AAV2-PDE6B restores retinal structure and function in the retinal degeneration 10 mouse model of retinitis pigmentosa by promoting phototransduction and inhibiting apoptosis

Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death.However,there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation.Adeno-associated virus(AAV)-mediated gene therapy is a promising strategy for treating retinitis pigmentosa.The aim of this study was to explore the molecular mechanisms by which AAV2-PDE6B rescues retinal function.To do this,we injected retinal degeneration 10(rd10)mice subretinally with AAV2-PDE6B and assessed the therapeutic effects on retinal function and structure using dark-and light-adapted electroretinogram,optical coherence tomography,and immunofluorescence.Data-independent acquisition-mass spectrometry-based proteomic analysis was conducted to investigate protein expression levels and pathway enrichment,and the results from this analysis were verified by real-time polymerase chain reaction and western blotting.AAV2-PDE6B injection significantly upregulated PDE6βexpression,preserved electroretinogram responses,and preserved outer nuclear layer thickness in rd10 mice.Differentially expressed proteins between wild-type and rd10 mice were closely related to visual perception,and treating rd10 mice with AAV2-PDE6B restored differentially expressed protein expression to levels similar to those seen in wild-type mice.Kyoto Encyclopedia of Genes and Genome analysis showed that the differentially expressed proteins whose expression was most significantly altered by AAV2-PDE6B injection were enriched in phototransduction pathways.Furthermore,the phototransductionrelated proteins Pde6α,Rom1,Rho,Aldh1a1,and Rbp1 exhibited opposite expression patterns in rd10 mice with or without AAV2-PDE6B treatment.Finally,Bax/Bcl-2,p-ERK/ERK,and p-c-Fos/c-Fos expression levels decreased in rd10 mice following AAV2-PDE6B treatment.Our data suggest that AAV2-PDE6B-mediated gene therapy promotes phototransduction and inhibits apoptosis by inhibiting the ERK signaling pathway and upregulating Bcl-2/Bax expression in retinitis pigmentosa.

High expression circRALGPS2 in atretic follicle induces chicken granulosa cell apoptosis and autophagy via encoding a new protein

Background The reproductive performance of chickens mainly depends on the development of follicles.Abnor-mal follicle development can lead to decreased reproductive performance and even ovarian disease among chick-ens.Chicken is the only non-human animal with a high incidence of spontaneous ovarian cancer.In recent years,the involvement of circRNAs in follicle development and atresia regulation has been confirmed.Results In the present study,we used healthy and atretic chicken follicles for circRNA RNC-seq.The results showed differential expression of circRALGPS2.It was then confirmed that circRALGPS2 can translate into a protein,named cir-cRALGPS2-212aa,which has IRES activity.Next,we found that circRALGPS2-212aa promotes apoptosis and autophagy in chicken granulosa cells by forming a complex with PARP1 and HMGB1.Conclusions Our results revealed that circRALGPS2 can regulate chicken granulosa cell apoptosis and autophagy through the circRALGPS2-212aa/PARP1/HMGB1 axis.

Loss of Fascin2 increases susceptibility to cisplatin-induced hearing impairment and cochlear cell apoptosis in mice

Objectives:Deletion of Fscn2 gene in mice has been linked to progressive hearing loss and degeneration of cochlear cells.Cisplatin,an antitumor drug,can cause various side effects,including ototoxicity.The aim of this study was to investigate the effects of Fscn2 on cisplatin-induced hearing impairment in mice and to explore the possible mechanism.Methods:Two-week-old Fscn2+/+mice and Fscn2−/−mice were treated with two doses of cisplatin,with a 3-day recovery period in between.ABR(auditory evoked brain stem response)thresholds were measured and cochlear pathology was observed at 3 weeks of age.Results:Both Fscn2+/+and Fscn2−/−mice showed hearing loss under the effect of cisplatin,but the impairment was more severe in Fscn2−/−mice.Further experiments showed that the percentages of outer hair cell(OHC)and spiral ganglion neuron(SGN)loss were significantly higher in cisplatin-treated Fscn2−/−mice compared to Fscn2+/+mice.Additionally,knockdown of Fscn2 in HEI-OC1 cells worsened cisplatin-induced cell apoptosis.Conclusion:FSCN2 mediates reduction of CDDP induced ototoxicity by inhibiting cell apoptosis.

