in serum levels of SIRT1 (P = 0.001), SIRT3 (P = 0.001), SIRT6 (P = 0.037), PGC1-α (P = 0.007), and telomerase enzyme (P = 0.001). CONCLUSIONS 12-Week RT increased the levels of proteins associated with the biological aging process in elderly men. It seems that the RT may have beneficial effects on cellular senescence and also improved impaired mitochondrial protein and enzymatic functional induced aging.
Collapse
Affiliation(s)
- Babak Hooshmand-Moghadam
- Department of Exercise Physiology, Ferdowsi University of Mashhad, Mashhad, Iran; Department of Exercise Physiology, University of Tehran, Tehran, Iran
| | - Mozhgan Eskandari
- Department of Exercise Physiology, University of Birjand, Birjand, Iran
| | - Fateme Golestani
- Department of Exercise Physiology, University of Birjand, Birjand, Iran
| | - Saeed Rezae
- Department of Exercise Physiology, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Nahid Mahmoudi
- Department of Exercise Physiology, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Abbas Ali Gaeini
- Department of Exercise Physiology, University of Tehran, Tehran, Iran.
| |
Collapse
|
7
|
Pańczyszyn A, Boniewska-Bernacka E, Goc A. The role of telomeres and telomerase in the senescence of postmitotic cells. DNA Repair (Amst) 2020; 95:102956. [PMID: 32937289 DOI: 10.1016/j.dnarep.2020.102956] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 08/18/2020] [Indexed: 12/13/2022]
Abstract
Senescence is a process related to the stopping of divisions and changes leading the cell to the SASP phenotype. Permanent senescence of many SASP cells contributes to faster aging of the body and development of age-related diseases due to the release of pro-inflammatory factors. Both mitotically active and non-dividing cells can undergo senescence as a result of activation of different molecular pathways. Telomeres, referred to as the molecular clock, direct the dividing cell into the aging pathway when reaching a critical length. In turn, the senescence of postmitotic cells depends not on the length of telomeres, but their functionality. Dysfunctional telomeres are responsible for triggering the signaling of DNA damage response (DDR). Telomerase subunits in post-mitotic cells translocate between the nucleus, cytoplasm and mitochondria, participating in the regulation of their activity. Among other things, they contribute to the reduction of reactive oxygen species generation, which leads to telomere dysfunction and, consequently, senescence. Some proteins of the shelterin complex also play a protective role by inhibiting senescence-initiating kinases and limiting ROS production by mitochondria.
Collapse
Affiliation(s)
- Anna Pańczyszyn
- University of Opole, Institute of Medical Sciences, Department of Biology and Genetics, Opole 45-040, Pl.Kopernika 11a, Poland.
| | - Ewa Boniewska-Bernacka
- University of Opole, Institute of Medical Sciences, Department of Biology and Genetics, Opole 45-040, Pl.Kopernika 11a, Poland.
| | - Anna Goc
- University of Opole, Institute of Medical Sciences, Department of Biology and Genetics, Opole 45-040, Pl.Kopernika 11a, Poland.
| |
Collapse
|
8
|
Razgonova MP, Zakharenko AM, Golokhvast KS, Thanasoula M, Sarandi E, Nikolouzakis K, Fragkiadaki P, Tsoukalas D, Spandidos DA, Tsatsakis A. Telomerase and telomeres in aging theory and chronographic aging theory (Review). Mol Med Rep 2020; 22:1679-1694. [PMID: 32705188 PMCID: PMC7411297 DOI: 10.3892/mmr.2020.11274] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/24/2020] [Indexed: 01/03/2023] Open
Abstract
The current review focuses on the connection of telomerase and telomeres with aging. In this review, we describe the changes in telomerase and telomere length (TEL) during development, their role in carcinogenesis processes, and the consequences of reduced telomerase activity. More specifically, the connection of TEL in peripheral blood cells with the development of aging‑associated diseases is discussed. The review provides systematic data on the role of telomerase in mitochondria, the biology of telomeres in stem cells, as well as the consequences of the forced expression of telomerase (telomerization) in human cells. Additionally, it presents the effects of chronic stress exposure on telomerase activity, the effect of TEL on fertility, and the effect of nutraceutical supplements on TEL. Finally, a comparative review of the chronographic theory of aging, presented by Olovnikov is provided based on currently available scientific research on telomere, telomerase activity, and the nature of aging by multicellular organisms.
Collapse
Affiliation(s)
- Mayya P. Razgonova
- N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190000 Saint-Petersburg, Russia
- Far Eastern Federal University, 690950 Vladivostok, Russia
| | - Alexander M. Zakharenko
- N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190000 Saint-Petersburg, Russia
- Far Eastern Federal University, 690950 Vladivostok, Russia
| | - Kirill S. Golokhvast
- N.I. Vavilov All-Russian Institute of Plant Genetic Resources, 190000 Saint-Petersburg, Russia
- Far Eastern Federal University, 690950 Vladivostok, Russia
- Pacific Geographical Institute, Far Eastern Branch of The Russian Academy of Sciences, 690041 Vladivostok, Russia
| | - Maria Thanasoula
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Evangelia Sarandi
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | | | - Persefoni Fragkiadaki
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece
- Spin-Off Toxplus S.A., 71601 Heraklion, Greece
| | - Dimitris Tsoukalas
- Metabolomic Μedicine, Health Clinics for Autoimmune and Chronic Diseases, 10674 Athens, Greece
| | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, Heraklion 71003, Greece
| | - Aristidis Tsatsakis
- Laboratory of Toxicology, Medical School, University of Crete, 71003 Heraklion, Greece
- Spin-Off Toxplus S.A., 71601 Heraklion, Greece
| |
Collapse
|
9
|
Abstract
Telomeres are specialised structures at the end of linear chromosomes. They consist of tandem repeats of the hexanucleotide sequence TTAGGG, as well as a protein complex called shelterin. Together, they form a protective loop structure against chromosome fusion and degradation. Shortening or damage to telomeres and opening of the loop induce an uncapped state that triggers a DNA damage response resulting in senescence or apoptosis.Average telomere length, usually measured in human blood lymphocytes, was thought to be a biomarker for ageing, survival and mortality. However, it becomes obvious that regulation of telomere length is very complex and involves multiple processes. For example, the "end replication problem" during DNA replication as well as oxidative stress are responsible for the shortening of telomeres. In contrast, telomerase activity can potentially counteract telomere shortening when it is able to access and interact with telomeres. However, while highly active during development and in cancer cells, the enzyme is down-regulated in most human somatic cells with a few exceptions such as human lymphocytes. In addition, telomeres can be transcribed, and the transcription products called TERRA are involved in telomere length regulation.Thus, telomere length and their integrity are regulated at many different levels, and we only start to understand this process under conditions of increased oxidative stress, inflammation and during diseases as well as the ageing process.This chapter aims to describe our current state of knowledge on telomeres and telomerase and their regulation in order to better understand their role for the ageing process.
