Autophagy Signaling Pathway Research Articles

Phycocyanin diminishes the viability of non-small cell lung cancer cells via induction of autophagy

• Phycocyanin inhibits the growth of NSCLC cells. • Phycocyanin induces autophagy and autophagy flux in NSCLC cells. • AMPK signaling pathway activation is involved in phycocyanin-treated lung cancer cells. • Phycocyanin attenuated viability of multiple lung cancer cells through promoting autophagy. Non-small cell lung cancer (NSCLC) remains a leading cause of cancer mortality worldwide. Phycocyanin, a type of marine food additives, has been reported to exert antineoplastic effects in NSCLC. The aim of this study was to investigate roles of autophagy in the anticancer process of phycocyanin in NSCLC. Results showed that phycocyanin increased LC3-II/LC3-I ratio and decreased p62 level of NSCLC cells in a dose- and time-dependent manner. Laser scanning confocal observation of autophagic LC3 puncta showed phycocyanin promotes autophagy flux of NSCLC cells. In addition, AMPK signaling was activated upon phycocyanin treatment. Strikingly, phycocyanin was shown to synergistically affect the autophagy of cells with rapamycin and chloroquine, thus concertedly inhibiting the viabilities of NSCLC cells. These results indicated that the antineoplastic effect of phycocyanin could be attributed to the activated autophagy and AMPK signaling pathway. Thus, targeting autophagy could be a promising way to improve NSCLC though phycocyanin.

Effects of Vestibular Damage on the Sleep and Expression Level of Orexin in the Hypothalamus of Rats and Its Correlation with Autophagy and Akt Tumor Signal Pathway.

The aim of this study was to investigate the effect of vestibular disruption on autophagy-related proteins and the tumour-associated pathway P13K/Akt in rat sleep and its hypothalamus tissue and to examine whether catechins trigger tumour autophagy. Healthy adult male rats were randomly selected and divided into the vestibular damage group, the sham operation group, and the control group, with 8 rats in each group. A vestibular damage model was established through penetrating the tympanic membrane of the external auditory canal by injecting sodium p-aminophenylarsonate. The electroencephalogram (EGG) activity was used to record the sleep-wakefulness cycle of rats, and the expression levels of hypothalamic orexin (orexin) mRNA and autophagy proteins were detected. Primary hippocampal neurons were intervened with orexin at different concentrations and at different times to detect cell viability and the expression of autophagy protein and P13K/Akt signal pathway protein. The results showed that compared with the control group and the sham operation group, NREM duration in the vestibular damage group decreased significantly (P < 0.05), while its W time increased significantly (P < 0.05). The expression level of orexin mRNA in the hypothalamus of the vestibular damage group was significantly higher than that of the other two groups (P < 0.05), the expression of autophagy microtubule-related proteins LC3B and Beclin-1 increased significantly (P < 0.05), and the protein expression level of p62 decreased significantly (P < 0.05). After orexin intervention, compared with the control group, the expression of Beclin-1 protein that positively correlated with autophagy decreased significantly (P < 0.05) and the expression of mTOR, PDK1, and Akt protein increased significantly (P < 0.05). Compared with the orexin intervention group, the expression of Beclin-1 and LC3B proteins in cells of the orexin receptor inhibitor (Almorexant) group, the autophagy activator (Rapamycin) group, the orexin + Almorexant group, and the orexin + Rapamycin group increased significantly (P < 0.05), and the expression of mTOR, PDK1, and Akt proteins decreased significantly (P < 0.05). Catechins trigger autophagy in part by regulating the p-Akt/p-mTOR and P13K pathways and by stimulating the MAPK pathway. Catechins initiate apoptosis in common tumour types of hepatocellular carcinoma cells by activating autophagy-related pathways. The conclusion is that vestibular damage can affect the sleep-wakefulness cycle of rats; the level of autophagy in hypothalamic tissue is upregulated and may affect cell proliferation and activity through mTOR-P13K/Akt, which has a certain reference value for tumor formation and provides a basis for the research of insomnia or sleep disorders caused by tumors. Autophagy activation is a key process by which catechins promote apoptosis in tumour cells, providing an avenue for more research on the use of catechins-rich diets for cardiovascular protection in the treatment of tumours.