Celastrol promotes apoptosis of breast cancer MDA-MB-231 cells by targeting HSDL2

Objective:Celastrol is a pentacyclic triterpenoid extracted from the traditional Chinese medicinal herb,Tripterygium wilfordii.This study aims to provide a scientific basis for the rational development and use of celastrol in breast cancer.Method:A quantitative chemical biology approach was used to investigate the protein targets and molecular mechanisms of celastrol in breast cancer cells.Results:Low-concentration celastrol exerted an anti-tumor effect by directly binding to hydroxysteroid dehydrogenase-like 2(HSDL2)and inhibiting its expression.Moreover,the expression of the pro-apoptotic protein,Bcl-2-associated X(BaX),increased,the level of the anti-apoptotic protein,B-cell lymphoma-2(Bcl-2),decreased,and the rate of apoptosis increased.After the transfection of cells with si-HSDL2,the apoptosis rate was similar to that observed after the administration of celastrol.However,apoptosis was reversed by the overexpression of HSDL2.Furthermore,our mass spectrometry(MS)data indicated a relationship between HSDL2 and the mitogen-activated protein kinase(MAPK)signaling pathway.We also found that the expression of HSDL2 was directly related to the degree of extracellular signal-regulated kinase(ERK)phosphorylation.Conclusion:Celastrol may promote apoptosis by suppressing the HSDL2/MAPK/ERK signaling pathway.

Absent in melanoma 2 attenuates proliferation and migration and promotes apoptosis of human colorectal cancer cells by activating P38MAPK signaling pathway

Colorectal cancer(CRC)stands among the top prevalent cancers worldwide and holds a prominent position as a major contributor to cancer-related mortality globally.Absent in melanoma 2(AIM2),a constituent of the interferoninducible hematopoietic interferon-inducible nuclear antigens with 200 amino acid repeats protein family,contributes to both cancer progression and inflammasome activation.Despite this understanding,the precise biological functions and molecular mechanisms governed by AIM2 in CRC remain elusive.Consequently,this study endeavors to assess AIM2’s expression levels,explore its potential antitumor effects,elucidate associated cancer-related processes,and decipher the underlying signaling pathways in CRC.Our findings showed a reduced AIM2 expression in most CRC cell lines.Elevation of AIM2 levels suppressed CRC cell proliferation and migration,altered cell cycle by inhibiting G1/S transition,and induced cell apoptosis.Further research uncovered the participation of P38 mitogen-activated protein kinase(P38MAPK)in AIM2-mediated modulation of CRC cell apoptosis and proliferation.Altogether,our achievements distinctly underscored AIM2’s antitumor role in CRC.AIM2 overexpression inhibited proliferation and migration and induced apoptosis of CRC cells via activating P38MAPK signaling pathway,indicating AIM2 as a prospective and novel therapeutic target for CRC.

Effects of Low Dose Radiation on Tumor Apoptosis, Cell Cycle and Apoptosis-Related Protein Bcl-2 in Tumor-Bearing Mice

To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.

Effects of Selenium Dioxide on Apoptosis, Bcl-2 and P53 Expression, Intracellular Reactive Oxygen Species and Calcium Level in Three Human Lung Cancer Cell Lines

Objective: To evaluate the anti-tumor effects of SeO2 and its mechanisms on three human lung cancer cell lines. Methods: Three lung cancer cells A549, GLC-82 and PG were treated with 3-30 μmol/L SeO2. Flow cytometry was used to detect apoptosis, and analyze the changes of expression of p53 and Bcl-2, as well as ROS and Ca2+ level within cells. Results:SeO2 markedly inhibited cell proliferation and viability, and prompted apoptosis after 48 h treatment. SeO2 at 10 μmol/L induced 47.8% apoptosis in A549 cells, 40.8% in GLC-82 cells, 18.2% in PG cells. SeO2 at 30 μmol/L induced 37.8% apoposis in PG cells,but did not increase apoptotic raes in other two cells. SeO2 could down-regulate the mean fluorescent intensity of Bcl-2 from 65.8 to 9.6 in A549, but not in GLC-82 and in PG cells, up-regulate wild type p53 level in all three cells. SeO2 decreased the ROS and Ca2+ level markedly within three tested cells. Conclusion: SeO2 showed anti-tumor effect via apoptosis pathway in three lung cancer cell lines. The decrease of ROS and Ca2+ level within cells as well as regulation of Bcl-2 and p53 expression may play important roles in above apoptotic procedure.

