Karger Publishers, Gerontology, 4(53), p. 228-233, 2007
DOI: 10.1159/000100960
Full text: Unavailable
<i>Background:</i> It is generally agreed that elderly subjects undergo progressive deterioration of their immune responsiveness, which leads to an increased susceptibility to autoimmune processes, neoplasm and inflammation. Thus there is a general consensus that regulation of inflammation results from a balance between pro-inflammatory and anti-inflammatory pathways. <i>Objective:</i> The present study aimed to investigate the possible alterations of cyclic AMP/protein kinase A (cAMP/PKA) and p38 mitogen-activated protein kinase (p38 MAPK) pathway signaling (reactive oxygen species (ROS) generation) and inositol 1,4,5-triphosphate (InsP3) production by neutrophils during the aging process. <i>Methods:</i> Age-induced ROS generation and InsP3 production were studied in healthy subjects ranging in age from 20 to 80 years. The subjects were divided into six age groups: (I) 20–29, (II) 30–39, (III) 40–49, (IV) 50–59, (V) 60–69, and (VI) 70–80 years old. The effect of cAMP, H89 (inhibitor PKA), and PD169316 (inhibitor p38 MAPK) on ROS production was quantified in a luminol-dependent chemiluminescence assay (relative light units/min) and by InsP3 release (cpm). <i>Results:</i> Our results demonstrated a lack of dibutyryl cAMP inhibitory effects on ROS generation and InsP3 production by granulocytes from PKA-dependent 50-year-olds. However, the inhibitory effect of cAMP is restored in neutrophils after the age of 50 years when p38 MAPK signaling is inhibited. <i>Conclusions:</i> The present study may be important towards a better understanding of the high susceptibility to infections and age-related inflammatory and deregulation diseases. The alteration of cAMP/PKA and p38 MAPK signaling pathways enhances the inflammatory process.