African swine fever virus MGF505-3R inhibits cGAS-STING-mediated IFN-β pathway activation by degrading TBK1

African swine fever virus (ASFV) is an important pathogen causing acute infectious disease in domestic pigs and wild boars that seriously endangers the global swine industry. As ASFV is structurally complex and encodes a large number of functional proteins, no effective vaccine has been developed to date. Thus, dissecting the mechanisms of immune escape induced by ASFV proteins is crucial. A previous study showed that the ASFV-encoded protein is an important factor in host immunity. In this study, we identified a negative regulator, MGF505-3R, that significantly downregulated cGAS/STING- and poly (dG:dC)-mediated IFN-β and interferon stimulation response element (ISRE) reporter activity and suppressed IFNB1 and IFIT2 mRNA levels. In addition, TBK1, IRF3 and IκBα phosphorylation levels were also inhibited. Mechanistically, MGF505-3R interacted with cGAS/TBK1/IRF3 and targeted TBK1 for degradation, thereby disrupting the cGAS-STING-mediated IFN-β signaling pathway, which appears to be highly correlated with autophagy. Knockdown MGF505-3R expression enhanced IFN-β and IL-1β production. Taken together, our study revealed a negative regulatory mechanism involving the MGF505-3R-cGAS-STING axis and provided insights into an evasion strategy employed by ASFV that involves autophagy and innate signaling pathways.

Expression analysis of Wnt signaling pathway related lncRNAs in periodontitis: A pilot case-control study

LncRNAs are involved in the modulation of several signaling pathways which have a crucial effect in the differentiation of periodontal ligament cells and the induction of cementum regeneration. Autophagy and Wnt signaling are two important pathways with a wide range of interrelationships associated with periodontitis. We chose four lncRNAs based on their potential interaction with these two pathways. We examined the expression of FOXD2-AS1, NNT-AS1, GAS8-AS1, and CCAT1 lncRNAs in tissues and blood specimens of patients with periodontitis and unaffected controls using qRT-PCR. Expression amounts of FOXD2-AS1 were lower in blood of cases compared with controls (relative expression (RE) = 0.08, P value<0.001). Tissue expression of FOXD2-AS1 was similar between cases and controls. Difference in blood levels of FOXD2-AS1 was significant among female subjects (RE = 0.07, P-value = 0.01), but not among male subjects. In addition, we reported lower levels of NNT-AS1 in blood samples of cases versus controls (RE = 0.25, P value = 0.05). But such a pattern was not seen in tissue samples. Expression of GAS8-AS1 was lower in both tissue and blood specimens of patients compared with control (RE = 0.49, P value = 0.02 and RE = 0.32, P value = 0.03 for tissue and blood specimens, respectively). Moreover, the differences in blood expression of GAS8-AS1 were significant in female patients compared with female controls (RE = 0.25, P-value = 0.04). Expression of CCAT1 was significantly lower in both gingival tissue and blood samples of patients compared with control (RE for tissue samples = 0.36, P-value = 0.02 and RE for blood samples = 0.33, P-value = 0.02). This pattern of expression was also detected in tissue specimens obtained from male persons (RE = 0.23, P value = 0.02) and blood samples acquired from female patients compared with corresponding control samples (RE = 0.21, P value<0.001). FOXD2-AS1 showed the best AUC values for distinguishing periodontitis in blood samples (AUC = 0.78). Combination of transcript levels of all four lncRNAs increased the diagnostic power to 0.81 and 0.74 in the gingival tissues and blood specimens, respectively. Our study demonstrates dysregulation of several lncRNAs in the periodontitis. These transcripts might partake in the pathogenesis of periodontitis and could have a possible correlation with autophagy and Wnt signaling pathways.

Interplay between exosomes and autophagy machinery in pain management: State of the art

Despite recent progress regarding inexpensive medical approaches, many individuals suffer from moderate to severe pain globally. The discovery and advent of exosomes, as biological nano-sized vesicles, has revolutionized current knowledge about underlying mechanisms associated with several pathological conditions. Indeed, these particles are touted as biological bio-shuttles with the potential to carry specific signaling biomolecules to cells in proximity and remote sites, maintaining cell-to-cell communication in a paracrine manner. A piece of evidence points to an intricate relationship between exosome biogenesis and autophagy signaling pathways at different molecular levels. A close collaboration of autophagic response with exosome release can affect the body’s hemostasis and physiology of different cell types. This review is a preliminary attempt to highlight the possible interface of autophagy flux and exosome biogenesis on pain management with a special focus on neuropathic pain. It is thought that this review article will help us to understand the interplay of autophagic response and exosome biogenesis in the management of pain under pathological conditions. The application of therapies targeting autophagy pathway and exosome abscission can be an alternative strategy in the regulation of pain.