The Expression of Apoptosis-Related Genes Bcl-2 and Bax Protein and Apoptosis Positivity in Cervical Carcinoma during Irradiation

To evaluate the apoptosis positivity, the expression of Bcl-2, bax proteinsin 30 patients with squamous cell cervix carcinoma before and after radiotherapy. Methods: By usingimmuno-histochemical and TDT-dUTP nick end labelling techniques, 30 cases of squamous cell cervicalcarcinoma were analyzed. Results: The apoptosis positivity before and after irradiation was 76.7%and 100% respectively, with the difference being significant (P 【 0.05); The positive rates of Bcl-2protein before and after irradiation were 73.3% and 46.7% respectively, with the difference beingsignificant (P 【 0.05); The positive rates of bax protein before and after irradiation were 86% and100% respectively, with the difference being significant (P 【 0.05). Conclusion: bax and Bcl-2protein play an important role in apoptosis induced by fractionated radiation therapy. Apoptosisinduced by irradiation is contributed to upregulation of bax protein or downregulation of Bcl-2protein.

Apoptosis Induced by Bcl-2 Antisense Peptide Acid in HL60 Cells

Objective To study the differences and similarities of the antisense drugs with different structures on the biological functions of HL60 cells. Methods Cytotoxic effects were measured by cell viability assay. The expression levels of protein were assayed by immunofluorescence using fluoresce isothiocyanate label. The morphological changes in apoptotic cells were observed. Flow cytometric analysis of DNA fragmentation was also performed. Results Antisense peptide nucleic acid (PNA) targeting the coding region of the Bcl-2 mRNA could effectively inhibit the growth of HL60 cells, down-regulate the synthesis of Bcl-2 protein and induce apoptosis. After HL60 cells were treated with 10 μmol/L Bcl-2 antisense PNA or antisense oligonucleotide for 72 h respectively, apoptotic rates of HL60 cells were 17.80±1.53 and 13.17±1.12, respectively( P <0.05). Conclusion Antisense PNA targeting the coding region of Bcl-2 mRNA may have stronger antisense effects than the antisense oligonucleotides and could induce apoptosis of HL60 cells.

MicroRNA-143 suppresses gastric cancer cell growth and induces apoptosis by targeting COX-2

AIM:To investigate the function of microRNA-143(miR-143)in gastric cancer and explore the target genes of miR-143.METHODS:A quantitative real-time reverse transcription-polymerase chain reaction(RT-PCR)analysis was performed to evaluate miR-143 expression in gastric cancer cell lines.After transfecting gastric cancer cells with miR-143-5p and miR-143-3p precursors,Alamar blue and apoptosis assays were used to measure the respective proliferation and apoptosis rates.Cyclooxygenase-2(COX-2)expression was determined by realtime RT-PCR and Western blot assays after miR-143transfection.Reporter plasmids were constructed,and a luciferase reporter assay was used to identify the miR-143 binding site on COX-2.RESULTS:Both miR-143-5p and miR-143-3p were significantly downregulated in multiple gastric cancer cell lines.Forced miR-143-5p and miR-143-3p expression in gastric cancer cells produced a profound cytotoxic effect.MiR-145-5p transfection into gastric cancer cells resulted in a greater growth inhibitory effect(61.23%±3.16%vs 46.58%±4.28%,P<0.05 in the MKN-1cell line)and a higher apoptosis rate(28.74%±1.93%vs 22.13%±3.31%,P<0.05 in the MKN-1 cell line)than miR-143-3p transfection.Further analysis indicated that COX-2 expression was potently suppressed by miR-143-5p but not by miR-143-3p.The activity of a luciferase reporter construct that contained the 3’-untranslated region(UTR)of COX-2 was downregulated by miR-143-5p(43.6%±4.86%,P<0.01)but not by miR-143-3p.A mutation in the miR-145-5p binding site completely ablated the regulatory effect on luciferase activity,which suggests that there is a direct miR-145-5p binding site in the 3’-UTR of COX-2.CONCLUSION:Both miR-143-5p and miR-143-3p function as anti-oncomirs in gastric cancer.However,miR-143-5p alone directly targets COX-2,and it exhibits a stronger tumor suppressive effect than miR-143-3p.

