In order to investigate the effect of nuclear factor-κB (NF-κB) on airway remodeling in asthmatic rats. 18 Wistar rats were divided into three groups: asthmatic group: pyrrolidine dithiocarbamate (PDTC) group, in which rats were injected intraperitoneally with NF-κB specific inhibitor PDTC (100 mg/kg) before ovalbumin (OVA) challenge; control group. The NF-κB activity and the expression of inhibitory protein κBα (I-κBα) in airway were detected by electrophoretic mobility shift assay (EMSA). Western blot and immunohistochemistry respectively. The infiltration of inflammatory cells, the number of Goblet cells, the area of collagen and smooth muscle in airway were measured by means of image analysis system. The results showed that with the up-regulation of airway NF-κB activity in asthmatic group, the number of goblet cells (3.08±0.86/100 μm basement membrane (BM)), the area of collagen (24.71±4.24 μm2/μm BM) and smooth muscle (13.81±2.11 μm2/μmBM) in airway were significantly increased (P<0.05) as compared with control group (0.14±0.05/100μmBM. 14.31±3.16 μm2/μm BM and 7.67±2.35 μm2/μm BM respectively) and PDTC group (0.33±0.14/100 μmBM, 18.16±2.85 μm2/μm BM and 8.95±2.16 μm2/μm BM respectively). However, there was no significant difference between PDTC group and control group (P>0.05). It was concluded that the activity of NF-κB is increased in airway of asthmatic rats. Inhibition of NF-κB, activation can attenuate constructional changes in asthma airway, suggesting NF-κB may contribute to asthmatic airway remodeling.
To study the effects of cyclooxygenase 2 selective inhibitor Nimesulide (NIM) combined with Cisplatin (DDP) on human lung cancer and the possible mechanisms, the proliferation and appoptosis of human lung cancer cell line A549 were evaluated by MTT reduction assay and flow cytometry respectively. The inhibitory effect on neoplasiain vivo was tested on nude mice subcutaneously implanted tumor. Our results showed that NIM and DDP could inhibit A549 cell proliferation in a concentration-dependent pattern; this action was enhanced when NIM (25 μmol/L) was given in combination with DDP and they worked in a synergistic or additive pattern as DDP concentration ≥1 μg/ml. NIM and DDP could induce A549 cells apoptosis and the action was augmented when used in combination (P<0.01). NIM and DDP could inhibit the growth of subcutaneously implanted tumors on nude mice (P<0.05,P<0.01) and the inhibitory rate of NIM combined with DDP was significantly higher than that of NIM or DDP group (P<0.01,P<0.01). It is concluded that combined use of NIM and DDP has significant synergistic antitumor effects on lung cancer cell line A549 and in animalsin vivo. The synergy may be achieved by growth inhibition and apoptosis induction.
The expression and functional activity of multiple drug resistance (MDR1) gene in human normal bone marrow CD34+ cells was observed. Human normal bone marrow CD34+ cells were enriched with magnetic cell sorting (MACS) system, and then liposome-mediated MDR1 gene was transferred into bone marrow CD34+ cells. Fluorescence-activated cell sorter was used to evaluate the expression and functional activity of P-glycoprotein (P-gp) encoded by MDR1 gene. It was found that the purity of bone marrow CD34+ cells was approximately (91±4.56) % and recovery rate was (72.3±2.36) % by MACS. The expression of P-gp in the transfected CD34+ cells was obviously higher than that in non-transfected CD34+ cells. The amount of P-gp in non-transfected CD34+ cells was (11.2±2.2) %, but increased to (23.6±2.34) % 48 h after gene transfection (P<0.01). The amount of P-gp was gradually decreased to the basic level one week later. The accumulation and extrusion assays showed that the overexpression of P-gp could efflux Rh-123 out of cells and there was low fluorescence within the transfected cells. The functional activity of P-gp could be inhibited by 10 μg/ml verapamil. It was suggested that the transient and highly effective expression and functional activity of P-gp could be obtained by liposome-mediated MRD1 transferring into human normal bone marrow CD34+ cells.
To explore the effects of bilirubin on alveolar macrophages (AM) and expression of iNOS and NO in them in emphysema model, the rats were pretreated with bilirubin before exposed to smoke. AM were isolated from bronchoalveolar lavage fluid (BALF) and cultured. Pathological microscopic examination of AM and immunohistochemical analysis of iNOS were performed. Nitric oxide (NO) content in the samples was determined by nitrate reductase technique. The results showed both alveoli and alveolar septum appeared normal in size and shape in normal group. AM showed kidney-shaped nucleus and were rich in Golgi complexes and primary lysosomes in the cytoplasm. The inner membrane of mitochondrion was continuous. Most cristae of the mitochondria were intact. In model group, the alveoli were expanded, ruptured and bullaes were formed. Both the population and sizes of AM increased significantly. Secondary lysosomes were rich in the cytoplasm. Deformation and pyknosis of the nucleus, swelling of the mitochondrions and rupture of the inner mitochondrial membrane could also be seen. At high magnification, most of the mitochondrial cristae were broken, or completely lost at certain points. In bilirubin group, alveoli partly expanded and the population of AM also increased, with morphological changes being slighter than that in model group. Both NO contents and expression of iNOS in model group were higher than those in normal group (P<0.05). In bilirubin group the two indice were lower than those in model group (P<0.05). Our findings suggested that high expression of iNOS and high NO content in AM accelerate the development of emphysema associated with smoking in rats. Bilirubin may exert protective effects on AM and retards the development of emphysema in rats.
By using Fura-2/AM, the effects of magnesium (Mg2+) on the glutamate-induced increase of intracellular free calcium ([Ca2+]i) in the cultured hippocampal neurons and the features were investigated by integrated photoelectric detecting system. The experiments were designed to three groups (The drug was spit to the cells for 20 s): Group A receiving 1×10−5 mol/L glutamate; Group B receiving 1×10−5 mol/L glutamate and 1×10−5 mol/L Mg2+ simultaneously; Group C receiving 1×10−5 mol/L glutamate again after [Ca2+]i in group B back to the baseline. The results showed that in group A, [Ca2+]i was obviously increased. In group B, the changes in [Ca2+] i and the peak value were significantly decreased. Moreover, the elevation of Phase 1 was slowed down and Phase 2 was shortened to some extent, and the plateau phase between them was relatively prolonged. In group C, calcium oscillation similar to that in group A occurred, but both the Phase 1 and Phase 2 were shortened and the Δ[Ca2+]i was slightly decreased. It was suggested that Mg2+ could quickly inhibit the rise of [Ca2+]i induced by glutamate in the cultured hippocampal neurons in rats.