ABSTRACT
OBJECTIVES@#Electroacupuncture can enhance autophagic flow, promote neuronal regeneration, axonal and myelin remodeling to achieve the protection of spinal cord injury, but its role in neurogenic urine retention is not completely clear. This study aims to investigate whether the mechanism of electroacupuncture in the treatment of neurogenic urine retention is through autophagy mediated by adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway.@*METHODS@#A rat model of neurogenic urine retention after sacral spinal cord injury was established. The rats with successful model were randomly divided into a model group, an electroacupuncture group (electro-acupuncture for Ciliao, Zhongji, and Sanyinjiao by electronic stimulation, once a day, 20 min each time for 7 days), and an electroacupuncture+AMP-activated protein kinase (AMPK) inhibitor group (on the basis of the treatment of electroacupuncture group, 100 μg of AMPK inhibitor compound C was injected intramuscularly around the L2-3 intervertebral space on the 1st and 4th day). The normal group did not receive any treatment. The maximum bladder volume, bladder basal pressure, leak point pressure, and bladder compliance were recorded by multi-channel physiological recorder; the morphology of bladder tissue was observed by HE staining; autophagy was observed under transmission electron microscope; the expressions of LC3II and Beclin1 protein were observed by immunofluorescence staining; the protein levels of AMPK, phosphorylated-AMPK (p-AMPK), mTOR, phosphorylated-mTOR (p-mTOR), microtubule associated protein 1 light chain 3 (LC3) II and Beclin1 in bladder tissue were detected by Western blotting.@*RESULTS@#Compared with the normal group, the maximum bladder capacity, leak point pressure, bladder compliance, p-AMPK, LC3II, Beclin1 protein expressions in the bladder tissue of the model group increased, and the p-mTOR protein expressions were decreased (all P<0.05); compared with the model group, the maximum bladder capacity, bladder compliance, p-mTOR protein expression in the bladder tissue of the electroacupuncture group were decreased, and the p-AMPK, LC3II, and Beclin1 protein expressions were increased (all P<0.05); compared with the electroacupuncture group, the maximum bladder capacity, bladder compliance, p-mTOR protein expression in the bladder tissue of the electroacupuncture+AMPK inhibitor group were increased, the p-AMPK, LC3II, and Beclin1 protein expressions were decreased (all P<0.05). In the model group, the bladder became larger, with unclear and varying degrees of degeneration, severe tissue damage and autophagosome appeared; the bladder of the electroacupuncture group was smaller than that of the model group, and all levels were clearly visible with autophagy bodies; the layers were slightly disordered and damaged in the electroacupuncture + AMPK inhibitor group.@*CONCLUSIONS@#Electroacupuncture can activate autophagy through AMPK/mTOR pathway, thereby reducing neurogenic urine retention caused by spinal cord injury.
Subject(s)
AMP-Activated Protein Kinases , Animals , Autophagy , Beclin-1 , Electroacupuncture , Mammals , Rats , Rats, Sprague-Dawley , Spinal Cord Injuries , TOR Serine-Threonine KinasesABSTRACT
OBJECTIVE@#To reveal the neuroprotective effect and the underlying mechanisms of a mixture of the main components of Panax notoginseng saponins (TSPN) on cerebral ischemia-reperfusion injury and oxygen-glucose deprivation/reoxygenation (OGD/R) of cultured cortical neurons.@*METHODS@#The neuroprotective effect of TSPN was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, flow cytometry and live/dead cell assays. The morphology of dendrites was detected by immunofluorescence. Middle cerebral artery occlusion (MCAO) was developed in rats as a model of cerebral ischemia-reperfusion. The neuroprotective effect of TSPN was evaluated by neurological scoring, tail suspension test, 2,3,5-triphenyltetrazolium chloride (TTC) and Nissl stainings. Western blot analysis, immunohistochemistry and immunofluorescence were used to measure the changes in the Akt/mammalian target of rapamycin (mTOR) signaling pathway.@*RESULTS@#MTT showed that TSPN (50, 25 and 12.5 µ g/mL) protected cortical neurons after OGD/R treatment (P<0.01 or P<0.05). Flow cytometry and live/dead cell assays indicated that 25 µ g/mL TSPN decreased neuronal apoptosis (P<0.05), and immunofluorescence showed that 25 µ g/mL TSPN restored the dendritic morphology of damaged neurons (P<0.05). Moreover, 12.5 µ g/mL TSPN downregulated the expression of Beclin-1, Cleaved-caspase 3 and LC3B-II/LC3B-I, and upregulated the levels of phosphorylated (p)-Akt and p-mTOR (P<0.01 or P<0.05). In the MCAO model, 50 µ g/mL TSPN improved defective neurological behavior and reduced infarct volume (P<0.05). Moreover, the expression of Beclin-1 and LC3B in cerebral ischemic penumbra was downregulated after 50 µ g/mL TSPN treatment, whereas the p-mTOR level was upregulated (P<0.05 or P<0.01).@*CONCLUSION@#TSPN promoted neuronal survival and protected dendrite integrity after OGD/R and had a potential therapeutic effect by alleviating neurological deficits and reversing neuronal loss. TSPN promoted p-mTOR and inhibited Beclin-1 to alleviate ischemic damage, which may be the mechanism that underlies the neuroprotective activity of TSPN.
Subject(s)
Animals , Beclin-1 , Brain Ischemia/metabolism , Glucose , Infarction, Middle Cerebral Artery/drug therapy , Mammals/metabolism , Neuroprotection , Neuroprotective Agents/therapeutic use , Oxygen , Panax notoginseng , Proto-Oncogene Proteins c-akt/metabolism , Rats , Reperfusion Injury/metabolism , Saponins/therapeutic use , TOR Serine-Threonine Kinases/metabolismABSTRACT
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.
