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Glioblastoma multiforme (GBM) is the most frequent, lethal, and aggressive tumor of the central nervous system in adults. In this study, we found for the first time that moschamindole (MCD), a rare phenolic amide with 8/6/6/5/5 rings, is a major bioactive constituent derived from Phragmites communis Trin (Poaceae) that exhibits a potential cytotoxic effect on both TMZ-resistant GBM cell lines and xenograft models. MCD-induced intrinsic apoptosis signals and mitochondrial dysfunction were confirmed by cell cycle arrest, caspase-3/7 activation, and membrane potential depolarization. Furthermore, investigations exploring the mechanism showed that MCD specifically inhibits Mia40-mediated oxidative folding of mitochondrial intermembrane space (IMS) proteins via PCR assay and immunoblot analysis. MCD relies on its positive charge to associate with mitochondrial oxidative respiration, thus blocking energy metabolism and inducing apoptosis. Overexpression and upregulation of Mia40 were proven to reverse MCD-induced apoptosis and were correlated with the chemoresistance of GBM in vitro and in vivo, respectively. Taken together, our study demonstrates that Mia40 is a potential target of the chemoresistance of glioblastoma and suggests that MCD might be a potential agent for the individualized treatment of chemoresistant GBM based on mitochondrial metabolic characteristics and Mia40 expression.

To observe the effect of electroacupuncture (EA) on learning and memory ability, hippocampal hypoxia inducible factor-1α(HIF-1α) and apoptosis in postoperative cognitive dysfunction(POCD) rats, and to investigate its mechanism underlying improvement of POCD.A total of 90 aged male SD rats were randomized into a sham-operation group, a model group and an EA group, 30 rats in each group, which were further divided into 3 time-point subgroups (1, 3 and 7 days after intevention, 10 rats in each subgroup). In the model group and the EA group, left hepatectomy was adopted to establish the model of POCD. In the sham-operation group, the skin was sectioned and no hepatectomy was operated. In the EA group, EA was applied at "Siguan" ["Hegu" (LI 4) and "Taichong" (LR 3)] with dilatational wave, 2 Hz/100 Hz in frequency, 1 mA in intensity, 20 min each time, once a day. Morris water maze test was adopted to observe the cognitive functions. Real-time PCR and Western blot were used to measure the hippocampal level of HIF-1α. TUNEL method was used to evaluate the hippocampal level of neurons apoptosis. Double immunofluorescence labeling was used to detect the colocalization of HIF-1α and apoptosis in the EA group.Compared with the sham-operation group, the escape latency was prolonged and the frequency of platform leaping was reduced in the model group (Electroacupuncture improves cognitive functions in postoperative cognitive dysfunction rats, which may be related to its effect in down-regulating the expression of hippocampal HIF-1α and inhibiting the neurons apoptosis.

PDB-1 is a new C-27-carboxylated-lupane-triterpenoid derivative isolated from Potentilla discolor Bunge. In our previous research, PDB-1 was suggested to have an obvious selectivity for tumor cells. This study focused on clarifying PDB-1’s anticancer mechanism in the inhibition of proliferation and in the induction of apoptosis and autophagy in A549 cells. In general, A549 cells were treated with PDB-1 for different times, and cell survival was assessed by a CCK8 assay. The assessment of intracellular reactive oxygen species, a mitochondrial membrane potential assay, a cell cycle assay, an annexin V-FITC/PI assay, and MDC staining were performed in A549 cells treated with PDB-1. Moreover, the mRNA and protein expression of cell cycle-, apoptosis- and autophagy-related factors were detected by RT-qPCR and western blotting. The results showed that PDB-1 inhibited A549 cell proliferation and colony formation in a dose- and time-dependent manner. The decrease in the viability of A549 cells was due to a G2/M cell cycle arrest. Moreover, PDB-1 induced cell apoptosis, accompanied by an increase in the Bax/Bcl-2 ratio and an increase in the expression levels of cleaved caspase-3/caspase-9. We also found that PDB-1 induced autophagy by increasing the conversion of LC3-I to LC3-II and elevating Beclin-1. In addition, further studies indicated that pretreatment with a specific PI3K inhibitor (LY294002) enhanced the effects of PDB-1 on the expression of proteins associated with apoptosis and autophagy, demonstrating that the PI3K/Akt/mTOR pathway was related to PDB-1-induced apoptosis and autophagy. These results indicated that PDB-1 may be considered a potential candidate for the future treatment of lung adenocarcinoma. These findings should benefit the development of the C14-COOH type of pentacyclic triterpenoids.

