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.

Paclitaxel induces human KOSC3 oral cancer cell apoptosis through caspase pathways

Background:Paclitaxel is a compound derived from Pacific yew bark that induces various cancer cell apoptosis.However,whether it also has anticancer activities in KOSC3 cells,an oral cancer cell line,is unclear.Methods:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,flow cytometry,and western blotting assays were carried out to assess cell viability,subG1 phase of the cell cycle,and apoptosis-related protein expression,respectively.Results:Ourfindings indicate that paclitaxel could inhibit cell viability and increase the expression of apoptotic markers,including plasma membrane blebbing and the cleavage of poly ADP-ribose polymerase in KOSC3 cells.Also,the treatment with paclitaxel remarkably elevated the percentage of the subG1 phase in KOSC3 cells.In addition,treatment with a pan-caspase inhibitor could recover paclitaxel-inhibited cell viability.Moreover,caspase-8,caspase-9,caspase-7,and BH3 interacting domain death agonist(Bid)were activated in paclitaxel-treated KOSC3 cells.Conclusions:Paclitaxel induced apoptosis through caspase cascade in KOSC3 cells.

Alu antisense RNA ameliorates methylglyoxal-induced human lens epithelial cell apoptosis by enhancing antioxidant defense

AIM:To determine whether an antisense RNA corresponding to the human Alu transposable element(Aluas RNA)can protect human lens epithelial cells(HLECs)from methylglyoxal-induced apoptosis.METHODS:Cell counting kit-8(CCK-8)and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assays were used to assess HLEC viability.HLEC viability/death was detected using a Calcein-AM/PI double staining kit;the annexin V-FITC method was used to detect HLEC apoptosis.The cytosolic reactive oxygen species(ROS)levels in HLECs were determined using a reactive species assay kit.The levels of malondialdehyde(MDA)and the antioxidant activities of total-superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-Px)were assessed in HLECs using their respective kits.RT-q PCR and Western blotting were used to measure m RNA and protein expression levels of the genes.RESULTS:Aluas RNA rescued methylglyoxal-induced apoptosis in HLECs and ameliorated both the methylglyoxalinduced decrease in Bcl-2 m RNA and the methylglyoxalinduced increase in Bax m RNA.In addition,Aluas RNA inhibited the methylglyoxal-induced increase in Alu sense RNA expression.Aluas RNA inhibited the production of ROS induced by methylglyoxal,restored T-SOD and GSHPx activity,and moderated the increase in MDA content after treatment with methylglyoxal.Aluas RNA significantly restored the methylglyoxal-induced down-regulation of Nrf2 gene and antioxidant defense genes,including glutathione peroxidase,heme oxygenase 1,γ-glutamylcysteine synthetase and quinone oxidoreductase 1.Aluas RNA ameliorated methylglyoxal-induced increases of the m RNA and protein expression of Keap1 that is the negative regulator of Nrf2.CONCLUSION:Aluas RNA reduces apoptosis induced by methylglyoxal by enhancing antioxidant defense.

Valproate reduces retinal ganglion cell apoptosis in rats after optic nerve crush

The retinal ganglion cells of the optic nerve have a limited capacity for self-repair after injury.Valproate is a histone deacetylase inhibitor and multitarget drug,which has been demonstrated to protect retinal neurons.In this study,we established rat models of optic nerve-crush injury and injected valproate into the vitreous cavity immediately after modeling.We evaluated changes in the ultrastructure morphology of the endoplasmic reticulum of retinal ganglion cells over time via transmission electron microscope.Immunohistochemistry and western blot assay revealed that valproate upregulated the expression of the endoplasmic reticulum stress marker glucose-regulated protein 78 and downregulated the expression of transcription factor C/EBP homologous protein,phosphorylated eukaryotic translation initiation factor 2α,and caspase-12 in the endoplasmic reticulum of retinal ganglion cells.These findings suggest that valproate reduces apoptosis of retinal ganglion cells in the rat after optic nerve-crush injury by attenuating phosphorylated eukaryotic translation initiation factor 2α-C/EBP homologous protein signaling and caspase-12 activation during endoplasmic reticulum stress.These findings represent a newly discovered mechanism that regulates how valproate protects neurons.

