Apoptosis of implanted tumor of human primary gastric cancer cells in nude mice induced by resveratrol

AIM: To investigate the molecular mechanism of the apoptosis of implanted tumor of human primary gastric cancer cells in nude mice induced by resveratrol. METHODS: Human primary gastric cancer cells were planted into nude mice to establish the cancer model. Resveratrol at different doses were injected near the carcinoma on the nude mice. After treatment, transmission electron microscope and TUNEL staining method were used to detect the apoptosis of implanted tumor cells. Immunohistochemical staining and RT-PCR were used to detect the expression of apoptosis-related genes bcl-2 and bax in implanted tumor. RESULTS: Resveratrol significantly inhibited carcinoma growth when it was injected near the carcinoma. The apoptotic cells in implanted tumor induced by resveratrol were detected by transmission electron microscope and TUNEL staining, immunohistochemical staining and RT-PCR showed resveratrol inhibited bcl-2 expression and increased bax expression in human primary gastric cancer cells. CONCLUSION: Resveratrol inhibits implanted tumor of human primary gastric cancer cells in nude mice through inducing apoptosis. This apoptosis may be mediated by down-regulation of bcl-2 expression and up-regulation of bax expression.     

Role of bcl-2 gene expression in inhabition of hepatocellular carcinoma by genistein in nude mice

AIM:To probe into the role of 1, 4, 5 - trisphosphate inositol (IP3) and bcl-2 gene expression in inhibiting hepatocellular carcinoma of nude mice by genistein. METHODS:Animals with hepatocellular carcinoma were treated with genistein 1 mg·kg-1·d-1 (ip) for 3 weeks. The volume and weight of tumaor were measured. IP3, bcl-2 mRNA, Bcl-2 protein were assayed by IP3-［3H］ Birtrak assay, RT-PCR, Western blotting, respectively. RESULTS:The tumor volume and weight of animals treated with genistein were lower than those in control (42.7mm3±27.8mm3 vs 52.3mm3±26.5mm3, 42.7mg±27.8 mg vs 91.3mg±31.4 mg). IP3 content was lower than that in control ［(13.4±1.4)nmol/g protein vs (35.3±6.6)nmol/g protein］. bcl-2 mRNA expression was lower in group treated with genistein than that in control (RI which was the gray degree multiply area of bcl-2 / the gray degree multiply area of β-actin 0.48±0.02 vs 0.56±0.15). Bcl-2 protein expression was lower in group treated with genistein than that in control (RI 1.69±0.52 vs 1.37±0.48). CONCLUSION:Genistein inhibits growth of transplanted hepatocellular carcinoma in nude mouse liver by reducing IP3 production and down-regulating bcl-2 gene expression.     

Resveratrol induces apoptosis in human primary gastric carcinoma cells

AIM: To investigate the apoptosis in primary gastric cancer cells induced by resveratrol, and the relation between this apoptosis and expression of bcl-2 and bax. METHODS: In in vitro experiments, MTT assay was used to determine the cell growth inhibitory rate. Transmission electron microscopy and TUNEL staining were used to quantitatively and qualitively detect the apoptosis of primary gastric cancer cells before and after the resveratrol treatment. Immunohistochemical staining and RT-PCR was used to detect the expression of apoptosis-regulated gene bcl-2 and bax. RESULTS: Resveratrol inhibited the growth of primary gastric cancer cells in a dose- and time-dependent manner. Resveratrol induced primary gastric cancer cells to undergo apoptosis with typically apoptotic characteristics. TUNEL assay showed that after the treatment of primary gastric cancer cells with resveratrol for 24, 48, 72, 96 hours, the apoptotic indexs were 4.93%±0.19%, 16.74%±0.43%, 27.88%±0.36%, 36.84%±1.07% respectively. Immunohistochemical staining showed that after the treatment of primary gastric cancer cells with resveratrol for 24, 48, 72, 96 hours, the positive rates of Bcl-2 proteins were 20.68%±0.49%, 10.84%±0.33%, 6.80%±0.34%, 3.91%±0.15% and the positive rates of Bax proteins were 19.79%±0.98%, 30.74%±0.85%, 40.14%±1.17%, 60.08%±1.64%. After exposed to resveratrol for 24 h, 48 h, 72 h and 96 h, the density of bcl-2 mRNA decreased progressively with elongation of time and the density of bax mRNA increased progressively with elongation of time by RT-PCR. CONCLUSION: Resveratrol is able to induce the apoptosis in primary gastric cancer. This apoptosis may be mediated by down-regulation of Bcl-2 and up-regulation of Bax.     

