Rosmarinic acid protects on rat bone marrow mesenchymal stem cells from hydrogen peroxide-induced apoptosis

To investigate the anti-oxidant activities and mechanism of rosmarinic acid (RA) on rat bone marrow mesenchymal stem cells (rBMSCs) from ischemia-induced apoptosis in vitro, which was established using H₂O₂-damage and analyzed for cell viability, cell apoptosis, ROS, morphological changes, and levels of apoptosis proteins. Pretreatment with RA significantly suppressed the generation of ROS, protected the morphological changes of cells, decrease the ratio of cell apoptosis, down-regulated the level of caspase-3, caspase-9, Bax/Bcl-2, and up-regulated the level of p-PI3K. These findings suggest that RA may protect rBMSCs from H₂O₂-induced apoptosis by partly regulating PI3K/Akt signaling pathway and can be developed as a potential anti-apoptotic agent for therapy in cardiovascular diseases.     

Taiwan cobra cardiotoxin III inhibits Src kinase leading to apoptosis and cell cycle arrest of oral squamous cell carcinoma Ca9-22 cells

Cardiotoxin III (CTX III), a basic polypeptide with 60-amino acid residues isolated from Naja naja atra venom, has been reported to have cytotoxic activity. CTX III exerted cytotoxicity with the S-phase cell cycle arrest, correlated with a marked decrease in the expression levels of cyclin A, cyclin B, and cyclin-dependent kinase 1 (CDK1), and apoptosis, accompanied with Bax and Bad up-regulation, and the down-regulation of Bcl-2, p-Bad, and X-linked inhibitor of apoptosis (XIAP) with cytochrome c release and sequential activation of caspase-9 and caspase-3 in Ca9-22 cells. Mechanistic studies showed that CTX III suppressed the phosphorylation of Src, EGFR, STAT3, STAT5, Akt, and activation of PI3 K (p110). Moreover, Src inactivation was observed earlier than that of the EGFR and the Src inhibitor PP2 suppressed the levels of phospho-EGFR, phospho-STAT3, phospho-STAT5, phospho-Akt, and PI3 K(p110). The PP2 also caused the S-phase arrest and apoptosis, and led to down-regulation of Bcl-2, p-Bad, XIAP, cyclin A, cyclin B, and CDK1, and up-regulation of Bax and Bad, similar to that observed in CTX III treatment. Taken together, these results indicate that CTX III induces apoptosis and S-phase arrest in Ca9-22 cells via concomitant inactivation of the Src, EGFR, STAT3, STAT5, PI3 K(p110), and Akt signaling pathways.     

基于ROS/PI3K/Akt/mTOR信号通路探讨玫瑰花甲醇提取物对前列腺癌PC-3细胞凋亡的影响

目的：探讨玫瑰花甲醇提取物（RE）对前列腺癌PC-3细胞增殖和凋亡的影响及潜在作用机制。方法：采用CCK8法检测不同浓度RE对PC-3细胞增殖的影响;采用Hoechst染色法和Annexin V/PI双染法检测细胞凋亡;DCFH-DA检测细胞ROS水平;Western blot法检测Bax、Bcl-2、cleaved caspase-3、Cyt-C、PI3K、p-PI3K、Akt、p-Akt、mTOR、p-mTOR的蛋白表达。结果：RE呈浓度依赖性抑制前列腺癌PC-3细胞增殖,24 h和48 h后的IC₅₀值分别为31.30 mg·mL^-1和16.76 mg·mL^-1;RE能显著诱导PC-3细胞凋亡（P<0.05,P<0.01）,且呈现浓度依赖性;RE可显著提高PC-3细胞ROS水平（P<0.05,P<0.01）,且具有浓度依赖性;RE能显著上调PC-3细胞Bax、cleaved caspase-3、Cyt-C的蛋白表达及Bax/Bcl-2的比值（P<0.05,P<0.01）,显著下调Bcl-2、p-PI3K、p-Akt、p-mTOR的蛋白表达（P<0.05,P<0.01）,以上均呈现浓度依赖性。结论：本研究表明RE在体外有明显抑制前列腺癌细胞PC-3的增殖作用,并可能通过调控ROS/PI3K/Akt/mTOR信号通路诱导其凋亡,研究结果可为玫瑰花及其组方临床治疗前列腺癌提供实验依据。     