Ligustilide protects PC12 cells from oxygen-glucose deprivation/reoxygenation-induced apoptosis via the LKB1-AMPK-mTOR signaling pathway

Autophagy has been shown to have a protective effect against brain damage.Ligustilide(LIG)is a bioactive substance isolated from Ligusticum chuanxiong,a traditional Chinese medicine.LIG has a neuroprotective effect;however,it is unclear whether this neuroprotective effect involves autophagy.In this study,PC12 cells were treated with 1×10^-5–1×10^-9 M LIG for 0,3,12 or 24 hours,and cell proliferation was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium(MTS)assay.Treatment with 1×10^-6 M LIG for 3 hours had the greatest effect on cell proliferation,and was therefore used for subsequent experiments.PC12 cells were pre-treated with 1×10^-6 M LIG for 3 hours,cultured in 95%N2/5%CO2 in Dulbecco’s modified Eagle’s medium without glucose or serum for 4 hours,and then cultured normally for 16 hours,to simulate oxygen-glucose deprivation/reoxygenation(OGD/R).Cell proliferation was assessed with the MTS assay.Apoptosis was detected by flow cytometry.The expression levels of apoptosis-related proteins,Bcl-2 and Bax,autophagy-related proteins,Beclin 1 and microtubule-associated protein l light chain 3B(LC3-II),and liver kinase B1(LKB1)-5′-adenosine monophosphate-activated protein kinase(AMPK)-mammalian target of rapamycin(mTOR)signaling pathway-related proteins were assessed by western blot assay.Immunofluorescence staining was used to detect LC3-II expression.Autophagosome formation was observed by electron microscopy.LIG significantly decreased apoptosis,increased Bcl-2,Beclin 1 and LC3-II expression,decreased Bax expression,increased LC3-II immunoreactivity and the number of autophagosomes,and activated the LKB1-AMPK-mTOR signaling pathway in PC12 cells exposed to OGD/R.The addition of the autophagy inhibitor 3-methyladenine or dorsomorphin before OGD/R attenuated the activation of the LKB1-AMPK-mTOR signaling pathway in cells treated with LIG.Taken together,our findings show that LIG promotes autophagy and protects PC12 cells from apoptosis induced by OGD/R via the LKB1-AMPK-mTOR signaling pathway.

Effects of Ethyl Pyruvate on Myocardial Apoptosis and Expression of Bcl-2 and Bax Proteins after Ischemia-reperfusion in Rats

In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion （I/R） in vitro and the expression of Bcl-2 and Bax proteins, isolated rat hearts were perfused in a Langendorff model. Twenty-four rats were randomly divided into 3 groups （n=8 in each group）： control group was perfused for 120 min. In the I/R group, after 30 min stabilization the injury was induced by 30 min global ischemia followed by 60 min reperfusion. Ethyl pyruvate （EP） group was set up with the same protocol as I/R group except that it was supplied with 2 mmol/L EP 15 rain before ischemia and throughout reperfusion. Myocardial malonaldehyde （MDA） content was measured. Myocardial apoptotic index （AI） was tested by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling （TUNEL） method. The expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in cardiac myocytes was detected by immunohistochemistry. As compared with control group, the content of MDA, myocardial AI and the expression of Bcl-2, Bax proteins were increased significantly in I/R group, but the content of MDA, myocardial AI and the expression of Bax protein were decreased obviously and the expression of Bcl-2 protein was up-regulated in EP group （P〈0.05）. These results demonstrate that EP could inhibit apoptosis of cardiac myocytes possibly via alleviating oxidative stress, up-regulating Bcl-2 and down-regulating Bax proteins.

