Autophagy in healthy aging and disease

Hypothalamic circuits and aging: keeping the circadian clock updated

Over the past century, age-related diseases, such as cancer, type-2 diabetes, obesity, and mental illness, have shown a significant increase, negatively impacting overall quality of life. Studies on aged animal models have unveiled a progressive discoordination at multiple regulatory levels, including transcriptional, translational, and post-translational processes, resulting from cellular stress and circadian derangements. The circadian clock emerges as a key regulator, sustaining physiological homeostasis and promoting healthy aging through timely molecular coordination of pivotal cellular processes, such as stem-cell function, cellular stress responses, and inter-tissue communication, which become disrupted during aging. Given the crucial role of hypothalamic circuits in regulating organismal physiology, metabolic control, sleep homeostasis, and circadian rhythms, and their dependence on these processes, strategies aimed at enhancing hypothalamic and circadian function, including pharmacological and non-pharmacological approaches, offer systemic benefits for healthy aging. Intranasal brain-directed drug administration represents a promising avenue for effectively targeting specific brain regions, like the hypothalamus, while reducing side effects associated with systemic drug delivery, thereby presenting new therapeutic possibilities for diverse age-related conditions.

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.

Molecular Insights into Aggrephagy: Their Cellular Functions in the Context of Neurodegenerative Diseases

Protein homeostasis or proteostasis is an equilibrium of biosynthetic production, folding and transport of proteins, and their timely and efficient degradation. Proteostasis is guaranteed by a network of protein quality control systems aimed at maintaining the proteome function and avoiding accumulation of potentially cytotoxic proteins. Terminal unfolded and dysfunctional proteins can be directly turned over by the ubiquitin-proteasome system (UPS) or first amassed into aggregates prior to degradation. Aggregates can also be disposed into lysosomes by a selective type of autophagy known as aggrephagy, which relies on a set of so-called selective autophagy receptors (SARs) and adaptor proteins. Failure in eliminating aggregates, also due to defects in aggrephagy, can have devastating effects as underscored by several neurodegenerative diseases or proteinopathies, which are characterized by the accumulation of aggregates mostly formed by a specific disease-associated, aggregate-prone protein depending on the clinical pathology. Despite its medical relevance, however, the process of aggrephagy is far from being understood. Here we review the findings that have helped in assigning a possible function to specific SARs and adaptor proteins in aggrephagy in the context of proteinopathies, and also highlight the interplay between aggrephagy and the pathogenesis of proteinopathies.

Autophagy and metabolic aging: Current understanding and future applications

"Metabolic aging" refers to the gradual decline in cellular metabolic function across various tissues due to defective hormonal signaling, impaired nutrient sensing, mitochondrial dysfunction, replicative stress, and cellular senescence. While this process usually corresponds with chronological aging, the recent increase in metabolic diseases and cancers occurring at younger ages in humans suggests the premature onset of cellular fatigue and metabolic aging. Autophagy, a cellular housekeeping process facilitated by lysosomes, plays a crucial role in maintaining tissue rejuvenation and health. However, various environmental toxins, hormones, lifestyle changes, and nutrient imbalances can disrupt autophagy in humans. In this review, we explore the connection between autophagy and cellular metabolism, its regulation by extrinsic factors and its modulation to prevent the early onset of metabolic aging.

Dysfunction of astrocytic glycophagy exacerbates reperfusion injury in ischemic stroke

Glycophagy has evolved from an alternative glycogen degradation pathway into a multifaceted pivot to regulate cellular metabolic hemostasis in peripheral tissues. However, the pattern of glycophagy in the brain and its potential therapeutic impact on ischemic stroke remain unknown. Here, we observed that the dysfunction of astrocytic glycophagy was caused by the downregulation of the GABA type A receptor-associated protein like 1 (GABARAPL1) during reperfusion in ischemic stroke patients and mice. PI3K-Akt pathway activation is involved in driving GABARAPL1 downregulation during cerebral reperfusion. Moreover, glycophagy dysfunction-induced glucosamine deficiency suppresses the nuclear translocation of specificity protein 1 and TATA binding protein, the transcription factors for GABARAPL1, by decreasing their O-GlcNAcylation levels, and accordingly feedback inhibits GABARAPL1 in astrocytes during reperfusion. Restoring astrocytic glycophagy by overexpressing GABARAPL1 decreases DNA damage and oxidative injury in astrocytes and improves the survival of surrounding neurons during reperfusion. In addition, a hypocaloric diet in the acute phase after cerebral reperfusion can enhance astrocytic glycophagic flux and accelerate neurological recovery. In summary, glycophagy in the brain links autophagy, metabolism, and epigenetics together, and glycophagy dysfunction exacerbates reperfusion injury after ischemic stroke.

Alterations of human CSF and serum-based mitophagy biomarkers in the continuum of Alzheimer disease

Defective mitophagy is consistently found in postmortem brain and iPSC-derived neurons from Alzheimer disease (AD) patients. However, there is a lack of extensive examination of mitophagy status in serum or cerebrospinal fluid (CSF), and the clinical potential of mitophagy biomarkers has not been tested. We quantified biomarkers of mitophagy/autophagy and lysosomal degradation (PINK1, BNIP3L and TFEB) in CSF and serum from 246 individuals, covering mild cognitive impairment due to AD (MCI-AD, n = 100), dementia due to AD (AD-dementia, n = 100), and cognitively unimpaired individuals (CU, n = 46), recruited from the Czech Brain Aging Study. Cognitive function and brain atrophy were also assessed. Our data show that serum and CSF PINK1 and serum BNIP3L were higher, and serum TFEB was lower in individuals with AD than in corresponding CU individuals. Additionally, the magnitude of mitophagy impairment correlated with the severity of clinical indicators in AD patients. Specifically, levels of PINK1 positively correlated with phosphorylated (p)-MAPT/tau (181), total (t)-MAPT/tau, NEFL (neurofilament light chain), and NRGN (neurogranin) levels in CSF and negatively with memory, executive function, and language domain. Serum TFEB levels negatively correlated with NEFL and positively with executive function and language. This study reveals mitophagy impairment reflected in biofluid biomarkers of individuals with AD and associated with more advanced AD pathology.Abbreviation: Aβ: amyloid beta; AD: Alzheimer disease; AVs: autophagic vacuoles; BNIP3L: BCL2 interacting protein 3 like; CU: cognitively unimpaired; CSF: cerebrospinal fluid; LAMP1: lysosomal-associated membrane protein 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MCI: mild cognitive impairment; NRGN: neurogranin; NEFL: neurofilament light chain; p-MAPT/tau: phosphorylated microtubule associated protein tau; PINK1: PTEN induced kinase 1; t-MAPT/tau: total microtubule associated protein tau; TFEB: transcription factor EB; TMT: Trail Making Test.

TP53INP2-dependent activation of muscle autophagy ameliorates sarcopenia and promotes healthy aging

Sarcopenia is a major contributor to disability in older adults, and thus, it is key to elucidate the mechanisms underlying its development. Increasing evidence suggests that impaired macroautophagy/autophagy contributes to the development of sarcopenia. However, the mechanisms leading to reduced autophagy during aging remain largely unexplored, and whether autophagy activation protects from sarcopenia has not been fully addressed. Here we show that the autophagy regulator TP53INP2/TRP53INP2 is decreased during aging in mouse and human skeletal muscle. Importantly, chronic activation of autophagy by muscle-specific overexpression of TRP53INP2 prevents sarcopenia and the decline of muscle function in mice. Acute re-expression of TRP53INP2 in aged mice also improves muscle atrophy, enhances mitophagy, and reduces ROS production. In humans, high levels of TP53INP2 in muscle are associated with increased muscle strength and healthy aging. Our findings highlight the relevance of an active muscle autophagy in the maintenance of muscle mass and prevention of sarcopenia.Abbreviation: ATG7: autophagy related 7; BMI: body mass index; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; ROS: reactive oxygen species; TP53INP2: tumor protein p53 inducible nuclear protein 2; WT: wild type.

