Autophagy-related Signaling Pathways Research Articles

Expression of concern: The effects of the long non-coding RNA MALAT-1 regulated autophagy-related signaling pathway on chemotherapy resistance in diffuse large B-cell lymphoma. [Biomedicine & Pharmacotherapy 89 (2017) 939–948

Expression of concern: The effects of the long non-coding RNA MALAT-1 regulated autophagy-related signaling pathway on chemotherapy resistance in diffuse large B-cell lymphoma. [Biomedicine & Pharmacotherapy 89 (2017) 939–948

Revealing the novel autophagy-related genes for ligamentum flavum hypertrophy in patients and mice model.

BackgroundFibrosis is a core pathological factor of ligamentum flavum hypertrophy (LFH) resulting in degenerative lumbar spinal stenosis. Autophagy plays a vital role in multi-organ fibrosis. However, autophagy has not been reported to be involved in the pathogenesis of LFH.MethodsThe LFH microarray data set GSE113212, derived from Gene Expression Omnibus, was analyzed to obtain differentially expressed genes (DEGs). Potential autophagy-related genes (ARGs) were obtained with the human autophagy regulator database. Functional analyses including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, Gene Set Enrichment Analysis (GSEA), and Gene Set Variation Analysis (GSVA) were conducted to elucidate the underlying biological pathways of autophagy regulating LFH. Protein-protein interaction (PPI) network analyses was used to obtain hub ARGs. Using transmission electron microscopy, quantitative RT-PCR, Western blotting, and immunohistochemistry, we identified six hub ARGs in clinical specimens and bipedal standing (BS) mouse model.ResultsA total of 70 potential differentially expressed ARGs were screened, including 50 up-regulated and 20 down-regulated genes. According to GO enrichment and KEGG analyses, differentially expressed ARGs were mainly enriched in autophagy-related enrichment terms and signaling pathways related to autophagy. GSEA and GSVA results revealed the potential mechanisms by demonstrating the signaling pathways and biological processes closely related to LFH. Based on PPI network analysis, 14 hub ARGs were identified. Using transmission electron microscopy, we observed the autophagy process in LF tissues for the first time. Quantitative RT-PCR, Western blotting, and immunohistochemistry results indicated that the mRNA and protein expression levels of FN1, TGFβ1, NGF, and HMOX1 significantly higher both in human and mouse with LFH, while the mRNA and protein expression levels of CAT and SIRT1 were significantly decreased.ConclusionBased on bioinformatics analysis and further experimental validation in clinical specimens and the BS mouse model, six potential ARGs including FN1, TGFβ1, NGF, HMOX1, CAT, and SIRT1 were found to participate in the fibrosis process of LFH through autophagy and play an essential role in its molecular mechanism. These potential genes may serve as specific therapeutic molecular targets in the treatment of LFH.

Enhancing autophagy and energy metabolism in the meniscus can delay the occurrence of PTOA in ACLT rat.

Osteoarthritis (OA) is a progressive degenerative joint disease characterized by the destruction of the articular cartilage, meniscus and the like. Autophagy and cellular energy metabolism are the mechanisms by which cells maintain homeostasis. However, little is known about the effects of autophagy and cellular energy metabolism on meniscus degeneration, and the pathogenesis of posttraumatic osteoarthritis (PTOA) after the meniscal injury is rarely reported. Therefore, this study aimed to investigate the relationship between changes in autophagy and cellular energy metabolism in the meniscus following anterior cruciate ligament transection (ACLT) and PTOA induced by subsequent articular cartilage injury. In this study, we use a combination of cell experiments in vitro and animal experiments in vivo. On the one hand, cell experiment results show that inhibiting the mTORC1 signaling pathway by inhibiting the phosphorylation of S6K and AKT proteins in meniscal cells will lead to the increase of Beclin1, LC-3B, ATG12, ULK1, P62, and activate autophagy-related signaling pathways, which in turn protects the extracellular matrix component COL1 of meniscal cells from degradation by catabolic factor MMP13. In addition, it increased the generation of mitochondrial membrane potential in meniscal cells, increased the expression of anti-apoptotic factor BCL-XL, decreased the expression of pro-apoptotic factors BAD and BAX, and reduced the apoptosis of meniscal cells. More importantly, under the stimulation of inflammatory factor IL-1β, the secretion of meniscus cells can reduce the elevated levels of MMP13 and Adamts5 caused by chondrocytes affected by IL-1β. On the other hand, the results of animal experiments in vivo further proved the validity of the results of the cell experiments, and also proved that the meniscus injury did prior to the articular cartilage degeneration after ACLT. In conclusion, this study suggests that the meniscus prior to articular cartilage damage during the development of PTOA after ACLT, and that promoting autophagy and energy metabolism of meniscal cells may be a potential therapeutic target for delaying PTOA.

