1.mTOR promotes oxLDL-induced vascular smooth muscle cell ferroptosis by inhibiting autophagy.
Yi LI ; Lijun ZHANG ; Yuke ZHANG ; Qi ZHANG ; Lijun ZHANG
Chinese Journal of Cellular and Molecular Immunology 2025;41(8):687-694
Objective To explore the role and mechanism of mammalian target of rapamycin (mTOR) in oxidized low-density lipoprotein (oxLDL)-induced ferroptosis in vascular smooth muscle cells (VSMCs). Methods A model of oxLDL-induced VSMC ferroptosis was established. VSMCs were co-treated with either the mTOR inhibitor rapamycin or the autophagy inducer carbonyl cyanide m-chlorophenylhydrazone (CCCP), followed by detection of autophagy and ferroptosis-related indexes. Quantitative real-time PCR and Western blot were used respectively to analyze the expression of mTOR, glutathione peroxidase 4 (GPX4), sequestosome 1 (p62), and microtubule-associated protein 1 light chain 3 (LC3). Flow cytometry was employed to assess VSMC death. C11 BODIPY fluorescent staining was used to measure cellular lipid peroxidation levels. Colorimetric assays were performed to determine the contents of malondialdehyde (MDA), ferrous ion (Fe2+) and glutathione (GSH). Results oxLDL significantly upregulated mTOR expression in VSMCs, while increasing p62 expression and reducing LC3 expression, thereby suppressing VSMC autophagy. Compared with oxLDL treatment alone, rapamycin co-treatment reversed oxLDL-induced VSMC ferroptosis, as characterized by reduced VSMC death, increased GPX4 expression and GSH contents, along with decreased MDA content, Fe2+ content and lipid peroxidation levels. Similarly, CCCP co-treatment activated autophagy characterized by reduced p62 expression and elevated LC3 expression, which subsequently alleviated oxLDL-induced ferroptosis, showing reduced VSMC death, increased GPX4 expressions and GSH contents, and decreased MDA content, Fe2+ content and lipid peroxidation levels. Moreover, mTOR inhibition by rapamycin significantly reversed the oxLDL-induced upregulation of p62 and downregulation of LC3. Conclusion mTOR may promote oxLDL-induced VSMC ferroptosis by suppressing autophagy.
Ferroptosis/drug effects*
;
Lipoproteins, LDL/metabolism*
;
TOR Serine-Threonine Kinases/physiology*
;
Autophagy/drug effects*
;
Muscle, Smooth, Vascular/metabolism*
;
Animals
;
Rats
;
Myocytes, Smooth Muscle/cytology*
;
Cells, Cultured
;
Lipid Peroxidation/drug effects*
;
Sequestosome-1 Protein/genetics*
;
Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism*
;
Microtubule-Associated Proteins/genetics*
;
Sirolimus/pharmacology*
2.Effects of kidney-tonifying Chinese herbs on thymus regene-ration after rapamycin-induced degeneration in mice.
Xunuo WEN ; Meiru ZHOU ; Fengjie ZHANG ; Yaoying SHU ; Jianli GAO
Journal of Zhejiang University. Medical sciences 2025;54(3):318-332
OBJECTIVES:
To investigate the effect of a variety of kidney-tonifying Chinese medicines on thymus regeneration after acute degeneration in mice.