Blood brain barrier dysfunction in healthy aging and dementia: Why, how, what for?

The blood brain barrier (BBB) is an indispensable structure that maintains the central nervous system (CNS) microenvironment for a correct neuronal function. It is composed by highly specialized microvessels, surrounded by astrocytes, pericytes, neurons and microglia cells, which tightly control the influx and efflux of substances to the brain parenchyma. During aging, the BBB becomes impaired, and it may contribute to the development of neurodegenerative and neurological disorders including Alzheimer's disease and other dementias. Restoring the BBB can be a strategy to prevent disease onset and development, reducing the symptoms of these conditions. This work critically reviews the major mechanisms underlying BBB breakdown in healthy and unhealthy aging, as well as biomarkers and methodologies that accurately assess its impairment. Complementarily, potential therapeutic targets are discussed as new strategies to restore the normal function of the BBB in aging.

From Reactive to Proactive - The Future Life Design to Promote Health and Extend the Human Lifespan

Disease treatment and prevention have improved the human lifespan. Current studies on aging, such as the biological clock and senolytic drugs have focused on the medical treatments of various disorders and health maintenance. However, to efficiently extend the human lifespan to its theoretical maximum, medicine can take a further proactive approach and identify the inapparent disorders that affect the gestation, body growth, and reproductive stages of the so-called "healthy" population. The goal is to upgrade the standard health status to a new level by targeting the inapparent disorders. Thus, future research can shift from reaction, response, and prevention to proactive, quality promotion and vigor prolonging; from single disease-oriented to multiple dimension protocol for a healthy body; from treatment of symptom onset to keep away from disorders; and from the healthy aging management to a healthy promotion design beginning at the birth.

Pathological mechanisms of kidney disease in ageing

The kidney is a metabolically active organ that requires energy to drive processes such as tubular reabsorption and secretion, and shows a decline in function with advancing age. Various molecular mechanisms, including genomic instability, telomere attrition, inflammation, autophagy, mitochondrial function, and changes to the sirtuin and Klotho signalling pathways, are recognized regulators of individual lifespan and pivotal factors that govern kidney ageing. Thus, mechanisms that contribute to ageing not only dictate renal outcomes but also exert a substantial influence over life expectancy. Conversely, kidney dysfunction, in the context of chronic kidney disease (CKD), precipitates an expedited ageing trajectory in individuals, leading to premature ageing and a disconnect between biological and chronological age. As CKD advances, age-related manifestations such as frailty become increasingly conspicuous. Hence, the pursuit of healthy ageing necessitates not only the management of age-related complications but also a comprehensive understanding of the processes and markers that underlie systemic ageing. Here, we examine the hallmarks of ageing, focusing on the mechanisms by which they affect kidney health and contribute to premature organ ageing. We also review diagnostic methodologies and interventions for premature ageing, with special consideration given to the potential of emerging therapeutic avenues to target age-related kidney diseases.

All-trans retinoic acid induces lipophagy through reducing Rubicon in Hepa1c1c7 cells

All-trans retinoic acid (atRA), a metabolite of vitamin A, reduces hepatic lipid accumulation in liver steatosis model animals. Lipophagy, a new lipolysis pathway, degrades a lipid droplet (LD) via autophagy in adipose tissue and the liver. We recently found that atRA induces lipophagy in adipocytes. However, it remains unclear whether atRA induces lipophagy in hepatocytes. In this study, we investigated the effects of atRA on lipophagy in Hepa1c1c7 cells and the liver of mice fed a high-fat diet (HFD). Firstly, we confirmed that atRA induced autophagy in Hepa1c1c7 cells by Western blotting and the GFP-LC3-mCherry probe. Next, we evaluated the lipolysis in fatty Hepa1c1c7 cells treated with the knockdown of Atg5, an essential gene in autophagy induction. Atg5-knockdown partly suppressed the atRA-induced lipolysis in fatty Hepa1c1c7 cells. We also found that atRA reduced the protein, but not mRNA, expression of Rubicon, a negative regulator of autophagy, in Hepa1c1c7 cells and the liver of HFD-fed mice. Rubicon-knockdown partly inhibited the atRA-induced lipolysis in fatty Hepa1c1c7 cells. In addition, atRA reduced hepatic Rubicon expression in young mice, but the effect of atRA on it diminished in aged mice. Lastly, we investigated the mechanism underlying reduced Rubicon protein expression by atRA in hepatocytes. A protein synthesis inhibitor, but not proteasome or lysosomal inhibitors, significantly blocked the reduction of Rubicon protein expression by atRA in Hepa1c1c7 cells. These results suggest that atRA may promote lipophagy in fatty hepatocytes by reducing hepatic Rubicon expression via inhibiting protein synthesis. (243/250 words).

Exploring the triad: VPS35, neurogenesis, and neurodegenerative diseases

Vacuolar protein sorting 35 (VPS35), a critical component of the retromer complex, plays a pivotal role in the pathogenesis of neurodegenerative diseases (NDs). It is involved in protein transmembrane sorting, facilitating the transport from endosomes to the trans-Golgi network (TGN) and plasma membrane. Recent investigations have compellingly associated mutations in the VPS35 gene with neurodegenerative disorders such as Parkinson's and Alzheimer's disease. These genetic alterations are implicated in protein misfolding, disrupted autophagic processes, mitochondrial dysregulation, and synaptic impairment. Furthermore, VPS35 exerts a notable impact on neurogenesis by influencing neuronal functionality, protein conveyance, and synaptic performance. Dysregulation or mutation of VPS35 may escalate the progression of neurodegenerative conditions, underscoring its pivotal role in safeguarding neuronal integrity. This review comprehensively discusses the role of VPS35 and its functional impairments in NDs. Furthermore, we provide an overview of the impact of VPS35 on neurogenesis and further explore the intricate relationship between neurogenesis and NDs. These research advancements offer novel perspectives and valuable insights for identifying potential therapeutic targets in the treatment of NDs.

Adverse outcome pathway-based approach to reveal the mechanisms of skin sensitization and long-term aging effects of chlorothalonil

Chlorothalonil (CHT) is a widely used antifungal agent and is reported to be a sensitizer that can cause allergic contact dermatitis (ACD). ACD initiation is associated with various innate immune cell contributions and is usually accompanied by persistent inflammation, which is a potential contributing factor to skin damage. However, detailed information on the mechanisms by which CHT induces skin sensitization and damage is still insufficient. This study focused on investigating the possible sensitization process and mechanism of CHT and the adverse effects of repeated CHT exposure. CHT activates dendritic cells and promotes the proliferation of lymph cells in the skin sensitization phase, causing severe inflammation. Keratinocytes activate the NLRP3 inflammasome pathway to cause inflammation during CHT treatment, and macrophages also secrete inflammatory cytokines. In addition, CHT-induced inflammation triggered skin wrinkles, decreased epidermal thickness and decreased collagen. Cell experiments also showed that repeated exposure to CHT led to cell proliferation inhibition and senescence, and CHT-induced autophagy dysfunction was not only the reason for inflammation but also for senescence. This study defined the possible process through which CHT is involved in the skin sensitization phase and elucidated the mechanism of CHT-induced inflammation in innate immune responses. We also determined that repeated CHT exposure caused persistent inflammation, ultimately leading to skin aging.

