Snapshot: Implications for mTOR in Aging-related Ischemia/Reperfusion Injury

Anti-Aging Effect of Traditional Plant-Based Food: An Overview

Aging is a complex process that involves many physiological mechanisms that gradually impair normal cellular and tissue function and make us more susceptible to diseases and death. It is influenced by intrinsic factors like cellular function and extrinsic factors like pollution and UV radiation. Recent scientific studies show that traditional plant-based foods and supplements can help mitigate the effects of aging. Nutraceuticals, which are dietary supplements with medicinal properties, have gained attention for their ability to prevent chronic and age-related diseases. Antioxidants like flavonoids, carotenoids, ascorbic acid, terpenes, tannins, saponins, alkaloids, minerals, etc. found in plants are key to managing oxidative stress, which is a major cause of aging. Well-known plant-based supplements from Bacopa monnieri, Curcuma longa, Emblica officinalis, Ginkgo biloba, Glycyrrhiza glabra, and Panax ginseng have been found to possess medicinal properties. These supplements have been shown to improve cognitive function, reduce oxidative stress, improve overall health, and potentially extend life and enhance the excellence of life. The obtained benefits from these plant species are due to the presence of their bioactive secondary metabolites, such as bacosides in Bacopa monnieri, curcumin in Curcuma longa, ginsenosides in Panax ginseng, and many more. These compounds not only protect against free radical damage but also modulate key biological pathways of aging. Also, traditional fermented foods (tempeh and kimchi), which are rich in probiotics and bioactive compounds, support gut health, boost immune function, and have anti-aging properties. The molecular mechanisms behind these benefits are the activation of nutrient-sensing pathways like AMPK, SIRT/NAD+, and mTOR, which are important for cellular homeostasis and longevity. This review shows the potential of traditional plant-based foods and dietary supplements for healthy aging, and more studies are needed to prove their efficacy and safety in humans. Incorporating these natural products into our diet may be a practical and effective way to counteract the effects of aging and overall well-being. The foremost goal of this review is to emphasize the importance of supporting the body's antioxidant system by consuming the right balance of natural ingredients in the diet.

Decoding the secrets of longevity: unraveling nutraceutical and miRNA-Mediated aging pathways and therapeutic strategies

MicroRNAs (miRNAs) are short RNA molecules that are not involved in coding for proteins. They have a significant function in regulating gene expression after the process of transcription. Their participation in several biological processes has rendered them appealing subjects for investigating age-related disorders. Increasing data indicates that miRNAs can be influenced by dietary variables, such as macronutrients, micronutrients, trace minerals, and nutraceuticals. This review examines the influence of dietary factors and nutraceuticals on the regulation of miRNA in relation to the process of aging. We examine the present comprehension of miRNA disruption in age-related illnesses and emphasize the possibility of dietary manipulation as a means of prevention or treatment. Consolidating animal and human research is essential to validate the significance of dietary miRNA control in living organisms, despite the abundance of information already provided by several studies. This review elucidates the complex interaction among miRNAs, nutrition, and aging, offering valuable insights into promising areas for further research and potential therapies for age-related disorders.

Autophagy of OTUD5 destabilizes GPX4 to confer ferroptosis-dependent kidney injury

Ferroptosis is an iron-dependent programmed cell death associated with severe kidney diseases, linked to decreased glutathione peroxidase 4 (GPX4). However, the spatial distribution of renal GPX4-mediated ferroptosis and the molecular events causing GPX4 reduction during ischemia-reperfusion (I/R) remain largely unknown. Using spatial transcriptomics, we identify that GPX4 is situated at the interface of the inner cortex and outer medulla, a hyperactive ferroptosis site post-I/R injury. We further discover OTU deubiquitinase 5 (OTUD5) as a GPX4-binding protein that confers ferroptosis resistance by stabilizing GPX4. During I/R, ferroptosis is induced by mTORC1-mediated autophagy, causing OTUD5 degradation and subsequent GPX4 decay. Functionally, OTUD5 deletion intensifies renal tubular cell ferroptosis and exacerbates acute kidney injury, while AAV-mediated OTUD5 delivery mitigates ferroptosis and promotes renal function recovery from I/R injury. Overall, this study highlights a new autophagy-dependent ferroptosis module: hypoxia/ischemia-induced OTUD5 autophagy triggers GPX4 degradation, offering a potential therapeutic avenue for I/R-related kidney diseases.