Background The identification of novel therapeutic candidates from natural products for the development of chemoresistant glioblastoma multiforme (GBM) treatment has been a highly significant and effective strategy. Purpose Sesquiterpenes are a class of naturally occurring 15-carbon isoprenoid compounds, and several types of sesquiterpenes have the ability to induce growth inhibition and apoptosis in a variety of cancer cell lines. In the present study, 56 sesquiterpenes of five types, namely, eudesmane-type (I) (1–24), eremophilane-type (II) (25–32), cadinane-type (III) (33–41), guaiane-type (IV) (42–49), and oplopanone-type (V) (50–56), were screened for their antiglioma activity, structure-activity relationship analysis (SAR), and underlying mechanism based on patient-derived recurrent GBM strains, patient-derived GBM cell sphere, GBM organoid (GBO) models, and temozolomide (TMZ)-resistant GBM cell lines. Results We found that compound 12 (oxyphyllanene B, OLB) showed the most potent antiglioma activity, and we confirmed that OLB could induce apoptosis in a time- and dose-dependent manner in TMZ-resistant GBM cells and GBOs. SAR announced that the presence of an α, β-unsaturated carbonyl moiety was likely to enhance cytotoxic activities. Mechanistic studies demonstrated that OLB induced abnormal changes in ER and mitochondria-associated membrane (MAM) networks, which triggered ER stress, mitochondrial dysfunction, and apoptosis. Furthermore, our findings suggested that OLB-triggered PACS2 activation might form a committed step to disrupt ER-mitochondria communication and showed for the first time that the expression levels of PACS2 might positively correlate with the progression and chemotherapy resistance of glioma. Conclusion Our results indicated that OLB might be a promising candidate for treating TMZ-resistant GBM cells by activating PACS2, which triggered a crucial event to promote the disruption of ER-mitochondria communication and overcome chemotherapy resistance of GBM.

Clavipyrrine A (1), a novel polycyclic nitrogenous meroterpenoid with a pyrrolo[1,2-a]imidazole and a 10-membered carbocycle fused with an α,β-epoxy-γ-lactone, was isolated from Clitocybe clavipes, a basidiomycete. X-ray crystallography and spectroscopic analysis were used to fully elucidate its structure. The biosynthetic origin of the pyrrole unit in this nitrogenous meroterpenoid was identified by incorporating 15N-labeled γ-aminobutyric acid. Compound 1 displayed promising anti-glioma activities and induced glioma cell apoptosis through inhibiting the JAK/STAT3 pathway and reinforcing SOCS1/3.

The chemical composition, antibacterial activity and mechanism of essential oil from Cyperus rotundus rhizomes against Staphylococcus aureus were investigated in this study. Results showed that α-cyperone, cyperene and α-selinene were the major components of the essential oil. The essential oil exhibited strong antibacterial activity against S. aureus with the minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) were 10 and 20 mg/mL respectively, and the antibacterial effects increased with increasing essential oil concentrations and treatment time. The electric conductivity, cell membrane integrity, NPN uptake, and membrane potential assays demonstrated that essential oil disrupted the membrane integrity of S. aureus . Electron microscope observations further confirmed that essential oil destroyed cell membrane. Moreover, we found that essential oil could induce cells death of S. aureus through apoptosis pathway based on apoptosis analysis. These findings suggested that essential oil mainly exerted antibacterial activity by damaging cell membrane and membrane-mediated apoptosis pathway.

Hepatic macrophages (MΦs) are important in the development and progression of alcoholic liver disease (ALD). This study investigates the role of gp91phox (nicotinamide adenine dinucleotide phosphate oxidase 2) in the severity of ALD and specifically in regulating hepatic MΦ efferocytic capability and the subsequent reprogramming associated with resolution of inflammation. After 4 weeks of ethanol feeding, more severe ALD developed in gp91phox-/- mice than in wild-type (WT) C57Bl/6J mice, evidenced by increased liver injury and inflammation. This phenomenon was not sex dependent, and thus the majority of experiments were performed with female mice. While total hepatic MΦ numbers did not differ between genotypes, hepatic infiltrating MΦs (IMs) were slightly more numerous in gp91phox-/- mice, and both IMs and resident Kupffer cells displayed enhanced proinflammatory and reduced tissue-restorative programming compared with these cells from WT mice. The ratio of proinflammatory IMs with higher expression of Ly6C (Ly6Chi) to anti-inflammatory IMs with lower expression of Ly6C (Ly6Clow) was significantly higher in gp91phox-/- mice compared to WT mice. Greater numbers of apoptotic cells accumulated in the liver of gp91phox-/- mice compared to WT mice, and receptors for binding and engulfing apoptotic cells were expressed at much lower levels on both Kupffer cells and IMs of gp91phox-/- mice. Interactions with apoptotic cells (binding and engulfment) in vitro were significantly fewer for gp91phox-/- MΦs than for WT MΦs, resulting in diminished expression of tissue restorative mediators by hepatic MΦs of gp91phox-/- mice. Conclusion: gp91phox plays a critical role in the differentiation of proinflammatory hepatic MΦs to a tissue-restorative phenotype, likely through programming for efferocytosis, and thereby lessens the severity of ALD. These findings enhance our understanding of the tissue environmental cues that regulate MΦ phenotypes. This knowledge could help in designing MΦ-targeting strategies to prevent and treat ALD. (Hepatology Communications 2017;1:765-779).

