Panax notogiseng saponin inhibits ischemia-induced apoptosis by activating PI3K/Akt signal pathway in cardiomyocytes

The panax notoginseng saponin(PNS) had been clinically used for the treatment of cardiovascular diseases and stroke in China.It had been demonstrated that PNS could protect cardiomyocytes from injury induced by ischemi- a,but the underlying molecular mechanisms of this protective effect were still unclear.This study was aimed to investigate the protective effect and molecular mechanisms of PNS on apoptosis in H9c2 cells in vitro and rat myocardial ischemia injury model in vivo.Annexin-V/PI assay shew that PNS could protect H9c2 cells from apoptosis induced by serum, glucose and oxygen deprivation(SGOD) in a dose-dependent manner.However,the anti-apoptotic effect of PNS was reversed by LY294002,a specific PI3K inhibitor.This antiapoptotic effect of PNS was confirmed by JC-1,a specific probe of mitochondrial membrane potential staining.PNS could significantly increase phos-Akt in H9c2 cells by Western blot assays and its effect could be inhibited by LY294002.Furthermore,PNS could improve ischemic-induced left ventricular function as reflected by EF,LVDd and LVDs.PNS could also inhibited cellular apoptosis in myocardial tissues in ischemic rats by TUNEL assay.PNS administration also increased the expression of phos-Akt in rat ischemic myocardial tissues.These results suggested that PNS could protect myocardial cells from apoptosis induced by ischemia in vitro model and in vivo model through activating-PI3K/Akt signal pathway which may be meaningful for further understanding the molecular mechanisms of cardiac protection of PNS.And the results might be useful in treatment of myocardial ischemia in future.

Kinetin Inhibits Proliferation of Hepatic Stellate Cells by Interrupting Cell Cycle and Induces Apoptosis by Down-regulating Ratio of Bcl-2/Bax

Liver fibrosis is an important health problem that can further progress into cirrhosis or liver cancer,and result in significant morbidity and mortality. Inhibiting proliferation and inducing apoptosis of hepatic stellate cells（HSCs） may be the key point to reverse liver fibrosis. At present,anti-fibrosis drugs are rare. Kinetin is a type of plant-derived cytokinin which has been reported to control differentiation and induce apoptosis of human cells. In this study,the HSCs were incubated with different concentrations of kinetin. The proliferation of rat HSCs was measured by MTT assay,cell cycle and apoptosis were analyzed by flow cytometry,and the apoptosis was examined by TUNEL method. The expression of Bcl-2 and Bax proteins was detected by immunocytochemistry staining. It was found that kinetin could markedly inhibit proliferation of HSCs. In a concentration range of 2 to 8 μg/m L,the inhibitory effects of kinetin on proliferation of HSCs were increased with the increased concentration and the extension of time（P〈0.01）. Flow cytometry indicated that kinetin could inhibit the DNA synthesis from G0/G1 to S phase in a dose-dependent manner（P〈0.01）. The apoptosis rates of the HSCs treated with 8,4 and 2 μg/m L kinetin（25.62%±2.21%,15.31%±1.9% and 6.18%±1.23%,respectively） were increased significantly compared with the control group（3.81%±0.93%）（P〈0.01）. All the DNA frequency histogram in kinetin-treated groups showed obvious hypodiploid peak（sub-G1 peak）,and with the increase of kinetin concentrations,the apoptosis rate of HSCs also showed a trend of increase. It was also found that kinetin could down-regulate the expression of Bcl-2,and up-regulate the expression of Bax,leading to the decreased ratio of Bcl-2/Bax significantly. The kinetin-induced apoptosis of HSCs was positively correlated with the expression of Bax,and negatively with the expression of Bcl-2. It was concluded that kinetin can inhibit activation and proliferation of HSCs by interrupting the cell cycle at G1/S restriction point and inducing apoptosis of HSCs via reducing the ratio of Bcl-2/Bax.

Inosine inhibits apoptosis and cytochrome C mRNA expression in rat neurons after cerebral ischemia/reperfusion