The genomic and transcriptome characteristics of lung adenocarcinoma patients with previous breast cancer

BackgroundBreast cancer and lung cancer are the top two malignancies in the female population and the number of patients with breast cancer and subsequent primary lung cancer has increased significantly in recent years. However, the unique molecular characteristics of this group of patients remains unclear.PurposeTo identify the genomic and transcriptome characteristics of primary lung adenocarcinoma patients with previous breast cancer by comparison with single primary lung adenocarcinoma (SPLA) patients.MethodsThe tumor and normal pulmonary tissue specimens of ten primary pulmonary adenocarcinoma patients with previous breast cancer (multiple primary cancer, MPC) and ten SPLA patients were prospectively collected. The whole exome sequencing (WES) and RNA sequencing (RNA-seq) were performed to analyze the gene mutation and expression differences between MPC and SPC patients.ResultsThe results of WES indicated that the mutations of TRIM73, DLX6 and CNGB1 only existed in MPC patients. The results of RNA-seq manifested the occurrence of second primary lung adenocarcinoma in breast cancer patients was closely associated with cytokine-cytokine receptor action, autophagy, PI3L-Akt, cAMP and calcium ion signaling pathways. Besides, the expression levels of FGF10 and VEGFA genes were significantly increased in MPC patients.ConclusionThe occurrence of second primary lung adenocarcinoma may be related to the cytokine-cytokine receptor action, autophagy, PI3L-Akt, cAMP and calcium ion signaling pathways. Furthermore, the mutations of TRIM73, DLX6 and CNGB1 and high expression of FGF10 and VEGFA might play an important role in the development of lung adenocarcinoma in breast cancer patients. However, more in-depth investigations are needed to verify above findings.

Mitochonic Acid-5 Inhibits Reactive Oxygen Species Production and Improves Human Chondrocyte Survival by Upregulating SIRT3-Mediated, Parkin-dependent Mitophagy.

Mitochondrial dysfunction is related to the pathogenesis of osteoarthritis (OA); however, there are no effective drugs to treat OA for maintaining mitochondrial homeostasis. Studies have shown that mitochonic acid-5 (MA-5) has a protective effect against mitochondrial damage and plays a role in mitophagy. However, it is not clear whether MA-5 has a beneficial effect on inflammatory articular cartilage. Here, human OA cartilage was obtained from patients undergoing total joint replacement. Interleukin-1β (IL-1β) was used to stimulate chondrocytes and induce inflammatory injury. Cell Counting Kit-8, TUNEL, and flow cytometry assays were used to assess apoptosis. Gene expression was examined using quantitative reverse transcription-polymerase chain reaction. Mitochondrial function was evaluated using immunoblotting, mitochondrial membrane potential assay, JC-1 staining, and immunofluorescence analysis. Mitophagy was detected using immunoblotting and immunofluorescence. 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP), a specific inhibitor of Sirtuin 3 (SIRT3), was used to block the SIRT3/Parkin pathway. Mitophagy in the cartilage sections was evaluated via immunohistochemistry. IL-1β was found to induce chondrocyte apoptosis by inhibiting SIRT3 expression and mitophagy. In addition, inflammatory damage reduced the mitochondrial membrane potential and promoted the production of intracellular reactive oxygen species (ROS), leading to increased mitochondrial division, mitochondrial fusion inhibition, and the consequent mitochondrial damage. In contrast, the MA-5 treatment inhibited excessive ROS production by upregulating mitophagy, maintaining the mitochondrial membrane potential, and reducing mitochondrial apoptosis. After chemically blocking SIRT3 with 3-TYP, Parkin-related mitophagy was also inhibited, an effect that was prevented by pretreatment of the chondrocytes with MA-5, thereby suggesting that SIRT3 is upstream of Parkin. Overall, MA-5 was found to enhance the activity of SIRT3, promote Parkin-dependent mitophagy, eliminate depolarized/damaged mitochondria in chondrocytes, and protect cartilage cells. In conclusion, MA-5 inhibits IL-1β-induced oxidative stress and protects chondrocytes by upregulating the SIRT3/Parkin-related autophagy signaling pathway.

Electroacupuncture Promotes Autophagy by Regulating the AKT/mTOR Signaling Pathway in Temporal Lobe Epilepsy.

