Berberine inhibits enterocyte apoptosis in septic mice

AIM: To observe the effects of berberine (Ber) on enterocyte apoptosis in septic mice and its possible mechanism. METHODS: Male C57BL/6 mice (8~10 weeks old) were randomly divided into sham group, cecal ligation and puncture (CLP) group, CLP+Ber group and sham+Ber group. The mice in CLP group underwent CLP ope-ration, and the mice in sham groups suffered a similar operation except the ligation and puncture. After the sham or CLP operation, the mice were administered intragastrically with distilled water or berberine (50 mg/kg) within 2 h. After 20 h, the mice were killed with excess pentobarbital sodium and the ileum tissues were removed. The histological changes of the intestine were observed and the enterocyte apoptosis was examined by determining the protein level of cleaved caspase-3. Furthermore, mitochondrial Bax, cytoplasm cytochrome C (Cyt C) and the total proteins of Bcl-2, Fas, FasL and Fas-associated protein with death domain (FADD) were examined by Western blot. The mRNA expression of tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) was measured by real-time PCR. RESULTS: The extensive ileum injuries, including remarkably increased leukocytes and necrosis of intestinal villus were observed 20 h after CLP. In CLP group, the protein levels of cleaved caspase-3, cytoplasm Cyt C, as well as Fas, FasL were significantly increased, but the Bcl-2 level was decreased. Bax translocation into mitochondria was promoted. However, FADD was not changed significantly. The mRNA expression of TH and DBH was also increased sharply in CLP group. On the contrary, treatment with berberine made a considerable alleviating alteration in the ileum of the septic mice.CONCLUSION: Treatment with berberine provides protective effects on intestinal injury in septic mice by reducing enterocyte apoptosis, and its possible mechanism may be involved in the inhibition of the endogenous and exogenous apoptosis pathways.     

Effects of Le Er Mai on apoptosis of hippocampus neuronal cells in anaphase of cerebral ischemic reperfusion injury in rats

AIM: To investigate the effects and mechanism of Le Er Mai (LEM) on the apoptosis of hippocampus neuronal cells in the anaphase of cerebral ischemic reperfusion injury in rats.METHODS: A rat model of middle cerebral artery occlusion reperfusion (MCAO) was produced with the intraluminal filament. During reperfusion for 30 d after 2 h of ischemia, the TUNEL staining methods were used to detect apoptosis of hippocampus neuronal cells, and immunohistochemical technique were employed to examine the protein expression of Fas, Bax, caspase-3 and caspase-9 in the hippocampial. The gene expressions of fas, bax, caspase-3 and caspase-9 in hippocampial were examined by RT-PCR. RESULTS: After 2 h ischemia and 30 d reperfusion, compared with sham-operated group, TUNEL-positive staining cells and expression levels of Fas, Bax as well as caspase-3 and caspase-9 obviously increased, and the mRNA expressions of fas, bax, caspase-3 and caspase-9 in hippocampial markedly up-regulated in model group. Compared with model group, LEM at dose of 2.00 g/kg or 0.87 g/kg, and flunarizinum significantly reduced apoptosis and decreased the protein expressions of Fas, Bax, caspase-3 and caspase-9 in hippocampial, and down-regulated the mRNA expressions of fas, bax, caspase-3 and caspase-9 (P<0.05), those action of LEM in 0.87 g/kg dosage group was lower than those in 2.00 g/kg dosage group.CONCLUSION: LEM obviously lower the injury of hippocampial in the anaphase of cerebral ischemia reperfusion through inhibiting the apoptosis of hippocampus neuronal cells. The mechanism of LEM may be related to regulate the expression of signal transduction pathway correlated gene of apoptosis in neuronal cells.     

