PQS attenuates cardiomyocyte apoptosis induced by thapsigargin through inhibiting endoplasmic reticulum stress

AIM:To study the effect of Panax quinquefoliumsaponin (PQS) on cardiomyocyte apoptosis induced by thapsigargin (TG). METHODS:Primary cultured cardiomyocytes from neonatal SD rats were divided into control group, TG group, PQS (40 mg/L, 80 mg/L and 160 mg/L)+TG group, si-PERK+TG group, and mock+TG group. The cells were treated with 1 μmol/L TG for 24 h to induce apoptosis. The PERKgene in the cardiomyocytes was knocked down by RNAi. The cell viability was detected by CCK-8 assay. Apoptosis was analyzed by flow cytometry. Wes-tern blotting was used to determine the expression of ERS molecules GRP78, CRT, ATF4 and CHOP, anti-apoptosis protein Bcl-2 and pro-apoptosis protein Bax. RESULTS:Compared with control group, TG significantly and the apoptosis, reduced the cell viability (P<0.05), increased the phosphorylation of PERK and eIF2α, increased the expression of GRP78, CRT, ATF4, CHOP and pro-apoptosis protein Bax, and decreased the expression of anti-apoptosis protein Bcl-2 (P<0.05). Compared with TG group, PQS treatment (160 mg/L) significantly reduced the apoptosis and increased the cell viability (P<0.05). All the 3 different concentrations of PQS significantly increased the expression of anti-apoptosis protein Bcl-2 and reduced the expression of pro-apoptosis protein Bax (P<0.05) in a dose-dependent manner. PQS pretreatment and knockdown of PERK both reduced the protein levels of GRP78, CRT, PERK, p-PERK, eIF2α, p-eIF2α, ATF4, CHOP and pro-apoptosis protein Bax, and increased the expression of anti-apoptosis protein Bcl-2 (P<0.05). CONCLUSION: PQS at concentration of 160 mg/L attenuated cardiomyocyte apoptosis induced by TG. PQS had the similar effect as PERKknockdown on cardiomyocyte apoptosis. The mechanism may be associated with inhibiting PERK-eIF2α-ATF4-CHOP pathway of ERS-related apoptosis.     

Effects of PDCD5 on hypoxia/reoxygenation-induced autophagy and apoptosis of cardiomyocytes

AIM: To investigate the influence of programmed cell death 5 (PDCD5) on apoptosis and autophagy in the cardiomyocytes exposed to hypoxia/reoxygenation (H/R) and its potential mechanism.METHODS: H9c2 cells were exposed to H/R. PDCD5 was downregulated by RNA interference. The cell viability was measured by MTT assay. TUNEL assay was used to detect cell apoptosis. The mRNA and protein levels were determined by RT-qPCR and Western blot.RESULTS: The expression of PDCD5 was upregulated in the cardiomyocytes after H/R injury. Furthermore, H/R injury obviously reduced the cell viability and enhanced the apoptosis and autophagy of the cardiomyocytes. However, knockdown of PDCD5 increased the cell viability, and attenuated H/R-induced apoptosis, accompany with reduction of Bax and augment of Bcl-2 expression. Additionally, silencing PDCD5 markedly inhibited H/R-induced autophagy by regulating the expression of LC3-II/LC3-I and beclin-1. Moreover, downregulation of PDCD5 suppressed NF-κB signaling by redu-cing the protein level of p-P65.CONCLUSION: Silencing PDCD5 suppresses H/R-induced H9c2 cells apoptosis and autophagy by blocking NF-κB signaling pathway. The result indicates a new strategy for the prevention and treatment of myocardial I/R injury.     

Preliminary mechanism of senegenin against H/R-induced apoptosis of primary cortical neurons

AIM：To explore the preliminary mechanism of senegenin (Sen) on inhibiting hypoxia/reoxygenation(H/R)-induced apoptosis of primary cortical neurons. METHODS：The cultured cortical neurons were randomly divided into normal group (control group), model group (H/R group), Sen+H/R group and Sen group. Flow cytometry was used to evaluate the effect of Sen on H/R-induced cell apoptosis. The protein levels of JNK, p-JNK, c-Jun, p-c-Jun, Bcl-2 and Bax were assessed by Western blotting. RESULTS：The apoptotic rate in H/R group was obviously higher than that in control group (P<0.05), while the apoptotic rate in Sen+H/R group was obviously lower than that in H/R group (P<0.05), suggesting that the model of apoptosis was established successfully. The results of Western blotting showed that Sen increased the expression of JNK and c-Jun, inhibited the phosphorylation of JNK and c-Jun (P<0.05), increased the protein level of Bcl-2 and inhibited the protein level of Bax in H/R treated primary cortical neurons (P<0.05). CONCLUSION：Sen has a protective effect against H/R-induced neuronal apoptosis by increasing the expression of JNK and c-Jun, inhibiting the phosphorylation of JNK and c-Jun, increasing the protein level of Bcl-2 and decreasing the protein level of Bax.     