The Role of NF-κB p65 in White Tea Aqueous Extract-Induced Cancer Cell Apoptosis

White tea encompasses a number of teas unique to eastern Fujian in China. Although white tea extracts have been reported to result in cancer cell apoptosis, to date, few studies have evaluated the mechanism of such apoptotic induction. A transcription factor that plays a critical role in cell apoptosis, NF-κB p65, is also likely critical by which white tea extracts induce cancer cell apoptosis. In this study, white tea aqueous extract (WTAE) was added to BEL-7402 and Hela cell media and NF-κB p65 activation was evaluated using western blotting and immunofluorescence. Results revealed that the phosphorylation of IKBα and p65 decreased in both cell lines after WTAE treatment. And the nuclear translocation of NF-κB p65 in both cell lines was also reduced with the WTAE treatment. NF-κB p65 inhibition was noted to accelerate apoptosis. Our findings suggest that NF-κB p65 was an important modulator in WTAE-induced apoptotic signal transduction and it acted as a negative regulator of apoptotic induction in BEL-7402 and Hela cancer cell lines.

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.

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.

Morphological and Hormonal Identifi cation of Porcine Atretic Follicles and Relationship Analysis of Hormone Receptor Levels During Granulosa Cell Apoptosis In vivo

Recent reports have demonstrated that follicular atresia is initiated or caused by granulosa cell apoptosis followed by theca cell degeneration in mammalian ovaries, but the mechanism of follicular atresia is still to be elucidated. Therefore, our present study was designed to examine our hypothesis that the changes of follicular microenvironment induce the granulosa cell apoptosis during pocrine follicular atresia in vivo. We firstly isolated intact porcine antral follicles and identified them into three groups, healthy follicles （HF）, early atretic follicles （EAF） and progressed atretic follicles （PAF） through morphology and histology. To further confirm their status, we detected hormone levels in follicular fluids and the expression level of apoptosis gene Bax in granulosa cells. The rate of progesterone （P） and estradiol （E2） was increased with the expression of Bax, indicating hormone can be used as a marker of granulosa cell apoptosis or follicular atresia. Finally, we analyzed the expression level of hormone receptor genes in granulosa cells and their relationship with follicular atresia. In PAF, the expression of Progesterone receptor （PGR） was increased significantly while estradiol receptor （ER） had no notable changes, which suggesting the increased-PGR accelerated the effect of P-stimulated granulosa cell apoptosis. The dramatic increasing of androgen receptor （AR） expression in PAF and the obvious increase of tumor necrosis factor-u receptor （TNFR） in EAF indicated that there are different pathways regulating granulosa cell apoptosis during follicular atresia. Together, our results suggested that different pathways of granulosa cell apoptosis was induced by changing the follicular microenvironment during follicular atresia.

NORHA,a novel follicular atresia-related lncRNA,promotes porcine granulosa cell apoptosis via the miR-183-96-182 cluster and FoxO1 axis

Background:Follicular atresia has been shown to be strongly associated with a low follicle utilization rate and female infertility,which are regulated by many factors such as microRNAs(miRNAs),which constitute a class of noncoding RNAs(ncRNAs).However,little is known about long noncoding RNAs(lncRNAs),which constitute another ncRNA family that regulate follicular atresia.Results:A total of 77 differentially expressed lncRNAs,including 67 upregulated and 10 downregulated lncRNAs,were identified in early atretic follicles compared to healthy follicles by RNA-Sequencing.We characterized a noncoding RNA that was highly expressed in atretic follicles(NORHA).As an intergenic lncRNA,NORHA was one of the upregulated lncRNAs identified in the atretic follicles.To determine NORHA function,RT-PCR,flow cytometry and western blotting were performed,and the results showed that NORHA was involved in follicular atresia by influencing GC apoptosis with or without oxidative stress.To determine the mechanism of action,bioinformatics analysis,luciferase reporter assay and RNA immunoprecipitation assay were performed,and the results showed that NORHA acted as a‘sponge’,that directly bound to the miR-183-96-182 cluster,and thus prevented its targeted inhibition of FoxO1,a major sensor and effector of oxidative stress.Conclusions:We provide a comprehensive perspective of lncRNA regulation of follicular atresia,and demonstrate that NORHA,a novel lncRNA related to follicular atresia,induces GC apoptosis by influencing the activities of the miR-183-96-182 cluster and FoxO1 axis.

