Topical rapamycin reduces markers of senescence and aging in human skin: an exploratory, prospective, randomized trial

Deciphering the role of skin aging in pigmentary disorders

Skin aging is a complex biological process involving intrinsic and extrinsic factors. Skin aging contains alterations at the tissue, cellular, and molecular levels. Currently, there is increasing evidence that skin aging occurs not only in time-dependent chronological aging but also plays a role in skin pigmentary disorders. This review provides an in-depth analysis of the impact of skin aging on different types of pigmentary disorders, including both hyperpigmentation disorders such as melasma and senile lentigo and hypopigmentation disorders such as vitiligo, idiopathic guttate hypomelanosis and graying of hair. In addition, we explore the mechanisms of skin aging on pigmentation regulation and suggest several potential therapeutic approaches for skin aging and aging-related pigmentary disorders.

Advancing Longevity: Exploring Antiaging Pharmaceuticals in Contemporary Clinical Trials Amid Aging Dynamics

Aging is an inevitable biological process that significantly impacts human health, leading to a decline in cellular function and an increase in cellular damage. This study elucidates the burgeoning potential of antiaging pharmaceuticals in mitigating the thriving burden of chronic conditions linked to advancing age. It underscores the pivotal role of these pharmacotherapeutic agents in fostering longevity free from debilitating age-related afflictions, notably cardiovascular disorders, neoplastic processes, and neurodegenerative pathologies. While commendable strides have been made evident in preclinical models, it is crucial to thoroughly investigate their effectiveness and safety in human groups. In addition, ethical concerns about fair access, societal impacts, and careful resource distribution are significant in discussions about developing and using antiaging medications. By approaching the development and utilization of antiaging medications with diligence and foresight, we can strive toward a future where individuals can enjoy extended lifespans free from the debilitating effects of age-related ailments.

TRPM7 controls skin keratinocyte senescence by targeting intracellular calcium signaling

Cellular senescence is described as an irreversible cell cycle arrest for proliferating cells and is associated with the secretion of senescence associated secretory phenotype factors. It has been known to accumulate with age and is regarded as a key driver of aging-associated skin pathologies. However, the lack of markers of skin senescence and partially understood skin cellular senescence mechanisms has limited the exploration of skin aging and anti-skin aging strategies. Recently, intracellular calcium signaling has emerged as an important regulator of cellular senescence and aging. However, little is known about the modulation of skin cellular senescence by calcium-associated factors. Here, we found that the expression of calcium channel transient receptor potential melastatin 7 (TRPM7) is elevated during skin keratinocyte senescence and aging. Importantly, TRPM7 promotes skin keratinocyte senescence by triggering intracellular calcium transfer from the endoplasmic reticulum to the mitochondria; accumulation of mitochondrial calcium then induces a drop in mitochondrial membrane potential and reactive oxygen species production, leading to subsequent nuclear enlargement and DNA damage. Altogether, these findings indicate that TRPM7 controls skin keratinocyte senescence through regulating intracellular calcium signaling, and thus, shed light on novel strategies for anti-skin aging therapy.

Collagen Type VII (COL7A1) as a Longevity Mediator in Caenorhabditis elegans: Anti-Aging Effects on Healthspan Extension and Skin Collagen Synthesis

Longevity genes and senescence-related signaling proteins are crucial targets in aging research, which aims to enhance the healthy period and quality of life. Identifying these target proteins remains challenging because of the need for precise categorization and validation methods. Our multifaceted approach combined bioinformatics with transcriptomic data to identify collagen as a key element associated with the lifespan of the model organism, Caenorhabditis elegans. By analyzing transcriptomic data from long-lived mutants that involved mechanisms such as antioxidation, dietary restriction, and genetic background, we identified collagen as a common longevity-associated gene. We validated these findings by confirming that collagen peptides positively affect lifespan, thereby strengthening the validity of the target. Further verification through healthspan factors in C. elegans and functional assays in skin fibroblasts provided additional evidence of the role of collagen in organismal aging. Specifically, our study revealed that collagen type VII is a significant target protein for mitigating age-related decline. By validating these findings across different aging models and cell-based studies, we present compelling evidence for the anti-aging effects of collagen type VII, highlighting its potential as a target for promoting healthy aging. This study proposes that collagen not only serves as an indicative marker of organismal longevity across various senescence-related signaling pathways, but also offers a mechanistic understanding of skin degeneration. Consequently, collagen is an effective target for interventions aimed at mitigating skin aging. This study underscores the potential of collagen type VII (bonding collagen T7) as a therapeutic target for enhancing skin health and overall longevity.

Characteristics and mechanisms of T-cell senescence: A potential target for cancer immunotherapy

Immunosenescence, the aging of the immune system, leads to functional deficiencies, particularly in T cells, which undergo significant changes. While numerous studies have investigated age-related T-cell phenotypes in healthy aging, senescent T cells have also been observed in younger populations during pathological conditions like cancer. This review summarizes the recent advancements in age-associated alterations and markers of T cells, mechanisms, and the relationship between senescent T cells and the tumor microenvironment. We also discuss potential strategies for targeting senescent T cells to prevent age-related diseases and enhance tumor immunotherapy efficacy.

Unraveling aging from transcriptomics

Research into aging constitutes a pivotal endeavor aimed at elucidating the underlying biological mechanisms governing aging and age-associated diseases, as well as promoting healthy longevity. Recent advances in transcriptomic technologies, such as bulk RNA sequencing (RNA-seq), single-cell transcriptomics, and spatial transcriptomics, have revolutionized our ability to study aging at unprecedented resolution and scale. These technologies present novel opportunities for the discovery of biomarkers, elucidation of molecular pathways, and development of targeted therapeutic strategies for age-related disorders. This review surveys recent breakthroughs in different types of transcripts on aging, such as mRNA, long noncoding (lnc)RNA, tRNA, and miRNA, highlighting key findings and discussing their potential implications for future studies in this field.

Ultraviolet Light Causes Skin Cell Senescence: From Mechanism to Prevention Principle

The skin is an effective protective barrier that significantly protects the body from damage caused by external environmental factors. Furthermore, skin condition significantly affects external beauty. In today's era, which is of material and spiritual prosperity, there is growing attention on skincare and wellness. Ultraviolet radiation is one of the most common external factors that lead to conditions like sunburn, skin cancer, and skin aging. In this review, several mechanisms of UV-induced skin cell senescence are discussed, including DNA damage, oxidative stress, inflammatory response, and mitochondrial dysfunction, which have their own characteristics and mutual effects. As an illustration, mitochondrial dysfunction triggers electron evasion and the generation of more reactive oxygen species, leading to oxidative stress and the activation of the NLRP3 inflammasome, which in turn causes mitochondrial DNA (mt DNA) damage. Based on the current mechanism, suitable prevention and treatment strategies are proposed from sunscreen, dietary, and experimental medications respectively, aimed at slowing down skin cell aging and providing protection from ultraviolet radiation. The effects of ultraviolet rays on skin is summarized, offering insights and directions for future studies on mechanism of skin cell senescence, with an anticipation of discovering more effective prevention and cure methods.

A single-center, double-blind, randomized, placebo-controlled, two-arm study to evaluate the safety and efficacy of once-weekly sirolimus (rapamycin) on muscle strength and endurance in older adults following a 13-week exercise program

BACKGROUND

Aging leads to a decline in muscle mass and strength, contributing to frailty and decreased quality of life. Sirolimus (rapamycin) , an mTOR inhibitor, has shown potential in preclinical studies to extend lifespan and improve health span. This study evaluates the safety and efficacy of once-weekly sirolimus (rapamycin) administration on muscle strength and endurance in older adults engaged in a 13-week exercise program.