Down-regulation of the JAK2/PI3K-mediated signaling activation is involved in Taiwan cobra cardiotoxin III-induced apoptosis of human breast MDA-MB-231 cancer cells

Cardiotoxin III (CTX III), a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom, has been reported to have anticancer activity. Exposure of MDA-MB-231 cells with 0.03, 0.09, and 0.15 μM of CTX III for 18 h, CTX III-induced cell apoptosis, as evidenced by accumulation of sub-G1 population, externalization of phosphatidylserine, loss of mitochondrial membrane potential (ΔΨm) with subsequent release of cytochrome c, and activation of both capases-9 and caspase-3. This correlated with up-regulation in Bax and Bad, and down-regulation of various anti-apoptotic proteins, including Bcl-2, Bcl-X_L, and survivin in CTX III-treated cells. Mechanistic studies showed that CTX III suppressed the phosphorylation of JAK2, STAT3, Akt, and activation of PI3K. Moreover, the PI3K inhibitor wortmannin blocked activation of STAT3 and Akt without affecting the JAK2 activation, whereas JAK2 inhibitor AG490 suppressed the levels of phospho-STAT3, phospho-Akt, and PI3K, suggesting that PI3K activation occurs after JAK2 phosphorylation, and both PI3K and JAK2 kinases cooperate to mediate STAT3 and Akt phosphorylation. Both AG490 and wortmannin also led to up-regulation in Bax and Bad, and down-regulation of Bcl-2, Bcl-X_L, and survivin in MDA-MB-231 cells. Taken together, these results indicate that CTX III induces apoptosis in MDA-MB-231 cells via concomitant inactivation of the JAK2, STAT3, PI3K, and Akt signaling pathways.     

牡丹苷A诱导人肺癌A549细胞凋亡的作用和机制

目的:研究牡丹苷A对人肺癌A549细胞株的作用以及其诱导人肺癌A549细胞株凋亡机制。方法:本研究采用MTT法检测牡丹苷A对体外人肺癌细胞株A549增殖率的影响。Annexin V/PI双标法检测牡丹苷A对A549凋亡率,蛋白免疫印迹法和细胞免疫细胞化学法分别检测牡丹苷A对A549细胞株PI3K,Akt,NF-κBp65,Bax,Bcl-2的表达,并采用PI3K/Akt/NF-κB通路的激动剂IGF-1和抑制剂wortmannin进一步探讨牡丹苷A对PI3K/Akt/NF-κB信号通路的作用。结果:牡丹苷A能够抑制A549的增殖,上调Bax蛋白的表达量,下调Bcl-2蛋白的表达量,Bcl-2/Bax比值显著降低,同时降低PI3K, NF-κBp65的蛋白表达,抑制Akt磷酸化。结论:牡丹苷A能够阻碍A549增殖,并促进其凋亡,其诱导凋亡的机制可能与抑制PI3K/Akt/NF-κB通路有关。     

Ginsenoside Rd prevents and rescues rat intestinal epithelial cells from irradiation-induced apoptosis

Panax ginseng has been shown to have a protective effect for irradiated animals or cells. Ginsenosides are the most active components isolated from ginseng, and ginsenoside Rd has been identified as one of the effective compounds responsible for the pharmaceutical actions of ginseng. In the present study, we studied the molecular mechanisms for the radio-protective action of ginsenoside Rd in rat intestinal epithelial IEC-6 cells. Cells were irradiated with gamma-ray, and apoptosis was examined using Hoechst staining and Western blot analysis. Treatment with ginsenoside Rd before gamma-irradiation inhibited irradiation-induced apoptosis in IEC-6 cells. Administration of Rd after irradiation also inhibited apoptosis in these cells. Irradiation of IEC-6 cells resulted in inactivation of Akt phosphorylation that was abrogated by Rd. On the other hand, irradiation activated phosphorylation of ERK1/2 but did not affect that of p38 MAPK. Inhibition of Akt phosphorylation prevented the reduction of apoptosis by Rd following irradiation. Pretreatment with an inhibitor of the MEK pathway further decreased the number of apoptotic cells. Rd decreased the ratios of Bax/Bcl-2 and Bax/Bcl-xL, the levels of cytochrome c, and the cleaved form of caspase-3 in irradiated IEC-6 cells. Our results suggest that ginsenoside Rd protects and rescues rat intestinal epithelial cells from irradiation-induced apoptosis through a pathway requiring activation of PI3K/Akt, inactivation of MEK, and also inhibition of a mitochondria/caspase pathway.     

