Canagliflozin extends life span in genetically heterogeneous male but not female mice

Impact of sodium-glucose cotransporter-2 inhibitors on aging biomarkers and plasma ceramide levels in type 2 diabetes: beyond glycemic control

BACKGROUND

Aging is a complex biological process marked by the decline of physiological functions and heightened susceptibility to chronic illnesses, notably cardiometabolic disorders. Ceramides (Cer) are lipid derivatives linked to aging and metabolic diseases. Sodium-Glucose Cotransporter-2 inhibitors (SGLT2i), widely used in managing type 2 diabetes, have an unclear impact on aging biomarkers and Cer profiles.

OBJECTIVE

This study explored the association between SGLT2i use, plasma Cer levels (CerC16:0, CerC18:0, CerC22:0, CerC24:0, and CerC24:1), and aging biomarkers-Human Insulin-Like Growth Factor 1 (IGF-1), mammalian target of rapamycin (mTOR), 5-Methylcytosine (5MC), and Human H2AFX (Histone H2AX) in patients with type 2 diabetes mellitus (T2DM).

METHODS

In this retrospective study, 95 participants were divided into three groups: patients on SGLT2i (n = 34), patients on non-SGLT2i anti-diabetic treatments (n = 36), and healthy controls (n = 25). Plasma Cer and aging biomarkers were quantified using Liquid Chromatography with tandem mass spectrometry (LC-MS-MS) and ELISA, respectively. Principal component analysis (PCA) assessed group-based clustering, while ANCOVA evaluated group differences with confounder adjustment.

RESULTS

SGLT2i-treated patients showed significantly lower CerC16:0, CerC22:0, and CerC24:1 levels (p < 0.01) and decreased 5MC and H2AX (p < 0.05) compared to non-SGLT2i patients. IGF-1 was significantly elevated in the SGLT2i group (p < 0.01), suggesting a possible protective effect on metabolic health. PCA distinguished control from diabetic groups but revealed overlap between SGLT2i and non-SGLT2i groups.

CONCLUSION

Beyond glucose control, SGLT2i may improve plasma Cer and aging markers in diabetic patients, supporting their broader therapeutic potential in aging and age-related diseases. Further large-scale studies are warranted to confirm these effects and underlying mechanisms.

Biomarkers of aging: from molecules and surrogates to physiology and function

Many countries face an unprecedented challenge in aging demographics. This has led to an exponential growth in research on aging, which, coupled to a massive financial influx of funding in the private and public sectors, has resulted in seminal insights into the underpinnings of this biological process. However, critical validation in humans has been hampered by the limited translatability of results obtained in model organisms, additionally confined by the need for extremely time-consuming clinical studies in the ostensible absence of robust biomarkers that would allow monitoring in shorter time frames. In the future, molecular parameters might hold great promise in this regard. In contrast, biomarkers centered on function, resilience, and frailty are available at the present time, with proven predictive value for morbidity and mortality. In this review, the current knowledge of molecular and physiological aspects of human aging, potential antiaging strategies, and the basis, evidence, and potential application of physiological biomarkers in human aging are discussed.

SGLT2 inhibitors as a novel senotherapeutic approach

Cellular senescence is the permanent cessation of cell proliferation and growth. Senescent cells accumulating in tissues and organs with aging contribute to many chronic diseases, mainly through the secretion of a pro-inflammatory senescence-associated secretory phenotype (SASP). Senotherapeutic (senolytic or senomorphic) strategies targeting senescent cells or/and their SASP are being developed to prolong healthy lifespan and treat age-related pathologies. Sodium-glucose co-transporter 2 (SGLT2) inhibitors are a new class of anti-diabetic drugs that promote the renal excretion of glucose, resulting in lower blood glucose levels. Beyond their glucose-lowering effects, SGLT2 inhibitors have demonstrated protective effects against cardiovascular and renal events. Moreover, SGLT2 inhibitors have recently been associated with the inhibition of cell senescence, making them a promising therapeutic approach for targeting senescence and aging. This review examines the latest research on the senotherapeutic potential of SGLT2 inhibitors.

Canagliflozin-Induced Adaptive Metabolism in Bone

Sodium-glucose transporter-2 inhibitor (SGLT2i) drugs are widely used for lowering blood glucose levels independent of insulin. Beyond this, these drugs induce various metabolic changes, including weight loss and impaired bone integrity. A significant gap exists in understanding SGLT2i-induced skeletal changes, as SGLT2 is not expressed in osteoblasts or osteocytes, which use glucose to remodel the bone matrix. We studied the impact of 1, 3, or 6 months of canagliflozin (CANA), an SGLT2i treatment, on the skeleton of 6-month-old genetically heterogeneous UM-HET3 mice. Significant metabolic adaptations to CANA were evident as early as 1.5 months after treatment, specifically in male mice. CANA-treated male mice exhibited notable reductions in body weight and decreased proinflammatory and bone remodeling markers associated with reduced cortical bone remodeling indices. Bone tissue metabolome indicated enrichment in metabolites related to amino acid transport and tryptophan catabolism in CANA-treated male mice. In contrast, CANA-treated female mice showed increases in nucleic acid metabolism. An integrOmics approach of source-matched bone tissue metabolome and bone marrow RNA sequencing indicated a positive correlation between the two omics data sets in male mice. Three clusters of transcripts and metabolites involved in energy metabolism, oxidative stress response, and cellular proliferation and differentiation were reduced in CANA-treated male mice. In conclusion, CANA affects bone metabolism mainly via the "glucose restriction state" it induces and impacts bone cell proliferation and differentiation. These findings underline the effects of SGLT2i on bone health and highlight the need to consider sex-specific responses when developing clinical treatments that alter substrate availability.

ARTICLE HIGHLIGHTS

Drug-Based Lifespan Extension in Mice Strongly Affects Lipids Across Six Organs

Caloric restriction is associated with slow aging in model organisms. Additionally, some drugs have also been shown to slow aging in rodents. To better understand metabolic mechanisms that are involved in increased lifespan, we analyzed metabolomic differences in six organs of 12-month-old mice using five interventions leading to extended longevity, specifically caloric restriction, 17-α estradiol, and caloric restriction mimetics rapamycin, canagliflozin, and acarbose. These interventions generally have a stronger effect in males than in females. Using Jonckheere's trend test to associate increased average lifespans with metabolic changes for each sex, we found sexual dimorphism in metabolism of plasma, liver, gastrocnemius muscle, kidney, and inguinal fat. Plasma showed the strongest trend of differentially expressed compounds, highlighting potential benefits of plasma in tracking healthy aging. Using chemical set enrichment analysis, we found that the majority of these affected compounds were lipids, particularly in male tissues, in addition to significant differences in trends for amino acids, which were particularly apparent in the kidney. We also found strong metabolomic effects in adipose tissues. Inguinal fat exhibited surprising increases in neutral lipids with polyunsaturated side chains in male mice. In female mice, gonadal fat showed trends proportional to lifespan extension effect across multiple lipid classes, particularly phospholipids. Interestingly, for most tissues, we found similar changes induced by lifespan-extending interventions to metabolomic differences between untreated 12-month-old mice and 4-month-old mice. This finding implies that lifespan-extending treatments tend to reverse metabolic phenotypes to a biologically younger stage.

A new clinical age of aging research

Aging is a major risk factor for a variety of diseases, thus, translation of aging research into practical applications is driven by the unmet need for existing clinical therapeutic options. Basic and translational research efforts are converging at a critical stage, yielding insights into how fundamental aging mechanisms are used to identify promising geroprotectors or therapeutics. This review highlights several research areas from a clinical perspective, including senescent cell targeting, alleviation of inflammaging, and optimization of metabolism with endogenous metabolites or precursors. Refining our understanding of these key areas, especially from the clinical angle, may help us to better understand and attenuate aging processes and improve overall health outcomes.

Obesity accelerates cardiovascular ageing

A global obesity pandemic, coupled with an increasingly ageing population, is exacerbating the burden of cardiovascular disease. Indeed, clinical and experimental evidence underscores a potential connection between obesity and ageing in the pathogenesis of various cardiovascular disorders. This is further supported by the notion that weight reduction not only effectively reduces major cardiovascular events in elderly individuals but is also considered the gold standard for lifespan extension, in obese and non-obese model organisms. This review evaluates the intricate interplay between obesity and ageing from molecular mechanisms to whole organ function within the cardiovascular system. By comparatively analysing their characteristic features, shared molecular and cell biological signatures between obesity and ageing are unveiled, with the intent to shed light on how obesity accelerates cardiovascular ageing. This review also elaborates on how emerging metabolic interventions targeting obesity might protect from cardiovascular diseases largely through antagonizing key molecular mechanisms of the ageing process itself. In sum, this review aims to provide valuable insight into how understanding these interconnected processes could guide the development of novel and effective cardiovascular therapeutics for a growing aged population with a concerning obesity problem.