Subject(s)
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/pharmacologyABSTRACT
Objective To investigate the effect and mechanism of isorhapontigenin (ISO) in the protection of mice from the lipopolysaccharide (LPS)-induced acute lung injury (ALI). Methods RAW264.7 cells were cultured in vitro with different concentrations of ISO and the viability of the cells was measured by CCK-8 assay.Further,RAW264.7 cells were induced with 200 ng/ml LPS and then treated with ISO and the autophagy inhibitor 3-methyladenine (3-MA).Western blotting was employed to determine the expression of inflammatory cytokines [interleukin (IL)-1β,IL-6,tumor necrosis factor-α (TNF-α),P65,phospho-P56 (p-P65),IκB,phospho-IκB (p-IκB),inducible nitric oxide synthase (iNOS),cyclooxygenase-2 (COX-2),and high mobility group box-1 (HMGB1)] and autophagy markers (LC3Ⅱ/Ⅰ,Beclin1,and P62).The reactive oxygen species (ROS) production of the cells was measured with the DCFH-DA probe.The mouse model of ALI was established by intraperitoneal injection of LPS (15 mg/kg).The pathological changes of the lung tissue were observed via HE staining.The expression of inflammatory cytokines and autophagy markers in the lung tissue was determined by Western blotting and the content of ROS in bronchoalveolar lavage fluid (BALF) by flow cytometry. Results ISO down-regulated the expression of IL-1β,IL-6,TNF-α,iNOS,COX-2,and HMGB1 and inhibited the ROS production in the LPS-induced RAW264.7 cells (all P<0.05).Furthermore,it promoted the expression of LC3Ⅱ/Ⅰ and Beclin1 and inhibited the expression of P62,thereby activating autophagy (all P<0.05).However,the addition of 3-MA up-regulated the expression of p-P65/P65,p-IκB,iNOS,COX-2,and HMGB1,down-regulated that of IκB (all P<0.001),and promote the production of ROS.ISO mitigated the pathological changes in the lung tissue of ALI mice.It down-regulated the expression of p-P65/P65,p-IκB,iNOS,COX-2,and HMGB1 and up-regulated that of IκB in the lung tissue (all P<0.001) and decreased the ROS production in BALF.However,such protective effect was reversed by 3-MA. Conclusion ISO may induce autophagy of macrophages to protect mice from LPS-induced ALI.
Subject(s)
Animals , Mice , Acute Lung Injury/pathology , Beclin-1/pharmacology , Cyclooxygenase 2/metabolism , Cytokines , HMGB1 Protein/metabolism , Interleukin-6 , Lipopolysaccharides , Lung/pathology , NF-kappa B/metabolism , Reactive Oxygen Species/metabolism , Tumor Necrosis Factor-alpha/metabolismABSTRACT
This study aimed to investigate the effects of hypoxia on RhoA/Rho-kinase (ROCK) signaling pathway and autophagy in pulmonary artery smooth muscle cells (PASMCs), and to explore the underlying mechanism of Umbelliferone (Umb) in ameliorating chronic hypoxic pulmonary hypertension. PASMCs were cultured from Sprague-Dawley (SD) rats and randomly divided into control group, hypoxia group, hypoxia + Umb intervention group and normoxia + Umb intervention group. Alpha smooth muscle actin (α-SMA) and LC3 were assessed by immunofluorescence staining. Protein expression of RhoA, ROCK2, p-MYPT1, LC3-II, Beclin-1, p62, C-Caspase 3, Bax and Bcl-2 was analyzed by Western blotting. In in vivo study, SD rats were divided into control group, hypoxia group and hypoxia + Umb intervention group. Weight ratio of the right ventricle (RV)/left ventricle plus septum (LV+S) was detected, and pulmonary arterial morphological features were examined by HE staining. The results indicated that compared with the control group, the LC3-II/LC3-I ratio and expression of Beclin-1 were significantly increased, while p62 expression was significantly decreased, and the expressions of RhoA, ROCK2 and p-MYPT1 were significantly increased in PASMCs of hypoxia group (P < 0.05). The changes of LC3-II/LC3-I ratio, the expressions of Beclin-1, p62, RhoA, ROCK2 and p-MYPT1 in PASMCs were reversed by Umb treatment (P < 0.05). Consistently, the pulmonary arterial wall was thickened and the RV/(LV+S) ratio was increased in hypoxic rats, which were significantly improved by Umb treatment (P < 0.05). These results suggest that Umb can improve hypoxia-induced pulmonary hypertension by inhibiting the RhoA/ROCK signaling pathway and autophagy in PASMCs.
Subject(s)
Animals , Autophagy , Beclin-1/pharmacology , Hypertension, Pulmonary/etiology , Hypoxia/complications , Myocytes, Smooth Muscle/metabolism , Pulmonary Artery , Rats , Rats, Sprague-Dawley , Signal Transduction , Umbelliferones/pharmacology , rho-Associated Kinases/pharmacologyABSTRACT
Objective: To explore the expression of autophagy related factors microtubule associated protein 1 light chain 3B (LC3B), p62, autophagy key factor Beclin1 in oral lichen planus (OLP) tissues and their relationships with the clinicopathological characteristics of OLP, investigating the function and significance of autophagy in pathogenesis of OLP. Methods: Forty-one lesion tissues (OLP group, twenty-one cases of erosive OLP and twenty cases of non-erosive OLP) were selected from OLP patients visiting the Department of Periodontal and Oral Medicine, School and Hospital of Stomatology, Guizhou Medical University from October 2017 to December 2019. Fifteen cases of normal oral mucosal tissues (control group) were collected from oral and maxillofacial surgery at The Affiliated Stomatology Hospital of Guizhou Medical University during the same period. Protein and mRNA expression levels of LC3B, p62 and Beclin1 were detected by immunohistochemistry (IHC) and real-time quantitative PCR (RT-qPCR) in OLP lesions respectively. The protein expression levels of LC3B, p62, Beclin1 and ratio of LC3B-Ⅱ/LC3B-Ⅰ in sixteen cases (eight cases of erosive OLP and eight cases of non-erosive OLP) from the OLP group were detected by Western blotting (WB). The potential relationship between LC3B, p62, Beclin1, LC3B-Ⅱ/LC3B-Ⅰ ratio and clinical features of OLP were analyzed. Results: IHC results showed that the positive expression rates of LC3B and p62 proteins in OLP lesion tissues [LC3B: 68% (28/41); p62: 59% (24/41)] were higher than those in the control group [LC3B: 5/15; p62: 3/15] (LC3B: χ2=5.55, P=0.019; p62: χ2=5.55, P=0.015). The positive expression rates of LC3B and p62 proteins in the erosive OLP group [LC3B: 86% (18/21); p62: 76% (16/21)] were higher than those in the non-erosive OLP group [LC3B: 50% (10/20); p62: 40% (8/20)] (LC3B: χ2=4.50, P=0.034; p62:χ2=5.53, P=0.019). The positive expression rate of Beclin1 