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《园艺学报》是中国园艺学会和中国农业科学院蔬菜花卉研究所主办的学术期刊,创刊于1962年,刊载有关果树、蔬菜、观赏植物、茶及药用植物等方面的学术论文、研究报告、专题文献综述、问题与讨论、新技术新品种以及园艺研究动态与信息等,适合园艺科研人员、大专院校师生及农业技术推广部门专业技术人员阅读参考。《园艺学报》是中文核心期刊,被英国《CAB文摘数据库》、美国CA化学文摘、日本CBST科学技术文献速     

Astragaloside IV attenuates apoptosis of H9c2 cardiomyocytes induced by angiotensin II

AIM: To investigate the protective effect of astragaloside IV (ASIV) on angiotensin II (Ang II)- induced apoptosis of H9c2 cardiomyocytes. METHODS: H9c2 cardiomyocytes were treated with different concentrations of Ang II and ASIV. The effects of Ang II and ASIV on the viability of H9c2 cells was measured by CCK-8 assay. The optimum concentration of Ang II was 1 μmol/L and the concentrations of ASIV were 25, 50 and 100 μmol/L. The H9c2 cells was divided into 6 groups:control group, ASIV group, Ang II group, Ang II+ASIV (25 μmol/L) group, Ang II+ASIV 50 (μmol/L) group and Ang II+ASIV (100 μmol/L) group. The morphological changes of the H9c2 cells were observed under inverted phase-contrast microscope. Apoptosis was detected by TUNEL assay. The generation of reactive oxygen species (ROS) was detected by DCFH-DA staining. The protein expression of Bax, Bcl-2, nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was determined by Western blot. H9c2 cardiomyocytes were transfected with negative control shRNA (NC) or Nrf2-shRNA (shRNA), and the cells were divided into 8 groups:NC+control group, NC+AngⅡgroup, NC+ASIV group, NC+AngⅡ+ASIV group, shRNA+control group, shRNA+AngⅡgroup, shRNA+ASIV group and shRNA+AngⅡ+ASIV group. ROS level was detected by ROS detection kit. The protein expression of Nrf2 and HO-1 was determined by Western blot. RESULTS: Ang II decreased the viability of H9c2 cells in a concentration-dependent manner (P<0.05). ASIV reversed the effect of Ang II on the viability of H9c2 cells in a concentration-dependent manner (P<0.05). Compared with control group, the apoptotic rate, the level of ROS and the protein expression of Bax in Ang II group were increased significantly, while the protein expression of Bcl-2, Nrf2 and HO-1 was decreased significantly (P<0.05). Compared with Ang II group, ASIV reversed the increase in apoptotic rate of H9c2 cells induced by Ang II in a concentration-dependent manner, reduced ROS level, down-regulated the protein expression of Bax and up-regulated the protein expression of Bcl-2, Nrf2 and HO-1 (P<0.05). After shRNA transfection, the effects of ASIV decreasing ROS production induced by Ang II and up-regulating the expression of Nrf2 and HO-1 were eliminated. CONCLUSION: ASIV protects H9c2 cardiomyocytes from apoptosis induced by Ang II, which may be related to reducing ROS generation and mediating the Nrf2/HO-1 signaling pathway.     

miRNA-7-mediated Bax/Bcl-2 expression promotes apoptosis of human nasopharyngeal carcinoma CNE-1 cells

