Reactive oxygen species are essential for autophagy and specifically regulate the activity of Atg4

Oxidative modification of miR-30c promotes cardiac fibroblast proliferation via CDKN2C mismatch

The response of cardiac fibroblast proliferation to detrimental stimuli is one of the main pathological factors causing heart remodeling. Reactive oxygen species (ROS) mediate the proliferation of cardiac fibroblasts. However, the exact molecular mechanism remains unclear. In vivo, we examined the oxidative modification of miRNAs with miRNA immunoprecipitation with O8G in animal models of cardiac fibrosis induced by Ang II injection or ischemia‒reperfusion injury. Furthermore, in vitro, we constructed oxidation-modified miR-30c and investigated its effects on the proliferation of cardiac fibroblasts. Additionally, luciferase reporter assays were used to identify the target of oxidized miR-30c. We found that miR-30c oxidation was modified by Ang II and PDGF treatment and mediated by excess ROS. We demonstrated that oxidative modification of G to O8G occurred at positions 4 and 5 of the 5' end of miR-30c (4,5-oxo-miR-30c), and this modification promoted cardiac fibroblast proliferation. Furthermore, CDKN2C is a negative regulator of cardiac fibroblast proliferation. 4,5-oxo-miR-30c misrecognizes CDKN2C mRNA, resulting in a reduction in protein expression. Oxidized miR-30c promotes cardiac fibroblast proliferation by mismatch mRNA of CDKN2C.

SRT1720 inhibits bladder cancer cell progression by impairing autophagic flux

Bladder cancer (BC) is the most common cancer of the urinary tract, with poor survival, high recurrence rates, and lacking of targeted drugs. In this study, we constructed a library to screen compounds inhibiting bladder cancer cells growth. Among them, SRT1720 was identified to inhibit bladder cancer cell proliferation in vitro and in vivo. SRT1720 treatment also suppressed bladder cancer cells migration, invasion and induced apoptosis. Mechanism studies shown that SRT1720 promoted autophagosomes accumulation by inducing early-stage autophagy but disturbed the late-stage of autophagy by blocking fusion of autophagosomes and lysosomes. SRT1720 appears to induce autophagy related proteins expression and alter autophagy-related proteins acetylation to impede the autophagy flux. LAMP2, an important lysosomal associated membrane protein, may mediate SRT1720-inhibited autophagy flux as SRT1720 treatment significantly deacetylated LAMP2 which may influence its activity. Taken together, our results demonstrated that SRT1720 mediated apoptosis and autophagy flux inhibition may be a novel therapeutic strategy for bladder cancer treatment.

Methylmercury induces inflammatory response and autophagy in microglia through the activation of NLRP3 inflammasome

Methylmercury (MeHg) is a global environmental pollutant with neurotoxicity, which can easily crosses the blood-brain barrier and cause irreversible damage to the human central nervous system (CNS). CNS inflammation and autophagy are known to be involved in the pathology of neurodegenerative diseases. Meanwhile, MeHg has the potential to induce microglia-mediated neuroinflammation as well as autophagy. This study aims to further explore the exact molecular mechanism of MeHg neurotoxicity. We conducted in vitro studies using BV2 microglial cell from the central nervous system of mice. The role of inflammation and autophagy in the damage of BV2 cells induced by MeHg was determined by detecting cell viability, cell morphology and structure, reactive oxygen species (ROS), antioxidant function, inflammatory factors, autophagosomes, inflammation and autophagy-related proteins. We further investigated the relationship between the inflammatory response and autophagy induced by MeHg by inhibiting them separately. The results indicated that MeHg could invade cells, change cell structure, activate NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome and autophagosome, release a large amount of inflammatory factors and trigger the inflammatory response and autophagy. It was also found that MeHg could disrupt the antioxidant function of cells. In addition, the inhibition of NLRP3 inflammasome alleviated both cellular inflammation and autophagy, while inhibition of autophagy increased cellular inflammation. Our current research suggests that MeHg might induce BV2 cytotoxicity through inflammatory response and autophagy, which may be mediated by the NLRP3 inflammasome activated by oxidative stress.

Death-associated protein 3 in cancer-discrepant roles of DAP3 in tumours and molecular mechanisms

Cancer, ranks as the secondary cause of death, is a group of diseases that are characterized by uncontrolled tumor growth and distant metastasis, leading to increased mortality year-on-year. To date, targeted therapy to intercept the aberrant proliferation and invasion is crucial for clinical anticancer treatment, however, mutant expression of target genes often leads to drug resistance. Therefore, it is essential to identify more molecules that can be targeted to facilitate combined therapy. Previous studies showed that death associated protein 3 (DAP3) exerts a pivotal role in regulating apoptosis signaling of tumors, meanwhile, aberrant DAP3 expression is associated with the tumorigenesis and disease progression of various cancers. This review provides an overview of the molecule structure of DAP3 and the discrepant roles played by DAP3 in various types of tumors. Considering the molecular mechanism of DAP3-regulated cancer development, new potential treatment strategies might be developed in the future.

A Nano-Autophagy Inhibitor Triggering Reciprocal Feedback Control of Cholesterol Depletion for Solid Tumor Therapy

Solid tumors are characterized by enhanced metabolism of lipid, particularly cholesterol, inspiring the exploration of metabolic therapy through cholesterol oxidase (COD)-mediated cholesterol deprivation. However, the therapeutic efficacy of COD is limited due to the hypoxic tumor microenvironment and the protective autophagy triggered by cholesterol deprivation. Herein, a combination therapy for metabolically treating solid tumors through COD in conjunction with molybdenum oxide nanodots (MONDs), which serve as both potent oxygen generators and autophagy inhibitors, is reported. MONDs convert H2 O2 (arising from COD-mediated cholesterol oxidation) into O2 , which is then recycled by COD to form reciprocal feedback for cholesterol depletion. Concurrently, MONDs can overcome autophagy-induced therapeutic resistance frequently occurring in conventional nutrient deprivation therapy by activating AKT/mTOR pathway phosphorylation. Combination therapy in the xenograft model results in an ≈5-fold increase in therapeutic efficiency as compared with COD treatment alone. This functionally cooperative metabolic coupling strategy holds great promise as a novel polytherapy approach that will benefit patients with solid tumors.

Potential relationship between autophagy and ferroptosis in myocardial ischemia/reperfusion injury

Autophagy is an evolutionarily conserved process involved in the degradation of long-lived proteins and excessive or dysfunctional organelles. As a pivotal cellular response, autophagy has been extensively studied and is known to be involved in various diseases. Ferroptosis is a recently discovered form of regulated cell death characterized by iron overload, leading to the accumulation of lethal levels of lipid hydroperoxides. Recently, an increasing number of studies have revealed a link between autophagy and ferroptosis. Myocardial ischemia/reperfusion injury (MIRI) is an urgent dilemma after myocardial infarction recanalization, which is regulated by several cell death pathways, including autophagy and ferroptosis. However, the potential relationship between autophagy and ferroptosis in MIRI remains unexplored. In this study, we briefly review the mechanisms of autophagy and ferroptosis, including their roles in MIRI. Moreover, we provide an overview of the potential crosstalk in MIRI. Clarifying the relationship between different cell death pathways may provide new ideas for the treatment of MIRI in the future.

