Effect of ulinastatin on expressions of hypoxia-inducible factor-1α and macrophage migration inhibitory factor in patients with acute lung injury induced by heat stroke

Objective To investigate the expressions of hypoxia-inducible factor-1α (HIF-1α) and macrophage migration inhibitory factor (MIF) in patients with acute lung injury induced by heat stroke, and the effect of ulinastatin on the expressions of HIF-1α and MIF. Methods Ninety heat stroke patients in Longgang Central Hospital of Shenzhen City from May 2015 to March 2018 were enrolled , they were randomly divided into conventional group (n=45) and ulinastatin group (n=45). Another ninety healthy adults were selected as controls.According to the clinical features, the ninety heat stroke patients were divided into premonitory heat stroke group (n=30), mild heat stroke group (n=30) , and severe heat stroke group (n=30). The levels of HIF-1α and MIF in peripheral blood and bronchoalveolar lavage fluid were measured with reverse transcription-polymerase chain reaction, enzyme linked immunosorbent assay and Western blot, the relationship of them with severity of heat stroke was analysed. Results The expressions of HIF-1α and MIF in the heat stroke group was obviously higher than those in the control group (all P<0.05). The levels of mRNA and protein of HIF-1α and MIF in the mild heat stroke group were obviously higher than those in the premonitory heat stroke group (all P<0.05), and the levels of mRNA and protein of HIF-1α and MIF in the severe heat stroke group were obviously higher than those in the mild heat stroke group and premonitory heat stroke group (all P<0.05). The expressions of HIF-1α and MIF were lower in the ulinastatin group than those in the conventional group (all P<0.05). There were positive correlations between HIF-1α and MIF level, HIF-1α level and clinical stages of heat stroke, MIF level and clinical stages of heat stroke, respectively (all P<0.05). Conclusions In the acute lung injury induced by heat stroke, the expressions of HIF-1α and MIF are significantly increased, which is closely related to the severity of heat stroke.Ulinastatin can play a protective role by reducing expressions of HIF-1α and MIF, attenuate acute lung injury induced by heat stroke and promote therapeutic effect. Key words: Hypoxia-inducible factor 1, alpha subunit; Macrophage migration inhibitory factor; Acute lung injury; Heat stroke; Ulinastatin