Re-establishing immune tolerance in multiple sclerosis: focusing on novel mechanisms of mesenchymal stem cell regulation of Th17/Treg balance

The T-helper 17 (Th17) cell and regulatory T cell (Treg) axis plays a crucial role in the development of multiple sclerosis (MS), which is regarded as an immune imbalance between pro-inflammatory cytokines and the maintenance of immune tolerance. Mesenchymal stem cell (MSC)-mediated therapies have received increasing attention in MS research. In MS and its animal model experimental autoimmune encephalomyelitis, MSC injection was shown to alter the differentiation of CD4+T cells. This alteration occurred by inducing anergy and reduction in the number of Th17 cells, stimulating the polarization of antigen-specific Treg to reverse the imbalance of the Th17/Treg axis, reducing the inflammatory cascade response and demyelination, and restoring an overall state of immune tolerance. In this review, we summarize the mechanisms by which MSCs regulate the balance between Th17 cells and Tregs, including extracellular vesicles, mitochondrial transfer, metabolic reprogramming, and autophagy. We aimed to identify new targets for MS treatment using cellular therapy by analyzing MSC-mediated Th17-to-Treg polarization.

Marine peptides as potential anti-aging agents: Preparation, characterization, mechanisms of action, and future perspectives

Aging is a universal biological process characterized by a decline in physiological functions, leading to increased susceptibility to diseases. With global aging trends, understanding and mitigating the aging process is paramount. Recent studies highlight marine peptides as promising bioactive substances with potential anti-aging properties. This review critically examines the potential of marine peptides as novel food ingredients in anti-aging, exploring their sources, preparation methods, physicochemical properties, and the underlying mechanisms through which they impact the aging process. Marine peptides exhibit significant potential in targeting aging, extending lifespan, and enhancing healthspan. They act through mechanisms such as reducing oxidative stress and inflammation, modulating mitochondrial dysfunction, inducing autophagy, maintaining extracellular matrix homeostasis, and regulating longevity-related pathways. Despite challenges in stability, bioavailability, and scalability, marine peptides offer significant potential in health, nutraceuticals, and pharmaceuticals, warranting further research and development in anti-aging.

Common bean polyphenolic enriched extracts decrease reactive oxygen species induced by heavy metals and polycyclic aromatic hydrocarbons in Hs27 and Hs68 human fibroblasts

The increase of coarse particulate matter (PM10) due to industrialization and urban sprawl has been identified as a significant contributor to air pollution and a threat to human skin health and premature aging. The objective was to analyze the antioxidant effect of phenolic-enriched extracts (PHE) obtained from black bean (BB) and pinto bean (PB) varieties (Phaseolus vulgaris L.) and pure phenolic compounds (rutin, catechin, and gallic acid) in two human dermal fibroblasts cell lines exposed to PM10. Petunidin-3-O-glucoside was the most abundant anthocyanin, with 57 ± 0.9 mg/g dry extract (DE) in PHE-BB. Gallic acid was the prevalent phenolic acid with 8.2 ± 2.8 mg/g DE in PHE-BB (p < 0.05). Hs27 and Hs68 cell lines were exposed to PM10 (100 μg/mL) to induce oxidative stress; PHE-BB reduced it by 69% ± 12 and PHE-PB by 80% ± 5 relative to PM10 treatment (p < 0.05). Delphinidin-3-O-glucoside showed the highest binding affinity in adenosine monophosphate-activated protein kinase (AMPK) with -9.0 kcal/mol and quercetin-3-D-galactoside with -6.9 kcal/mol in sirtuin 1 (Sirt1). Rutin increased the expression of Sirt1 by 30% (p < 0.05) in the Hs27 cell line treated with PM10. Common bean extracts can potentially reduce oxidative stress induced by PM10 in human dermal fibroblasts.

No energy, no autophagy-Mechanisms and therapeutic implications of autophagic response energy requirements

Autophagy is a lysosome-mediated self-degradation process of central importance for cellular quality control. It also provides macromolecule building blocks and substrates for energy metabolism during nutrient or energy deficiency, which are the main stimuli for autophagy induction. However, like most biological processes, autophagy itself requires ATP, and there is an energy threshold for its initiation and execution. We here present the first comprehensive review of this often-overlooked aspect of autophagy research. The studies in which ATP deficiency suppressed autophagy in vitro and in vivo were classified according to the energy pathway involved (oxidative phosphorylation or glycolysis). A mechanistic insight was provided by pinpointing the critical ATP-consuming autophagic events, including transcription/translation/interaction of autophagy-related molecules, autophagosome formation/elongation, autophagosome fusion with the lysosome, and lysosome acidification. The significance of energy-dependent fine-tuning of autophagic response for preserving the cell homeostasis, and potential implications for the therapy of cancer, autoimmunity, metabolic disorders, and neurodegeneration are discussed.

Ameliorating Mitochondrial Dysfunction for the Therapy of Parkinson's Disease

Parkinson's disease (PD) is currently the second most incurable central neurodegenerative disease resulting from various pathogenesis. As the "energy factory" of cells, mitochondria play an extremely important role in supporting neuronal signal transmission and other physiological activities. Mitochondrial dysfunction can cause and accelerate the occurrence and progression of PD. How to effectively prevent and suppress mitochondrial disorders is a key strategy for the treatment of PD from the root. Therefore, the emerging mitochondria-targeted therapy has attracted considerable interest. Herein, the relationship between mitochondrial dysfunction and PD, the causes and results of mitochondrial dysfunction, and major strategies for ameliorating mitochondrial dysfunction to treat PD are systematically reviewed. The study also prospects the main challenges for the treatment of PD.

Lutein and the Underlying Neuroprotective Promise against Neurodegenerative Diseases

Alzheimer's disease (AD) and Parkinson's diseases (PD) are the two most common progressive neurodegenerative diseases with limited knowledge on their cause and, presently, have no cure. There is an existence of multiple treatment methods that target only the symptoms temporarily and do not stop the progression or prevent the onset of disease. Neurodegeneration is primarily attributed to the natural process of aging and the deleterious effects of heightened oxidative stress within the brain, whether via direct or indirect mechanisms. Emerging evidence suggests that certain nutritional aspects play a crucial role in the prevention and management of neurodegenerative diseases. Lutein, a dietary carotenoid, has been studied for its antioxidant properties for more than a decade with several applications against age-related macular degeneration. It is high antioxidant potential and selective accumulation in the brain makes it a versatile compound for combatting various neurodegenerative diseases. In this review, the studies exhibiting neuroprotective properties of lutein against neurodegenerative conditions, more specifically AD and PD in various model systems as well as clinical observations have been reviewed. Accordingly, the concerns associated with lutein absorption and potential strategies to improve its bioavailability have been discussed.

Research progress on the role and mechanism of Sirtuin family in doxorubicin cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a widely utilized anthracycline chemotherapy drug in cancer treatment, yet its efficacy is hindered by both short-term and long-term cardiotoxicity. Although oxidative stress, inflammation and mitochondrial dysfunction are established factors in DOX-induced cardiotoxicity, the precise molecular pathways remain elusive. Further exploration of the pathogenesis and identification of novel molecular targets are imperative. Recent studies have implicated the Sirtuins family in various physiological and pathological processes, suggesting their potential in ameliorating DOX-induced cardiotoxicity. Moreover, research on Sirtuins has discovered small-molecule compounds or medicinal plants with regulatory effects, representing a notable advancement in preventing and treating DOX-induced cardiac injury.

PURPOSE

In this review, we delve into the pathogenesis of DOX-induced cardiotoxicity and explore the therapeutic effects of Sirtuins in mitigating this condition, along with the associated molecular mechanisms. Furthermore, we delineate the roles and mechanisms of small-molecule regulators of Sirtuins in the prevention and treatment of DOX-induced cardiotoxicity.

STUDY-DESIGN/METHODS

Data for this review were sourced from various scientific databases (such as Web of Science, PubMed and Science Direct) up to March 2024. Search terms included "Sirtuins," "DOX-induced cardiotoxicity," "DOX," "Sirtuins regulators," "histone deacetylation," among others, as well as several combinations thereof.

RESULTS

Members of the Sirtuins family regulate both the onset and progression of DOX-induced cardiotoxicity through anti-inflammatory, antioxidative stress and anti-apoptotic mechanisms, as well as by maintaining mitochondrial stability. Moreover, natural plant-derived active compounds such as Resveratrol (RES), curcumin, berberine, along with synthetic small-molecule compounds like EX527, modulate the expression and activity of Sirtuins.

