Role of AMPK in autophagy

Blockage of Autophagy for Cancer Therapy: A Comprehensive Review

The incidence and mortality of cancer are increasing, making it a leading cause of death worldwide. Conventional treatments such as surgery, radiotherapy, and chemotherapy face significant limitations due to therapeutic resistance. Autophagy, a cellular self-degradation mechanism, plays a crucial role in cancer development, drug resistance, and treatment. This review investigates the potential of autophagy inhibition as a therapeutic strategy for cancer. A systematic search was conducted on Embase, PubMed, and Google Scholar databases from 1967 to 2024 to identify studies on autophagy inhibitors and their mechanisms in cancer therapy. The review includes original articles utilizing in vitro and in vivo experimental methods, literature reviews, and clinical trials. Key terms used were "Autophagy", "Inhibitors", "Molecular mechanism", "Cancer therapy", and "Clinical trials". Autophagy inhibitors such as chloroquine (CQ) and hydroxychloroquine (HCQ) have shown promise in preclinical studies by inhibiting lysosomal acidification and preventing autophagosome degradation. Other inhibitors like wortmannin and SAR405 target specific components of the autophagy pathway. Combining these inhibitors with chemotherapy has demonstrated enhanced efficacy, making cancer cells more susceptible to cytotoxic agents. Clinical trials involving CQ and HCQ have shown encouraging results, although further investigation is needed to optimize their use in cancer therapy. Autophagy exhibits a dual role in cancer, functioning as both a survival mechanism and a cell death pathway. Targeting autophagy presents a viable strategy for cancer therapy, particularly when integrated with existing treatments. However, the complexity of autophagy regulation and the potential side effects necessitate further research to develop precise and context-specific therapeutic approaches.

The AMPK activator ATX-304 alters cellular metabolism to protect against cisplatin-induced acute kidney injury

Acute kidney injury (AKI) disrupts energy metabolism. Targeting metabolism through AMP-activated protein kinase (AMPK) may alleviate AKI. ATX-304, a pan-AMPK activator, was evaluated in C57Bl/6 mice and tubular epithelial cell (TEC) cultures. Mice received ATX-304 (1 mg/g) or control chow for 7 days before cisplatin-induced AKI (CI-AKI). Primary cultures of tubular epithelial cells (TECs) were pre-treated with ATX-304 (20 µM, 4 h) prior to exposure to cisplatin (20 µM, 23 h). ATX-304 increased acetyl-CoA carboxylase phosphorylation, indicating AMPK activation. It protected against CI-AKI measured by serum creatinine (control 0.05 + 0.03 mM vs ATX-304 0.02 + 0.01 mM, P = 0.03), western blot for neutrophil gelatinase-associated lipocalin (NGAL) (control 3.3 + 1.8-fold vs ATX-304 1.2 + 0.55-fold, P = 0.002), and histological injury (control 3.5 + 0.59 vs ATX-304 2.7 + 0.74, P = 0.03). In TECs, pre-treatment with ATX-304 protected against cisplatin-mediated injury, as measured by lactate dehydrogenase release, MTS cell viability, and cleaved caspase 3 expression. ATX-304 protection against cisplatin was lost in AMPK-null murine embryonic fibroblasts. Metabolomic analysis in TECs revealed that ATX-304 (20 µM, 4 h) altered 66/126 metabolites, including fatty acids, tricarboxylic acid cycle metabolites, and amino acids. Metabolic studies of live cells using the XFe96 Seahorse analyzer revealed that ATX-304 increased the basal TEC oxygen consumption rate by 38%, whereas maximal respiration was unchanged. Thus, ATX-304 protects against cisplatin-mediated kidney injury via AMPK-dependent metabolic reprogramming, revealing a promising therapeutic strategy for AKI.

Cadmium toxicity and autophagy: a review

Cadmium (Cd) is an important environmental pollutant that poses a threat to human health and represents a critical component of air pollutants, food sources, and cigarette smoke. Cd is a known carcinogen and has toxic effects on the environment and various organs in humans. Heavy metals within an organism are difficult to biodegrade, and those that enter the respiratory tract are difficult to remove. Autophagy is a key mechanism for counteracting extracellular (microorganisms and foreign bodies) or intracellular (damaged organelles and proteins that cannot be degraded by the proteasome) stress and represents a self-protective mechanism for eukaryotes against heavy metal toxicity. Autophagy maintains cellular homeostasis by isolating and gathering information about foreign chemicals associated with other molecular events. However, autophagy may trigger cell death under certain pathological conditions, including cancer. Autophagy dysfunction is one of the main mechanisms underlying Cd-induced cytotoxicity. In this review, the toxic effects of Cd-induced autophagy on different human organ systems were evaluated, with a focus on hepatotoxicity, nephrotoxicity, respiratory toxicity, and neurotoxicity. This review also highlighted the classical molecular pathways of Cd-induced autophagy, including the ROS-dependent signaling pathways, endoplasmic reticulum (ER) stress pathway, Mammalian target of rapamycin (mTOR) pathway, Beclin-1 and Bcl-2 family, and recently identified molecules associated with Cd. Moreover, research directions for Cd toxicity regarding autophagic function were proposed. This review presents the latest theories to comprehensively reveal autophagy behavior in response to Cd toxicity and proposes novel potential autophagy-targeted prevention and treatment strategies for Cd toxicity and Cd-associated diseases in humans.

AMPK-mediated autophagy pathway activation promotes ΔFosB degradation to improve levodopa-induced dyskinesia

BACKGROUND

Parkinson's disease patients on chronic levodopa often suffer from motor complications, which tend to reduce their quality of life. Levodopa-induced dyskinesia (LID) is one of the most prevalent motor complications, often characterized by abnormal involuntary movements, and the pathogenesis of LID is still unclear but recent studies have suggested the involvement of autophagy.

METHODS

The onset of LID was mimicked by chronic levodopa treatment in a unilateral 6-hydroxydopamine (6-OHDA) -lesion rat model. Overexpression of ΔFosB in HEK293 cells to mimic the state of ΔFosB accumulation. The modulation of the AMP-activated protein kinase (AMPK)-mediated autophagy pathway using by metformin, AICAR (an AMPK activator), Compound C (an AMPK inhibitor) and chloroquine (an autophagy pathway inhibitor). The severity of LID was assessed by axial, limb, and orofacial (ALO) abnormal involuntary movements (AIMs) score and in vivo electrophysiology. The activity of AMPK pathway as well as autophagy markers and FosB-ΔFosB levels were detected by western blotting. RT-qPCR was performed to detect the transcription level of FosB-ΔFosB. The mechanism of autophagy dysfunction was further explored by immunofluorescence and transmission electron microscopy.

RESULTS

In vivo experiments demonstrated that chronic levodopa treatment reduced AMPK phosphorylation, impaired autophagosome-lysosomal fusion and caused FosB-ΔFosB accumulation in the striatum of PD rats. Long-term metformin intervention improved ALO AIMs scores as well as reduced the mean power of high gamma (hγ) oscillations and the proportion of striatal projection neurons unstable in response to dopamine for LID rats. Moreover, the intervention of metformin promoted AMPK phosphorylation, ameliorated the impairment of autophagosome-lysosomal fusion, thus, promoting FosB-ΔFosB degradation to attenuate its accumulation in the striatum of LID rats. However, the aforementioned roles of metformin were reversed by Compound C and chloroquine. The results of in vitro studies demonstrated the ability of metformin and AICAR to attenuate ΔFosB levels by promoting its degradation, while Compound C and chloroquine could block this effect.

CONCLUSIONS

In conclusion, our results suggest that long-term metformin treatment could promote ΔFosB degradation and thus attenuate the development of LID through activating the AMPK-mediated autophagy pathway. Overall, our results support the AMPK-mediated autophagy pathway as a novel therapeutic target for LID and also indicate that metformin is a promising therapeutic candidate for LID.

The mechanism of curcumin to protect mouse ovaries from oxidative damage by regulating AMPK/mTOR mediated autophagy

BACKGROUND

Oxidative stress is considered the main cause of granulosa cell apoptosis in ovarian disease. Curcumin has various biological roles, but its potential role in protecting granulosa cells from oxidative damage remains unidentified.

PURPOSE

The study revealed the protective effect of curcumin on granulosa cell survival under oxidative stress, and explored its mode of action.