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

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

The Regulatory Role of Non-coding RNA in Autophagy in Myocardial Ischemia-Reperfusion Injury

Following an acute myocardial infarction (AMI), thrombolysis, coronary artery bypass grafting and primary percutaneous coronary intervention (PPCI) are the best interventions to restore reperfusion and relieve the ischemic myocardium, however, the myocardial ischemia-reperfusion injury (MIRI) largely offsets the benefits of revascularization in patients. Studies have demonstrated that autophagy is one of the important mechanisms mediating the occurrence of the MIRI, while non-coding RNAs are the main regulatory factors of autophagy, which plays an important role in the autophagy-related mTOR signaling pathways and the process of autophagosome formation Therefore, non-coding RNAs may be used as novel clinical diagnostic markers and therapeutic targets in the diagnosis and treatment of the MIRI. In this review, we not only describe the effect of non-coding RNA regulation of autophagy on MIRI outcome, but also zero in on the regulation of non-coding RNA on autophagy-related mTOR signaling pathways and mitophagy. Besides, we focus on how non-coding RNAs affect the outcome of MIRI by regulating autophagy induction, formation and extension of autophagic vesicles, and the fusion of autophagosome and lysosome. In addition, we summarize all non-coding RNAs reported in MIRI that can be served as possible druggable targets, hoping to provide a new idea for the prediction and treatment of MIRI.

Identification and validation of an autophagy-related gene signature for predicting prognosis in patients with esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the main subtype of esophageal cancer. Since autophagy-related genes (ARGs) play a key role in the pathogenesis of many tumors, including ESCC, the purpose of this study is to establish an autophagy-related prognostic risk signature based on ARGs expression profile, and to provide a new method for improving prediction of clinical outcomes. We obtained the expression profiles of ESCC from public data (GSE53625) and extracted the portion of ARGs. Differential expression analysis and enrichment analysis were performed to confirm abnormal autophagy-related biological functions. Univariate and multivariate Cox regression analyses were performed on RNA microarray data (GSE53625) to construct a prognostic risk signature associated with autophagy. The performance of the model was evaluated by receiver operating characteristic (ROC) analysis, survival analysis and Brier score. The model was subjected to bootstrap internal validation. The potential molecular mechanism of gene signature was explored by gene set enrichment analysis (GSEA). Spearman correlation coefficient examined the correlation between risk score and immune status and ferroptosis. The expression levels of genes and proteins were validated by qRT-PCR and immunohistochemistry in ESCC cell lines and ESCC tissues. We constructed and validated an autophagy-related prognostic risk signature in 179 patients with ESCC. The long-term survival of patients in high-risk group was lower than that in low-risk group (log-rank, P value < 0.001). ROC analysis and Brier score confirmed the reliability of the signature. GSEA results showed significant enrichment of cancer- and autophagy-related signaling pathways in the high-risk ESCC patients and immunoregulatory signaling pathways in the low-risk ESCC patients. Correlation analysis showed that the risk signature can effectively predict the effect of immunotherapy. About 33.97% (71/209) ferroptosis-related genes were significantly correlated with risk scores. Finally, the results of qRT-PCR and immunohistochemistry experiments were consistent with bioinformatics analysis. In brief, we constructed a novel autophagy-related gene signature (VIM, UFM1, TSC2, SRC, MEFV, CTTN, CFTR and CDKN1A), which could improve the prediction of clinical outcomes in patients with ESCC.

Non-Structural Protein 3 of Duck Tembusu Virus Induces Autophagy via the ERK and PI3K-AKT-mTOR Signaling Pathways.