Expression of apoptosis signal protein induced by Fas in labial salivary gland of patients with primary Sjgren’s syndrome

AIM:To study the expression of apoptosis signal proteins induced by Fas in labial salivary gland of patients with primary Sjgren’s syndrome (pSS), and investigate the possible pathway of the cell signaling transduction in pSS. METHODS:Biopsies of minor submucosal labial salivary gland were obtained from 32 patients with pSS and 8 normal controls. Fas, FasL and FADD were detected by Western blotting. Caspase-3 was measured by immunohistochemistry and CAD mRNA expression was determined by RT-PCR. RESULTS:The expressions of Fas, FasL, FADD, caspase-3 and CAD mRNA in labial salivary glands of patients with pSS were significantly higher than those in control group (P＜0.05). CONCLUSION:The apoptosis signalling transduction in labial salivary glands of patients with pSS may be that the product of FasL combined with Fas activates caspase-8 through FADD, then ICE family is cascaded, and finally CAD is splited by caspase-3 from ICAD, which catalyzes the degradation of DNA.      

Mesenteric lymph drainage alleviates spleen injury in hemorrhagic shock rats

AIM：To observe the effects of post-shock mesenteric lymph (PSML) drainage on histopathology, apoptosis, cell cycle and proliferation of the spleen in rats with hemorrhagic shock. METHODS：Eighteen Wistar rats were randomly divided into sham, shock and shock+drainage groups (n=6 in each group). The hemorrhagic shock model was established in the shock and shock+drainage groups. Fluid resuscitation for 30 min was performed 1.5 h after hypotension, and PSML was drained in the rats in shock+drainage group from 1 h after hypotension to 3 h after resuscitation finished. The fixed spleen tissue was harvested from each rat for histological observation with HE staining. The apoptosis of splenocytes was observed by Hoechst 33258 staining. The expression of Bcl-2 and Bax proteins was detected by immunohistochemical staining. The cell cycle and the expression of p53 protein were measured by flow cytometry, and the proliferation index (PI) was calculated. RESULTS：Compared with sham group, splenic tissue injury appeared in the shocked rats. The apoptotic cells and the expression of Bax and p53 in shock group were increased, while Bcl-2 expression was decreased. The percentage of G2/M cells in shock group was decreased. Compared with shock group, the splenic tissue damage in shock+drainage group was significantly attenuated. Moreover, the number of apoptotic cells, the percentage of G0/G1 cells, and the expression of Bax and p53 were obviously decreased, and the G2/M cells, Bcl-2 protein expression and PI were significantly increased in shock+drainage group. CONCLUSION: PSML drainage alleviates splenic injury in hemorrhagic shock rats, which may be related to reducing the apoptosis of splenocytes.     

Cardiomyocyte apoptosis and related gene expression after acute myocardial infarction in rats

AIM: To investigate cardiomyocyte apoptosis and the expression of caspase-3, Bcl-2 and Bax after acute myocardial infarction (AMI) in rats.METHODS: AMI model was established with the ligation of left coronary artery in 78 randomly selected female SD rats.Twenty-four hours after operation, 43 survivors were randomly divided into 48-hour and 4-week two groups according to the time points: MI 48 h (n=11) and MI4 weeks (n=13) groups, sham-operated rats (S, n=27) were also randomly selected and reassigned to S48 h (n=10) and S4 weeks (n=10) groups.Cardiomyocyte apoptosis was detected with in situ terminal deoxynucleotidyl transferase (TdT)-dUTP nick-end labeling (TUNEL staining) and DNA gel electrophoresis.Caspase-3, Bcl-2 expression and Bax expression were detected with immunohistochemistry and Western blotting analysis.RESULTS: Compared with sham-operated group, after AMI, systolic, diastolic, and mean arterial blood pressures (SBP, DBP, MAP), left ventricular systolic pressure (LVSP) and the maximum change rate of left ventricular pressure rise and fall (±dp/dt) were significantly decreased (P<0.05, P＜0.01), while left ventricular end diastolic pressure (LVEDP) was significantly increased (P<0.05) in MI 48 h group.All the above indices in MI 4 weeks group had the same change as that in MI48h group, with the LVEDP significantly higher (P<0.01), except for a non-significantly change in SBP, DBP and MAP (all P>0.05).In both MI 48 h and MI 4 weeks groups, myocyte apoptotic index was significantly increased in the infracted/scar, border and non-infarcted areas (P<0.05,P＜0.01) with caspase-3 and Bax expressions increased significantly (P<0.05, P＜0.01) in myocytes of the above three areas and Bcl-2 expression increased only in myocytes of the infracted area in MI 48 h group.Western blotting indicated that Bcl-2/Bax ratio was also decreased in MI 48 h subgroup.CONCLUSIONS: After AMI in rats, cardiomyocyte apoptosis happened in the infarction/scar, border and non-infarcted areas, with caspase-3 and Bax expression in myocytes increased, and with Bcl-2 expression increased in myocytes of infracted area and Bcl-2/Bax ratio decreased only early after AMI.     