Collapse
|
10
|
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: 15] [Impact Index Per Article: 3.0] [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.
Collapse
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
| |
Collapse
|
11
|
El-Badawy A, Ghoneim NI, Nasr MA, Elkhenany H, Ahmed TA, Ahmed SM, El-Badri N. Telomerase reverse transcriptase coordinates with the epithelial-to-mesenchymal transition through a feedback loop to define properties of breast cancer stem cells. Biol Open 2018; 7:bio.034181. [PMID: 29907642 PMCID: PMC6078341 DOI: 10.1242/bio.034181] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Telomerase and its core component, telomerase reverse transcriptase (hTERT), are critical for stem cell compartment integrity. Normal adult stem cells have the longest telomeres in a given tissue, a property mediated by high hTERT expression and high telomerase enzymatic activity. In contrast, cancer stem cells (CSCs) have short telomeres despite high expression of hTERT, indicating that the role of hTERT in CSCs is not limited to telomere elongation and/or maintenance. The function of hTERT in CSCs remains poorly understood. Here, we knocked down hTERT expression in CSCs and observed a morphological shift to a more epithelial phenotype, suggesting a role for hTERT in the epithelial-to-mesenchymal transition (EMT) of CSCs. Therefore, in this study, we systematically explored the relationship between hTERT and EMT and identified a reciprocal, bi-directional feedback loop between hTERT and EMT in CSCs. We found that hTERT expression is mutually exclusive to the mesenchymal phenotype and that, reciprocally, loss of the mesenchymal phenotype represses hTERT expression. We also showed that hTERT plays a critical role in the expression of key CSC markers and nuclear β-catenin localization, increases the percentage of cells with side-population properties, and upregulates the CD133 expression. hTERT also promotes chemoresistance properties, tumorsphere formation and other important functional CSC properties. Subsequently, hTERT knockdown leads to the loss of the above advantages, indicating a loss of CSC properties. Our findings suggest that targeting hTERT might improve CSCs elimination by transitioning them from the aggressive mesenchymal state to a more steady epithelial state, thereby preventing cancer progression. Summary: This study describe a reciprocal, bi-directional feedback loop between hTERT and EMT to regulate properties of CSCs, suggesting that targeting hTERT may eliminate CSCs, thereby preventing cancer progression.
Collapse
Affiliation(s)
- Ahmed El-Badawy
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, 6th of October City 12588, Egypt
| | - Nehal I Ghoneim
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, 6th of October City 12588, Egypt
| | - Mohamed A Nasr
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, 6th of October City 12588, Egypt
| | - Hoda Elkhenany
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, 6th of October City 12588, Egypt.,Department of Surgery, College of Veterinary Medicine, Alexandria University, Alexandria 22785, Egypt
| | - Toka A Ahmed
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, 6th of October City 12588, Egypt
| | - Sara M Ahmed
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, 6th of October City 12588, Egypt
| | - Nagwa El-Badri
- Center of Excellence for Stem Cells and Regenerative Medicine (CESC), Zewail City of Science and Technology, 6th of October City 12588, Egypt
| |
Collapse
|
12
|
Staffaroni AM, Tosun D, Lin J, Elahi FM, Casaletto KB, Wynn MJ, Patel N, Neuhaus J, Walters SM, Epel ES, Blackburn EH, Kramer JH. Telomere attrition is associated with declines in medial temporal lobe volume and white matter microstructure in functionally independent older adults. Neurobiol Aging 2018; 69:68-75. [PMID: 29859365 DOI: 10.1016/j.neurobiolaging.2018.04.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 03/29/2018] [Accepted: 04/28/2018] [Indexed: 12/24/2022]
Abstract
Although leukocyte telomere length (TL) shortens over the lifespan and is associated with diseases of aging, little is known about the relationships between TL, memory, and brain structure. Sixty-nine functionally normal older adults (mean age = 71.7) were assessed at 2 time points (mean interval = 2.9 years). Linear mixed models assessed relationships between TL and hippocampal volume, fractional anisotropy, and mean diffusivity (MD) of the fornix and verbal and visual episodic memory. Unstandardized coefficients are reported in the following, and p values are not corrected for multiple comparisons. A negative baseline trend was observed between TL and fornix MD (b = -0.01, p = 0.06), but no other cross-sectional associations were significant (ps > 0.16). Greater TL shortening at follow-up was associated with greater hippocampal volume loss (b = 27.09, p < 0.001), even after controlling for global volume loss (b = 10.83, p = 0.002). Greater telomere attrition was also associated with larger increases in fornix MD (b = -0.01, p = 0.012) and decreases in fornix fractional anisotropy (b = 0.004, p = 0.002). TL was not associated with changes in episodic memory (ps > 0.23). These relationships may reflect neurobiological influences that affect both TL and brain structure, as well as the effect of TL on brain aging via mechanisms such as cellular senescence and inflammation.