Obcordata A (OA) is a polyoxypregnane glycoside derived from the Dai medicine Aspidopterys obcordata vines. This study aims to investigate the efficacy of OA on renal tubular epithelial cells exposed to calcium oxalate crystals. We incubated renal tubular cells with 28 &mu, g&middot, cm2 calcium oxalate crystals for 24 h with and without OA, GKT137831, phorbol-12-myristate-13-acetate (PMA), and tocopherol. The MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, microscopic examination, flow cytometry, and immunofluorescence staining revealed that calcium oxalate crystals decreased cell viability and elevated reactive oxygen species (ROS) levels. OA, GKT137831, and tocopherol protected cells and decreased ROS levels. However, OA did not exhibit direct DPPH scavenging ability. In addition, immunoblotting illustrated that OA inhibited the NOX4 (nicotinamide adenine dinucleotide phosphate oxidases 4) expression and downregulated the protein expression in the NOX4/ROS/p38 MAPK (p38 mitogen-activated protein kinase) pathway. The findings suggest that the cytoprotective and antioxidant effects of OA can be blocked by the NOX4 agonist PMA. In conclusion, OA could be used as a NOX4 inhibitor to prevent kidney stones.

Background Glioblastoma multiforme (GBM) is the most frequent, lethal and aggressive tumour of the central nervous system in adults. The discovery of novel anti-GBM agents based on the isocitrate dehydrogenase (IDH) mutant phenotypes and classifications have attracted comprehensive attention. Purpose Diterpenoids are a class of naturally occurring 20-carbon isoprenoid compounds, and have previously been shown to possess high cytotoxicity for a variety of human tumours in many scientific reports. In the present study, 31 cassane diterpenoids of four types, namely, butanolide lactone cassane diterpenoids (I) (1-10), tricyclic cassane diterpenoids (II) (11-15), polyoxybutanolide lactone cassane diterpenoids (III) (16-23), and fused furan ring cassane diterpenoids (IV) (24-31), were tested for their anti-glioblastoma activity and mechanism underlying based on IDH1 mutant phenotypes of primary GBM cell cultures and human oligodendroglioma (HOG) cell lines. Results We confirmed that tricyclic-type (II) and compound 13 (Caesalpin A, CSA) showed the best anti-neoplastic potencies in IDH1 mutant glioma cells compared with the other types and compounds. Furthermore, the structure-relationship analysis indicated that the carbonyl group at C-12 and an α, β-unsaturated ketone unit fundamentally contributed to enhancing the anti-glioma activity. Studies investigating the mechanism demonstrated that CSA induced oxidative stress via causing glutathione reduction and NOS activation by negatively regulating glutaminase (GLS), which proved to be highly dependent on IDH mutant type glioblastoma. Finally, GLS overexpression reversed the CSA-induced anti-glioma effects in vitro and in vivo, which indicated that the reduction of GLS contributed to the CSA-induced proliferation inhibition and apoptosis in HOG-IDH1-mu cells. Conclusion Therefore, the present results demonstrated that compared with other diterpenoids, tricyclic-type diterpenoids could be a targeted drug candidate for the treatment of secondary IDH1 mutant type glioblastoma through negatively regulating GLS.

Doxorubicin (DOX) is a commonly used anthracycline in treatments of leukemia, lymphoma and breast cancer in humans and has been limited by its cardiotoxicity, which is manifested congestive heart failure in the worst condition. The present study showed that the marine carotenoid of fucoxanthin could exert cardioprotective effect against the DOX-induced injury in ICR mice. And then, the protective effects and mechanisms of fucoxanthin on DOX-induced injury of neonatal rat cardiomyocytes were investigated. The results demonstrated that fucoxanthin significantly reduced mice toxic death triggered by DOX. The protective effects were also showed by the suppression of apoptotic cell death in cardiomyocytes. Further study revealed that fucoxanthin-produced suppression of MAPK activated by DOX was involved in the cardioprotection. The findings confirmed the cardioprotective effect of fucoxanthin against DOX-induced cardiotoxicity by protecting myocardial cells from lipid peroxidation and apoptosis, which would likely result in an increased therapeutic window of DOX in cancer therapy.