protein in the OLP lesions[20% (8/41)] was lower than that in the control group (7/15) (χ2=4.13, P=0.042), but was not statistically different between the two types of OLP (P>0.05). The RT-qPCR results showed that the mRNA expression levels of LC3B and p62 in OLP lesions [LC3B: 2.78 (1.59, 6.15); p62: 4.30 (2.34, 6.29)] were higher than those in the control group [LC3B: 1.05 (0.88, 1.21); p62: 1.12 (0.89, 1.36)] (LC3B: Z=-4.56, P<0.001; p62: Z=-4.78, P<0.001), and the mRNA expression levels of LC3B and p62 in the erosive OLP group were higher than those in the non-erosive OLP group (LC3B: Z=-2.87, P=0.004; p62: Z=-2.95, P=0.003). The mRNA expression level of Beclin1 in OLP tissues was lower than that in the control group (Z=-2.43, P=0.015), but the difference was not statistically significant between the two types of OLP (P>0.05). WB results showed that the LC3B-Ⅱ/LC3B-Ⅰ ratio was higher in the OLP lesions than that in the control group (t=-2.45, P=0.021), and the LC3B-Ⅱ/LC3B-Ⅰ ratio was higher in the non-erosive OLP group than in the erosive OLP group (t=-2.38, P=0.032). Spearman's correlation analysis showed that the ratio was negatively correlated with the clinical staging and the degree of basal cell liquefaction in OLP (clinical staging: r=-0.57, P=0.021; basal cell liquefaction: r=-0.54, P=0.032), but not with the disease duration and the degree of lymphocytic infiltration (P>0.05). Conclusions: Autophagy related factors LC3B, p62 and Beclin1 may play a role in the formation and progression of OLP lesions. The autophagy level was relatively lack in erosive OLP compared to non-erosive OLP, contributing to the increased local lesion destruction in erosive OLP. Abnormal cellular autophagy may play an important role in the formation of OLP lesions.
Subject(s)
Humans , Lichen Planus, Oral/metabolism , Beclin-1 , Microtubule-Associated Proteins/metabolism , Autophagy , RNA, Messenger/metabolismABSTRACT
OBJECTIVES@#Sufentanil has a good protective effect on myocardial and liver injury caused by ischemia reperfusion (IR), but its protective effect on kidney is still unclear. This study aims to investigate whether sufentanil can prevent IR-induced acute kidney injury (AKI) and to determine whether its efficacy is related to miR-145-mediated autophagy.@*METHODS@#A total of 40 rats were randomly divided into 5 groups (n=8 in each group): A sham group, an IR group, a sufentanil group, a sufentanil+miR-145 inhibitor control group (an anti-NC group) and a sufentanil+miR-145 inhibitor group (an anti-miR-145 group). Except for the sham group, the other groups established a rat AKI model induced by IR. The sufentanil group, the sufentanil+anti-NC group, and the sufentanil+anti-miR-145 were injected with sufentanil (1 μg/kg) through femoral vein 30 min before ischemia. The sufentanil+anti-NC group and the sufentanil+anti-miR-145 group were injected with miR-145 inhibitor control or anti-miR-145 (80 mg/kg) through the tail vein before sufentanil pretreatment. The structure and function of kidneys harvested from the rats were evaluated, and the protein levels of autophagy-related proteins, oxidative stress levels, and apoptosis levels were measured.@*RESULTS@#Compared with the IR group, the renal structure and function were improved in the sufentanil group. The levels of blood urea nitrogen (BUN), creatinine (Cr), urinary kidney injury molecule 1 (KIM-1), neutrophil gelatinase related lipid transporter (NGAL), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and ROS were significantly decreased (all P<0.05). In addition, compared with the IR group, the levels of Beclin-1 and LC3 in renal tissues in the sufentanil group were significantly increased (both P<0.05), and the apoptosis in renal tissues was significantly reduced (P<0.05). Compared with the sufentanil+anti-NC group, the levels of BUN, Cr, KIM-1, NGAL, TNF-α, IL-1β, IL-6 and ROS in the sufentanil+anti-miR-145 group were significantly increased (all P<0.05), the levels of Beclin-1 and LC3 in renal tissues were significantly decreased (both P<0.05), and the apoptosis in renal tissues was significantly increased (P<0.05).@*CONCLUSIONS@#Sufentanil can prevent the AKI induced by IR, which is related to the up-regulation of miR-145-mediated autophagy.
Subject(s)
Animals , Rats , Acute Kidney Injury/pathology , Antagomirs , Autophagy , Beclin-1/metabolism , Creatinine , Interleukin-6/metabolism , Ischemia , Kidney/pathology , Lipocalin-2 , MicroRNAs/metabolism , Reactive Oxygen Species , Reperfusion , Reperfusion Injury/metabolism , Sufentanil/therapeutic use , Tumor Necrosis Factor-alpha , Up-RegulationABSTRACT
OBJECTIVE@#To investigate the effect of BECN1 expression on proliferation and invasion of human multiple myeloma (MM) cell line RPMI-8226.@*METHODS@#RPMI-8226 cells were cultured in vitro, the recombinant plasmid pcDNA3.1-BECN1 was constructed and transfected into RPMI-8226 cells, then the cells were divided into three groups: control group, negative transfection group and BECN1 transfection group. The expression of BECN1 mRNA in cells of each group was detected by real-time fluorescent quantitative polymerase chain reaction (qRT-PCR); the effect of BECN1 overexpression on cell proliferation inhibition rate was detected by cell counting kit 8 (CCK-8); the effect of BECN1 overexpression on the colony formation rate was detected by plate cloning assay; the effect of BECN1 overexpression on cell invasion was detected by Transwell assay; the effects of BECN1 overexpression on the expression of cell proliferation, invasion and autophagy-related proteins were detected by Western blot.@*RESULTS@#The expression of BECN1 mRNA in BECN1 transfection group was significantly higher than that in control group and negative transfection group (P<0.05); the inhibition rate of cell proliferation and the expression of autophagy-related proteins Beclin1, Atg5 and invasion-related protein E-cadherin in BECN1 transfection group were significantly higher than those in control group and negative transfection group; the colony formation rate, invasion number and the expression of proliferation-related proteins CyclinD1, β-catenin and invasion-related protein N-cadherin were significantly lower than those in control group and negative transfection group (P<0.05).@*CONCLUSION@#Overexpression of BECN1 can inhibit the proliferation and invasion of human MM cells RPMI-8226, which may be a potential research target of MM.