Collapse
Affiliation(s)
- Adam M Staffaroni
- Department of Neurology, Memory and Aging Center, University of California at San Francisco, San Francisco, CA, USA.
| | - Duygu Tosun
- Department of Veteran Affairs Medical Center, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | - Jue Lin
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Fanny M Elahi
- Department of Neurology, Memory and Aging Center, University of California at San Francisco, San Francisco, CA, USA
| | - Kaitlin B Casaletto
- Department of Neurology, Memory and Aging Center, University of California at San Francisco, San Francisco, CA, USA
| | - Matthew J Wynn
- Department of Neurology, Memory and Aging Center, University of California at San Francisco, San Francisco, CA, USA
| | - Nihar Patel
- Department of Neurology, Memory and Aging Center, University of California at San Francisco, San Francisco, CA, USA
| | - John Neuhaus
- Department of Epidemiology and Biostatistics, University of California, San Francisco, USA
| | - Samantha M Walters
- Department of Neurology, Memory and Aging Center, University of California at San Francisco, San Francisco, CA, USA
| | - Elissa S Epel
- Department of Psychiatry, University of California at San Francisco, San Francisco, CA, USA
| | | | - Joel H Kramer
- Department of Neurology, Memory and Aging Center, University of California at San Francisco, San Francisco, CA, USA
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Zhang K, Guo Y, Wang X, Zhao H, Ji Z, Cheng C, Li L, Fang Y, Xu D, Zhu HH, Gao WQ. WNT/β-Catenin Directs Self-Renewal Symmetric Cell Division of hTERThigh Prostate Cancer Stem Cells. Cancer Res 2017; 77:2534-2547. [PMID: 28209613 DOI: 10.1158/0008-5472.can-16-1887] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/30/2016] [Accepted: 01/11/2017] [Indexed: 11/16/2022]
Affiliation(s)
- Kai Zhang
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Yanjing Guo
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xue Wang
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Huifang Zhao
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhongzhong Ji
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Chaping Cheng
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Li Li
- School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Yuxiang Fang
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Dawei Xu
- Department of Medicine, Division of Haematology and Centre for Molecular Medicine (CMM), Karolinska University Hospital Solna and Karolinska Institutet, Stockholm, Sweden
| | - Helen He Zhu
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
| | - Wei-Qiang Gao
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
- School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
- Collaborative Innovation Center of Systems Biomedicine, Shanghai, China
| |
Collapse
|
15
|
Zhao T, Hu F, Liu X, Tao Q. Blockade of telomerase reverse transcriptase enhances chemosensitivity in head and neck cancers through inhibition of AKT/ERK signaling pathways. Oncotarget 2016; 6:35908-21. [PMID: 26497550 PMCID: PMC4742150 DOI: 10.18632/oncotarget.5468] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 10/06/2015] [Indexed: 12/14/2022] Open
Abstract
Head and Neck squamous cell carcinomas (HNSCC), characterized by the high frequency of local recurrence and distant metastases, is mostly related to highly malignant and resistant to apoptosis, resulting in significant insensitivity to chemotherapy. Telomerase reverse transcriptase (TERT), as the catalytic subunit of telomerase, was implicated in the telomerase-mediated cellular transformation, proliferation, stemness and cell survival. Moreover, overexpression of human TERT (hTERT) is reported to be correlated with advanced invasive stage of the tumor progression and poor prognosis. Here, we show that hTERT potentially mediated the apoptotic resistance and blockade of telomerase reverse transcriptase could enhance chemosensitivity in head and neck cancers. Mechanistically, hTERT interacts with the phosphorylation of AKT and ERK to suppress the expression of p53, ultimately, leading to modulation of the cellular sensitivity to chemotherapy. Thus, these findings suggest that hTERT targeting could be an attractive approach in combination with conventional chemotherapies for patients suffering from chemoinsensitivity or refractory HNSCC.
Collapse
Affiliation(s)
- Tengda Zhao
- Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China.,Department of Oral and Maxillofacial Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Fengchun Hu
- Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China.,Department of Stomatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Xingguang Liu
- Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China
| | - Qian Tao
- Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China
| |
Collapse
|
16
|
Lu Y, Yan C, Du J, Ji Y, Gao Y, Zhu X, Yu F, Huang T, Dai J, Ma H, Jiang Y, Chen J, Shen H, Jin G, Yin Y, Hu Z. Genetic variants affecting telomere length are associated with the prognosis of esophageal squamous cell carcinoma in a Chinese population. Mol Carcinog 2016; 56:1021-1029. [PMID: 27597395 DOI: 10.1002/mc.22567] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 08/22/2016] [Accepted: 09/04/2016] [Indexed: 02/02/2023]
Abstract
Telomeres are essential for maintaining chromosomal stability and are crucial in tumor progression. Previous studies have explored the associations between telomere length and cancer prognosis, but the findings are inconclusive. Genome-wide association studies have identified several genetic variants associated with telomere length in Caucasians. However, the roles of telomere length and related genetic variants on esophageal squamous cell carcinoma (ESCC) prognosis are largely unknown. Therefore, we conducted a case-cohort study with 431 ESCC patients to assess the associations between relative telomere length (RTL), eight known telomere length related variants and the overall survival of ESCC in Chinese population. We found that as compared with the reference group, patients in the fifth (the longest) quintile had a significantly better prognosis [(adjusted hazard ratio (HR) = 0.58, 95% confidence interval (CI) = 0.34-0.98, P = 0.041]. Furthermore, A allele of rs2736108 was significantly associated with both the increased RTL (P = 0.048) and the better prognosis of ESCC (adjusted HR = 0.55, 95%CI = 0.38-0.79, P = 1.31 × 10-3 ). Mediation analysis indicated that the effect of rs2736108 on ESCC prognosis was partly explained by RTL (1.99%). Stepwise Cox proportional hazard analysis suggested that rs2736108 played an important protective role in ESCC prognosis (HR = 0.57, 95%CI = 0.40-0.81, P = 1.97 × 10-3 ). Our findings provide evidence that prolonged telomere length is a protective factor for ESCC patients' survival and the known telomere length related genetic variant rs2736108 can contribute to the prognosis of ESCC as well in Chinese population. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yue Lu
- Department of Radiotherapy, the Affiliated Cancer Hospital of Jiangsu Province of Nanjing Medical University, Nanjing, China
| | - Caiwang Yan
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Jiangbo Du
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Yong Ji
- Department of Cardiothoracic Surgery, the Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, China
| | - Yong Gao
- Department of Medical Oncology, the Affiliated Huaian First People's Hospital of Nanjing Medical University, Huaian, China
| | - Xun Zhu
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Fei Yu
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Tongtong Huang
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Juncheng Dai
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Hongxia Ma
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Yue Jiang
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Jiaping Chen
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Hongbing Shen
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Guangfu Jin
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Yongmei Yin
- Department of Cardiothoracic Surgery, the First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zhibin Hu
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| |
Collapse
|
17
|
Telomerase Activity is Downregulated Early During Human Brain Development. Genes (Basel) 2016; 7:genes7060027. [PMID: 27322326 PMCID: PMC4929426 DOI: 10.3390/genes7060027] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 05/25/2016] [Accepted: 06/06/2016] [Indexed: 12/14/2022] Open
Abstract
Changes in hTERT splice variant expression have been proposed to facilitate the decrease of telomerase activity during fetal development in various human tissues. Here, we analyzed the expression of telomerase RNA (hTR), wild type and α-spliced hTERT in developing human fetal brain (post conception weeks, pcw, 6-19) and in young and old cortices using qPCR and correlated it to telomerase activity measured by TRAP assay. Decrease of telomerase activity occurred early during brain development and correlated strongest to decreased hTR expression. The expression of α-spliced hTERT increased between pcw 10 and 19, while that of wild type hTERT remained unchanged. Lack of expression differences between young and old cortices suggests that most changes seem to occur early during human brain development. Using in vitro differentiation of neural precursor stem cells (NPSCs) derived at pcw 6 we found a decrease in telomerase activity but no major expression changes in telomerase associated genes. Thus, they do not seem to model the mechanisms for the decrease in telomerase activity in fetal brains. Our results suggest that decreased hTR levels, as well as transient increase in α-spliced hTERT, might both contribute to downregulation of telomerase activity during early human brain development between 6 and 17 pcw.
