miR‑423 sponged by lncRNA NORHA inhibits granulosa cell apoptosis

Background Atresia and degeneration,a follicular developmental fate that reduces female fertility and is triggered by granulosa cell(GC)apoptosis,have been induced by dozens of miRNAs.Here,we report a miRNA,miR-423,that inhibits the initiation of follicular atresia(FA),and early apoptosis of GCs.Results We showed that miR-423 was down-regulated during sow FA,and its levels in follicles were negatively correlated with the GC density and the P4/E2 ratio in the follicular fluid in vivo.The in vitro gain-of-function experiments revealed that miR-423 suppresses cell apoptosis,especially early apoptosis in GCs.Mechanically speaking,the miR-423 targets and interacts with the 3’-UTR of the porcine SMAD7 gene,which encodes an apoptosis-inducing factor in GCs,and represses its expression and pro-apoptotic function.Interestingly,FA and the GC apoptosis-related lncRNA NORHA was demonstrated as a ceRNA of miR-423.Additionally,we showed that a single base deletion/insertion in the miR-423 promoter is significantly associated with the number of stillbirths(NSB)trait of sows.Conclusion These results demonstrate that miR-423 is a small molecule for inhibiting FA initiation and GC early apoptosis,suggesting that treating with miR-423 may be a novel approach for inhibiting FA initiation and improving female fertility.

Dihydroartemisinin enhances cell apoptosis in diffuse large B cell lymphoma by inhibiting the STAT3 activity

Background:Dihydroartemisinin(DHA)is reported to be a potential anticancer agent,and the mechanisms underlying the effects of DHA on diffuse large B cell lymphoma however are still obscure.This study aimed to assess the antitumor effect of DHA on diffuse large B cell lymphoma cells and to determine the potential underlying mechanisms of DHA-induced cell apoptosis.Methods:Here,the Cell Counting Kit 8 assay was conducted to study cell proliferation.We performed Annexin V-FITC/propidium iodide staining,real-time polymerase chain reaction,and western blot analysis to analyze cell apoptosis and potential molecular mechanisms.Results:The results showed that DHA substantially suppressed cell proliferation and induced cell apoptosis in vitro in a time-and concentration-dependent fashion.Moreover,STAT3 activity could be inhibited after stimulation with DHA.Conclusion:These results imply that the underlying anti-tumoral effect of DHA may increase apoptosis in diffuse large B cell lymphoma cells via the STAT3 signaling pathway.In addition,DHA might be an effective drug for diffuse large B cell lymphoma therapy.

Discovery and structure-activity relationship studies of novel tetrahydro-β-carboline derivatives as apoptosis initiators for treating bacterial infections

Developing and excavating new agrochemicals with highly active and safe is an important tactic for protecting crop health and food safety.In this paper,to discover the new bactericide candidates,we designed,prepared a new type of1,2,3,4-tetrahydro-β-carboline(THC)derivatives and evaluated the in vitro and in vivo bioactivities against the Xanthomonas oryzae pv.oryzae(Xoo),Xanthomonas axonopodis pv.citri(Xac),and Pseudomonas syringae pv.actinidiae(Psa).The in vitro bioassay results exhibited that most title molecules possessed good activity toward the three plant pathogenic bacteria,the compound A17 showed the most active against Xoo and Xac with EC50 values of 7.27 and 4.89 mg mL^(-1)respectively,and compound A8 exhibited the best inhibitory activity against Psa with EC50value of 4.87 mg mL^(-1).Pot experiments showed that compound A17 exhibited excellent in vivo antibacterial activities to manage rice bacterial leaf blight and citrus bacterial canker,with protective efficiencies of 52.67 and 79.79%at 200 mgmL^(-1),respectively.Meanwhile,compound A8 showed good control efficiency(84.31%)against kiwifruit bacterial canker at 200 mg mL^(-1).Antibacterial mechanism suggested that these compounds could interfere with the balance of the redox system,damage the cell membrane,and induce the apoptosis of Xoo cells.Taken together,our study revealed that tetrahydro-β-carboline derivatives could be a promising candidate model for novel broadspectrum bactericides.