Neferine Targets the Oncogenic Characteristics of Androgen-Dependent Prostate Cancer Cells via Inducing Reactive Oxygen Species

Castration resistance poses a significant challenge in the management of advanced prostate cancer (PCa), with androgen deprivation therapy (ADT) or chemotherapy being the primary treatment options. However, these approaches often lead to significant side effects and the development of therapeutic resistance. Therefore, it is crucial to explore novel treatment options that can efficiently target PCa, improve patient survival, and enhance their quality of life. Neferine (Nef), a bioactive compound derived from plants, has emerged as a promising candidate for cancer treatment due to its ability to induce apoptosis, autophagy, and cell cycle arrest. In this study, we investigated the potential anticancer effects of Nef in androgen receptor (AR)-positive LNCaP and VCaP cells, representative models of androgen-dependent PCa. Our findings demonstrate that Nef effectively inhibits cell growth, proliferation, and the tumorigenic potential of androgen-dependent PCa cells. Furthermore, Nef treatment resulted in the excessive production of reactive oxygen species (ROS), leading to the activation of key markers of autophagy and apoptosis. These results suggest that Nef has the potential to target the oncogenic characteristics of androgen-dependent PCa cells by exploiting the potency of ROS and inducing autophagy and apoptosis in AR-positive PCa cells. These findings shed light on the therapeutic potential of Nef as a novel treatment option with reduced side effects for androgen-dependent prostate cancer. Further investigations are warranted to assess its efficacy and safety in preclinical and clinical settings.

ROS in hepatocellular carcinoma: What we know

Hepatocellular carcinoma (HCC), which is a primary liver cancer subtype, has a poor prognosis due to its high degree of malignancy. The lack of early diagnosis makes systemic therapy the only hope for HCC patients with advanced disease; however, resistance to drugs is a major obstacle. In recent years, targeted molecular therapy has gained popularity as a potential treatment for HCC. An increase in reactive oxygen species (ROS), which are cancer markers and a potential target for HCC therapy, can both promote and inhibit the disease. At present, many studies have examined targeted regulation of ROS in the treatment of HCC. Here, we reviewed the latest drugs that are still in the experimental stage, including nanocarrier drugs, exosome drugs, antibody drugs, aptamer drugs and polysaccharide drugs, to provide new hope for the clinical treatment of HCC patients.

Importance of DJ-1 in autophagy regulation and disease

Autophagy is a highly conserved biological process that has evolved across evolution. It can be activated by various external stimuli including oxidative stress, amino acid starvation, infection, and hypoxia. Autophagy is the primary mechanism for preserving cellular homeostasis and is implicated in the regulation of metabolism, cell differentiation, tolerance to starvation conditions, and resistance to aging. As a multifunctional protein, DJ-1 is commonly expressed in vivo and is associated with a variety of biological processes. Its most widely studied role is its function as an oxidative stress sensor that inhibits the production of excessive reactive oxygen species (ROS) in the mitochondria and subsequently the cellular damage caused by oxidative stress. In recent years, many studies have identified DJ-1 as another important factor regulating autophagy; it regulates autophagy in various ways, most commonly by regulating the oxidative stress response. In particular, DJ-1-regulated autophagy is involved in cancer progression and plays a key role in alleviating neurodegenerative diseases(NDS) and defective reperfusion diseases. It could serve as a potential target for the regulation of autophagy and participate in disease treatment as a meaningful modality. Therefore, exploring DJ-1-regulated autophagy could provide new avenues for future disease treatment.

Pharmacological modulation of autophagy for epilepsy therapy: opportunities and obstacles

Epilepsy (EP) is a long-term neurological disorder characterized by neuroinflammatory responses, neuronal apoptosis, imbalance between excitatory and inhibitory neurotransmitters, and oxidative stress in the brain. Autophagy is a process of cellular self-regulation to maintain normal physiological functions. Emerging evidence suggests that dysfunctional autophagy pathways in neurons are a potential mechanism underlying EP pathogenesis. In this review, we discuss current evidence and molecular mechanisms of autophagy dysregulation in EP and the probable function of autophagy in epileptogenesis. Moreover, we review the autophagy modulators reported for the treatment of EP models, and discuss the obstacles to, and opportunities for, the potential therapeutic applications of novel autophagy modulators as EP therapies. Teaser: Defective autophagy affects the onset and progression of epilepsy, and many anti-epileptic drugs have autophagy-modulating effects.

The Interplay Between Autophagy and Regulated Necrosis

Significance: Autophagy is critical to cellular homeostasis. Emergence of the concept of regulated necrosis, such as necroptosis, ferroptosis, pyroptosis, and mitochondrial membrane-permeability transition (MPT)-derived necrosis, has revolutionized the research into necrosis. Both altered autophagy and regulated necrosis contribute to major human diseases. Recent studies reveal an intricate interplay between autophagy and regulated necrosis. Understanding the interplay at the molecular level will provide new insights into the pathophysiology of related diseases. Recent Advances: Among the three forms of autophagy, macroautophagy is better studied for its crosstalk with regulated necrosis. Macroautophagy seemingly can either antagonize or promote regulated necrosis, depending upon the form of regulated necrosis, the type of cells or stimuli, and other cellular contexts. This review will critically analyze recent advances in the molecular mechanisms governing the intricate dialogues between macroautophagy and main forms of regulated necrosis. Critical Issues: The dual roles of autophagy, either pro-survival or pro-death characteristics, intricate the mechanistic relationship between autophagy and regulated necrosis at molecular level in various pathological conditions. Meanwhile, key components of regulated necrosis are also involved in the regulation of autophagy, which further complicates the interrelationship. Future Directions: Resolving the controversies over causation between altered autophagy and a specific form of regulated necrosis requires approaches that are more definitive, where rigorous evaluation of autophagic flux and the development of more reliable and specific methods to quantify each form of necrosis will be essential. The relationship between chaperone-mediated autophagy or microautophagy and regulated necrosis remains largely unstudied. Antioxid. Redox Signal. 38, 550-580.