蜜环菌多糖对大鼠INS-1细胞凋亡的拮抗作用

培养大鼠胰岛素瘤细胞(INS-1),以四氧嘧啶损伤细胞,培养液中加入不同浓度的AMP-1,MTT法测定细胞存活率,PI荧光染色观测凋亡细胞密度,流式细胞术法检测细胞凋亡率,Western blot法检测蛋白bcl-2和bax的表达。结果表明,AMP-1浓度在50 mg·L~(-1)至500 mg·L~(-1)之间,均可提高受四氧嘧啶损伤的INS-1细胞的存活率,其中浓度为400 mg·L~(-1)时存活率最高;凋亡细胞密度,随AMP-1浓度的增大而降低;AXN+AMP-1组INS-1细胞凋亡率均低于四氧嘧啶组;Western blot法检测显示bcl-2蛋白表达量升高,bax蛋白表达量降低。AMP-1对四氧嘧啶诱导大鼠INS-1细胞凋亡具有明显的拮抗作用,其作用机制可能是通过对线粒体途径中bcl-2和bax蛋白表达的调控而抑制了细胞的凋亡。     

C-reactive protein induces apoptosis in human renal tubular epithelial cells

ATM: To explore whether the C-reactive protein (CRP) level in microinflammation state induces the apoptosis of renal tubular epithelial cells. METHODS: HK-2 cells were stimulated with recombinant human CRP. Annexin-FITC-PI staining and flow cytometry were used to detect the percentage of apoptotic cells. Morphology observation of apoptosis was assessed by Hoechst 33258 staining. Caspase-3 activity was measured by a colorimetric assay. The expression of apoptotic gene bax and anti-apoptotic gene bcl-2 at mRNA levels was determined by real-time PCR. RESULTS: CRP induced apoptosis of HK-2 cells in a time- and dose-dependent manner. The maximal apoptotic effect of CRP concentration was 10 mg/L CRP at concentration of 20 mg/L. CRP treatment was associated with the characteristic morphological features of apoptosis such as condensation, fragmentation or margination of nuclear chromatin. CRP exposure increased caspase-3 activity, up-regulated the mRNA expression of Bax and down-regulated the mRNA expression of Bcl-2. CONCLUSION: Slightly increased CRP level has the potential to induce apoptosis of renal tubular cells.     

Effect of fucoidan on inhibition of proliferation and induction of apoptosis in human breast carcinoma cell line MCF-7

AIM: To investigate the effects and related mechanism of fucoidan on the proliferation and apoptosis in breast carcinoma cell line MCF-7. METHODS: MCF-7 cells were treated with different concentrations of fucoidan (100 mg/L, 300 mg/L, 500 mg/L, 1 000 mg/L) for 48 h. Cell viability was measured by MTT assay. Apoptosis morphological and biochemical changes were detected by Hoechst 33258 staining and agarose gel electrophoresis. The expression of 〖STBX〗bcl-2〖STBZ〗 and bax was examined by RT-PCR and Western blotting. RESULTS: Fucoidan at different concentrations (100 mg/L, 300 mg/L, 500 mg/L, 1 000 mg/L) effectively inhibited the proliferation of MCF-7 cells (P<0.01). The inhibitory ratio and apoptosis rate increased in a concentration-dependent manner. Agarose gel electrophoresis of DNA revealed the characteristic “ladder” pattern of apoptosis. Fucoidan down-regulated the expression of 〖STBX〗bcl-2〖STBZ〗 and up-regulated bax in the levels of mRNA and protein. The ratio of Bcl-2 to Bax decreased as the concentrations of fucoidan increased (P<0.05). CONCLUSION: Fucoidan inhibits the cell proliferation by inducing cell apoptosis, and the apoptosis is related to the down-regulation of anti-apoptotic protein Bcl-2 and up-regulation of apoptotic protein Bax.     