AIM: To investigate the relationship of microRNA-7 (miRNA-7) over-expression and Bax/Bcl-2 expression in human nasopharyngeal carcinoma CNE-1 cells.METHODS: The CNE-1 cells were transfected with miRNA-7 mimics using Lipofectamine 2000. The expression of miRNA-7 was detected by real-time PCR. CCK-8 assay and Hoechst 33258 staining were used to detect the cell activity and apoptosis. The expression of Bax/Bcl-2 at mRNA and protein levels was determined by real-time PCR and Western blot. RESULTS: The expression of miRNA-7 was increased significantly in the CNE-1 cells compared with negative control group and mock group (P<0.01). The activity of CNE-1 cells were extremely decreased after tansfected with miRNA-7 mimics (P<0.01). The typical apoptotic nuclear morphological changes were observed in the CNE-1 cells under the fluorescence microscope with Hoechst 33258 staining. The expression of Bax at mRNA and protein levels was significantly increased compared with the other 2 groups (P<0.01), while the Bcl-2 expression at mRNA and protein levels was significantly down-regulated (P<0.01).CONCLUSION: Over-expression of miRNA-7 significantly inhibits the growth and promotes the apoptosis of nasopharyngeal carcinoma CNE-1 cells by increasing the expression of Bax and down-regulating Bcl-2.     

Effects of HSP90 on complement-mediated hypoxia/reoxygenation injury of H9c2 cardiomyocytes during hypoxic postconditioning

AIM To investigate the effects and mechanisms of heat shock protein 90 （HSP90） on complement-mediated hypoxia/reoxygenation （H/R） injury of rat H9c2 cardiomyocytes during hypoxic postconditioning （HPC）. METHODS Rat H9c2 cardiomyocytes were divided into 7 groups according to different treatments： （1） control group （cultured for 10 h under normal oxygen）; （2） H/R group （hypoxia for 4 h and reoxygenation for 6 h）; （3） HPC group （3 cycles of 5 min H/R after hypoxia for 4 h, followed by reoxygenation for 6 h）; （4） HPC+geldanamycin （GA） group （1 μmol/L HSP90 inhibitor GA was added 20 min before HPC）; （5） negative control group （empty plasmid was transfected before HPC）; （6） C3 over-expression group （C3a plasmid was transfected before HPC）; （7） C5 over-expression group （C5a plasmid was transfected before HPC）. Morphological changes of the H9c2 cells were detected by Hoechst 33242 staining. The effects of HPC on the apoptosis of H9c2 cells were examined by flow cytometry. The protein levels of HSP90, C3a, C5a, NF-κB p65, TNF-α, IL-1β, IL-6, Bcl-2 and Bax were determined by Western blot. RESULTS With up-regulation of HSP90, HPC significantly reduced H/R-induced apoptosis of the H9c2 cells, inhibited the expression of C3a, C5a, NF-κB p65, TNF-α, IL-1β, IL-6 and Bax, and increased the expression of Bcl-2. These effects were blocked by GA. The inhibitory effects of HPC on NF-κB p65 expression and H9c2 cell apoptosis were offset after over-expression of C3a or C5a. CONCLUSION HSP90 attenuates H/R injury of H9c2 cardiomyocytes by inhibiting complement-NF-κB signaling pathway during HPC.     

Apelin-13 inhibits nicotine-induced apoptosis of H9c2 cells via PI3K/Akt signaling pathway

AIM:To investigate the effect of apelin-13 on nicotine-induced apoptosis of cardiomyocytes and its potential molecular mechanism. METHODS:Rat H9c2 cells were treated with nicotine (10 μmol/L) to induced apoptosis. Flow cytometry was used to detect apoptotic rate. Western blot was used to determined the expression of related proteins. RESULTS:Compared with control group, nicotine treatment significantly increased the apoptotic rate of the H9c2 cells (P<0.01), and the protein levels of apoptosis-related proteins Bax and cleaved caspase-3, but markedly decreased the protein levels of Bcl-2, p-Akt, p-PI3K and APJ (P<0.05). Compared with nicotine group, apelin-13+nicotine significantly decreased the apoptotic rate of the H9c2 cells (P<0.01) and the the protein levels of Bax and cleaved caspase-3, but markedly increased the protein levels of Bcl-2, p-Akt, p-PI3K and APJ (P<0.05). Compared with apelin-13+nicotine group, apelin-13+nicotine+PI3K/Akt inhibitor LY294002 significantly increased the apoptotic rate of the H9c2 cells (P<0.01) and the protein levels of Bax and cleaved caspase-3, but markedly decreased the protein levels of Bcl-2, p-Akt and p-PI3K (P<0.05). CONCLUSION:Apelin-13 inhibits nicotine-induced apoptosis of H9c2 cells through PI3K/Akt signaling pathway.     

