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MicroRNAs (miRNAs) have been reported as key gene regulators, and they control many fundamental biological processes. Previously, we demonstrated that miR-214 had a protective effect against myocardial apoptosis and myocardial fibrosis. In this study, we sought to investigate the expression of miR-214 in L6 skeletal myoblast (SKM), the regulatory effect of miR-214 on hydrogen peroxide (H2O2) induced cell apoptosis and the underlying mechanisms of the antiapoptotic effect. MiR-214 expression was up-regulated by H2O2 in a dose and time-dependent manner in L6 SKMs. To investigate the regulatory effects of miR-214 on L6 SKM, both gain-of-function and loss-of-function approaches were applied. The results showed that miR-214 improved cell survival and inhibited cell apoptosis, and blockage of miR-214 abrogated the protective effect on cell survival and resistance to apoptosis. Phosphatase and tensin homolog (PTEN) was negatively regulated by miR-214, and PTEN inhibitor obviously reversed the effect of miR-214 blockage on enhancing cell apoptosis. In addition, miR-214 up-regulated antiapoptotic protein Bcl-2, down-regulated proapoptotic protein Bax, prevented release of cytochrome c and inhibited caspase-3 activation. In summary, H2O2-induced injury increases miR-214 expression in L6 SKM, and miR-214 contributes to the protection of L6 SKM against apoptosis via lowering PTEN and subsequently inhibiting the mitochondrial-mediated caspase-dependent apoptotic signaling pathway. [ABSTRACT FROM AUTHOR]

Due to the significance of reactive oxygen species (ROS) in numerous physiological processes including pathogen response, apoptosis, and induction of defense genes, various methods have been developed for their quantitative analysis. However, the conventional methods using exogenous tracers lack the capability to conduct real-time in vivo measurements. The electrochemical biosensors have shown their potentials for in vivo applications with the rapid and reagentless detection processes. In this article, electrochemical biosensors that are capable of making in vivo ROS detections are reviewed. The different configurations of these biosensors with corresponding strategies to enhance sensitivity and selectivity are discussed in detail. With further studies to promote the biosensor performance, these devices promise to provide more facile ways for ROS research in life sciences. [ABSTRACT FROM AUTHOR]

Purpose : To assess the in-vitro effects of dexamethasone (DEX) on the proliferation, apoptosis, and Na+-K+-ATPase activity of bovine corneal endothelial cells. Methods : Bovine corneal endothelial cells were cultured with DEX ranging from 10 -10 to 10 -3 M. The effect of DEX on the proliferation was analyzed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay. Apoptosis and necrosis were detected by staining with fluorescein-conjugated annexin V and propidium iodide, followed by flow cytometry. The effect of DEX on Na+-K+-ATPase activity was evaluated using non-isotopic methods. Results : DEX did not affect cellular proliferation or induce apoptosis/necrosis from 10 -10 to 10 -5 M. At 10 -4 and 10 -3 M, DEX significantly decreased proliferation and increased apoptosis and/or necrosis. DEX significantly increased the Na+-K+-ATPase activity from 10 -8 to 10 -6 M, with the maximal effect at 10 -6 M ( p [ABSTRACT FROM AUTHOR]

To explore whether resveratrol (Res) pretreatment could exert a protective effect on cyclophosphamide (Cy) induced ovarian toxicity in a rat model. Twenty-four female 7-week old Sprague-Dawley rats were randomly divided into four groups: Con, administered with vehicle solutions; Cy, treated with Cy; Res + Cy, treated with Cy + Res combined; Res, treated with Res. After 21 d of treatments, the rats were euthanized and blood samples were collected to evaluate the levels of anti-Müllerian hormone (AMH). The Ovaries were processed for immunohistochemical and western blotting. Cy-treat caused the decrease of body weights and ovarian weight. AMH was lower in Cy group, whereas AMH levels were similar among other groups. Histomorphology showed a large number of primordial follicles were activated in Cy groups, whereas the primordial follicles were inhibited in the Res and Res + Cy groups. The expressions of Sirt1, Foxo3a were up-regulated and p53, Caspase-3, and Bax were down-regulated in Res + Cy and Res groups (p <.05). Res can prevent the primordial follicle activation and decrease apoptosis induced by Cy. Res may be an effective protection for ovarian function during chemotherapy, which means a new nonsurgical application for protection of ovarian reserve. [ABSTRACT FROM AUTHOR]

