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Autophagy is a highly conserved intracellular catabolic process used to degrade cytoplasmic components. In recent years, it has attracted much attention because of its importance in the pathogenesis and targeted therapy of acute and chronic kidney disease. Autophagy plays an important role in maintaining renal homeostasis under physiological and pathological conditions. The study of conditional autophagy related gene knockout specific to various renal cells has gradually revealed the role of autophagy in renal diseases. Recent studies have found that autophagy deficiency may play a key role in different pathological states of the kidney. Activated autophagy shows cytoprotective function in both glomerulus and renal tubulointerstitium, suggesting that the up regulation of autophagy may become a potential therapeutic strategy. However, there is also contrary evidence that autophagy may be harmful, which poses a great challenge to the development of therapeutic strategies for up-regulated autophagy.
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Objective:To investigate the effect of Guizhi Fulingwan on ovulation dysfunction in rats with polycystic ovary syndrome with insulin resistance （PCOS-IR） induced by letrazole combined with high fat emulsion. Method:A total of 72 female SD rats were randomly divided into control group， model group， metformin group and Guizhi Fulingwan low， medium and high dose groups， with 12 rats in each group. Except for control group， rats were given letrozole 0.001g·kg<sup>-1</sup> combined with high-fat emulsion 15 mL·kg<sup>-1</sup> for 21 consecutive days to establish model of PCOS-IR. Guizhi Fulingwan low， medium and high-dose groups were administrated with Guizhi Fulingwan 0.31， 0.62， 1.24 g·kg<sup>-1</sup> respectively， metformin group was administrated with metformin 0.27 g·kg<sup>-1</sup>， control group and model group were administrated with 12 mL·kg<sup>-1</sup> of normal saline daily for 30 days. Hematoxylin-eosin（HE） staining was used to observe ovarian tissue pathology morphology， and enzyme-linked immunoassay method （ELISA） was used to detect serum follicle stimulating hormone （FSH）， luteinizing hormone （LH）， testosterone （T）， fasting insulin （FINS） level，and LH/FSH and insulin resistance index （HOMA-IR） were calculated． Western blot was used to detect the expression levels of autophagy key molecular Atg6 yeast homologue （Beclin-1）， autophagy related gene 5（Atg5）， microtubule associated protein light chain 3 （LC3） Ⅱ proteins in the phosphatidylinositol 3-kinase/protein kinase B/rapamycin target protein （PI3K/Akt/mTOR） signaling pathway and autophagy related indicators in rat ovarian tissue. Beclin-1 and LC3Ⅱ protein expressions were detected by immunohistochemistry （IHC）. Result:Compared with control group， the thickness of follicles and follicular granulosa cells in the ovary of the model group also decreased， and the number of corpus luteum significantly decreased， while the white membrane thickness of the ovary increased， and the number of atresia follicles and cystic dilatation follicles increased significantly. Serum T， LH， LH/FSH， FINS， FINS， HOMA-IR were significantly increased （<italic>P</italic><0.01）. Phosphorylated （p） -PI3K， p-Akt， and p-mTOR proteins in ovarian tissue were all decreased （<italic>P</italic><0.05，<italic>P</italic><0.01）. The relative expression levels of autophagy-related protein LC3Ⅱ and Beclin-1 were significantly increased （<italic>P</italic><0.05，<italic>P</italic><0.01）. Compared with model group， the number of follicles in the low， medium and high dose Guizhi Fulingwan group and the metformin group decreased， the number of follicles in atresia and atresia increased， and the follicular granulosa cell layer thickness increased. Serum T， LH， LH/FSH， FINS and HOMA-IR of Guizhi Fulingwan group were significantly decreased （<italic>P</italic><0.05，<italic>P</italic><0.01）， and serum FINS and HOMA-IR of metformin group were significantly decreased （<italic>P</italic><0.01）. The expressions of p-PI3K， p-Akt， and p-mTOR proteins were increased （<italic>P</italic><0.05，<italic>P</italic><0.01）. The expression levels of LC3Ⅱ， Atg5 and Beclin-1 in the medium and high dose groups were significantly decreased （<italic>P</italic><0.01）. Conclusion:Guizhi Fulingwan can activate the PI3K/Akt/mTOR signaling pathway of granular cells， inhibit excessive autophagy of granular cells， improve ovarian function and insulin resistance， and restore ovulation， and the effect is better with high dose.
