Animals ; Hyperbaric Oxygenation ; Lung ; enzymology ; Oxygen ; Protein Kinase C ; metabolism ; Rats

OBJECTIVETo investigate the effect of different pressure oxygen pre-breathing in preventing decompression sickness of rats.

METHODSForty male SD rats were randomly divided into 4 groups: decompression sickness (DCS) group and three oxygen pre-breathing groups with 1 ATA, 2 ATA and 3 ATA pressure respectively. The rats of DCS group were placed in the hyperbaric chamber and the chamber was compressed evenly within 3 minutes to depths of 7 absolute atmosphere(ATA) and held at the designated depth for 60 min, then decompressed (3 min) at constant speed to the surface pressure. After that, the rats were taken out for further detection. While the rats of oxygen pretreatment groups pre-breathed different pressure oxygen for 20 min before entering into chamber. The mortality and behavioral of rats were observed with 30 min post decompression. The dry/wet ratio of the lung, protein levels in the bronchoalveolar lavage fluid (BALF), and the inflammatory cytokine tumor necrosis factor (TNF-alpha) expression were also tested.

RESULTSCompared with that of the DCS group, the mortality and morbidity of oxygen pre-breathe groups didn't change obviously. But the total BALF protein level and the inflammatory cytokine TNF-alpha expression of 1 ATA oxygen pre-breathe group were obviously decreased, while the dry/wet ratio of lung as obviously increased instead (P < 0.05).

CONCLUSIONAlthough preoxygenation can' t obviously change the mortality and mobidity of rats, normal pressure oxygen pre-breathing can mitigate the protein infiltration in BALF and the expression of inflammatory cytokine in lung tissue.

Animals ; Bronchoalveolar Lavage Fluid ; chemistry ; Decompression Sickness ; Diving ; Lung ; pathology ; Oxygen ; physiology ; Pressure ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo study the effects of suppressor of variegation 3-9 homolog 1 (SUV39H1) gene silencing by small interfering RNA (siRNA) on the proliferation, tumor suppressor gene p15 expression and histone modification in acute myeloid leukemia cell line KG-1 cells, and to explore novel therapeutic target of leukemia.

METHODSThe SUV39H1 gene specific siRNA was synthesized in vitro and transfected into KG-1 cells by Lipofectamine(TM) 2000. The SUV39H1 mRNA and protein were detected by RT-PCR and Western blot. Cell growth affected by SUV39H1 siRNA was determined by MTS. The expressions of tumor suppressor gene p15, histone methylation of H3K9 and histone acetylation of H3, H3K9, H3K14, H3K27 and H4 were detected by Western blot.

RESULTSSUV39H1 mRNA was markedly suppressed by the SUV39H1 specific siRNA in a concentration-dependent manner. SUV39H1 siRNA inhibited the proliferation of KG-1 cells. Proliferation inhibition rate was (23.57 ± 1.98)%, (48.69 ± 1.84)%, (62.69 ± 1.61)% and (81.06 ± 3.22)% after transfected with SUV39H1 siRNA at 30, 60, 120 and 240 nmol/L for 48 hours, respectively. SUV39H1 siRNA down-regulated histone tri-methylated-H3K9 by 25%, 33% and 49% compared to control group when treated with SUV39H1 siRNA at 30, 60 and 120 nmol/L for 48 hours, while up-regulated histone acetylated H3K9 by 1.83, 2.16 and 3.07 folds, and global histone H3 in 1.35, 1.87 and 2.37 folds, but no changes were observed in histone acetylation of H3K14, H3K27 and H4. Expression of p15 increased 1.52, 2.89 and 3.08 folds after SUV39H1 siRNA treatment.

CONCLUSIONSSUV39H1 gene silencing could induce the re-expression of p15 and inhibit cell proliferation by down-regulation of histone methylation of H3K9, up-regulation of histone acetylation of H3K9 and global H3. SUV39H1 might be a new target for cancer therapy.