METHODS:
Forty-eight 8-week-old male BALB/c mice were randomly divided into normal control group, model control group, negative control group, positive control group, the fructus of Cnidium monnieri (L.) Cuss. group, the fructus of Psoralea corylifolia (L.) group, the fructus of Rubus chingii Hu group, and the tuber onion seed group, with 6 mice in each group. Except for the normal control group, mice in the other groups received intraperitoneal injections of rapamycin (1 mg·kg-1·d-1) for 5 consecutive days followed by 14 h of starvation to induce acute thymus degeneration. After successful modeling, in treatment groups ethanol extract of the fructus of Cnidium monnieri (L.) Cuss. (0.78 g·kg-1·d-1), fructus of Psoralea corylifolia (L.) (0.39 g·kg-1·d-1), fructus of Rubus chingii Hu (0.78 g·kg-1·d-1) or the tuber onion seed(0.39 g·kg-1·d-1) was intraperitoneally injected once a day for 5 days; while the negative control group was given equal volume of normal saline, and the positive control group was given metformin (300 mg·kg-1·d-1). The grip strength was measured with a grip tester 2 h after the last administration. The pathological changes of thymus were observed by hematoxylin and eosin (HE) staining. The structure and distribution of thymic epithelial cells were observed by multiple immunofluorescence method. The proportion of T cell subsets in thymus and peripheral blood was analyzed by flow cytometry. The level of T cell receptor excision circles (TREC) in the genomic DNA of mouse spleen mononuclear cells was detected by quantitative polymerase chain reaction (PCR) for evaluation of thymic output function. The expression of thymus aging- and function-related factors in the thymus tissue were detected by quantitative reverse transcription PCR. The expression of cyclin-dependent kinase inhibitor 1A (p21) and tumor protein 53 (p53) were verified by immunohistochemistry.
RESULTS:
Rapamycin induced thymic atrophy and significantly reduced limb grip strength in mice (P<0.01). Compared with the negative control group, the limb grip strength of mice in the fructus of Psoralea corylifolia (L.) group, the fructus of Rubus chingii Hu group and the tuber onion seed group was significantly enhanced (all P<0.05), and the level of TREC in spleen of the mice in each administration group was reduced (all P<0.05). Among Chinese herb medicine-treatment groups, the recovery of thymus function and tissue structure in the tuber onion seed group was most obvious. Further study showed that compared with the negative control group, the proportion of CD4 single positive cells (CD3+TCR-β+CD4+CD8-) in the thymus of the tuber onion seed group was significantly increased (P<0.01), and the proportion of CD3+CD28+ T cell and CD3+CD8+CD28+ T cell in peripheral blood was significantly increased (all P<0.01). The mRNA levels of IL-1α, IL-6, p21 and p53 in thymocytes were decreased (all P<0.05). The results of immunohistochemistry further confirmed the decrease in p21 and p53 expression. In normal mice, tuber onion seed was observed to enhance limb grip strength (P<0.01), while suppressing thymus output and change the distribution of T cell subsets, and there was no significant effect on thymus weight and the expression of Foxn1, SIRT1, p21, CXCL2 and PTMα.
CONCLUSIONS
The tuber onion seed and other kidney-tonifying traditional Chinese medicines can accelerate the regeneration process of mouse thymus after acute degeneration induced by rapamycin in mice, and the tuber onion seed exhibits the most pronounced therapeutic effect.
Animals
;
Mice
;
Male
;
Mice, Inbred BALB C
;
Thymus Gland/physiology*
;
Drugs, Chinese Herbal/pharmacology*
;
Sirolimus/adverse effects*
;
Regeneration/drug effects*
3.Preliminary Study on the Effect of Silencing Nucleostemin Com- bined with Rapamycin on Autophagy and Apoptosis of HL-60 Cells.
Ya-Qi WANG ; Xiao-Juan GAO ; Bao-Hong YUE
Journal of Experimental Hematology 2023;31(6):1629-1634
OBJECTIVE:
To investigate the effects of knocking down nucleostemin ( NS) combined with rapamycin (RAPA) on autophagy and apoptosis in HL-60 cells , and to explore its role in HL-60 cells .
METHODS:
The expression of NS protein was detected using Western blot , after transfection of HL-60 cells was achieved by the recombinant lentviral vector NS -RNAi-GV248 . Flow cytometry was used to detect changes in cells apoptosis after NS silencing/ rapamycin for 24 , 48 hours , and the expressions of NS , LC3 , p62 , BCL-2 and Bax proteins in cells were detected by Western blot.
RESULTS:
The expression of NS in HL-60 cells was successfully down-regulated by recombinant lentiviral vector. After treatment with rapamycin for 24 and 48 h , the apoptosis rate of cells in each group increased (P < 0.05) , and the apoptosis was more obvious at 48 hours . Compared with the NS silencing group or rapamycin group , after treated with NS down-regulation combined with rapamycin for 48 hours , the apoptosis of HL-60 cells was significantly increased ( P < 0.05 ) , LC3 -II/LC3 -I ratio was significantly increased ( P < 0.05 ) , p62 protein expression was significantly decreased (P < 0.05) , and BCL-2/Bax ratio was significantly decreased ( P < 0.05) .
