Redox control of senescence and age-related disease

Bioactivities of morroniside: A comprehensive review of pharmacological properties and molecular mechanisms

Morroniside (MOR) is an iridoid glycoside and the main active principle of the medicinal plant, Cornus officinalis Sieb. This phytochemical is associated with numerous health benefits due to its antioxidant properties. The primary objective of the present study was to assess the pharmacological effects and underlying mechanisms of MOR, utilizing published data obtained from literature databases. Data collection involved accessing various sources, including PubMed/Medline, Scopus, Science Direct, Google Scholar, Web of Science, and SpringerLink. Our findings demonstrate that MOR can be utilized for the treatment of several diseases and disorders, as numerous studies have revealed its significant therapeutic activities. These activities encompass anti-inflammatory, antidiabetic, lipid-lowering capability, anticancer, trichogenic, hepatoprotective, gastroprotective, osteoprotective, renoprotective, and cardioprotective effects. MOR has also shown promising benefits against various neurological ailments, including Alzheimer's disease, Parkinson's disease, spinal cord injury, cerebral ischemia, and neuropathic pain. Considering these therapeutic features, MOR holds promise as a lead compound for the treatment of various ailments and disorders. However, further comprehensive preclinical and clinical trials are required to establish MOR as an effective and reliable therapeutic agent.

Small extracellular vesicles from young plasma reverse age-related functional declines by improving mitochondrial energy metabolism

Recent investigations into heterochronic parabiosis have unveiled robust rejuvenating effects of young blood on aged tissues. However, the specific rejuvenating mechanisms remain incompletely elucidated. Here we demonstrate that small extracellular vesicles (sEVs) from the plasma of young mice counteract pre-existing aging at molecular, mitochondrial, cellular and physiological levels. Intravenous injection of young sEVs into aged mice extends their lifespan, mitigates senescent phenotypes and ameliorates age-associated functional declines in multiple tissues. Quantitative proteomic analyses identified substantial alterations in the proteomes of aged tissues after young sEV treatment, and these changes are closely associated with metabolic processes. Mechanistic investigations reveal that young sEVs stimulate PGC-1α expression in vitro and in vivo through their miRNA cargoes, thereby improving mitochondrial functions and mitigating mitochondrial deficits in aged tissues. Overall, this study demonstrates that young sEVs reverse degenerative changes and age-related dysfunction, at least in part, by stimulating PGC-1α expression and enhancing mitochondrial energy metabolism.

Unraveling the Anti-Aging Properties of Phycocyanin from the Cyanobacterium Spirulina (Arthrospira platensis)

In recent years, marine natural products have become one of the most important resources of novel lead compounds for critical diseases associated with age. Spirulina, a dietary supplement made from blue-green algae (cyanobacteria: scientific name Arthrospira platensis), is particularly rich in phycocyanin, a phycobiliprotein, which accounts for up to 20% of this cyanobacterium's dry weight and is considered responsible for its anti-cancer, anti-inflammatory and antioxidant activities. Although the anti-aging activity of phycocyanin has been investigated, how exactly this compound works against aging remains elusive. The aim of our research is to use the yeast Saccharomyces cerevisiae as a model organism to investigate the anti-aging properties of phycocyanin from A. platensis. Our results show that phycocyanin has a powerful anti-aging effect, greatly extending the chronological life span of yeast cells in a dose-dependent way, as the effect was also pronounced when cells were grown in SD medium under calorie restriction conditions (0.2% glucose). Both ROS and accumulation of dead cells were followed by staining chronologically aged cells with dihydrorhodamine 123 (DHR123) and propidium iodide (PI). Interestingly, we found that most of the aged phycocyanin-treated cells, which were unable to form colonies, were actually ROS+/PI-. Finally, we show that the moment in which phycocyanin is added to the culture does not substantially influence its effectiveness in counteracting chronological aging.

Redox changes and cellular senescence in Alzheimer's disease

The redox process and cellular senescence are involved in a range of essential physiological functions. However, they are also implicated in pathological processes underlying age-related neurodegenerative disorders, including Alzheimer's disease (AD). Elevated levels of reactive oxygen species (ROS) are generated as a result of abnormal accumulation of beta-amyloid peptide (Aβ), tau protein, and heme dyshomeostasis and is further aggravated by mitochondria dysfunction and endoplasmic reticulum (ER) stress. Excessive ROS damages vital cellular components such as proteins, DNA and lipids. Such damage eventually leads to impaired neuronal function and cell death. Heightened oxidative stress can also induce cellular senescence via activation of the senescence-associated secretory phenotype to further exacerbate inflammation and tissue dysfunction. In this review, we focus on how changes in the redox system and cellular senescence contribute to AD and how they are affected by perturbations in heme metabolism and mitochondrial function. While potential therapeutic strategies targeting such changes have received some attention, more research is necessary to bring them into clinical application.

Aging, Cellular Senescence, and Glaucoma

Aging is one of the most serious risk factors for glaucoma, and according to age-standardized prevalence, glaucoma is the second leading cause of legal blindness worldwide. Cellular senescence is a hallmark of aging that is defined by a stable exit from the cell cycle in response to cellular damage and stress. The potential mechanisms underlying glaucomatous cellular senescence include oxidative stress, DNA damage, mitochondrial dysfunction, defective autophagy/mitophagy, and epigenetic modifications. These phenotypes interact and generate a sufficiently stable network to maintain the cell senescent state. Senescent trabecular meshwork (TM) cells, retinal ganglion cells (RGCs) and vascular endothelial cells reportedly accumulate with age and stress and may contribute to glaucoma pathologies. Therapies targeting the suppression or elimination of senescent cells have been found to ameliorate RGC death and improve vision in glaucoma models, suggesting the pivotal role of cellular senescence in the pathophysiology of glaucoma. In this review, we explore the biological links between aging and glaucoma, specifically delving into cellular senescence. Moreover, we summarize the current data on cellular senescence in key target cells associated with the development and clinical phenotypes of glaucoma. Finally, we discuss the therapeutic potential of targeting cellular senescence for the management of glaucoma.

Amide Alkaloids as Privileged Sources of Senomodulators for Therapeutic Purposes in Age-Related Diseases

Nature is an important source of bioactive compounds and has continuously made a large contribution to the discovery of new drug leads. Particularly, plant-derived compounds have long been identified as highly interesting in the field of aging research and senescence. Many plants contain bioactive compounds that have the potential to influence cellular processes and provide health benefits. Among them, Piper alkaloids have emerged as interesting candidates in the context of age-related diseases and particularly senescence. These compounds have been shown to display a variety of features, including antioxidant, anti-inflammatory, neuroprotective, and other bioactive properties that may help counteracting the effects of cellular aging processes. In the review, we will put the emphasis on piperlongumine and other related derivatives, which belong to the Piper alkaloids, and whose senomodulating potential has emerged during the last several years. We will also provide a survey on their potential in therapeutic perspectives of age-related diseases.

The potential use of nanozyme in aging and age-related diseases

The effects of an increasingly elderly population are among the most far-reaching in 21st-century society. The growing healthcare expense is mainly attributable to the increased incidence of chronic illnesses that accompany longer life expectancies. Different ideas have been put up to explain aging, but it is widely accepted that oxidative damage to proteins, lipids, and nucleic acids contributes to the aging process. Increases in life expectancy in all contemporary industrialized cultures are accompanied by sharp increases in the prevalence of age-related diseases such as cardiovascular and neurological conditions, type 2 diabetes, osteoporosis, and cancer. Therefore, academic and public health authorities should prioritize the development of therapies to increase health span. Nanozyme (NZ)-like activity in nanomaterials has been identified as promising anti-aging nanomedicines. More than that, nanomaterials displaying catalytic activities have evolved as artificial enzymes with high structural stability, variable catalytic activity, and functional diversity for use in a wide range of biological settings, including those dealing with age-related disorders. Due to their inherent enzyme-mimicking qualities, enzymes have attracted significant interest in treating diseases associated with reactive oxygen species (ROS). The effects of NZs on aging and age-related disorders are summarized in this article. Finally, prospects and threats to enzyme research and use in aging and age-related disorders are offered.