Compression of morbidity by interventions that steepen the survival curve

Longevity research aims to extend the healthspan while minimizing the duration of disability and morbidity, known as the sickspan. Most longevity interventions in model organisms extend healthspan, but it is not known whether they compress sickspan relative to the lifespan. Here, we present a theory that predicts which interventions compress relative sickspan, based on the shape of the survival curve. Interventions such as caloric restriction that extend mean lifespan while preserving the shape of the survival curve, are predicted to extend the sickspan proportionally, without compressing it. Conversely, a subset of interventions that extend lifespan and steepen the shape of the survival curve are predicted to compress the relative sickspan. We explain this based on the saturating-removal mathematical model of aging, and present evidence from longitudinal health data in mice, Caenorhabditis elegans and Drosophila melanogaster. We apply this theory to identify potential interventions for compressing the sickspan in mice, and to combinations of longevity interventions. This approach offers potential strategies for compressing morbidity and extending healthspan.

The Effect of SGLT2 Inhibition on Brain-related Phenotypes and Aging: A Drug Target Mendelian Randomization Study

INTRODUCTION

An observational study suggested sodium-glucose cotransporter 2 (SGLT2) inhibitors might promote healthy aging. However, whether brain-related phenotypes mediate this association is still a question. We applied Mendelian randomization (MR) to investigate the effect of SGLT2 inhibition on chronological age, biological age, and cognition and explore the mediation effects of brain imaging-derived phenotypes (IDPs).

METHODS

We selected genetic variants associated with both expression levels of SLC5A2 (Genotype-Tissue Expression and eQTLGen data; n = 129 to 31 684) and hemoglobin A1c (HbA1c) levels (UK Biobank; n = 344 182) and used them to proxy the effect of SGLT2 inhibition. Aging-related outcomes, including parental longevity (n = 389 166) and epigenetic clocks (n = 34 710), and cognitive phenotypes, including cognitive function (n = 300 486) and intelligence (n = 269 867) were derived from genome-wide association studies. Two-step MR was conducted to explore the associations between SGLT2 inhibition, IDPs, and aging outcomes and cognition.

RESULTS

SGLT2 inhibition was associated with longer father's attained age [years of life increase per SD (6.75 mmol/mol) reduction in HbA1c levels = 6.21, 95% confidence interval (CI) 1.27-11.15], better cognitive function (beta = .17, 95% CI 0.03-0.31), and higher intelligence (beta = .47, 95% CI 0.19-0.75). Two-step MR identified 2 IDPs as mediators linking SGLT2 inhibition with chronological age (total proportion of mediation = 22.6%), where 4 and 5 IDPs were mediators for SGLT2 inhibition on cognitive function and intelligence, respectively (total proportion of mediation = 61.6% and 68.6%, respectively).

CONCLUSION

Our study supported that SGLT2 inhibition increases father's attained age, cognitive function, and intelligence, which was mediated through brain images of different brain regions. Future studies are needed to investigate whether a similar effect could be observed for users of SGLT2 inhibitors.

Salutary effects of transdermal curcumin on multiple indices of health span in rodent models of normal aging and hypertension

Geroscience has helped to usher in a new and exciting era of aging drug development and evaluation of novel and repurposed agents, as well as natural compounds purported to target one or more aging hallmarks. Among the latter, curcumin has long been pursued as a promising strategy but has failed to provide convincing evidence in human trials. Oral intake is the typical route of administration tested for the vast majority of gerotherapeutic candidates, including curcumin, but efficacy is dependent upon good oral bioavailability and pharmacokinetics. However, unlike FDA-approved oral medications, many natural compounds, such as curcumin, have poor oral bioavailability, which may explain their limited success in translation. To overcome these inherent limitations, we tested a novel solvent-based formulation of concentrated curcumin (VASCEPTOR®), developed for effective skin penetration and delivery of high amounts of bioactive curcuminoids directly to the circulation on aging and age-related conditions. We demonstrate that short-term topical treatment (7.5 mg per dose) with VASCEPTOR® twice per week can improve both vascular health in a rat model of hypertension, while a late-life intervention in aged mice improves multiple indices of health span, including improved exercise tolerance, motor coordination, diastolic function (p < 0.05), a reduction in frailty status (p < 0.05) and expression of some age-related markers in tissues, particular heart and kidney. Thus, these data suggest that the therapeutic potential of curcumin can potentially be dramatically enhanced by topical delivery and, along with other promising candidates, should be prioritized for further development, testing and deployment to potentially target some manifestations of aging in humans.

The Mitochondria-Targeted Peptide Therapeutic Elamipretide Improves Cardiac and Skeletal Muscle Function During Aging Without Detectable Changes in Tissue Epigenetic or Transcriptomic Age

Aging-related decreases in cardiac and skeletal muscle function are strongly associated with various comorbidities. Elamipretide (ELAM), a novel mitochondria-targeted peptide, has demonstrated broad therapeutic efficacy in ameliorating disease conditions associated with mitochondrial dysfunction across both clinical and pre-clinical models. Herein, we investigated the impact of 8-week ELAM treatment on pre- and post-measures of C57BL/6J mice frailty, skeletal muscle, and cardiac muscle function, coupled with post-treatment assessments of biological age and affected molecular pathways. We found that health status, as measured by frailty index, cardiac strain, diastolic function, and skeletal muscle force, is significantly diminished with age, with skeletal muscle force changing in a sex-dependent manner. Conversely, ELAM mitigated frailty accumulation and was able to partially reverse these declines, as evidenced by treatment-induced increases in cardiac strain and muscle fatigue resistance. Despite these improvements, we did not detect statistically significant changes in gene expression or DNA methylation profiles indicative of molecular reorganization or reduced biological age in most ELAM-treated groups. However, pathway analyses revealed that ELAM treatment showed pro-longevity shifts in gene expression, such as upregulation of genes involved in fatty acid metabolism, mitochondrial translation, and oxidative phosphorylation, and downregulation of inflammation. Together, these results indicate that ELAM treatment is effective at mitigating signs of sarcopenia and cardiac dysfunction in an aging mouse model, but that these functional improvements occur independently of detectable changes in epigenetic and transcriptomic age. Thus, some age-related changes in function may be uncoupled from changes in molecular biological age.

Advances in sodium-glucose transporter protein 2 inhibitors and tumors

Tumor is a major challenge to global health and has received extensive attention worldwide due to its high degree of malignancy and poor prognosis. Although the clinical application of targeted therapy and immunotherapy has improved the status quo of tumor treatment, the development of new therapeutic tools for tumors is still necessary. Sodium-glucose transporter protein 2 (SGLT2) inhibitors are a new type of glycemic control drugs, which are widely used in clinical practice because of their effects on weight reduction and protection of cardiac and renal functions. SGLT2 has been found to be overexpressed in many tumors and involved in tumorigenesis, progression and metastasis, suggesting that SGLT2i has a wide range of applications in tumor therapy. The aim of this article is to provide a comprehensive understanding of the research progress of SGLT2i in different tumors by integrating the latest studies and to encourage further exploration of SGLT2i therapies in clinical trials. This could pave the way for more effective management strategies and improved outcomes for tumor patients.