Despite autophagy’s pivotal role in the replication of viruses such as duck Tembusu virus (DTMUV), which has caused massive economic losses to the poultry industry in the world, the specific relationships between DTMUV and cellular autophagy remain largely unknown. In response, we investigated the interactions between autophagy and DTMUV, the effects of the structural and non-structural proteins of DTMUV on autophagy, and the autophagy-related signaling pathways induced by DTMUV. Among the results, DTMUV increased the autophagy flux in duck embryo fibroblasts (DEF) and BHK-21 cells, while autophagy facilitated viral replication. After we pharmacologically induced autophagy with rapamycin (RAPA), the replication of DTMUV increased by 15.23-fold compared with the control group of DEF cells. To identify which DTMUV protein primarily induced autophagy, all three structural proteins and seven non-structural proteins of DTMUV were transfected into cells, and the results showed that non-structural protein 3 (NS3) induced significant autophagy in DEF cells. By means of Western blot, immunofluorescence, and transmission electron microscopy, we confirmed that NS3 protein could significantly induce autophagy and autophagy flux. Furthermore, we showed that NS3 induced autophagy in DEF cells through extracellular signal-regulated kinase 2 (ERK2) and phosphatidylinositol-3-kinase (PI3K)/AKT and the mammalian target of rapamycin (mTOR) signaling pathways using specific inhibitors and RNA interference assays. Finally, autophagy induced by NS3 promoted DTMUV replication. These results provide novel insight into the relationship between DTMUV and autophagy, broadening the current understanding of the molecular pathogenesis of DTMUV.

Mechanistic Insight on Autophagy Modulated Molecular Pathways in Cerebral Ischemic Injury: From Preclinical to Clinical Perspective.

Cerebral ischemia is one of the most devastating brain injuries and a primary cause of acquired and persistent disability worldwide. Despite ongoing therapeutic interventions at both the experimental and clinical levels, options for stroke-related brain injury are still limited. Several evidence suggests that autophagy is triggered in response to cerebral ischemia, therefore targeting autophagy-related signaling pathways can provide a new direction for the therapeutic implications in the ischemic injury. Autophagy is a highly conserved lysosomal-dependent pathway that degrades and recycles damaged or non-essential cellular components to maintain neuronal homeostasis. But, whether autophagy activation promotes cell survival against ischemic injury or, on the contrary, causes neuronal death is still under debate. We performed an extensive literature search from PubMed, Bentham and Elsevier for various aspects related to molecular mechanisms and pathobiology involved in autophagy and several pre-clinical studies justifiable further in the clinical trials. Autophagy modulates various downstream molecular cascades, i.e., mTOR, NF-κB, HIF-1, PPAR-γ, MAPK, UPR, and ROS pathways in cerebral ischemic injury. In this review, the various approaches and their implementation in the translational research in ischemic injury into practices has been covered. It will assist researchers in finding a way to cross the unbridgeable chasm between the pre-clinical and clinical studies.

Study on the autophagy-related mechanism of puerarin in improving the cognitive impairment induced by alcohol in female mice

ABSTRACT Primary Objective This study aimed to investigate the effects of low-, medium-, and high-dose puerarin on cognitive impairment induced by 50% alcohol in mice and revealed the role of autophagy-related signaling pathways (mTOR and JNK pathways) in this process. Research Design The alcohol-induced brain injury model was treated with different concentrations of puerarin. The cognitive function of mice was evaluated by the behavioral test, and the changes of target proteins in hippocampus of each experimental group were detected. Methods and Procedures 40 female Kunming mice were randomly divided into 5 groups. The cognitive ability of mice was tested by Morris water maze, the morphological changes in the CA1 area of hippocampus were observed by HE staining, and the target proteins in hippocampus were measured by WB and IHC. Main Outcomes and Results Compared with the 50% alcohol group, the expression of p-mTOR/mTOR and p-4E-BP1/4E-BP1 in hippocampus was significantly decreased, while the expression of p-JNK/JNK, Beclin1, and LC3 was significantly increased in the medium- and high-dose puerarin groups. Conclusions Puerarin could improve the cognitive impairment induced by 50% alcohol. The mTOR and JNK pathways related to autophagy might be involved in this process.

The role of autophagy in idiopathic pulmonary fibrosis: from mechanisms to therapies.

Idiopathic pulmonary fibrosis (IPF) is an interstitial pulmonary disease with an extremely poor prognosis. Autophagy is a fundamental intracellular process involved in maintaining cellular homeostasis and regulating cell survival. Autophagy deficiency has been shown to play an important role in the progression of pulmonary fibrosis. This review focused on the six steps of autophagy, as well as the interplay between autophagy and other seven pulmonary fibrosis related mechanisms, which include extracellular matrix deposition, myofibroblast differentiation, epithelial-mesenchymal transition, pulmonary epithelial cell dysfunction, apoptosis, TGF-β1 pathway, and the renin-angiotensin system. In addition, this review also summarized autophagy-related signaling pathways such as mTOR, MAPK, JAK2/STAT3 signaling, p65, and Keap1/Nrf2 signaling during the development of IPF. Furthermore, this review also illustrated the commonly used autophagy detection methods, the currently approved antifibrotic drugs pirfenidone and nintedanib, and several prospective compounds targeting autophagy for the treatment of IPF.

