Regulation of mammalian autophagy in physiology and pathophysiology

Rosmarinic acid activates the Ras/Raf/MEK/ERK signaling pathway to regulate CD8+ T cells and autophagy to clear Chlamydia trachomatis in reproductive tract-infected mice

Chlamydia trachomatis (CT) is the leading cause of bacterial sexually transmitted diseases worldwide, which can cause diseases such as pelvic inflammatory disease, and cervical and fallopian tube inflammation, and poses a threat to human health. Rosmarinic acid (RosA) is an active ingredient of natural products with anti-inflammatory and immunomodulatory effects. This study aimed to investigate the role of RosA in inhibiting autophagy-regulated immune cells-CD8+ T cells via the Ras/Raf/MEK/ERK signaling pathway in a CT-infected mouse model. Mice were inoculated with CT infection solution vaginally, and the mechanistic basis of RosA treatment was established using H&E staining, flow cytometry, immunofluorescence, transmission electron microscopy, and western blot. The key factors involved in RosA treatment were further validated using the MEK inhibitor cobimetinib. Experimental results showed that both RosA and the reference drug azithromycin could attenuate the pathological damage to the endometrium caused by CT infection; flow cytometry showed that peripheral blood CD8+ T cells increased after CT infection and decreased after treatment with RosA and the positive drug azithromycin (positive control); immunofluorescence showed that endometrial CD8 and LC3 increased after CT infection and decreased after RosA and positive drug treatment; the results of transmission electron microscopy showed that RosA and the positive drug azithromycin inhibited the accumulation of autophagosomes; western bolt experiments confirmed the activation of autophagy proteins LC3Ⅱ/Ⅰ, ATG5, Beclin-1, and p62 after CT infection, as well as the inhibition of Ras/Raf/MEK/ERK signaling. RosA and azithromycin inhibition of autophagy proteins activates Ras/Raf/MEK/ERK signaling. In addition, the MEK inhibitor cobimetinib attenuated RosA's protective effect on endometrium by further activating CD8+ T cells on a CT-induced basis, while transmission electron microscopy, immunofluorescence, and western blots showed that cobimetinib blocked ERK signals activation and further induced phagocytosis on a CT-induced basis. These data indicated that RosA can activate the Ras/Raf/MEK/ERK signaling pathway to inhibit autophagy, and RosA could also regulate the activation of immune cells-CD8+T cells to protect the reproductive tract of CT-infected mice.

Management of ROS and Regulatory Cell Death in Myocardial Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion injury (MIRI) is fatal to patients, leading to cardiomyocyte death and myocardial remodeling. Reactive oxygen species (ROS) and oxidative stress play important roles in MIRI. There is a complex crosstalk between ROS and regulatory cell deaths (RCD) in cardiomyocytes, such as apoptosis, pyroptosis, autophagy, and ferroptosis. ROS is a double-edged sword. A reasonable level of ROS maintains the normal physiological activity of myocardial cells. However, during myocardial ischemia-reperfusion, excessive ROS generation accelerates myocardial damage through a variety of biological pathways. ROS regulates cardiomyocyte RCD through various molecular mechanisms. Targeting the removal of excess ROS has been considered an effective way to reverse myocardial damage. Many studies have applied antioxidant drugs or new advanced materials to reduce ROS levels to alleviate MIRI. Although the road from laboratory to clinic has been difficult, many scholars still persevere. This article reviews the molecular mechanisms of ROS inhibition to regulate cardiomyocyte RCD, with a view to providing new insights into prevention and treatment strategies for MIRI.

Gypenoside XLIX alleviates intestinal injury by inhibiting sepsis-induced inflammation, oxidative stress, apoptosis, and autophagy

Intestinal barrier dysfunction is a significant complication induced by sepsis, yet therapeutic strategies targeting such dysfunction remain inadequate. This study investigates the protective effects of Gypenoside XLIX (Gyp XLIX) against intestinal damage induced by sepsis. Septic intestinal injury in mice was induced by cecum ligation and puncture (CLP) surgery. The biological activity and potential mechanisms of Gyp XLIX were explored through intraperitoneal injection of Gyp XLIX (40 mg/kg). The study demonstrates that Gyp XLIX improves the pathological structural damage of the intestine and increases tight junction protein expression as well as the number of cup cells. Through activation of the nuclear factor erythroid 2-related factor 2 - Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathway, Gyp XLIX enhances antioxidant enzyme levels while reducing the excessive accumulation of reactive oxygen species (ROS). In addition, Gyp XLIX effectively alleviates sepsis-induced intestinal inflammation by inhibiting the nuclear factor kappa B (NF-κB) pathway and activation of the NLRP3 inflammasome. Moreover, Gyp XLIX inhibits cell death through modifying phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, further enhancing its ability to shield the intestinal barrier. The combined action of these molecular mechanisms promotes the restoration of immune balance and reduces excessive autophagy activity induced under septic conditions. In summary, Gyp XLIX exhibits a significant preventive action against intestinal damage brought on by sepsis, with its mechanisms involving the improvement of intestinal barrier function, antioxidative stress, inhibition of inflammatory response, and cell apoptosis. This research offers a potential strategy for addressing intestinal barrier impairment brought on by sepsis.

The Role of Anti-Müllerian Hormone in Ovarian Function

Anti-Müllerian hormone (AMH) is a member of the transforming growth factor β (TGFβ) superfamily, whose actions are restricted to the endocrine-reproductive system. Initially known for its role in male sex differentiation, AMH plays a role in the ovary, acting as a gatekeeper in folliculogenesis by regulating the rate of recruitment and growth of follicles. In the ovary, AMH is predominantly expressed by granulosa cells of preantral and antral follicles (i.e., post primordial follicle recruitment and prior to follicle-stimulating hormone (FSH) selection). AMH signals through a BMP-like signaling pathway in a manner distinct from other TGFβ family members. In this review, the latest insights in AMH processing, signaling, its regulation of spatial and temporal expression pattern, and functioning in folliculogenesis are summarized. In addition, effects of AMH variants on ovarian function are reviewed.

Skeletal muscle atrophy after sciatic nerve damage: Mechanistic insights

Sciatic nerve injury leads to molecular events that cause muscular dysfunction advancement in atrophic conditions. Nerve damage renders muscles permanently relaxed which elevates intracellular resting Ca2+ levels. Increased Ca2+ levels are associated with several cellular signaling pathways including AMPK, cGMP, PLC-β, CERB, and calcineurin. Also, multiple enzymes involved in the tricarboxylic acid cycle and oxidative phosphorylation are activated by Ca2+ influx into mitochondria during muscle contraction, to meet increased ATP demand. Nerve damage induces mitophagy and skeletal muscle atrophy through increased sensitivity to Ca2+-induced opening of the permeability transition pore (PTP) in mitochondria attributed to Ca2+, ROS, and AMPK overload in muscle. Activated AMPK interacts negatively with Akt/mTOR is a highly prevalent and well-described central pathway for anabolic processes. Over the decade several reports indicate abnormal behavior of signaling machinery involved in denervation-induced muscle loss but end up with some controversial outcomes. Therefore, understanding how the synthesis and inhibitory stimuli interact with cellular signaling to control muscle mass and morphology may lead to new pharmacological insights toward understanding the underlying mechanism of muscle loss after sciatic nerve damage. Hence, the present review summarizes the existing literature on denervation-induced muscle atrophy to evaluate the regulation and expression of differential regulators during sciatic damage.