Rutaecarpine inhibits hypoxia/reoxygenation-induced apoptosis in rat hippocampal neurons

Our previous studies showed that rutaecarpine (Rut) protected against myocardial ischemia/reperfusion (I/R) injury, which was associated with activation of transient receptor potential vanilloid subtype 1 (TRPV1). Recently, TRPV1 activation was also reported to exert neuroprotective effects. The present study was to investigate the effect of Rut on hypoxia/reoxygenation (H/R)-induced apoptosis in primary rat hippocampal neurons. Three-hour hypoxia (1% O2) and consequent 24-h reoxygenation significantly increased the apoptotic death of hippocampal neurons as evidenced by increases in both TUNEL-positive cell number and caspase-3 activity. However, pretreatment with Rut (1-10microM) or caspase-3 specific inhibitor DEVD-CHO could markedly attenuate H/R-induced apoptosis in neurons. Rut markedly induced the phosphorylation of Akt and PI3K inhibitor LY294002 prevented the survival effect of Rut on neurons. Intracellular oxidative stress was significantly induced after H/R, which was inhibited by Rut and LY294002 as well as antioxidant PDTC. TRPV1 antagonist capsazepine or intracellular Ca2+ chelator BAPTA/AM could abolish these effects of Rut mentioned above. In summary, the present data suggest that Rut inhibits H/R-induced apoptosis of hippocampal neurons via TRPV1-[Ca2+]i-dependent and PI3K/Akt signaling pathway, which is related to inhibiting oxidative stress and caspase-3 activation.     

β-lapachone-Induced Apoptosis of Human Gastric Carcinoma AGS Cells Is Caspase-Dependent and Regulated by the PI3K/Akt Pathway

β-lapachone is a naturally occurring quinone that selectively induces apoptotic cell death in a variety of human cancer cells in vitro and in vivo; however, its mechanism of action needs to be further elaborated. In this study, we investigated the effects of β-lapachone on the induction of apoptosis in human gastric carcinoma AGS cells. β-lapachone significantly inhibited cellular proliferation, and some typical apoptotic characteristics such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells were observed in β-lapachone-treated AGS cells. Treatment with β-lapachone caused mitochondrial transmembrane potential dissipation, stimulated the mitochondria-mediated intrinsic apoptotic pathway, as indicated by caspase-9 activation, cytochrome c release, Bcl-2 downregulation and Bax upregulation, as well as death receptor-mediated extrinsic apoptotic pathway, as indicated by activation of caspase-8 and truncation of Bid. This process was accompanied by activation of caspase-3 and concomitant with cleavage of poly(ADP-ribose) polymerase. The general caspase inhibitor, z-VAD-fmk, significantly abolished β-lapachone-induced cell death and inhibited growth. Further analysis demonstrated that the induction of apoptosis by β-lapachone was accompanied by inactivation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. The PI3K inhibitor LY29004 significantly increased β-lapachone-induced apoptosis and growth inhibition. Taken together, these findings indicate that the apoptotic activity of β-lapachone is probably regulated by a caspase-dependent cascade through activation of both intrinsic and extrinsic signaling pathways, and that inhibition of the PI3K/Akt signaling may contribute to β-lapachone-mediated AGS cell growth inhibition and apoptosis induction.     