Effect of Herba Taxilli extracts combined with miR-375 on viability and apoptosis of osteoarthritic chondrocytes

AIM To study the effects of extracts of Herba Taxilli (Sangjisheng, SJS) on the viability and apoptosis of osteoarthritic chondrocytes and the underlying mechanism. METHODS Human primary osteoarticular chondrocytes (RPOC) were divided into control group, interleukin-1β (IL-1β) group, IL-1β+low-dose extracts of SJS (SJS-L) group, IL-1β+medium-dose extracts of SJS (SJS-M) group, IL-1β+high-dose extracts of SJS (SJS-H) group, IL-1β+anti-miR-NC group, IL-1β+anti-miR-375 group, IL-1β+SJS-H+miR-NC group, IL-1β+SJS-H+miR-375 group. The cell viability was measured by MTT assay, apoptosis was analyzed by flow cytometry, miR-375 expression was detected by qPCR, and the protein levels of cyclin D1, P21, Bcl-2, Bax and caspase-3 were determined by Western blot. RESULTS Compared with control group, the viability of RPOC at 24 h, 48 h and 72 h and the protein expression levels of cyclin D1 and Bcl-2 were significantly decreased (P<0.05), the protein levels of P21, Bax and caspase-3, the apoptotic rate and the expression level of miR-375 were remarkably increased in IL-1β group(P<0.05). Compared with IL-1β group, the cell viability at 24 h, 48 h and 72 h and the protein expression of cyclin D1 in the RPOC were greatly increased (P<0.05), while the expression of P21 was significantly decreased in IL-1β+SJS-M group and IL-1β+SJS-H group(P<0.05).The apoptotic rate, Bax, caspase-3 protein and miR-375 expression were obviously decreased (P<0.05), and Bcl-2 protein level was significantly increased in IL-1β+SJS-H group compared with IL-1β group(P<0.05). Compared with IL-1β+anti-miR-NC group, the expression of miR-375, the protein levels of P21, Bax, caspase-3 and the apoptotic rate in the RPOC of IL-1β+anti-miR-375 group were markedly decreased (P<0.05), while the cell viability at 24 h, 48 h and 72 h and the protein levels of cyclin D1 and Bcl-2 were significantly increased (P<0.05). Over-expression of miR-375 reversed the effects of extracts of SJS on the viability and apoptosis of RPOC with IL-1β stimulation. CONCLUSION The extracts of Herba Taxilli promotes the viability and inhibits apoptosis of RPOC treated with IL-1β, which is related to the regulation of miR-375 expression.     

