Acute hypobaric hypoxic brain damage is a potentially fatal high-altitude sickness. Autophagy plays a critical role in ischemic brain injury, but its role in hypobaric hypoxia (HH) remains unknown. Here we used an HH chamber to demonstrate that acute HH exposure impairs autophagic activity in both the early and late stages of the mouse brain, and is partially responsible for HH-induced oxidative stress, neuronal loss, and brain damage. The autophagic agonist rapamycin only promotes the initiation of autophagy. By proteome analysis, a screen showed that protein dynamin2 (DNM2) potentially regulates autophagic flux. Overexpression of DNM2 significantly increased the formation of autolysosomes, thus maintaining autophagic flux in combination with rapamycin. Furthermore, the enhancement of autophagic activity attenuated oxidative stress and neurological deficits after HH exposure. These results contribute to evidence supporting the conclusion that DNM2-mediated autophagic flux represents a new therapeutic target in HH-induced brain damage.
Mice ; Animals ; Hypoxia ; Oxidative Stress ; Autophagy ; Cognition ; Sirolimus/therapeutic use*

Early secreted antigenic target of 6 kDa protein (ESAT-6) is the major virulence factor of Mycobacterium tuberculosis (MTB), which can resist the clearance of MTB in bodies by inhibiting macrophage phagocytosis and autophagy reaction, thus impeding the immune defense function of the body against MTB infection. In addition, ESAT-6-induced apoptosis of macrophage and massive necrosis of innate immune cells can foster MTB proliferation and colonization, leading to systemic MTB infection. Moreover, ESAT-6 hampers the protective immune response of Th1 cells, reducing the secretion of pro-inflammatory cytokines and contributing to immune dysfunction, thus accelerating the course of MTB infection. During the process, the high immunogenicity of ESAT-6 can be leveraged as a dominant antigen in the development of new TB vaccines, making it a promising candidate with broad prospects for further development.
Humans ; Mycobacterium tuberculosis ; Vaccines ; Cytokines ; Apoptosis ; Autophagy ; Sepsis

OBJECTIVE: To explore the mechanism of electroacupuncture (EA) in promoting recovery of the facial function with the involvement of autophagy, glial cell line-derived neurotrophic factor (GDNF), and phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway. METHODS: Seventy-two male Sprague-Dawley rats were randomly allocated into the control, sham-operated, facial nerve injury (FNI), EA, EA+3-methyladenine (3-MA), and EA+GDNF antagonist groups using a random number table, with 12 rats in each group. An FNI rat model was established with facial nerve crushing method. EA intervention was conducted at Dicang (ST 4), Jiache (ST 6), Yifeng (SJ 17), and Hegu (LI 4) acupoints for 2 weeks. The Simone's 10-Point Scale was utilized to monitor the recovery of facial function. The histopathological evaluation of facial nerves was performed using hematoxylin-eosin (HE) staining. The levels of Beclin-1, light chain 3 (LC3), and P62 were detected by immunohistochemistry (IHC), immunofluorescence, and reverse transcription-polymerase chain reaction, respectively. Additionally, IHC was also used to detect the levels of GDNF, Rai, PI3K, and mTOR. RESULTS: The facial functional scores were significantly increased in the EA group than the FNI group (P<0.05 or P<0.01). HE staining showed nerve axons and myelin sheaths, which were destroyed immediately after the injury, were recovered with EA treatment. The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats (P<0.01); however, EA treatment reversed these abnormal changes (P<0.01). Meanwhile, EA stimulation significantly increased the levels of GDNF, Rai, PI3K, and mTOR (P<0.01). After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist, the repair effect of EA on facial function was attenuated (P<0.05 or P<0.01). CONCLUSIONS EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI. EA may exert this neuroreparative effect through mediating the release of GDNF, activating the PI3K/mTOR signaling pathway, and further regulating the autophagy of facial nerves.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Electroacupuncture ; Phosphatidylinositol 3-Kinase/metabolism* ; Facial Nerve Injuries/therapy* ; Phosphatidylinositol 3-Kinases/metabolism* ; Beclin-1 ; Glial Cell Line-Derived Neurotrophic Factor ; Signal Transduction ; TOR Serine-Threonine Kinases/metabolism* ; Autophagy ; Mammals/metabolism*

Carrier Proteins ; Autophagy ; Lipid Metabolism

Lipophagy, the selective engulfment of lipid droplets (LDs) by autophagosomes for lysosomal degradation, is critical to lipid and energy homeostasis. Here we show that the lipid transfer protein ORP8 is located on LDs and mediates the encapsulation of LDs by autophagosomal membranes. This function of ORP8 is independent of its lipid transporter activity and is achieved through direct interaction with phagophore-anchored LC3/GABARAPs. Upon lipophagy induction, ORP8 has increased localization on LDs and is phosphorylated by AMPK, thereby enhancing its affinity for LC3/GABARAPs. Deletion of ORP8 or interruption of ORP8-LC3/GABARAP interaction results in accumulation of LDs and increased intracellular triglyceride. Overexpression of ORP8 alleviates LD and triglyceride deposition in the liver of ob/ob mice, and Osbpl8-/- mice exhibit liver lipid clearance defects. Our results suggest that ORP8 is a lipophagy receptor that plays a key role in cellular lipid metabolism.
Animals ; Mice ; Lipid Droplets ; Autophagy ; Autophagosomes ; Homeostasis ; Triglycerides