8-Oxoguanine DNA glycosylase protects cells from senescence via the p53-p21 pathway

Cellular senescence is an important factor leading to pulmonary fibrosis. Deficiency of 8-oxoguanine DNA glycosylase (OGG1) in mice leads to alleviation of bleomycin (BLM)-induced mouse pulmonary fibrosis, and inhibition of the OGG1 enzyme reduces the epithelial mesenchymal transition (EMT) in lung cells. In the present study, we find decreased expression of OGG1 in aged mice and BLM-induced cell senescence. In addition, a decrease in OGG1 expression results in cell senescence, such as increases in the percentage of SA-β-gal-positive cells, and in the p21 and p-H2AX protein levels in response to BLM in lung cells. Furthermore, OGG1 promotes cell transformation in A549 cells in the presence of BLM. We also find that OGG1 siRNA impedes cell cycle progression and inhibits the levels of telomerase reverse transcriptase (TERT) and LaminB1 in BLM-treated lung cells. The increase in OGG1 expression results in the opposite phenomenon. The mRNA levels of senescence-associated secretory phenotype (SASP) components, including IL-1α, IL-1β, IL-6, IL-8, CXCL1/CXCL2, and MMP-3, in the absence of OGG1 are obviously increased in A549 cells treated with BLM. Interestingly, we demonstrate that OGG1 binds to p53 to inhibit the activation of p53 and that silencing of p53 reverses the inhibition of OGG1 on senescence in lung cells. Additionally, the augmented cell senescence is shown in vivo in OGG1-deficient mice. Overall, we provide direct evidence in vivo and in vitro that OGG1 plays an important role in protecting tissue cells against aging associated with the p53 pathway.

Antioxidant Metabolism Pathways in Vitamins, Polyphenols, and Selenium: Parallels and Divergences

Free radicals (FRs) are unstable molecules that cause reactive stress (RS), an imbalance between reactive oxygen and nitrogen species in the body and its ability to neutralize them. These species are generated by both internal and external factors and can damage cellular lipids, proteins, and DNA. Antioxidants prevent or slow down the oxidation process by interrupting the transfer of electrons between substances and reactive agents. This is particularly important at the cellular level because oxidation reactions lead to the formation of FR and contribute to various diseases. As we age, RS accumulates and leads to organ dysfunction and age-related disorders. Polyphenols; vitamins A, C, and E; and selenoproteins possess antioxidant properties and may have a role in preventing and treating certain human diseases associated with RS. In this review, we explore the current evidence on the potential benefits of dietary supplementation and investigate the intricate connection between SIRT1, a crucial regulator of aging and longevity; the transcription factor NRF2; and polyphenols, vitamins, and selenium. Finally, we discuss the positive effects of antioxidant molecules, such as reducing RS, and their potential in slowing down several diseases.

Extracellular microvesicles: biologic properties, biogenesis, and applications in leukemia

Microvesicles are cellular membrane vesicles of which size is limited to 30-1000 nm. Almost all cells release them in response to activation signals and apoptosis. Their ability for intercellular communication and enhancement of potential for information exchange (between them) has attracted much interest. Their content is affected by the content of the mother cell, which can help identify their origin. Furthermore, these particles can change the physiology of the target cells by transferring a set of molecules to them and changing the epigenetics of the cells by transferring DNA and RNA. These changes can be induced in cells close to the mother and distant cells. Significant activities of these microvesicles are known both in physiological and pathologic conditions. In this regard, we have reviewed these small particle elements, their contents, and the way of synthesis. Finally, we discussed their current known roles to reveal more potential applications in leukemia.

Pharmacological modulation of vascular ageing: A review from VascAgeNet

Vascular ageing, characterized by structural and functional changes in blood vessels of which arterial stiffness and endothelial dysfunction are key components, is associated with increased risk of cardiovascular and other age-related diseases. As the global population continues to age, understanding the underlying mechanisms and developing effective therapeutic interventions to mitigate vascular ageing becomes crucial for improving cardiovascular health outcomes. Therefore, this review provides an overview of the current knowledge on pharmacological modulation of vascular ageing, highlighting key strategies and promising therapeutic targets. Several molecular pathways have been identified as central players in vascular ageing, including oxidative stress and inflammation, the renin-angiotensin-aldosterone system, cellular senescence, macroautophagy, extracellular matrix remodelling, calcification, and gasotransmitter-related signalling. Pharmacological and dietary interventions targeting these pathways have shown potential in ameliorating age-related vascular changes. Nevertheless, the development and application of drugs targeting vascular ageing is complicated by various inherent challenges and limitations, such as certain preclinical methodological considerations, interactions with exercise training and sex/gender-related differences, which should be taken into account. Overall, pharmacological modulation of endothelial dysfunction and arterial stiffness as hallmarks of vascular ageing, holds great promise for improving cardiovascular health in the ageing population. Nonetheless, further research is needed to fully elucidate the underlying mechanisms and optimize the efficacy and safety of these interventions for clinical translation.

Crowdsourcing temporal transcriptomic coronavirus host infection data: Resources, guide, and novel insights

The emergence of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) reawakened the need to rapidly understand the molecular etiologies, pandemic potential, and prospective treatments of infectious agents. The lack of existing data on SARS-CoV-2 hampered early attempts to treat severe forms of coronavirus disease-2019 (COVID-19) during the pandemic. This study coupled existing transcriptomic data from severe acute respiratory syndrome-related coronavirus 1 (SARS-CoV-1) lung infection animal studies with crowdsourcing statistical approaches to derive temporal meta-signatures of host responses during early viral accumulation and subsequent clearance stages. Unsupervised and supervised machine learning approaches identified top dysregulated genes and potential biomarkers (e.g. CXCL10, BEX2, and ADM). Temporal meta-signatures revealed distinct gene expression programs with biological implications to a series of host responses underlying sustained Cxcl10 expression and Stat signaling. Cell cycle switched from G1/G0 phase genes, early in infection, to a G2/M gene signature during late infection that correlated with the enrichment of DNA damage response and repair genes. The SARS-CoV-1 meta-signatures were shown to closely emulate human SARS-CoV-2 host responses from emerging RNAseq, single cell, and proteomics data with early monocyte-macrophage activation followed by lymphocyte proliferation. The circulatory hormone adrenomedullin was observed as maximally elevated in elderly patients who died from COVID-19. Stage-specific correlations to compounds with potential to treat COVID-19 and future coronavirus infections were in part validated by a subset of twenty-four that are in clinical trials to treat COVID-19. This study represents a roadmap to leverage existing data in the public domain to derive novel molecular and biological insights and potential treatments to emerging human pathogens.

Sarcopenia Is Associated with Changes in Circulating Markers of Antioxidant/Oxidant Balance and Innate Immune Response

(1) Background: The involvement of redox balance alterations and innate immunity is suggested to play a key role in the pathogenesis of sarcopenia. This investigation aimed to define and relate modifications in circulating markers of redox homeostasis and the innate immune response in human sarcopenia. (2) Methods: A total of 32 subjects aged >65 years old and affected by sarcopenia according to the second "European Working Group on sarcopenia in older people" guidelines were compared with 40 non-sarcopenic age-matched controls. To assess systemic redox homeostasis, reduced (GSH) and oxidized (GSSG) blood glutathione and plasma malondialdehyde (MDA)- and 4-hydroxy-2,3-nonenal (HNE)-protein adducts were measured. Immune cells and circulating interleukins were determined to compare the innate immune response between both groups. (3) Results: Impaired redox balance in sarcopenic patients, characterized by a high blood GSSG/GSH ratio and plasma MDA/HNE-protein adducts, was sustained by reduced antioxidants in peripheral blood mononuclear cells. Furthermore, sarcopenic patients showed higher neutrophil-to-lymphocyte ratios and interleukin (IL)-4, IL-6, IL-10, and tumor necrosis factor (TNF) with respect to non-sarcopenic patients. Linear regression analysis resulted in a strong association between redox balance and immune response markers in the sarcopenic group. (4) Conclusions: These results support the interplay between redox homeostasis alteration and disruption of the innate immune response in the pathogenesis of sarcopenia.

