OBJECTIVE: To observe the effects of electroacupuncture (EA) at "Shenting" (GV24) and "Baihui" (GV20) on mitochondrial autophagy in hippocampal neurons and silent information regulator sirtuin 1 (Sirt1)/forkhead box O3 (FOXO3)/PTEN-inducible kinase 1 (PINK1)/Parkin pathway in rats with learning-memory impairment after cerebral ischemia reperfusion injury. METHODS: A total of 35 male SD rats were randomly divided into a sham operation group (9 rats) and a modeling group (26 rats). In the modeling group, middle cerebral artery occlusion method was used to establish the middle cerebral artery ischemia-reperfusion (MCAO/R) model, and 18 rats of successful modeling were randomly divided into a model group and an EA group, 9 rats in each one. EA was applied at "Shenting" (GV24) and "Baihui" (GV20) in the EA group, 30 min a time, once a day for 14 days. After modeling and on 7th and 14th days of intervention, neurologic deficit score was observed; the learning-memory ability was detected by Morris water maze test; the morphology of neurons in CA1 area of hippocampus was detected by Nissl staining; the mitochondrial morphology was observed by transmission electron microscopy; the protein expression of Beclin-1, microtubule-associated protein 1 light chain 3B (LC3B), P62, Sitrt1, FOXO3, PINK1 and Parkin was detected by Western blot. RESULTS: After modeling, the neurologic deficit scores in the model group and the EA group were higher than that in the sham operation group (P<0.001); on 7th and 14th days of intervention, the neurologic deficit scores in the model group were higher than those in the sham operation group (P<0.001), the neurologic deficit scores in the EA group were lower than those in the model group (P<0.05, P<0.01). After modeling, the escape latency in the model group and the EA group was prolonged compared with that in the sham operation group (P<0.001); on 9th-13th days of intervention, the escape latency in the model group was prolonged compared with that in the sham operation group (P<0.001), the escape latency in the EA group was shortened compared with that in the model group (P<0.05, P<0.01, P<0.001). The number of crossing plateau in the model group was less than that in the sham operation group (P<0.001); the number of crossing plateau in the EA group was more than that in the model group (P<0.05). In the model group, in CA1 area of hippocampus, the number of neurons was less, with sparse arrangement, nuclear fixation, deep cytoplasmic staining, and reduction of Nissl substance; the morphology of mitochondrion was swollen, membrane structure was fragmented, and autophagic lysosomes were formed. Compared with the model group, in the EA group, in CA1 area of hippocampus, the number of neurons was increased, the number of cells of abnormal morphology was decreased, and the number of Nissl substance was increased; the morphology of mitochondrion was more intact and the number of autophagic lysosomes was increased. Compared with the sham operation group, in the model group, the protein expression of Beclin-1, FOXO3, PINK1, Parkin and the LC3BⅡ/Ⅰ ratio in hippocampus were increased (P<0.01, P<0.001), while the protein expression of P62 was decreased (P<0.05). Compared with the model group, in the EA group, the protein expression of Beclin-1, Sirt1, FOXO3, PINK1, Parkin and the LC3BⅡ/Ⅰratio in hippocampus were increased (P<0.001, P<0.01), while the protein expression of P62 was decreased (P<0.001). CONCLUSION EA at "Shenting" (GV24) and "Baihui" (GV20) can relieve the symptoms of neurological deficits and improve the learning-memory ability in MCAO/R rats, its mechanism may relate to the modulation of Sirt1/FOXO3/PINK1/Parkin pathway and the enhancement of mitochondrial autophagy.