CONCLUSION

The therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity represents a potential molecular target. However, further research is urgently needed to elucidate the relevant molecular mechanisms and to assess the safety and biological activity of Sirtuins regulators. This review offers an in-depth understanding of the therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity, providing a preliminary basis for the clinical application of Sirtuins regulators in this condition.

Primary cilia formation requires the Leigh syndrome-associated mitochondrial protein NDUFAF2

Mitochondria-related neurodegenerative diseases have been implicated in the disruption of primary cilia function. Mutation in an intrinsic mitochondrial complex I component NDUFAF2 has been identified in Leigh syndrome, a severe inherited mitochondriopathy. Mutations in ARMC9, which encodes a basal body protein, cause Joubert syndrome, a ciliopathy with defects in the brain, kidney, and eye. Here, we report a mechanistic link between mitochondria metabolism and primary cilia signaling. We discovered that loss of NDUFAF2 caused both mitochondrial and ciliary defects in vitro and in vivo and identified NDUFAF2 as a binding partner for ARMC9. We also found that NDUFAF2 was both necessary and sufficient for cilia formation and that exogenous expression of NDUFAF2 rescued the ciliary and mitochondrial defects observed in cells from patients with known ARMC9 deficiency. NAD+ supplementation restored mitochondrial and ciliary dysfunction in ARMC9-deficient cells and zebrafish and ameliorated the ocular motility and motor deficits of a patient with ARMC9 deficiency. The present results provide a compelling mechanistic link, supported by evidence from human studies, between primary cilia and mitochondrial signaling. Importantly, our findings have significant implications for the development of therapeutic approaches targeting ciliopathies.

The Angiotensin Metabolite His-Leu Is a Strong Copper Chelator Forming Highly Redox Active Species

His-Leu is a hydrolytic byproduct of angiotensin metabolism, whose concentration in the bloodstream could be at least micromolar. This encouraged us to investigate its Cu(II) binding properties and the concomitant redox reactivity. The Cu(II) binding constants were derived from isothermal titration calorimetry and potentiometry, while identities and structures of complexes were obtained from ultraviolet-visible, circular dichroism, and room-temperature electronic paramagnetic resonance spectroscopies. Four types of Cu(II)/His-Leu complexes were detected. The histamine-like complexes prevail at low pH. At neutral and mildly alkaline pH and low Cu(II):His-Leu ratios, they are superseded by diglycine-like complexes involving the deprotonated peptide nitrogen. At His-Leu:Cu(II) ratios of ≥2, bis-complexes are formed instead. Above pH 10.5, a diglycine-like complex containing the equatorially coordinated hydroxyl group predominates at all ratios tested. Cu(II)/His-Leu complexes are also strongly redox active, as demonstrated by voltammetric studies and the ascorbate oxidation assay. Finally, numeric competition simulations with human serum albumin, glycyl-histydyl-lysine, and histidine revealed that His-Leu might be a part of the low-molecular weight Cu(II) pool in blood if its abundance is >10 μM. These results yield further questions, such as the biological relevance of ternary complexes containing His-Leu.

The Janus face of HIF-1α in ischemic stroke and the possible associated pathways

Stroke is the most devastating disease, causing paralysis and eventually death. Many clinical and experimental trials have been done in search of a new safe and efficient medicine; nevertheless, scientists have yet to discover successful remedies that are also free of adverse effects. This is owing to the variability in intensity, localization, medication routes, and each patient's immune system reaction. HIF-1α represents the modern tool employed to treat stroke diseases due to its functions: downstream genes such as glucose metabolism, angiogenesis, erythropoiesis, and cell survival. Its role can be achieved via two downstream EPO and VEGF strongly related to apoptosis and antioxidant processes. Recently, scientists paid more attention to drugs dealing with the HIF-1 pathway. This review focuses on medicines used for ischemia treatment and their potential HIF-1α pathways. Furthermore, we discussed the interaction between HIF-1α and other biological pathways such as oxidative stress; however, a spotlight has been focused on certain potential signalling contributed to the HIF-1α pathway. HIF-1α is an essential regulator of oxygen balance within cells which affects and controls the expression of thousands of genes related to sustaining homeostasis as oxygen levels fluctuate. HIF-1α's role in ischemic stroke strongly depends on the duration and severity of brain damage after onset. HIF-1α remains difficult to investigate, particularly in ischemic stroke, due to alterations in the acute and chronic phases of the disease, as well as discrepancies between the penumbra and ischemic core. This review emphasizes these contrasts and analyzes the future of this intriguing and demanding field.

Unlocking a New Path: An Autophagometer that Measures Flux Using a Non-Fluorescent Immunohistochemistry Method

Macroautophagy/autophagy, a crucial cellular process, is typically measured using fluorescence-based techniques, which can be costly, complex, and impractical for clinical settings. In this paper, we introduce a novel, cost-effective, non-fluorescent immunohistochemistry (IHC) method for evaluating autophagy flux. This technique, based on antigen-antibody reactions and chromogenic detection, provides clear, quantifiable results under standard light microscopy, eliminating the need for expensive equipment and specialized reagents. Our method simplifies technical requirements, making it accessible to routine clinical laboratories and research settings with limited resources. By comparing our approach with traditional fluorescence methods, we demonstrate its superior effectiveness, cost-efficiency, and applicability to patient samples. This innovative technique has the potential to significantly advance autophagy research and improve clinical diagnostics, offering a practical and robust tool for studying autophagy mechanisms in diseases such as cancer and neurodegenerative disorders. Our non-fluorescent IHC method represents a significant step forward in evaluating autophagy flux, making it more accessible and reliable, with the promise of enhancing our understanding and treatment of autophagy-related diseases.

Antistress and Antiaging Potentials of Alpha-Lipoic Acid: Insights from Cell Culture-Based Experiments

Chronic stress has been linked to a large number of pathologies, including cancer, premature aging, and neurodegenerative diseases. The accumulation of molecular waste resulting from oxidative and heavy metal-induced stress has been ascribed as a major factor contributing to these diseases. With this in mind, we started by screening 13 small molecules to determine their antistress potential in heavy metal stress-exposed C6 glioblastoma and found that alpha-lipoic acid (ALA) (a natural antioxidant abundantly present in yeast, spinach, broccoli, and meat) was the most effective candidate. We then conducted molecular analyses to validate its mechanism of action. Dose-dependent toxicity assays of cells treated with two ALA enantiomers, R-ALA and S-ALA, showed that they are nontoxic and can be tolerated at relatively high doses. Cells exposed to heavy metal, heat, and oxidative stress showed better recovery when cultured in R-ALA-/S-ALA-supplemented medium, supported by reduction of reactive oxygen species (ROS), aggregated proteins, and mitochondrial and deoxyribonucleic acid (DNA) damage. Molecular analyses revealed protection against stress-induced apoptosis and induction of autophagy in R-ALA- and S-ALA-treated C6/U2OS cells. Consistent with these findings, normal human fibroblasts showed lifespan extension. Taken together, this study demonstrates that lipoic acid has antiaging and antistress potential and warrants further attention in laboratory and clinical studies.

Characterization of Proteome Changes in Aged and Collagen VI-Deficient Human Pericyte Cultures

Pericytes are a distinct type of cells interacting with endothelial cells in blood vessels and contributing to endothelial barrier integrity. Furthermore, pericytes show mesenchymal stem cell properties. Muscle-derived pericytes can demonstrate both angiogenic and myogenic capabilities. It is well known that regenerative abilities and muscle stem cell potential decline during aging, leading to sarcopenia. Therefore, this study aimed to investigate the potential of pericytes in supporting muscle differentiation and angiogenesis in elderly individuals and in patients affected by Ullrich congenital muscular dystrophy or by Bethlem myopathy, two inherited conditions caused by mutations in collagen VI genes and sharing similarities with the progressive skeletal muscle changes observed during aging. The study characterized pericytes from different age groups and from individuals with collagen VI deficiency by mass spectrometry-based proteomic and bioinformatic analyses. The findings revealed that aged pericytes display metabolic changes comparable to those seen in aging skeletal muscle, as well as a decline in their stem potential, reduced protein synthesis, and alterations in focal adhesion and contractility, pointing to a decrease in their ability to form blood vessels. Strikingly, pericytes from young patients with collagen VI deficiency showed similar characteristics to aged pericytes, but were found to still handle oxidative stress effectively together with an enhanced angiogenic capacity.