SGLT2 Inhibitors in Aging-Related Cardiovascular Disease: A Review of Potential Mechanisms

Population aging combined with higher susceptibility to cardiovascular diseases in older adults is increasing the incidence of conditions such as atherosclerosis, myocardial infarction, heart failure, myocardial hypertrophy, myocardial fibrosis, arrhythmia, and hypertension. sodium-glucose cotransporter 2 inhibitors (SGLT2i) were originally developed as a novel oral drug for patients with type 2 diabetes mellitus. Unexpectedly, recent studies have shown that, beyond their effect on hyperglycemia, SGLT2i also have a variety of beneficial effects on cardiovascular disease. Experimental models of cardiovascular disease have shown that SGLT2i ameliorate the process of aging-related cardiovascular disease by inhibiting inflammation, reducing oxidative stress, and reversing endothelial dysfunction. In this review, we discuss the role of SGLT2i in aging-related cardiovascular disease and propose the use of SGLT2i to prevent and treat these conditions in older adults.

Olovnikov, Telomeres, and Telomerase. Is It Possible to Prolong a Healthy Life?

The science of telomeres and telomerase has made tremendous progress in recent decades. In this review, we consider it first in a historical context (the Carrel-Hayflick-Olovnikov-Blackburn chain of discoveries) and then review current knowledge on the telomere structure and dynamics in norm and pathology. Central to the review are consequences of the telomere shortening, including telomere position effects, DNA damage signaling, and increased genetic instability. Cell senescence and role of telomere length in its development are discussed separately. Therapeutic aspects and risks of telomere lengthening methods including use of telomerase and other approaches are also discussed.

Aging, oxidative stress and degenerative diseases: mechanisms, complications and emerging therapeutic strategies

Aging accompanied by several age-related complications, is a multifaceted inevitable biological progression involving various genetic, environmental, and lifestyle factors. The major factor in this process is oxidative stress, caused by an abundance of reactive oxygen species (ROS) generated in the mitochondria and endoplasmic reticulum (ER). ROS and RNS pose a threat by disrupting signaling mechanisms and causing oxidative damage to cellular components. This oxidative stress affects both the ER and mitochondria, causing proteopathies (abnormal protein aggregation), initiation of unfolded protein response, mitochondrial dysfunction, abnormal cellular senescence, ultimately leading to inflammaging (chronic inflammation associated with aging) and, in rare cases, metastasis. RONS during oxidative stress dysregulate multiple metabolic pathways like NF-κB, MAPK, Nrf-2/Keap-1/ARE and PI3K/Akt which may lead to inappropriate cell death through apoptosis and necrosis. Inflammaging contributes to the development of inflammatory and degenerative diseases such as neurodegenerative diseases, diabetes, cardiovascular disease, chronic kidney disease, and retinopathy. The body's antioxidant systems, sirtuins, autophagy, apoptosis, and biogenesis play a role in maintaining homeostasis, but they have limitations and cannot achieve an ideal state of balance. Certain interventions, such as calorie restriction, intermittent fasting, dietary habits, and regular exercise, have shown beneficial effects in counteracting the aging process. In addition, interventions like senotherapy (targeting senescent cells) and sirtuin-activating compounds (STACs) enhance autophagy and apoptosis for efficient removal of damaged oxidative products and organelles. Further, STACs enhance biogenesis for the regeneration of required organelles to maintain homeostasis. This review article explores the various aspects of oxidative damage, the associated complications, and potential strategies to mitigate these effects.

Dynamics of redox signaling in aging via autophagy, inflammation, and senescence

Review paper attempts to explain the dynamic aspects of redox signaling in aging through autophagy, inflammation, and senescence. It begins with ROS source in the cell, then states redox signaling in autophagy, and regulation of autophagy in aging. Next, we discuss inflammation and redox signaling with various pathways involved: NOX pathway, ROS production via TNF-α, IL-1β, xanthine oxidase pathway, COX pathway, and myeloperoxidase pathway. Also, we emphasize oxidative damage as an aging marker and the contribution of pathophysiological factors to aging. In senescence-associated secretory phenotypes, we link ROS with senescence, aging disorders. Relevant crosstalk between autophagy, inflammation, and senescence using a balanced ROS level might reduce age-related disorders. Transducing the context-dependent signal communication among these three processes at high spatiotemporal resolution demands other tools like multi-omics aging biomarkers, artificial intelligence, machine learning, and deep learning. The bewildering advancement of technology in the above areas might progress age-related disorders diagnostics with precision and accuracy.

Molecular mechanism of caloric restriction mimetics-mediated neuroprotection of age-related neurodegenerative diseases: an emerging therapeutic approach

Aging-induced neurodegenerative diseases (NDs) are significantly increasing health problem worldwide. It has been well documented that oxidative stress is one of the potential causes of aging and age-related NDs. There are no drugs for the treatment of NDs, therefore there is an immediate necessity for the development of strategies/treatments either to prevent or cure age-related NDs. Caloric restriction (CR) and intermittent fasting have been considered as effective strategies in increasing the healthspan and lifespan, but it is difficult to adhere to these routines strictly, which has led to the development of calorie restriction mimetics (CRMs). CRMs are natural compounds that provide similar molecular and biochemical effects of CR, and activate autophagy process. CRMs have been reported to regulate redox signaling by enhancing the antioxidant defense systems through activation of the Nrf2 pathway, and inhibiting ROS generation through attenuation of mitochondrial dysfunction. Moreover, CRMs also regulate redox-sensitive signaling pathways such as the PI3K/Akt and MAPK pathways to promote neuronal cell survival. Here, we discuss the neuroprotective effects of various CRMs at molecular and cellular levels during aging of the brain. The CRMs are envisaged to become a cornerstone of the pharmaceutical arsenal against aging and age-related pathologies.

Saudi date cultivars' seed extracts inhibit developing hepatic steatosis in rats fed a high-fat diet

This research aim was to assess the impact of the seed extracts of the date cultivars (Qatara, Barhi, and Ruthana) on rat's liver steatosis, oxidative stress, and inflammation triggered by feeding a high-fat diet (HFD). The experimental design was based on random partitioning into two groups; one that received the standard diet and another that received the HFD diet. The HFD rats were orally administered Lipitor or date seed extracts at 300 or 600 mg/kg/day for 4 weeks. Accordingly, feeding rats HFD significantly increased body and liver weights, hepatic and serum lipid levels, glucose, insulin, HOMA-IR, liver function enzymes, and inflammation markers, and decreased oxidative stress enzymes. Oral administration of Barhi and Ruthana date seed extracts significantly decreased body and liver weights. Serum and liver total cholesterol TC, Triglycerides TGs, and free fatty acids FFAs were also decreased as were AST, ALT, MAD, leptin, and CRP, with a concomitant increase in SOD, GSH, and CAT. Furthermore, similar to Lipitor, oral administration of the extracts reduced inflammation markers such as TNF-α, serum CRP, IL-6, IL-1β, and leptin while increasing IL-10 and adiponectin levels. Histological observation revealed that extract administration improved hepatocyte and parenchymal structures and decreased lipid deposition. In conclusion, both Barhi and Ruthana seed extracts showed strong hepatoprotective, anti-inflammatory, and antioxidant effects against HFD-induced liver steatosis. And date seeds have other beneficial potential for prevention and treatment of various diseases, which can be studied in the future.

R-phycocyanin from porphyra haitanensis influences drosophila melanogaster lifespan in a sex-specific manner

Aging has become a major global public health challenge. Our previous research showed that R-phycocyanin (R-PC) possessed anti-aging activity. Notably, studies already revealed that gender may affect the responses to the anti-aging drug. Therefore, it is worth investigating whether the anti-aging effects and their underlying molecular mechanisms of R-PC differ between genders. Firstly, R-PC was isolated from porphyra haitanensis and its anti-aging mechanisms were explored using the nature aging male and female drosophila melanogaster as model. Next, the regulation pathway of longevity was analyzed by KEGG pathway analysis. The longevity pathways-associated molecules were also examined to explore anti-aging mechanisms of R-PC. The results showed that R-PC increased AMPK activity, thus enhanced the key regulatory factors of autophagy (Atg1, Atg8, Atg5), and consequently induced autophagy. Hence, the longevity activity of R-PC life was related with AMPK/mTOR/S6K autophagic signaling pathways in aging female drosophila melanogaster. Meanwhile, R-PC significantly down-regulated TNF-α, MMP3, IL-1β, IL-6, IL-8 expression levels, and the anti-inflammatory and longevity was associated with R-PC-induced regulation of pI3k/AKT/FOXO3 signaling pathway in aging male drosophila melanogaster. These finding showed that R-PC from porphyra haitanensis might exert the anti-aging actions via different mechanisms in male and female drosophila melanogaste.