Collapse
|
18
|
Telomere Length Maintenance and Cardio-Metabolic Disease Prevention Through Exercise Training. Sports Med 2016; 46:1213-37. [DOI: 10.1007/s40279-016-0482-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
19
|
Castorina A, Szychlinska MA, Marzagalli R, Musumeci G. Mesenchymal stem cells-based therapy as a potential treatment in neurodegenerative disorders: is the escape from senescence an answer? Neural Regen Res 2015; 10:850-8. [PMID: 26199588 PMCID: PMC4498333 DOI: 10.4103/1673-5374.158352] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2015] [Indexed: 01/09/2023] Open
Abstract
Aging is the most prominent risk factor contributing to the development of neurodegenerative disorders. In the United States, over 35 million of elderly people suffer from age-related diseases. Aging impairs the self-repair ability of neuronal cells, which undergo progressive deterioration. Once initiated, this process hampers the already limited regenerative power of the central nervous system, making the search for new therapeutic strategies particularly difficult in elderly affected patients. So far, mesenchymal stem cells have proven to be a viable option to ameliorate certain aspects of neurodegeneration, as they possess high proliferative rate and differentiate in vitro into multiple lineages. However, accumulating data have demonstrated that during long-term culture, mesenchymal stem cells undergo spontaneous transformation. Transformed mesenchymal stem cells show typical features of senescence, including the progressive shortening of telomers, which results in cell loss and, as a consequence, hampered regenerative potential. These evidences, in line with those observed in mesenchymal stem cells isolated from old donors, suggest that senescence may represent a limit to mesenchymal stem cells exploitation in therapy, prompting scholars to either find alternative sources of pluripotent cells or to arrest the age-related transformation. In the present review, we summarize findings from recent literature, and critically discuss some of the major hurdles encountered in the search of appropriate sources of mesenchymal stem cells, as well as benefits arising from their use in neurodegenerative diseases. Finally, we provide some insights that may aid in the development of strategies to arrest or, at least, delay the aging of mesenchymal stem cells to improve their therapeutic potential.
Collapse
Affiliation(s)
- Alessandro Castorina
- Department of Biomedical and Biotechnological Science, Section of Human Anatomy and Histology, School of Medicine, University of Catania, Via S. Sofia 87, Catania, Italy
| | - Marta Anna Szychlinska
- Department of Biomedical and Biotechnological Science, Section of Human Anatomy and Histology, School of Medicine, University of Catania, Via S. Sofia 87, Catania, Italy
| | - Rubina Marzagalli
- Department of Biomedical and Biotechnological Science, Section of Human Anatomy and Histology, School of Medicine, University of Catania, Via S. Sofia 87, Catania, Italy
| | - Giuseppe Musumeci
- Department of Biomedical and Biotechnological Science, Section of Human Anatomy and Histology, School of Medicine, University of Catania, Via S. Sofia 87, Catania, Italy
| |
Collapse
|
20
|
Liu JP. Molecular mechanisms of ageing and related diseases. Clin Exp Pharmacol Physiol 2015; 41:445-58. [PMID: 24798238 DOI: 10.1111/1440-1681.12247] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 04/07/2014] [Accepted: 04/24/2014] [Indexed: 11/29/2022]
Abstract
Human and other multicellular life species age, and ageing processes become dominant during the late phase of life. Recent studies challenge this dogma, suggesting that ageing does not occur in some animal species. In mammals, cell replicative senescence occurs as early as before birth (i.e. in embryos) under physiological conditions. How the molecular machinery operates and why ageing cells dominate under some circumstances are intriguing questions. Recent studies show that cell ageing involves extensive cellular remodelling, including telomere attrition, heterochromatin formation, endoplasmic reticulum stress, mitochondrial disorders and lysosome processing organelles and chromatins. This article provides an update on the molecular mechanisms underlying the ageing of various cell types, the newly described developmental and programmed replicative senescence and the critical roles of cellular organelles and effectors in Parkinson's disease, diabetes, hypertension and dyskeratosis congenita.