Neuroprotection impact of biochanin A against pentylenetetrazol-kindled mice: Targeting NLRP3 inflammasome/TXNIP pathway and autophagy modulation

Recurrent seizures characterize epilepsy, a complicated and multifaceted neurological disease. Several neurological alterations, such as cell death and the growth of gorse fibers, have been linked to epilepsy. The dentate gyrus of the hippocampus is particularly vulnerable to neuronal loss and abnormal neuroplastic changes in the pentylenetetrazol (PTZ) kindling model. Biochanin A has potent anti-inflammatory and antioxidant properties, according to previous evidence and its possible impact in epilepsy has never previously been claimed. The current work aimed to investigate biochanin A's anti-epileptic potential in PTZ-induced kindling model in mice. Chronic epilepsy was established in mice by giving PTZ (35 mg/kg, i.p) every other day for 21 days. Biochanin A (20 mg/kg) was given daily till the end of the experiment. Biochanin A pretreatment significantly reduced the severity of epileptogenesis by 51.7% and downregulated the histological changes in the CA3 region of the hippocampus by 42% along with displaying antioxidant/anti-inflammatory efficacy through upregulated hemeoxygenase-1 (HO-1) and, erythroid 2-related factor 2 (Nrf2) levels in the brain by 1.9-fold and 2-fold respectively, parallel to reduction of malondialdehyde (MDA), myeloperoxidase (MPO), glial fibrillary acidic protein (GFAP) and L-glutamate/IL-1β/TXNIB/NLRP3 axis. Moreover, biochanin A suppressed neuronal damage by reducing the astrocytes' activation and significantly attenuated the PTZ-induced increase in LC3 levels by 55.5%. Furthermore, molecular docking findings revealed that BIOCHANIN A has a higher affinity for phosphoinositide 3-kinase (PI3k), threonine kinase2 (AKT2), and mammalian target of rapamycin complex 1 (mTORC1) indicating the neuroprotective and anti-epileptic characteristics of biochanin A in the brain tissue of PTZ-kindled mice.

An updated pharmacological insight into calotropin as a potential therapeutic agent in cancer

Calotropin is a pharmacologically active compound isolated from milkweed plants like Calotropis procera, Calotropis gigantea, and Asclepias currasavica that belong to the Asclepiadaceae family. All of these plants are recognised as medical traditional plants used in Asian countries. Calotropin is identified as a highly potent cardenolide that has a similar chemical structure to cardiac glycosides (such as digoxin and digitoxin). During the last few years, cytotoxic and antitumor effects of cardenolides glycosides have been reported more frequently. Among cardenolides, calotropin is identified as the most promising agent. In this updated and comprehensive review, we aimed to analyze and discuss the specific mechanisms and molecular targets of calotropin in cancer treatment to open new perspectives for the adjuvant treatment of different types of cancer. The effects of calotropin on cancer have been extensively studied in preclinical pharmacological studies in vitro using cancer cell lines and in vivo in experimental animal models that have targeted antitumor mechanisms and anticancer signaling pathways. The analyzed information from the specialized literature was obtained from scientific databases until December 2022, mainly from PubMed/MedLine, Google Scholar, Scopus, Web of Science, and Science Direct databases using specific MeSH search terms. The results of our analysis demonstrate that calotropin can be a potential chemotherapeutic/chemopreventive adjunctive agent in cancer pharmacotherapeutic management.

Molecular mechanisms behind ROS regulation in cancer: A balancing act between augmented tumorigenesis and cell apoptosis

ROS include hydroxyl radicals (HO^.), superoxide (O₂^..), and hydrogen peroxide (H₂O₂). ROS are typically produced under physiological conditions and play crucial roles in living organisms. It is known that ROS, which are created spontaneously by cells through aerobic metabolism in mitochondria, can have either a beneficial or detrimental influence on biological systems. Moderate levels of ROS can cause oxidative damage to proteins, DNA and lipids, which can aid in the pathogenesis of many disorders, including cancer. However, excessive concentrations of ROS can initiate programmed cell death in cancer. Presently, a variety of chemotherapeutic drugs and herbal agents are being investigated to induce ROS-mediated cell death in cancer. Therefore, preserving ROS homeostasis is essential for ensuring normal cell development and survival. On account of a significant association of ROS levels at various concentrations with carcinogenesis in a number of malignancies, further studies are needed to determine the underlying molecular mechanisms and develop the possibilities for intervening in these processes.

Low dimensional nanomaterials for treating acute kidney injury

Acute kidney injury (AKI) is one of the most common severe complications among hospitalized patients. In the absence of specific drugs to treat AKI, hemodialysis remains the primary clinical treatment for AKI patients. AKI treatment has received significant attention recently due to the excellent drug delivery capabilities of low-dimensional nanomaterials (LDNs) and their unique therapeutic effects. Diverse LDNs have been proposed to treat AKI, with promising results and the potential for future clinical application. This article aims to provide an overview of the pathogenesis of AKI and the recent advances in the treatment of AKI using different types of LDNs. In addition, it is intended to provide theoretical support for the design of LDNs and implications for AKI treatment.

Redox balance and autophagy regulation in cancer progression and their therapeutic perspective

Cellular ROS production participates in various cellular functions but its accumulation decides the cell fate. Malignant cells have higher levels of ROS and active antioxidant machinery, a characteristic hallmark of cancer with an outcome of activation of stress-induced pathways like autophagy. Autophagy is an intracellular catabolic process that produces alternative raw materials to meet the energy demand of cells and is influenced by the cellular redox state thus playing a definite role in cancer cell fate. Since damaged mitochondria are the main source of ROS in the cell, however, cancer cells remove them by upregulating the process of mitophagy which is known to play a decisive role in tumorigenesis and tumor progression. Chemotherapy exploits cell machinery which results in the accumulation of toxic levels of ROS in cells resulting in cell death by activating either of the pathways like apoptosis, necrosis, ferroptosis or autophagy in them. So understanding these redox and autophagy regulations offers a promising method to design and develop new cancer therapies that can be very effective and durable for years. This review will give a summary of the current therapeutic molecules targeting redox regulation and autophagy for the treatment of cancer. Further, it will highlight various challenges in developing anticancer agents due to autophagy and ROS regulation in the cell and insights into the development of future therapies.

Siderophore iucA of hypermucoviscous Klebsiella pneumoniae promotes liver damage in mice by inducing oxidative stress

The hypermucoviscosity/hypervirulent K. pneumoniae (hvKP) is a dominant cause of pyogenic liver abscess (PLA) and has contributed to the endemicity of disease in Asian country. The siderophore aerobactin (iucA) is highly expressed in hvKP and acting virulence role during hvKP infection. However, its role in the PLA is poorly understood. We constructed iucA deletion mutant (ΔiucA-hvKP852) and used animal study to characterize the role of siderophore iucA in K. pneumoniae liver abscess. The animal experiments showed that ΔiucA-hvKP852 strain had lower virulence in mice compared to hvKP852 wild type strain. At 24 h after infection, only two of ten mice developed liver abscess during infection with ΔiucA-hvKP852 strain, while nine of ten mice infected with wild type hvKP852 strain showed multiple lesions of liver abscess. The liver tissue infected with ΔiucA-hvKP852 exhibited low reactive oxygen stress levels compared to those infected by wild type hvKP852 strain (P < 0.05). The results suggest that siderophore iucA play an important role in the liver abscess by inducing oxidative stress.

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iucA positive strains produces more siderophore than iucA negative hvK. pneumoniae.

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Siderophore production is positively related with Oxidative stress in hvK. pneumoniae.

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iucA enhances oxidative stress in liver and forms liver abscess during hvK. pneumoniae infection.