Attenuation of Aging-Related Oxidative Stress Pathways by Phytonutrients: A Computational Systems Biology Analysis

Aging results from gradual accumulation of damage to the cellular functions caused by biochemical processes such as oxidative stress, inflammation-driven prolonged cellular senescence state, immune system malfunction, psychological stress, and epigenetic changes due to exposure to environmental toxins. Plant-derived bioactive molecules have been shown to ameliorate the damage from oxidative stress. This research seeks to uncover the mechanisms of action of how phytochemicals from fruit/berry/vegetable (FBV) juice powder mitigate oxidative stress. The study uses a computational systems biology approach to (1) identify biomolecular pathways of oxidative stress; (2) identify phytochemicals from FBV juice powder and their specific action on oxidative stress mechanisms; and (3) quantitatively estimate the effects of FBV juice powder bioactive compounds on oxidative stress. The compounds in FBV affected two oxidative stress molecular pathways: (1) reactive oxygen species (ROS) production and (2) antioxidant enzyme production. Six bioactive compounds including cyanidin, delphinidin, ellagic acid, kaempherol, malvidin, and rutin in FBV significantly lowered production of ROS and increased the production of antioxidant enzymes such as catalase, heme oxygenase-1, superoxide dismutase, and glutathione peroxidase. FBV juice powder provides a combination of bioactive compounds that attenuate aging by affecting multiple pathways of oxidative stress.

The Aging Ovary and the Tales Learned Since Fetal Development

BACKGROUND

While the term "aging" implies a process typically associated with later life, the consequences of ovarian aging are evident by the time a woman reaches her forties, and sometimes earlier. This is due to a gradual decline in the quantity and quality of oocytes which occurs over a woman's reproductive lifespan. Indeed, the reproductive potential of the ovary is established even before birth, as the proper formation and assembly of the ovarian germ cell population during fetal life determines the lifetime endowment of oocytes and follicles. In the ovary, sophisticated molecular processes have been identified that regulate the timing of ovarian aging and these are critical to ensuring follicular maintenance.

SUMMARY

The mechanisms thought to contribute to overall aging have been summarized under the term the "hallmarks of aging" and include such processes as DNA damage, mitochondrial dysfunction, telomere attrition, genomic instability, and stem cell exhaustion, among others. Similarly, in the ovary, molecular processes have been identified that regulate the timing of ovarian aging and these are critical to ensuring follicular maintenance. In this review, we outline critical processes involved in ovarian aging, highlight major achievements for treatment of ovarian aging, and discuss ongoing questions and areas of debate.

KEY MESSAGES

Ovarian aging is recognized as what may be a complex process in which age, genetics, environment, and many other factors contribute to the size and depletion of the follicle pool. The putative hallmarks of reproductive aging outlined herein include a diversity of plausible processes contributing to the depletion of the ovarian reserve. More research is needed to clarify if and to what extent these putative regulators do in fact govern follicle and oocyte behavior, and how these signals might be integrated in order to control the overall pattern of ovarian aging.

Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis

Introduction

Numerous meta-analyses have demonstrated the beneficial effects of probiotics on oxidative stress biomarkers, although some studies have contradictory results. Therefore, the current research was conducted to obtain a precise and definite understanding on the impact of probiotics on oxidative stress biomarkers in adults.

Methods

We conducted a comprehensive systematic search of results on Scopus, PubMed, Embase, Web of Science, and Google Scholar dating up to March 2022. Fifteen meta-analyses were included in this umbrella meta-analysis. The random-effects model was employed to obtain the overall effect size. Subgroup analyses were carried out based on supplementation dosage and duration, mean age, and study population.

Results

Our results indicated that probiotics supplementation meaningfully decreased serum malondialdehyde (MDA) (ESWMD = -0.56, 95% CI: -0.72, -0.39; p < 0.001, and ESSMD = -0.50, 95% CI: -0.66, -0.34; p < 0.001). Moreover, the findings showed that probiotics resulted in a significant increase in total antioxidant capacity (TAC) (ESWMD = 29.18, 95% CI: 16.31, 42.04; p < 0.001, and ESSMD = 0.25, 95% CI: 0.02, 0.47; p = 0.032), total glutathione (GSH) (ESWMD: 30.65; 95% CI: 16.94, 44.35, p < 0.001), and nitric oxide (NO) (ESWMD: 1.48; 95% CI: 0.31, 2.65, p = 0.013; I2 = 51.7%, p = 0.043).

Discussion

Probiotics could be considered a strong agent in the reinforcement of antioxidant status and preventing the incidence of chronic diseases.

Restoration of CPEB4 prevents muscle stem cell senescence during aging

Age-associated impairments in adult stem cell functions correlate with a decline in somatic tissue regeneration capacity. However, the mechanisms underlying the molecular regulation of adult stem cell aging remain elusive. Here, we provide a proteomic analysis of physiologically aged murine muscle stem cells (MuSCs), illustrating a pre-senescent proteomic signature. During aging, the mitochondrial proteome and activity are impaired in MuSCs. In addition, the inhibition of mitochondrial function results in cellular senescence. We identified an RNA-binding protein, CPEB4, downregulated in various aged tissues, which is required for MuSC functions. CPEB4 regulates the mitochondrial proteome and activity through mitochondrial translational control. MuSCs devoid of CPEB4 induced cellular senescence. Importantly, restoring CPEB4 expression rescued impaired mitochondrial metabolism, improved geriatric MuSC functions, and prevented cellular senescence in various human cell lines. Our findings provide the basis for the possibility that CPEB4 regulates mitochondrial metabolism to govern cellular senescence, with an implication of therapeutic intervention for age-related senescence.

Osteoclast-derived IGF1 induces RANKL production in osteocytes and contributes to pagetic lesion formation

We previously reported that measles virus nucleocapsid protein (MVNP) expression in osteoclasts (OCLs) of patients with Paget disease (PD) or targeted to the OCL lineage in MVNP-transgenic mice (MVNP mice) increases IGF1 production in osteoclasts (OCL-IGF1) and leads to development of PD OCLs and pagetic bone lesions (PDLs). Conditional deletion of Igf1 in OCLs of MVNP mice fully blocked development of PDLs. In this study, we examined whether osteocytes (OCys), key regulators of normal bone remodeling, contribute to PD. OCys in PDLs of patients and of MVNP mice expressed less sclerostin, and had increased RANKL expression compared with OCys in bones from WT mice or normal patients. To test whether increased OCL-IGF1 is sufficient to induce PDLs and PD phenotypes, we generated TRAP-Igf1 (T-Igf1) transgenic mice to determine whether increased IGF1 expression in the absence of MVNP in OCLs is sufficient to induce PDLs and pagetic OCLs. We found that T-Igf1 mice at 16 months of age developed PD OCLs, PDLs, and OCys, with decreased sclerostin and increased RANKL, similar to MVNP mice. Thus, pagetic phenotypes could be induced by OCLs expressing increased IGF1. OCL-IGF1 in turn increased RANKL production in OCys to induce PD OCLs and PDLs.

The Role of Oxidative Stress and Cellular Senescence in the Pathogenesis of Metabolic Associated Fatty Liver Disease and Related Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) represents a worryingly increasing cause of malignancy-related mortality, while Metabolic Associated Fatty Liver Disease (MAFLD) is going to become its most common cause in the next decade. Understanding the complex underlying pathophysiology of MAFLD-related HCC can provide opportunities for successful targeted therapies. Of particular interest in this sequela of hepatopathology is cellular senescence, a complex process characterised by cellular cycle arrest initiated by a variety of endogenous and exogenous cell stressors. A key biological process in establishing and maintaining senescence is oxidative stress, which is present in multiple cellular compartments of steatotic hepatocytes. Oxidative stress-induced cellular senescence can change hepatocyte function and metabolism, and alter, in a paracrine manner, the hepatic microenvironment, enabling disease progression from simple steatosis to inflammation and fibrosis, as well as HCC. The duration of senescence and the cell types it affects can tilt the scale from a tumour-protective self-restricting phenotype to the creator of an oncogenic hepatic milieu. A deeper understanding of the mechanism of the disease can guide the selection of the most appropriate senotherapeutic agent, as well as the optimal timing and cell type targeting for effectively combating HCC.