The mechanism of apoptosis induced by homoharringtonine in HL-60 cells

AIM: To study the signal transduction pathway of apoptosis initiation induced by homoharringtonine in HL-60 cells. METHODS: After establishing the model of apoptosis initiation induced by homoharringtonine in HL-60 cells, at the point of apoptosis initiation, molecular caspase-3, Bcl-2, Bax and Fas/FasL were measured with flow cytometry and transmission electron microscope. ERK2 and P38 expression in HL-60 cells were detected by using immunohistochemistry. RESULTS: The model of apoptosis initiation induced by homoharringtonine was established in HL-60 cells. At the point of apoptosis initiation, upregulation of caspase-3 and decrease in Bcl-2/Bax were observed. However, the expression of Fas/FasL did not significantly change. ERK2 expression decreased and P38 expression increased. CONCLUSIONS: Caspase-3, Bcl-2, Bax and mitogen activated protein kinase pathways were involved in signal transduction of apoptosis initiation induced by homoharringtonine in HL-60 cells.     

Berberine promotes apoptosis of human breast cancer cells by regulating miRNA-146a

ATM: To observe the effect of berberine on apoptosis of MCF-7 cells and its potential mechanism. METHODS: The MCF-7 cells were divided into control group and the groups with 3 different doses of berberine. The cell viability was detected by MTT assay, while the cell apoptosis was measured by Hoechst 33258 staining and flow cytometry assay. The protein levels of p-P65, Bax and Bcl-2 were Western blot. The levels of microRNA-146a(miRNA-146a) in the MCF-7 cells were detected by RT-qPCR. The miRNA-146a siRNA was transfected to the MCF-7 cells after an evaluation of transfection efficacy, which was co-incubated with berberine to observe its effects on the mRNA levels of Bax and Bcl-2. RESULTS: Compared with control group, the cell viabilities were decreased significantly in medium and high doses of berberine treatment groups with a dose-dependent manner (P<0.01). The cell apoptosis was increased significantly in medium and high doses of berberine treatment groups dose-dependently (P<0.05). The protein levels of Bax were up-regulated, while those of Bcl-2 and p-P65 were down-regulated significantly by the treatment of berberine (P<0.05). In addition, the miRNA-146a levels were increased significantly in medium and high doses of berberine treatment groups (P<0.05) and showed a dose-dependent manner. The mRNA levels of Bax were decreased, while the mRNA levels of Bcl-2 were increased after transfection with miRNA-146a siRNA and co-incubated with berberine.CONCLUSION: Berberine promotes apoptosis of MCF-7 cells. The mechanism may be related to inhibit the activity of NF-κB by incresing the levels of miRNA-146a.     

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.     

Effects of norepinephrine preconditioning and ischemic preconditioning on apoptosis and Bcl-2, Bax expression in rat myocardial cells during myocardial ischemic reperfusion

AIM: To study the effects of norepinephrine preconditioning(NE-P) and ischemic preconditioning (IP)on apoptosis and Bcl-2, Bax expression in rat myocardial cells in myocardial ischemic reperfusion (I/R). METHODS: The model of rat ischemic-reperfusion was used to conduct NE-preconditioning. Apoptotic myocytes were detected with TUNEL. Bcl-2, Bax expression were detected with immunohistochemistry. RESULTS: The rate of apoptosis cells in I/R group was higher, the rate of apoptosis cells in NE-P group and IP was lower significantly than that in I/R group(P＜0.01). The expression of Bcl-2 in I/R group was lower, but the expression of Bax was higher, the expression of Bcl-2 in NE-P group was higher significantly than that in I/R group(P＜0.01), the expression of Bax in NE-P group was lower than that in I/R group(P＜0.01). There was no significantly difference between NE-P and IP group in the above parameters (P＞0.05). CONCLUSION: NE-P reduced myocyte apoptosis by I/R in rats; The expression of Bcl-2 ,Bax genes played an important role in myocardial apoptosis.     

