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1.
AIM:To observe whether autophagy occurs in curcumin-induced human acute myeloid leukemia KG1a cells in the presence of chemotherapeutic drug cytarabine and the possible mechanism. METHODS:KG1a cells were cultured in vitro. The ultrastructural changes of the cells were observed under transmission electron microscope. Autophagy was detected by acridine orange staining. The cell viability was measured by MTT assay. The cell cycle distribution was analyzed by flow cytometry. The expression of autophagy-related molecules beclin-1 and LC3 at mRNA and protein le-vels was determined by RT-qPCR and Western blot. RESULTS:Curcumin dose-dependently inhibited the viability of KG1a cells (P<0.05). The growth inhibition rate in combination group was significantly higher than that in single reagent group and control group (P<0.01). Electron microscopical observation showed that curcumin induced the occurrence of autophagosomes, and cytarabine increased curcumin-induced autophagosomes. Acridine orange staining showed that the combined treatment with cytarabine increased the autophagy induced by curcumin, and the number of autophagic acid vesicles and cells containing autophagic acid vesicles were increased. Curcumin blocked the cell cycle in the G0/G1 phase. The mRNA expression levels of beclin-1 and LC3 in combination group were significantly higher than those in single reagent group and control group(P<0.01). The results of Western blot showed that the protein expression of beclin-1 was significantly up-regulated in combination group (P<0.05), and the ratio of LC3-Ⅱ/LC3-I was higher than that in control group (P<0.01). CONCLUSION:Curcumin inhibits the viability of KG1a cells and induces autophagy. Cytarabine promotes autophagy, which is superior to curcumin alone. It may be related to the up-regulation of beclin-1 and LC3-Ⅱ by the two reagents.  相似文献   

2.
AIM:To explore the effect of Xinshuaikang on myocardial autophagy in the rats with chronic heart failure and its relationship with the MAPK/ERK1/2 signaling pathway. METHODS:The rats were divided into sham group, model group (rat model of chronic heart failure was established by ligation of anterior descending branch of left coronary artery), low-, middle-, and high-dose Xinshuaikang treatment (TL, TM and TH) groups and captopril group (treated with captopril as positive control), with 12 in each group. Doppler echocardiography was used to evaluate the cardiac function. The morphological changes of the myocardium were observed by HE staining. TUNEL staining was used to detect cardiomyocyte apoptosis. The expression of microtubule-associated protein 1 light chain 3-Ⅱ (LC3-Ⅱ) in the myocardium was detected by immunofluorescence labeling. The protein levels of p-ERK, p-p38 MAPK, LC3-Ⅱ, beclin-1 and p62 in the myocardium were determined by Western blot. RESULTS:Compared with sham group, left ventricular end-diastolic dia-meter (LVEDD) and left ventricular end-systolic diameter (LVESD) in model group were increased, while left ventricular posterior wall thickness at end-diastole (LVPWTd), left ventricular posterior wall thickness at end-systole (LVPWTs), left ventricular ejection fraction (LVEF), cardiac output (CO), left ventricular diastolic pressure (LVDP), left ventricular systolic pressure (LVSP) and maximum rate of rise/decrease of left ventricular pressure (+dp/dtmax/-dp/dtmax) were decreased (P<0.05). The myocardial cells were deformed and necrotic, and the myocardial fibers were broken, with inflammatory cell infiltration. The apoptotic rate, the positive rate of LC3-Ⅱ, and the protein levels of p-ERK, p-p38 MAPK, LC3-Ⅱ/LC3-I and beclin-1 were increased, and the protein expression of p62 was decreased (P<0.05). Compared with model group, the levels of LVEDD and LVESD were decreased, LVPWTd, LVPWTs, LVEF, CO, LVSP, LVDP, +dp/dtmax and -dp/dtmax were increased in Xinshuaikang groups and captopril group (P<0.05). The morphological changes of myocardial cells were gradually returned to normal, and inflammatory cell infiltration, the apoptotic rate and the positive rate of LC3-Ⅱ were decreased. The protein levels of p-ERK, p-p38 MAPK, LC3-Ⅱ/LC3-I and beclin-1 were decreased, and the protein expression of p62 was increased (P<0.05). CONCLUSION:Xinshuaikang inhibits myocardial auto-phagy to play a role of cardiac protection in the rats with chronic heart failure, and its mechanism may be related to inhibition of MAPK/ERK1/2 signaling pathway.  相似文献   