Temporal lobe epilepsy (TLE) is a complex neurological disease, and its occurrence and development are closely related to the autophagy signaling pathway. However, the mechanism by which electroacupuncture (EA) affects the regulation of autophagy has not been fully elucidated. TLE gene chip dataset GSE27166 and data from rats without epilepsy (n = 6) and rats with epilepsy (n = 6) were downloaded from Gene Expression Omnibus. The differentially expressed genes (DEGs) in the TLE and control groups were identified with the online tool GEO2R. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to analyse the functional and pathway enrichment of genes in the most important modules. A rat model of TLE induced by lithium-pilocarpine treatment was established. EA treatment at DU20 and DU14 in TLE rats was performed for 2weeks. Neuronal regeneration was determined using immunofluorescence staining. The protein levels of AKT/mTOR signaling pathway and autophagy markers were detected through western blotting and immunohistochemistry. This study identified 1837 DEGs, including 798 upregulated genes and 1039 downregulated genes. GO enrichment and KEGG analyses were performed on DEGs and revealed functional enrichment mainly in the mTOR signaling pathway and autophagy-animal. Furthermore, the number of mature neurons was significantly increased upon coexpressing BrdU/NeuN in TLE rats treated with EA. Western blotting and immunohistochemistry results showed significantly decreased levels of the phosphorylated-AKT and p-mTOR in the hippocampal CA3 and DG regions of TLE rats with EA treatment. And increased p-ULK1/ULK1, LC3-II/LC3-I and p62 levels in TLE rats with EA stimulation. Therefore, this study suggested that EA promoted autophagy in hippocampal neurons during the onset of epilepsy by regulating the AKT/mTOR signaling pathway to treat epilepsy.

Comparative analysis on transcriptomics of ivermectin resistant and susceptible strains of Haemonchus contortus.

BackgroundIvermectin (IVM) is one of the most important and widely used anthelmintics in veterinary medicine. However, its efficacy is increasingly compromised by widespread resistance, and the exact mechanism of IVM resistance remains unclear for most parasitic nematodes, including Haemonchus contortus, a blood-sucking parasitic nematode of small ruminants.MethodsIn this study, an H. contortus IVM-resistant strain from Zhaosu, Xinjiang, China, was isolated and assessed by the control test, faecal egg count reduction test (FECRT) and the larval development assay (LDA). Subsequently, comparative analyses on the transcriptomics of IVM-susceptible and IVM-resistant adult worms of this parasite were carried out using RNA sequencing (RNA-seq) and bioinformatics.ResultsIn total, 543 (416 known, 127 novel) and 359 (309 known, 50 novel) differentially expressed genes (DEGs) were identified in male and female adult worms of the resistant strain compared with those of the susceptible strain, respectively. In addition to several previously known candidate genes which were supposed to be associated with IVM resistance and whose functions were involved in receptor activity, transport, and detoxification, we found some new potential target genes, including those related to lipid metabolism, structural constituent of cuticle, and important pathways such as antigen processing and presentation, lysosome, autophagy, apoptosis, and NOD1-like receptor signalling pathways. Finally, the results of quantitative real-time polymerase chain reaction confirmed that the transcriptional profiles of selected DEGs (male: 8 genes, female: 10 genes) were consistent with those obtained by the RNA-seq.ConclusionsOur results indicate that IVM has multiple effects, including both neuromuscular and non-neuromuscular targets, and provide valuable information for further studies on the IVM resistance mechanism in H. contortus.Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s13071-022-05274-y.

Scutellarin Improves Type 2 Diabetic Cardiomyopathy by Regulating Cardiomyocyte Autophagy and Apoptosis.

Diabetes cardiomyopathy has metabolic disorder and abnormality of cardiomyocytes, which is closely related to autophagy or apoptosis of cardiomyocytes. Scutellarin (SCU) is an important monomer extracted from Erigeron breviscapus (vant.) Hand.-Mazz. This study was conducted to investigate the function of SCU on apoptosis and autophagy of myocardial cells. We established a model of type 2 diabetic cardiomyopathy by high-fat and high-sugar diet. The results indicated that SCU downregulated blood glucose, total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) levels and upregulated high-density lipoprotein (HDL) level. In addition, SCU downregulated lactic dehydrogenase 1 (LDH1) and creatine kinase (CK) levels. Meanwhile, SCU improved the myocardium morphology and reduced myocardial apoptosis. Furthermore, SCU promoted the mRNA and protein expression of autophagy-related factors (Beclin-1 and LC3-II) and inhibited the mRNA and protein expression of apoptosis-related factors (caspase-3, caspase-8, caspase-9, caspase-12, Bax, and Cyt-C). In conclusion, SCU can promote autophagy signal pathway by upregulating the autophagy-related factors and inhibit the apoptotic signal pathway by downregulating apoptosis-related factors, thereby relieving type 2 diabetic cardiomyopathy (T2DC).

