Rapamycin extends maximal lifespan in cancer-prone mice

Chemotherapy's effects on autophagy in the treatment of Hodgkin's lymphoma: a scoping review

BACKGROUND

Classical Hodgkin Lymphomas (HL) are a unique malignant growth with an excellent initial prognosis. However, 10-30% of patients will still relapse after remission. One primary cellular function that has been the focus of tumor progression is autophagy. This process can preserve cellular homeostasis under stressful conditions. Several studies have shown that autophagy may play a role in developing HL. Therefore, this review aimed to explore chemotherapy's effect on autophagy in HL, and the effects of autophagy on HL.

METHODS

A scoping review in line with the published PRISMA extension for scoping reviews (PRISMA-ScR) was conducted. A literature search was conducted on the MEDLINE database and the Cochrane Central Register of Controlled Trials (CENTRAL). All results were retrieved and screened, and the resulting articles were synthesized narratively.

RESULTS

The results showed that some cancer chemotherapy also induces autophagic flux. Although the data on HL is limited, since the mechanisms of action of these drugs are similar, we can infer a similar relationship. However, this increased autophagy activity may reflect a mechanism for increasing tumor growth or a cellular compensation to inhibit its growth. Although evidence supports both views, we argued that autophagy allowed cancer cells to resist cell death, mainly due to DNA damage caused by cytotoxic drugs.

CONCLUSION

Autophagy reflects the cell's adaptation to survive and explains why chemotherapy generally induces autophagy functions. However, further research on autophagy inhibition is needed as it presents a viable treatment strategy, especially against drug-resistant populations that may arise from HL chemotherapy regimens.

Chronotherapeutic Approaches

The chapter provides a comprehensive review of current approaches to personalized chronodiagnosis and chronotherapy. We discuss circadian clock drug targets that aim to affect cellular clock machinery, circadian mechanisms of pharmacokinetics/pharmacodynamics, and chronotherapeutic approaches aimed at increasing treatment efficacy and minimizing its side effects. We explore how chronotherapy can combat acquired and compensatory drug resistance. Non-pharmacological interventions for clock preservation and enhancement are also overviewed, including light treatment, melatonin, sleep scheduling, time-restricted feeding, physical activity, and exercise.

My battle with cancer. Part 1

In January 2023, diagnosed with numerous metastases of lung cancer in my brain, I felt that I must accomplish a mission. If everything happens for a reason, my cancer, in particular, I must find out how metastatic cancer can be treated with curative intent. This is my mission now, and the reason I was ever born. In January 2023, I understood the meaning of life, of my life. I was born to write this article. In this article, I argue that monotherapy with targeted drugs, even when used in sequence, cannot cure metastatic cancer. However, preemptive combinations of targeted drugs may, in theory, cure incurable cancer. Also, I share insights on various topics, including rapamycin, an anti-aging drug that can delay but not prevent cancer, through my personal journey.

A Review on the Efficacy of Plant-derived Bio-active Compounds Curcumin and Aged Garlic Extract in Modulating Cancer and Age-related Diseases

Aging is a process characterized by accumulating degenerative changes resulting in the death of an organism. Aging is mediated by various pathways that are directly linked to the individual's lifespan and are shunted for many age-related diseases. Many strategies for alleviating age-related diseases have been studied, which can target cells and molecules. Modern drugs such as Metformin, Rapamycin, and other drugs are used to reduce the effects of age-related diseases. Despite their beneficial activity, they possess some side effects which can limit their applications, mainly in older adults. Natural phytochemicals which have anti-aging activities have been studied by many researchers from a broader aspect and suggested that plant-based compounds can be a possible, direct, and practical way to treat age-related diseases which has enormous anti-aging activity. Also, studies indicated that the synergistic action of phytochemicals might enhance the biological effect rather than the individual or summative effects of natural compounds. Curcumin has an antioxidant property and is an effective scavenger of reactive oxygen species. Curcumin also has a beneficial role in many age-related diseases like diabetes, cardiovascular disease, neurological disorder, and cancer. Aged garlic extracts are also another bioactive component that has high antioxidant properties. Many studies demonstrated aged garlic extract, which has high antioxidant properties, could play a significant role in anti-aging and age-related diseases. The synergistic effect of these compounds can decrease the requirement of doses of a single drug, thus reducing its side effects caused by increased concentration of the single drug.

Case report: Severe asymptomatic hypertriglyceridemia associated with long-term low-dose rapamycin administration in a healthy middle-aged Labrador retriever

Rapamycin is an mTOR inhibitor that has been shown to extend the lifespan of laboratory model organisms. In humans, rapamycin is used at higher doses as an immunosuppressive medication to prevent organ rejection. Numerous adverse effects are seen with rapamycin treatment in humans, with one of the most common being dysregulation of lipid metabolism. In humans, this often manifests as mild to moderate serum lipid elevations, with a small subset developing extreme triglyceride elevations. This case report describes an eight-year-old, castrated male, clinically healthy Labrador retriever who developed severe hypertriglyceridemia associated with low-dose rapamycin administration over a six-month period. During this time, the dog was asymptomatic and displayed no other clinical abnormalities, aside from a progressive lipemia. Within 15 days of discontinuing rapamycin treatment, and with no targeted lipemic intervention, the dog's lipemia and hypertriglyceridemia completely resolved.

Towards disease-oriented dosing of rapamycin for longevity: does aging exist or only age-related diseases?

Both individuals taking rapamycin, an anti-aging drug, and those not taking it will ultimately succumb to age-related diseases. However, the former, if administered disease-oriented dosages for a long time, may experience a delayed onset of such diseases and live longer. The goal is to delay a particular disease that is expected to be life-limiting in a particular person. Age-related diseases, quasi-programmed during development, progress at varying rates in different individuals. Rapamycin is a prophylactic anti-aging drug that decelerates early development of age-related diseases. I further discuss hyperfunction theory of quasi-programmed diseases, which challenges the need for the traditional concept of aging itself.