Animals ; Electroacupuncture ; Male ; Rats, Sprague-Dawley ; Rats ; Forkhead Box Protein O3/genetics* ; Reperfusion Injury/metabolism* ; Ubiquitin-Protein Ligases/genetics* ; Brain Ischemia/complications* ; Mitochondria/genetics* ; Autophagy ; Protein Kinases/genetics* ; Sirtuin 1/genetics* ; Humans ; Memory Disorders/psychology* ; Signal Transduction

OBJECTIVE: To investigate the regulatory effect of electroacupuncture (EA) at "Neiguan" (PC6) on mitochondrial autophagy in rats with myocardial ischemia-reperfusion injury (MIRI) at different phases (ischemia and reperfusion phases), and to explore the bidirectional regulatory effects of EA at "Neiguan" (PC6) and its potential mechanism. METHODS: Forty-five male SD rats were randomly divided into 6 groups according to the random number table method, namely, sham-operation group (n=9), model-A group (n=6), model-B group (n=9), EA-A1 group (n=6), EA-B1 group (n=6), and EA-B2 group (n=9). Except the rats in the sham-operation group, the MIRI model was established in the other groups with the physical ligation and tube pushing method. In the model-A group, the samples were collected directly after ligation, and in the model-B group, the samples were collected after ligation and reperfusion. In the EA-A1 group, EA was delivered while the ligation was performed, and afterwards, the samples were collected. In the EA-B1 group, while the ligation was performed, EA was operated at the same time, and after reperfusion, the samples were collected. In the EA-B2 group, during ligation and the opening of the left anterior descending branch of the coronary artery, EA was delivered, and after reperfusion, the samples were collected. EA was performed at bilateral "Neiguan" (PC6), with a disperse-dense wave, a frequency of 2 Hz/100 Hz, a current of 1 mA, and a duration of 30 min. HE staining was employed to observe the morphology of cardiomyocytes, TUNEL was adopted to detect the apoptosis of cardiomyocytes, transcriptome sequencing was to detect the differentially expressed genes in the left ventricle, JC-1 flow cytometry was to detect the mitochondrial membrane potential (MMP) of cardiomyocytes, Western blot was to detect the protein expression of phosphatase and tensin homolog-induced kinase 1 (Pink1), Parkin and p62 in the left ventricle of rats, and ELISA was to detect the levels of serum creatine kinase isoenzyme (CK-MB) and cardiac troponin I (cTn-I) in the rats. RESULTS: Compared with the sham-operation group, the cardiomyocytes of rats in the model-B group were severely damaged, with disordered arrangement, unclear boundaries, broken muscle fibers, edema and loose distribution; and the cardiomyocytes in the EA-B2 group were slightly damaged, the cell structure was partially unclear, the cells were arranged more regularly, and the intact cardiomyocytes were visible. Compared with the sham-operation group, the apoptosis of cardiomyocytes increased in the model-B group (P<0.001); and when compared with the model-B group, the apoptosis alleviated in the EA-B2 group (P<0.001). The differentially expressed genes among the EA-B2 group, the sham-operation group and the model-B group were closely related to cell autophagy and mitochondrial autophagy. Compared with the sham-operation group, MMP of cardiomyocytes was reduced (P<0.001), the protein expression of Pink1, Parkin, and p62 of the left ventricle and the levels of serum CK-MB and cTn-I were elevated in the model B group (P<0.001). In comparison with model-A group, the MMP of cardiomyocytes and the levels of serum CK-MB and cTn-I were reduced (P<0.001, P<0.05), and the protein expression of Pink1 in the left ventricle rose in the EA-A1 group (P<0.01). Compared with the model-B group, MMP of cardiomyocytes increased (P<0.001), the protein expression of Pink1, Parkin, and p62 of the left ventricle, and the levels of serum CK-MB and cTn-I decreased (P<0.001) in the EA-B1 group and the EA-B2 group. When compared with the EA-A1 group, MMP of cardiomyocytes increased (P<0.001), and the protein expression of Pink1, Parkin, and p62 of the left ventricle, and the levels of serum CK-MB and cTn-I decreased in the EA-B1 group (P<0.01). CONCLUSION EA at "Neiguan" (PC6) can ameliorate MIRI in rats, which may be achieved through the Pink1/Parkin-mediated mitochondrial autophagy pathway. EA can alleviate myocardial injury by enhancing mitochondrial autophagy at the ischemia phase, and it can reduce reperfusion injury by weakening mitochondrial autophagy at the reperfusion phase.
Animals ; Electroacupuncture ; Male ; Myocardial Reperfusion Injury/metabolism* ; Rats, Sprague-Dawley ; Rats ; Acupuncture Points ; Autophagy ; Humans ; Mitochondria/genetics*

