Resolvin D1 attenuates ventilator-induced lung injury by reducing HMGB1 release in a HO-1-dependent pathway.

Mechanical ventilation (MV) is a major support for patients with severe clinical disease, surgery and anesthesia. However, complications of mechanical ventilation especially ventilator-induced lung injury(VILI) can make the course and prognosis worse. Resolvin D1(RvD1) is a class of endogenous polyunsaturated fatty acid derivative, which has protective effects on various pulmonary inflammatory diseases. However, the mechanism of RvD1 in the process of VILI has not been fully elucidated. Our study found that RvD1 does have a protective effect on VILI including inhibiting inflammatory responses, reducing tissue damage and improving pulmonary function. The protective effect of RvD1 is positively related to its dose. Our research suggested RvD1 plays a role that increases the expression of heme oxygenase‑1 (HO-1) and decreases the expression of the high mobility group chromosomal protein B1 (HMGB-1) in VILI. HO-1 can exert the protective effect of organism through multiple mechanisms such as anti-inflammatory, anti-oxidation, anti-apoptosis, etc. HMGB1 is a potent inflammatory response factor in the body, which can aggravate the inflammatory response of the body. Our study demonstrated that RvD1 can ameliorate lung inflammation and reduce pathological changes in lung tissue in a model of lung injury induced by mechanical ventilation. The protective role of RvD1 is closely linked to the increased expression of HO-1 and the decreased expression of HMGB1. Moreover, we found that RvD1 can increase the expression of Nrf2 and inhibit the expression of NF-κB. We found the specific inhibitor of HO-1, ZnPP, can significantly inhibit the protective role of RvD1 in VILI. When HO-1 is inhibited, pathological damage and inflammatory reaction in the lungs are considerably aggravated, and pulmonary function is significantly weakened. In addition, the expression of HMGB1 is drastically increased. This indicates that the HO-1-HMGB1 pathway plays an important role in the protective effect of RvD1 on mechanical ventilation lung injury.