Atmospheric fine particulate matter (PM2.5) induces pulmonary fibrosis by regulating different cell fates via autophagy

The presence of respiratory diseases demonstrates a positive correlation with atmospheric fine particulate matter (PM2.5) exposure. The respiratory system is the main target organ affected by PM2.5, and exposure to PM2.5 elevates the likelihood of developing pulmonary fibrosis (PF). In this study, lung epithelial cell (BEAS-2B) and fibroblast (NIH-3T3) were used as in vitro exposure models to explore the mechanisms of PF. PM2.5 exposure caused mitochondrial damage in BEAS-2B cells and increased a fibrotic phenotype in NIH-3T3 cells. Epithelial cells and fibroblasts have different fates after PM2.5 exposure due to their different sensitivities to trigger autophagy. Exposure to PM2.5 inhibits mitophagy in BEAS-2B cells, which hinders the removal of damaged mitochondria and triggers cell death. In this process, the nuclear retention of the mitophagy-related protein Parkin prevents it from being recruited to mitochondria, resulting in mitophagy inhibition. In contrast, fibroblasts exhibit increased levels of autophagy, which may isolate PM2.5 and cause abnormal fibroblast proliferation and migration. Fibrotic phenotypes such as collagen deposition and increased α-actin also appear in fibroblasts. Our results identify PM2.5 as a trigger of PF and delineate the molecular mechanism of autophagy in PM2.5 induced PF, which provides new insights into the pulmonary injury.

Effects of sevoflurane on lung alveolar epithelial wound healing and survival in a sterile in vitro model of acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a serious lung condition that often leads to hospitalization in intensive care units and a high mortality rate. Sevoflurane is a volatile anesthetic with growing interest for sedation in ventilated patients with ARDS. It has been shown to have potential lung-protective effects, such as reduced inflammation and lung edema, or improved arterial oxygenation. In this study, we investigated the effects of sevoflurane on lung injury in cultured human carcinoma-derived lung alveolar epithelial (A549) cells. We found that sevoflurane was associated with improved wound healing after exposure to inflammatory cytokines, with preserved cell proliferation but no effect on cell migration properties. Sevoflurane exposure was also associated with enhanced cell viability and active autophagy in A549 cells exposed to cytokines. These findings suggest that sevoflurane may have beneficial effects on lung epithelial injury by promoting alveolar epithelial wound healing and by influencing the survival and proliferation of A549 epithelial cells in vitro. Further research is needed to confirm these findings and to investigate the key cellular mechanisms explaining sevoflurane's potential effects on lung epithelial injury.

The involvement of ROS-regulated programmed cell death in hepatocellular carcinoma

Reactive oxidative species (ROS) is a crucial factor in the regulation of cellular biological activity and function, and aberrant levels of ROS can contribute to the development of a variety of diseases, particularly cancer. Numerous discoveries have affirmed that this process is strongly associated with "programmed cell death (PCD)," which refers to the suicide protection mechanism initiated by cells in response to external stimuli, such as apoptosis, autophagy, ferroptosis, etc. Research has demonstrated that ROS-induced PCD is crucial for the development of hepatocellular carcinoma (HCC). These activities serve a dual function in both facilitating and inhibiting cancer, suggesting the existence of a delicate balance within healthy cells that can be disrupted by the abnormal generation of reactive oxygen species (ROS), thereby influencing the eventual advancement or regression of a tumor. In this review, we summarize how ROS regulates PCD to influence the tumorigenesis and progression of HCC. Studying how ROS-induced PCD affects the progression of HCC at a molecular level can help develop better prevention and treatment methods and facilitate the design of more effective preventative and therapeutic strategies.

Autophagy, a double-edged sword for oral tissue regeneration

BACKGROUND

Oral health is of fundamental importance to maintain systemic health in humans. Stem cell-based oral tissue regeneration is a promising strategy to achieve the recovery of impaired oral tissue. As a highly conserved process of lysosomal degradation, autophagy induction regulates stem cell function physiologically and pathologically. Autophagy activation can serve as a cytoprotective mechanism in stressful environments, while insufficient or over-activation may also lead to cell function dysregulation and cell death.

AIM OF REVIEW

This review focuses on the effects of autophagy on stem cell function and oral tissue regeneration, with particular emphasis on diverse roles of autophagy in different oral tissues, including periodontal tissue, bone tissue, dentin pulp tissue, oral mucosa, salivary gland, maxillofacial muscle, temporomandibular joint, etc. Additionally, this review introduces the molecular mechanisms involved in autophagy during the regeneration of different parts of oral tissue, and how autophagy can be regulated by small molecule drugs, biomaterials, exosomes/RNAs or other specific treatments. Finally, this review discusses new perspectives for autophagy manipulation and oral tissue regeneration.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Overall, this review emphasizes the contribution of autophagy to oral tissue regeneration and highlights the possible approaches for regulating autophagy to promote the regeneration of human oral tissue.

Interplay of mitochondria-associated membrane proteins and autophagy: Implications in neurodegeneration

Since the discovery of membrane contact sites between ER and mitochondria called mitochondria-associated membranes (MAMs), several pieces of evidence identified their role in the regulation of different cellular processes such as Ca2+ signalling, mitochondrial transport, and dynamics, ER stress, inflammation, glucose homeostasis, and autophagy. The integrity of these membranes was found to be essential for the maintenance of these cellular functions. Accumulating pieces of evidence suggest that MAMs serve as a platform for autophagosome formation. However, the alteration within MAMs structure is associated with the progression of neurodegenerative diseases. Dysregulated autophagy is a hallmark of neurodegeneration. Here, in this review, we highlight the present knowledge on MAMs, their structural composition, and their roles in different cellular functions. We also discuss the association of MAMs proteins with impaired autophagy and their involvement in the progression of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.

Corydaline alleviates Parkinson's disease by regulating autophagy and GSK-3β phosphorylation

BACKGROUND

Jitai tablet, a traditional Chinese medicine, has a neuroprotective effect on 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mice. As one of the main active ingredients in the Jitai tablet, corydaline (Cory) has analgesic and anti-allergic effects, but it has not been studied in PD. Here, we investigated the role and mechanism of Cory in PD.

METHODS

The PD model was induced by MPTP. Cell viability was measured by 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide assay. The Pole test and traction test were performed to detect the behaviors of mice. The expression of tyrosine hydroxylase (Th) was detected by immunohistochemistry and Western blot. Immunofluorescence staining, monodansylcadaverine staining, and Western blot were conducted to assess autophagy. A lactic dehydrogenase release assay was used to detect cytotoxicity. Network pharmacology was used to screen the targets.

RESULTS

There existed cytotoxicity when the concentration of Cory reached 40 μg/mL. Cory (not exceeding 20 μg/mL) could alleviate MPTP-induced cell damage. In vivo experiments indicated that Cory could improve the motor coordination of mice with PD. Besides, Cory could increase LC3-II/LC3-I levels both in vivo and in vitro. In addition, the Th levels reduced in the striatum and middle brain tissues of Parkinson's mice were recovered by Cory injection. We also found that Cory decreased the phosphorylation of glucogen synthase kinase-3 beta (GSK-3β) at Tyr216 and increased the phosphorylation of GSK-3β at Ser9 not only in primary neurons and SH-SY5Y cells but also in the striatum and middle brain tissues. Furthermore, Cory increased LC3-II/LC3-I levels and decreased p62 levels by regulating GSK-3β.

CONCLUSION

Cory enhanced autophagy, attenuated MPTP-induced cytotoxicity, and alleviated PD partly through the regulation of GSK-3β phosphorylation.

Antioxidants activities of phytochemicals perspective modulation of autophagy and apoptosis to treating cancer

The study of chemicals extracted from natural sources should be encouraged due to the significant number of cancer deaths each year and the financial burden imposed by this disease on society. The causes of almost all cancers involve a combination of lifestyle, environmental factors, and genetic and inherited factors. Modern medicine researchers are increasingly interested in traditional phytochemicals as they hold potential for new bioactive compounds with medical applications. Recent publications have provided evidence of the antitumor properties of phytochemicals, a key component of traditional Chinese medicine, thereby opening new avenues for their use in modern medicine. Various studies have demonstrated a strong correlation between apoptosis and autophagy, two critical mechanisms involved in cancer formation and regulation, indicating diverse forms of crosstalk between them. Phytochemicals have the ability to activate both pro-apoptotic and pro-autophagic pathways. Therefore, understanding how phytochemicals influence the relationship between apoptosis and autophagy is crucial for developing a new cancer treatment strategy that targets these molecular mechanisms. This review aims to explore natural phytochemicals that have demonstrated anticancer effects, focusing on their role in regulating the crosstalk between apoptosis and autophagy, which contributes to uncontrolled tumor cell growth. Additionally, the review highlights the limitations and challenges of current research methodologies while suggesting potential avenues for future research in this field.

