Search

Neuronal death is the main cause of nerve function impairment after spinal cord injury (SCI). Exosome-based therapy has become a novel strategy for tissue injury repair. We designed a method to treat SCI using exosomes secreted by adipose tissue–derived stromal cells (ADSCs) under hypoxic conditions. We established a neuronal oxygen-glucose deprivation and reperfusion (OGD/R) model in vitro to simulate the hypoxic environment after SCI. We observed that exosomes derived from hypoxia-conditioned ADSCs (Hypo-exo) significantly reduced neuronal apoptosis after OGD. By establishing a rat SCI model, we found that Hypo-exo can significantly reduce the formation of cavities in the injured area and improve the functional recovery of the hindlimbs of rats after injury. To explore the molecular mechanism, we conducted microRNA sequencing analysis of exosomes. Through real-time polymerase chain reaction, dual luciferase reporter assays and signaling pathway chip analysis, we determined that miR-499a-5p regulates the JNK3/c-jun-apoptotic signaling pathway by targeting JNK3. Further, we verified the expression of the key proteins in the JNK3/c-jun-apoptotic signaling pathway by immunofluorescence and Western blotting. These results support the hypothesis that Hypo-exo can reduce neuronal apoptosis after SCI and may provide new methods to treat SCI. [ABSTRACT FROM AUTHOR]

Helicobacter pylori-associated gastritis is amajor threat to public health and Polygonum capitatum (PC) may have beneficial effects on the disease. However, the molecular mechanism remains unknown. Quercetin was isolated from PC and found to be a main bioactive compound. The effects of quercetin on human gastric cancer cells GES-1 were determined by xCELLigence. H. pylori-infected mouse models were established. All mice were divided into three groups: control (CG, healthy mice), model (MG, H. pylori infection) and quercetin (QG, mouse model treated by quercetin) groups. IL-8 (interleukin-8) levels were detected via enzyme-linked immunosorbent assay (ELISA). Cell cycle and apoptosis were measured by flow cytometry (FCM). Quantitative reverse transcription PCR (qRT-PCR) and Western Blot were used to detect the levels of p38MAPK (38-kD tyrosine phosphorylated protein kinase), apoptosis regulator BCL-2-associated protein X (BAX) and B cell lymphoma gene 2 (BCL-2). The levels of IL-8 were increased by 8.1-fold in a MG group and 4.3-fold in a QG group when compared with a CG group. In a MG group, G0-G1(phases of the cell cycle)% ratio was higher than a CG group while S phase fraction was lower in a model group than in a control group (p < 0.01). After quercetin treatment, G0-G1% ratio was lower in a QG group than a MG group while S phase fraction was higher than a MG group (p < 0.01). Quercetin treatment reduced the levels of p38MAPK and BAX, and increased the levels of BCL-2 when compared with a MG group (p < 0.05). Quercetin regulates the balance of gastric cell proliferation and apoptosis to protect against gastritis. Quercetin protects against gastric inflammation and apoptosis associated with H. pylori infection by affecting the levels of p38MAPK, BCL-2 and BAX. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the association between microRNA (mi)-155 and apoptosis of monocytes infected by Mycobacterium tuberculosis, to examine the effect of forkhead box O3 (FOXO3) on miR-155. The present study analysed the apoptosis of CD14+ in the peripheral blood of patients with active tuberculosis, disposed the THP-1 human monocytic cell line by BCG and examined the expression of miR-155. Furthermore, the expression of FOXO3 in THP-1 cells was determined, and wild- and mutant-type luciferase reporter plasmids containing FOXO3 3'-untranslated regions (UTRs) were constructed to analyse the expression of luciferase. Finally, an over-expression plasmid was constructed, and THP-1 cells were transfected with control miRNA, miR-155 and the plasmid, which revealed that miR-155 inhibited the apoptosis of THP-1 cells. miR-155 in the THP-1 cells infected by BCG was upregulated and apoptosis also increased. However, the apoptosis declined when the cells were transfected with the control miRNA and miR-155. Folllowing transfection with miR-155, the expression of FOXO3 decreased. Transfection with miR-155 and the FOXO3 3'-UTRs significantly reduced luciferase, and overexpression of FOXO3 reversed the inhibitory role of miR-155. From these results, it was concluded that mycobacteria can improve the level of miR-155, while BCG can induce apoptosis in THP-1 cells. The results suggested FOXO3 is a downstream target gene of miR-155, which combines 3'-UTRs to inhibit the expression of FOXO3. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) has shown various physiological effects including anti-inflammatory activity in several diseases, whereas the therapeutic efficacy of CO on sepsis-induced acute kidney injury (AKI) has not been reported as of yet. The purpose of the present study was to explore the effects of exogenous CO on sepsis-induced AKI and nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome activation in rats. Male rats were subjected to cecal ligation and puncture (CLP) to induce sepsis and AKI. Exogenous CO delivered from CO-releasing molecule 2 (CORM-2) was used intraperitoneally as intervention after CLP surgery. Therapeutic effects of CORM-2 on sepsis-induced AKI were assessed by measuring serum creatinine (Scr) and blood urea nitrogen (BUN), kidney histology scores, apoptotic cell scores, oxidative stress, levels of cytokines TNF-α and IL-1β, and NLRP3 inflammasome expression. CORM-2 treatment protected against the sepsis-induced AKI as evidenced by reducing serum Scr/BUN levels, apoptotic cells scores, increasing survival rates, and decreasing renal histology scores. Furthermore, treatment with CORM-2 significantly reduced TNF-α and IL-1β levels and oxidative stress. Moreover, CORM-2 treatment significantly decreased NLRP3 inflammasome protein expressions. Our study provided evidence that CORM-2 treatment protected against sepsis-induced AKI and inhibited NLRP3 inflammasome activation, and suggested that CORM-2 could be a potential therapeutic candidate for treating sepsis-induced AKI. [ABSTRACT FROM AUTHOR]