Protective effect of paeoniflorin on nerve cells in APP/PS1 mice and its mechanism

AIM: To investigate the therapeutic and preventive effects of paeoniflorin (PF) on APP/PS1 mice, and to explore the possible mechanism. METHODS: Fifteen male 5-month-old APP/PS1 non-dominant mice were chosen as normal control group, 15 male 5-month-old APP/PS1 double transgenic mice were used as model group, and 15 male 5-month-old APP/PS1 double transgenic mice treated with 5 mg/kg PF by intraperitoneal injection were allocated in administation group. The learning and memory ability of the mice in each group was detected by Morris water maze. The apoptosis was assessed by TUNEL fluorescence staining. The protein expression of PI3K, Akt, p-PI3K, p-Akt, caspase-3, caspase-9, Bcl-2 and Bax in cerebral cortex and hippocampus was detected by Western Blot. The protein expression levels and distribution of caspase-3 and caspase-9 were detected by immunohistochemistry. RESULTS: (1) Compared with normal control group, the learning and memory ability declined in APP/PS1 model group. Compared with APP/PS1 model group, PF obviously improve the ability of learning and memory in mice. (2) Compared with normal control group, the apoptosis of nerve cells in APP/PS1 model group significantly increased and distributed in wider areas, while that in PF group was reduced (P<0.05). (3) Compared with APP/PS1 model group, PF could significantly lower pro-apoptotic factors, caspase-3, caspase-9 and Bax (P<0.05), and increase the expression of anti-apoptotic factors, p-PI3K, p-Akt and Bcl-2 (P<0.05). CONCLUSION: PF can up-regulate the expression of Bcl-2 and down-regulate the expression levels of caspase-9, caspase-3 and Bax via the activation of PI3K/Akt pathway, thereby inhibiting the nerve cell apoptosis and protecting the nerve cells, so as to treat neurodegenerative diseases.     

Effects of phycocyanin on apoptosis of human laryngeal cancer HEP-2 cells

AIM: To investigate the effect of phycocyanin on the apoptosis of human laryngeal cancer HEP-2 cells and to explore the inhibitory mechanism of phycocyanin to tumor. METHODS: Highly purified phycocyanin was extracted from spirulina. The effects of phycocyanin at different concentrations on the growth of human laryngeal cancer HEP-2 cells were detected by MTT assay. In addition, the cell structures were observed under electron microscope. The cell apoptosis was analyzed by flow cytometry. The production of reactive oxygen species (ROS) was measured by flow cytometry. Enzymatic activities of caspase-3, -8 and -9 were measured by chemical colorimatry. The expression of Bax, Bcl-2, Fas, P53, caspase-3 and caspase-9 at mRNA and protein levels was determined by RT-PCR and Western blot. RESULTS: MTT test confirmed that phycocyanin inhibited the cell activity of HEP-2 cells with time and dose dependent manners. The result of electron microscope observation and flow cytometry indicated that phycocyanin induced the apoptosis of HEP-2 cells. The intracellular content of ROS was increased. The activities of caspase-3, -8 and -9 were increased. RT-PCR showed that the mRNA expression of Bax, Fas, P53, caspase-3, caspase-9 was increased and Bcl-2 was decreased. The results of Western blot were consistent with the results of RT-PCR. CONCLUSION: Phycocyanin might induce apoptosis of HEP-2 cells by down-regulating Bcl-2, up-regulating Bax, Fas and P53, and the transduction of apoptotic signals in the human laryngeal cancer cells.     

Effect of 27nt-miRNA on apoptosis of human umbilical vein endothelial cells induced by oxidized low-density lipoprotein