Targeting the biology of aging with mTOR inhibitors

Inhibition of the protein kinase mechanistic target of rapamycin (mTOR) with the Food and Drug Administration (FDA)-approved therapeutic rapamycin promotes health and longevity in diverse model organisms. More recently, specific inhibition of mTORC1 to treat aging-related conditions has become the goal of basic and translational scientists, clinicians and biotechnology companies. Here, we review the effects of rapamycin on the longevity and survival of both wild-type mice and mouse models of human diseases. We discuss recent clinical trials that have explored whether existing mTOR inhibitors can safely prevent, delay or treat multiple diseases of aging. Finally, we discuss how new molecules may provide routes to the safer and more selective inhibition of mTOR complex 1 (mTORC1) in the decade ahead. We conclude by discussing what work remains to be done and the questions that will need to be addressed to make mTOR inhibitors part of the standard of care for diseases of aging.

Geroprotective interventions in the 3xTg mouse model of Alzheimer's disease

Alzheimer's disease (AD) is an age-associated neurodegenerative disease. As the population ages, the increasing prevalence of AD threatens massive healthcare costs in the coming decades. Unfortunately, traditional drug development efforts for AD have proven largely unsuccessful. A geroscience approach to AD suggests that since aging is the main driver of AD, targeting aging itself may be an effective way to prevent or treat AD. Here, we discuss the effectiveness of geroprotective interventions on AD pathology and cognition in the widely utilized triple-transgenic mouse model of AD (3xTg-AD) which develops both β-amyloid and tau pathologies characteristic of human AD, as well as cognitive deficits. We discuss the beneficial impacts of calorie restriction (CR), the gold standard for geroprotective interventions, and the effects of other dietary interventions including protein restriction. We also discuss the promising preclinical results of geroprotective pharmaceuticals, including rapamycin and medications for type 2 diabetes. Though these interventions and treatments have beneficial effects in the 3xTg-AD model, there is no guarantee that they will be as effective in humans, and we discuss the need to examine these interventions in additional animal models as well as the urgent need to test if some of these approaches can be translated from the lab to the bedside for the treatment of humans with AD.

Rapamycin supplementation of Drosophila melanogaster larvae results in less viable adults with smaller cells

The intrinsic sources of mortality relate to the ability to meet the metabolic demands of tissue maintenance and repair, ultimately shaping ageing patterns. Anti-ageing mechanisms compete for resources with other functions, including those involved in maintaining functional plasma membranes. Consequently, organisms with smaller cells and more plasma membranes should devote more resources to membrane maintenance, leading to accelerated intrinsic mortality and ageing. To investigate this unexplored trade-off, we reared Drosophila melanogaster larvae on food with or without rapamycin (a TOR pathway inhibitor) to produce small- and large-celled adult flies, respectively, and measured their mortality rates. Males showed higher mortality than females. As expected, small-celled flies (rapamycin) showed higher mortality than their large-celled counterparts (control), but only in early adulthood. Contrary to predictions, the median lifespan was similar between the groups. Rapamycin administered to adults prolongs life; thus, the known direct physiological effects of rapamycin cannot explain our results. Instead, we invoke indirect effects of rapamycin, manifested as reduced cell size, as a driver of increased early mortality. We conclude that cell size differences between organisms and the associated burdens of plasma membrane maintenance costs may be important but overlooked factors influencing mortality patterns in nature.

PGC-1α Is a Master Regulator of Mitochondrial Lifecycle and ROS Stress Response

Mitochondria play a major role in ROS production and defense during their life cycle. The transcriptional activator PGC-1α is a key player in the homeostasis of energy metabolism and is therefore closely linked to mitochondrial function. PGC-1α responds to environmental and intracellular conditions and is regulated by SIRT1/3, TFAM, and AMPK, which are also important regulators of mitochondrial biogenesis and function. In this review, we highlight the functions and regulatory mechanisms of PGC-1α within this framework, with a focus on its involvement in the mitochondrial lifecycle and ROS metabolism. As an example, we show the role of PGC-1α in ROS scavenging under inflammatory conditions. Interestingly, PGC-1α and the stress response factor NF-κB, which regulates the immune response, are reciprocally regulated. During inflammation, NF-κB reduces PGC-1α expression and activity. Low PGC-1α activity leads to the downregulation of antioxidant target genes resulting in oxidative stress. Additionally, low PGC-1α levels and concomitant oxidative stress promote NF-κB activity, which exacerbates the inflammatory response.

Cancer prevention with rapamycin

Rapamycin (sirolimus) and other rapalogs (everolimus) are anti-cancer and anti-aging drugs, which delay cancer by directly targeting pre-cancerous cells and, indirectly, by slowing down organism aging. Cancer is an age-related disease and, figuratively, by slowing down time (and aging), rapamycin may delay cancer. In several dozen murine models, rapamycin robustly and reproducibly prevents cancer. Rapamycin slows cell proliferation and tumor progression, thus delaying the onset of cancer in carcinogen-treated, genetically cancer-prone and normal mice. Data on the use of rapamycin and everolimus in organ-transplant patients are consistent with their cancer-preventive effects. Treatment with rapamycin was proposed to prevent lung cancer in smokers and former smokers. Clinical trials in high-risk populations are warranted.

Catalase-deficient mice induce aging faster through lysosomal dysfunction

BACKGROUND

Lysosomes are a central hub for cellular metabolism and are involved in the regulation of cell homeostasis through the degradation or recycling of unwanted or dysfunctional organelles through the autophagy pathway. Catalase, a peroxisomal enzyme, plays an important role in cellular antioxidant defense by decomposing hydrogen peroxide into water and oxygen. In accordance with pleiotropic significance, both impaired lysosomes and catalase have been linked to many age-related pathologies with a decline in lifespan. Aging is characterized by progressive accumulation of macromolecular damage and the production of high levels of reactive oxygen species. Although lysosomes degrade the most long-lived proteins and organelles via the autophagic pathway, the role of lysosomes and their effect on catalase during aging is not known. The present study investigated the role of catalase and lysosomal function in catalase-knockout (KO) mice.

METHODS

We performed experiments on WT and catalase KO younger (9 weeks) and mature adult (53 weeks) male mice and Mouse embryonic fibroblasts isolated from WT and KO mice from E13.5 embryos as in vivo and in ex-vivo respectively. Mouse phenotyping studies were performed with controls, and a minimum of two independent experiments were performed with more than five mice in each group.