Oxidative stress and metabolic syndrome in acne vulgaris: Pathogenetic connections and potential role of dietary supplements and phytochemicals

Acne vulgaris is a highly prevalent skin condition caused by androgen-induced elevated sebum secretion, abnormal keratinization, bacterial colonization, and inflammation. Current research indicates a link between acne vulgaris and the metabolic syndrome, a group of disorders that includes obesity, insulin resistance, hypertension, and dyslipidemia. This link is thought to be modulated by excessive concentrations of oxidative stress markers and chronic inflammation, which are included in the pathophysiological mechanisms shared by both conditions. Excessive generation of reactive oxygen species damages cellular components and initiates an inflammatory response, hence promoting the development of both disorders. The current narrative review focuses on the molecular implications of inflammatory, hormonal, and environmental factors in the acne-metabolic syndrome correlation. Furthermore, it outlines the current state of knowledge related to the phyto-therapeutic approach to these conditions as an adjuvant strategy to allopathic treatment, but future multicenter and larger-scale research studies are needed establish new algorithms to be included in the future management of patients with these conditions.

Effects of chronic core training on serum and erythrocyte oxidative stress parameters in amputee football players

Objective: The positive impact of aerobic exercise on blood oxidative stress parameters is well documented. However, the effect of core exercises on these parameters in amputee football players (AF) remains unclear. Therefore, this study aims to investigate the impact of core exercises on blood oxidative stress parameters in this population. Methods: Experimental method was adopted in the study. Eleven elite AF players participated in the study. The participants were divided randomly into two groups a core exercise group (CEG) and a control group (CG). Blood measurements were taken before and after the 8-week core exercise program. Blood measurements included erythrocyte Total Oxidant Status (eTOS), erythrocyte Total Antioxidant Status (eTAS), erythrocyte oxidative stress index (eOSI), serum nitric oxide (sNO), serum Total Oxidant Status (sTOS), serum Total Antioxidant Status (sTAS), serum oxidative stress index (sOSI), serum total thiol (sTT), serum native thiol (sNT), and serum disulfide (sDS) parameters were studied. Results: According to the results of the study, a significant difference was found between the 0th and eighth week pre-aerobic training load (ATL) sTOS (p = .028) values of CEG values. A significant difference was found in sTOS (p = .028) and sOSI (p = .028) values after the 0th and eighth-week pre-ATL. A significant difference was found in the sTOS (p = .043) and sOSI values (p = .043) of CG at week 0th and eighth-week pre-ATL. Conclusion: Overall, the results suggest that core exercises had a positive effect on blood oxidative stress parameters in AF players by reducing blood total oxidant levels.

Recent progress in the development of fluorescent probes for imaging pathological oxidative stress

Oxidative stress is closely related to the physiopathology of numerous diseases. Reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS) are direct participants and important biomarkers of oxidative stress. A comprehensive understanding of their changes can help us evaluate disease pathogenesis and progression and facilitate early diagnosis and drug development. In recent years, fluorescent probes have been developed for real-time monitoring of ROS, RNS and RSS levels in vitro and in vivo. In this review, conventional design strategies of fluorescent probes for ROS, RNS, and RSS detection are discussed from three aspects: fluorophores, linkers, and recognition groups. We introduce representative fluorescent probes for ROS, RNS, and RSS detection in cells, physiological/pathological processes (e.g., Inflammation, Drug Induced Organ Injury and Ischemia/Reperfusion Injury etc.), and specific diseases (e.g., neurodegenerative diseases, epilepsy, depression, diabetes and cancer, etc.). We then highlight the achievements, current challenges, and prospects for fluorescent probes in the pathophysiology of oxidative stress-related diseases.

Immunotherapeutic approach to reduce senescent cells and alleviate senescence-associated secretory phenotype in mice

Accumulation of senescent cells (SNCs) with a senescence-associated secretory phenotype (SASP) has been implicated as a major source of chronic sterile inflammation leading to many age-related pathologies. Herein, we provide evidence that a bifunctional immunotherapeutic, HCW9218, with capabilities of neutralizing TGF-β and stimulating immune cells, can be safely administered systemically to reduce SNCs and alleviate SASP in mice. In the diabetic db/db mouse model, subcutaneous administration of HCW9218 reduced senescent islet β cells and SASP resulting in improved glucose tolerance, insulin resistance, and aging index. In naturally aged mice, subcutaneous administration of HCW9218 durably reduced the level of SNCs and SASP, leading to lower expression of pro-inflammatory genes in peripheral organs. HCW9218 treatment also reverted the pattern of key regulatory circadian gene expression in aged mice to levels observed in young mice and impacted genes associated with metabolism and fibrosis in the liver. Single-nucleus RNA Sequencing analysis further revealed that HCW9218 treatment differentially changed the transcriptomic landscape of hepatocyte subtypes involving metabolic, signaling, cell-cycle, and senescence-associated pathways in naturally aged mice. Long-term survival studies also showed that HCW9218 treatment improved physical performance without compromising the health span of naturally aged mice. Thus, HCW9218 represents a novel immunotherapeutic approach and a clinically promising new class of senotherapeutic agents targeting cellular senescence-associated diseases.

Carteolol triggers senescence via activation of β-arrestin-ERK-NOX4-ROS pathway in human corneal endothelial cells in vitro

Carteolol is a commonly-used topical medication for primary open-angle glaucoma. However, long-term and frequent ocular application of carteolol entails its residuals at low concentration in the aqueous humor for a long duration and may exert latent toxicity in the human corneal endothelial cells (HCEnCs). Here, we treated the HCEnCs in vitro with 0.0117% carteolol for 10 days. Thereafter, we removed the cartelolol and normally cultured the cells for 25 days to investigate the chronical toxicity of carteolol and the underlying mechanism. The results exhibited that 0.0117% carteolol induces senescent features in the HCEnCs, such as increased senescence-associated β-galactosidase positive rates, enlarged relative cell area and upregulated p16^INK4A and senescence-associated secretory phenotypes, including IL-1α, TGF-β1, IL-10, TNF-α, CCL-27, IL-6 and IL-8, as well as decreased Lamin B1 expression and cell viability and proliferation. Thereby, further exploration demonstrated that the carteolol activates β-arrestin-ERK-NOX4 pathway to increase reactive oxygen species (ROS) production that imposes oxidative stress on energetic metabolism causing a vicious cycle between declining ATP and increasing ROS production and downregulation of NAD⁺ resulting in metabolic disturbance-mediated senescence of the HCEnCs. The excess ROS also impair DNA to activate the DNA damage response (DDR) pathway of ATM-p53-p21^WAF1/CIP1 with diminished poly(ADP-Ribose) polymerase (PARP) 1, a NAD⁺-dependent enzyme for DNA damage repair, resulting in cell cycle arrest and subsequent DDR-mediated senescence. Taken together, carteolol induces excess ROS to trigger HCEnC senescence via metabolic disturbance and DDR pathway.

New Directions to Approach Oxidative Stress Related to Physical Activity and Nutraceuticals in Normal Aging and Neurodegenerative Aging

Oxidative stress (OS) plays, perhaps, the most important role in the advanced aging process, cognitive impairment and pathogenesis of neurodegenerative disorders. The process generates tissue damage via specific mechanisms on proteins, lipids and nucleic acids of the cells. An imbalance between the excessive production of oxygen- and nitrogen-reactive species and antioxidants leads to a progressive decline in physiological, biological and cognitive functions. Accordingly, we need to design and develop favourable strategies for stopping the early aging process as well as the development of neurodegenerative diseases. Exercise training and natural or artificial nutraceutical intake are considered therapeutic interventions that reduce the inflammatory process, increase antioxidant capacities and promote healthy aging by decreasing the amount of reactive oxygen species (ROS). The aim of our review is to present research results in the field of oxidative stress related to physical activity and nutraceutical administration for the improvement of the aging process, but also related to reducing the neurodegeneration process based on analysing the beneficial effects of several antioxidants, such as physical activity, artificial and natural nutraceuticals, as well as the tools by which they are evaluated. In this paper, we assess the recent findings in the field of oxidative stress by analysing intervention antioxidants, anti-inflammatory markers and physical activity in healthy older adults and the elderly population with dementia and Parkinson's disease. By searching for studies from the last few years, we observed new trends for approaching the reduction in redox potential using different tools that evaluate regular physical activity, as well as antioxidant and anti-inflammatory markers preventing premature aging and the progress of disabilities in neurodegenerative diseases. The results of our review show that regular physical activity, supplemented with vitamins and oligomolecules, results in a decrease in IL-6 and an increase in IL-10, and has an influence on the oxidative metabolism capacity. In conclusion, physical activity provides an antioxidant-protective effect by decreasing free radicals and proinflammatory markers.

