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Bhargavan B, Chhunchha B, Kubo E, Singh DP. DNA methylation as an epigenetic mechanism in the regulation of LEDGF expression and biological response in aging and oxidative stress. Cell Death Discov 2024; 10:296. [PMID: 38909054 PMCID: PMC11193803 DOI: 10.1038/s41420-024-02076-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 06/15/2024] [Accepted: 06/18/2024] [Indexed: 06/24/2024] Open
Abstract
The physiological quantum of stress-inducible transcriptional protein, Lens Epithelium-Derived Growth Factor (LEDGF), is vital for the maintenance of cellular physiology. Erratic epigenetic reprogramming in response to oxidative stress or with advancing age is found to be a major cause in the gene silencing, leading to pathobiologies. Using aging human (h) eye lens/lens epithelial cells (LECs) coupled with redox-active Peroxiredoxin 6 (Prdx6)-deficient (Prdx6-/-) mLECs as model systems, herein, we showed that in aging/oxidative stress, the human LEDGF gene was regulated by unique methylation patterns of CGs nucleotides within and around the Sp1 binding site(s) of CpG island of the LEDGF promoter (-170 to -27nts). The process caused the repression of LEDGF and its target, Hsp27, resulting in reactive oxygen species (ROS) amplification and cellular insults. This phenomenon was opposed to the unmethylated promoter in LECs. Clinically, we observed that the loss of LEDGF in the Prdx6-/- mLECs or aging lenses/LECs, correlating with increased expression of DNMT1, DNMT3a, and DNMT3b along with the methyl CpG binding protein 2 (MeCP2). Upon oxidative stress, the expression of these molecules was increased with the dramatic reduction in LEDGF expression. While demethylating agent, 5-Aza deoxycytidine (5-AzaC) transposed the aberrant methylation status, and revived LEDGF and Hsp27 expression. Mechanistically, the chloramphenicol acetyltransferase (CAT) reporter gene driven by the LEDGF promoter (-170/ + 35) and ChIP assays uncovered that 5-AzaC acted on GC/Sp1 sites to release LEDGF transcription. The data argued, for the first time, that de novo methylation of CGs around and within Sp1 sites of the CpG island directly disrupted Sp1 activity, which ensued in LEDGF repression and its biological functions. The findings should improve our understanding of cellular insults-associated with aberrant DNMTs-mediated LEDGF's activity, and can offer strategies for therapeutic intervention to halt aging/oxidative stress-induced abnormalities.
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Affiliation(s)
- Biju Bhargavan
- Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Bhavana Chhunchha
- Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA.
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa, 9200293, Japan
| | - Dhirendra P Singh
- Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA.
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Chhunchha B, Kumar R, Kubo E, Thakur P, Singh DP. Prdx6 Regulates Nlrp3 Inflammasome Activation-Driven Inflammatory Response in Lens Epithelial Cells. Int J Mol Sci 2023; 24:16276. [PMID: 38003466 PMCID: PMC10671722 DOI: 10.3390/ijms242216276] [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: 10/15/2023] [Revised: 11/06/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
The continuum of antioxidant response dysregulation in aging/oxidative stress-driven Nlrp3 inflammasome activation-mediated inflammatory response is associated with age-related diseases. Peroxiredoxin (Prdx) 6 is a key antioxidant that provides cytoprotection by regulating redox homeostasis. Herein, using lens epithelial cells (LECs) derived from the targeted inactivation of Prdx6 gene and aging lenses, we present molecular evidence that Prdx6-deficiency causes oxidative-driven Nlrp3 inflammasome activation, resulting in pyroptosis in aging/redox active cells wherein Prdx6 availability offsets the inflammatory process. We observed that Prdx6-/- and aging LECs harboring accumulated reactive oxygen species (ROS) showed augmented activation of Nlrp3 and bioactive inflammatory components, like Caspase-1, IL-1β, ASC and Gasdermin-D. Similar to lipopolysaccharide treatment, oxidative exposure led to further ROS amplification with increased activation of the Nlrp3 inflammasome pathway. Mechanistically, we found that oxidative stress enhanced Kruppel-like factor 9 (Klf9) expression in aging/Prdx6-/- mLECs, leading to a Klf9-dependent increase in Nlrp3 transcription, while the elimination of ROS by the delivery of Prdx6 or by silencing Klf9 prevented the inflammatory response. Altogether, our data identify the biological significance of Prdx6 as an intrinsic checkpoint for regulating the cellular health of aging or redox active LECs and provide opportunities to develop antioxidant-based therapeutic(s) to prevent oxidative/aging-related diseases linked to aberrant Nlrp3 inflammasome activation.
