UC Irvine

Ischemia/reperfusion (I/R) injury of the lung can lead to extensive pulmonary damage. Sodium-glucose cotransporter-2 (SGLT2) inhibitors are insulin-independent, oral antihyperglycemic agents used for treating type 2 diabetes mellitus (T2DM). Although their cardioprotective properties have been reported, their potential roles in pulmonary protection in vivo are poorly characterized. Here, we tested a hypothesis that empagliflozin, an SGLT2 inhibitor, can protect lungs in a mouse model of lung I/R injury induced by pulmonary hilum ligation in vivo. We assigned C57/BL6 mice to sham-operated, nonempagliflozin-treated control, or empagliflozin-treated groups. Pulmonary I/R injury was induced by 1-hour left hilum ligation followed by 2-hour reperfusion. Using quantitative polymerase chain reaction (q-PCR) and Western blot analysis, we demonstrate that SGLT2 is highly expressed in mouse kidney but is weakly expressed in mouse lung (n = 5-6 per group, P < 0.01 or P < 0.001). Empagliflozin improved respiratory function, attenuated I/R-induced lung edema, lessened structural damage, inhibited apoptosis, and reduced inflammatory cytokine production and protein concentration in bronchoalveolar lavage (BAL) fluid [P < 0.05 or P < 0.001 versus control group (CON)]. In addition, empagliflozin enhanced phosphorylation of pulmonary extracellular signal-regulated kinases 1 and 2 (ERK1/2) post-I/R injury in vivo (P < 0.001, versus CON, n = 5 per group). We further showed that pharmacological inhibition of ERK1/2 activity reversed these beneficial effects of empagliflozin. In conclusion, we showed that empagliflozin exerts strong lung protective effects against pulmonary I/R injury in vivo, at least in part via the ERK1/2-mediated signaling pathway. SIGNIFICANCE STATEMENT: Pulmonary ischemia-reperfusion (I/R) can exacerbate lung injury. Empagliflozin is a new antidiabetic agent for type 2 diabetes mellitus. This study shows that empagliflozin attenuates lung damage after pulmonary I/R injury in vivo. This protective phenomenon was mediated at least in part via the extracellular signal-regulated kinases 1 and 2-mediated signaling pathway. This opens a new avenue of research for sodium-glucose cotransporter-2 inhibitors in the treatment of reperfusion-induced acute pulmonary injury.