Melatonin as mitochondria-targeted drug

Oxidative damage is associated to numerous diseases as well as aging development. Mitochondria found in most eukaryotic organisms to create the energy of the cell, generate free radicals during its action and they are chief targets of the oxidants. Mitochondrial activities outspread outside the borders of the cell and effect human physiology by modulating interactions among cells and tissues. Therefore, it has been implicated in several human disorders and conditions. Melatonin (MLT) is an endogenously created indole derivative that modifies several tasks, involving mitochondria-associated activities. These possessions make MLT a powerful defender against a selection of free radical-linked disorders. MLT lessens mitochondrial anomalies causing from extreme oxidative stress and may improve mitochondrial physiology. It is a potent and inducible antioxidant for mitochondria. MLT is produced in mitochondria of conceivably of all cells and it also appears to be a mitochondria directed antioxidant which has related defensive properties as the synthesized antioxidant molecules. This chapter summarizes the suggestion that MLT is produced in mitochondria as well as disorders of mitochondrial MLT production that may associate to a number of mitochondria-linked diseases. MLT as a mitochondria-targeted drug is also discussed.

Genetic Networks of Alzheimer's Disease, Aging, and Longevity in Humans

Human genomic analysis and genome-wide association studies (GWAS) have identified genes that are risk factors for early and late-onset Alzheimer's disease (AD genes). Although the genetics of aging and longevity have been extensively studied, previous studies have focused on a specific set of genes that have been shown to contribute to or are a risk factor for AD. Thus, the connections among the genes involved in AD, aging, and longevity are not well understood. Here, we identified the genetic interaction networks (referred to as pathways) of aging and longevity within the context of AD by using a gene set enrichment analysis by Reactome that cross-references more than 100 bioinformatic databases to allow interpretation of the biological functions of gene sets through a wide variety of gene networks. We validated the pathways with a threshold of p-value < 1.00 × 10^-5 using the databases to extract lists of 356 AD genes, 307 aging-related (AR) genes, and 357 longevity genes. There was a broad range of biological pathways involved in AR and longevity genes shared with AD genes. AR genes identified 261 pathways within the threshold of p < 1.00 × 10^-5, of which 26 pathways (10% of AR gene pathways) were further identified by overlapping genes among AD and AR genes. The overlapped pathways included gene expression (p = 4.05 × 10^-11) including ApoE, SOD2, TP53, and TGFB1 (p = 2.84 × 10^-10); protein metabolism and SUMOylation, including E3 ligases and target proteins (p = 1.08 × 10^-7); ERBB4 signal transduction (p = 2.69 × 10^-6); the immune system, including IL-3 and IL-13 (p = 3.83 × 10^-6); programmed cell death (p = 4.36 × 10^-6); and platelet degranulation (p = 8.16 × 10^-6), among others. Longevity genes identified 49 pathways within the threshold, of which 12 pathways (24% of longevity gene pathways) were further identified by overlapping genes among AD and longevity genes. They include the immune system, including IL-3 and IL-13 (p = 7.64 × 10^-8), plasma lipoprotein assembly, remodeling and clearance (p < 4.02 × 10^-6), and the metabolism of fat-soluble vitamins (p = 1.96 × 10^-5). Thus, this study provides shared genetic hallmarks of aging, longevity, and AD backed up by statistical significance. We discuss the significant genes involved in these pathways, including TP53, FOXO, SUMOylation, IL4, IL6, APOE, and CEPT, and suggest that mapping the gene network pathways provide a useful basis for further medical research on AD and healthy aging.

Effects of crude methanol extract of Adansonia digitata fruit pulp on Naja nigricollis venom-induce toxicity in Wistar rats

OBJECTIVES

This study evaluated the effects of Crude Methanol Extract of Adansonia digitata Fruit Pulp on Naja nigricollis Venom-Induce Toxicity in Wistar rats.

METHODS

A. digitata was extracted using 70% methanol and median lethal dose (LD₅₀) of both the extract and venom were determined using the up-and-down method. Sixty Wistar rats were randomly assigned into 10 groups of 6 rats each and were administered with normal saline, venom only, venom + antivenom, 125 mg/kg, 250 mg/kg and 500 mg/kg crude methanol extract (CME) pre-envenomation, 125 mg/kg, 250 mg/kg and 500 mg/kg CME post-envenomation, and venom + antivenom + 250 mg/kg CME, respectively. Blood samples were collected 8-h post-envenomation in EDTA and plain sample bottles. Erythrocyte osmotic fragility (EOF) test was carried out on the EDTA blood samples while serum was harvested and used for Malondialdehyde (MDA) and Superoxide Dismutase (SOD) assays.

RESULTS

LD₅₀ of the CME and venom was >5,000 mg/kg and 0.889 mg/kg, respectively. N. nigricollis-induced oxidative stress was evident in group B through increased % haemolysis, MDA and lowered SOD activities. The groups treated with antivenom only, 250 mg/kg CME post-envenomation and antivenom +250 mg/kg CME significantly (p<0.05) reduced EOF, MDA values and increased SOD. The CME revealed better ameliorative effect than protective via inhibition of EOF, MDA values and increased SOD activity.

CONCLUSIONS

The CME when administered singly showed more ameliorative properties and the combination of CME with antivenom for protection was not as effective as when compared to single administration.

Perceived Age as a Mortality and Comorbidity Predictor: A Systematic Review

INTRODUCTION

Perceived age is defined as how old a person looks to external evaluators. It reflects the underlying biological age, which is a measure based on physical and physiological parameters reflecting a person's aging process more accurately than chronological age. People with a higher biological age have shorter lives compared to those with a lower biological age with the same chronological age. Our review aims to find whether increased perceived age is a risk factor for overall mortality risk or comorbidities.

METHODS

A literature search of three databases was conducted following the PRISMA guidelines for studies analyzing perceived age or isolated facial characteristics of old age and their relationship to mortality risk or comorbidity outcomes. Data on the number of patients, type and characteristics of evaluation methods, evaluator characteristics, mean chronologic age, facial characteristics studied, measured outcomes, and study results were collected.

RESULTS

Out of 977 studies, 15 fulfilled the inclusion criteria. These studies found an increase in mortality risk of 6-51% in older-looking people compared to controls (HR 1.06-1.51, p < 0.05). In addition, perceived age and some facial characteristics of old age were also associated with cardiovascular risk and myocardial infarction, cognitive function, bone mineral density, and chronic obstructive pulmonary disease (COPD).

CONCLUSION

Perceived age promises to be a clinically useful predictor of overall mortality and cardiovascular, pulmonary, cognitive, and osseous comorbidities.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

COVID-19 inhibits spermatogenesis in the testes by inducing cellular senescence

Introduction: COVID-19 (SARS-CoV-2) has been linked to organ damage in humans since its worldwide outbreak. It can also induce severe sperm damage, according to research conducted at numerous clinical institutions. However, the exact mechanism of damage is still unknown. Methods: In this study, testicular bulk-RNA-seq Data were downloaded from three COVID-19 patients and three uninfected controls from GEO to evaluate the effect of COVID-19 infection on spermatogenesis. Relative expression of each pathway and the correlation between genes or pathways were analyzed by bioinformatic methods. Results: By detecting the relative expression of each pathway and the correlation between genes or pathways, we found that COVID-19 could induce testicular cell senescence through MAPK signaling pathway. Cellular senescence was synergistic with MAPK pathway, which further affected the normal synthesis of cholesterol and androgen, inhibited the normal synthesis of lactate and pyruvate, and ultimately affected spermatogenesis. The medications targeting MAPK signaling pathway, especially MAPK1 and MAPK14, are expected to be effective therapeutic medications for reducing COVID-19 damage to spermatogenesis. Conclusion: These results give us a new understanding of how COVID-19 inhibits spermatogenesis and provide a possible solution to alleviate this damage.

Ageing and the Autonomic Nervous System

The vertebrate nervous system is divided into central (CNS) and peripheral (PNS) components. In turn, the PNS is divided into the autonomic (ANS) and enteric (ENS) nervous systems. Ageing implicates time-related changes to anatomy and physiology in reducing organismal fitness. In the case of the CNS, there exists substantial experimental evidence of the effects of age on individual neuronal and glial function. Although many such changes have yet to be experimentally observed in the PNS, there is considerable evidence of the role of ageing in the decline of ANS function over time. As such, this chapter will argue that the ANS constitutes a paradigm for the physiological consequences of ageing, as well as for their clinical implications.