METHODS

This randomized, double-blind, placebo-controlled trial will enroll 40 participants aged 65-85. Participants will be randomly assigned to receive either sirolimus (rapamycin) 6 mg/week or placebo for 13 weeks, in conjunction with an at-home exercise program. The primary outcome measure is the change in muscle strength and endurance, assessed by the 30-Second Chair-Stand Test. Secondary outcome measures include adverse events, changes in muscle strength and endurance as measured by the 6-min walk test, handgrip strength, and participant-reported outcomes using the SF-36 survey. Assessments will be conducted at baseline, mid-intervention (week 6), and post-intervention (week 13). Blood samples will be collected for hematology and biochemistry analyses, including full blood count, urea and electrolytes, liver function tests, HbA1c, lipids, serum IGF-1, and hs-CRP. DNA methylation will be analyzed using TruDiagnostic™ to explore changes in biological age.

DISCUSSION

This study aims to provide insights into the potential benefits of intermittent sirolimus (rapamycin) administration on muscle performance in older adults. By alternating periods of mTOR inhibition through rapamycin and activation via exercise, this study will explore a novel approach to enhancing muscle strength and endurance in the aging population. The results could have significant implications for developing interventions to improve physical function and overall health outcomes in older adults. Safety and tolerability will also be closely monitored to ensure the feasibility of this regimen for wider application.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry, ACTRN12624000790549. Registered on 26 June 2024 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12624000790549 .

Inflammation and aging-related disease: A transdisciplinary inflammaging framework

Inflammaging, a state of chronic, progressive low-grade inflammation during aging, is associated with several adverse clinical outcomes, including frailty, disability, and death. Chronic inflammation is a hallmark of aging and is linked to the pathogenesis of many aging-related diseases. Anti-inflammatory therapies are also increasingly being studied as potential anti-aging treatments, and clinical trials have shown benefits in selected aging-related diseases. Despite promising advances, significant gaps remain in defining, measuring, treating, and integrating inflammaging into clinical geroscience research. The Clin-STAR Inflammation Research Interest Group was formed by a group of transdisciplinary clinician-scientists with the goal of advancing inflammaging-related clinical research and improving patient-centered care for older adults. Here, we integrate insights from nine medical subspecialties to illustrate the widespread impact of inflammaging on diseases linked to aging, highlighting the extensive opportunities for targeted interventions. We then propose a transdisciplinary approach to enhance understanding and treatment of inflammaging that aims to improve comprehensive care for our aging patients.

Senescence in the ageing skin: a new focus on mTORC1 and the lysosome

Ageing is defined as the progressive loss of tissue function and regenerative capacity and is caused by both intrinsic factors i.e. the natural accumulation of damage, and extrinsic factors i.e. damage from environmental stressors. Cellular senescence, in brief, is an irreversible exit from the cell cycle that occurs primarily in response to excessive cellular damage, such as from ultraviolet (UV) exposure and oxidative stress, and it has been comprehensively demonstrated to contribute to tissue and organismal ageing. In this review, we will focus on the skin, an organ which acts as an essential protective barrier against injury, insults, and infection. We will explore the evidence for the existence and contribution of cellular senescence to skin ageing. We discuss the known molecular mechanisms driving senescence in the skin, with a focus on the dysregulation of the master growth regulator, mechanistic Target of Rapamycin Complex 1 (mTORC1). We explore the interplay of dysregulated mTORC1 with lysosomes and how they contribute to senescence phenotypes.

Age-associated changes in innate and adaptive immunity: role of the gut microbiota

Aging is generally regarded as an irreversible process, and its intricate relationship with the immune system has garnered significant attention due to its profound implications for the health and well-being of the aging population. As people age, a multitude of alterations occur within the immune system, affecting both innate and adaptive immunity. In the realm of innate immunity, aging brings about changes in the number and function of various immune cells, including neutrophils, monocytes, and macrophages. Additionally, certain immune pathways, like the cGAS-STING, become activated. These alterations can potentially result in telomere damage, the disruption of cytokine signaling, and impaired recognition of pathogens. The adaptive immune system, too, undergoes a myriad of changes as age advances. These include shifts in the number, frequency, subtype, and function of T cells and B cells. Furthermore, the human gut microbiota undergoes dynamic changes as a part of the aging process. Notably, the interplay between immune changes and gut microbiota highlights the gut's role in modulating immune responses and maintaining immune homeostasis. The gut microbiota of centenarians exhibits characteristics akin to those found in young individuals, setting it apart from the microbiota observed in typical elderly individuals. This review delves into the current understanding of how aging impacts the immune system and suggests potential strategies for reversing aging through interventions in immune factors.

A nutrigeroscience approach: Dietary macronutrients and cellular senescence

Cellular senescence, a process in which a cell exits the cell cycle in response to stressors, is one of the hallmarks of aging. Senescence and the senescence-associated secretory phenotype (SASP)-a heterogeneous set of secreted factors that disrupt tissue homeostasis and promote the accumulation of senescent cells-reprogram metabolism and can lead to metabolic dysfunction. Dietary interventions have long been studied as methods to combat age-associated metabolic dysfunction, promote health, and increase lifespan. A growing body of literature suggests that senescence is responsive to diet, both to calories and specific dietary macronutrients, and that the metabolic benefits of dietary interventions may arise in part through reducing senescence. Here, we review what is currently known about dietary macronutrients' effect on senescence and the SASP, the nutrient-responsive molecular mechanisms that may mediate these effects, and the potential for these findings to inform the development of a nutrigeroscience approach to healthy aging.

ROS-mediated lysosomal membrane permeabilization and autophagy inhibition regulate bleomycin-induced cellular senescence

Bleomycin exhibits effective chemotherapeutic activity against multiple types of tumors, and also induces various side effects, such as pulmonary fibrosis and neuronal defects, which limit the clinical application of this drug. Macroautophagy/autophagy has been recently reported to be involved in the functions of bleomycin, and yet the mechanisms of their crosstalk remain insufficiently understood. Here, we demonstrated that reactive oxygen species (ROS) produced during bleomycin activation hampered autophagy flux by inducing lysosomal membrane permeabilization (LMP) and obstructing lysosomal degradation. Exhaustion of ROS with N-acetylcysteine relieved LMP and autophagy defects. Notably, we observed that LMP and autophagy blockage preceded the emergence of cellular senescence during bleomycin treatment. In addition, promoting or inhibiting autophagy-lysosome degradation alleviated or exacerbated the phenotypes of senescence, respectively. This suggests the alternation of autophagy activity is more a regulatory mechanism than a consequence of bleomycin-induced cellular senescence. Taken together, we reveal a specific role of bleomycin-induced ROS in mediating defects of autophagic degradation and further regulating cellular senescence in vitro and in vivo. Our findings, conversely, indicate the autophagy-lysosome degradation pathway as a target for modulating the functions of bleomycin. These provide a new perspective for optimizing bleomycin as a clinically applicable chemotherapeutics devoid of severe side-effects.Abbreviations: AT2 cells: type II alveolar epithelial cells; ATG7: autophagy related 7; bEnd.3: mouse brain microvascular endothelial cells; BNIP3L: BCL2/adenovirus E1B interacting protein 3-like; CCL2: C-C motif chemokine ligand 2; CDKN1A: cyclin dependent kinase inhibitor 1A; CDKN2A: cyclin dependent kinase inhibitor 2A; FTH1: ferritin heavy polypeptide 1; γ-H2AX: phosphorylated H2A.X variant histone; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HUVEC: human umbilical vein endothelial cells; HT22: hippocampal neuronal cell lines; Il: interleukin; LAMP: lysosomal-associated membrane protein; LMP: lysosome membrane permeabilization; MTORC1: mechanistic target of rapamycin kinase complex 1; NAC: N-acetylcysteine; NCOA4: nuclear receptor coactivator 4; PI3K: phosphoinositide 3-kinase; ROS: reactive oxygen species; RPS6KB/S6K: ribosomal protein S6 kinase; SA-GLB1/β-gal: senescence-associated galactosidase, beta 1; SAHF: senescence-associated heterochromatic foci; SASP: senescence-associated secretory phenotype; SEC62: SEC62 homolog, preprotein translocation; SEP: superecliptic pHluorin; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB.