Collapse
Affiliation(s)
- Jun-Ping Liu
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Zhejiang, China; Department of Immunology, Monash University Central Clinical School, Prahran, Victoria, Australia; Department of Genetics, University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
21
|
Zhao T, Hu F, Qiao B, Chen Z, Tao Q. Telomerase reverse transcriptase potentially promotes the progression of oral squamous cell carcinoma through induction of epithelial-mesenchymal transition. Int J Oncol 2015; 46:2205-15. [PMID: 25775973 DOI: 10.3892/ijo.2015.2927] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 02/18/2015] [Indexed: 11/06/2022] Open
Abstract
In recent years, researchers have found the critical role of telomerase in cellular transformation, proliferation, stemness and cell survival. High levels of telomerase reverse transcriptase (TERT) expression and telomerase activation have been reported in most cancer cells. Moreover, overexpression of human TERT (hTERT) is reported to be correlated with advanced invasive stage of the tumor progression and poor prognosis. Epithelial-mesenchymal transition (EMT), characterized by the loss of the cell-cell contact of epithelial cells and the acquisition of migratory and motile properties, is known to be a central mechanism responsible for invasiveness and metastasis of various cancers. Thus, we investigated whether hTERT plays a potential role in the development of EMT. As we expected, our clinical results showed that hTERT is overexpressed in oral epithelial dysplasia (OED) and OSCC tissues and correlates with clinical aggressiveness of oral squamous cell carcinoma (OSCC) patients. We then overexpressed hTERT in primary human oral epithelial cells (HOECS) and found that hTERT has the potential to prolong the lifespan, a process confering the characteristics of EMT by activating the Wnt/β-catenin pathway. Our findings provided an explanation for the aggressive nature of human tumors overexpressing hTERT and the possibly mechanism that links hTERT to EMT property, which represents a possible therapeutic target in highly metastatic cancers.
Collapse
Affiliation(s)
- Tengda Zhao
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, P.R. China
| | - Fengchun Hu
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, P.R. China
| | - Bin Qiao
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, P.R. China
| | - Zhifeng Chen
- Department of Oral and Maxillofacial Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, P.R. China
| | - Qian Tao
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, P.R. China
| |
Collapse
|
22
|
Wu TT, Chen C, Chen SM, Xu Y, Wang Y, Chen Z, Wang F, Xiao BK, Tao ZZ. Nuclear translocation of telomerase reverse transcriptase is a critical process in lymphatic metastasis of nasopharyngeal carcinoma. Oncol Lett 2014; 9:265-269. [PMID: 25435972 PMCID: PMC4246691 DOI: 10.3892/ol.2014.2689] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 09/08/2014] [Indexed: 01/21/2023] Open
Abstract
Telomerase reverse transcriptase (TERT) is the predominant functional unit of telomerase and maintains the telomere length and the stability of chromosomes. Recently, TERT has been shown to be a critical factor in a number of other biological processes, including cell proliferation and cancer metastasis. In addition, although numerous studies have been conducted, the subcellular localization of the TERT protein and the association of such with cancer metastasis remains unclear. To investigate the involvement of TERT in in vivo metastasis, quantum dots-based immunofluorescence and western blot analysis were conducted to detect changes in the subcellular localization of TERT in human nasopharyngeal carcinoma (NPC) tissues and metastatic lymph nodes. To further investigate, metastatic and non-metastatic models of NPC were generated using 5-8F (high metastasis capability) and 6-10B (low metastasis capability) cell lines, respectively. It was found that TERT protein was overexpressed in NPC tissue samples and metastatic lymph nodes and TERT was predominantly located in the cytoplasm of primary NPC tissues, while TERT was predominantly located in the nucleus of the metastatic lymph nodes. The ratio of cytoplasmic TERT/nuclear TERT for the primary tumor of the 6-10B cell line was almost six-fold higher than that of the metastatic lymph nodes of the 5-8F cell line. TERT translocation from the cytoplasm to nucleus may present a critical step in the lymphatic metastasis of NPC. Thus, TERT translocation may be more useful than TERT expression level and telomerase activity for predicting the metastasis of NPC.
Collapse
Affiliation(s)
- Ting-Ting Wu
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Chen Chen
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Shi-Ming Chen
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Yong Xu
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Yan Wang
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Zhe Chen
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Fei Wang
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Bo-Kui Xiao
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Ze-Zhang Tao
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| |
Collapse
|
23
|
Liu Z, Wang W, Jin B, Li G, Du G, Zhang Z, Han L, Huang G, Tang Z. Protection Against Ischemia-Reperfusion Injury in Aged Liver Donor by the Induction of Exogenous Human Telomerase Reverse Transcriptase Gene. Transplant Proc 2014; 46:1567-72. [DOI: 10.1016/j.transproceed.2013.12.071] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 10/29/2013] [Accepted: 12/16/2013] [Indexed: 01/08/2023]
|
24
|
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.
Collapse
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.
| |
Collapse
|
25
|
Jiang Y, Chen C, Chen SM, Wang YQ, Xu Y, Wang Y, Chen Z, Xiao BK, Tao ZZ. Telomerase reverse transcriptase promotes the proliferation of human laryngeal carcinoma cells through activation of the activator protein 1. Oncol Lett 2013; 6:75-80. [PMID: 23946780 PMCID: PMC3742814 DOI: 10.3892/ol.2013.1344] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 05/18/2012] [Indexed: 12/17/2022] Open
Abstract
TERT is the main functional unit of telomerase, which maintains telomere length and chromosome structure stability. TERT has been shown to act as a key factor in various biological processes, such as cell proliferation, via uncharacterized mechanisms. We transfected HEp-2 laryngeal carcinoma cells with a TERT overexpressing adenovirus (Ad-TERT) and TERT shRNA silencing adenovirus (Ad-sh-TERT), and examined the effect on TERT and the AP-1 transcription factor subunits c-Fos and c-Jun using RT-PCR and western blot analysis. TERT mRNA expression was quantified using RT-PCR in 24 human laryngeal carcinoma samples, and TERT protein co-expression with AP-1 was investigated in a human laryngeal carcinoma tissue microarray using quantum-dot based immunofluorescence. The effect of specific ERK and p38 inhibitors on ERK, p38, c-Jun and c-Fos phosphorylation was investigated in TERT-overexpressing HEp-2 cells. TERT overexpression led to increased TERT, c-Jun and c-Fos mRNA and protein expression and increased cell proliferation, while TERT silencing had the opposite effects. TERT mRNA expression levels were positively correlated with c-Fos and c-Jun mRNA in human laryngeal carcinoma tissue. TERT and AP-1 protein were expressed at high levels and positively correlated in laryngeal carcinoma tissues. Treatment of TERT-overexpressing HEp-2 cells with specific p38 and ERK inhibitors indicated that TERT modulates the expression and phosphorylation of the AP-1 subunits c-Jun and c-Fos through the p38 and ERK signaling pathways. In conclusion, the results of this study indicate that TERT is capable of promoting cell proliferation via activation of the AP-1 subunits, c-Jun and c-Fos, in laryngeal carcinoma cells.
