A novel animal model of primary blast lung injury and its pathological changes in mice.

BACKGROUND: Primary blast lung injury (PBLI) is a major cause of death in military conflict and terrorist attacks on civilian populations. However, the mechanisms of PBLI are not well understood, and a standardized animal model is urgently needed. This study aimed to establish an animal model of PBLI for laboratory study. METHODS: The animal model of PBLI was established using a self-made mini shock tube simulation device. In brief, mice were randomly divided into two groups: the control group and the model group, the model group were suffered 0.5 bar shock pressures. Mice were sacrificed at 2 hours, 4 hours, 6 hours, 12 hours, and 24 hours after injury. Lung tissue gross observation, hematoxylin and eosin staining and lung pathology scoring were performed to evaluated lung tissue damage. Evans blue dye leakage and bronchoalveolar lavage fluid examination were performed to evaluated pulmonary edema. The relative expression levels of inflammation factors were measured by real-time quantitative polymerase chain reaction and Western blotting analysis. The release of neutrophil extracellular traps was observed by immunofluorescence stain. RESULTS: In the model group, the gross observation and hematoxylin and eosin staining assay showed the inflammatory cell infiltration, intra-alveolar hemorrhage, and damaged lung tissue structure. The Evans blue dye and bronchoalveolar lavage fluid examination revealed that the lung tissue permeability and edema was significantly increased after injury. Real-time quantitative polymerase chain reaction and Western blotting assays showed that IL-1ß, IL-6, TNF-α were upregulated in the model group. Immunofluorescence assay showed that the level of neutrophil extracellular traps in the lung tissue increased significantly in the model group. CONCLUSION: The self-made mini shock tube simulation device can be used to establish the animal model of PBLI successfully. Pathological changes of PBLI mice were characterized by mechanical damage and inflammatory response in lung tissue.

The role of ZFP580, a novel zinc finger protein, in TGF-mediated cytoprotection against chemical hypoxia­induced apoptosis in H9c2 cardiac myocytes.

Zing finger protein 580 (ZFP580) is a novel Cys2-His2 zinc-finger transcription factor that has an anti-apoptotic role in myocardial cells. It is involved in the endothelial transforming growth factor­ß1 (TGF­ß1) signal transduction pathway as a mothers against decapentaplegic homolog (Smad)2 binding partner. The aim of the present study was to determine the involvement of ZFP580 in TGF­ß1­mediated cytoprotection against chemical hypoxia­induced apoptosis, using H9c2 cardiac myocytes. Hypoxia was chemically induced in H9c2 myocardial cells by exposure to cobalt chloride (CoCl2). In response to hypoxia, cell viability was decreased, whereas the expression levels of hypoxia inducible factor-1α and ZFP580 were increased. Pretreatment with TGF­ß1 attenuated CoCl2­induced cell apoptosis and upregulated ZFP580 protein expression; however, these effects could be suppressed by SB431542, an inhibitor of TGF­ß type I receptor and Smad2/3 phosphorylation. Furthermore, suppression of ZFP580 expression by RNA interference reduced the anti­apoptotic effects of TGF­ß1 and thus increased CoCl2­induced apoptosis. B­cell lymphoma (Bcl)­2­associated X protein/Bcl­2 ratio, reactive oxygen species generation and caspase­3 activation were also increased following ZFP580 inactivation. In conclusion, these results indicate that ZFP580 is a component of the TGF-ß1/Smad signaling pathway, and is involved in the protective effects of TGF­ß1 against chemical hypoxia­induced cell apoptosis, through inhibition of the mitochondrial apoptotic pathway.

[Effects of ZFP580 on ventricular remodeling after myocardial ischemia/reperfusion in rats].