3.
AIM:To investigate the effects of rapamycin (Rapa) on hydrogen peroxide (H2O2)-induced vascular endothelial cell senescence and to explore the underlying mechanisms. METHODS:The human umbilical vascular endothelial cells (HUVECs) were divided into 4 groups:control group, senescence group, Rapa+H2O2 group and 3-methyladenine (3-MA)+H2O2 group. MTT assay was performed to assess the cell viability. Senescence-associated β-ga-lactosidase (SA-β-Gal) staining was performed to measure the senescent cells in each group. The subcellular structures were observed under transmission electron microscope (TEM). The protein levels of phosphorylated Rb (p-Rb), Rb, p21, LC3-Ⅱ and beclin-1 were determined by Western blot. RESULTS:Compared with control group, the cell viability in H2O2 group was significantly decreased accompanied with higher rate of SA-β-Gal staining positive cells (P<0.05) and markedly damaged structure. Additionally, the protein levels of p-Rb and p21 in senescence group were increased markedly compared with control group (P<0.05). However, the cells pre-treated with Rapa prior to stimulation with H2O2 showed increased viability, decreased number of senescent cells and decreased protein levels of p-Rb and p21 as compared with the cells stimulated with H2O2 alone (P<0.05). Moreover, the TEM observation showed that the structure of the cells in Rapa+H2O2 group was roughly normal and the autophagosome was captured, and the expression levels of beclin-1 and LC3-Ⅱ were increased (P<0.05). Conversely, pre-treatment with autophagy inhibitor 3-MA resulted in opposite results. The cell viability was decreased significantly, more senescent cells were stained blue, higher protein levels of p-Rb and p21 were detected (P<0.05), poor subcellular structures were captured, and no beclin-1 and LC3-Ⅱ was detected. CONCLUSION:Rapa may retard the senescence of HUVECs induced by H2O2, and promoting autophagy may be the underlying mechanism.  相似文献   

4.
AIM: To observe the effect of remote ischemic post-conditioning (RIPostC) on autophagy of hippocampal neural cells after cardiopulmonary resuscitation (CPR) in rats. METHODS: Male SD rats (n=45) were randomly divided into sham operation group (sham group), cardiac arrest (CA)/CPR group and RIPostC group, with 15 rats in each group. A CPR model of asphyxiated CA was established by clamping the tracheal tube. Neurological deficit scoring (NDS) was performed at different time points after return of spontaneous circulation (ROSC). The rats were sacrificed 24 h after ROSC and hippocampal tissues were removed. Western blot was used to detect autophagy markers LC3-Ⅱ/LC3-I and beclin-1 in the hippocampal tissues. The apoptosis was detected by TUNEL method. The formation of LC3 particles was observed by immunofluorescence. The ultrastructural changes of autophagosomes and mitochondria were observed under transmission electron microscope. RESULTS: Compared with sham group, the NDS scores of CA/CPR group were decreased, the protein expression of LC3-Ⅱ/LC3-I and beclin-1 was increased (P<0.05), and the apoptosis of the neural cells was increased (P<0.05). Compared with CA/CPR group, the NDS scores in RIPostC group was increased, the protein expression of LC3-Ⅱ/LC3-I and beclin-1 was decreased (P<0.05), and the neural cell apoptosis was decreased (P<0.05). The number of LC3 particles was decreased, intracellular autophagosome number was reduced, and the mitochondrial structure damage was alleviated. CONCLUSION: Remote ischemic post-conditioning improves neurological function in rats after CPR, which may be related to inhibition of excessive autophagy in hippocampus.  相似文献   

5.
AIM: To explore whether autophagy is involved in the excessive death of renal tubular epithelial cells in subtotal nephrectomy(SNx) rats and the relationship between autophagy and necroptosis in the kidney of SNx rats. METHODS: Male Sprague-Dawley rats were randomly assigned to control group(n=6) and SNx group(n=42). The rats in SNx group were subjected to SNx. Sham surgery was performed in the rats in control group. The rats in SNx group were divided into subgroups at 0, 4, 8 and 12 weeks(n=6) and the other rats in SNx group were divided into SNx+vehicle group, SNx+necrostatin-1(Nec-1) group and SNx+3-methyladenine(3-MA) group. The expression of RIP1, RIP3, LC3 and beclin-1 at mRNA and protein levels was measured at 0, 4, 8 and 12 weeks by qPCR and immunohistochemistry. The effects of Nec-1 or 3-MA on the protein expression of LC3-I, LC3-II and beclin-1, and production of reactive oxygen species(ROS) in the rat kidney were determined by Western blot and DCFH-DA staining. The death of renal tubular epithelial cells in the SNx rats was observed by TUNEL staining and electron microscopy. Finally, the effects of Nec-1 and 3-MA on blood urea nitrogen(BUN), serum creatinine(SCr) and the pathological changes of the renal tissues were analyzed. RESULTS: The highest mRNA and protein levels of RIP1, RIP3, LC3 and beclin-1 appeared at the 8th week after SNx(P<0.01). Compared with the rats in SNx+vehicle group, the protein over-expression of LC3-II/I and beclin-1, renal tubular epithelial cells with typical morphological features of necroptotic cell death and TUNEL-positive renal tubular cells were decreased in the SNx rats treated with Nec-1 and 3-MA(P<0.01), but 3-MA did not reduce the increased concentration of ROS. In addition, treatment with Nec-1 and 3-MA obviously reduced BUN, SCr(P<0.05), glomerulosclerosis index and tubulointerstitial injury score(P<0.01). CONCLUSION: Autophagy participates in the excessive death of renal tubular epithelial cells in SNx rats. Inhibition of autograph prevents necroptotic cell death of renal tubular cells, and alleviates chronic renal injury in SNx rats.  相似文献   