BACKGROUND: It has been demonstrated that adenosine can induce glial cell to release cytochrome C, enhance expression of apoptotic gene bax, inhibit anti-apoptotic gene bcl-2, and activate caspase-3 to apoptosis; Whereas inosine can inhibit neuronal apoptosis which is similar to bcl-2. OBJECTIVE: To observe the effects of inosine on neuronal apoptosis and expression of cytochrome C mRNA in rats after focal cerebral ischemia/reperfusion, and analyze the pathway of its neuroprotective effect. DESIGN: A randomised controlled animal trial. SETTINGS: Department of Neurology, Rongcheng Second People's Hospital; Department of Neurology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: Sixty-eight rats, weighing 230-280 g and clean grade, were used. TdT-mediated dUTP-biotin nick end labeling (TUNEL) and cytochrome C mRNA in situ hybridization kits and DAB staining kit were purchased from Wuhan Boster Biological Co., Ltd.; Inosine injection [200 mg (2 mL) each] from Qingdao First Pharmaceutical Factory. METHODS: The experiment was accomplished in the animal experimental center in Tongji Medical College of Huazhong University of Science and Technology from December 2003 to June 2005. ① Sixty-four rats were made into focal ischemia by middle cerebral artery occlusion (MCAO) with a nylon monofilament suture. The successfully induced rats were assigned to inosine group (n =32) and model group (n =32) at random. Rats in the inosine group were intraperitoneally administrated with inosine in dose of 100 mg/kg preoperatively, twice a day, 7 days in all. The rats in the control group were injected with the same dose of saline solution by the similar way preoperatively. Each group was randomized into ischemia /reperfusion 2, 6, 12, 24 hours, 2, 3, 7 and 14 days subgroups consisted of 4 rats. The other 4 rats were taken as the sham-operated group, the rats were given the same treatment except for not introduced the filament into the external carotid artery stump, and brain tissue was removed at 2 hours of reperfusion. ② In situ hybridization was performed to examine the expression of cytochrome C mRNA while TUNEL staining was made to characterize apoptosis. ③ The t test was used to compare the difference of measurement data. MAIN OUTCOME MEASURES: ① Neuronal apoptosis in the different regions of the ischemic brain tissue; ② Expression of cytochrome C mRNA in the different regions at different time points after MCAO. RESULTS: All the 68 rats were involved in the analysis of results. ① Neuronal apoptosis: A small number of TUNEL-positive cells were detected in the sham-operated brain and non-ischemic brain. The number of apoptotic cells in the ischemic cortex peaked at 24 hours of reperfusion [(72.00±1.98) cells] and that in the striatum peaked at 2 days [(94.75±3.57) cells], then decreased to the level of sham-operated group at 14 days. Inosine could reduce apoptotic cells from 12 hours to 7 days of reperfusion as compared with the model group (t =6.19-26.67, P < 0.01). ② Cytochrome C mRNA expression: There was weak expression of cytochrome C mRNA in both sham-operated brain and contralateral brain. Cytochrome C was detected at 2 hours of reperfusion in ischemic brain [(25.75±3.50), (39.75±2.49) cells], and strongly increased to a peak at 12 hours and 24 hours of reperfusion in cortex and striatum [(122.50±6.69), (119.25±5.12) cells], respectively. Furthermore, inosine could significantly decrease cytochrome C expression in cortex at 12 hours to 14 days of reperfusion after ischemic reperfusion and that in striatum at 12 hours to 3 days (t =8.67-43.26, P < 0.01). CONCLUSION: Inosine can exert a neuroprotective effect by inhibiting apoptosis and cytochrome C mRNA expression.

Knockdown of Bmi1 Inhibits Bladder Cancer Cell Growth Both In Vitro and In Vivo by Blocking Cell Cycle at G_1 Phase and Inducing Apoptosis

Bmi1 is a member of the polycomb group family of proteins,and it drives the carcinogenesis of various cancers and governs the self-renewal of multiple types of stem cells. However,its role in the initiation and progression of bladder cancer is not clearly known. The present study aimed to investigate the function of Bmi1 in the development of bladder cancer. Bmi1 expression was detected in human bladder cancer tissues and their adjacent normal tissues（n=10） by immunohistochemistry,q RT-PCR and Western blotting,respectively. Bmi1 small interference RNA（si RNA） was synthesized and transfected into human bladder carcinoma cells（EJ） by lipofectamine 2000. The Bmil expression at m RNA and protein levels was measured in EJ cells transfected with Bmil si RNA（0,80,160 nmol/L） by q RT-PCR and Western blotting,respectively. Cell viability and Ki67 expression（a marker of cell proliferation） were determined in Bmi1 si RNA-transfected cells by CCK-8 assay and q RT-PCR,respectively. Cell cycle of transfected cells was flow-cytometrically determined. Immunofluorescence and Western blotting were used to detect the expression levels of cell cycle-associated proteins cyclin D1 and cyclin E in the cells. Pro-apoptotic proteins Bax and caspase 3 and anti-apoptotic protein Bcl-2 were detected by Western blotting as well. Additionally,xenograft tumor models were established by inoculation of EJ cells（infected with Bmil sh RNA/p LKO.1 lentivirus or not） into nude mice. The tumor volumes were measured every other day for 14 days. The results showed that the Bmil expression was significantly increased in bladder tumor tissues when compared with that in normal tissues（P〈0.05）. Perturbation of Bmi1 expression by using si RNA could significantly inhibit the proliferation of EJ cells（P〈0.05）. Bmi1 si RNA-trasnfected EJ cells were accumulated in G1 phase and the expression levels of cyclin D1 and cyclin E were down-regulated. Bax and caspase-3 expression levels were significantly increased and Bcl-2 levels decreased after Bmi1 knockdown. Tumor volume was conspicuously reduced in mice injected with EJ cells with Bmi1 knockdown. Our findings indicate that Bmi1 is a potential driver oncogene of bladder cancer and it may become a potential treatment target for human bladder cancer.