CONCLUSION
NS down-regulation combined with rapamycin can enhance the apoptosis and autophagy of HL-60 cells , and the induction of apoptosis of HL-60 cells may be related to the expression of BCL-2 and Bax proteins .
Humans
;
HL-60 Cells
;
Sirolimus/pharmacology*
;
bcl-2-Associated X Protein
;
Autophagy
;
Apoptosis
4.Emodin Ameliorates High Glucose-Induced Podocyte Apoptosis via Regulating AMPK/mTOR-Mediated Autophagy Signaling Pathway.
Hong LIU ; Wei-Dong CHEN ; Yang-Lin HU ; Wen-Qiang YANG ; Tao-Tao HU ; Huan-Lan WANG ; Yan-Min ZHANG
Chinese journal of integrative medicine 2023;29(9):801-808
OBJECTIVE:
To investigate the effect of emodin on high glucose (HG)-induced podocyte apoptosis and whether the potential anti-apoptotic mechanism of emodin is related to induction of adenosine-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)-mediated autophagy in podocytes (MPC5 cells) in vitro.
METHODS:
MPC5 cells were treated with different concentrations of HG (2.5, 5, 10, 20, 40, 80 and 160 mmol/L), emodin (2, 4, 8 µ mol/L), or HG (40 mmol/L) and emodin (4 µ mol/L) with or without rapamycin (Rap, 100 nmol/L) and compound C (10 µ mol/L). The viability and apoptosis of MPC5 cells were detected using cell counting kit-8 (CCK-8) assay and flow cytometry analysis, respectively. The expression levels of cleaved caspase-3, autophagy marker light chain 3 (LC3) I/II, and AMPK/mTOR signaling pathway-related proteins were determined by Western blot. The changes of morphology and RFP-LC3 fluorescence were observed under microscopy.
RESULTS:
HG at 20, 40, 80 and 160 mmol/L dose-dependently induced cell apoptosis in MPC5 cells, whereas emodin (4 µ mol/L) significantly ameliorated HG-induced cell apoptosis and caspase-3 cleavage (P<0.01). Emodin (4 µ mol/L) significantly increased LC3-II protein expression levels and induced RFP-LC3-containing punctate structures in MPC5 cells (P<0.01). Furthermore, the protective effects of emodin were mimicked by rapamycin (100 nmol/L). Moreover, emodin increased the phosphorylation of AMPK and suppressed the phosphorylation of mTOR. The AMPK inhibitor compound C (10 µ mol/L) reversed emodin-induced autophagy activation.
CONCLUSION
Emodin ameliorated HG-induced apoptosis of MPC5 cells in vitro that involved induction of autophagy through the AMPK/mTOR signaling pathway, which might provide a potential therapeutic option for diabetic nephropathy.
Emodin/pharmacology*
;
AMP-Activated Protein Kinases/metabolism*
;
Podocytes
;
Caspase 3/metabolism*
;
TOR Serine-Threonine Kinases/metabolism*
;
Signal Transduction
;
Apoptosis
;
Sirolimus/pharmacology*
;
Glucose/metabolism*
;
Autophagy
5.Increased autophagy of peripheral blood neutrophils and neutrophils extracellular traps formation in systemic lupus erythematosus.