Collapse
Affiliation(s)
- Yang Jiang
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, P.R. China
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Cottage CT, Neidig L, Sundararaman B, Din S, Joyo AY, Bailey B, Gude N, Hariharan N, Sussman MA. Increased mitotic rate coincident with transient telomere lengthening resulting from pim-1 overexpression in cardiac progenitor cells. Stem Cells 2013; 30:2512-22. [PMID: 22915504 PMCID: PMC3479348 DOI: 10.1002/stem.1211] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cardiac regeneration following myocardial infarction rests with the potential of c-kit+ cardiac progenitor cells (CPCs) to repopulate damaged myocardium. The ability of CPCs to reconstitute the heart is restricted by patient age and disease progression. Increasing CPC proliferation, telomere length, and survival will improve the ability of autologous CPCs to be successful in myocardial regeneration. Prior studies have demonstrated enhancement of myocardial regeneration by engineering CPCs to express Pim-1 kinase, but cellular and molecular mechanisms for Pim-1-mediated effects on CPCs remain obscure. We find CPCs rapidly expand following overexpression of cardioprotective kinase Pim-1 (CPCeP), however, increases in mitotic rate are short-lived as late passage CPCePs proliferate similar to control CPCs. Telomere elongation consistent with a young phenotype is observed following Pim-1 modification of CPCeP; in addition, telomere elongation coincides with increased telomerase expression and activity. Interestingly, telomere length and telomerase activity normalize after several rounds of passaging, consistent with the ability of Pim-1 to transiently increase mitosis without resultant oncogenic transformation. Accelerating mitosis in CPCeP without immortalization represents a novel strategy to expand the CPC population in order to improve their therapeutic efficacy. Stem Cells2012;30:2512–2522
Collapse
Affiliation(s)
- Christopher T Cottage
- San Diego State Heart Institute, San Diego State University, San Diego, California, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Telomerase reverse transcriptase promotes epithelial-mesenchymal transition and stem cell-like traits in cancer cells. Oncogene 2012; 32:4203-13. [PMID: 23045275 DOI: 10.1038/onc.2012.441] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/09/2012] [Indexed: 12/20/2022]
Abstract
Telomerase activation through induction of telomerase reverse transcriptase (hTERT) contributes to malignant transformation by stabilizing telomeres. Clinical studies demonstrate that higher hTERT expression is associated with cancer progression and poor outcomes, but the underlying mechanism is unclear. Because epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs) are key factors in cancer metastasis and relapse, and hTERT has been shown to exhibit multiple biological activities independently of its telomere-lengthening function, we address a potential role of hTERT in EMT and CSCs using gastric cancer (GC) as a model. hTERT overexpression promotes, whereas its inhibition suppresses, EMT and stemness of GC cells, respectively. Transforming growth factor (TGF)-β1 and β-catenin-mediated EMT was abolished by small interfering RNA depletion of hTERT expression. hTERT interacts with β-catenin, enhances its nuclear localization and transcriptional activity, and occupies the β-catenin target vimentin promoter. All these hTERT effects were independent of its telomere-lengthening function or telomerase activity. hTERT and EMT marker expression correlates positively in GC samples. Mouse experiments demonstrate the in vivo stimulation of hTERT on cancer cell colonization. Collectively, hTERT stimulates EMT and induces stemness of cancer cells, thereby promoting cancer metastasis and recurrence. Thus, targeting hTERT may prevent cancer progression by inhibiting EMT and CSCs.
Collapse
|
28
|
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) induces cancer cell senescence by interacting with telomerase RNA component. Proc Natl Acad Sci U S A 2012; 109:13308-13. [PMID: 22847419 DOI: 10.1073/pnas.1206672109] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Oxidative stress regulates telomere homeostasis and cellular aging by unclear mechanisms. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a key mediator of many oxidative stress responses, involving GAPDH nuclear translocation and induction of cell death. We report here that GAPDH interacts with the telomerase RNA component (TERC), inhibits telomerase activity, and induces telomere shortening and breast cancer cell senescence. The Rossmann fold containing NAD(+) binding region on GAPDH is responsible for the interaction with TERC, whereas a lysine residue in the GAPDH catalytic domain is required for inhibiting telomerase activity and disrupting telomere maintenance. Furthermore, the GAPDH substrate glyceraldehyde-3-phosphate (G3P) and the nitric oxide donor S-nitrosoglutathione (GSNO) both negatively regulate GAPDH inhibition of telomerase activity. Thus, we demonstrate that GAPDH is regulated to target the telomerase complex, resulting in an arrest of telomere maintenance and cancer cell proliferation.
Collapse
|
29
|
Li P, Hou M, Lou F, Björkholm M, Xu D. Telomere dysfunction induced by chemotherapeutic agents and radiation in normal human cells. Int J Biochem Cell Biol 2012; 44:1531-40. [PMID: 22728163 DOI: 10.1016/j.biocel.2012.06.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 05/02/2012] [Accepted: 06/12/2012] [Indexed: 01/10/2023]
Abstract
The number of long-term survivors of patients with various malignancies (>5 years) is increasing mainly owing to advances in cancer therapeutics, but long-term side effects of the cancer treatment in this population have emerged as an important health and socio-economical issue. Telomeres and telomerase are known to be essential for regulation of cellular life-span and maintenance of genomic stability, and earlier studies have demonstrated that cancer patients who receive chemotherapy have shorter telomeres in their blood cells, indicating accelerated telomere erosion and a potential contribution of telomere loss to late side-effects. Little is currently known about the effect of chemotherapeutic agents and radiation on telomere dynamics including potential effects on telomere length, structure, function, telomerase activity, and telomere shelterin proteins in normal human cells. In the present study, we had addressed this issue experimentally. The treatment of normal human T lymphocytes and fibroblasts with chemotherapeutic agents doxorubicin (DOX) or etoposide (VP16) led to significant shortening of telomeres, down-regulation of telomerase activity, and diminished expression of telomerase reverse transcriptase (hTERT) and the telomere binding proteins TPP1 and POT1. More importantly, telomere dysfunction was observed in cells treated with DOX or VP16. Furthermore, all the above alterations were similarly found in the cells receiving γ-irradiation. Taken together, both chemotherapy and radiotherapy significantly impair telomere maintenance and function in normal human cells. Conceivably telomere dysfunction causes shortened life-span and genomic instability of normal human cells, and thereby contributes to tissue/organ damage and secondary malignancies in long-term survivors of cancer.
