BACKGROUNDDermatomyositis (DM) and polymyositis (PM) are common inflammatory myopathies whose immunopathogenic mechanisms remain poorly understood. The NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome is a type of cytoplasmic multiprotein inflammasome and is responsible for the activation of inflammatory reactivations. Responding to a wide range of exogenous and endogenous microbial or sterile stimuli, NLRP3 inflammasomes can cleave pro-caspase-1 into active caspase-1, which processes the pro-inflammatory cytokines pro-interleukin (IL)-1β and pro-IL-18 into active and secreted IL-1β and IL-18. The NLRP3 inflammasome is implicated in infectious and sterile inflammatory diseases. However, it remains unclear whether it is involved in the pathogenesis of DM/PM, which we aim to address in our research.

METHODSIn this study, 22 DM/PM patients and 24 controls were recruited. The protein and RNA expression of IL-1β, IL-18, NLRP3, and caspase-1 in serum and muscle samples were tested and compared between the two groups.

RESULTSThe serum IL-1β and IL-18 levels were significantly higher in DM/PM patients than those in the controls by enzyme linked immunosorbent assay (ELISA, DM vs. control, 25.02 ± 8.29 ng/ml vs. 16.49 ± 3.30 ng/ml,P < 0.001; PM vs. control, 26.49 ± 7.79 ng/ml vs. 16.49 ± 3.30 ng/ml,P < 0.001). Moreover, the real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) showed that DM/PM patients exhibited higher RNA expression of IL-1β, IL-18, and NLRP3 in the muscle (for IL-1β, DM vs. control, P= 0.0012, PM vs. control, P= 0.0021; for IL-18, DM vs. control, P= 0.0045, PM vs. control, P= 0.0031; for NLRP3, DM vs. control, P= 0.0017, PM vs. control, P= 0.0006). Moreover, the protein expression of NLRP3 and caspase-1 in muscle samples of DM/PM patients were also significantly elevated compared to that in the muscles of the controls.

CONCLUSIONSOur findings demonstrate that the NLRP3 inflammasome is implicated in the pathogenesis of DM/PM. High NLRP3 expression led to elevated levels of IL-1β and IL-18 and could be one of the factors promoting disease progress.

Adult ; Caspase 1 ; analysis ; genetics ; Dermatomyositis ; etiology ; Female ; Humans ; Inflammasomes ; physiology ; Interleukin-18 ; analysis ; genetics ; Interleukin-1beta ; analysis ; genetics ; Male ; Middle Aged ; NLR Family, Pyrin Domain-Containing 3 Protein ; analysis ; genetics ; physiology ; Polymyositis ; etiology

To investigate the effect of silencing DJ-1 on xenografted human laryngeal squamous cell carcinoma (LSCC) Hep-2 cells in nude mice.Xenograft model of human LSCC was established by subcutaneous transplantation of Hep-2 cells in 24 nude mice. The LSCC-bearing nude mice were randomly divided into 3 groups (=8 in each):DJ-1 siRNA low dose group and DJ-1 siRNA high dose group were injected in tumors with 20 μg of DJ-1 siRNA or 40 μg of DJ-1 siRNA in 50 μL, respectively; control group was injected with 5% glucose solution in 50 μL, twice a week for 3 weeks. The weight and size of tumors were measured before injection. The animals were sacrificed 48 h after the final treatment, and the tumors were harvested and weighed. The apoptosis and proliferation of tumor cells were determined; the expressions of Caspase-3 and Ki-67 in tumor specimens were detected with immunohistochemistry. The expression of DJ-1, PTEN, survivin mRNA and protein in tumor tissues were detected by RT-PCR and Western blotting, respectively.Tumor weight in low dose group[(0.66±0.15)g] and high dose group[(0.48±0.11)g] were significantly lower than that in control group[(0.83±0.16)g, all<0.05]. The inhibition rates of low dose group and high dose group were (20.48±0.18)% and (42.16±0.13)%, respectively. Immunohistochemistry showed that the expression of Caspase-3 was increased and Ki-67 was reduced in tumor specimens, compared with the control group (all<0.05). RT-PCR and Western blot results showed that in low dose group and high dose group the mRNA and protein expression of DJ-1 and survivin significantly decreased (all<0.05), while PTEN mRNA and protein content increased (all<0.05).High dose DJ-1 siRNA can inhibit the tumor growth in human LSCC xenograft nude mouse model, which indicates that down-regulating DJ-1 and survivin, and up-regulating PTEN expression may lead to blockage of PI3K-PKB/Akt signaling pathway and promoting tumor cell apoptosis.
Animals ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; genetics ; Carcinoma, Squamous Cell ; chemistry ; genetics ; physiopathology ; Caspase 3 ; analysis ; drug effects ; Cell Line, Tumor ; chemistry ; drug effects ; physiology ; transplantation ; Cell Proliferation ; drug effects ; Down-Regulation ; Gene Expression Regulation ; drug effects ; genetics ; physiology ; Head and Neck Neoplasms ; chemistry ; genetics ; physiopathology ; Heterografts ; drug effects ; physiology ; Humans ; Inhibitor of Apoptosis Proteins ; analysis ; drug effects ; Ki-67 Antigen ; analysis ; drug effects ; Laryngeal Neoplasms ; chemistry ; genetics ; physiopathology ; Mice, Nude ; PTEN Phosphohydrolase ; analysis ; drug effects ; Phosphatidylinositol 3-Kinases ; drug effects ; Protein Deglycase DJ-1 ; pharmacology ; Proto-Oncogene Proteins c-akt ; drug effects ; RNA Interference ; physiology ; RNA, Messenger ; pharmacology ; RNA, Small Interfering ; physiology ; Signal Transduction ; drug effects ; genetics ; physiology

