Effects of CGRP on the E-cadherin expression in human bronchial epithelial cells / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To discuss the effect of calcitonin gene-related peptides (CGRP) on epithelial cadherin (E-cd) expression in human bronchial epithelial cells (HBECs) in vitro.</p><p><b>METHODS</b>The effect of CGRP on E-cd protein and mRNA expression in both normal and O3-challenged HBECs were determined by immunocytochemistry and RT-PCR. The signal transduction pathways of CGRP were observed by using protein kinase C(PKC) inhibitor (H-7), calmodulin(CaM) inhibitor (W-7) and PKA inhibitor (H-89).</p><p><b>RESULTS</b>CGRP increased E-cd mRNA and protein expressions of normal and O3-challenged HBECs in a dose-dependent manner. CGRP had no effect on cytoplasm E-cd expression. Pre-treatment with H-89, H-7 and W-7, the up-regulatory effect of CGRP on E-cd expression was partly abolished.</p><p><b>CONCLUSION</b>CGRP increased in cytomembrane E-cd expression of normal and O3-challenged HBECs in a dose-dependent manner. E-cd expression on HBECs was strengthened by CGRP via PKA, PKC and CaM pathways.</p>

Effects of CGRP on LPS-induced MMP-9 secretion by alveolar macrophages / 中国应用生理学杂志

<p><b>AIM</b>To explore the effects of calcitonin-gene-related peptide (CGRP) on LPS-induced MMP-9 secretion by alveolar macrophages (AM) in vitro.</p><p><b>METHODS</b>The supernatant of LPS-induced Wistar rat AM from different intervention groups were collected to measure the activity by gelatin zymography.</p><p><b>RESULTS</b>(Only secreting a small amount of MMP-9 with unstimulated AM, LPS stimulated MMP-9 production in a concentration-dependent manner (p < 0.01). (2) The activity of MMP-9 in CGRP intervention groups at different levels were significantly lower than those in non-intervention group (p < 0.01). (3) The inhibiting effects of CGRP were diminished by H-7 and W-7, an antagonist of protein kinase C (PKC) and calmodulin (CaM) (p < 0.05).</p><p><b>CONCLUSION</b>These data suggested that CGRP involved in the MMP-9 secretion by AM, partly, via PKC and CaM pathway.</p>

Effect of calcitonin-gene-related peptide on MMP-9 production in human bronchial epithelial cells / 中南大学学报(医学版)

OBJECTIVE@#To examine the expression of matrix metalloproteinase-9 (MMP-9) in human bronchial epithelial cells treated with calcitonin-gene-related peptide (CGRP).@*METHODS@#RT-PCR and gelatin zymography were performed to examine the dynamic expression and activity of MMP-9 in human bronchial epithelial cells at different doses (10(-10), 10(-9), 10(-8), 10(-7), and 10(-6)mol/L) and different time points (6,12,18,24,36, and 48h) after the stimulation of CGRP.@*RESULTS@#The unstimulated human bronchial epithelial cells only secreted a small amount of MMP-9. After the CGRP stimulation, the expression of MMP-9 presented in a concentration-dependent (10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) mol/L) and time-dependent (6,12,18,24,36, and 48 h) manners (P<0.01) in human bronchial epithelial cells. The effect of CGRP could be diminished by H-7 and W-7, an antagonist of protein kinase C (PKC) and calmodulin (CaM) (P<0.05).@*CONCLUSION@#CGRP can stimulate the secretion and expression of MMP-9 in human bronchial epithelial cells, and the signal transduction is partly via the PKC and CaM pathway.

Effects of vasoactive intestinal peptide on LPS-induced MMP-9 expression by alveolar macrophages in rats / 中南大学学报(医学版)

OBJECTIVE@#To explore the role of vasoactive intestinal peptide (VIP) on LPS-induced MMP-9 expression by alveolar macrophages (AM) in rats.@*METHODS@#LPS-induced cultured Wistar rats AMs were treated with different concentrations of VIP (10(-10) to approximately 10(-6) mol/L) for 24 h. AMs and the supernatant were collected to measure the MMP-9 expression and activity by RT-PCR and gelatin zymography, respectively. Results The MMP-9 activity and expression of LPS-induced AMs were significantly higher than those in the control group (P < 0.01). VIP (10(-9) to approximately 10(-6) mol/L) down-regulated LPS-induced MMP-9 activity and its expression. The effects were diminished by H-7 and W-7, an antagonist of protein kinase C (PKC) and calmodulin (CaM) (P < 0.01).@*CONCLUSION@#VIP can decrease LPS-induced MMP-9 activity and its expression, which may be related to protein kinase C and calmodulin pathway. VIP may have protective roles in the lung injury.