Natural autophagy activators: A promising strategy for combating photoaging

BACKGROUND

Photodamage to the skin stands out as one of the most widespread epidermal challenges globally. Prolonged exposure to sunlight containing ultraviolet radiation (UVR) instigates stress, thereby compromising the skin's functionality and culminating in photoaging. Recent investigations have shed light on the importance of autophagy in shielding the skin from photodamage. Despite the acknowledgment of numerous phytochemicals possessing photoprotective attributes, their potential to induce autophagy remains relatively unexplored.

PURPOSE

Diminished autophagy activity in photoaged skin underscores the potential benefits of restoring autophagy through natural compounds to enhance photoprotection. Consequently, this study aims to highlight the role of natural compounds in safeguarding against photodamage and to assess their potential to induce autophagy via an in-silico approach.

METHODS

A thorough search of the literature was done using several databases, including PUBMED, Science Direct, and Google Scholar, to gather relevant studies. Several keywords such as Phytochemical, Photoprotection, mTOR, Ultraviolet Radiation, Reactive oxygen species, Photoaging, and Autophagy were utilized to ensure thorough exploration. To assess the autophagy potential of phytochemicals through virtual screening, computational methodologies such as molecular docking were employed, utilizing tools like AutoDock Vina. Receptor preparation for docking was facilitated using MGLTools.

RESULTS

The initiation of structural and functional deterioration in the skin due to ultraviolet radiation (UVR) or sunlight-induced reactive oxygen species/reactive nitrogen species (ROS/RNS) involves the modulation of various pathways. Natural compounds like phenolics, flavonoids, flavones, and anthocyanins, among others, possess chromophores capable of absorbing light, thereby offering photoprotection by modulating these pathways. In our molecular docking study, these phytochemicals have shown binding affinity with mTOR, a negative regulator of autophagy, indicating their potential as autophagy modulators.

CONCLUSION

This integrated review underscores the photoprotective characteristics of natural compounds, while the in-silico analysis reveals their potential to modulate autophagy, which could significantly contribute to their anti-photoaging properties. The findings of this study hold promise for the advancement of cosmeceuticals and therapeutics containing natural compounds aimed at addressing photoaging and various skin-related diseases. By leveraging their dual benefits of photoprotection and autophagy modulation, these natural compounds offer a multifaceted approach to combatting skin aging and related conditions.

Mechanisms of Senescence and Anti-Senescence Strategies in the Skin

The skin is the layer of tissue that covers the largest part of the body in vertebrates, and its main function is to act as a protective barrier against external environmental factors, such as microorganisms, ultraviolet light and mechanical damage. Due to its important function, investigating the factors that lead to skin aging and age-related diseases, as well as understanding the biology of this process, is of high importance. Indeed, it has been reported that several external and internal stressors contribute to skin aging, similar to the aging of other tissues. Moreover, during aging, senescent cells accumulate in the skin and express senescence-associated factors, which act in a paracrine manner on neighboring healthy cells and tissues. In this review, we will present the factors that lead to skin aging and cellular senescence, as well as ways to study senescence in vitro and in vivo. We will further discuss the adverse effects of the accumulation of chronic senescent cells and therapeutic agents and tools to selectively target and eliminate them.

mTOR and SGLT-2 Inhibitors: Their Synergistic Effect on Age-Related Processes

The aging process contributes significantly to the onset of chronic diseases, which are the primary causes of global mortality, morbidity, and healthcare costs. Numerous studies have shown that the removal of senescent cells from tissues extends lifespan and reduces the occurrence of age-related diseases. Consequently, there is growing momentum in the development of drugs targeting these cells. Among them, mTOR and SGLT-2 inhibitors have garnered attention due to their diverse effects: mTOR inhibitors regulate cellular growth, metabolism, and immune responses, while SGLT-2 inhibitors regulate glucose reabsorption in the kidneys, resulting in various beneficial metabolic effects. Importantly, these drugs may act synergistically by influencing senescence processes and pathways. Although direct studies on the combined effects of mTOR inhibition and SGLT-2 inhibition on age-related processes are limited, this review aims to highlight the potential synergistic benefits of these drugs in targeting senescence.

Long COVID as a disease of accelerated biological aging: An opportunity to translate geroscience interventions

It has been four years since long COVID-the protracted consequences that survivors of COVID-19 face-was first described. Yet, this entity continues to devastate the quality of life of an increasing number of COVID-19 survivors without any approved therapy and a paucity of clinical trials addressing its biological root causes. Notably, many of the symptoms of long COVID are typically seen with advancing age. Leveraging this similarity, we posit that Geroscience-which aims to target the biological drivers of aging to prevent age-associated conditions as a group-could offer promising therapeutic avenues for long COVID. Bearing this in mind, this review presents a translational framework for studying long COVID as a state of effectively accelerated biological aging, identifying research gaps and offering recommendations for future preclinical and clinical studies.

Rejuvenation of the Aging Heart: Molecular Determinants and Applications

In Canada and worldwide, the elderly population (ie, individuals > 65 years of age) is increasing disproportionately relative to the total population. This is expected to have a substantial impact on the health care system, as increased aged is associated with a greater incidence of chronic noncommunicable diseases. Within the elderly population, cardiovascular disease is a leading cause of death, therefore developing therapies that can prevent or slow disease progression in this group is highly desirable. Historically, aging research has focused on the development of anti-aging therapies that are implemented early in life and slow the age-dependent decline in cell and organ function. However, accumulating evidence supports that late-in-life therapies can also benefit the aged cardiovascular system by limiting age-dependent functional decline. Moreover, recent studies have demonstrated that rejuvenation (ie, reverting cellular function to that of a younger phenotype) of the already aged cardiovascular system is possible, opening new avenues to develop therapies for older individuals. In this review, we first provide an overview of the functional changes that occur in the cardiomyocyte with aging and how this contributes to the age-dependent decline in heart function. We then discuss the various anti-aging and rejuvenation strategies that have been pursued to improve the function of the aged cardiomyocyte, with a focus on therapies implemented late in life. These strategies include 1) established systemic approaches (caloric restriction, exercise), 2) pharmacologic approaches (mTOR, AMPK, SIRT1, and autophagy-targeting molecules), and 3) emerging rejuvenation approaches (partial reprogramming, parabiosis/modulation of circulating factors, targeting endogenous stem cell populations, and senotherapeutics). Collectively, these studies demonstrate the exciting potential and limitations of current rejuvenation strategies and highlight future areas of investigation that will contribute to the development of rejuvenation therapies for the aged heart.