An mTOR inhibitor discovery system using drug-sensitized yeast

Inhibition of the target of rapamycin (TOR/mTOR) protein kinase by the drug rapamycin extends lifespan and health span across diverse species. However, rapamycin has potential off-target and side effects that warrant the discovery of additional TOR inhibitors. TOR was initially discovered in Saccharomyces cerevisiae (yeast) which contains two TOR paralogs, TOR1 and TOR2. Yeast lacking functional Tor1 are viable but are hypersensitive to growth inhibition by TORC1 inhibitors, which is a property of yeast that can be exploited to identify TOR inhibitors. Additionally, yeast lacking FK506-sensitive proline rotamase (FPR1) or containing a tor1-1 allele (a mutation in the Fpr1-rapamycin binding domain of Tor1) are robustly and selectively resistant to rapamycin and analogs that allosterically inhibit TOR activity via an FPR1-dependent mechanism. To facilitate the identification of TOR inhibitors, we generated a panel of yeast strains with mutations in TOR pathway genes combined with the removal of 12 additional genes involved in drug efflux. This creates a drug-sensitive strain background that can sensitively and effectively identify TOR inhibitors. In a wild-type yeast strain background, 25 µM of Torin1 and 100 µM of GSK2126458 (omipalisib) are necessary to observe TOR1-dependent growth inhibition by these known TOR inhibitors. In contrast, 100 nM Torin1 and 500 nM GSK2126458 (omipalisib) are sufficient to identify TOR1-dependent growth inhibition in the drug-sensitized background. This represents a 200-fold and 250-fold increase in detection sensitivity for Torin1 and GSK2126458, respectively. Additionally, for the TOR inhibitor AZD8055, the drug-sensitive system resolves that the compound results in TOR1-dependent growth sensitivity at 100 µM, whereas no growth inhibition is observed in a wild-type yeast strain background. Our platform also identifies the caffeine analog aminophylline as a TOR1-dependent growth inhibitor via selective tor1 growth sensitivity. We also tested nebivolol, isoliquiritigenin, canagliflozin, withaferin A, ganoderic acid A, and taurine and found no evidence for TOR inhibition using our yeast growth-based model. Our results demonstrate that this system is highly effective at identifying compounds that inhibit the TOR pathway. It offers a rapid, cost-efficient, and sensitive tool for drug discovery, with the potential to expedite the identification of new TOR inhibitors that could serve as geroprotective and/or anti-cancer agents.

Caloric restriction and its mimetics in heart failure with preserved ejection fraction: mechanisms and therapeutic potential

The global increase in human life expectancy, coupled with an unprecedented rise in the prevalence of obesity, has led to a growing clinical and socioeconomic burden of heart failure with preserved ejection fraction (HFpEF). Mechanistically, the molecular and cellular hallmarks of aging are omnipresent in HFpEF and are further exacerbated by obesity and associated metabolic diseases. Conversely, weight loss strategies, particularly caloric restriction, have shown promise in improving health status in patients with HFpEF and are considered the gold standard for promoting longevity and healthspan (disease-free lifetime) in model organisms. In this review, we implicate fundamental mechanisms of aging in driving HFpEF and elucidate how caloric restriction mitigates the disease progression. Furthermore, we discuss the potential for pharmacologically mimicking the beneficial effects of caloric restriction in HFpEF using clinically approved and emerging caloric restriction mimetics. We surmise that these compounds could offer novel therapeutic avenues for HFpEF and alleviate the challenges associated with the implementation of caloric restriction and other lifestyle modifications to reduce the burden of HFpEF at a population level.

Sex Differences in Response to Diet Enriched With Glutathione Precursors in the Aging Heart

Common features of the aging heart are dysregulated metabolism, inflammation, and fibrosis. Elevated oxidative stress is another hallmark of cardiac aging that can exacerbate each of these conditions. We hypothesize that by increasing natural antioxidant levels (glutathione), we will improve cardiac function. Twenty-one-month-old mice were fed glycine and N-acetyl cysteine (GlyNAC; glutathione precursors)-supplemented or control diets for 12 weeks. Heart function was monitored longitudinally, and the exercise performance was determined at the end of the study. We found that the GlyNAC diet was beneficial for old male but not old female mice, leading to an increase of Ndufb8 expression (a subunit of the mitochondrial respiratory chain complex), and higher enzymatic activity for CPT1b and CrAT, 2 carnitine acyltransferases that are critical to cardiomyocyte metabolism. Although no quantifiable change of collagen turnover was detected, hearts from GlyNAC-fed old males exhibited a slight but significant enrichment in Fmod, a protein that can inhibit collagen fibril formation, possibly reducing extracellular matrix stiffness and thus improving diastolic function. Cardiac diastolic function was modestly improved in males but not females, and surprisingly GlyNAC-fed female mice showed a decline in exercise performance. In summary, our work supports the concept that aged male and female hearts are phenotypically different. These basic differences may affect the response to pharmacological and diet interventions, including antioxidants.

Anti-aging properties of the aminosterols of the dogfish shark

The development of anti-aging drugs is challenged by both the apparent complexity of the physiological mechanisms involved in aging and the likelihood that many of these mechanisms remain unknown. As a consequence, the development of anti-aging compounds based on the rational targeting of specific pathways has fallen short of the goal. To date, the most impressive compound is rapamycin, a natural bacterial product initially identified as an antifungal, and only subsequently discovered to have anti-aging properties. In this review, we focus on two aminosterols from the dogfish shark, Squalus acanthias, that we discovered initially as broad-spectrum anti-microbial agents. This review is the first to gather together published studies conducted both in vitro and in numerous vertebrate species to demonstrate that these compounds target aging pathways at the cellular level and provide benefits in multiple aging-associated conditions in relevant animal models and in humans. The dogfish aminosterols should be recognized as potential anti-aging drugs.

Deciphering the Timing and Impact of Life-extending Interventions: Temporal Efficacy Profiler Distinguishes Early, Midlife, and Senescence Phase Efficacies

Evidence that life-extending interventions are not uniformly effective across the lifespan calls for an analytic tool that can estimate age-specific treatment effects on mortality hazards. Here we report such a tool, applying it to mouse data from 42 compounds tested in the NIA Interventions Testing Program. This tool identified agents that either reduced (22) or increased (15) mortality hazards or did both (2) in at least one sex, most with marked variation in the duration of efficacy and magnitude of effect size. Only 8 reduced mortality hazards after 90% mortality, when the burden of senescence is the greatest. Sex differences were common. This new analytic tool complements the commonly used log-rank test. It detects more potential life-extending candidates (22 versus 10) and indicates when during the life course they are effective. It also uncovers adverse effects.

Canagliflozin treatment prevents follicular exhaustion and attenuates hallmarks of ovarian aging in genetically heterogenous mice

Ovarian aging is characterized by declines in follicular reserve and the emergence of mitochondrial dysfunction, reactive oxygen species production, inflammation, and fibrosis, which eventually results in menopause. Menopause is associated with increased systemic aging and the development of numerous comorbidities; therefore, the attenuation of ovarian aging could also delay systemic aging processes in women. Recent work has established that the anti-diabetic drug Canagliflozin (Cana), a sodium-glucose transporter 2 inhibitor, elicits benefits on aging-related outcomes, likely through the modulation of nutrient-sensing pathways and metabolic homeostasis. Given that nutrient-sensing pathways play a critical role in controlling primordial follicle activation, we sought to determine if chronic Cana administration would delay ovarian aging and curtail the emergence of pathological hallmarks associated with reproductive senescence. We found that mice receiving Cana maintained their ovarian reserve through 12 months of age, which was associated with declines in primordial follicles FoxO3a phosphorylation, a marker of activation, when compared to the age-matched controls. Furthermore, Cana treatment led to decreased collagen, lipofuscin, and T cell accumulation at 12 months of age. Whole ovary transcriptomic and proteomic analyses revealed subtle improvements, predominantly in mitochondrial function and the regulation of cellular proliferation. Pathway analyses of the transcriptomic data revealed a downregulation in cell proliferation and mitochondrial dysfunction signatures, with an upregulation of oxidative phosphorylation. Pathway analyses of the proteomic data revealed declines in signatures associated with PI3K/AKT activity and lymphocyte accumulation. Collectively, we demonstrate that Cana treatment can delay ovarian aging in mice and could potentially have efficacy for delaying ovarian aging in women.

Downregulation of the NF-κB protein p65 is a shared phenotype among most anti-aging interventions

Many aspects of inflammation increase with aging in mice and humans. Transcriptomic analysis revealed that many murine anti-aging interventions produce lower levels of pro-inflammatory proteins. Here, we explore the hypothesis that different longevity interventions diminish NF-κB levels, potentially mediating some of the anti-inflammatory benefits of lifespan-extending interventions. We found that the NF-κB protein p65 is significantly downregulated in the liver of several kinds of slow-aging mice. These included both sexes of GHRKO and Snell Dwarf mutant mice, and in females only of PAPPA KO mice. P65 is also lower in both sexes of mice treated with rapamycin, canagliflozin, meclizine, or acarbose, and in mice undergoing caloric restriction. Two drugs that extend lifespan of male mice, i.e. 17α-estradiol and astaxanthin, however, did not produce lower levels of p65. We also measured other canonical NF-κB signaling regulators, including the activators IKKα and IKKβ and the inhibitor IκB-α. We found that those regulators do not consistently change in a direction that would lead to of NF-κB inhibition. In contrast, we found that NCoR1, an HDAC3 cofactor and a transcription co-repressor that regulates p65 activity, was also downregulated in many of these mouse models. Finally, we report downregulation of three p65 target proteins that regulate the metabolic and inflammatory states of the liver (HNF4α, IL-1β, and CRP) in multiple slow-aging mouse models. Together, these data suggest that NF-κB signaling, might be inhibited in liver of multiple varieties of slow aging mice. This establishes p65 as a potential target for novel longevity interventions.

