Autophagy: cellular and molecular mechanisms

Role of Autophagy in Myocardial Remodeling After Myocardial Infarction

ABSTRACT

Autophagy is the process of reusing the body's senescent and damaged cell components, which can be regarded as the cellular circulatory system. There are 3 distinct forms of autophagy: macroautophagy, microautophagy, and chaperone-mediated autophagy. In the heart, autophagy is regulated mainly through mitophagy because of the metabolic changes of cardiomyocytes caused by ischemia and hypoxia. Myocardial remodeling is characterized by gradual heart enlargement, cardiac dysfunction, and extraordinary molecular changes. Cardiac remodeling after myocardial infarction is almost inevitable, which is the leading cause of heart failure. Autophagy has a protective effect on myocardial remodeling improvement. Autophagy can minimize cardiac remodeling by preventing misfolded protein accumulation and oxidative stress. This review summarizes the nestest molecular mechanisms of autophagy and myocardial remodeling, the protective effects, and the new target of autophagy medicine in cardiac remodeling. The future development and challenges of autophagy in heart disease are also summarized.

1,3-butanediol administration as an alternative strategy to calorie restriction for neuroprotection - Insights into modulation of stress response in hippocampus of healthy rats

Ketogenic diet has a wide range of beneficial effects but presents practical limitations due to its low compliance, hence dietary supplements have been developed to induce ketosis without nutrient deprivation. The alcohol 1,3-butanediol (BD) is a promising molecule for its ability to induce ketosis, but its effects on brain have been investigated so far only in disease models, but never in physiological conditions. To support BD use to preserve brain health, the analysis of its activity is mandatory. Therefore, we investigated, in healthy rats, the effect of a fourteen-days BD-administration on the hippocampus, an area particularly vulnerable to oxidative and inflammatory damage. Since BD treatment has been reported to reduce energy intake, results were compared with those obtained from rats undergoing a restricted dietary regimen, isoenergetic with BD group (pair fed, PF). Reduced pro-inflammatory signaling pathways and glial activation were revealed in hippocampus of BD treated rats in comparison to control (C) and PF groups. ROS content and the extent of protein oxidative damage were lower in BD and PF groups than in C. Interestingly, higher amounts of nuclear factor erythroid 2-related factor 2 (Nrf2), decreased level of lipid hydroperoxides, lower susceptibility to oxidative insult, higher amounts of superoxide dismutase-2, glutathione reductase and glutathione peroxidase (GPx), and increased GPx activity were observed in BD animals. BD administration, but not dietary restriction, attenuated endoplasmic reticulum stress, reduced autophagic response activation, and was associated with an increase of both the neurotrophin BDNF and pre-synaptic proteins synaptophysin and synaptotagmin. Our results highlight that BD plays a neuroprotective role in healthy conditions, thus emerging as an effective strategy to support brain function without the need of implementing ketogenic nutritional interventions.

Pharmacological activity, phytochemistry, and organ protection of lithospermic acid

Lithospermic acid (LA) is a water-soluble phenolic acid compound extracted and separated from the dried root and the rhizome of Salviamiltiorrhiza Bge (Labiatae), possessing multiple biological activities. Firstly, in terms of pharmacological activities, LA has been proven to possess anti-inflammatory, antioxidant, autophagy activation, and antiapoptotic properties. Secondly, the pharmacokinetic characteristics of LA show rapid and extensive distribution in various tissues after intravenous administration, followed by rapid elimination and excretion. Additionally, potential therapeutic effects of LA have been found in various diseases such as thrombosis, Parkinson's disease, hepatitis B, diabetes, and psoriasis, among others. Particularly, LA has shown promising prospects in the treatment of clinical heart diseases and has been included in new drug formulations for the treatment of chronic angina, demonstrating superior efficacy compared to current cardiovascular drugs. In conclusion, this review comprehensively introduces the pharmacological mechanisms, pharmacokinetics, and protective effects in diseases of LA. These information can lay a theoretical foundation for the future development and new clinical applications of LA.

Lipids determine the toxicity of human islet polypeptide aggregates in vivo

The onset and progression of type 2 diabetes is linked to the accumulation and aggregation of human islet amyloid polypeptide (hIAPP) in the pancreas. Amyloid oligomers and fibrils formed as a result of such aggregation exert high cytotoxicity. Although some pieces of evidence suggest that lipids could alter the rate of hIAPP aggregation, the effect of lipids on the aggregation properties of this peptide remains unclear. In this study, we investigate the effect of sphingophospholipid and anionic and zwitterionic phospholipids with different lengths of fatty acids on the aggregation of hIAPP. We found that anionic lipids drastically accelerate peptide aggregation, whereas this effect was substantially weaker for sphingophospholipid and zwitterionic phospholipid. Biophysical analysis revealed that the presence of lipids resulted in substantial differences in morphology and secondary structure of hIAPP fibrils compared to the protein aggregates grown in the lipid-free environment. We also found that zwitterionic phospholipids drastically increased cytotoxicity of hIAPP aggregates, whereas this effect was less evident for sphingophospholipid and anionic phospholipid. Our results showed that drastic differences in lipid-determined cytotoxicity of hIAPP aggregates were linked to molecular mechanisms of autophagy, exocytosis, and unfolded protein response. These findings suggest that molecular candidates that could disrupt protein-lipid interactions would allow for deceleration of the onset and progression of type 2 diabetes.

Guarding against digestive-system cancers: Unveiling the role of Chk2 as a potential therapeutic target

Digestive-system cancers represent major threats to human health; however, the mechanisms underlying tumorigenesis and radiochemotherapy resistance have remained elusive. Therefore, an urgent need exists for identifying key drivers of digestive system tumorigenesis and novel targeted therapeutics. The checkpoint kinase 2 (Chk2) regulates cell-cycle progression, and Chk2 dysregulation or Chk2 mutations can lead to the development of various cancers, which makes Chk2 an important research topic. This review summarizes the roles of Chk2 in DNA-damage responses, cell-cycle regulation, autophagy, and homeostasis maintenance. We describe relationships between tumorigenesis and cell-cycle dysregulation induced by Chk2 mutations. In addition, we summarize evidence indicating that Chk2 can serve as a novel therapeutic target, based on its contributions to radiochemotherapy-resistance reversion and progress made in developing antitumor agents against Chk2. The prevailing evidence supports the conclusion that further research on Chk2 will provide a deeper understanding of digestive-system tumorigenesis and should suggest novel therapeutic targets.

Optimizing autophagy modulation for enhanced TRAIL-mediated therapy: Unveiling the superiority of late-stage inhibition over early-stage inhibition to overcome therapy resistance in cancer

Autophagy is a vital mechanism that eliminates large cytoplasmic components via lysosomal degradation to maintain cellular homeostasis. The role of autophagy in cancer treatment has been studied extensively. Autophagy primarily prevents tumour initiation by maintaining genomic stability and preventing cellular inflammation. However, autophagy also supports cancer cell survival and growth by providing essential nutrients for therapeutic resistance. Thus, autophagy has emerged as a promising strategy for overcoming resistance and enhancing anti-cancer therapy. Inhibiting autophagy significantly improves the sensitivity of lung, colorectal, breast, liver and prostate cancer cells to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). This review investigates the intricate interplay between autophagy modulation and TRAIL-based therapy, specifically focussing on comparing the efficacy of late-stage autophagy inhibition versus early-stage inhibition in overcoming cancer resistance. We expose the distinctive advantages of late-stage autophagy inhibition by exploring the mechanisms underlying autophagy's impact on TRAIL sensitivity. Current preclinical and clinical investigations are inspected, showing the potential of targeting late-stage autophagy for sensitizing resistant cancer cells to TRAIL-induced apoptosis. This review emphasizes the significance of optimizing autophagy modulation to enhance TRAIL-mediated therapy and overcome the challenge of treatment resistance in cancer. We offer insights and recommendations for guiding the development of potential therapeutic strategies aimed at overcoming the challenges posed by treatment-resistant cancers.

A Review on Recent Trends in Photo-Drug Efficiency of Advanced Biomaterials in Photodynamic Therapy of Cancer

Photodynamic Therapy (PDT) has emerged as a highly efficient and non-invasive cancer treatment, which is crucial considering the significant global mortality rates associated with cancer. The effectiveness of PDT primarily relies on the quality of the photosensitizers employed. When exposed to appropriate light irradiation, these photosensitizers absorb energy and transition to an excited state, eventually transferring energy to nearby molecules and generating Reactive Oxygen Species (ROS), including singlet oxygen [1O2]. The ability to absorb light in visible and nearinfrared wavelengths makes porphyrins and derivatives useful photosensitizers for PDT. Chemically, Porphyrins, composed of tetra-pyrrole structures connected by four methylene groups, represent the typical photosensitizers. The limited water solubility and bio-stability of porphyrin photosensitizers and their non-specific tumor-targeting properties hinder PDT effectiveness and clinical applications. Therefore, a wide range of modification and functionalization techniques have been used to maximize PDT efficiency and develop multidimensional porphyrin-based functional materials. Recent progress in porphyrin-based functional materials has been investigated in this review paper, focusing on two main aspects including the development of porphyrinic amphiphiles that improve water solubility and biocompatibility, and the design of porphyrin-based polymers, including block copolymers with covalent bonds and supramolecular polymers with noncovalent bonds, which provide versatile platforms for PDT applications. The development of porphyrin-based functional materials will allow researchers to significantly expand PDT applications for cancer therapy by opening up new opportunities. With these innovations, porphyrins will overcome their limitations and push PDT to the forefront of cancer treatment options.