Effect of CHOP/GADD153 on cardiomyocyte apoptosis induced by angiotensin Ⅱ in vitro

AIM: To investigate the relationship between alteration of CHOP/GADD153 protein expression and cardiomyocyte apoptosis induced by angiotensin Ⅱ (AngⅡ),and inhibitory effects of CHOP/GADD153 antisense oligodeoxynucleotide (anti-ODN) on apoptosis in vitro.METHODS: Cultured neonatal cardiomyocytes were exposed to AngⅡ with or without preincubation of CHOP/GADD153 anti-ODN.Variability of myocytes was measured by MTT assay,the lactate dehydrogenase (LDH) release was also detected,the percentage of annexin V positive myocytes was monitored by flow cytometry as apoptosis rate,CHOP/GADD153,Bcl-2 and Bax expressions were determined by Western blotting.RESULTS: Compared with control group,the expression of CHOP/GADD153 was obviously increased from (0.20±0.02 to 0.75±0.06) in AngⅡ group (P＜0.01).The variability of myocytes was obviously decreased from (100.00%±0.00% to 66.32%±7.16%,P＜0.05).The LDH release was significantly increased from (20.23 U/L±2.83 U/L to 79.36 U/L±5.69 U/L,P＜0.05) and apoptosis rate was significantly increased from (3.33%±0.28% to 16.62%±2.09%,P＜0.05).Bcl-2 expression was obviously decreased from (0.73±0.05 to 0.44±0.05,P＜0.01).Bax expression was obviously increased from (0.69±0.08 to 0.90±0.10,P＜0.01) and Bax/Bcl-2 ratio was obviously increased from (0.93±0.09 to 2.00±0.22,P＜0.01).Preincubation of CHOP/GADD153 anti-ODN in the medium significantly reversed above changes except the expression of Bax,but the Bax/Bcl-2 ratio was lower than that in AngⅡ group significantly (P＜0.01).These effects were not observed in mis-ODN group and there was no significant difference between lipofectin and control group.CONCLUSION: The increased expression of CHOP/GADD153 protein may be one of the mechanisms of AngⅡ-induced cardiomyocyte apoptosis,and CHOP/GADD153 anti-ODN can inhibit the apoptosis.     

Mangiferin attenuates hypoxia/reoxygenation-induced injury of human myocardial cells

AIM To investigate the effect of mangiferin on hypoxia/reoxygenation (H/R)-induced injury of human myocardial cells and its mechanism. METHODS Human myocardial AC16 cells were divided into normal group, H/R group and H/R + mangiferin (50, 100 and 200 μmol/L) treatment groups. The mRNA and protein expression levels of Kelch-like epichlorohydrin-associated protein-1 (Keap-1), Bax, Bcl-2, caspase-3, caspase-9 and superoxide dismutase 2 (SOD2) were detected by RT-qPCR and Western blot, respectively. The protein expression of nuclear factor E2-related factor 2 (Nrf-2) in nucleus was determined by Western blot. The expression of microRNA-432-3p (miR-432-3p) was detected by RT-qPCR. The generation of reactive oxygen speciess (ROS) in the cells was measured by DCFH-DA probing. The cell viability was measured by CCK-8 assay. Apoptosis was analyzed by flow cytometry. RESULTS No significant difference in the expression of miR-432-3p and Keap-1 between normal group and H/R group was observed. Compared with normal group, the nuclear translocation of Nrf-2, the ROS level, and the mRNA and protein expression of Bax, caspase-3 and caspase-9 were significantly increased in H/R group （P<0.05）. The mRNA and protein expression of SOD2 and Bcl-2, and the cell viability significantly decreased in H/R group compared with normal group, while the apoptosis was increased significantly （P<0.05）. Treatment with mangiferin resulted in an increase in the miR-432-3p expression and a decrease in the ROS level, and the expression of Keap-1, Bax, caspase-3 and caspase-9 was also inhibited as compared with H/R group （P<0.05）. The Nrf-2 nuclear translocation, and the protein levels of SOD2 and Bcl-2 in mangiferin treatment groups were significantly increased as compared with H/R group （P<0.05）. The cell viability was increased significantly, and the apoptosis was decreased significantly in mangiferin treatment groups as compared with H/R group （P<0.05）. The effects of mangiferin in middle- and high-dose groups were better than those in low-dose group, and no significant difference between middle- and high-dose groups was found. CONCLUSION Mangiferin inhibits the decrease in myocardial cell viability and the apoptosis induced by H/R injury. The mechanism may be related to the up-regulation of Nrf-2 antioxidant stress effect via enhancing the expression of miR-432-3p.     