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Objective:To observe the effect of Qiyu Sanlong decoction （QYSL） on the expressions of key molecules in signal axis of mammalian rapamycin target protein （mTOR）/yeast Atg6 homologous （Beclin1）/ microtubule-associated protein1 light chain3 （LC3） in A549 cells. Method:With A549 cells as the research object， the effect of QYSL medicated serum on cell viability of A549 cells were detected by cell counting kit-8 （CCK-8） method. The effect of QYSL decoction on A549 cell apoptosis， autophagosome formation and the expression of autophagy markers were detected by Terminal-deoxynucleoitidyl transferase mediated nick end labeling （TUNEL） method， transmission electron microscope （TEM）， Real-time polymerase chain reaction （Real-time PCR） and Western blot. Result:QYSL medicated serum could inhibit the viability of A549 cells in a concentration-dependent manner. Compared with the blank serum group， the number of apoptotic A549 cells in the QYSL medicated serum group was significantly increased （P<0.01）， and the formation of autophagosome was significantly increased. Compared with the blank serum group， the mRNA and protein expressions of mTOR in A549 cells in the QYSL serum group were significantly decreased （P<0.01）， while mRNA and protein expressions of Beclin-1， autophagy related genes 5 （ATG5）， autophagy related genes 13 （ATG13） were significantly increased （P<0.01）. Conclusion:QYSL decoction can induce autophagy in A549 cells， and its specific mechanism may be related to the down-regulation of mTOR expression， the up-regulation of Beclin1， ATG5， ATG13 and LC3 expression， and the promotion of LC3Ⅰ conversion to LC3Ⅱ.
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To observe the effects of propofol on the activation of hepatic stellate cell line HSC2-T6 induced by transforming growth factor-beta 1 (TGF-β1) and explore its possible mechanism. The cells were divided into control group, TGF-β1 group, propofol group, TGF-β1 + propofol group, rapamycin group, TGF-β1 + propofol + rapamycin group. Cells were treated with rapamycin (5 μmol/L) for 1 hour, propofol (100 μmol/L) for 1 hour, then TGF-β1 (5 ng/ml) was added to co-culture for 24 hours. Cell proliferation was measured by MTT assay. The concentrations of hyaluronic acid (HA), collagen IV (IV-C) and laminin (LN) in the supernatant of cell culture medium were measured by ELISA. The ultrastructure of cells was observed by transmission electron microscopy. The expressions of alpha-smooth muscle actin (α-SMA), mammalian rapamycin target protein (mTOR), phosphorylated mTOR (p-mTOR) and the autophagy related gene Beclin 1, LC3 and p62 were measured by Western blot. Compared with control group, cell proliferation, the expression of α-SMA, the concentrations of HA, IV-C and LN in culture supernatant, the number of autophages, the expressions of Beclin-1 and LC3-II, the ratio of LC3-II/LC3-I in HSC2-T6 cells were increased significantly, while the expression of p-mTOR, the ratio of p-mTOR/mTOR and the expression of p62 protein were decreased significantly in TGF-β1 group (All P＜0.05). Compared with TGF-β1 group, cell proliferation, the expression of α-SMA, the concentrations of HA, IV-C and LN in culture supernatant, the number of autophages, the expressions of Beclin-1 and LC3-II, the ratio of LC3-II/LC3-I in HSC2-T6 cells in TGF-β1 group were decreased significantly, and the expression of p-mTOR, the ratio of p-mTOR/mTOR and expression of p62 protein were increased significantly in TGF-β1 + propofol group (All P＜0.05). Propofol inhibits the activation of hepatic stellate cells induced by TGF-beta 1, and its mechanism involves the mTOR-autophagy pathway.