Multifunctional scaffolds for bone repair following age-related biological decline: Promising prospects for smart biomaterial-driven technologies

The repair of large bone defects due to trauma, disease, and infection can be exceptionally challenging in the elderly. Despite best clinical practice, bone regeneration within contemporary, surgically implanted synthetic scaffolds is often problematic, inconsistent, and insufficient where additional osteobiological support is required to restore bone. Emergent smart multifunctional biomaterials may drive important and dynamic cellular crosstalk that directly targets, signals, stimulates, and promotes an innate bone repair response following age-related biological decline and when in the presence of disease or infection. However, their role remains largely undetermined. By highlighting their mechanism/s and mode/s of action, this review spotlights smart technologies that favorably align in their conceivable ability to directly target and enhance bone repair and thus are highly promising for future discovery for use in the elderly. The four degrees of interactive scaffold smartness are presented, with a focus on bioactive, bioresponsive, and the yet-to-be-developed autonomous scaffold activity. Further, cell- and biomolecular-assisted approaches were excluded, allowing for contemporary examination of the capabilities, demands, vision, and future requisites of next-generation biomaterial-induced technologies only. Data strongly supports that smart scaffolds hold significant promise in the promotion of bone repair in patients with a reduced osteobiological response. Importantly, many techniques have yet to be tested in preclinical models of aging. Thus, greater clarity on their proficiency to counteract the many unresolved challenges within the scope of aging bone is highly warranted and is arguably the next frontier in the field. This review demonstrates that the use of multifunctional smart synthetic scaffolds with an engineered strategy to circumvent the biological insufficiencies associated with aging bone is a viable route for achieving next-generation therapeutic success in the elderly population.

Old age alters inflammation and autophagy signaling in the brain, leading to exacerbated neurological outcomes after spinal cord injury in male mice

Older patients with spinal cord injury (SCI) have different features with regard to neurological characteristics after injury. Recent large-scale longitudinal population-based studies showed that individuals with SCI are at a higher risk of developing dementia than non-SCI patients, indicating that SCI is a potential risk factor for dementia. Aging is known to potentiate inflammation and neurodegeneration at the injured site leading to impaired recovery from SCI. However, no research has been aimed at studying the mechanisms of SCI-mediated cognitive impairment in the elderly. The present study examined neurobehavioral and molecular changes in the brain and the underlying mechanisms associated with brain dysfunction in aged C57BL/6 male mice using a contusion SCI model. At 2 months post-injury, aged mice displayed worse performance in locomotor, cognitive and depressive-like behavioral tests compared to young adult animals. Histopathology in injured spinal cord tissue was exacerbated in aged SCI mice. In the brain, transcriptomic analysis with NanoString neuropathology panel identified activated microglia and dysregulated autophagy as the most significantly altered pathways by both age and injury. These findings were further validated by flow cytometry, which demonstrated increased myeloid and lymphocytes infiltration at both the injured site and brain of aged mice. Moreover, SCI in aged mice altered microglial function and dysregulated autophagy in microglia, resulting in worsened neurodegeneration. Taken together, our data indicate that old age exacerbates neuropathological changes in both the injured spinal cord and remote brain regions leading to poorer functional outcomes, at least in part, through altered inflammation and autophagy function.

Exploring the therapeutic potential of Nelumbo nucifera leaf extract against amyloid-beta-induced toxicity in the Caenorhabditis elegans model of Alzheimer's disease

Introduction: Alzheimer's disease (AD) represents a critical global health challenge with limited therapeutic options, prompting the exploration of alternative strategies. A key pathology in AD involves amyloid beta (Aβ) aggregation, and targeting both Aβ aggregation and oxidative stress is crucial for effective intervention. Natural compounds from medicinal and food sources have emerged as potential preventive and therapeutic agents, with Nelumbo nucifera leaf extract (NLE) showing promising properties. Methods: In this study, we utilized transgenic Caenorhabditis elegans (C. elegans) models to investigate the potential of NLE in countering AD and to elucidate the underlying mechanisms. Various assays were employed to assess paralysis rates, food-searching capabilities, Aβ aggregate accumulation, oxidative stress, lifespan under stress conditions, and the expression of stress-resistance-related proteins. Additionally, autophagy induction was evaluated by measuring P62 levels and the formation of LGG-1+ structures, with RNAi-mediated inhibition of autophagy-related genes to confirm the mechanisms involved. Results: The results demonstrated that NLE significantly reduced paralysis rates in CL4176 and CL2006 worms while enhancing food-searching capabilities in CL2355 worms. NLE also attenuated Aβ aggregate accumulation and mitigated Aβ-induced oxidative stress in C. elegans. Furthermore, NLE extended the lifespan of worms under oxidative and thermal stress conditions, while concurrently increasing the expression of stress-resistance-related proteins, including SOD-3, GST-4, HSP-4, and HSP-6. Moreover, NLE induced autophagy in C. elegans, as evidenced by reduced P62 levels in BC12921 worms and the formation of LGG-1+ structures in DA2123 worms. The RNAi-mediated inhibition of autophagy-related genes, such as bec-1 and vps-34, negated the protective effects of NLE against Aβ-induced paralysis and aggregate accumulation. Discussion: These findings suggest that NLE ameliorates Aβ-induced toxicity by activating autophagy in C. elegans. The study underscores the potential of NLE as a promising candidate for further investigation in AD management, offering multifaceted approaches to mitigate AD-related pathology and stress-related challenges.

Mitochondrial clearance and increased HSF-1 activity are coupled to promote longevity in fasted Caenorhabditis elegans

Fasting has emerged as a potent means of preserving tissue function with age in multiple model organisms. However, our understanding of the relationship between food removal and long-term health is incomplete. Here, we demonstrate that in the nematode worm Caenorhabditis elegans, a single period of early-life fasting is sufficient to selectively enhance HSF-1 activity, maintain proteostasis capacity and promote longevity without compromising fecundity. These effects persist even when food is returned, and are dependent on the mitochondrial sirtuin, SIR-2.2 and the H3K27me3 demethylase, JMJD-3.1. We find that increased HSF-1 activity upon fasting is associated with elevated SIR-2.2 levels, decreased mitochondrial copy number and reduced H3K27me3 levels at the promoters of HSF-1 target genes. Furthermore, consistent with our findings in worms, HSF-1 activity is also enhanced in muscle tissue from fasted mice, suggesting that the potentiation of HSF-1 is a conserved response to food withdrawal.

An HIV-1 CRISPR-Cas9 membrane trafficking screen reveals a role for PICALM intersecting endolysosomes and immunity

HIV-1 hijacks host proteins involved in membrane trafficking, endocytosis, and autophagy that are critical for virus replication. Molecular details are lacking but are essential to inform on the development of alternative antiviral strategies. Despite their potential as clinical targets, only a few membrane trafficking proteins have been functionally characterized in HIV-1 replication. To further elucidate roles in HIV-1 replication, we performed a CRISPR-Cas9 screen on 140 membrane trafficking proteins. We identified phosphatidylinositol-binding clathrin assembly protein (PICALM) that influences not only infection dynamics but also CD4+ SupT1 biology. The knockout (KO) of PICALM inhibited viral entry. In CD4+ SupT1 T cells, KO cells exhibited defects in intracellular trafficking and increased abundance of intracellular Gag and significant alterations in autophagy, immune checkpoint PD-1 levels, and differentiation markers. Thus, PICALM modulates a variety of pathways that ultimately affect HIV-1 replication, underscoring the potential of PICALM as a future target to control HIV-1.