The effects of black rice anthocyanidins (BRACs) on retinal damage induced by photochemical stress are not well known. In the present study, Sprague-Dawley rats were fed AIN-93M for 1 week, after which 80 rats were randomly divided into two groups and treated with (n = 40) or without BRACs (n = 40) for 15 days, respectively. After treatment, both groups were exposed to fluorescent light (3,000 +/- 200 lux; 25degrees C), and the protective effect of dietary BRACs were evaluated afterwards. Our results showed that dietary BRACs effectively prevented retinal photochemical damage and inhibited the retinal cells apoptosis induced by fluorescent light (p < 0.05). Moreover, dietary BRACs inhibited expression of AP-1 (c-fos/c-jun subunits), up-regulated NF-kappaB (p65) expression and phosphorylation of IkappaB-alpha, and decreased Caspase-1 expression (p < 0.05). These results suggest that BRACs improve retinal damage produced by photochemical stress in rats via AP-1/NF-kappaB/Caspase-1 apoptotic mechanisms.
Animal Feed/analysis ; Animals ; Anthocyanins/administration & dosage/*pharmacology ; Antioxidants/administration & dosage/*physiology ; Blotting, Western ; Caspase 1/*genetics/metabolism ; Diet ; Dietary Supplements/analysis ; I-kappa B Proteins/genetics/metabolism ; NF-kappa B/*genetics/metabolism ; Neoplasm Proteins/genetics/metabolism ; Nucleocytoplasmic Transport Proteins/genetics/metabolism ; Oryza sativa/chemistry ; Proto-Oncogene Proteins c-fos/genetics/metabolism ; Proto-Oncogene Proteins c-jun/genetics/metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Retinal Diseases/etiology/*prevention & control ; Signal Transduction/*drug effects/radiation effects ; Transcription Factor AP-1/*genetics/metabolism

Activation of caspase-1 by NALP3 inflammasomes has been shown to be important in initiating acute gouty arthritis. The objectives of this study were to measure the levels of caspase-1 in synovial fluid in gout and various arthritides, and to elucidate the clinical significance of caspase-1 levels in synovial fluid. Caspase-1, IL-1beta, IL-18, and uric acid were measured in synovial fluid from 112 patients with gout and other arthritides, such as rheumatoid arthritis, osteoarthritis, and spondyloarthropathy. Caspase-1 in synovial fluid from patients with crystal-induced arthritis, inflammatory arthritis, osteoarthritis, and spondyloarthropathy was 35.9 +/- 86.7, 49.7 +/- 107.7, 2.1 +/- 7.0, and 152.6 +/- 155.7 pg/mL, respectively. The mean level and the frequency of high levels (> or =125 pg/mL) of caspase-1 in spondyloarthropathy were significantly higher than those in the other arthritides including gout. Caspase-1 was detectible in the synovial fluid of patients with the various arthritides. Contrary to our hypothesis, the caspase-1 level in the synovial fluid of patients with gout was not higher than in that of other arthritides. High levels of caspase-1 may be helpful in differentiating spondyloarthropathy from other arthritides.
Adult ; Aged ; Arthritis, Rheumatoid/enzymology/metabolism/pathology ; Caspase 1/*analysis ; Female ; Gout/*enzymology/metabolism/pathology ; Humans ; Interleukin-18/analysis ; Interleukin-1beta/analysis ; Leukocyte Count ; Male ; Middle Aged ; Osteoarthritis/enzymology/metabolism/pathology ; Spondylarthropathies/*enzymology/metabolism/pathology ; Synovial Fluid/*enzymology/metabolism ; Uric Acid/analysis