6.
AIM To observe the changes of liver structure, the levels of transforming growth factor-β1 (TGF-β1), microRNA-181a, LC3-II/-I, beclin-1 and collagen deposition in hepatic fibrosis (HF) rats induced by carbon tetrachloride (CCl4), and the effect of microRNA-181a on autophagy of rat hepatic stellate cells (HSCs) induced by TGF-β1, and to explore the possible mechanism of microRNA-181a in regulating HSC activation and HF. METHODS Wistar rats (n=40) were randomly divided into 5 groups (with 8 in each): control group (subcutaneous injection of olive oil, 3 mL/kg, twice a week), and CCl4-induced HF groups of 2, 4, 6 and 8 weeks (subcutaneous injection of 40% CCl4, 3 mL/kg, twice a week for 2, 4, 6 and 8 weeks, respectively). Masson staining was used to evaluate the changes of HF in rats. The levels of TGF-β1 in serum and liver tissue of the rats were measured by ELISA. The level of microRNA-181a in rat liver tissues was detected by RT-qPCR. The protein levels of LC3-II/-I, beclin-1, α-smooth muscle actin (α-SMA), collagen type I (Col I) and collagen type Ⅲ (Col Ⅲ) in rat liver tissues were measured by Western blot. HSC-T6 cells were transfected with microRNA-181a inhibitor, or pretreated with the autophagy inhibitor 3-methyladenine (3-MA), before treatment with TGF-β1 to stimulate autophagy. The expression of microRNA-181a, LC3-II/-I, beclin-1, α-SMA, Col I and Col Ⅲ in HSC-T6 cells were determined by RT-qPCR and Western blot. RESULTS The levels of TGF-β1, microRNA-181a, LC3-II/-I ratio and beclin-1 in liver tissues showed an overall trend of increasing with the progression of HF, and microRNA-181a expression showed a positive correlation with autophagy-associated proteins (P<0.01). MicroRNA-181a level was significantly increased, which was associated with TGF-β1-induced autophagy and activation of HSC-T6 cells.MicroRNA-181a expression was significantly down-regulated in the HSC-T6 cells transfected with microRNA-181a inhibitor, along with suppression of autophagy and cell activation (P<0.01), which were similar to the effects of 3-MA treatment. CONCLUSION CCl4 promotes rat HF, the microRNA-181a expression of liver tissue, and autophagy in a time-dependent manner. Reducing the expression of microRNA-181a in HSC-T6 cells inhibits the autophagy of HSCs-T6 cells induced by TGF-β1. The regulation of HSC autophagy by microRNA-181a may be involved in rat HF.  相似文献   