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.

β-Carboline derivatives are potent against Acute Myeloid Leukemia in vitro and in vivo

BACKGROUND

β-carboline alkaloids exert a distinguished ability to impair cell growth and induce cell death in a variety of cancers and the evaluation of such new therapeutic candidates may denote new possibilities for leukemia treatment. In this present study, we screened 12 β-carboline derivatives containing different substituents at 1- and 3-positions of β-carboline nucleus for their antineoplastic activities in a panel of leukemia cell lines.

METHODS

The cytotoxic effects of the β-carboline derivatives were evaluated in different leukemia cell lines as well as reactive oxygen species (ROS) generation, autophagy, and important signaling pathways.

RESULTS

Treatment with the β-carboline derivatives resulted in a potent antineoplastic activity leading to a reduced cell viability that was associated with increased cell death in a concentration-dependent manner. Interestingly, the treatment of primary mononuclear cells isolated from the peripheral blood of healthy donors with the β-carboline derivatives showed a minor change in cell survival. The antineoplastic activity occurs by blocking ROS production causing consequent interruption of the PI3K/AKT and MAPK/ERK signaling and modulating autophagy processes. Notably, in vivo, AML burden was diminished in peripheral blood and bone marrow of a xenograft mouse model.

CONCLUSIONS

Our results indicated that β-carboline derivatives have an on-target malignant cell-killing activity and may be promising candidates for treating leukemia cells by disrupting crucial events that promote leukemia expansion and chemotherapy resistance.

Age-dependent heat shock hormesis to HSF-1 deficiency suggests a compensatory mechanism mediated by the unfolded protein response and innate immunity in young Caenorhabditis elegans

The transcription factor HSF-1 (heat shock factor 1) acts as a master regulator of heat shock response in eukaryotic cells to maintain cellular proteostasis. The protein has a protective role in preventing cells from undergoing ageing, and neurodegeneration, and also mediates tumorigenesis. Thus, modulating HSF-1 activity in humans has a promising therapeutic potential for treating these pathologies. Loss of HSF-1 function is usually associated with impaired stress tolerance. Contrary to this conventional knowledge, we show here that inactivation of HSF-1 in the nematode Caenorhabditis elegans results in increased thermotolerance at young adult stages, whereas HSF-1 deficiency in animals passing early adult stages indeed leads to decreased thermotolerance, as compared to wild-type. Furthermore, a gene expression analysis supports that in young adults, distinct cellular stress response and immunity-related signaling pathways become induced upon HSF-1 deficiency. We also demonstrate that increased tolerance to proteotoxic stress in HSF-1-depleted young worms requires the activity of the unfolded protein response of the endoplasmic reticulum and the SKN-1/Nrf2-mediated oxidative stress response pathway, as well as an innate immunity-related pathway, suggesting a mutual compensatory interaction between HSF-1 and these conserved stress response systems. A similar compensatory molecular network is likely to also operate in higher animal taxa, raising the possibility of an unexpected outcome when HSF-1 activity is manipulated in humans.

Dysregulation of pancreatic β-cell autophagy and the risk of type 2 diabetes

Macroautophagy/autophagy is an essential degradation process that removes abnormal cellular components, maintains homeostasis within cells, and provides nutrition during starvation. Activated autophagy enhances cell survival during stressful conditions, although overactivation of autophagy triggers induction of autophagic cell death. Therefore, early-onset autophagy promotes cell survival whereas late-onset autophagy provokes programmed cell death, which can prevent disease progression. Moreover, autophagy regulates pancreatic β-cell functions by different mechanisms, although the precise role of autophagy in type 2 diabetes (T2D) is not completely understood. Consequently, this mini-review discusses the protective and harmful roles of autophagy in the pancreatic β cell and in the pathophysiology of T2D.

Metformin instigates cellular autophagy to ameliorate high-fat diet-induced pancreatic inflammation and fibrosis/EMT in mice

BACKGROUND

Chronic pancreatic dysfunction is frequently observed as a consequence of prolonged high-fat diet consumption and is a serious public health concern. This pro-diabetic insult aggravates inflammation-influenced fibrotic lesions and is associated with deregulated autophagy. Metformin, a conventional anti-hyperglycemic drug, might be beneficial for pancreatic health, but the complex molecular regulations are not clarified. Considering the worldwide prevalence of chronic pancreatic dysfunction in obese individuals, we aimed to unwind the molecular intricacies explaining the involvement of oxidative stress, inflammation and fibrosis and to approbate metformin as a plausible intervention in this crossroad.

MAIN METHODS

Age-matched Swiss Albino mice were exposed to high-fat diet (60 kcal%) against control diet (10 kcal%) to establish diet-induced stress model. Metformin treatment was introduced after 4 weeks to metformin-control and HFD-exposed metformin groups. After 8 weeks, metabolic and molecular outcomes were assessed to establish the impact of metformin on chronic consequences of HFD-mediated injury.

KEY FINDINGS

High-fat diet administration to healthy mice primes oxidative stress-mediated chronic inflammation through Nrf2/Keap1/NF-κB interplay. Besides, pro-inflammatory cytokine bias leading to fibrotic (increased TGF-β, α-SMA, and MMP9) and pro-EMT (Twist1, Slug, Vimentin, E-cadherin) repercussions in pancreatic lobules were evident. Metformin distinctly rescues high-fat diet-induced remodeling of pancreatic pro-diabetic alterations and cellular survival/death switch. Further, metformin abrogates the p62-Twist1 crosstalk in an autophagy-dependent manner (elevated beclin1, LC3-II/I, Lamp2) to restore pancreatic homeostasis.

CONCLUSION

Our research validates the therapeutic potential of metformin in the inflammation-fibrosis nexus to ameliorate high-fat diet-induced pancreatic dysfunction and related metabolic alterations.

Integrating network pharmacology with experimental validation to investigate the mechanism of Wuwei Zishen formula in improving perimenopausal syndrome

OBJECTIVES

To investigate the role of the Wuwei Zishen formula (WWZSF) in treating and preventing perimenopausal syndrome (PMS) and to understand its mechanism.

METHODS

Network pharmacology and molecular docking was used to predict active compounds, potential targets, and pathways for PMS treatment using WWZSF. Female Sprague-Dawley (SD) rats were induced with D-galactose (D-gal) to establish a PMS model and treated with Kunbao pill (KBP) and WWZSF. Estrus cycles were observed using vaginal smears. Serum sex hormones were measured using the enzyme-linked immunosorbent assay (ELISA). Histological changes in the uterus and ovaries were evaluated using hematoxylin-eosin staining (HE). Western blot was used to assess the protein expression levels of Cleaved Caspase-3, p62, BAX/Bcl-2, p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR in the uterus and ovaries.

RESULTS

A total of 70 active compounds and 440 potential targets were screened out. Important targets and pathways, including AKT1, Bcl-2, Caspase-3, mTOR, and the PI3K/AKT/mTOR pathways, and molecular docking verified their high affinities to key WWZSF components. In vivo experiments showed that WWZSF can ameliorate the morphological abnormalities of the uterus and ovaries, increase sex hormone levels and organ index, and restore the estrus cycles in PMS rats. Moreover, the western blot results showed decreased Cleaved Caspase-3 and BAX/Bcl-2 protein levels in the ovarian and uterine tissues after WWZSF therapy. Concurrently, there was an increase in the expression of p62 and the ratios of p-AKT/AKT, p-mTOR/mTOR, and p-PI3K/PI3K.

CONCLUSION

The PI3K/AKT/mTOR signaling pathway-mediated apoptosis and autophagy pathways may be how WWZSF efficiently reduces PMS.