Context: Oleanolic acid (OA) belongs to the triterpenoid compound group existing widely in food, medicinal herbs and other plants. Its effects on gastric cancer cells and the mechanisms involved have not been investigated. Objective: This study aimed to substantiate whether OA induces apoptosis of gastric cancer cell line (MKN28) and to elucidate the molecular mechanism involved. Materials and methods: Cell viability was assessed by MTT assay within the range of 0-160 μg/mL. The effects of OA (5, 10 and 20 μg/mL) on apoptosis of MKN28 cells were evaluated by flow cytometry, DNA fragmentation and mitochondrial membrane potential assays. Western blot and FQRT-PCR assays were used to investigate the mechanism of cell apoptosis induced by OA (5 and 10 μg/mL). Results: OA evidently inhibited cell viability with IC50 of 44.8 and 15.9 μg/mL at 12 and 24 h, respectively. Furthermore, OA increased JNK phosphorylation, decreased AKT phosphorylation, but did not affect p38 and ERK phosphorylation in MKN28 cells. In contrast, OA also significantly enhanced the mRNA expression levels of caspase 3, caspase 9 and Apaf-1 in MKN28 cells. Conclusion: OA induces apoptosis of MKN28 cells via the mitochondrial pathway regulated by AKT and JNK signaling pathways. [ABSTRACT FROM AUTHOR]

Homocysteine (Hcy) is a neurotoxic amino acid that accumulates in several neurodegenerative disorders. We examined the consequences of treatment of cultured rat hippocampal neurons with Hcy and the effects of folate, S-adenosyl methionine (SAM) and MK-801 on Hcy-induced neuron apoptosis and the related molecular mechanisms were also observed. Primary hippocampal neurons were treated with 250 μM Hcy for 4 h resulted in apoptosis time-dependently. 100 μM S-adenosyl methionine (SAM) and 10 μM folate significantly repressed, although 1 μM MK-801, an NMDA receptor inhibitor did not, Hcy-induced neuron apoptosis. SAM and folate significantly repressed Hcy-induced neuron DNA damage. Hcy induced neuron calcium overload through activation of NMDA receptors. Hcy treatment also induced a significant increase in MDA level, but did not affect the neurons' total antioxidant capacity (T-AOC). Hcy (250 μM) significantly increased the expression of p53 and Bax while decreased the expression of Bcl-2. SAM and folate inhibited the changes of apoptosis-related protein expression induced by Hcy. These findings indicate that Hcy compromises neuronal homeostasis by not only DNA damage, but also neuron exitotoxicity, oxidative injury, apoptosis, and expression changes of apoptosis-related proteins. [ABSTRACT FROM AUTHOR]

Growing evidences have shown that patients recovering from stroke experience high and unremitting stress. Chronic restraint stress (CRS) has been found to exacerbate neurological impairments in an experimental focal cortical ischemia model. However, there have been no studies reporting the effect and mechanism of CRS on intracerebral hemorrhage (ICH). This study aimed to evaluate the effect of CRS on a mouse ICH model. Adult male C57BL mice were subjected to infusion of collagenase IV (to induce ICH) or saline (for sham) into the left striatum. After ICH, animals were stressed with application of CRS protocol for 21 days. Our results showed that CRS significantly exacerbated neurological deficits (Garcia test, corner turn test, and wire grip test) and the ipsilateral brain atrophy and reduced body weight gain after ICH. Immunofluorescence staining indicated that CRS exerted significant suppressive effects on neuron, astrocyte, vascular endothelial cell and pericyte and excessively activated microglia post ICH. All of the key cellular components mentioned above are involved in the neurovascular unit (NVU) remodeling in the peri-hemorrhagic region after ICH. Western blot results showed that matrix metalloproteinase (MMP)-9 and tight junction (TJ) proteins including zonula occludens-1, occludin and claudin-5 were increased after ICH, but MMP-9 protein was further up-regulated and TJ-related proteins were down-regulated by CRS. In addition, ICH-induced activation of endoplasmic reticulum stress and apoptosis were further strengthened by CRS. Collectively, CRS exacerbates neurological deficits and disrupts the remodeling of the peri-hemorrhagic NVU after ICH, which may be associated with TJ proteins degradation and excessive activation of MMP-9 and endoplasmic reticulum stress-apoptosis. CRS exacerbates neurological deficits and disrupts the remodeling of the NVU in the recovery stage after ICH, which suggest that monitoring chronic stress levels in patients recovering from ICH may merit consideration in the future. [ABSTRACT FROM AUTHOR]

Dendritic cell (DC) vaccines were generated by apoptotic squamous cell carcinoma (SCC) cells induced by 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT). ALA-PDT-DC vaccine inhibited the growth of SCC in mice, indicating that immunogenic apoptotic cells can activate an effective antitumor adaptive immunity and lead to a DC vaccine-based cancer immunotherapy. [ABSTRACT FROM AUTHOR]