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Affiliation(s)
- Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Rakesh Kumar
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Kahoku 9200293, Ishikawa, Japan;
| | - Priyanka Thakur
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Dhirendra P. Singh
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
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3
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Cozzolino F, Canè L, Sacchettino L, Gatto MC, Iacobucci I, Gatta C, De Biase D, Di Napoli E, Paciello O, Avallone L, Monti M, d’Angelo D, Napolitano F. Preliminary evaluation of the proteomic profiling in the hippocampus of aged grazing cattle. Front Aging Neurosci 2023; 15:1274073. [PMID: 37965495 PMCID: PMC10641839 DOI: 10.3389/fnagi.2023.1274073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/11/2023] [Indexed: 11/16/2023] Open
Abstract
Brain aging is a physiological process associated with physical and cognitive decline; however, in both humans and animals, it can be regarded as a risk factor for neurodegenerative disorders, such as Alzheimer's disease. Among several brain regions, hippocampus appears to be more susceptible to detrimental effects of aging. Hippocampus belongs to limbic system and is mainly involved in declarative memories and context-dependent spatial-learning, whose integrity is compromised in an age-dependent manner. In the present work, taking advantage of liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics, we sought to identify proteins differentially expressed in the hippocampus of the aged grazing milk cows. Our exploratory findings showed that, out of 707 identified proteins, 112 were significantly altered in old cattle, when compared to the adult controls, and functional clusterization highlighted their involvement in myelination, synaptic vesicle, metabolism, and calcium-related biological pathways. Overall, our preliminary data pave the way for the future studies, aimed at better characterizing the role of such a subcortical brain region in the age-dependent cognitive decline, as well as identifying early aging markers to improve animal welfare and husbandry practices of dairy cattle from intensive livestock.
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Affiliation(s)
- Flora Cozzolino
- CEINGE-Biotecnologie Avanzate “Franco Salvatore”-Via G. Salvatore, Naples, Italy
- Department of Chemical Sciences, University of Naples, Federico II, Naples, Italy
| | - Luisa Canè
- CEINGE-Biotecnologie Avanzate “Franco Salvatore”-Via G. Salvatore, Naples, Italy
- Department of Translational Medical Sciences, University of Naples Federico II, Naples, Italy
| | - Luigi Sacchettino
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Maria Claudia Gatto
- CEINGE-Biotecnologie Avanzate “Franco Salvatore”-Via G. Salvatore, Naples, Italy
| | - Ilaria Iacobucci
- CEINGE-Biotecnologie Avanzate “Franco Salvatore”-Via G. Salvatore, Naples, Italy
- Department of Chemical Sciences, University of Naples, Federico II, Naples, Italy
| | - Claudia Gatta
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Davide De Biase
- Department of Pharmacy, University of Salerno, Fisciano, Italy
| | - Evaristo Di Napoli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Orlando Paciello
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Luigi Avallone
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Maria Monti
- CEINGE-Biotecnologie Avanzate “Franco Salvatore”-Via G. Salvatore, Naples, Italy
- Department of Chemical Sciences, University of Naples, Federico II, Naples, Italy
| | - Danila d’Angelo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Francesco Napolitano
- CEINGE-Biotecnologie Avanzate “Franco Salvatore”-Via G. Salvatore, Naples, Italy
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
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Wodrich APK, Scott AW, Giniger E. What do we mean by "aging"? Questions and perspectives revealed by studies in Drosophila. Mech Ageing Dev 2023; 213:111839. [PMID: 37354919 PMCID: PMC10330756 DOI: 10.1016/j.mad.2023.111839] [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: 05/01/2023] [Revised: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 06/26/2023]
Abstract
What is the nature of aging, and how best can we study it? Here, using a series of questions that highlight differing perspectives about the nature of aging, we ask how data from Drosophila melanogaster at the organismal, tissue, cellular, and molecular levels shed light on the complex interactions among the phenotypes associated with aging. Should aging be viewed as an individual's increasing probability of mortality over time or as a progression of physiological states? Are all age-correlated changes in physiology detrimental to vigor or are some compensatory changes that maintain vigor? Why do different age-correlated functions seem to change at different rates in a single individual as it ages? Should aging be considered as a single, integrated process across the scales of biological resolution, from organismal to molecular, or must we consider each level of biological scale as a separate, distinct entity? Viewing aging from these differing perspectives yields distinct but complementary interpretations about the properties and mechanisms of aging and may offer a path through the complexities related to understanding the nature of aging.