Intermittent fasting boosts antitumor immunity by restricting CD11b^(+)Ly6C^(low)Ly6G^(low) cell viability through glucose metabolism in murine breast tumor model

Intermittent fasting can benefit breast cancer patients undergoing chemotherapy or immunotherapy.However,it is still uncertain how to select immunotherapy drugs to combine with intermittent fasting.Herein we observed that two cycles of fasting treatment significantly inhibited breast tumor growth and lung tissue metastasis,as well as prolonged overall survival in mice bearing 4T1 and 4T07 breast cancer.During this process,both the immunosuppressive monocytic-(M-)and granulocytic-(G-)myeloid-derived suppressor cell(MDSC)decreased,accompanied by an increase in interleukin(IL)7R^(+)and granzyme B^(+)T cells in the tumor microenvironment.Interestingly,we observed that Ly6G^(low)G-MDSC sharply decreased after fasting treatment,and the cell surface markers and protein mass spectrometry data showed potential therapeutic targets.Mechanistic investigation revealed that glucose metabolism restriction suppressed the splenic granulocytemonocyte progenitor and the generation of colony-stimulating factors and IL-6,which both contributed to the accumulation of G-MDSC.On the other hand,glucose metabolism restriction can directly induce the apoptosis of Ly6G^(low)G-MDSC,but not Ly6G^(high)subsets.In summary,these results suggest that glucose metabolism restriction induced by fasting treatment attenuates the immune-suppressive milieu and enhances the activation of CD3^(+)T cells,providing potential solutions for enhancing immune-based cancer interventions.

Effects of Downregulation of Inhibin α Gene Expression on Apoptosis and Proliferation of Goose Granulosa Cells

Inhibin a is one of the candidate genes that control the ovulation in poultry. To study the genetic effects of inhibin a on apoptosis and proliferation of goose granulosa cells cultured in vitro, two RNA interference （RNAi） expression vectors, psiRNA-INHal and psiRNA-INHα2, were constructed to knock down inhibin α gene expression. After 48 h of transfection, the efficiency of these two RNAi expression vectors was examined by fluorescence microscopy. Meanwhile, inhibin protein expression levels, apoptosis indexes （AI） and proliferation indexes （PI） of granulosa cells were analyzed by flow cytometry. In addition, the supernatants were collected to assay the concentrations of estrogen （E2） and progesterone （P） by radioimmunoassay. The results showed that the expression level of inhibin a in the RNAi group were decreased 30%--40% than those in the control groups （P 〈0.05） and the apoptosis indexes and proliferation indexes in the RNAi groups were significantly higher than those in the control groups （P 〈0.05）. However, the E2 concentrations in the RNAi groups were lower than those in the control groups （P 〈0.05）. These results indicate that inhibin a has antagonistic effect on granulosa cell apoptosis.

Study on Induction of Microcystis aeruginosa Cell Apoptosis by Signal Molecule N-acetyl-homoserine Lactones(AHLs)

[Objective]The relationship between signal molecule N-acety-homoserine lactones（AHLs） and Microcystis aeruginosa cell apoptosis was studied.[Method]With M.aeruginosa as the test materials treated by 5 μmol/L N-acety-homoserine lactones（AHLs）,the morphology of cell apoptosis was observed through staining with DAPI.[Result]Microcystis aeruginosa cell apoptosis was induced by signal molecule N-acetyhomoserine lactones（AHLs） with the concentration of 1 μmol/L to inhibit the growth and proliferation of Microcystis aeruginosa.[Conclusion] The results provided the important scientific basis and new management ideas for the treatment of water bloom of Microcystis aeruginosa.

Moxibustion down-regulates colonic epithelial cell apoptosis and repairs tight junctions in rats with Crohn's disease

