Abstract:  Objective     To explore in vivo the role and molecular mechanism of small ubiquitin-like modifier (SUMO) specific protease 3 (SENP3) in regulating autophagy in mouse lung. Methods   Immunofluorescence was performed to detect SENP3 localization in lung tissues. SENP3+/-       and SENP3+/+ mice were starved to induce autophagy. Immunoblotting was used to evaluate the overall autophagy level. Electron microscopy and immunofluorescence were used to detect autophagy, and to identify which type(s) of cells undergoing autophagy in mouse lung. Co-immunoprecipitation was used to detect the SUMOylation modification of autophagy-related molecule coiled-coil myosin-like Bcl-2-interacting protein 1 (BECN1). Results     SENP3 was highly expressed in alveolar typeⅡ epithelial cells in lung tissues. After starvation, the mouse alveolar type Ⅱ epithelial cells underwent autophagy, and SENP3+/- mice was more pronounced than SENP3+/+ mice. SUMO2/3 modification of BECN1 in lung tissue samples was removed by SENP3. Conclusion     SENP3 plays a role on regulating the degree of autophagy of mouse alveolar typeⅡ epithelial cells during starvation in fine-tuning manner.

Key words: Small ubiquitin-like modifier specific protease 3, Autophagy, Alveolar typeⅡ epithelial cells, Mice