Subject(s)
Beclin-1/metabolism , Cadherins/metabolism , Cell Line, Tumor , Cell Movement , Cell Proliferation , Gene Expression Regulation, Neoplastic , Humans , Multiple Myeloma/genetics , RNA, Messenger/metabolism , Sincalide/metabolism , beta Catenin/geneticsABSTRACT
OBJECTIVE@#To study the molecular mechanism of PI3K-Ⅲ like functional domain inducing programmed cell death of leukemia cell line K562.@*METHODS@#The purified PI3K-Ⅲ like functional domain protein was obtained by Pichia pastoris expression system. MTT assay and colony-forming assay were used to detect the effects of PI3K-Ⅲ like functional domain protein on K562 cell proliferation. The effects of PI3K-Ⅲ like functional domain protein on apoptosis and cell cycle of on K562 cells were detected by flow cytometry. The ultrastructural changes were detected by transmission electron microscopy. The expression of caspase-3 was detected by ELISA. The protein expressions of ATG4B, Beclin-1, Bcl-2 and LC3-II were evaluated by Western blot.@*RESULTS@#PI3K-Ⅲ like functional domain protein could inhibit the proliferation and clony formation of K562 cells, which was significantly higher than the control group (P<0.05). In the experimental group, apoptosis and autophagosome were shown in K562 cells. The proportion of cells in G0/G1 phase increased significantly, while in S phase decreased significantly. Cell growth mostly stagnated in G0/G1 phase, which was significantly different from the control group (P<0.05). With the increase of concentration, the expression of caspase-3 protein increased significantly compared with the control group (r=0.966, P<0.05). The expression of ATG4B and beclin-1 appeared from increase to decrease, LC3-II increased while Bcl-2 decreased at different time points.@*CONCLUSION@#PI3K-Ⅲ like functional polypeptide could induce programmed cell death of leukemia cell K562. Beclin-1/Bcl-2 and caspase pathway may be involved in this way, which suggesting meant autophagy and apoptosis may work together at the same time.
Subject(s)
Apoptosis , Beclin-1/pharmacology , Caspase 3/metabolism , Cell Proliferation , Humans , K562 Cells , Leukemia , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolismABSTRACT
OBJECTIVES@#To study the role and mechanism of autophagy in lipopolysaccharide (LPS)-induced inflammatory response of human alveolar epithelial A549 cells.@*METHODS@#A549 cells were stimulated with LPS to establish a cell model of inflammatory response, and were then grouped (n=3 each) by concentration (0, 1, 5, and 10 μg/mL) and time (0, 4, 8, 12, and 24 hours). The A549 cells were treated with autophagy inhibitor 3-methyladenine (3-MA) to be divided into four groups (n=3 each): control, LPS, 3-MA, and 3-MA+LPS. The A549 cells were treated with autophagy agonist rapamycin (RAPA) to be divided into four groups (n=3 each): control, LPS, RAPA, and RAPA+LPS. The A549 cells were transfected with the Toll-like receptor 4 (TLR4) overexpression plasmid to be divided into four groups (n=3 each): TLR4 overexpression control, TLR4 overexpression, TLR4 overexpression control+LPS, and TLR4 overexpression+LPS. The A549 cells were transfected with TLR4 siRNA to be divided into four groups (n=3 each): TLR4 silencing control,TLR4 silencing, TLR4 silencing control+LPS, and TLR4 silencing+LPS. CCK-8 assay was used to measure cell viability. Western blot was used to measure the protein expression levels of inflammatory indicators (NLRP3, Caspase-1, and ASC), autophagic indicators (LC3B, Beclin-1, and P62), and TLR4.@*RESULTS@#After stimulation with 1 μg/mL LPS for 12 hours, the levels of inflammatory indicators (NLRP3, Caspase-1, and ASC), autophagic indicators (LC3B, Beclin-1, and P62), and TLR4 increased and reached the peak (P<0.05). Compared with the LPS group, the 3-MA+LPS group had reduced expression of autophagy-related proteins and increased expression of inflammation-related proteins and TLR4, while the RAPA+LPS group had increased expression of autophagy-related proteins and reduced inflammation-related proteins and TLR4 (P<0.05). The TLR4 overexpression+LPS group had reduced autophagy-related proteins and increased inflammation-related proteins compared with the TLR4 overexpression control+LPS group, and the TLR4 silencing+LPS group had increased autophagy-related proteins and reduced inflammation-related proteins compared with the TLR4 silencing control+LPS group (P<0.05).@*CONCLUSIONS@#In the LPS-induced inflammatory response of human alveolar epithelial A549 cells, autophagic flux has a certain protective effect on A549 cells. TLR4-mediated autophagic flux negatively regulates the LPS-induced inflammatory response of A549 cells.