SPK1 interferes with LLC cell apoptosis by regulating Bcl-2/Bax pathway

AIM: To investigate whether sphingosine kinase 1 (SPK1) interferes with apoptosis of Lewis lung cancer (LLC) cells by regulating the Bcl-2/Bax pathway. METHODS: The SPK1 gene siRNA eukaryotic expression vector was constructed, and transfected into the LLC cells. The transfected LLC cells was observed under a fluorescence microscope. The apoptotic rate of LLC cells after transfection was analyzed by flow cytometry. The expression levels of SPK1, Bcl-2 and Bax in LLC cells after transfection were detected by Western blot. The protein levels of Bax and Bcl-2 were measured by ELISA. RESULTS: Transfected LLC cells emitted green fluorescence under a fluorescence microscope. Apoptosis in siRNA-SPK1 group was significantly higher than that in siRNA-SPK1-Neg group (P<0.01). Western blot analysis showed that the expression of Bax in siRNA-SPK1 group was significantly higher than that in siRNA-SPK1-Neg group, and the expression of Bcl-2 was lower than that in siRNA-SPK1-Neg group. The ELISA results showed that the protein level of Bax in siRNA-SPK1 group was significantly higher than that in siRNA-SPK1-Neg group (P<0.01), and the protein level of Bcl-2 in siRNA-SPK1 group was significantly lower than that in siRNA-SPK1-Neg group (P<0.01). CONCLUSION: The expression of SPK1 in LLC cells is related to the apoptotic rate. SPK1 may interfere with the apoptosis of LLC cells via Bcl-2/Bax pathway.     

Effect of HIPK2 gene on viability,apoptosis and JAK2/STAT3 signaling pathway in NRK-52E renal tubular epithelial cells induced by hypoxia and reoxygenation

AIM: To investigate the effect of homeodomain-interacting protein kinase 2 (HIPK2) on the viabi-lity, apoptosis and JAK2/STAT3 signaling pathway in NRK-52E renal tubular epithelial cells induced by hypoxia and reoxygenation (H/R). METHODS: HIPK2 small interfering RNA (siRNA) was transfected into NRK-52E cells by Lipofectamine^TM 2000, and normal control group (control group) and negative control group (HIPK2-NC group) were set up. After H/R, the cell viability was measured by CCK-8 assay, the apoptotic rate and Ca²⁺ fluorescence intensity were analyzed by flow cytometry, and the protein levels of Ki67, cleaved caspase-3, caspase-12, Bcl-2, Bax, p-JAK2 and p-STAT3 were determined by Western blot. RESULTS: Compared with control group, the protein expression of HIPK2 in the NRK-52E cells was significantly decreased after transfection with HIPK2 siRNA (P<0.05). Compared with control group, the cell viability and the protein expression of Ki67 and Bcl-2 in H/R group were also significantly decreased, and the apoptotic rate, the Ca²⁺ fluorescence intensity and the protein levels of cleaved caspase-3, caspase-12, Bax, p-JAK2 and p-STAT3 were significantly increased (P<0.05). Compared with H/R group, the cell viability and the protein expression of Ki67 and Bcl-2 in HIPK2-siRNA+H/R group were significantly increased, while the apoptotic rate, the Ca²⁺ fluorescence intensity and the protein levels of cleaved caspase-3, caspase-12, Bax, p-JAK2 and p-STAT3 were significantly decreased (P<0.05). CONCLUSION: Inhibition of HIPK2 gene expression promotes H/R-induced growth of NRK-52E renal tubular epithelial cells, and reduces the apoptosis. The mechanism is related to down-regulating the JAK2/STAT3 signaling pathway.     