Late-life protein or isoleucine restriction impacts physiological and molecular signatures of aging

Restricting the intake of protein or the branched-chain amino acid isoleucine promotes healthspan and extends lifespan in young or adult mice. However, their effects when initiated in aged animals are unknown. Here we investigate the consequences of consuming a diet with 67% reduction of all amino acids (low AA) or of isoleucine alone (low Ile), in male and female C57BL/6J.Nia mice starting at 20 months of age. Both dietary regimens effectively promote overall metabolic health without reducing calorie intake. Both low AA and low Ile diets improve aspects of frailty and slow multiple molecular indicators of aging rate; however, the low Ile diet reduces grip strength in both sexes and has mixed, sexually dimorphic effects on the heart. These results demonstrate that low AA and low Ile diets can promote aspects of healthy aging in aged mice and suggest that similar interventions might promote healthy aging in older adults.

In nondiabetic C57BL/6J mice, canagliflozin affects the skeleton in a sex- and age-dependent manner

Canagliflozin (CANA) is a sodium glucose cotransporter-2 inhibitor that reduces blood glucose levels. Sodium glucose cotransporter-2 is primarily expressed in the kidney, but not in any bone cells, therefore effects on the skeleton are likely to be non-cell autonomous. Originally developed to treat type II diabetes, CANA use has expanded to treat cardiovascular and renovascular disease. Clinical trials examining CANA in diabetic patients have produced contradictory reports on fracture risk, but there are limited data of CANA in nondiabetic conditions. In nondiabetic preclinical models, short-term treatment with CANA negatively affected trabecular bone whereas long-term treatment reduced cortical bone mineralization in male but not female mice. To investigate the skeletal effects of an intermediate period of CANA treatment, we treated male and female C57BL/6 J mice with CANA (180 ppm) for 6 months. Age at treatment initiation was also evaluated, with cohorts starting CANA prior to skeletal maturity (3-months-old) or in adulthood (6-months-old). Longitudinal assessments of bone mineral density revealed early benefits of CANA treatment in female mice. At euthanasia, both trabecular and cortical bone morphology were improved by CANA treatment in males and females. Bone formation was reduced at the endosteal surface. CANA decreased osteoblast number in male mice and bone marrow adiposity in females. Overall, more skeletal benefits were recorded in CANA-treated females than males. Urinary calcium output increased with CANA treatment, but parathyroid hormone was not changed. Despite reduced fasting blood glucose, body composition and whole-body metabolism were minimally changed by CANA treatment. For all outcome measures, limited differences were recorded based on age at treatment initiation. This study demonstrated that in nondiabetic C57BL/6 J mice, an intermediate period of CANA treatment improved bone morphology, but reduced osteoblast and bone marrow adipocyte number as well as serum procollagen type 1 N-terminal pro-peptide in a sex-specific manner.

The mitochondrial-targeted peptide therapeutic elamipretide improves cardiac and skeletal muscle function during aging without detectable changes in tissue epigenetic or transcriptomic age

Aging-related decreases in cardiac and skeletal muscle function are strongly associated with various comorbidities. Elamipretide (ELAM), a novel mitochondrial-targeted peptide, has demonstrated broad therapeutic efficacy in ameliorating disease conditions associated with mitochondrial dysfunction across both clinical and pre-clinical models. ELAM is proposed to restore mitochondrial bioenergetic function by stabilizing inner membrane structure and increasing oxidative phosphorylation coupling and efficiency. Although ELAM treatment effectively attenuates physiological declines in multiple tissues in rodent aging models, it remains unclear whether these functional improvements correlate with favorable changes in molecular biomarkers of aging. Herein, we investigated the impact of 8-week ELAM treatment on pre- and post- measures of C57BL/6J mice frailty, skeletal muscle, and cardiac muscle function, coupled with post-treatment assessments of biological age and affected molecular pathways. We found that health status, as measured by frailty index, cardiac strain, diastolic function, and skeletal muscle force are significantly diminished with age, with skeletal muscle force changing in a sex-dependent manner. Conversely, ELAM mitigated frailty accumulation and was able to partially reverse these declines, as evidenced by treatment-induced increases in cardiac strain and muscle fatigue resistance. Despite these improvements, we did not detect statistically significant changes in gene expression or DNA methylation profiles indicative of molecular reorganization or reduced biological age in most ELAM-treated groups. However, pathway analyses revealed that ELAM treatment showed pro-longevity shifts in gene expression such as upregulation of genes involved in fatty acid metabolism, mitochondrial translation and oxidative phosphorylation, and downregulation of inflammation. Together, these results indicate that ELAM treatment is effective at mitigating signs of sarcopenia and heart failure in an aging mouse model, but that these functional improvements occur independently of detectable changes in epigenetic and transcriptomic age. Thus, some age-related changes in function may be uncoupled from changes in molecular biological age.

Lifespan effects in male UM-HET3 mice treated with sodium thiosulfate, 16-hydroxyestriol, and late-start canagliflozin

Genetically heterogeneous UM-HET3 mice born in 2020 were used to test possible lifespan effects of alpha-ketoglutarate (AKG), 2,4-dinitrophenol (DNP), hydralazine (HYD), nebivolol (NEBI), 16α-hydroxyestriol (OH_Est), and sodium thiosulfate (THIO), and to evaluate the effects of canagliflozin (Cana) when started at 16 months of age. OH_Est produced a 15% increase (p = 0.0001) in median lifespan in males but led to a significant (7%) decline in female lifespan. Cana, started at 16 months, also led to a significant increase (14%, p = 0.004) in males and a significant decline (6%, p = 0.03) in females. Cana given to mice at 6 months led, as in our previous study, to an increase in male lifespan without any change in female lifespan, suggesting that this agent may lead to female-specific late-life harm. We found that blood levels of Cana were approximately 20-fold higher in aged females than in young males, suggesting a possible mechanism for the sex-specific disparities in its effects. NEBI was also found to produce a female-specific decline (4%, p = 0.03) in lifespan. None of the other tested drugs provided a lifespan benefit in either sex. These data bring to 7 the list of ITP-tested drugs that induce at least a 10% lifespan increase in one or both sexes, add a fourth drug with demonstrated mid-life benefits on lifespan, and provide a testable hypothesis that might explain the sexual dimorphism in lifespan effects of the SGLT2 inhibitor Cana.

Empagliflozin rescues lifespan and liver senescence in naturally aged mice

Empagliflozin is currently known to decrease blood glucose levels, delay renal failure, and reduce the risk of cardiovascular death and all-cause mortality in patients with type 2 diabetes with cardiovascular disease. However, the effects of empagliflozin on the lifespan and health of naturally aged organisms are unclear. This study was designed to investigate the impacts and potential mechanisms of empagliflozin on lifespan and liver senescence in naturally aged mice. Our study revealed that empagliflozin improved survival and health in naturally aged mice. Empagliflozin extended the median survival of male mice by 5.9%. Meanwhile, empagliflozin improved learning memory and motor balance, decreased body weight, and downregulated the hepatic protein expression of P21, P16, α-SMA, and COL1A1. Empagliflozin modulates the structure of the intestinal flora, increasing the relative abundance of Lachnospiraceae, Ruminococcaceae, Lactobacillus, Blautia, and Muribaculaceae and decreasing the relative abundance of Erysipelotrichaceae, Turicibacter, and Dubosiella in naturally aged mice. Further exploration discovered that empagliflozin increased the concentration of SCFAs, decreased the levels of the inflammatory factors TNF-α, IL-6, and CXCL9, and regulated the PI3K/AKT/P21 and AMPK/SIRT1/NF-κB pathways, which may represent the underlying mechanisms involved in these beneficial hepatic effects. Taken together, the above results indicated that empagliflozin intervention could be considered a potential strategy for extending lifespan and slowing liver senescence in naturally aged mice.