Hepatocellular carcinoma HepG2 cell apoptosis and caspase-8 and Bcl-2 expression induced by injectable seed extract of Coix lacryma-jobi

BACKGROUND:Many Chinese herbs,especially herbal injections,have been shown to have anti-tumor effects in recent years.However,since most reports focus on the clinical effectiveness of these herbs,their mechanisms of action are not well understood.In this study,we assessed apoptosis in the hepatocellular carcinoma (HCC) cell line HepG2 induced by an injectable extract from the seed of Coix lacryma-jobi (Semen coicis,SC),and monitored the expression of Bcl-2 and caspase-8.METHODS:Injectable SC was applied to HepG2 cells at different concentrations and the cells were collected 12,24 and 48 hours later.5-fluorouracil was used as a positive control group,and fluorescence-activated cell-sorting cytometry was used to measure the apoptosis rate of HepG2 cells and the expression of Bcl-2 and caspase-8 proteins.RESULTS:SC induced apoptosis in HepG2 cells in a concentration and time-dependent manner,and the expression of caspase-8 was elevated and prolonged.However,it did not significantly influence the expression of Bcl-2.CONCLUSION:Injectable SC may induce apoptosis in HCC cells by regulating the expression of caspase-8.

Regulating effect of glycyrrhetinic acid on bronchial asthma smooth muscle proliferation and apoptosis as well as inflammatory factor expression through ERK1/2 signaling pathway

Objective: To study the influence of glycyrrhetinic acid(GA) on bronchial asthma(BA)smooth muscle proliferation and apoptosis as well as inflammatory factor expression and its molecular mechanism.Methods: Male SD guinea pigs were selected and made into asthma models, bronchial asthma smooth muscle cells were cultured and divided into BA group, GA group and GA + LM group that were treated with serum-free RPMI1640 culture medium, serumfree RPMI1640 culture medium containing 50 ng/mL glycyrrhetinic acid, serum-free RPMI1640 culture medium containing 50 ng/mL glycyrrhetinic acid and 100 ng/mL LM22B-10 respectively; normal guinea pigs were collected and bronchial smooth muscle cells were cultured as control group. The cell proliferation activity as well as the expression of proliferation and apoptosis genes, inflammatory factors and p-ERK1/2 was determined.Results: Proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6,YKL-40, protein expression of p-ERK1/2 of airway smooth muscle cell in BA group were significantly higher than those of control group while m RNA expression levels of Bax,caspase-9 as well as caspase-3 were significantly lower than that of control group(P < 0.05); proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6, YKL-40, protein expression of p-ERK1/2 of airway smooth muscle cell in GA group were significantly lower than those of BA group(P < 0.05) while the m RNA expression levels of Bax, caspase-9 as well as caspase-3 were significantly higher than those of BA group(P < 0.05); proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6, YKL-40 of airway smooth muscle cell in GA + LM group were significantly higher than those of GA group(P < 0.05) while m RNA expression levels of Bax, caspase-9 as well as caspase-3 were significantly lower that of GA group(P < 0.05).Conclusion: GA can inhibit the proliferation of bronchial smooth muscle cells and reduce the expression of inflammatory factors by inhibiting the phosphorylation of ERK1/2.

Dioscin-induced Apoptosis of Human LNCaP Prostate Carcinoma Cells through Activation of Caspase-3 and Modulation of Bcl-2 Protein Family

