Inflammasomes are multiprotein complexes that serve as a platform for caspase-1 activation and interleukin-1β (IL-1β) maturation as well as pyroptosis. Though a number of inflammasomes have been described, the NLRP3 inflammasome is the most extensively studied. NLRP3 inflammasome is triggered by a variety of stimuli, including infection, tissue damage and metabolic dysregulation, and then activated through an integrated cellular signal. Many regulatory mechanisms have been identified to attenuate NLRP3 inflammasome signaling at multiple steps. Here, we review the developments in the negative regulation of NLRP3 inflammasome that protect host from inflammatory damage.
Animals ; Autophagy ; Carrier Proteins ; antagonists & inhibitors ; metabolism ; Caspase 1 ; metabolism ; Humans ; Inflammasomes ; metabolism ; Interferon Type I ; metabolism ; MicroRNAs ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; Nitric Oxide ; metabolism ; Signal Transduction ; T-Lymphocytes ; immunology ; metabolism

OBJECTIVETo investigate the effect of monocyte chemotactic protein-3 (MCP-3) on the expressions of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), tissue factor (TF, and tissue factor pathway inhibitor (TFPI) and cell apoptosis in human umbilical vein endothelial cells (HUVECs).

METHODSCultured HUVECs were treated with MCP-3 at the optimal concentration determined previously 1 h after treatments with or without MCP-3 antibody (20 ng/ml), PI3K inhibitor, or LY-294002 (5 mmol/ml). The expressions of ICAM-1, VCAM-1, TF and TFPI were analyzed using RT-PCR and Western blot after the treatments. MCP-3 mRNA and protein expressions were detected in HUVECs exposed to 50 µg/ml ox-LDL for 24 h. The cell apoptosis and caspase-3 protein production in HUVECs treated with MCP-3 or with MCP-3 plus CCR2 antagonist for 24 h and 48 h were evaluated by flow cytometry and Western blotting.

RESULTSAt the optimal concentration of 0.3 ng/ml, MCP-3 treatment for 24 h caused significantly increased ICAM-1, VCAM-1, and TF expressions with lowered expression of TFPI in HUVECs (P<0.05), and such effects were significantly inhibited by the application of MCP-3 antibody, PI3K inhibitor, or LY-294002 (P<0.05). Ox-LDL exposure significantly increased the expression of MCP-3 in HUVECs (P<0.05). HUVECs showed a significantly increased apoptosis rate after treatment with MCP-3 or with MCP-3 plus CCR2 antagonist (P<0.05), and the apoptosis rate increased significantly as the treatment time prolonged (P<0.05); caspase-3 protein expression in the cells showed a similar pattern of alterations following the treatments.

CONCLUSIONox-LDL can induce MCP-3 expression in HUVECs. MCP-3 induces apoptosis of HUVECs and significantly affects the cellular function partially through the PI3K signaling pathway.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Adhesion ; Cells, Cultured ; Chemokine CCL7 ; pharmacology ; Chromones ; pharmacology ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; metabolism ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; Lipoproteins ; metabolism ; Lipoproteins, LDL ; pharmacology ; Morpholines ; pharmacology ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; Receptors, CCR2 ; antagonists & inhibitors ; Signal Transduction ; Thromboplastin ; metabolism ; Vascular Cell Adhesion Molecule-1 ; metabolism

AIMTo determine how SDF-1 alpha/CXCR4 activates nuclear factor-kappa B (NF-kappaB) and promotes oral squamous cell carcinoma (OSCC) invasion.

METHODOLOGYA lentivirus-based knockdown approach was utilized to deplete gene expression. NF-kappaB activation was evaluated by Western blot analysis and electrophoretic mobility shift (EMSA).

RESULTSWe show that the activation of NF-kappaB by CXCR4 occurs through the Carma3/Bcl10/Malt1 (CBM) complex in OSCC. We found that loss of components of the CBM complex in HNSCC can inhibit SDF-1 alpha induced phosphorylation and degradation of IkappaBalpha, while TNF alpha induced IKK activation remains unchanged. Further, we identified a role for novel and atypical, but not classical, PKCs in activating IKK through CXCR4. Importantly, inhibition of the CBM complex leads to a significant decrease in SDF-1 alpha mediated invasion of OSCC.