The purpose of this study was to further evaluate the role of myxoma virus (MYXV) as an oncolytic agent against experimental human gliomas in vitro, and analyze the effect of MYXV on malignant glioma cells at different incubation periods and infected at different multiplicities of infection. Neuroglioma cell lines U251 and A172 were cultured with various infective doses of myxoma virus at different time points (0-3 days) and cellular survival rates were evaluated using an MTT assay. Cell viability and cell death rates were assessed using Annexin V/propidium iodide and applying flow cytometry. Furthermore, the expression levels of phosphorylated AKT (p-AKT) in malignant gliomas were detected by western blot analysis to investigate the possible cell signaling targets in the pathway. MYXV exhibited a dose and time-dependent cytotoxic effect on neuroglioma cells, and there was increased expression of p-AKT in malignant gliomas. The present study confirms that MYXV induces oncolysis of malignant gliomas through regulating the activation of AKT. As such, MYXV is a potential therapeutic agent against human malignant gliomas. [ABSTRACT FROM AUTHOR]

Small ubiquitin-related modifier protein (SUMO) is an evolutionarily conserved protein in a broad range of eukaryotic organisms. De-SUMOylation, the reverse reaction of SUMOylation, is regulated by a family of SUMO-specific proteases (SENPs). SENP1 is a member of the de-SUMOylation protease family involved in the de-SUMOylation of a variety of SUMOylated proteins. The present study demonstrates that small hairpin RNA (shRNA)-mediated downregulation of SENP1 inhibits cell proliferation and migration, and promotes apoptosis in human glioma cells. Firstly, LN-299 cells were transfected with a plasmid expressing SENP1 shRNA (pGenesil-1-SENP1). The messenger RNA and protein expression of SENP1 was detected by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Cell proliferation in vitro was assessed using a methyl thiazolyl tetrazolium assay. Flow cytometry (FCM) was used to detect the apoptosis of LN-299 cells. The effect of the downregulation of SENP1 on cell migration was detected by a Transwell migration system. The present results showed that, compared with the control shRNA group, the expression of SENP1 was significantly reduced in the SENP1 shRNA group. The proliferation was markedly inhibited in the SENP1 shRNA group. FCM findings revealed that apoptosis increased significantly in the SENP1 shRNA group. In addition, it was found that downregulation of SENP1 evidently suppressed tumor cell migration. Downregulation of SENP1 expression inhibited the proliferation and migration and promoted apoptosis in LN-299 cells. These results indirectly demonstrate that SENP1 is likely to play a critical role in human glioma cells. [ABSTRACT FROM AUTHOR]