Hypothalamic sex-specific metabolic shift by canagliflozin during aging

The hypothalamus undergoes significant changes with aging and plays crucial roles in age-related metabolic alterations. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are anti-diabetic agents that promote glucose excretion, and metabolic homeostasis. Recent studies have shown that a SGLT2i, Canagliflozin (Cana), can extend the median survival of genetically heterogeneous UM-HET3 male mice and improve central metabolic control via increases in hypothalamic insulin responsiveness in aged males, as well as reduced age-associated hypothalamic inflammation. We studied the long- and short-term effects of Cana on hypothalamic metabolic control in UM-HET3 mice. Starting the treatment from 7 months of age, we show that 4 weeks of Cana treatment significantly reduced body weight and fat mass in male but not female mice that was associated with enhanced glucose tolerance and insulin sensitivity observed by 12 months. Indirect calorimetry showed that Cana treatment increased energy expenditure in male, but not female mice, at 12 months of age. Long-term Cana treatment increased metabolic rates in both sexes, and markedly increasing formation of both orexigenic and anorexigenic projections to the paraventricular nucleus of the hypothalamus (PVH) mostly in females by 25 months. Hypothalamic RNA-sequencing analysis revealed increased sex-specific genes and signaling pathways related to insulin signaling, glycogen catabolic pathway, neuropeptide signaling, and mitochondrial function upregulated by Cana, with males showing a more pronounced and sustained effect on metabolic pathways at both age groups. Overall, our data provide critical evidence for sex-specific mechanisms that are affected by Cana during aging suggesting key targets of hypothalamic Cana-induced neuroprotection for metabolic control.

The Gehan test identifies life-extending compounds overlooked by the log-rank test in the NIA Interventions Testing Program: Metformin, Enalapril, caffeic acid phenethyl ester, green tea extract, and 17-dimethylaminoethylamino-17-demethoxygeldanamycin hydrochloride

The National Institute on Aging Interventions Testing Program (ITP) has so far identified 12 compounds that extend the lifespan of genetically heterogeneous mice using the log-rank test. However, the log-rank test is relatively insensitive to any compound that does not uniformly reduce mortality across the lifespan. This test may thus miss compounds that only reduce mortality before midlife, for example, a plausible outcome if a compound only mitigates risk factors before midlife or if its efficacy is reduced at later ages. We therefore reanalyzed all data collected by the ITP from 2004-2022 using the Gehan test, which is more sensitive to mortality differences earlier in the life course and does not assume a uniformly reduced mortality hazard across the lifespan. The Gehan test identified 5 additional compounds, metformin, enalapril, 17-dimethylaminoethylamino-17-demethoxygeldanamycin hydrochloride (17-DMAG), caffeic acid phenethyl ester (CAPE), and green tea extract (GTE), which significantly increased survival but were previously missed by the log-rank test. Three (metformin, enalapril, and 17-DMAG) were only effective in males and two (CAPE and GTE) were only effective in females. In addition, 1,3-butanediol, which by log-rank analysis increased survival in females but not males, increased survival in males by the Gehan test. These results suggest that statistical tests sensitive to non-uniformity of drug efficacy across the lifespan should be included in the standard statistical testing protocol to minimize overlooking geroprotective interventions.

Ergothioneine promotes longevity and healthy aging in male mice

Healthy aging has emerged as a crucial issue with the increase in the geriatric population worldwide. Food-derived sulfur-containing amino acid ergothioneine (ERGO) is a potential dietary supplement, which exhibits various beneficial effects in experimental animals although the preventive effects of ERGO on aging and/or age-related impairments such as frailty and cognitive impairment are unclear. We investigated the effects of daily oral supplementation of ERGO dissolved in drinking water on lifespan, frailty, and cognitive impairment in male mice from 7 weeks of age to the end of their lives. Ingestion of 4 ~ 5 mg/kg/day of ERGO remarkably extended the lifespan of male mice. The longevity effect of ERGO was further supported by increase in life and non-frailty spans of Caenorhabditis elegans in the presence of ERGO. Compared with the control group, the ERGO group showed significantly lower age-related declines in weight, fat mass, and average and maximum movement velocities at 88 weeks of age. This was compatible with dramatical suppression by ERGO of the age-related increments in plasma biomarkers (BMs) such as the chemokine ligand 9, creatinine, symmetric dimethylarginine, urea, asymmetric dimethylarginine, quinolinic acid, and kynurenine. The oral intake of ERGO also rescued age-related impairments in learning and memory ability, which might be associated with suppression of the age-related decline in hippocampal neurogenesis and TDP43 protein aggregation and promotion of microglial shift to the M2 phenotype by ERGO ingestion. Ingestion of ERGO may promote longevity and healthy aging in male mice, possibly through multiple biological mechanisms.

Canagliflozin Inhibits Palmitic Acid-Induced Vascular Cell Aging In Vitro through ROS/ERK and Ferroptosis Pathways

Vascular aging is one of the reasons for the high incidence of cardiovascular diseases nowadays, as vascular cells age due to various internal and external factors. Among them, high fat is an important inducer. Canagliflozin (CAN) is one of the SGLT2 inhibitors that has been shown to have cardiovascular protective effects in addition to lowering blood sugar, but the specific mechanism is not clear. This study first established a vascular aging model using palmitic acid (PA), then tested the effect of CAN on PA-induced vascular aging, and finally examined the mechanism of CAN's anti-vascular aging via ROS/ERK and ferroptosis pathways. We found that CAN alleviates PA-induced vascular cell aging by inhibiting the activation of ROS/ERK and ferroptosis signaling pathways. This study reveals new mechanisms of lipid-induced vascular aging and CAN inhibition of vascular aging from the perspectives of ROS/ERK and ferroptosis pathways, which is expected to provide new ideas for the development of related drugs in the future.

Repurposing effect of cardiovascular-metabolic drug to increase lifespan: a systematic review of animal studies and current clinical trial progress

With the increase in life expectancy, aging has emerged as a significant health concern. Due to its various mechanisms of action, cardiometabolic drugs are often repurposed for other indications, including aging. This systematic review analyzed and highlighted the repositioning potential of cardiometabolic drugs to increase lifespan as an aging parameter in animal studies and supplemented by information from current clinical trial registries. Systematic searching in animal studies was performed based on PICO: "animal," "cardiometabolic drug," and "lifespan." All clinical trial registries were also searched from the WHO International Clinical Trial Registry Platform (ICTRP). Analysis of 49 animal trials and 10 clinical trial registries show that various cardiovascular and metabolic drugs have the potential to target lifespan. Metformin, acarbose, and aspirin are the three most studied drugs in animal trials. Aspirin and acarbose are the promising ones, whereas metformin exhibits various results. In clinical trial registries, metformin, omega-3 fatty acid, acarbose, and atorvastatin are currently cardiometabolic drugs that are repurposed to target aging. Published clinical trial results show great potential for omega-3 and metformin in healthspan. Systematic Review Registration: crd.york.ac.uk/prospero/display_record.php?RecordID=457358, identifier: CRD42023457358.

Candidate molecular targets uncovered in mouse lifespan extension studies

INTRODUCTION

Multiple interventions have demonstrated an increase in mouse lifespan. However, non-standardized controls, sex or strain-specific factors, and insufficient focus on targets, hinder the translation of these findings into clinical applications.

AREAS COVERED

We examined the effects of genetic and drug-based interventions on mice from databases DrugAge, GenAge, the Mouse Phenome Database, and publications from PubMed that led to a lifespan extension of more than 10%, identifying specific molecular targets that were manipulated to achieve the maximum lifespan in mice. Subsequently, we characterized 10 molecular targets influenced by these interventions, with particular attention given to clinical trials and potential indications for each.

EXPERT OPINION

To increase the translational potential of mice life-extension studies to clinical research several factors are crucial: standardization of mice lifespan research approaches, the development of clear criteria for control and experimental groups, the establishment of criteria for potential geroprotectors, and focusing on targets and their clinical application. Pinpointing the targets affected by geroprotectors helps in understanding species-specific differences and identifying potential side effects, ensuring the safety and effectiveness of clinical trials. Additionally, target review facilitates the optimization of treatment protocols and the evaluation of the clinical feasibility of translating research findings into practical therapies for humans.

Proteomic changes induced by longevity-promoting interventions in mice

Using mouse models and high-throughput proteomics, we conducted an in-depth analysis of the proteome changes induced in response to seven interventions known to increase mouse lifespan. This included two genetic mutations, a growth hormone receptor knockout (GHRKO mice) and a mutation in the Pit-1 locus (Snell dwarf mice), four drug treatments (rapamycin, acarbose, canagliflozin, and 17α-estradiol), and caloric restriction. Each of the interventions studied induced variable changes in the concentrations of proteins across liver, kidney, and gastrocnemius muscle tissue samples, with the strongest responses in the liver and limited concordance in protein responses across tissues. To the extent that these interventions promote longevity through common biological mechanisms, we anticipated that proteins associated with longevity could be identified by characterizing shared responses across all or multiple interventions. Many of the proteome alterations induced by each intervention were distinct, potentially implicating a variety of biological pathways as being related to lifespan extension. While we found no protein that was affected similarly by every intervention, we identified a set of proteins that responded to multiple interventions. These proteins were functionally diverse but tended to be involved in peroxisomal oxidation and metabolism of fatty acids. These results provide candidate proteins and biological mechanisms related to enhancing longevity that can inform research on therapeutic approaches to promote healthy aging.