Afzelin protects against doxorubicin-induced cardiotoxicity by promoting the AMPKα/SIRT1 signaling pathway

BACKGROUND

Doxorubicin (DOX), a chemotherapeutic drug, could relieve the progressions of various diseases. However, its clinical application is limited due to its cardiotoxicity. This study aimed to investigate the effects of afzelin (a flavonol glycoside found in Houttuynia cordata) on the cardiotoxicity induced by DOX.

METHODS

In ex-vivo, H9C2 cells were incubated with 20, 40, or 80 μM afzelin for 12 h, followed by the treatment with 1 μM DOX for 12 h. In vivo, C57BL/6 J mice were intraperitoneally injected with 4 mg/kg/day DOX on days 1, 7, and 14. Meanwhile, starting from day 1, mice were intragastrically administrated with 5 mg/kg/day or 10 mg/kg/day afzelin for 20 days. The cardiac function of mice was evaluated by detecting hemodynamic parameters using the M-mode echocardiography.

RESULTS

DOX decreased the cell survival rate, and elevated apoptotic rate, as well as induced the oxidative stress and mitochondrial dysfunction in H9C2 cells. All these changes were alleviated by afzelin treatment in a concentration-dependent manner. The results were further proven by the mitigation of cardiac injury in vivo, as evidenced by the elevation of fractional shortening, heart weight/tibia length, and the rate of the increase/decrease of left ventricular pressure in mice subjected to DOX-induced cardiotoxicity. Furthermore, afzelin upregulated the expression of p-AMP-activated protein kinase alpha (AMPKα) and sirtuin1 (SIRT1). Dorsomorphin (an AMPKα inhibitor) abrogated the anti-cardiotoxicity effects of afzelin in H9C2 cells induced by DOX.

CONCLUSION

Afzelin protected against DOX-induced cardiotoxicity by promoting the AMPKα/SIRT1 signaling pathway.

Hypoxic State of Cells and Immunosenescence: A Focus on the Role of the HIF Signaling Pathway

Hypoxia activates hypoxia-related signaling pathways controlled by hypoxia-inducible factors (HIFs). HIFs represent a quick and effective detection system involved in the cellular response to insufficient oxygen concentration. Activation of HIF signaling pathways is involved in improving the oxygen supply, promoting cell survival through anaerobic ATP generation, and adapting energy metabolism to meet cell demands. Hypoxia can also contribute to the development of the aging process, leading to aging-related degenerative diseases; among these, the aging of the immune system under hypoxic conditions can play a role in many different immune-mediated diseases. Thus, in this review we aim to discuss the role of HIF signaling pathways following cellular hypoxia and their effects on the mechanisms driving immune system senescence.

Antiaging effects of dietary supplements and natural products

Aging is an inevitable process influenced by genetics, lifestyles, and environments. With the rapid social and economic development in recent decades, the proportion of the elderly has increased rapidly worldwide, and many aging-related diseases have shown an upward trend, including nervous system diseases, cardiovascular diseases, metabolic diseases, and cancer. The rising burden of aging-related diseases has become an urgent global health challenge and requires immediate attention and solutions. Natural products have been used for a long time to treat various human diseases. The primary cellular pathways that mediate the longevity-extending effects of natural products involve nutrient-sensing pathways. Among them, the sirtuin, AMP-activated protein kinase, mammalian target of rapamycin, p53, and insulin/insulin-like growth factor-1 signaling pathways are most widely studied. Several studies have reviewed the effects of individual natural compounds on aging and aging-related diseases along with the underlying mechanisms. Natural products from food sources, such as polyphenols, saponins, alkaloids, and polysaccharides, are classified as antiaging compounds that promote health and prolong life via various mechanisms. In this article, we have reviewed several recently identified natural products with potential antiaging properties and have highlighted their cellular and molecular mechanisms. The discovery and use of dietary supplements and natural products that can prevent and treat multiple aging-related diseases in humans will be beneficial. Thus, this review provides theoretical background for existing dietary supplements and natural products as potential antiaging agents.