Role of ROS‑mediated autophagy in melanoma (Review)

Melanoma is the most aggressive form of skin cancer with the poorest prognosis and its pathogenesis has yet to be fully elucidated. As key factors that regulate cellular homeostasis, both reactive oxygen species (ROS) and autophagy are involved in the development of melanoma, from melanomagenesis to progression and drug resistance. However, the interaction between ROS and autophagy in the etiology and treatment of melanoma is not well characterized. The present review examined the production of ROS and the role of oxidative stress in melanoma, and summarized the role of ROS‑mediated autophagy in melanomagenesis and melanoma cell fate decision following treatment with various anticancer drugs. The present findings may lead to a better understanding of the pathogenesis and progression of melanoma, and suggest promising treatment options for this disease.

Role of oxidative stress-mediated cell death and signaling pathways in experimental fluorosis

Free radicals and other oxidants have enticed the interest of researchers in the fields of biology and medicine, owing to their role in several pathophysiological conditions, including fluorosis (Fluoride toxicity). Radical species affect cellular biomolecules such as nucleic acids, proteins, and lipids, resulting in oxidative stress. Reactive oxygen species-mediated oxidative stress is a common denominator in fluoride toxicity. Fluorosis is a global health concern caused by excessive fluoride consumption over time. Fluoride alters the cellular redox homeostasis, and its toxicity leads to the activation of cell death mechanisms like apoptosis, autophagy, and necroptosis. Even though a surfeit of signaling pathways is involved in fluorosis, their toxicity mechanisms are not fully understood. Thus, this review aims to understand the role of reactive species in fluoride toxicity with an outlook on the effects of fluoride in vitro and in vivo models. Also, we emphasized the signal transduction pathways and the mechanism of cell death implicated in fluoride-induced oxidative stress.

Effect of starvation and refeeding on reactive oxygen species, autophagy and oxidative stress in Chinese perch (Siniperca chuatsi) muscle growth

In skeletal muscle, autophagy regulates the development and growth of muscle fibres and maintains the normal muscle metabolism. Under starvation and refeeding conditions, the effect of reactive oxygen species (ROS) levels on skeletal muscle autophagy is still unclear, although the excessive accumulation of ROS has been shown to increase autophagy in cells. The purpose of this study was to explore the effects of starvation and diet after starvation on the autophagy of adult Chinese perch muscle, and to determine the level of ROS in the muscle. We performed zero (Normal control), three and seven starvation treatments on adult Chinese perch, and returned to normal feeding for 3 days after starvation for 7 days. In the muscles of the adult Chinese perch muscle after 3 days of starvation, the autophagy marker protein LC3 and the number of autophagosomes remained basically the same as in the normal feeding situation. However, on starvation for 7 days, the mitochondrial autophagy was sensitive and the number of autophagosomes increased, but the antioxidant-related molecules (malondialdehyde, catalase, glutathione S-transferase, glutathione and anti-superoxide anion) decreased and the accumulation of ROS was obvious. In addition, the extended starvation time also increased the level of LC3 protein. However, by refeeding after starvation this nutritional stress resulted in a decrease in ROS levels and a partial restoration of antioxidant enzyme activity. Our data show that in the adult Chinese perch muscle, starvation could reduce the antioxidant activity through the accumulation of ROS, and that the number of autophagosomes continues to increase. Refeeding after starvation could effectively compensate for the level of ROS, and restore the mRNA abundance of antioxidant genes and the activity of antioxidant enzymes to reduce autophagy and improve feed efficiency. Further research should optimize starvation conditions to reduce autophagy in muscles and maintain normal muscle metabolism.

From Intestinal Epithelial Homeostasis to Colorectal Cancer: Autophagy Regulation in Cellular Stress

The intestinal epithelium is continuously exposed to abundant stress stimuli, which relies on an evolutionarily conserved process, autophagy, to maintain its homeostasis by degrading and recycling unwanted and damaged intracellular substances. Otherwise, disruption of this balance will result in the development of a wide range of disorders, including colorectal cancer (CRC). Dysregulated autophagy is implicated in the regulation of cellular responses to stress during the development, progression, and treatment of CRC. However, experimental investigations addressing the impact of autophagy in different phases of CRC have generated conflicting results, showing that autophagy is context-dependently related to CRC. Thus, both inhibition and activation of autophagy have been proposed as therapeutic strategies against CRC. Here, we will discuss the multifaceted role of autophagy in intestinal homeostasis and CRC, which may provide insights for future research directions.

The Role of Reactive Oxygen Species in the Rheumatoid Arthritis-Associated Synovial Microenvironment

Rheumatoid arthritis (RA) is an inflammatory disease that begins with a loss of tolerance to modified self-antigens and immune system abnormalities, eventually leading to synovitis and bone and cartilage degradation. Reactive oxygen species (ROS) are commonly used as destructive or modifying agents of cellular components or they act as signaling molecules in the immune system. During the development of RA, a hypoxic and inflammatory situation in the synovium maintains ROS generation, which can be sustained by increased DNA damage and malfunctioning mitochondria in a feedback loop. Oxidative stress caused by abundant ROS production has also been shown to be associated with synovitis in RA. The goal of this review is to examine the functions of ROS and related molecular mechanisms in diverse cells in the synovial microenvironment of RA. The strategies relying on regulating ROS to treat RA are also reviewed.

Crosstalk Between ROS and Autophagy in Tumorigenesis: Understanding the Multifaceted Paradox

Cancer formation is a highly regulated and complex process, largely dependent on its microenvironment. This complexity highlights the need for developing novel target-based therapies depending on cancer phenotype and genotype. Autophagy, a catabolic process, removes damaged and defective cellular materials through lysosomes. It is activated in response to stress conditions such as nutrient deprivation, hypoxia, and oxidative stress. Oxidative stress is induced by excess reactive oxygen species (ROS) that are multifaceted molecules that drive several pathophysiological conditions, including cancer. Moreover, autophagy also plays a dual role, initially inhibiting tumor formation but promoting tumor progression during advanced stages. Mounting evidence has suggested an intricate crosstalk between autophagy and ROS where they can either suppress cancer formation or promote disease etiology. This review highlights the regulatory roles of autophagy and ROS from tumor induction to metastasis. We also discuss the therapeutic strategies that have been devised so far to combat cancer. Based on the review, we finally present some gap areas that could be targeted and may provide a basis for cancer suppression.