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Affiliation(s)
- Andrew P K Wodrich
- National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD, United States; Interdisciplinary Program in Neuroscience, Georgetown University, Washington DC, United States; College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Andrew W Scott
- National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Edward Giniger
- National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD, United States.
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5
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He K, Nie L, Ali T, Liu Z, Li W, Gao R, Zhang Z, Liu J, Dai Z, Xie Y, Zhang Z, Liu G, Dong M, Yu ZJ, Li S, Yang X. Adiponectin deficiency accelerates brain aging via mitochondria-associated neuroinflammation. Immun Ageing 2023; 20:15. [PMID: 37005686 PMCID: PMC10067304 DOI: 10.1186/s12979-023-00339-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 03/10/2023] [Indexed: 04/04/2023]
Abstract
BACKGROUND A wide spectrum of changes occurs in the brain with age, from molecular to morphological aspects, and inflammation accompanied by mitochondria dysfunction is one of the significant factors associated with age. Adiponectin (APN), an essential adipokine in glucose and lipid metabolism, is involved in the aging; however, its role in brain aging has not been adequately explored. Here, we aimed to explore the relationship between APN deficiency and brain aging using multiple biochemical and pharmacological methods to probe APN in humans, KO mice, primary microglia, and BV2 cells. RESULTS We found that declining APN levels in aged human subjects correlated with dysregulated cytokine levels, while APN KO mice exhibited accelerated aging accompanied by learning and memory deficits, anxiety-like behaviors, neuroinflammation, and immunosenescence. APN-deficient mice displayed aggravated mitochondrial dysfunction and HDAC1 upregulation. In BV2 cells, the APN receptor agonist AdipoRon alleviated the mitochondrial deficits and aging markers induced by rotenone or antimycin A. HDAC1 antagonism by Compound 60 (Cpd 60) improved mitochondrial dysfunction and age-related inflammation, as validated in D-galactose-treated APN KO mice. CONCLUSION These findings indicate that APN is a critical regulator of brain aging by preventing neuroinflammation associated with mitochondrial impairment via HDAC1 signaling.
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Affiliation(s)
- Kaiwu He
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China
| | - Lulin Nie
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China
| | - Tahir Ali
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Zizhen Liu
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Weifen Li
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Ruyan Gao
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Zena Zhang
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China
| | - Jianjun Liu
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China
| | - Zhongliang Dai
- Department of Anesthesiology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, Shenzhen, 518020, Guangdong, China
- Department of Anesthesiology, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, 518020, Guangdong, China
- Shenzhen Engineering Research Center of Anesthesiology, Shenzhen, 518020, Guangdong, China
| | - Yongmei Xie
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu, 610041, China
| | - Zaijun Zhang
- Institute of New Drug Research, College of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Gongping Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Ministry of Education of China and Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ming Dong
- Guangzhou International Bio Island, Guangzhou, 510005, Guangdong Province, China
| | - Zhi-Jian Yu
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, The 6Th Affiliated Hospital of Shenzhen University Health Science, Center. No 89, Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
| | - Shupeng Li
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
- Campbell Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
| | - Xifei Yang
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China.
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6
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Rangan AV, McGrouther CC, Bhadra N, Venn-Watson S, Jensen ED, Schork NJ. A time-series analysis of blood-based biomarkers within a 25-year longitudinal dolphin cohort. PLoS Comput Biol 2023; 19:e1010890. [PMID: 36802395 PMCID: PMC9983899 DOI: 10.1371/journal.pcbi.1010890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 03/03/2023] [Accepted: 01/23/2023] [Indexed: 02/23/2023] Open
Abstract
Causal interactions and correlations between clinically-relevant biomarkers are important to understand, both for informing potential medical interventions as well as predicting the likely health trajectory of any individual as they age. These interactions and correlations can be hard to establish in humans, due to the difficulties of routine sampling and controlling for individual differences (e.g., diet, socio-economic status, medication). Because bottlenose dolphins are long-lived mammals that exhibit several age-related phenomena similar to humans, we analyzed data from a well controlled 25-year longitudinal cohort of 144 dolphins. The data from this study has been reported on earlier, and consists of 44 clinically relevant biomarkers. This time-series data exhibits three starkly different influences: (A) directed interactions between biomarkers, (B) sources of biological variation that can either correlate or decorrelate different biomarkers, and (C) random observation-noise which combines measurement error and very rapid fluctuations in the dolphin's biomarkers. Importantly, the sources of biological variation (type-B) are large in magnitude, often comparable to the observation errors (type-C) and larger than the effect of the directed interactions (type-A). Attempting to recover the type-A interactions without accounting for the type-B and type-C variation can result in an abundance of false-positives and false-negatives. Using a generalized regression which fits the longitudinal data with a linear model accounting for all three influences, we demonstrate that the dolphins exhibit many significant directed interactions (type-A), as well as strong correlated variation (type-B), between several pairs of biomarkers. Moreover, many of these interactions are associated with advanced age, suggesting that these interactions can be monitored and/or targeted to predict and potentially affect aging.