STUDY DESIGN

The protective effect of curcumin on oxidative stress-induced ovarian cell apoptosis was evaluated in vivo and in vitro, and the role of autophagy and AMPK/mTOR signaling pathway in this process was also demonstrated.

METHODS

First, mice were injected to 3-nitropropionic acid (3-NPA, 20 mg/kg/day) for 14 consecutive days to establish the ovarian oxidative stress model, at same time, curcumin (50, 100, 200 mg/kg/day) was given orally. Thereafter, functional changes, cell apoptosis, and autophagy in ovarian tissue were evaluated by hematoxylin-eosin staining, enzyme-linked immunosorbent assay, western blotting, TUNEL assays, and transmission electron microscopy. Finally, oxidative stress model of granulosa cells was established with H2O2in vitro and treated with curcumin. The underlying mechanisms of curcumin to protect the apoptosis under oxidative stress in vitro were determined using western blotting and TUNEL assays.

RESULTS

In our study, after curcumin treatment, the mouse ovarian function disorder under 3-nitropropionic acid-induced oxidative stress recovered significantly, and ovarian cell apoptosis decreased. H2O2 induced granulosa cell apoptosis in vitro, and curcumin antagonized this process. Autophagy contributes to tissue and cell survival under stress. We therefore examined the role of autophagy in this process. According to the in vivo and in vitro results, curcumin restored autophagy under oxidative stress. The autophagy inhibitor (chloroquine) exhibited the same effect as curcumin, whereas the autophagy activator (rapamycin) antagonized the effect of curcumin. In addition, the study found that the AMPK/mTOR pathway plays a crucial role in curcumin- mediated autophagy to protect against oxidative stress-induced apoptosis.

CONCLUSION

Our findings for the first time systematically revealed a new mechanism through which curcumin protects ovarian granulosa cells from oxidative stress-induced damage through AMPK/mTOR-mediated autophagy and suggested that it can be a new therapeutic direction for female ovarian diseases.

Antioxidants and Mechanistic Insights for Managing Dry Age-Related Macular Degeneration

Age-related macular degeneration (AMD) severely affects central vision due to progressive macular degeneration and its staggering prevalence is rising globally, especially in the elderly population above 55 years. Increased oxidative stress with aging is considered an important contributor to AMD pathogenesis despite multifaceted risk factors including genetic predisposition and environmental agents. Wet AMD can be managed with routine intra-vitreal injection of angiogenesis inhibitors, but no satisfactory medicine has been approved for the successful management of the dry form. The toxic carbonyls due to photo-oxidative degradation of accumulated bisretinoids within lysosomes initiate a series of events including protein adduct formation, impaired autophagy flux, complement activation, and chronic inflammation, which is implicated in dry AMD. Therapy based on antioxidants has been extensively studied for its promising effect in reducing the impact of oxidative stress. This paper reviews the dry AMD pathogenesis, delineates the effectiveness of dietary and nutrition supplements in clinical studies, and explores pre-clinical studies of antioxidant molecules, extracts, and formulations with their mechanistic insights.

Autophagy in Its (Proper) Context: Molecular Basis, Biological Relevance, Pharmacological Modulation, and Lifestyle Medicine

Autophagy plays a critical role in maintaining cellular homeostasis and responding to various stress conditions by the degradation of intracellular components. In this narrative review, we provide a comprehensive overview of autophagy's cellular and molecular basis, biological significance, pharmacological modulation, and its relevance in lifestyle medicine. We delve into the intricate molecular mechanisms that govern autophagy, including macroautophagy, microautophagy and chaperone-mediated autophagy. Moreover, we highlight the biological significance of autophagy in aging, immunity, metabolism, apoptosis, tissue differentiation and systemic diseases, such as neurodegenerative or cardiovascular diseases and cancer. We also discuss the latest advancements in pharmacological modulation of autophagy and their potential implications in clinical settings. Finally, we explore the intimate connection between lifestyle factors and autophagy, emphasizing how nutrition, exercise, sleep patterns and environmental factors can significantly impact the autophagic process. The integration of lifestyle medicine into autophagy research opens new avenues for promoting health and longevity through personalized interventions.

PGC-1a mediated mitochondrial biogenesis promotes recovery and survival of neuronal cells from cellular degeneration

Neurodegenerative disorders are characterized by the progressive loss of structure and function of neurons, often including the death of the neuron. Previously, we reported that, by removing the cell death stimulus, dying/injured neurons could survive and recover from the process of regulated cell death, even if the cells already displayed various signs of cellular damage. Now we investigated the role of mitochondrial dynamics (fission/fusion, biogenesis, mitophagy) in both degeneration and in recovery of neuronal cells. In neuronal PC12 cells, exposure to ethanol (EtOH) induced massive neurite loss along with widespread mitochondrial fragmentation, mitochondrial membrane potential loss, reduced ATP production, and decreased total mitochondrial volume. By removing EtOH timely all these mitochondrial parameters recovered to normal levels. Meanwhile, cells regrew neurites and survived. Study of the mitochondrial dynamics showed that autophagy was activated only during the cellular degeneration phase (EtOH treatment) but not in the recovery phase (EtOH removed), and it was not dependent on the Parkin/PINK1 mediated mitophagy pathway. Protein expression of key regulators of mitochondrial fission, phospho-Drp1Ser616 and S-OPA1, increased during EtOH treatment and recovered to normal levels after removing EtOH. In addition, the critical role of PGC-1α mediated mitochondrial biogenesis in cellular recovery was revealed: inhibition of PGC-1α using SR-18292 after EtOH removal significantly impeded recovery of mitochondrial damage, regeneration of neurites, and cell survival in a concentration-dependent manner. Taken together, our study showed reversibility of mitochondrial morphological and functional damage in stressed neuronal cells and revealed that PGC-1α mediated mitochondrial biogenesis played a critical role in the cellular recovery. This molecular mechanism could be a target for neuroprotection and neurorescue in neurodegenerative diseases.

Molecular mechanisms in regulation of autophagy and apoptosis in view of epigenetic regulation of genes and involvement of liquid-liquid phase separation

Cellular physiology is critically regulated by multiple signaling nexuses, among which cell death mechanisms play crucial roles in controlling the homeostatic landscape at the tissue level within an organism. Apoptosis, also known as programmed cell death, can be induced by external and internal stimuli directing the cells to commit suicide in unfavourable conditions. In contrast, stress conditions like nutrient deprivation, infection and hypoxia trigger autophagy, which is lysosome-mediated processing of damaged cellular organelle for recycling of the degraded products, including amino acids. Apparently, apoptosis and autophagy both are catabolic and tumor-suppressive pathways; apoptosis is essential during development and cancer cell death, while autophagy promotes cell survival under stress. Moreover, autophagy plays dual role during cancer development and progression by facilitating the survival of cancer cells under stressed conditions and inducing death in extreme adversity. Despite having two different molecular mechanisms, both apoptosis and autophagy are interconnected by several crosslinking intermediates. Epigenetic modifications, such as DNA methylation, post-translational modification of histone tails, and miRNA play a pivotal role in regulating genes involved in both autophagy and apoptosis. Both autophagic and apoptotic genes can undergo various epigenetic modifications and promote or inhibit these processes under normal and cancerous conditions. Epigenetic modifiers are uniquely important in controlling the signaling pathways regulating autophagy and apoptosis. Therefore, these epigenetic modifiers of both autophagic and apoptotic genes can act as novel therapeutic targets against cancers. Additionally, liquid-liquid phase separation (LLPS) also modulates the aggregation of misfolded proteins and provokes autophagy in the cytosolic environment. This review deals with the molecular mechanisms of both autophagy and apoptosis including crosstalk between them; emphasizing epigenetic regulation, involvement of LLPS therein, and possible therapeutic approaches against cancers.