Dongmei YANG ; Jing ZHU ; Jianbo XIAO ; Rendong HE ; Yan XING
Chinese Journal of Cellular and Molecular Immunology 2023;39(4):356-362
Objective To explore the role of autophagy, apoptosis of neutrophils and neutrophils extracellular traps (NET) formation in systemic lupus erythematosus (SLE). Methods Thirty-six patients with SLE were recruited as research subjects, and 32 healthy controls matched accordingly were enrolled as control subjects. The expression levels of microtubule associated protein 1 light chain 3B (LC3B), autophagy-related gene5(ATG5), P62, B-cell lymphoma 2(Bcl2), Bcl2-related X protein (BAX) in neutrophils were detected by Western blot analysis. Flow cytometry was employed to analyze the expression of LC3B on neutrophils. The expression level of myeloperoxidase(MPO) in plasma was estimated by ELISA. Furthermore, neutrophils were cultured in vitro and stimulated by 100 nmol/L rapamycin and 10 μg/mL lipopolysaccharide (LPS) for 6 hours, respectively. And then, the expression levels of LC3B, ATG5, P62, Bcl2 and BAX in neutrophils were detected by Western blot analysis. The level of MPO in culture supernatant was detected by ELISA. The change of fluorescence intensity of NET in culture supernatant was assayed by SytoxTM Green staining combined with fluorescence spectrophotometry. Results Compared with healthy controls, the levels of autophagy and apoptosis of neutrophils and NET formation in SLE patients were increased. The level of apoptosis and NET formation was positively associated with neutrophil autophagy. The level of autophagy showed an increase but had no effect on apoptosis and NET formation for neutrophil stimulated by rapamycin. The levels of autophagy and NET formation also increased with no significant effect on apoptosis for neutrophil induced by LPS. Conclusion The autophagy, apoptosis and NET formation of neutrophils increase in SLE patients. The activation of autophagy and NET in neutrophils possibly result from the inflammatory internal environment in SLE patients.
Humans
;
Neutrophils
;
Extracellular Traps/metabolism*
;
Lipopolysaccharides/pharmacology*
;
bcl-2-Associated X Protein/metabolism*
;
Sirolimus/pharmacology*
;
Lupus Erythematosus, Systemic
;
Autophagy
6.Dichloroacetic acid and rapamycin synergistically inhibit tumor progression.
Huan CHEN ; Kunming LIANG ; Cong HOU ; Hai-Long PIAO
Journal of Zhejiang University. Science. B 2023;24(5):397-405
Mammalian target of rapamycin (mTOR) controls cellular anabolism, and mTOR signaling is hyperactive in most cancer cells. As a result, inhibition of mTOR signaling benefits cancer patients. Rapamycin is a US Food and Drug Administration (FDA)-approved drug, a specific mTOR complex 1 (mTORC1) inhibitor, for the treatment of several different types of cancer. However, rapamycin is reported to inhibit cancer growth rather than induce apoptosis. Pyruvate dehydrogenase complex (PDHc) is the gatekeeper for mitochondrial pyruvate oxidation. PDHc inactivation has been observed in a number of cancer cells, and this alteration protects cancer cells from senescence and nicotinamide adenine dinucleotide (NAD+) exhaustion. In this paper, we describe our finding that rapamycin treatment promotes pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1) phosphorylation and leads to PDHc inactivation dependent on mTOR signaling inhibition in cells. This inactivation reduces the sensitivity of cancer cells' response to rapamycin. As a result, rebooting PDHc activity with dichloroacetic acid (DCA), a pyruvate dehydrogenase kinase (PDK) inhibitor, promotes cancer cells' susceptibility to rapamycin treatment in vitro and in vivo.
Humans
;
Sirolimus/pharmacology*
;
Dichloroacetic Acid/pharmacology*
;
Pyruvate Dehydrogenase Complex
;
TOR Serine-Threonine Kinases
;
Mechanistic Target of Rapamycin Complex 1
;
Neoplasms/drug therapy*
7.Hepatocyte growth factor protects pulmonary endothelial barrier against oxidative stress and mitochondria-dependent apoptosis.
Shanshan MENG ; Feiping XIA ; Jingyuan XU ; Xiwen ZHANG ; Ming XUE ; Mingyuan GU ; Fengmei GUO ; Yingzi HUANG ; Haibo QIU ; Yi YANG
Chinese Medical Journal 2022;135(7):837-848
BACKGROUND:
Pulmonary microvascular endothelial cells (PMVECs) were not complex, and the endothelial barrier was destroyed in the pathogenesis progress of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Previous studies have demonstrated that hepatocyte growth factor (HGF), which was secreted by bone marrow mesenchymal stem cells, could decrease endothelial apoptosis. We investigated whether mTOR/STAT3 signaling acted in HGF protective effects against oxidative stress and mitochondria-dependent apoptosis in lipopolysaccharide (LPS)-induced endothelial barrier dysfunction and ALI mice.