OBJECTIVE: To observe the effects of electroacupuncture (EA) at changbing fang (prescription for intestinal disease) on autophagy of colonic cells and gut microbiota in rats with ulcerative colitis (UC), and to explore the mechanism of EA in the treatment of UC. METHODS: Thirty-two SD male rats were randomly divided into a control group, a model group, an EA group and a sham-EA group, with 8 rats in each group. Except the control group, the UC rat model was established by free drinking of 5% dextran sulfate sodium solution for 7 days in the other groups. In the EA group, changbing fang was adopted, in which, EA was applied at "Tianshu" (ST25) and "Shangjuxu" (ST37), at disperse-dense wave and frequency of 10 Hz/50 Hz, for 20 min in each intervention. In the sham-EA group, shallow transcutaneous puncture was performed at the sites, 5 mm away from the points as the EA group, with the same parameters as the EA group. The intervention was delivered once daily for 3 consecutive days. The body weight was measured daily and the disease activity index (DAI) score was calculated before and after intervention. After intervention completion, the colon length was measured. Using HE staining, the colon morphology was observed and the score of colonic pathology was assessed. With ELISA adopted, the contents of tumor necrosis factor (TNF-α), interleukin (IL)-1β, IL-2 and IL-10 in the serum of the rats were detected. The ultrastructure of the colon tissue was observed under electron microscopy. Using Western blotting, the protein expression was detected for microtubule-associated protein 1 light chain 3 (LC3)Ⅱ, LC3Ⅰ, autophagy-related genes (ATG) 5, ATG12, sequestosome 1 (p62), phosphatidylinositol 3-kinase (PI3K), phosphorylated protein kinase B (p-AKT), protein kinase B (AKT), and phosphorylated mammalian target of rapamycin (p-mTOR), mammalian target of rapamycin (mTOR) in the colon tissue. The mRNA expression of PI3K, AKT and m-TOR in the colon tissue was detected by real-time fluorescence quantitative PCR. The 16S rRNA gene sequencing was used to analyze the structure of gut flora in the feces of rats. RESULTS: From day 1 to day 7, compared with the control group, the body weight decreased in the model group, EA group, and SEA group (P<0.05, P<0.01). From day 9 to day 10, the EA group showed an increase in body weight compared with the model group and SEA group (P<0.05, P<0.01). Before intervention, the DAI score in the model group, EA group, and SEA group was higher than the score of the control group, respectively (P<0.01). After intervention, the DAI score in the EA group was reduced compared with the model group and SEA group (P<0.01). Compared with the control group, in the model group, the colon length of rats was shorter (P<0.01); it showed the distorted crypts, thinner mucosal layer, reduced goblet cells, inflammatory cell infiltration and the disarranged histological structure; and the pathological score of the colon tissue increased (P<0.01); the serum contents of TNF-α and IL-1β increased (P<0.01), and those of IL-2 and IL-10 decreased (P<0.01). The structure of colon epithelial cells was disarranged, with cilia pelt off, and a large number of vacuoles in the cytoplasm; the mitochondria were swollen, with unclear structure and cristae partially disappeared; and few autophagosomes were observed. The value of LC3Ⅱ/LC3Ⅰand the protein expression of ATG5 and ATG12 in the colon tissues were reduced (P<0.01), the protein expression of p62 and PI3K, and the values of p-AKT/AKT, and p-mTOR/mTOR increased (P<0.01), and mRNA expression of PI3K, AKT and mTOR was elevated (P<0.01). The indexes of Chao1, Ace and Shannon decreased (P<0.01). At the phylum level, the relative abundance of Firmicutes decreased (P<0.05), that of Bacteroidetes and Proteobacteria increased (P<0.05, P<0.01). At the genus level, the relevant abundance of Lactobacillus decreased (P<0.05), while that of Lachnospiraceae_NK4A136_group and Phascolarctobacterium increased (P<0.01, P<0.05 ). Compared with the model group and SEA group, in the EA group, the colon length increased (P<0.01), the infiltration of inflammatory cells was reduced, the arrangement of intestinal epithelial cells was arranged regularly, with a small amount of shedding, and the pathological score of the colon tissue decreased (P<0.01). The serum contents of TNF-α and IL-1β decreased (P<0.01), and those of IL-2 and IL-10 increased (P<0.01). The colonic epithelial cells were arranged relatively, the morphology of organelles was basically normal, and autophagosomes were visible. The value of LC3Ⅱ/LC3Ⅰand the protein expression of ATG5 and ATG12 in colon tissue increased (P<0.01, P<0.05), the protein expression of p62 and PI3K, and the values of p-AKT/AKT, and p-mTOR/mTOR decreased (P<0.01); and mRNA expression of PI3K, AKT, m-TOR was reduced (P<0.01). The indexes of Chao1, Ace and Shannon increased (P<0.01). At the phylum level, the relative abundance of Firmicutes increased (P<0.01), while that of Bacteroidetes decreased (P<0.01). At the genus level, the relative abundance of Lactobacillus increased (P<0.05), whereas that of Lachnospiraceae_NK4A136_group decreased (P<0.01). When compared with the model group, the relative abundance of Proteobacteria decreased (P<0.05), and that of Phascolarctobacterium was reduced (P<0.05) in the EA group. CONCLUSION EA at changbingfang alleviates UC symptoms probably through inhibiting the PI3K/AKT/mTOR signaling pathway to regulate colonic autophagy and improve the intestinal flora.