SGLT2i improves kidney senescence by down-regulating the expression of LTBP2 in SAMP8 mice

Senescent kidney can lead to the maladaptive repairment and predispose age-related kidney diseases. Here, we explore the renal anti-senescence effect of a known kind of drug, sodium-dependent glucose transporters 2 inhibitor (SGLT2i). After 4 months intragastrically administration with dapagliflozin on senescence-accelerated mouse prone 8 (SAMP8) strain mice, the physiologically effects (lowering urine protein, enhancing glomerular blood perfusion, inhibiting expression of senescence-related biomarkers) and structural changes (improving kidney atrophy, alleviating fibrosis, decreasing glomerular mesangial proliferation) indicate the potential value of delaying kidney senescence of SGLT2i. Senescent human proximal tubular epithelial (HK-2) cells induced by H2 O2 also exhibit lower senescent markers after dapagliflozin treatment. Further mechanism exploration suggests LTBP2 have the great possibility to be the target for SGLT2i to exert its renal anti-senescence role. Dapagliflozin down-regulate the LTBP2 expression in kidney tissues and HK-2 cells with senescent phenotypes. Immunofluorescence staining show SGLT2 and LTBP2 exist colocalization, and protein-docking analysis implies there is salt-bridge formation between them; these all indicate the possibility of weak-interaction between the two proteins. Apart from reducing LTBP2 expression in intracellular area induced by H2 O2 , dapagliflozin also decrease the concentration of LTBP2 in cell culture medium. Together, these results reveal dapagliflozin can delay natural kidney senescence in non-diabetes environment; the mechanism may be through regulating the role of LTBP2.

Responses to Many Anti-Aging Interventions Are Sexually Dimorphic

There is increasing appreciation that sex differences are not limited to reproductive organs or traits related to reproduction and that sex is an important biological variable in most characteristics of a living organism. The biological process of aging and aging-related traits are no exception and exhibit numerous, often major, sex differences. This article explores one aspect of these differences, namely sex differences in the responses to anti-aging interventions. Aging can be slowed down and/or postponed by a variety of environmental ("lifestyle"), genetic or pharmacological interventions. Although many, particularly older studies utilized only one sex of experimental animals, there is considerable evidence that responses to these interventions can be very different in females and males. Calorie restriction (CR), that is reducing food intake without malnutrition can extend longevity in both sexes, but specific metabolic alterations and health benefits induced by CR are not the same in women and men. In laboratory mice, several of the genetic alterations that reduce insulin-like growth factor I (IGF-1) signaling extend longevity more effectively in females or in females only. Beneficial effects of rapamycin, an inhibitor of mTOR signaling, on mouse longevity are greater in females. In contrast, several anti-aging compounds, including a weak estrogen, 17 alpha estradiol, extend longevity of male, but not female, mice. Apparently, fundamental mechanisms of aging are not identical in females and males and it is essential to use both sexes in studies aimed at identifying novel anti-aging interventions. Recommendations for lifestyle modifications, drugs, and dietary supplements to maintain good health and functionality into advanced age and to live longer will likely need to be tailored to the sex of the user.

Geroprotector drugs and exercise: friends or foes on healthy longevity?

Physical activity and several pharmacological approaches individually combat age-associated conditions and extend healthy longevity in model systems. It is tantalizing to extrapolate that combining geroprotector drugs with exercise could extend healthy longevity beyond any individual treatment. However, the current dogma suggests that taking leading geroprotector drugs on the same day as exercise may limit several health benefits. Here, we review leading candidate geroprotector drugs and their interactions with exercise and highlight salient gaps in knowledge that need to be addressed to identify if geroprotector drugs can have a harmonious relationship with exercise.

On the wake of metformin: Do anti-diabetic SGLT2 inhibitors exert anti-aging effects?

Here we propose that SGLT2 inhibitors (SGLT2i), a class of drugs primarily used to treat type 2 diabetes, could also be repositioned as anti-aging senomorphic drugs (agents that prevent the extrinsic harmful effects of senescent cells). As observed for metformin, another anti-diabetic drug with established anti-aging potential, increasing evidence suggests that SGLT2i can modulate some relevant pathways associated with the aging process, such as free radical production, cellular energy regulation through AMP-activated protein kinase (AMPK), autophagy, and the activation of nuclear factor (NF)-kB/inflammasome. Some interesting pro-healthy effects were also observed on human microbiota. All these mechanisms converge on fueling a systemic proinflammatory condition called inflammaging, now recognized as the main risk factor for accelerated aging and increased risk of age-related disease development and progression. Inflammaging can be worsened by cellular senescence and immunosenescence, which contributes to the increased burden of senescent cells during aging, perpetuating the proinflammatory condition. Interestingly, increasing evidence suggested the direct effects of SGLT-2i against senescent cells, chronic activation of immune cells, and metabolic alterations induced by overnutrition (meta-inflammation). In this framework, we analyzed and discussed the multifaceted impact of SGLT2i, compared with metformin effects, as a potential anti-aging drug beyond diabetes management. Despite promising results in experimental studies, rigorous investigations with well-designed cellular and clinical investigations will need to validate SGLT2 inhibitors' anti-aging effects.

Canagliflozin mediates tumor suppression alone and in combination with radiotherapy in non-small cell lung cancer (NSCLC) through inhibition of HIF-1α

Non-small cell lung cancer (NSCLC) has a poor prognosis, and effective therapeutic strategies are lacking. The diabetes drug canagliflozin inhibits NSCLC cell proliferation and the mammalian target of rapamycin (mTOR) pathway, which mediates cell growth and survival, but it is unclear whether this drug can enhance response rates when combined with cytotoxic therapy. Here, we evaluated the effects of canagliflozin on human NSCLC response to cytotoxic therapy in tissue cultures and xenografts. Ribonucleic acid sequencing (RNA-seq), real-time quantitative PCR (RT-qPCR), metabolic function, small interfering ribonucleic acid (siRNA) knockdown, and protein expression assays were used in mechanistic analyses. We found that canagliflozin inhibited proliferation and clonogenic survival of NSCLC cells and augmented the efficacy of radiotherapy to mediate these effects and inhibit NSCLC xenograft growth. Canagliflozin treatment alone moderately inhibited mitochondrial oxidative phosphorylation and exhibited greater antiproliferative capacity than specific mitochondrial complex-I inhibitors. The treatment downregulated genes mediating hypoxia-inducible factor (HIF)-1α stability, metabolism and survival, activated adenosine monophosphate-activated protein kinase (AMPK) and inhibited mTOR, a critical activator of hypoxia-inducible factor-1α (HIF-1α) signaling. HIF-1α knockdown and stabilization experiments suggested that canagliflozin mediates antiproliferative effects, in part, through suppression of HIF-1α. Transcriptional regulatory network analysis pinpointed histone deacetylase 2 (HDAC2), a gene suppressed by canagliflozin, as a key mediator of canagliflozin's transcriptional reprogramming. HDAC2 knockdown eliminated HIF-1α levels and enhanced the antiproliferative effects of canagliflozin. HDAC2-regulated genes suppressed by canagliflozin are associated with poor prognosis in several clinical NSCLC datasets. In addition, we include evidence that canagliflozin also improves NSCLC response to chemotherapy. In summary, canagliflozin may be a promising therapy to develop in combination with cytotoxic therapy in NSCLC.

Effect of mitochondrial quantity and quality controls in white adipose tissue on healthy lifespan: Essential roles of GH/IGF-1-independent pathways in caloric restriction-mediated metabolic remodeling

Long-term caloric restriction is a conventional and reproducible dietary intervention to improve whole body metabolism, suppress age-related pathophysiology, and extend lifespan. The beneficial actions of caloric restriction are widely accepted to be regulated in both growth hormone/insulin-like growth factor 1-dependent and -independent manners. Although growth hormone/insulin-like growth factor 1-dependent regulatory mechanisms are well described, those occurring independent of growth hormone/insulin-like growth factor 1 are poorly understood. In this review, we focus on molecular mechanisms of caloric restriction regulated in a growth hormone/insulin-like growth factor 1-independent manner. Caloric restriction increases mitochondrial quantity and improves mitochondrial quality by activating an axis involving sterol regulatory element binding protein-c/peroxisome proliferator-activated receptor γ coactivator-1α/mitochondrial intermediate peptidase in a growth hormone/insulin-like growth factor 1-independent manner, particularly in white adipose tissue. Fibroblast growth factor 21 is also involved in this axis. Moreover, the axis may be regulated by lower leptin signaling. Thus, caloric restriction appears to induce beneficial actions partially by regulating mitochondrial quantity and quality in white adipose tissue in a growth hormone/insulin-like growth factor 1-independent manner.