OBJECTIVE: To investigate the relationship between zinc finger protein(ZFP580)and ventricular remodeling after myocardial is-chemia/reperfusion(I/R) injury in rats. METHODS: Seventy-two rats were divided into sham group and I/R groups which would be tested in se-ries time of 0.5 h, 1 h, 2 h, 4 h, 1 d,7 d,14 d,28 d after reperfusion to observe the expression of ZFP580 in rat myocardium. The H9C2 cells were cultured and treated with transforming growth factor-beta1 (TGF-ß 1) to establish cardiac hypertrophy in vitro model in series time of 0 h, 8h, 16 h and 24 h. The cardiomyocyte hypertrophy morphology was measured. The mRNA levels of atrial natriuretic peptide(ANP), myosin heavey chain beta(ß -MHC) and ZFP580 genes were quantified. The protein levels of MMP-3 and ZFP580 were quantified after H9C2 cells were transfected by lentiviral-mediated ZFP580 gene. RESULTS: Myocardial I/R injury model was successfully established. Myocardial tis-sue in rats had large area infarction, and myocardial cells were eosinophilic changed. The increased level of ZFP580 protein was observed in the cardiomyocytes around infarction zone. The expression of TGF-ß 1 in myocardium was up-regulated after myocardial I/R injury. TGF-ß 1 (5 ng/ml) treatment could induce cardiomyocyte hypertrophy in H9C2 cells. TGF-ß 1 treatment increased the cell size and mRNA levels of ANP andß -MHC genes (P < 0.05), which represent degree of cardiac hypertrophy. TGF-ß 1 treatment also increased the protein levels of ZFP580 in H9C2 cells (P < 0.05). In the H9C2 cells transfected by lentiviral-mediated gene, the protein level of MMP3 was decreased (P < 0.05). CONCLUSIONS: ZFP580 is probably related with ventricular remodeling after myocardial I/R injury by involving TGF-ß 1 induced cardiomyocyte hypertrophy and attenuating MMP-3 production.

SILAC-based proteomic analysis reveals that salidroside antagonizes cobalt chloride-induced hypoxic effects by restoring the tricarboxylic acid cycle in cardiomyocytes.

Hypoxic status alters the energy metabolism and induces cell injury in cardiomyocytes, and it further triggers the occurrence and development of cardiovascular diseases. Our previous studies have shown that salidroside (SAL) exhibits anti-hypoxic activity. However, the mechanisms remain obscure. In the present study, we successfully screened 92 different expression proteins in CoCl2-induced hypoxic conditions, 106 different expression proteins in the SAL-mediated anti-hypoxic group were compared with the hypoxic group using quantitative proteomics strategy, respectively. We confirmed that SAL showed a positive protective function involving the acetyl-CoA metabolic, tricarboxylic acid (TCA) cycle using bioinformatics analysis. We also demonstrated that SAL plays a critical role in restoring the TCA cycle and in protecting cardiomyocytes from oxidative injury via up-regulation expressions of PDHE1-B, ACO2, SUCLG1, SUCLG2 and down-regulation of MDH2. SAL also inhibited H9c2 cell apoptosis by inhibiting the activation of pro-apoptotic molecules caspase 3 and caspase 9 as well as activation of the anti-apoptotic molecular Bcl-2. Additionally, SAL also improved mitochondrial membrane potential (ΔΨm), reduced reactive oxygen species (ROS) and intercellular Ca(2+) concentration ([Ca(2+)]i) accumulation and inhibited the excessive consumption of ATP in H9c2 cells.

ZFP580, a novel zinc-finger transcription factor, is involved in cardioprotection of intermittent high-altitude hypoxia against myocardial ischemia-reperfusion injury.

BACKGROUND: ZFP580 is a novel C2H2 type zinc-finger transcription factor recently identified by our laboratory. We previously showed that ZFP580 may be involved in cell survival and growth. The aim of this study was to elucidate whether ZFP580 is involved in the cardioprotective effects of intermittent high-altitude (IHA) hypoxia against myocardial ischemia-reperfusion (I/R) injury. METHODS AND RESULTS: After rats were subjected to myocardial ischemia for 30 min followed by reperfusion, ZFP580 expression in the left ventricle was measured. ZFP580 protein expression was found to be up-regulated within 1 h and decreased at 2 h after reperfusion. Comparing normoxic and IHA hypoxia-adapted rats (5000 m, 6 h day-1, 6 weeks) following I/R injury (30 min ischemia and 2 h reperfusion), we found that adaptation to IHA hypoxia attenuated infarct size and plasma leakage of lactate dehydrogenase and creatine kinase-MB. In addition, ZFP580 expression in the myocardium was up-regulated by IHA hypoxia. Consistent with this result, ZFP580 expression was found to be significantly increased in cultured H9c2 myocardial cells in the hypoxic preconditioning group compared with those in the control group following simulated I/R injury (3 h simulated ischemic hypoxia and 2 h reoxygenation). To determine the role of ZFP580 in apoptosis, lentivirus-mediated gene transfection was performed in H9c2 cells 72 h prior to simulated I/R exposure. The results showed that ZFP580 overexpression significantly inhibited I/R-induced apoptosis and caspase-3 activation. H9c2 cells were pretreated with or without PD98059, an inhibitor of ERK1/2 phosphorylation, and Western blot results showed that PD98059 (10 µM) markedly suppressed I/R-induced up-regulation of ZFP580 expression. CONCLUSIONS: Our findings demonstrate that the cardioprotective effect of IHA hypoxia against I/R injury is mediated via ZFP580, a downstream target of ERK1/2 signaling with anti-apoptotic roles in myocardial cells.

