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

To 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 A_1, A_2 and A_3 and the group B was sub-divided into the group of B_1, B_2, B_3, B_4 and B_5. No other agents were added to the group A_1 and B_1. The cells of group A_2 and B_2 were stimulated with 5 % CSE for 24 h. HASMCs from group A_3 and B_3 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 B_4 for 24 h. The cells from group B_5 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 and 3H-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 of 3H-TdR incorporation, the ratios of A value of PKC-α mRNA and the A value of PKC-α protein in HASMCs from group B_1, B_2 and B_3 were significantly increased compared to those of group A_1, A_2 and A_3 correspondingly and respectively (P<0.01). The proliferation of HASMCs of group A_2 and B_2 stimulated with CSE and group A_3 and B_3 stimulated with CSE and PMA were also significantly enhanced when group A_1, A_2 and A_3 and group B_1, B_2 and B_3 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 of A value of PKC-α mRNA and the A value of PKC-α protein in HASMCs from group B_4 treated with Ro-31-8220 and group B_5 treated with CSE and Ro-31-8220 were significantly decreased as compared to those of group B_1 and B_2 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.

Effects of Mitochondrial ATP-sensitive K^+ Channel on Protein Kinase C Pathway and Airway Smooth Muscle Cell Proliferation in Asthma

The effects of ATP-sensitive mitochondrial K + channel(mitoK ATP) on mitochondrial membrane potential(Δψm),cell proliferation and protein kinase C alpha(PKCα) expression in airway smooth muscle cells(ASMCs) were investigated.Thirty-six Sprague-Dawley(SD) rats were immunized with saline(controls) or ovalbumin(OVA) with alum(asthma models).ASMCs were cultured from the lung of control and asthma rats.ASMCs were treated with diazoxide(the potent activator of mitoK ATP) or 5-hydroxydencanote(5-HD,the inhibitor of mitoK ATP).Rhodamine-123(R-123) was used to detect Δψm.The expression of PKCα protein was examined by using Western blotting,while PKCα mRNA expression was detected by using real-time PCR.The proliferation of ASMCs was measured by MTT assay and cell cycle analysis.In diazoxide-treated normal ASMCs,the R-123 fluorescence intensity,protein and mRNA levels of PKCα,MTT A values and percentage of cells in S phase were markedly increased as compared with untreated controls.The ratio of G 0 /G 1 cells was decreased(P<0.05) in diazoxide-treated ASMCs from normal rats.However,there were no significant differences between the ASMCs from healthy rats treated with 5-HD and the normal control group.In untreated and diazoxide-treated ASMCs of asthmatic rats,the R-123 fluorescence intensity,protein and mRNA levels of PKCα,MTT A values and the percentage of cells in S phase were increased in comparison to the normal control group.Furthermore,in comparison to ASMCs from asthmatic rats,these values were considerably increased in asthmatic group treated with diazoxide(P<0.05).After exposure to 5-HD for 24 h,these values were decreased as compared with asthma control group(P<0.05).In ASMCs of asthma,the signal transduction pathway of PKCα may be involved in cell proliferation,which is induced by the opening of mitoK ATP and the depolarization of Δψm.

Contribution of protein kinase C to passively sensitized human airway smooth muscle cells proliferation

Background Airway smooth muscle proliferation plays an important role in airway remodeling in asthma. But little is known about the intracellular signal pathway in the airway smooth muscle cell proliferation in asthma. The objective of this paper is to investigate the contribution of protein kinase C (PKC) and its alpha isoform to passively sensitized human airway smooth muscle cells (HASMCs) proliferation. Methods HASMCs in culture were passively sensitized with 10% serum from asthmatic patients,with non-asthmatic human serum treated HASMCs used as the control. The proliferation of HASMCs was examined by cell cycle analysis,3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazoliumbromide (MTT) colorimetric assay and proliferating cell nuclear antigen (PCNA) immunofluorescence staining. The effect of PKC agonist phorbol 12-myristate 13-acetate (PMA) and PKC inhibitor Ro-31-8220 on the proliferation of HASMCs exposed to human asthmatic serum and non-asthmatic control serum was also examined by the same methods. The protein and mRNA expression of PKC-α in passively sensitized HASMCs were detected by immunofluorescence staining and reverse transcription-polymerase chain reaction. Results The percentage of S phase,absorbance (value A) and the positive percentage of PCNA protein expression in HASMCs passively sensitized with asthmatic serum were (16.30±2.68)%,0.430±0.060 and (63.4±7.4)% respectively,which were significantly increased compared with HASMCs treated with control serum [(10.01±1.38)%,0.328±0.034 and (37.2±4.8)%,respectively] ( P <0.05). After HASMCs were passively sensitized with asthmatic serum,they were treated with PMA,the percentage of S phase,value A and the positive percentage of PCNA protein expression were (20.33±3.39)%,0.542±0.065 and (76.0±8.7)% respectively,which were significantly increased compared with asthmatic serum sensitized HASMCs without PMA( P <0.05). After HASMCs passively sensitized with asthmatic serum were treated with Ro-31-8220,the percentage of S phase,value A and the positive percentage of PCNA protein expression were (11.21±1.56)%,0.331±0.047 and (38.8±6.0)% respectively,which were significantly decreased compared with asthmatic serum sensitized HASMCs without Ro-31-8220 ( P <0.05). The relative ratio of value A of PKC-α mRNA and the positive percentage of PKC-α protein expression in passively sensitized HASMCs were 1.23±0.10 and (61.1±9.4)% respectively, which were significantly increased compared with HASMCs treated with control serum [1.05±0.09 and (34.9±6.7)%,respectively] ( P <0.05). Conclusions The proliferation of HASMCs passively sensitized with human asthmatic serum is increased. PKC and its alpha isoform may contribute to this proliferation.