Effects of tetrahydroxystilbene-2-O-β-D-glucoside on apoptosis and expression of bcl-2/bax/caspase-3 in HUVECs treated with homocysteine

AIM：To explore the effects of tetrahydroxystilbene-2-O-β-D-glucoside (TSG) from Polygonum multiflorum on the apoptosis and the mRNA expression of bcl-2, bax and caspase-3 in human umbilical vein endothelial cells (HUVECs) treated with homocysteine (Hcy). METHODS：Cultured HUVECs were treated with Hcy (3 mmol/L) to establish a Hcy-damaged model. HUVECs in TSG treated groups were pre-incubated with TSG at concentrations of 1 μmol/L and 10 μmol/L for 2 h before treated with Hcy. Cell nuclear damage was detected by Hoechst 33342 staining. Cell apoptosis was determined by flow cytometry. The mRNA expression of bcl-2, bax and caspase-3 was measured by real-time fluorescence quantitative RT-PCR. RESULTS： After treatment with Hcy at concentration of 3 mmol/L, the nuclear damage and apoptotic rate of HUVECs were higher than that in normal group. The expression of bcl-2 was lower, and the expression of Bax and caspase-3 was higher than that in normal group. On the other hand, pre-incubation with TSG at concentrations of 1 μmol/L and 10 μmol/L decreased the nuclear damage and cell apoptosis, increased the expression of bcl-2, and decreased the expression of bax and caspase-3 as compared with the cells only treated with Hcy. CONCLUSION：TSG reduces the apoptosis of HUVECs induced by Hcy, and the mechanism might be associated with regulating the expression of bcl-2, bax and caspase-3.     

Effect of epigallocatechin gallate on cardiomyocyte apoptosis induced by ischemia-reperfusion in rats

AIM: To observe the effects of epigallocatechin gallate (EGCG) on cardiomyocyte apoptosis induced by ischemia-reperfusion (IR) in rats. METHODS: The left anterior descending branch of coronary artery was ligated for 30 min and reperfused for 60 min to make a the myocardial ischemia-reperfusion model in rats. The experiment was divided into five groups: sham, ischemia/reperfusion (IR), EGCG (10 mg/kg and 20 mg/kg) and salvia miltiorrhizae (SM, 100 mg/kg) group. The apoptotic cardiomyocytes were detected by in situ end labeling method, and the expressions of Bcl-2 and Bax were shown through immunohistochemistry method. RESULTS: There was no apoptosis myocardial cell in sham operation group. The apoptosis index and expression of bax significantly increased, and bcl-2/bax reduced in IR group (P<0.01). In EGCG-treated group, however, the changes above were obviously alleviated (P<0.01). CONCLUSION: EGCG significantly inhibits cardiomyocyte apoptosis in ischemia-reperfusion rat hearts. The possible mechanism is to raise the ratio of Bcl-2/Bax proteins by increasing in the expression of bcl-2 gene and decreasing in the expression of bax gene.     

Effects of lentivirus-mediated caspase-3 silencing on proliferation and apoptosis of rat bone marrow mesenchymal stem cells

AIM：To investigate the effects of caspase-3 gene silencing on proliferation, cell cycle and apoptosis of rat bone marrow mesenchymal stem cells (MSCs). METHODS：A lentiviral vector expressing caspase-3 shRNA was constructed and transfected into rat bone marrow MSCs．The expression of caspase-3 at mRNA and protein levels was detected by real-time PCR and Western blotting, respectively. Cell proliferation and cell cycle were evaluated by MTS assay and flow cytometry, respectively. The expression of bcl-2 and bax mRNA was detected by real-time PCR. The apoptosis of the cells was evaluated by Hoechst 33258 staining. RESULTS：Recombinant lentivirus was successfully transfected into MSCs. The proliferation of the MSCs transfected with caspase-3 shRNA was significantly promoted (P<0.05) and the proportion of the cells in S phase was increased to (52.66±0.30) %. Compared with control groups, caspase-3 silencing up-regulated the mRNA level of bcl-2 and down-regulated the mRNA level of bax, and the ratio of bcl-2 to bax increased (P<0.05). The apoptotic rate in MSCs-shRNA group was (15.01±1.73) %, which was significantly lower than those in MSCs and MSCs-vector group ［(23.67±1.16) % and (25.67±3.05) %, respectively; P<0.05］. CONCLUSION: Caspase-3 silencing regulates cell cycle, promotes the proliferation and attenuates the apoptosis of rat bone marrow MSCs.     

