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Osteoporosis （OP）， a common systemic skeletal disease in the elderly， is characterised by bone loss and bone microstructural degeneration. Its clinical manifestations include increased bone fragility and bone pain. Furthermore， OP increases the risk of fracture due to the high bone fragility， which leads to lifelong disability or death， imposing a heavy economic and psychological burden on the patients and their families. The pathogenesis of OP is extremely complex and associated with a variety of factors such as proliferation and differentiation of osteoblasts， impairment of osteoclast activity and function， and abnormalities in autophagy activation. Recent studies have found that mammalian target of rapamycin （mTOR） signaing pathway is involved in the regulation of bone homeostasis， which can promote bone formation and improve bone metabolism and bone microstructure by regulating osteoblast proliferation and differentiation and osteoclast function and activating cellular autophagy， thus playing a crucial role in the prevention and treatment of OP. The prevention and treatment of OP with Chinese medicine has a long history， clear efficacy， multiple targets of action， low adverse effects， and wide medicine sources. Therefore， this paper briefly describes the role of mTOR signaling pathway in the development of OP by reviewing the latest research reports and summarizes in detail the latest research results on the treatment of OP with Chinese medicine extracts and prescriptions via the mTOR signaling pathway. This review aims to provide a basis for the in-depth research on the relationship between mTOR signaling pathway and OP and the clinical application of traditional Chinese medicine in the prevention and treatment of OP.
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Aim To investigate the regulatory effects of 3-bromopyruvate (3-BrPA) on apoptosis and autophagy of fibroblast-like synoviocytes (FLS) in rats based on AMPK/mTOR signaling pathway and the underlying mechanism. Methods FLS of rats in vitro were cultured and induced by tumor necrosis factor-α (TNF-α) to construct a model of rheumatoid arthritis (R A). MTT assay was used to explore the optimal concentration of TNF-α and 3 -BrPA for induction and treatment of FLS. The effects of 3-BrPA on the migration and invasion of FLS were detected by Wound healing assay and Transwell assay. The apoptosis of FLS was tested by flow cytometry and mitochondrial membrane potential assay kit (JC-1). Moreover, FLS autophagic flux was detected by mCherry-EGFP-LC3B-overexpressed plasmids, and the expression of apoptosis/autophagy-related proteins as well as AMPK/mTOR pathway-related proteins were detected by Western blot. Results 3-BrPA (15 μmol • L) significantly inhibited the proliferation, migration, and invasion of FLS stimulated by TNF-a (25 μg • L
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Aim To investigate the role of autophagy regulated by the AMPK/mTOR pathway in the prevention of oxygen-glucose deprivation/reperfusion injury ( OGD/R) in astrocytes using oxymatrine ( OMT ) . Methods The isolated and purified astrocytes ( AS) were randomly divided into control group ( CON group), OGD/R group and OGD/R + OMT group (0. 1, 0. 2, 0. 4 mmol · L
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Aim To investigate the mechanism by which ginsenoside Rgl regulates autophagy anrl delays brain aging in mice through AMPK/mTOR signaling pathway.Methods C57BL/6J male mice were ran¬domly divided into four groups, namely brain aging model group ,control group, Rgl anti-aging group,auto¬phagy activator Rapamycin anti-aging group.After the modeling was completed, the test of each experimental index would be carried out on the next day.Morris wa¬ter maze experiment was used to detect the learning and memory ability of mice.Paraffin sections of the hippocampus were prepared, HE , Nissl and immunohis- tochemical staining were used to observe the morpholo¬gy of hippocampal neurons, the number of neurons and Nissl bodies was counted, and autophagy-related proteins p62 , ATG5 , ULK1 were detected.Brain tissue homogenates were prepared to detect the aetivity of brain tissue acetylcholinesterase ( AChE ).Western blot was userl to detect brain tissue autophagy-related proteins LC3II, P62, beclinl, P-AMPK/AMPK, P- mTOR/mTOR and apoptosis protein P53.Results Water maze test showed that Rgl and Hap significantly improved the learning and memory abilities of brain-ag¬ing mice.HE and Nissl staining showed that Rgl and Rap decreased necrotic cells and increased the number of Nissl bodies in the hippocampus of brain-aging mice.Immunohistochemistry staining showed that Rgl and Rap decreased the expression of neuronal autoph- agv protein P62 in hippocampus and increased the ex-pression of ATG5 and ULK1.Rgl and Rap decreased the activity of AhcE in brain-aging mice.Western blot showed that Rgl and Rap increased autophagy-related proteins LC3II, Beclinl , P-AMPK/AMPK, but de¬creased the expression of P-mTOR/mTOR, P62, P53.Conclusions Ginsenoside Rgl can effectively antago¬nize the aging effect of D-gal on mouse brain.The pos¬sible mechanism is related to the regulation of autoph- agv by Rgl through AMPK/mTOR signaling pathway.