Receptor Expressed in Lymphoid Tissues (RELT) is a human Tumor Necrosis Factor Receptor (TNFR) family member that has two identified homologous binding partners, RELL1 and RELL2. This study sought to further understand the pattern of RELT expression, the functional role of RELT family members, and the mechanism of RELT-induced apoptosis. RELT protein expression was detected in the spleen, lymph node, brain, breast and peripheral blood leukocytes (PBLs). A smaller than expected size of RELT was observed in PBLs, suggesting a proteolytically cleaved form of RELT. RELL1 and RELL2 overexpression activated the p38 MAPK pathway more substantially than RELT in HEK-293 cells, and this activation of p38 by RELT family members was blocked by dominant-negative mutant forms of OSR1 or TRAF2, implicating these molecules in RELT family member signaling. RELT was previously shown to induce apoptosis in human epithelial cells despite lacking the characteristic death domain (DD) found in other TNFRs. Seven deletion mutants of RELT that lacked differing portions of the intracellular domain were created to assess whether RELT possesses a novel DD. None of the deletion mutants induced apoptosis as efficiently as full-length RELT, a result that is consistent with a novel DD being located at the carboxyl-terminus. Interestingly, induction of apoptotic morphology by RELT overexpression was not prevented when signaling by FADD or Caspase-8 was blocked, indicating RELT induces apoptosis by a pathway distinct from other death-inducing TNFRs such as TNFR1. Collectively, this study provides more insights into RELT expression, RELT family member function, and the mechanism of RELT-induced death.

Morroniside is a water-soluble compound extracted from the fruit of Cornus officinalis and is used to protect lung activity against aging. In the present study, the manner in which morroniside regulates normal lung and cancer cells was examined. The human embryonic lung fibroblast (HELF) cell line and lung cancer A549 cell line, and their responses to morroniside treatment, were examined. Results showed that morroniside reverses the apoptotic effect of H2O2 on HELF cell growth, protecting cell proliferation and normal cell morphology and inhibiting apoptosis. However, these effects were not present in A549 cells. Western blotting showed that morroniside also markedly downregulated retinoblastoma protein in HELF cells. These results suggest that morroniside treatment exhibits different effects on apoptosis in HELF and A549 cells, making it a viable compound for decreasing the side effects of anticancer medicines in normal cells.

Background The use of plant essential oils as pharmaceuticals is a fast-growing market especially in China. Throughout the 20th century, a rapid increase took place in the use of many essential oil-derived products in the medicinal industry as nutraceuticals, medicinal supplements, and pharmaceuticals. Purpose The objective of this study was to explore the chemical composition of Croton crassifolius essential oil as well as its potential anti-tumour properties and related anti-proliferative, autophagic, and apoptosis-inducing effects. Methods Supercritical CO2 fluid extraction technology was used to extract CCEO and the chemical constituents of the essential oil were identified by comparing the retention indices and mass spectra data taken from the NIST library with those calculated based on the C7-C40 n-alkanes standard. The cytotoxic activity and anti-proliferative effects of CCEO were evaluated against five cancer cell lines and one normal human cell line via CCK-8 assays. In addition, flow cytometry was used to detect cell cycle arrest. The efficacy of CCEO treatments in controlling cancer cell proliferation was assessed by cell cycle analysis, clonal formation assays, RT-qPCR, and western blot analysis. Autophagic and apoptosis-inducing effects of oils and the associated molecular mechanisms were assessed by flow cytometry, cell staining, reactive oxygen species assays, RT-qPCR, and western blot analysis. Conclusion Forty compounds representing 92.90% of the total oil were identified in CCEO. The results showed that CCEO exerted a measurable selectivity for cancer cell lines, especially for A549 with the lowest IC50 value of 25.00 ± 1.62 μg/mL. Assessment of the anti-proliferative effects of CCEO on A549 cells showed that the oil inhibited cell proliferation and colony formation in a dose- and time-dependent manner. Investigation of the molecular mechanisms of cell cycle regulation confirmed that the oil arrested A549 cells in G2/M phase by decreasing the expression of cyclin B1-CDK1 and cyclin A-CDK1 and increasing the expression of cyclin-dependent kinase inhibitor (CKI) P21 at both the transcriptional and translational levels. Autophagy staining assays and western blot analysis revealed that CCEO promoted the formation of autophagic vacuoles in A549 cells and increased the expression of autophagy-related proteins beclin-1 and LC3-II in a dose-dependent manner. A series of apoptosis analyses indicated that CCEO induces apoptosis through a mitochondria-mediated intrinsic pathway. This study revealed that CCEO is a promising candidate for development into an anti-tumour drug of the future.