Growth-inhibitory effects of selective cyclooxygenase-2 inhibitor on colon cancer cells and its possible mechanisms

AIM: To evaluate the growth-inhibitory effects of NS-398, a selective cyclooxygenase-2 inhibitor, in human colon cancer HT-29 cells and its possible mechanisms. METHODS: MTT assay was applied to detect the cell proliferation. Flow cytometry was performed to detect apoptosis rate and cell cycle. RT-PCR was used to detect the expression of bcl-2 mRNA and bax mRNA. Alteration of cytoskeleton component F-actin was observed by confocal laser scanning microscope. RESULTS: NS-398 could inhibit growth of HT-29 cells in dose-and time-dependent manners. Flow cytometry revealed that NS-398 could induce apoptosis and cause G0/G1 arrest of HT-29 cells in a dose-dependent manner. After 72 h incubation with NS-398 at different concentrations, the expression level of bcl-2 mRNA was lowered and the ratio of bcl-2 to bax was decreased in HT-29 cells. F-actin was mainly distributed around nuclei forming annular structure in HT-29 cells. After exposure to NS-398, the annular structure around nuclei disappeared and fluorescence intensity of F-actin decreased obviously. CONCLUSION: NS-398 can inhibit the growth effectively and induce apoptosis in HT-29 cells in vitro, which is associated with the down-regulation of bcl-2 to bax ratio and the disruption of cytoskeleton.     

Effects of genistein on proliferation,apoptosis and invasiveness in methotrexate-resistant human choriocarcinoma JAR/MTX cells and it s mechanism

AIM:To study the effects of genistein on JAR/MTX cell proliferation, apoptosis and invasion and it's mechanism in vitro. METHODS:MTT assay, Annexin-Ⅴ and propidium iodide label analysis and invasion assay were used to determine the effects of genistein on proliferation, apoptosis and invasiveness in JAR/MTX methotrexate- resistant human choriocarcinoma cells. RT-PCR was used to estimate the relative mRNA amounts of estrogen receptor(ER), MTA3 and snail in the cells. Western blotting and gelatin zymography assay were used to estimate the relative protein amounts of MMP-2, MMP-9 and E-cadherin in the cells. RESULTS:After treatment of genistein, the proliferation and invasiveness of JAR/MTX cells were decreased significantly in a dose-dependent manner. 10 μmol/L genistein induced apoptosis, whereas 25, 50, 100 μmol/L genistein induced apoptosis and necrosis significantly. Genistein led to an increase in ERβ, MTA3 mRNA and E-cadherin protein expression, and decreases in the amounts for snail mRNA and MMP-2 and MMP-9 protein expression of JAR/MTX cells. CONCLUSIONS:Genistein inhibits the cell proliferation by inducing cell apoptosis and necrosis. Genistein also may inhibit JAR/MTX cell invasion in part through the upregulation of E-cadherin and downregulation of MMP-2 and MMP-9. The signal transduction pathway of invasion suppression induced by genistein in JAR/MTX cells may be as follows: MTA3→snail→ E-cadherin.     

Cytochrome C induces apoptosis in HL-60 cells through inhibiting bcl-2,bcl-xl mRNA expression

AIM:To study the effect of cytochrome C on HL-60 cells in vitro and the expression of relevant apoptotic genes.METHODS:HL-60 cells were treated with different concentrations of cytochrome C for 24 h.The suppressing rate was assayed by MTT.The morphology of cell was observed by microscope and fluorescence microscope.The apoptosis was assayed by flow cytometry (FCM) and DNA electrophoresis.The expression changes of bcl-2 and bcl-xl mRNA was examined by RT-PCR.RESULTS:The suppressing rate increased with the increase in the cytochrome C concentrations.When treated with 0-37.5 mg/L cytochrome C for 24 h,the percentage of apoptotic HL-60 cells increased in a dose-dependent manner,and the typical cells and the appearance of apoptotic DNA ladder were observed.At the same time,within this range of concentration,the expression of bcl-2 and bcl-xl mRNA decreased gradually.When treated with cytochrome C at concentration higher than 37.5 mg/L,the percentage of apoptotic HL-60 cells did not increase,but decreased,while the cell necrosis was observed.CONCLUSIONS:It suggested from the results that at certain range of concentration,cytochrome C induces apoptosis or necrosis in HL-60 cells.The percentage of apoptosis,the changes of expression of bcl-2 and bcl-xl depend on the dose of cytochrome C.The mechanism that cytochrome C induces apoptosis in HL-60 cells may be related to suppressing the expression of bcl-2 and bcl-xl.     