Cell Line, Tumor ; Gene Silencing ; Histones ; genetics ; Humans ; Leukemia ; genetics ; Methyltransferases ; genetics ; RNA, Small Interfering ; Repressor Proteins ; genetics

OBJECTIVETo study the effect of small interfering RNA(siRNA) targeting JARID1B gene on the proliferation and apoptosis in HL-60 acute promyelocytic leukemia cell line, and to explore its mechanisms.

METHODSThe JARID1B siRNA was transfected into HL-60 cells using Lipofectamine(TM) 2000(Lipo) vector. The proliferation inhibition by siRNA targeting JARID1B was detected by MTT, cells apoptosis by flow cytometry, the mRNA expression of JARID1B by RT-PCR, the protein expression of JARID1B, Bcl-2, procaspase-9, procaspase-3, c-myc and P27 and histone methylated H3K4 by Western blot.

RESULTSsiRNA targeting JARID1B upregulated histone methylated H3K4 level, inhibited the proliferation of HL-60 cells, and induced the cells apoptosis. After transfection of siRNA targeting JARID1B at 0, 30, 60, 120 nmmol/L for 24 hours, the apoptotic rate were (11.0 ± 3.6)%, (35.2 ± 5.1)%, (52.7 ± 3.8)%, and (62.0 ± 5.7)% respectively (F = 70.27, P < 0.01). The protein expression of P27 was upregulated, and Bcl-2, procaspase-9, procaspase-3, c-myc was down regulated.

CONCLUSIONSJARID1B siRNA upregulates histone methylated H3K4. It reduces HL-60 cells proliferation and apoptosis by up regulating the p27 expression and down regulating the Bcl-2, procaspase-9, procaspase-3, c-myc expression. It might be a new therapeutic targeting for human leukemia.

Apoptosis ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p27 ; metabolism ; Gene Expression Regulation, Leukemic ; Gene Targeting ; HL-60 Cells ; Histones ; metabolism ; Humans ; Jumonji Domain-Containing Histone Demethylases ; genetics ; Leukemia ; genetics ; Methylation ; Nuclear Proteins ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; RNA Interference ; RNA, Messenger ; genetics ; RNA, Small Interfering ; Repressor Proteins ; genetics

This study is to investigate the effect of downregulation histone deacetylases 1 (HDAC1) gene by the technology of RNA interference on the differentiation of HL-60 cells line. The optimal segment targeting HDAC1 gene was designed and transfected into HL-60 cells by Lipofectamine 2000. The HDAC1 mRNA and protein level were detected by RT-PCR and Western blotting. The morphologic change of HL-60 cells was detected by an optical microscope with Wright-Giemsa. Cell differentiation was tested by NBT reduction assay. Expression of CD13, CD33 and CD14 was measured by flow cytometry. The results indicated that HDAC1 mRNA and protein were markedly suppressed by the siRNA targeting HDAC1 in a concentration-dependent manner. HDAC1 siRNA promoted cell differentiation. HL-60 cells became more mature in morphology after transfected to HDAC1 siRNA at a concentration of 30-60 nmol x L(-1) for 24 h. NBT reduction ability of HDAC1 siRNA with 30 nmol x L(-1) was 0.31 +/- 0.09, compared with negative control (0.20 +/- 0.02) (t = -3.1, P < 0.01), and with 60 nmol x L(-1) was 0.25 +/- 0.02 in comparison with negative control (0.21 +/- 0.04) (t = -2.12, P < 0.05). But it has no change in HDAC1 siRNA > or = 120 nmol x L(-1). After transfection with 60 nmol x L(-1) HDAC1 siRNA to HL-60 cells, the expression of CD13 was (96.50 +/- 0.70)% in compared to siRNA-NC (3.39 +/- 0.68) % (t = 164.9, P < 0.000 5), CD33 was (66.73 +/- 0.50) % in compared to siRNA-NC (96.80 +/- 1.70) % (t = 43.4, P < 0.000 5). CD14 was (0.53 +/- 0.00) % by comparison with siRNA-NC (0.49 +/- 0.02) % (t = -0.97, P > 0.1). HDAC1 siRNA promoted cell differentiation in indicated concentration. HDAC1 might be one of the targets of gene therapy for leukemia.
CD13 Antigens ; metabolism ; Cell Differentiation ; Down-Regulation ; HL-60 Cells ; Histone Deacetylase 1 ; genetics ; metabolism ; Humans ; Lipopolysaccharide Receptors ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Sialic Acid Binding Ig-like Lectin 3 ; metabolism ; Transfection