Interleukin-27 as a novel player in alleviating hepatic steatosis: Mechanistic insights from an in vitro analysis

Interleukin-27 (IL-27) is a recently discovered cytokine that has been implicated in inflammatory and metabolic conditions, such as atherosclerosis and insulin resistance. However, the mechanisms by which IL-27 attenuates hepatic lipid accumulation in hyperlipidemic conditions and counteracts endoplasmic reticulum (ER) stress, a known risk factor for impaired hepatic lipid metabolism, have not been elucidated. This in vitro study was designed to examine the effect of IL-27 on hepatic lipid metabolism. The study included the evaluation of lipogenesis-associated proteins and ER stress markers by Western blotting, the determination of hepatic lipid accumulation by Oil Red O staining, and the examination of autophagosome formation by MDC staining. The results showed that IL-27 treatment reduced lipogenic lipid deposition and the expression of ER stress markers in cultured hepatocytes exposed to palmitate. Moreover, treatment with IL-27 suppressed CD36 expression and enhanced fatty acid oxidation in palmitate-treated hepatocytes. The effects of IL-27 on hyperlipidemic hepatocytes were attenuated when adenosine monophosphate-activated protein kinase (AMPK) or 3-methyladenine (3 MA) were inhibited by small interfering RNA (siRNA). These results suggest that IL-27 attenuates hepatic ER stress and fatty acid uptake and stimulates fatty acid oxidation via AMPK/autophagy signaling, thereby alleviating hepatic steatosis. In conclusion, this study identified IL-27 as a promising therapeutic target for nonalcoholic fatty liver disease (NAFLD).

Allelic heterogeneity of TTNtv dilated cardiomyopathy can be modeled in adult zebrafish

Allelic heterogeneity (AH) has been noted in truncational TTN-associated (TTNtv-associated) dilated cardiomyopathy (DCM); i.e., mutations affecting A-band-encoding exons are pathogenic, but those affecting Z-disc-encoding exons are likely benign. The lack of an in vivo animal model that recapitulates AH hinders the deciphering of the underlying mechanism. Here, we explored zebrafish as a candidate vertebrate model by phenotyping a collection of zebrafish ttntv alleles. We noted that cardiac function and sarcomere structure were more severely disrupted in ttntv-A than in ttntv-Z homozygous embryos. Consistently, cardiomyopathy-like phenotypes were present in ttntv-A but not ttntv-Z adult heterozygous mutants. The phenotypes observed in ttntv-A alleles were recapitulated in null mutants with the full titin-encoding sequences removed. Defective autophagic flux, largely due to impaired autophagosome-lysosome fusion, was also noted only in ttntv-A but not in ttntv-Z models. Moreover, we found that genetic manipulation of ulk1a restored autophagy flux and rescued cardiac dysfunction in ttntv-A animals. Together, our findings presented adult zebrafish as an in vivo animal model for studying AH in TTNtv DCM, demonstrated TTN loss of function is sufficient to trigger ttntv DCM in zebrafish, and uncovered ulk1a as a potential therapeutic target gene for TTNtv DCM.

Galectin-3 and Autophagy in Renal Acute Tubular Necrosis

Acute kidney injury (AKI) is a public health burden with increasing morbidity and mortality rates and health care costs. Acute tubular necrosis (ATN) is the most common cause of AKI. Cisplatin (CIS) is a platinum-based chemotherapeutic agent used in the treatment of a wide variety of malignancies such as lung, breast, ovary, testis, bladder, cervix, and head and neck cancers. Autophagy plays an important role in AKI. Galectin-3 (Gal-3) is significantly increased in renal tubules in AKI; however, its role in autophagy is not well understood. Male C57B6/J and B6.Cg-Lgals3 /J Gal-3 knockout (KO) mice were used to induce AKI using a CIS mouse model of ATN. Renal Gal-3 and autophagy proteins' expression were measured using standard histologic, immunofluorescent, and enzyme-linked immunosorbent assay techniques. The data were presented as the mean ± S.E. Statistically significant differences (p < 0.05) were calculated between experimental groups and corresponding control groups by one-way analysis of variance. There was a significant increase in renal concentrations of Gal-3 in the Gal-3 wild-type CIS-treated mice when compared with sham control mice. There were significantly higher concentrations of renal LC3B, ATG13, Ulk-1, Beclin, ATG5, ATG12, ATG9A, and p-AMPK in the CIS-treated Gal-3 KO mice than in the Gal-3 wild-type CIS-treated mice. Further, there were significantly higher concentrations of mTOR, p- NF-κB, beta-catenin, and p62 in the kidneys of the Gal-3 wild-type CIS-treated mice than in the Gal-3 KO CIS-treated mice. Our findings affirm the connection between Gal-3 and autophagy, revealing its central role as a connector with prosurvival signaling proteins. Gal-3 plays a pivotal role in orchestrating cellular responses by interacting with prosurvival signal pathways and engaging with autophagy proteins. Notably, our observations highlight that the absence of Gal-3 can enhance autophagy in CIS-induced ATN.

LEDT and Idebenone treatment modulate autophagy and improve regenerative capacity in the dystrophic muscle through an AMPK-pathway

PURPOSE

Considering the difficulties and challenges in Duchenne muscular dystrophy (DMD) treatment, such as the adverse effects of glucocorticoids, which are the main medical prescription used by dystrophic patients, new treatment concepts for dystrophic therapy are very necessary. Thus, in this study, we explore the effects of photobiomodulation (PBM; a non-invasive therapy) and Idebenone (IDE) treatment (a potent antioxidant), applied alone or in association, in dystrophic muscle cells and the quadriceps muscle, with special focus on autophagy and regenerative pathways.

METHODS

For the in vitro studies, the dystrophic primary muscle cells received 0.5J LEDT and 0.06μM IDE; and for the in vivo studies, the dystrophic quadriceps muscle received 3J LEDT and the mdx mice were treated with 200mg/kg IDE.

RESULTS

LEDT and IDE treatment modulate autophagy by increasing autophagy markers (SQSTM1/p62, Beclin and Parkin) and signaling pathways (AMPK and TGF-β). Concomitantly, the treatments prevented muscle degeneration by reducing the number of IgG-positive fibers and the fibers with a central nucleus; decreasing the fibrotic area; up-regulating the myogenin and MCH-slow levels; and down-regulating the MyoD and MHC-fast levels.

CONCLUSION

These results suggest that LEDT and IDE treatments enhance autophagy and prevented muscle degeneration in the dystrophic muscle of the experimental model. These findings illustrate the potential efficacy of LEDT and IDE treatment as an alternative therapy focused on muscle recovery in the dystrophic patient.

Unexpected roles for AMPK in the suppression of autophagy and the reactivation of mTORC1 signaling during prolonged amino acid deprivation

AMPK promotes catabolic and suppresses anabolic cell metabolism to promote cell survival during energetic stress, in part by inhibiting mTORC1, an anabolic kinase requiring sufficient levels of amino acids. We found that cells lacking AMPK displayed increased apoptotic cell death during nutrient stress caused by prolonged amino acid deprivation. We presumed that impaired autophagy explained this phenotype, as a prevailing view posits that AMPK initiates autophagy (often a pro-survival response) through phosphorylation of ULK1. Unexpectedly, however, autophagy remained unimpaired in cells lacking AMPK, as monitored by several autophagic readouts in several cell lines. More surprisingly, the absence of AMPK increased ULK1 signaling and LC3b lipidation during amino acid deprivation while AMPK-mediated phosphorylation of ULK1 S555 (a site proposed to initiate autophagy) decreased upon amino acid withdrawal or pharmacological mTORC1 inhibition. In addition, activation of AMPK with compound 991, glucose deprivation, or AICAR blunted autophagy induced by amino acid withdrawal. These results demonstrate that AMPK activation and glucose deprivation suppress autophagy. As AMPK controlled autophagy in an unexpected direction, we examined how AMPK controls mTORC1 signaling. Paradoxically, we observed impaired reactivation of mTORC1 in cells lacking AMPK upon prolonged amino acid deprivation. Together these results oppose established views that AMPK promotes autophagy and inhibits mTORC1 universally. Moreover, they reveal unexpected roles for AMPK in the suppression of autophagy and the support of mTORC1 signaling in the context of prolonged amino acid deprivation. These findings prompt a reevaluation of how AMPK and its control of autophagy and mTORC1 impact health and disease.