阿托伐他汀对谷氨酸引起大鼠神经元损伤保护作用机制的研究

目的探讨阿托伐他汀对谷氨酸所致培养大鼠皮层神经元损伤保护作用的机制。方法 MTT法测定细胞存活率;Hoechst33258核染色观察细胞凋亡的形态学改变;Western blot检测活性的半胱氨酸天冬氨酸蛋白酶-3(caspase-3)和钙蛋白酶Ⅰ蛋白表达水平。结果谷氨酸(100μmol.L-1)可使神经元细胞存活率下降,细胞凋亡百分比明显增加,活性的caspase-3和钙蛋白酶Ⅰ蛋白表达增加。阿托伐他汀明显对抗谷氨酸诱导的神经元存活率下降及细胞凋亡百分比增加,同时明显抑制活性的caspase-3和钙蛋白酶Ⅰ蛋白表达增加。磷酯酰肌醇-3激酶(phos-phoinositide3-kinase,PI3K)/磷酸化蛋白激酶B(protein ki-nase B,Akt)通路特异性阻断剂LY294002(10μmol.L-1)能抑制阿托伐他汀对抗谷氨酸引起神经元细胞存活率下降,细胞凋亡百分比增加及活性caspase-3和钙蛋白酶Ⅰ蛋白表达增加的作用。结论阿托伐他汀能够明显对抗谷氨酸引起的皮层神经元损伤作用,这种作用可能与激活PI3K/Akt信号转导通路有关。     

Propentofylline protects beta-amyloid protein-induced apoptosis in cultured rat hippocampal neurons

beta-Amyloid protein 1-42 (beta42) can induce apoptosis in the cultured hippocampal neurons, suggesting that it plays an important role in causing neurodegeneration in Alzheimer's disease. Recently, propentofylline, a synthetic xanthine derivative, has been reported to depress ischemic degeneration of hippocampal neurons in gerbils. The present study investigated whether or not propentofylline affected the beta42-induced apoptosis of hippocampal neurons, and if so, which type of signaling machinery works in the neuroprotective action of propentofylline. Addition of propentofylline markedly attenuated the beta42-induced cell death of rat hippocampal neurons. The amyloid protein certainly induced apoptosis in the cultured hippocampal cells revealed by nuclear condensation, caspase-3 activation and an increase of Bax. Intriguingly, propentofylline blocked both the apoptotic features induced by beta42 and further induced an anti-apoptotic protein, Bcl-2, during a short time of incubation. The neuroprotective action of propentofylline was comparably replaced with dibutyryl cAMP (dbcAMP) and was completely suppressed by a low concentration of specific protein kinase A (PKA) inhibitor. Taken altogether, the data strongly suggest that the protection of propentofylline on the beta42-induced neurotoxicity is caused by enhancing anti-apoptotic action through cAMP-PKA system. Propentofylline as a therapeutic agent to Alzheimer's disease is discussed.     

Cadmium induces apoptotic cell death in WI 38 cells via caspase-dependent Bid cleavage and calpain-mediated mitochondrial Bax cleavage by Bcl-2-independent pathway

Previous reports have demonstrated that cadmium (Cd) may induce cell death via apoptosis, but the mechanism responsible for cellular death is not clear. In this study, we investigated the signaling pathways implicated in Cd-induced apoptosis in lung epithelial fibroblast (WI 38) cells. Apoptotic features were observed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, propidium iodide staining and DNA laddering. A treatment of cadmium caused the caspase-8-dependent Bid cleavage, the release of cytochrome c (Cyt c), activation of caspase-9 and -3, and PARP cleavage. A caspase-8 specific inhibitor prevented the Bid cleavage, caspase-3 activation and cell death. Alternatively, we observed that full-length Bax was cleaved into 18-kDa fragment (p18/Bax); this was initiated after 12 h and by 36 h the full-length Bax protein was totally cleaved to the p18/Bax, which caused a drastic release of Cyt c from mitochondria. The p18/Bax was detected exclusively in the mitochondrial fraction, and it originated from mitochondrial full-length Bax, but not from the cytosol full-length Bax. Cd also induced the activation of the mitochondrial 30-kDa small subunit of calpain that was preceded by Bax cleavage. Cd induced the upregulation of Bcl-2 and the degradation of p53 protein. N-acetyl cysteine effectively inhibited the Cd-induced DeltaPsim reduction, indicating ROS acts upstream of mitochondrial membrane depolarization. Taken together, our results suggest that Cd-induced apoptosis was thought to be mediated at least two pathways; caspase-dependent Bid cleavage, and the other is calpain-mediated mitochondrial Bax cleavage. Moreover, we found that the function of Bid and Bax was not dependent of Bcl-2, and that ROS can also contribute in the Cd-induced cell death.     