LncRNA H19 promotes glioblastoma multiforme development by activating autophagy by sponging miR-491-5p

ABSTRACT Glioblastoma multiforme (GBM) is a malignant cancer with severely poor survival, and the cells continue to thrive during hypoxia and toxic stress through autophagy. To validate the oncogenic role of long noncoding RNA H19 in GBM progression and examine whether autophagy and/or miR-491-5p participate in the process. The expression of H19 and autophagy-related genes in GBM and healthy control tissues was assessed via quantitative polymerase chain reaction. In addition, cell viability, proliferation, apoptosis and autophagy were respectively determined via cell counting kit-8 assay, clone formation assay, flow cytometry, western blotting and green fluorescent protein–microtubule-associated protein 1 light chain 3 alpha fluorescence analysis in vitro. Furthermore, a rescue assay was performed using rapamycin or miR-491-5p antagomir to examine the role of autophagy or miR-491-5p in H19-mediated regulation of proliferation and apoptosis. RNA pull-down and dual-luciferase reporter assays were employed to analyze the interaction between H19 and miR-491-5p. Additionally, tumor growth in a xenograft-bearing mouse model and autophagy in tumor mass were analyzed in vivo. The expression H19 was increased in GBM and was positively correlated with LC3 or Beclin-1. Silencing H19 inhibited growth and promoted apoptosis in GBM cells both in vitro and in vivo, and miR-491-5p was identified as one of the important mediators. H19 regulated the autophagy signaling pathway at least partly via miR-491-5p. Increased H19 expression in GBM exerts oncogenic effects by sponging miR-491-5p and enhancing autophagy. Therefore, H19 may be explored as a target for GBM therapy.

Single‐Cell Sequencing Reveals Distinct Expression Patterns of the Integrated Stress Response (ISR) Pathway Regulating Cell Survival in Secretory Cells in Colon of Hnrnp I Knockout Mice

ObjectivesHeterogeneous nuclear ribonucleoprotein I (Hnrnp I) is an RNA‐binding protein functions during pre‐mRNA splicing and regulation of alternative splicing events. Previously we found that ablation of Hnrnp I activates NF‐κB signaling in intestinal epithelial cells (IECs), resulting in increased nuclear translocation of P65 (NF‐κB subunit) and upregulation of proinflammatory cytokines and chemokines. Integrated stress response (ISR) signaling was linked to activation of canonical NF‐κB pathway. Therefore, in this study, we aimed to investigate ISR in the colon of Hnrnp I knockout mice. We hypothesize that cellular stress from Hnrnp I knockout triggers ISR, consequently affects the cellular dynamics among secretory cell types on colon epithelium (enteroendocrine, Paneth and goblet cells).MethodsTotal RNA was isolated from total colon cell preparations from WT and KO mice. Single‐cell RNAseq libraries (biological replicates, n=3) were prepared using Chromium Single‐Cell Gene Expression NextGem (v3.1, 10X Genomics). Analyses from raw counts were performed using the Seurat (v3.2.0) R package using default parameters, a computational cell calling algorithm was used to identify cell type using two published annotated mouse cell datasets. Pathway analysis was performed for secretary cell clusters including enteroendocrine cells (EECs), Paneth cells, and goblet cellsResultsComparing to WT, number of EECs in colon was significantly increased in KO mice. Total mRNA level of Atf4, the principal regulator of ISR, was significantly increased in colon secretory cells in KO mice. We also examined mRNA expression of ATF4 target genes in secretory cells. Specifically, gene encoding the regulator of apoptosis and autophagy, members of Bcl2 family, Bnip3, was significantly increased in secretory cells in KO mice, while Mlx and Gabarapl2 (Atg8), both are involved in apoptosis and autophagy signaling pathways, have a trend of increase in secretory cells in KO mice, all comparing to WT.ConclusionsCellular stress from Hnrnp I knockout activated ISR in IECs, specially in those secretory cell types – EECs, Paneth, and goblet cells. The activation of ISR led to both autophagy and apoptosis signaling in these cells through the upregulation of Bnip3, Mlxand Gabarapl2. Taken together, our results suggest that in response to the cellular stresses from the depletion of Hnrnp I in IECs, ISR activation in colonic secretory cells, stimulating apoptosis and autophagy pathway signaling, particularly in EECs, resulting in the proliferation of EECs in KO. The overall manipulation by ISR signaling in the colon secretary cells may present a critical early response to modulations in colon, potentially leading to perturbations to homeostasis among host colon epithelia, colon residential immunity, and gut microbiota.