Inhibition of Autophagy Facilitates XY03-EA-Mediated Neuroprotection against the Cerebral Ischemia/Reperfusion Injury in Rats

Objective. L-3-n-Butylphthalide (NBP) is used to treat moderate and severe acute ischemia stroke. A previous screening study indicates that XY03-EA, a novel derivative of NBP, is more potent than NBP in the oxyradical scavenging capacity. In this study, in vivo and in vitro ischemia/reperfusion (I/R) models were used to test whether the XY03-EA offered therapeutic benefits in the ischemic stroke and explore the underlying mechanism of action. Methods. For this purpose, behavioral scores, cerebral infarct volume, cerebral blood flow, oxidative stress levels, inflammatory factor expression, energy metabolism levels, and autophagy activation were estimated in the rat middle cerebral artery occlusion and reperfusion (MCAO/R) model. The nonhuman primate MCAO/R model was conducted to validate the therapeutic effect of XY03-EA applied for 3 weeks. The neurological deficit score (NDS) progression rate and the infarct volume were continuously recorded on days 3, 7, 14, and 21. The PC-12 cell OGD/R model was used to assess the cell survival rate, reactive oxygen species (ROS) levels, the expression of autophagy execution molecules, and the activation of autophagy-related signaling pathways. Results. XY03-EA decreased the cerebral injuries and NDS by increasing cerebral blood flow, improving brain energy metabolism, accelerating ROS clearance, suppressing inflammatory responses, and inhibiting autophagy in the MCAO/R model rats. In the nonhuman primate MCAO/R model, the treatment of XY03-EA for 3 weeks could significantly inhibit the NDS progression rate and indicate a positive trend to reduce the infarct volume in a dose-dependent way. Mechanistically, XY03-EA inhibited ROS-dependent autophagy activation and thereby protected the PC-12 cells from the autophagic cell death induced by OGD/R. Conclusions. In this study, we found that XY03-EA alleviated the cerebral I/R injuries in rats and nonhuman primates. Our results demonstrated that XY03-EA exerted neuroprotective effects against the ROS-mediated autophagic neurocyte death and had great potential for the treatment of ischemic stroke.

Mitochondrial Quality and Quantity Control: Mitophagy Is a Potential Therapeutic Target for Ischemic Stroke

Ischemic stroke is a cerebrovascular disease with high mortality and disability, which seriously affects the health and lives of people around the world. Effective treatment for ischemic stroke has been limited by its complex pathological mechanisms. Increasing evidence has indicated that mitochondrial dysfunction plays an essential role in the occurrence, development, and pathological processes of ischemic stroke. Therefore, strict control of the quality and quantity of mitochondria via mitochondrial fission and fusion as well as mitophagy is beneficial to the survival and normal function maintenance of neurons. Under certain circumstances, excessive mitophagy also could induce cell death. This review discusses the dynamic changes and double-edged roles of mitochondria and related signaling pathways of mitophagy in the pathophysiology of ischemic stroke. Furthermore, we focus on the possibility of modulating mitophagy as a potential therapy for the prevention and prognosis of ischemic stroke. Notably, we reviewed recent advances in the studies of natural compounds, which could modulate mitophagy and exhibit neuroprotective effects, and discussed their potential application in the treatment of ischemic stroke.

Autophagy in cancer: The cornerstone during glutamine deprivation

Over the past two decades, researchers have revealed the crucial functions of glutamine in supporting the hyperproliferation state of cancer cells. Glutamine acts on maintaining high energy production, supporting redox status and amino acid homeostasis. Therefore, cancer cells exhibit excessive uptake of the extracellular glutamine, synthesize it in some cases, and recycle intracellular and extracellular proteins to provide an additional source of glutamine to satisfy the increasing glutamine demand. On the other hand, autophagy's role is still debated regarding tumor initiation and progression. However, most cancer cells urgently need autophagy to overcome the existential threats during glutamine restriction stress. Downstream to various stress pathways induced during such a condition, autophagy is considered an indispensable cytoprotective tool to maintain cell integrity and survival. However, the overactivation of the autophagy process is related to lethal consequences. This review summarized glutamine pathways to control autophagy and highlighted autophagy's primary activation pathways, and discussed the roles during glutamine deprivation.

Understanding the Role of Autophagy in Cancer Formation and Progression Is a Real Opportunity to Treat and Cure Human Cancers

Simple Summary

The modulation of autophagy represents a potential therapeutic strategy for cancer. More than one hundred clinical trials have been conducted or are ongoing to explore the efficacy of autophagy modulators to reduce the tumor growth and potentiate the anti-cancer effects of conventional therapy. Despite this, the effective role of autophagy during tumor initiation, growth, and metastasis remains not well understood. Depending on the cancer type and stage of cancer, autophagy may have tumor suppressor properties as well as help cancer cells to proliferate and evade cancer therapy. The current review aims to summarize the current knowledge about the autophagy implications in cancer and report the therapeutic opportunities based on the modulation of the autophagy process.

Abstract

The malignant transformation of a cell produces the accumulation of several cellular adaptions. These changes determine variations in biological processes that are necessary for a cancerous cell to survive during stressful conditions. Autophagy is the main nutrient recycling and metabolic adaptor mechanism in eukaryotic cells, represents a continuous source of energy and biomolecules, and is fundamental to preserve the correct cellular homeostasis during unfavorable conditions. In recent decades, several findings demonstrate a close relationship between autophagy, malignant transformation, and cancer progression. The evidence suggests that autophagy in the cancer context has a bipolar role (it may act as a tumor suppressor and as a mechanism of cell survival for established tumors) and demonstrates that the targeting of autophagy may represent novel therapeutic opportunities. Accordingly, the modulation of autophagy has important clinical benefits in patients affected by diverse cancer types. Currently, about 30 clinical trials are actively investigating the efficacy of autophagy modulators to enhance the efficacy of cytotoxic chemotherapy treatments. A deeper understanding of the molecular pathways regulating autophagy in the cancer context will provide new ways to target autophagy for improving the therapeutic benefits. Herein, we describe how autophagy participates during malignant transformation and cancer progression, and we report the ultimate efforts to translate this knowledge into specific therapeutic approaches to treat and cure human cancers.

Establishment of an Autophagy-Related Clinical Prognosis Model for Predicting the Overall Survival of Osteosarcoma

Purpose

Osteosarcoma is the most common primary and highly invasive bone tumor in children and adolescents. The purpose of this study is to construct a multi-gene expression feature related to autophagy, which can be used to predict the prognosis of patients with osteosarcoma. Materials and methods. The clinical and gene expression data of patients with osteosarcoma were obtained from the target database. Enrichment analysis of autophagy-related genes related to overall survival (OS-related ARGs) screened by univariate Cox regression was used to determine OS-related ARGs function and signal pathway. In addition, the selected OS-related ARGs were incorporated into multivariate Cox regression to construct prognostic signature for the overall survival (OS) of osteosarcoma. Use the dataset obtained from the GEO database to verify the signature. Besides, gene set enrichment analysis (GSEA) were applied to further elucidate the molecular mechanisms. Finally, the nomogram is established by combining the risk signature with the clinical characteristics.

Results

Our study eventually included 85 patients. Survival analysis showed that patients with low riskScore had better OS. In addition, 16 genes were included in OS-related ARGs. We also generate a prognosis signature based on two OS-related ARGs. The signature can significantly divide patients into low-risk groups and high-risk groups, and has been verified in the data set of GEO. Subsequently, the riskScore, primary tumor site and metastasis status were identified as independent prognostic factors for OS and a nomogram were generated. The C-index of nomogram is 0.789 (95% CI: 0.703~0.875), ROC curve and calibration chart shows that nomogram has a good consistency between prediction and observation of patients.