Inflammasome is a large protein complex activated upon cellular stress or microbial infection, which triggers maturation of pro-inflammatory cytokines interleukin-1β and interleukin-18 through caspase-1 activation. Nod-like receptor family protein 3 (NLRP3) is the most characterized inflammasome activated by various stimuli. However, the mechanism of its activation is unclear and its exact cellular localization is still unknown. We examined the potential co-localization of NLRP3 inflammasome with mitochondria and seven other organelles under adenosine triphosphate, nigericin or monosodium urate stimulation in mouse peritoneal macrophages using confocal microscopy approach. Our results revealed that the activated endogenous apoptosis-associated speck-like protein containing a CARD (ASC) pyroptosome forms in the cytoplasm and co-localizes with NLRP3 and caspase-1, but not with any of the organelles screened. This study indicates that the ASC pyroptosome universally localizes within the cytoplasm rather than with any specific organelles.
Adenosine Triphosphate ; pharmacology ; Animals ; Apoptosis Regulatory Proteins ; CARD Signaling Adaptor Proteins ; Carrier Proteins ; analysis ; metabolism ; Caspase 1 ; analysis ; metabolism ; Cytoplasm ; metabolism ; Cytoskeletal Proteins ; analysis ; metabolism ; Inflammasomes ; analysis ; metabolism ; Macrophages, Peritoneal ; cytology ; drug effects ; metabolism ; Mice ; Mice, Inbred C57BL ; Microscopy, Confocal ; Mitochondria ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; Nigericin ; pharmacology ; Uric Acid ; pharmacology

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

The tubby mouse is characterized by progressive retinal and cochlear degeneration and late-onset obesity. These phenotypes are caused by a loss-of-function mutation in the tub gene and are shared with several human syndromes, suggesting the importance of tubby protein in central nervous system (CNS) functioning. Although evidence suggests that tubby may act as a transcription factor mediating G-protein coupled receptor (GPCR) signaling, any downstream gene regulated by tubby has yet to be identified. To explore potential target genes of tubby with region-specific transcription patterns in the brain, we performed a microarray analysis using the cerebral cortex and hypothalamus of tubby mice. We also validated the changes of gene expression level observed with the microarray analysis using real-time RT-PCR. We found that expression of erythroid differentiation factor 1 (Erdr1) and caspase 1 (Casp1) increased, while p21-activated kinase 1 (Pak1) and cholecystokinin 2 receptor (Cck2r) expression decreased in the cerebral cortex of tubby mice. In the hypothalamic region, Casp 1 was up-regulated and micro-crystallin (CRYM) was down-regulated. Based on the reported functions of the differentially expressed genes, these individual or grouped genes may account for the phenotype of tubby mice. We discussed how altered expression of genes in tubby mice might be understood as the underlying mechanism behind tubby phenotypes.
Activins ; Animals ; Brain ; Caspase 1 ; Central Nervous System ; Cerebral Cortex ; Gene Expression ; GTP-Binding Proteins ; Humans ; Hypothalamus ; Mice ; Microarray Analysis ; Negotiating ; Obesity ; p21-Activated Kinases ; Phenotype ; Receptor, Cholecystokinin B ; Retinaldehyde ; Transcription Factors

OBJECTIVEThe neuroprotective effect of erythropoietin (EPO) against 1-methyl-4-phenylpyridinium (MPP(+))-induced oxidative stress in cultured PC12 cells, as well as the underlying mechanism, were investigated.

METHODSPC12 cells impaired by MPP(+) were used as the cell model of Parkinson's disease. Methyl thiazolyl tetrazolium (MTT) was used to assay the viability of the PC12 cells exposed to gradient concentrations of EPO, and the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay was used to analyze the apoptosis ratio of PC12 cells. The expression of Bcl-2 and Bax in PC12 cells were examined by Western blot, and the reactive oxygen species (ROS), the mitochondrial transmembrane potential and the activity of caspase-3 in each group were detected by spectrofluorometer.

RESULTSTreatment of PC12 cells with MPP(+) caused the loss of cell viability, which may be associated with the elevation in apoptotic rate, the formation of ROS and the disruption of mitochondrial transmembrane potential. It was also shown that MPP(+) significantly induced the upregulation of Bax/Bcl-2 ratio and the activation of caspase-3. In contrast, EPO significantly reversed these responses and had the maximum protective effect at 1 U/mL.

CONCLUSIONThe inhibitive effect of EPO on the MPP(+)-induced cytotoxicity may be ascribed to its anti-oxidative property and anti-apoptotic activity, and EPO may provide a useful therapeutic strategy for treatment of neurodegenerative diseases such as Parkinson's disease.