The Comparation of Renal Anti-Senescence Effects and Blood Metabolites between Dapagliflozin and Metformin in Non-Diabetes Environment

Delaying kidney senescence process will benefit renal physiologic conditions, and prompt the kidney recovering from different pathological states. The renal anti-senescence effects of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and metformin have been proven in diabetic settings, but the roles of each one and combination of two drugs in natural kidney aging process remain undefined and deserve further research. Senescence-accelerated mouse prone 8 (SAMP8) were orally administered dapagliflozin, metformin, and a combination of them for 16 weeks. Dapagliflozin exhibits better effects than metformin in lowering senescence related markers, and the combination therapy shows the best results. In vitro experiments demonstrate the same results that the combination of dapagliflozin and metformin can exert a better anti-senescence effect. Blood metabolites detection in vivo shows dapagliflozin mainly leads to the change of blood metabolites enriched in choline metabolism, and metformin tends to induce change of blood metabolites enriched in purine metabolism. In conclusion, the results suggest dapagliflozin may have a better renal anti-senescence effect than metformin in non-diabetes environment, and the combination of the two drugs can strengthen the effect. The two drugs can lead to different blood metabolites alteration, which may lead to different systemic effects.

Empagliflozin improves kidney senescence induced by D-galactose by reducing sirt1-mediated oxidative stress

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors have received widespread attention because of their significant protective effects on the kidney. Previous studies have shown that Sirt1, as which is an antiaging protein, is closely related to the maintenance of redox homeostasis. The goal of this study was to determine whether empagliflozin could ameliorate D-galactose-induced renal senescence in mice, and examine the possible mechanisms of Sirt1. We constructed a rapid ageing model in mice by administering D-galactose. An ageing model was constructed by treating cells with high glucose. Treadmill and Y-maze tests were used to assess exercise tolerance and learning memory ability. Pathologically stained sections were used to assess kidney injury. Tissue and cell senescence were evaluated by senescence-associated β-galactosidase staining. The expression levels of P16, SOD1, SOD2 and Sirt1 were detected by immunoblotting. D-gal-treated mice exhibited significant age-related changes, as measured by behavioural tests and ageing marker protein levels. empagliflozin alleviated these ageing manifestations. In addition, Sirt1, SOD1 and SOD2 levels were downregulated in model mice and upregulated by empagliflozin treatment. Empagliflozin had similar protective effects at the cellular level, and these effects were reduced by the Sirt1 inhibitor. Empagliflozin has an antiaging effect, which may be related to reducing Sirt1-mediated oxidative stress.

The SGLT2 inhibitor canagliflozin suppresses growth and enhances prostate cancer response to radiotherapy

Radiotherapy is a non-invasive standard treatment for prostate cancer (PC). However, PC develops radio-resistance, highlighting a need for agents to improve radiotherapy response. Canagliflozin, an inhibitor of sodium-glucose co-transporter-2, is approved for use in diabetes and heart failure, but is also shown to inhibit PC growth. However, whether canagliflozin can improve radiotherapy response in PC remains unknown. Here, we show that well-tolerated doses of canagliflozin suppress proliferation and survival of androgen-sensitive and insensitive human PC cells and tumors and sensitize them to radiotherapy. Canagliflozin blocks mitochondrial respiration, promotes AMPK activity, inhibits the MAPK and mTOR-p70S6k/4EBP1 pathways, activates cell cycle checkpoints, and inhibits proliferation in part through HIF-1α suppression. Canagliflozin mediates transcriptional reprogramming of several metabolic and survival pathways known to be regulated by ETS and E2F family transcription factors. Genes downregulated by canagliflozin are associated with poor PC prognosis. This study lays the groundwork for clinical investigation of canagliflozin in PC prevention and treatment in combination with radiotherapy.

Canagliflozin shares common mTOR and MAPK signaling mechanisms with other lifespan extension treatments

Long-lived mouse models and treatments that extend lifespan, such as Rapamycin, acarbose and 17α- -estradiol, lead to reduction in mTORC1 activity, declines in cap-dependent translation and increases in cap-independent translation. In addition, these treatments reduce the MEK-ERK-MNK (ERK1-2) signaling cascade, leading to reduction in eIF4E phosphorylation, which also regulates mRNA translation. Here, we report that Canagliflozin, a drug that extends lifespan only in male mice reduces mTORC1 and ERK1-2 signaling in male mice only. The data suggest reduction in mTORC1 and ERK pathways are common mechanisms shared by both genetic and pharmacological models of slowed aging in mice. Our data also reveal a significant sexual dimorphism in the ERK1-2 signaling pathway which might help to explain why some drugs can extend lifespan in males but have no effects in female mice.

Impact of Geroscience on Therapeutic Strategies for Older Adults With Cardiovascular Disease: JACC Scientific Statement

Geroscience posits that cardiovascular disease (CVD) and other chronic diseases result from progressive erosion of the effectiveness of homeostatic mechanisms that oppose age-related accumulation of molecular damage. This hypothetical common root to chronic diseases explains why patients with CVD are often affected by multimorbidity and frailty and why older age negatively affects CVD prognosis and treatment response. Gerotherapeutics enhance resilience mechanisms that counter age-related molecular damage to prevent chronic diseases, frailty, and disability, thereby extending healthspan. Here, we describe the main resilience mechanisms of mammalian aging, with a focus on how they can affect CVD pathophysiology. We next present novel gerotherapeutic approaches, some of which are already used in management of CVD, and explore their potential to transform care and management of CVD. The geroscience paradigm is gaining traction broadly in medical specialties, with potential to mitigate premature aging, reduce health care disparities, and improve population healthspan.

Four anti-aging drugs and calorie-restricted diet produce parallel effects in fat, brain, muscle, macrophages, and plasma of young mice

Average and maximal lifespan can be increased in mice, in one or both sexes, by four drugs: rapamycin, acarbose, 17a-estradiol, and canagliflozin. We show here that these four drugs, as well as a calorie-restricted diet, can induce a common set of changes in fat, macrophages, plasma, muscle, and brain when evaluated in young adults at 12 months of age. These shared traits include an increase in uncoupling protein UCP1 in brown fat and in subcutaneous and intra-abdominal white fat, a decline in proinflammatory M1 macrophages and corresponding increase in anti-inflammatory M2 macrophages, an increase in muscle fibronectin type III domain containing 5 (FNDC5) and its cleavage product irisin, and higher levels of doublecortin (DCX) and brain-derived neurotrophic factor (BDNF) in brain. Each of these proteins is thought to play a role in one or more age-related diseases, including metabolic, inflammatory, and neurodegenerative diseases. We have previously shown that the same suite of changes is seen in each of four varieties of slow-aging single-gene mutant mice. We propose that these changes may be a part of a shared common pathway that is seen in slow-aging mice whether the delayed aging is due to a mutation, a low-calorie diet, or a drug.

Lifespan-extending interventions induce consistent patterns of fatty acid oxidation in mouse livers

Aging manifests as progressive deteriorations in homeostasis, requiring systems-level perspectives to investigate the gradual molecular dysregulation of underlying biological processes. Here, we report systemic changes in the molecular regulation of biological processes under multiple lifespan-extending interventions. Differential Rank Conservation (DIRAC) analyses of mouse liver proteomics and transcriptomics data show that mechanistically distinct lifespan-extending interventions (acarbose, 17α-estradiol, rapamycin, and calorie restriction) generally tighten the regulation of biological modules. These tightening patterns are similar across the interventions, particularly in processes such as fatty acid oxidation, immune response, and stress response. Differences in DIRAC patterns between proteins and transcripts highlight specific modules which may be tightened via augmented cap-independent translation. Moreover, the systemic shifts in fatty acid metabolism are supported through integrated analysis of liver transcriptomics data with a mouse genome-scale metabolic model. Our findings highlight the power of systems-level approaches for identifying and characterizing the biological processes involved in aging and longevity.