RESULTS

We found that at the age of 53 weeks (mature adult), catalase-KO mice exhibited an aging phenotype faster than wild-type (WT) mice. We also found that mature adult catalase-KO mice induced leaky lysosome by progressive accumulation of lysosomal content, such as cathespin D, into the cytosol. Leaky lysosomes inhibited autophagosome formation and triggered impaired autophagy. The dysregulation of autophagy triggered mTORC1 (mechanistic target of rapamycin complex 1) activation. However, the antioxidant N-acetyl-L-cysteine and mTORC1 inhibitor rapamycin rescued leaky lysosomes and aging phenotypes in catalase-deficient mature adult mice.

CONCLUSIONS

This study unveils the new role of catalase and its role in lysosomal function during aging. Video abstract.

Rapamycin treatment early in life reprograms aging: hyperfunction theory and clinical practice

Making provocative headlines, three outstanding publications demonstrated that early-life treatment with rapamycin, including treatments during developmental growth, extends lifespan in animals, confirming predictions of hyperfunction theory, which views aging as a quasi-program (an unintended continuation of developmental growth) driven in part by mTOR. Despite their high theoretical importance, clinical applications of two of these studies in mice, Drosophila and Daphnia cannot be implemented in humans because that would require growth retardation started at birth. A third study demonstrated that a transient (around 20% of total lifespan in Drosophila) treatment with rapamycin early in Drosophila adult life is as effective as lifelong treatment, whereas a late-life treatment is not effective. However, previous studies in mice demonstrated that a transient late-life treatment is highly effective. Based on hyperfunction theory, this article attempts to reconcile conflicting results and suggests the optimal treatment strategy to extend human lifespan.

Therapeutic Antiaging Strategies

Aging constitutes progressive physiological changes in an organism. These changes alter the normal biological functions, such as the ability to manage metabolic stress, and eventually lead to cellular senescence. The process itself is characterized by nine hallmarks: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. These hallmarks are risk factors for pathologies, such as cardiovascular diseases, neurodegenerative diseases, and cancer. Emerging evidence has been focused on examining the genetic pathways and biological processes in organisms surrounding these nine hallmarks. From here, the therapeutic approaches can be addressed in hopes of slowing the progression of aging. In this review, data have been collected on the hallmarks and their relative contributions to aging and supplemented with in vitro and in vivo antiaging research experiments. It is the intention of this article to highlight the most important antiaging strategies that researchers have proposed, including preventive measures, systemic therapeutic agents, and invasive procedures, that will promote healthy aging and increase human life expectancy with decreased side effects.

Peripheral tissular analysis of rapamycin's effect as a neuroprotective agent in vivo

Rapamycin is the best-characterized autophagy inducer, which is related to its antiaging and neuroprotective effects. Although rapamycin is an FDA-approved drug for human use in organ transplantation and cancer therapy, its administration as an antiaging and neuroprotective agent is still controversial because of its immunosuppressive and reported side effects. Therefore, it is critical to determine whether the dose that exerts a neuroprotective effect, 35 times lower than that used as an immunosuppressant agent, harms peripheral organs. We validated the rapamycin neuroprotective dosage in a Parkinson's disease (PD) model induced with paraquat. C57BL/6 J mice were treated with intraperitoneal (IP) rapamycin (1 mg/kg) three times per week, followed by paraquat (10 mg/kg) twice per week for 6 weeks, along with rapamycin on alternate days. Rapamycin significantly decreased dopaminergic neuronal loss induced by paraquat. Since rapamycin's neuroprotective effect in a PD model was observed at 7 weeks of treatment; we evaluated its effect on the liver, kidney, pancreas, and spleen. In addition, we prolonged treatment with rapamycin for 14 weeks. Tissue sections were subjected to histochemical, immunodetection, and morphometric analysis. Chronic rapamycin administration does not affect bodyweight, survival, and liver or kidney morphology. Although the pancreas tissular architecture and cellular distribution in Langerhans islets are modified, they may be reversible. The spleen B lymphocyte and macrophage populations were decreased. Notably, the lymphocyte T population was not affected. Therefore, chronic administration of a rapamycin neuroprotective dose does not produce significant tissular alterations. Our findings support the therapeutic potential of rapamycin as a neuroprotective agent.

mTOR Complex 1 Content and Regulation Is Adapted to Animal Longevity

Decreased content and activity of the mechanistic target of rapamycin (mTOR) signalling pathway, as well as the mTOR complex 1 (mTORC1) itself, are key traits for animal species and human longevity. Since mTORC1 acts as a master regulator of intracellular metabolism, it is responsible, at least in part, for the longevous phenotype. Conversely, increased content and activity of mTOR signalling and mTORC1 are hallmarks of ageing. Additionally, constitutive and aberrant activity of mTORC1 is also found in age-related diseases such as Alzheimer’s disease (AD) and cancer. The downstream processes regulated through this network are diverse, and depend upon nutrient availability. Hence, multiple nutritional strategies capable of regulating mTORC1 activity and, consequently, delaying the ageing process and the development of age-related diseases, are under continuous study. Among these, the restriction of calories is still the most studied and robust intervention capable of downregulating mTOR signalling and feasible for application in the human population.

Pharmacological Approaches to Decelerate Aging: A Promising Path

Biological aging or senescence is a course in which cellular function decreases over a period of time and is a consequence of altered signaling mechanisms that are triggered in stressed cells leading to cell damage. Aging is among the principal risk factors for many chronic illnesses such as cancer, cardiovascular disorders, and neurodegenerative diseases. Taking this into account, targeting fundamental aging mechanisms therapeutically may effectively impact numerous chronic illnesses. Selecting ideal therapeutic options in order to hinder the process of aging and decelerate the progression of age-related diseases is valuable. Along therapeutic options, life style modifications may well render the process of aging. The process of aging is affected by alteration in many cellular and signaling pathways amid which mTOR, SIRT1, and AMPK pathways are the most emphasized. Herein, we have discussed the mechanisms of aging focusing mainly on the mentioned pathways as well as the role of inflammation and autophagy in aging. Moreover, drugs and natural products with antiaging properties are discussed in detail.

Hallmarks of cancer and hallmarks of aging

A thought-provoking article by Gems and de Magalhães suggests that canonic hallmarks of aging are superficial imitations of hallmarks of cancer. I took their work a step further and proposed hallmarks of aging based on a hierarchical principle and the hyperfunction theory.

