Inhibiting USP30 preserves lung endothelial barrier integrity

A mitochondrial de-ubiquitinating enzyme, USP30, plays a vital role in regulation of mitochondrial outer membrane protein homeostasis. USP30 has been considered as a potential target for treating Parkinson’s disease and cancers; however, the role of USP30 in microvascular endothelial cells (ECs) and acute inflammatory diseases has not been reported. We found that USP30 activity was increased in response to lipopolysaccharide (LPS) exposure. Downregulation of USP30 expression by USP30 siRNA transfection attenuated LPS- or TNFa-induced VCAM1 expression in human lung microvascular endothelial cells (HLMVECs). The similar effect was observed in USP30 inhibitor-treated HLMVECs, indicating that inhibiting USP30 attenuates EC inflammation. Further, we showed that knockdown of USP30 preserved HLMVEC barrier function by using trans-well permeability assay and the electric cell-substrate impedance sensing (ECIS) system. To further investigate the role of EC USP30 in lung injury, we generated EC-specific USP30 deficient mice (EC-USP30KO). Depletion of USP30 in ECs were confirmed by immunostaining in lung tissues and immunoblotting in isolated lung ECs. In response to intratracheal LPS challenge, EC-USP30KO mice showed reduced cytokine (IL-6 and IL-1b) and protein levels in bronchoalveolar lavage fluids (BAL) and severity of lung injury. Further, we found that depletion of USP30 in ECs protects against lung ischemia-reperfusion injury. To investigate the molecular mechanisms by which inhibiting USP30 preserves lung EC function, we performed an unbiased microRNA-seq and found that knockdown of USP30 upregulated miR-30a-5p. Overexpression of miR-30a-5p attenuated LPS- or TNFa-induced VCAM1 expression. miR-30a-5p inhibitor promoted LPS-induced EC hyperpermeability. Taken together, we revealed that inhibiting USP30 preserves lung EC barrier integrity and reduced severity of acute lung injury through upregulation of miR-30a-5p. NIH R01HL136284 and R01HL157164 to Yutong Zhao; R01HL151513 and R01HL167846 to Jing Zhao This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.