Animals ; Electroacupuncture ; Colitis, Ulcerative/metabolism* ; Male ; Rats ; Gastrointestinal Microbiome ; Rats, Sprague-Dawley ; Colon/metabolism* ; Humans ; Autophagy ; Acupuncture Points ; Tumor Necrosis Factor-alpha/genetics* ; Interleukin-10/genetics*

OBJECTIVE: To observe the effects of acupuncture on podocyte autophagy and long non-coding RNA SOX2 overlapping transcript (LncRNA SOX2OT)/mammalian target of rapamycin C1 (mTORC1)/Unc-51-like kinase 1 (ULK1) pathway in rats with diabetic kidney disease (DKD), and to explore the mechanism by which acupuncture reduces urinary protein. METHODS: A total of 40 SPF-grade male Sprague-Dawley rats were randomly divided into a control group (n=10) and a modeling group (n=30). The DKD model was established by feeding a high-fat, high-sugar diet combined with intraperitoneal injection of streptozotocin (STZ) in the modeling group. Twenty rats with successful DKD model were randomly divided into a model group (n=10) and an acupuncture group (n=10). The acupuncture group received "spleen and stomach-regulating" acupuncture at bilateral "Zusanli" (ST36), "Fenglong" (ST40), "Yinlingquan" (SP9), and "Zhongwan" (CV12), 30 min per session, once daily, five times per week, for four weeks. The general condition, fasting blood glucose (FBG), 2-hour postprandial glucose (2hPG), serum creatinine (SCr), blood urea nitrogen (BUN), 24-hour urinary protein quantification, and urine albumin-to-creatinine ratio (UACR) were compared before and after the intervention. After intervention, urinary podocyte injury marker SPON2 was measured by ELISA. Podocyte autophagosomes and glomerular basement membrane ultrastructure in renal tissue were observed via transmission electron microscopy. Podocyte apoptosis was assessed by TUNEL staining. The protein expression of microtubule-associated protein 1 light chain 3Ⅱ (LC3-Ⅱ), mTORC1, ULK1, Beclin-1, and p62 in renal tissue was detected by Western blot. LncRNA SOX2OT expression in renal tissue was measured by real-time PCR. RESULTS: After the intervention, compared with the control group, the model group exhibited increased food and water intake, increased urine output, weight loss, and loose stools; compared with the model group, the food and water intake, urine volume, and loose stools were improved in the acupuncture group. Compared with the control group, FBG, 2hPG, SCr, BUN, 24-hour urinary protein quantification, UACR, and urinary SPON2 were all higher in the model group (P<0.01); compared with the model group, the FBG, 2hPG, SCr, BUN, 24-hour urinary protein quantification, UACR, and urinary SPON2 were all lower in the acupuncture group (P<0.01). Compared with the control group, the model group showed reduced podocyte autophagosomes and thickened glomerular basement membrane; compared with the model group, the acupuncture group had increased podocyte autophagosomes and less thickened basement membrane. Compared with the control group, the podocyte apoptosis index (AI) was higher in the model group (P<0.01); compared with the model group, the AI was lower in the acupuncture group (P<0.01). Compared with the control group, the expression of ULK1, Beclin-1, and LC3-Ⅱ proteins was lower, and the expression of mTORC1 and p62 proteins was higher in the model group (P<0.01). Compared with the model group, the expression of ULK1, Beclin-1, and LC3-Ⅱ proteins was higher, and the expression of mTORC1 and p62 proteins was lower in the acupuncture group (P<0.01). Compared with the control group, the LncRNA SOX2OT expression was lower in the model group (P<0.01). Compared with the model group, LncRNA SOX2OT expression was higher in the acupuncture group (P<0.01). CONCLUSION The "spleen and stomach-regulating" acupuncture method could improve renal function in DKD rats, reduce blood glucose and urinary protein excretion, alleviate podocyte injury, and enhance podocyte autophagy. The mechanism may be related to modulation of the renal LncRNA SOX2OT/mTORC1/ULK1 pathway.
Animals ; Podocytes/cytology* ; Diabetic Nephropathies/physiopathology* ; Rats, Sprague-Dawley ; Male ; Rats ; Mechanistic Target of Rapamycin Complex 1/genetics* ; Autophagy ; Acupuncture Therapy ; Autophagy-Related Protein-1 Homolog/genetics* ; RNA, Long Noncoding/metabolism* ; Humans ; Signal Transduction