Interactions between autophagy and phytohormone signaling pathways in plants.

Autophagy is a conserved recycling process with important functions in plant growth, development, and stress responses. Phytohormones also play key roles in the regulation of some of the same processes. Increasing evidence indicates that a close relationship exists between autophagy and phytohormone signaling pathways, and the mechanisms of interaction between these pathways have begun to be revealed. Here, we review recent advances in our understanding of how autophagy regulates hormone signaling and, conversely, how hormones regulate the activity of autophagy, both in plant growth and development and in environmental stress responses. We highlight in particular recent mechanistic insights into the coordination between autophagy and signaling events controlled by the stress hormone abscisic acid and by the growth hormones brassinosteroid and cytokinin and briefly discuss potential connections between autophagy and other phytohormones.

Delineating the Neuropathology of Lysosomal Storage Diseases Using Patient-Derived Induced Pluripotent Stem Cells.

Lysosomal storage diseases (LSDs) are inherited metabolic diseases caused by deficiency of lysosomal enzymes, essential for the normal development of the brain and other organs. Approximately two-thirds of the patients suffering from LSD exhibit neurological deficits and impose an escalating challenge to the medical and scientific field. The advent of induced pluripotent stem cell (iPSC) technology has aided researchers in efficiently generating functional neuronal and non-neuronal cells through directed differentiation protocols, as well as in decoding the cellular, subcellular, and molecular defects associated with LSDs using two-dimensional cultures and cerebral organoid models. This review highlights the information assembled from patient-derived iPSCs on neurodevelopmental and neuropathological defects identified in LSDs. Multiple studies have identified neural progenitor cell migration and differentiation defects, substrate accumulation, axon growth and myelination defects, impaired calcium homeostasis, and altered electrophysiological properties, using patient-derived iPSCs. In addition, these studies have also uncovered defective lysosomes, mitochondria, endoplasmic reticulum, Golgi complex, autophagy and vesicle trafficking and signaling pathways, oxidative stress, neuroinflammation, blood-brain barrier dysfunction, neurodegeneration, gliosis, and altered transcriptomes in LSDs. The review also discusses the therapeutic applications such as drug discovery, repurposing of drugs, synergistic effects of drugs, targeted molecular therapies, gene therapy, and transplantation applications of mutation-corrected lines identified using patient-derived iPSCs for different LSDs.

Long Noncoding RNA Expression Rofiles Elucidate the Potential Roles of lncRNA- XR_003496198 in Duck Hepatitis A Virus Type 1 Infection.

Duck hepatitis A virus type 1 (DHAV-1) is a highly lethal virus that severely affects the duck industry worldwide. Long noncoding RNAs (lncRNAs) exert crucial roles in pathogen attacks. Here, we conducted deep transcriptome analysis to investigate the dynamic changes of host lncRNAs profiles in DHAV-1-infected duck embryo fibroblasts. We identified 16,589 lncRNAs in total and characterized their genomic features. Moreover, 772 and 616 differentially expressed lncRNAs (DELs) were screened at 12 and 24 h post-infection. Additionally, we predicted the DELs’ cis- and trans-target genes and constructed lncRNA-target genes regulatory networks. Functional annotation analyses indicated that the putative target genes of DELs participated in diverse vital biological processed, including immune responses, cellular metabolism, and autophagy. For example, we confirmed the dysregulation of pattern recognition receptors (TLR3, RIG-I, MDA5, LGP2, cGAS), signal transducers (STAT1), transcription factors (IRF7), immune response mediators (IL6, IL10, TRIM25, TRIM35, TRIM60, IFITM1, IFITM3, IFITM5), and autophagy-related genes (ULK1, ULK2, EIF4EBP2) using RT-qPCR. Finally, we confirmed that one DHAV-1 induced lncRNA-XR_003496198 is likely to inhibit DHAV-1 replication in DEFs. Our study comprehensively analyzed the lncRNA profiles upon DHAV-1 infection and screened the target genes involved in the innate immune response and autophagy signaling pathway, thereby revealing the essential roles of duck lncRNAs and broadening our understanding of host-virus interactions.