AIM: To investigate the effects of moxibustion on down-regulation of the colonic epithelial cell apoptosis and repair of the tight junctions in rats with Crohn's disease (CD). METHODS: Sixty male Sprague-Dawley rats were randomly divided into a normal control (NC) group, a model control (MC) group, an herbs-partitioned moxibustion (HPM) group, a mild-warm moxibustion (MWM) group and a salicylazosulphapyridine (SASP) group, with 12 rats in each group. The CD model rats were treated with trinitrobenzene sulphonic acid to induce intestinal inflammation. The rats in the HPM and MWM groups were treated at the Tianshu (ST25) and Qihai (CV6) acupoints once daily for 14 d, and the SASP group was fed SASP twice daily for 14 d. No additional treatment was given to the MC and NC groups. Themicrostructure of the colonic epithelium was observed under a transmission electron microscope, the transepithelial resistance was measured using a shortcircuit current, colonic epithelial cell apoptosis was determined by terminal deoxynucleotidyl transferasemediated dUTP-biotin nick end labelling assay, and the expression of occludin, claudin-1 and zonula occludens-l (ZO-1) in the colonic epithelial junction was determined by Western blotting and immunofluorescence staining. RESULTS: Compared with the MC group, the microstructure of the colonic epithelial barrier was signifi-cantly improved in rats treated with HPM, MWM or SASP, meanwhile, the current flow was reduced signifi-cantly, with values of 168.20 ± 6.14 vs 99.70 ± 3.13, 99.10 ± 4.28 and 120.30 ± 3.65 mA, respectively (P = 0.001). However, the HPM and MWM groups had higher current flow rates than the SASP group (99.70 ± 3.13, 99.10 ± 4.28 vs 120.30 ± 3.65 mA, P = 0.001). The number of the apoptotic colonic epithelial cells in HPM, MWM and SASP groups was largely reduced (61.5 ± 16.91 vs 15.5 ± 8.89, 14.8 ± 6.27 and 24.7 ± 9.68, respectively (P = 0.001); and the expression of occlu- din, claudin-1 and ZO-1 in the MWM and HPM groups was signifi cantly enhanced (0.48 ± 0.10, 0.64 ± 0.09 vs 0.18 ± 0.05 for occludin, 0.12 ± 0.02, 0.17 ± 0.03 vs 0.05 ± 0.01 for claudin-1, and 0.08 ± 0.01, 0.11 ± 0.01 vs 0.02 ± 0.01 for ZO-1). And in SASP group, the expression of occludin and ZO-1 was also signifi cantly increased (0.27 ± 0.04 vs 0.18 ± 0.05 for occludin and 0.05 ± 0.01 vs 0.02 ± 0.01 for ZO-1), but there was no significant difference for claudin-1. The HPM and MWM groups had higher expression of occludin, claudin-1 and ZO-1 than the SASP group. CONCLUSION: HPM and MWM treatment can down-regulate apoptosis of colonic epithelial cells, repair tight junctions and enhance colonic epithelial barrier function in rats with CD.

Phosphatidylinositol 3-kinase/Akt pathway regulates hepatic stellate cell apoptosis

AIM: To investigate the role of phosphatidylinositol 3-kinase (PI 3-K)/Akt signaling pathway in the balance of HSC activation and apoptosis in rat hepatic stellate cells (HSC). METHODS: An activated HSC cell line was used in this study. LY 294002, the PI 3-K/Akt signal pathway block-er was used to investigate the molecular events on apoptosis in HSC and to interpret the role of this path-way in HSC apoptosis. Immunocytochemistry, Western blot and reverse transcription polymerase chain reac-tion (RT-PCR) analysis were applied to detect the ex-pression of PI 3-K, and simultaneously phosphorylated-Akt (p-Akt) and total-Akt were determined by Western blot. The HSC apoptosis was examined by annexin-V/ propidium iodide double-labelled flow cytometry and transmission electron microscopy. RESULTS: The apoptosis rates in LY 294002 (30.82% ± 2.90%) and LY 294002 + PDGF-BB (28.16% ± 2.58%) groups were signif icantly increased compared with those of control (9.02% ± 1.81%) and PDGF-BB (4.35% ± 1.18%). PDGF-BB augmented PI 3-K and p-Akt expres-sion. LY 294002 signif icantly reduced the contents of PI 3-K and p-Akt. mRNA transcription evaluated by RT-PCR showed similar tendencies as protein expression. CONCLUSION: Inhibition of PI 3-K/Akt signaling path-way induces apoptosis in HSC.