Temporal and spatial distribution of VIP, CGRP and their receptors in the development of airway hyperresponsiveness in the lungs / 生理学报

To explore the role of intrapulmonary neuropeptides in the development of airway hyperresponsiveness, we established an animal model of airway hyperresponsiveness (AHR) in rabbits by using ozone exposure. With the model, after test of the mechanics of respiration and bronchoalveolar lavage assay, the levels of vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) in the lungs were determined by radioimmunoassay, and the expression of mRNA coding receptors of these two neuropeptides was evaluated by reverse transcriptional-polymerase chain reaction (RT-PCR). At the same time, the distribution of VIP receptor-1 (VIPR1) and CGRP receptor-1 (CGRPR1) in lung tissues and its time-course were examined by in situ hybridization. The results showed: (1) in ozone-stressing groups, airway resistance increased significantly and typical inflammatory pathological changes were observed in pulmonary tissue slides, including neutrophil and eosinophil infiltration, mucus exudation and bronchial epithelial cells (BECs) shedding; (2) with elongation of ozone exposure, the levels of VIP and CGRP in the lungs increased at first, reaching a peak on d 2 to 4, then decreased slowly, and CGRP peaked somewhat earlier than VIP; (3) mRNA expression of the two neuropeptide receptors in the lungs changed in a similar manner like VIP and CGRP, but the high level of mRNA expression of VIPR1 lasted longer than that of CGRPR1; and (4) in situ hybridization for neuropeptide receptors demonstrated that, in unstressed control, VIPR1 and CGRPR1 positive cells appeared in the airway epithelium, pulmonary interstitial and focal areas of airway and vascular smooth muscles. With the elongation of ozone exposure, hybridization stained deeper and the majority of positive cells were located around the vessels and bronchus except a few in the alveoli. At 8 d, only a small number of positive cells were seen in the lungs. From the results, it is concluded that ozone-stressing can induce the development of AHR, in which VIP and CGRP may play important roles. That implies, through binding to CGRPR1, CGRP stimulates an early inflammation response which contributes in cleaning up of irritants, while VIP exerts a later dampening of pulmonary inflammation response. These two neuropeptides may play sequential and complementary roles in the development of AHR.

Fibronectin upregulates catalase gene expression in rabbit bronchial epithelial cells / 生理学报

We have previously shown that the binding of integrins with extracellular matrix component fibronectin (Fn) can improve the ability of bronchial epithelial cells (BECs) in resisting oxidant injury by up-regulating the activity of catalase and increasing the content of GSH. However, the molecular mechanism or its signaling pathway of this protection is still unclear. In order to examine the intracellular signaling mechanism activated by Fn-integrin binding reaction, the present study investigated the mRNA expression of catalase in primary cultured rabbit BECs using RT-PCR based on a cell-injury model made with ozone exposure. The product bands of target gene CAT were checked with Southern blot and oligonucleotide probe hybridization. The results showed that Fn (10 microg/ml) promoted the catalase mRNA transcription (P<0.01). This effect was abolished either by protein-tyrosine kinase inhibitor genistein or calmodulin inhibitor W(7) (P<0.01). These results indicate that the promotion of catalase activity induced by Fn-integrin reaction is partly due to the elevation of catalase mRNA transcription, and that its signalling are possibly relevant to tyrosine phosphorylation or calmodulin pathway.

Regulatory peptides modulate ICAM-1 gene expression and NF-kappaB activity in bronchial epithelial cells / 生理学报

Intercellular adhesion molecule-1 (ICAM-1) is an important adhesion molecule leading to adhesion between cells; NF-kappaB, being universally distributed in the organism, is an important nuclear transcription factor leading to a rapid response to the stimuli. Line of evidence have shown that ICAM-1 transcription and NF-kappaB activation is an important step of inflammatory reaction. To testify that intrapulmonary regulatory peptides modulate inflammatory lesion of bronchial epithelial cells (BECs) through their effect on ICAM-1 expression and nuclear factor kappaB (NF-kappaB) activation, we used immunocytochemistry, RT-PCR, and electrophoretic mobility-shift assay (EMSA) to determine the ICAM-1 expression and NF-kappaB activity in BECs. The effects of NF-kappaB inhibitor MG-132 on ICAM-1 expression were also observed. The results showed that vasoactive intestinal peptide (VIP) and epidermal growth factor (EGF) decreased ICAM-1 expression in O(3)-stressed BECs, while endothelin-1 (ET-1) and calcitonin gene-related peptides (CGRP) increased ICAM-1 expression in resting BECs. MG-132 blocked ICAM-1 expression induced by O(3), ET-1 and CGRP. The results obtained by using EMSA confirmed that VIP and EGF restrained the activation of NF-kappaB in O(3)-stressed BECs; CGRP and ET-1 promoted activation of NF-kappaB. These observations indicate that VIP and EGF abated the injury by means of down-regulatory effects on ICAM-1 transcription and NF-kappaB activation, while ET-1 and CGRP enhanced the inflammation reaction by an up-regulatory effect. It is suggested that a developing and intensive airway inflammation correlates closely with a persistent expression of ICAM-1 and repeated activation of NF-kappaB.