7.
AIM: To investigate the effects of astragaloside IV (AS-IV) on autophagy in rats with cerebral ischemia/reperfusion (I/R) injury. METHODS: The focal cerebral ischemia/reperfusion of rat left middle cerebral artery occlusion (MCAO) was induced by suture method. Male SD rats (n=70) were randomly divided into sham operation group, I/R group, solvent control group, AS-IV group, AS-IV+autophagy inhibitor (3-methyladenine, 3-MA) group, 3-MA group and autophagy activator (rapamycin, Rapa) group. Except for sham operation group, the rats in other groups were subjected to ischemia for 2 h and reperfusion for 24 h. The rats with successful modeling were selected according to Zea Longa scoring criteria. The volume of cerebral infarction was measured by TTC staining. The morphological changes of nerve cells in the rats were observed with Nissl staining. The phenomenon of autophagy was observed under transmission electron microscope. The protein expression of beclin-1 and LC3-Ⅱ was determined by Western blot. RESULTS: No neurological deficit in sham operation group was observed, and the cerebral infarction was not found. Compared with sham operation group, obvious cerebral infarction was observed, the Nissl bodies were small in size and number and stained light, typical autophagosomes were observed, and the protein expression of beclin-1 and LC3-Ⅱ was increased in I/R group (P<0.05). Compared with I/R group, the volume of cerebral infarction was decreased obviously, neurological deficit restored significantly, and the number of autophagosomes and the protein expression of beclin-1 and LC3-Ⅱ were increased in AS-IV group and Rapa group (P<0.05). However, no significant difference between solvent control group and I/R group was observed (P>0.05). Compared with AS-IV group, the neurological deficit was serious, the volume of cerebral infarction and the number of autophagosomes were increased, while the expression of beclin-1 and LC3-Ⅱ was decreased in AS-IV+3-MA group and 3-MA group (P<0.05). CONCLUSION: Astragaloside IV may play an important role in atte-nuating cerebral ischemia/reperfusion injury by activating autophagy.  相似文献   

8.
AIM: To investigate the possibility that p38 MAPK-iNOS-NO pathway mediates the chemical hypoxia-induced injury in PC12 cells. METHODS: PC12 cells were treated with cobalt chloride (CoCl2, 600 μmol/L) to set up a chemical hypoxia-induced cellular injury model. Cell viability was tested by cell counter kit-8(CCK-8). The morphological changes of the apoptotic cells were detected by Hochest33258 staining. The expression of iNOS was determined by Western blotting. Nitrite accumulation, an indicator of NO production, was measured in cell culture supernatants by Griess reagent assay. RESULTS: Exposure of PC12 cells to CoCl2 for 24 h significantly enhanced iNOS expression. Exposure of PC12 cells to CoCl2 for 24 h and 48 h significantly enhanced nitrite accumulation. Pretreatment with L-canavanine (an inhibitor of iNOS,5-20 μmol/L) for 60 min prior to exposure of PC12 cells to CoCl2 protected PC12 cells against the injuries induced by CoCl2 with enhanced cell viability and decreased amount of apoptotic cells. Pretreatment with SB203580 (an inhibitor of p38 MAPK) for 60 min prior to exposure of PC12 cells to CoCl2 down-regulated the expression of iNOS induced by CoCl2. CONCLUSION: p38 MAPK-iNOS-NO pathway mediates CoCl2-induced injuries in PC12 cells.  相似文献   

9.
AIM: To investigate the effects of induced pluripotent stem cells-derived mesenchymal stem cells (iPSC-MSCs) on cobalt chloride (CoCl2)-induced injuries of PC12 cells and its possible mechanism. METHODS: PC12 cells were exposed to CoCl2 to set up a chemical-induced cellular injury model and were cocultured with iPSC-MSCs. The cell viability was tested by CCK-8 assay. The apoptosis was measured by flow cytometry using Annexin V/PI staining. The mitochondrial membrane potential (MMP) was analyzed by flow cytometry using JC-1 staining. Immunofluorescence was employed to observe mitochondrial transfer from iPSC-MSCs to PC12 cells. RESULTS: Apoptosis of PC12 cells was increased and MMP of PC12 cells was decreased after exposed to CoCl2 at concentration of 400 μmol/L for 24 h. Coculture of PC12 cells with iPSC-MSCs reduced the apoptosis and recovered the MMP of the PC12 cells. Tunneling nanotubes were formed between iPSC-MSCs and PC12 cells, through which the iPSC-MSCs transferred the mitochondria to the PC12 cells. CONCLUSION: iPSC-MSCs protect PC12 cells from CoCl2-induced injuries, which may be associated with the mitochondrial transfer from iPSC-MSCs to PC12 cells.  相似文献   

