[Effect of aging on pulmonary ICAM-1 and MCP-1 expressions in rats with lipopolysaccharide- induced acute lung injury].

Objective To investigate the effect of aging on the expressions of monocyte chemoattractant protein 1 (MCP-1) and intercellular adhesion molecule 1 (ICAM-1) in the lung tissue of rats with lipopolysaccharide (LPS)-induced acute lung injury (ALI). Methods Both young (3 months old) and aged (27 months old) female Wistar rats were randomly divided into two groups (n=8), namely the normal control and LPS-induced ALI groups. Immunohistochemistry for of ED-1 was used to detect the infiltrating inflammatory cells. Western blot and Northern blot analyses were employed for evaluating the expressions of MCP-1 and ICAM-1 at the protein and mRNA levels. Results Virtually no ED-1-positive cells were found in the lung tissue of the control rats in the young and aged groups. After LPS-induced ALI, ED-1-positive cells in the lung tissues increased significantly in both young and aged groups (P0.05), and the increment was more obviously in the aged group (P0.05). In the two normal control groups, the aged rats showed significantly higher expressions of MCP-1 and ICAM-1 than the young rats (P0.05); LPS significantly up-regulated their expression in the young and aged groups (P0.05), but the latter showed greater increments (P0.05). The aged rats with ALI also showed significantly greater MCP-1 and ICAM-1 increments than those of the young rats (P0.05). Conclusions Aging may upregulate lung MCP-1 and ICAM-1 expressions and enhance LPS-induced increments of MCP-1 and ICAM-1 expressions to exacerbate the pulmonary inflammation in rats.