Blocking NF-kB nuclear translocation leads to p53-related autophagy activation and cell apoptosis

AIM: To investigate the anti-tumor effects of nuclear factor-κB (NF-κB) inhibitor SN50 and related mechanisms of SGC7901 human gastric carcinoma cells. METHODS: MTT assay was used to determine the cytotoxic effects of SN50 in gastric cancer cell line SGC7901. Hoechst 33258 staining was used to detect apoptosis morphological changes after SN50 treatment. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after SN50 treatment.Immunofluorescence staining was used to detect the expression of light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. Western blotting analysis were used to determine the expression of proteins involved in apoptosis and autophagy including p53, p53 upregulated modulator of apoptosis (PUMA), damage-regulated autophagy modulator (DRAM), LC3 and Beclin 1. We detected the effects of p53-mediated autophagy activation on the apoptosis of SGC7901 cells with the p53 inhibitor pifithrin-α. RESULTS: The viability of SGC7901 cells was inhibited after SN50 treatment. Inductions in the expression of apoptotic protein p53 and PUMA as well as autophagic protein DRAM, LC3 and Beclin 1 were detected with Western blotting analysis. SN50-treated cells exhibited punctuate microtubule-associated protein 1 LC3 in immunoreactivity and MDC-labeled vesicles increased after treatment of SN50 by MDC staining. Collapse of mitochondrial membrane potential Δψ were detected for 6 to 24 h after SN50 treatment. SN50-induced increases in PUMA, DRAM, LC3 and Beclin 1 and cell death were blocked by the p53 specific inhibitor pifithrin-α. CONCLUSION: The anti-tumor activity of NF-κB inhibitors is associated with p53-mediated activation of autophagy.

Molecular mechanisms of apoptosis in hepatocellular carcinoma cells induced by ethanol extracts of Solanum lyratum Thumb through the mitochondrial pathway

AIM To explore the induction effects and mechanism of Solanum lyratum Thumb(ST) on human hepatocellularcarcinoma SMMC-7721 cells through the mitochondrial pathway.METHODS The experiments were conducted on three groups: an experimental group (with ST ethanol extracts' concentration being 2.5, 5 and 10 mg/L), a negative control group (with only nutrient solution, 0 mg/L ST ethanol extracts), and a positive control group (2.5 mg/L DDP). The inhibition rate of cell proliferation was checked by using the methyl thiazolyl tetrazolium method, and cell apoptosis was tested by TUNEL method. Furthermore, RT-PCR was used to examine m RNA expression of Fas, Fas L, caspase-8, caspase-3, p53 and Bcl-2 genes.RESULTS Compared with the negative control group, the inhibition and apoptosis rates of the experimental group with different concentrations of ST extracts on human hepatocellular carcinoma SMMC-7721 cells significantly increased(P<0.05). Besides, the m RNA expression of Fas L and Bcl-2 significantly decreased(P<0.05) while the m RNA expression of Fas, caspase-8, caspase-3 and p53 increased significantly. When compared with the positive control group, the experimental groups with 5 mg/L ST ethanol extracts showed effects similar to the positive control group.CONCLUSION ST ethanol extracts induced the apoptosis of hepatocellular carcinoma SMMC-7721 cells through up-regulated Fas, caspase-8, caspse-3 and p53, and down-regulated Fas L and Bcl-2 in the mitochondrial pathway.

Role of cell adhesion signal molecules in hepatocellular carcinoma cell apoptosis

AIM： Cell adhesion molecules and their signal molecules play a very important role in carcinogenesis. The aim of this study is to elucidate the role of these molecules and the signal molecules of integrins and E-cadherins, such as （focal adhesion kinase） FAK, （integrin linked kinase） ILK, and β-catenin in hepatocellular carcinoma cell apoptosis. METHODS： We first synthesized the small molecular compound, S-（1,2-dichlorovinyl）-L-cysteine （DCVC）, and identified it, by element analysis and ^1H NMR. To establish the apoptosis model of the SMMC-7721 hepatocellular carcinoma cell, we treated cells with DCVC in EBSS for different concentrations or for various length times in the presence of 20 μmol/L N,N-cliphenyl-p-phenylenediamine, which blocks necrotic cell death and identified this model by flow cytometry and DNA ladder. Then we studied the changes of FAK, ILK, β-catenin, and PKB in this apoptotic model by Western blot. RESULTS： We found that the loss or decrease of cell adhesion signal molecules is an important reason in apoptosis of SMMC-7721 hepatocellular carcinoma cell and the apoptosis of SMMC-7721 cell was preceded by the loss or decrease of FAK, ILK, PKB, and β-catenin or the damage of cell-matrix and cell-cell adhesion. CONCLUSION： Our results suggested that the decrease of adhesion signal molecules, FAK, ILK, PKB, and β-catenin, could induce hepatocellular carcinoma cell apoptosis.