Para-Hydroxycinnamic Acid Mitigates Senescence and Inflammaging in Human Skin Models

Para-hydroxycinnamic acid (pHCA) is one of the most abundant naturally occurring hydroxycinnamic acids, a class of chemistries known for their antioxidant properties. In this study, we evaluated the impact of pHCA on different parameters of skin aging in in vitro skin models after H2O2 and UV exposure. These parameters include keratinocyte senescence and differentiation, inflammation, and energy metabolism, as well as the underlying molecular mechanisms. Here we demonstrate that pHCA prevents oxidative stress-induced premature senescence of human primary keratinocytes in both 2D and 3D skin models, while improving clonogenicity in 2D. As aging is linked to inflammation, referred to as inflammaging, we analyzed the release of IL-6, IL-8, and PGE2, known to be associated with senescence. All of them were downregulated by pHCA in both normal and oxidative stress conditions. Mechanistically, DNA damage induced by oxidative stress is prevented by pHCA, while pHCA also exerts a positive effect on the mitochondrial and glycolytic functions under stress. Altogether, these results highlight the protective effects of pHCA against inflammaging, and importantly, help to elucidate its potential mechanisms of action.

Unveiling the impact of aging on BBB and Alzheimer's disease: Factors and therapeutic implications

Alzheimer's disease (AD) is a highly prevalent neurodegenerative condition that has devastating effects on individuals, often resulting in dementia. AD is primarily defined by the presence of extracellular plaques containing insoluble β-amyloid peptide (Aβ) and neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein (P-tau). In addition, individuals afflicted by these age-related illnesses experience a diminished state of health, which places significant financial strain on their loved ones. Several risk factors play a significant role in the development of AD. These factors include genetics, diet, smoking, certain diseases (such as cerebrovascular diseases, obesity, hypertension, and dyslipidemia), age, and alcohol consumption. Age-related factors are key contributors to the development of vascular-based neurodegenerative diseases such as AD. In general, the process of aging can lead to changes in the immune system's responses and can also initiate inflammation in the brain. The chronic inflammation and the inflammatory mediators found in the brain play a crucial role in the dysfunction of the blood-brain barrier (BBB). Furthermore, maintaining BBB integrity is of utmost importance in preventing a wide range of neurological disorders. Therefore, in this review, we discussed the role of age and its related factors in the breakdown of the blood-brain barrier and the development of AD. We also discussed the importance of different compounds, such as those with anti-aging properties, and other compounds that can help maintain the integrity of the blood-brain barrier in the prevention of AD. This review builds a strong correlation between age-related factors, degradation of the BBB, and its impact on AD.

Towards Healthy Longevity: Comprehensive Insights from Molecular Targets and Biomarkers to Biological Clocks

Aging is a complex and time-dependent decline in physiological function that affects most organisms, leading to increased risk of age-related diseases. Investigating the molecular underpinnings of aging is crucial to identify geroprotectors, precisely quantify biological age, and propose healthy longevity approaches. This review explores pathways that are currently being investigated as intervention targets and aging biomarkers spanning molecular, cellular, and systemic dimensions. Interventions that target these hallmarks may ameliorate the aging process, with some progressing to clinical trials. Biomarkers of these hallmarks are used to estimate biological aging and risk of aging-associated disease. Utilizing aging biomarkers, biological aging clocks can be constructed that predict a state of abnormal aging, age-related diseases, and increased mortality. Biological age estimation can therefore provide the basis for a fine-grained risk stratification by predicting all-cause mortality well ahead of the onset of specific diseases, thus offering a window for intervention. Yet, despite technological advancements, challenges persist due to individual variability and the dynamic nature of these biomarkers. Addressing this requires longitudinal studies for robust biomarker identification. Overall, utilizing the hallmarks of aging to discover new drug targets and develop new biomarkers opens new frontiers in medicine. Prospects involve multi-omics integration, machine learning, and personalized approaches for targeted interventions, promising a healthier aging population.

Extracellular vesicles originating from steatotic hepatocytes promote hepatic stellate cell senescence via AKT/mTOR signaling

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing rapidly due to the obesity epidemic. In the inflammatory stages of MASLD (MASH), activation of hepatic stellate cells (HSCs) leads to initiation and progression of liver fibrosis. Extracellular vesicles (EVs) are released from all cell types and play an important role in intercellular communication. However, the role of EVs released from hepatocytes in the context of MASLD is largely unknown. Therefore, the present study aimed to investigate the role of EVs derived from both normal and steatotic (free fatty acid-treated) hepatocytes on the phenotype of HSCs via the senescence pathway. Primary rat hepatocytes were treated with free fatty acids (FFAs: oleic acid and palmitic acid). EVs were collected by ultracentrifugation. EVs markers and HSCs activation and senescence markers were assessed by Western blot analysis, qPCR and cytochemistry. Reactive oxygen species (ROS) production was assessed by fluorescence assay. RNA profiles of EVs were evaluated by sequencing. We found that EVs from hepatocytes treated with FFAs (FFA-EVs) inhibit collagen type 1 and α-smooth muscle actin expression, increase the production of ROS and the expression of senescence markers (IL-6, IL-1β, p21 and senescence-associated β-galactosidase activity) in early activating HSCs via the AKT-mTOR pathway. Sequencing showed differentially enriched RNA species between the EVs groups. In conclusion, EVs from FFA-treated hepatocytes inhibit HSC activation by inducing senescence via the AKT-mTOR signaling pathway. Determining the components in EVs from steatotic hepatocytes that induce HSC senescence may lead to the identification of novel targets for intervention in the treatment of MASLD in the future.

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.

Double-blind, vehicle-controlled clinical investigation of peptide OS-01 for skin rejuvenation

INTRODUCTION

Senescent cells contribute to age-related tissue deterioration, including the skin, which plays important roles in overall health and social interactions. This study aimed to assess the effects of the senotherapeutic peptide, OS-01 (a.k.a. Pep 14), on skin.

METHODS

A 12-week split-face, double-blinded, vehicle-controlled study involving 22 participants was conducted. The OS-01-containing formulation was applied to one side of the face, while the other side received an identical control formulation lacking the peptide. Skin characteristics were assessed using instrumental measurements, expert clinical grading, and subjective questionnaires.

RESULTS

Results showed that the OS-01 formulation significantly improved one aspect of skin barrier function, as evidenced by reduced trans-epidermal water loss compared to both baseline and vehicle control. Expert grading and Antera 3D image analysis revealed a reduction in wrinkle appearance and indentation in the periorbital area, and improved skin texture and radiance on both sides of the face, with the OS-01-containing formulation demonstrating superior results. Participants also perceived improvements in skin hydration, smoothness, radiance, and overall appearance.

CONCLUSION

The findings suggest that the OS-01 formulation promotes skin health by strengthening the skin barrier, protecting against dehydration, reducing the appearance of wrinkles, and improving skin texture and radiance. These effects are likely attributed to the senotherapeutic properties of OS-01 in reducing cellular senescence and its associated detrimental effects.

Role of epigenetics in the regulation of skin aging and geroprotective intervention: A new sight

Multiple epigenetic factors play a regulatory role in maintaining the homeostasis of cutaneous components and are implicated in the aging process of the skin. They have been associated with the activation of the senescence program, which is the primary contributor to age-related decline in the skin. Senescent species drive a series of interconnected processes that impact the immediate surroundings, leading to structural changes, diminished functionality, and heightened vulnerability to infections. Geroprotective medicines that may restore the epigenetic balance represent valid therapeutic alliances against skin aging. Most of them are well-known Western medications such as metformin, nicotinamide adenine dinucleotide (NAD+), rapamycin, and histone deacetylase inhibitors, while others belong to Traditional Chinese Medicine (TCM) remedies for which the scientific literature provides limited information. With the help of the Geroprotectors.org database and a comprehensive analysis of the referenced literature, we have compiled data on compounds and formulae that have shown potential in preventing skin aging and have been identified as epigenetic modulators.