Role of Non-coding RNAs on the Radiotherapy Sensitivity and Resistance in Cancer Cells

Radiotherapy (RT) is an integral part of treatment management in cancer patients. However, one of the limitations of this treatment method is the resistance of cancer cells to radiotherapy. These restrictions necessitate the introduction of modalities for the radiosensitization of cancer cells. It has been shown that Noncoding RNAs (ncRNAs), along with modifiers, can act as radiosensitivity and radioresistant regulators in a variety of cancers by affecting double strand break (DSB), wnt signaling, glycolysis, irradiation induced apoptosis, ferroptosis and cell autophagy. This review will provide an overview of the latest research on the roles and regulatory mechanisms of ncRNA after RT in in vitro and preclinical researches.

Thyroid hormone and the Liver

It is known that thyroid hormone can regulate hepatic metabolic pathways including cholesterol, de novo lipogenesis, fatty acid oxidation, lipophagy, and carbohydrate metabolism. Thyroid hormone action is mediated by the thyroid hormone receptor (THR) isoforms and their coregulators, and THRβ is the main isoform expressed in the liver. Dysregulation of thyroid hormone levels, as seen in hypothyroidism, has been associated with dyslipidemia and metabolic dysfunction-associated fatty liver disease. Given the beneficial effects of thyroid hormone in liver metabolism and the advances illuminating the use of thyroid hormone analogs such as resmetirom as therapeutic agents in the treatment of metabolic dysfunction-associated fatty liver disease, this review aims to further explore the relationship between TH, the liver, and metabolic dysfunction-associated fatty liver disease. Herein, we summarize the current clinical therapies and highlight future areas of research.

Involvement of Autophagic Machinery in Neuropathogenesis: Targeting and Relevant Methods of Detection

The exquisite balance between cellular prosurvival and death pathways is extremely necessary for homeostasis. Different forms of programmed cell death have been widely studied and reported such as apoptosis, necroptosis, pyroptosis, and autophagy. Autophagy is a catabolic process important for normal cellular functioning. The main aim of this machinery is to degrade the misfolded or damaged proteins, unuseful organelles, and pathogens, which invade the cells, thereby maintaining cellular homeostasis and assuring the regular renewal of cell components. This prosurvival function of autophagy highlights its importance in many human diseases, as the disturbance of this tightly organized process ultimately causes detrimental effects. Interestingly, neurons are particularly susceptible to damage upon the presence of any alteration in the basal level of the autophagic activity; this could be due to their high metabolic demand, post-mitotic nature, and the contribution of autophagy in the different fundamental functions of neurons. Herein, we have reported the role of autophagy in different CNS disorders such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and epilepsy, besides the pharmacological agents targeting autophagy. Due to the significant contribution of autophagy in the pathogenesis of many diseases, it is crucial to develop effective methods to detect this dynamic process. In this chapter, we have summarized the most frequently employed techniques in studying and detecting autophagy including electron microscopy, fluorescence microscopy, Western blotting, intracellular protein degradation, and sequestration assay.

How lipids, as important endogenous nutrient components, affect the quality of aquatic products: An overview of lipid peroxidation and the interaction with proteins

As the global population continues to grow and the pressure on livestock and poultry supply increases, the oceans have become an increasingly important source of quality food for future generations. However, nutrient-rich aquatic product is susceptible to lipid oxidation during storage and transport, reducing its nutritional value and increasing safety risks. Therefore, identifying the specific effects of lipid oxidation on aquatic products has become particularly critical. At the same time, some lipid oxidation products have been found to interact with aquatic product proteins in various ways, posing a safety risk. This paper provides an in-depth exploration of the pathways, specific effects, and hazards of lipid oxidation in aquatic products, with a particular focus on the interaction of lipid oxidation products with proteins. Additionally, it discusses the impact of non-thermal treatment techniques on lipids in aquatic products and examines the application of natural antioxidants in aquatic products. Future research endeavors should delve into the interactions between lipids and proteins in these products and their specific effects to mitigate the impact of non-thermal treatment techniques on lipids, thereby enhancing the safety of aquatic products and ensuring food safety for future generations.

Axonal distribution of mitochondria maintains neuronal autophagy during aging via eIF2β

Neuronal aging and neurodegenerative diseases are accompanied by proteostasis collapse, while cellular factors that trigger it are not identified. Impaired mitochondrial transport in the axon is another feature of aging and neurodegenerative diseases. Using Drosophila, we found that genetic depletion of axonal mitochondria causes dysregulation of protein degradation. Axons with mitochondrial depletion showed abnormal protein accumulation and autophagic defects. Lowering neuronal ATP levels by blocking glycolysis did not reduce autophagy, suggesting that autophagic defects are associated with mitochondrial distribution. We found that eIF2β was increased by the depletion of axonal mitochondria via proteome analysis. Phosphorylation of eIF2α, another subunit of eIF2, was lowered, and global translation was suppressed. Neuronal overexpression of eIF2β phenocopied the autophagic defects and neuronal dysfunctions, and lowering eIF2β expression rescued those perturbations caused by depletion of axonal mitochondria. These results indicate the mitochondria-eIF2β axis maintains proteostasis in the axon, of which disruption may underly the onset and progression of age-related neurodegenerative diseases.

NS1 binding protein regulates stress granule dynamics and clearance by inhibiting p62 ubiquitination

The NS1 binding protein, known for interacting with the influenza A virus protein, is involved in RNA processing, cancer, and nerve cell growth regulation. However, its role in stress response independent of viral infections remains unclear. This study investigates NS1 binding protein's function in regulating stress granules during oxidative stress through interactions with GABARAP subfamily proteins. We find that NS1 binding protein localizes to stress granules, interacting with core components, GABARAP proteins, and p62, a protein involved in autophagy. In cells lacking NS1 binding protein, stress granule dynamics are altered, and p62 ubiquitination is increased, suggesting impaired stress granule degradation. Overexpression of NS1 binding protein reduces p62 ubiquitination. In amyotrophic lateral sclerosis patient-derived neurons, reduced NS1 binding protein and p62 disrupt stress granule morphology. These findings identify NS1 binding protein as a negative regulator of p62 ubiquitination and a facilitator of GABARAP recruitment to stress granules, implicating it in stress granule regulation and amyotrophic lateral sclerosis pathogenesis.

Omentin-1 mitigates non-alcoholic fatty liver disease by preserving autophagy through AMPKα/mTOR signaling pathway

Adipose tissue-derived adipokines facilitate inter-organ communication between adipose tissue and other organs. Omentin-1, an adipokine, has been implicated in the regulation of glucose and insulin metabolism. However, limited knowledge exists regarding the regulatory impact of endogenous omentin-1 on hepatic steatosis. C57BL/6J mice were fed with high-fat diet (HFD) for 8 weeks to induce nonalcoholic fatty liver disease (NAFLD), while HepG2 cells were exposed to a 0.1 mM free fatty acid (FFA) mixture for 24 h to induce hepatic steatosis. Both the mice and cells were treated with omentin-1, and the therapeutic effects as well as the underlying molecular mechanisms were investigated. Our data demonstrate that omentin-1 attenuates weight and fat mass gain, preserves glucose homeostasis, normalizes the expression of lipogenesis-related proteins, and alleviates hepatic lipid accumulation in HFD fed mice. Furthermore, omentin-1 normalized AMPKα/mTOR signaling and preserves autophagy in these mice. In vitro, omentin-1 also preserves autophagy and attenuates lipid accumulation by normalizing AMPKα/mTOR signaling in a cell model of FFA treated HepG2 cells. However, inhibition of AMPK with Compound C or AMPKα whole-body knockout reverses the above beneficial effects of omentin-1. The present study demonstrates that omentin-1 exerts a preventive effect on non-alcoholic fatty liver disease (NAFLD) by preserving autophagy through normalizing the AMPKα/mTOR pathway, thereby suggesting its potential as a promising therapeutic agent against NAFLD.

TEFM facilitates uterine corpus endometrial carcinoma progression by activating ROS-NFκB pathway

BACKGROUND

Mitochondrial transcription elongation factor (TEFM) is a recently discovered factor involved in mitochondrial DNA replication and transcription. Previous studies have reported that abnormal TEFM expression can disrupt the assembly of mitochondrial respiratory chain and thus mitochondrial function. However, the role of TEFM on Uterine corpus endometrial carcinoma (UCEC) progression remains unclear. The present study aims to investigate the expression of TEFM in tumor tissue of UCEC and the effect of abnormal TEFM expression on malignant phenotype of UCEC cells.

METHODS

The expressions of TEFM were measured in tumor tissues and cell lines of UCEC by immunohistochemistry, Western blotting, and real-time quantitative PCR assays. Besides, the effects of TEFM knockdown or overexpression on UCEC cell growth, metastasis, apoptosis, and autophagy were also determined using EdU, colony formation, flow cytometry, TUNEL, and transmission electron microscopy assays. Xenograft model was used to confirm the role of TEFM on proliferative potential of UECE cells in vivo.