AIM To investigate the effect of 27nt-miRNA （27nt-miR） on apoptosis of human umbilical vein endothelial cells （HUVECs） induced by oxidized low-density lipoprotein （Ox-LDL） and its underlying mechanism. METHODS HUVECs were cultured in vitro and grouped as below： normal control group, Ox-LDL group, 27nt-miR+Ox-LDL group, anti-27nt-miR+Ox-LDL group and negative control+Ox-LDL group. The cells in Ox-LDL group were treated with Ox-LDL at 40 mg/L for 48 h, while those in normal control group were untreated but cultured normally. The cells in 27nt-miR+Ox-LDL group, anti-27nt-miR+Ox-LDL group and negative control+Ox-LDL group were transfected with their corresponding lentiviral vectors under the same procedure, followed by treatment with Ox-LDL at 40 mg/L for 48 h to induce apoptosis. The cell viability was measured by CCK-8 assay. The migration capacity was detected by scratch assay. The caspase-3 activity was measured by caspase-3 activity assay kit. The apoptotic rate was analyzed by Hoechst 33258 and flow cytometry. The mRNA and protein expression levels of Bcl-2, Bax and caspase-3 were determined by RT-qPCR and Western blot. RESUITS： Compared with negative control+Ox-LDL group, the cell viability and migration ability were significantly decreased by over-expression of 27nt-miR in the HUVECs （P<0.05）, while the activity of caspase-3 and apoptosis induced by Ox-LDL were significantly increased （P<0.05）. Furthermore, the mRNA and protein expression levels of Bax and caspase-3 were significantly up-regulated （P<0.05）, and the mRNA and protein expression level of Bcl-2 was down-regulated in 27nt-miR+Ox-LDL group （P<0.05）. Meanwhile, all the above indexes showed an opposite tendency in anti-27nt-miR+Ox-LDL group. CONCLUSION 27nt-miR promotes Ox-LDL-induced apoptosis and inhibits the viability and migration of HUVECs in vitro, possibly through regulating the expression of apoptotic/anti-apoptotic proteins such as Bax,caspase-3 and Bcl-2.     

Effects of CARHSP1 gene expression on viability,apoptosis and immune factors of vascular endothe-lial cells induced by hypoxia in atherosclerosis

AIM: To investigate the effect of calcium-regulated heat stable protein 1 (CARHSP1) gene expression on the viability, apoptosis and expression of interleukin-6 (IL-6) and C-reactive protein (CRP) in vascular endothe-lial cells induced by hypoxia.METHODS: The protein expression of CARHSP1 was detected by Western blot in atherosclerotic plaques. Human umbilical vein endothelial cells (HUVECs) were treated with hypoxia, and the cells were divided into normal culture group, hypoxia group, hypoxia+CARHSP1-siRNA group and hypoxia+pcDNA3.1-CARHSP1 group. The viability and apoptotic rate of the HUVECs were measured by CCK-8 assay and flow cytometry, respectively. The mRNA expression of IL-6 and CRP was detected by RT-PCR. The protein levels of caspase-3, cleaved caspase-3, Bcl-2 and Bax were determined by Western blot.RESULTS: The protein expression of CARHSP1 in atherosclerotic plaques was significantly higher than that in control group (P<0.05). Hypoxia significantly increased the expression of CARHSP1. The cell viability and the protein expression of Bcl-2 were significantly lower in hypoxia group than those in normal culture group (P<0.05). The apoptotic rate and the protein levels of IL-6, CRP, cleaved caspase-3 and Bax were significantly higher than those in normal culture group (P<0.05). Compared with hypoxia group, the cell viability and protein expression of Bcl-2 were significantly increased in hypoxia+CARHSP1-siRNA group, while the apoptotic rate and the protein levels of IL-6, CRP, cleaved caspase-3 and Bax were decreased significantly (P<0.05). The cell viability and protein expression of Bcl-2 were decreased significantly in hypoxia+pcDNA3.1-CARHSP1 group, while the apoptotic rate and the protein le-vels of IL-6, CRP, cleaved caspase-3 and Bax were increased significantly (P<0.05).CONCLUSION: The expression of CARHSP1 is increased in atherosclerotic plaques, and inhibition of CARHSP1 expression improves the viability, reduces the apoptosis, and down-regulates the expression of IL-6 and CRP in the HUVECs. Over-expression of CARHSP1 exerts the opposite effect.     