Newer glucose-lowering drugs and risk of dementia: A systematic review and meta-analysis of observational studies

BACKGROUND

Preclinical studies have suggested potential beneficial effects of newer glucose-lowering drugs (GLDs) including dipeptidyl peptidase (DPP)-4 inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1RAs), and sodium glucose co-transporter-2 (SGLT2) inhibitors, in protecting humans against cognitive decline and dementia. However, population studies aiming to demonstrate such cognitive benefits from newer GLDs have produced mixed findings. This meta-analysis aimed to evaluate the association between newer GLDs and risk of dementia in adults with type 2 diabetes (T2D).

METHODS

Electronic databases were searched up to March 11, 2022 to include observational studies that examined the association between DPP-4 inhibitors, GLP-1RAs, and SGLT2 inhibitors and risk of dementia (including all-cause dementia, Alzheimer's disease [AD], and vascular dementia [VD]) in people with T2D. We conducted a random-effects meta-analysis to calculate the relative risk (RR) with 95% confidence interval (CI) for each class of newer GLD.

RESULTS

Ten studies (from nine articles) involving 819,511 individuals with T2D were included. Three studies found that SGLT2 inhibitor users had a lower risk of all-cause dementia than non-SGLT2 inhibitor users (RR, 0.62; 95% CI, 0.39-0.97). Five studies found that users versus nonusers of GLP-1RAs were associated with a significant reduction in the risk of all-cause dementia (RR, 0.72; 95% CI, 0.54-0.97). However, a meta-analysis for AD and VD was unavailable for SGLT2 inhibitors and GLP-1RAs because only one study was included for each drug. In seven studies, users vs. nonusers of DPP-4 inhibitors were significantly associated with a decreased risk of all-cause dementia (RR, 0.84; 95% CI, 0.74-0.94) and VD (RR, 0.59; 95% CI, 0.47-0.75) but not AD (RR, 0.82; 95% CI, 0.63-1.08).

CONCLUSION

Newer GLDs were associated with a decreased risk of all-cause dementia in people with T2D. Because of the observational nature and significant heterogeneity between studies, the results should be interpreted with caution. Further research is warranted to confirm our findings.

Aging Rate Indicators: Speedometers for Aging Research in Mice

A "biomarker of aging" is conceptualized as an index of how far an individual has moved along the path from youth to old age. In contrast, an aging rate indicator (ARI) represents a measure of speed, rather than distance, that is, a measure of how rapidly the individual is moving toward the phenotypic changes typical of old age. This essay presents and reviews recent data suggesting common characteristics of slow-aging mice, whether the slowed aging is caused by a mutant allele, the calorie restriction diet, or drugs that slow aging and extend mean and maximal lifespan. Some of the candidate ARIs, shared by nine varieties of slow-aging mice, are physiological changes seen in fat, fat-associated macrophages, muscle, liver, brain, and plasma. Others are molecular measurements, reflecting activity of mTORC1, selective mRNA translation, or each of six MAP kinases in two distinct MAPK cascades in liver, muscle, or kidney. Changes in ARIs are notable in young adult mice after 8 months of drug or diet exposure, are detectable in mutant mice at least as early as 4-6 months of age, and persist until at least 18-22 months. Many of the candidate ARIs are thought to play an influential role in cognition, inflammation, exercise responses, and control of metabolic rate, and are thus plausible as modulators of age-related physiological and neurological illnesses. In principle, screening for drugs that induce alterations in ARIs in normal young adult mice might facilitate the search for preventive medicines that can retard aging and late-life illnesses in mice or in human populations.

Testing the evidence that lifespan-extending compound interventions are conserved across laboratory animal model species

A growing number of pharmaceutical and small molecule interventions are reported to extend the lifespan of laboratory animals including Caenorhabditis, Drosophila, and mouse. However, the degree to which these pro-longevity interventions are conserved across species is unclear. Here, we took two approaches to ask the question: to what extent do longevity intervention studies in Caenorhabditis and Drosophila recapitulate effects on mouse lifespan? The first approach analyzes all published reports on longevity in the literature collated by the DrugAge database, and the second approach focused on results designed for reproducibility as reported from the NIA-supported Interventions Testing Program (ITP) and the Caenorhabditis Interventions Testing Program (CITP). Using published data sources, we identify only modest sensitivity and specificity of Drosophila interventional studies for identifying pro-longevity compounds in mouse lifespan studies. Surprisingly, reported studies in C. elegans show little predictive value for identifying drugs that extend lifespan in mice. The results therefore suggest caution should be used when making assumptions about the translatability of lifespan-extending compounds across species, including human intervention.

Sex differences in pharmacological interventions and their effects on lifespan and healthspan outcomes: a systematic review

With an increasing aging population, the burden of age-related diseases magnifies. To alleviate this burden, geroprotection has been an area of intense research focus with the development of pharmacological interventions that target lifespan and/or healthspan. However, there are often sex differences, with compounds mostly tested in male animals. Given the importance of considering both sexes in preclinical research, this neglects potential benefits for the female population, as interventions tested in both sexes often show clear sexual dimorphisms in their biological responses. To further understand the prevalence of sex differences in pharmacological geroprotective intervention studies, we performed a systematic review of the literature according to the PRISMA guidelines. Seventy-two studies met our inclusion criteria and were classified into one of five subclasses: FDA-repurposed drugs, novel small molecules, probiotics, traditional Chinese medicine, and antioxidants, vitamins, or other dietary supplements. Interventions were analyzed for their effects on median and maximal lifespan and healthspan markers, including frailty, muscle function and coordination, cognitive function and learning, metabolism, and cancer. With our systematic review, we found that twenty-two out of sixty-four compounds tested were able to prolong both lifespan and healthspan measures. Focusing on the use of female and male mice, and on comparing their outcomes, we found that 40% of studies only used male mice or did not clarify the sex. Notably, of the 36% of pharmacologic interventions that did use both male and female mice, 73% of these studies showed sex-specific outcomes on healthspan and/or lifespan. These data highlight the importance of studying both sexes in the search for geroprotectors, as the biology of aging is not the same in male and female mice. Systematic Review Registration: [website], identifier [registration number].

Mapping the metabolic reprogramming induced by sodium-glucose cotransporter 2 inhibition

Diabetes is associated with increased risk for kidney disease, heart failure, and mortality. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) prevent these adverse outcomes; however, the mechanisms involved are not clear. We generated a roadmap of the metabolic alterations that occur in different organs in diabetes and in response to SGLT2i. In vivo metabolic labeling with 13C-glucose in normoglycemic and diabetic mice treated with or without dapagliflozin, followed by metabolomics and metabolic flux analyses, showed that, in diabetes, glycolysis and glucose oxidation are impaired in the kidney, liver, and heart. Treatment with dapagliflozin failed to rescue glycolysis. SGLT2 inhibition increased glucose oxidation in all organs; in the kidney, this was associated with modulation of the redox state. Diabetes was associated with altered methionine cycle metabolism, evident by decreased betaine and methionine levels, whereas treatment with SGLT2i increased hepatic betaine along with decreased homocysteine levels. mTORC1 activity was inhibited by SGLT2i along with stimulation of AMPK in both normoglycemic and diabetic animals, possibly explaining the protective effects against kidney, liver, and heart diseases. Collectively, our findings suggest that SGLT2i induces metabolic reprogramming orchestrated by AMPK-mTORC1 signaling with common and distinct effects in various tissues, with implications for diabetes and aging.

The potential of integrating human and mouse discovery platforms to advance our understanding of cardiometabolic diseases

Cardiometabolic diseases encompass a range of interrelated conditions that arise from underlying metabolic perturbations precipitated by genetic, environmental, and lifestyle factors. While obesity, dyslipidaemia, smoking, and insulin resistance are major risk factors for cardiometabolic diseases, individuals still present in the absence of such traditional risk factors, making it difficult to determine those at greatest risk of disease. Thus, it is crucial to elucidate the genetic, environmental, and molecular underpinnings to better understand, diagnose, and treat cardiometabolic diseases. Much of this information can be garnered using systems genetics, which takes population-based approaches to investigate how genetic variance contributes to complex traits. Despite the important advances made by human genome-wide association studies (GWAS) in this space, corroboration of these findings has been hampered by limitations including the inability to control environmental influence, limited access to pertinent metabolic tissues, and often, poor classification of diseases or phenotypes. A complementary approach to human GWAS is the utilisation of model systems such as genetically diverse mouse panels to study natural genetic and phenotypic variation in a controlled environment. Here, we review mouse genetic reference panels and the opportunities they provide for the study of cardiometabolic diseases and related traits. We discuss how the post-GWAS era has prompted a shift in focus from discovery of novel genetic variants to understanding gene function. Finally, we highlight key advantages and challenges of integrating complementary genetic and multi-omics data from human and mouse populations to advance biological discovery.