Conclusions

ARGs was related to the prognosis of osteosarcoma and can be used as a biomarker of prognosis in patients with osteosarcoma. Nomogram can be used to predict OS of patients and improve treatment strategies.

Melatonin Attenuates Dextran Sodium Sulfate Induced Colitis in Obese Mice

Epidemiological studies have indicated that obesity is an independent risk factor for colitis and that a high-fat diet (HFD) increases the deterioration of colitis-related indicators in mice. Melatonin has multiple anti-inflammatory effects, including inhibiting tumor growth and regulating immune defense. However, the mechanism of its activity in ameliorating obesity-promoted colitis is still unclear. This study explored the possibility that melatonin has beneficial functions in HFD-induced dextran sodium sulfate (DSS)-induced colitis in mice. Here, we revealed that HFD-promoted obesity accelerated DSS-induced colitis, while melatonin intervention improved colitis. Melatonin significantly alleviated inflammation by increasing anti-inflammatory cytokine release and reducing the levels of proinflammatory cytokines in HFD- and DSS-treated mice. Furthermore, melatonin expressed antioxidant activities and reversed intestinal barrier integrity, resulting in improved colitis in DSS-treated obese mice. We also found that melatonin could reduce the ability of inflammatory cells to utilize fatty acids and decrease the growth-promoting effect of lipids by inhibiting autophagy. Taken together, our study indicates that the inhibitory effect of melatonin on autophagy weakens the lipid-mediated prosurvival advantage, which suggests that melatonin-targeted autophagy may provide an opportunity to prevent colitis in obese individuals.

Nitazoxanide impairs mitophagy flux through ROS-mediated mitophagy initiation and lysosomal dysfunction in bladder cancer

Bladder cancer is one of the most common malignancy in the urinary tract with high recurrence and drug resistance in clinics. Alternative treatments from existing drugs might be a promising strategy. Nitazoxanide (NTZ), an FDA-approved antiprotozoal drug, has got increasingly noticed because of its favorable safety profile and antitumor potential, yet the effects in bladder cancer and underlying mechanisms remain poorly understood. Herein, we find that NTZ induces mitochondrial damage and mitophagy initiation through PINK1-generated phospho-ubiquitin(pS65-Ub) and autophagy receptor-mediated pathway even in the absence of Atg5/Beclin1. Meanwhile, NTZ inhibits lysosomal degradation activity, leading to mitophagy flux impairment at late stage. Mitochondrial reactive oxygen species (ROS) production is critical in this process, as eliminating ROS with N-acetylcysteine (NAC) efficiently inhibits PINK1 signaling-mediated mitophagy initiation and alleviates lysosomal dysfunction. Co-treatment with NTZ and autophagy inhibitor Chloroquine (CQ) to aggravate mitophagy flux impairment promotes NTZ-induced apoptosis, while alleviation of mitophagy flux impairment with ROS scavenger reduces cell death. Moreover, we also discover a similar signaling response in the 3D bladder tumor spheroid after NTZ exposure. In vivo study reveals a significant inhibition of orthotopic bladder tumors with no obvious systemic toxicity. Together, our results uncover the anti-tumor activities of NTZ with the involvement of ROS-mediated mitophagy modulation at different stages and demonstrate it as a potential drug candidate for fighting against bladder tumors.

Cisplatin-induced hydroxyl radicals mediate pro-survival autophagy in human lung cancer H460 cells

Background

Accumulated evidence demonstrates cisplatin, a recommended chemotherapy, modulating pro-survival autophagic response that contributes to treatment failure in lung cancer patients. However, distinct mechanisms involved in cisplatin-induced autophagy in human lung cancer cells are still unclear.

Results

Herein, role of autophagy in cisplatin resistance was indicated by a decreased cell viability and increased apoptosis in lung cancer H460 cells pre-incubated with wortmannin, an autophagy inhibitor, prior to treatment with 50 µM cisplatin for 24 h. The elevated level of hydroxyl radicals detected via flow-cytometry corresponded to autophagic response, as evidenced by the formation of autophagosomes and autolysosomes in cisplatin-treated cells. Interestingly, apoptosis resistance, autophagosome formation, and the alteration of the autophagic markers, LC3-II/LC3-I and p62, as well as autophagy-regulating proteins Atg7 and Atg3, induced by cisplatin was abrogated by pretreatment of H460 cells with deferoxamine, a specific hydroxyl radical scavenger. The modulations in autophagic response were also indicated in the cells treated with hydroxyl radicals generated via Fenton reaction, and likewise inhibited by pretreatment with deferoxamine.

Conclusions

In summary, the possible role of hydroxyl radicals as a key mediator in the autophagic response to cisplatin treatment, which was firstly revealed in this study would benefit for the further development of novel therapies for lung cancer.

Pink1/PARK2/mROS-Dependent Mitophagy Initiates the Sensitization of Cancer Cells to Radiation

Autophagy plays a double-edged sword for cancer; particularly, mitophagy plays important roles in the selective degradation of damaged mitochondria. However, whether mitophagy is involved in killing effects of tumor cells by ionizing radiation (IR) and its underlying mechanism remain elusive. The purpose is to evaluate the effects of mitochondrial ROS (mROS) on autophagy after IR; furthermore, we hypothesized that KillerRed (KR) targeting mitochondria could induce mROS generation, subsequent mitochondrial depolarization, accumulation of Pink1, and recruitment of PARK2 to promote the mitophagy. Thereby, we would achieve a new strategy to enhance mROS accumulation and clarify the roles and mechanisms of radiosensitization by KR and IR. Our data demonstrated that IR might cause autophagy of both MCF-7 and HeLa cells, which is related to mitochondria and mROS, and the ROS scavenger N-acetylcysteine (NAC) could reduce the effects. Based on the theory, mitochondrial targeting vector sterile α- and HEAT/armadillo motif-containing protein 1- (Sarm1-) mtKR has been successfully constructed, and we found that ROS levels have significantly increased after light exposure. Furthermore, mitochondrial depolarization of HeLa cells was triggered, such as the decrease of Na⁺K⁺ ATPase, Ca²⁺Mg²⁺ ATPase, and mitochondrial respiratory complex I and III activities, and mitochondrial membrane potential (MMP) has significantly decreased, and voltage-dependent anion channel 1 (VDAC1) protein has significantly increased in the mitochondria. Additionally, HeLa cell proliferation was obviously inhibited, and the cell autophagic rates dramatically increased, which referred to the regulation of the Pink1/PARK2 pathway. These results indicated that mitophagy induced by mROS can initiate the sensitization of cancer cells to IR and might be regulated by the Pink1/PARK2 pathway.