Serum autoantibodies against tumor-associated antigen have important value in the early diagnosis of hepatocellular carcinoma (HCC), but the mechanism of autoantibody production is poorly understood. We previously showed that autoantibodies against the centromere protein F (CENPF) may be useful as an early diagnostic marker for HCC. Here we explored the mechanism of cell apoptosis-based CENPF autoantibody production and verified the correlation of CENPF autoantibody level with HCC development. We demonstrated that CENPF was overexpressed and aberrantly localized throughout the nuclei and cytoplasm in human HCC cells compared with hepatic cells. CENPF overexpression promoted the production of CENPF autoantibodies in a manner that correlated with tumor growth of mouse HCC model. During apoptosis of HCC cells, CENPF protein translocated to apoptotic vesicles and relocalized at the cell surface. Through isolating apoptotic components, we found apoptotic body and blebs with lower CD31 and CD47 expression more effectively induced DC phagocytosis and maturation compared with apoptotic intact cells in vitro, and this DC response was independent of CENPF expression. Moreover, injection of mice with apoptotic bodies and blebs effectively induced an immune response and the production of CENPF-specific antibodies. Our findings provide a first elucidation of mechanisms underlying the CENPF autoantibody production via cell apoptosis-induced CENPF translocation, and demonstrate a direct correlation between CENPF autoantibody levels and HCC progression, suggesting the potential of CENPF autoantibody as an HCC diagnostic marker. [ABSTRACT FROM AUTHOR]

Background/Aims: Lung cancer (LC) continues to be one of the most prevalent cancers around the world. During this study we aimed to investigate the involvement of endoplasmic reticulum stress (ERS) in autophagy, apoptosis, and chemotherapy resistance of mutant p53 LC cells. Methods: Immunohistochemistry was employed to help determine the p53 mutation status of cancer cells from 92 primary LC patients, who were subsequently assigned to either the mutant p53 (n = 39) or wild-type p53 group (n = 53). Results: Mutant p53 cells exhibited increased expression of the C/EBP homologous protein (CHOP), glucose-regulated protein 78 (GRP78), and inositol-requiring enzyme-1a (IRE1a). The Mutant p53 cells were also found to be sensitive to chemotherapy and displayed decreased expression of PI3K, Akt, and mTOR. The mutant p53 cell lines were treated with tunicamycin to induce ERS and rapamycin in order to inhibit mTOR. Both agents increased the expression of CHOP, GRP78, IRE1a, LC3-II/LC3-I, Atg5, Atg7, caspase-3, caspase-12, cleaved caspase-3, cleaved caspase-12, as well as decreases in cell proliferation as well as the expression levels of PI3K, Akt, and mTOR. Enhanced levels of cell apoptosis and reduced chemotherapy resistance were also detected. Conclusion: The findings of our study suggest that ERS promotes autophagy and apoptosis, while acting to reduce chemotherapy resistance in mutant p53 LC cells by downregulating the PI3K/Akt/mTOR signaling pathway. [ABSTRACT FROM AUTHOR]

Background/Aims: CINN is the main ingredient of the traditional Chinese medicine cinnamon. The purpose of the present study was to investigate the effects of CINN on the proliferation and apoptosis of NPC cells and to elucidate the underlying molecular mechanisms. Materials and Methods: CNE2 human NPC cells were treated with various CINN concentrations. The effects of CINN on the proliferation and apoptosis of CNE2 NPC cells were examined using the MTT assay and flow cytometric analysis. Additionally, western blotting was performed to analyze the expression of a number of cell cycle- and apoptosis-related proteins. Results: The proliferation of CNE2 cells was significantly inhibited after treatment with different CINN concentrations for various lengths of time. The inhibitory effect of CINN was concentration-and time-dependent. Flow cytometric analysis showed that 2 mmol/L CINN displayed a significant apoptosis-inducing effect. The western blot analysis results showed that KLF6, Fas-L, Bax, P53 and caspase-3 protein expression was drastically increased in the CNE2 cells after treatment with 2 mmol/L CINN, whereas Bcl-2 and cyclin D1 protein expression was markedly reduced. Conclusion: CINN inhibits the proliferation and induces the apoptosis of CNE2 cells. Therefore, CINN possesses a potential anti-tumor effect. [ABSTRACT FROM AUTHOR]