RESULTS

Our bioinformatics analysis of CPTAC data showed that TEFM is abnormally overexpressed in UCEC and its upregulation was significantly associated with poor survival of patients with UCEC. We found that TEFM upregulation significantly promoted the growth and metastasis of UCEC cells. Mechanically, TEFM upregulation impaired the function of mitochondria, decreased their membrane potential and activated the AKT-NFκB pathway by promoting reactive oxygen species (ROS) production, leading to enhanced intracellular autophagy and thus UCEC growth and metastasis.

CONCLUSION

This study demonstrates that TEFM positively regulates autophagy to promote the growth and metastasis of UCEC cells, which provides a potential prognostic biomarker and therapeutic target for the treatment of UCEC.

Comparative analysis of BAG1 and BAG2: Insights into their structures, functions and implications in disease pathogenesis

As BAG family members, Bcl-2 associated athanogene family protein 1 (BAG1) and 2 (BAG2) are implicated in multiple cellular processes, including apoptosis, autophagy, protein folding and homeostasis. Although structurally similar, they considerably differ in many ways. Unlike BAG2, BAG1 has four isoforms (BAG1L, BAG1M, BAG1S and BAG1 p29) displaying different expression features and functional patterns. BAG1 and BAG2 play different cellular functions by interacting with different molecules to participate in the regulation of various diseases, including cancer/tumor and neurodegenerative diseases. Commonly, BAG1 acts as a protective factor to predict a good prognosis of patients with some types of cancer or a risk factor in some other cancers, while BAG2 is regarded as a risk factor to promote cancer/tumor progression. In neurodegenerative diseases, BAG2 commonly acts as a neuroprotective factor. In this review, we summarized the differences in molacular structure and biological function between BAG1 and BAG2, as well as the influences of them on pathogenesis of diseases, and explore the prospects for their clinical therapy application by specifying the activators and inhibitors of BAG1 and BAG2, which might provide a better understanding of the underlying pathogenesis and developing the targeted therapy strategies for diseases.

The critical role of miRNA in bacterial zoonosis

The public's health and the financial sustainability of international societies remain threatened by bacterial zoonoses, with limited reliable diagnostic and therapeutic options available for bacterial diseases. Bacterial infections influence mammalian miRNA expression in host-pathogen interactions. In order to counteract bacterial infections, miRNAs participate in gene-specific expression and play important regulatory roles that rely on translational inhibition and target gene degradation by binding to the 3' non-coding region of target genes. Intriguingly, according to current studies, that exogenous miRNAs derived from plants could potentially serve as effective medicinal components sourced from traditional Chinese medicine plants. These exogenous miRNAs exhibit stable functionality in mammals and mimic the regulatory roles of endogenous miRNAs, illuminating the molecular processes behind the therapeutic effects of plants. This review details the immune defense mechanisms of inflammation, apoptosis, autophagy and cell cycle disturbance caused by some typical bacterial infections, summarizes the role of some mammalian miRNAs in regulating these mechanisms, and introduces the cGAS-STING signaling pathway in detail. Evidence suggests that this newly discovered immune defense mechanism in mammalian cells can also be affected by miRNAs. Meanwhile, some examples of transboundary regulation of mammalian mRNA and even bacterial diseases by exogenous miRNAs from plants are also summarized. This viewpoint provides fresh understanding of microbial tactics and host mechanisms in the management of bacterial illnesses.

Regulated Cell Death of Alveolar Macrophages in Acute Lung Inflammation: Current Knowledge and Perspectives

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a common and serious clinical lung disease characterized by extensive alveolar damage and inflammation leading to impaired gas exchange. Alveolar macrophages (AMs) maintain homeostatic properties and immune defenses in lung tissues. Several studies have reported that AMs are involved in and regulate ALI/ARDS onset and progression via different regulated cell death (RCD) programs, such as pyroptosis, apoptosis, autophagic cell death, and necroptosis. Notably, the effects of RCD in AMs in disease are complex and variable depending on the environment and stimuli. In this review, we provide a comprehensive perspective on how regulated AMs death impacts on ALI/ARDS and assess its potential in new therapeutic development. Additionally, we describe the crosstalk between different RCD types in ALI, and provide new perspectives for the treatment of ALI/ARDS and other severe lung diseases.

Inhibition of TFAM-Mediated Mitophagy by Oroxylin A Restored Sorafenib Sensitivity Under Hypoxia Conditions in HepG2 Cells

Background: Liver cancer treatment encounters considerable therapeutic challenges, especially because hypoxic microenvironments markedly reduce sensitivity to chemotherapeutic agents. TFAM (mitochondrial transcription factor A) plays a crucial role in maintaining mitochondrial function. Oroxylin A (OA), a flavonoid with potential therapeutic properties, demonstrated prospects in cancer treatment. However, the mechanism of the sensitizing effect of OA on cancer cells has not been elucidated. Methods: MTT assays were utilized to evaluate a hypoxia-induced resistance model. Plate colony formation assays, TEM, and JC-1 staining were used to examine the effects of siTFAM on proliferation and mitochondrial damage of HepG2 cells. Cox8-EGFP-mCherry plasmid transfection, LysoTracker and MitoTracker colocalization analysis, and WB were conducted to evaluate the influence of OA on mitophagy. The effect of OA on p53 ubiquitination levels was investigated by Co-IP and the CHX chase assay. A mouse xenograft tumor model was utilized to assess the therapeutic effect of OA on HepG2 cells in vivo. Results: OA significantly improved the inhibitory effect of sorafenib by inhibiting mitophagy on HepG2 cells in in vitro and in vivo models. Notably, the molecular docking and thermal shift assays indicated a clear binding of OA and TFAM. Further research revealed that OA suppressed p53 acetylation and promoted its degradation by downregulating TFAM expression, which ultimately inhibited mitophagy in hypoxia. Conclusions: OA has demonstrated the potential to enhance the efficacy of sorafenib treatment for liver cancer, and TFAM may be one of its targets.

Guanylate-binding protein 5-mediated autophagy can promote the clearance of intracellular F. nucleatum in dental pulp cells during pulpitis

BACKGROUND

IFN-γ is crucial in induction of inducible cell-autonomous immunity, and IFN-γ signaling pathway is activated in pulpitis. Guanylate-binding proteins (GBPs) are a family of IFN-inducible GTPases and could utilize autophagy or pyroptosis to mitigate infection. GBP5 is abundantly expressed in inflamed pulp and human dental pulp cells (HDPCs). Therefore, we hypothesize that GBP5 in HDPCs exerts an immune-regulatory role in defending against bacterium infection.

METHODS

Fusobacterium nucleatum (F. nucleatum) was used to infect HDPCs, and immunoblotting and qRT-PCR were used to detect pyroptosis and autophagy. Pharmacological or genetic approaches were used to enhance or knock down GBP5 expression in HDPCs. Blood agar plate counting and immunoblotting were used to observe bacteria clearance effect and activation of autophagy. Student's t-test and one-way ANOVA were individually used for comparisons between two and multiple groups. Statistical significance was set at P < 0.05.

RESULTS

Following F. nucleatum infection in HDPCs, the autophagy marker LC3B was significantly upregulated while the mRNA and protein expression levels of p62 were increased. IFN-γ priming significantly inhibited the intracellular survival of F. nucleatum and enhanced the autophagic activity of HDPCs. GBP5 overexpression significantly increased the efficiency of HDPCs in clearing intracellular F. nucleatum and activated autophagic flux in HDPCs, while downregulating GBP5 in HDPCs suppressed autophagic flux.

CONCLUSION

IFN-γ-mediated GBP5 overexpression in HDPCs during F. nucleatum infection exerts an anti-microbial function through autophagy activation.

Scutellaria barbata D.Don and Hedyotis diffusa Willd herb pair combined with cisplatin synergistically inhibits ovarian cancer progression through modulating oxidative stress via NRF2-FTH1 autophagic degradation pathway

BACKGROUND

Cisplatin (DDP) is one of the most effective anticancer drugs, commonly used to treat advanced ovarian cancer (OC). However, DDP has significant limitations of platinum-based drugs, including chemical resistance and high-dose toxic side effects. Traditional Chinese medicines (TCMs) often presented in the form of formula, in which the herb pair was the basic unit. Scutellaria barbata D.Don and Hedyotis diffusa Willd (SB-HD) are famous TCMs herb pair that have been shown to help treat multiple types of cancers. However, the synergistic effects and mechanism of combination of SB-HD and DDP to enhance DDP chemosensitivity in OC are still unknown.

RESULTS

In vitro, we found that the optimal proportion of SB-HD to inhibit the proliferation of OC cells was 2:1, SB-HD and DDP were shown to synergistically reduce the viability of OC cells, inhibit the colony formation, promote cell cycle arrest and apoptosis, as well as inhibit cell migration and invasion. In vivo, combination treatment significantly inhibited the growth of subcutaneous tumors in BALB/c nude mice and reduced the toxic side effects of DDP. Mechanistically, SB-HD and DDP combination treatment significantly promoted oxidative stress response, decreased MMP, inhibited ATP production, decreased ROS levels and increased SOD activity, increased the expression of NRF2, HO-1, ATG5 and LC3, decreased the expression of p62 and FTH1 both in OC cells and tumor tissue of mice. Inhibitor 3-MA (Methyladenine, autophagy inhibitor) and Fer-1 (Ferrostatin-1, iron ion inhibitor) can effectively reverse the expression changes of the key target proteins, but not ZnPP (Zinc protoporphyrin, HO-1 inhibitor). Through bioinformatics analysis, it was found that the abnormal expression level of NRF2 and FTH1 mRNA has a high prognostic value, at the same time, the other four key proteins respectively or interacting with NRF2 and FTH1, also play important roles in the occurrence and development of OC.