Effect of 17beta-estradiol on phosphorylcholine cytidylyltransferase activity from cultured rat lung explants / 中国应用生理学杂志

<p><b>AIM</b>To investigate the influence and mechanisms of 17beta-estradiol on the CTP: phosphorylcholine cytidylyltransferase (CCT) activity from cultured lung explants without serum.</p><p><b>METHODS</b>We detected the amount of [M-14C] choline incorporation into phosphatidylcholine so as to reflect CCT activity by liquid scintillation.</p><p><b>RESULTS</b>(1) 17beta-estradiol increased the CCT activity in dose-dependence and time-dependence. (2) Both the protein kinase C inhibitor H-7 and calmodulin antagonist W-7 abolished the stimulatory effect of 17beta-estradiol (3 x 10(-6) mol/L) on the CCT activity.</p><p><b>CONCLUSION</b>17beta-estradiol can increase CCT activity in cultured lung explants, its mechanism is related to protein kinase C and calmodulin.</p>

Effect of sex hormones on secretion of lysozyme in alveolar macrophage / 中国应用生理学杂志

<p><b>AIM AND METHODS</b>To further explore the functions of alveolar macrophage and their modulation mechanisms, the activity of lysozyme in rat alveolar macrophage assessed by electrophoresis was determined. The effects of androsterone and estradiol on lysozyme secretion and their mechanisms were also studied.</p><p><b>RESULTS</b>The results showed that androsterone and estradiol increased activity of lysozyme significantly (P < 0.01), indomethacin abolished those effects. This suggests that the insufficiency of sex hormones secretion as the retrogression of gonads is involved in the decrease of immunological functions, and the susceptibility to infectious diseases.</p><p><b>CONCLUSION</b>Sex hormones increased activity of lysozyme, and those effects related to prostaglandin.</p>

Effects of regulatory peptides on adhesion of eosinophil to bronchial epithelial cells / 生理学报

To explore the roles of regulatory peptides in the process of various anaphylactic inflammation of the airway, we observed the influence of four peptides, i.e., vasoactive intestinal peptide (VIP), epidermal growth factor (EGF), endothelin-1 (ET-1), and calcitonin gene-related peptide (CGRP), on the adhesion of eosinophil (EOS) to unstimulated and O(3)-stressed bronchial epithelial cells (BEC). From the experiments we observed that VIP and EGF decreased EOS adherence to O(3)-stressed BEC and downregulated airway inflammation; ET-1 and CGRP increased the adhesion of EOS to BEC in the inflammatory process; and CGRP aggravated O(3)-stressed reactions. The effects of ET-1 and CGRP were inhibited by W(7)and H(7). Anti-ICAM-1 antibody inhibited the adhesion of EOS to BEC, which brings to light that EOS adherence to BEC may be related to the expression of ICAM-1 of BEC.

Effects of vasoactive intestinal peptide on chemotaxis of bronchial epithelial cells / 生理学报

To investigate the influence of vasoactive intestinal peptide (VIP) on chemotaxis of bronchial epithelial cells (BECs). Rabbit chemotactic migration of primary BEC was assessed in a blind-well Boyden chamber. Radioimmunoassay and radio-ligand affinity analysis were used for determining VIP secretion and vasoactive intestinal peptide receptor (VIPR) expression. The results showed: (1) the method for determining chemotaxis of BECs by using insulin as chemotactic factor was stable and reproducible (r=0.9703, P<0.01). (2) VIP (0.001-1 micromol/L) elicited chemotaxis of BECs which was substantial and concentration-dependent. The effects of VIP were inhibited by W-7 and H-7 (P<0.01). (3) Heat stress enhanced the secretion of VIP (P<0.01) and upregulated the expression of VIPR on BECs (P<0.05). These results indicate that VIP in the lungs may play an important role in the repair of damaged epithelium, accelerating restoration of the airway to its normal state. Calmodulin and protein kinase C may be involved in the signal transduction of VIP effects.

Influence of regulatory peptides on the secretion of interleukins from bronchial epithelial cells of the rabbit / 生理学报

To explore the role of regulatory peptides in the secretion of bronchial epithelial cells (BECs), we observed the effects of four peptides, i.e.vasoactive intestinal peptide (VIP), epidermal growth factor (EGF), endothelin-1 (ET-1), and calcitonin gene-related peptide (CGRP), on the secretion of ILs from unstimulated or O3-stressed BECs. The results of the experiments showed that VIP exerted an inhibitory effect on the secretion of IL-1 and IL-8 from unstimulated and O3-stressed BECs, VIP also decreased the secretion of IL-5 from O3-stressed BECs; EGF promoted secretion of IL-1 and IL-8 from unstimulated BECs, but decreased the secretion of ILs from O3-stressed BECs; ET-1 and CGRP enhanced the secretion of IL-1, IL-5, and IL-8 from unstimlated BECs, CGRP also increased the secretion of ILs from O3-stressed BECs. The results obtained demonstrate that intrapulmonary regulatory peptides modulate the secretion of ILs from BECs, and may play an important part in transduction of inflammatory signals.