Subject(s)
Humans , A549 Cells , Autophagy , Beclin-1/metabolism , Caspase 1/metabolism , Inflammation , Lipopolysaccharides/pharmacology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Toll-Like Receptor 4/metabolismABSTRACT
OBJECTIVE@#To explore the role of salt-inducible kinase 2 (SIK2) in myocardial ischemia-reperfusion (IR) injury in rats.@*METHODS@#Fifteen male SD rats were randomized equally into sham operation group, myocardial IR model group, and SIK2 inhibitor group (in which the rats were treated with intravenous injection of 10 mg/kg bosutinib via the left femoral vein 24 h before modeling). Ultrasound was used to detect the cardiac function of the rats, and myocardial pathologies were observed with HE staining. Transmission electron microscopy was used to observe autophagy of myocardial cells, and Western blotting was performed to detect the contents of the autophagy-related proteins SIK2, LC3B, Beclin-1, p62 and the expressions of p-mTOR, mTOR, p-ULK1, and ULK1 in myocardial tissue.@*RESULTS@#Myocardial IR injury significantly increased the number of autophagosomes (P < 0.05) and the expression of SIK2 protein (P < 0.01) in the myocardial tissues. Treatment with bosutinib before modeling obviously lowered the expression of SIK2 protein (P < 0.01), alleviated myocardial pathologies, and reduced the number of autophagosomes (P < 0.05) in the myocardial tissue. The rats with myocardial IR injury showed obviously lowered LVEF and FS values (P < 0.001), which were significantly improved by bosutinib treatment (P < 0.05); no significant difference was detected in IVSDd or LVPWDd among the 3 groups (P > 0.05). Myocardial IR injury obviously increased the expressions of LC3-II/LC3-I and Beclin-1 proteins and lowered the expression of p62 protein (P < 0.01), and these changes were significantly rescued by bosutinib treatment (P < 0.05). The rat models of myocardial IR injury showed significantly increased expression of p-ULK1 (Ser757) (P < 0.01) and lowered expression of p-mTOR protein (P < 0.0001) in the myocardium, and these changes were obviously reversed by bosutinib (P < 0.01 or 0.05); there was no significant difference in mTOR and ULK1 expressions among the 3 groups (P > 0.05).@*CONCLUSION@#SIK2 may promote autophagy through the mTOR/ULK1 signaling pathway, and inhibiting SIK2 can reduce abnormal autophagy and alleviate myocardial IR injury in rats.
Subject(s)
Animals , Autophagy , Autophagy-Related Protein-1 Homolog/metabolism , Beclin-1/metabolism , Down-Regulation , Male , Myocardial Reperfusion Injury , Protein Serine-Threonine Kinases , Rats , Rats, Sprague-Dawley , Signal Transduction , TOR Serine-Threonine Kinases/metabolismABSTRACT
OBJECTIVE@#To investigate the effect of suppressing high-mobility group box 1 (HMGB1) on neuronal autophagy and apoptosis in rats after intracerebral hemorrhage (ICH) in rats.@*METHODS@#Rat models of ICH induced by intracerebral striatum injection of 0.2 U/mL collagenase Ⅳ were treated with 1 mg/kg anti-HMGB1 mAb or a control anti-IgG mAb injected via the tail immediately and at 6 h after the operation (n=5). The rats in the sham-operated group (with intracranial injection of 2 μL normal saline) and ICH model group (n=5) were treated with PBS in the same manner after the operation. The neurological deficits of the rats were evaluated using modified neurological severity score (mNSS). TUNEL staining was used to detect apoptosis of the striatal neurons, and the expressions of HMGB1, autophagy-related proteins (Beclin-1, LC3-Ⅱ and LC3-Ⅰ) and apoptosis-related proteins (Bcl-2, Bax and cleaved caspase-3) in the brain tissues surrounding the hematoma were detected using Western blotting. The expression of HMGB1 in the striatum was detected by immunohistochemistry, and serum level of HMGB1 was detected with ELISA.@*RESULTS@#The rat models of ICH showed significantly increased mNSS (P < 0.05), which was markedly lowered after treatment with anti- HMGB1 mAb (P < 0.05). ICH caused a significant increase of apoptosis of the striatal neurons (P < 0.05), enhanced the expressions of beclin-1, LC3-Ⅱ, Bax and cleaved caspase-3 (P < 0.05), lowered the expressions of LC3-Ⅰ and Bcl-2 (P < 0.05), and increased the content of HMGB1 (P < 0.05). Treatment with anti-HMGB1 mAb obviously lowered the apoptosis rate of the striatal neurons (P < 0.05), decreased the expressions of Beclin-1, LC3-Ⅱ, Bax and cleaved caspase-3 (P < 0.05), increased the expressions of LC3-Ⅰ and Bcl-2 (P < 0.05), and reduced the content of HMGB1 in ICH rats (P < 0.05).@*CONCLUSION@#Down- regulation of HMGB1 by anti-HMGB1 improves neurological functions of rats after ICH possibly by inhibiting autophagy and apoptosis of the neurons.
Subject(s)
Animals , Apoptosis , Apoptosis Regulatory Proteins/metabolism , Autophagy , Beclin-1 , Caspase 3/metabolism , Cerebral Hemorrhage/therapy , Proto-Oncogene Proteins c-bcl-2/metabolism , Rats , Rats, Sprague-Dawley , bcl-2-Associated X Protein/metabolismABSTRACT
OBJECTIVE@#"Multi-targeting" drugs can prove fruitful to combat drug-resistance of multifactorial disease-cervical cancer. This study envisioned to reveal if Thuja homeopathic mother tincture (MT) and its bioactive component could combat human papillomavirus (HPV)-16-infected SiHa cervical cancer cells since it is globally acclaimed for HPV-mediated warts.@*METHODS@#Thuja MT was studied for its antiproliferative and antimigratory properties in SiHa cells followed by microscopic determination of reactive oxygen species (ROS) generation by 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) staining and loss in mitochondrial membrane potential (MtMP) by rhodamine 123 (Rh123) staining. Apoptosis and autophagy inductions were studied by acridine orange/ethidium bromide (AO/EB) staining and immunoblot analyses of marker proteins. The bioactive component of Thuja MT detected by gas chromatography-mass spectrometry was studied for antiproliferative and antimigratory properties along with in silico prediction of its cellular targets by molecular docking and oral drug forming competency.@*RESULTS@#Thuja MT showed significant antiproliferative and antimigratory potential in SiHa cells at a 50% inhibitory concentration (IC50) of 17.3 µL/mL. An increase in DCFDA fluorescence and loss in Rh123 fluorescence prove that Thuja MT acted through the burst of ROS and loss in MtMP respectively. AO/EB-stained cells under the microscope and immunoblot analyses supported Thuja-induced cellular demise via dual pathways-apoptosis and autophagy. Immunoblots showed cleavage of caspase-3 and poly(adenosine diphosphate-ribose) polymerase-1 (PARP-1) along with upregulation of Beclin-1, microtubule-associated protein 1 light chain 3B (LC3B)-II, and p62 proteins. Hence, the apoptotic cascade followed a caspase-3-dependent pathway supported by PARP-1 cleavage, while autophagic death was Beclin-1-dependent and mediated by accumulation of LC3BII and p62 proteins. Thujone, detected as the bioactive principle of Thuja MT, showed greater anti-proliferative and anti-migratory potential at an IC50 of 77 µg/mL, along with excellent oral drug competency with the ability for gastrointestinal absorption and blood-brain-barrier permeation with nil toxicity. Molecular docking depicted thujone with the strongest affinity for mammalian target of rapamycin, phosphoinositide 3-kinase, and protein kinase B followed by B-cell lymphoma 2, murine double minute 2 and adenosine monophosphate-activated protein kinase, which might act as upstream triggers of apoptotic-autophagic crosstalk.@*CONCLUSION@#Robust "multi-targeting" anticancer potential of Thuja drug and thujone for HPV-infected cervical cancer ascertained its therapeutic efficacy for HPV infections.
