Chen Shi-xin

TNF-α Up-regulates matrix metalloproteinase-9 expression and activity in alveolar macrophages from patients with chronic obstructive pulmonary disease

To study the effects of tumor necrosis factor (TNF)-α on matrix metalloproteinase (MMP)-9 expression and activity in alveolar macrophages (AM) and to investigate the role of NF-κB in the induction, AM were collected from bronchoalveolar lavage fluid (BALF) of healthy subjects and patients with chronic obstructive pulmonary disease (COPD). MMP-9 expression and activity were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), Western blotting and zymography. NF-κB activity was detected by electrophoretic mobility shift assay (EMSA). MMP-9 expression and activity induced by TNF-α in AM from healthy subjects or patients with COPD were significantly increased in a dose-dependent manner (P<0.05). NF-κB activity induced by TNF-α was significantly increased in AM from patients with COPD, and pyrrolidine dithiocarbamate (PDTC) and N-acetyl-L-cysteine (NAC) significantly inhibited the activation of NF-κB induced by TNF-α (P<0.05). The presents study suggested that the expression and activity of MMP-9 from AM can be induced by TNF-α, and TNF-α/NF-κB signal pathway may play an important role in the induction.

Effect of Nuclear Factor-κB on Airway Remodeling in Asthmatic Rats

SummaryIn 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.

Effect of Cigarette Smoke Extract on the Role of Protein Kinase C in the Proliferation of Passively Sensitized Human Airway Smooth Muscle Cells

SummaryTo investigate the effect of cigarette smoke extract (CSE) on the role of protein kinase C (PKC) in the proliferation of passively sensitized human airway smooth muscle cells (HASMCs). After synchronization of cultured HASMCs, they were divided into a group A and Group B. The group A was treated with normal human serum and served as controls and the group B was treated with the serum of asthma patients. The group A was further divided into group of A1, A2 and A3 and the group B was sub-divided into the group of B1, B2, B3, B4 and B5. No other agents were added to the group A1 and B1. The cells of group A2 and B2 were stimulated with 5 % CSE for 24 h. HASMCs from group A3 and B3 were treated with PKC agonist PMA (10 nmol/L) and CSE (5 %) for 24 h. PKC inhibitor Ro-31-8220 (5 μmol/L) was added to the HASMCs of group B4 for 24 h. The cells from group B5 were stimulated with Ro-31-8220 (5 μmol/L) and CSE (5 %) for 24 h. The proliferation of HASMCs isolated from group A and B was examined by cell cycle analysis, MTT colorimetric assay and3H-TdR incorporation test. The expression of PKC-α in each group was observed by Western blotting and RT-PCR, respectively. The results showed that the percentage of S phase, absorbance (A) value, the rate of3H-TdR incorporation, the ratios ofA value of PKC-α mRNA and theA value of PKC-α protein in HASMCs from group B1, B2 and B3 were significantly increased compared to those of group A1, A2 and A3 correspondingly and respectively (P<0.01). The proliferation of HASMCs of group A2 and B2 stimulated with CSE and group A3 and B3 stimulated with CSE and PMA were also significantly enhanced when group A1, A2 and A3 and group B1, B2 and B3 compared to each other (P<0.05,P<0.01, respectively). The percentage of S phase, absorbency (A) value,3H-TdR incorporation rate, the ratios ofA value of PKC-α mRNA and theA value of PKC-α protein in HASMCs from group B4 treated with Ro-31-8220 and group B5 treated with CSE and Ro-31-8220 were significantly decreased as compared to those of group B1 and B2 correspondingly and respectively (P<0.05,P<0.01). It was concluded that CSE can enhance the passively sensitized HASMC proliferation and the expression of PKC alpha. PKC and its alpha subtype may contribute to this process. Our results suggest cigarette may play an important role in ASMCs proliferation of asthma through PKC signal pathway.

Heat shock protein 70 gene polymorphisms in Han nationality of China with chronic obstructive pulmonary diseases

SummaryIn order to investigate whether polymorphism in gene for heat shock protein 70 (HSP70) has any bearing on individual susceptibility to the development of chronic obstructive pulmonary disease (COPD), the geotypes of 88 patients with COPD and 87 healthy smoking control subjects were tested by polymerase chain reaction followed by restriction fragment polymorphism analysis for HSP70 gene. In COPD group, HSP70-1 genotype A/A, A/B and B/B was 59. 1%, 35.2% and 5.7%, HSP70-2 genotype A/A, A/B and B/B was 26.1%, 54.6% and 19.3%, and HSP70-hom genotype A/A, A/B and B/B was 70.4%, 27.3% and 2.3% respectively. In the control group, it was 60.9%, 27.5% and 3.5%, 20.7%, 56.3% and 23.0%, and 54.0%, 42.5% and 3.5%, respectively. The frequency of polymorphic genetypes showed no difference between the COPD group and the control group (P>0.05). It was suggested that geneic polymorphism in HSP70 is not associated with development of COPD in Han nationality of China.