10.
AIM: To observe the effect of rapamycin (Rapa) on human neuroblastoma SH-SY5Y cell injury induced by oxygen-glucose deprivation (OGD), and to explore the role of autophagy in this process. METHODS: The SH-SY5Y cells were randomly divided into 4 groups:normal control group:the cells were cultured without OGD treatment; Rapa group:the cells were pretreated with Rapa for 1 h; OGD group:the culture medium was replaced by glucose-free medium and the cells were transferred to a humidified incubation chamber flushed by a gas mixture of 1% O2, 94% N2 and 5% CO2 for 12 h; Rapa+OGD group:the cultured cells were treated with Rapa for 1 h, and then were given the same treatments as those in OGD group. The cell viability was assessed by MTT assay. The degree of the cell damage was evaluated by determining the leakage of lactate dehydrogenase (LDH). The enzyme activity of caspase-3 was detected. TUNEL staining were used to detect the variation of cell apoptosis. The protein levels of apoptosis-related proteins Bax and Bcl-2, autophagy-related protein beclin-1 and autophagy marker protein LC3B were determined by Western blot. RESULTS: Compared with OGD group, the viability of the SH-SY5Y cells was significantly increased, and the activity of caspase-3 was significantly reduced in Rapa+OGD group (P<0.05). The SH-SY5Y cell injury was apparent after OGD with a great increase in the apoptotic rate (P<0.05). Compared with OGD group, the apoptotic rate significantly decreased in Rapa+OGD group (P<0.05). Compared with control group, the protein level of Bcl-2 was significantly decreased (P<0.05) and the protein level of Bax was significantly increased in OGD group. Compared with OGD group, the levels of Bcl-2, beclin-1 and LC3B-Ⅱ were significantly increased and the protein level of Bax was significantly increased in Rapa+OGD group (P<0.05). CONCLUSION: Rapamycin has a protective effect on in vitro cultured SH-SY5Y cells injured by OGD. The mechanism may be related to the promotion of autophagy.  相似文献   

11.
AIM: To investigate the effect of hyperoxia exposure on the paracrine function of endothelial progenitor cells (EPCs), and to explore the effects of paracrine factors of EPCs on the proliferation and differentiation of type Ⅱ alveolar epithelial cells (AECⅡ) exposed to hyperoxia. METHODS: Bone marrow-derived mononuclear cells were isolated and cultured in EGM-2MV medium for 7~10 d to obtain and identify EPCs. EPCs were cultured in room air (RA) or 60% O2. The normoxia EPC-conditioned medium (E-CM-RA) and hyperoxia EPC-conditioned medium (E-CM-O2) were collected. The levels of VEGF, FGF10, PDGF-BB and EGF in E-CM-RA and E-CM-O2 were detected by ELISA. AECⅡ from adult rats were isolated, purified and cultured for 2 d, then divided into RA group, O2 group, O2+E-CM-RA group and O2+E-CM-O2 group. The proliferation of AECⅡ was detected by MTT assay and cell counting. The mRNA expression of SP-C and AQP5 was quantified by real-time PCR. RESULTS: The expression of VEGF and FGF10 in E-CM-O2 group decreased significantly compared with E-CM-RA group (P<0.01). There were significant differences in AECⅡ viability and number among the 4 groups at 12 h, 24 h, 2 d and 3 d (P<0.01). Compared with RA group, AECⅡ viability and number in O2 group decreased significantly at 12 h, 24 h, 2 d and 3 d (P<0.05). The AECⅡ viability and number in O2+E-CM-RA group were significantly higher than those in O2 group at 12 h, 24 h, 2 d and 3 d (P<0.05). However, no significant difference in AECⅡ viability and number between O2+E-CM-O2 group and O2 group at 12 h, 2 d and 3 d was observed. There were significant differences in the mRNA expression of SP-C and AQP5 in the 4 groups at 24 h, 2 d and 3 d (P<0.01). Compared with RA group, the mRNA expression of SP-C in O2 group was significantly inhibited (P<0.01), but the mRNA expression of AQP5 was promoted (P<0.01) at 24 h, 2 d and 3 d. Compared with O2 group, the mRNA level of SP-C in O2+E-CM-RA group and O2+E-CM-O2 group (P<0.05) at 24 h, 2 d and 3 d was increased, and the mRNA expression of AQP5 (P<0.01) at 2 d and 3 d was inhibited.CONCLUSION: EPCs secrete VEGF and FGF10, and hyperoxia impairs this paracrine function. Hyperoxia exposure inhibits AECⅡ proliferation and the mRNA expression of SP-C, but promotes the mRNA expression of AQP5. EPC-conditioned medium improves the proliferation of hyperoxia-exposed AECⅡ, and inhibits the transformation of AECⅡ. Hyperoxia exposure impairs the paracrine function of EPCs, and weakened the effects of E-CM-O2 on AECⅡ.  相似文献   