鱼腥草总黄酮调控PI3K/Akt信号通路诱导人乳腺癌细胞株MCF-7凋亡的实验研究

目的：探讨鱼腥草总黄酮调控磷脂酰肌醇3-激酶（PI3K）/蛋白激酶B（Akt）信号通路对人乳腺癌细胞株MCF-7凋亡的诱导作用。方法：取对数期MCF-7细胞,随机分为4组（5个复孔）,低、中、高剂量组分别用3,6,9 g·L^-1鱼腥草总黄酮处理,对照组用磷酸盐缓冲液（PBS）处理。干预48 h后进行细胞形态学观察;对比干预12,24,48 h时的细胞凋亡率;对比干预48 h时PI3K、Akt、B淋巴细胞瘤-2基因（Bcl-2）、Bcl-2相关X蛋白（Bax）mRNA和PI3K、Akt、磷酸化Akt（pAkt）、Bcl-2、Bax蛋白相对表达量。结果：Hoechst 33258染色结果显示,干预后3剂量组部分细胞体积缩小、染色质浓缩,出现凋亡小体,且中剂量组凋亡现象最为明显;细胞凋亡率、Bax mRNA和蛋白相对表达量组间比较,中剂量组最高、高剂量组其次、低剂量组其稍低、对照组最低,且每2组间比较差异均有显著性（P<0.05）;细胞凋亡率组内比较,对照组随时间的延长变化不显著（P>0.05）,3剂量组均随时间的延长显著增加（P<0.05）;PI3K、Bcl-2 mRNA和PI3K、pAkt、Bcl-2蛋白相对表达量组间比较,中剂量组最低、高剂量组其次、低剂量组稍高、对照组最高,且每2组间比较差异均有显著性（P<0.05）;Akt mRNA和蛋白相对表达量组间比较差异均不显著（P>0.05）。结论：鱼腥草总黄酮可促进人乳腺癌细胞株MCF-7的凋亡,其中浓度为6 g·L^-1时促凋亡作用最强,推测是通过下调PI3K、Bcl-2 mRNA和PI3K、pAkt、Bcl-2蛋白表达,上调Bax mRNA和蛋白的表达,与PI3K/Akt信号通路有关。     

Involvement of Na+/H+ exchanger in hypoxia/re-oxygenation-induced neonatal rat cardiomyocyte apoptosis

Although increased Na(+)/H(+) exchanger type-1 (NHE-1) activity has been implicated in the pathogenesis of myocardial infarction, the role of NHE-1 in induction of apoptosis, and the potential mechanisms involved have not been fully characterized. This study tested the hypothesis that NHE-1 activity is involved in hypoxia (H)/re-oxygenation (Re)-induced cardiomyocyte apoptosis by increasing mitochondrial Ca(2+) ([Ca(2+)]m). Primary cultured neonatal rat cardiomyocytes were subjected to 4.5 h of H followed by 12 h of Re. Relative to H alone, the level of X-rhod-1 acetoxymethyl (AM)-labeled [Ca(2+)]m was increased, and the frequency of cell death (propidium iodide (PI) staining) and apoptotic cells (terminal deoxynucleotidyl transferase (TdT)-mediated-UTP nick end labeling [TUNEL]), confirmed by Annexin-V, were augmented at the end of Re, along with appearance of cytosolic cytochrome c, activation of caspase-3, and increased ratio of Bax and Bcl-2. Addition of cariporide (20 micromol/l), a well-known NHE-1 inhibitor, to cultured cells before H significantly reduced [Ca(2+)]m, the number of PI and TUNEL positive cells relative to the levels at end of Re, but did not completely eliminate these changes compared to Sham control. There was a strong trend for attenuation in increased levels of [Ca(2+)]m, and the number of PI and TUNEL positive cells when same dose of cariporide was added only at Re, but the difference in these variables did not reach significance. In contrast, the levels of [Ca(2+)]m and the number of PI and TUNEL positive cells were significantly reduced to a level comparable to Sham control when cariporide (20 micromol/l) was administered before H and during Re, respectively, associated with a reduction in cytosolic cytochrome c, caspase-3 activity and ratio of Bax and Bcl-2. In conclusion, these data suggest that NHE-1 is involved in induction of cardiomyocyte apoptosis during both H and Re through a [Ca(2+)]m-dependent manner, thereby resulting in activation of cytochrome c-caspase-3 signaling pathways.     