Dioscin is a natural steroid saponin derived from several plants, showing potent anti-cancer effect against a variety of tumor cell lines. In the present study, we investigated the anti-cancer activity of dioscin against human LNCaP cells, and evaluated the possible mechanism involved in its antineoplastic action. It was found that dioscin（1, 2 and 4 μmol/L） could significantly inhibit the viability of LNCaP cells in a time- and concentration-dependent manner. Flow cytometry revealed that the apoptosis rate was increased after treatment of LNCaP cells with dioscin for 24 h, indicating that apoptosis was an important mechanism by which dioscin inhibited cancer. Western blotting was employed to detect the expression of caspase-3, Bcl-2 and Bax in LNCaP cells. The expression of cleaved caspase-3 was significantly increased, and meanwhile procaspase-3 was markedly decreased. The expression of anti-apoptotic protein Bcl-2 was down-regulated, whereas the pro-apoptotic protein Bax was up-regulated. Moreover, the Bcl-2/Bax ratio was drastically decreased. These results suggested that dioscin possessed potential anti-tumor activity in human LNCaP cells through the apoptosis pathway, which might be associated with caspase-3 and Bcl-2 protein family.

Effect of Hypoxic Preconditioning on Neural Cell Apoptosis and Expression of Bcl-2 and Bax in Cerebral Ischemia-Reperfusion in Rats

In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebral ischemia followed by 1, 6, 12, 24 and 48 h reperfusion respectively in rats treated with or without hypoxic preconditioning before cerebral ischemia. In addition, the apoptosis of neural cells and the behavioral scores for neurological functions recovery were evaluated by TUNEL staining and ＂crawling method＂, respectively. Compared with control group （cerebral ischemia-reperfusion without hypoxic preconditioning）, the expression of Bcl-2 was significantly increased, but that of Bax decreased in the hypoxic preconditioning group （cerebral ischemiareperfusion with hypoxie preconditioning）, both P〈0.05. The pre-treatment with hypoxic preconditioning could reduce the apoptosis of neural cells and promote the neurological function recovery as compared to control group. It was suggested that hypoxic preconditioning may have protective effects on the cerebral ischemia-reperfusion injury by inhibiting the apoptosis of neural cells, increase the expression of Bcl-2 and decrease the expression of Bax.

Harmine induces apoptosis in HepG2 cells via mitochondrial signaling pathway

BACKGROUND:Harmine has antitumor and antinociceptive effects,and inhibits human DNA topoisomerase.However no detailed data are available on the mechanisms of action of harmine in hepatocellular carcinoma.This study aimed to investigate the effects of harmine on proliferation and apoptosis and the underlying mechanisms in the human hepatocellular carcinoma cell line HepG2.METHODS:The proliferation of HepG2 cells was determined by the cell counting kit-8 (CCK-8) assay and the clone formation test.The morphology of HepG2 cells was examined using fluorescence microscopy after Hoechst 33258 staining Annexin V/propidium iodide (PI) was used to analyze apoptosis and PI to analyze the cell cycle.Western blotting was used to assess expression of the apoptosis-regulated genes Bcl-2,Bax,Bcl-xl,Mcl-1,caspase-3,and caspase-9 Mitochondrial transmembrane potential (Ψ m) was determined using JC-1.RESULTS:Harmine inhibited the proliferation of HepG2 cells in a dose-dependent manner.Hoechst 33258 staining revealed nuclear fragmentation and chromosomal condensation,cell shrinkage,and attachment loss in HepG2 cells treated with harmine.The percentage of the sub/G1 fraction was increased in a concentration-dependent manner,indicating apoptotic cell death.PI staining showed that harmine changed the cell cycle distribution,by decreasing the proportion of cells inG0/G1 and increasing the proportion in S and G2/M.Harmine induced apoptosis in a concentration-dependent manner,with rates of 20.0%,32.7% and 64.9%,respectively.JC-1 revealed a decrease in Ψ m.Apoptosis of HepG2 cells was associated with caspase-3 and caspase-9 activation,down-regulation of Bcl-2,Mcl-1,and Bcl-xl,and no change in Bax.CONCLUSIONS:Harmine had an anti-proliferative effect in HepG2 cells by inducing apoptosis.Mitochondrial signal pathways were involved in the apoptosis.The cancer-specific selectivity shown in this study suggested that harmine is a promising novel drug for human hepatocellular carcinoma.