CONCLUSION

Our findings uncover a synergistic effect of SB-HD and DDP against OC through modulating oxidative stress via NRF2-FTH1 autophagic degradation pathway, which may provide an important theoretical foundation for the use of SB-HD and a new strategy for enhancing DDP chemosensitivity as well as reducing toxic side effects.

Impacts and potential mechanisms of fine particulate matter (PM2.5) on male testosterone biosynthesis disruption

Exposure to PM2.5 is the most significant air pollutant for health risk. The testosterone level in male is vulnerable to environmental toxicants. In the past, researchers focused more attention on the impacts of PM2.5 on respiratory system, cardiovascular system, and nervous system, and few researchers focused attention on the reproductive system. Recent studies have reported that PM2.5 involved in male testosterone biosynthesis disruption, which is closely associated with male reproductive health. However, the underlying mechanisms by which PM2.5 causes testosterone biosynthesis disruption are still not clear. To better understand its potential mechanisms, we based on the existing scientific publications to critically and comprehensively reviewed the role and potential mechanisms of PM2.5 that are participated in testosterone biosynthesis in male. In this review, we summarized the potential mechanisms of PM2.5 triggering the change of testosterone level in male, which involve in oxidative stress, inflammatory response, ferroptosis, pyroptosis, autophagy and mitophagy, microRNAs (miRNAs), endoplasmic reticulum (ER) stress, and N6-methyladenosine (m6A) modification. It will provide new suggestions and ideas for prevention and treatment of testosterone biosynthesis disruption caused by PM2.5 for future research.

A Structural Proteomics Exploration of Synphilin-1 and Alpha-Synuclein Interaction in Pathogenesis of Parkinson's Disease

Pathological significance of interaction of Synphilin-1 with mutated alpha-synuclein is well known to have serious consequences in causing the formation of inclusion bodies that are linked to Parkinson's disease (PD). Information extracted so far pointed out that specific mutations, A53T, A30P, and E46K, in alpha-synuclein promote such interactions. However, a detailed structural study of this interaction is pending due to the unavailability of the complete structures of the large protein Synphilin-1 of chain length 919 residues and the mutated alpha-synuclein having all the reported specific mutations so far. In this study, a semi-automatic pipeline-based meta-predictor, AlphaLarge, is created to predict high-fidelity structures of large proteins like Synphilin-1 given the limitations of the existing protocols. AlphaLarge recruits a novel augmented AlphaFold model that uses a divide and conquer based strategy on the foundation of a self-sourced template dataset to choose the best structure model through their standard validations. The structure models were re-validated by a Protein Mediated Interaction Analysis (PMIA) formalism that uses the existing structurally relevant information of these proteins. For the training dataset, the new method, AlphaLarge, performed reasonably better than AlphaFold. Also, the new residue- and domain-based structural details of interactions of resultant best structure models of Synphilin-1 and both wild and mutated alpha-synuclein are extracted using PMIA. This result paves the way for better screening of target specific drugs to control the progression of PD, in particular, and research on any kind of pathophysiology involving large proteins of unknown structures, in general.

Hapalindole Q suppresses autophagosome-lysosome fusion by promoting YAP1 degradation via chaperon-mediated autophagy

Autophagy is a conserved catabolic process crucial for maintaining cellular homeostasis and has emerged as a promising therapeutic target for many diseases. Mechanistically novel small-molecule autophagy regulators are highly desirable from a pharmacological point of view. Here, we report the macroautophagy-inhibitory effect of hapalindole Q, a member of the structurally intriguing but biologically understudied hapalindole family of indole terpenoids. This compound promotes the noncanonical degradation of Yes-associated protein 1 (YAP1), the downstream effector of the Hippo signaling pathway, via chaperone-mediated autophagy, disrupting proper distribution of Rab7 and suppressing autophagosome-lysosome fusion in macroautophagy. Its binding to YAP1 is further confirmed by using biophysical techniques. A preliminary structure-activity relationship study reveals that the hapalindole Q scaffold, rather than the isothiocyanate group, is essential for YAP1 binding and degradation. This work not only identifies a macroautophagy inhibitor with a distinct mechanism of action but also provided a molecular scaffold for direct targeting of YAP1, which may benefit the development of therapeutics for both autophagy-related and Hippo-YAP-related diseases.

Novel prospects in targeting neurodegenerative disorders via autophagy

Protein aggregation occurs as a consequence of dysfunction in the normal cellular proteostasis, which leads to the accumulation of toxic fibrillar aggregates of certain proteins in the cell. Enhancing the activity of proteolytic pathways may serve as a way of clearing these aggregates in a cell, and consequently, autophagy has surfaced as a promising target for the treatment of neurodegenerative disorders. Several strategies involving small molecule compounds that stimulate autophagic pathway of cell have been discovered. However, despite many compounds having demonstrated favorable outcomes in experimental disease models, the translation of these findings into clinical benefits for patient's remains limited. Consequently, alternative strategies are actively being explored to effectively target neurodegeneration via autophagy modulation. Recently, newer approaches such as modulation of expression of autophagic genes have emerged as novel and interesting areas of research in this field, which hold promising potential in neuroprotection. Similarly, as discussed for the first time in this review, the use of autophagy-inducing nanoparticles by utilizing their physicochemical properties to stimulate the autophagic process, rather than relying on their role as drug carriers, offers a completely fresh avenue for targeting neurodegeneration without the risk of drug-associated adverse effects. This review provides fresh perspectives on developing autophagy-targeted therapies for neurodegenerative disorders. Additionally, it discusses the challenges and impediments of implementing these strategies to alleviate the pathogenesis of neurodegenerative disorders in clinical settings and highlights the prospects and directions of future research in this context.

Autophagy and nutrigenomics: a winning team against chronic disease and tumors

Autophagy, a vital cell process, has garnered attention for its role in various diseases and potential therapeutic interventions. Dysregulation of autophagy contributes to conditions such as metabolic diseases, neurodegenerative disorders, and cancer. In diseases such as diabetes, autophagy plays a crucial role in islet β-cell maintenance and glucose homeostasis, offering potential targets for therapeutic intervention. Nutrigenomics, which explores how dietary components interact with the genome, has emerged as a promising avenue for disease management. It sheds light on how diet influences gene expression and cellular processes, offering personalized approaches to disease prevention and management. Studies have showed the impact of specific dietary components, such as polyphenols and omega-3 fatty acids, on autophagy processes, suggesting their potential therapeutic benefits in neurodegenerative conditions and metabolic disorders. In cancer, autophagy's dual role in either suppressing tumorigenesis or promoting cancer cell survival underscores the importance of understanding its modulation through dietary interventions. Combined with conventional chemotherapy drugs, dietary compounds show synergistic effects in cancer treatment. Furthermore, phytochemicals such as indicaxanthin have been found to epigenetically regulate genes involved in autophagy, offering novel insights into personalized cancer therapies. This comprehensive review has the aim to study the autophagy in a combined view with nutrigenomics effects of some dietary molecules in maintaining cellular homeostasis and responding to pathological stimuli. Overall, the intersection of autophagy and nutrigenomics effect of bioactive compounds holds promise for developing targeted interventions for various diseases, emphasizing the significance of dietary interventions in disease prevention and management.

Protective effects of Gumibao recipe on glucocorticoid-included bone microcirculatory endothelial cell injury and the underlying mechanism

OBJECTIVE

To investigate the protective effects of Gumibao recipe on glucocorticoid-included bone microcirculatory endothelial cell (BMEC) injury, and elucidate the possible underlying mechanism.

METHODS

BMECs were treated with different concentrations of hydrocortisone at different time points, and the viability as well as migration of BMECs were evaluated; furthermore, the release of LDH, levels of VEGF, PAI-1, t-PA, and the content of NO by BMECs have been evaluated by commercially available kits; moreover, the expressions of eNOS, p-PI3K, p-Akt and p-mTOR in BMECs were examined by WB methods. Next, hydrocortisone treated BMECs were co-treated with Gumibao recipe, and the viability, migration and autophagy of BMECs were evaluated.

RESULTS

0.2 mg/ml and 0.3 mg/ml hydrocortisone significantly decreased viability and migration ability of BMECs, and also impeded the endothelial function of BMECs by decreasing the levels of VEGF, t-PA, the content of NO, and increasing the level of PAI-1. Gumibao medicated serum markedly increased the viability and migration of BMECs, and also increased the levels of VEGF, t-PA, the content of NO, meanwhile decreased the level of PAI-1 in 0.3 mg/ml hydrocortisone treated BMECs; moreover, glucocorticoids inhibited the autophagy of BMECs, and Gumibao recipe significantly increased the autophagy of BMECs; meanwhile, autophagy inhibitor 3-MA partially blocked the protective effects of Gumibao recipe. Finally, gumibao recipe partially abrogated the inhibitory effects of hydrocortisone on the activation of PI3K/Akt/mTOR singling, and these effects were further counteracted by PI3K and mTOR inhibitor NVP-BEZ235.