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Affiliation(s)
- Aaditya V. Rangan
- Courant Institute of Mathematical Sciences, New York University, New York, New York, United States of America
- * E-mail:
| | - Caroline C. McGrouther
- Courant Institute of Mathematical Sciences, New York University, New York, New York, United States of America
| | - Nivedita Bhadra
- Quantitative Medicine and Systems Biology, The Translational Genomics Research Institute, Phoenix, Arizona, United States of America
| | | | - Eric D. Jensen
- US Navy Marine Mammal Program, Naval Information Warfare Center Pacific, San Diego, California, United States of America
| | - Nicholas J. Schork
- Quantitative Medicine and Systems Biology, The Translational Genomics Research Institute, Phoenix, Arizona, United States of America
- Seraphina Therapeutics, Inc., San Diego, California, United States of America
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Paxman J, Zhou Z, O'Laughlin R, Liu Y, Li Y, Tian W, Su H, Jiang Y, Holness SE, Stasiowski E, Tsimring LS, Pillus L, Hasty J, Hao N. Age-dependent aggregation of ribosomal RNA-binding proteins links deterioration in chromatin stability with challenges to proteostasis. eLife 2022; 11:e75978. [PMID: 36194205 PMCID: PMC9578700 DOI: 10.7554/elife.75978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 10/03/2022] [Indexed: 11/13/2022] Open
Abstract
Chromatin instability and protein homeostasis (proteostasis) stress are two well-established hallmarks of aging, which have been considered largely independent of each other. Using microfluidics and single-cell imaging approaches, we observed that, during the replicative aging of Saccharomyces cerevisiae, a challenge to proteostasis occurs specifically in the fraction of cells with decreased stability within the ribosomal DNA (rDNA). A screen of 170 yeast RNA-binding proteins identified ribosomal RNA (rRNA)-binding proteins as the most enriched group that aggregate upon a decrease in rDNA stability induced by inhibition of a conserved lysine deacetylase Sir2. Further, loss of rDNA stability induces age-dependent aggregation of rRNA-binding proteins through aberrant overproduction of rRNAs. These aggregates contribute to age-induced proteostasis decline and limit cellular lifespan. Our findings reveal a mechanism underlying the interconnection between chromatin instability and proteostasis stress and highlight the importance of cell-to-cell variability in aging processes.