1-Methyl-4-phenylpyridinium ; toxicity ; Analysis of Variance ; Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Drug Interactions ; Erythropoietin ; pharmacology ; Flow Cytometry ; methods ; Herbicides ; toxicity ; In Situ Nick-End Labeling ; methods ; Membrane Potential, Mitochondrial ; drug effects ; Neuroprotective Agents ; pharmacology ; PC12 Cells ; drug effects ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Rats ; Reactive Oxygen Species ; metabolism ; Tetrazolium Salts ; Thiazoles ; bcl-2-Associated X Protein ; genetics ; metabolism

BACKGROUNDAngiopoietin-1 (Ang-1) is an endothelial-specific growth factor that can promote angiogenesis. Studies demonstrated that Ang-1 can inhibit apoptosis of umbilical endothelial cells, but so far little is known about its effects on apoptosis of microvascular endothelial cells. With the apoptotic model of murine-cerebral-derived microvascular endothelial cells (bEnd.3) induced by serum-free culture, we attempted to clarify the molecular mechanism of bEnd.3 apoptosis, particularly its relation to cytochrome C (Cyt C).

METHODSThe cultured microvascular endothelial cell strain, bEnd.3 cell, was employed. An apoptotic model of bEnd.3 was established by serum-free culture. Flow cytometry after Annexin labeling and PI staining were used to assess the apoptotic effects of Ang-1 on bEnd.3, and the expression of Bax/Bcl-2, caspase 8, caspase 3, and Cyt C were detected with Western blotting and ELISA.

RESULTSThe apoptotic rate of bEnd.3 cells after stimulation with Ang-1 (100 ng/L) in serum-free medium was significantly higher than that in control group. Ang-1 inhibited early-stage apoptosis more than late-stage apoptosis provided by propidium iodide (PI) and AnnexinV double staining. The inhibition of Ang-1 on bEnd.3 cell apoptosis was strengthened with the increase in concentration (0 - 400 ng/ml). Ang-1 could decrease the expression of Bax, caspase3 and 8, and increase that of Bcl-2. The results of ELISA indicated that Ang-1 significantly decreased CytC content in cytoplasm and increase that in mitochondria.

CONCLUSIONSAng-1 could inhibit bEnd.3 apoptosis induced by serum-free medium culture. The apoptosis was associated with decreased Bax expression, increased Bcl-2 expression, which result in Cyt C transferring from mitochondria to cytoplasm, and then caspases activation are reduced and cell apoptosis is suppressed.

Angiopoietin-1 ; pharmacology ; Animals ; Annexin A5 ; analysis ; Apoptosis ; drug effects ; Caspase 3 ; Caspase 8 ; Caspases ; analysis ; Cells, Cultured ; Cytochromes c ; physiology ; Endothelial Cells ; cytology ; drug effects ; Mice ; Microcirculation ; drug effects ; bcl-2-Associated X Protein ; analysis

OBJECTIVEThe expressions of caspase-1 and cytokines activated by caspase-1 are associated with the pathophysiology of many diseases for its proinflammatory and proapototic peculiarity. However its relationship to brain injury of developing rats following recurrent seizures has not yet been identified. This study aimed to investigate the role of caspase-1 and cytokines activated by caspase-1 in brain injury of developing rats following recurrent seizures.

METHODSA total of 96 postnatal 20 day Sprague-Dawley rats were randomly assigned into Control and Seizure groups. Seizures were induced in the Seizure group by flurothyl inhalation daily for six days. Brain tissues were sampled at 6 hrs, and at 1, 3, and 7 days after last seizure. The expressions of caspase-1, interleukin (IL)-18 and IL-1beta mRNA in the cerebral cortex were detected by RT-PCR. The water content of the brain and the pathological changes of cortex nerve cells were observed. Brain injury was evaluated using a semiquantitative neuropathological scoring system.

RESULTSThe levels of caspase-1 and IL-18 mRNA in the cerebral cortex of the Seizure group were obviously higher than those in the Control group at 6 hrs, and at 1, 3, and 7 days after seizure (P < 0.05 or P < 0.01). The expression of IL-1beta mRNA in the Seizure group exhibited a biphasic pattern: increased significantly at 6 hrs, and at 1 and 7 days post-seizure (P < 0.01), but was not significantly different from the Control group at 3 days post-seizure. Edema, degeneration and necrosis of nerve cells in cerebral cortex, accompanying by inflammatory cell infiltration and apoptosis of nerve cells, were observed under a light microscope in the Seizure group after recurrent seizures. The water content of the brain in the Seizure group increased significantly compared with that in the Control group at 6 hrs, and at 1 and 3 days after recurrent seizures (P < 0.01). The Seizure group had significantly higher neuropathological scores than the Control group at each time point (P < 0.01).

CONCLUSIONSCaspase-1 and cytokines activated by caspase-1 play an important role in the developing brain injury after recurrent seizures.

Animals ; Brain ; pathology ; Caspase 1 ; genetics ; physiology ; Female ; Interleukin-1 ; genetics ; physiology ; Interleukin-18 ; genetics ; physiology ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Recurrence ; Seizures ; pathology