METHODS:
In our current study, we introduced LPS-induced PMEVCs with HGF treatment. To investigate the effects of mammalian target of rapamycin (mTOR)/signal transducer and activator of transcription 3 (STAT3) pathway in endothelial oxidative stress and mitochondria-dependent apoptosis, mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 were, respectively, used to inhibit mTOR/STAT3 signaling. Moreover, lentivirus vector-mediated mTORC1 (Raptor) and mTORC2 (Rictor) gene knockdown modifications were introduced to evaluate mTORC1 and mTORC1 pathways. Calcium measurement, reactive oxygen species (ROS) production, mitochondrial membrane potential and protein, cell proliferation, apoptosis, and endothelial junction protein were detected to evaluate HGF effects. Moreover, we used the ALI mouse model to observe the mitochondria pathological changes with an electron microscope in vivo.
RESULTS:
Our study demonstrated that HGF protected the endothelium via the suppression of ROS production and intracellular calcium uptake, which lead to increased mitochondrial membrane potential (JC-1 and mitochondria tracker green detection) and specific proteins (complex I), raised anti-apoptosis Messenger Ribonucleic Acid level (B-cell lymphoma 2 and Bcl-xL), and increased endothelial junction proteins (VE-cadherin and occludin). Reversely, mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 could raise oxidative stress and mitochondria-dependent apoptosis even with HGF treatment in LPS-induced endothelial cells. Similarly, mTORC1 as well as mTORC2 have the same protective effects in mitochondria damage and apoptosis. In in vivo experiments of ALI mouse, HGF also increased mitochondria structural integrity via the mTOR/STAT3 pathway.
CONCLUSION
In all, these reveal that mTOR/STAT3 signaling mediates the HGF suppression effects to oxidative level, mitochondria-dependent apoptosis, and endothelial junction protein in ARDS, contributing to the pulmonary endothelial survival and barrier integrity.
Animals
;
Apoptosis
;
Calcium/metabolism*
;
Endothelial Cells/metabolism*
;
Endothelium/metabolism*
;
Hepatocyte Growth Factor/metabolism*
;
Lipopolysaccharides/pharmacology*
;
Mammals/metabolism*
;
Mechanistic Target of Rapamycin Complex 1/metabolism*
;
Mechanistic Target of Rapamycin Complex 2/metabolism*
;
Mice
;
Mitochondria/metabolism*
;
Oxidative Stress
;
Reactive Oxygen Species/metabolism*
;
Respiratory Distress Syndrome
;
Sirolimus/pharmacology*
;
TOR Serine-Threonine Kinases/metabolism*
8.Effect of moxibustion on autophagy in mice with Alzheimer's disease based on mTOR/p70S6K signaling pathway.
Yang-Yang WU ; Xiao-Ge SONG ; Cai-Feng ZHU ; Sheng-Chao CAI ; Xia GE ; Ling WANG ; Yu-Mei JIA
Chinese Acupuncture & Moxibustion 2022;42(9):1011-1016
OBJECTIVE:
To investigate the effect of moxibustion on autophagy and amyloid β-peptide1-42 (Aβ1-42) protein expression in amyloid precursor protein/presenilin 1 (APP/PS1) double-transgenic mice with Alzheimer's disease (AD).
METHODS:
After 2-month adaptive feeding, fifty-six 6-month-old APP/PS1 double transgenic AD mice were randomly divided into a model group, a moxibustion group, a rapamycin group and an inhibitor group, 14 mice in each group. Another 14 C57BL/6J mice with the same age were used as a normal group. The mice in the moxibustion group were treated with monkshood cake-separated moxibustion at "Baihui"(GV 20), "Fengfu" (GV 16) and "Dazhui" (GV 14) for 20 min; the mice in the rapamycin group were intraperitoneally injected with rapamycin (2 mg/kg); the mice in the inhibitor group were treated with moxibustion and injection of 1.5 mg/kg 3-methyladenine (3-MA). All the treatments were given once a day for consecutive 2 weeks. The morphology of hippocampal tissue was observed by HE staining; the ultrastructure of hippocampal tissue was observed by transmission electron microscopy; the expression of Aβ1-42 protein in frontal cortex and hippocampal tissue was detected by immunohistochemistry; the expressions of mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), p70 ribosomal protein S6 kinase (p70S6K) and phosphorylated p70S6K (p-p70S6K) protein in hippocampus were detected by Western blot method.