The multifaceted role of autophagy in skin autoimmune disorders: a guardian or culprit?

Autophagy is a cellular process that functions to maintain intracellular homeostasis via the degradation and recycling of defective organelles or damaged proteins. This dynamic mechanism participates in various biological processes, such as the regulation of cellular differentiation, proliferation, survival, and the modulation of inflammation and immune responses. Recent evidence has demonstrated the involvement of polymorphisms in autophagy-related genes in various skin autoimmune diseases. In addition, autophagy, along with autophagy-related proteins, also contributes to homeostasis maintenance and immune regulation in the skin, which is associated with skin autoimmune disorders. This review aims to provide an overview of the multifaceted role of autophagy in skin autoimmune diseases and shed light on the potential of autophagy-targeting therapeutic strategies in dermatology.

Mechanism of Decision Making between Autophagy and Apoptosis Induction upon Endoplasmic Reticulum Stress

Dynamic regulation of the cellular proteome is mainly controlled in the endoplasmic reticulum (ER). Accumulation of misfolded proteins due to ER stress leads to the activation of unfolded protein response (UPR). The primary role of UPR is to reduce the bulk of damages and try to drive back the system to the former or a new homeostatic state by autophagy, while an excessive level of stress results in apoptosis. It has already been proven that the proper order and characteristic features of both surviving and self-killing mechanisms are controlled by negative and positive feedback loops, respectively. The new results suggest that these feedback loops are found not only within but also between branches of the UPR, fine-tuning the response to ER stress. In this review, we summarize the recent knowledge of the dynamical characteristic of endoplasmic reticulum stress response mechanism by using both theoretical and molecular biological techniques. In addition, this review pays special attention to describing the mechanism of action of the dynamical features of the feedback loops controlling cellular life-and-death decision upon ER stress. Since ER stress appears in diseases that are common worldwide, a more detailed understanding of the behaviour of the stress response is of medical importance.

Lysosomal storage, impaired autophagy and innate immunity in Gaucher and Parkinson's diseases: insights for drug discovery

Impairment of autophagic-lysosomal pathways is increasingly being implicated in Parkinson's disease (PD). GBA1 mutations cause the lysosomal storage disorder Gaucher disease (GD) and are the commonest known genetic risk factor for PD. GBA1 mutations have been shown to cause autophagic-lysosomal impairment. Defective autophagic degradation of unwanted cellular constituents is associated with several pathologies, including loss of normal protein homeostasis, particularly of α-synuclein, and innate immune dysfunction. The latter is observed both peripherally and centrally in PD and GD. Here, we will discuss the mechanistic links between autophagy and immune dysregulation, and the possible role of these pathologies in communication between the gut and brain in these disorders. Recent work in a fly model of neuronopathic GD (nGD) revealed intestinal autophagic defects leading to gastrointestinal dysfunction and immune activation. Rapamycin treatment partially reversed the autophagic block and reduced immune activity, in association with increased survival and improved locomotor performance. Alterations in the gut microbiome are a critical driver of neuroinflammation, and studies have revealed that eradication of the microbiome in nGD fly and mouse models of PD ameliorate brain inflammation. Following these observations, lysosomal-autophagic pathways, innate immune signalling and microbiome dysbiosis are discussed as potential therapeutic targets in PD and GD. This article is part of a discussion meeting issue 'Understanding the endo-lysosomal network in neurodegeneration'.

Chronic Rapamycin administration via drinking water mitigates the pathological phenotype in a Krabbe disease mouse model through autophagy activation

Krabbe disease (KD) is a rare disorder arising from the deficiency of the lysosomal enzyme galactosylceramidase (GALC), leading to the accumulation of the cytotoxic metabolite psychosine (PSY) in the nervous system. This accumulation triggers demyelination and neurodegeneration, and despite ongoing research, the underlying pathogenic mechanisms remain incompletely understood, with no cure currently available. Previous studies from our lab revealed the involvement of autophagy dysfunctions in KD pathogenesis, showcasing p62-tagged protein aggregates in the brains of KD mice and heightened p62 levels in the KD sciatic nerve. We also demonstrated that the autophagy inducer Rapamycin (RAPA) can partially reinstate the wild type (WT) phenotype in KD primary cells by decreasing the number of p62 aggregates. In this study, we tested RAPA in the Twitcher (TWI) mouse, a spontaneous KD mouse model. We administered the drug ad libitum via drinking water (15 mg/L) starting from post-natal day (PND) 21-23. We longitudinally monitored the mouse motor performance through grip strength and rotarod tests, and a set of biochemical parameters related to the KD pathogenesis (i.e. autophagy markers expression, PSY accumulation, astrogliosis and myelination). Our findings demonstrate that RAPA significantly enhances motor functions at specific treatment time points and reduces astrogliosis in TWI brain, spinal cord, and sciatic nerves. Utilizing western blot and immunohistochemistry, we observed a decrease in p62 aggregates in TWI nervous tissues, corroborating our earlier in-vitro results. Moreover, RAPA treatment partially removes PSY in the spinal cord. In conclusion, our results advocate for considering RAPA as a supportive therapy for KD. Notably, as RAPA is already available in pharmaceutical formulations for clinical use, its potential for KD treatment can be rapidly evaluated in clinical trials.

Effects of ambient UVB light on Pacific oyster Crassostrea gigas mantle tissue based on multivariate data

Ambient ultraviolet radiation (UVB) from solar and artificial light presents serious environmental risks to aquatic ecosystems. The Pacific oyster, Crassostrea gigas, perceives changes in the external environment primarily through its mantle tissue, which contains many nerve fibers and tentacles. Changes within the mantles can typically illustrate the injury of ambient UVB. In this study, a comprehensive analysis of phenotypic, behavioral, and physiological changes demonstrated that extreme UVB radiation (10 W/m²) directly suppressed the behavioral activities of C. gigas. Conversely, under ambient UVB radiation (5 W/m²), various physiological processes exhibited significant alterations in C. gigas, despite the behavior remaining relatively unaffected. Using mathematical model analysis, the integrated analysis of the full-length transcriptome, proteome, and metabolome showed that ambient UVB significantly affected the metabolic processes (saccharide, lipid, and protein metabolism) and cellular biology processes (autophagy, apoptosis, oxidative stress) of the C. gigas mantle. Subsequently, using Procrustes analysis and Pearson correlation analysis, the association between multi-omics data and physiological changes, as well as their biomarkers, revealed the effect of UVB on three crucial biological processes: activation of autophagy signaling (key factors: Ca2+, LC3B, BECN1, caspase-7), response to oxidative stress (reactive oxygen species, heat shock 70, cytochrome c oxidase), and recalibration of energy metabolism (saccharide, succinic acid, translation initiation factor IF-2). These findings offer a fresh perspective on the integration of multi-data from non-model animals in ambient UVB risk assessment.

Anti-Müllerian hormone induces autophagy to preserve the primordial follicle pool in mice

The reserve pool of primordial follicles (PMFs) is finely regulated by molecules implicated in follicular growth or PMF survival. Anti-Müllerian hormone (AMH), produced by granulosa cells of growing follicles, is known for its inhibitory role in the initiation of PMF growth. We observed in a recent in vivo study that injection of AMH into mice seemed to induce an activation of autophagy. Furthermore, injection of AMH into mice activates the transcription factor FOXO3A which is also known for its implication in autophagy regulation. Many studies highlighted the key role of autophagy in the ovary at different stages of folliculogenesis, particularly in PMF survival. Through an in vitro approach with organotypic cultures of prepubertal mouse ovaries, treated or not with AMH, we aimed to understand the link among AMH, autophagy, and FOXO3A transcription factor. Autophagy and FOXO3A phosphorylation were analyzed by western blot. The expression of genes involved in autophagy was quantified by RT-qPCR. In our in vitro model, we confirmed the decrease in FOXO3A phosphorylation and the induction of autophagy in ovaries incubated with AMH. AMH also induces the expression of genes involved in autophagy. Interestingly, most of these genes are known to be FOXO3A target genes. In conclusion, we have identified a new role for AMH, namely the induction of autophagy, probably through FOXO3A activation. Thus, AMH protects the ovarian reserve not only by inhibiting the growth of PMFs but also by enabling their survival through activation of autophagy.