Background/Aims: CINN is the main ingredient of the traditional Chinese medicine cinnamon. The purpose of the present study was to investigate the effects of CINN on the proliferation and apoptosis of NPC cells and to elucidate the underlying molecular mechanisms. Materials and Methods: CNE2 human NPC cells were treated with various CINN concentrations. The effects of CINN on the proliferation and apoptosis of CNE2 NPC cells were examined using the MTT assay and flow cytometric analysis. Additionally, western blotting was performed to analyze the expression of a number of cell cycle- and apoptosis-related proteins. Results: The proliferation of CNE2 cells was significantly inhibited after treatment with different CINN concentrations for various lengths of time. The inhibitory effect of CINN was concentrationand time-dependent. Flow cytometric analysis showed that 2 mmol/L CINN displayed a significant apoptosis-inducing effect. The western blot analysis results showed that KLF6, Fas-L, Bax, P53 and caspase-3 protein expression was drastically increased in the CNE2 cells after treatment with 2 mmol/L CINN, whereas Bcl-2 and cyclin D1 protein expression was markedly reduced. Conclusion: CINN inhibits the proliferation and induces the apoptosis of CNE2 cells. Therefore, CINN possesses a potential anti-tumor effect. [ABSTRACT FROM AUTHOR]

The abnormal expression of microRNAs (miRs) as oncogenes or tumor-suppressor genes has been widely investigated in various tumor types. However, the roles of miR-335 in bladder cancer cells have remained elusive. The aim of the present study was to assess the expression of miR-335 in bladder cancer as well as the effects of miR-335 on bladder cancer cell proliferation, metastasis and apoptosis. PCR and western blot analyses revealed that miR-335 was significantly downregulated in bladder cancer tissues, and low levels of miR-335 were associated with more aggressive phenotypes of bladder cancer. Overexpression of miR-335 in T24 cells inhibited cell proliferation and induced apoptosis as indicated by an MTT assay and flow cytometric analysis, respectively. Furthermore, overexpression of miR-335 significantly suppressed cell migration, as indicated by a Transwell assay. The expression of mitogen-activated protein kinase (MAPK)1 was decreased after overexpression of miR-335, indicating that MAPK1 may be a target gene of miR-335. In addition, silencing of MAPK1 inhibited the proliferation and migration of bladder cancer cells. In conclusion, the results of the present study demonstrated that miR-335 was significantly downregulated in bladder cancer, and may act as a tumor suppressor through repression of MAPK1. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to evaluate the effects of uric acid in promoting tubular cell apoptosis and verify the role of nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4)-induced oxidative stress in this process. HK-2 cells were used as a human proximal tubular cell model and co-cultured with various concentrations of uric acid with or without pre-treatment with the Nox4 inhibitor diphenylene iodonium (DPI). The apoptotic rate and the amount of reactive oxygen species (ROS) were examined by flow cytometry. Furthermore, levels of Nox4, phosphorylated (p)-P38, p-extracellular signal-regulated kinase (ERK), B-cell lymphoma 2 (Bcl-2) and Bcl-2-extra large (Bax) were detected by western blot analysis. The results showed that treatment with uric acid decreased HK-2 cell viability and promoted apoptosis in a dose-dependent manner. This was paralleled with an upregulation of Nox4 as well as ROS overproduction, which activated the phosphorylation of P38/ERK and caused an imbalance of Bax/Bcl-2 in HK-2 cells. Of note, inhibition of Nox4 with DPI prevented uric acid-induced cell injury by suppressing ROS generation and P38/ERK activation. In conclusion, it was demonstrated that elevated uric acid promoted ROS-induced tubular cell apoptosis by upregulating Nox4 expression. The present study therefore provided possible mechanisms and a potential therapeutic target of uric acid-induced chronic kidney disease. [ABSTRACT FROM AUTHOR]

8-p-Hdroxybenzoyl tovarol (TAW) is a germacrane-type sesquiterpenoid that can be isolated from the roots of Ferula dissecta (Ledeb.) Ledeb. In this study, the growth inhibitory effects induced by TAW were screened on some types of tumor cells, and the mechanism was investigated on TAW-induced growth inhibition, including paraptosis and autophagy in human cervical cancer HeLa cells. TAW-induced paraptosis involved extensive cytoplasmic vacuolization in the absence of caspase activation. Additionally, TAW evoked cell paraptotic death mediated by endoplasmic reticulum (ER) stress and unfolded protein response (UPR). Autophagy induced by TAW was found to antagonize paraptosis in HeLa cells. This effect was enhanced by rapamycin and suppressed by the autophagy inhibitor, 3-methyladenine (3MA). Loss of beclin 1 (an autophagic regulator) function led to promote ER stress. Taken together, these results suggest that TAW induces paraptosis like cell death and protective autophagy in HeLa cells, which would provide a new clue for exploiting TAW as a promising agent for the treatment of cervical cancer. [ABSTRACT FROM AUTHOR]

