Targeting the biology of ageing with mTOR inhibitors to improve immune function in older adults: phase 2b and phase 3 randomised trials

Joan B Mannick, Grace Teo, Patti Bernardo, Dean Quinn, Kerry Russell, Lloyd Klickstein, William Marshall, Sarb Shergill

Summary

Background： The COVID-19 pandemic highlights the need for therapies that improve immune function in older adults, including interferon (IFN)-induced antiviral immunity that declines with age. In a previous phase 2a trial, RTB101 (previously known as BEZ235), an oral mechanistic target of rapamycin (mTOR) inhibitor, was observed to increase IFN-induced antiviral gene expression and decrease the incidence of respiratory tract infections (RTIs) in older adults. Therefore, we aimed to investigate whether oral RTB101 upregulated IFN-induced antiviral responses and decreased the incidence of viral RTIs when given once daily for 16 weeks during winter cold and flu season.

Methods ：We did a phase 2b and a phase 3 double-blind, randomised, placebo-controlled trial in adults aged at least 65 years enrolled in New Zealand, Australia, and the USA at 54 sites. In the phase 2b trial, patients were aged 65–85 years, with asthma, type 2 diabetes, chronic obstructive pulmonary disease (COPD), congestive heart failure, were current smokers, or had an emergency room or hospitalisation for an RTI within the past 12 months. In the phase 3 trial, patients were aged at least 65 years, did not have COPD, and were not current smokers. In the phase 2b trial, patients were randomly assigned to using a validated automated randomisation system to oral RTB101 5 mg, RTB101 10 mg once daily, or placebo in part 1 and RTB101 10 mg once daily, RTB101 10 mg twice daily, RTB101 10 mg plus everolimus once daily, or matching placebo in part 2. In the phase 3 trial, patients were randomly assigned to RTB101 10mg once daily or matching placebo. The phase 2b primary outcome was the incidence of laboratoryconfirmed RTIs during 16 weeks of winter cold and influenza season and the phase 3 primary outcome was the incidence of clinically symptomatic respiratory illness defined as symptoms consistent with an RTI, irrespective of whether an infection was laboratory-confirmed. Patients, investigators, and sponsor were masked to treatment assignments. All patients who received at least part of one dose of study drug were included in the primary and safety analyses. The phase 2b trial was registered with ANZCTR, ACTRN12617000468325, ClinicalTrials.gov, NCT03373903, and the phase 3 trial was registered with ANZCTR, ACTRN12619000628145.

Findings: In the phase 2b trial, we recruited 652 participants in total between May 16, 2017, and Jan 10, 2018, 179 participants to part 1 of the study (randomly assigned 1:1:1 to RTB101 5 mg once daily [61 participants], RTB101 10 mg once daily [58 participants], or matching placebo [60 participants]) and 473 patients to part 2 (randomly assigned 1:1:1:1 to RTB101 10 mg once daily [118 participants], RTB101 10 mg twice daily [120 participants], RTB101 10 mg in combination with everolimus 0·1 mg daily [115 participants] or matching placebo [120 participants]). In our first prespecified statistical analysis of the primary efficacy endpoint for part 2 of the phase 2b trial efficacy of RTB101 10 mg in combination with everolimus 0·1 mg once daily compared with placebo did not meet statistical significance but, in our second prespecified analysis, which included data from part 1 and part 2, we found a statistically significant reduction in the proportion of patients who had one or more laboratory-confirmed RTIs in the RTB101 10 mg once daily treatment group (34 [19%] of 176) compared with the pooled placebo group (50 [28%] of 180; odds ratio [OR] 0·601 [90% CI 0·391–0·922]; p=0·02). In the phase 3 trial, we enrolled 1024 patients between May 7, 2018, and July 19, 2019. 513 (50·1%) participants were randomly assigned to RTB101 10 mg once daily and 510 (49·9%) to placebo. In the full analysis set of the phase 3 trial, RTB101 did not reduce the proportion of patients with clinically symptomatic respiratory illness (134 [26%] of 511 patients in the RTB101 treatment group vs 125 [25%] 510 patients in the placebo treatment group; OR 1·07 [90% CI 0·80–1·42]; p=0·65). In both trials, significantly more IFN-induced antiviral genes were upregulated in patients treated with RTB101 as compared with placebo. The study drug was found to be safe and well-tolerated across trials and treatment groups. Only one patient in the placebo group in the phase 3 trial had serious adverse events (nausea, fatigue, hyponatraemia, and arthralgia) which were considered related to study drug treatment. Three patients died in the phase 2b trial and one in the phase 3 trial but no deaths were considered related to study treatment.

Interpretation: The combined results indicate that low doses of the mTOR inhibitor RTB101 are well tolerated and upregulate IFN-induced antiviral responses in older adults. Further refinement of clinical trial endpoints and patient populations might be required to identify whether upregulation of IFN responses by mTOR inhibitors consistently decreases the incidence or severity of viral infections in older adults.