RESULTS:
Compared with the normal group, the number of neuron cells was decreased, cells were necrotic and deformed, and autophagy vesicle and lysosome were decreased in the model group. Compared with the model group, the number of neuron cells was increased, cell necrosis was decreased, and autophagy vesicle and lysosome were increased in the moxibustion group and the rapamycin group. Compared with the normal group, the protein expressions of Aβ1-42, mTOR, p-mTOR, p70S6K and p-p70S6K in the model group were increased (P<0.05); compared with the model group, the protein expressions of Aβ1-42, mTOR, p-mTOR, p70S6K and p-p70S6K in the moxibustion group, rapamycin group and inhibitor group were decreased (P<0.05); compared with the inhibitor group, the protein expressions of Aβ1-42, mTOR, p-mTOR, p70S6K and p-p70S6K in the moxibustion group and rapamycin group were decreased (P<0.05); compared with the rapamycin group, the protein expressions of mTOR, p-mTOR, p70S6K and p-p70S6K in the moxibustion group were decreased (P<0.05).
CONCLUSION
Moxibustion could enhance autophagy in hippocampal tissue of APP/PS1 double transgenic AD mice and reduce abnormal Aβ aggregation in brain tissue, the mechanism may be related to the inhibition of mTOR/p70S6K signaling pathway.
Alzheimer Disease/therapy*
;
Amyloid beta-Peptides/genetics*
;
Animals
;
Autophagy
;
Disease Models, Animal
;
Hippocampus/metabolism*
;
Mammals/metabolism*
;
Mice
;
Mice, Inbred C57BL
;
Mice, Transgenic
;
Moxibustion
;
Ribosomal Protein S6 Kinases, 70-kDa/pharmacology*
;
Signal Transduction
;
Sirolimus/pharmacology*
;
TOR Serine-Threonine Kinases/metabolism*
9.Calcitonin gene-related peptides protect against oxidative stress-induced lung injury via increasing autophagy in neonatal rats.
Zhen-Zhuang ZOU ; Shao-Hua WANG ; Yuan-Lu HUANG ; Wei FENG
Acta Physiologica Sinica 2022;74(4):548-554
Our previous studies have shown that calcitonin gene-related peptide (CGRP) exerts protective effects on the acute lung injury induced by oxidative stress. This study was aimed to investigate whether autophagy was involved in the protection of CGRP against oxidative stress-induced lung injury in neonatal rats. Newborn Sprague-Dawley (SD) rats were randomly divided into five groups: Control group, oxidative stress model group (Model group), Model + CGRP group, Model + CGRP + Rapamycin (an autophagy agonist) group, and Model + CGRP + LY294002 (an autophagy inhibitor) group. The model of hyperoxia-induced lung injury was established by continuous inhalation of oxygen (FiO2 = 90%-95%) for 14 days in neonatal SD rats. Pathological changes of lung tissue were observed by hematoxylin and eosin (HE) staining, and mean linear intercept (MLI) was measured. The quantitative changes of autophagic vesicles (AV) in type II alveolar epithelial cells (AECII) were measured under the transmission electron microscope. The protein expressions of Caspase-3, Bcl-2, mTOR, and Beclin-1 in lung tissue lysates were detected by Western blot. The results showed that, compared to the Model group at the same time point, the number of AV in AECII and the expression level of Beclin-1 protein of the lung tissue were increased, while the expression level of mTOR protein was decreased, with alleviated pathological changes, reduced MLI value and Caspase-3 protein expression level, increased Bcl-2 protein expression level in the lung tissue of Model + CGRP group. In addition, we found that the protective effect of CGRP on hyperoxia-induced lung injury could be enhanced by autophagy activator Rapamycin and abolished by autophagy inhibitor LY294002. Together, these findings indicate that CGRP could attenuate hyperoxia-induced lung injury in neonatal rats by enhancing autophagy.