Implications of Oxidative and Nitrosative Post-Translational Modifications in Therapeutic Strategies against Reperfusion Damage

Post-translational modifications based on redox reactions "switch on-off" the biological activity of different downstream targets, modifying a myriad of processes and providing an efficient mechanism for signaling regulation in physiological and pathological conditions. Such modifications depend on the generation of redox components, such as reactive oxygen species and nitric oxide. Therefore, as the oxidative or nitrosative milieu prevailing in the reperfused heart is determinant for protective signaling, in this review we defined the impact of redox-based post-translational modifications resulting from either oxidative/nitrosative signaling or oxidative/nitrosative stress that occurs during reperfusion damage. The role that cardioprotective conditioning strategies have had to establish that such changes occur at different subcellular levels, particularly in mitochondria, is also presented. Another section is devoted to the possible mechanism of signal delivering of modified proteins. Finally, we discuss the possible efficacy of redox-based therapeutic strategies against reperfusion damage.

Protection of melatonin against long-term radon exposure-caused lung injury

Radon is one of the major pathogenic factors worldwide. Recently, epidemiological studies have suggested that radon exposure plays an important role in lung injury, which could further cause cancer. However, the toxic effects and underlying mechanism on lung injury are still not clear. Here, we identified the detailed toxic effects of long-term radon exposure. Specifically, the manifestations were inflammatory response and cell apoptosis in dose- and time-dependent manners. In detail, it caused the mitochondrial dysfunction and oxidative stress as determined by the abnormal levels of mitochondrial DNA copy number, adenosine triphosphate, mitochondrial membrane potential, superoxide dismutase, and cycloxygenase-2. Furthermore, we found that melatonin treatment ameliorated mitochondrial dysfunction and attenuated the levels of oxidative stress caused by long-term radon exposure, which could further inhibit the lung tissue apoptosis as determined by the decreased levels of cleaved caspase 3. Our study would provide potential therapeutic application of melatonin on lung tissue injury caused by long-term radon exposure.

The critical role of FXR is associated with the regulation of autophagy and apoptosis in the progression of AKI to CKD

Autophagy is important for cells to break down and recycle cellular proteins, remove damaged organelles, and especially, for recovery from acute kidney injury (AKI). Despite research on the role and cellular mechanism of autophagy in AKI, the role of autophagy in the progression to chronic kidney disease (CKD) remains poorly understood. Here, using farnesoid X receptor (FXR) knockout (KO) mice, we determined whether FXR prevents the progression of AKI to CKD after renal ischemic-reperfusion (such as I/R) injury through the regulation of renal autophagy and apoptosis. FXR regulated genes that participate in renal autophagy under feeding and fasting conditions, such as hepatic autophagy, and the activation of FXR by agonists, such as GW4064 and INT-747, attenuated the increased autophagy and apoptosis of hypoxia-induced human renal proximal tubule epithelial (HK2) cells. The expression levels of autophagy-related and apoptosis-related proteins in FXR KO mice were increased compared with those in wild-type (WT) mice. We also showed that the increase in reactive oxidative species (ROS) in hypoxia-treated HK2 cells was attenuated by treatment with FXR agonist or by FXR overexpression, and that the level of ROS was elevated in FXR-deficient cells and mice. At 28 days after I/R injury, the autophagy levels were still elevated in FXR KO mice, and the expression levels of fibrosis-related proteins and ROS deposits were higher than those in WT mice. In conclusion, the regulation of renal autophagy and apoptosis by FXR may be a therapeutic target for the early stages of kidney damage, and the progression of AKI to CKD.

Mechanisms of Oxidative Stress and Therapeutic Targets following Intracerebral Hemorrhage

Oxidative stress (OS) is induced by the accumulation of reactive oxygen species (ROS) following intracerebral hemorrhage (ICH) and plays an important role in secondary brain injury caused by the inflammatory response, apoptosis, autophagy, and blood-brain barrier (BBB) disruption. This review summarizes the current state of knowledge regarding the pathogenic mechanisms of brain injury after ICH, markers for detecting OS, and therapeutic strategies that target OS to mitigate brain injury.

Coenzyme Q redox signalling and longevity

Mitochondria are the powerhouses of the cell. They produce a significant amount of the energy we need to grow, survive and reproduce. The same system that generates energy in the form of ATP also produces Reactive Oxygen Species (ROS). Mitochondrial Reactive Oxygen Species (mtROS) were considered for many years toxic by-products of metabolism, responsible for ageing and many degenerative diseases. Today, we know that mtROS are essential redox messengers required to determine cell fate and maintain cellular homeostasis. Most mtROS are produced by respiratory complex I (CI) and complex III (CIII). How and when CI and CIII produce ROS is determined by the redox state of the Coenzyme Q (CoQ) pool and the proton motive force (pmf) generated during respiration. During ageing, there is an accumulation of defective mitochondria that generate high levels of mtROS. This causes oxidative stress and disrupts redox signalling. Here, we review how mtROS are generated in young and old mitochondria and how CI and CIII derived ROS control physiological and pathological processes. Finally, we discuss why damaged mitochondria amass during ageing as well as methods to preserve mitochondrial redox signalling with age.

The Potent Antioxidant MitoQ Protects Against Preeclampsia During Late Gestation but Increases the Risk of Preeclampsia When Administered in Early Pregnancy

Aims: Although preeclampsia (PE) has been attributed to excessive oxidative stress (OS) in the placenta, mild antioxidants failed to prevent PE in clinical trials. As mitochondria are a major source of OS, this study assessed the potential of a potent mitochondria-targeting antioxidant MitoQ in the prevention of PE. Results: Placentas from women with PE and from reduced uterine perfusion pressure (RUPP) mice demonstrated significantly higher OS, along with increased mitochondrial damage and compromised glutathione peroxidase (GPx) activities. MitoQ administration during late gestation alleviated RUPP-induced PE; whereas early-pregnancy MitoQ treatment not only exacerbated blood pressure, fetal growth restriction, and proteinuria but also reduced the labyrinth/spongiotrophoblast ratio and blood sinuses in the labyrinth. Invasion (Matrigel transwell) and migration (wound healing assay) of trophoblasts were greatly improved by 1 μM hydrogen peroxide (H₂O₂), but this improvement was abolished by MitoQ or MitoTempo. Mild OS enhanced the expression of miR-29b-3p, which regulates five genes involved in viability and mobility, in HTR8-S/Vneo cells. Innovation and Conclusions: Although the potent mitochondrial-targeting antioxidant MitoQ protects against hypertension and kidney damage induced by RUPP in mice when administered in late gestation, it exacerbates the PE-like phenotype when given in early gestation by interfering with placenta formation because mild OS is required to stimulate trophoblast proliferation, invasion, and migration. Eliminating trophoblastic OS during early pregnancy may lead to compromised placentation and a risk of diseases of placental origin. Therefore, antioxidant therapy for pregnant women should be carefully considered.

Autophagy and heat: a potential role for heat therapy to improve autophagic function in health and disease

Autophagy is a crucial cell survival mechanism that involves the degradation and recycling of old or damaged organelles and proteins to maintain cellular homeostasis. Impairments in autophagy are central to the pathogenesis of many conditions including metabolic and neurodegenerative disorders, cardiovascular and pulmonary diseases, diabetes, and aging. Although various pharmacological agents may be able to stimulate autophagic function, to our knowledge, few interventions exist that have been deemed safe and effective in humans. An emerging body of evidence suggests that targeting the autophagic pathway via passive heating (heat therapy) may stimulate autophagic function. Therefore, the primary focus of the present review is to analyze the mechanisms in which passive heating induces autophagy as defined by in vitro and in vivo (animal and human) models. Our secondary focus is to examine the implications of utilizing passive heating to restore dysfunctional autophagy in chronic disease and aging. Finally, we discuss potential therapeutic strategies to implement passive heating to stimulate autophagic function in humans.