Objective This study aims to investigate the effects of endoplasmic reticulum stress (ERS) on autophagy, apoptosis and chemoresistance of human small cell lung cancer (SCLC) cells via the PI3K/AKT/mTOR signaling pathway. Results The expressions of ERS-related proteins (PEAK, eIF2α and CHOP) up-regulated, autophagy-related proteins (LC3, LC3-II and Beclin1) and apoptosis-related proteins (Bax and procaspase-3) down-regulated in NCI-H446 and H69 cells after tunicamycin treatment for 24 h. Compared with the blank group, the tunicamycin, BEZ235 and tunicamycin + BEZ235 groups exhibited decreased expressions of p-PI3K, p-AKT and p-mTOR, and increased expressions of autophagy-related proteins (LC3, LC3-II and Beclin1) and apoptosis proteins (Bax and procaspase-3), and the most obvious changes were observed in the tunicamycin + BEZ235 group. Materials and Methods CCK-8 assay was applied to select the best cell line from five SCLC cell lines (NCI-H446, H69, H526, H146 and H209). Finally, NCI-H446 and H69 cells were selected for further experiments. NCI-H446/CDDP and H69/CDDP were selected and divided into the blank group, tunicamycin (an ESR inducer) group, BEZ235 (inhibitors of PI3K/AKT/mTOR pathway) group and tunicamycin + BEZ235 group. Cell apoptosis was detected by flow cytometry. Autophagy was observed by fluorescence microscopy and flow cytometry. Western blotting was used to detect the expressions of ERS-related proteins, autophagy-related proteins, apoptosis-related proteins and PI3K/AKT/mTOR pathway-related proteins. Conclusions Our findings provide evidence that the activation of ERS could promote autophagy and apoptosis and reverse chemoresistance of human SCLC cells by inhibiting the PI3K/AKT/mTOR pathway.

Plant-derived natural products have been the highly significant sources of novel antitumor agents. The cassane-type diterpenes of genus Caesalpinia have been reported to bear antiproliferative activities toward different types of cancer cells. In this study, we evaluated the antineoplasmic activities of 16 natural origin cassane-type diterpenes isolated from the CHCl3 extract of the seeds of C. minax in pituitary adenomas cells and identified caesalpin G (CAG) showed the strongest cytotoxicity. Moreover, we further investigated the structure-activity relationship and molecular mechanism of these derivatives systematically. The results confirmed the unsaturated lactone-type ring, hydroxyl at C-7, and alkenyl at C-11 or C-14 functionality as critical for anticancer activity in this family of natural products. In addition, the mechanism experiments also demonstrated unfolded protein response and ER stress and Wnt/β-catenin pathway were involved in the CAG-induced apoptosis.

Two new abietane diterpenoid glycosides, named clinopoditerpenes B (1) and C (2), were isolated from Clinopodium chinese. The structures of the new compounds were determined on the basis of extensive spectral analysis. Compound 1 exhibited cardioprotective effect against H2O2-induced apoptosis in H9c2 cells.

Here, we report the identification of GIDE, a mitochondrially located E3 ubiquitin ligase. GIDE contains a C-terminal RING finger domain, which is mostly conserved with those of the IAP family members and is required for GIDE's E3 ligase activity. Overexpression of GIDE induces apoptosis via a pathway involving activation of caspases, since caspase inhibitors, XIAP and an inactive mutant of caspase-9 block GIDE-induced apoptosis. GIDE also activates JNK, and blockage of JNK activation inhibits GIDE-induced release of cytochrome c and Smac as well as apoptosis, suggesting that JNK activation precedes release of cytochrome c and Smac and is required for GIDE-induced apoptosis. These pro-apoptotic properties of GIDE require its E3 ligase activity. When somewhat over- or underexpressed, GIDE slows or accelerates cell growth, respectively. These pro-apoptotic or growth inhibition effects of GIDE may account for its absence in tumor cells.

The tumor necrosis factor receptor-associated factor (TRAF) protein family members are critically involved in activation of NF-kappaB, JNK, and p38 activation triggered by tumor necrosis factor (TNF) receptor family members and toll/interleukin-1 receptor (TIR)-containing receptors. TRAF proteins (except for TRAF1) contain an N-terminal RING finger domain that is essential for their functions. In this report, we identified a protein designated as TRAF7, which contains a RING finger domain and a zinc finger domain that are mostly conserved with those of TRAFs. TRAF7 also contains seven WD40 repeats at its C terminus. TRAF7 specifically interacted with MEKK3 and potentiated MEKK3-mediated AP1 and CHOP activation. Depletion of TRAF7 by antisense RNA inhibited MEKK3-mediated AP1 and CHOP activation. Moreover, overexpression of TRAF7 induced caspase-dependent apoptosis. Domain mapping experiments indicated that TRAF7 potentiated MEKK3-mediated AP1 and CHOP activation and induced apoptosis through distinct domains. Our studies identified a novel TRAF family member that is involved in MEKK3 signaling and apoptosis.