To do this, I first reexamine the hallmarks of cancer proposed by Hanahan and Weinberg in 2000. Although six hallmarks of cancer are genuine, they are not hierarchically arranged, i.e., molecular, intra-cellular, cellular, tissue, organismal and extra-organismal. (For example, invasion and angiogenesis are manifestations of molecular alterations on the tissue level; metastasis on the organismal level, whereas cell immortality is observed outside the host).

The same hierarchical approach is applicable to aging. Unlike cancer, however, aging is not a molecular disease. The lowest level of its origin is normal intracellular signaling pathways such as mTOR that drive developmental growth and, later in life, become hyperfunctional, causing age-related diseases, whose sum is aging. The key hallmark of organismal aging, from worms to humans, are age-related diseases. In addition, hallmarks of aging can be arranged as a timeline, wherein initial hyperfunction is followed by dysfunction, organ damage and functional decline.

Physiological Systems in Promoting Frailty

Frailty is a complex syndrome affecting a growing sector of the global population as medical developments have advanced human mortality rates across the world. Our current understanding of frailty is derived from studies conducted in the laboratory as well as the clinic, which have generated largely phenotypic information. Far fewer studies have uncovered biological underpinnings driving the onset and progression of frailty, but the stage is set to advance the field with preclinical and clinical assessment tools, multiomics approaches together with physiological and biochemical methodologies. In this article, we provide comprehensive coverage of topics regarding frailty assessment, preclinical models, interventions, and challenges as well as clinical frameworks and prevalence. We also identify central biological mechanisms that may be at play including mitochondrial dysfunction, epigenetic alterations, and oxidative stress that in turn, affect metabolism, stress responses, and endocrine and neuromuscular systems. We review the role of metabolic syndrome, insulin resistance and visceral obesity, focusing on glucose homeostasis, adenosine monophosphate-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and nicotinamide adenine dinucleotide (NAD+ ) as critical players influencing the age-related loss of health. We further focus on how immunometabolic dysfunction associates with oxidative stress in promoting sarcopenia, a key contributor to slowness, weakness, and fatigue. We explore the biological mechanisms involved in stem cell exhaustion that affect regeneration and may contribute to the frailty-associated decline in resilience and adaptation to stress. Together, an overview of the interplay of aging biology with genetic, lifestyle, and environmental factors that contribute to frailty, as well as potential therapeutic targets to lower risk and slow the progression of ongoing disease is covered. © 2022 American Physiological Society. Compr Physiol 12:1-46, 2022.

Atlos Labs and the quest for immortality: but can we live longer right now?

Some visionaries prefer to dream of immortality rather than to actually live longer. Here I discuss how combining rapamycin with other modalities may let us live long enough to benefit from future discoveries in cellular reprogramming and what needs to be done at Atlos Labs to make this happen.

Common Pathogenetic Mechanisms Underlying Aging and Tumor and Means of Interventions

Recently, there has been an increase in the incidence of malignant tumors among the older population. Moreover, there is an association between aging and cancer. During the process of senescence, the human body suffers from a series of imbalances, which have been shown to further accelerate aging, trigger tumorigenesis, and facilitate cancer progression. Therefore, exploring the junctions of aging and cancer and searching for novel methods to restore the junctions is of great importance to intervene against aging-related cancers. In this review, we have identified the underlying pathogenetic mechanisms of aging-related cancers by comparing alterations in the human body caused by aging and the factors that trigger cancers. We found that the common mechanisms of aging and cancer include cellular senescence, alterations in proteostasis, microbiota disorders (decreased probiotics and increased pernicious bacteria), persistent chronic inflammation, extensive immunosenescence, inordinate energy metabolism, altered material metabolism, endocrine disorders, altered genetic expression, and epigenetic modification. Furthermore, we have proposed that aging and cancer have common means of intervention, including novel uses of common medicine (metformin, resveratrol, and rapamycin), dietary restriction, and artificial microbiota intervention or selectively replenishing scarce metabolites. In addition, we have summarized the research progress of each intervention and revealed their bidirectional effects on cancer progression to compare their reliability and feasibility. Therefore, the study findings provide vital information for advanced research studies on age-related cancers. However, there is a need for further optimization of the described methods and more suitable methods for complicated clinical practices. In conclusion, targeting aging may have potential therapeutic effects on aging-related cancers.

The mTOR-lysosome axis at the centre of ageing

Age‐related diseases represent some of the largest unmet clinical needs of our time. While treatment of specific disease‐related signs has had some success (for example, the effect of statin drugs on slowing progression of atherosclerosis), slowing biological ageing itself represents a target that could significantly increase health span and reduce the prevalence of multiple age‐related diseases. Mechanistic target of rapamycin complex 1 (mTORC1) is known to control fundamental processes in ageing: inhibiting this signalling complex slows biological ageing, reduces age‐related disease pathology and increases lifespan in model organisms. How mTORC1 inhibition achieves this is still subject to ongoing research. However, one mechanism by which mTORC1 inhibition is thought to slow ageing is by activating the autophagy–lysosome pathway. In this review, we examine the special bidirectional relationship between mTORC1 and the lysosome. In cells, mTORC1 is located on lysosomes. From this advantageous position, it directly controls the autophagy–lysosome pathway. However, the lysosome also controls mTORC1 activity in numerous ways, creating a special two‐way relationship. We then explore specific examples of how inhibition of mTORC1 and activation of the autophagy–lysosome pathway slow the molecular hallmarks of ageing. This body of literature demonstrates that the autophagy–lysosome pathway represents an excellent target for treatments that seek to slow biological ageing and increase health span in humans.

No limit to maximal lifespan in humans: how to beat a 122-year-old record

Although average human life expectancy is rising, the maximum lifespan is not increasing. Leading demographers claim that human lifespan is fixed at a natural limit around 122 years. However, there is no fixed limit in animals. In animals, anti-aging interventions (dietary restrictions, rapamycin, genetic manipulations) postpone age-related diseases and thus automatically extend maximum lifespan. In humans, anti-aging interventions have not been yet implemented. Instead, by treating individual diseases, medical interventions allow a patient to live longer (despite morbidity), expanding morbidity span. In contrast, slowly aging individuals (centenarians) enter very old age in good health, but, when diseases finally develop, they do not receive thorough medical care and die fast. Although the oldest old die from age-related diseases, death certificates often list "old age", meaning that diseases were not even diagnosed and even less treated. The concept of absolute compression of morbidity is misleading in humans (in truth, there is no other way to compress morbidity as by denying thorough medical care) and false in animals (in truth, anti-aging interventions do not condense morbidity, they postpone it). Anti-aging interventions such as rapamycin may potentially extend both healthspan and maximal lifespan in humans. Combining anti-aging medicine with cutting-edge medical care, regardless of chronological age, will extend maximal lifespan further.