Funding resTORbio and the National Institute on Aging.

Copyright © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license.

Senolytics decrease senescent cells in humans: Preliminary report from a clinical trial of Dasatinib plus Quercetin in individuals with diabetic kidney disease

LaTonya J. Hickson a,b,c,1 , Larissa G.P. Langhi Prata a,1 , Shane A. Bobart c , Tamara K. Evans a,d , Nino Giorgadze a , Shahrukh K. Hashmi a,e , Sandra M. Herrmann c , Michael D. Jensen f , Qingyi Jia f , Kyra L. Jordan c , Todd A. Kellogg g , Sundeep Khosla a,f , Daniel M. Koerber a , Anthony B. Lagnado a,h , Donna K. Lawson i , Nathan K. LeBrasseur a,j,k , Lilach O. Lerman c , Kathleen M. McDonald a,l , Travis J. McKenzie g , João F. Passos a,h , Robert J. Pignolo a,b,f,i,j , Tamar Pirtskhalava a , Ishran M. Saadiq c , Kalli K. Schaefer a , Stephen C. Textor c , Stella G. Victorelli a,h , Tammie L. Volkman a,d , Ailing Xue a , Mark A. Wentworth a,l , Erin O. Wissler Gerdes a,d , Yi Zhu a , Tamara Tchkonia a, ⁎, James L. Kirkland a,b,i,m, ⁎

a Cellular Senescence and Translation and Pharmacology Programs, Robert and Arlene Kogod Center on Aging, Mayo Clinic, United States of America

b Division of Geriatric Medicine and Gerontology, Department of Medicine, Mayo Clinic, United States of America

c Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, United States of America

d Department of Medicine Clinical Trials Unit, Department of Medicine, Mayo Clinic, United States of America

e Division of Hematology, Department of Medicine, Mayo Clinic, United States of America

f Division of Endocrinology, Department of Medicine, Mayo Clinic, United States of America

g Department of Surgery, Mayo Clinic, United States of America

h Department of Physiology and Biomedical Engineering, Mayo Clinic, United States of America

i Division of Hospital Medicine, Department of Medicine, Mayo Clinic, United States of America

j Department of Physiology, Mayo Clinic, United States of America

k Department of Physical Medicine and Rehabilitation, Mayo Clinic, United States of America

l Office of Research Regulatory Support, Mayo Clinic, United States of America

m Division of General Internal Medicine, Department of Medicine, Mayo Clinic, United States of America

article info

Article history:

Received 31 July 2019

Received in revised form 16 August 2019

Accepted 29 August 2019

Keywords:

Senolytics

Cellular senescence

Dasatinib

Quercetin

Diabetic kidney disease

Senescence-associated secretory phenotype

Corresponding authors at: Cellular Senescence Program, Robert and Arlene Kogod Center on Aging, Mayo Clinic, 200 First St., S.W., Rochester, MN 55905, United States of America.

E-mail addresses: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (T. Tchkonia), 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (J.L. Kirkland).

1 These authors contributed equally.

https://doi.org/10.1016/j.ebiom.2019.08.069

2352-3964/© 2019 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Stems Cells and the Pathways to Aging and Cancer

Derrick J. Rossi,1, * Catriona H.M. Jamieson,2 and Irving L. Weissman3

1Immune Disease Institute, Harvard Stem Cell Institute, and the Department of Pathology, Harvard Medical School, Boston, MA 02115, USA

2Moores Cancer Center, Division of Hematology/Oncology and Department of Medicine, University of California, San Diego, CA 92093, USA

3Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University Cancer Center, and Department of Pathology,

Stanford University School of Medicine, Stanford, CA 94305-5323, USA

*Correspondence: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。

DOI 10.1016/j.cell.2008.01.036

The aging of tissue-specific stem cell and progenitor cell compartments is believed to be central to the decline of tissue and organ integrity and function in the elderly. Here, we examine evidence linking stem cell dysfunction to the pathophysiological conditions accompanying aging, focusing on the mechanisms underlying stem cell decline and their contribution to disease pathogenesis.

Benefits of Metformin in Attenuating the Hallmarks of Aging

Ameya S. Kulkarni,1,2, * Sriram Gubbi,3 and Nir Barzilai1,2

1Institute for Aging Research, Albert Einstein College of Medicine, Bronx, New York, NY, USA

2Department of Medicine, Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York, NY, USA

3Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA

*Correspondence: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (A.S.K.), 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (N.B.)

https://doi.org/10.1016/j.cmet.2020.04.001

Biological aging involves an interplay of conserved and targetable molecular mechanisms, summarized as the hallmarks of aging. Metformin, a biguanide that combats age-related disorders and improves health span, is the first drug to be tested for its age-targeting effects in the large clinical trial—TAME (targeting aging by metformin). This review focuses on metformin’s mechanisms in attenuating hallmarks of aging and their interconnectivity, by improving nutrient sensing, enhancing autophagy and intercellular communication, protecting against macromolecular damage, delaying stem cell aging, modulating mitochondrial function, regulating transcription, and lowering telomere attrition and senescence. These characteristics make metformin an attractive gerotherapeutic to translate to human trials.