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

OBJECTIVES: To explore the effect mechanism of electroacupuncture (EA) on functional constipation (FC) at the combined lower he-sea and front-mu points of large intestine based on enteric neuronal autophagy. METHODS: A total of 40 SPF Kunming mice were randomly divided into 5 groups (n = 8), i.e. a control group, a model group, an acupuncture group, a 3-methyl adenine (3-MA) group, and a 3-MA + acupuncture group. Except the control group, the FC model was established by gavage with compound diphenoxylate suspension for 14 days in the other 4 groups. After successful modeling, the mice of the acupuncture group and the 3-MA + acupuncture group received EA at bilateral "Tianshu" (ST 25) and "Shangjuxu" (ST 37), stimulated for 30 min with disperse-dense wave, 2 Hz/15 Hz of frequency, 1 mA of intensity. EA was delivered once daily. One course of treatment was composed of 5 days and 2 courses were needed, with an interval of 2 days. An intraperitoneal injection of 3-MA (15 mg/kg) was administered 30 min before EA in the mice of the 3-MA group and the 3-MA + acupuncture group, once daily. Before and after intervention, the time of the first black stool defecation and defecation behaviors in 6 h were observed in each group. After intervention, in every group, the small intestine propulsion rate was calculated, the colon tissue morphology was observed using HE staining, the ultrastructure of enteric neuronal autophagy was observed under transmission electron microscope, and the expressions of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1 and neuronal nuclear antigen protein (NeuN) in neurons of colonic muscularis were determined by immunohistochemistry. RESULTS: Before intervention, when compared with those in the control group, the time of the first black stool defecation was prolonged (P<0.01, P<0.05), and numbers (P<0.01), wet weight (P<0.01, P<0.05) and water content (P<0.05, P<0.01) of stool in 6 h were reduced in the model, acupuncture, 3-MA and 3-MA + acupuncture groups. After intervention, compared with those in the control group, the time of the first black stool defecation was longer (P<0.05), and numbers (P<0.01), wet weight (P<0.01) and water content (P<0.01) of stool in 6 h were decreased in the model group. The time of the first black stool defecation was shortened (P<0.01), and numbers (P<0.01), wet weight (P<0.01) and water content (P<0.01) of stool in 6 h were increased in the acupuncture group when compared with those in the model group. The time of the first black stool defecation was extended (P<0.01), and numbers (P<0.01), wet weight (P<0.01) and water content (P<0.01) of stool in 6 h were declined in the 3-MA + acupuncture group in comparison with those in the acupuncture group. All layers of colon tissue were normal and intact in each group. When compared with the control group, the small intestine propulsion rate and the average optical density (OD) values of LC3, Beclin-1 and NeuN in neurons of colonic muscularis were decreased (P<0.01), and autophagosomes were dropped in the model group. In the acupuncture group, the small intestine propulsion rate and the average OD values of NeuN, LC3 and Beclin-1 in neurons of colonic muscularis increased (P<0.01,P<0.05), and autophagosomes were elevated when compared with those in the model group. The small intestine propulsion rate and the average OD values of NeuN, LC3 and Beclin-1 in neurons of colonic muscularis were dropped (P<0.05,P<0.01) in the 3-MA + acupuncture group in comparison with those in the acupuncture group. CONCLUSIONS Electroacupuncture may promote enteric neuronal autophagy and increase the number of neurons so that the intestinal motility can be improved and constipation symptoms can be relieved in FC mice.
Mice ; Animals ; Electroacupuncture ; Beclin-1 ; Acupuncture Points ; Constipation/therapy* ; Intestine, Small ; Autophagy ; Water

BACKGROUND: Osteopenia has been well documented in adolescent idiopathic scoliosis (AIS). Bone marrow stem cells (BMSCs) are a crucial regulator of bone homeostasis. Our previous study revealed a decreased osteogenic ability of BMSCs in AIS-related osteopenia, but the underlying mechanism of this phenomenon remains unclear. METHODS: A total of 22 AIS patients and 18 age-matched controls were recruited for this study. Anthropometry and bone mass were measured in all participants. Bone marrow blood was collected for BMSC isolation and culture. Osteogenic and adipogenic induction were performed to observe the differences in the differentiation of BMSCs between the AIS-related osteopenia group and the control group. Furthermore, a total RNA was extracted from isolated BMSCs to perform RNA sequencing and subsequent analysis. RESULTS: A lower osteogenic capacity and increased adipogenic capacity of BMSCs in AIS-related osteopenia were revealed. Differences in mRNA expression levels between the AIS-related osteopenia group and the control group were identified, including differences in the expression of LRRC17 , DCLK1 , PCDH7 , TSPAN5 , NHSL2 , and CPT1B . Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed several biological processes involved in the regulation of autophagy and mitophagy. The Western blotting results of autophagy markers in BMSCs suggested impaired autophagic activity in BMSCs in the AIS-related osteopenia group. CONCLUSION Our study revealed that BMSCs from AIS-related osteopenia patients have lower autophagic activity, which may be related to the lower osteogenic capacity and higher adipogenic capacity of BMSCs and consequently lead to the lower bone mass in AIS patients.
Humans ; Adolescent ; Scoliosis/genetics* ; Cell Differentiation/physiology* ; Osteogenesis/genetics* ; Bone Diseases, Metabolic/genetics* ; Kyphosis ; Autophagy/genetics* ; Bone Marrow Cells ; Cells, Cultured ; Doublecortin-Like Kinases