The Role of Rapamycin in Healthspan Extension via the Delay of Organ Aging

Aging can not only shorten a healthy lifespan, but can also lead to multi-organ dysfunction and failure. Anti-aging is a complex and worldwide conundrum for eliminating the various pathologies of senility. The past decade has seen great progress in the understanding of the aging-associated signaling pathways and their application for developing anti-aging approaches. Currently, some drugs can improve quality of life. The activation of mammalian target of rapamycin (mTOR) signaling is one of the core and detrimental mechanisms related to aging; rapamycin can reduce the rate of aging, improve age-related diseases by inhibiting the mTOR pathway, and prolong lifespan and healthspan effectively. However, the current evidence for rapamycin in lifespan extension and organ aging is fragmented and scattered. In this review, we summarize the efficacy and safety of rapamycin in prolonging a healthy lifespan by systematically alleviating aging in multiple organ systems, i.e., the nervous, urinary, digestive, circulatory, motor, respiratory, endocrine, reproductive, integumentary and immune systems, to provide a theoretical basis for the future clinical application of rapamycin in anti-aging.

Anti-aging: senolytics or gerostatics (unconventional view)

Senolytics are basically anti-cancer drugs, repurposed to kill senescent cells selectively. It is even more difficult to selectively kill senescent cells than to kill cancer cells. Based on lessons of cancer therapy, here I suggest how to exploit oncogene-addiction and to combine drugs to achieve selectivity. However, even if selective senolytic combinations will be developed, there is little evidence that a few senescent cells are responsible for organismal aging. I also discuss gerostatics, such as rapamycin and other rapalogs, pan-mTOR inhibitors, dual PI3K/mTOR inhibitors, which inhibit growth- and aging-promoting pathways. Unlike senolytics, gerostatics do not kill cells but slow down cellular geroconversion to senescence. Numerous studies demonstrated that inhibition of the mTOR pathways by any means (genetic, pharmacological and dietary) extends lifespan. Currently, only two studies demonstrated that senolytics (fisetin and a combination Dasatinib plus Quercetin) extend lifespan in mice. These senolytics slightly inhibit the mTOR pathway. Thus, life extension by these senolytics can be explained by their slight rapamycin-like (gerostatic) effects.

Balancing DNA repair to prevent ageing and cancer

DNA damage is a constant stressor to the cell. Persistent damage to the DNA over time results in an increased risk of mutation and an accumulation of mutations with age. Loss of efficient DNA damage repair can lead to accelerated ageing phenotypes or an increased cancer risk, and the trade-off between cancer susceptibility and longevity is often driven by the cell's response to DNA damage. High levels of mutations in DNA repair mutants often leads to excessive cell death and stem cell exhaustion which may promote premature ageing. Stem cells themselves have distinct characteristics that enable them to retain low mutation rates. However, when mutations do arise, stem cell clonal expansion can also contribute to age-related tissue dysfunction as well as heightened cancer risk. In this review, we will highlight increasing DNA damage and mutation accumulation as hallmarks common to both ageing and cancer. We will propose that anti-ageing interventions might be cancer preventative and discuss the mechanisms through which they may act.

The role of mTOR in age-related diseases

The ageing population is becoming a significant socio-economic issue. To address the expanding health gap, it is important to deepen our understanding of the mechanisms underlying ageing in various organisms at the single-cell level. The discovery of the antifungal, immunosuppressive, and anticancer drug rapamycin, which possesses the ability to extend the lifespan of several species, has prompted extensive research in the areas of cell metabolic regulation, development, and senescence. At the centre of this research is the mTOR pathway, with key roles in cell growth, proteosynthesis, ribosomal biogenesis, transcriptional regulation, glucose and lipid metabolism, and autophagy. Recently, it has become obvious that mTOR dysregulation is involved in several age-related diseases, such as cancer, neurodegenerative diseases, and type 2 diabetes mellitus. Additionally, mTOR hyperactivation affects the process of ageing per se. In this review, we provide an overview of recent insights into the mTOR signalling pathway, including its regulation and its influence on various hallmarks of ageing at the cellular level.

Effect of rapamycin on aging and age-related diseases-past and future

In 2009, rapamycin was reported to increase the lifespan of mice when implemented later in life. This observation resulted in a sea-change in how researchers viewed aging. This was the first evidence that a pharmacological agent could have an impact on aging when administered later in life, i.e., an intervention that did not have to be implemented early in life before the negative impact of aging. Over the past decade, there has been an explosion in the number of reports studying the effect of rapamycin on various diseases, physiological functions, and biochemical processes in mice. In this review, we focus on those areas in which there is strong evidence for rapamycin's effect on aging and age-related diseases in mice, e.g., lifespan, cardiac disease/function, central nervous system, immune system, and cell senescence. We conclude that it is time that pre-clinical studies be focused on taking rapamycin to the clinic, e.g., as a potential treatment for Alzheimer's disease.

DNA- and telomere-damage does not limit lifespan: evidence from rapamycin

Failure of rapamycin to extend lifespan in DNA repair mutant and telomerase-knockout mice, while extending lifespan in normal mice, indicates that neither DNA damage nor telomere shortening limits normal lifespan or causes normal aging.

The goal of geroscience is life extension

Although numerous drugs seemingly extend healthspan in mice, only a few extend lifespan in mice and only one does it consistently. Some of them, alone or in combination, can be used in humans, without further clinical trials.