The crude extract obtained from Cinnamomum macrostemon Hayata regulates oxidative stress and mitophagy in keratinocytes

Four ethanol fractionated crude extracts (EFCEs [A-D]) purified from the leaves of Cinnamomum macrostemon Hayata were screened for antioxidative effects and mitochondrial function in HaCaT cells. The higher cell viability indicated that EFCE C was mildly toxic. Under the treatment of 50 ng/mL EFCE C, the hydrogen peroxide (H2O2)-induced cytosolic and mitochondrial reactive oxygen species levels were reduced as well as the H2O2-impaired cell viability, mitochondrial membrane potential (MMP), ATP production, and mitochondrial mass. The conversion of globular mitochondria to tubular mitochondria is coincident with EFCE C-restored mitochondrial function. The mitophagy activator rapamycin showed similar effects to EFCE C in recovering the H2O2-impaired cell viability, MMP, ATP production, mitochondrial mass, and also mitophagic proteins such as PINK1, Parkin, LC3 II, and biogenesis protein PGC-1α. We thereby propose the application of EFCE C in the prevention of oxidative stress in skin cells.

A Glance into the Destiny of Transcriptomic Activity, Embodied by the HOX Genes, in Neonatal and Aging Dermal Cells

Skin is an organ having a crucial role in the protection of muscle, bone, and internal organs and undergoing continuous self-renewal and aged. The growing interest in the prevention of skin aging and rejuvenation has sparked a surge of industrial and research studies focusing on the biological and transcriptional changes that occur during skin development and aging. In this study, the aim is to identify transcriptional differences between two main types of human skin cells: the human dermal fibroblasts (HDFs) and the human epidermis keratinocytes (HEKs) isolated from 30 neonatal and 30 adults (old) skin. Through differentially expressed gene (DEG) profiling using DEseq2, 604 up-, and 769 down-regulated genes are identified in the old group. A functional analysis using Metascape Gene Ontology and Reactome pathways revealed systematic transcriptomic shifts in key skin formation and maintenance markers, alongside a distinct difference in HOX gene families crucial for embryonic development and diverse biological processes. Among the 39 human HOX gene family, ten posterior HOX genes (HOXA10, 11, 13, HOXB13, HOXC11, and HOXD9-13) are significantly downregulated, and anterior 25 genes (HOXA2-7, HOXB1-9, HOXC4-6 and 8-9, and HOXD1,3,4 and 8) are upregulated, especially in the old HDFs. The study successfully demonstrates the correlation between HOX genes and the skin aging process, providing strong evidence that HOX genes are proposed as a new marker for skin aging assessment.

Quercetin activates autophagy to protect rats ovarian granulosa cells from H2O2-induced aging and injury

Autophagy is closely related to the aging of various organ systems, including ovaries. Quercetin has a variety of biological activities, including potential regulation of autophagy. However, whether quercetin-regulated autophagy activity affects the process of ovarian aging and injury has not been clarified yet. This study explores whether quercetin can resist H2O2-induced aging and injury of granulosa cells by regulating autophagy and its related molecular mechanisms in vitro experiments. The cell viability, endocrine function, cell aging, and apoptosis were detected to evaluate the effects of quercetin and autophagy regulators like 3-methyladenine and rapamycin. The levels of autophagy markers Atg5, Atg12, Atg16L, Lc3B II/I, and Beclin1 were determined by Western blot to assess the effects of quercetin, 3-methyladenine and rapamycin on autophagy. Our results showed quercetin resisted H2O2-induced granulosa cell aging and injury by activating protective autophagy. The treatment of 3-methyladenine and rapamycin confirmed the protective function of autophagy in H2O2-induced granulosa cells. 3-methyladenine treatment inhibited the expression of autophagy markers Atg5, Atg12, Atg16L, Lc3B II/I, and Beclin1 and abolished the positive effects on cell viability, estradiol secretion, and cell apoptosis activated by quercetin. In conclusion, quercetin activates autophagy by upregulating the expression of autophagy-related proteins to resist H2O2-induced aging and injury, which is crucial for stabilizing the function of granulosa cells under oxidative injury conditions and delaying aging. This study may explain the protective effects of quercetin on ovarian aging and injury from the perspective of regulating autophagy.

The application of a multi-component reaction peptide as a model regenerative active to enhance skin wound-healing postlaser procedure in a double-blinded placebo-controlled clinical trial

INTRODUCTION

Esthetic procedures are currently among the most effective options for consumers seeking to correct aging signs such as fine lines, wrinkles, and skin tone unevenness. Currently, there is a scientific need for an adjunct active to be paired with esthetic procedures to encourage wound recovery and address postprocedure pigmentation concerns.

OBJECTIVE

Toward that goal, this study assessed the efficacy of a peptide created from a multi-component reaction (multi-component peptide, MCP) as a model active for postprocedure care and evaluated its ability to promote skin healing in an ablative laser-induced wound model on the forearm.

METHODS

The mechanism of action of MCP was investigated using tubo assays, 2D melanocyte, and fibroblast cultures, reconstructed skin equivalents, and ex vivo skin explants. The MCP formula and the clinical benchmark formula of Aquaphor were assessed head-to-head by applying the products topically in an ablative laser-induced wound model (n = 20 subjects). The promotion of wound healing was evaluated by the investigator assessment of epithelial confluence, crusting or scabbing, general wound appearance, erythema, and edema.

RESULTS

MCP was determined to be beneficial to postprocedure skin recovery and healing by four main mechanisms of action: barrier repair as determined in an ex vivo tape-stripping model, reduction of inflammation and postinflammatory hyperpigmentation, reduction of elastase activity, and stimulation of fibroblast through the mTOR pathway. The formula containing 10% MCP enhanced the kinetics of epithelial confluence and improvement of the crusting or scabbing appearance of the laser-generated wounds in a laser-induced mini-zone wound healing study on the forearm.

CONCLUSION

This study demonstrates the use of MCP as a proof of concept regenerative active that when incorporated into an optimized postprocedure skincare formula can improve skin healing and enhance the appearance of skin after injury with relevance to ablative aesthetic procedures.

Pharmacological interventions in human aging

Pharmacological interventions are emerging as potential avenues of alleviating age-related disease. However, the knowledge of ongoing clinical trials as they relate to aging and pharmacological interventions is dispersed across a variety of mediums. In this review we summarize 136 age-related clinical trials that have been completed or are ongoing. Furthermore, we establish a database that describe the trials (AgingDB, www.agingdb.com) keeping track of the previous and ongoing clinical trials, alongside their outcomes. The aim of this review and database is to give people the ability to easily query for their trial of interest and stay up to date on the latest results. In sum, herein we give an overview of the current pharmacological strategies that have been applied to target human aging.

Human trials exploring anti-aging medicines

Here, we summarize the current knowledge on eight promising drugs and natural compounds that have been tested in the clinic: metformin, NAD+ precursors, glucagon-like peptide-1 receptor agonists, TORC1 inhibitors, spermidine, senolytics, probiotics, and anti-inflammatories. Multiple clinical trials have commenced to evaluate the efficacy of such agents against age-associated diseases including diabetes, cardiovascular disease, cancer, and neurodegenerative diseases. There are reasonable expectations that drugs able to decelerate or reverse aging processes will also exert broad disease-preventing or -attenuating effects. Hence, the outcome of past, ongoing, and future disease-specific trials may pave the way to the development of new anti-aging medicines. Drugs approved for specific disease indications may subsequently be repurposed for the treatment of organism-wide aging consequences.