矮化中间砧‘宫藤富士’苹果栽植密度对树体生长、冠层光照和果实产量的影响

2011 年春季定植的矮化中间砧苹果成品苗（3 年根 1 年干的‘宫藤富士’/SH6/平邑甜茶）为试材，设置 7 种不同的栽植密度（株行距分别为 1 m × 3 m、1.5 m × 3 m、2 m × 3 m、0.75 m × 4 m、1 m × 4 m、1.25 m × 4 m 和 1.5 m × 4 m），细纺锤形整枝修剪，自栽植第 2 年，连续 7 年调查 7 种栽植密度对树体生长、冠层光照分布、果实产量和品质的影响。随着树龄的增长，不同栽植密度下树干粗度和总枝量逐年增加，不同处理间树干粗度无显著差异，第 7 年 1 m × 3 m 和 0.75 m × 4 m 两个栽植密度下树体总枝量超过 140 万条 · hm-2，第 8 年均超过 140 万条 · hm-2。栽植前期（第 2 ~ 4 年）各栽植密度树体短枝比例不断增加，长枝比例不断减少，第 5 年各栽植密度枝类组成趋于稳定；综合稳产 3 年（第 6 ~ 8 年）树体的枝类组成数据，4 m 行距的短枝比例明显高于 3 m 行距，长枝比例略低。树体冠层平均相对光照强度由高到低的株行距处理依次为 1.5 m × 4 m（63.87%）、1.25 m × 4 m（61.44%）、2 m × 3 m（61.27%）、1 m × 4 m（59.19%）、0.75 m × 4 m（55.79%）、1.5 m × 3 m（53.67%）和 1 m × 3 m（49.37%）；相同栽植株数下，4 m 行距处理低光效（相对光照强度小于 40%）的区域比例显著小于 3 m 行距。比较前 5 年的累计产量，以行距 4 m 和 1 m × 3 m 的最高。综合稳产 3 年的结果情况，大果率（单果质量 > 200 g 的果实产量占总产量的比例）以 4 m 行距和 2 m × 3 m 的最高。各栽植密度下的果实的可溶性固形物含量、固酸比、果形指数和果实硬度均无显著差异。综上，采用 4 m 行距，1 ~ 1.25 m 株距，树体成形快，稳产后树体结构合理，冠层光照充足，低效光区比例少，前期产量高。     

Inhibitory effect of hypoxia preconditioning on hypoxia/reoxygenation-induced apoptosis in cardiomyocytes

AIM: To study the role of hypoxia preconditioning (HP) in hypoxia-reoxygenation (HR)-induced apoptosis in neonatal rat cardiomyocytes and the possible mechanisms. METHODS: Cultured neonatal rat cardiomyocytes were divided into three groups: normal group, HP+H/R group and H/R group. Acridine orange (AO) staining was performed to detect morphological changes of apoptotic cells. Apoptosis rates of cardiomyocytes were detected by flow cytometry. Colorimetric assay was used to detect caspase-3 activity. Expression of Bcl-2 protein was detected by immunohistochemistry combined with computer image analysis. RESULTS: Apoptotic cells were detected by AO staining after hypoxia of 6 h followed by 3 h-reoxygenation. The hypodiploid apoptotic peak was detected by flow cytometry with the apoptotic rates of (29.7±5.4)%. A significantly reduced apoptotic rates of (7.8±1.3)% was detected in HP group（P＜0.01）. The caspase-3 relative activity of cardiomyocytes induced by H/R was 5.9±0.8, significantly higher than that of control group. HP markedly reduced caspase-3 relative activity to 2.6±0.5 in contrast with H/R group （P＜0.01）. Bcl-2 protein was positive in normal cardiomyocytes with an A value of 119.4±7.1. The A value of H/R group was 99.6±5.0, significantly lower than that in normal group （P＜0.01）. The A value of HP+H/R group was 126.5±6.2, significantly higher than that in H/R group（P＜0.01）. CONCLUSION: HP inhibits H/R-induced apoptosis of cardiomyocytes by improving the expression of Bcl-2 and reducing caspase-3 activity.     

Effects of human thioredoxin on pneumocyte apoptosis and Bcl-2/Bax expression in rats with lung ischemia/reperfusion injury