Unlike dietary restriction, rapamycin fails to extend lifespan and reduce transcription stress in progeroid DNA repair-deficient mice

Dietary restriction (DR) and rapamycin extend healthspan and life span across multiple species. We have recently shown that DR in progeroid DNA repair‐deficient mice dramatically extended healthspan and trippled life span. Here, we show that rapamycin, while significantly lowering mTOR signaling, failed to improve life span nor healthspan of DNA repair‐deficient Ercc1^∆/− mice, contrary to DR tested in parallel. Rapamycin interventions focusing on dosage, gender, and timing all were unable to alter life span. Even genetically modifying mTOR signaling failed to increase life span of DNA repair‐deficient mice. The absence of effects by rapamycin on P53 in brain and transcription stress in liver is in sharp contrast with results obtained by DR, and appoints reducing DNA damage and transcription stress as an important mode of action of DR, lacking by rapamycin. Together, this indicates that mTOR inhibition does not mediate the beneficial effects of DR in progeroid mice, revealing that DR and rapamycin strongly differ in their modes of action.

Aging and age-related diseases: from mechanisms to therapeutic strategies

Aging is a physiological process mediated by numerous biological and genetic pathways, which are directly linked to lifespan and are a driving force for all age-related diseases. Human life expectancy has greatly increased in the past few decades, but this has not been accompanied by a similar increase in their healthspan. At present, research on aging biology has focused on elucidating the biochemical and genetic pathways that contribute to aging over time. Several aging mechanisms have been identified, primarily including genomic instability, telomere shortening, and cellular senescence. Aging is a driving factor of various age-related diseases, including neurodegenerative diseases, cardiovascular diseases, cancer, immune system disorders, and musculoskeletal disorders. Efforts to find drugs that improve the healthspan by targeting the pathogenesis of aging have now become a hot topic in this field. In the present review, the status of aging research and the development of potential drugs for aging-related diseases, such as metformin, rapamycin, resveratrol, senolytics, as well as caloric restriction, are summarized. The feasibility, side effects, and future potential of these treatments are also discussed, which will provide a basis to develop novel anti-aging therapeutics for improving the healthspan and preventing aging-related diseases.

Still Living Better through Chemistry: An Update on Caloric Restriction and Caloric Restriction Mimetics as Tools to Promote Health and Lifespan

Caloric restriction (CR), the reduction of caloric intake without inducing malnutrition, is the most reproducible method of extending health and lifespan across numerous organisms, including humans. However, with nearly one-third of the world’s population overweight, it is obvious that caloric restriction approaches are difficult for individuals to achieve. Therefore, identifying compounds that mimic CR is desirable to promote longer, healthier lifespans without the rigors of restricting diet. Many compounds, such as rapamycin (and its derivatives), metformin, or other naturally occurring products in our diets (nutraceuticals), induce CR-like states in laboratory models. An alternative to CR is the removal of specific elements (such as individual amino acids) from the diet. Despite our increasing knowledge of the multitude of CR approaches and CR mimetics, the extent to which these strategies overlap mechanistically remains unclear. Here we provide an update of CR and CR mimetic research, summarizing mechanisms by which these strategies influence genome function required to treat age-related pathologies and identify the molecular fountain of youth.

The use of geroprotectors to prevent multimorbidity: Opportunities and challenges

Over 60 % of people over the age of 65 will suffer from multiple diseases concomitantly but the common approach is to treat each disease separately. As age-associated diseases have common underlying mechanisms there is potential to tackle many diseases with the same pharmacological intervention. These are known as geroprotectors and could overcome the problems related to polypharmacy seen with the use of the single disease model. With some geroprotectors now reaching the end stage of preclinical studies and early clinical trials, there is a need to review the evidence and assess how they can be translated practically and effectively into routine practice. Despite promising evidence, there are many gaps and challenges in our understanding that must be addressed to make geroprotective medicine effective in the treatment of age-associated multimorbidity. Here we highlight the key barriers to clinical translation and discuss whether geroprotectors such as metformin, rapamycin and senolytics can tackle all age-associated diseases at the same dose, or whether a more nuanced approach is required. The evidence suggests that geroprotectors' mode of action may differ in different tissues or in response to different inducers of accelerating ageing, suggesting that a blunt 'one drug for many diseases' approach may not work. We make the case for the use of artificial intelligence to better understand multimorbidity, allowing identification of clusters and networks of diseases that are significantly associated beyond chance and the underpinning molecular pathway of ageing causal to each cluster. This will allow us to better understand the development of multimorbidity, select a more homogenous group of patients for intervention, match them with the appropriate geroprotector and identify biomarkers specific to the cluster.

Next Generation Strategies for Geroprotection via mTORC1 Inhibition

Inhibition of mTORC1 (mechanistic Target Of Rapamycin Complex 1) with the pharmaceutical rapamycin prolongs the lifespan and healthspan of model organisms including rodents, with evidence now emerging that rapamycin and its analogs may also have rejuvenative effects in dogs and humans. However, the side effects associated with long-term rapamycin treatment, many of which are due to inhibition of a second mTOR complex, mTORC2, have seemed to preclude the routine use of rapamycin as a therapy for age-related diseases. Here, we discuss recent findings suggesting that strong, chronic inhibition of both mTOR complexes may not be necessary to realize the geroprotective effects of rapamycin. Instead, modestly but specifically inhibiting mTORC1 via a variety of emerging techniques, including intermittent or transient treatment with rapamycin derivatives, or specific dietary regimens, may be sufficient to promote health and longevity with reduced side effects. We will also discuss prospects for the development of new molecules that, by harnessing the detailed molecular understanding of mTORC1 signaling developed over the last decade, will provide new routes to the selective inhibition of mTORC1. We conclude that therapies based on the selective inhibition of mTORC1 may soon permit the safer treatment of diseases of aging.

Mechanistic target of rapamycin signaling in mouse models of accelerated aging

The mechanistic target of rapamycin (mTOR) is an essential nutrient-sensing kinase that integrates and regulates a number of fundamental cellular processes required for cell growth, cell motility, translation, metabolism, and autophagy. mTOR signaling has been implicated in the progression of many human diseases, and its dysregulation has been reported in several pathological processes, especially in age-related human diseases and mouse models of accelerated aging. In addition, many studies have demonstrated that the regulation of mTOR activity has a beneficial effect on longevity in several mouse models of aging. However, not all mouse models of accelerated aging show positive effects on aging-associated phenotypes in response to targeting mTOR signaling. Here, we review the effects of interventions that modulate mTOR signaling on aging-related phenotypes in different mouse models of accelerated aging and discuss their implications with respect to aging and aging-related disorders.