The Mitochondrial Connection: The Nek Kinases' New Functional Axis in Mitochondrial Homeostasis

Mitochondria provide energy for all cellular processes, including reactions associated with cell cycle progression, DNA damage repair, and cilia formation. Moreover, mitochondria participate in cell fate decisions between death and survival. Nek family members have already been implicated in DNA damage response, cilia formation, cell death, and cell cycle control. Here, we discuss the role of several Nek family members, namely Nek1, Nek4, Nek5, Nek6, and Nek10, which are not exclusively dedicated to cell cycle-related functions, in controlling mitochondrial functions. Specifically, we review the function of these Neks in mitochondrial respiration and dynamics, mtDNA maintenance, stress response, and cell death. Finally, we discuss the interplay of other cell cycle kinases in mitochondrial function and vice versa. Nek1, Nek5, and Nek6 are connected to the stress response, including ROS control, mtDNA repair, autophagy, and apoptosis. Nek4, in turn, seems to be related to mitochondrial dynamics, while Nek10 is involved with mitochondrial metabolism. Here, we propose that the participation of Neks in mitochondrial roles is a new functional axis for the Nek family.

Celastrol regulates psoriatic inflammation and autophagy by targeting IL-17A

Anti-IL-17A antibodies, such as secukinumab and ixekizumab, are effective proinflammatory cytokine inhibitors for autoimmune disorders, including psoriasis. However, anti-IL-17A small molecule treatments are yet to be commercialized. Celastrol, a natural compound extracted from the roots of traditional Chinese medicinal plants, has anti-inflammatory and antioxidant properties. However, the binding of celastrol to IL-17A and the associated anti-inflammatory mechanisms remain unclear. This study investigated whether celastrol could directly bind to IL-17A and regulate inflammation in psoriatic in vitro and in vivo models. The results showed that celastrol directly binds to IL-17A and inhibits its downstream signaling, including the NF-kB and MAPK pathways. Interestingly, celastrol restored autophagy dysfunction and reduced proinflammatory cytokine secretion in keratinocytes. In addition, celastrol increased autophagy in the epidermis of a mouse model of psoriasis. Celastrol decreased Th17 cell populations and proinflammatory cytokine levels in mice. Thus, IL-17A-targeting celastrol reduced inflammation by rescuing impaired autophagy in in vitro and in vivo models of psoriasis, demonstrating its potential as a substitute for anti-IL-17A antibodies for treating psoriasis.

The Multiple Roles of Autophagy in Neural Function and Diseases

Autophagy involves the sequestration and delivery of cytoplasmic materials to lysosomes, where proteins, lipids, and organelles are degraded and recycled. According to the way the cytoplasmic components are engulfed, autophagy can be divided into macroautophagy, microautophagy, and chaperone-mediated autophagy. Recently, many studies have found that autophagy plays an important role in neurological diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, neuronal excitotoxicity, and cerebral ischemia. Autophagy maintains cell homeostasis in the nervous system via degradation of misfolded proteins, elimination of damaged organelles, and regulation of apoptosis and inflammation. AMPK-mTOR, Beclin 1, TP53, endoplasmic reticulum stress, and other signal pathways are involved in the regulation of autophagy and can be used as potential therapeutic targets for neurological diseases. Here, we discuss the role, functions, and signal pathways of autophagy in neurological diseases, which will shed light on the pathogenic mechanisms of neurological diseases and suggest novel targets for therapies.

PTPN2 inhibits the proliferation of psoriatic keratinocytes by dephosphorylation of STAT3

Psoriasis is a recurrent and protracted disease that severely impacts the patient's physical and mental health. Thus, there is an urgent need to explore its pathogenesis to identify therapeutic targets. The expression level of protein tyrosine phosphatase nonreceptor type 2 (PTPN2) was analyzed by immunohistochemistry techniques in psoriatic tissues and imiquimod-induced psoriatic mouse models. PTPN2 and signal transducer and activator of transcription 3 (STAT3) were overexpressed or silenced in human keratinocytes or an interleukin (IL)-6-induced psoriasis HaCaT cell model using overexpression plasmid transfection or small interfering RNA technology in vitro, and the effects of PTPN2 on STAT3, HaCaT cell function, and autophagy levels were investigated using reverse transcription-quantitative polymerase chain reaction, Western blot, Cell Counting Kit 8, 5-ethynyl-20-deoxyuridine, flow cytometry, and transmission electron microscopy. PTPN2 expression was found to be significantly downregulated in psoriatic tissues. Then, the in vitro antipsoriatic properties of PTPN2 were investigated in an IL-6-induced psoriasis-like cell model, and the results demonstrated that inhibition of keratinocyte proliferation by PTPN2 may be associated with elevated STAT3 dephosphorylation and autophagy levels. These findings provide novel insights into the mechanisms of autophagy in psoriatic keratinocytes and may be essential for developing new therapeutic strategies to improve inflammatory homeostasis in psoriatic patients.

Exploring the Interplay of RUNX2 and CXCR4 in Melanoma Progression

Overexpression of the Runt-related transcription factor 2 (RUNX2) has been reported in several cancer types, and the C-X-C motif chemokine receptor 4 (CXCR4) has an important role in tumour progression. However, the interplay between CXCR4 and RUNX2 in melanoma cells remains poorly understood. In the present study, we used melanoma cells and a RUNX2 knockout (RUNX2-KO) in vitro model to assess the influence of RUNX2 on CXCR4 protein levels along with its effects on markers associated with cell invasion and autophagy. Osteotropism was assessed using a 3D microfluidic model. Moreover, we assessed the impact of CXCR4 on the cellular levels of key cellular signalling proteins involved in autophagy. We observed that melanoma cells express both RUNX2 and CXCR4. Restored RUNX2 expression in RUNX2 KO cells increased the expression levels of CXCR4 and proteins associated with the metastatic process. The protein markers of autophagy LC3 and beclin were upregulated in response to increased CXCR4 levels. The CXCR4 inhibitor WZ811 reduced osteotropism and activated the mTOR and p70-S6 cell signalling proteins. Our data indicate that the RUNX2 transcription factor promotes the expression of the CXCR4 chemokine receptor on melanoma cells, which in turn promotes autophagy, cell invasiveness, and osteotropism, through the inhibition of the mTOR signalling pathway. Our data suggest that RUNX2 promotes melanoma progression by upregulating CXCR4, and we identify the latter as a key player in melanoma-related osteotropism.

Tomatidine activates autophagy to improve lung injury and inflammation in sepsis by inhibiting NF-κB and MAPK pathways

Sepsis-induced acute lung injury (ALI) is a life-threatening medical condition with high mortality and morbidity. Autophagy is involved in the pathophysiological process of sepsis-induced ALI, including inflammation, which indicates that regulating autophagy may be beneficial for this disease. Tomatidine, a natural compound abundant in unripe tomatoes, has been reported to have anti-inflammatory, anti-tumorigenic, and lipid-lowering effects. However, the biological functions and mechanisms of tomatidine in sepsis-induced ALI remain unknown. The principal objective of this study was to investigate the effect of tomatidine on sepsis-induced ALI. Cecal ligation and puncture (CLP) was used to induce septic lung injury in mice, and 10 mg/kg tomatidine was intraperitoneally injected into mice 2 h after the operation. The results of hematoxylin and eosin staining and assessment of lung edema and total protein levels in bronchoalveolar lavage fluid (BALF) demonstrated that tomatidine alleviated CLP-induced severe lung injuries such as hemorrhage, infiltration of inflammatory cells, and interstitial and alveolar edema in mice. Additionally, the levels of proinflammatory cytokines in BALF and lung tissues were measured by enzyme-linked immunosorbent assay (ELISA), and the results showed that tomatidine inhibited CLP-induced inflammatory damage to lungs. Moreover, the results of western blotting showed that tomatidine promoted autophagy during CLP-induced ALI. Mechanistically, immunofluorescence staining and western blotting were used to measure the protein levels of TLR4, phosphorylated NF-κB, phosphorylated IκBα, and phosphorylated MAPKs, showing that tomatidine inactivated NF-κB and MAPK signaling in lung tissues of CLP-induced ALI mice. In conclusion, tomatidine exerts protective effects against sepsis-induced severe damage to the lungs by inhibiting inflammation and activating autophagy in CLP-treated mice through inactivating the NF-κB and MAPK pathways, which may be an effective candidate for treating septic ALI.