Senotherapeutics to Counteract Senescent Cells Are Prominent Topics in the Context of Anti-Ageing Strategies

Cellular senescence is implicated in ageing and associated with a broad spectrum of age-related diseases. Importantly, a cell can initiate the senescence program irrespective of the organism's age. Various stress signals, including those defined as ageing hallmarks and alterations leading to cancer development, oncogene activation, or loss of cancer-suppressive functions, can trigger cellular senescence. The primary outcome of these alterations is the activation of nuclear factor (NF)-κB, thereby inducing the senescence-associated secretory phenotype (SASP). Proinflammatory cytokines and chemokines, components of this phenotype, contribute to chronic systemic sterile inflammation, commonly referred to as inflamm-ageing. This inflammation is linked to age-related diseases (ARDs), frailty, and increased mortality in older individuals. Additionally, senescent cells (SCs) accumulate in multiple tissues with age and are believed to underlie the organism functional decline, as demonstrated by models. An escalating effort has been dedicated to identify senotherapeutics that selectively target SCs by inducing apoptosis; these drugs are termed senolytics. Concurrently, small molecules that suppress senescent phenotypes without causing cell death are known as senomorphics. Both natural and synthetic senotherapeutics, along with immunotherapies employing immune cell-mediated clearance of SCs, currently represent the most promising strategies to combat ageing and ARDs. Indeed, it is fascinating to observe that information regarding the immune reaction to SCs indicates that regulation by specific lymphocyte subsets, elevated in the oldest centenarians, plays a role in attaining extreme longevity. Regardless, the application of methods already utilized in cancer treatment, such as CAR cells and monoclonal antibodies, broadens the spectrum of potential approaches to be utilized.

Cutaneous Redox Senescence

Our current understanding of skin cell senescence involves the role of environmental stressors (UV, O3, cigarette smoke, particulate matter, etc.), lifestyle (diet, exercise, etc.) as well as genetic factors (metabolic changes, hormonal, etc.). The common mechanism of action of these stressors is the disturbance of cellular redox balance characterized by increased free radicals and reactive oxygen species (ROS), and when these overload the intrinsic antioxidant defense system, it can lead to an oxidative stress cellular condition. The main redox mechanisms that activate cellular senescence in the skin involve (1) the oxidative damage of telomeres causing their shortening; (2) the oxidation of proteomes and DNA damage; (3) an a in lysosomal mass through the increased activity of resident enzymes such as senescence-associated β-galactosidase (SA-β-gal) as well as other proteins that are products of lysosomal activity; (4) and the increased expression of SASP, in particular pro-inflammatory cytokines transcriptionally regulated by NF-κB. However, the main targets of ROS on the skin are the proteome (oxi-proteome), followed by telomeres, nucleic acids (DNAs), lipids, proteins, and cytoplasmic organelles. As a result, cell cycle arrest pathways, lipid peroxidation, increased lysosomal content and dysfunctional mitochondria, and SASP synthesis occur. Furthermore, oxidative stress in skin cells increases the activity of p16INK4A and p53 as inhibitors of Rb and CDks, which are important for maintaining the cell cycle. p53 also promotes the inactivation of mTOR-mediated autophagic and apoptotic pathways, leading to senescence. However, these markers alone cannot establish the state of cellular senescence, and multiple analyses are encouraged for confirmation. An updated and more comprehensive approach to investigating skin senescence should include further assays of ox-inflammatory molecular pathways that can consolidate the understanding of cutaneous redox senescence.

Fisetin, a potential skin rejuvenation drug that eliminates senescent cells in the dermis

Accumulation of senescent fibroblasts, chronic inflammation, and collagen remodeling due to aging-related secretory phenotypes have been hypothesized to cause age-related skin aging, which results in wrinkles and loss of skin elasticity, thus compromising appearance attractiveness. However, the rejuvenating effects of removing senescent cells from the human skin and the efficacy of related therapeutic agents remain unclear. Here, we investigated the effects of fisetin, a potential anti-aging component found in various edible fruits and vegetables, on senescent human dermal fibroblasts (HDFs) and aging human skin. Senescence was induced in primary HDFs using long-term passaging and treatment with ionizing radiation, and cell viability was assessed after treatment with fisetin and a control component. A mouse/human chimeric model was established by subcutaneously transplanting whole skin grafts from aged individuals into nude mice, which were treated intraperitoneally with fisetin or control a component for 30 d. Skin samples were obtained and subjected to senescence-associated-beta-galactosidase staining; the extent of aging was evaluated using western blotting, reverse transcription-quantitative PCR, and histological analysis. Fisetin selectively eliminated senescent dermal fibroblasts in both senescence-induced cellular models; this effect is attributable to cell death induction by caspases 3, 8, and 9-mediated endogenous and exogenous apoptosis. Fisetin-treated senescent human skin grafts showed increased collagen density and decreased senescence-associated secretory phenotypes (SASP), including matrix metalloproteinases and interleukins. No apparent adverse events were observed. Thus, fisetin could improve skin aging through selective removal of senescent dermal fibroblasts and SASP inhibition, indicating its potential as an effective novel therapeutic agent for combating skin aging.

Rapamycin does not alter bone microarchitecture or material properties quality in young-adult and aged female C57BL/6 mice

Advancing age is the strongest risk factor for osteoporosis and skeletal fragility. Rapamycin is an FDA-approved immunosuppressant that inhibits the mechanistic target of rapamycin (mTOR) complex, extends lifespan, and protects against aging-related diseases in multiple species; however, the impact of rapamycin on skeletal tissue is incompletely understood. We evaluated the effects of a short-term, low-dosage, interval rapamycin treatment on bone microarchitecture and strength in young-adult (3 mo old) and aged female (20 mo old) C57BL/6 mice. Rapamycin (2 mg/kg body mass) was administered via intraperitoneal injection 1×/5 d for a duration of 8 wk; this treatment regimen has been shown to induce geroprotective effects while minimizing the side effects associated with higher rapamycin dosages and/or more frequent or prolonged delivery schedules. Aged femurs exhibited lower cancellous bone mineral density, volume, trabecular connectivity density and number, higher trabecular thickness and spacing, and lower cortical thickness compared to young-adult mice. Rapamycin had no impact on assessed microCT parameters. Flexural testing of the femur revealed that both yield strength and ultimate strength were lower in aged mice compared to young-adult mice. There were no effects of rapamycin on these or other measures of bone biomechanics. Age, but not rapamycin, altered local and global measures of bone turnover. These data demonstrate that short-term, low-dosage interval rapamycin treatment does not negatively or positively impact the skeleton of young-adult and aged mice.

Targeting ageing with rapamycin and its derivatives in humans: a systematic review

Rapamycin and its derivatives (rapalogs) are inhibitors of mTOR, a major regulator of the ageing process. We aimed to summarise the effects of rapamycin and its derivatives on the severity of ageing-related physiological changes and disease in adults. A search across five databases yielded 18 400 unique articles, resulting in 19 included studies. Rapamycin and its derivatives improved physiological parameters associated with ageing in the immune, cardiovascular, and integumentary systems of healthy individuals or individuals with ageing-related diseases. Overall, no significant effects on the endocrine, muscular, or neurological systems were found. The effects of rapamycin or its derivatives on the respiratory, digestive, renal, and reproductive systems were not assessed. No serious adverse events attributed to rapamycin and its derivatives were reported in healthy individuals; however, there were increased numbers of infections and increases in total cholesterol, LDL cholesterol, and triglycerides in individuals with ageing-related diseases. Future studies should assess the remaining unexamined systems and test the effects of long-term exposure to rapamycin and its derivatives.