Phytochemicals Mediate Autophagy Against Osteoarthritis by Maintaining Cartilage Homeostasis.

Osteoarthritis (OA) is a common degenerative joint disease and is a leading cause of disability and reduced quality of life worldwide. There are currently no clinical treatments that can stop or slow down OA. Drugs have pain-relieving effects, but they do not slow down the course of OA and their long-term use can lead to serious side effects. Therefore, safe and clinically appropriate long-term treatments for OA are urgently needed. Autophagy is an intracellular protective mechanism, and targeting autophagy-related pathways has been found to prevent and treat various diseases. Attenuation of the autophagic pathway has now been found to disrupt cartilage homeostasis and plays an important role in the development of OA. Therefore, modulation of autophagic signaling pathways mediating cartilage homeostasis has been considered as a potential therapeutic option for OA. Phytochemicals are active ingredients from plants that have recently been found to reduce inflammatory factor levels in cartilage as well as attenuate chondrocyte apoptosis by modulating autophagy-related signaling pathways, which are not only widely available but also have the potential to alleviate the symptoms of OA. We reviewed preclinical studies and clinical studies of phytochemicals mediating autophagy to regulate cartilage homeostasis for the treatment of OA. The results suggest that phytochemicals derived from plant extracts can target relevant autophagic pathways as complementary and alternative agents for the treatment of OA if subjected to rigorous clinical trials and pharmacological tests.

DHOK Exerts Anti-Cancer Effect Through Autophagy Inhibition in Colorectal Cancer.

DHOK (14,15β-dihydroxyklaineanone) is a novel diterpene isolated from roots of Eurycoma longifolia Jack, a traditional herb widely applied in Southeast Asia. It is reported that DHOK has cytotoxic effect on cancer cells, but its anti-cancer mechanism has still been not clear. In our study, we first observed that DHOK inhibits cell proliferation of colorectal cancer cells in a time- and dose-dependent manner. Next, we performed transcriptome sequencing to identify the targets of DHOK and found that autophagy-related signaling pathways are involved under DHOK treatment. Indeed, in DHOK-treated cells, the level of autophagosome marker LC3 and the formation of GFP-LC3 puncta were decreased, indicating the reduction of autophagy. Moreover, confocal microscopy results revealed the lysosomal activity and the formation of autolysosomes are also inhibited. Our western blotting results demonstrated the activation of mammalian target of rapamycin (mTOR) signaling pathway by DHOK, which may be attributed to the enhancement of ERK and AKT activity. Functionally, activation of autophagy attenuated DHOK-caused cell death, indicating that autophagy serves as cell survival. In xenograft mouse model, our results also showed that DHOK activates the mTOR signaling pathway, decreases autophagy level and inhibits the tumorigenesis of colon cancer. Taken together, we revealed the molecular mechanism of DHOK against cancer and our results also demonstrate great potential of DHOK in the treatment of colorectal cancer.

κ-Carrageenan oligosaccharides induce microglia autophagy through AMPK/ULK1 pathway to regulate their immune response

Microglia are the main effector cells of immune response in central nervous system and are important targets for disease prevention and treatment. Κ-carrageenan Oligosaccharide (KOS), obtained by enzymatic hydrolysis from carrageenan of marine red algae, can inhibit the release of inflammatory factors from the over-activated microglia. The mechanism of microglia autophagy induced by KOS and its relationship with inflammation were studied to explore the development prospect of KOS in the research and treatment of inflammatory related diseases. The effect of KOS on inducing autophagy was detected by the secretion of cytokines by lipopolysaccharide (LPS)-activated microglia, respectively. The protein expression of autophagy-related signaling pathways were detected by Western Blot. The results showed that KOS could significantly protect the microglia from over-activated inflammatory by inducing the autophagy and inhibiting the release of inflammatory cytokines. And KOS could reduce the expression of the protein that related to the AMPK/ULK1 pathways in microglia, so as to regulate the autophagy pathway, and inhibit the inflammatory response of over-activated microglia. The study on the effect of KOS on microglia autophagy and excessive inflammatory response will provide a theoretical basis for further studies on the inhibition of nerve injury by regulating microglia autophagy and inflammatory response.