CONCLUSIONS

We reported for the first time the protective effects of Gumibao recipe on glucocorticoid-included BMECs injury, and the possible underlying mechanism may be regulating the autophagy of BMECs via PI3K/AKT/mTOR signaling pathway.

MiRNAs and Neutrophil-Related Membrane Proteins from Plasma-Derived Extracellular Vesicles for Early Prediction of Organ Dysfunction and Prognosis in Septic Patients

Purpose

The pathogenesis of sepsis-induced organ dysfunction remains elusive, and the mortality remains alarmingly high. We sought to investigate the profile of extracellular vesicles (EVs)-mediated communication between plasma and polymorphonuclear neutrophils (PMNs) in sepsis, and to elucidate whether miRNAs and PMN-related membrane proteins from plasma-derived EVs (plasma-EVs) are associated with sepsis-induced organ dysfunction and prognosis.

Methods

PMN-derived EVs (PMN-EVs) were isolated from the blood samples of healthy controls (N=3) and patients with septic shock (N=3) after ICU admission. We performed miRNA sequencing of the isolated EVs, followed by bioinformatic analysis. A miRNA model for comparing PMN-EVs and plasma-EVs was successfully established in the training cohort. Furthermore, miRNAs and PMN-related membrane proteins from the plasma-EV model were confirmed in the validation cohort. A logistic regression model, receiver operating characteristic (ROC) curves, and Kaplan-Meier analyses were performed to evaluate the efficiency of diagnostic and/or prognostic performance. Further, in vivo and in vitro experiments were conducted to explore the involvement of plasma-EVs in PMNs autophagy.

Results

Fifty-five miRNAs from PMN-EVs differed significantly between the healthy controls and patients with septic shock. Furthermore, the plasma-EV model (six miRNAs and eight PMN-related membrane proteins) was confirmed in the validation cohort, demonstrating that miR-34a-5p, miR-503-5p, miR-4772-3p, ITGAM, MPO, and MMP9 serve as sepsis biomarkers for distinguishing lung, liver, and kidney dysfunction. Kaplan-Meier survival analysis showed that miR-34a-5p, miR-4772-3p, ITGAM, and MMP9 were potential prognostic predictors. Finally, we found that plasma-EVs from sepsis patients exert an inhibitory effect on PMNs autophagy, which can be reversed by EV inhibitors such as GW4869 and enoxaparin.

Conclusion

These findings suggest that miRNAs and PMN-related membrane proteins from plasma-EVs could be valuable diagnostic tools for identifying sepsis-induced organ dysfunction and predicting prognosis, enabling proactive management of sepsis by physicians and improving the prognosis of sepsis patients.

Wnt Signaling in Hepatocellular Carcinoma: Biological Mechanisms and Therapeutic Opportunities

Hepatocellular carcinoma (HCC), characterized by significant morbidity and mortality rates, poses a substantial threat to human health. The expression of ligands and receptors within the classical and non-classical Wnt signaling pathways plays an important role in HCC. The Wnt signaling pathway is essential for regulating multiple biological processes in HCC, including proliferation, invasion, migration, tumor microenvironment modulation, epithelial-mesenchymal transition (EMT), stem cell characteristics, and autophagy. Molecular agents that specifically target the Wnt signaling pathway have demonstrated significant potential for the treatment of HCC. However, the precise mechanism by which the Wnt signaling pathway interacts with HCC remains unclear. In this paper, we review the alteration of the Wnt signaling pathway in HCC, the mechanism of Wnt pathway action in HCC, and molecular agents targeting the Wnt pathway. This paper provides a theoretical foundation for identifying molecular agents targeting the Wnt pathway in hepatocellular carcinoma.

Thiouracil and triazole conjugate induces autophagy through the downregulation of Wnt/β-catenin signaling pathway in human breast cancer cells

Autophagy is vital for maintaining cellular homeostasis by breaking down unnecessary organelles and proteins within cells. Its activity varies abnormally in several diseases, including cancer, making it a potential target for therapeutic strategies. The Wnt/β-catenin signaling pathway significantly impacts cancer by stabilizing β-catenin protein and promoting the transcription of its target genes. Therefore, we aimed to identify candidate substances targeting this signaling pathway. We designed and tested a thiouracil conjugate, discovering that TTP-8 had anti-tumor effects on human breast cancer cell lines MCF-7 and MDA-MB231. Our findings showed that TTP-8 upregulated the expression of LC3 protein, a marker of autophagy in breast cancer cells, suggesting that TTP-8 might induce autophagy. Further analysis confirmed an increase in autophagy-related proteins, with consistent results obtained from flow cytometry and confocal microscopy. Interestingly, the induction of LC3 expression by TTP-8 was even more pronounced in MCF-7 and MDA-MB231 cells transfected with β-catenin siRNA. Thus, our research supports the idea that the Wnt/β-catenin signaling pathway influences the regulation of autophagy-related proteins, thereby inducing autophagy. This suggests that TTP-8 could serve as a novel agent for treating breast cancer.

Autophagy in the Cellular Consequences of Tobacco Smoking: Insights into Senescence

Smoking is a significant contributing factor to the development of many complex diseases. One of the most important stimuli for aging in the human body is constant exposure to environmental factors such as cigarette smoke. Free radicals in cigarette smoke cause reactive oxygen species production at the cellular level and induce inflammatory responses. The respiratory system of smokers exhibits age-related characteristics, such as enhanced oxidative stress, accumulated damaged proteins, and increased inflammation. Autophagy is triggered by tobacco smoke as a protective mechanism to prevent and reduce molecular stress. However, smoking can interfere with the normal functioning of autophagy in various ways. Smoking-induced impairment of autophagy leads to irreversible cellular damage accumulation, causing cells to undergo cellular aging or senescence. Senescent cells lose their ability to divide and display a distinct secretory phenotype called the senescence-associated secretory phenotype (SASP) and produce numerous growth factors, immune modulators, and inflammatory cytokines. This review discusses the effects of tobacco smoke exposure on autophagy alteration, cellular aging, and senescence induction in exposed animal models, as well as in exposed epithelial and immune cells in the body.

DEHP regulates ferritinophagy to promote testicular ferroptosis via suppressing SIRT1/PGC-1α pathway

To increase elasticity and flexibility, di-2-ethylhexyl phthalate (DEHP) is used in a variety of industrial products, but excessive exposure to it can pose a threat to human health. In epidemiological studies of population exposure to DEHP, attention has been paid to damage to the male reproductive system. However, the toxicological mechanism of DEHP regarding testicular injury is not well understood. We used Western blot analysis, transmission electron microscopy, fluorescence staining, transient transfection and assay kit to detect relevant indicators, and the results were as follows: After DEHP exposure, the expression levels of ACSL4, COX2, TF, FTH1, LC3, AMPK, p-AMPK, ULK1, p-ULK1, serum iron, tissue iron and MDA in the exposure group were significantly increased. The expression levels of GPX4, NCOA4, p62, SIRT1, and PGC-1α, as well as the contents of GSH and ATP, decreased. Electron microscopy showed that more autophagosomes were observed. Our findings suggest that exposure to DEHP induced ferritinophagy and ferroptosis in the testis. In vitro, the promoting effect of ferritinophagy on ferroptosis was verified by applying the autophagy inhibitor (3-MA) and si-NCOA4. Moreover, Mono-(2-ethylhexyl) phthalate (MEHP) inhibited the mitochondrial regulatory protein SIRT1/PGC-1α, leading to mitochondrial dysfunction. Changes in mitochondrial reactive oxygen species (MtROS) and energy over-activated AMPK/ULK1 autophagy pathway, and then promoted ferritinophagy, which increased the sensitivity of TM4 cells to ferroptosis. This research offers a theoretical framework for the prevention and management of DEHP-induced harm.

The pivotal role of autophagy in the pathogenesis and therapy of medulloblastoma

Medulloblastoma (MB) is the most frequent malignant brain tumor in children. MB originates from neural precursor cells in distinctive regions of the rhombic lip and their maturation occurs in the cerebellum or the brain stem during embryonal development. Autophagy is also referred to as self-eating' which is a catabolic process that often triggers cellular homeostasis through the salvaging of degenerated proteins as well as organelles. Autophagy influence cell survival via aberrant proteins that could accumulate within the cell and influence potential signaling and transport mechanisms. The role of autophagy in MB aggressiveness as well as tumorigenesis is a very complex process. This review targets specifically data reporting the key roles of autophagy in the pathogenesis and therapy of MB.

Non-pathogenic Trojan horse Nissle1917 triggers mitophagy through PINK1/Parkin pathway to discourage colon cancer

Bacteria-mediated antitumor therapy has gained widespread attention for its innate tumor-targeting capability and excellent immune activation properties. Nevertheless, the clinical approval of bacterial therapies remains elusive primarily due to the formidable challenge of balancing safety with enhancing in vivo efficacy. In this study, leveraging the probiotic Escherichia coli Nissle1917 (EcN) emerges as a promising approach for colon cancer therapy, offering a high level of safety attributed to its lack of virulence factors and its tumor-targeting potential owing to its obligate anaerobic nature. Specifically, we delineate the erythrocyte (RBC) membrane-camouflaged EcN, termed as Trojan horse EcN@RBC, which triggers apoptosis in tumor cells by mitigating mitochondrial membrane potential (MMP) and subsequently activating the PINK1/Parkin pathway associated with mitophagy. Concurrently, the decline in MMP induced by mitophagy disrupts the mitochondrial permeability transition pore (MPTP), leading to the release of Cytochrome C and subsequent apoptosis induction. Moreover, synergistic effects were observed through the combination of the autophagy activator rapamycin, bolstering the antitumor efficacy in vivo. These findings offer novel insights into probiotic-mediated antitumor mechanisms and underscore the therapeutic potential of EcN@RBC for colon cancer patients.