Effect of shock lymph on apoptosis relative gene expression in pulmonary micro-vascular endothelial cells

AIM:To observe the effects of shock lymph on apoptosis relative gene expressions of pulmonary micro-vascular endothelial cells (PMVECs), and explore its mechanism.METHODS:The model of severe hemorrhagic shock was established by maintaining the blood pressure of rats in the condition of sepsis, mesentery lymph and shock portal vein blood was taken out. As control, mesentery lymph, portal vein blood of normal rats was taken out. The primary PMVECs of passages 3 were treated by different treatment factors, respectively. The apoptosis rate was analyzed by flow cytometry, and the expressions of relative genes of apoptosis such as fas, fas L, bcl-2 and bax were detected by RT-PCR. RESULTS:The apoptosis rate of PMVECs was 9.86%±3.24% after exposed to shock lymph at the final concentration of 4% for 4 hours and significantly higher than that in control (P<0.01). The expression levels of fas, fas L and bax mRNA were higher and bcl-2 mRNA was lower in shock lymph group than those in control group.CONCLUSION:The results demonstrated that the apoptosis of PMVECs of rats was induced by shock lymph, and its mechanism relate to high expression of apoptosis accelerative genes such as fas, fas L, bax mRNA and low expression of apoptosis inhibitory gene bcl-2.     

Effect of L-arginine on expression of bcl-2 and bax mRNA in pulmonary injury induced by ischemia-reperfusion in rabbits

AIM:To investigate the effect of L-arginine (L-Arg) on expression of bcl-2, bax mRNA during pulmonary ischemia and reperfusion injury (PIRI) in rabbits.METHODS:Single lung ischemia and reperfusion animal model was used in vivo. The rabbits were randomly divided into three groups: sham operated group (sham, n=12), ischemia-reperfusion group (I/R, n=12) and I/R+ L-arginine group (L-Arg, n=12). Changes of several parameters, which included apoptotic index (AI), wet to dry ratio of lung tissue weight (W/D) and index of quantitative assessment of histologic lung injury (IQA), were measured at 300 min after reperfusion in lung tissue. Meanwhile the location and expression of bcl-2, bax mRNA as well as the ratio of bcl-2 mRNA/bax mRNA were observed. The lung tissue was prepared for light microscopic and electron microscopic observation at 60, 180 and 300 min after reperfusion. RESULTS:As compared with I/R group, in intima and extima of small pulmonary artery, alveoli, and bronchiole epithelia, the expression of bcl-2 mRNA and the ratio of bcl-2 mRNA/bax mRNA were increased, and the expression of bax mRNA was decreased in L-Arg treatment group. The values of AI, W/D and IQA showed significantly lower than that in I/R group at 180 minutes after reperfusion in lung tissue (P<0.01 and P<0.05). Meanwhile, abnormal changes of the lung tissue in morphologically were markedly lessened in L-Arg treatment group.CONCLUSION:L-arginine produces a notable protective effect on PIRI in rabbits by up-regulating bcl-2 mRNA expression, down-regulating bax mRNA expression in lung tissue and regulating the balance of bcl-2 mRNA and bax mRNA to decrease apoptosis.     