We investigated the effects of troglitazone on human cervical cancer SiHa cells and its mechanisms of action. SiHa cells were incubated with different concentrations of troglitazone (100, 200, or 400 µg/mL) for 24, 48, and 72 hours. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay; cell cycle and apoptosis were detected by flow cytometry; and morphology of SiHa cells was observed under an inverted microscope. pcDNA3.1 and pcDNA3.1-Skp2 plasmids were constructed and then transfected into SiHa cells. Protein expression was analyzed by Western blotting. Troglitazone inhibited the proliferation of SiHa cells in a time- and concentration-dependent manner. Troglitazone caused G0/1 phase arrest but failed to reduce apoptosis in SiHa cells. Troglitazone significantly increased expression of p27 but decreased Skp2 expression. Skp2 overexpression inhibited the role of troglitazone in increasing expression of p27, and the cell cycle inhibitory effect of troglitazone. Troglitazone can inhibit SiHa cell viability by affecting cell cycle distribution but not apoptosis, and Skp2 and p27 may play a critical role. [ABSTRACT FROM AUTHOR]

Oxidative stress represents a major cause of cellular damage and death in pathological conditions including osteoporosis, in which oxidative stress is associated with increased bone resorption and low bone mass. And grape seed proanthocyanidins are a group of polyphenolic bioflavonoids which are known to possess broad pharmacological activity and therapeutic potential, exerting a protective role against oxidant injury. The aim of our study was to investigate whether proanthocyanidins exert an anti-apoptosis effect in osteoblastic MC3T3-E1 cells, via their antioxidant activity. Firstly, we determined the anti-apoptosis effect of proanthocyanidins in osteoblastic MC3T3-E1 cells, which were subject to H2O2 treatment, then we determined the association of the antioxidant activity exerted by proanthocyanidins with their anti-apoptosis effect. Results demonstrated that proanthocyanidins inhibit H2O2-promoted apoptosis in MC3T3-E1 cells, via ameliorating the viability of MC3T3-E1 cells post H2O2treatment and reducing the apoptotic cell numbers. And the proanthocyanidins treatment also ameliorates the H2O2-induced mitochondrial dysfunction via promoting the mitochondrial membrane potential (MMP) and respiratory chain complex IV, and reducing the mitochondrial free radical production, ROS and mitochondrial superoxide. Moreover, the proanthocyanidins inhibit H2O2-induced apoptosis signaling which is mediated by p53. This study implied a possible anti-osteoporosis effect of proanthocyanidins via their antioxidant and anti-apoptosis activity. [ABSTRACT FROM AUTHOR]

BACKGROUND: Retinoid X receptor (RXR) plays a central role in the regulation of intracellular receptor signaling pathways. The activation of RXR has protective effect on H2O2-induced apoptosis of H9c2 ventricular cells in rats. But the protective effect and mechanism of activating RXR in cardiomyocytes against hypoxia/reoxygenation (H/R)-induced oxidative iniury are still unclear. METHODS: The model of H/R injury was established through hypoxia for 2 hours and reoxygenation for 4 hours in H9c2 cardiomyocytes of rats. 9-cis-retinoic acid (9-cis RA) was obtained as an RXR agonist, and HX531 as an RXR antagonist. Cultured cardiomyocytes were randomly divided into four groups: sham group, H/R group, H/R+9-cis RA -pretreated group (100 nmol/L 9-cis RA), and H/R+9-cis RA+HX531-pretreated group (2.5 μmol/L HX531). The cell viability was measured by MTT, apoptosis rate of cardiomyocytes by flow cytometry analysis, and mitochondrial membrane potential ("#m) by JC-1 fluorescent probe, and protein expressions of Bcl-2, Bax and cleaved caspase-9 with Western blotting. All measurement data were expressed as mean±standard deviation, and analyzed using one-way ANOVA and the Dunnett test. Differences were considered significant when P was <0.05. RESULTS: Pretreatment with RXR agonist enhanced cell viability, reduced apoptosis ratio, and stabled "#m. Dot blotting experiments showed that under H/R stress conditions, Bcl-2 protein level decreased, while Bax and cleaved caspase-9 were increased. 9-cis RA administration before H/R stress prevented these effects, but the protective effects of activating RXR on cardiomyocytes against H/R induced oxidative injury were abolished when pretreated with RXR pan-antagonist HX531. CONCLUSION: The activation of RXR has protective effects against H/R injury in H9c2 cardiomyocytes of rats through attenuating signaling pathway of mitochondria apoptosis. [ABSTRACT FROM AUTHOR]