The longevity factor spermidine is part of a highly heritable complex erythrocyte phenotype associated with longevity

Extreme longevity in humans is known to be a heritable trait. In a well-established twin erythrocyte metabolomics and proteomics database, we identified the longevity factor spermidine and a cluster of correlated molecules with high heritability estimates. Erythrocyte spermidine is 82% heritable and significantly correlated with 59 metabolites and 22 proteins. Thirty-eight metabolites and 19 proteins were >20% heritable, with a mean heritability of 61% for metabolites and 49% for proteins. Correlated metabolites are concentrated in energy metabolism, redox homeostasis, and autophagy pathways. Erythrocyte mean cell volume (MCV), an established heritable trait, was consistently negatively correlated with the top 25 biomolecules most strongly correlated with spermidine, indicating that smaller MCVs are associated with higher concentrations of spermidine and correlated molecules. Previous studies have linked larger MCVs with poorer memory, cognition, and all-cause mortality. Analysis of 432,682 unique patient records showed a linear increase in MCV with age but a significant deviation toward smaller than expected MCVs above age 86, suggesting that smaller MCVs are associated with extreme longevity. Consistent with previous reports, a subset of 78,158 unique patient records showed a significant skewing toward larger MCV values in a deceased cohort compared to an age-matched living cohort. Our study supports the existence of a complex, heritable phenotype in erythrocytes associated with health and longevity.

Anticancer role of flubendazole: Effects and molecular mechanisms (Review)

Flubendazole, an anthelmintic agent with a well-established safety profile, has emerged as a promising anticancer drug that has demonstrated efficacy against a spectrum of cancer types over the past decade. Its anticancer properties encompass a multifaceted mechanism of action, including the inhibition of cancer cell proliferation, disruption of microtubule dynamics, regulation of cell cycle, autophagy, apoptosis, suppression of cancer stem cell characteristics, promotion of ferroptosis and inhibition of angiogenesis. The present review aimed to provide a comprehensive overview of the molecular underpinnings of the anticancer activity of flubendazole, highlighting key molecules and regulatory pathways. Given the breadth of the potential of flubendazole, further research is imperative to identify additional cancer types sensitive to flubendazole, refine experimental methodologies for enhancing its reliability, uncover synergistic drug combinations, improve its bioavailability and explore innovative administration methods. The present review provided a foundation for future studies on the role of flubendazole in oncology and described its molecular mechanisms of action.

Cepharanthine sensitizes gastric cancer cells to chemotherapy by targeting TRIB3-FOXO3-FOXM1 axis to inhibit autophagy

BACKGROUND

Gastric cancer is among the common solid tumors. Chemotherapy resistance is the most common issue in gastric cancer treatment. Inhibiting intracellular autophagy may be a feasible method for overcoming chemotherapy resistance. Cepharanthine (CEP), a natural small molecule extracted from the stephania cephalantha Hayata plant, has been demonstrated to significantly inhibit cancer growth and can regulate autophagy. Although CEP can significantly inhibit cancer growth, it remains unclear whether CEP can regulate autophagy in gastric cancer. This study aimed to investigate whether CEP can enhance the sensitivity of gastric cancer to chemotherapy and elucidate its molecular mechanism.

METHODS

Three gastric cancer cell lines (AGS, SGC7901, and MFC) and one normal gastric mucosal epithelial cell line (GES-1) were used for in vitro experiments. The characterization of autophagy in gastric cancer cells included the detection of autophagy markers and autophagy flux through immunofluorescence staining and Western blotting, as well as the assessment of lysosomal function using fluorescence staining (LysoTracker Red DND-99, Acridine Orange staining) and Western blotting. The cytotoxicity of CEP, autophagy inhibitors (chloroquine [CQ] and 3-methyladenine [3MA]), and chemotherapy drugs (doxorubicin [DOX] and cisplatin [CIS]) was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, cell colony formation, and fluorescence staining techniques (H2DCFDA, Dihydroethidium, and JC-1 staining). The interaction between CEP and autophagy inhibitors was tested in a 615 mice model, and changes in the gut microbiota were determined through accurate 16S absolute quantification sequencing. The signaling pathway and autophagy regulatory target TRIB3-FOXO3-FOXM1 were confirmed through molecular docking, RNA sequencing, bioinformatic analysis, transfection techniques, and Western blotting.

RESULTS

CEP blocked autophagic flux in gastric cancer cells without affecting lysosomal function. As a novel autophagy inhibitor, CEP could combine with conventional autophagy inhibitors (CQ and 3MA) to block intracellular autophagy, thereby inhibiting gastric cancer growth. During this process, changes in the gut microbiota were observed, including low-level changes in Odoribacterium, Erysipelatoclostridium, and ParaPrevotella and high-level changes in Ileibacterium, Enterorhabdus, and Bifidobacterium. Additionally, CEP synergistically inhibited the growth of gastric cancer when combined with chemotherapy drugs. Mechanistically, the TRIB3-FOXO3-FOXM1 signaling axis was found to be involved in the inhibition of gastric cancer by CEP combined with autophagy inhibitors and chemotherapy drugs, thereby mediating cell apoptosis.

CONCLUSION

This study links the TRIB3-FOXO3-FOXM1 axis with chemotherapy efficacy. Our findings demonstrated that CEP inhibits autophagy by modulating the FOXO3-FOXM1 axis. When combined with chemotherapy drugs (DOX and CIS), CEP, as an autophagy inhibitor, can limit TRIB3 protein expression, thereby regulating the FOXO3-FOXM1 axis and enhancing its ability to prevent gastric cancer growth. These findings may contribute to improving the prognosis of patients with gastric cancer. Furthermore, these results enrich the fundamental understanding of how autophagy inhibition can enhance clinical cancer treatment efficacy and provide insights into the potential mechanisms by which CEP functions as an anti-tumor drug, thereby exploring its value for clinical application.

Significant enhancement of anticancer effect of iridium (III) complexes encapsulated in liposomes

In this study, the ligand EIPP (5-ethoxy-2-(1H-imidazo[4,5-f] [1,10] phenanthrolin-2-yl)phenol) and [Ir(ppy)2(EIPP)](PF6)] (5a, ppy = 2-phenylpyridine) and [Ir(piq)2(EIPP)](PF6)] (5b, piq = 1-phenylisoquinoline) were synthesized and they were entrapped into liposomes to produce 5alipo and 5blipo. 5a and 5b were characterized via HRMS, NMR, UV-vis and IR. The cytotoxicity of 5a, 5b, 5alipo and 5blipo on cancer and non-cancer cells was estimated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). MTT assay demonstrated that 5a and 5b did not show any significant cellular activity but their liposome-encapsulated 5alipo and 5blipo had significant toxic effects. The mechanism of 5alipo, 5blipo-inducing apoptosis was explored by studying cellular uptake, mitochondrial localization, mitochondrial membrane potential, cytochrome C, glutathione (GSH), malondialdehyde (MDA) and protein immunoblotting. The results demonstrated that 5alipo and 5blipo caused a release of cytochrome C, downregulated the expression of Bcl-2, upregulated the expression of BAX, activated caspase 3, and downregulated PARP expression. It was shown that 5alipo and 5blipo could inhibit cancer cell proliferation in G2/M phase by regulating p53 and p21 proteins. Additionally, 5alipo and 5blipo induced autophagy through an adjustment from LC3-I to LC3-II and caused ferroptosis. The in vivo antitumor activity of 5alipo was examined in detail.

Everolimus alleviates CD4+ T cell inflammation by regulating autophagy and cellular redox homeostasis

Aging is associated with the onset and progression of multiple diseases, which limit health span. Chronic low-grade inflammation in the absence of overt infection is considered the simmering source that triggers age-associated diseases. Failure of many cellular processes during aging is mechanistically linked to inflammation; however, the overall decline in the cellular homeostasis mechanism of autophagy has emerged as one of the top and significant inducers of inflammation during aging, frequently known as inflammaging. Thus, physiological or pharmacological interventions aimed at improving autophagy are considered geroprotective. Rapamycin analogs (rapalogs) are known for their ability to inhibit mTOR and thus regulate autophagy. This study assessed the efficacy of everolimus, a rapalog, in regulating inflammatory cytokine production in T cells from older adults. CD4+ T cells from older adults were treated with a physiological dose of everolimus (0.01 µM), and indices of autophagy and inflammation were assessed to gain a mechanistic understanding of the effect of everolimus on inflammation. Everolimus (Ever) upregulated autophagy and broadly alleviated inflammatory cytokines produced by multiple T cell subsets. Everolimus's ability to alleviate the cytokines produced by Th17 subsets of T cells, such as IL-17A and IL-17F, was dependent on autophagy and antioxidant signaling pathways. Repurposing the antineoplastic drug everolimus for curbing inflammaging is promising, given the drug's ability to restore multiple cellular homeostasis mechanisms.