BACKGROUND: Metastasis is the main cause of tumor-associated death and mainly responsible for treatment failure of breast cancer. Autophagy accelerates tumor metastasis. In our work, we aimed to investigate the possibility of microRNAs (miRNAs) which participate in the regulation of autophagy to inhibit tumor metastasis. METHODS: MiRNA array and comprehensive analysis were performed to identify miRNAs which participated in the regulation of autophagy to inhibit tumor metastasis. The expression levels of miR-3653 in breast cancer tissues and cells were detected by quantitative real-time polymerase chain reaction. In vivo and in vitro assays were conducted to determine the function of miR-3653. The target genes of miR-3653 were detected by a dual luciferase reporter activity assay and Western blot. The relationship between miR-3653 and epithelial-mesenchymal transition (EMT) was assessed by Western blot. Student's t -test was used to analyze the difference between any two groups, and the difference among multiple groups was analyzed with one-way analysis of variance and a Bonferroni post hoc test. RESULTS: miR-3653 was downregulated in breast cancer cells with high metastatic ability, and high expression of miR-3653 blocked autophagic flux in breast cancer cells. Clinically, low expression of miR-3653 in breast cancer tissues (0.054 ± 0.013 vs . 0.131 ± 0.028, t  = 2.475, P  = 0.014) was positively correlated with lymph node metastasis (0.015 ± 0.004 vs . 0.078 ± 0.020, t  = 2.319, P  = 0.023) and poor prognosis ( P  < 0.001). miR-3653 ameliorated the malignant phenotypes of breast cancer cells, including proliferation, migration (MDA-MB-231: 0.353 ± 0.013 vs . 1.000 ± 0.038, t  = 16.290, P  < 0.001; MDA-MB-468: 0.200 ± 0.014 vs . 1.000 ± 0.043, t  = 17.530, P  < 0.001), invasion (MDA-MB-231: 0.723 ± 0.056 vs . 1.000 ± 0.035, t  = 4.223, P  = 0.013; MDA-MB-468: 0.222 ± 0.016 vs . 1.000 ± 0.019, t  = 31.050, P  < 0.001), and colony formation (MDA-MB-231: 0.472 ± 0.022 vs . 1.000 ± 0.022, t  = 16.620, P  < 0.001; MDA-MB-468: 0.650 ± 0.040 vs . 1.000 ± 0.098, t  = 3.297, P  = 0.030). The autophagy-associated genes autophagy-related gene 12 ( ATG12 ) and activating molecule in beclin 1-regulated autophagy protein 1 ( AMBRA1 ) are target genes of miR-3653. Further studies showed that miR-3653 inhibited EMT by targeting ATG12 and AMBRA1 . CONCLUSIONS Our findings suggested that miR-3653 inhibits the autophagy process by targeting ATG12 and AMBRA1 , thereby inhibiting EMT, and provided a new idea and target for the metastasis of breast cancer.
Cell Line, Tumor ; Epithelial-Mesenchymal Transition/genetics* ; MicroRNAs/metabolism* ; Autophagy/genetics* ; Genes, Regulator ; Gene Expression Regulation, Neoplastic/genetics* ; Cell Proliferation/genetics* ; Cell Movement/genetics* ; Neoplasms/genetics*

Ferroptosis is a new type of programmed cell death different from other cell death pathways such as apoptosis,autophagy,necrosis,and pyroptosis in terms of initiation,mechanisms,and molecular characteristics.As the accumulation of phospholipid hydroperoxides is the hallmark of ferroptosis,the balance between oxidative damage and antioxidant defense is critical to the regulatory mechanism of ferroptosis.In cancer,the upregulation of antioxidant defense pathways can inhibit ferroptosis,thereby promoting cancer cells to survive the oxidative stress and develop drug resistance.This review systematically introduces the main features and regulatory mechanisms of ferroptosis.In addition,we summarize the role of ferroptosis in the progression and drug resistance of malignant tumors,providing novel implications for further research on the pathogenesis of malignant tumors and discovery of new targets for anti-cancer therapy.
Humans ; Ferroptosis ; Antioxidants ; Apoptosis ; Neoplasms ; Autophagy