OBJECTIVE: To observe the effect of acupuncture on chondrocyte autophagy in rats of knee osteoarthritis (KOA) and explore its underlying mechanisms. METHODS: Forty male SPF-grade SD rats were randomized into a blank group, a model group, a suspension group, an acupuncture group, and a combined therapy group, 8 rats in each one. Except the blank group, KOA model was prepared by the injection with papain. The suspension exercise therapy (10 min each time, three times daily), acupuncture (at "Yanglingquan" [GB34], "Zusanli" [ST36], and "Dubi" [ST35] on the right side, 30 min each intervention, once daily) and the combined therapy (the suspension exercise therapy combined with acupuncture) were delivered in the suspension group, the acupuncture group and the combined therapy group, respectively. The intervention of each group was performed continuously for 6 days, and 4 consecutive weeks, at the interval of 1 day. Before and after intervention, Lequesne MG score was assessed in the rats. After intervention, HE staining was adopted to observe the cartilaginous tissue morphology of the right knee joints, and Mankin score was evaluated; the serum levels of interleukin (IL)-1β, IL-6, and tumor neurosis factor-α (TNF-α) were measured using ELISA; the real-time PCR was provided to determine the mRNA expression of collagen protein type Ⅱ(COL2), collagen protein type Ⅹ (COL10), phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR), and autophagy-regulated protein (Beclin-1) in the cartilaginous tissue of the right knee joint; Western blot was employed to detect the protein expression of PI3K, phosphorylated PI3K (p-PI3K), Akt, phosphorylated Akt (p-Akt), mTOR, phosphorylated mTOR (p-mTOR) and Beclin-1 in the cartilaginous tissue of the right knee joint. RESULTS: Compared with the blank group, the rats in the model group showed the higher Lequesne MG score (P<0.01), thinner cartilage of the right knee, reduced chondrocytes and disordered arrangement, and higher Mankin score (P<0.01). Besides, in the model group, the serum levels of IL-1β, IL-6 and TNF-α were elevated (P<0.01), the mRNA expression of COL2 and Beclin-1 and the protein expression of Beclin-1 decreased (P<0.01), the mRNA expression of COL10, PI3K, Akt and mTOR, and the protein expression of p-PI3K, p-Akt and p-mTOR increased (P<0.01) in the cartilaginous tissue of the right knee joint. Compared with the model group, in the suspension group, the acupuncture group and the combined therapy group, the Lequesne MG scores were reduced (P<0.01), the cartilage of the right knee was thickened, the arrangement of chondrocytes was improved, and the Mankin scores were lower (P<0.01). Besides, in these intervention groups, the serum levels of IL-1β, IL-6 and TNF-α were reduced (P<0.01), the mRNA expression of COL2 and Beclin-1 and the protein expression of Beclin-1 increased (P<0.05, P<0.01), the mRNA expression of COL10, PI3K, Akt and mTOR, and the protein expression of p-PI3K, p-Akt and p-mTOR decreased (P<0.05, P<0.01) in the cartilaginous tissue of the right knee joint. When compared with the suspension group and the acupuncture group, in the combined therapy group, the Lequesne MG score was reduced (P<0.01), and the Mankin score was reduced (P<0.05, P<0.01). Besides, the serum levels of IL-1β, IL-6 and TNF-α were reduced (P<0.05), the mRNA expression of COL2 and Beclin-1 and the protein expression of Beclin-1 increased (P<0.05), the mRNA expression of COL10, PI3K, Akt and mTOR, and the protein expression of p-PI3K, p-Akt and p-mTOR decreased (P<0.05, P<0.01) in the cartilaginous tissue of the right knee joint. CONCLUSION Acupuncture can promote cartilage regeneration of knee joint and autophagy in KOA rats, alleviate inflammation, so as to retard cartilage degeneration, which may be possibly associated with the PI3K/Akt/mTOR signaling pathway.
Animals ; Male ; Acupuncture Therapy ; Proto-Oncogene Proteins c-akt/genetics* ; TOR Serine-Threonine Kinases/genetics* ; Osteoarthritis, Knee/physiopathology* ; Phosphatidylinositol 3-Kinases/genetics* ; Rats ; Signal Transduction ; Rats, Sprague-Dawley ; Chondrocytes/metabolism* ; Humans ; Autophagy ; Acupuncture Points

Oligodendrocyte lineage cells, including oligodendrocyte precursor cells (OPCs) and oligodendrocytes (OLs), are essential in establishing and maintaining brain circuits. Autophagy is a conserved process that keeps the quality of organelles and proteostasis. The role of autophagy in oligodendrocyte lineage cells remains unclear. The present study shows that autophagy is required to maintain the number of OPCs/OLs and myelin integrity during brain aging. Inactivation of autophagy in oligodendrocyte lineage cells increases the number of OPCs/OLs in the developing brain while exaggerating the loss of OPCs/OLs with brain aging. Inactivation of autophagy in oligodendrocyte lineage cells impairs the turnover of myelin basic protein (MBP). It causes MBP to accumulate in the cytoplasm as multimeric aggregates and fails to be incorporated into integral myelin, which is associated with attenuated endocytic recycling. Inactivation of autophagy in oligodendrocyte lineage cells impairs myelin integrity and causes demyelination. Thus, this study shows autophagy is required to maintain myelin quality during aging by controlling the turnover of myelin components.