OBJECTIVETo investigate the change of adhesion molecules in the lungs of rats suffered with decompression sickness (DCS).

METHODSMale SD rats were placed in the hyperbaric chamber, the chamber was compressed within 3 minutes to depths of 7 absolute atmosphere (ATA) and held at the designated depth for 60 min, then rapidly decompressed (3 min) to the surface. Rats were observed for signs of DCS after decompression. The brains, hepatis, and lungs were removed at 30 min, 6 h, 24 h post decompression, fixed and stained with hematoxylin eosin for routine histologic analysis. Lung paraffin sections were immunostained for the expression of intercellular adhesion molecule-1 (ICAM-1), E-selectin and major histocompatibility complex class II molecule (MHC-II). 2% evans blue dye in normal saline was injected 30 minutes prior to 6 h, 24 h before decompression. After 30 min, animals were perfused with 0.9% normal saline and lungs were harvested. Evans blue in the plasma was quantified by wavelength spectrophotometric analysis at 620 nm.

RESULTSResults showed that there were hemorrhage and edema changes in the lungs, liver and brain at 30 min post decompression. Compared with control animals maintained at 1 ATA, the levels of E-selectin, ICAM-1 and MHC-II in the lungs of DCS rats were significantly increased post decompression. Compared with control animals, evans blue in the plasma was much higher at 6 h, 24 h post decompression.

CONCLUSIONThe bubble-induced adhesion molecule-mediated endothelial activation may be involved in the pathogenesis of DCS.

Animals ; Brain ; pathology ; Cell Adhesion Molecules ; metabolism ; Decompression Sickness ; metabolism ; E-Selectin ; metabolism ; Endothelium, Vascular ; metabolism ; Genes, MHC Class II ; Intercellular Adhesion Molecule-1 ; metabolism ; Liver ; pathology ; Lung ; metabolism ; pathology ; Male ; Rats ; Rats, Sprague-Dawley

This study was purposed to investigate the effect of phenylhexyl isothiocyanate (PHI) on Wnt/β-catenin signaling pathway, histone acetylation, histone methylation and cell apoptosis in Jurkat cell line. The viability of Jurkat cells after treatment with PHI was tested by MTT. Apoptotic rate of Jurkat cells was measured by flow cytometry. The levels of Wnt/β-catenin related proteins including β-catenin, TCF, c-myc, and cyclinD1, histone acetylated H3 and H4, histone methylated H3K9 and H3K4 were detected by Western blot. The results showed that PHI inhibited the cell growth and induced apoptosis in Jurkat cells in time-and dose-dependent manners. Its IC50 at 48 h was about 20 µmol/L. Expression of histone acetylated H3, H4 and histone methylated H3k4 increased after exposure to PHI for 3 h, while histone methylated H3K9 decreased. Expression of β-catenin was not changed after exposure to PHI for 3 h, but expression of β-catenin, and its cell cycle-related genes such as TCF, c-myc and cyclinD1 decreased after exposure to PHI for 7 h. It is concluded that PHI regulates acetylation and methylation of histone, inhibits Wnt/β-catenin signal pathway, and is able to induce apoptosis and inhibits growth of Jurkat cells.
Acetylation ; Acylation ; Cyclin D1 ; metabolism ; Histones ; metabolism ; Humans ; Isothiocyanates ; pharmacology ; Jurkat Cells ; Methylation ; Proto-Oncogene Proteins c-myc ; metabolism ; TCF Transcription Factors ; metabolism ; Wnt Signaling Pathway ; drug effects ; beta Catenin ; metabolism

OBJECTIVETo investigate the effect of phenylhexyl isothiocyanate (PHI) on the drug-resistance to imatinib in K562/G01 cell line and to elucidate its possible mechanisms.