MicroRNA-455-3p improves synaptic, cognitive functions and extends lifespan: Relevance to Alzheimer’s disease

Subodh Kumar a,**, Hallie Morton a , Neha Sawant a , Erika Orlov a , Lloyd E Bunquin a , Jangampalli Adi Pradeepkiran a , Razelle Alvir a , P. Hemachandra Reddy a , b ,c,d,e,

a Internal Medicine Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA

b Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA

c Neurology Departments School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA

d Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA

e Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, USA

ARTICLE INFO

Keywords: Alzheimer’s disease     MicroRNA-455-3p   Mouse models   Mitochondrial biogenesis   Synaptic activity

ABSTRACT

Background: MicroRNA-455-3p is one of the highly conserved miRNAs involved in multiple cellular functions in humans and we explored its relevance to learning and memory functions in Alzheimer’s disease (AD). Our recent in vitro studies exhibited the protective role of miR-455-3p against AD toxicities in reducing full-length APP and amyloid-β (Aβ) levels, and also in reducing defective mitochondrial biogenesis, impaired mitochondrial dynamics and synaptic deficiencies. In the current study, we sought to determine the function of miR-455-3p in mouse models. 

Methods: For the first time we generated both transgenic (TG) and knockout (KO) mouse models of miR-455-3p. We determined the lifespan extension, cognitive function, mitochondrial biogenesis, mitochondrial dynamics, mitochondrial morphology, dendritic spine density, synapse numbers and synaptic activity in miR-455-3p TG and KO mice.

Results: MiR-455-3p TG mice lived 5 months longer than wild-type (WT) counterparts, whereas KO mice lived 4 months shorter than WT mice. Morris water maze test showed improved cognitive behavior, spatial learning and memory in miR-455-3p TG mice relative to age-matched WT mice and miR-455-3p KO mice. Further, mitochondrial biogenesis, dynamics and synaptic activities were enhanced in miR-455-3p TG mice, while these were reduced in KO mice. Overall, overexpressed miR-455-3p in mice displayed protective effects, whereas depleted miR-455-3p in mice exhibited deleterious effects in relation to lifespan, cognitive behavior, and mitochondrial and synaptic activities.

Conclusion: Both mouse models could be ideal research tools to understand the molecular basis of aging and its relevance to AD and other age-related diseases.

* Corresponding author. Internal Medicine, Cell Biology & Biochemistry, Neuroscience & Pharmacology, Neurology, Public Health and School of Health Professions, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, 79430, United States.

** Corresponding author. Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, 79430, United States. E-mail addresses: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (S. Kumar), 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (P.H. Reddy).

https://doi.org/10.1016/j.redox.2021.102182

Received 14 October 2021; Received in revised form 2 November 2021; Accepted 6 November 2021

Available online 9 November 2021

2213-2317/© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Fisetin is a senotherapeutic that extends health and lifespan

Matthew J. Yousefzadeh a,1 , Yi Zhu b,1 , Sara J. McGowan a,1 , Luise Angelini a,1 , Heike Fuhrmann-Stroissnigg a ,Ming Xu b , Yuan Yuan Ling a , Kendra I. Melos a , Tamar Pirtskhalava b , Christina L. Inman b , Collin McGuckian a ,Erin A. Wade a , Jonathon I. Kato a , Diego Grassi a , Mark Wentworth c , Christin E. Burd d , Edgar A. Arriaga e ,Warren L. Ladiges f , Tamara Tchkonia b , James L. Kirkland b , Paul D. Robbins a, ⁎, Laura J. Niedernhofer a, ⁎

a Department of Molecular Medicine and the Center on Aging, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, United States

b Robert and Arlene Kogod Center on Aging, Mayo Clinic, 200 First St., S.W., Rochester, MN 55905, United States

c Office of Research Regulatory Support, Mayo Clinic, Rochester, MN 55905, United States

d Department of Molecular Genetics and Cancer Biology and Genetics, The Ohio State University, Columbus, OH 43210, United States

e Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, United States

f Department of Comparative Medicine, University of Washington, Seattle, WA 98195, United States

article info

Article history:

Received 11 July 2018

Received in revised form 30 August 2018

Accepted 10 September 2018

Available online 29 September 2018

Keywords: Senolytic  Aging  Progeria  Healthspan  Lifespan  Senescence

⁎ Corresponding author at: Institute on the Biology of Aging and Metabolism, Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, 6-155 Jackson Hall, 321 Church Street, SE, Minneapolis, MN 55455, United States. E-mail addresses: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (P.D. Robbins), 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (L.J. Niedernhofer). 1 Contributed equally.

abstract

Background: Senescence is a tumor suppressor mechanism activated in stressed cells to prevent replication of damaged DNA. Senescent cells have been demonstrated to play a causal role in driving aging and age-related diseases using genetic and pharmacologic approaches. We previously demonstrated that the combination of dasatinib and the flavonoid quercetin is a potent senolytic improving numerous age-related conditions including frailty, osteoporosis and cardiovascular disease. The goal of this study was to identify flavonoids with more potent senolytic activity.

Methods: A panel of flavonoid polyphenols was screened for senolytic activity using senescent murine and human fibroblasts, driven by oxidative and genotoxic stress, respectively. The top senotherapeutic flavonoid was tested in mice modeling a progeroid syndrome carrying a p16INK4a-luciferase reporter and aged wild-type mice to determine the effects of fisetin on senescence markers, age-related histopathology, disease markers, health span and lifespan. Human adipose tissue explants were used to determine if results translated.

Findings: Of the 10 flavonoids tested, fisetin was the most potent senolytic. Acute or intermittent treatment of progeroid and old mice with fisetin reduced senescence markers in multiple tissues, consistent with a hit-and run senolytic mechanism. Fisetin reduced senescence in a subset of cells in murine and human adipose tissue, demonstrating cell-type specificity. Administration of fisetin to wild-type mice late in life restored tissue homeostasis, reduced age-related pathology, and extended median and maximum lifespan.

Interpretation: The natural product fisetin has senotherapeutic activity in mice and in human tissues. Late life intervention was sufficient to yield a potent health benefit. These characteristics suggest the feasibility to translation to human clinical studies.

Fund: NIH grants P01 AG043376 (PDR, LJN), U19 AG056278 (PDR, LJN, WLL), R24 AG047115 (WLL), R37 AG013925 (JLK), R21 AG047984 (JLK), P30 DK050456 (Adipocyte Subcore, JLK), a Glenn Foundation/American Federation for Aging Research (AFAR) BIG Award (JLK), Glenn/AFAR (LJN, CEB), the Ted Nash Long Life and Noaber Foundations (JLK), the Connor Group (JLK), Robert J. and Theresa W. Ryan (JLK), and a Minnesota Partnership Grant (AMAY-UMN#99)-P004610401–1 (JLK, EAA).

© 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/4.0/).

Research in Context

Evidence before this study

      Pharmacological targeting of fundamental mechanisms of aging has the ability to reduce the severity or delay the onset of multiple age-associated co-morbidities simultaneously. One key mechanism demonstrated to drive aging is cellular senescence, whereby accumulation of DNA damage and/or other cellular stressors cause proliferating or terminally differentiated non-dividing cells to enter a state characterized by profound chromatin and secretome changes, increased expression of the cell cycle inhibitor p16Ink4a in many but not all senescent cells, replicative arrest, and resistance to apoptosis. Senescent cells can develop a senescence-associated secretory phenotype (SASP), which has deleterious paracrine and systemic effects. Senescent cells are rare in young individuals, but increase with age in multiple tissues. Drugs able to selectively kill senescent cells, termed senolytics, have been identified including the combination of dastinib and quercetin (D ± Q), which improves many aspects of aging in mouse models of accelerated and natural aging. However, safer and improved drugs targeting senescence likely are needed to eliminate senescent cells safely from multiple organs or even within a single tissue.

Added value of the study

      This study identifies the flavonoid polyphenol fisetin as having greater senotherapeutic activity in cultured cells than quercetin. In addition, fisetin had potent senotherapeutic activity in vivo. Treatment of progeroid and aged wild-type mice acutely or intermittently with fisetin reduced senescence markers in multiple tissues and a subset of cell types in adipose tissue. Importantly, chronic administration of fisetin to wild-type mice late in life improved tissue homeostasis, suppressed age-related pathology, and extended median and maximum lifespan. This result, similar to a recent report on the combination of D ± Q, is the first to document extension of both health span and lifespan by a senolytic with few side effects, even though administration was started late in life.

Implications of all the available evidence

      Taken together, these data establish the natural product fisetin as a potent senotherapeutic, able to reduce the burden of senescent T, NK, progenitor, and endothelial cells from fat tissue, and demonstrate that reducing the senescent cell burden in mice even late in life is sufficient to have a significant health impact. Given the known safety profile of fisetin in humans, clinical trials are beginning in order to test if fisetin can be used effectively to reduce senescent cell burden and alleviate dysfunction in elderly subjects.