Simulated Microgravity Conditions and Carbon Ion Irradiation Induce Spermatogenic Cell Apoptosis and Sperm DNA Damage

Objective To investigate the effect of simulated microgravity and carbon ion irradiation （CIR） on spermatogenic cell apoptosis and sperm DNA damage to the testis of male Swiss Webster mice, and assess the risk associated with space environment. Methods Sperm DNA damage indicated by DNA fragmentation index （DFI） and high DNA stainability （HDS） was measured by sperm chromatin structure assay （SCSA）. Apoptosis of spermatogenic cells was detected by annexin V-propidium iodide assay. Bax （the expression levels of p53） and proliferating cell nuclear antigen （PCNAI were measured by immunoblotting; p53 and PCNA were located by immunohistology. Results HDS, DFI, apoptosis index, and the expression levels of p53 and Bax were detected to be significantly higher in the experimental groups （P〈0.05） compared with those in the control group, however, the PCNA expression varied to a certain degree, p53- and PCNA- positive expression were detected in each group, mainly in relation to the spermatogonic cells and spermatocytes. Conclusion The findings of the present study demonstrated that simulated microgravity and CIR can induce spermatogenic cell apoptosis and sperm DNA damage. Sperm DNA damage may be one of the underlying mechanisms behind male fertility decline under space environment. These findings may provide a scientific basis for protectint~ astronauts and space traveler＇s health and safety.

Quantification of choline concentration following liver cell apoptosis using ~1H magnetic resonance spectroscopy

AIM: To evaluate the feasibility of quantifying liver choline concentrations in both normal and apoptotic rabbit livers in vivo, using 1H magnetic resonance spectroscopy (1H-MRS). METHODS: 1H-MRS was performed in 18 rabbits using a 1.5T GE MR system with an eight-channel head/neck receiving coil. Fifteen rabbits were injected with sodium selenite at a dose of 10 μmol/kg to induce the liver cell apoptosis. Point-resolved spectroscopy sequencelocalized spectra were obtained from 10 livers once before and once 24 h after sodium selenite injection in vivo. T1 and T2 relaxation time of water and choline was measured separately in the livers of three healthy rabbits and three selenite-treated rabbits. Hematoxylin and eosin and dUTP-biotin nick end labeling (TUNEL) staining was used to detect and confirm apoptosis. Choline peak areas were measured relative to unsuppressed water using LCModel. Relaxation attenuation was corrected using the average of T1 and T2 relaxation time. The choline concentration was quantified using a formula, which was tested by a phantom with a known concentration. RESULTS: Apoptosis of hepatic cells was confirmed by TUNEL assay. In phantom experiment, the choline concentration (3.01 mmol/L), measured by 1H-MRS, was in good agreement with the actual concentration (3 mmol/L). The average T1 and T2 relaxation time of choline was 612 ± 15 ms and 74 ± 4 ms in the control group and 670 ± 27 ms and 78 ± 5 ms in apoptotic livers in vivo, respectively. Choline was quantified in 10 rabbits, once before and once after the injection with sodium selenite. The choline concentration decreased from 14.5 ± 7.57 mmol/L before sodium selenite injection to 10.8 ± 6.58 mmol/L (mean ± SD, n = 10) after treatment (Z = -2.395, P < 0.05, two-sample paired Wilcoxon test). CONCLUSION: 1H-MRS can be used to quantify liver choline in vivo using unsuppressed water as an internal reference. Decreased liver choline concentrations are found in sodium selenite-treated rabbits undergoing liver cell apoptosis.