To squeeze or not: Regulation of cell size by mechanical forces in development and human diseases

Physical constraints, such as compression, shear stress, stretching and tension play major roles during development and tissue homeostasis. Mechanics directly impact physiology, and their alteration is also recognized as having an active role in driving human diseases. Recently, growing evidence has accumulated on how mechanical forces are translated into a wide panel of biological responses, including metabolism and changes in cell morphology. The aim of this review is to summarize and discuss our knowledge on the impact of mechanical forces on cell size regulation. Other biological consequences of mechanical forces will not be covered by this review. Moreover, wherever possible, we also discuss mechanosensors and molecular and cellular signaling pathways upstream of cell size regulation. We finally highlight the relevance of mechanical forces acting on cell size in physiology and human diseases.

Sinapic Acid Attenuates Chronic DSS-Induced Intestinal Fibrosis in C57BL/6J Mice by Modulating NLRP3 Inflammasome Activation and the Autophagy Pathway

Ulcerative colitis (UC) is a chronic gastrointestinal disease that results from repeated inflammation and serious complications. Sinapic acid (SA) is a hydroxycinnamic acid present in a variety of plants that has antioxidant, anti-inflammatory, anticancer, and other protective effects. This study investigated the antifibrotic effect of SA on chronic colitis induced by dextran sulfate sodium salt (DSS) in mice. We observed that SA could significantly reduce clinical symptoms (such as improved body weight loss, increased colon length, and decreased disease activity index score) and pathological changes in mice with chronic colitis. SA supplementation has been demonstrated to repair intestinal mucosal barrier function and maintain epithelial homeostasis by inhibiting activation of the NLRP3 inflammasome and decreasing the expression of IL-6, TNF-α, IL-17A, IL-18, and IL-1β. Furthermore, SA could induce the expression of antioxidant enzymes (Cat, Sod1, Sod2, Mgst1) by activating the Nrf2/keap1 pathway, thus improving antioxidant capacity. Additionally, SA could increase the protein expression of downstream LC3-II/LC3-I and Beclin1 and induce autophagy by regulating the AMPK-Akt/mTOR signaling pathway, thereby reducing the production of intestinal fibrosis-associated proteins Collagen-I and α-SMA. These findings suggest that SA can enhance intestinal antioxidant enzymes, reduce oxidative stress, expedite intestinal epithelial repair, and promote autophagy, thereby ameliorating DSS-induced colitis and intestinal fibrosis.

The study of the mechanism of non-coding RNA regulation of programmed cell death in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) represents a distinct myocardial disorder elicited by diabetes mellitus, characterized by aberrations in myocardial function and structural integrity. This pathological condition predominantly manifests in individuals with diabetes who do not have concurrent coronary artery disease or hypertension. An escalating body of scientific evidence substantiates the pivotal role of programmed cell death (PCD)-encompassing apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis-in the pathogenic progression of DCM, thereby emerging as a prospective therapeutic target. Additionally, numerous non-coding RNAs (ncRNAs) have been empirically verified to modulate the biological processes underlying programmed cell death, consequently influencing the evolution of DCM. This review systematically encapsulates prevalent types of PCD manifest in DCM as well as nascent discoveries regarding the regulatory influence of ncRNAs on programmed cell death in the pathogenesis of DCM, with the aim of furnishing novel insights for the furtherance of research in PCD-associated disorders relevant to DCM.

Transcription Factor EB: A Promising Therapeutic Target for Ischemic Stroke

Transcription factor EB (TFEB) is an important endogenous defensive protein that responds to ischemic stimuli. Acute ischemic stroke is a growing concern due to its high morbidity and mortality. Most survivors suffer from disabilities such as numbness or weakness in an arm or leg, facial droop, difficulty speaking or understanding speech, confusion, impaired balance or coordination, or loss of vision. Although TFEB plays a neuroprotective role, its potential effect on ischemic stroke remains unclear. This article describes the basic structure, regulation of transcriptional activity, and biological roles of TFEB relevant to ischemic stroke. Additionally, we explore the effects of TFEB on the various pathological processes underlying ischemic stroke and current therapeutic approaches. The information compiled here may inform clinical and basic studies on TFEB, which may be an effective therapeutic drug target for ischemic stroke.

Autophagy Behavior in Endothelial Cell Regeneration

Autophagy plays a crucial role in maintaining endothelial cell homeostasis through the turnover of intracellular components during stress conditions in a lysosomal-dependent manner. The regeneration strategy involves several aspects, including autophagy. Autophagy is a catabolic degenerative lysosomal-dependent degradation of intracellular components. Autophagy modifies cellular and subcellular endothelial cell functions, including mitochondria stress, lysosomal stress, and endoplasmic reticulum unfolded protein response. Activation of common signaling pathways of autophagy and regeneration and enhancement of intracellular endothelial cell metabolism serve as the bases for the induction of endothelial regeneration. Endothelial progenitor cells include induced pluripotent stem cells (iPSC), embryonic stem cells, and somatic cells, such as fibroblasts. Future strategies of endothelial cell regeneration involve the induction of autophagy to minimize the metabolic degeneration of the endothelial cells and optimize the regeneration outcomes.

Lnc-HIBADH-4 Regulates Autophagy-Lysosome Pathway in Amyotrophic Lateral Sclerosis by Targeting Cathepsin D

Amyotrophic lateral sclerosis (ALS) is the most prevalent and lethal class of severe motor neuron diseases (MND) with no efficacious treatment. The pathogenic mechanisms underlying ALS remain unclear. Nearly 90% of patients exhibit sporadic onset (sALS). Therefore, elucidating the pathophysiology of ALS is imperative. Long non-coding RNA (lncRNA) is a large class of non-coding RNAs that regulate transcription, translation, and post-translational processes. LncRNAs contribute to the pathogenesis of diverse neurodegenerative disorders and hold promise as targets for interference in the realm of neurodegeneration. However, the mechanisms of which lncRNAs are involved in ALS have not been thoroughly investigated. We identified and validated a downregulated lncRNA, lnc-HIBADH-4, in ALS which correlated with disease severity and overall survival. Lnc-HIBADH-4 acted as a "molecular sponge" regulating lysosomal function through the lnc-HIBADH-4/miR-326/CTSD pathway, thereby impacting autophagy-lysosome dynamics and the levels of cell proliferation and apoptosis. Therefore, this study discovered and revealed the role of lnc-HIBADH-4 in the pathogenesis of ALS. With further research, lnc-HIBADH-4 is expected to provide a new biomarker in the diagnosis and treatment of ALS.

Targeting the RAS/RAF/MAPK pathway for cancer therapy: from mechanism to clinical studies

Metastatic dissemination of solid tumors, a leading cause of cancer-related mortality, underscores the urgent need for enhanced insights into the molecular and cellular mechanisms underlying metastasis, chemoresistance, and the mechanistic backgrounds of individuals whose cancers are prone to migration. The most prevalent signaling cascade governed by multi-kinase inhibitors is the mitogen-activated protein kinase (MAPK) pathway, encompassing the RAS-RAF-MAPK kinase (MEK)-extracellular signal-related kinase (ERK) pathway. RAF kinase is a primary mediator of the MAPK pathway, responsible for the sequential activation of downstream targets, such as MEK and the transcription factor ERK, which control numerous cellular and physiological processes, including organism development, cell cycle control, cell proliferation and differentiation, cell survival, and death. Defects in this signaling cascade are associated with diseases such as cancer. RAF inhibitors (RAFi) combined with MEK blockers represent an FDA-approved therapeutic strategy for numerous RAF-mutant cancers, including melanoma, non-small cell lung carcinoma, and thyroid cancer. However, the development of therapy resistance by cancer cells remains an important barrier. Autophagy, an intracellular lysosome-dependent catabolic recycling process, plays a critical role in the development of RAFi resistance in cancer. Thus, targeting RAF and autophagy could be novel treatment strategies for RAF-mutant cancers. In this review, we delve deeper into the mechanistic insights surrounding RAF kinase signaling in tumorigenesis and RAFi-resistance. Furthermore, we explore and discuss the ongoing development of next-generation RAF inhibitors with enhanced therapeutic profiles. Additionally, this review sheds light on the functional interplay between RAF-targeted therapies and autophagy in cancer.