Animals ; Autophagy/physiology* ; Oligodendroglia/metabolism* ; Myelin Sheath/physiology* ; Aging/pathology* ; Myelin Basic Protein/metabolism* ; Cell Lineage/physiology* ; Mice ; Oligodendrocyte Precursor Cells ; Mice, Inbred C57BL ; Brain/cytology* ; Cells, Cultured ; Cell Count

Alzheimer's disease (AD) poses one of the most urgent medical challenges in the 21st century as it affects millions of people. Unfortunately, the etiopathogenesis of AD is not yet fully understood and the current pharmacotherapy options are somewhat limited. Here, we report a novel inhibitor, Compound 44, for targeting cholinesterases, amyloid-β (Aβ) aggregation, and glycogen synthase kinase 3β (GSK-3β) simultaneously with the aim of achieving symptomatic relief and disease modification in AD therapy. We found that Compound 44 had good inhibitory effects on all intended targets with IC₅₀s of submicromolar or better, significant neuroprotective effects in cell models, and beneficial improvement of cognitive deficits in the triple transgenic AD (3 × Tg AD) mouse model. Moreover, we showed that Compound 44 acts as an autophagy regulator by inducing nuclear translocation of transcription factor EB through GSK-3β inhibition, enhancing the biogenesis of lysosomes and elevating autophagic flux, thus ameliorating the amyloid burden and tauopathy, as well as mitigating the disease phenotype. Our results suggest that triple-target inhibition via Compound 44 could be a promising strategy that may lead to the development of effective therapeutic approaches for AD.
Animals ; Alzheimer Disease/genetics* ; Mice, Transgenic ; Glycogen Synthase Kinase 3 beta/metabolism* ; Disease Models, Animal ; Mice ; Amyloid beta-Peptides/metabolism* ; Cholinesterase Inhibitors/therapeutic use* ; Humans ; Autophagy/drug effects* ; Cognitive Dysfunction/pathology* ; Neuroprotective Agents/pharmacology*

Hypoxia and aberrant activation of epidermal growth factor receptor (EGFR) are considered important features of various malignancies. However, whether hypoxia can directly trigger EGFR activation and its clinical implications remain unclear. In this study, we demonstrated that in oral cancer, a typical hypoxic tumor, hypoxia can induce chronic but constitutive phosphorylation of wild-type EGFR in the absence of ligands. Oral cancer cell lines exhibit different EGFR phosphorylation responses to hypoxia. In hypoxic HN4 and HN6 cells, ubiquitination-mediated endocytosis, lysosomal sorting, and degradation lead to low levels of EGFR phosphorylation. However, in CAL-27 and HN30 cells, a novel HIF-1α-induced long noncoding RNA (lncRNA), EUDAL, can compete with the E3 ligase/adaptor complex c-Cbl/Grb2 for binding to EGFR, stabilizing phosphorylated EGFR (pEGFR) and resulting in sustained activation of EGFR and its downstream STAT3/BNIP3 signaling. STAT3/BNIP3-mediated autophagy leads to antitumor drug resistance. A high EUDAL/EGFR/STAT3/autophagy pathway activation predicts poor response to chemotherapy in oral cancer patients. Collectively, hypoxia can induce noncanonical ligand-independent EGFR phosphorylation. High EUDAL expression facilitates sustained EGFR phosphorylation in hypoxic tumor cells and leads to autophagy-related drug resistance.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/pathology* ; RNA, Long Noncoding/genetics* ; Drug Resistance, Neoplasm/genetics* ; Cell Line, Tumor ; Phosphorylation ; Signal Transduction ; STAT3 Transcription Factor/metabolism* ; Cell Hypoxia ; Autophagy ; Proto-Oncogene Proteins c-cbl/metabolism*

OBJECTIVE: To investigate the effects of calcitonin gene-related peptide (CGRP) on autophagy in hypoxic/reoxygenated (H/R) cardiomyocytes and its relationship with the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway. METHODS: The rat cardiomyocyte cell line H9c2 was routinely cultured in vitro and passaged for experiments when the cells grew to 80% fusion. (1) CGRP dosage screening experiment: the cells were divided into blank control group, H/R group and different dosages of CGRP pretreatment groups. H9c2 cells were placed in a closed hypoxia chamber for 2 hours and then reoxygenated in a conventional incubator for 12 hours to prepare the H/R model. The