Autophagy-related signaling pathways in non-small cell lung cancer.

Lung cancer is one of the most prevalent causes of morbidity and mortality in both men and women across the globe. The disease has a quiet phenotype at first, which leads to chronic tumor development. Non-small cell lung cancer (NSCLC) is the most common kind of lung cancer, accounting for 85 percent of all lung malignancies. Autophagy has been described as an intracellular "recycle bin" where damaged proteins and molecules are degraded. Autophagy regulation is mainly dependent on signaling pathways such as phosphoinositide 3-kinases (PI3K), AKT, and the mammalian target of rapamycin (mTOR). In the context of NSCLC, studies on these signaling pathways are inconsistent, but our literature review suggests that the inhibition of mTOR, PI3K/AKT, and epidermal growth factor receptor signaling pathways by different medications can active autophagy and inhibit NSCLC progression. In conclusion, signaling pathways related to autophagy are effective therapeutic approaches for the treatment of NSCLC.

Revealing the Mechanism of Friedelin in the Treatment of Ulcerative Colitis Based on Network Pharmacology and Experimental Verification.

Objectives Ulcerative colitis (UC) is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide. This study was designed to uncover the healing effect of friedelin, a bioactive compound against UC through bioinformatics of network pharmacology and experimental verification of UC model mice. Materials and Methods Targets of friedelin and potential mechanism of friedelin on UC were predicted through target searching, PPI network establishing, and enrichment analyzing. We explored effects of friedelin on dextran sulfate sodium (DSS)-induced colitis. Severity of UC was investigated by body weight, disease activity index (DAI), and length of the colon. Inflammation severity was examined by determination of proinflammatory and anti-inflammatory cytokines. The numbers of autophagosome around the epithelial cells were observed by autophagy inhibition via a transmission electron microscope. The expressions of autophagy-related ATG5 protein and AMPK-mTOR signaling pathway were determined by immunofluorescence staining. Results In this study, 17 potential targets of friedelin and 1111 UC-related targets were identified. 10 therapeutic targets of friedelin against UC were acquired from overlapped targets of UC and friedelin. PPI network construction filtered 14 core targets through target amplification and confidence enhancement. The results of molecular docking showed that the docking scores of the top 5 active targets were higher than the threshold values. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were carried out, showing friedelin alleviates UC through anti-inflammatory pathways and molecular function of autophagy. Subsequently, animal-based experiments revealed the intraperitoneal injection of friedelin ameliorated DSS-induced body weight loss, DAI decrease, colon length shortening and colonic pathological damage with lower myeloperoxidase and proinflammatory cytokines (IL-1β and IL-6) and higher IL-10 levels, and more autophagosomes in transmission electron microscope results. The AMPK-mTOR signaling pathway plays important role in the friedelin's effect in autophagy as KEGG pathway result and experiment verification. Furthermore, the 3 ma validated the role of autophagy as an improvement in the friedelin's pharmacologic effect to UC model mice. Conclusions Friedelin ameliorated DSS-induced colitis in mice through of inflammatory inhibition and regulation of autophagy.

A Novel Autophagy-Related Long Non-Coding RNA Signature to Predict Prognosis and Therapeutic Response in Esophageal Squamous Cell Carcinoma.