Regulatory mechanisms of autophagy-related ncRNAs in bone metabolic diseases

Bone metabolic diseases have been tormented and are plaguing people worldwide due to the lack of effective and thorough medical interventions and the poor understanding of their pathogenesis. Non-coding RNAs (ncRNAs) are heterogeneous transcripts that cannot encode the proteins but can affect the expressions of other genes. Autophagy is a fundamental mechanism for keeping cell viability, recycling cellular contents through the lysosomal pathway, and maintaining the homeostasis of the intracellular environment. There is growing evidence that ncRNAs, autophagy, and crosstalk between ncRNAs and autophagy play complex roles in progression of metabolic bone disease. This review investigated the complex mechanisms by which ncRNAs, mainly micro RNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), regulate autophagic pathway to assist in treating bone metabolism disorders. It aimed at identifying the autophagy role in bone metabolism disorders and understanding the role, potential, and challenges of crosstalk between ncRNAs and autophagy for bone metabolism disorders treatment.

Finding New Targets for the Treatment of Heart Failure: Endoplasmic Reticulum Stress and Autophagy

Heart failure is a progressive disease with an annual mortality rate of about 10% and is the end-stage stage of various heart diseases, which places a huge socioeconomic burden on the healthcare system. The development of heart failure has received increasing attention as a potential way to improve the treatment of this disease. Many studies have shown that endoplasmic reticulum stress and autophagy play an important role in the occurrence and development of heart failure. With the in-depth study of endoplasmic reticulum stress and autophagy, both are considered promising targets for pharmacological interventions to treat heart failure, but the mechanism of heart failure between the two is not clear. This review will highlight the effects of endoplasmic reticulum stress, autophagy, and their interactions in the development and development of heart failure, thereby helping to provide direction for the future development of targeted therapies for patients with heart failure. CLINICAL RELEVANCE: This study explored the new targets for the treatment of heart failure: endoplasmic reticulum stress and autophagy. Targeted drug therapy for endoplasmic reticulum stress and autophagy is expected to provide a new intervention target for the treatment of heart failure.

Sensitivity of osteosarcoma cell lines to autophagy inhibition as determined by pharmacologic and genetic manipulation

Pharmacologic inhibition of autophagy can be achieved using lysosomotropic agents such as hydroxychloroquine (HCQ) that interfere with fusion of the autophagosome to the lysosome thus preventing completion of the recycling process. The goal of the present study is to determine the sensitivity of eight canine (cOSA) and four human (hOSA) osteosarcoma tumour cell lines to antiproliferative and cytotoxic effects of lysosomal autophagy inhibitors, and to compare these results to the autophagy-dependence measured using a CRISPR/Cas9 live-cell imaging assay in OSA and other tumour cell lines. Antiproliferative and cytotoxic response to HCQ and Lys05 was determined using live cell imaging and YOYO-1 staining. CRISPR/Cas9 live cell imaging screen was done using species specific guide RNA's and transfection of reagents into cells. Response to autophagy core genes was compared to response to an essential (PCNA) and non-essential (FOXO3A) gene. cOSA and hOSA cell lines showed similar antiproliferative and cytotoxic responses to HCQ and Lys05 with median lethal dose (Dm ) values ranging from 4.6-15.8 μM and 2.1-5.1 μM for measures of anti-proliferative response, respectively. A relationship was observed between antiproliferative responses to HCQ and Lys05 and VPS34 CRISPR score with Dm values correlating with VPS34 response (r = 0.968 and 0.887) in a species independent manner. The results show that a subset of cOSA and hOSA cell lines are autophagy-dependent and sensitive to HCQ at pharmacologically-relevant exposures.

The engagement of autophagy in maniac disease

AIMS

Mania is a prevalent psychiatric disorder with undefined pathological mechanism. Here, we reviewed current knowledge indicating the potential involvement of autophagy dysregulation in mania and further discussed whether targeting autophagy could be a promising strategy for mania therapy.

DISCUSSIONS

Accumulating evidence indicated the involvement of autophagy in the pathology of mania. One of the most well-accepted mechanisms underlying mania, circadian dysregulation, showed mutual interaction with autophagy dysfunction. In addition, several first-line drugs for mania therapy were found to regulate neuronal autophagy. Besides, deficiencies in mitochondrial quality control, neurotransmission, and ion channel, which showed causal links to mania, were intimately associated with autophagy dysfunction.

CONCLUSIONS

Although more efforts should be made to either identify the key pathology of mania, the current evidence supported that autophagy dysregulation may act as a possible mechanism involved in the onset of mania-like symptoms. It is therefore a potential strategy to treat manic disorder by correting autophagy.

Dioscorea nipponica Makino: A comprehensive review of its chemical composition and pharmacology on chronic kidney disease

Chronic kidney disease (CKD) is a widespread ailment that significantly impacts global health. It is characterized by high prevalence, poor prognosis, and substantial healthcare costs, making it a major public health concern. The current clinical treatments for CKD are not entirely satisfactory, leading to a high demand for alternative therapeutic options. Chinese herbal medicine, with its long history, diverse varieties, and proven efficacy, offers a promising avenue for exploration. One such Chinese herbal medicine, Dioscorea nipponica Makino (DNM), is frequently used to treat kidney diseases. In this review, we have compiled studies examining the mechanisms of action of DNM in the context of CKD, focusing on five primary areas: improvement of oxidative stress, inhibition of renal fibrosis, regulation of metabolism, reduction of inflammatory response, and regulation of autophagy.

Environment factors, DNA methylation, and cancer

Today, the rapid development of science and technology and the rapid change in economy and society are changing the way of life of human beings and affecting the natural, living, working, and internal environment on which human beings depend. At the same time, the global incidence of cancer has increased significantly yearly, and cancer has become the number one killer that threatens human health. Studies have shown that diet, living habits, residential environment, mental and psychological factors, intestinal flora, genetics, social factors, and viral and non-viral infections are closely related to human cancer. However, the molecular mechanisms of the environment and cancer development remain to be further explored. In recent years, DNA methylation has become a key hub and bridge for environmental and cancer research. Some environmental factors can alter the hyper/hypomethylation of human cancer suppressor gene promoters, proto-oncogene promoters, and the whole genome, causing low/high expression or gene mutation of related genes, thereby exerting oncogenic or anticancer effects. It is expected to develop early warning markers of cancer environment based on DNA methylation, thereby providing new methods for early detection of cancers, diagnosis, and targeted therapy. This review systematically expounds on the internal mechanism of environmental factors affecting cancer by changing DNA methylation, aiming to help establish the concept of cancer prevention and improve people's health.

Reactive nitrogen species as therapeutic targets for autophagy/mitophagy modulation to relieve neurodegeneration in multiple sclerosis: Potential application for drug discovery

Multiple sclerosis (MS) is a neuroinflammatory disease with limited therapeutic effects, eventually developing into handicap. Seeking novel therapeutic strategies for MS is timely important. Active autophagy/mitophagy could mediate neurodegeneration, while its roles in MS remain controversial. To elucidate the exact roles of autophagy/mitophagy and reveal its in-depth regulatory mechanisms, we conduct a systematic literature study and analyze the factors that might be responsible for divergent results obtained. The dynamic change levels of autophagy/mitophagy appear to be a determining factor for final neuron fate during MS pathology. Excessive neuronal autophagy/mitophagy contributes to neurodegeneration after disease onset at the active MS phase. Reactive nitrogen species (RNS) serve as key regulators for redox-related modifications and participate in autophagy/mitophagy modulation in MS. Nitric oxide (•NO) and peroxynitrite (ONOO-), two representative RNS, could nitrate or nitrosate Drp1/parkin/PINK1 pathway, activating excessive mitophagy and aggravating neuronal injury. Targeting RNS-mediated excessive autophagy/mitophagy could be a promising strategy for developing novel anti-MS drugs. In this review, we highlight the important roles of RNS-mediated autophagy/mitophagy in neuronal injury and review the potential therapeutic compounds with the bioactivities of inhibiting RNS-mediated autophagy/mitophagy activation and attenuating MS progression. Overall, we conclude that reactive nitrogen species could be promising therapeutic targets to regulate autophagy/mitophagy for multiple sclerosis treatment.