Neuroprotection by tetrahydroxystilbene glucoside in the MPTP mouse model of Parkinson's disease

Our in vitro experiments suggested that tetrahydroxystilbene glucoside (TSG) affords a significant neuroprotective effect against MPP⁺-induced damage and apoptosis in PC12 cells though activation of the PI3K/Akt pathway. This study was aimed to investigate the potential neuroprotective effect of TSG in 1-methyl-4-phenyl-1,2,3,6-tetrahydropypridine (MPTP)-treated mouse model of Parkinson's disease (PD). We found that treatment of TSG protected dopaminergic neurons by preventing MPTP-induced decreases in substantia nigra tyrosine hydroxylase (TH)-positive cells and striatal dopaminergic transporter (DAT) protein levels. Furthermore, it was also associated with increasing striatal Akt and GSK3β phosphorylation, up-regulation of the Bcl-2/BAD ratio, and inhibition of the activation of caspase-9 and caspase-3. These results showed that TSG promoted dopamine neuron survival in vivo, the PI3K/Akt signaling pathway may have mediated the protection of TSG against MPTP, suggesting that TSG treatment might represent a neuroprotective treatment for PD.     

Furazolidone induces apoptosis through activating reactive oxygen species-dependent mitochondrial signaling pathway and suppressing PI3K/Akt signaling pathway in HepG2 cells

Furazolidone (FZD), a synthetic nitrofuran with a broad spectrum of antimicrobial activities, has been shown to be genotoxic and potentially carcinogenic in several types of cells. However, the proper molecular mechanisms of FZD toxicity remain unclear. This study was aimed to explore the effect of FZD on apoptosis in HepG2 cells and uncover signaling pathway underlying the cytotoxicity of FZD. The results showed that FZD induced apoptosis in HepG2 cells in a dose-dependent manner characterized by nuclei morphology changes, cell membrane phosphatidylserine translocation, poly (ADP-ribose) polymerase (PARP) cleavage and a cascade activation of caspase-9 and -3. FZD could enhance reactive oxygen species (ROS) generation, up-regulate Bax/Bcl-2 ratio, disrupt mitochondrial membrane potential (MMP) and subsequently cause cytochrome c release. Both ROS scavenger (N-acetyl cysteine, NAC) and caspase inhibitors suppressed FZD-induced apoptosis. Furthermore, NAC attenuated FZD-induced ROS generation and mitochondrial dysfunction. Meanwhile, FZD treatment inhibited both the activation and expression of Akt, and PI3K/Akt inhibitor LY294002 promoted FZD-induced apoptosis. On the contrary, PI3K/Akt activator insulin-like growth factor-1 (IGF-1) attenuated lethality of FZD in HepG2 cells. In conclusion, it is first demonstrated that FZD-induced apoptosis in HepG2 cells might be mediated through ROS-dependent mitochondrial signaling pathway and involves PI3K/Akt signaling.     

PI3K/Akt信号通路在小檗碱联合人参皂苷Rg3诱导鼻咽癌细胞凋亡中的调控作用

目的研究PI3K/Akt信号通路在小檗碱联合人参皂苷Rg3诱导鼻咽癌细胞凋亡中的作用。方法RTCA法检测小檗碱联合人参皂苷Rg3对鼻咽癌CNE2、6-10B细胞增殖的影响;Hoechst 33342染色法、荧光双染流式细胞仪检测药物对CNE2细胞凋亡的影响;Western blot法检测PI3K/Akt信号通路关键蛋白及凋亡相关蛋白表达的变化。结果小檗碱联合人参皂苷Rg3可抑制鼻咽癌CNE2、6-10B细胞的增殖,诱导CNE2细胞的凋亡。与单独用药组相比,联合用药组细胞的PI3K/Akt信号通路关键蛋白PI3K p110α和p-Akt的表达明显下调(P<0.05)。加入PI3K/Akt信号通路的激活剂SC79后,小檗碱联合人参皂苷Rg3抑制CNE2细胞增殖和诱导细胞凋亡的效应降低,p-Akt、Survivin、PCNA及Bcl-2表达量增加,Bax的表达下降。结论小檗碱联合人参皂苷Rg3可通过PI3K/Akt信号通路发挥抑制鼻咽癌细胞增殖和诱导细胞凋亡的作用。     

基于PI3K-Akt信号通路研究罗哌卡因对肺癌细胞A549细胞生物学功能的影响

目的 探讨罗哌卡因(Ropivacaine)通过磷脂酰肌醇-3激酶(Phospoinositide 3-kinase,PI3K)/蛋白激酶B(Protein kinase B,Akt)信号通路影响肺癌细胞A549增殖、迁移、侵袭和凋亡.方法 采用细胞计数试剂盒8(CCK-8)法检测(0、100、200和400 μg/m...     