Targeting autophagy drug discovery: Targets, indications and development trends

Autophagy plays a vital role in sustaining cellular homeostasis and its alterations have been implicated in the etiology of many diseases. Drugs development targeting autophagy began decades ago and hundreds of agents were developed, some of which are licensed for the clinical usage. However, no existing intervention specifically aimed at modulating autophagy is available. The obstacles that prevent drug developments come from the complexity of the actual impact of autophagy regulators in disease scenarios. With the development and application of new technologies, several promising categories of compounds for autophagy-based therapy have emerged in recent years. In this paper, the autophagy-targeted drugs based on their targets at various hierarchical sites of the autophagic signaling network, e.g., the upstream and downstream of the autophagosome and the autophagic components with enzyme activities are reviewed and analyzed respectively, with special attention paid to those at preclinical or clinical trials. The drugs tailored to specific autophagy alone and combination with drugs/adjuvant therapies widely used in clinical for various diseases treatments are also emphasized. The emerging drug design and development targeting selective autophagy receptors (SARs) and their related proteins, which would be expected to arrest or reverse the progression of disease in various cancers, inflammation, neurodegeneration, and metabolic disorders, are critically reviewed. And the challenges and perspective in clinically developing autophagy-targeted drugs and possible combinations with other medicine are considered in the review.

Sorafenib extends the lifespan of C. elegans through mitochondrial uncoupling mechanism

Sorafenib is a targeted anticancer drug in clinic. Low-dose sorafenib has been reported to activate AMPK through inducing mitochondrial uncoupling without detectable toxicities. AMPK activation has been the approach for extending lifespan, therefore, we investigated the effect of sorafenib on lifespan and physical activity of C. elegans and the underlying mechanisms. In the present study, we found that the effect of sorafenib on C. elegans lifespan was typically hermetic. Sorafenib treatment at higher concentrations (100 μM) was toxic but at lower concentrations (1, 2.5, 5 μM) was beneficial to C. elegans. Sorafenib (1 μM) treatment for whole-life period extended C. elegans lifespan and improved C. elegans physical activity as manifested by increasing pharyngeal pumping and body movement, preserving intestinal barrier integrity, muscle fibers organization and mitochondrial morphology. In addition, sorafenib (1 μM) treatment enhanced C. elegans stress resistance. Sorafenib activated AMPK through inducing mitochondrial uncoupling in C. elegans. Sorafenib treatment activated DAF-16, SKN-1, and increased SOD-3, HSP-16.2, GST-4 expression in C. elegans. Sorafenib treatment induced AMPK-dependent autophagy in C. elegans. We conclude that low-dose sorafenib protects C. elegans against aging through activating AMPK/DAF-16 dependent anti-oxidant pathways and stimulating autophagy responses. Low-dose sorafenib could be a strategy for treating aging and aging-related diseases.

AMPK Signaling Pathway as a Potential Therapeutic Target for Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease caused by the loss of dopaminergic neurons. Genetic factors, inflammatory responses, oxidative stress, metabolic disorders, cytotoxic factors, and mitochondrial dysfunction are all involved in neuronal death in neurodegenerative diseases. The risk of PD can be higher in aging individuals due to decreased mitochondrial function, energy metabolism, and AMP-activated protein kinase (AMPK) function. The potential of AMPK to regulate neurodegenerative disorders lies in its ability to enhance antioxidant capacity, reduce oxidative stress, improve mitochondrial function, decrease mitophagy and macroautophagy, and inhibit inflammation. In addition, it has been shown that modulating the catalytic activity of AMPK can protect the nervous system. This article reviews the mechanisms by which AMPK activation can modulate PD.

Exploring the Prospective Role of Propolis in Modifying Aging Hallmarks

Aging populations worldwide are placing age-related diseases at the forefront of the research agenda. The therapeutic potential of natural substances, especially propolis and its components, has led to these products being promising agents for alleviating several cellular and molecular-level changes associated with age-related diseases. With this in mind, scientists have introduced a contextual framework to guide future aging research, called the hallmarks of aging. This framework encompasses various mechanisms including genomic instability, epigenetic changes, mitochondrial dysfunction, inflammation, impaired nutrient sensing, and altered intercellular communication. Propolis, with its rich array of bioactive compounds, functions as a potent functional food, modulating metabolism, gut microbiota, inflammation, and immune response, offering significant health benefits. Studies emphasize propolis' properties, such as antitumor, cardioprotective, and neuroprotective effects, as well as its ability to mitigate inflammation, oxidative stress, DNA damage, and pathogenic gut bacteria growth. This article underscores current scientific evidence supporting propolis' role in controlling molecular and cellular characteristics linked to aging and its hallmarks, hypothesizing its potential in geroscience research. The aim is to discover novel therapeutic strategies to improve health and quality of life in older individuals, addressing existing deficits and perspectives in this research area.

THSD1 Suppresses Autophagy-Mediated Focal Adhesion Turnover by Modulating the FAK-Beclin 1 Pathway

Focal adhesions (FAs) play a crucial role in cell spreading and adhesion, and their autophagic degradation is an emerging area of interest. This study investigates the role of Thrombospondin Type 1 Domain-Containing Protein 1 (THSD1) in regulating autophagy and FA stability in brain endothelial cells, shedding light on its potential implications for cerebrovascular diseases. Our research reveals a physical interaction between THSD1 and FAs. Depletion of THSD1 significantly reduces FA numbers, impairing cell spreading and adhesion. The loss of THSD1 also induces autophagy independently of changes in mTOR and AMPK activation, implying that THSD1 primarily governs FA dynamics rather than serving as a global regulator of nutrient and energy status. Mechanistically, THSD1 negatively regulates Beclin 1, a central autophagy regulator, at FAs through interactions with focal adhesion kinase (FAK). THSD1 inactivation diminishes FAK activity and relieves its inhibitory phosphorylation on Beclin 1. This, in turn, promotes the complex formation between Beclin 1 and ATG14, a critical event for the activation of the autophagy cascade. In summary, our findings identify THSD1 as a novel regulator of autophagy that degrades FAs in brain endothelial cells. This underscores the distinctive nature of THSD1-mediated, cargo-directed autophagy and its potential relevance to vascular diseases due to the loss of endothelial FAs. Investigating the underlying mechanisms of THSD1-mediated pathways holds promise for discovering novel therapeutic targets in vascular diseases.

Angiogenic activity of mitochondria; beyond the sole bioenergetic organelle

Angiogenesis is a complex process that involves the expansion of the pre-existing vascular plexus to enhance oxygen and nutrient delivery and is stimulated by various factors, including hypoxia. Since the process of angiogenesis requires a lot of energy, mitochondria play an important role in regulating and promoting this phenomenon. Besides their roles as an oxidative metabolism base, mitochondria are potential bioenergetics organelles to maintain cellular homeostasis via sensing alteration in oxygen levels. Under hypoxic conditions, mitochondria can regulate angiogenesis through different factors. It has been indicated that unidirectional and bidirectional exchange of mitochondria or their related byproducts between the cells is orchestrated via different intercellular mechanisms such as tunneling nanotubes, extracellular vesicles, and gap junctions to maintain the cell homeostasis. Even though, the transfer of mitochondria is one possible mechanism by which cells can promote and regulate the process of angiogenesis under reperfusion/ischemia injury. Despite the existence of a close relationship between mitochondrial donation and angiogenic response in different cell types, the precise molecular mechanisms associated with this phenomenon remain unclear. Here, we aimed to highlight the possible role of mitochondria concerning angiogenesis, especially the role of mitochondrial transport and the possible relation of this transfer with autophagy, the housekeeping phenomenon of cells, and angiogenesis.

Interconnection of cellular autophagy and endosomal vesicle trafficking and its role in hepatitis B virus replication and release

Hepatitis B virus (HBV) produces and releases various particle types, including complete virions, subviral particles with envelope proteins, and naked capsids. Recent studies demonstrate that HBV exploits distinct intracellular membrane trafficking pathways, including the endosomal vesicle trafficking and autophagy pathway, to assemble and release viral and subviral particles. Herein, we summarize the findings about the distinct roles of autophagy and endosomal membrane trafficking and the interaction of both pathways in HBV replication, assembly, and release.

Heat treatment in health and disease: How water-filtered infrared-A (wIRA) irradiation affects key cellular mechanisms in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients compared to healthy donors

Heat treatment or hyperthermia is a promising therapy for many diseases, especially cancer, and can be traced back thousands of years. Despite its long history, little is known about the cellular and molecular effects of heat on human cells. Therefore, we investigated the impact of water-filtered infrared-A (wIRA) irradiation (39 °C, 60 min) on key cellular mechanisms, namely autophagy, mitochondrial function and mRNA expression, in human fibroblasts and peripheral blood mononuclear cells (PBMCs) from healthy donors and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients. Our results show an induction of autophagy in healthy fibroblasts and PBMCs from healthy donors and ME/CFS patients. ME/CFS patients have higher mitochondrial function compared to healthy donors. The wIRA treatment leads to a slight reduction in mitochondrial function in PBMCs from ME/CFS patients, thereby approaching the level of mitochondrial function of healthy donors. Furthermore, an activation of the mRNA expression of the autophagy-related genes MAP1LC3B and SIRT1 as well as for HSPA1, which codes for a heat shock protein, can be observed. These results confirm an impact of heat treatment in human cells on key cellular mechanisms, namely autophagy and mitochondrial function, in health and disease, and provide hope for a potential treatment option for ME/CFS patients.