CONCLUSIONThe CBM complex plays a critical role in CXCR4-induced NF-kappaB activation in OSCC. Targeting molecular components of the NF-kappaB signaling pathway may provide an important therapeutic opportunity in controlling the progression and metastasis of OSCC mediated by SDF-1 alpha.

Adaptor Proteins, Signal Transducing ; antagonists & inhibitors ; physiology ; B-Cell CLL-Lymphoma 10 Protein ; CARD Signaling Adaptor Proteins ; antagonists & inhibitors ; physiology ; Carcinoma, Squamous Cell ; pathology ; Caspase Inhibitors ; Caspases ; physiology ; Cell Line, Tumor ; Chemokine CXCL12 ; antagonists & inhibitors ; physiology ; Enzyme Activation ; drug effects ; Gene Silencing ; Genetic Vectors ; genetics ; Humans ; I-kappa B Kinase ; drug effects ; I-kappa B Proteins ; metabolism ; Isoenzymes ; antagonists & inhibitors ; Lentivirus ; genetics ; Membrane Proteins ; antagonists & inhibitors ; physiology ; Mouth Neoplasms ; pathology ; Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein ; NF-KappaB Inhibitor alpha ; NF-kappa B ; antagonists & inhibitors ; physiology ; Neoplasm Invasiveness ; Neoplasm Proteins ; antagonists & inhibitors ; physiology ; Phosphorylation ; Plasmids ; genetics ; Protein Kinase C ; antagonists & inhibitors ; Receptors, CXCR4 ; physiology ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo investigate the protective mechanism of neuroactive steroid allopregnanolone on N-methyl-D-aspartate (NMDA) induced toxicity in primary mouse cortical neurons.

METHODSPrimary cultured mouse cortical neurons were subjected to allopregnanolone, the expression of beta-aminobutyric acid receptor beta2 subunit (beta2-GABA-R) mRNAs was detected by RT-PCR and Akt phosphorylation was assayed by Western blot using Akt-phosphoserine 473-specific antibody. After the cultured mouse cortical neurons were pretreated with or without allopregnanolone prior to treatment with NMDA , DNA isolated was analyzed by agarose gel electrophoresis and proteins collected were analyzed by Western blot with anti-cleaved-PARP, anti-cleaved caspase-3, and anti-cleaved caspase-9 antibodies.

RESULTSWhen cultured mouse cortical neurons were exposed to allopregnanolone both the expression of beta2-GABA-R mRNAs and Akt phosphorylation increased. Allopregnanolone inhibited the NMDA-induced apoptosis and decreased the level of active-PARP, active-caspase-3 and active-caspase-9 notably at a final concentration of 5 x 10(6) mol/L.

CONCLUSIONPretreatment with allopregnanolone may be neuroprotective on NMDA-induced neuronal cells apoptosis by increasing beta2-GABA-R expression and Akt phosphorylation.

Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cerebral Cortex ; cytology ; Mice ; N-Methylaspartate ; antagonists & inhibitors ; toxicity ; Neurons ; cytology ; Neuroprotective Agents ; pharmacology ; Poly (ADP-Ribose) Polymerase-1 ; Poly(ADP-ribose) Polymerases ; metabolism ; Pregnanolone ; pharmacology ; Primary Cell Culture ; RNA, Messenger ; genetics ; metabolism ; Receptors, GABA-B ; genetics ; metabolism