Enhancing and stabilization of cord blood regulatory T-cell suppressive function by human mesenchymal stem cell (MSC)-derived exosomes.

FOXP3+ regulatory T cells (Tregs) are central to maintaining peripheral tolerance and immune homeostasis. They have the potential to be developed as a cellular therapy to treat various clinical ailments such as autoimmune disorders, inflammatory diseases and to improve transplantation outcomes. However, a major question remains whether Tregs can persist and exert their function effectively in a disease state, where a broad spectrum of inflammatory mediators could inactivate Tregs. In this study, we investigated the potential of mesenchymal stem cell (MSC)-derived exosomes to promote and sustain Tregs function. MSC-conditioned media (MSC-CM) cultured Tregs were more suppressive in both polyclonal and allogeneic responses and were resistant to inflammatory stimulation in vitro compared with the controls. A similar enhancement of Treg function was also observed by culturing Tregs with MSC-derived exosomes alone. The enhanced suppressive activity and stability of Treg cultured in MSC-CM was reduced when exosomes were depleted from MSC-CM. We identified that MSC-derived exosomes could upregulate the expression of LC3(II/I), phosphorylate Jak3 and Stat5 to promote Treg survival, and regulate FOXP3 expression in Tregs. Overall, our study demonstrates that MSC-derived exosomes are capable of enhancing Hucb-Tregs function and stability by activating autophagy and Stat5 signalling pathways. Our findings provide a strong rationale for utilizing MSC-derived exosomes as an effective strategy to enhance Treg function, and improve the overall Tregs-based cell therapy landscape.

Exosomes From Human Umbilical Cord Mesenchymal Stem Cells Treat Corneal Injury via Autophagy Activation.

Corneal injury (CI) affects corneal integrity and transparency, deteriorating the patient’s quality of life. This study aimed to explore the molecular mechanisms by which exosomes secreted from human umbilical cord mesenchymal stem cells (hucMSC-Exos) affect autophagy in human corneal epithelial cells (HCECs) and CI models. We isolated and identified hucMSC-Exos using nanoparticle tracking analysis, transmission electron microscopy, and western blotting. The effects of hucMSC-Exos combined with autophagy regulators on HCECs and CI mice were assessed using cell viability assays, scratch assay, cell cycle assay, apoptosis assay, corneal fluorescein staining, haze grades, pathological examinations, western blotting, and quantitative polymerase chain reaction (qPCR). In vitro results indicated that hucMSC-Exos combined with the autophagy activator had positive effects in promoting the cell proliferation, migration capacity, and the cell cycle by upregulating the proportions of cells in the S phase and the expression of PCNA, Cyclin A, Cyclin E, and CDK2. Meanwhile, the combination treatment reduced the apoptotic rate of HCECs. In vivo results indicated that hucMSC-Exos especially combined them with the autophagy activator significantly alleviated corneal epithelial defects and stromal opacity, reduced the levels of the apoptotic markers Bax and cleaved Caspase-3, reduced the inflammatory response products TNF-α, IL-1β, IL-6, and CXCL-2, and increased the Bcl-2. This was achieved by upregulating pAMPK/AMPK and pULK1/ULK1 ratios, and Beclin-1 and LC3B II/I, and by downregulating the pmTOR/mTOR ratio and p62. In contrast, clinical indications, apoptosis, and inflammation were aggravated after the application of the autophagy inhibitor. HucMSC-Exos combined with an autophagy activator significantly enhanced HCECs functions and alleviated corneal defects, apoptosis, and inflammation by activating the autophagy signaling pathway, AMPK-mTOR-ULK1, providing a new biological therapy for corneal wound healing and ocular surface regeneration.

Autophagy Signaling by Neural-Induced Human Adipose Tissue-Derived Stem Cell-Conditioned Medium during Rotenone-Induced Toxicity in SH-SY5Y Cells.