Effect of berberine on Helicobacter pylori-induced human gastric epithe-lial cells injury

AIM: To investigate the effect of berberine (Ber) on Helicobacter pylori (Hp)-induced human gastric epithelial cells (GES-1) injury and the underlying mechanism. METHODS: Berberine (5, 10 and 20 μmol/L) and PD98059 (20 μmol/L), a selective inhibitor of extracellular regulated protein kinases (ERK)1/2 signaling pathway, were added to Hp-infected GES-1 cells. The cell activity and apoptosis, the levels of interleukin (IL)-1β and IL-8, lactic dehydrogenase (LDH) activity and the protein levels of Bax, Bcl-2 and p-ERK1/2 in the GES-1 cells were determined by MTT assay, flow cytometry, ELISA, colorimetry and Western blot, respectively. RESULTS: Compared with control group, Hp significantly inhibited the cell activity, increased the apoptotic rate, LDH activity, IL-1β and IL-8 levels, the Bax and p-ERK1/2 protein levels but decreased the Bcl-2 protein level in GES-1 cells (P<0.05). However, these effects of Hp were reversed by berberine at medium-dose and high-dose, as compared with the Hp-infected GES-1 cells (P<0.05). Moreover, the protective effects of berberine were significantly enhanced by the co-incubation of berberine with PD98059, as compared with the berberine at higher dose (P<0.05). CONCLUSION: Berberine may attenuate Hp-induced human gastric epithelial GES-1 cells injury by anti-inflammation, promoting cell growth and anti-apoptosis via the inhibition of ERK1/2 signaling pathway.     

Effect of bim silencing by siRNA on hypoxia-induced apoptosis of rat cardiomyocytes

AIM：To investigate the effect of BH3-only protein Bim (Bcl-2 interacting mediator of cell death) on apoptosis of rat cardiomyocytes induced by hypoxia. METHODS：Rat cardiomyocytes were isolated from infant rats aged 1~3 days and then primarily cultured. The antibody targeting α-actin of striated muscle was used to identify the cardiomyocytes. The siRNAs of bim were transfected into the cardiomyocytes with liposome, and the expression of Bim was determined by Western blotting. The cardiomyocytes were divided into blank control group, hypoxia group, hypoxia+liposome group, hypoxia+negative control siRNA group and hypoxia+bim-siRNA group.The frequency and rhythm of cardiomyocyte beating were observed and recorded under inverted microscope. The activity of lactate dehydrogenase (LDH) in the culture medium was assessed by automatic biochemical analyzer. The viability of the cells was analyzed by MTT assay. The cell apoptotic rate was measured by flow cytometry. The protein expression of Bim, Bax, Bcl-2, p-p38 MAPK and p38 MAPK was detected by Western blotting. RESULTS：Immunohistochemical identification confirmed that the rat cardiomyocytes were successfully cultured. The expression of Bim was obviously inhibited after transfected with bim-siRNAs and the silencing efficiency of bim-siRNA-2 was the highest (86.73%). The frequency of cardiomyocyte beating was slowed down after hypoxia and the rhythm was disordered, while the frequency of beating was obviously increased after silencting the expression of bim. Compared with control group, the LDH in the culture medium was increased (P<0.01), and the viability of the cardiomyocytes was reduced in hypoxia group (P<0.05). The apoptotic rate was increased (P<0.01). After transfection with bim-siRNA, the release of LDH was decreased, and the viability of the cardiomyocytes was increased. The apoptotic rate was decreased. The results of Western blotting showed that hypoxia increased the expression of Bax and p-p38 MAPK (P<0.05), and decreased the expression of Bcl-2 (P<0.01), while transfection with bim-siRNA reduced the effects caused by hypoxia (P<005). These were greatly related to the decrease of apoptosis. However, the expression of p38 MAPK was not changed. CONCLUSION：The apoptosis of cardiomyocytes induced by hypoxia can be inhibited by silencing the expression of bim gene by down-regulation of p-p38 MAPK and Bax expression and up-regulation of Bcl-2 expression.     