The transcription factor NFκB plays important roles in immune regulation, inflammatory responses, and anti-apoptosis. Activation of NFκB requires the activity of IκB kinase, a kinase complex that contains two catalytic subunits, IKKα and IKKβ, and a non-enzymatic regulatory subunit, IKKγ. To understand how NFκB activation is regulated at the IKKγ level, we searched for IKKγ-interacting proteins by the yeast two-hybrid system. This search identified ZNF216, a zinc finger protein with unknown biological functions. ZNF216 contains an A20-like zinc finger domain (ZnF-A20) at its N terminus and an AN1-like domain (ZnF-AN1) at its C terminus. Similar to A20, ZNF216 interacted with IKKγ, RIP, and TRAF6 in co-immunoprecipitation experiments. Domain mapping experiments indicated that the ZnF-A20 domain was responsible for interacting with IKKγ and RIP, whereas the ZnF-AN1 domain interacted with TRAF6. ZNF216 inhibited NFκB activation triggered by overexpression of RIP and TRAF6 but not of p65. ZNF216 also inhibited tumor necrosis factor (TNF)-, interleukin-1-, and Toll-like receptor 4-induced NFκB activation in a dose-dependent manner. The ZnF-A20 domain was essential for ZNF216-mediated inhibition of NFκB activation. The ZnF-A20 and ZnF-AN1 domains of ZNF216 could interact with each other, whereas ZNF216 could form homo-oligomers or hetero-oligomers with A20. Unlike A20, which inhibits TNF-induced apoptosis, overexpression of ZNF216 sensitized cells to TNF-induced apoptosis. Our findings suggest that ZNF216 and A20 have redundant and distinct roles in regulating NFκB activation and apoptosis.

Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein that triggers caspase-independent apoptosis. We describe here the cloning and characterization of a novel AIF-homologous molecule designated AMID (AIF-homologous mitochondrion-associated inducer of death). AMID lacks a mitochondrial localization sequence but shares significant homology with AIF and NADH oxidoreductases from bacteria to mammalian species. Immunofluorescent staining and biochemical experiments indicated that AMID was co-localized with mitochondria. Overexpression of AMID induced cell death with characteristic apoptotic morphology. Furthermore, AMID-induced apoptosis was independent of caspase activation and p53 and was not inhibited by Bcl-2. These findings suggest that AMID induces a novel caspase-independent apoptotic pathway.

Purpose: To investigate the apoptosis in retinal ganglion cells (RGCs) and insulin-like growth factor 1 receptor (IGF-1R) in the retina following optic nerve crush. Methods: Healthy Wistar rats (N = 70) were divided into two groups: a normal control group and an optic nerve injury group. Immunohistochemistry and flow cytometry were performed to detect the expression of IGF-1R and to measure the apoptosis of RGCs, respectively. Results: Immunohistochemistry revealed that at 1 hr after optic nerve injury, IGF-1R immunoreactivity began to increase and reached a maximal level at 24 hr (p

To investigate the effect of conjugated trienoic fatty acids on the growth inhibition, apoptosis in rat glioblastoma cells and to elucidate its mechanism of activity.Rat glioblastoma cells were tested in vitro cytotoxicity, colony formation inhibition, Brdu incorporation after treatment with TCLA. Its effect of apoptosis induction was detected through Hoechst 33342 staining, cell cycle analysis. The expressions of ADPRTL1, CYP1A1 and PPAR-gamma genes were detected through RT-PCR.After TCLA treatment, the proliferation of C6 cells were inhibited (40 micrommol/L, 72 h, viability 56.71% +/- 0.98%), this action acted as dose-time-dependent relations; colony formation decreased significantly (40 micrommol/L, 0) and BrdU labeling index of cancer cells decreased (63.1% +/- 1.0% vs 95.6 % +/- 1.4%); apoptotic cells increased; By FCM analysis, the apoptotic indices increased, the cells increased in G0/G1 phase, decreased in S phase, which have signigicant difference; RT-RCR showed that TCLA signigicantly increased the level of ADPRTL1, CYP1A1, and PPAR-gamma mRNA expression.The findings in this experimental study suggested that TCLA has potent cytotoxicity and induction apoptosis in human and rat glioblastoma cells, its mechanism of activity might be associated with the inhibition of DNA synthesis, cell cycle arrest, up-regulation the expression of apoptosis related genes ADPRTL, CYP1A1, PPAR-gamma.

Endothelial cell migration and survival might be called “major angiogenic responses”. Tumor conditioned medium (CM) has been widely used to stimulate endothelial cells to form capillary-like structures in angiogenesis models in vitro. However, the molecular events triggered by tumor CM are not fully understood. Here, we examined the effects of the CM from human lung carcinoma cell lines A549 and SPC-A-1 on cultures of primary human umbilical veins endothelial cells (HUVECs). After treatment of HUVECs with the CM, cell migration was assessed by wound-healing assay, cell viability was evaluated by XTT assay, and apoptosis and cell death of HUVECs was analyzed by flow cytometry. Phosphorylation of Akt was assessed by Western blotting. To dissect the direct role of Akt, small interfering RNA (siRNA) against Akt1 was used. Both A549 and SPC-A-1 CM significantly stimulated cell migration. However, only A549 CM promoted cell viability and inhibited low serum-induced apoptosis and cell death of HUVECs, but SPC-A-1-CM showed no effects on survival of HUVECs. Meanwhile, A549 CM was found to be able to induce much more phosphorylation of Akt compared to SPC-A-1 CM treated group. The inhibitor of PI3K (wortmaninn) or Akt1 siRNA blocked A549 CM-induced migration and survival of HUVECs. These results indicated that the angiogenic effects of A549 CM are largely mediated through activation of the PI3K-Akt in endothelial cells, and that the Akt1 is crucial in this process, which may provide a therapeutic target for decreasing tumor angiogenesis.

