Influence of intrapulmonary regulatory peptides on the expressions of HLA-DR, CD80 and CD86 in human bronchial epithelial cells / 生理学报

Antigen presenting is the initial step of the immune responses. In order to verify that human bronchial epithelial cells (HBECs) can express antigen presentation molecules, which can be modulated by intrapulmonary regulatory peptides, the present study was designed to examine the expressions of human leukocyte antigen DR (HLA-DR), CD80 and CD86 in resting or ozone-stressed HBECs by using immunocytochemistry and flow cytometry analysis. The results showed that HBECs expressed HLA-DR, CD80 and the expressions of HLA-DR and CD80 molecules were down-regulated under ozone stress. While VIP, P3513 and CGRP upregulated the expression of HLA-DR in resting or ozone-stressed HBECs, they had different effects on CD80 expression. VIP did not influence the expression of CD80 under resting state, but increased the expression of CD80 under ozone stress. CGRP decreased CD80 expression in resting HBECs, but increased CD80 expression in ozone-stressed HBECs. P3513 increased CD80 expression in resting HBECs, but decreased CD80 expression in ozone-stressed HBECs. The expression of CD86 was absent in resting or ozone-stressed HBECs. The results obtained demonstrate that HBECs have the capability to act as antigen presenting cells and the expression of HLA-DR and costimulatory molecules can be modulated by intrapulmonary regulatory peptides.

The role of bronchial epithelial cells in airway hyperresponsiveness / 生理学报

It is commonly accepted that airway hyperresponsiveness (AHR) is a chronic airway inflammation although the exact mechanism of its pathogenesis is still unclear. In the past ten years, an epithelial defect hypothesis has gradually gained supports from the main stream. Airway epithelium is no longer considered only as a simple mechanic barrier but an active interface between the inner and outer environment. Bronchial epithelial cells play a critical role in maintenance of homeostasis in the airway local microenvironment through a wide range of physiologic functions including anti-oxidation, exocrine/endocrine secretions, mucus production and antigen presentation under health and stressed/inflamed/injured conditions. It is reasonably hypothesized that disruption of these functional processes or defects in airway epithelium integrity may be the initial steps leading to airway hyperresponsiveness such as in asthma and chronic obstructive pulmonary disease.

Effect of vasoactive intestinal peptide and epidermal growth factor on the adhesion of eosinophils to bronchial epithelial cells / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of intrapulmonary regulatory peptides on adhesion of eosinophils (EOS) to bronchial epithelial cells (BECs).@*METHODS@#Two regulatory peptides, namely vasoactive intestinal peptide (VIP) and epidermal growth factor (EGF) were investigated. VIP and EGF were observed on the secretion of ILs and expression of intercellular adhesion molecule-1 (ICAM-1).@*RESULTS@#VIP and EGF could decrease ILs secretion and ICAM-1 expression.@*CONCLUSION@#VIP and EGF inhibited the adhesion of EOS to BEC in the inflammatory process to lighten the airway inflammation.

Protective effect of bombesin receptor subtype-3 on human brochial epithelial cells against injury / 中南大学学报(医学版)

OBJECTIVE@#To investigate the role and mechanism of bombesin receptor subtype 3 (BRS-3) in the proliferation and protection against injury of human brochial epithelial cells (HBECs).@*METHODS@#Effect of P3513 (a specific agonist of BRS-3) on the proliferation of HBECs was observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method; the release rate of 3H-Udr, and LDH activity, catalase activity, and the expression of cadherin and integrin beta1 were also analyzed under O3 stress with or without P3513 treatment.@*RESULTS@#The proliferation of HBECs was accelerated by P3513 in a concentration-dependent manner (10(-9) approximately 10(-7) mol/L). Ozone stress could promote the release rate of 3H-Udr, and LDH activity, which could be inhibited by P3513. P3513 could promote the activity of catalase. The effect of proliferation and protection against injury caused by P3513 could be inhibited by W7 (calmodulin inhibitor), PD98059 (tyrosin kinase inhibitor) and H89 (PKA inhibitor). P3513 could stimulate the expression of caderin and integrinbeta1 of ozone-stressed HBECs.@*CONCLUSION@#Activation of BRS-3 caused by P3513 may play an important role in protecting HBECs from oxidant injury, and the signal pathway is possibly relevant to Ca2+, MEK and PKA.

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.

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.