Collapse
Affiliation(s)
- Ping Li
- Department of Medicine, Division of Haematology and Centre for Molecular Medicine, Karolinska University Hospital Solna and Karolinska Institutet, Stockholm, Sweden
| | | | | | | | | |
Collapse
|
30
|
Burnett-Hartman AN, Fitzpatrick AL, Kronmal RA, Psaty BM, Jenny NS, Bis JC, Tracy RP, Kimura M, Aviv A. Telomere-associated polymorphisms correlate with cardiovascular disease mortality in Caucasian women: the Cardiovascular Health Study. Mech Ageing Dev 2012; 133:275-81. [PMID: 22449406 PMCID: PMC3391009 DOI: 10.1016/j.mad.2012.03.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 02/22/2012] [Accepted: 03/09/2012] [Indexed: 01/09/2023]
Abstract
Leukocyte telomere length (LTL) is linked to cardiovascular disease (CVD); however, it is unclear if LTL has an etiologic role in CVD. To gain insight into the LTL and CVD relationship, a cohort study of CVD mortality and single nucleotide polymorphisms (SNPs) in OBFC1 and TERC, genes related to LTL, was conducted among 3271 Caucasian participants ages ≥65 years enrolled 1989-1990 in the Cardiovascular Health Study. Leukocyte DNA was genotyped for SNPs in OBFC1 (rs4387287 and rs9419958) and TERC (rs3772190) that were previously associated with LTL through genome-wide association studies. Cox regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). The OBFC1 SNPs were in linkage disequilibrium (r(2)=0.99), and both SNPs were similarly associated with CVD mortality in women. For women, there was a decreased risk of CVD death associated with the minor allele (rs4387287), HR=0.7; 95% CI: 0.5-0.9 (CC vs. AC) and HR=0.5; 95% CI: 0.20-1.4 (CC vs. AA) (P-trend <0.01). For men there was no association, HR=1.0; 95% CI: 0.7-1.3 (CC vs. AC) and HR=1.7; 95% CI: 0.8-3.6 (CC vs. AA) (P-trend=0.64). These findings support the hypothesis that telomere biology and associated genes may play a role in CVD-related death, particularly among women.
Collapse
|
31
|
Nicholls C, Li H, Wang JQ, Liu JP. Molecular regulation of telomerase activity in aging. Protein Cell 2011; 2:726-38. [PMID: 21976062 DOI: 10.1007/s13238-011-1093-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2011] [Accepted: 08/30/2011] [Indexed: 11/25/2022] Open
Abstract
The process of aging is mitigated by the maintenance and repair of chromosome ends (telomeres), resulting in extended lifespan. This review examines the molecular mechanisms underlying the actions and regulation of the enzyme telomerase reverse transcriptase (TERT), which functions as the primary mechanism of telomere maintenance and regulates cellular life expectancy. Underpinning increased cell proliferation, telomerase is also a key factor in facilitating cancer cell immortalization. The review focuses on aspects of hormonal regulations of telomerase, and the intracellular pathways that converge to regulate telomerase activity with an emphasis on molecular interactions at protein and gene levels. In addition, the basic structure and function of two key telomerase enzyme components-the catalytic subunit TERT and the template RNA (TERC) are discussed briefly.
Collapse
Affiliation(s)
- Craig Nicholls
- Molecular Signalling Laboratory, Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia
| | | | | | | |
Collapse
|
32
|
Lin J, Epel E, Blackburn E. Telomeres and lifestyle factors: roles in cellular aging. Mutat Res 2011; 730:85-9. [PMID: 21878343 DOI: 10.1016/j.mrfmmm.2011.08.003] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 08/04/2011] [Accepted: 08/16/2011] [Indexed: 02/06/2023]
Abstract
Recent research has demonstrated that telomere maintenance might be a key integrating point for the cumulative effects of genetic, environmental and lifestyle factors on aging and aging-related diseases. It is timely to 'take stock' of where this work has led the field. This review summarizes studies that have examined associations between lifestyle factors and telomere length and telomerase activity. In most of the studies described in this chapter, telomere length was measured in leukocytes (LTL) or peripheral blood mononuclear cells (PBMCs), taken from blood draws from the study subjects. Much of this chapter focuses on psychological stress, a widespread factor often intimately tied in with lifestyle or behavioral factors that in turn are related to risks of clinical diseases. Together, these findings suggest that cellular aging is linked to a range of influences, with an individual's life events and lifestyle parameters playing significant roles. Lastly, we propose possible biochemical mechanisms that mediate these associations and discuss future directions.
Collapse
Affiliation(s)
- Jue Lin
- University of California, San Francisco, CA 94158, USA.
| | | | | |
Collapse
|
33
|
Han JB, Tao ZZ, Chen SM, Kong YG, Xiao BK. Adenovirus-mediated transfer of tris-shRNAs induced apoptosis of nasopharyngeal carcinoma cell in vitro and in vivo. Cancer Lett 2011; 309:162-9. [PMID: 21669490 DOI: 10.1016/j.canlet.2011.05.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 05/21/2011] [Accepted: 05/25/2011] [Indexed: 10/18/2022]
Abstract
RNA interference (RNAi) is an evolutionary conserved mechanism for specific gene silencing. There are currently numerous cancer therapy clinical trials based on RNAi technology. Using an adenoviral system as a delivery mediator of RNAi, we investigated the therapeutic effects of targeting three genes simultaneously in vitro and in vivo. In this study, we constructed an recombinant adenoviral shRNA expression system as Adv-pEGFP-shVEGF-shTERT-shBcl-xl for multi-genes silencing. Our results showed that the adenoviral vector can achieve above 90% of transfection efficiency and induced obvious apoptosis in CNE-2 cell both in vitro and in vivo compared with targeting the TERT alone or controlled group.