Subject(s)
Animals , Apoptosis , Autophagy , Beclin-1/pharmacology , Bicyclic Monoterpenes , Caspase 3 , Cell Line, Tumor , Female , Humans , Mammals/metabolism , Mice , Molecular Docking Simulation , Papillomavirus Infections/drug therapy , Phosphatidylinositol 3-Kinases , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Reactive Oxygen Species/metabolism , Thuja/metabolism , Uterine Cervical Neoplasms/pathologyABSTRACT
AbstractObjective: To investigate the effect of γδ T cells on the proliferation, apoptosis and autophagy of multiple myeloma cells.@*METHODS@#Peripheral blood mononuclear cells (PBMNC) were isolated from healthy volunteers, and stimulated with zoledronic acid (Zol) in combination with rhIL-2. Flow cytometry analysis was used to detected the purity of γδ T cells. γδ T cells were collected and co-cultured with RPMI-8226 or U-266 cells at different effector target ratios. The proliferation of RPMI-8226 or U-266 cell lines were detected by CCK-8. Cell cycle and cell apoptosis were detected by flow cytometry and Western blot.The expressions of autophagy-related proteins were detected by Western blot.@*RESULTS@#γδ T cells can be expanded in vitro. γδ T cells could inhibit the proliferation of RPMI-8226 or U-266 cells, induced cell cycle arrest and promoted apoptosis in an effector target-dependent manner. In addition, γδ T cells could induce autophagy of myeloma cells, inhibited the expression of autophagy-related PI3K, P-AKT and P-mTOR, while increased the expression of AMPK and Beclin-1.@*CONCLUSION@#γδ T cells can inhibit the proliferation of RPMI-8226 and U-266 myeloma cells, induce cell cycle arrest, promote apoptosis, and enhance autophagy in vitro. The mechanism may be related to inhibition of PI3K/AKT/mTOR signaling pathway and/or activation of AMPK/Beclin-1 signaling pathway.
Subject(s)
AMP-Activated Protein Kinases/pharmacology , Apoptosis , Autophagy , Beclin-1/pharmacology , Cell Proliferation , Humans , Leukocytes, Mononuclear/metabolism , Multiple Myeloma/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , T-Lymphocytes , TOR Serine-Threonine Kinases/metabolismABSTRACT
OBJECTIVE@#To explore the effect of hnRNPK/Beclin1 signaling on the drug resistance of imatinib in Ph+ leukemia.@*METHODS@#Expression level of hnRNPK was verified in the imatinib resistant and sensitive Ph+ leukemia cell lines by using Western blot. hnRNPK expression was down-regulated by using RNAi. Expression level of LC3I/II and Beclin1 were detected by Western blot and the sensitivity of imatinib was analyzed by CCK-8 assay before and after modulation of hnRNPK expression.@*RESULTS@#hnRNPK showed overexpressed in imatinib resistant leukemia cell line. After the expression level of hnRNPK was down-regulated by RNAi, the sensitivity of drug resistance lines to imatinib restored, while the expression level of LC3I/II and Beclin1 were consistant with the modulation of hnRNPK expression.@*CONCLUSION@#hnRNP K/Beclin1 signaling may be involved in the development of imatinib resistance in Ph+ leukemia through the regulation of autophagy.
Subject(s)
Antineoplastic Agents/pharmacology , Beclin-1 , Cell Line, Tumor , Drug Resistance , Drug Resistance, Neoplasm , Heterogeneous-Nuclear Ribonucleoprotein K , Humans , Imatinib Mesylate/pharmacology , LeukemiaABSTRACT
OBJECTIVE@#To explore the mechanism underlying the hepatoprotective effect of dihydromyricetin (DMY) against lipid accumulation in light of the lipophagy pathway and the inhibitory effect of DMY on HepG2 cell proliferation.@*METHODS@#LO2 cells were cultured in the presence of 10% FBS for 24 h and treated with 100 μg/mL DMY, or exposed to 50% FBS for 24 h followed by treatment with 50, 100, or 200 μg/mL DMY; the cells in recovery group were cultured in 50% FBS for 24 h and then in 10% FBS for another 24 h. Oil red O staining was used to observe the accumulation of lipid droplets in the cells, and the levels of TC, TG, and LDL and activities of AST, ALT and LDH were measured. The expression of LC3 protein was detected using Western blotting. AO staining and transmission electron microscopy were used to determine the numbers of autophagolysosomes and autophagosomes, respectively. The formation of autophagosomes was observed with MDC staining, and the mRNA expression levels of LC3, ATG7, AMPK, mTOR, p62 and Beclin1 were determined with q-PCR. Flow cytometry was performed to analyze the effect of 50, 100, and 200 μg/mL DMY on cell cycle and apoptosis of HepG2 cells; DNA integrity in the treated cells was examined with cell DNA fragmentation test.@*RESULTS@#DMY treatment and pretreatment obviously inhibited lipid accumulation and reduced the levels of TC, TG, LDL and enzyme activities of AST, ALT and LDH in LO2 cells (P < 0.05). In routinely cultured LO2 cells, DMY significantly promoted the formation of autophagosomes and autophagolysosomes and upregulated the expression of LC3 protein. DMY obviously attenuated high FBS-induced inhibition of autophagosome formation in LO2 cells, up- regulated the mRNA levels of LC3, ATG7, Beclin1 and AMPK, and downregulated p62 and mTOR mRNA levels (P < 0.05 or 0.01). In HepG2 cells, DMY caused obvious cell cycle arrest, inhibited cell proliferation, and induced late apoptosis and DNA fragmentation.@*CONCLUSION@#DMY reduces lipid accumulation in LO2 cells by regulating the AMPK/ mTOR-mediated lipophagy pathway and inhibits the proliferation of HepG2 by causing cell cycle arrest and promoting apoptosis.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Autophagy , Beclin-1 , Cell Proliferation , Flavonols , Hep G2 Cells , Humans , Lipids , RNA, Messenger , Signal Transduction , TOR Serine-Threonine Kinases/metabolismABSTRACT