METHODSMTT assay was employed to access K562/G01 cell growth inhibition after exposure to PHI and/or imatinib at different concentrations. Apoptotic rate of K562/G01 cells was measured by flow cytometry. The levels of P-gp, P210(bcr-abl) and p-P210(bcr-abl) protein were detected by Western blot.

RESULTSPHI inhibited proliferation and induced apoptosis of K562/G01 cells after treated with PHI alone for 24 h. PHI concentration increased from 0 to 40 µmol/L, the inhibitory rate of cell proliferation from 0 to (51.22 ± 1.41)%, and the apoptosis rate from (3.76 ± 1.46)% to (35.35 ± 3.70)%. Combination of 10, 20, 40 µmol/L PHI and various concentrations of imatinib, IC50 s of imatinib were (10.49 ± 1.24), (6.33 ± 1.42), and (0.85 ± 0.17) µmol/L, respectively. When K562/G01 cells treated with 20 µmol/L PHI combined with 10 and 20µmol/L imatinib for 24 hours, apoptosis rate were (43.62 ± 4.23)% and (55.41 ± 4.35)%, respectively, being significantly higher than that with imatinib or PHI alone. PHI concentrations increased from 0 to 40 µmol/L for 7 hours, the P210(bcr-abl)/β-actin decreased from (0.944 ± 0.034) to (0.392 ± 0.025), and the p-P210(bcr-abl)/β-actin decreased from (0.906 ± 0.019) to (0.361 ± 0.021), while the alteration of P-gp was not seen.

CONCLUSIONSPHI inhibits the proliferation and induces apoptosis of K562/G01 cell line. PHI has synergistic effect with imatinib. It partially reverses the drug-resistance to imatinib. The mechanism of reversal of drug resistance in K562/G01 cells might be by inhibiting P210(bcr-abl) and p-P210(bcr-abl).

ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Apoptosis ; drug effects ; Benzamides ; pharmacology ; Cell Proliferation ; drug effects ; Drug Resistance, Neoplasm ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Imatinib Mesylate ; Isothiocyanates ; pharmacology ; K562 Cells ; Piperazines ; pharmacology ; Pyrimidines ; pharmacology

Objective To explore the advantages and disadvantages of magnetic resonance susceptibility effect applied clinically and countermeasures. Methods The application range of susceptibility weighted imaging (SWI) technique and the harm of susceptibility artifact were introduced with considerations on MRI clinical application and experiences, and then some countermeasures were put forward accordingly. Results SWI technique could be used for the diagnoses of multi diseases, and susceptibility artifact could be suppressed by sequence, parameter and corresponding techniques. Conclusion Susceptibility effect contributes to extending the clinical application of MRI, and references are provided for the development and reform of other new techniques.

Aim To investigate the effect of p-hydroxybenzaldehyde ( HD) on intestinal fibrosis in mice based on mouse intestinal fibrosis model and in vitro EMT model,and to explore the underlying mechanism Methods HE staining, Masson staining, immunohisto-chemistry ,qPCR, Western blot and other experimental methods were used to verify the effect of HD on intestinal fibrosis in mice and the potential mechanism. Results In vivo experiments showed that compared with the normal group, the DSS-induced intestinal fibrosis model group had shortened colon, increased colon his-topathological score, increased collagen volume fraction, and significantly increased collagen I expression. After treatment with 4, 10, and 25 mg • kg