Effects of hypoxia on expression of formyl peptide receptor 1 in rat lung fibroblasts in vitro

Di-san junyi daxue xuebao

JIAO Li1¹  LI Xiaoxu1³  HUANG Jian1⁴  HUANG Jian1⁶ 

[1] Department of High Altitude Physiology and Pathology, Facalty of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038;Key Laboratory of Extreme Environmental Medicine of Ministry of Education, Facalty of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038;;Department of High Altitude Physiology and Pathology, Facalty of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038;Key Laboratory of Extreme Environmental Medicine of Ministry of Education, Facalty of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038;Key Laboratory of High Altitude Medicine of PLA, Facalty of High Altitude Military Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038;

关键词: fibroblast;    hypoxia;    chemotaxis;    formyl peptide receptor;   

DOI  :  10.16016/j.1000-5404.201909154

来源: DOAJ

【 摘 要 】

Objective To study the effect of hypoxia on the expression of formyl peptide receptor 1 (FPR1) in rat lung fibroblasts. Methods We tested the chemotactic activity of 10, 100, and 1 000 nmol/L FPR agonist (fMLF) for lung fibroblasts isolated from adult female SD rats using Boyden chemotaxis chamber assay. The cells were cultured in a hypoxic incubator (1% O2, 5% CO2, and 94% N2) at 37 ℃ for 24 h, and the culture supernatant was collected and treated with the FPR-specific antagonist tBoc before assessing fibroblast chemotactic activity mediated by FPR. Rat lung fibroblasts cultured in a normoxic condition or in a hypoxic incubator (1% O2) for 2, 12, and 24 h were tested for mRNA and protein levels of FPR1 and FPR agonist annexin A1 (AnxA1) using real-time PCR and Western blotting. The protein levels of FPR1 and AnxA1 were also examined in cells treated with different concentrations of fMLF and in cells treated with tBoc prior to hypoxia for 24 h. Results fMLF induced obvious chemotactic migration of rat lung fibroblasts, and 100 nmol/L exhibited the strongest chemotactic activity for the fibroblasts (P < 0.05). The supernatant of the cells with hypoxic exposure showed a significantly higher chemotactic activity than that of the cells cultured in a normoxic condition (P < 0.05); the addition of tBoc significantly decreased in the chemotactic activity of the supernatants, and the reduction was more obvious with the hypoxic cell culture supernatant (P < 0.05). Hypoxia for 12 h significantly increased FPR1 protein expression in the lung fibroblasts (P < 0.05); hypoxia for 12 and 24 h significantly enhanced the protein expression of AnxA1 in the fibroblasts (P < 0.05). The mRNA levels of FPR1 and AnxA1 increased significantly in the lung fibroblasts after hypoxia for 2, 12, and 24 h (P < 0.05); increasing the concentration of fMLF in the cell culture resulted in progressively increased protein levels of FPR1 and AnxA1, and their increments became significant after treatment with fMLF at 100 and 1 000 nmol/L (P < 0.05); this effect was significantly attenuated by the application of the FPR antagonist tBoc. Conclusion FPR1 is expressed in primary cultured rat lung fibroblasts. Hypoxia promotes the expression and secretion of FPR1 and its agonists in rat lung fibroblasts, and FPR1 activation further enhances the expression and secretion of the receptor and its agonists.

【 授权许可】

Unknown