CGRP pretreatment groups were pretreated with 0.01, 0.1, 0.5, 1, 5, and 10 μmol/L CGRP before the modeling process. The blank control group was not given any treatment. Cell counting kit-8 (CCK-8) was used to detect the cell survival rate, and the most suitable drug dosage was screened out. (2) Intervention experiment: H9c2 cells were divided into blank control group, H/R group, CGRP+H/R group, and CGRP+PI3K target inhibitor ly294002 (LY)+H/R group. H/R group was prepared as cellular H/R model. CGRP (1 μmol/L) alone or in combination with LY (10 μmol/L) was administered to CGRP+H/R group and CGRP+LY+H/R group, respectively, prior to the preparation of cellular H/R model. The blank control group was cultured routinely without treatment. The cell survival rate was detected by CCK-8. The level of lactate dehydrogenase (LDH) release was detected by colorimetric assay. The expressions of autophagy-related proteins [autophagy effector protein Beclin-1, microtubule-associated protein 1 light chain 3-II (LC3-II), autophagy protein p62] and PI3K/Akt/mTOR signaling pathway proteins [phosphorylated Akt (p-Akt), phosphorylated mTOR (p-mTOR)] were detected by Western blotting. RESULTS: (1) Results of CGRP dosage screening experiment: compared with the blank control group, the cell survival rate of the H/R group decreased significantly; and after giving 0.1, 0.5, 1, 5 μmol/L CGRP for pretreatment, the cell survival rate increased significantly, and intervention effect of 1 μmol/L CGRP was the best, and the difference was statistically significant when compared with that of the H/R group [(74.23±6.18)% vs. (23.43±4.09)%, P < 0.01], so it was used as the intervention dosage for the subsequent experiment. (2) Intervention experiment results: compared with the blank control group, the cell survival rate in the H/R group was significantly reduced, the level of LDH release was significantly increased, the protein expressions of Beclin-1 and LC3-II were significantly increased, and the protein expressions of p62, p-Akt and p-mTOR were significantly reduced, indicating that the death of cardiomyocytes occurred after the treatment of H/R and was accompanied by the elevation of autophagy level, and this process was associated with the activation of PI3K/Akt/mTOR signaling pathway. Compared with the H/R group, CGRP pretreatment increased cell survival rate [(76.02±2.43)% vs. (46.15±3.29)%, P < 0.01], decreased the level of LDH release (U/L: 169.83±11.65 vs. 590.17±34.50, P < 0.01), and down-regulated the protein expressions of Beclin-1 and LC3-II [Beclin-1 protein (Beclin-1/β-actin): 1.27±0.15 vs. 1.93±0.19, LC3-II protein (LC3-II/LC3-I): 1.27±0.13 vs. 1.98±0.18, both P < 0.01], up-regulated the protein expressions of p62, p-Akt, p-mTOR [p62 protein (p62/β-actin): 0.96±0.02 vs. 0.63±0.05, p-Akt protein (p-Akt/Akt): 0.76±0.04 vs. 0.48±0.02, p-mTOR protein (p-mTOR/mTOR): 1.13±0.09 vs. 0.68±0.15, all P < 0.05], suggesting that CGRP was able to reduce the H/R-induced cardiomyocyte injury, and this process was accompanied by a decrease in the level of cellular autophagy and activation of the PI3K/Akt/mTOR signaling pathway. Compared with the CGRP+H/R group, the cell survival rate was significantly lower than that in the CGRP+LY+H/R group [(56.95±6.63)% vs. (76.02±2.43)%, P < 0.01], LDH release level was significantly higher (U/L: 436.00±27.44 vs. 169.83±11.65, P < 0.01), and the protein expressions of Beclin-1 and LC3-II were significantly up-regulated [Beclin-1 protein (Beclin-1/β-actin): 1.63±0.12 vs. 1.27±0.15, LC3-II protein (LC3-II/LC3-I): 1.61±0.13 vs. 1.27±0.13, both P < 0.01], and significantly down-regulated p62, p-Akt, and p-mTOR protein expressions [p62 protein (p62/β-actin): 0.57±0.09 vs. 0.96±0.02, p-Akt protein (p-Akt/Akt): 0.45±0.01 vs. 0.76±0.04, p-mTOR protein (p-mTOR/mTOR): 0.66±0.06 vs. 1.13±0.09, all P < 0.05], suggesting that PI3K-targeted inhibitor was able to reverse the protective effect of CGRP on H/R cells. CONCLUSIONS CGRP pretreatment attenuated H/R-induced cardiomyocyte injury, increased cell survival rate, and reduced cellular LDH release. This effect may be achieved through inhibiting the activation of PI3K/Akt/mTOR signaling pathway.