Loss of the vitamin D receptor in human breast and prostate cancers strongly induces cell apoptosis through downregulation of Wnt/β-catenin signaling

Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.

Germ cell apoptosis induced by Ureaplasma urealyticum infection

Aim: To study the effect of Ureaplasma urealyticum (UU) infection on germ cell apoptosis of male rats. Meth-ods: Male rats were infected artificially with UU serotype 8 (T_(960)). Morphological changes of germ cells in the sem-iniferous tubules and the lumen of the epididymides were observed under the light microscope. Fluorescence-conjugatedpolyclonal antibodies to Fas and Fas ligand (FasL) were used to localize Fas and FasL. TUNEL staining of germ cellsand Sertoli cells was performed by the AKPase method. TUNEL-positive rate (% positive cells) and TUNEL-positivearea (area occupied by stained cells) were analysed by KS400 Image Analysis System. The DNA laddering analysiswas performed by agarose gels electrophoresis. Results: In those rats infected with UU; (1) Exfoliated germ cellswere dramatically increased. Many multinucleated giant cells were found in the seminiferous tubules and the lumen ofthe epididymides. (2) The number of TUNEL-positive cells and the TUNEL-positive area were significantly increased.(3) The expression of Fas and FasL in germ cells and Sertoli cells was up-regulated. (4) Discrete bands of fragmentedDNA were found in the testicular cells. Conclusion: In male rats, germ cell apoptosis was increased in UU infec-tion . (Asian J Androl 2001 Sep; 3: 199 - 204)

Assessment of germ cell apoptosis in cryptorchid rats

Aim: To investigate the relationship between germ cell degeneration and apoptosis in cryptorchid rats. Methods: Thirteen 21-day-old Wistar rats were made unilaterally cryptorchid by closing the left inguinal canal. At day 30 (Group 1, n=6) and day 60 (Group 2, n=7) after operation, the testes were removed for histopathological examination. The controls (n=8) were sham operated and were sacrificed at day 60. Germ cell apoptosis was assessed by means of the TUNEL method. Results: Spermatogenesis was arrested and the testicular and seminiferous tubular diameters were significantly reduced In the unilateral undescended testes (UUTs) compared with the contralateral descended testes (CDTs) and the control rats. However, atrophic changes, pathological calcification, necrosis of seminiferous tubule, and absence or sloughing of germ cells were not found in all the animals. The spermatocytes were the main type of germ cells undergoing apoptosis in all the groups. In the UUTs, there was a significant and time-dependent increase in the mean apoptotic index. By 60 days after surgery, increased apoptosis in germ cells was also observed in the CDTs. Conclusion: Apoptosis is the predominant mechanism of germ cell death rather than atrophy and necrosis in cryptorchidism.

Protective effect of resveratrol on lens epithelial cell apoptosis in diabetic cataract rat

Objective:To study the protective effect of resveratrol on lens epithelial cell apoptosis in diabetic cataract rat.Methods:A total of 84 Wistar rats were divided into 4 groups:12 in Group A(control group).24 in Group B(diabetic cataract group),24 in Group C(therapeutic-dose of resveratrol group) and 24 in Group D(low-dose of resveratrol group).Rats in Group B-D were given with60 mg/kg streptozotocin through intraperitoneal injection.Rats in Group C were given with 100mg/kg resveratrol and rats in Group D were given with 20 mg/kg resveratrol.The caspase-3expression levels and apoptosis ratios of LEC among each group were observed:the degrees of lens opacity in Group B-D after 12 weeks were compared.Results:There were significant differences in caspase-3 expression levels,apoptosis ratios of T.F.C among groups at 4 w,8 w and12 w(P<0.05).After 12 weeks,in Group B the degree of lens opacity was as follow:0(0.00%) in grade Ⅰ,3(37.50%) in grade Ⅱ,2(25.00%)in grade Ⅲ,2(25.00%)grade Ⅳ,and 1(12.50%) in gradeⅤ:in Group C:2(25.00%)in grade Ⅰ,4(50.00%) in grade Ⅱ.2(25.00%)in grade Ⅲ,0(0.00%)gradeⅣ,and 0(0.00%) in grade Ⅴ;in Group D:1(12.50%)in grade Ⅰ,4(50.00%) in grade Ⅱ,2(25.00%)in grade Ⅲ,1(12.50%) grade Ⅳ,and 0(0.00%) in grade Ⅴ.The.difference among Group B-D was statistically significant(P<0.05).Conclusions:Resveratrol has protective effect on lens epithelial cell apoptosis in diabetic cataract rat,and the effect is relative to its dose.