β-hydroxybutyrate administered at reperfusion reduces infarct size and preserves cardiac function by improving mitochondrial function through autophagy in male mice

Ischemia/reperfusion (I/R) injury after revascularization contributes ∼50% of infarct size and causes heart failure, for which no established clinical treatment exists. β-hydroxybutyrate (β-OHB), which serves as both an energy source and a signaling molecule, has recently been reported to be cardioprotective when administered immediately before I/R and continuously after reperfusion. This study aims to determine whether administering β-OHB at the time of reperfusion with a single dose can alleviate I/R injury and, if so, to define the mechanisms involved. We found plasma β-OHB levels were elevated during ischemia in STEMI patients, albeit not to myocardial protection level, and decreased after revascularization. In mice, compared with normal saline, β-OHB administrated at reperfusion reduced infarct size (by 50%) and preserved cardiac function, as well as activated autophagy and preserved mtDNA levels in the border zone. Our treatment with one dose β-OHB reached a level achievable with fasting and strenuous physical activity. In neonatal rat ventricular myocytes (NRVMs) subjected to I/R, β-OHB at physiologic level reduced cell death, increased autophagy, preserved mitochondrial mass, function, and membrane potential, in addition to attenuating reactive oxygen species (ROS) levels. ATG7 knockdown/knockout abolished the protective effects of β-OHB observed both in vitro and in vivo. Mechanistically, β-OHB's cardioprotective effects were associated with inhibition of mTOR signaling. In conclusion, β-OHB, when administered at reperfusion, reduces infarct size and maintains mitochondrial homeostasis by increasing autophagic flux (potentially through mTOR inhibition). Since β-OHB has been safely tested in heart failure patients, it may be a viable therapeutic to reduce infarct size in STEMI patients.

The role of autophagy in insulin resistance and glucolipid metabolism and potential use of autophagy modulating natural products in the treatment of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a severe, long-term condition characterised by disruptions in glucolipid and energy metabolism. Autophagy, a fundamental cellular process, serves as a guardian of cellular health by recycling and renewing cellular components. To gain a comprehensive understanding of the vital role that autophagy plays in T2DM, we conducted an extensive search for high-quality publications across databases such as Web of Science, PubMed, Google Scholar, and SciFinder and used keywords like 'autophagy', 'insulin resistance', and 'type 2 diabetes mellitus', both individually and in combinations. A large body of evidence underscores the significance of activating autophagy in alleviating T2DM symptoms. An enhanced autophagic activity, either by activating the adenosine monophosphate-activated protein kinase and sirtuin-1 signalling pathways or inhibiting the mechanistic target of rapamycin complex 1 signalling pathway, can effectively improve insulin resistance and balance glucolipid metabolism in key tissues like the hypothalamus, skeletal muscle, liver, and adipose tissue. Furthermore, autophagy can increase β-cell mass and functionality in the pancreas. This review provides a narrative summary of autophagy regulation with an emphasis on the intricate connection between autophagy and T2DM symptoms. It also discusses the therapeutic potentials of natural products with autophagy activation properties for the treatment of T2DM conditions. Our findings suggest that autophagy activation represents an innovative approach of treating T2DM.

The role and function of autophagy through signaling and pathogenetic pathways and lncRNAs in ovarian cancer

Lysosomal-driven autophagy is a tightly controlled cellular catabolic process that breaks down and recycles broken or superfluous cell parts. It is involved in several illnesses, including cancer, and is essential in preserving cellular homeostasis. Autophagy prevents DNA mutation and cancer development by actively eliminating pro-oxidative mitochondria and protein aggregates from healthy cells. Oncosuppressor and oncogene gene mutations cause dysregulation of autophagy. Increased autophagy may offer cancer cells a pro-survival advantage when oxygen and nutrients are scarce and resistance to chemotherapy and radiation. This finding justifies the use of autophagy inhibitors in addition to anti-neoplastic treatments. Excessive autophagy levels can potentially kill cells. The diagnosis and treatment of ovarian cancer present many difficulties due to its complexity and heterogeneity. Understanding the role of autophagy, a cellular process involved in the breakdown and recycling of cellular components, in ovarian cancer has garnered increasing attention in recent years. Of particular note is the increasing amount of data indicating a close relationship between autophagy and ovarian cancer. Autophagy either promotes or restricts tumor growth in ovarian cancer. Dysregulation of autophagy signaling pathways in ovarian cancers can affect the development, metastasis, and response to tumor treatment. The precise mechanism underlying autophagy concerning ovarian cancer remains unclear, as does the role autophagy plays in ovarian carcinoma. In this review, we tried to encapsulate and evaluate current findings in investigating autophagy in ovarian cancer.

The Role of AMPK Signaling in Ulcerative Colitis

Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease characterized by inflammation and ulcer formation of the intestinal mucosa. Due to its high recurrence rate, prolonged course, limited curative options, and significant impact on patients' quality of life, along with a notable potential for malignant transformation, UC is designated as a refractory global health challenge by the World Health Organization (WHO). The elucidation of the pathogenesis and therapeutic strategies for UC requires further in-depth investigation. AMP-activated protein kinase (AMPK) serves as a central regulator of cellular energy metabolic homeostasis. Emerging evidence indicates that interventions involving traditional Chinese medicine (TCM) components, as well as other pharmacological measures, exert beneficial effects on the intestinal mucosal inflammation and epithelial barrier dysfunction in UC by modulating AMPK signaling, thereby influencing biological processes such as cellular autophagy, apoptosis, inflammatory responses, macrophage polarization, and NLRP3 inflammasome-mediated pyroptosis. The role of AMPK in UC is of significant importance. This manuscript provides a comprehensive overview of the mechanisms through which AMPK is involved in UC, as well as a compilation of pharmacological agents capable of activating the AMPK signaling pathway within the context of UC. The primary objective is to facilitate a deeper comprehension of the pivotal role of AMPK in UC among researchers and clinical practitioners, thereby advancing the identification of novel therapeutic targets for interventions in UC.

Chronic Ouabain Targets Pore-Forming Claudin-2 and Ameliorates Radiation-Induced Damage to the Rat Intestinal Tissue Barrier

Ionizing radiation (IR) causes disturbances in the functions of the gastrointestinal tract. Given the therapeutic potential of ouabain, a specific ligand of the Na,K-ATPase, we tested its ability to protect against IR-induced disturbances in the barrier and transport properties of the jejunum and colon of rats. Male Wistar rats were subjected to 6-day intraperitoneal injections of vehicle or ouabain (1 µg/kg/day). On the fourth day of injections, rats were exposed to total-body X-ray irradiation (10 Gy) or a sham irradiation. Isolated tissues were examined 72 h post-irradiation. Electrophysiological characteristics and paracellular permeability for sodium fluorescein were measured in an Ussing chamber. Histological analysis and Western blotting were also performed. In the jejunum tissue, ouabain exposure did not prevent disturbances in transepithelial resistance, paracellular permeability, histological characteristics, as well as changes in the expression of claudin-1, -3, -4, tricellulin, and caspase-3 induced by IR. However, ouabain prevented overexpression of occludin and the pore-forming claudin-2. In the colon tissue, ouabain prevented electrophysiological disturbances and claudin-2 overexpression. These observations may reveal a mechanism by which circulating ouabain maintains tight junction integrity under IR-induced intestinal dysfunction.