Recently, it has been shown that really interesting new gene (RING)–in between ring finger (IBR)–RING domain-containing proteins, such as Parkin and Parc, are E3 ubiquitin ligases and are involved in regulation of apoptosis. In this report, we show that p53-inducible RING-finger protein (p53RFP), a p53-inducible E3 ubiquitin ligase, induces p53-dependent but caspase-independent apoptosis. p53RFP contains an N-terminal RING–IBR–RING domain and an uncharacterized, evolutionally highly conserved C-terminal domain. p53RFP interacts with E2 ubiquitin-conjugating enzymes UbcH7 and UbcH8 but not with UbcH5, and this interaction is mediated through the RING–IBR–RING domain of p53RFP. Interestingly, the conserved C-terminal domain of p53RFP is required and sufficient for p53RFP-mediated apoptosis, suggesting p53RFP-mediated apoptosis does not require its E3 ubiquitin ligase activity. Together with a recent report showing that p53RFP is involved in ubiquitination and degradation of p21, a p53 downstream protein promoting growth arrest and antagonizing apoptosis, our findings suggest that p53RFP is involved in switching a cell from p53-mediated growth arrest to apoptosis.

AIM: To investigate the role of p38 mitogen-activated protein kinase in rat small intestine after ischemia-reperfusion (I/R) insult and the relationship between activation of p38 MAPK and apoptotic cell death of intestine. METHODS: Ninety Wistar rats were divided randomly into three groups, namely sham-operated group (C), I/R vehicle group (R) and SB203580 pre-treated group (S). In groups R and S, the superior mesenteric artery (SMA) was separated and occluded for 45 min, then released for reperfusion for 0.25, 0.5, 1, 2, 6, 12 and 24 h. In group C, SMA was separated without occlusion. Plasma D-lactate levels were examined and histological changes were observed under a light microscope. The activity of p38 MAPK was determined by Western immunoblotting and apoptotic cells were detected by the terminal deoxynucleotidyl transferase (TdT)-mediated dUDP-biotin nick end labeling (TUNEL). RESULTS: Intestinal ischemia followed by reperfusion activated p38 MAPK, and the maximal level of activation (7.3-fold vs sham-operated group) was reached 30 min after I/R. Treatment with SB 203580, a p38 MAPK inhibitor, reduced intestinal apoptosis (26.72±3.39% vs 62.50±3.08% in I/R vehicle, P

AMID, also called PRG3, is an AIF-homologous and mitochondria-associated protein that has been implicated in caspase-independent apoptosis. In this report, we demonstrated that human AMID gene promoter was activated by p53 in reporter gene assays. Chromatin immunoprecipitation experiments indicated that p53 could bind to human AMID promoter. Deletion mutagenesis indicated that human AMID promoter contains two p53-responsive elements. Furthermore, expression array analysis indicated that human AMID mRNA expression was downregulated in a majority of human tumors. Our findings point to the possibility that AMID is a p53-downstream gene involved in tumorigenesis.

The transcription factor NF-kappaB plays important roles in inflammation and cell survival. NF-kappaB is composed of homodimeric and heterodimeric complexes of Rel/NF-kappaB family members, including p65 (RelA), c-Rel (Rel), RelB, NF-kappaB1/p50, and NF-kappaB2/p52. Here we report the identification and characterization of a novel ZU5 and death domain-containing protein designated ZUD. In reporter gene assays, overexpression of ZUD inhibited NF-kappaB-dependent transcription induced by both tumor necrosis factor (TNF) and interleukin-1 and their downstream signaling proteins. Gel shift assays indicated that the overexpression of ZUD inhibited binding of NF-kappaB to its target sequence. ZUD is a cytoplasmic protein, and coimmunoprecipitation assays indicated that ZUD interacted with the NF-kappaB subunit p105 and transactivator p65. Consistent with its role in inhibition of NF-kappaB-dependent transcription, ZUD sensitized cells to apoptosis induced by TNF and the TNF-related apoptosis-inducing ligand (TRAIL). Our findings suggest that ZUD is an inhibitor of NF-kappaB activation and that this protein may provide an alternative regulatory mechanism for NF-kappaB-mediated transcription.