Development of Clioquinol Platinum(IV) Conjugates as Autophagy-Targeted Antimetastatic Agents

A series of autophagy-targeted antimetastatic clioquinol (CLQ) platinum(IV) conjugates were designed and prepared by incorporating an autophagy activator CLQ into the platinum(IV) system. Complex 5 with the cisplatin core bearing dual CLQ ligands with potent antitumor properties was screened out as a candidate. More importantly, it displayed potent antimetastatic properties both in vitro and in vivo as expected. Mechanism investigation manifested that complex 5 induced serious DNA damage to increase γ-H2AX and P53 expression and caused mitochondria-mediated apoptosis through the Bcl-2/Bax/caspase3 pathway. Then, it promoted prodeath autophagy by suppressing PI3K/AKT/mTOR signaling and activating the HIF-1α/Beclin1 pathway. The T-cell immunity was elevated by restraining the PD-L1 expression and subsequently increasing CD3⁺ and CD8⁺ T cells. Ultimately, metastasis of tumor cells was suppressed by the synergistic effects of DNA damage, autophagy promotion, and immune activation aroused by CLQ platinum(IV) complexes. Key proteins VEGFA, MMP-9, and CD34 tightly associated with angiogenesis and metastasis were downregulated.

Empagliflozin suppresses mitochondrial reactive oxygen species generation and mitigates the inducibility of atrial fibrillation in diabetic rats

Introduction

Recent studies have demonstrated that sodium-glucose co-transporter-2 inhibitors (SGLT2-i) reduce the risk of atrial fibrillation (AF) in patients with diabetes mellitus (DM), in which oxidative stress due to increased reactive oxygen species (ROS) contributes to the pathogenesis of AF. We aimed to further investigate this, and examine whether the SGLT2-i empagliflozin suppresses mitochondrial-ROS generation and mitigates fibrosis.

Methods

A high-fat diet and low-dose streptozotocin treatment were used to induce type-2 DM (T2DM) in Sprague-Dawley rats. The rats were randomly divided into three groups: control, DM, and DM treated with empagliflozin (30 mg/kg/day) for 8 weeks. The mitochondrial respiratory capacity and ROS generation in the atrial myocardium were measured using a high-resolution respirometer. Oxidative stress markers and protein expression related to mitochondrial biogenesis and dynamics as well as the mitochondrial morphology were examined in the atrial tissue. Additionally, mitochondrial function was examined in H9c2 cardiomyoblasts. Atrial tachyarrhythmia (ATA) inducibility, interatrial conduction time (IACT), and fibrosis were also measured.

Results

Inducibility of ATA, fibrosis, and IACT were increased in rats with DM when compared to controls, all of which were restored by empagliflozin treatment. In addition, the rats with DM had increased mitochondrial-ROS with an impaired complex I-linked oxidative phosphorylation capacity. Importantly, empagliflozin seemed to ameliorate these impairments in mitochondrial function. Furthermore, empagliflozin reversed the decrease in phosphorylated AMPK expression and altered protein levels related to mitochondrial biogenesis and dynamics, and increased mitochondrial content. Empagliflozin also improved mitochondrial function in H9c2 cells cultured with high glucose medium.

Discussion

These data suggest that empagliflozin has a cardioprotective effect, at least in part, by reducing mitochondrial ROS generation through AMPK signaling pathways in the atrium of diabetic rats. This suggests that empagliflozin might suppress the development of AF in T2DM.

Melatonin Inhibits the Ferroptosis Pathway in Rat Bone Marrow Mesenchymal Stem Cells by Activating the PI3K/AKT/mTOR Signaling Axis to Attenuate Steroid-Induced Osteoporosis

Steroid-induced osteoporosis (SIOP) is a form of secondary osteoporosis, but its specific mechanism remains unclear. Glucocorticoid (GC-)-induced death of osteoblasts and bone marrow mesenchymal stem cells (BMSCs) is an important factor in SIOP. Ferroptosis is an iron-dependent type of programmed cell death and can be induced by many factors. Herein, we aimed to explore whether GCs cause ferroptosis of BMSCs, identify pathways as possible therapeutic targets, and determine the underlying mechanisms of action. In this study, we used high-dose dexamethasone (DEX) to observe whether GCs induce ferroptosis of BMSCs. Additionally, we established a rat SIOP model and then assessed whether melatonin (MT) could inhibit the ferroptosis pathway to provide early protection against GC-induced SIOP and investigated the signaling pathways involved. In vitro experiments confirmed that DEX induces ferroptosis in BMSCs. MT significantly alleviates GC-induced ferroptosis of BMSCs. Pathway analysis showed that MT ameliorates ferroptosis by activating the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) axis. MT upregulates the expression of PI3K, which is an important regulator of ferroptosis resistance. PI3K activators mimic the antiferroptotic effect of MT, but when the PI3K pathway is blocked, the effect of MT is weakened. Using in vivo experiments, we confirmed the in vitro results and observed that MT can obviously protect against SIOP induced by GC. Notably, even after the initiation of GC-induced ferroptosis, MT can confer protection against SIOP. Our research confirms that GC-induced ferroptosis is closely related to SIOP. MT can inhibit ferroptosis by activating the PI3K/AKT/mTOR signaling pathway, thereby inhibiting the occurrence of SIOP. Therefore, MT may be a novel agent for preventing and treating SIOP.