Dual Implications of Nanosilver-Induced Autophagy: Nanotoxicity and Anti-Cancer Effects

In recent years, efforts have been made to identify new anti-cancer therapies. Various types of nanomaterials, including silver nanoparticles (AgNPs), are being considered as an option. In addition to its well-known antibacterial activity, AgNPs exhibit cytotoxic potential in both physiological and cancer cells by inducing stress-mediated autophagy and apoptotic cell death. A rapidly growing collection of data suggests that the proper regulation of autophagic machinery may provide an efficient tool for suppressing the development of cancer. In this light, AgNPs have emerged as a potential anti-cancer agent to support therapy of the disease. This review summarizes current data indicating the dual role of AgNP-induced autophagy and highlights factors that may influence its protective vs. its toxic potential. It also stresses that our understanding of the cellular and molecular mechanisms of autophagy machinery in cancer cells, as well as AgNP-triggered autophagy in both normal and diseased cells, remains insufficient.

Autophagy modulates the stability of Wee1 and cell cycle G2/M transition

The mammalian cell cycle is divided into four sequential phases, namely G1 (Gap 1), S (synthesis), G2 (Gap 2), and M (mitosis). Wee1, whose turnover is tightly and finely regulated, is a well-known kinase serving as a gatekeeper for the G2/M transition. However, the mechanism underlying the turnover of Wee1 is not fully understood. Autophagy, a highly conserved cellular process, maintains cellular homeostasis by eliminating intracellular aggregations, damaged organelles, and individual proteins. In the present study, we found autophagy deficiency in mouse liver caused G2/M arrest in two mouse models, namely Fip200 and Atg7 liver-specific knockout mice. To uncover the link between autophagy deficiency and G2/M transition, we combined transcriptomic and proteomic analysis for liver samples from control and Atg7 liver-specific knockout mice. The data suggest that the inhibition of autophagy increases the protein level of Wee1 without any alteration of its mRNA abundance. Serum starvation, an autophagy stimulus, downregulates the protein level of Wee1 in vitro. In addition, the half-life of Wee1 is extended by the addition of chloroquine, an autophagy inhibitor. LC3, a central autophagic protein functioning in autophagy substrate selection and autophagosome biogenesis, interacts with Wee1 as assessed by co-immunoprecipitation assay. Furthermore, overexpression of Wee1 leads to G2/M arrest both in vitro and in vivo. Collectively, our data indicate that autophagy could degrade Wee1-a gatekeeper of the G2/M transition, whereas the inhibition of autophagy leads to the accumulation of Wee1 and causes G2/M arrest in mouse liver.

Advances in mass spectrometry-based multi-scale metabolomic methodologies and their applications in biological and clinical investigations

Metabolomics is a nascent field of inquiry that emerged in the late 20th century. It encompasses the comprehensive profiling of metabolites across a spectrum of organisms, ranging from bacteria and cells to tissues. The rapid evolution of analytical methods and data analysis has greatly accelerated progress in this dynamic discipline over recent decades. Sophisticated techniques such as liquid chromatograph mass spectrometry (MS), gas chromatograph MS, capillary electrophoresis MS, and nuclear magnetic resonance serve as the cornerstone of metabolomic analysis. Building upon these methods, a plethora of modifications and combinations have emerged to propel the advancement of metabolomics. Despite this progress, scrutinizing metabolism at the single-cell or single-organelle level remains an arduous task over the decades. Some of the most thrilling advancements, such as single-cell and single-organelle metabolic profiling techniques, offer profound insights into the intricate mechanisms within cells and organelles. This allows for a comprehensive study of metabolic heterogeneity and its pivotal role in multiple biological processes. The progress made in MS imaging has enabled high-resolution in situ metabolic profiling of tissue sections and even individual cells. Spatial reconstruction techniques enable the direct representation of metabolic distribution and alteration in three-dimensional space. The application of novel metabolomic techniques has led to significant breakthroughs in biological and clinical studies, including the discovery of novel metabolic pathways, determination of cell fate in differentiation, anti-aging intervention through modulating metabolism, metabolomics-based clinicopathologic analysis, and surgical decision-making based on on-site intraoperative metabolic analysis. This review presents a comprehensive overview of both conventional and innovative metabolomic techniques, highlighting their applications in groundbreaking biological and clinical studies.

Vitamin D and autophagy in knee osteoarthritis: A review

Knee osteoarthritis (KOA), the highly prevalent degenerative disease affecting the joint, perpetually devastates the health of the elderly. Of various mechanisms known to participate in KOA etiology, apoptosis of chondrocytes is widely regarded as the primary cause of cartilage degradation. It has been suggested that the induction of autophagy in chondrocytes could potentially prolong the progression of KOA by modulating intracellular metabolic processes, which may be helpful for ameliorating chondrocyte apoptosis and eventual cartilage degeneration. Autophagy, a physiological process characterized by intracellular self-degradation, has been reportedly implicated in various pathologic conditions including KOA. Interestingly, vitamin D has been shown to regulate autophagy in human chondrocytes through multiple pathways, specifically AMPK/mTOR signaling pathway. This observation underscores the potential of vitamin D as a novel approach for restoring the functionality and survivability of chondrocytes in KOA. Supporting vitamin D's clinical significance, previous studies have demonstrated its substantial involvement in the symptoms and irregular joint morphology observed in KOA patients, strengthening potential therapeutic efficacy of vitamin D in treatment of KOA. Herein, the purpose of this review was to determine the mechanisms underlying the multi-processes of vitamin D implicated in autophagy in several cells including chondrocytes, which would bring unique insights into KOA pathogenesis.

Arctigenin improves neuropathy via ameliorating apoptosis and modulating autophagy in streptozotocin-induced diabetic mice

BACKGROUND

Oxidative stress mediates the pathophysiology of diabetic neuropathy (DN) with activation of apoptotic pathway and reduction of autophagy. Arctigenin (ARC) is a natural lignan isolated from some plants of the Asteraceae family that shows antioxidant property. The present study aimed to explore the mechanistic neuroprotective effect of ARC on animal model for DN.

METHODS

DN was induced using streptozotocin (STZ) at a dose of 45 mg/kg, i.p, for five consecutive days and ARC was administered orally (25 or 50 mg) for 3 weeks. The mechanical sensitivity and thermal latency were determined using von Frey and hotplate, respectively. Beclin, p62, and LC3 were detected as markers for autophagy by western blot. Levels of reduced glutathione, lipid peroxides, and activities of catalase and superoxide dismutase were detected as readout for oxidative stress. Apoptotic parameters and histopathological changes were revealed in all experimental groups.

RESULTS

The present study showed deterioration of the function and structure of neurons as a result of hyperglycemia. Oxidative stress and impaired autophagy were observed in diabetic neurons as well as the activation of apoptotic pathway. ARC improved the behavioral and histopathological changes of diabetic mice. ARC combated oxidative stress through diminishing lipid peroxidation and improving the activity of antioxidant enzymes. This was concomitant by reducing the biomarkers of apoptosis. ARC augmented the expression of Beclin and LC3 while it lessened the expression of p62 indicating the activation of autophagy. These findings suggest that ARC can ameliorate DN by combating apoptosis and oxidative stress and improving autophagy.