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Affiliation(s)
- Julie Paxman
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Zhen Zhou
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Richard O'Laughlin
- Department of Bioengineering, University of California, San DiegoLa JollaUnited States
| | - Yuting Liu
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Yang Li
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Wanying Tian
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Hetian Su
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Yanfei Jiang
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Shayna E Holness
- Department of Chemistry and Biochemistry, University of California, San DiegoLa JollaUnited States
| | - Elizabeth Stasiowski
- Department of Bioengineering, University of California, San DiegoLa JollaUnited States
| | - Lev S Tsimring
- Synthetic Biology Institute, University of California, San DiegoLa JollaUnited States
| | - Lorraine Pillus
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
- UCSD Moores Cancer Center, University of California San, DiegoLa JollaUnited States
| | - Jeff Hasty
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
- Department of Bioengineering, University of California, San DiegoLa JollaUnited States
- Synthetic Biology Institute, University of California, San DiegoLa JollaUnited States
| | - Nan Hao
- Department of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
- Department of Bioengineering, University of California, San DiegoLa JollaUnited States
- Synthetic Biology Institute, University of California, San DiegoLa JollaUnited States
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Chhunchha B, Kubo E, Singh DP. Obligatory Role of AMPK Activation and Antioxidant Defense Pathway in the Regulatory Effects of Metformin on Cellular Protection and Prevention of Lens Opacity. Cells 2022; 11:3021. [PMID: 36230981 PMCID: PMC9563310 DOI: 10.3390/cells11193021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/15/2022] [Accepted: 09/21/2022] [Indexed: 11/18/2022] Open
Abstract
Increasing levels of oxidative-stress due to deterioration of the Nrf2 (NFE2-related factor)/ARE (antioxidant response element) pathway is found to be a primary cause of aging pathobiology. Metformin having anti-aging effects can delay/halt aging-related diseases. Herein, using lens epithelial cell lines (LECs) of human (h) or mouse (m) and aging h/m primary LECs along with lenses as model systems, we demonstrated that Metformin could correct deteriorated Bmal1/Nrf2/ARE pathway by reviving AMPK-activation, and transcriptional activities of Bmal1/Nrf2, resulting in increased antioxidants enzymatic activity and expression of Phase II enzymes. This ensued reactive oxygen species (ROS) mitigation with cytoprotection and prevention of lens opacity in response to aging/oxidative stress. It was intriguing to observe that Metformin internalized lens/LECs and upregulated OCTs (Organic Cation Transporters). Mechanistically, we found that Metformin evoked AMPK activation-dependent increase of Bmal1, Nrf2, and antioxidants transcription by promoting direct E-Box and ARE binding of Bmal1 and Nrf2 to the promoters. Loss-of-function and disruption of E-Box/ARE identified that Metformin acted by increasing Bmal1/Nrf2-mediated antioxidant expression. Data showed that AMPK-activation was a requisite for Bmal1/Nrf2-antioxidants-mediated defense, as pharmacologically inactivating AMPK impeded the Metformin's effect. Collectively, the results for the first-time shed light on the hitherto incompletely uncovered crosstalk between the AMPK and Bmal1/Nrf2/antioxidants mediated by Metformin for blunting oxidative/aging-linked pathobiology.
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Affiliation(s)
- Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 9200293, Japan
| | - Dhirendra P. Singh
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
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9
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Rinaldi S, Pallikkuth S, De Armas L, Richardson B, Pan L, Pahwa R, Williams S, Cameron M, Pahwa S. Distinct Molecular Signatures of Aging in Healthy and HIV-Infected Individuals. J Acquir Immune Defic Syndr 2022; 89:S47-S55. [PMID: 35015745 PMCID: PMC8751284 DOI: 10.1097/qai.0000000000002864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 09/27/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Virally suppressed chronic HIV-infected individuals on antiretroviral therapy experience similar immune impairments as HIV-uninfected elderly. However, they manifest symptoms of premature immune aging such as suboptimal responses to vaccination at a younger age. Mechanisms underlying premature immune aging are unclear. SETTING The study site was University of Miami Miller School of Medicine. METHODS In this study, we aimed to identify molecular signatures of aging in HIV-infected (HIV) individuals compared with age-matched healthy control (HC) participants. Transcriptomic profiles of peripheral blood mononuclear cells collected cross-sectionally from study participants were evaluated using RNA sequencing, and genes and pathways associated with age and HIV status were identified and compared between study groups. Generalized linear modeling was used to identify transcriptional signatures associated with age. RESULTS Despite that fewer differentially expressed genes between young (<40 yrs) and old (>59 yrs) were observed in the HIV group, metabolic and innate immune activation pathways were associated with increasing age in both HIV and HC. Age was also associated with pathways involved with T-cell immune activation in HC and with interferon signaling pathways in HIV. We observed signs of precocious immune aging at the transcriptional level in HIV and defined a transcriptional perturbation associated with innate immunity and glucose metabolism induced by aging in both HC and HIV. CONCLUSION In this study, we identified distinct molecular signatures predictive of age in HIV versus HC, which suggest precocious immune aging in HIV. Overall, our results highlight the molecular pathways of immune aging in both HC and HIV that may be targeted for additional mechanistic insights or in a therapeutic setting.