DNA Damage and Senescence in the Aging and Alzheimer's Disease Cortex Are Not Uniformly Distributed

Alzheimer's disease (AD) is a neurodegenerative illness with a typical age of onset exceeding 65 years of age. The age dependency of the condition led us to track the appearance of DNA damage in the frontal cortex of individuals who died with a diagnosis of AD. The focus on DNA damage was motivated by evidence that increasing levels of irreparable DNA damage are a major driver of the aging process. The connection between aging and the loss of genomic integrity is compelling because DNA damage has also been identified as a possible cause of cellular senescence. The number of senescent cells has been reported to increase with age, and their senescence-associated secreted products are likely contributing factors to age-related illnesses. We tracked DNA damage with 53BP1 and cellular senescence with p16 immunostaining of human post-mortem brain samples. We found that DNA damage was significantly increased in the BA9 region of the AD cortex compared with the same region in unaffected controls (UCs). In the AD but not UC cases, the density of cells with DNA damage increased with distance from the pia mater up to approximately layer V and then decreased in deeper areas. This pattern of DNA damage was overlaid with the pattern of cellular senescence, which also increased with cortical depth. On a cell-by-cell basis, we found that the intensities of the two markers were tightly linked in the AD but not the UC brain. To test whether DNA damage was a causal factor in the emergence of the senescence program, we used etoposide treatment to damage the DNA of cultured mouse primary neurons. While DNA damage increased after treatment, after 24 h, no change in the expression of senescence-associated markers was observed. Our work suggests that DNA damage and cellular senescence are both increased in the AD brain and increasingly coupled. We propose that in vivo, the relationship between the two age-related processes is more complex than previously thought.

Kidney Aging and Chronic Kidney Disease

The process of aging inevitably leads to an increase in age-related comorbidities, including chronic kidney disease (CKD). In many aspects, CKD can be considered a state of accelerated and premature aging. Aging kidney and CKD have numerous common characteristic features, ranging from pathological presentation and clinical manifestation to underlying mechanisms. The shared mechanisms underlying the process of kidney aging and the development of CKD include the increase in cellular senescence, the decrease in autophagy, mitochondrial dysfunction, and the alterations of epigenetic regulation, suggesting the existence of potential therapeutic targets that are applicable to both conditions. In this review, we provide a comprehensive overview of the common characteristics between aging kidney and CKD, encompassing morphological changes, functional alterations, and recent advancements in understanding the underlying mechanisms. Moreover, we discuss potential therapeutic strategies for targeting senescent cells in both the aging process and CKD.

CCDC50 mediates the clearance of protein aggregates to prevent cellular proteotoxicity

Protein aggregation caused by the disruption of proteostasis will lead to cellular cytotoxicity and even cell death, which is implicated in multiple neurodegenerative diseases. The elimination of aggregated proteins is mediated by selective macroautophagy receptors, which is termed aggrephagy. However, the identity and redundancy of aggrephagy receptors in recognizing substrates remain largely unexplored. Here, we find that CCDC50, a highly expressed autophagy receptor in brain, is recruited to proteotoxic stresses-induced polyubiquitinated protein aggregates and ectopically expressed aggregation-prone proteins. CCDC50 recognizes and further clears these cytotoxic aggregates through autophagy. The ectopic expression of CCDC50 increases the tolerance to stress-induced proteotoxicity and hence improved cell survival in neuron cells, whereas CCDC50 deficiency caused accumulation of lipid deposits and polyubiquitinated protein conjugates in the brain of one-year-old mice. Our study illustrates how aggrephagy receptor CCDC50 combats proteotoxic stress for the benefit of neuronal cell survival, thus suggesting a protective role in neurotoxic proteinopathy.

A-Syn(ful) MAM: A Fresh Perspective on a Converging Domain in Parkinson's Disease

Parkinson's disease (PD) is a disease of an unknown origin. Despite that, decades of research have provided considerable evidence that alpha-synuclein (αSyn) is central to the pathogenesis of disease. Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) are functional domains formed at contact sites between the ER and mitochondria, with a well-established function of MAMs being the control of lipid homeostasis within the cell. Additionally, there are numerous proteins localized or enriched at MAMs that have regulatory roles in several different molecular signaling pathways required for cellular homeostasis, such as autophagy and neuroinflammation. Alterations in several of these signaling pathways that are functionally associated with MAMs are found in PD. Taken together with studies that find αSyn localized at MAMs, this has implicated MAM (dys)function as a converging domain relevant to PD. This review will highlight the many functions of MAMs and provide an overview of the literature that finds αSyn, in addition to several other PD-related proteins, localized there. This review will also detail the direct interaction of αSyn and αSyn-interacting partners with specific MAM-resident proteins. In addition, recent studies exploring new methods to investigate MAMs will be discussed, along with some of the controversies regarding αSyn, including its several conformations and subcellular localizations. The goal of this review is to highlight and provide insight on a domain that is incompletely understood and, from a PD perspective, highlight those complex interactions that may hold the key to understanding the pathomechanisms underlying PD, which may lead to the targeted development of new therapeutic strategies.

Dialogue between mitochondria and endoplasmic reticulum-potential therapeutic targets for age-related cardiovascular diseases

Mitochondria-associated endoplasmic reticulum membranes (MAMs) act as physical membrane contact sites facilitating material exchange and signal transmission between mitochondria and endoplasmic reticulum (ER), thereby regulating processes such as Ca2+/lipid transport, mitochondrial dynamics, autophagy, ER stress, inflammation, and apoptosis, among other pathological mechanisms. Emerging evidence underscores the pivotal role of MAMs in cardiovascular diseases (CVDs), particularly in aging-related pathologies. Aging significantly influences the structure and function of the heart and the arterial system, possibly due to the accumulation of reactive oxygen species (ROS) resulting from reduced antioxidant capacity and the age-related decline in organelle function, including mitochondria. Therefore, this paper begins by describing the composition, structure, and function of MAMs, followed by an exploration of the degenerative changes in MAMs and the cardiovascular system during aging. Subsequently, it discusses the regulatory pathways and approaches targeting MAMs in aging-related CVDs, to provide novel treatment strategies for managing CVDs in aging populations.

Propolis as an autophagy modulator in relation to its roles in redox balance and inflammation regulation

Autophagy is a degradation process that is evolutionarily conserved and is essential in maintaining cellular and physiological homeostasis through lysosomal removal and elimination of damaged peptides, proteins and cellular organelles. The dysregulation of autophagy is implicated in various diseases and disorders, including cancers, infection-related, and metabolic syndrome-related diseases. Propolis has been demonstrated in various studies including many human clinical trials to have antimicrobial, antioxidant, anti-inflammatory, immune-modulator, neuro-protective, and anti-cancer. Nevertheless, the autophagy modulation properties of propolis have not been extensively studied and explored. The role of propolis and its bioactive compounds in modulating cellular autophagy is possibly due to their dual role in redox balance and inflammation. The present review attempts to discuss the activities of propolis as an autophagy modulator in biological models in relation to various diseases/disorders which has implications in the development of propolis-based nutraceuticals, functional foods, and complementary therapies.