Nutlin-3 Loaded Ethosomes and Transethosomes to Prevent UV-Associated Skin Damage

The skin's protective mechanisms, in some cases, are not able to counteract the destructive effects induced by UV radiations, resulting in dermatological diseases, as well as skin aging. Nutlin-3, a potent drug with antiproliferative activity in keratinocytes, can block UV-induced apoptosis by activation of p53. In the present investigation, ethosomes and transethosomes were designed as delivery systems for nutlin-3, with the aim to protect the skin against UV damage. Vesicle size distribution was evaluated by photon correlation spectroscopy and morphology was investigated by cryogenic transmission electron microscopy, while nutlin-3 entrapment capacity was evaluated by ultrafiltration and HPLC. The in vitro diffusion kinetic of nutlin-3 from ethosomes and transethosomes was studied by Franz cell. Moreover, the efficiency of ethosomes and transethosomes in delivering nutlin-3 and its protective role were evaluated in ex vivo skin explants exposed to UV radiations. The results indicate that ethosomes and transethosomes efficaciously entrapped nutlin-3 (0.3% w/w). The ethosome vesicles were spherical and oligolamellar, with a 224 nm mean diameter, while in transethosome the presence of polysorbate 80 resulted in unilamellar vesicles with a 146 nm mean diameter. The fastest nutlin-3 kinetic was detected in the case of transethosomes, with permeability coefficients 7.4-fold higher, with respect to ethosomes and diffusion values 250-fold higher, with respect to the drug in solution. Ex vivo data suggest a better efficacy of transethosomes to promote nutlin-3 delivery within the skin, with respect to ethosomes. Indeed, nutlin-3 loaded transethosomes could prevent UV effect on cutaneous metalloproteinase activation and cell proliferative response.

Anti-Aging Drugs and the Related Signal Pathways

Aging is a multifactorial biological process involving chronic diseases that manifest from the molecular level to the systemic level. From its inception to 31 May 2022, this study searched the PubMed, Web of Science, EBSCO, and Cochrane library databases to identify relevant research from 15,983 articles. Multiple approaches have been employed to combat aging, such as dietary restriction (DR), exercise, exchanging circulating factors, gene therapy, and anti-aging drugs. Among them, anti-aging drugs are advantageous in their ease of adherence and wide prevalence. Despite a shared functional output of aging alleviation, the current anti-aging drugs target different signal pathways that frequently cross-talk with each other. At present, six important signal pathways were identified as being critical in the aging process, including pathways for the mechanistic target of rapamycin (mTOR), AMP-activated protein kinase (AMPK), nutrient signal pathway, silent information regulator factor 2-related enzyme 1 (SIRT1), regulation of telomere length and glycogen synthase kinase-3 (GSK-3), and energy metabolism. These signal pathways could be targeted by many anti-aging drugs, with the corresponding representatives of rapamycin, metformin, acarbose, nicotinamide adenine dinucleotide (NAD+), lithium, and nonsteroidal anti-inflammatory drugs (NSAIDs), respectively. This review summarized these important aging-related signal pathways and their representative targeting drugs in attempts to obtain insights into and promote the development of mechanism-based anti-aging strategies.

Clinically Actionable Topical Strategies for Addressing the Hallmarks of Skin Aging: A Primer for Aesthetic Medicine Practitioners

In this narrative review, we sought to provide a comprehensive overview of the mechanisms underlying cutaneous senescence, framed by the twelve traditional hallmarks of aging. These include genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, impaired macroautophagy, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, chronic inflammation, and dysbiosis. We also examined how topical interventions targeting these hallmarks can be integrated with conventional aesthetic medicine techniques to enhance skin rejuvenation. The potential of combining targeted topical therapies against the aging hallmarks with minimally invasive procedures represents a significant advancement in aesthetic medicine, offering personalized and effective strategies to combat skin aging. The reviewed evidence paves the way for future advancements and underscores the transformative potential of integrating scientifically validated interventions targeted against aging hallmarks into traditional aesthetic practices.

A cohort study on IVF outcomes in infertile endometriosis patients: the effects of rapamycin treatment

RESEARCH QUESTION

Can rapamycin, used as an anti-senescence drug before IVF cycles, improve the IVF outcomes of women with endometriosis by reducing oxidative stress and senescence?

DESIGN

This retrospective analysis involved 168 endometriosis patients undergoing two successive IVF cycles. The treatment group (n = 80) received 3 months of rapamycin before the second IVF cycle, while the non-treatment group (n = 88) had no adjuvant treatment. The first and second IVF cycles were compared between and within groups. Follicular fluid from both IVF cycles (treatment group n = 28, non-treatment group n = 32) were tested for senescence-associated and oxidative stress-related markers.

RESULTS

Comparing the follicular fluid from the second cycles, the rapamycin treatment group showed decreased markers of oxidative stress (8-hydroxydesoxyguanosine, malondialdehyde) and increased antioxidant markers (superoxidase dismutase, glutathione peroxidase) (all P < 0.001); the expression of senescence-related markers p16 and p21 was also significantly lower in the treatment group than in the non-treatment group (P < 0.001). Comparing the second IVF cycles, the treatment group needed fewer days of ovarian stimulation, with increased numbers of oocytes obtained and mature oocytes compared with the non-treatment group (all P < 0.001). Furthermore, rates of fertilization, implantation and clinical pregnancy were significantly higher in the treatment group (P = 0.008, 0.034 and 0.038 respectively), as was the live birth rate (P = 0.003). No structural abnormalities were seen in fetuses born to women treated with rapamycin.

CONCLUSIONS

This study suggested an association between short-term rapamycin treatment and improved pregnancy outcomes via IVF. This result needs to be further investigated in prospective randomized controlled clinical trials.

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.

Collagen study advances for photoaging skin

BACKGROUND

Collagen dominates the skin's extracellular matrix (ECM). Type I collagen comprises 80%-90% of the skin's collagen, followed by type III (8%-12%) and type V (5%). Reactive oxygen species, matrix metalloproteinases, and collagen degradation all increase during photoaging, which disrupts the ECM's dynamic balance and lowers the amount of total collagen in the body. In recent years, domestic and foreign researchers have conducted multidimensional and multifaceted studies on collagen and skin photoaging. Collagen and the peptides that are derivates of it are currently being used more and more in biomedicine and medical esthetics.

OBJECTIVE

Offering new suggestions for both the avoidance and remedy of photoaging.

METHODS

This article reviews collagen and its potential connection to skin photoaging, illustrates the effects of collagen and peptide supplementation derivatives on photoaged skin, and briefly describes other compounds that can also be used to fight photoaging by increasing collagen synthesis in the skin.

RESULT

Both internal and external aging are inevitable, and as the main component of extracellular matrix, collagen plays a variety of functions in maintaining skin structure and fighting skin aging, and its role in photoaging is undeniable. Ultraviolet radiation can induce increased fragmentation and degradation of cutaneous collagen, while conversely, supplementation with collagen can effectively counteract photodamage-induced skin impairment.

CONCLUSION

Collagen and its derived peptides are indispensable in photoaging skin, holding promising prospects for applications in skin aging.

Hallmarks of Skin Aging: Update

Aging is defined as impaired physiological integrity, decreased function, increased susceptibility to external risk factors and various diseases. Skin, the largest organ in our body, may become more vulnerable to insult as time goes by and behave as aged skin. Here, we systemically reviewed three categories including seven hallmarks of skin aging. These hallmarks including genomic instability and telomere attrition, epigenetic alterations and loss of proteostasis, deregulated nutrient-sensing, mitochondrial damage and dysfunction, cellular senescence, stem cell exhaustion/dysregulation, and altered intercellular communication. These seven hallmarks can generally be divided into three categories including (i) causes of damages as primary hallmarks in skin aging; (ii) responses to damage as antagonistic hallmarks in skin aging; and (iii) culprits of the phenotype as integrative hallmarks in skin aging.