[The effects of intermittent hypobaric hypoxia on myocardial ischemia/reperfusion injury and ZFP580 expression].

OBJECTIVE: To elucidate whether ZFP580 is involved in the cardioprotective effects of intermittent hypobaric hypoxia (IHH) against myocardial ischemia/reperfusion (I/R) injury. METHODS: Thirty two male Wistar rats were randomly divided into 2 groups (n = 16): normoxia control group and IHH preconditioning group. Rats in IHH group were exposed in a hypobaric chamber (equivalent to an altitude of 5 000 m) for a 6 h period each day for 42 d. Plasma was collected and lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) were measured after 2 h of myocardial I/R injury. ZFP580 protein expression in myocardial tissue was assayed by Western blot. Other 8 rats in each group were used to evaluate I/R-induced cardiac infarction by TTC staining. Lentivirus-mediated gene transfection was performed in H9c2 cells 72 h prior to simulated ischemia/reperfusion (SI/R) exposure. The degree of cell apoptosis was determined by annexin V/7-AAD staining and flow cytometry analysis. RESULTS: Compared with normoxia control group, adaptation to IHH attenuated infarct size and plasma leakage of LDH and CK-MB. In addition, ZFP580 expression in the myocardium was up-regulated by IHH. The results of gene transfection showed that ZFP580 overexpression significantly inhibited cells apoptosis induced by SI/R. CONCLUSION: Our findings demonstrate that the cardioprotective effect of IHH against I/R injury is mediated via ZFP580, a novel transcription factor, with anti-apoptotic roles in myocardial cells.

Interleukin-8 secretion by ovarian cancer cells increases anchorage-independent growth, proliferation, angiogenic potential, adhesion and invasion.

It has been shown that IL-8 is elevated in ovarian cyst fluid, ascites, serum, and tumor tissue from ovarian cancer (OVCA) patients, and increased IL-8 expression correlates with poor prognosis and survival. However, the exact role that IL-8 plays in this malignancy or whether IL-8 can regulate malignant behavior has not been established. Here we demonstrate that overexpression of IL-8 in non-IL-8-expressing A2780 cells (by transfecting with plasmid encoding for sense IL-8) increases anchorage-independent growth, proliferation, angiogenic potential, adhesion and invasion while depletion of endogenous IL-8 expression in IL-8-overexpressing SKOV-3 cells (by transfecting with plasmid encoding for antisense IL-8) decreases the above effects. Further investigation indicates that IL-8-stimulated cell proliferation correlates with alteration of cell cycle distribution by increasing levels of cell cycle-regulated Cyclin D1 and Cyclin B1 proteins as well as activation of PI3K/Akt and Raf/MEK/ERK, whereas IL-8-enhanced OVCA cell invasive correlates with increased MMP-2 and MMP-9 activity and expression. Our data suggest that IL-8 secreted by OVCA cells promotes malignant behavior of these cells via inducing intracellular molecular signaling. Therefore, modulation of IL-8 expression or its related signaling pathway may be a promising strategy for controlling the progression and metastasis of OVCA.

[Administration of hydrogen sulfide intraperitoneally reverses the hyporesponsiveness of rat pulmonary artery induced by lipopolysaccharide and its relationship with carbon monoxide].