Evidence for the Benefits of Melatonin in Cardiovascular Disease

The pineal gland is a neuroendocrine gland which produces melatonin, a neuroendocrine hormone with critical physiological roles in the circadian rhythm and sleep-wake cycle. Melatonin has been shown to possess anti-oxidant activity and neuroprotective properties. Numerous studies have shown that melatonin has significant functions in cardiovascular disease, and may have anti-aging properties. The ability of melatonin to decrease primary hypertension needs to be more extensively evaluated. Melatonin has shown significant benefits in reducing cardiac pathology, and preventing the death of cardiac muscle in response to ischemia-reperfusion in rodent species. Moreover, melatonin may also prevent the hypertrophy of the heart muscle under some circumstances, which in turn would lessen the development of heart failure. Several currently used conventional drugs show cardiotoxicity as an adverse effect. Recent rodent studies have shown that melatonin acts as an anti-oxidant and is effective in suppressing heart damage mediated by pharmacologic drugs. Therefore, melatonin has been shown to have cardioprotective activity in multiple animal and human studies. Herein, we summarize the most established benefits of melatonin in the cardiovascular system with a focus on the molecular mechanisms of action.

The dynamic changes in autophagy activity and its role in lung injury after deep hypothermic circulatory arrest

Deep hypothermic circulatory arrest (DHCA) can cause acute lung injury (ALI), and its pathogenesis mimics ischaemia/reperfusion (I/R) injury. Autophagy is also involved in lung I/R injury. The present study aimed to elucidate whether DHCA induces natural autophagy activation and its role in DHCA‐mediated lung injury. Here, rats were randomly assigned to the Sham or DHCA group. The sham group (n = 5) only received anaesthesia and air intubation. DHCA group rats underwent cardiopulmonary bypass (CPB) followed by the DHCA procedure. The rats were then sacrificed at 3, 6 and 24 h after the DHCA procedure (n = 5) to measure lung injury and autophagy activity. Chloroquine (CQ) was delivered to evaluate autophagic flux. DHCA caused lung injury, which was prominent 3–6 h after DHCA, as confirmed by histological examination and inflammatory cytokine quantification. Lung injury subsided at 24 h. Autophagy was suppressed 3 h but was exaggerated at 6 h. At both time points, autophagic flux appeared uninterrupted. To further assess the role of autophagy in DHCA‐mediated lung injury, the autophagy inducer rapamycin and its inhibitor 3‐methyladenine (3‐MA) were applied, and lung injury was reassessed. When rapamycin was administered at an early time point, lung injury worsened, whereas administration of 3‐MA at a late time point ameliorated lung injury, indicating that autophagy contributed to lung injury after DHCA. Our study presents a time course of lung injury following DHCA. Autophagy showed adaptive yet protective suppression 3 h after DHCA, as induction of autophagy caused worsening of lung tissue. In contrast, autophagy was exaggerated 6 h after DHCA, and autophagy inhibition attenuated DHCA‐mediated lung injury.

Key Signaling Pathways in Aging and Potential Interventions for Healthy Aging

Aging is a fundamental biological process accompanied by a general decline in tissue function. Indeed, as the lifespan increases, age-related dysfunction, such as cognitive impairment or dementia, will become a growing public health issue. Aging is also a great risk factor for many age-related diseases. Nowadays, people want not only to live longer but also healthier. Therefore, there is a critical need in understanding the underlying cellular and molecular mechanisms regulating aging that will allow us to modify the aging process for healthy aging and alleviate age-related disease. Here, we reviewed the recent breakthroughs in the mechanistic understanding of biological aging, focusing on the adenosine monophosphate-activated kinase (AMPK), Sirtuin 1 (SIRT1) and mammalian target of rapamycin (mTOR) pathways, which are currently considered critical for aging. We also discussed how these proteins and pathways may potentially interact with each other to regulate aging. We further described how the knowledge of these pathways may lead to new interventions for antiaging and against age-related disease.

