Abstract: Objective To explore the correlation of pulmonary expressions of fibroblast growth factor receptors (FGFR1-4) with
lung fibrosis and aging. Methods Real-time fluorescence quantitative PCR was used to detect the expression levels of FGFR1-4
in the lung tissues, and lung fibrosis was observed by HE and Masson staining in mice at different ages. Results The 4
subtypes of FGFR showed different expression levels in the lung tissues of mice, and FGFR2 had the highest expressions. The
expression levels of all the 4 FGFR subtypes in 8-month-old mice were significantly lower than those in 5-week-old mice. The
8-month-old mice tended to present with histological changes of lung fibrosis. Conclusion FGFR expressions is
down-regulated with aging in mice. Among the FGFR subtypes, FGFR2 is expressed at the highest level. The occurrence of
lung fibrosis with aging is probably associated with down-regulated FGFR expression. FGF/FGFR signaling may participate in
the aging process and regulation of lung fibrosis.