LC3A-mediated autophagy elicits PERK-eIF2α-ATF4 axis activation and mitochondrial dysfunction: Exposing vulnerability in aggresome-positive cancer cells

The unfolded protein response pathways (UPR), autophagy, and compartmentalization of misfolded proteins into inclusion bodies are critical components of the protein quality control network. Among inclusion bodies, aggresomes are particularly intriguing due to their association with cellular survival, drug resistance, and aggresive cancer behavior. Aggresomes are molecular condensates formed when collapsed vimentin cages encircle misfolded proteins before final removal by autophagy. Yet significant gaps persist in the mechanisms governing aggresome formation and elimination in cancer cells. Understanding these mechanisms is crucial, especially considering the involvement of LC3A, a member of the MAP1LC3 family, which plays a unique role in autophagy regulation and has been reported to be epigenetically silenced in many cancers. Herein, we utilized the tetracycline-inducible expression of LC3A to investigate its role in choroid plexus carcinoma cells, which inherently exhibit the presence of aggresomes. Live cell imaging was employed to demonstrate the effect of LC3A expression on aggresome-positive cells, while SILAC-based proteomics identified LC3A-induced protein and pathway alterations. Our findings demonstrated that extended expression of LC3A is associated with cellular senescence. However, the obstruction of lysosomal degradation in this context has a deleterious effect on cellular viability. In response to LC3A-induced autophagy, we observed significant alterations in mitochondrial morphology, reflected by mitochondrial dysfunction and increased ROS production. Furthermore, LC3A expression elicited the activation of the PERK-eIF2α-ATF4 axis of the UPR, underscoring a significant change in the protein quality control network. In conclusion, our results elucidate that LC3A-mediated autophagy alters the protein quality control network, exposing a vulnerability in aggresome-positive cancer cells.

Sea cucumber plasmalogen enhance lipophagy to alleviate abnormal lipid accumulation induced by high-fat diet

Sea cucumber phospholipids, including the plasmalogen (PlsEtn) and plasmanylcholine (PakCho), have been shown to play a regulatory role in lipid metabolism disorders, but their mechanism of action remains unclear. Therefore, high-fat diet (HFD) and palmitic acid were used to establish lipid accumulation models in mice and HepG2 cells, respectively. Results showed that PlsEtn can reduce lipid deposition both in vivo and in vitro. HFD stimulation abnormally activated lipophagy through the phosphorylation of the AMPK/ULK1 pathway. The lipophagy flux monitor revealed abnormalities in the fusion stage of lipophagy. Of note, only PlsEtn stimulated the dynamic remodeling of the autophagosome membrane, which was indicated by the significantly decreased LC3 II/I ratio and p62 level. In all experiments, the effect of PlsEtn was significantly higher than that of PakCho. These findings elucidated the mechanism of PlsEtn in alleviating lipid accumulation, showed that it might be a lipophagy enhancer, and provided new insights into the high-value utilization of sea cucumber as an agricultural resource.

Antioxidant and anti-ageing effects of oleuropein aglycone in canine skeletal muscle cells

Reactive oxygen species (ROS) are normally produced in skeletal muscle. However, an imbalance in their regulatory systems can lead to their accumulation and ultimately to oxidative stress, which is one of the causes of the ageing process. Companion dogs share the same environment and lifestyle as humans, making them an excellent comparative model for the study of ageing, as well as they constitute a growing market for bioactive molecules that improve the quality of life of pets. The anti-ageing properties of oleuropein aglycone (OLE), a bioactive compound from olive leaves known for its antioxidant properties, were investigated in Myok9 canine muscle cell model. After incubation with OLE, senescence was induced in the canine cellular model by hydrogen peroxide (H2O2). Analyses were performed on cells after seven days of differentiation. The oxidative stress induced by H2O2 treatment on differentiated canine muscle cells led to a significant increase in ROS formation, which was reduced by OLE pretreatment alone or in combination with H2O2 by about 34% and 32%, respectively. Cells treated with H2O2 showed a 48% increase the area of senescent cells stained by SA-β-gal, while OLE significantly reduced the coloured area by 52%. OLE, alone or in combination with H2O2, showed a significant antioxidant activity, possibly through autophagy activation, as indicated by the expression of autophagic markers.

The plasma metabolome is associated with preservation of physiological function following lifelong aerobic exercise in mice

Declines in physiological function with aging are strongly linked to age-related diseases. Lifelong voluntary aerobic exercise (LVAE) preserves physiological function with aging, possibly by increasing cellular quality control processes, but the circulating molecular transducers mediating these processes are incompletely understood. The plasma metabolome may predict biological aging and is impacted by a single bout of aerobic exercise. Here, we conducted an ancillary analysis using plasma samples, and physiological function data, from previously reported studies of LVAE in male C57BL/6N mice randomized to LVAE (wheel running) or sedentary (SED) (n = 8-9/group) to determine if LVAE alters the plasma metabolome and whether these changes correlated with preservation of physiological function with LVAE. Physical function (grip strength, coordination, and endurance) was assessed at 3 and 18 months of age; vascular endothelial function and the plasma metabolome were assessed at 19 months. Physical function was preserved (%decline; mean ± SEM) with LVAE vs SED (all p < 0.05)-grip strength, 0.4 ± 1.7% vs 12 ± 4.0%; coordination, 10 ± 4% vs 73 ± 10%; endurance, 1 ± 15% vs 61 ± 5%. Vascular endothelial function with LVAE (88.2 ± 2.0%) was higher than SED (79.1 ± 2.5%; p = 0.03) and similar to the young controls (91.4 ± 2.9%). Fifteen metabolites were different with LVAE compared to SED (FDR < 0.05) and correlated with the preservation of physiological function. Plasma spermidine, a polyamine that increases cellular quality control (e.g., autophagy), correlated with all assessed physiological indices. Autophagy (LC3A/B abundance) was higher in LVAE skeletal muscle compared to SED (p < 0.01) and inversely correlated with plasma spermidine (r =  - 0.5297; p = 0.054). These findings provide novel insight into the circulating molecular transducers by which LVAE may preserve physiological function with aging.

NBR1-dependent autophagy activation protects against environmental cadmium-evoked placental trophoblast senescence

Cadmium (Cd), a well-established developmental toxicant, accumulates in the placentae and disrupts its structure and function. Population study found adverse pregnancy outcomes caused by environmental Cd exposure associated with cell senescence. However, the role of autophagy activation in Cd-induced placental cell senescence and its reciprocal mechanisms are unknown. In this study, we employed animal experiments, cell culture, and case-control study to investigate the above mentioned. We have demonstrated that exposure to Cd during gestation induces placental senescence and activates autophagy. Pharmacological and genetic interventions further exacerbated placental senescence induced by Cd through the suppression of autophagy. Conversely, activation of autophagy ameliorated Cd-induced placental senescence. Knockdown of NBR1 exacerbated senescence in human placental trophoblast cells. Further investigations revealed that NBR1 facilitated the degradation of p21 via LC3B. Our case-control study has demonstrated a positive correlation between placental senescence and autophagy activation in all-cause fetal growth restriction (FGR). These findings offer a novel perspective for mitigating placental aging and placental-origin developmental diseases induced by environmental toxicants.

Human tNeurons reveal aging-linked proteostasis deficits driving Alzheimer's phenotypes

Aging is a prominent risk factor for Alzheimer's disease (AD), but the cellular mechanisms underlying neuronal phenotypes remain elusive. Both accumulation of amyloid plaques and neurofibrillary tangles in the brain1 and age-linked organelle deficits2-7 are proposed as causes of AD phenotypes but the relationship between these events is unclear. Here, we address this question using a transdifferentiated neuron (tNeuron) model directly from human dermal fibroblasts. Patient-derived tNeurons retain aging hallmarks and exhibit AD-linked deficits. Quantitative tNeuron proteomic analyses identify aging and AD-linked deficits in proteostasis and organelle homeostasis, particularly affecting endosome-lysosomal components. The proteostasis and lysosomal homeostasis deficits in aged tNeurons are exacerbated in sporadic and familial AD tNeurons, promoting constitutive lysosomal damage and defects in ESCRT-mediated repair. We find deficits in neuronal lysosomal homeostasis lead to inflammatory cytokine secretion, cell death and spontaneous development of Aß and phospho-Tau deposits. These proteotoxic inclusions co-localize with lysosomes and damage markers and resemble inclusions in brain tissue from AD patients and APP-transgenic mice. Supporting the centrality of lysosomal deficits driving AD phenotypes, lysosome-function enhancing compounds reduce AD-associated cytokine secretion and Aβ deposits. We conclude that proteostasis and organelle deficits are upstream initiating factors leading to neuronal aging and AD phenotypes.