Antioxidants Targeting Mitochondrial Oxidative Stress: Promising Neuroprotectants for Epilepsy

Mitochondria are major sources of reactive oxygen species (ROS) within the cell and are especially vulnerable to oxidative stress. Oxidative damage to mitochondria results in disrupted mitochondrial function and cell death signaling, finally triggering diverse pathologies such as epilepsy, a common neurological disease characterized with aberrant electrical brain activity. Antioxidants are considered as promising neuroprotective strategies for epileptic condition via combating the deleterious effects of excessive ROS production in mitochondria. In this review, we provide a brief discussion of the role of mitochondrial oxidative stress in the pathophysiology of epilepsy and evidences that support neuroprotective roles of antioxidants targeting mitochondrial oxidative stress including mitochondria-targeted antioxidants, polyphenols, vitamins, thiols, and nuclear factor E2-related factor 2 (Nrf2) activators in epilepsy. We point out these antioxidative compounds as effectively protective approaches for improving prognosis. In addition, we specially propose that these antioxidants exert neuroprotection against epileptic impairment possibly by modulating cell death interactions, notably autophagy-apoptosis, and autophagy-ferroptosis crosstalk.

Detrimental and Beneficial Effect of Autophagy and a Potential Therapeutic Target after Ischemic Stroke

Autophagy, a physiologic mechanism that promotes energy recycling and orderly degradation through self-regulated disassembly of cellular components, helps maintain homeostasis. A series of evidences suggest that autophagy is activated as a response to ischemia and has been well-characterized as a therapeutic target. However, the role of autophagy after ischemia remains controversial. Activated-autophagy can remove necrotic substances against ischemic injury to promote cell survival. On the contrary, activation of autophagy may further aggravate ischemic injury, causing cell death. Therefore, the present review will examine the current understanding of the precise mechanism and role of autophagy in ischemia and recent neuroprotective therapies on autophagy, drug therapies, and nondrug therapies, including electroacupuncture (EA).

Redox Post-translational Modifications of Protein Thiols in Brain Aging and Neurodegenerative Conditions-Focus on S-Nitrosation

Reactive oxygen species and reactive nitrogen species (RONS) are by-products of aerobic metabolism. RONS trigger a signaling cascade that can be transduced through oxidation-reduction (redox)-based post-translational modifications (redox PTMs) of protein thiols. This redox signaling is essential for normal cellular physiology and coordinately regulates the function of redox-sensitive proteins. It plays a particularly important role in the brain, which is a major producer of RONS. Aberrant redox PTMs of protein thiols can impair protein function and are associated with several diseases. This mini review article aims to evaluate the role of redox PTMs of protein thiols, in particular S-nitrosation, in brain aging, and in neurodegenerative diseases. It also discusses the potential of using redox-based therapeutic approaches for neurodegenerative conditions.

Oxidative Inactivation of the Proteasome Augments Alveolar Macrophage Secretion of Vesicular SOCS3

Extracellular vesicles (EVs) contain a diverse array of molecular cargoes that alter cellular phenotype and function following internalization by recipient cells. In the lung, alveolar macrophages (AMs) secrete EVs containing suppressor of cytokine signaling 3 (SOCS3), a cytosolic protein that promotes homeostasis via vesicular transfer to neighboring alveolar epithelial cells. Although changes in the secretion of EV molecules-including but not limited to SOCS3-have been described in response to microenvironmental stimuli, the cellular and molecular machinery that control alterations in vesicular cargo packaging remain poorly understood. Furthermore, the use of quantitative methods to assess the sorting of cytosolic cargo molecules into EVs is lacking. Here, we utilized cigarette smoke extract (CSE) exposure of AMs as an in vitro model of oxidative stress to address these gaps in knowledge. We demonstrate that the accumulation of reactive oxygen species (ROS) in AMs was sufficient to augment vesicular SOCS3 release in this model. Using nanoparticle tracking analysis (NTA) in tandem with a new carboxyfluorescein succinimidyl ester (CFSE)-based intracellular protein packaging assay, we show that the stimulatory effects of CSE were at least in part attributable to elevated amounts of SOCS3 packaged per EV secreted by AMs. Furthermore, the use of a 20S proteasome activity assay alongside treatment of AMs with conventional proteasome inhibitors strongly suggest that ROS stimulated SOCS3 release via inactivation of the proteasome. These data demonstrate that tuning of AM proteasome function by microenvironmental oxidants is a critical determinant of the packaging and secretion of cytosolic SOCS3 protein within EVs.

Oxidative damage under As3+ and/or Cu2+ stress leads to apoptosis and autophagy and may be cross-talking with mitochondrial disorders in bursa of Fabricius

Arsenic (As) exists in many forms in the whole natural environment, with As³⁺ the highest toxicity. Herein our study demonstrated that arsenic trioxide (As₂O₃) at a dose of 30 mg/kg caused serious oxidative damage to chickens' bursa of Fabricius (BF) in a time-dependent manner. Copper (Cu) is a necessary micronutrient and a key catalytic cofactor of many enzymes. We found excessive Cu (in the form of 300 mg/kg copper sulfate (CuSO₄)) also induced severe oxidative stress (OxS), and its co-exposure with As³⁺ had a greater destructive power against oxidative system. Under electron microscope, swollen mitochondria, disappeared cristae and agglutinated chromatin were observed, accompanied by myeloid structure and autophagosome. The results showed apoptosis and autophagy occurred under the action of As³⁺ and Cu²⁺, and the situation was more serious in combined exposure group, which was further explained by terminal deoxynucleotidyl transferase (TdT)-mediated 2'-Deoxyuridine 5'-Triphosphate (dUTP) Nick-End Labeling (TUNEL). By quantitative real time polymerase chain reaction (RT-qPCR) and western blot, we found that mitochondrial dynamics were disordered under OxS, and the abnormal changes of B-cell lymphoma (Bcl)-2, p53, Bcl-2-interacting protein (Beclin)-1 and autophagy-related gene (ATG) 4B indicated the crosstalk between apoptosis and autophagy. In conclusion, apoptosis and autophagy of BF induced by As³⁺ and Cu²⁺ and mitochondrial disorder are closely related to the collapse of antioxidant system, and their connections are inseparable. Our results provide a reference for environmental risk prevention and selection of poultry feed additives and pesticides to avoid the health risks caused by As³⁺ and Cu²⁺ exposure.

Self-correction prevents withdrawal syndrome

The scientific research paper remains the primary mode for documenting scholarly achievement in a stable, citable manner, yet the toolkit that allows for changes and corrections to research papers limits the optimal dissemination of reliable research findings.