Heme oxygenase-1 expression were decreased in monocytes from Systemic Lupus Erithematosus patients (119.6)

Abstract

Abstract Systemic Lupus Erithematosus (SLE) is a complex disease characterized by alterations affecting innate and adaptive immune cells. In SLE, monocytes and dendritic cells (DCs) present a stimulatory phenotype that promotes the activation of T cells. One of the molecules that control monocyte function is Heme oxigenase-1 (HO-1) which possesses anti-inflammatory capacity. The aim of this work was to assess HO-1 levels in monocytes of SLE patients (SLEp) and HC. PBMCs were obtained from 43 SLEp and 30 HC. CD14+ monocytes and CD4+ cells were sorted by FACS and HO-1 expression was measured by RT-PCR. HO-1 protein expression was determined by FACS. Parameters of CD4+ T cell activation such as CD69 and CD25 expression and IL2 production after staphylococcal enterotoxin A (SEA) stimulation were used as surrogate to evaluate the stimulatory capacity of monocytes from PBMCs cultures. MHCII and CD86 expression was analyzed by FACS. HO-1 mRNA levels were decreased in monocytes from SLEp compared to HC (P<0.0075, t test). When HO-1 protein expression were assessed by FACS similar results were observed (relative MFI expression to HC; 0.73 ± 0.05; P<0.0001, t test). When CD4+ activation in response to SEA was evaluated, no differences were found. MHCII and CD86 expression in CD14+ cells showed no differences between SLEp and HC. In conclusion, we found a significant decrease in HO-1 expression in monocytes from SLEp, suggesting that an imbalance in HO-1 could play a role in SLE pathogenesis.