BackgroundConsidering the significance of autophagy and long non-coding RNAs (lncRNAs) in the biology of esophageal squamous cell carcinoma (ESCC), the present study aimed to identify a new autophagy-related lncRNA signature to forecast the clinical outcomes of ESCC patients and to guide individualized treatment.MethodsThe expression profiles were obtained from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database. We extracted autophagy-related genes from the Human Autophagy Database and identified autophagy-related lncRNAs through Spearman correlation analysis. Univariate, least absolute shrinkage and selection operator and multivariate Cox regression analyses were performed on GSE53625 to construct an autophagy-related lncRNAs prognostic signature. The model was subjected to bootstrap internal validation, and the expression levels of lncRNAs were verified by TCGA database. The potential molecular mechanism of the model was explored by gene set enrichment analysis (GSEA). Spearman correlation coefficient examined the correlation between risk score and ferroptosis-associated genes as well as the response to immunotherapy and chemotherapy.ResultsWe identified and validated an autophagy-related lncRNAs prognostic signature in 179 patients with ESCC. The prognosis of patients in the low-risk group was significantly better than that in the high-risk group (p-value <0.001). The reliability of the model was verified by Brier score and ROC. GSEA results showed significant enrichment of cancer- and autophagy-related signaling pathways in the high-risk group and metabolism-related pathways in the low-risk group. Correlation analysis indicated that the model can effectively forecast the effect of immunotherapy and chemotherapy. About 35.41% (74/209) ferroptosis-related genes were significantly correlated with risk scores.ConclusionIn brief, we constructed a novel autophagy-related lncRNAs signature (LINC02024, LINC01711, LINC01419, LCAL1, FENDRR, ADAMTS9-AS1, AC025244.1, AC015908.6 and AC011997.1), which could improve the prediction of clinical outcomes and guide individualized treatment of ESCC patients.

A Novel Autophagy-Related lncRNA Prognostic Signature Associated with Immune Microenvironment and Survival Outcomes of Gastric Cancer Patients.

PurposeAutophagy plays a crucial role in the initiation and progression of gastric cancer (GC). However, the role of autophagy-related lncRNAs in GC remains unknown. This study aimed to investigate the prognostic value of the autophagy-related lncRNA signature and its role in the tumor immune microenvironment (TIME) of GC.MethodsRNA-sequencing (RNA-seq) and clinical data of GC patients were extracted from The Cancer Genome Atlas (TCGA) database. Univariate and multivariate Cox regression analyses were performed to identify the autophagy-related lncRNA prognostic signature which was validated in the test set and entire set. The survival and predictive performance were analyzed based on the Kaplan–Meier and ROC curves. Furthermore, the CIBERSORT algorithm was applied to explore the relationship between this signature and the immune cell infiltration. To elucidate the potential functions of autophagy-related lncRNAs in GC, we constructed the lncRNA-mRNA co-expression network and performed enrichment analysis. Principal component analysis (PCA) and Gene Set Enrichment Analysis (GSEA) were further performed to compare the different statuses between the high-risk and low-risk groups.ResultsWe identified 5 autophagy-related lncRNAs (AL355574.1, AC010768.2, AP000695.2, AC087286.2, and HAGLR) to construct a prognostic signature. This signature could be an independent prognostic indicator for GC patients and had a higher prediction efficiency than other clinicopathological parameters. Furthermore, patients in the high-risk score group had a stronger immunosuppressive microenvironment than the low-risk group. The enrichment analysis for mRNAs co-expressed with these lncRNAs indicated that autophagy-related signaling pathways were remarkably enriched. PCA and GSEA further revealed different autophagy and immune statuses in the high- and low-risk groups.ConclusionThe 5 autophagy-related lncRNA signature has significant clinical implications in prognosis prediction of GC. Meanwhile, our study elucidates the critical role of the autophagy-related lncRNA signature in the TIME of GC.

Changes and significance of autophagy in rat lung injury induced by gas explosion

Objective: To explore the changes and significance of autophagy in acute lung injury (ALI) induced by gas explosion in rats. Methods: In February 2018, the gas explosion in underground coal mine was simulated by large tunnel explosion experiment system, SD rats were randomly divided into control group and 6 distance groups (40 m, 80 m, 120 m, 160 m, 200 m, 240 m) with 18 rats in each group. The respiratory function of rats 24 h before and after explosion was detected. Post-explosion rats were anesthetized and sacrificed, histopathological changes of lung were observed by HE staining. Immunohistochemistry was performed to detect the in situ expression of autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3B) . The expression levels of autophagy related gene 12 (Atg12) , LC3B, P62, lysosomal associated membrane protein 2 (Lamp2) , B-cell lymphoma/leukemia-2 (Bcl-2) and Bcl2 interaction protein (Beclin-1) were detected by Western blot. Results: After gas explosion, the rats in 80 m distance point group had the hightest mortality (n=13, 72.22%) and the most severe lung injury degree, and the histopathological scores was (4.00±0.00) point. After gas explosion, the minute ventilation volume (MVb) , maximum inspiratory flow rate (PIFb) and maximum expiratory flow rate (PEFb) of rats were lower than before the gas explosion (P<0.05) . The respiratory frequency of rats in 80 m, 200 m, and 240 m distance point groups were significantly higher than that in the control group (P<0.05) . The expression levels of LC3B in 40 m, 80 m, 120 m, 160 m, and 200 m distance point groups were higher than that in the control group (P<0.05) . The relative expression levels of Atg12 and LC3BⅡ/Ⅰ in lung tissues of rats in different distance point groups were higher than those in the control group (P<0.05) . The relative expression levels of Beclin1 in 40 m, 80 m, 120 m, and 160 m distance point groups were significantly higher than that in the control group (P<0.05) . The relative expression levels of P62 in 80 m, 160 m and 200 m distance point groups were lower than that in the control group (P<0.05) . The relative expression levels of Lamp2 and Bcl-2 in lung tissues of rats in all distance groups except 240 m distance group were lower than those in the control group (P<0.05) . Conclusion: Gas explosion could induce increased autophagy in lung tissues of ALI rats. Autophagy-related signaling pathway could be involved in the pathophysiological process of ALI in rats caused by gas explosion, then the autophagy and the severity of the lesion showed a significant positive correlation.