The role of HDAC6 in enhancing macrophage autophagy via the autophagolysosomal pathway to alleviate legionella pneumophila-induced pneumonia

Legionella pneumophila (L. pneumophila) is a prevalent pathogenic bacterium responsible for significant global health concerns. Nonetheless, the precise pathogenic mechanisms of L. pneumophila have still remained elusive. Autophagy, a direct cellular response to L. pneumophila infection and other pathogens, involves the recognition and degradation of these invaders in lysosomes. Histone deacetylase 6 (HDAC6), a distinctive member of the histone deacetylase family, plays a multifaceted role in autophagy regulation. This study aimed to investigate the role of HDAC6 in macrophage autophagy via the autophagolysosomal pathway, leading to alleviate L. pneumophila-induced pneumonia. The results revealed a substantial upregulation of HDAC6 expression level in murine lung tissues infected by L. pneumophila. Notably, mice lacking HDAC6 exhibited a protective response against L. pneumophila-induced pulmonary tissue inflammation, which was characterized by the reduced bacterial load and diminished release of pro-inflammatory cytokines. Transcriptomic analysis has shed light on the regulatory role of HDAC6 in L. pneumophila infection in mice, particularly through the autophagy pathway of macrophages. Validation using L. pneumophila-induced macrophages from mice with HDAC6 gene knockout demonstrated a decrease in cellular bacterial load, activation of the autophagolysosomal pathway, and enhancement of cellular autophagic flux. In summary, the findings indicated that HDAC6 knockout could lead to the upregulation of p-ULK1 expression level, promoting the autophagy-lysosomal pathway, increasing autophagic flux, and ultimately strengthening the bactericidal capacity of macrophages. This contributes to the alleviation of L. pneumophila-induced pneumonia.

FGF21 promotes angiotensin II-induced abdominal aortic aneurysm via PI3K/AKT/mTOR pathway

BACKGROUND

Abdominal aortic aneurysm (AAA) is a potentially fatal vascular disorder with a high mortality rate. It was previously reported that fibroblast growth factor 21 (FGF21) was highly expressed in AAA patients. Nonetheless, its underlying mechanism in AAA progression is unclarified.

METHODS

Angiotensin II (Ang-II) was used to induce AAA in human aortic vascular smooth muscle cells (HASMCs) and mouse models. Western blotting and RT-qPCR were utilized for measuring protein and RNA levels. Immunofluorescence staining was utilized for detecting LC3B expression in HASMCs. Elastica van Gieson staining was conducted for histological analysis of the abdominal aortas of mice.

RESULTS

FGF21 displayed a high level in Ang-II-stimulated HASMCs and AAA mice. FGF21 depletion ameliorated abdominal aorta dilation and Ang-II-triggered pathological changes in mice. FGF21 silencing hindered autophagy and PI3K/AKT/mTOR pathway.

CONCLUSIONS

FGF21 contributes to AAA progression by enhancing autophagy and activating PI3K/AKT/mTOR pathway.

Photobiomodulation therapy at 650 nm enhances osteogenic differentiation of osteoporotic bone marrow mesenchymal stem cells through modulating autophagy

BACKGROUND

Photobiomodulatiom therapy (PBMT) has biostimulatory effects on bone marrow mesenchymal stem cells (BMSCs), which takes a pivotal role in maintaining bone mass and avoiding osteoporosis (OP). Autophagy is an important regulator for cell survival and homeostasis. Previous researchers found that BMSCs derived from osteoporotic rats (OP-BMSCs) were with the feature of reduced osteogenic differentiation and autophagy dysfunction. However, the potential regulation of PBMT in osteogenic differentiation of OP-BMSCs and its underling relationship with autophagy remain unclear.

METHODS

650 nm red light-emitting diode (LED) was selected to initiate PBMT effects. The isolation and culture of OP-BMSCs were implemented after the establishment of the OP rat model. Firstly, the optimal dose of LED was screened on OP-BMSCs by CCK-8. Meanwhile, the osteogenic and mineralization activities were studied through the detection of Alkaline phosphatase (ALP) and alizarin red S (ARS). Then, the levels of osteogenesis and autophagy were investigated via western blot and immunofluorescence staining. Finally, the autophagy inhibitor 3-MA was applied to illustrate the underlying mechanism of the osteogenic effect of PBMT on OP-BMSCs.

RESULTS

Firstly, the optimal dose of 6 J/cm2 LED was selected in the subsequent experiments according to CCK-8. Then, the ALP activity and the mineralization ability of OP-BMSCs were obviously increased by PBMT. Meanwhile, Runx-2, OCN and OPN were significantly upregulated in LED group. Furthermore, the expressions of autophagic proteins increased significantly in LED group by immunofluorescence staining and western blot assay. At last, the promoted effects of PBMT on osteogenic differentiation in OP-BMSCs were distinctly reversed via inhibiting autophagy.

CONCLUSION

Our research illustrated that 650 nm LED could improve osteogenic differentiation of OP-BMSCs, suggesting a potential correlation between PBMT-mediated activation of autophagy and promotion of osteogenic differentiation.

Autophagy in oral cancer: Promises and challenges (Review)

Autophagy captures damaged or dysfunctional proteins and organelles through the lysosomal pathway to achieve proper cellular homeostasis. Autophagy possesses distinct characteristics and is given recognized functions in numerous physiological and pathological conditions, such as cancer. Early stage cancer development can be stopped by autophagy. After tumor cells have successfully undergone transformation and progressed to a late stage, the autophagy-mediated system of dynamic degradation and recycling will support cancer cell growth and adaptation to various cellular stress responses while preserving energy homeostasis. In the present study, the dual function that autophagy plays in various oral cancer development contexts and stages, the existing arguments for and against autophagy, and the ways in which autophagy contributes to oral cancer modifications, such as carcinogenesis, drug resistance, invasion, metastasis and self-proliferation, are reviewed. Special attention is paid to the mechanisms and functions of autophagy in oral cancer processes, and the most recent findings on the application of certain conventional drugs or natural compounds as novel agents that modulate autophagy in oral cancer are discussed. Overall, further research is needed to determine the validity and reliability of autophagy promotion and inhibition while maximizing the difficult challenge of increasing cancer suppression to improve clinical outcomes.

TFEB signaling promotes autophagic degradation of NLRP3 to attenuate neuroinflammation in diabetic encephalopathy

Diabetic encephalopathy (DE), a neurological complication of diabetes mellitus, has an unclear etiology. Shreds of evidence show that the nucleotide-binding oligomerization domain-like receptor family protein 3 (NLRP3) inflammasome-induced neuroinflammation and transcription factor EB (TFEB)-mediated autophagy impairment may take part in DE development. The cross talk between these two pathways and their contribution to DE remains to be explored. A mouse model of type 2 diabetes mellitus (T2DM) exhibiting cognitive dysfunction was created, along with high-glucose (HG) cultured BV2 cells. Following, 3-methyladenine (3-MA) and rapamycin were used to modulate autophagy. To evaluate the potential therapeutic benefits of TFEB in DE, we overexpressed and knocked down TFEB in both mice and cells. Autophagy impairment and NLRP3 inflammasome activation were noticed in T2DM mice and HG-cultured BV2 cells. The inflammatory response caused by NLRP3 inflammasome activation was decreased by rapamycin-induced autophagy enhancement, while 3-MA treatment further deteriorated it. Nuclear translocation and expression of TFEB were hampered in HG-cultured BV2 cells and T2DM mice. Exogenous TFEB overexpression boosted NLRP3 degradation via autophagy, which in turn alleviated microglial activation as well as ameliorated cognitive deficits and neuronal damage. In addition, TFEB knockdown exacerbated neuroinflammation by decreasing autophagy-mediated NLRP3 degradation. Our findings have unraveled the pathogenesis of a previously underappreciated disease, implying that the activation of NLRP3 inflammasome and impairment of autophagy in microglia are significant etiological factors in the DE. The TFEB-mediated autophagy pathway can reduce neuroinflammation by enhancing NLRP3 degradation. This could potentially serve as a viable and innovative treatment approach for DE.NEW & NOTEWORTHY This article delves into the intricate connections between inflammation, autophagy, diabetes, and neurodegeneration, with a particular focus on a disease that is not yet fully understood-diabetic encephalopathy (DE). TFEB emerges as a pivotal regulator in balancing autophagy and inflammation in DE. Our findings highlight the crucial function of the TFEB-mediated autophagy pathway in mitigating inflammatory damage in DE, suggesting a new treatment strategy.

p75NTR mediated chronic restraint stress-induced depression-like behaviors in mice via hippocampal mTOR pathway

AIMS

Major depressive disorder (MDD) is an enduring and severe mood disorder. Previous studies have indicated that p75NTR is involved in neuronal survival and death. However, the specific mechanism of p75NTR in depression remains unknown. The present study aimed to explore the role and mechanism of p75NTR in depression, and try to provide a new target for the treatment of MDD.

MAIN METHODS

The p75NTR knockout and overexpression mice were used to establish a mouse model of depression induced by chronic restraint stress (CRS), and the behavioral effects and potential mechanisms associated with p75NTR knockout/overexpression on CRS-induced depressive mice were investigated by animal behavior, histopathology, immunofluorescence and western blot, respectively.