Synchronous Extraction, Antioxidant Activity Evaluation, and Composition Analysis of Carbohydrates and Polyphenols Present in Artichoke Bud

This study investigated the optimization of ultrasonic-assisted aqueous two-phase synchronous extraction of carbohydrates and polyphenols present in artichoke bud, evaluated their antioxidant activities in vitro, and analyzed the composition of carbohydrates and polyphenols by high-performance liquid chromatography (HPLC). The powder mass, ultrasonic time, ammonium sulfate concentration, and alcohol-water ratio were considered the influencing factors based on the single-factor experiment results, and a dual-response surface model was designed to optimize the synchronous extraction process to extract carbohydrates and polyphenols. The antioxidant activity was evaluated by measuring the scavenging capacity of ABTS⁺· and DPPH· and the reducing capacity of Fe³⁺. The optimal process conditions in this study were as follows: the powder mass of 1.4 g, ammonium sulfate concentration of 0.34 g/mL, alcohol-water ratio of 0.4, and ultrasonic time of 43 min. The polyphenol content in artichoke bud was 5.32 ± 0.13 mg/g, and the polysaccharide content was 74.78 ± 0.11 mg/g. An experiment on in vitro antioxidant activity showed that both carbohydrates and polyphenols had strong antioxidant activities, and the antioxidant activity of polyphenols was stronger than that of carbohydrates. The HPLC analysis revealed that the carbohydrates in artichoke bud were mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose, and the molar ratio was 10.77:25.22:2.37:15.74:125.39:48.62:34.70. The polyphenols comprised chlorogenic acid, 4-dicaffeoylquinic acid, caffeic acid, 1,3-dicaffeoylqunic acid, isochlorogenic acid B, isochlorogenic acid A, cynarin, and isochlorogenic acid C, and the contents were 0.503, 0.029, 0.022, 0.017, 0.008, 0.162, 1.621, 0.030 mg/g, respectively. This study also showed that the carbohydrates and polyphenols in artichoke bud could be important natural antioxidants, and the composition analysis of HPLC provided directions for their future research. Carbohydrates and polyphenols in artichoke buds can be separated and enriched using the optimized process technology, and it is an effective means of extracting ingredients from plants.

The Relationship between Reactive Oxygen Species and the cGAS/STING Signaling Pathway in the Inflammaging Process

During Inflammaging, a dysregulation of the immune cell functions is generated, and these cells acquire a senescent phenotype with an increase in pro-inflammatory cytokines and ROS. This increase in pro-inflammatory molecules contributes to the chronic inflammation and oxidative damage of biomolecules, classically observed in the Inflammaging process. One of the most critical oxidative damages is generated to the host DNA. Damaged DNA is located out of the natural compartments, such as the nucleus and mitochondria, and is present in the cell's cytoplasm. This DNA localization activates some DNA sensors, such as the cGAS/STING signaling pathway, that induce transcriptional factors involved in increasing inflammatory molecules. Some of the targets of this signaling pathway are the SASPs. SASPs are secreted pro-inflammatory molecules characteristic of the senescent cells and inducers of ROS production. It has been suggested that oxidative damage to nuclear and mitochondrial DNA generates activation of the cGAS/STING pathway, increasing ROS levels induced by SASPs. These additional ROS increase oxidative DNA damage, causing a loop during the Inflammaging. However, the relationship between the cGAS/STING pathway and the increase in ROS during Inflammaging has not been clarified. This review attempt to describe the potential connection between the cGAS/STING pathway and ROS during the Inflammaging process, based on the current literature, as a contribution to the knowledge of the molecular mechanisms that occur and contribute to the development of the considered adaptative Inflammaging process during aging.

RNA sequencing profiles reveal dynamic signaling and glucose metabolic features during bone marrow mesenchymal stem cell senescence

Background

Stem cell senescence is considered as a significant driver of organismal aging. As individuals age, the number of stem cells is declined, and the ability to proliferate and survive is also weakened. It has been reported that metabolism plays an important role in stem cell self-renewal, multilineage differentiation, senescence and fate determination, which has aroused widespread concerns. However, whether metabolism-related genes or signalling pathways are involved in physiological aging remain largely undetermined.

Results

In the current study, we showed 868 up-regulated and 2006 down-regulated differentially expressed genes (DEGs) in bone marrow mesenchymal stem cells (MSCs) from old rats in comparison with that from young rats by performing RNA sequence. And DEGs functions and pathways were further selected by function enrichment analysis. The results indicated that the high expression of DEGs might participate in cell differentiation, growth factor binding and etc., while the down-regulated DEGs were majorly enriched in metabolism process, such as the cellular metabolic process and mitochondria. Then, we screened and verified DEGs related to glucose metabolism and investigated the glycolysis levels. We identified that glucose uptake, lactate secretion, ATP production and relative extracellular acidification rates (ECAR) were all diminished in MSCs from old rats. More importantly, we conducted microRNA prediction on the key DEGs of glycolysis to elucidate the potential molecular mechanisms of glucose metabolism affecting MSC senescence.

Conclusions

Our study unravelled the profiles of DEGs in age-associated MSC senescence and their functions and pathways. We also clarified DEGs related to glucose metabolism and down-regulated glycolysis level in age-associated MSC senescence. This study will uncover the metabolic effects on regulating stem cell senescence, and provide novel therapeutic targets for ameliorating age-associated phenotypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00796-5.

Endothelin A receptors contribute to senescence of brain microvascular endothelial cells

Cellular senescence plays a pivotal role in the aging and progression of neurodegenerative diseases, including vascular cognitive impairment and dementia (VCID). In postmortem brains from individuals with VCID, endothelin-1 (ET-1) levels closely correlate with blood barrier breakdown and cerebral hypoperfusion. Brain microvascular endothelial cells (BMVECs), previously thought to have exclusively endothelin B receptors, also possess endothelin A (ETA) receptors; however, the functional significance of this receptor in BMVECs is not known. We hypothesize that ETA receptors mediate BMVEC senescence. Serum-starved human BMVECs (HBEC5i) were incubated with ET-1 (1 µmol/L) in the presence/absence of ETA receptor antagonist BQ-123 (20 µmol/L). Cells were collected for Western blot and quantitative real-time PCR analyses. Treatment of ET-1 increased protein expression of ETA receptor, while it was prevented by the ETA receptor antagonist. ET-1 increased p21, p16, p53, LIF1 and cyclin D1 protein levels, and β-galactosidase accumulation, which were prevented in the presence of ETA blockade. While there was no change in tight junction proteins, ET-1 decreased adherent junction protein vascular endothelial cadherin (VE-cadherin) levels. In conclusion, ET-1 upregulates ETA receptors in BMVECs in an autocrine manner and triggers the activation of senescence. These in vitro findings need to be further studied in vivo to establish the role of ETA receptors in the progression of endothelial senescence in VCID.

Selenoproteins and the senescence-associated epitranscriptome

Selenium is a naturally found trace element, which provides multiple benefits including antioxidant, anticancer, and antiaging, as well as boosting immunity. One unique feature of selenium is its incorporation as selenocysteine, a rare 21st amino acid, into selenoproteins. Twenty-five human selenoproteins have been discovered, and a majority of these serve as crucial antioxidant enzymes for redox homeostasis. Unlike other amino acids, incorporation of selenocysteine requires a distinctive UGA stop codon recoding mechanism. Although many studies correlating selenium, selenoproteins, aging, and senescence have been performed, it has not yet been explored if the upstream events regulating selenoprotein synthesis play a role in senescence-associated pathologies. The epitranscriptomic writer alkylation repair homolog 8 (ALKBH8) is critical for selenoprotein production, and its deficiency can significantly decrease levels of selenoproteins that are essential for reactive oxygen species (ROS) detoxification, and increase oxidative stress, one of the major drivers of cellular senescence. Here, we review the potential role of epitranscriptomic marks that govern selenocysteine utilization in regulating the senescence program.