12.
AIM: To examined the effects of hypoxic preconditioning(HPC) on oxygen-glucose deprivation(OGD)-induced PC12 cells, and to investigate its possible mechanisms of autophagy.METHODS: Cultured PC12 cells were randomly divided into control group, HPC group, 3-methyladenine(3-MA) group, HPC+OGD group, 3-MA+HPC+OGD group and OGD group. CCK-8 assay was used to detect the cell viability. The caspase-3 activity was also tested. TUNEL staining and flow cytometry were used to detect the cell apoptosis. The protein levels of apoptosis-related protein caspase-3 and autophagy-marked protein LC3-2 and beclin-1 were determined by Western blot.RESULTS: Compared with control group, the viability of PC12 cells was significantly reduced, and the activity of caspase-3 was significantly increased in OGD group. Compared with 3-MA+ HPC+OGD group and OGD group, the viability of PC12 cells was significantly increased, and the activity of caspase-3 was significantly reduced in HPC+OGD group(P<0.05). The PC12 cell injury was apparent after OGD with a great increase in the apoptotic rate(P<0.05). Compared with OGD group, the apoptotic rate significantly decreased in HPC+OGD group(P<0.05). Compared with control group, the protein level of cleaved caspase-3 was significantly increased in OGD group(P<0.05). Compared with OGD group, the protein level of cleaved caspase-3 was significantly decreased, and the levels of LC3-2 and beclin-1 were significantly increased in HPC+OGD group(P<0.05).CONCLUSION: OGD decreases cell survival and induces apoptosis.Activation of cell autophagy may be the mechanism by which hypoxic preconditioning protects the PC12 cells from OGD induced injury.  相似文献   

13.
14.
AIM: To investigate the neuroprotective effect of hydrogen sulfide (H2S) after cardiopulmonary resuscitation in rats with cardiac arrest (CA), and to explore the effects of H2S on neuron autophagy. METHODS: The CA model was established through asphyxia. Male Wistar rats were randomly divided into sham group, model group and NaHS group. The levels of beclin-1 and LC3 II/I were measured by Western blot at 2 h, 4 h, 12 h and 24 h after the restoration of spontaneous circulation (ROSC). At 12 h after ROSC, the formation of autophagic vacuole with LC3 dots was determined by immunohistochemical (IHC) method. The phenomenon of neuron autophagy was observed under transmission electron microscope. The numbers of apoptotic neurons were counted by TUNEL staining at 72 h after ROSC. The neurolo-gic deficit score (NDS) was used to evaluate the neurologic function after ROSC. RESULTS: The level of beclin-1 was gradually increased in model group, but it was increased and then gradually recovered in NaHS group (P < 0.05). The conversion of LC3 II in the cerebral cortex was the same as beclin-1. The results of IHC showed that LC3-positive nuclei in model group were more than those in NaHS group (P < 0.05). The number of autophagic vacuole in model group was more than that in NaHS group (P < 0.05). The number of the TUNEL-positive cells in model group was more than that in NaHS group (P<0.05). The NDS of the animals in NaHS group after ROSC was lower than that in model group(P < 0.05). CONCLUSION: H2S inhibits neuronal autophagy, decreases apoptosis and improves neurologic function in CA rats after ROSC.  相似文献   

15.
AIM:To investigate the effects of hypoxia/reoxygenation (H/R) for different reoxygenation times on cardiomyocyte injury. METHODS:Human cardiomyocyte AC16 was cultured in glucose-free and serum-free DMEM with 1% O2 for 24 h, 10% fetal bovine serum and low glucose DMEM combined with 21% O2 were used to establish reoxygenation for 2 h, 6 h and 12 h, respectively. The cell viability was measured by CCK-8 assay. The protein levels of different cell injury pathway related molecules, such as LC3-Ⅱ/-I (autophagy), caspase-1 and gasdermin D (pyroptosis) and caspase-3 and Bax/Bcl2 (apoptosis), were determined by Western blot. RESULTS:Compared with blank control group, the cell viability in each H/R group was continuously decreased with the extension of reoxygenation time (P<0.05). The expression of LC3-Ⅱ/-I was up-regulated in hypoxia group and H/R group compared with blank control group (P<0.05). In addition, the protein levels of cleaved caspase-1 and cleaved gasdermin D were increased in H/R groups for 6 h and 12 h, respectively (P<0.05). Cleaved caspase-3 and Bax/Bcl2 were increased after reoxygenation for 12 h (P<0.05). CONCLUSION:Autophagy in hypoxia-induced AC16 cells is up-regulated, and then decreased by reoxygenation. The cell pyroptosis is activated earlier than the apoptosis during reoxygenation.  相似文献   