This study is to investigate the effect of Vam3, a dimeric derivative of resveratrol, on SNP-induced apoptosis and its potential mechanism in rat articular chondrocytes. Isolated rat articular chondrocytes were treated with sodium nitroprusside (SNP), a NO donor, to induce apoptosis. Apoptosis percentage was evaluated by Annexin V-PI and nucleus fracture was examined by DAPI staining. Level of intracellular reactive oxygen species (ROS) was detected using 2, 7'-dichlorofluorescin diacetate (DCFH-DA) as a fluorescence probe by fluorescence microplate reader. The change in mitochondrial membrane potential was detected by TMRE staining. Expressions of SIRT1, acetylated p53 (ac-p53), cleaved caspase 9 and cleaved caspase 3 were determined by Western blotting. It showed that Vam3 up to 10 micromol x L(-1) could significantly reduce SNP-induced rat articular chondrocytes apoptosis (P < 0.01) and nucleus fracture, inhibit the increase of intracellular ROS level (P < 0.01) and reverse the decrease in mitochondrial membrane potential (P < 0.01). Simultaneously, Vam3 could upregulate the expression of SIRT1, deacetylate p53, and inhibit the cleavage of caspase 9 and caspase 3 (P < 0.01) of rat articular chondrocytes exposed to SNP. This study indicates Vam3 could protect rat articular chondrocytes against SNP-induced apoptosis, perhaps through the upregulation of SIRT1 and deacetylation of p53.
Animals ; Apoptosis ; drug effects ; Arabidopsis Proteins ; pharmacology ; Cartilage, Articular ; cytology ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cells, Cultured ; Chondrocytes ; cytology ; metabolism ; Male ; Membrane Potential, Mitochondrial ; drug effects ; Nitric Oxide Donors ; antagonists & inhibitors ; pharmacology ; Nitroprusside ; pharmacology ; Qa-SNARE Proteins ; pharmacology ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism ; Sirtuin 1 ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

Mcl-1 and Bcl-xL, key anti-apoptotic proteins of the Bcl-2 family, have attracted attention as important molecules in the cell survival and drug resistance. In this study, we investigated whether inhibition of Bcl-xL influences cell growth and apoptosis against simultaneous treatment of resveratrol and clofarabine in the human malignant mesothelioma H-2452 cells. Resveratrol and clofarabine decreased Mcl-1 protein levels but had little effect on Bcl-xL levels. In the presence of two compounds, any detectable change in the Mcl-1 mRNA levels was not observed in RT-PCR analysis, whereas pretreatment with the proteasome inhibitor MG132 led to its accumulation to levels far above basal levels. The knockdown of Bcl-xL inhibited cell proliferation with cell accumulation at G2/M phase and the appearance of sub-G0/G1 peak in DNA flow cytometric assay. The suppression of cell growth was accompanied by an increase in the caspase-3/7 activity with the resultant cleavages of procaspase-3 and its substrate poly (ADP-ribose) polymerase, and increased percentage of apoptotic propensities in annexin V binding assay. Collectively, our data represent that the efficacy of resveratrol and clofarabine for apoptosis induction was substantially enhanced by Bcl-xL-lowering strategy in which the simultaneous targeting of Mcl-1 and Bcl-xL could be a more effective strategy for treating malignant mesothelioma.
Adenine Nucleotides/*pharmacology ; Antimetabolites, Antineoplastic/*pharmacology ; Apoptosis/*drug effects ; Arabinonucleosides/*pharmacology ; Caspase 3/metabolism ; Caspase 7/metabolism ; Cell Line, Tumor ; Cell Proliferation/drug effects ; G2 Phase Cell Cycle Checkpoints/drug effects ; Gene Knockdown Techniques ; Humans ; Leupeptins/pharmacology ; Lung Neoplasms/metabolism/pathology ; M Phase Cell Cycle Checkpoints/drug effects ; Mesothelioma/metabolism/pathology ; Myeloid Cell Leukemia Sequence 1 Protein/antagonists & inhibitors/genetics/metabolism ; RNA Interference ; RNA, Messenger/metabolism ; RNA, Small Interfering/metabolism ; Stilbenes/*pharmacology ; bcl-X Protein/antagonists & inhibitors/*genetics/*metabolism

The biflavonoid isochamaejasmin is mainly distributed in the root of Stellera chamaejasme L. (Thymelaeaceae) that is used in traditional Chinese medicine (TCM) to treat tumors, tuberculosis, and psoriasis. Herein, isochamaejasmin was found to show similar bioactivity against Bcl-2 family proteins to the reference Bcl-2 ligand (-)-gossypol through 3D similarity search. It selectively bound to Bcl-xl and Mcl-1 with Ki values being 1.93 ± 0.13 μmol·L(-1) and 9.98 ± 0.21 μmol·L(-1), respectively. In addition, isochamaejasmin showed slight growth inhibitory activity against HL-60 with IC50 value being 50.40 ± 1.21 μmol·L(-1) and moderate growth inhibitory activity against K562 cells with IC50 value being 24.51 ± 1.62 μmol·L(-1). Furthermore, isochamaejasmin induced apoptosis of K562 cells by increasing the intracellular expression levels of proteins of the cleavage of caspase-9, caspase-3, and PARP which involved in the Bcl-2-induced apoptosis pathway. These results indicated that isochamaejasmin induces apoptosis in leukemia cells by inhibiting the activity of Bcl-2 family proteins, providing evidence for further studying the underlying anti-cancer mechanism of S. chamaejasme L.
Antineoplastic Agents, Phytogenic ; pharmacology ; therapeutic use ; Apoptosis ; drug effects ; Biflavonoids ; pharmacology ; therapeutic use ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Gossypol ; pharmacology ; HL-60 Cells ; Humans ; Inhibitory Concentration 50 ; K562 Cells ; Leukemia ; drug therapy ; metabolism ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Poly(ADP-ribose) Polymerases ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; antagonists & inhibitors ; metabolism ; Signal Transduction ; Thymelaeaceae ; chemistry ; bcl-2-Associated X Protein ; metabolism