The bcl-2 mRNA Expression in GCDC-induced Obstructive Jaundice in Rats and Its Implication in Hepatocellular Apoptosis

The modulatory role of bcl 2 gene in hepatocellular apoptosis of rats with glycochenodeoxycholate (GCDC) induced obstructive jaundice was investigated. The hepatocytes in normal rats and those with bile duct ligation for 7 days, 14 days and 21 days were isolated and obtained by in situ collagenase perfusion and primary culture. The expression of bcl 2 mRNA in the hepatocytes was detected by RT PCR. Primary culture was performed on the hepatocytes from normal rats and those with bile duct ligation for 14 days. 100 μmol/L GCDC was added to the hepatocytes for incubation for 24 h. The hepatocellular apoptotic ratio was measured by using FCM and hepatocellular apoptosis detected in situ by using TUNEL technique. Results showed that the expression of bcl 2 mRNA was not detectable in the hepatocytes of normal rats by RT PCR technique, while detectable in the hepatocytes of those with bile duct ligation (BDL) for 7, 14 and 21 days. Hepatocellular apoptosis in the BDL group was obviously decreased as compared with normal control group after addition of 100 μmol/L GCDC to the cells for 24 h. It was concluded that the hepatocytes in the BDL rats expressed bcl 2. During obstructive jaundice, expression of bcl 2 from the hepatocytes can inhibit the bile salt induced hepatocellular apoptosis.

MicroRNA-34a Regulates High Glucose-induced Apoptosis in H9c2 Cardiomyocytes

Hyperglycemia is an important initiator of cardiovascular disease, contributing to the de- velopment of cardiomyocyte death and diabetic complications. The purpose of the present study was to investigate whether high glucose state could induce apoptosis of rat cardiomyocyte cell line H9c2 through microRNA-mediated Bcl-2 signaling pathway. The expression of miR-34a and Bcl-2 mRNA was detected by using real-time PCR. Western blotting was used to examine the changes in apop- tosis-associated protein Bcl-2. Apoptosis of H9c2 cells was tested by using flow cytometry. The results showed that the expression of miR-34a was significantly elevated and that of Bcl-2 was strongly re- duced, and apoptosis of cardiomyocytes was apparently increased in the high-glucose-treated H9c2 cells as compared with normal-glucose-treated controls. In addition, we identified Bcl-2 gene was the target of miR-34a, miR-34a mimics reduced the expression of Bcl-2 and increased glucose-induced apoptosis, but miR-34a inhibitor acted as the opposite mediator. Our data demonstrate that miR-34a contributes to high glucose-induced decreases in Bcl-2 expression and subsequent cardiomyocyte apoptosis.

Visfatin Protects Rat Pancreatic β-cells against IFN-γ-Induced Apoptosis through AMPK and ERK1/2 Signaling Pathways

Objective Interferon-γ （IFN-γ） plays an important role in apoptosis and was shown to increase the riskof diabetes. Visfatin, an adipokine, has anti-diabetic, anti-tumor, and regulating inflammatoryproperties. In this study we investigated the effect of visfatin on IFN-γ-induced apoptosis in ratpancreatic β-cells.Methods The RINm5F （rat insulinoma cell line） cells exposed to IFN-γ were treated with or withoutvisfatin. The viability and apoptosis of the cells were assessed by using MTT and flow cytometry. Theexpressions of mRNA and protein were detected by using real-time PCR and western blot analysis.Results The exposure of RINm5F cells to IFN-γ for 48 h led to increased apoptosis percentage of thecells. Visfatin pretreatment significantly increased the cell viability and reduced the cell apoptosisinduced by IFN-γ. IFN-γ-induced increase in expression of p53 mRNA and cytochrome c protein,decrease in mRNA and protein levels of anti-apoptotic protein Bcl-2 were attenuated by visfatinpretreatment. Visfatin also increased AMPK and ERK1/2 phosphorylation and the anti-apoptotic actionof visfatin was attenuated by the AMPK and ERK1/2 inhibitor.Conclusion These results suggested that visfatin protected pancreatic islet cells against IFN-γ-inducedapoptosis via mitochondria-dependent apoptotic pathway. The anti-apoptotic action of visfatin ismediated by activation of AMPK and ERK1/2 signaling molecules.