16.
AIM: To investigate the change of late sodium current (INaL) and the effect of Ca2+/calmodulin-dependent protein kinaseⅡ (CaMKⅡ) inhibitor KN-93 on INaL in the cardiomyocytes after isoproterenol-induced heart fai-lure (HF) in rabbits. METHODS: The rabbit model of HF was induced by injecting isoproterenol (300 μg·kg-1·d-1) for 15 d. One month later, all rabbits received by echocardiography and HE staining to observe the morphological changes of myocardium for evaluating the HF model. The protein expression of NaV1.5, CaMKⅡδ and phosphorylated CaMKⅡδ was determined by Western blot. The ventricular myocytes were isolated from the rabbits of normal saline (NS) group and HF group by Langendorff perfusion, and the whole-cell patch-clamp technique was used to record INaL. RESULTS: Compared with NS group, the heart rate in HF group was increased (P<0.01), the ventricular cavity was enlarged (P<0.05), and the cardiac function was decreased (P<0.01). Compared with NS group, the cardiomyocytes in HF group arranged in disorder, vacuolar degeneration and myocardial interstitial edema were observed, and fibrous tissue increased. The protein levels of NaV1.5, CaMKⅡδ and phosphorylated CaMKⅡδ in HF group were higher than those in NS group (P<0.01). INaL in HF group significantly increased compared with NS group (P<0.01). After adding sea anemone toxin Ⅱ (ATXⅡ), the density of INaL in HF group and NS group was significantly increased, but that in HF group increased more obviously than that in NS group (P<0.01). After ATXⅡ had induced stable current, we added KN-93 into NS group and HF group, and we found that the ATXⅡ-increased INaL in NS group and HF group was significantly decreased (P<0.05).CONCLUSION: CaMKⅡ inhibitor KN-93 inhibits the increase in INaL in HF rabbits, which may be related to the activity of CaMKⅡδ and the regulation of CaMKⅡ δ on INaL.  相似文献   

17.
AIM: To investigate the effect of oxymatrine (OM) on the autophagy of hepatic stellate cells (HSC) during HSC activation induced by arsenic (As). METHODS: Supernatant of human LO2 hepatocytes cultured with 100 μmol/L NaAsO2 for 24 h was collected. Human HSC line LX-2 was cultured for 24 h before mingling culture supernatant of LO2 cells with arsenic exposure and normal culture media in a 1:4 ratio, and then treated with low dose (0.25 g/L) and high dose (1 g/L) of OM. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in culture medium were measured by biochemical method. The level of transforming growth factor-β1 (TGF-β1) in the culture supernatant of LO2 cells with arsenic exposure was detected by ELISA. The cell viability was examined by MTT assay. The protein levels of α-smooth muscle actin (α-SMA), autophagy-related gene 12 (Atg12), autophagy-related gene 5 (Atg5) and microtubule-associated protein 1 light chain 3-Ⅱ (LC3-Ⅱ) were determined by Western blot. Lipid droplets were observed by oil red O staining under microscope. RESULTS: The levels of AST and ALT were obviously increased in the culture supernatant of LO2 cells with arsenic exposure (P<0.05). The viability of LX-2 cells was obviously enhanced while adding supernatant of LO2 cells with arsenic exposure into the culture media of LX-2 cells (P<0.05), the number of lipid drops decreased, and the expression of α-SMA was increased (P<0.05). Co-incubation with supernatant of LO2 cells and arsenic exposure obviously increased the expression of Atg12, Atg5, LC3-Ⅱ at protein level in the LX-2 cells as compared with control group (P<0.05). Low dose and high dose of OM inhibited the viability of LX-2 cells caused by co-incubation of the supernatant of LO2 cells with arsenic exposure (P<0.05) and decreased the protein expression of α-SMA, Atg12, Atg5 and LC3-Ⅱ in the LX-2 cells (P<0.05). High dose of OM was more effective in expression of LC3-Ⅱ than low dose (P<0.05). The number of lipid droplets in the LX-2 cells treated with OM was increased obviously as compared with the supernatant of LO2 cells with arsenic exposure. CONCLUSION: Arsenic exposure promotes the activation of HSC by damage of hepatocytes. Autophagy participates in the activation of HSC, and the mechanism is concerned with providing energy by degrading the lipid droplet of HSC. Oxymatrine intervention alleviates liver fibrosis by inhibiting autophagy and activation of HSC.  相似文献   