蛋白激酶C在支气管哮喘模型大鼠气道平滑肌细胞增殖中的信号转导机制研究

目的 探讨蛋白激酶C(PKC)信号转导途径在支气管哮喘 (简称哮喘 )大鼠气道平滑肌细胞 (ASMC)增殖中的作用。方法 (1) 4 8只Wistar大鼠分为哮喘组 (A组 )及对照组 (B组 ) ,根据激发时间 (2、4、8周 )又分别分为A1、A2 、A3 组和B1、B2 、B3 组 ,其中A、B组大鼠各 12只 ,A2 、A3 、B2 及B3 组各 6只。用流式细胞术、四甲基偶氮唑盐 (MTT)法、增殖细胞核抗原 (PCNA)染色等方法观察每组ASMC增殖 ;(2 )用PKC激活剂 12 肉蔻酰 13 乙酸佛波酯 (PMA)及抑制剂Ro 31 82 2 0分别干预A1、B1组ASMC ,观察ASMC增殖的变化 ;(3)用逆转录 聚合酶链测定 (RT PCR)和免疫细胞化学法检测A1、A2 、A3 组和B1组ASMCPKC α的表达。结果 (1)A组ASMCS期比例、吸光度 (A)值、PCNA表达增高 ,与B组比较差异有显著性 (P <0 0 1)。 (2 )A1组ASMCS期比例、A值、PCNA阳性表达率在干预前分别为 (19± 3) %、0 4 5 9± 0 0 36、(80± 10 ) % ;10nmol/LPMA处理后分别为 (2 7± 4 ) %、0 5 99± 0 0 78、(95± 9) % ;5 0nmol/LPMA处理后为 (14± 3) %、0 346± 0 0 38、(5 3± 8) % ;Ro 31 82 2 0处理后为 (14± 3) %、0 343± 0 0 4 8、(4 9± 8) %。各干预剂处理后与处理前比较差异均有显著性 (P <0 0 1) ;5 0nmol/LPMA处?

蛋白激酶C对致敏人气道平滑肌张力的影响

目的探讨蛋白激酶C(protein kinase C,PKC)对体外被动致敏人气道平滑肌(human airway smooth muscle,HASM)张力的影响。方法行肺叶切除术患者6例,其中肺癌5例,支气管扩张1例,取手术切除的正常支气管组织标本分为哮喘组与对照组,哮喘组支气管组织用哮喘患者的血清致敏,对照组支气管组织用体检健康者的血清致敏。2组采用肌张力试验观察不同浓度组胺和PKC激活剂豆蔻酰佛波醇乙酯(Phorbol 12-myristate 13-acetate,PMA)对HASM张力的影响。2组均给予PMA阻断剂Ro31-8220和钙通道阻断剂硝苯地平,观察其对PMA所致HSAM收缩反应的抑制情况。结果哮喘组1×10-7、1×10-6、1×10-5、1×10-4 mol/L组胺作用的HASM张力((11.6±3.1)、(21.9±4.1)、(40.1±6.2)、(54.1±13.2)mg/mg)均较对照组((6.4±1.3)、(11.3±2.5)、(23.3±4.7)、(34.1±5.7)mg/mg)明显增高(P<0.05),1×10-7、5×10-7、1×10-6、5×10-6 mol/L PMA作用的HASM张力((12.1±2.7)、(30.9±7.0)、(41.2±9.2)、(53.1±12.3)mg/mg)均较对照组((8.6±1.9)、(22.8±4.8)、(30.9±5.4)、(38.3±7.9)mg/mg)明显增高(P<0.05);2组组胺和PMA作用的HASM张力均随浓度增高而增高,呈剂量依赖性;2组PMA所致HSAM的收缩反应均可被Ro31-8220和硝苯地平完全抑制。结论激活PKC可导致HASM张力增高,该效应在体外被动致敏的HASM中表现更明显。

核因子KB在被动致敏的人气道平滑肌细胞增殖中的信号转导作用

目的 探讨核因子κB(NF κB)是否参与被动致敏的人气道平滑肌细胞 (HASMC)增殖及是否是蛋白激酶C(PKC)激活后的下游途径。方法 用 10 %哮喘患者血清被动致敏HASMC ,以10 %非哮喘者血清为对照 ,并用吡咯烷二硫氨基甲酸 (PDTC)及 12 肉豆蔻酰 13 乙酸佛波酯 (PMA)干预HASMC ,用流式细胞术、MTT法及增殖细胞核抗原 (PCNA)免疫荧光技术检测HASMC增殖 ;NF κBp6 5 免疫荧光技术及电泳迁移率改变分析 (EMSA)检测NF κB活性。结果 (1)哮喘血清处理的HASMC ,S期细胞比例、吸光度值 (A值 )、PCNA表达阳性率、NF κBp6 5阳性率及EMSA灰度值均较对照血清组增加 (均P <0 0 5 ) ,PDTC预处理后上述指标均下降 (均P <0 0 5 )。 (2 )PMA +哮喘血清处理HASMC后 ,S期细胞比例、A值、PCNA表达阳性率、NF κBp6 5阳性率及EMSA灰度值分别为 (2 5 5 2± 3 38) %、0 5 72± 0 0 5 4、(81 2± 10 2 ) %、(2 6 5± 5 0 ) %和 716 5 4± 12 2 93,PDTC预处理后上述指标均下降 (均P <0 0 5 )。结论 NF κB参与了哮喘血清被动致敏的HASMC增殖 ,在其增殖中存在着PKC/NF κB信号途径。