Objective: To investigate the effects of Zhongfeng capsule on the autophagy-related proteins expression in rats with cerebral ischemia/reperfusion injury (CI/ RI), and to explore its neural protection mechanisms of the decoction. Methods: Rat middle cerebral artery ischemia/reperfusion injury model (ischemia for 2 h, reperfusion for 24 h) was prepared by the improved line plug method. Sixty male SD rats were randomly divided into sham operation group, model group, butylphthalide group(0.054 g/kg), Zhongfeng capsule high-dose groups (1.08 g/kg), Zhongfeng capsule middle-dose groups (0.54 g/kg), Zhongfeng capsule low-dose groups (0.27 g/kg), with 10 rats in each group. Rats were treated with Zhongfeng capsule by gavage once a day for 10 days. The rats were sacrificed and the brain tissue was obtained after the experiment in each group. Score neurological deficit was evaluated after 24 h of the last intervention in rat of each group. The pathological changes of brain tissue were observed by HE staining. The serum levels of estradiol (E2) and follicle stimulating hormone (FSH) were determined by ELISA. The expressions of key genes and proteins of PI3K/Akt/Beclin1 signaling pathway in brain tissue were detected by qRT-PCR and Western blot respectively. Results: Compared with the sham operation group, the body weight and protein expressions of p-PI3k and p-Akt in brain tissue of rats were decreased significantly in the model group, while the brain index, neurological deficit score, gene and protein expressions of Beclin1 and LC3 were increased markedly in the model group(P<0.05 or P<0.01). In the model group, nerve cells of brain tissue were loosely packed, interstitial edema, triangular in shape, nuclear pyknosis and dark-blue staining were observed. Compared with the model group, the body weight of rats was increased obviously, the neurological deficit score was decreased significantly and the pathological injury of brain tissue was alleviated evidently in high-dose of Zhongfeng capsule group (P<0.05). The brain index, the gene and protein expressions of Beclin1 and LC3 were decreased apparently in Zhongfeng capsule treatment groups(P<0.05 or P<0.01), while the expressions of p-PI3k and p-Akt in brain tissue were increased evidently in Zhongfeng capsule treatment groups(P<0.05 or P<0.01). Conclusion: Zhongfeng capsule can inhibit autophagy and improve brain neurons lesion of CIRI rats, the mechanism may be related to regulate the expression of Beclin1 and LC3 in PI3K/Akt/Beclin1 signaling pathway.
Subject(s)
Animals , Autophagy-Related Proteins/pharmacology , Beclin-1/metabolism , Body Weight , Brain , Brain Ischemia/metabolism , Male , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Rats , Rats, Sprague-Dawley , Reperfusion Injury/drug therapyABSTRACT
OBJECTIVE@#To observe the effect of wheat-grain moxibustion at "Dazhui" (GV 14) on the expressions of Beclin-1 and GRP78 in spinal dorsal horn in rats with cervical spondylotic radiculopathy (CSR), and to explore the possible analgesic mechanism of wheat-grain moxibustion for CSR.@*METHODS@#A total of 48 SD rats were randomly divided into a sham operation group, a model group, a wheat-grain moxibustion group and a wheat-grain moxibustion+3-MA group, 12 rats in each group. The CSR model was prepared by spinal cord insertion method. Three days after modeling, the rats in the model group were intraperitoneally injected with 1 mL of 0.9% sodium chloride solution; the rats in the wheat-grain moxibustion group were treated with wheat-grain moxibustion at "Dazhui" (GV 14, 6 cones per time) on the basis of the model group; the rats in the wheat-grain moxibustion+3-MA group were intraperitoneally injected with 3-MA solution and wheat-grain moxibustion at "Dazhui" (GV 14, 6 cones per time). The three groups were intervened for 7 days, once a day. The gait score and mechanical pain threshold were observed before treatment and 7 days into treatment; after the treatment, the expressions of mRNA and protein of Beclin-1 in spinal dorsal horn were detected by real-time fluorescence quantitative PCR and immunohistochemistry; the expression of GRP78 protein in spinal dorsal horn was detected by Western blot method; the autophagosomes and ultrastructure in spinal dorsal horn neurons were observed by electron microscope.@*RESULTS@#After the treatment, compared with the sham operation group, in the model group, the gait score was increased and the mechanical pain threshold was decreased (P<0.01), and the expression of GRP78 protein in spinal dorsal horn was increased (P<0.01). Compared with the model group and the wheat-grain moxibustion+3-MA group, in the wheat-grain moxibustion group, the gait score was decreased and mechanical pain threshold was increased (P<0.01), and the expression of GRP78 protein in spinal dorsal horn was decreased, and the expressions of mRNA and protein of Beclin-1 were increased (P<0.01). Under electron microscope, the ultrastructure of spinal dorsal horn neurons in the wheat-grain moxibustion group was not significantly damaged, and its structure was basically close to normal, and the number of autophagosomes was more than the other three groups.@*CONCLUSION@#Wheat-grain moxibustion at "Dazhui" (GV 14) has analgesic effect on CSR rats. The mechanism may be related to moderately up-regulate the expression of Beclin-1, enhance autophagy and reduce endoplasmic reticulum stress.