Melatonin Administered before or after a Cytotoxic Drug Increases Mammary Cancer Stabilization Rates in HER2/Neu Mice

INTRODUCTION

The effects of chemotherapy are known to depend on the time of administration. Circadian rhythms are disturbed in tumors and in tumor bearers. Agents involved in controlling the circadian rhythms (chronobiotics) potentially can modify the outcomes of chemotherapeutics administered at different times of the day. Pineal hormone melatonin (MT) is a prototypic chronobiotic.

OBJECTIVE

The aim of the study was to investigate if MT can affect efficacy or toxicity of chemotherapy drugs administered at the extreme time points of the working day of hospital personnel.

METHODS

Cyclophosphamide, adriamycin, and 5-fluorouracil (CAF) and adriamycin and docetaxel (AT) cytotoxic drug combinations were administered on day 0 at 11:00 a.m. or at 5:00 p.m. (UTC+03:00) to 6-month-old female HER2/neu transgenic FVB/N mice bearing mammary adenocarcinomas. Some mice were additionally provided with MT in drinking water (20 mg/L) at night 1 week before or 3 weeks after treatment or during both periods. Tumor node sizes, body weight, and blood cell counts were determined right before treatment and on days 2, 7, 14, and 21.

RESULTS

Significant decrease in the mean tumor node volume was found by days 14 and 21 upon all CAF and AT treatment schedules, except in animals treated with AT at 5:00 p.m. without supplementation with MT. In the latter case, mean tumor node volume on day 21 was the same as in the control. Supplementation of AT administered at 5:00 p.m. with MT improved the tumor response. CAF and AT regimens supplemented with MT also augmented the number of tumor nodes that did not increase by more than 20% by day 21 as compared to CAF or AT alone, respectively. This effect was significant in groups treated with AT at 5:00 p.m. and consistent upon other schedules. On day 7, leukopenia and anemia were registered in groups treated with CAF regimen; however, blood cell counts normalized by day 14. Both CAF and AT were associated with drop in the body weight registered on day 7. Supplementation with MT did not affect changes of the body weight and blood counts.

CONCLUSIONS

MT supplementation to cytotoxic drugs can improve antitumor response, especially if it is blunted because of an inappropriate time of administration.

Nanoemulsions as Delivery Systems for Poly-Chemotherapy Aiming at Melanoma Treatment

Aims: Advanced melanoma is characterized by poor outcome. Despite the number of treatments having been increased over the last decade, current pharmacological strategies are only partially effective. Therefore, the improvement of the current systemic therapy is worthy of investigation. Methods: a nanotechnology-based poly-chemotherapy was tested at preclinical level. Temozolomide, rapamycin, and bevacizumab were co-loaded as injectable nanoemulsions for total parenteral nutrition (Intralipid^®), due to suitable devices, and preliminarily tested in vitro on human and mouse cell models and in vivo on the B16-F10 melanoma mouse model. Results: Drug combination was efficiently loaded in the liquid lipid matrix of Intralipid^®, including bevacizumab monoclonal antibody, leading to a fast internalization in tumour cells. An increased cytotoxicity towards melanoma cells, as well as an improved inhibition of tumour relapse, migration, and angiogenesis were demonstrated in cell models for the Intralipid^®-loaded drug combinations. In preliminary in vivo studies, the proposed approach was able to reduce tumour growth significantly, compared to controls. A relevant efficacy towards tumour angiogenesis and mitotic index was determined and immune response was involved. Conclusions: In these preliminary studies, Intralipid^® proved to be a safe and versatile poly-chemotherapy delivery system for advanced melanoma treatment, by acting on multiple mechanisms.

Superior cancer preventive efficacy of low versus high dose of mTOR inhibitor in a mouse model of prostate cancer

The mechanistic target of rapamycin (mTOR) is a PI3K-related kinase that regulates cell growth, proliferation and survival in response to the availability of energy sources and growth factors. Cancer development and progression is often associated with constitutive activation of the mTOR pathway, thus justifying mTOR inhibition as a promising approach to cancer treatment and prevention. However, development of previous rapamycin analogues has been complicated by their induction of adverse side effects and variable efficacy. Since mTOR pathway regulation involves multiple feedback mechanisms that may be differentially activated depending on the degree of mTOR inhibition, we investigated whether rapamycin dosing could be adjusted to achieve chemopreventive efficacy without side effects. Thus, we tested the efficacy of two doses of a novel, highly bioavailable nanoformulation of rapamycin, Rapatar, in a mouse prostate cancer model (male mice with prostate epithelium-specific Pten-knockout). We found that the highest efficacy was achieved by the lowest dose of Rapatar used in the study. While both doses tested were equally effective in suppressing proliferation of prostate epithelial cells, higher dose resulted in activation of feedback circuits that reduced the drug’s tumor preventive efficacy. These results demonstrate that low doses of highly bioavailable mTOR inhibitor, Rapatar, may provide safe and effective cancer prevention.

Long-term treatment with spermidine increases health span of middle-aged Sprague-Dawley male rats

Let alone calorie restriction, life span extension in higher organisms has proven to be difficult to achieve using simple drugs. Previous studies have shown that the polyamine spermidine increased the maximum life span in C. elegans and the median life span in mice. However, younger subjects (< 40 years of age) are infrequently prescribed nor self-medicating with antiaging drugs. Therefore, in the present study, we aimed at assessing the effect of long-term treatment with spermidine given in the drinking water on behavioral performance and longevity of male, middle-aged Sprague-Dawley rats. We report that spermidine given in the drinking water did not extend neither the median nor the maximum life span of the middle-aged male Sprague-Dawley rats. However, spermidine treatment had a beneficial effect on the body weight and the kidney tubules, liver, and heart morphology. Behaviorally, spermidine led to a reduction in anxiety and an increase in curiosity, as assessed by exploratory behavior. Moreover, long-term treatment with spermidine enhanced autophagy in the brain and led to a diminished expression of the inflammatory markers, Tgfb, CD11b, Fcgr1, Stat1, CR3, and GFAP mRNAs in several cortical region and hippocampus of the treated rats suggesting that one beneficial effect of the long-term treatment with spermidine is an attenuated proinflammatory state in the aged brain. Our results suggest that long-term treatment with spermidine increases health span of middle-aged rats by attenuating neuroinflammation and improving anxiety and exploratory behavior.

