At 9?months after pristane injection, however, total IgG level was significantly lower in not significant LRRK2 deficiency attenuates pristane-induced lupus-like pathology in mice Considering that high LRRK2 expression in B cells from SLE patients was strongly correlated with low levels of serum C3 and C4, two indicators related to renal injury during SLE pathogenesis [29], whether decreased total IgG and autoantibodies levels in gene polymorphism is originally dedicated to PD incidence, a disease characterized as a neurodegenerative disorder with the loss of midbrain dopaminergic neurons [13]. to those Lathyrol from healthy controls, as well as in activated CD19hi B cells. More significantly, expression in B cells was positively correlated with system lupus erythematosus disease activity index (SLEDAI), an indicator for disease severity, and serum IgG levels in SLE patients. Unfavorable correlations were observed between expression and serum Lathyrol C3 or C4 levels, two clinical features associated with SLE-related nephritis. deficiency reduced the death rate of pristane treated mice. Decreased levels of total IgG Lathyrol and autoantibody were detected in the serum with less deposition of immune complexes and attenuated pathological symptoms in the kidneys of [18] and [19]. Our recent study also suggested that LRRK2 was critical for NLRC4 inflammasome activation in macrophages, which was indispensable for host defense against Salmonella contamination [20]. In addition to the involvement of LRRK2 in innate immunity, the functions of LRRK2 in B cells were firstly proposed due to its high expression in peripheral B cells in an age-dependent manner [21]. Considering its susceptibility to SLE and high expression in B cells, whether LRRK2 functions in the pathogenesis of SLE is usually worthy of investigation. In this study, we found that LRRK2 expression was dramatically increased in B cells from SLE patients compared to that from healthy controls (HCs). Of note, LRRK2 expression in B cells was positively correlated with disease severity and the levels of serum IgG in SLE patients. Furthermore, we exhibited that LRRK2 promoted B cell terminal differentiation, humoral immune response and consequently Rabbit polyclonal to IL27RA lupus-like syndrome in a pristane-induced mouse model, thus implicating LRRK2 as a novel target in SLE therapy. Methods Human subjects SLE patients (n?=?22) enrolled in this study were from Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine (Shanghai, China). All SLE patients fulfilled the American Rheumatism Association Criteria for the diagnosis of SLE. The study was approved by the Ethic Committee of Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine. All experiments were performed according to the principles of the Declaration of Helsinki. Informed consent forms were assigned individually. HCs (n?=?31) were volunteer donors undergoing annual physical examination. SLE patients and HCs were both gender and age matched (Table?1). Table?1 Demographic and clinical characteristics of SLE and healthy controls were as forward: 5-GAGCACGCCTCCAAGTTATTT-3 and reverse: 5-ACTGGCATTATGAACTGTTAGCA-3. House-keeping gene was used as an internal control (primers: forward: 5-GGAGCGAGATCCCTCCAAAAT-3; reverse: 5-GGCTGTTGTCATACTTCTCATGG-3). The expression level of was calculated based on cycle threshold (Ct) values of target gene and test for the data with gaussian distribution, and by MannCWhitney test for those with non-gaussian distribution. Unless stated, p? ?0.05 was considered statistically significant. Results Up-regulation of LRRK2 in B cells from SLE patients as well as in activated B cells To explore the possible relationship between LRRK2 and SLE pathogenesis, the expression levels of LRRK2 in PBMCs were firstly compared between SLE patients and HC donors (Table?1). Consistent with the previous study [9], expression in PBMCs was significantly increased in SLE patients when compared to HCs (Fig.?1a). CD4+ T cells and B cells from SLE patients or HCs were further isolated separately with high purity (Additional file 1: Physique S1) and the expression levels of in cell subsets were determined. When precisely comparing expression in CD4+ T cells and B cells, it was obvious that B cells from both SLE and HCs groups expressed more dramatically than CD4+ T cells. More significantly, the expression of was elevated in B cells from SLE patients than that from HCs whereas was comparable in CD4+ T cells from SLE patients and HC individuals (Fig.?1b). Open in a separate windows Fig.?1 LRRK2 expression profiles in the peripheral immune cells. Whole blood was collected from SLE patients and healthy volunteer donors. The expression levels of in PBMCs (a), CD4+ T cells and B cells (b) from SLE patients and healthy donors were determined by RT-qPCR. c The expression levels of in resting CD19lo B cells and CD19hi B cells from three healthy donors were calculated based on transcriptome assay data [24]. *p? ?0.05; ***p?? ??0.001 CD19hi B cells were previously reported existing in certain antibody-driven autoimmune diseases, such as common variable immunodeficiency (CVID) [22], SLE [23] and pemphigus [24]. These CD19hi B cells exhibit activated phenotypes, and function.