Acute Lung Injury/pathology*
;
Animals
;
Animals, Newborn
;
Autophagy
;
Calcitonin/metabolism*
;
Calcitonin Gene-Related Peptide/metabolism*
;
Caspase 3/metabolism*
;
Hyperoxia/pathology*
;
Lung/pathology*
;
Lung Injury/prevention & control*
;
Oxidative Stress
;
Proto-Oncogene Proteins c-bcl-2/metabolism*
;
Rats
;
Rats, Sprague-Dawley
;
Sirolimus/pharmacology*
10.Mechanism of Atractylodes macrocephala against Alzheimer's disease via regulating lysophagy based on LKB1-AMPK-TFEB pathway.
Li-Min WU ; Jie ZHAO ; Xiao-Wei ZHANG ; Zhong-Hua LI ; Pan WANG ; Yi-Ran SUN ; Zhen-Qiang ZHANG ; Zhi-Shen XIE
China Journal of Chinese Materia Medica 2022;47(17):4723-4732
Myloid beta(Aβ) is produced by cleavage of amyloid precursor protein(APP), which is a main reason for Alzheimer's disease(AD) occurrence and development. This study preliminarily investigated the mechanism of Atractylodes macrocephala(AM) against AD based on LKB1-AMPK-TFEB pathway. The effect of AM on memory ability of AD transgenic Caenorhabditis elegans CL2241 was detected, and then the APP plasmid was transiently transferred to mouse neuroblastoma(N2 a) cells in vitro. The mice were divided into the blank control group, APP group(model group), positive control group(100 μmol·L~(-1) rapamycin), and AM low-, medium-and high-dose groups(100, 200 and 300 μg·mL~(-1)). The content of Aβ_(1-42) in cell medium, the protein level of APP, the fluorescence intensity of APP, the transcriptional activity of transcription factor EB(TFEB), the activity of lysosomes in autophagy, and autophagy flux were determined by enzyme-linked immunosorbent assay(ELISA), Western blot, fluorescence microscope, luciferase reporter gene assay, RLuc-LC3 wt/RLuc-LC3 G120 A, and mRFP-GFP-LC3, respectively. The protein expression of TFEB, LC3Ⅱ, LC3Ⅰ, LAMP2, Beclin1, LKB1, p-AMPK and p-ACC was detected by Western blot. Immunofluorescence and reverse transcription-polymerase chain reaction(RT-PCR) were used to detect the fluorescence intensity of TFEB and the mRNA expression of TFEB and downstream target genes, respectively. The results showed that AM reduced the chemotactic index of transgenic C. elegans CL2241, and decreased the content of Aβ in the supernatant of cell culture medium at different concentrations. In addition, AM lowered the protein level of APP and the fluorescence intensity of APP in a dose-dependent manner. Transcriptional activity of TFEB and fluorescence intensity of mRFP-GFP-LC3 plasmid were enhanced after AM treatment, and the value of RLuc-LC3 wt/RLuc-LC3 G120 A was reduced. AM promoted the protein levels of TFEB, LAMP2 and Beclin1 at different concentrations, and increased the protein expression ratio of LC3Ⅱ/LC3Ⅰ in a dose-dependent manner. Immunofluorescence results revealed that AM improved the fluorescence intensity and nuclear expression of TFEB, and RT-PCR results indicated that AM of various concentrations elevated the mRNA expression of TFEB in APP transfected N2 a cells and promoted the transcription level of LAMP2 in a dose-dependent manner, and high-concentration AM also increased the mRNA levels of LC3 and P62. The protein levels of LKB1, p-AMPK and p-ACC were elevated by AM of different concentrations. In summary, AM regulating lysophagy and degrading APP are related to the activation of LKB1-AMPK-TFEB pathway.
AMP-Activated Protein Kinases/metabolism*
;
Alzheimer Disease/drug therapy*
;
Amyloid beta-Peptides/metabolism*
;
Amyloid beta-Protein Precursor/metabolism*
;
Animals
;
Atractylodes/chemistry*
;
Autophagy/drug effects*
;
Beclin-1/pharmacology*
;
Caenorhabditis elegans/metabolism*
;
Macroautophagy
;
Mice
;
RNA, Messenger
;
Sirolimus/pharmacology*

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