Up-regulation of mRNA expressions of fas,bcl-2, bim,bax, caspase-3, caspase-9, and bcl2l12 in K562 treated with bortezomib

AIM: To detect the treatment of K562 leukemia cells with bortezomib altering the expression of genes fas, bcl-2, bcl2l12, bim, bax, caspase-9 and caspase-3.METHODS: MTT assay was used to detect the inhibition of proliferation. Apoptosis was detected by Annexin-V staining and mitochondrial transmembrane potential (Δψm). RT-PCR was used to analyze the mRNA expressions of fas, bcl-2, bcl2l12, bim, bax, caspase-3 and caspase-9.RESULTS: Bortezomib caused a time- and dose-dependent inhibition of cell proliferation and IC50 of 24 h and 48 h were 161.41 nmol/L and 96.33 nmol/L, respectively. At the concentration of 104 nmol/L, bortezomib induced apoptosis in a time-dependent manner, including increasing annexin-V positivity and decreasing the Δψm. RT-PCR showed that bortezomib up-regulated the mRNA expression of fas, bcl2l12, caspase-9 and caspase-3, but mRNA expressions of bcl-2, bim and bax did not changed obviously.CONCLUSION: Bortezomib inhibits the proliferation of K562 and induces apoptosis, in which fas, bcl2l12, caspase-9 or caspase-3 gene is one of the main genes taking part in.     

Effect of sodium ferulate on bcl-2 and bax gene expression of apoptotic hippocampal neurons induced by sodium ferulate

AIM: To investigate the protective effects of sodium ferulate (SF) on apoptosis in cultured hippocampal neurons induced by sodium nitroprusside (SNP), and the effect of SF on expression of bcl-2 and bax. METHODS: The primary cultured hippocampal neurons were exposed to 50 μmol SNP, a nitric oxide-donor, for 24 h after pretreatment with different concentrations of SF (10-160 μmol/mL) for 6 h. Then neuronal viability was tested by MTT assay. Fluorescent staining with Hoechst 33258 and agarose gel electrophoresis was used to analyze apoptosis. The expressions of bcl-2, bax mRNA and protein were tested by RT-PCR and Western blotting. RESULTS: Pretreatment with SF(10-160 μmol/L) for 6 h increased the survival rate of neurons. SF prevented the neuronal nuclei from shrinkage, condensation and cleavage and blocked neuronal nuclear DNA fragmentation induced by SNP. SF also increased the expressions of bcl-2 mRNA and Bcl-2 protein and decreased the expressions of bax mRNA and Bax protein. CONCLUSION: SF prevents the cultured hippocampal neurons against SNP neurotoxicity. The mechanism of protection is related to the increase in Bcl-2 level and the decrease in Bax level. As a result, the ratio of Bcl-2/Bax is changed.     

Inhibitory effect of geinistein on apoptosis in hUVECs induced by MCP-1

AIM: To study the inhibitory effect of genistein on apoptosis in human umbilical vein endothelial cells (hUVECs) induced by monocyte chemotactic protein-1 (MCP-1). METHODS: The hUVECs were cultured in vitro and identified. Growth-arrested hUVECs were stimulated with genistein at different concentrations (0.1 μmol, 1.0 μmol, 10 μmol, 100 μmol) and co-treated with MCP-1 (10 μg/L). The survival rates of hUVECs were detected by MTT assay. The cell cycle and DNA content were detected by flow cytometry. To explore the possible mechanism of the genistein interventions, the expressions of Bcl-2, Fas and Bax proteins were detected by flow cytometry and Western blotting.RESULTS: Genistein increased the survival rate and the level of Bcl-2, inhibited Fas and Bax, decreased the ratios of apoptosis compared with MCP-1-induced hUVECs apoptotic group in a dose-dependent-manner. CONCLUSION: Genistein inhibits the apoptosis induced by MCP-1 and the inhibitory effect was relative to the dose of genistein. Its mechanism might be involved in the down-regulation of Fas and Bax expressions and the up-regulation of Bcl-2.     

Therapeutic effect of neuregulin-1β on pressure overload-induced myocardial hypertrophy in rats