Gender difference in the neuroprotective effect of rat bone marrow mesenchymal cells against hypoxiainduced apoptosis of retinal ganglion cells

Bone marrow mesenchymal stem cells can reduce retinal ganglion cell death and effectively prevent vision loss. Previously, we found that during differentiation, female rhesus monkey bone marrow mesenchymal stem cells acquire a higher neurogenic potential compared with male rhesus monkey bone marrow mesenchymal stem cells. This suggests that female bone marrow mesenchymal stem cells have a stronger neuroprotective effect than male bone marrow mesenchymal stem cells. Here, we first isolated and cultured bone marrow mesenchymal stem cells from female and male rats by density gradient centrifugation. Retinal tissue from newborn rats was prepared by enzymatic digestion to obtain primary retinal ganglion cells. Using the transwell system, retinal ganglion cells were co-cultured with bone marrow mesenchymal stem cells under hypoxia. Cell apoptosis was detected by flow cytometry and caspase-3 activity assay. We found a marked increase in apoptotic rate and caspase-3 activity of retinal ganglion cells after 24 hours of hypoxia compared with normoxia. Moreover, apoptotic rate and caspase-3 activity of retinal ganglion cells significantly decreased with both female and male bone marrow mesenchymal stem cell co-culture under hypoxia compared with culture alone, with more significant effects from female bone marrow mesenchymal stem cells. Our results indicate that bone marrow mesenchymal stem cells exert a neuroprotective effect against hypoxia-induced apoptosis of retinal ganglion cells, and also that female cells have greater neuroprotective ability compared with male cells.

MiR-96-5p inhibition induces cell apoptosis in gastric adenocarcinoma

BACKGROUND Gastric adenocarcinoma(GAC)mortality rates have remained relatively changed over the past 30 years,and it continues to be one of the leading causes of cancerrelated death.AIM To search for novel miRNAs related to GAC prognosis and further investigate the effect of miR-96-5p on MGC-803 cells.METHODS The miRNA expression profile data of GAC based on The Cancer Genome Atlas were obtained and used to screen differently expressed miRNAs(DEMs)and DEMs related to GAC prognosis.Then,the expression of DEMs related to GAC prognosis was identified in GAC tumor samples and adjacent normal samples by qRT-PCR.The target gene,ZDHHC5,of miR-96-5p was predicted using TargetScan,miRTarBase,and miRDB databases and confirmed by luciferase reporter assay.Furthermore,MGC-803 cells were transfected with inhibitor NC,miR-96-5p inhibitor,si-ZDHHC5,or miR-96-5p inhibitor+si-ZDHHC5,and then cell apoptosis was detected by flow cytometry.The expression of ZDHHC5,Bcl-2,and COX-2 was detected using western blotting.RESULTS A total of 299 DEMs and 35 DEMs related to GAC prognosis were screened based on The Cancer Genome Atlas.Then compared with adjacent normal samples,the levels of miR-96-5p,miR-222-5p,and miR-652-5p were remarkably increased,while miR-125-5p,miR-145-3p,and miR-379-3p levels were reduced in GAC tumor samples(P<0.01),which were consistent with bioinformatics analysis.Furthermore,ZDHHC5 was defined as a direct target gene of miR-96-5p.miR-96-5p inhibition increased the number of apoptotic cells as well as promoted the expression of ZDHHC5,Bcl-2,and COX-2 in MGC-803 cells(P<0.01).After ZDHHC5 inhibition,the number of apoptotic cells and the expression of ZDHHC5,Bcl-2,and COX-2 were reduced.The addition of an miR-96-5p inhibitor partly reversed these effects(P<0.01).CONCLUSION Our findings identified six miRNAs related to GAC prognosis and suggested that downregulated miR-96-5p might induce cell apoptosis via upregulating ZDHHC5 expression in MGC-803 cells.