Diabetes and renal tubular cell apoptosis

Apoptosis contributes to the development of diabetic nephropathy, but the mechanism by which high glucose induces apoptosis is not fully understood. Apoptosis of tubular epithelial cells is a major feature of diabetic kidney disease, and hyperglycemia triggers the generation of free radicals and oxidant stress in tubular cells. Hyperglycemia and high glucose in vitro also lead to apoptosis, a form of programmed cell death. High glucose similar to those seen with hyperglycemia in people with diabetes mellitus, lead to accelerated apoptosis, a form of programmed cell death characterized by cell shrinkage, chromatin condensation and DNA fragmentation, in variety of cell types, including renal proximal tubular epithelial cells.

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.

Effect of prolonged cryptorchidism on germ cell apoptosisand testicular sperm count

Aim: To evaluate the long term effect of experimental cryptorchidism on germ cell apoptotic rate and testicular sperm content in adult rats. Methods: Bilateral cryptorchidism was created in 40 adult male Sprague-Dawley rats by surgically manipulating the testes into the abdominal cavity and closing the internal inguinal ring. The rats were sacrificed and the testes removed 6 hours and 2, 4, 7, 21, 28 and 56 days after cryptorchidism. Germ cell apoptosis was quantified by means of TUNEL assay and apoptosis was confirmed using transmission electron microscopy. Results: The rate of apoptosis peaked at 4 days of cryptorchidism and then progressively declined to a nadir at 14 days of cryptorchidism. At 56 days of cryptorchidism, the germinal epithelium was largely depleted by the apoptotic process and only a few mature sperm were seen within the testis. At this point, a few tubules were seen to be repopulating with primary spermatocytes and the level of germ cell apoptosis began to increase marginally. Testicular sperm count (TSC) began to decline rapidly at day 7 of cryptorchidism. Only a few mature sperm were found in the testes of rats following 56 days of cryptorchidism. Multinucleated giant cells (MGC) were most numerous within the seminiferous tubules at day 4. At day 7, 35 % of MGCs were TUNEL positive. At all subsequent time points, however, MGCs fail to stain positive for apoptosis. This resumption of increased apoptosis coincided with the appearance of a population of primary spermatocytes in some seminiferous tubules. Moreover, there was not a corresponding increase in the number of mature sperm after 56 days of cryptorchidism. Conclusion: The decline in germ cell apoptosis after 4 days of cryptorchidism can be attributed to be the result of an overall depletion of germ cells. It appears that after a prolonged cryptorchidism (56 days), there is a limited resumption of spermatogenesis presumably as a result of a decrease in the maturing germ cells undergoing programmed cell death.

Melatonin and Doxorubicin synergistically induce cell apoptosis in human hepatoma cell lines

AIM:To investigate whether Melatonin has synergistic effects with Doxorubicin in the growth-inhibition and apoptosis-induction of human hepatoma cell lines HepG2 and Bel-7402.METHODS:The synergism of Melatonin and Doxorubicin inhibited the cell growth and induced cell apoptosis in human hepatoma cell lines HepG2 and Bel-7402.Cell viability was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT)assay.Cell apoptosis was evaluated using TUNEL method and flow cytometry.Apoptosis-related protein Bax,Bcl-2 and caspase-3 expressions were measured by immunohistochemical staining.RESULTS:Treatment with Melatonin(10 -8 -10 -5 mol/L) alone had a dose-related inhibitory effect on cell proliferation but no cytotoxic effect on hepatoma cell lines HepG2 and Bel-7402.Interestingly,when combined with Doxorubicin,Melatonin significantly increased the effects of cell growth inhibition and cell apoptosis.Furthermore,TUNEL staining and flow cytometry revealed that cooperative apoptosis induction was associated with decreased expression of Bcl-2 as well as increased expression of Bax and Caspase3.CONCLUSION:The synergism of Melatonin and Doxorubicin inhibits hepatoma cell growth and induces cell apoptosis.

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.

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.

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.