Biofactors regulating mitochondrial function and dynamics in podocytes and podocytopathies

Podocytes are terminally differentiated kidney cells acting as the main gatekeepers of the glomerular filtration barrier; hence, inhibiting proteinuria. Podocytopathies are classified as kidney diseases caused by podocyte damage. Different genetic and environmental risk factors can cause podocyte damage and death. Recent evidence shows that mitochondrial dysfunction also contributes to podocyte damage. Understanding alterations in mitochondrial metabolism and function in podocytopathies and whether altered mitochondrial homeostasis/dynamics is a cause or effect of podocyte damage are issues that need in-depth studies. This review highlights the roles of mitochondria and their bioenergetics in podocytes. Then, factors/signalings that regulate mitochondria in podocytes are discussed. After that, the role of mitochondrial dysfunction is reviewed in podocyte injury and the development of different podocytopathies. Finally, the mitochondrial therapeutic targets are considered.

Function and autophagy of monocyte-derived dendritic cells is affected by hepatitis B virus infection

BACKGROUND

The role of dendritic cells and the autophagy state of dendritic cells in the immune response of hepatitis B virus (HBV) infection was still controversial. In this study, we carefully examined the phenotype, function and autophagy pathway of dendritic cells in HBV infection.

METHODS

Monocyte-derived dendritic cells from healthy blood donors and patients with chronic HBV infection were stimulated by lipopolysaccharide, supernatant of HepG2.2.15 cells or supernatant of HepG2 cells respectively. Phenotype of dendritic cells was examined by flow cytometry and cytokines secretion was detected by enzyme-linked immunosorbent assay. Autophagy related proteins were detected by western blot and immunofluorescence analysis.

RESULTS

Our results showed that the expression of both major histocompatibility complex II molecules and co-stimulated molecules including cluster of differentiation antigen 80, cluster of differentiation antigen 86 in the monocyte-derived dendritic cells from patients with chronic HBV infection was significantly higher than that from healthy donors when cultured with supernatant of HepG2.2.15 cells. The amount of cytokines, including tumour necrosis factor-α, interleukin-10 and interleukin-12, secreted by monocyte-derived dendritic cells from patients with chronic HBV infection was also significantly higher than that from healthy donors when stimulate by HBV. Interestingly, the expression level of autophagy-related proteins including autophagy-related protein5 and associated protein 1 light chain in dendritic cells from patients with chronic HBV infection was significantly increased when compared with that from healthy donors when re-exposed to HBV.

CONCLUSIONS

Our results indicated that dendritic cells from patients with chronic HBV infection could intensively present antigen and express co-stimulatory molecules. The increased activation of dendritic cells might be related to the enhanced autophagy of dendritic cells in HBV infection.

Autophagy in Parkinson's Disease

Parkinson's disease (PD) is a devastating disease associated with accumulation of α-synuclein (α-Syn) within dopaminergic neurons, leading to neuronal death. PD is characterized by both motor and non-motor clinical symptoms. Several studies indicate that autophagy, an important intracellular degradation pathway, may be involved in different neurodegenerative diseases including PD. The autophagic process mediates the degradation of protein aggregates, damaged and unneeded proteins, and organelles, allowing their clearance, and thereby maintaining cell homeostasis. Impaired autophagy may cause the accumulation of abnormal proteins. Incomplete or impaired autophagy may explain the neurotoxic accumulation of protein aggregates in several neurodegenerative diseases including PD. Indeed, studies have suggested the contribution of impaired autophagy to α-Syn accumulation, the death of dopaminergic neurons, and neuroinflammation. In this review, we summarize the recent literature on the involvement of autophagy in PD pathogenesis.

Dihydroartemisinin attenuates ischemia/reperfusion-induced renal tubular senescence by activating autophagy

Acute kidney injury (AKI) is an important factor for the occurrence and development of CKD. The protective effect of dihydroartemisinin on AKI and and reported mechanism have not been reported. In this study, we used two animal models including ischemia-reperfusion and UUO, as well as a high-glucose-stimulated HK-2 cell model, to evaluate the protective effect of dihydroartemisinin on premature senescence of renal tubular epithelial cells in vitro and in vivo. We demonstrated that dihydroartemisinin improved renal aging and renal injury by activating autophagy. In addition, we found that co-treatment with chloroquine, an autophagy inhibitor, abolished the anti-renal aging effect of dihydroartemisinin in vitro. These findings suggested that activation of autophagy/elimination of senescent cell might be a useful strategy to prevent AKI/UUO induced renal tubular senescence and fibrosis.

Autophagy blockage and lysosomal dysfunction are involved in diallyl sulfide-induced inhibition of malignant growth in hepatocellular carcinoma cells

Diallyl sulfide (DAS), as a major component of garlic extracts, has been shown to inhibit growth of hepatocellular carcinoma cells (HCC), but the underlying mechanism is still elusive. In this study, we aimed to explore the involvement of autophagy in DAS-induced growth inhibition of HepG2 and Huh7 hepatocellular carcinoma cells. We studied growth of DAS-treated HepG2 and Huh7 cells using the MTS and clonogenic assays. Autophagic flux was examined by immunofluorescence and confocal microscopy. The expression levels of autophagy-related proteins AMPK, mTOR, p62, LC3-II, LAMP1, and cathepsin D in the HepG2 and Huh7 cells treated with DAS as well as the tumors formed by HepG2 cells in the nude mice in the presence or absence of DAS were examined using western blotting and immunohistochemistry analysis. We found that DAS treatment induced activation of AMPK/mTOR, and accumulation of LC3-II and p62 both in vivo and in vitro. DAS inhibited autophagic flux through blocking the fusion of autophagosomes with lysosomes. Furthermore, DAS induced an increase in lysosomal pH and inhibition of Cathepsin D maturation. Co-treatment with an autophagy inhibitor (Chloroquine, CQ) further enhanced the growth inhibitory activity of DAS in HCC cells. Thus, our findings indicate that autophagy is involved in DAS-mediated growth inhibition of HCC cells both in vitro and in vivo.

Bidirectional interplay between SARS-CoV-2 and autophagy

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as the causative agent of the recent COVID-19 pandemic, continues representing one of the main health concerns worldwide. Autophagy, in addition to its role in cellular homeostasis and metabolism, plays an important part for the host antiviral immunity. However, viruses including SARS-CoV-2 have evolved diverse mechanisms to not only overcome autophagy's antiviral pressure but also manipulate its machinery in order to enhance viral replication and propagation. Here, we discuss our current knowledge on the impact that autophagy exerts on SARS-CoV-2 replication, as well as the different counteracting measures that this virus has developed to manipulate autophagy's complex machinery. Some of the elements regarding this interplay may become future therapeutic targets in the fight against SARS-CoV-2.

Cogs in the autophagic machine-equipped to combat dementia-prone neurodegenerative diseases

Neurodegenerative diseases are often characterized by hydrophobic inclusion bodies, and it may be the case that the aggregate-prone proteins that comprise these inclusion bodies are in fact the cause of neurotoxicity. Indeed, the appearance of protein aggregates leads to a proteostatic imbalance that causes various interruptions in physiological cellular processes, including lysosomal and mitochondrial dysfunction, as well as break down in calcium homeostasis. Oftentimes the approach to counteract proteotoxicity is taken to merely upregulate autophagy, measured by an increase in autophagosomes, without a deeper assessment of contributors toward effective turnover through autophagy. There are various ways in which autophagy is regulated ranging from the mammalian target of rapamycin (mTOR) to acetylation status of proteins. Healthy mitochondria and the intracellular energetic charge they preserve are key for the acidification status of lysosomes and thus ensuring effective clearance of components through the autophagy pathway. Both mitochondria and lysosomes have been shown to bear functional protein complexes that aid in the regulation of autophagy. Indeed, it may be the case that minimizing the proteins associated with the respective neurodegenerative pathology may be of greater importance than addressing molecularly their resulting inclusion bodies. It is in this context that this review will dissect the autophagy signaling pathway, its control and the manner in which it is molecularly and functionally connected with the mitochondrial and lysosomal system, as well as provide a summary of the role of autophagy dysfunction in driving neurodegenerative disease as a means to better position the potential of rapamycin-mediated bioactivities to control autophagy favorably.