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Objective@# To investigate the expression of the mTORC1 signaling pathway during the osteogenic differentiation of mouse bone marrow mesenchymal cells (BMMSCs) under cyclic uniaxial tension and explore its possible role.@*Methods @# The BMMSCs of mice were affected by uniaxial dynamic tensile force. Western blot was used to detect the expression changes of major molecules (mTOR, Raptor, S6K) in the endogenous mTORC1 signaling pathway at 0, 1, 2, 4, and 8 hours after stretching. Chemical colorimetry, ELISA and PCR were used to detect alkaline phosphatase (ALP), osteocalcin (OCN) and Runx2 mRNA, respectively. Then, inhibition, activation and control groups were established by administration of the drugs PP242, MHY1485 and PBS, respectively. Two hours after the stress, the expression of S6K was detected by western blot, and the expression of the osteogenic signal was continuously detected by the above methods.@*Results @#Western blot analysis showed that the main molecules of the mTORC1 signaling pathway were all expressed within 8 hours after traction, and the highest expression was 2 hours after the stress. Compared with those in the control group, the ALP activity and OCN expression decreased and the Runx2 mRNA levels increased after the mTORC1 signal pathway was inhibited (P ＜ 0.001); ALP activity and OCN expression increased after the mTORC1 signal pathway was activated, while the Runx2 mRNA levels decreased (P ＜ 0.001). @*Conclusion @#The mTORC1 signaling pathway participates in the osteogenic differentiation of mouse BMMSCs under tension. The osteogenesis of BMMSCs under cyclic uniaxial tension would be enhanced if the mTORC1 signaling pathway was activated.
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OBJECTIVE: To study the effect of sub-chronic aluminum exposure on synaptic plasticity in the hippocampus of rats and to explore the mechanism of phosphatidylinositol 3 kinase(PI3 K)/protein kinase B(AKT)/rapamycin target protein(mTOR) signaling pathway. METHODS: Specific pathogen free adult healthy male SD rats were randomly divided into control group and low-, medium-and high-dose groups based on body weight, with 10 rats in each group. Rats were treated with maltol aluminum solution at the concentrations of 0, 10, 20 and 40 μmol/kg body weight by intraperitoneal injection, 5 days per week for 3 months. After the exposure, rats were weighed. Morris water maze was used to test the learning and memory ability, and the two-electrode binding technique was used to record the long-term potentiation(LTP) amplitude in the hippocampus CA1 area of rats. The protein expression of PI3 K, AKT and mTOR in rat hippocampus tissues was detected by Western blot. RESULTS: After the exposure, the body weights of rats in the medium-and high-dose groups were lower than that of the control group(P<0.05). The results of the positioning navigation experiment showed that the escape latencies of the rats in the medium-and high-dose groups were shorter than that in the control group during the 2 nd to 4 th days of the experiment(P<0.05). The results of space exploration experiments showed that there was no statistical difference on the target quadrant retention time and the number of crossing the platform among the 4 groups(P>0.05). At 1, 30, and 60 min after high-frequency stimulation, the LTP amplitudes in the hippocampus CA1 area of the aluminum-treated groups were lower than that of the control group at the same time point(P<0.05), and the LTP amplitudes of hippocampus CA1 area of rats decreased with the increase of maltol aluminum exposure dose(P<0.01). The relative expression of PI3 K, AKT and mTOR protein in the hippocampus tissues of the aluminum-treated groups was lower than that of the control group(P<0.05), and the relative expression of the above three proteins decreased with the increase of the maltol aluminum exposure dose(P <0.01). CONCLUSION: Sub-chronic aluminum exposure could lead to dose-dependent inhibition of hippocampus synaptic plasticity in rats, thereby impairing the spatial learning ability of rats. This process may be related to inhibition of PI3 K/AKT/mTOR signaling pathway by aluminum.