Protective effects of berberine in pancreatic islet beta cells

AIM: To explore the protective effects of berberine （Ber） on islet beta cells and related possible mechanisms. METHODS: The injury of INS-1 cells was induced by treatment with alloxan (Axn). Berverine was then given at serial concentrations. The cells were divided into control group (Con), injury group (Axn), low-dose berberine group (LBer), medium-dose berberine group (MBer) and high-dose berberine group (HBer). Flow cytometry was employed to detect the apoptosis. The activation of PTEN/PI3K/Akt and HNF-1α/PDX-1 pathways and the protein level of cleaved caspase-3 were evaluated by Western blotting. The insulin releases under normal or high-glucose stimulation were measured by ELISA. RESULTS: Compared with Con group, the apoptotic rate increased significantly in Axn group. Berberine treatment reduced the apoptotic rate in LBer group, MBer group and HBer group in a concentration-dependent manner. Compared with Con group, the protein levels of PTEN and cleaved caspase-3 increased, while PI3K and phosphorylation of Akt decreased significantly in Axn group. However, this effect was reversed by berberine in a concentration-dependent manner. Compared with Con group, the activation of HNF-1α/PDX-1 signaling pathway was inhibited in Axn group but recovered by berberine administration. The abilities of releasing insulin under normal or high-glucose stimulation were impaired in Axn group but recovered by berberine treatment in LBer group, MBer group and HBer group in a concentration-dependent manner.CONCLUSION: Berberine shows protective effects against alloxan-induced damage in beta cells by inhibiting apoptosis and recovering insulin secretion, thus attenuating the activation of PTEN/PI3K/Akt and HNF-1α/PDX-1 signaling pathways.     

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.     

Effect of ghrelin on iNOS expression in alveolar macrophages and lung tissues in rats with sepsis-associated lung injury

AIM: To investigate the effect of ghrelin on inducible nitric oxide synthase (iNOS) expression in alveolar macrophages and lung tissues in sepsis-induced acute lung injury (ALI) rats. METHODS: The septic rat model was established by cecal ligation and puncture (CLP). Male SD rats were divided into sham group, CLP group and CLP+ghrelin group. The rats in the former 2 groups were further divided into 3 subgroups, which were 6 h, 12 h and 20 h post-operation groups. Ghrelin was administered by intraperitoneal injection at 3 h and 15 h after operation in ghrelin group. The samples were harvested 20 h after operation. The mRNA expression of iNOS in alveolar macrophages collected from bronchoalveolar lavage was detected by RT-PCR. The protein levels of lung iNOS were measured by Western blotting. The lung pathological examination was performed 20 h after operation. RESULTS: In CLP group, the mRNA expression levels of iNOS in the alveolar macrophages were 1.33±0.05, 1.44±0.08, 1.57±0.11 at 6 h, 12 h and 20 h after CLP, respectively, which were higher than that in sham group, but did not show time correlation. However, it was lower in CLP group than that in CLP+ghrelin group at 20 h after CLP (2.27±0.37, P<0.05). At 20 h after CLP, the protein level of lung iNOS was decreased in CLP+ghrelin group (0.87± 0.03) as compared with CLP group (1.08±0.05). Compared with sham group, the histopathological score was increased in both CLP group and CLP+ghrelin group, but it was lower in CLP+ghrelin group (5.83±0.477) than that in CLP group (7.83±0.75). CONCLUSION: Ghrelin treatment improves the degree of ALI. During 6 h to 20 h after CLP, the mRNA expression of iNOS in alveolar macrophages was elevated, but the difference was not seen as the time went on. Ghrelin up-regulates the mRNA expression of iNOS in alveolar macrophages and inhibits iNOS expression in lungs of septic rats.