18.
AIM: To study the effect of Lycium barbarum polysaccharides (LBP) on oxidative stress injury of human endothelium-like EA.hy926 cells induced by hydrogen peroxide (H2O2). METHODS: The EA.hy926 cell model of oxidative stress injury was established by H2O2 treatment. The EA.hy926 cells were divided into 5 groups:control group, damage (H2O2 at 50 mmol/L) group, LBP (100 mg/L) group, anti-damage groups (LBP at 50 mg/L, 100 mg/L or 200 mg/L+50 mol/L H2O2), and LY294002 (20 μmol/L) group. The effect of LBP at different concentrations on the cell viability of EA.hy926 cells was measured by CCK-8 assay, and the optimum concentration of LBP was screened out. The apoptotic of EA.hy926 cells was analyzed by flow cytometry. Acridine orange/ethidium bromide (AO/EB) staining was used to observe the morphological characteristics of the apoptotic cells. The cell migration ability was detected by scratch method. The levels of nitric oxide (NO) and vascular endothelial growth factor (VEGF) in the cell culture medium were examined. The protein levels of cleaved caspase-3, Bax, Bcl-2, endothelial NO synthase (eNOS), p-eNOS and p-Akt were determined by Western blot. RESULTS: LBP at concentration of 100 mg/L significantly attenuated the injury of EA.hy926 cells induced by H2O2, as indicated by improved cell viability (P<0.05) and decreased apoptosis (P<0.05). Pretreatment with LBP elevated the levels of NO and VEGF (P<0.05), and promoted the migration ability of EA.hy926 cells. LBP also increased the Bcl-2/Bax ratio, down-regulated the protein level of cleaved caspase-3, and up-regulated the protein levels of eNOS and p-eNOS. The protective effect of LBP were abolished by pretreatment of the EA.hy926 cells with the inhibitor of PI3K (P<0.05). As a result, the protein level of p-Akt was down-regulated, and the level of NO was also significantly reduced. CONCLUSION: LBP has protective effect on H2O2 -induced EA.hy926 cells by attenuating apoptosis of the cells. The mechanism is closely related to the activation of PI3K/Akt/eNOS signaling pathway.  相似文献   

19.
LI Bai-he  YUAN Lei 《园艺学报》2016,32(5):852-856
AIM: To investigate the effect of digoxin on hypoxia-induced epithelial-mesenchymal transition (EMT), migration and invasion in human breast carcinoma MCF-7 cells. METHODS: MCF-7 cells were treated in vitro with a chemical hypoxia inducer cobalt chloride (CoCl2) to imitate hypoxia. Cell migration was observed by wound healing assay, and cell invasion was measured by Transwell invasion assay. The protein levels of hypoxia-inducible factor-1α (HIF-1α), Snail, E-cadherin and vimentin in MCF-7 cells were detected by Western blot. RESULTS: Digoxin inhibited CoCl2-induced EMT and reversed the mesenchymal phenotype. CoCl2 enhanced the abilities of migration and invasion (P<0.01), significantly decreased the expression of E-cadherin and increased the expression of HIF-1α, Snail and vimentin (P<0.01), but these effects were blocked by digoxin. CONCLUSION: Digoxin inhibits CoCl2-induced EMT and invasion most likely via HIF1-α-Snail signaling pathway.  相似文献   

20.
AIM: To explore whether NOD8 inhibits autophagy in human pancreatic cancer cells and its underlying mechanisms, and to investigate the effect of apoptosis on the autophagy regulated by NOD8. METHODS: The empty plasmid pEGFP-C2 and recombinant plasmid pEGFP-NOD8 were transfected into the Panc-1 cells using JetPRIME reagent.The untransfected cells served as control group. The protein levels of NOD8, autophagy-related proteins beclin-1 and LC3-II, and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway-related proteins Akt, p-Akt, mTOR and p-mTOR were determined by Western blot 48 h after transfection. Meanwhile, the number of LC3 spots was quantified by immunofluorescence staining. Furthermore, after a broad caspase inhibitor Z-VAD-FMK was applied to NOD8-over-expressing cells, the protein expression levels of beclin-1 and LC3-II were detected by Western blot and the number of LC3 spots was observed by immunofluorescence staining. RESULTS: The protein level of NOD8 in pEGFP-NOD8 group was significantly higher than that in control group and pEGFP-C2 group (P<0.01). The protein expression of beclin-1 and LC3-II, and the number of LC3 spots in pEGFP-NOD8 group were significantly decreased as compared with control group and pEGFP-C2 group. Moreover, the protein levels of p-AKT and p-mTOR in pEGFP-NOD8 group were higher than those in control group and pEGFP-C2 group, while no significant difference of mTOR and AKT protein expression was found among these 3 groups. Furthermore, the protein levels of beclin-1 and LC3-II, and the number of LC3 spots in pEGFP-NOD8+Z-VAD-FMK group were significantly increased compared with pEGFP-NOD8 group. CONCLUSION: NOD8 inhibits autophagy in the Panc-1 cells and its mechanism may be related to the activation of PI3K/Akt/mTOR pathways. Apoptosis enhances the inhibitory effect of NOD8 on autophagy.  相似文献   

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