Autophagy in Xp11 translocation renal cell carcinoma: from bench to bedside.

Xp11 translocation renal cell carcinoma (tRCC) characterized by the rearrangement of the TFE3 is recently identified as a unique subtype of RCC that urgently requires effective prevention and treatment strategies. Therefore, determining suitable therapeutic targets and fully understanding the biological significance of tRCC is essential. The importance of autophagy is increasingly acknowledged because it shows carcinogenic activity or suppressor effect. Autophagy is a physiological cellular process critical to maintaining cell homeostasis, which is involved in the lysosomal degradation of cytoplasmic organelles and macromolecules via the lysosomal pathway, suggesting that targeting autophagy is a potential therapeutic approach for cancer therapies. However, the underlying mechanism of autophagy in tRCC is still ambiguous. In this review, we summarize the autophagy-related signaling pathways associated with tRCC. Moreover, we examine the roles of autophagy and the immune response in tumorigenesis and investigate how these factors interact to facilitate or prevent tumorigenesis. Besides, we review the findings regarding the treatment of tRCC via induction or inhibition of autophagy. Hopefully, this study will shed some light on the functions and implications of autophagy and emphasize its role as a potential molecular target for therapeutic intervention in tRCC.

Biosynthesis of gold nanoparticles using Nigella sativa and Curtobacterium proimmune K3 and evaluation of their anticancer activity

In recent times, the development of functionalized nanoparticle methodology for biomedical applications has become a major challenge. In the present study, we prepared a novel gold nanoparticle (AuNP), named Curto-Cumin AuNP (CC-AuNP), using the biosynthetic process involving Nigella sativa (black cumin) seed extract and membrane vesicles isolated from the novel probiotic strain, Curtobacterium proimmune K3. Various spectrometric and microscopic analyses were performed to characterize the physicochemical properties of the nanoparticles. CC-AuNP exhibited significant cytotoxicity against human gastric adenocarcinoma (AGS) cells but not against normal cells. The toxic effects of the nanoparticles were associated with the excessive production of reactive oxygen species (ROS) in damaged mitochondria. Further, we investigated the molecular mechanisms underlying the cytotoxic effect of CC-AuNP. Results showed that except for B cell lymphoma 2 (Bcl-2), the intracellular apoptotic signaling molecules, such as p53, Bcl-associated X protein (Bax), and Caspase 9/Caspase 3 were significantly upregulated in AGS cells. ROS production and alterations in mitochondrial membrane potential were observed in AGS cells treated with CC-AuNP. The activation of autophagy flux-related biomarkers, such as LC3b/a, Beclin-1, p62, and Caspase 8, was confirmed by qPCR and western blotting. Autophagy pathway was suppressed in CC-AuNP-treated AGS cells and could not proceed further to the mature state. This was confirmed by the evaluation of both apoptosis and autophagy signaling pathways using autophagy-induced AGS cells treated with rapamycin, a well-studied autophagy activator. Overall, our results showed that CC-AuNP upregulates apoptotic signaling and suppresses the autophagy-related signaling pathway, and thus has potential as an anticancer agent. To our knowledge, the present study is the first to demonstrate that CC-AuNP may serve as novel therapeutic agent against gastric cancer. Furthermore, our study provides preliminary data which can be used to develop novel anticancer candidates and understand their anticancer mechanisms, and seems to be a good starting point for the development of alternative medications based on CC-AuNP.