Demethylation of miR-34a upregulates expression of membrane palmitoylated proteins and promotes the apoptosis of liver cancer cells

BACKGROUND Liver cancer is a common cancer and the main cause of cancer-related deaths worldwide.Liver cancer is the sixth most common cancer in the world.Although miR-34a and palmitoyl membrane palmitoylated protein(MPP2)are reportedly involved in various cell processes,their precise roles in liver cancer are still unclear.AIM To investigate the expression of micro RNA 34a(miR-34a),methylation of the miR-34a promoter and the expression of MPP2 in liver cancer cells and their related mechanisms.METHODS Together,78 cases of liver cancer tissues and 78 cases of adjacent tissues were collected.The methylation degree of miR-34a promoter in liver cancer/paracancerous tissue and liver cancer cells/normal liver cells,and the expression levels of miR-34a and MPP2 in the above samples were detected.Demethylation of liver cancer cells or transfection of liver cancer cells with miR-34a mimetic was performed.The MPP2 overexpression vector was used to transfect liver cancer cells,and the changes in proliferation,invasion,apoptosis,migration,and other biological functions of liver cancer cells after the above interventions were observed.Double luciferase reporter genes were used to detect the targeting relationship between miR-34a and MPP2.RESULTS Clinical samples showed that the expression levels of miR-34a and MPP2 in liver cancer tissues were lower than those in the normal tissues.The methylation degree of miR-34a promoter region in liver cancer cells was higher than that in normal liver cells.After miR-34a demethylation/mimetic transfection/MPP2 overexpression,the apoptosis of liver cancer cells was increased;the proliferation,invasion and migration capabilities were decreased;the expression levels of caspase 3,caspase 9,E-cadherin,and B-cell lymphoma 2(Bcl-2)-associated X protein were increased;and the expression levels of Bcl-2,N-cadherin,andβ-catenin were decreased.Double luciferase reporter genes confirmed that MPP2 is targeted by miR-34a.Rescue experiments showed that small interfering MPP2 could counteract the promoting effect of miR-34a demethylation on apoptosis and the inhibitory effect on cell proliferation,invasion,and migration.CONCLUSION miR-34a demethylation upregulates the expression level of MPP2 in liver cancer cells and promotes the apoptosis of liver cancer cells.miR-34a demethylation is a potential method for liver cancer treatment.

The Relationship between p38MAPK and Apoptosis during Paclitaxel Resistance of Ovarian Cancer Cells

To investigate the relationship between p38 mitogen-activated protein kinase （p38MAPK） and cell apoptosis during the paclitaxel resistance of ovarian carcinoma cell lines, flow cytometry （FCM） and PI staining were employed to determine the effect of p38MAPK inhibitor SB203580 on the apoptosis of A2780/Taxol cells, a drug-resistant human ovarian carcinoma cell line. p38MAPK protein expression in SB203580-treated cells was immunochemically measured. The 50% inhibition concentration （IC50） of paclitaxel on A2780/Taxol cells was determined by MTT assay. MDR-1 mRNA, and expression of p38MAPK and phospho-p53 protein were detected by RToPCR and Western blotting, respectively. The apoptosis rate of A2780/Taxol cells was （19.7±1.04）% 24 h after SB203580 treatment. A significant difference in apoptosis rate was found among experiment group, control group and untreated group （p〈0.05）. The relative reversal rate of A2780/Taxol cells to paclitaxel was （57.18±2.01）%. As compared with the control group and the untreated group, p38MAPK protein and MDR-1 mRNA in SB203580-treated cells was substantially decreased. The expression of p53 protein was significantly increased. It is concluded that p38MAPK pathway is related to paclitaxel resistance of ovarian carcinoma, and blockade of this pathway can promote the apoptosis of the drug-resistant cells and reverse the drug-resistance. Moreover, p38MAPK-mediated apoptosis in paclitaxel-resistant ovarian carcinoma cells depends on the activation of p53.

JNK3 involvement in nerve cell apoptosis and neurofunctional recovery after traumatic brain injury

Increasing evidence has revealed that the activation of the JNK pathway participates In apoptosis o1 nerve cells and neurological function recovery after traumatic brain injury. However, which genes inI the JNK family are activated and their role in traumatic brain injury remain unclear. Therefore, in this study, in situ end labeling, reverse transcription-PCR and neurological function assessment were adopted to investigate the alteration of JNK1, JNK2 and JNK3 gene expression in cerebral injured rats, and their role in celt apoptosis and neurological function restoration. Results showed that JNK3 expression significantly decreased at 1 and 6 hours and 1 and 7 days post injury, but that JNK1 and JNK2 expression remained unchanged. In addition, the number of apoptotic nerve cells surrounding the injured cerebral cortex gradually reduced over time post injury. The Neurological Severity Scores gradually decreased over 1,3, 5, 14 and 28 days post injury. These findings suggested that JNK3 expression was downregulated at early stages of brain injury, which may be associated with apoptosis of nerve cells. Downregulation of JNK3 expression may promote the recovery of neurological function following traumatic brain injury.

