[The effects of adenosine, interleukin-1 and theophylline on the expression of A2 adenosine receptor mRNAs in peripheral blood mononuclear cells from asthmatic patients].
OBJECTIVE
To explore the roles of A2a and A2b adenosine receptors(A2aAR and A2bAR) in the pathogenesis of bronchial asthma.


METHODS
Eleven asthmatics and 11 healthy subjects were included in this investigation. Peripheral blood mononuclear cells(PBMCs) were obtained after density centrifugation on Ficoll-Hypaque. The expression of A2aAR and A2bAR mRNAs in PBMCs was examined by use of the reverse transcription-polymerase chain reaction (RT-PCR) and image pattern analysis semiquantitation method.


RESULTS
The expression of A2aAR mRNA in PBMCs from asthmatics was not enhanced, compared with that of healthy subjects(P > 0.05). Adenosine or IL-1 or theophylline was not observed to have effect on A2aAR mRNA (P > 0.05). A2bAR gene expression in PBMCs was more markedly in patients with asthma than in normal individuals (P < 0.05). Adenosine and IL-1 significantly increased A2bAR mRNAs in asthmatics. Theophylline inhibited A2bAR gene expressions. The expression of A2bAR mRNA in PBMCs was positively correlated to serum total immunoglobulin E (TIgE) level in asthmatics (r = 0.72, P < 0.01). The expressions of A2bAR mRNA elevated by adenosine or IL-1 were correlated positively with serum TIgE(r = 0.78 or r = 0.61; P < 0.05) and negatively with the forced expiratory volume in first second to predicted value ratio (FEV1%) (r = -0.62 or r = -0.81; P < 0.05) in asthmatics.


CONCLUSIONS
These results indicated that the expression of A2bAR mRNAs in PBMCs was more remarkable in asthmatics than in healthy subjects; that adenosine or IL-1 potentiated the mRNA expression of A2bAR in PBMCs in asthmatic patients, which was correlated with allergy state and the degree of airway obstruction; and that theophylline might antagonize adenosine by inhibiting A2bAR mRNA.
Zhou
X
X
Department of Respiratory Medicine, First Affiliated Hospital, WCUMS, Chengdu 610041, China.
Wang
Z
Z
Lin
Y
Y
Zhu
Y
Y
D000241:Adenosine / Q000494:pharmacology*; D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000097:blood*; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D018047:Receptors, Purinergic P1 / Q000096:biosynthesis* / Q000235:genetics; D013806:Theophylline / Q000494:pharmacology*
D007375:Interleukin-1; D012333:RNA, Messenger; D018047:Receptors, Purinergic P1; D013806:Theophylline; D000241:Adenosine