Geroprotective and senoremediative strategies to reduce the comorbidity, infection rates, severity, and lethality in gerophilic and gerolavic infections

The recently identified SARS-CoV-2 betacoronavirus responsible for the COVID-19 pandemic has uncovered the age-associated vulnerability in the burden of disease and put aging research in the spotlight. The limited data available indicates that COVID-19 should be referred to as a gerolavic (from Greek, géros "old man" and epilavís, "harmful") infection because the infection rates, severity, and lethality are substantially higher in the population aged 60 and older. This is primarily due to comorbidity but may be partially due to immunosenescence, decreased immune function in the elderly, and general loss of function, fitness, and increased frailty associated with aging. Immunosenescence is a major factor affecting vaccination response, as well as the severity and lethality of infectious diseases. While vaccination reduces infection rates, and therapeutic interventions reduce the severity and lethality of infections, these interventions have limitations. Previous studies showed that postulated geroprotectors, such as sirolimus (rapamycin) and its close derivative rapalog everolimus (RAD001), decreased infection rates in a small sample of elderly patients. This article presents a review of the limited literature available on geroprotective and senoremediative interventions that may be investigated to decrease the disease burden of gerolavic infections. This article also highlights a need for rigorous clinical validation of deep aging clocks as surrogate markers of biological age. These could be used to assess the need for, and efficacy of, geroprotective and senoremediative interventions and provide better protection for elderly populations from gerolavic infections. This article does not represent medical advice and the medications described are not yet licensed or recommended as immune system boosters, as they have not undergone clinical evaluation for this purpose.

Analysis of Bone Mineral Profile After Prolonged Every-Other-Day Feeding in C57BL/6J Male and Female Mice

Intermitted fasting or every-other-day feeding (EOD) has many positive effects in rodents and humans. Our goal was to describe how EOD influences bone mineral composition in female and male mice under prolonged EOD feeding. Male and female adult mice were fed EOD for 9 months. After this time, we used a direct method of measurement of mineral components in ashes of long bones (humerus and radius) to estimate the content of calcium (Ca), phosphorus (P), potassium (K), magnesium (Mg), and sodium (Na). We also performed histological analysis of sections of long bones. We found no significant changes in mineral composition between ad libitum and EOD fed males and females. We noted higher Ca and P contents in control males vs. females and lower content of Mg in control males vs. females. We observed the presence of marrow adipose tissue (MAT) in sections of EOD-fed females. EOD without supplementation during feeding days did not increase loss of mineral content of bones in C57BL/6J mice, but the presence of MAT only in EOD females indicates a gender-dependent response to EOD treatment in C57BL/6J mice.

Disease or not, aging is easily treatable

Is aging a disease? It does not matter because aging is already treated using a combination of several clinically-available drugs, including rapamycin. Whether aging is a disease depends on arbitrary definitions of both disease and aging. For treatment purposes, aging is a deadly disease (or more generally, pre-disease), despite being a normal continuation of normal organismal growth. It must and, importantly, can be successfully treated, thereby delaying classic age-related diseases such as cancer, cardiovascular and metabolic diseases, and neurodegeneration.

Rapamycin for longevity: opinion article

From the dawn of civilization, humanity has dreamed of immortality. So why didn't the discovery of the anti-aging properties of mTOR inhibitors change the world forever? I will discuss several reasons, including fear of the actual and fictional side effects of rapamycin, everolimus and other clinically-approved drugs, arguing that no real side effects preclude their use as anti-aging drugs today. Furthermore, the alternative to the reversible (and avoidable) side effects of rapamycin/everolimus are the irreversible (and inevitable) effects of aging: cancer, stroke, infarction, blindness and premature death. I will also discuss why it is more dangerous not to use anti-aging drugs than to use them and how rapamycin-based drug combinations have already been implemented for potential life extension in humans. If you read this article from the very beginning to its end, you may realize that the time is now.

PGC-1α, a potential therapeutic target against kidney aging

Aging is defined as changes in an organism over time. The proportion of the aged population is markedly increasing worldwide. The kidney, as an essential organ with a high energy requirement, is one of the most susceptible organs to aging. It is involved in glucose metabolism via gluconeogenesis, glucose filtration and reabsorption, and glucose utilization. Proximal tubular epithelial cells (PTECs) depend on lipid metabolism to meet the high demand for ATP. Recent studies have shown that aging‐related kidney dysfunction is highly associated with metabolic changes in the kidney. Peroxisome proliferator‐activated receptor gamma coactivator‐1 alpha (PGC‐1α), a transcriptional coactivator, plays a major role in the regulation of mitochondrial biogenesis, peroxisomal biogenesis, and glucose and lipid metabolism. PGC‐1α is abundant in tissues, including kidney PTECs, which demand high energy. Many in vitro and in vivo studies have demonstrated that the activation of PGC‐1α by genetic or pharmacological intervention prevents telomere shortening and aging‐related changes in the skeletal muscle, heart, and brain. The activation of PGC‐1α can also prevent kidney dysfunction in various kidney diseases. Therefore, a better understanding of the effect of PGC‐1α activation in various organs on aging and kidney diseases may unveil a potential therapeutic strategy against kidney aging.

An overview of two decades of diet restriction studies using Drosophila

Dietary restriction (DR) is a potent forerunner in aging studies capable of influencing lifespan and improving health in various model organisms even in their old age. Despite the importance of protein and carbohydrates in the diet (regulation of fecundity and body maintenance respectively), different ratio based combinations of these components has played a major role in lifespan extension studies. In spite of differences existing in dietary protocols across laboratories, diet manipulations have evolved as a major area of research in Drosophila lifespan studies, prominently shedding light on the multi-faceted process over the last two decades. Here, we review various advances and technicalities involved in understanding the DR-mediated lifespan alongside discussing the pros and cons of various existing approaches/diets used across labs. The current review also focuses on the importance of life-stage specific DR implementation and their influence on the life-history traits including lifespan and fecundity, by taking examples of results from different studies comprising diet dilution, calorie restriction, protein restriction, carbohydrate: protein ratios and the modulations in various minor diet components. We thereby intend to gather the major advances made in these fields alongside reviewing the practical implementations that need to be made to get a better view of the DR-mediated lifespan studies.