OBJECTIVE: To explore the effect of hydrogen sulfide (H(2)S) on abnormal pulmonary artery reactivity induced by lipopolysaccharide (LPS) and its relationship with carbon monoxide (CO). METHODS: Forty eight rats were divided into four groups randomly according to table of random number: control group (normal saline, NS), LPS group, a donor of H(2)S sodium hydrosulfide (NaHS)+LPS group, and NaHS+NS group (n=12 in each group). Rats were given LPS by intratracheal instillation (0.8 ml/kg). 0.5 ml of NaHS (28 µmol/kg) was injected intraperitoneally 10 minutes before LPS or NS instillation and 2 hours after LPS or NS instillation in NaHS+LPS and NaHS+NS groups. Twelve hours after instillation of LPS, 6 rats from each group were sacrificed. The pulmonary artery rings (PARs) were prepared and the changes in cumulative relaxation response of PARs to NaHS were detected before and after incubation with an inhibitor of heme oxygenase-1 (HO-1) zinc protoporphyrinIX (ZnPPIX) using isolated vascular ring tension detecting technique. Twelve hours after LPS instillation, the remaining 6 rats in each group were sacrificed, and the contents of carboxyhemoglobin (COHb) in efferent pulmonary blood (EPB) and afferent pulmonary blood (APB) were measured, and the difference between the contents of COHb in EPB and that of APB was calculated to represent content of CO from pulmonary circulation. RESULTS: In the present study, compared with control group, after the instillation of LPS the percentage of relaxation response of PARs to NaHS was significantly declined [(75.72±7.22)% vs. (96.40±4.40)%, P<0.01]. After being incubated with ZnPPIX, the decreased relaxation response of PARs to NaHS induced by LPS was further depressed [(62.91±8.22)% vs. (75.72±7.22)%, P<0.01]. Administration of NaHS intraperitoneally reversed the hyporesponsiveness of PARs to NaHS, the percentage of relaxation response of PARs to NaHS was significantly increased [(94.65±8.45)% vs. (75.72±7.22)%, P<0.01]. However ZnPPIX also attenuated the effect [(83.75±9.76)% vs. (94.65±8.45)%, P<0.01]. NO significant changes were observed between NaHS+NS group and control group, also between the results before and after ZnPPIX incubation . Compared with control group, the difference between the contents of COHb in EPB and that of APB increased after instillation of LPS [(3.12±0.48)% vs. (2.12±0.32)%, P<0.05], which further increased after intraperitoneal administration of NaHS [(4.03±0.56)%, P<0.01]. CONCLUSION: The results suggested that intraperitoneal administration of H(2)S could reverse hyporesponsiveness of PARs to H(2)S induced by LPS, and the result might be related to an intensification of HO-1/CO system in pulmonary artery tissue.

Arsenic biotransformation and volatilization in transgenic rice.

• Biotransformation of arsenic includes oxidation, reduction, methylation, and conversion to more complex organic arsenicals. Members of the class of arsenite (As(III)) S-adenosylmethyltransferase enzymes catalyze As(III) methylation to a variety of mono-, di-, and trimethylated species, some of which are less toxic than As(III) itself. However, no methyltransferase gene has been identified in plants. • Here, an arsM gene from the soil bacterium Rhodopseudomonas palustris was expressed in Japonica rice (Oryza sativa) cv Nipponbare, and the transgenic rice produced methylated arsenic species, which were measured by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). • Both monomethylarsenate (MAs(V)) and dimethylarsenate (DMAs(V)) were detected in the roots and shoots of transgenic rice. After 12 d exposure to As(III), the transgenic rice gave off 10-fold greater volatile arsenicals. • The present study demonstrates that expression of an arsM gene in rice induces arsenic methylation and volatilization, theoretically providing a potential stratagem for phytoremediation.

[Effect of hydrogen sulfide on rat pulmonary artery reactivity and injury induced by lipopolysaccharide].