Subject(s)
Animals , Beclin-1/genetics , Endoplasmic Reticulum Chaperone BiP , Moxibustion , RNA, Messenger , Radiculopathy/therapy , Rats , Rats, Sprague-Dawley , Spinal Cord , Spinal Cord Dorsal Horn , Spondylosis , Triticum/geneticsABSTRACT
OBJECTIVE@#To observe the effect of needle knife on chondrocyte autophagy and expressions of autophagy-related protein and mammalian target of rapamycin (mTOR) in rats with knee osteoarthritis (KOA), and to explore the possible mechanism of needle knife for KOA.@*METHODS@#A total of 42 SD rats were randomly divided into a normal group, a model group and a needle knife group, 14 rats in each group. Except for the normal group, the other two groups were injected with the mixture of papain and L-cysteine into the left hind knee joint to establish the KOA model. After modeling, the rats in the needle knife group were treated with needle knife at strip or nodule around the quadriceps femoris and medial and lateral collateral ligament on the affected side, once a week for 3 times (3 weeks). The changes of left knee circumference in each group were observed; the chondrocytes and ultrastructure of left knee joint were observed by HE staining and electron microscope; the mRNA and protein expressions of autophagy-related genes (Atg5, Atg12, Atg4a), Unc-51 like autophagy activated kinase 1 (ULK1), autophagy gene Beclin-1 and mTOR in left knee cartilage were detected by real-time fluorescence quantitative PCR and Western blot.@*RESULTS@#After modeling, the left knee circumferences in the model group and the needle knife group were increased compared with those before modeling and in the normal group (P<0.05); after intervention, the left knee circumference in the needle knife group was smaller than that in the model group and after modeling (P<0.05). Compared with the normal group, the number of chondrocytes was decreased, and a few cells swelled, nuclei shrank, mitochondria swelled and autophagosomes decreased in the model group; compared with the model group, the number of chondrocytes was increased , and most cell structures returned to normal, and autophagosomes was increased. Compared with the normal group, the mRNA and protein expressions of Atg5, Atg12, Atg4a, Beclin-1 and ULK1 in the knee cartilage in the model group were decreased (P<0.05); compared with the model group, the expressions of the above indexes in the needle knife group were increased (P<0.05). Compared with the normal group, the mRNA and protein expressions of mTOR in the knee cartilage in the model group were increased (P<0.05); compared with the model group, the expressions of the above indexes in the needle knife group were decreased (P<0.05).@*CONCLUSION@#The needle knife intervention could improve knee cartilage injury in rats with KOA, and its mechanism may be related to reducing the expression of mTOR and up-regulating the expressions of Atg5, Atg12, Atg4a, ULK1 and Beclin-1, so as to promote chondrocyte autophagy and delay the aging and degeneration of chondrocytes.
Subject(s)
Animals , Autophagy , Autophagy-Related Protein-1 Homolog/genetics , Beclin-1/genetics , Chondrocytes , Osteoarthritis, Knee/therapy , Rats , Rats, Sprague-Dawley , TOR Serine-Threonine Kinases/geneticsABSTRACT
Abstract Background and objectives The mechanisms by which local anesthetics cause neurotoxicity are very complicated. Apoptosis and autophagy are highly coordinated mechanisms that maintain cellular homeostasis against stress. Studies have shown that autophagy activation serves as a protective mechanism in vitro. However, whether it also plays the same role in vivo is unclear. The aim of this study was to explore the role of autophagy in local anesthetic-induced neurotoxicity and to elucidate the mechanism of neurotoxicity in an intrathecally injected rat model. Methods Eighteen healthy adult male Sprague-Dawley rats were randomly divided into three groups. Before receiving an intrathecal injection of 1% bupivacaine, each rat received an intraperitoneal injection of vehicle or rapamycin (1 mg.kg-1) once a day for 3 days. The pathological changes were examined by Haematoxylin and Eosin (HE) staining. Apoptosis was analysed by TdT-mediated dUTP Nick-End Labelling (TUNEL) staining. Caspase-3, Beclin1 and LC3 expression was examined by Immunohistochemical (IHC) staining. Beclin1 and LC3 expression and the LC3-II/LC3-I ratio were detected by western blot analysis. Results After bupivacaine was injected intrathecally, pathological damage occurred in spinal cord neurons, and the levels of apoptosis and caspase-3 increased. Enhancement of autophagy with rapamycin markedly alleviated the pathological changes and decreased the levels of apoptosis and caspase-3 while increasing the expression of LC3 and Beclin1 and the ratio of LC3-II to LC3-I. Conclusions Enhancement of autophagy decreases caspase-3-dependent apoptosis and improves neuronal survivalin vivo. Activation of autophagy may be a potential therapeutic strategy for local anaesthetic-induced neurotoxicity.
Resumo Introdução e objetivos Os mecanismos de neurotoxicidade dos anestésicos locais são complexos. A apoptose e a autofagia são mecanismos altamente organizados que mantêm a homeostase celular durante o estresse. Estudos revelam que a ativação da autofagia atua como mecanismo de proteção in vitro. Não está claro se a autofagia também desempenha essa função in vivo. O objetivo deste estudo foi analisar o papel da autofagia na neurotoxicidade induzida por anestésico local e esclarecer o mecanismo dessa neurotoxicidade utilizando um modelo de injeção intratecal em ratos. Métodos Dezoito ratos Sprague‐Dawley machos adultos saudáveis foram divididos aleatoriamente em três grupos. Antes de receber a injeção intratecal de bupivacaína a 1%, cada rato recebeu injeção intraperitoneal de veículo ou rapamicina (1 mg.kg‐1) uma vez ao dia durante 3 dias. As alterações patológicas foram examinadas por coloração com Hematoxilina e Eosina (HE). A apoptose foi analisada por coloração com o método dUTP Nick‐End Labeling (TUNEL) mediado por TdT. A expressão de caspase‐3, Beclin1 e LC3 foram examinadas por coloração Imunohistoquímica (IHQ). A expressão de Beclin1 e LC3 e a razão LC3‐II/LC3‐I foram detectadas por análise de western blot. Resultados Após a injeção intratecal de bupivacaína, ocorreu lesão patológica nos neurônios da medula espinhal e os níveis de apoptose e caspase‐3 aumentaram. A ativação da autofagia causada pela rapamicina mitigou de forma expressiva as alterações patológicas e diminuiu os níveis de apoptose e caspase‐3, aumentando a expressão de LC3 e Beclin1 e a razão LC3‐II/LC3‐I. Conclusões O aumento da autofagia diminui a apoptose dependente da caspase‐3 e melhora a sobrevivência neuronal in vivo. A ativação da autofagia pode ser uma estratégia terapêutica potencial para a neurotoxicidade induzida por anestésicos locais.