KEY FINDINGS

The results demonstrate that p75NTR knockout/overexpression can ameliorate the depressive-like behaviors observed in CRS-induced depressive mice. Furthermore, p75NTR knockout/overexpression safeguards the tissue morphology of the hippocampus, inhibits the mTOR signaling pathway to restore autophagy, and modulates apoptosis-related proteins (Bcl-2 and Bax) to reestablish normal levels of autophagy and apoptosis in hippocampal neurons of depressed mice. Importantly, p75NTR knockout/overexpression can improve synaptic plasticity through protecting the dendritic structure and dendritic spines of hippocampal neurons, and upregulating the expression of hippocampal synaptic-related proteins (PSD95 and SYN1).

SIGNIFICANCE

These findings suggest that p75NTR knockout/overexpression can alleviate CRS-induced depression-like behaviors by reinstating autophagy and suppressing apoptosis in hippocampal neurons, and enhancing hippocampal synaptic plasticity via mTOR pathway. These insights may provide potential targets for clinical treatment of depression.

Establishing network pharmacology between natural polyphenols and Alzheimer's disease using bioinformatic tools - An advancement in Alzheimer's research

Alzheimer's disease (AD) is a major cause of disability and one of the top causes of mortality globally. AD remains a major public health challenge due to its prevalence, impact on patients and caregivers, and the current lack of a cure. In recent years, polyphenols have garnered attention for their potential therapeutic effects on AD. The objective of the study was to establish network pharmacology between selected polyphenols of plant origin and AD. Insilico tools such as SwissADME, ProTox3.0, pkCSM, Swiss Target Prediction, DisGeNET, InterActiVenn, DAVID database, STRING database, Cytoscape/CytoHubba were employed to establish the multi-target potential of the polyphenolic compounds. The present study revealed that out of 17 polyphenols, 10 ligands were found to possess a drug-likeness nature along with desirable pharmacokinetic parameters and a lesser toxicity profile. Also, the results highlighted the possible interactions between the polyphenols and the disease targets involved in AD. Further, this study has shed light on the mTOR pathway and its impact on AD through the autophagic mechanism. Overall, this study indicated that polyphenols could be a better therapeutic option for treating AD. Hence, the consumption of polyphenolic cocktails as a part of the diet could produce more effective outcomes against the disease. Additional studies are warranted in the future to explore additional pathways and genes to provide a comprehensive understanding regarding the usage of the shortlisted polyphenols and their derivatives for the prevention and treatment of AD.

Kidney Injury in a Murine Hemorrhagic Shock/Resuscitation Model Is Alleviated by sulforaphane's Anti-Inflammatory and Antioxidant Action

Hemorrhagic shock/resuscitation (HS/R) can lead to acute kidney injury, mainly manifested as oxidative stress and inflammatory injury in the renal tubular epithelial cells, as well as abnormal autophagy and apoptosis. Sulforaphane (SFN), an agonist of the nuclear factor-erythroid factor 2-related factor 2 (Nrf2) signaling pathway, is involved in multiple biological activities, such as anti-inflammatory, antioxidant, autophagy, and apoptosis regulation. This study investigated the effect of SFN on acute kidney injury after HS/R in mice. Hemorrhagic shock was induced in mice by controlling the arterial blood pressure at a range of 35-45 mmHg for 90 min within arterial blood withdrawal. Fluid resuscitation was carried out by reintroducing withdrawn blood and 0.9% NaCl. We found that SFN suppressed the elevation of urea nitrogen and serum creatinine levels in the blood induced by HS/R. SFN mitigated pathological alterations including swollen renal tubules and renal casts in kidney tissue of HS/R mice. Inflammation levels and oxidative stress were significantly downregulated in mouse kidney tissue after SFN administration. In addition, the kidney tissue of HS/R mice showed high levels of autophagosomes as observed by electron microscopy. However, SFN can further enhance the formation of autophagosomes in the HS/R + SFN group. SFN also increased autophagy-related proteins Beclin1 expression and suppressed P62 expression, while increasing the ratio of microtubule-associated protein 1 light chain 3 (LC3)-II and LC3-I (LC3-II/LC3-I). SFN also effectively decreased cleaved caspase-3 level and enhanced the ratio of anti-apoptotic protein B cell lymphoma 2 and Bcl2-associated X protein (Bcl2/Bax). Collectively, SFN effectively inhibited inflammation and oxidative stress, enhanced autophagy, thereby reducing HS/R-induced kidney injury and apoptosis levels in mouse kidneys.

Impaired autophagy-mediated macrophage polarization contributes to age-related hyposalivation

Age-related dysfunction of salivary glands (SGs) leading to xerostomia or dry mouth is typically associated with increased dental caries and difficulties in mastication, deglutition or speech. Inflammaging-induced hyposalivation plays a significant role in aged SGs; however, the mechanisms by which ageing shapes the inflammatory microenvironment of SGs remain unclear. Here, we show that reduced salivary secretion flow rate in aged human and mice SGs is associated with impaired autophagy and increased M1 polarization of macrophages. Our study reveals the crucial roles of SIRT6 in regulating macrophage autophagy and polarization through the PI3K/AKT/mTOR pathway, as demonstrated by generating two conditional knock out mice. Furthermore, triptolide (TP) effectively rejuvenates macrophage autophagy and polarization via targeting this pathway. We also design a local delivery of TP-loaded apoptotic extracellular vesicles (ApoEVs) to improve age-related SGs dysfunction therapeutically. Collectively, our findings uncover a previously unknown link between SIRT6-regulated autophagy and macrophage polarization in age-mediated hyposalivation, while our locally therapeutic strategy exhibits potential preventive effects for age-related hyposalivation.

Tert-butylhydroquinone promotes skin flap survival by inhibiting oxidative stress mediated by the Nrf2/HO-1 signalling pathway

BACKGROUND AND PURPOSE

Skin flaps are among the most important means of wound repair in clinical settings. However, partial or even total distal necrosis may occur after a flap operation, with severe consequences for both patients and doctors. This study investigated whether tert-butylhydroquinone (TBHQ), a known agonist of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), and an antioxidant, could promote skin flap survival.

EXPERIMENTAL APPROACH

McFarlane skin flap models were established in male Sprague-Dawley rats and then randomly divided into control, low-dose TBHQ, and high-dose TBHQ treatment groups. On postoperative day 7, the survival and blood flow of the skin flaps were assessed. Using flap tissue samples, angiogenesis, inflammation, apoptosis, autophagy, and Nrf2/haem oxygenase 1 (HO-1) signalling pathway activity were measured with immunohistochemical techniques and western blotting.

KEY RESULTS

TBHQ dose-dependently stimulated the Nrf2/HO-1 signalling pathway, inducing autophagy through the up-regulation of LC3B and beclin 1 and concurrently suppressing p62 expression. Additionally, TBHQ hindered apoptosis by enhancing Bcl-2 expression while inhibiting the expression of Bax. It suppressed inflammation by inhibiting the expression of interleukin 1β, interleukin 6, and tumour necrosis factor-α and enhanced angiogenesis by promoting the expression of vascular endothelial growth factor.

CONCLUSION AND IMPLICATIONS

In summary, TBHQ promoted flap survival in rats by up-regulating the Nrf2/HO-1 signalling pathway. As TBHQ is already widely used as a food additive, it could offer an acceptable means of improving clinical outcomes following skin flap surgery in patients.

RNF38 promotes gilteritinib resistance in acute myeloid leukemia via inducing autophagy by regulating ubiquitination of LMX1A

BACKGROUND

Gilteritinib is a commonly used targeted drug for acute myeloid leukemia (AML), but the emergence of gilteritinib resistance greatly reduces the therapeutic effect. RING finger protein 38 (RNF38), a protein with RING Finger domain and E3 ubiquitin ligase activity, has been implicated in tumorigenesis and drug resistance. However, the role and mechanism of RNF38 in the gilteritinib resistance of AML remains unclear.

METHODS

Normal AML cells were treated with gilteritinib to construct gilteritinib-resistant cells (MV4-11/Gilteritinib and MOLM-13/Gilteritinib). CCK8 assay, TUNEL staining and EdU assay were used to assess gilteritinib resistance, cell apoptosis and proliferation. The protein levels of autophagy-related markers, RNF38 and LIM homeobox transcription factor 1 alpha (LMX1A) were determined by western blot. Also, RNF38 and LMX1A mRNA levels were tested using qRT-PCR. Autophagic flux was assessed using mRFP-GFP-LC3 labeling, and autophagosome numbers was counted under transmission electron microscopy. Co-IP assay was employed to analyze interaction between RNF38 and LMX1A. The effects of LMX1A and RNF38 on AML tumorigenesis were analyzed by in vivo experiments.

RESULTS

In gilteritinib-resistant AML cells, autophagy-related markers, mRFP-GFP-LC3 signals and autophagosome numbers were significantly enhanced. Autophagy inhibitor 3-MA could suppress gilteritinib resistance in AML cells. RNF38 knockdown inhibited gilteritinib resistance and autophagy in AML cells. Mechanistically, RNF38 reduced LMX1A expression by inducing its ubiquitination. RNF38 overexpression reversed the inhibitory effect of LMX1A on gilteritinib resistance and autophagy in AML cells, as well as AML tumor growth in vivo, while these effects could be abolished by proteasome inhibitor MG132.

CONCLUSIONS

RNF38 induced autophagy to promote gilteritinib resistance in AML by increasing the ubiquitination of LMX1A.