OBJECTIVE: To explore the effects of hydrogen sulfide (H2S) on abnormal pulmonary artery reactivity and injury induced by lipopolysaccharide (LPS). METHODS: Seventy-two rats were divided into four groups randomly according to table of random number: control group, LPS group, sodium hydrosulfide (NaHS) as a donor of H2S+LPS group and NaHS+normal saline (NS) group (n=18 in each group). Rats were challenged with 0.8 ml/kg LPS (200 microg/200 microl) by intratracheal instillation. NaHS (28 micromol/kg, 0.5 ml) was injected intraperitoneally 10 minutes before LPS instillation and 2 hours after LPS instillation. Twelve hours later, 6 rats from each group were sacrificed. Blood from carotid artery was collected to detect H2S content in serum. After that, pulmonary artery rings (PARs) were prepared carefully, then the contraction response of PARs to phenylephrine (PE, 10(-6) mol/L) and the endothelium-dependent relaxation response to acetylcholine (ACh, 10(-6) mol/L) were measured using isolated vascular ring tension detecting technique. Six rats from each group were sacrificed for determination of malondialdehyde (MDA) content of pulmonary artery, and the remaining 6 rats from each group were sacrificed for observation of morphological changes in pulmonary artery tissue. RESULTS: Compared with control group, after LPS instillation, the contraction response (g/mg) of PARs to PE increased greatly (0.86+/-0.20 vs. 0.56+/-0.13), the relaxation response to ACh significantly decreased [(65.18+/-7.05)% vs. (84.13+/-8.84)%]. MDA content (mmol/L) in pulmonary artery tissues increased (32.03+/-7.81 vs. 5.82+/-0.92), and H2S (micromol/L) content in serum decreased (175.23+/-27.36 vs. 238.12+/-16.38). Changes of all results were significant (P<0.05 or P<0.01). The pulmonary artery tissue and endothelium were injured. However, these changes were reversed by administration of NaHS intraperitoneally, the contraction response of PARs to PE decreased [(0.61+/-0.17) g/mg], the relaxation response to ACh increased [(82.92+/-9.71)%], MDA content in pulmonary artery tissue decreased [(16.88+/-3.54) mmol/L] and H2S content in serum increased [(242.70+/-38.80) micromol/L]. There was significant difference in all results (P<0.05 or P<0.01). The injury to the tissue induced by LPS were alleviated significantly. There was no statistical difference in above indexes between NaHS+NS group and control group, except for the level of H2S. CONCLUSION: Exogenous H2S could not only reverse abnormal vascular reactivity of PARs induced by LPS but also alleviate the injury to pulmonary artery tissue induced by LPS.

[Role of endogenous hydrogen sulfide in pulmonary hypertension induced by lipopolysaccharide].

The purpose of the present study was to explore the role of endogenous hydrogen sulfide (H2S) in pulmonary arterial hypertension induced by endotoxin. Adult male Sprague-Dawley (SD) rats were randomly divided into four groups: Control group (0.5 mL/kg body weight of normal saline, i.v.), lipopolysaccharide (LPS)-treated group (5 mg/kg body weight of LPS, i.v.), LPS + NaHS (5 mg/kg body weight of LPS, i.v., and 28 µmol/kg body weight of NaHS, i.p.) and LPS + PPG group (5 mg/kg body weight of LPS, i.v., and 30 µmol/kg body weight of PPG, i.p.). Rats were anesthetized with 20% urethane (1 g/kg body weight, i.p.). A polyethylene catheter was inserted into the pulmonary artery through the right external jugular vein to measure the mean pulmonary arterial pressure (mPAP) for 7 h, and then the pulmonary artery was isolated rapidly by the method described previously. Pulmonary arterial activity was detected. H2S concentration and cystathionine γ-lyase (CSE) activity in pulmonary artery tissues were determined by biochemical method. CSE mRNA expression was detected by competitive reverse transcriptase-polymerase chain reaction (RT-PCR). Compared with control, LPS significantly increased mPAP [(1.82±0.29) kPa vs (1.43±0.26) kPa, P<0.01], decreased H2S production [(26.33±7.84) vs (42.92±8.73) pmol/g wet tissue per minute, P<0.01), and reduced endothelium-dependent relaxation response [(75.72±7.22)% vs (86.40±4.40) %, P<0.01) induced by ACh (1×10(-6) mol/L). These effects were partly reversed by co-administration of NaHS and enhanced by co-administration of PPG. Both CSE activity and CSE mRNA expression were consistent with H2S production. It is suggested that the inhibitory effect of LPS on endothelium-dependent relaxation results in pulmonary hypertension, which might be mediated through H(2)S.