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ObjectiveTo observe the protective effect of Chaihu Jia Longgu Mulitang （CLMT） on dopaminergic neurons in Parkinson's disease with depression （PDD） model rats， and to explore the mechanism based on adenosine monophosphate-activated protein kinase/mammalian target of rapamycin （AMPK/mTOR） signaling pathway. MethodAmong the 80 male SD rats， 10 were randomly selected as normal group and the rest were treated with long-term low-dose subcutaneous injection of rotenone in the neck and back combined with chronic unpredictable mild stress （CUMS） to establish PDD rat model. The successfully modeled PDD rats were randomly divided into model group， western medicine group （madopar 0.032 g·kg-1+fluoxetine hydrochloride 0.002 g·kg-1）， CLMT low-dose， medium-dose and high-dose groups （5， 10 and 20 g·kg-1）， 10 rats in each group. Normal group and model group were administrated with the same amount of normal saline by gavage for 4 consecutive weeks. Behavioral changes of rats in each group were evaluated by open field test and pole climbing test. The content of dopamine （DA） and 5-hydroxytryptamine （5-HT） in cerebrospinal fluid was determined by high performance liquid chromatography （HPCL）. The pathological changes of dopaminergic neurons in substantia nigra of rats were observed by hematoxylin-eosin （HE） staining. The positive expression of tyrosine hydroxylase （TH） and expression of α-synuclein in substantia nigra were detected by immunohistochemistry （IHC） and immunofluorescence （IF）， repsectively. The protein expression of microtubule-associated protein 1 light chain 3 （LC3）， adenosine monophosphate-activated protein kinase （AMPK）， phosphorylated AMPK （p-AMPK）， mammalian target of rapamycin （mTOR） and phosphorylated mTOR （p-mTOR） was detected by Western blot. ResultCompared with the conditions in normal group， the total horizontal distance and the activity time in the central region in open field test and the content of DA and 5-HT in cerebrospinal fluid were decreased （P<0.05， P<0.01）， and the time of pole climbing was shortened （P<0.01）， with increased score （P<0.01） in model group. Compared with model group， CLMT high-dose group and western medicine group increased the total horizontal distance and activity time in the central region and the content of DA and 5-HT （P<0.05， P<0.01）， and extended the time of climbing pole （P<0.05）， with decreased score （P<0.05， P<0.01）. Compared with those in normal group， the number of dopaminergic neurons in the substantia nigra was reduced， with narrowed and loosely arranged cell body. The fluorescence expression of α-synuclein was enhanced （P<0.01）， and the positive expression of TH was decreased （P<0.01） in model group. Compared with model group， CLMT high-dose group and western medicine group showed elevated number of dopaminergic neurons in the substantia nigra， with enlarged cell body， and decreased fluorescence expression of α-synuclein， and enhanced the positive expression of TH （P<0.05， P<0.01）. Compared with normal group， model group had lowered expression of LC3Ⅱ/Ⅰ， p-AMPK/AMPK in striatum （P<0.05， P<0.01） and increased expression of p-mTOR/mTOR （P<0.01）. Compared with those in model group， LC3Ⅱ/Ⅰ and p-AMPK/AMPK expression were increased （P<0.05， P<0.01） and p-mTOR /mTOR expression was decreased （P<0.01） in CLMT high-dose group and western medicine group. ConclusionCLMT exerts a neuroprotective effect by inhibiting rotenone neurotoxicity. It enhances the level of DA， and thus improves the depression condition in rats with Parkinson's disease. The underlying mechanism may be related to the regulation of AMPK/mTOR signaling pathway， activation of autophagy， and promotion of degrading α-synuclein.
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Objective: To investigate the effects of antimicrobial peptide LL-37 on the tumor growth and apoptosis of the mice with colon cancer, and to elucidate the possible molecular mechanism of its anti-tumor effect. Methods: The LL-37 over-expression colon cancer HT-29 cells were constructed, and the expression levels of LL-37 mRNA and protein in the HT-29 cells were detected by qRT-PCR and Western blotting methods. A total of 30 BALB/c mice were randomly divided into control group (given the uninfected HT-29 cells)' empty vector group (given the HT-29 cells infected with empty plasmid), LL-37 over-expression group (given the HT-29 cells infected with LL-37 over-expression vector), AMPK inhibitor group [given the HT-29 cells infected with empty vector, and then injected with 2 mg • kg Dorsomorphin (Dor) in the tail vein