The role of cellular senescence in skin aging and age-related skin pathologies

Aging is the result of a gradual functional decline at the cellular, and ultimately, organismal level, resulting in an increased risk of developing a variety of chronic illnesses, such as cardiovascular disease, stroke, cancer and diabetes. The skin is the largest organ of the human body, and the site where signs of aging are most visible. These signs include thin and dry skin, sagging, loss of elasticity, wrinkles, as well as aberrant pigmentation. The appearance of these features is accelerated by exposure to extrinsic factors such as ultraviolet (UV) radiation or pollution, as well as intrinsic factors including time, genetics, and hormonal changes. At the cellular level, aging is associated with impaired proteostasis and an accumulation of macromolecular damage, genomic instability, chromatin reorganization, telomere shortening, remodelling of the nuclear lamina, proliferation defects and premature senescence. Cellular senescence is a state of permanent growth arrest and a key hallmark of aging in many tissues. Due to their inability to proliferate, senescent cells no longer contribute to tissue repair or regeneration. Moreover, senescent cells impair tissue homeostasis, promote inflammation and extracellular matrix (ECM) degradation by secreting molecules collectively known as the "senescence-associated secretory phenotype" (SASP). Senescence can be triggered by a number of different stimuli such as telomere shortening, oncogene expression, or persistent activation of DNA damage checkpoints. As a result, these cells accumulate in aging tissues, including human skin. In this review, we focus on the role of cellular senescence during skin aging and the development of age-related skin pathologies, and discuss potential strategies to rejuvenate aged skin.

The impact of aging and oxidative stress in metabolic and nervous system disorders: programmed cell death and molecular signal transduction crosstalk

Life expectancy is increasing throughout the world and coincides with a rise in non-communicable diseases (NCDs), especially for metabolic disease that includes diabetes mellitus (DM) and neurodegenerative disorders. The debilitating effects of metabolic disorders influence the entire body and significantly affect the nervous system impacting greater than one billion people with disability in the peripheral nervous system as well as with cognitive loss, now the seventh leading cause of death worldwide. Metabolic disorders, such as DM, and neurologic disease remain a significant challenge for the treatment and care of individuals since present therapies may limit symptoms but do not halt overall disease progression. These clinical challenges to address the interplay between metabolic and neurodegenerative disorders warrant innovative strategies that can focus upon the underlying mechanisms of aging-related disorders, oxidative stress, cell senescence, and cell death. Programmed cell death pathways that involve autophagy, apoptosis, ferroptosis, and pyroptosis can play a critical role in metabolic and neurodegenerative disorders and oversee processes that include insulin resistance, β-cell function, mitochondrial integrity, reactive oxygen species release, and inflammatory cell activation. The silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), AMP activated protein kinase (AMPK), and Wnt1 inducible signaling pathway protein 1 (WISP1) are novel targets that can oversee programmed cell death pathways tied to β-nicotinamide adenine dinucleotide (NAD+), nicotinamide, apolipoprotein E (APOE), severe acute respiratory syndrome (SARS-CoV-2) exposure with coronavirus disease 2019 (COVID-19), and trophic factors, such as erythropoietin (EPO). The pathways of programmed cell death, SIRT1, AMPK, and WISP1 offer exciting prospects for maintaining metabolic homeostasis and nervous system function that can be compromised during aging-related disorders and lead to cognitive impairment, but these pathways have dual roles in determining the ultimate fate of cells and organ systems that warrant thoughtful insight into complex autofeedback mechanisms.

Lysosomes in senescence and aging

Dysfunction of lysosomes, the primary hydrolytic organelles in animal cells, is frequently associated with aging and age-related diseases. At the cellular level, lysosomal dysfunction is strongly linked to cellular senescence or the induction of cell death pathways. However, the precise mechanisms by which lysosomal dysfunction participates in these various cellular or organismal phenotypes have remained elusive. The ability of lysosomes to degrade diverse macromolecules including damaged proteins and organelles puts lysosomes at the center of multiple cellular stress responses. Lysosomal activity is tightly regulated by many coordinated cellular processes including pathways that function inside and outside of the organelle. Here, we collectively classify these coordinated pathways as the lysosomal processing and adaptation system (LYPAS). We review evidence that the LYPAS is upregulated by diverse cellular stresses, its adaptability regulates senescence and cell death decisions, and it can form the basis for therapeutic manipulation for a wide range of age-related diseases and potentially for aging itself.

Cellular Senescence in Human Skin Aging: Leveraging Senotherapeutics

BACKGROUND

As the largest organ in the human body, the skin is continuously exposed to intrinsic and extrinsic stimuli that impact its functionality and morphology with aging. Skin aging entails dysregulation of skin cells and loss, fragmentation, or fragility of extracellular matrix fibers that are manifested macroscopically by wrinkling, laxity, and pigmentary abnormalities. Age-related skin changes are the focus of many surgical and nonsurgical treatments aimed at improving overall skin appearance and health.

SUMMARY

As a hallmark of aging, cellular senescence, an essentially irreversible cell cycle arrest with apoptosis resistance and a secretory phenotype, manifests across skin layers by affecting epidermal and dermal cells. Knowledge of skin-specific senescent cells, such as melanocytes (epidermal aging) and fibroblasts (dermal aging), will promote our understanding of age-related skin changes and how to optimize patient outcomes in esthetic procedures.

KEY MESSAGES

This review provides an overview of skin aging in the context of cellular senescence and discusses senolytic intervention strategies to selectively target skin senescent cells that contribute to premature skin aging.

Longevity through diet restriction and immunity

The share of the population that is aging is growing rapidly. In an aging society, technologies and interventions that delay the aging process are of great interest. Dietary restriction (DR) is the most reproducible and effective nutritional intervention tested to date for delaying the aging process and prolonging the health span in animal models. Preventive effects of DR on age-related diseases have also been reported in human. In addition, highly conserved signaling pathways from small animal models to human mediate the effects of DR. Recent evidence has shown that the immune system is closely related to the effects of DR, and functions as a major mechanism of DR in healthy aging. This review discusses the effects of DR in delaying aging and preventing age-related diseases in animal, including human, and introduces the molecular mechanisms that mediate these effects. In addition, it reports scientific findings on the relationship between the immune system and DRinduced longevity. The review highlights the role of immunity as a potential mediator of the effects of DR on longevity, and provides insights into healthy aging in human. [BMB Reports 2023; 56(10): 537-544].

Blazing a trail for the clinical use of rapamycin as a geroprotecTOR

Treatment with rapamycin, an inhibitor of the mechanistic Target Of Rapamycin Complex One (mTORC1) protein kinase, has been repeatedly demonstrated to extend lifespan and prevent or delay age-related diseases in diverse model systems. Concerns over the risk of potentially serious side effects in humans, including immunosuppression and metabolic disruptions, have cautiously limited the translation of rapamycin and its analogs as a treatment for aging associated conditions. During the last decade, we and others have developed a working model that suggests that while inhibition of mTORC1 promotes healthy aging, many of the negative side effects of rapamycin are associated with "off-target" inhibition of a second mTOR complex, mTORC2. Differences in the kinetics and molecular mechanisms by which rapamycin inhibits mTORC1 and mTORC2 suggest that a therapeutic window for rapamycin could be exploited using intermittent dosing schedules or alternative rapalogs that may enable more selective inhibition of mTORC1. However, the optimal dosing schedules and the long-term efficacy of such interventions in humans are unknown. Here, we highlight ongoing or upcoming clinical trials that will address outstanding questions regarding the safety, pharmacokinetics, pharmacodynamics, and efficacy of rapamycin and rapalogs on several clinically oriented outcomes. Results from these early phase studies will help guide the design of phase 3 clinical trials to determine whether rapamycin can be used safely to inhibit mTORC1 for the treatment and prevention of age-related diseases in humans.