Redox signaling and metabolism in Alzheimer's disease

Reduction and oxidation reactions are essential for biochemical processes. They are part of metabolic pathways and signal transduction. Reactive oxygen species (ROS) as second messengers and oxidative modifications of cysteinyl (Cys) residues are key to transduce and translate intracellular and intercellular signals. Dysregulation of cellular redox signaling is known as oxidative distress, which has been linked to various pathologies, including neurodegeneration. Alzheimer's disease (AD) is a neurodegenerative pathology linked to both, abnormal amyloid precursor protein (APP) processing, generating Aβ peptide, and Tau hyperphosphorylation and aggregation. Signs of oxidative distress in AD include: increase of ROS (H2O2, O2 •-), decrease of the levels or activities of antioxidant enzymes, abnormal oxidation of macromolecules related to elevated Aβ production, and changes in mitochondrial homeostasis linked to Tau phosphorylation. Interestingly, Cys residues present in APP form disulfide bonds that are important for intermolecular interactions and might be involved in the aggregation of Aβ. Moreover, two Cys residues in some Tau isoforms have been shown to be essential for Tau stabilization and its interaction with microtubules. Future research will show the complexities of Tau, its interactome, and the role that Cys residues play in the progression of AD. The specific modification of cysteinyl residues in redox signaling is also tightly connected to the regulation of various metabolic pathways. Many of these pathways have been found to be altered in AD, even at very early stages. In order to analyze the complex changes and underlying mechanisms, several AD models have been developed, including animal models, 2D and 3D cell culture, and ex-vivo studies of patient samples. The use of these models along with innovative, new redox analysis techniques are key to further understand the importance of the redox component in Alzheimer's disease and the identification of new therapeutic targets in the future.

OR2AT4, an Ectopic Olfactory Receptor, Suppresses Oxidative Stress-Induced Senescence in Human Keratinocytes

Olfactory receptors (ORs) are the largest protein superfamily in mammals. Certain ORs are ectopically expressed in extranasal tissues and regulate cell type-specific signal transduction pathways. OR2AT4 is ectopically expressed in skin cells and promotes wound healing and hair growth. As the capacities of wound healing and hair growth decline with aging, we investigated the role of OR2AT4 in the aging and senescence of human keratinocytes. OR2AT4 was functionally expressed in human keratinocytes (HaCaT) and exhibited co-expression with G-protein-coupled receptor signaling components, Golfα and adenylate cyclase 3. The OR2AT4 ligand sandalore modulates the intracellular calcium, inositol phosphate, and cyclic adenosine monophosphate (cAMP) levels. The increased calcium level induced by sandalore was attenuated in cells with OR2AT4 knockdown. OR2AT4 activation by sandalore inhibited the senescent cell phenotypes and restored cell proliferation and Ki-67 expression. Sandalore also inhibited the expression of senescence-associated β-galactosidase and increased p21 expression in senescent HaCaT cells in response to hydrogen peroxide. Additionally, sandalore activated the CaMKKβ/AMPK/mTORC1/autophagy signaling axis and promoted autophagy. OR2AT4 knockdown attenuated the increased in the intracellular calcium level, cell proliferation, and AMPK phosphorylation induced by sandalore. These findings demonstrate that the effects of sandalore are mediated by OR2AT4 activation. Our findings suggest that OR2AT4 may be a novel therapeutic target for anti-aging and anti-senescence in human keratinocytes.

Ultraviolet B irradiation induces senescence of human corneal endothelial cells in vitro by DNA damage response and oxidative stress

The human corneal endothelial cells (HCEnCs) play a vital role in the maintenance of corneal transparency and visual acuity. In our daily life, HCEnCs are inevitably exposed to ultraviolet B (UVB) radiation leading to decreases of visual acuity and corneal transparency resulting in visual loss eventually. Therefore, understanding the UVB-induced cytotoxicity in HCEnCs is of importance for making efficient strategies to protect our vision from UVB-damage. However, in-depth knowledge about UVB-induced cytotoxicity in HCEnCs is missing. Herein, we pulse-irradiated the HCEnCs in vitro with 150 mJ/cm² UVB (the environmental dose) at each subculture for 4 passages to explore the insights into UVB-induced phototoxicity. The results showed that the UVB-treated HCEnCs exhibit typical senescent characteristics, including significantly enlarged relative cell area, increased senescence-associated β-galactosidase positive staining, and upregulated p16^INK4A and senescence associated secretory phenotypes (SASPs) such as CCL-27, IL-1α/6/8/10, TGF-β1 and TNF-α, as well as decreased cell proliferation and Lamin B1 expression, and translocation of Lamin B1. Furthermore, we explored the causative mechanisms of senescence and found that 150 mJ/cm² UVB pulse-irradiation impairs DNA to activate DNA damage response (DDR) pathway of ATM-p53-p21^WAF1/CIP1 with downregulated DNA repair enzyme PARP1, leading to cell cycle arrest resulting in DDR-mediated senescence. Meanwhile, UVB pulse-irradiation also elicits a consistent increase of ROS production to aggravate DNA damage and impose oxidative stress on energy metabolism leading to metabolic disturbance resulting in metabolic disturbance-mediated senescence. Altogether, the repeated pulse-irradiation of 150 mJ/cm² UVB induces HCEnC senescence via both DDR pathway and energy metabolism disturbance.

High Hemin Concentration Induces Escape from Senescence of Normoxic and Hypoxic Colon Cancer Cells

Simple Summary

High red-meat consumption as well as bleeding or bruising can promote oxidative stress and, in consequence, cancer development. However, the mechanism of that phenomenon is not understood. The induction of therapy-induced senescence (TIS) might also be induced by oxidative stress. Recently, TIS cells, despite their inhibited proliferation potential, have been identified as one of the sources of tumor re-growth. Here, with the use of molecular analyses, we found that oxidative stress, promoted by high doses of hemin or H₂O₂, can trigger TIS escape and cell re-population. It is closely related to the activity of antioxidative enzymes, especially heme oxygenase-1. Hypoxia might accelerate these effects. Therefore, we propose that the prevention of excessive oxidative stress could be a potential target in senolytic therapies.

Abstract

Hemoglobin from either red meat or bowel bleeding may promote oxidative stress and increase the risk of colorectal cancer (CRC). Additionally, solid cancers or their metastases may be present with localized bruising. Escape from therapy-induced senescence (TIS) might be one of the mechanisms of tumor re-growth. Therefore, we sought to study whether hemin can cause escape from TIS in CRC. To induce senescence, human colon cancer cells were exposed to a chemotherapeutic agent irinotecan (IRINO). Cells treated with IRINO exhibited common hallmarks of TIS. To mimic bleeding, colon cancer cells were additionally treated with hemin. High hemin concentration activated heme oxygenase-1 (HO-1), induced escape from TIS and epithelial-to-mesenchymal transition, and augmented progeny production. The effect was even stronger in hypoxic conditions. Similar results were obtained when TIS cells were treated with another prooxidant agent, H₂O₂. Silencing of antioxidative enzymes such as catalase (CAT) or glutathione peroxidase-1 (GPx-1) maintained colon cancer cells in a senescent state. Our study demonstrates that a high hemin concentration combined with an increased activity of antioxidative enzymes, especially HO-1, leads to escape from the senescence of colon cancer cells. Therefore, our observations could be used in targeted anti-cancer therapy.

Oxidative stress, lipid peroxidation and premature placental senescence in preeclampsia

Accelerated placental senescence is associated with preeclampsia (PE) and other pregnancy complications. It is characterized by an accelerated decline in placental function due to the accumulation of senescence patterns such as telomere shortening, mitochondrial dysfunction, oxidative damages, increased expression of phosphorylated (serine-139) histone γ-H2AX, a sensitive marker of double-stranded DNA breaks, accumulation of cross-linked ubiquitinated proteins and sirtuin inhibition. Among the lipid oxidation products generated by the peroxidation of polyunsaturated fatty acids, aldehydes such as acrolein, 4-hydroxy-2-nonenal, 4-oxo-2-nonenal, are present in the blood and placenta from PE-affected women and could contribute to PE pathogenesis and accelerated placental aging. In this review we summarize the current knowledge on premature placental senescence and the role of oxidative stress and lipid oxidation-derived aldehydes in this process, as well as their links with PE pathogenesis. The interest of developing (or not) new therapeutic strategies targeting lipid peroxidation is discussed, the objective being a better understanding of accelerated placental aging in PE pathophysiology, and the prevention of PE bad outcomes.