Sickle cell transgenic (HbSS) mice lungs produce greater inflammatory mediators with downregulation of dilator proteins (1175.10)

Abstract

Sickle cell chronic lung disease is one of the notable causes of death in patients with sickle cell disease (SCD). Prevention and treatment of acute chest syndrome (ACS) constitutes a major concern in clinical management of SCD. Some lung complications in SCD result from direct or indirect effect of pulmonary microvascular occlusion by sickle erythrocytes and their adhesion to the vascular endothelium. Vasoactive eicosanoids are released resulting in inflammatory response. Studies with HbSS mice have enhanced knowledge of SCD pathology, but the biochemical mechanisms of initiation and progression of ACS is not well understood. We hypothesized that lungs of SCD patients are under greater inflammatory stress due to decreased expression of anti‐inflammatory proteins and metabolites, but greater inflammatory proteins and metabolites. We studied baseline expression of 5‐Lox, cysLT1 as well as PKA, COX1 and COX2 and CREB and measured Leukotrienes and PGI2 release by lungs of HbSS mice and transgenic HbAA mice. HbSS mice lungs expressed 40‐60% more 5‐Lox and CysLT1, but 40‐70% less COX1/COX2 and CREB proteins; produced 68% greater LTs, but PGI2 was not detected. Expression of PKA was not different. The data suggest that SCD lungs are under greater inflammatory stress which may trigger ACS and sustain sickle cell chronic lung disease in SCD patients. Grant Funding Source: LA Biomed Seed grant 520522