Rotenone (ROT) inhibits mitochondrial complex I, leading to reactive oxygen species formation, which causes neurodegeneration and alpha-synuclein (α-syn) aggregation and, consequently, Parkinson’s disease. We previously found that a neurogenic differentiated human adipose tissue-derived stem cell-conditioned medium (NI-hADSC-CM) was protective against ROT-induced toxicity in SH-SY5Y cells. In the present study, ROT significantly decreased the phospho (p)-mTORC1/total (t)-mTOR, p-mTORC2/t-mTOR, and p-/t-ULK1 ratios and the ATG13 level by increasing the DEPTOR level and p-/t-AMPK ratio. Moreover, ROT increased the p-/t-Akt ratio and glycogen synthase kinase-3β (GSK3β) activity by decreasing the p-/t-ERK1/2 ratios and beclin-1 level. ROT also promoted the lipidation of LC3B-I to LC3B-II by inducing autophagosome formation in Triton X-100-soluble and -insoluble cell lysate fractions. Additionally, the levels of ATG3, 5, 7, and 12 were decreased, along with those of lysosomal LAMP1, LAMP2, and TFEB, leading to lysosomal dysfunction. However, NI-hADSC-CM treatment increased the p-mTORC1, p-mTORC2, p-ULK1, p-Akt, p-ERK1/2, ATG13, and beclin-1 levels and decreased the p-AMPK level and GSK3β activity in response to ROT-induced toxicity. Additionally, NI-hADSC-CM restored the LC3B-I level, increased the p62 level, and normalized the ATG and lysosomal protein amounts to control levels. Autophagy array revealed that the secreted proteins in NI-hADSC-CM could be crucial in the neuroprotection. Taken together, our results showed that the neuroprotective effects of NI-hADSC-CM on the autophagy signaling pathways could alleviate the aggregation of α-syn in Parkinson’s disease and other neurodegenerative disorders.

Pulsed Electromagnetic Field Alleviates Intervertebral Disc Degeneration by Activating Sirt1-Autophagy Signaling Network.

Intervertebral disc (IVD) degeneration is regarded as a major contributor to low back pain (LBP), causing serious economic burden on individuals and society. Unfortunately, there are limited effective treatment for IVD degeneration. Pulsed electromagnetic field (PEMF) is an economical and effective physical therapy method, with reduced side-effects. It offers certain protection to a number of degenerative diseases. Therefore, understanding the underlying mechanism of PEMF on IVD is important for improving the PEMF therapeutic efficiency. In this study, PEMF up-regulated extracellular matrix (ECM) related genes in degenerated nucleus pulposus (NP) cells. It also increased SIRT1 expression and promoted autophagy in degenerated NP cells. In contrast, the autophagy suppressor 3-methyladenine (3-MA) reversed the beneficial effect of PEMF on ECM production. Similarly, the SIRT1 enzyme activity suppressor EX 527 also inhibited the effect of PEMF on autophagy and ECM production in NP cells, thereby suggesting that PEMF regulated ECM related genes expression through SIRT1-autophagy signaling pathway. Lastly, PEMF significantly reduced IVD degeneration in a rat model of IVD degeneration in vivo. In summary, our study uncovers a critical role of SIRT1-dependent autophagy signaling pathway in ECM protection and thus in the establishment of therapeutic effect of PEMF on IVD degeneration.

Thioredoxin interacting protein protects mice from fasting induced liver steatosis by activating ER stress and its downstream signaling pathways

Under normal conditions, fasting results in decreased protein disulfide isomerase (PDI) activity and accumulation of unfolded proteins, leading to the subsequent activation of the unfolded protein response (UPR)/autophagy signaling pathway to eliminate damaged mitochondria. Fasting also induces upregulation of thioredoxin-interacting protein (TXNIP) expression and mice deficient of this protein (TXNIP-KO mice) was shown to develop severe hypoglycemia, hyperlipidemia and liver steatosis (LS). In the present study, we aimed to determine the role of TXNIP in fasting-induced LS by using male TXNIP-KO mice that developed LS without severe hypoglycemia. In TXNIP-KO mice, fasting induced severe microvesicular LS. Examinations by transmission electron microscopy revealed mitochondria with smaller size and deformities and the presence of few autophagosomes. The expression of β-oxidation-associated genes remained at the same level and the level of LC3-II was low. PDI activity level stayed at the original level and the levels of p-IRE1 and X-box binding protein 1 spliced form (sXBP1) were lower. Interestingly, treatment of TXNIP-KO mice with bacitracin, a PDI inhibitor, restored the level of LC3-II after fasting. These results suggest that TXNIP regulates PDI activity and subsequent activation of the UPR/autophagy pathway and plays a protective role in fasting-induced LS.