Bmi1 is a member of the polycomb group family of proteins, and it drives the carcinogenesis of various cancers and governs the self-renewal of multiple types of stem cells. However, its role in the initiation and progression of bladder cancer is not clearly known. The present study aimed to investigate the function of Bmi1 in the development of bladder cancer. Bmi1 expression was detected in human bladder cancer tissues and their adjacent normal tissues (n=10) by immunohistochemistry, qRT-PCR and Western blotting, respectively. Bmi1 small interference RNA (siRNA) was synthesized and transfected into human bladder carcinoma cells (EJ) by lipofectamine 2000. The Bmil expression at mRNA and protein levels was measured in EJ cells transfected with Bmil siRNA (0, 80, 160 nmol/L) by qRT-PCR and Western blotting, respectively. Cell viability and Ki67 expression (a marker of cell proliferation) were determined in Bmi1 siRNA-transfected cells by CCK-8 assay and qRT-PCR, respectively. Cell cycle of transfected cells was flow-cytometrically determined. Immunofluorescence and Western blotting were used to detect the expression levels of cell cycle-associated proteins cyclin D1 and cyclin E in the cells. Pro-apoptotic proteins Bax and caspase 3 and anti-apoptotic protein Bcl-2 were detected by Western blotting as well. Additionally, xenograft tumor models were established by inoculation of EJ cells (infected with Bmil shRNA/pLKO.1 lentivirus or not) into nude mice. The tumor volumes were measured every other day for 14 days. The results showed that the Bmil expression was significantly increased in bladder tumor tissues when compared with that in normal tissues (P<0.05). Perturbation of Bmi1 expression by using siRNA could significantly inhibit the proliferation of EJ cells (P<0.05). Bmi1 siRNA-transfected EJ cells were accumulated in G1 phase and the expression levels of cyclin D1 and cyclin E were down-regulated. Bax and caspase-3 expression levels were significantly increased and Bcl-2 levels decreased after Bmi1 knockdown. Tumor volume was conspicuously reduced in mice injected with EJ cells with Bmi1 knockdown. Our findings indicate that Bmi1 is a potential driver oncogene of bladder cancer and it may become a potential treatment target for human bladder cancer.
Animals ; Apoptosis ; genetics ; Carcinogenesis ; genetics ; metabolism ; pathology ; Carcinoma ; genetics ; metabolism ; pathology ; therapy ; Caspase 3 ; genetics ; metabolism ; Cell Line, Tumor ; Cyclin D1 ; antagonists & inhibitors ; genetics ; metabolism ; Cyclin E ; antagonists & inhibitors ; genetics ; metabolism ; G1 Phase Cell Cycle Checkpoints ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Injections, Intralesional ; Ki-67 Antigen ; genetics ; metabolism ; Mice ; Mice, Nude ; Polycomb Repressive Complex 1 ; antagonists & inhibitors ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; antagonists & inhibitors ; genetics ; metabolism ; RNA, Small Interfering ; administration & dosage ; genetics ; metabolism ; Signal Transduction ; Tumor Burden ; Urinary Bladder ; metabolism ; pathology ; Urinary Bladder Neoplasms ; genetics ; metabolism ; pathology ; therapy ; Xenograft Model Antitumor Assays ; bcl-2-Associated X Protein ; agonists ; genetics ; metabolism

OBJECTIVETo investigate the neuro-protective effects of baicalin in Wistar rats with focal cerebral ischemic reperfusion injury.