Animals ; Myocytes, Cardiac/drug effects* ; Signal Transduction/drug effects* ; Rats ; TOR Serine-Threonine Kinases/metabolism* ; Calcitonin Gene-Related Peptide/pharmacology* ; Proto-Oncogene Proteins c-akt/metabolism* ; Autophagy/drug effects* ; Cell Line ; Cell Hypoxia ; Phosphatidylinositol 3-Kinases/metabolism*

OBJECTIVE: To investigate the impact of autophagy on cardiac tissue injury following common bile duct ligation (CBDL) in rats. METHODS: Twenty-four SPF grade healthy adult male Sprague-Dawley (SD) rats were randomly divided into four groups, with 6 rats in each group. The sham-operated (Sham) group underwent only dissection of the common bile duct without ligation. The CBDL group underwent CBDL to simulate jaundice-induced myocardial injury. The autophagy inhibitor 3-methyladenine (3-MA)+CBDL group was intraperitoneally injected with 15 mg/kg 3-MA 2 hours before modeling, and then injected once every other day. The CBDL+autophagy enhancer rapamycin (Rapa) group was intraperitoneally injected with Rapa 1 mg/kg 0.5 hour after modeling, and then injected once every other day. The rats in each group were sacrificed 2 weeks after surgery, and blood was taken from the inferior vena cava. Serum total bilirubin (TBil), alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), and MB isoenzyme of creatine kinase (CK-MB) were detected by using a fully automated animal biochemical analyzer. Serum oxidative stress marker superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were detected by colorimetric assay. The heart tissues of rats were taken and pathological changes were observed under a light microscope after hematoxylin-eosin (HE) staining. Transmission electron microscope was used to observe autophagosomes after double staining with uranyl acetate and lead citrate. The expressions of autophagy-related proteins were detected using Western blotting. RESULTS: Compared with the Sham group, the serum SOD activity of rats in the CBDL group was significantly decreased, while the serum MDA, TBil, ALT, AST, LDH, and CK-MB were significantly increased; the expressions of autophagy-related proteins Beclin-1 and microtubule-associated protein 1 light chain 3-II/I (LC3-II/I) were significantly increased, and p62 protein expression was significantly decreased. Autophagosomes were seen under electron microscopy in the CBDL group, and cardiac histopathological morphology showed focal necrosis in the myocardium as well as infiltration of inflammatory cells, dilatation of small interstitial blood vessels, and myocardial fiber degeneration. Compared with the CBDL group, cardiac tissue injury in rats was attenuated by pretreatment with the autophagy inhibitor 3-MA, with a decrease in inflammatory cell infiltration in myocardial tissue, a reduction in interstitial vasodilatation, and a decrease in the area of myocardial fibrosis; a decrease in the number of autophagosomes by electron microscopy; and a further rise in the viability of serum TBil, ALT, and AST [TBil (μmol/L): 184.40±6.74 vs. 120.70±16.93, ALT (U/L): 501.10±62.18 vs. 178.80±22.30, AST (U/L): 806.50±76.92 vs. 275.50±55.81, all P < 0.01], as well as a decrease in the levels of serum SOD, MDA, LDH, and CK-MB [SOD (kU/L): 85.00±5.29 vs. 107.50±7.86, MDA (μmol/L): 10.72±0.93 vs. 15.06±1.88, LDH (U/L): 387.40±119.50 vs. 831.30±84.35, CK-MB (U/L): 320.10±14.04 vs. 814.70±75.66, all P < 0.05]. The expressions of the autophagy-related proteins Beclin-1 and LC3-II/I in cardiac tissues were significantly decreased [Beclin-1 protein (Beclin-1/GAPDH): 0.67±0.04 vs. 0.89±0.01, LC3-II/I ratio: 0.93±0.03 vs. 1.09±0.01, both P < 0.01], and p62 protein expression was significantly increased (p62/GAPDH: 0.99±0.01 vs. 0.60±0.01, P < 0.01). In contrast, compared with the CBDL group, after administration of the autophagy enhancer Rapa, the rats showed increased cardiac tissue injury, increased inflammatory cell infiltration in myocardial tissues, increased interstitial vasodilatation, and increased area of myocardial fibrosis; an increase in autophagosomes was seen by electron microscopy; the change tendency of serum biochemical indicators and proteins in myocardial tissues were opposite with autophagy inhibition group with a decrease in serum TBil, ALT, and AST [TBil (μmol/L): 22.00±3.21 vs. 120.70±16.93, ALT (U/L): 72.13±5.97 vs. 178.80±22.30, AST (U/L): 135.20±12.95 vs. 275.50±55.81, all P < 0.05], as well as a increase in the levels of serum SOD, MDA, LDH, and CK-MB [SOD (kU/L): 208.00±2.65 vs. 107.50±7.86, MDA (μmol/L): 20.38±0.40 vs. 15.06±1.88, LDH (U/L): 1 268.00±210.90 vs. 831.30±84.35, CK-MB (U/L): 1 150.00±158.70 vs. 814.70±75.66, all P < 0.05]. The protein expressions of Beclin-1 and LC3-II/I in cardiac tissues were significantly increased [Beclin-1 protein (Beclin-1/GAPDH): 0.96±0.01 vs. 0.89±0.01, LC3-II/I ratio: 1.19±0.01 vs. 1.09±0.01, both P < 0.05], and p62 protein expression was significantly decreased (p62/GAPDH: 0.19±0.02 vs. 0.60±0.01, P < 0.01). CONCLUSIONS Activation of autophagy in CBDL rats led to myocardial tissue injury and reduced cardiac function. Inhibition of autophagy improved cardiac tissue injury in CBDL rats, while increasing autophagy exacerbated myocardial tissue injury.
Animals ; Autophagy ; Rats, Sprague-Dawley ; Male ; Ligation ; Rats ; Common Bile Duct/surgery* ; Myocardium/pathology* ; Adenine/pharmacology*