A Novel Schiff Base Zinc Coordination Compound Inhibits Proliferation and Induces Apoptosis of Human Osteosarcoma Cells

Various kinds of schiff base metal complexes have been proven to induce apoptosis of tumor cells. However,it remains largely unknown whether schiff base zinc complexes induce apoptosis in human cancer cells. Here,we synthesized a novel schiff base zinc coordination compound（SBZCC） and investigated its effects on the growth,proliferation and apoptosis of human osteosarcoma MG-63 cells. A novel SBZCC was synthesized by chemical processes and used to treat MG-63 cells. The cell viability was determined by CCK-8 assay. The cell cycle progression,mitochondrial membrane potential and apoptotic cells were analyzed by flow cytometry. The apoptosis-related proteins levels were determined by immunoblotting. Treatment of MG-63 cells with SBZCC resulted in inhibition of cell proliferation and cell cycle arrest at G1 phase. Moreover,SBZCC significantly reduced the mitochondrial membrane potential and induced apoptosis,accompanied with increased Bax/Bcl-2 and Flas L/Fas expression as well as caspase-3/8/9 cleavage. Our results demonstrated that the synthesized novel SBZCC could inhibit the proliferation and induce apoptosis of MG-63 cells via activating both the mitochondrial and cell death receptor apoptosis pathways,suggesting that SBZCC is a promising agent for the development as anticancer drugs.

Total Triterpenoids from Ganoderma Lucidum Suppresses Prostate Cancer Cell Growth by Inducing Growth Arrest and Apoptosis

In this study,one immortalized human normal prostatic epithelial cell line（BPH） and four human prostate cancer cell lines（LNCa P,22Rv1,PC-3,and DU-145） were treated with Ganoderma Lucidum triterpenoids（GLT） at different doses and for different time periods. Cell viability,apoptosis,and cell cycle were analyzed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR and Western blotting. It was found that GLT dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. GLT-induced apoptosis was due to activation of Caspases-9 and-3 and turning on the downstream apoptotic events. GLT-induced cell cycle arrest（mainly G1 arrest） was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4（CDK4） and E2F1 expression at the late time. These findings demonstrate that GLT suppresses prostate cancer cell growth by inducing growth arrest and apoptosis,which might suggest that GLT or Ganoderma Lucidum could be used as a potential therapeutic drug for prostate cancer.

Pure Total Flavonoids from Citrus paradisi Macfad InduceLeukemia Cell Apoptosis In Vitro

Objective： To investigate the potential effect of pure total flavonoids from Citrus paradisi Macfad peel（PTFC） on the proliferation and apoptosis of human myeloid leukemia cells Kasumi-1, HL-60 and K562, and the underlying mechanisms. Methods： PTFC was extracted from Citrus paradisi Macfad peel and was identified by high performance liquid chromatography. The effect of PTFC on the proliferation and apoptosis of leukemia cells were determined by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide, fluorescent microscopy and flow cytometry, respectively. The effect of PTFC on the expression levels of apoptosis-related regulators was determined by Western blot assay. Results： Treatment with PTFC inhibited leukemia cell proliferation in a dose-and time-dependent manner and triggered Kasumi-1 cell apoptosis. Treatment with PTFC significantly increased the levels of activated poly adenosine diphosphate-ribosepolymerase and caspase-3/-9, but reduced the levels of Mcl-1 expression in Kasumi-1 cells. However, PTFC did not obviously induce HL-60 cell apoptosis. Conclusion： PTFC inhibited leukemia cell proliferation and induced their apoptosis by modulating apoptosisrelated regulator expression in leukemia cells in vitro.

Research Progress on Neuroprotective Effects of Salvianolic Acid B in an Animal Model of Parkinson's Disease

As an active ingredient extracted from Salvia miltiorrhiza,the neuroprotective effects of salvianolic acid B in Parkinson's disease include antioxidation,improvement of mitochondrial function,modulation of neuroinflammation,inhibition of apoptosis,promotion of neuronal differentiation and proliferation,and influence on intestinal flora.As an adjuvant drug,salbutamol B can be used in combination with conventional therapeutic drugs to enhance the efficacy and minimize the side effects,which provides a method and basis for the early diagnosis and treatment of Parkinson's disease in clinical practice.

Dodging the bullet: therapeutic resistance mechanisms in pediatric cancers

While advances in the treatment of pediatric cancers have improved survival to>80%across all tumor types,drug resistance continues to limit survival for a considerable number of patients.We review the known mechanisms of resistance in pediatric cancers,including processes that impair conventional chemotherapies,newer classes of targeted small molecule antineoplastic drugs,and monoclonal antibodies.We highlight similarities and differences in treatment approach and resistance between pediatric and adult cancers.We also discuss newer areas of research into drug resistance,including extracellular and immune factors.