Anthocyanin Oligomers Induce Apoptosis and Autophagy by Inhibiting the mTOR Signaling Pathway in Human Breast Cancer Cells

Anthocyanin oligomers (AOs) are phytochemicals synthesized by fermenting anthocyanins extracted from grape skins and are more biologically active than monomeric anthocyanins. In this study, we evaluate the effects of an AO on triple-negative MDA-MB-231 and HER2-overexpressing SK-BR-3 breast cancer cells. The cell viability of MDA-MB-231 and SK-BR-3 cells was significantly inhibited in a concentration-dependent manner by AO treatment for 24 h, while delphinidin (a monomeric anthocyanin) had no effect on cell viability. In addition, the AO increased H2A.X phosphorylation (a marker of DNA damage), reduced RAD51 (a DNA repair protein) and survivin (a cell survival factor) protein levels, and induced apoptosis by caspase-3-dependent PARP1 cleavage in both cell lines. Surprisingly, the AO induced autophagy by increasing intracellular LC3-II puncta and LC3-II and p62 protein levels. In addition, the AO inhibited the mTOR pathway in MDA-MB-231 and SK-BR-3 cells by suppressing the HER2, EGFR1, and AKT pathways. These results demonstrate that the anti-cancer effect of the AO was due to the induction of apoptosis and autophagy via cleaved caspase-3-mediated PARP1 cleavage and mTOR pathway inhibition, respectively. Furthermore, our results suggest that anthocyanin oligomers could be considered potential candidates for breast cancer treatment.

FGF21 Improves Glycolipid Metabolism in Rainbow Trout (Oncorhynchus mykiss) Fed a High-Carbohydrate Diet by Inhibiting Inflammatory Responses and Activating Autophagy

In this study, the coding region of rainbow trout fgf21 was cloned and sequenced to synthesize a recombinant protein (rFGF21) and investigate its potential role in improving glycolipid metabolism. Acute injection of rFGF21 into rainbow trout effectively reduced serum glucose levels. To investigate the effect of rFGF21 on high-carbohydrate diet (HCD)-induced metabolic disorders in rainbow trout, a 31-day feeding experiment was conducted. At the end of the third week, fish were injected with either PBS or rFGF21. The results showed that the final body weight (FBW) significantly increased in rainbow trout on an HCD (P < 0.05), but there were potential risks including disturbances in glycolipid metabolism and increased inflammatory responses. However, these effects were altered by rFGF21 treatment. In addition, rFGF21 promotes glucose uptake by increasing the phosphorylation levels of AKT (protein kinase B) and GSK3β (glycogen synthase kinase 3β), increasing hepatic glycogen, thereby lowering serum glucose. Notably, the rFGF21 did not exacerbate the inflammatory response but downregulated the expression of inflammatory factors. Interestingly, the activation of autophagy and the AMPK pathway may contribute to the positive effect of rFGF21, where rFGF21 injection significantly increased the levels of LC3I/II protein and phosphorylate AMPKα (P < 0.05).

Impaired Autophagic Flux in Glucose-Deprived Cells: An Outcome of Lysosomal Acidification Failure Exacerbated by Mitophagy Dysfunction

Autophagy dysfunction is associated with human diseases and conditions including neurodegenerative diseases, metabolic issues, and chronic infections. Additionally, the decline in autophagic activity contributes to tissue and organ dysfunction and aging-related diseases. Several factors, such as down-regulation of autophagy components and activators, oxidative damage, microinflammation, and impaired autophagy flux, are linked to autophagy decline. An autophagy flux impairment (AFI) has been implicated in neurological disorders and in certain other pathological conditions. Here, to enhance our understanding of AFI, we conducted a comprehensive literature review of findings derived from two well-studied cellular stress models: glucose deprivation and replicative senescence. Glucose deprivation is a condition in which cells heavily rely on oxidative phosphorylation for ATP generation. Autophagy is activated, but its flux is hindered at the autolysis step, primarily due to an impairment of lysosomal acidity. Cells undergoing replicative senescence also experience AFI, which is also known to be caused by lysosomal acidity failure. Both glucose deprivation and replicative senescence elevate levels of reactive oxygen species (ROS), affecting lysosomal acidification. Mitochondrial alterations play a crucial role in elevating ROS generation and reducing lysosomal acidity, highlighting their association with autophagy dysfunction and disease conditions. This paper delves into the underlying molecular and cellular pathways of AFI in glucose-deprived cells, providing insights into potential strategies for managing AFI that is driven by lysosomal acidity failure. Furthermore, the investigation on the roles of mitochondrial dysfunction sheds light on the potential effectiveness of modulating mitochondrial function to overcome AFI, offering new possibilities for therapeutic interventions.

Mechanisms of weight-loss effect in obese mice by the endogenous cannabinoid receptor 2 agonist beta-caryophyllene

BACKGROUND AND AIMS

The endogenous cannabinoid system (ECS) is involved in the regulation of a variety of physiological activities in the body, such as metabolism and energy uptake, and cannabinoid receptor 2 (CNR2) is one of these receptors that is predominantly distributed in the periphery. β-caryophyllene (BCP) is an agonist of CNR2 which is known to possess pharmacological activities such as anti-inflammatory and antioxidant properties. In this study, we wanted to investigate whether BCP possesses pharmacological effects on obese mice and its mechanism.

METHODS

Reversed feeding rhythm, propylthiouracil was delivered intraperitoneally, and BCP was gavaged once daily for four weeks to establish a hyperlipidemic obese mouse model. A glucose tolerance test, lipid level measurements, liver, peritoneal, and subcutaneous fat removal, HE and Oil Red O staining of the liver, and immunohistochemistry (IHC) staining with an anti-CNR2 antibody were all carried out. The liver was examined using tools like GO and KEGG databases for differentially expressed genes and signaling pathways linked to medication effectiveness.

RESULTS

BCP had significant effects on weight reduction and improvement of dyslipidemia. What's more, it significantly reduced body fat percentage, improved steatosis and ballooning of liver cells, and reduced fat accumulation, while inhibiting the proliferation of peri-abdominal adipocytes. BCP exerted its effects to improve dyslipidemia and reduce body weight probably through circadian regulation and cholesterol metabolic pathways. Finally, and its efficacy in improving dyslipidemia and reducing body weight may be mainly through activating CNR2, activating SIRT1/PGC-1α/PPARγ and SIRT1/AMPK pathways.

CONCLUSION

BCP activates the CNR2, SIRT1/PGC-1α/PPARγ signaling pathway, and SIRT1/AMPK signaling pathway to exert dyslipidemia-improving and weight-loss effects.

Kaempferol stimulation of autophagy regulates the ferroptosis under the oxidative stress as mediated with AMP-activated protein kinase

Recent studies have highlighted the positive effects of Kaempferol (KP), including its anti-inflammatory and antioxidant properties. However, its impact on oxidative damage induced by heavy metals and pro-inflammatory mediators, such as arachidonic acid (AA), has not yet been identified. Our objective was to specifically evaluate liver damage due to AA + iron-induced oxidative stress, both in vitro and in vivo. In HepG2 cells, KP activated the AMP-activated protein kinase (AMPK), suggesting a hepatoprotective effect through AMPK inhibition, as assessed by immunoblot and FACS analysis (EC50 = 10 μM). KP also stimulated autophagy, a degradation process that eliminates aged, damaged, and unnecessary components, via mTOR inhibition and ULK1 phosphorylation. This activation was further validated by the upregulation of autophagy-related genes (ATG5) and Beclin-1, along with the conversion of LC3BI to LC3BII. Ferroptosis, a non-apoptotic type of cell death characterized by oxidative stress from the production of reactive oxygen species (ROS) and excessive iron accumulation, was linked to the activation of autophagy, as confirmed through the protein expression of deferoxamine (DFO) and ferrostatin-1 (Fer-1), the representative ferroptosis inhibitors (positive controls). In mice, oral administration of KP demonstrated protective effects against CCl4-induced hepatotoxicity. In conclusion, KP provides hepatoprotective effects against oxidative stress induced by AA + iron treatment in vitro and CCl4 treatment in vivo.