PBK/TOPK: A Therapeutic Target Worthy of Attention

Accumulating evidence supports the role of PDZ-binding kinase (PBK)/T-lymphokine-activated killer-cell-originated protein kinase (TOPK) in mitosis and cell-cycle progression of mitotically active cells, especially proliferative malignant cells. PBK/TOPK was confirmed to be associated with the development, progression, and metastasis of malignancies. Therefore, it is a potential therapeutic target in cancer therapy. Many studies have been conducted to explore the clinical applicability of potent PBK/TOPK inhibitors. However, PBK/TOPK has also been shown to be overexpressed in normal proliferative cells, including sperm and neural precursor cells in the subventricular zone of the adult brain, as well as under pathological conditions, such as ischemic tissues, including the heart, brain, and kidney, and plays important roles in their physiological functions, including proliferation and self-renewal. Thus, more research is warranted to further our understanding of PBK/TOPK inhibitors before we can consider their applicability in clinical practice. In this study, we first review the findings, general features, and signaling mechanisms involved in the regulation of mitosis and cell cycle. We then review the functions of PBK/TOPK in pathological conditions, including tumors and ischemic conditions in the heart, brain, and kidney. Finally, we summarize the advances in potent and selective inhibitors and describe the potential use of PBK/TOPK inhibitors in clinical settings.

Sestrin 2, a potential star of antioxidant stress in cardiovascular diseases

Physiological reactive oxygen species (ROS) play an important role in cellular signal transduction. However, excessive ROS is an important pathological mechanism in most cardiovascular diseases (CVDs), such as myocardial aging, cardiomyopathy, ischemia/reperfusion injury (e.g., myocardial infarction) and heart failure. Programmed cell death, hypertrophy and fibrosis may be due to oxidative stress. Sestrin 2 (Sesn2), a stress-inducible protein associated with various stress conditions, is a potential antioxidant. Sesn2 can suppress the process of heart damage caused by oxidative stress, promote cell survival and play a key role in a variety of CVDs. This review discusses the effect of Sesn2 on the redox signal, mainly via participation in the signaling pathway of nuclear factor erythroid 2-related factor 2, activation of adenosine monophosphate-activated protein kinase and inhibition of mammalian target of rapamycin complex 1. It also discusses the effect of Sesn2's antioxidant activity on different CVDs. We speculate that Sesn2 plays an important role in CVDs by stimulating the process of antioxidation and promoting the adaptation of cells to stress conditions and/or the environment, opening a new avenue for related therapeutic strategies.

P2X4R Overexpression Upregulates Interleukin-6 and Exacerbates 6-OHDA-Induced Dopaminergic Degeneration in a Rat Model of PD

The pathogenesis of Parkinson’s disease (PD) remains elusive. Current thinking suggests that the activation of microglia and the subsequent release of inflammatory factors, including interleukin-6 (IL-6), are involved in the pathogenesis of PD. P2X4 receptor (P2X4R) is a member of the P2X superfamily of ion channels activated by ATP. To study the possible effect of the ATP-P2X4R signal axis on IL-6 in PD, lentivirus carrying the P2X4R-overexpression gene or empty vector was injected into the substantia nigra (SN) of rats, followed by treatment of 6-hydroxydopamine (6-OHDA) or saline 1 week later. The research found the relative expression of P2X4R in the 6-OHDA-induced PD rat models was notably higher than that in the normal. And P2X4R overexpression could upregulate the expression of IL-6, reduce the amount of dopaminergic (DA) neurons in the SN of PD rats, suggesting that P2X4R may mediate the production of IL-6 to damage DA neurons in the SN. Our data revealed the important role of P2X4R in modulating IL-6, which leads to neuroinflammation involved in PD pathogenesis.

Hamartin: An Endogenous Neuroprotective Molecule Induced by Hypoxic Preconditioning

Hypoxic/ischemic preconditioning (HPC/IPC) is an innate neuroprotective mechanism in which a number of endogenous molecules are known to be involved. Tuberous sclerosis complex 1 (TSC1), also known as hamartin, is thought to be one such molecule. It is also known that hamartin is involved as a target in the rapamycin (mTOR) signaling pathway, which functions to integrate a variety of environmental triggers in order to exert control over cellular metabolism and homeostasis. Understanding the role of hamartin in ischemic/hypoxic neuroprotection will provide a novel target for the treatment of hypoxic-ischemic disease. Therefore, the proposed molecular mechanisms of this neuroprotective role and its preconditions are reviewed in this paper, with emphases on the mTOR pathway and the relationship between the expression of hamartin and DNA methylation.