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Objective:Through phosphatidylinositol 3-kinase（PI3K）/protein kinase B （Akt）/mammalian rapamycin target protein （mTOR） signaling pathway， explore the effect of Zhigancao Tang on myocardial ischemia-reperfusion injury（MIRI）The role and mechanism of arrhythmia（ventricular tachycardia and ventricular fibrillation）. Method:The 72 SD rats were randomly divided into sham operation group，model group， Zhigancao Tang low，medium and high dose group（11.43，22.86，45.72 g·kg-1），Wenxin granule group（2.43 g·kg-1），continuous drug intervention for 10 days. Two hours after the last administration，the MIRI model of rat was prepared by ligating the left anterior descending coronary artery，and the changes of electrocardiogram were recorded. After successful modeling，blood and heart tissue were collected to detect the content of creatine creatine（CK），lactate dehydrogenase（LDH）and aspartate aminotransferase（AST）in the serum, the enzyme-linked immunoassay（ELISA） method was used to detect cardiac troponin（CtnI）content, immunohistochemical detection of myocardial PI3K，Akt，mTOR expression. Western blot was used to detect the myocardial autophagy-related protein microtubule-associated protein 1 light chain 3（LC-3），autophagy markers Beclin1 and PI3K/Akt/mTOR signaling pathway related protein expression and phosphorylated p-PI3K，p-Akt，p-mTOR levels. Result:In model group， 100% of ventricular tachycardia and 91.67% of ventricular fibrillation occurred. Compared with sham operation group， the serum levels of CK，LDH，AST，and CtnI in the model group were significantly increased（P<0.01），PI3K，Akt，mTOR AOD values in myocardial tissue were significantly increased （P<0.01），the relative expression of the ratio of LC3-Ⅱ/LC3-Ⅰ and Beclin1 was significantly increased（P<0.01），p-PI3K/PI3K，p-Akt/Akt，and p-mTOR/mTOR were significantly reduced （P<0.01）. Compared with model group， the incidence of ventricular tachycardia and ventricular fibrillation in the high-dose Zhigancao Tang group was significantly reduced （P<0.01），and the duration was the shortest compared with other administration groups（P<0.01）， CK，LDH，AST level and CtnI content were significantly reduced（P<0.01）， the expression of PI3K，Akt and mTOR of Zhigancao Tang group was significantly decreased with increasing dose（P<0.01）， the expression of LC-3 and Beclin1 was accompanied by Zhigancao Tang increase of each dose group of soup had different degrees of decrease （P<0.01），while the expression ratio of PI3K/Akt/mTOR-related protein was significantly increased （P<0.05，P<0.01）. Conclusion:Pretreatment of Zhigancao Tang can reduce the abusually elevated cardiac enzymes CK, LDH, AST and CtnI, inhibit excessive autophagy of cells, and up-regulate the expression of PI3K, Akt and mTOR, indicating that the anti-MIRI arrhythmia effect of Zhigancao Tang may be related to the PI3K/Akt/mTOR signaling pathway.
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Objective:To explore the intervention effect of modified Shengjiangsan in rats with membranous nephropathy (MN) and its related mechanism. Method:Rats were injected with cationized bovine serum Albumin (C-BSA) in the tail vein to establish a rat model of membranous nephropathy. The normal group, model group, modified Shengjiangsan group (27.3 g·kg-1) and benazepril group (10 mg·kg-1) were established in this study. Each group was given corresponding dosage of the drug once a day for 4 weeks of continuous intervention. After the administration, the levels of 24-hour urine protein (UTP), total cholesterol (TC), triglyceride (TG), total protein (TP), Albumin (Alb), creatinine (SCr), urea nitrogen (BUN) level was detected. we observed the pathological changes of rat kidneys by the technology of Masson staining, silver hexylamine iodate (PASM) staining and transmission electron microscopy. immunofluorescence technology was used to detect immunoglobulin （Ig）G deposition in rat kidneys. Western blot was used to detect the expression levels of key proteins in phosphatidylinositol 3-kinase/proline protein kinase B/rapamycin target protein (PI3K/Akt/mTOR) signaling pathway and autophagy marker proteins LC3 and Beclin1. Result:Compared with normal group, the UTP, serum TC and TG levels were significantly increased, TP and Alb levels were significantly reduced in model group(P<0.05). We detected the kidney pathological changes include of glomerulus enlargement, basement membrane thickening,vacuolar degeneration, pheotropin deposition, glomerular capillary loop IgG diffuse deposition, electron dense deposits of varying sizes and podocytes under the epithelium extensive integration of foot processes， the expression of p-PI3K, p-Akt and p-mTOR protein was significantly increased (P<0.05). The expression of autophagy marker proteins LC3 and Beclin1 protein decreased significantly(P<0.05). Compared with model group, the UTP, serum TC and TG levels were decreased in the benazepril group and modified Shengjiangsan group, and the TP and Alb levels were increased (P<0.05)， the histopathological changes of rat kidney were all reduced， the expression of p-PI3K, p-Akt and p-mTOR protein was significantly reduced(P<0.05)， autophagy marker proteins LC3 and Beclin1 protein expression were significantly increased. Conclusion:Modified Shengjiangsan can reduce urinary protein, reduce kidney pathological damage and delay disease progression, which is related to its inhibition of PI3K/Akt/mTOR signaling pathway and activation of renal autophagy.