Anti-inflammation is an important way that Qingre-Huazhuo-Jiangsuan recipe treats acute gouty arthritis

Background: Acute gouty arthritis (AGA) significantly impairs patients' quality of life. Currently, existing therapeutic agents exhibit definite efficacy but also lead to serious adverse reactions. Therefore, it is essential to develop highly efficient therapeutic agents with minimal adverse reactions, especially within traditional Chinese medicine (TCM). Additionally, food polyphenols have shown potential in treating various inflammatory diseases. The Qingre-Huazhuo-Jiangsuan-Recipe (QHJR), a modification of Si-Miao-San (SMS), has emerged as a TCM remedy for AGA with no reported side effects. Recent research has also highlighted a strong genetic link to gout. Methods: The TCM System Pharmacology (TCMSP) database was used to collect the main chemical components of QHJR and AGA-related targets for predicting the metabolites in QHJR. HPLC-Q-Orbitrap-MS was employed to identify the ingredients of QHJR. The collected metabolites were then used to construct a Drugs-Targets Network in Cytoscape software, ranked based on their "Degree" of significance. Differentially expressed genes (DEGs) were screened in the Gene Expression Omnibus (GEO) database using GEO2R online analysis. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. The DEGs were utilized to construct a Protein-Protein Interaction (PPI) Network via the STRING database. In vivo experimental validation was conducted using colchicine, QHJR, rapamycin (RAPA), and 3-methyladenine (3-MA) as controls to observe QHJR's efficacy in AGA. Synovial tissues from rats were collected, and qRT-PCR and Western blot assays were employed to investigate Ampk-related factors (Ampk, mTOR, ULK1), autophagy-related factors (Atg5, Atg7, LC3, p62), and inflammatory-related factors (NLRP3). ELISA assays were performed to measure inflammatory-related factor levels (IL-6, IL-1β, TNF-α), and H&E staining was used to examine tissue histology. Results: Network analysis screened out a total of 94 metabolites in QHJR for AGA. HPLC-Q-Orbitrap-MS analysis identified 27 of these metabolites. Notably, five metabolites (Neochlorogenic acid, Caffeic acid, Berberine, Isoliquiritigenin, Formononetin) were not associated with any individual herbal component of QHJR in TCMSP database, while six metabolites (quercetin, luteolin, formononetin, naringenin, taxifolin, diosgenin) overlapped with the predicted results from the previous network analysis. Further network analysis highlighted key components, such as Caffeic acid, cis-resveratrol, Apigenin, and Isoliquiritigenin. Other studies have found that their treatment of AGA is achieved through reducing inflammation, consistent with this study, laying the foundation for the mechanism study of QHJR against AGA. PPI analysis identified TNF, IL-6, and IL-1β as hub genes. GO and KEGG analyses indicated that anti-inflammation was a key mechanism in AGA treatment. All methods demonstrated that inflammatory expression increased in the Model group but was reversed by QHJR. Additionally, autophagy-related expression increased following QHJR treatment. The study suggested that AMPKα and p-AMPKα1 proteins were insensitive to 3 MA and RAPA, implying that AMPK may not activate autophagy directly but through ULK1 and mTOR. Conclusion: In conclusion, this study confirms the effectiveness of QHJR, a modified formulation of SMS (a classic traditional Chinese medicine prescription for treating gout), against AGA. QHJR, as a TCM formula, offers advantages such as minimal safety concerns and potential long-term use. The study suggests that the mechanism by which QHJR treats AGA may involve the activation of the AMPK/mTOR/ULK1 pathway, thereby regulating autophagy levels, reducing inflammation, and alleviating AGA. These findings provide new therapeutic approaches and ideas for the clinical treatment of AGA.

Physiological and genetic regulation of anhydrobiosis in yeast cells

Anhydrobiosis is a state of living organisms during which their metabolism is reversibly delayed or suspended due to a high degree of dehydration. Yeast cells, which are widely used in the food industry, may be induced into this state. The degree of viability of yeast cells undergoing the drying process also depends on rehydration. In an attempt to explain the essence of the state of anhydrobiosis and clarify the mechanisms responsible for its course, scientists have described various cellular compounds and structures that are responsible for it. The structures discussed in this work include the cell wall and plasma membrane, vacuoles, mitochondria, and lysosomes, among others, while the most important compounds include trehalose, glycogen, glutathione, and lipid droplets. Various proteins (Stf2p; Sip18p; Hsp12p and Hsp70p) and genes (STF2; Nsip18; TRX2; TPS1 and TPS2) are also responsible for the process of anhydrobiosis. Each factor has a specific function and is irreplaceable, detailed information is presented in this overview.

Omega-3 Fatty Acids Attenuate Renal Fibrosis via AMPK-Mediated Autophagy Flux Activation

The unilateral ureteral obstruction (UUO) injury model is well-known to mimic human chronic kidney disease, promoting the rapid onset and development of kidney injury. ω3-poly unsaturated fatty acids (PUFAs) have been observed to protect against tissue injury in many disease models. In this study, we assessed the efficacy of ω3-PUFAs in attenuating UUO injury and investigated their mechanism of action. The immortalized human proximal tubular cells human kidney-2 (HK2) were incubated for 72 h with docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) in various concentrations, in the presence or absence of transforming growth factor (TGF)-β. DHA/EPA reduced the epithelial-mesenchymal transition in the TGF-β-treated HK2 cells by enhancing autophagy flux and adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. C57BL/6 mice were divided into four groups and treated as follows: sham (no treatment, n = 5), sham + ω3-PUFAs (n = 5), UUO (n = 10), and UUO + ω3-PUFAs (n = 10). Their kidneys and blood were harvested on the seventh day following UUO injury. The kidneys of the ω3-PUFAs-treated UUO mice showed less oxidative stress, inflammation, and fibrosis compared to those of the untreated UUO mice. Greater autophagic flux, higher amounts of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II, Beclin-1, and Atg7, lower amounts of p62, and higher levels of cathepsin D and ATP6E were observed in the kidneys of the omega-3-treated UUO mice compared to those of the control UUO mice. In conclusion, ω3-PUFAs enhanced autophagic activation, leading to a renoprotective response against chronic kidney injury.

Autophagy in BRAF-mutant cutaneous melanoma: recent advances and therapeutic perspective

Macroautophagy, hereafter referred to as autophagy, represents a highly conserved catabolic process that maintains cellular homeostasis. At present, the role of autophagy in cutaneous melanoma (CM) is still controversial, since it appears to be tumor-suppressive at early stages of malignant transformation and cancer-promoting during disease progression. Interestingly, autophagy has been found to be often increased in CM harboring BRAF mutation and to impair the response to targeted therapy. In addition to autophagy, numerous studies have recently conducted in cancer to elucidate the molecular mechanisms of mitophagy, a selective form of mitochondria autophagy, and secretory autophagy, a process that facilitates unconventional cellular secretion. Although several aspects of mitophagy and secretory autophagy have been investigated in depth, their involvement in BRAF-mutant CM biology has only recently emerged. In this review, we aim to overview autophagy dysregulation in BRAF-mutant CM, along with the therapeutic advantages that may arise from combining autophagy inhibitors with targeted therapy. In addition, the recent advances on mitophagy and secretory autophagy involvement in BRAF-mutant CM will be also discussed. Finally, since a number of autophagy-related non-coding RNAs (ncRNAs) have been identified so far, we will briefly discussed recent advances linking ncRNAs to autophagy regulation in BRAF-mutant CM.

Alpinumisoflavone Activates Disruption of Calcium Homeostasis, Mitochondria and Autophagosome to Suppress Development of Endometriosis

Alpinumisoflavone is an isoflavonoid extracted from the Cudrania tricuspidate fruit and Genista pichisermolliana. It has various physiological functions, such as anti-inflammation, anti-proliferation, and apoptosis, in malignant tumors. However, the effect of alpinumisoflavone is still not known in chronic diseases and other benign reproductive diseases, such as endometriosis. In this study, we examined the cell death effects of alpinumisoflavone on the endometriosis cell lines, End1/E6E7 and VK2/E6E7. Results indicated that alpinumisoflavone inhibited cell migration and proliferation and led to cell cycle arrest, depolarization of mitochondria membrane potential, apoptosis, and disruption of calcium homeostasis in the endometriosis cell lines. However, the cellular proliferation of normal uterine epithelial cells was not changed by alpinumisoflavone. The alteration in Ca²⁺ levels was estimated in fluo-4 AM-stained End1/E6E7 and VK2/E6E7 cells after alpinumisoflavone treatment with or without calcium inhibitor, 2-aminoethoxydiphenyl borate (2-APB). The results indicated that a combination of alpinumisoflavone and a calcium inhibitor reduced the calcium accumulation in the cytosol of endometriosis cells. Additionally, alpinumisoflavone decreased oxidative phosphorylation (OXPHOS) in the endometriotic cells. Moreover, protein expression analysis revealed that alpinumisoflavone inactivated AKT signaling pathways, whereas it increased MAPK, ER stress, and autophagy regulatory proteins in End1/E6E7 and VK2/E6E7 cell lines. In summary, our results suggested that alpinumisoflavone could be a promising effective management agent or an adjuvant therapy for benign disease endometriosis.