Collapse
Affiliation(s)
- Ji-Bo Han
- Department of Otolaryngology, Head & Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, PR China
| | | | | | | | | |
Collapse
|
34
|
Bayne S, Li H, Jones MEE, Pinto AR, van Sinderen M, Drummond A, Simpson ER, Liu JP. Estrogen deficiency reversibly induces telomere shortening in mouse granulosa cells and ovarian aging in vivo. Protein Cell 2011; 2:333-46. [PMID: 21574023 DOI: 10.1007/s13238-011-1033-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 03/21/2011] [Indexed: 12/31/2022] Open
Abstract
Estrogen is implicated as playing an important role in aging and tumorigenesis of estrogen responsive tissues; however the mechanisms underlying the mitogenic actions of estrogen are not fully understood. Here we report that estrogen deficiency in mice caused by targeted disruption of the aromatase gene results in a significant inhibition of telomerase maintenance of telomeres in mouse ovaries in a tissue-specific manner. The inhibition entails a significant shortening of telomeres and compromised proliferation in the follicular granulosa cell compartment of ovary. Gene expression analysis showed decreased levels of proto-oncogene c-Myc and the telomerase catalytic subunit, telomerase reverse transcriptase (TERT), in response to estrogen deficiency. Estrogen replacement therapy led to increases in TERT gene expression, telomerase activity, telomere length and ovarian tissue growth, thereby reinstating ovary development to normal in four weeks. Our data demonstrate for the first time that telomere maintenance is the primary mechanism mediating the mitogenic effect of estrogen on ovarian granulosa cell proliferation by upregulating the genes of c-Myc and TERT in vivo. Estrogen deficiency or over-activity may cause ovarian tissue aging or tumorigenesis, respectively, through estrogen regulation of telomere remodeling.
Collapse
Affiliation(s)
- Sharyn Bayne
- Department of Immunology, Central Eastern Clinical School, Monash University, Victoria 3800, Australia
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Wolkowitz OM, Reus VI, Mellon SH. Of sound mind and body: depression, disease, and accelerated aging. DIALOGUES IN CLINICAL NEUROSCIENCE 2011. [PMID: 21485744 PMCID: PMC3181963 DOI: 10.31887/dcns.2011.13.1/owolkowitz] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Major depressive disorder (MDD) is associated with a high rate of developing serious medical comorbidities such as cardiovascular disease, stroke, dementia, osteoporosis, diabetes, and the metabolic syndrome. These are conditions that typically occur late in life, and it has been suggested that MDD may be associated with “accelerated aging.” We review several moderators and mediators that may accompany MDD and that may give rise to these comorbid medical conditions. We first review the moderating effects of psychological styles of coping, genetic predisposition, and epigenetic modifications (eg, secondary to childhood adversity). We then focus on several interlinked mediators occurring in MDD (or at least in subtypes of MDD) that may contribute to the medical comorbidity burden and to accelerated aging: limbic-hypothalamic-pituitary-adrenal axis alterations, diminution in glucocorticoid receptor function, altered glucose tolerance and insulin sensitivity, excitotoxicity, increases in intracellular calcium, oxidative stress, a proinflammatory milieu, lowered levels of “counter-regulatory” neurosteroids (such as allopregnanolone and dehydroepiandrosterone), diminished neurotrophic activity, and accelerated cell aging, manifest as alterations in telomerase activity and as shortening of telomeres, which can lead to apoptosis and cell death. In this model, MDD is characterized by a surfeit of potentially destructive mediators and an insufficiency of protective or restorative ones. These factors interact in increasing the likelihood of physical disease and of accelerated aging at the cellular level. We conclude with suggestions for novel mechanism-based therapeutics based on these mediators.
Collapse
Affiliation(s)
- Owen M Wolkowitz
- Department of Psychiatry, School of Medicine, University of California, San Francisco, California, USA.
| | | | | |
Collapse
|
36
|
Telomere length and cardiovascular aging: the means to the ends? Ageing Res Rev 2011; 10:297-303. [PMID: 21109027 DOI: 10.1016/j.arr.2010.11.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 11/09/2010] [Accepted: 11/12/2010] [Indexed: 01/05/2023]
Abstract
Epidemiologic and other evidence clearly indicates that peripheral blood leukocyte telomere length, a systemic marker for biological aging, can be useful as a cardiovascular aging biomarker. Although telomere biology might yield new insights into the underlying molecular biology of vascular aging and even radically improve current cardiovascular risk stratification, the specific nature of the association between telomere length and cardiovascular disease still remains to be elucidated. Here, we review several candidate hypotheses and critically review supporting and contesting scientific evidence for the underlying theories. For each hypothesis, we discuss the potential implications. We conclude that the most promising theory is based on an acceleration of the telomere attrition rate due to cardiovascular aging related factors, possibly complemented by telomere mediated hematopoietic senescence.
Collapse
|
37
|
Li P, Tian C, Ge N, Wang H, Liu L, Lou F, Björkholm M, Xu D. Premature senescence of T cells in long-term survivors of renal transplantation. Biochem Biophys Res Commun 2011; 407:599-604. [PMID: 21426898 DOI: 10.1016/j.bbrc.2011.03.079] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 03/16/2011] [Indexed: 01/10/2023]
Abstract
Prevention of graft rejection in renal transplant recipients depends on chronic treatment with immunosuppressive agents. However, impaired immune functions and immunosurveillance may cause infection, cancer and many other problems, which subsequently compromise quality of life and survival of patients. In the present study, we assessed potential premature immune-senescence in long-term survivors of kidney transplant patients receiving immunosuppressive agents. Peripheral blood lymphocytes derived from patients had significantly shorter telomeres than those from age- and sex-matched healthy individuals. Consistent with this, lower expression of telomerase reverse transcriptase (hTERT) and telomerase activity was observed in patients' lymphocytes. The level of p16(ink4A) expression was elevated in patients' cells. Moreover, the CD8(+)/CD28(-) fraction of late-stage differentiated T cells was significantly increased in the patients. In vitro studies further showed that cyclosporine A, a widely used immunosuppressive drug in transplant patients, attenuated induction of hTERT and telomerase activation in T cells treated with the mitogenic agent concanavalin A. Taken together, immunosuppressant-mediated premature senescence of T lymphocytes occurs in renal transplant recipients.
Collapse
Affiliation(s)
- Ping Li
- Nursing School, Shandong University, Jinan, China
| | | | | | | | | | | | | | | |
Collapse
|