Utilizing Melatonin to Alleviate Side Effects of Chemotherapy: A Potentially Good Partner for Treating Cancer with Ageing

Persistent senescence seems to exert detrimental effects fostering ageing and age-related disorders, such as cancer. Chemotherapy is one of the most valuable treatments for cancer, but its clinical application is limited due to adverse side effects. Melatonin is a potent antioxidant and antiageing molecule, is nontoxic, and enhances the efficacy and reduces the side effects of chemotherapy. In this review, we first summarize the mitochondrial protective role of melatonin in the context of chemotherapeutic drug-induced toxicity. Thereafter, we tabulate the protective actions of melatonin against ageing and the harmful roles induced by chemotherapy and chemotherapeutic agents, including anthracyclines, alkylating agents, platinum, antimetabolites, mitotic inhibitors, and molecular-targeted agents. Finally, we discuss several novel directions for future research in this area. The information compiled in this review will provide a comprehensive reference for the protective activities of melatonin in the context of chemotherapy drug-induced toxicity and will contribute to the design of future studies and increase the potential of melatonin as a therapeutic agent.

PGC1α activation by pterostilbene ameliorates acute doxorubicin cardiotoxicity by reducing oxidative stress via enhancing AMPK and SIRT1 cascades

Doxorubicin (DOX) is a widely used and potent anticancer agent, but DOX dose-dependently induced cardiotoxicity greatly limits its use in clinic. Pterostilbene, a natural analog of resveratrol, is a known antioxidant and exerts myocardial protection. The present study explored the action and detailed mechanism of pterostilbene on DOX-treated cardiomyocytes. We investigated the effects of pterostilbene on established acute DOX-induced cardiotoxicity models in both H9c2 cells treated with 1 μM DOX and C57BL/6 mice with DOX (20 mg/kg cumulative dose) exposure. Pterostilbene markedly alleviated the DOX exposure-induced acute myocardial injury. Both in vitro and in vivo studies revealed that pterostilbene inhibited the acute DOX exposure-caused oxidative stress and mitochondrial morphological disorder via the PGC1α upregulation through activating AMPK and via PGC1α deacetylation through enhancing SIRT1. However, these effects were partially reversed by knockdown of AMPK or SIRT1 in vitro and treatment of Compound C (AMPK inhibitor) or EX527 (SIRT1 inhibitor) in vivo. Our results indicate that pterostilbene protects cardiomyocytes from acute DOX exposure-induced oxidative stress and mitochondrial damage via PGC1α upregulation and deacetylation through activating AMPK and SIRT1 cascades.

Neuroprotection by nicotinamide mononucleotide adenylyltransferase 1 with involvement of autophagy in an aged rat model of transient cerebral ischemia and reperfusion

Recent researches suggest that autophagic degradation declines with age, and this leads to an accumulation of damage that contributes to age-related cellular dysfunction. Nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1) shows therapeutic potential for cerebral ischemia in young-adult animals. This study investigated the role of NMNAT1 in focal cerebral ischemia in aged rats with a focus on neuronal autophagy. Focal cerebral ischemia was induced in aged rats by middle cerebral artery occlusion (MCAO). NMNAT1 levels in the peri-infarct penumbra increased at 12 and 24 h after ischemia in aged rats. Knockdown of NMNAT1 significantly increased infarct volume, whereas overexpression of NMNAT1 reduced ischemia-induced cerebral injuries in aged rats with acute ischemic stroke. Meanwhile, lentiviral overexpression of NMNAT1 increased autophagy, reduced the phosphorylation of mammalian target of rapamycin (mTOR), and enhanced the sirtuin 1 (SIRT1) protein level. In cultured cortical neurons, SIRT1 regulated the mTOR-mediated autophagy upon oxygen-glucose deprivation (OGD) stress and the effect of NMNAT1 on autophagy was blocked in cultured SIRT1-knockout neurons. Furthermore, autophagy inhibitor 3-methyladenine (3-MA) partly abolished the neuroprotection induced by NMNAT1 overexpression. The results suggest NMNAT1 protects against acute ischemic stroke in aged rats by inducing autophagy via regulating the SIRT1/mTOR pathway.