Abstract: Objective To investigate the expression levels of SUMO1 and SENP1 during lung development in rats. Methods Neonatal rats were randomly assigned to 4 groups with 8 rats each group. Pulmonary tissue were collected for further study at 1 d, 4 d, 7 d, 14 d after birth. The mRNA expressions of SUMO1 and SENP1 were detected by RT-qPCR. Western blot was used to analysis the protein expressions of SUMO1 and SENP1. Results The expression of SUMO1 mRNA had no significant changes at 1 to 14 d. Compared with 4 d, free SUMO1 decreased and conjugated SUMO1 increased at 14 d (P<0.05). The protein expression of free SUMO1 at 4 d was significantly higher than 1 and 7 d (P<0.05), then remained stable at 7 to 14 d. The expressions levels of SENP1 mRNA and protein showed the same tendency with free SUMO1. Conclusions SENP1 maintain the dynamic balance of SUMOylation by mediating deconjugation of SUMO1 protein, this process may play an important role during lung development.

Key words: SUMO1, SENP1, dynamic balance, lung development