Naphtho[1,2-b]furan-4,5-dione disrupts Janus kinase-2 and induces apoptosis in breast cancer MDA-MB-231 cells

Naphtho[1,2-b]furan-4,5-dione (NFD), prepared from 2-hydroxy-1,4-naphthoquinone and chloroacetaldehyde in an efficient one-pot reaction, exhibits an anti-carcinogenic effect. NFD-induced apoptosis in MDA-MB-231 cells, as indicated by the accumulation of sub-G1 population, externalization of phosphatidylserine, loss of mitochondrial membrane potential (ΔΨm) with subsequent release of cytochrome c, and activation of both capase-9 and caspase-3. This correlated with up-regulation in Bax and Bad, and down-regulation of various anti-apoptotic proteins, including Bcl-2, Bcl-X_L, Mcl-1, and survivin in NFD-treated cells. In the analysis of signal transduction pathway, NFD suppressed the phosphorylation of JAK2 in MDA-MB-231 cells without altering the expression of JAK2 protein. Activation of STAT3, Src, and PI3K/Akt were also inhibited by NFD. Moreover, the JAK2 inhibitor AG490 blocked JAK2, STAT3, Src, PI3K, and Akt activation, whereas both Src inhibitor PP2 and PI3K inhibitor wortmannin did not affect JAK2 activation. This suggests that STAT3, Src, and PI3K/Akt are downstream molecules of the JAK2 signaling pathway. AG490 treatment also mimics the cytotoxic effects of NFD. Taken together, these results indicate that NFD disrupts JAK2 pathway and induces apoptosis in MDA-MB-231 cells.     

阿魏酸钠对抗谷氨酸诱导的鼠皮层神经元凋亡作用的影响

目的探讨MEK/ERK信号转导通路是否参与了阿魏酸钠(SF)对抗谷氨酸诱导的鼠皮层神经元凋亡作用。方法以谷氨酸诱导大鼠皮层神经元凋亡为模型。采用Westernblot观察Bcl-2、caspase-3、磷酸化ERK1/2表达的改变。结果阿魏酸钠能够显著降低谷氨酸诱导的神经细胞caspase-3的表达,提高Bcl-2、磷酸化ERK1/2的表达。PD98059可以减弱SF的保护作用。结论 MEK/ERK1/2通路参与阿魏酸钠对抗谷氨酸诱导的鼠皮层神经元凋亡。     

丹酚酸 A对脂多糖诱导人肾小球系膜细胞凋亡的作用机制研究

目的探究丹酚酸 A对脂多糖(lipopolysaccharide,LPS)诱导人肾小球系膜细胞凋亡的作用机制。方法该研究起止时间为 2018年 5月至 2019年 5月。购买华拓生物生产的 HGMC人肾小球系膜细胞,分为 A组、 B组、 C组、 D组、 E组五组, A组细胞不添加任何药物, B组、 C组、 D组、 E组细胞均加入 10 mg/L LPS培养, 1h后 C组、 D组、 E组分别加入低剂量丹酚酸 A(10 mg/L)、中剂量丹酚酸 A(20 mg/L)、高剂量丹酚酸 A(40 mg/L)处理 24 h后做后续试验。检测细胞增殖、凋亡、细胞周期分布以及磷脂酰肌醇 3激酶(PI3K)/蛋白激酶 B(protein kinase,AKT)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路指标表达量。结果与 A组相比, B组细胞凋亡率、 G0/G1期细胞分布率降低, S期、 G2/M期细胞分布率升高;与 B组相比, C组、 D组、 E组 G0/G1期细胞分布率、细胞凋亡率升高, S期、 G2/M期细胞分布率降低;与 C组相比, D组、 E组细胞凋亡率、 G0/G1期细胞分布率升高, S期、 G2/M期细胞分布率降低(均 P<0.05);与 D组相比, E组细胞凋亡率(37.59±4.62)%、G0/G1期细胞分布率(86.95±11.62)%升高, S期、 G2/M期细胞分布率分别为