AIM: To explore the relationship between apoptosis in the lung tissues and lung ischemia/reperfusion injury, and to observe the effects of human thioredoxin (hTrx) on apoptosis in lung ischemia/reperfusion injury. METHODS: The single lung in situ ischemia/reperfusion animal model was used. Eighty four Wistar rats were randomly divided into control group (control), groups of ischemia for 1 h and reperfusion for different times (IR1h, IR3h, IR5h), and groups of IR+human thioredoxin treatment (IR1h +hTrx, IR3h +hTrx and IR5h +hTrx). Transmission electron microscope (TEM), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunocytochemistry techniques were used to observe apoptosis, apoptosis signal-regulating kinase 1 (ASK1) and expression of Bcl-2 and Bax in various phases of lung ischemia/reperfusion. RESULTS: Cell apoptosis in lung tissues was significantly high, ASK1, Bcl-2 and Bax protein were up-regulated in lung tissues of lung ischemia/reperfusion injury as compared to control (all P<0.01). Compared to IR group, hTrx suppressed apoptosis as well as expression of ASK1 and Bax protein (P<0.01), Bcl-2 protein and the ratio of Bcl-2/Bax were up-regulated in lung tissues (all P<0.05 or P<0.01). There was a significant correlation between the expression of ASK1, Bax protein and cell apoptosis (r=0.775, r=0.814, respectively; all P<0.01). There was a negative correlation between cell apoptosis and Bcl-2/Bax protein (r=-0.275, P<0.05). CONCLUSION: Initiating cell apoptosis by the activation of Bcl-2/Bax system in lung tissues may contribute to the pathogenesis of lung ischemia/reperfusion injury. The protective effects of hTrx include suppressing the expression of ASK1, down-regulating the ratio of Bcl-2/Bax and blocking apoptosis in lung tissues in lung ischemia/ reperfusion injury.     

MicroRNA-146a promotes apoptosis of gastric cancer SGC-7901 cells by targeting TAK1

AIM: To explore the effect of microRNA-146a (miR-146a) on apoptosis of human gastric cancer SGC-7901 cells and the underluing mechanism. METHODS: miR-146a mimic (up-regulated miR-146a expression) and miR-146a inhibitor (down-regulated miR-146a expression) were transfected into the SGC-7901 cells by liposome method. At the same time, miRNA nonsense sequence transfection group as the negative control group (NC group) was set up. RT-qPCR was used to evaluate the levels of miR-146a in the SGC-7901 cells after transfection. The effects of miR-146a on the cell apoptosis and growth were assessed by flow cytometry analysis and CCK-8 assay, respectively. The effect of over-expression or knockdown of miR-146a on transforming growth factor-β-activated kinase 1 (TAK1)/nuclear factor-kappa B (NF-κB) signaling was evaluated by RT-qPCR and Western blot. RESULTS: miR-146a modulated apoptosis of SGC-7901 cells. Over-expression of miR-146a significantly increased apoptosis, whereas knockdown of miR-146a inhibited the apoptosis of SGC-7901 cells. The expression of TAK1 at mRNA and protein levels was significantly decreased when miR-146a mimic was transfected into the SGC-7901 cells (P<0.05). On the contrast, the expression of TAK1 at mRNA and protein were significantly higher in miR-146a inhibitor transfection group than that in NC group (P<0.05), suggesting that miR-146a negatively regulated TAK1 expression. Moreover, knockdown of TAK1 enhanced the apoptosis of SGC-7901 cells (P<0.01), while over-expression of TAK1 inhibited the apoptosis of SGC-7901 cells(P<0.01). Additionally, both over-expression of miR-146a and knockdown of TAK1 led to a prominent increase in the expression of NF-κB inhibitor protein alpha (IκBα) and a significat decrease in B cell lymphoma-2 (Bcl-2) level in the SGC-7901 cells. CONCLUSION: miR-146a significantly promotes apoptosis of SGC-7901 cells by inhibition of NF-κB pathway via targeting TAK1.     

苹果miR396家族鉴定及在不定根发育过程中的表达分析

分析了苹果miR396家族进化特性及其在苹果不定根发育过程中的表达模式。结果表明：苹果miR396家族有4条成熟体和7条前体序列（pre-miRNA）。Mfold预测显示Pre-miR396家族7个成员序列均可形成典型稳定的茎环二级结构,最小折叠自由能介于–62.9 kal ? mol-1（pre-miR396b）~–51.9 kal ? mol-1（pre-miR396g）之间。系统发育进化树分析显示,pre-miR396家族亲缘关系可分为3个亚组（G1、G2、G3）,每个亚组内基因数量不同,分别含有11、9、19个。靶基因预测显示,苹果miR396靶基因包括MdGRF1、MdGRF2和MdGRF5等,降解组测序进一步验证了miR396对其候选靶基因MdGRF1、MdGRF2和MdGRF5的剪切关系。苹果miR396家族成员在侧根和果实中的表达量显著高于其他组织,其候选靶基因表达量则在花芽和腋芽中显著高于其他组织;不定根发育过程中,miR396家族不同成员表达模式存在显著差异,整体上呈上调表达趋势,其候选靶基因呈下调表达趋势;外源IBA处理显著诱导miR396家族成员的表达,尤其是在不定根诱导期和根系生长期更为显著。