METHODSNinety adult male Wistar rats weighing 320-350 g were randomly divided into the following groups (n=5): (a) sham control group; (b) vehicle group, subjected to middle cerebral artery occlusion and received vehicle intraperitoneally; (c-e) baicalin groups, which were subjected to the middle cerebral artery occlusion and treated with baicalin 25, 50 and 100 mg/kg, respectively. The neurological scores were determined at postoperative 1, 3 and 7 d after the treatment. The expression of protease-activated receptor-1 (PAR-1), PAR-1 mRNA and Caspase-3 were determined using Western blot, reverse transcription polymerase chain reaction (RTPCR) analysis and immunohistochemistry, respectively.

RESULTSSignificant decrease was noted in the neurological score in the baicalin group compared with that of the vehicle group (P<0.01). Additionally, down-regulation of PAR-1 mRNA, PAR-1 and Caspase-3 was observed in the baicalin groups compared with those obtained from the vehicle group (P<0.01). Compared with the low-dose baicalin group (25 mg/kg), remarkable decrease was noted in neurological score, and the expression of PAR-1 mRNA, PAR-1 as well as Caspase-3 in the high-dose group (P<0.05).

CONCLUSIONBaicalin showed neuro-protective effects in focal cerebral ischemic reperfusion injury through inhibiting the expression of PAR-1 and apoptosis.

Animals ; Apoptosis ; drug effects ; Brain Ischemia ; complications ; drug therapy ; genetics ; pathology ; Caspase 3 ; metabolism ; Flavonoids ; administration & dosage ; pharmacology ; therapeutic use ; Gene Expression Regulation ; drug effects ; Male ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Receptor, PAR-1 ; antagonists & inhibitors ; genetics ; metabolism ; Reperfusion Injury ; complications ; drug therapy ; genetics ; pathology

BACKGROUNDNeuregulin-1 (NRG-1), the ligand of the myocardial ErbB receptor, is a protein mediator with regulatory actions in the heart. This study investigated whether NRG-1 preconditioning has protective effects on myocardial ischemia/reperfusion (I/R) injury and its potential mechanism.

METHODSWe worked with an in vivo rat model with induced myocardial ischemia (45 minutes) followed by reperfusion (3 hours). NRG-1 message was detected in the heart using RT-PCR and the protein levels of NRG-1 and ErbB4 were detected by Western blotting analysis. Infarct size was assessed using the staining agent triphenyltetrazolium chloride and cardiac function was continuously monitored. The levels of creatine kinase and lactate dehydrogenase in plasma were analyzed to assess the degree of cardiac injury. The extent of cardiac apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and by Western blotting analysis of cleaved caspase-3. We examined the phosphorylation of Akt in the myocardium and the effect of PI3K/Akt inhibition on NRG-1-induced cardioprotection.

RESULTSTranscription and expression of NRG-1 and phosphorylation of its ErbB4 receptor were significantly upregulated in the I/R hearts. NRG-1 pretreatment reduced the infarct size following cardiac I/R in a concentration-dependent manner with an optimal concentration of 4 µg/kg in vivo. NRG-1 pretreatment with 4 µg/kg, i.v. markedly reduced the plasma creatine kinase and lactate dehydrogenase levels. Pretreatment with NRG-1 also significantly reduced the percentage of TUNEL positive myocytes and the level of cleaved caspase-3 in the I/R hearts. Pretreatment with NRG-1 significantly increased phosphorylation of Akt following I/R. Furthermore, the cardioprotective effect limiting the infarct size that was induced by NRG-1 was abolished by co-administration of the PI3K inhibitor LY294002.

CONCLUSIONSThe concentration of NRG-1, a new autacoid, was rapidly upregulated after myocardial I/R. NRG-1 preconditioning has cardioprotective effects against I/R injury through a PI3K/Akt-dependent mechanism in vivo.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Dose-Response Relationship, Drug ; Ischemic Preconditioning, Myocardial ; L-Lactate Dehydrogenase ; blood ; Male ; Myocardial Reperfusion Injury ; prevention & control ; Neuregulin-1 ; analysis ; pharmacology ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; physiology ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; physiology ; Rats ; Rats, Sprague-Dawley ; Receptor, Epidermal Growth Factor ; analysis ; Receptor, ErbB-4