The transcription factor NFkappaB plays important roles in immune regulation, inflammatory responses, and anti-apoptosis. Activation of NFkappaB requires the activity of IkappaB kinase, a kinase complex that contains two catalytic subunits, IKKalpha and IKKbeta, and a non-enzymatic regulatory subunit, IKKgamma. To understand how NFkappaB activation is regulated at the IKKgamma level, we searched for IKKgamma-interacting proteins by the yeast two-hybrid system. This search identified ZNF216, a zinc finger protein with unknown biological functions. ZNF216 contains an A20-like zinc finger domain (ZnF-A20) at its N terminus and an AN1-like domain (ZnF-AN1) at its C terminus. Similar to A20, ZNF216 interacted with IKKgamma, RIP, and TRAF6 in co-immunoprecipitation experiments. Domain mapping experiments indicated that the ZnF-A20 domain was responsible for interacting with IKKgamma and RIP, whereas the ZnF-AN1 domain interacted with TRAF6. ZNF216 inhibited NFkappaB activation triggered by overexpression of RIP and TRAF6 but not of p65. ZNF216 also inhibited tumor necrosis factor (TNF)-, interleukin-1-, and Toll-like receptor 4-induced NFkappaB activation in a dose-dependent manner. The ZnF-A20 domain was essential for ZNF216-mediated inhibition of NFkappaB activation. The ZnF-A20 and ZnF-AN1 domains of ZNF216 could interact with each other, whereas ZNF216 could form homo-oligomers or hetero-oligomers with A20. Unlike A20, which inhibits TNF-induced apoptosis, overexpression of ZNF216 sensitized cells to TNF-induced apoptosis. Our findings suggest that ZNF216 and A20 have redundant and distinct roles in regulating NFkappaB activation and apoptosis.

Toll-like receptor-3 is critically involved in host defense against viruses through induction of type I interferons (IFNs). Recent studies suggest that a Toll/interleukin-1 receptor domain-containing adapter protein (TRIF) and two protein kinases (TANK-binding kinase-1 (TBK1) and IkappaB kinase (IKK)-epsilon) are critically involved in Toll-like receptor-3-mediated IFN-beta production through activation of IFN regulatory factor (IRF)-3 and IRF-7. In this study, we demonstrate that TRIF interacts with both IRF-7 and IRF-3. In addition to TBK1 and IKKepsilon, our results indicate that IKKbeta can also phosphorylate IRF-3 and activate the IFN-stimulated response element. TRIF-induced IRF-3 and IRF-7 activation was mediated by TBK1 and its downstream kinases IKKbeta and IKKepsilon. TRIF induced NF-kappaB activation through an IKKbeta- and tumor necrosis factor receptor-associated factor-6-dependent (but not TBK1- and IKKepsilon-dependent) pathway. In addition, TRIF also induced apoptosis through a RIP/FADD/caspase-8-dependent and mitochondrion-independent pathway. Furthermore, our results suggest that the TRIF-induced IFN-stimulated response element and NF-kappaB activation and apoptosis pathways are uncoupled and provide a molecular explanation for the divergent effects induced by the adapter protein TRIF.

The transcription factor NF-kappaB plays important roles in inflammation and cell survival. In this study, we identified SINK, an NF-kappaB-inducible protein. Overexpression of SINK inhibited NF-kappaB-dependent transcription induced by tumor necrosis factor (TNF) stimulation or its downstream signaling proteins but did not inhibit NF-kappaB translocation to the nucleus and binding to DNA. Co-immunoprecipitation and in vitro kinase assays indicated that SINK specifically interacted with the NF-kappaB transactivator p65 and inhibited p65 phosphorylation by the catalytic subunit of protein kinase A, which has previously been shown to regulate NF-kappaB activation. Consistent with its role in inhibition of NF-kappaB-dependent transcription, SINK also sensitized cells to apoptosis induced by TNF and TRAIL (TNF-related apoptosis-inducing ligand). Taken together, these data suggest that SINK is critically involved in a novel negative feedback control pathway of NF-kappaB-induced gene expression.

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is a member of the tumor necrosis factor family that selectively induces apoptosis of cancer cells. However, some cancer cells or subpopulations within cancer cell lines are resistant to TRAIL-induced apoptosis. We developed a retroviral cDNA library-based functional cloning approach to unambiguously identify putative inhibitory genes of TRAIL-induced apoptosis. This effort identified the short splice form of Casper/c-FLIP, Casper-S/c-FLIPs, as a major cellular protein that confers resistance to TRAIL-induced apoptosis. Furthermore, we found that Casper deficient embryonic fibroblasts (EFs) were highly sensitive while their wild-type counterparts were completely resistant to TRAIL-induced apoptosis. Retroviral-mediated transduction of Casper-S/c-FLIPs into Casper(−/−) EFs restored resistance to TRAIL. These data suggest that Casper-S/c-FLIPs is a major cellular inhibitor of TRAIL-induced apoptosis.