Effects of extracellular iron concentration on calcium absorption and relationship between Ca^(2+) and cell apoptosis in Caco-2 cells

AIM: To determine the method of growing small intestinal epithelial cells in short-term primary culture and to investigate the effect of extracellular iron concentration ([Fe3+]) on calcium absorption and the relationship between the rising intracellular calcium concentration ([Ca2+]i) and cell apoptosis in human intestinal epithelial Caco-2 cells. METHODS: Primary culture was used for growing small intestinal epithelial cells. [Ca2+]i was detected by a confocal laser scanning microscope. The changes in [Ca2+]i were represented by fluorescence intensity (FI). The apoptosis was evaluated by flow cytometry. RESULTS: Isolation of epithelial cells and preservation of its three-dimensional integrity were achieved using the digestion technique of a mixture of collagenase Ⅺ and dispase Ⅰ. Purification of the epithelial cells was facilitated by using a simple differential sedimentation method. The results showed that proliferation of normal gut epithelium in vitro was initially dependent upon the maintenance of structural integrity of the tissue. If 0.25% trypsin was used for digestion, the cells were severely damaged and very difficult to stick to the Petri dish for growing. The Fe3+ chelating agent desferrioxamine (100, 200 and 300 μmol/L) increased the FI of Caco-2 cells from 27.50±13.18 (control, n = 150) to 35.71±13.99 (n = 150, P<0.01), 72.19±35.40 (n = 150, P<0.01) and 211.34±29.03 (n = 150,P<0.01) in a concentration-dependent manner. There was a significant decrease in the FI of Caco-2 cells treated by ferric ammonium citrate (FAC, a Fe3+ donor; 10, 50 and 100 μmol/L). The FI value of Caco-2 cells treated by FAC was 185.85±33.77 (n = 150, P<0.01), 122.73±58.47 (n = 150, P<0.01), and 53.29±19.82 (n= 150,P<0.01), respectively, suggesting that calcium absorption was influenced by [Fe3+]. Calcium ionophore A23187(0.1,1.0 and 10 μmol/L) increased the FI of Caco-2 cells from 40.45±13.95 (control, n = 150) to 45.19±21.95 (n = 150, P<0.01), 89.87±43.29 (n = 150, P<0.01) and 104.64±51.07 (n = 150,P<0.01) in a concentration-dependent manner. The positive apoptotic cell number of the Caco-2 cells after being treated with A23187 increased from 0.32% to 0.69%, 0.90% and 1.10%, indicating that the increase in the positive apoptotic cell number was positively correlated with [Ca2+]i. CONCLUSION: Ca2+ absorbability is increased with the decrease of extracellular iron concentration Fe3+ and hindered with the increase of Fe3+ consistence out of them. Furthermore, increase of [Ca2+]i can induce apoptosis in Caco-2 cells.

Cellular Adhesion Tripeptide RGD Inhibits Growth of Human Ileocecal Adenocarcinoma Cells HCT-8 and Induces Apoptosis

The tripeptide,Arg-Gly-Asp（RGD）motif is an integrin-recognition site found in adhesive proteins present in extracellular matrices（ECM）and in the blood.HCT-8 cells were treated with cellular adhesion tripeptide RGD at various concentrations.MTT assay was performed to examine the growth and proliferation of HCT-8 cells after treatment with RGD for 48 h.Haematoxylin and Eosin（HE）staining and electromicroscope were used to observe the morphology of apoptotic cells.Survivin and flow cytometry were also used to analyze the HCT-8 apoptosis.Cellular adhesion tripeptide RGD significantly inhibits the growth and proliferation of HCT-8 cells in a dose-dependent manner and induces apoptosis of HCT-8.These results indicate that cellular adhesion tripeptide RGD inhibits the growth and proli-feration of tumor HCT-8 cell,probably by the aid of inducing apoptosis of HCT-8 cell.