AIM：To investigate the therapeutic effect and the mechanism of neuregulin-1β (NRG-1β) on the rat model of myocardial hypertrophy induced by pressure overload．METHODS：Eight weeks after coarctation of abdominal aorta, the Wistar rats were randomly divided into 4 groups: myocardial hypertrophy (model) group, sham operation (sham) group, NRG-1β treatment group (intravenous injection of NRG-1β at dose of 10 μg/kg daily for 7 d) and NRG-1β+Herceptin (HERCE) treatment group ［intravenous injection of NRG-1β (10 μg/kg) plus HERCE (10 μg/kg) daily for 7 d］. The characteristics of heart functions were evaluated by the methods of hemodynamics and echocardiography. Masson staining was employed to observe the pathological changes of myocardial tissues. The concentration of angiotensin II (Ang II) in myocardial tissues was measured by radioimmunoassay. The level of tumor necrosis factor α (TNF-α) in myocardial tissues was detected by ELISA. The mRNA expression of B-cell lymphoma/leukemia-2 (bcl-2) and bcl-2-associated X protein (bax) in the myocardium was determined by RT-PCR. RESULTS：The left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were higher, while the left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD) were smaller in NRG-1β group than those in model group. The left ventricular end-systolic pressure (LVESP) and maximal rate of increase/decrease in left ventricular pressure (±dp/dtmax) were higher, and left ventricular end-diastolic pressure (LVEDP) was significantly lower in NRG-1β group than those in model group. Compared with model group, treatment with NRG-1β decreased collagen volume fraction (CVF), reduced the Ang II and TNF-α, increased bcl-2 mRNA expression, and decreased bax mRNA expression in myocardial tissues. No difference of the above parameters between model group and NRG-1β+HERCE treatment group was observed. CONCLUSION：NRG-1 reduces the expression of Ang II and TNF-α in myocardial tissues in pressure-overload rats, thus reducing Ang II and TNF-α mediated myocardial interstitial remodeling. Increase in the mRNA expression of bcl-2 and decrease in the mRNA expression of bax by NRG-1 inhibit myocardial cell apoptosis, which is responsible for its role of improving cardiac function of myocardial hypertrophy induced by pressure overload.     

Effect of puerarin on myocardial injury in KKAy diabetic mice

AIM:To observe the effect of puerarin on myocardial injury according to the time of occurrence of myocardial injury in the development of type 2 diabetic mice. METHODS: The serum levels of glucose (GLU), triglyceride (TG), total cholesterin (TC), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) in 17-week, 20-week, 24-week, 28-week KKAy mice were detected by automatic biochemical methods. The apoptotic percentage of cardiomyocytes was examined by flow cytometry. The expressions of bax and bcl-2 mRNA in cardiomyocytes were detected by RT-PCR. Caspase-3 expression in cardiomyocytes was determined by immunohistochemical staining. RESULTS: Compared to normal control mice, not only GLU level increased, but also the levels of TG, TC, LDL-C, HDL-C in 20-week, 24-week and 28-week KKAy mice increased apparently (P<0.01). Apoptosis of cardiomyocytes in KKAy mice began to show up at 28-week. The expression of bax mRNA increased and expression of bcl-2 mRNA reduced. At the same time, the expression of caspase-3 increased. Puerarin obviously decreased the apoptotic percentage of cardiomyocytes, reduced the expression level of bax mRNA, improved the expression level of bcl-2 mRNA (P<0.01), inhibited the expression of caspase-3 (P<0.01). CONCLUSION:Myocardial injury exits in type 2 diabetic mice. Mitochondria apoptotic pathway might participate in the hurting course.     

NKX3.1 down-regulates bcl-2 gene expression in prostate cancer PC-3 cells

AIM: To investigate the effect of NKX3.1 on the gene expression of bcl-2 and apoptosis in prostate cancer PC-3 cells. METHODS: The eukaryotic expression plasmid pcDNA3.1- NKX3.1 was transiently transfected into PC-3 cells. RT-PCR and Western blotting were used to detect the effects of NKX3.1 on the expression of bcl-2 gene. Down-regulatory effect of NKX3.1 on bcl-2 gene was detected by EMSA. Flow cytometry and apoptotic body staining were carried out to study the effects of NKX3.1 on apoptosis of PC-3 cells. RESULTS: The mRNA and protein expression of bcl-2 in PC-3 cells was down-regulated by over-expression of NKX3.1. The EMSA result showed that NKX3.1 interacted with the NKX3.1 binding elements in upstream regulatory region of bcl-2 gene. The results of flow cytometry showed that the number of apoptotic PC-3 cells increased by 1.41-fold after NKX3.1 transfection to PC-3 cells. NKX3.1 increased the apoptotic bodies stained by Hoechst 33258 significantly. CONCLUSION: NKX3.1 down-regulates the expression of anti-apoptotic gene bcl-2 and induces the apoptosis of prostate cancer PC-3 cells.