The mitochondrial uncoupling effects of nitazoxanide enhances cellular autophagy and promotes the clearance of α-synuclein: Potential role of AMPK-JNK pathway

Upregulation and aggregation of the pre-synaptic protein, α-synuclein plays a key role in Parkinson's disease (PD) and mitochondrial dysfunction was surmised to be an upstream event in the disease pathogenesis. Emerging reports identified the role of nitazoxanide (NTZ), an anti-helminth drug, in enhancing mitochondrial oxygen consumption rate (OCR) and autophagy. In the present study, we have examined the mitochondrial effects of NTZ in mediating cellular autophagy and subsequent clearance of both endogenous and pre-formed aggregates of α-synuclein in cellular model of PD. Our results demonstrate that the mitochondrial uncoupling effects of NTZ results in the activation of AMPK and JNK, which in-turn leads to the enhancement of cellular autophagy. Also,1-methyl-4-phenylpyridinium (MPP⁺) mediated decrease in autophagic flux with a concomitant increase in the α-synuclein levels were ameliorated in cells treated with NTZ. However, in cells lacking functional mitochondria (ρ0 cells), NTZ did not mitigate MPP⁺ mediated alterations in the autophagic clearance of α-synuclein, indicating that the mitochondrial effects of NTZ play a crucial role in the clearance of α-synuclein by autophagy. Also, the ability of AMPK inhibitor, compound C, in abrogating NTZ mediated enhancement in the autophagic flux and α-synuclein clearance highlight the pivotal role of AMPK in NTZ mediated autophagy. Further, NTZ per se enhanced the clearance of preformed α-synuclein aggregates that were exogenously added to the cells. Overall, the results of our present study suggest that NTZ activates macroautophagy in cells due to its uncoupling effects on mitochondrial respiration via activation of AMPK-JNK pathway resulting in the clearance of both endogenous and pre-formed α-synuclein aggregates. As NTZ happens to possess good bioavailability and safety profile, considering this drug for PD based on its mitochondrial uncoupling and autophagy enhancing properties for mitigating mitochondrial reactive oxygen species (ROS) and α-synuclein toxicity appears to be a promising therapeutic option.

Inhibition of autophagy; an opportunity for the treatment of cancer resistance

The process of macroautophagy plays a pivotal role in the degradation of long-lived, superfluous, and damaged proteins and organelles, which are later recycled for cellular use. Normal cells rely on autophagy to combat various stressors and insults to ensure survival. However, autophagy is often upregulated in cancer cells, promoting a more aggressive phenotype that allows mutated cells to evade death after exposure to therapeutic treatments. As a result, autophagy has emerged as a significant factor in therapeutic resistance across many cancer types, with underlying mechanisms such as DNA damage, cell cycle arrest, and immune evasion. This review provides a comprehensive summary of the role of autophagy in therapeutic resistance and the limitations of available autophagic inhibitors in cancer treatment. It also highlights the urgent need to explore new inhibitors that can synergize with existing therapies to achieve better patient treatment outcomes. Advancing research in this field is crucial for developing more effective treatments that can help improve the lives of cancer patients.

Asymmetric dimethylation of AMPKα1 by PRMT6 contributes to the formation of phase-separated puncta

AMP-activated protein kinase (AMPK) is a heterotrimeric serine/threonine kinase comprising α, β, and γ subunits. AMPK is involved in intracellular energy metabolism and functions as a switch that turns various biological pathways in eukaryotes on and off. Several post-translational modifications regulating AMPK function have been demonstrated, including phosphorylation, acetylation, and ubiquitination; however, arginine methylation has not been reported in AMPKα1. We investigated whether arginine methylation occurs in AMPKα1. Screening experiments revealed arginine methylation of AMPKα1 mediated by protein arginine methyltransferase 6 (PRMT6). In vitro methylation and co-immunoprecipitation assays indicated that PRMT6 can directly interact with and methylate AMPKα1 without involvement of other intracellular components. In vitro methylation assays with truncated and point mutants of AMPKα1 revealed that Arg403 is the residue methylated by PRMT6. Immunocytochemical studies showed that the number of AMPKα1 puncta was enhanced in saponin-permeabilized cells when AMPKα1 was co-expressed with PRMT6, suggesting that PRMT6-mediated methylation of AMPKα1 at Arg403 alters the physiological characteristics of AMPKα1 and may lead to liquid-liquid phase separation.

Hydroxytyrosol Interference with Inflammaging via Modulation of Inflammation and Autophagy

Inflammaging refers to a chronic, systemic, low-grade inflammation, driven by immune (mainly macrophages) and non-immune cells stimulated by endogenous/self, misplaced or altered molecules, belonging to physiological aging. This age-related inflammatory status is characterized by increased inflammation and decreased macroautophagy/autophagy (a degradation process that removes unnecessary or dysfunctional cell components). Inflammaging predisposes to age-related diseases, including obesity, type-2 diabetes, cancer, cardiovascular and neurodegenerative disorders, as well as vulnerability to infectious diseases and vaccine failure, representing thus a major target for anti-aging strategies. Phenolic compounds-found in extra-virgin olive oil (EVOO)-are well known for their beneficial effect on longevity. Among them, hydroxytyrosol (HTyr) appears to greatly contribute to healthy aging by its documented potent antioxidant activity. In addition, HTyr can modulate inflammation and autophagy, thus possibly counteracting and reducing inflammaging. In this review, we reference the literature on pure HTyr as a modulatory agent of inflammation and autophagy, in order to highlight its possible interference with inflammaging. This HTyr-mediated activity might contribute to healthy aging and delay the development or progression of diseases related to aging.

Chemotherapy-Induced Molecular Changes in Skeletal Muscle

Paraneoplastic conditions such as cancer cachexia are often exacerbated by chemotherapy, which affects the patient’s quality of life as well as the response to therapy. The aim of this narrative review was to overview the body-composition-related changes and molecular effects of different chemotherapy agents used in cancer treatment on skeletal-muscle remodeling. A literature search was performed using the Web of Science, Scopus, and Science Direct databases and a total of 77 papers was retrieved. In general, the literature survey showed that the molecular changes induced by chemotherapy in skeletal muscle have been studied mainly in animal models and mostly in non-tumor-bearing rodents, whereas clinical studies have essentially assessed changes in body composition by computerized tomography. Data from preclinical studies showed that chemotherapy modulates several molecular pathways in skeletal muscle, including the ubiquitin–proteasome pathway, autophagy, IGF-1/PI3K/Akt/mTOR, IL-6/JAK/STAT, and NF-κB pathway; however, the newest chemotherapy agents are underexplored. In conclusion, chemotherapy exacerbates skeletal-muscle wasting in cancer patients; however, the incomplete characterization of the chemotherapy-related molecular effects on skeletal muscle makes the development of new preventive anti-wasting strategies difficult. Therefore, further investigation on molecular mechanisms and clinical studies are necessary.

Chinese herbal medicine and its active compounds in attenuating renal injury via regulating autophagy in diabetic kidney disease

Diabetic kidney disease (DKD) is the main cause of end-stage renal disease worldwide, and there is a lack of effective treatment strategies. Autophagy is a highly conserved lysosomal degradation process that maintains homeostasis and energy balance by removing protein aggregates and damaged organelles. Increasing evidence suggests that dysregulated autophagy may contribute to glomerular and tubulointerstitial lesions in the kidney under diabetic conditions. Emerging studies have shown that Chinese herbal medicine and its active compounds may ameliorate diabetic kidney injury by regulating autophagy. In this review, we summarize that dysregulation or insufficiency of autophagy in renal cells, including podocytes, glomerular mesangial cells, and proximal tubular epithelial cells, is a key mechanism for the development of DKD, and focus on the protective effects of Chinese herbal medicine and its active compounds. Moreover, we systematically reviewed the mechanism of autophagy in DKD regulated by Chinese herb compound preparations, single herb and active compounds, so as to provide new drug candidates for clinical treatment of DKD. Finally, we also reviewed the candidate targets of Chinese herbal medicine regulating autophagy for DKD. Therefore, further research on Chinese herbal medicine with autophagy regulation and their targets is of great significance for the realization of new targeted therapies for DKD.