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Affiliation(s)
- Stefano Rinaldi
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL
| | - Suresh Pallikkuth
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL
- Miami Center for AIDS Research, University of Miami Miller School of Medicine, Miami, FL
| | - Lesley De Armas
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL
| | - Brian Richardson
- Department of Population & Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH.
| | - Li Pan
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL
| | - Rajendra Pahwa
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL
| | - Sion Williams
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL
- Miami Center for AIDS Research, University of Miami Miller School of Medicine, Miami, FL
| | - Mark Cameron
- Miami Center for AIDS Research, University of Miami Miller School of Medicine, Miami, FL
- Department of Population & Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH.
| | - Savita Pahwa
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL
- Miami Center for AIDS Research, University of Miami Miller School of Medicine, Miami, FL
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A 25-y longitudinal dolphin cohort supports that long-lived individuals in same environment exhibit variation in aging rates. Proc Natl Acad Sci U S A 2020; 117:20950-20958. [PMID: 32778591 PMCID: PMC7456138 DOI: 10.1073/pnas.1918755117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Aging is a degradative process that varies among individuals. Due to limitations in defining and differentiating aging rates in human populations, understanding why some people appear to age slower than others has proven difficult. We analyzed 44 blood-based indices of health as candidate aging rate biomarkers collected over a 25-y period on a relevant, long-lived population of dolphins. Evidence of subsets of dolphins exhibiting slow and accelerated aging rates were detected, despite sharing the same environment, diet, and health care. Furthermore, some dolphin subsets were more likely to develop clinically relevant conditions, including anemia and immunosenescence. Our results support the notion that aging rates in long-lived mammals may be defined and provide insight into novel interventions to delay aging. While it is believed that humans age at different rates, a lack of robust longitudinal human studies using consensus biomarkers meant to capture aging rates has hindered an understanding of the degree to which individuals vary in their rates of aging. Because bottlenose dolphins are long-lived mammals that develop comorbidities of aging similar to humans, we analyzed data from a well-controlled, 25-y longitudinal cohort of 144 US Navy dolphins housed in the same oceanic environment. Our analysis focused on 44 clinically relevant hematologic and clinical chemistry measures recorded during routine blood draws throughout the dolphins’ lifetimes. Using stepwise regression and general linear models that accommodate correlations between measures obtained on individual dolphins, we demonstrate that, in a manner similar to humans, dolphins exhibit independent and linear age-related declines in four of these measures: hemoglobin, alkaline phosphatase, platelets, and lymphocytes. Using linear regressions and analyses of covariance with post hoc Tukey–Kramer tests to compare slopes (i.e., linear age-related rates) of our four aging rate biomarkers among 34 individual dolphins aging from 10 y to up to 40 y old, we could identify slow and accelerated agers and differentiate subgroups that were more or less likely to develop anemia and lymphopenia. This study successfully documents aging rate differences over the lifetime of long-lived individuals in a controlled environment. Our study suggests that nonenvironmental factors influencing aging rate biomarkers, including declining hemoglobin and anemia, may be targeted to delay the effects of aging in a compelling model of human biology.
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Felker DP, Robbins CE, McCormick MA. Automation of C. elegans lifespan measurement. TRANSLATIONAL MEDICINE OF AGING 2020. [DOI: 10.1016/j.tma.2019.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Felker DP, Robbins CE, McCormick MA. Automation of C. elegans lifespan measurement. TRANSLATIONAL MEDICINE OF AGING 2019; 4:1-10. [PMID: 33134648 PMCID: PMC7597742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023] Open
Abstract
Aging is a fundamental biological process that is still not fully understood. As many of the most significant human diseases have aging as their greatest risk factor, a better understanding of aging potentially has enormous practical implications in treating these diseases. The nematode C. elegans is an exceptionally useful genetic model organism that had been used with great success to shed light on many genes and pathways that are involved in aging. Many of these pathways and mechanisms have been shown to be conserved through mammals. The standard methods for assaying survival in C. elegans to measure changes in lifespan are tedious and time consuming. This limits the throughput and productivity of C. elegans aging researchers. In recent years, many inroads have been made into automating various facets of the collection and analysis of C. elegans lifespan experimental data. The advances described in this review all work to ameliorate some of the hurdles that come with manual worm lifespan scoring, by automating or eliminating some of the most time consuming aspects of the assay. By greatly increasing the throughput of lifespan assays, these methods will enable types of experiments (e.g., drug library screens) whose scale is currently impractical. These methods have already proved exceptionally useful, and some of them are likely to be the predecessors of even more refined methods that could lead to breakthroughs in the ability to study lifespan in C. elegans. This could in turn potentially revolutionize our understanding of the basic biology of aging, and one day lead to treatments that could offset or delay age-related diseases in humans.
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Affiliation(s)
- Daniel P Felker
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Christine E Robbins
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Mark A McCormick
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Autophagy Inflammation and Metabolism Center of Biomedical Research Excellence
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