Association of rs10954213 polymorphisms and haplotype diversity in interferon regulatory factor 5 with systemic lupus erythematosus: a meta-analysis.

The rs10954213 polymorphism and the haplotype diversity in interferon regulatory factor 5 (IRF5) play a special role in systemic lupus erythematosus (SLE) but with inconclusive results. We conducted a meta-analysis integrating case-control and haplotype variant studies in multiple ethnic populations to clearly discern the effect of these two variants on SLE. Eleven studies on the relation between rs10954213 polymorpisms in IRF5 and SLE were included and we selected a random effect model to calculate the pooled odds ratios (ORs) and the corresponding 95% confidence interval (95% CI). A total of 6982 cases and 8077 controls were involved in the meta-analysis. The pooled results indicated that A allele was significantly associated with increased risk of SLE as compared with the IRF5 rs10954213 G allele (A vs. G, P<0.00001) in all subjects. The same pattern of the results was also obtained in the European, African American, and Latin American. Asian population had a much lower prevalence of the A allele (49.1%) than any other population studied, and Europeans had the highest frequency of the IRF5 rs10954213 A allele (62.1%). The significant association of increased SLE risk and TCA haplotype was indicated in the contrast of TCA vs. TTA as the pooled OR was 2.14 (P=0.002). The same result was also found in the contrast of TCA vs. TTG as the pooled OR was 1.45 (P=0.004). This meta-analysis suggests that the A allele of rs10954213 and TCA haplotype (rs2004640-rs2070197-rs10954213) in IRF5 is associated with the increased risk of SLE in different ethnic groups, and its prevalence is ethnicity dependent.

Silencing endothelin-3 expression attenuates the malignant behaviors of human melanoma cells by regulating SPARC levels.

Endothelin-3 (ET-3) is aberrantly expressed in both metastatic melanoma tissues and cultured melanoma cells. Our previous work showed that ET-3 could promote survival of metastatic melanoma cells via its altered expression. In this study, we investigated the mechanisms responsible for these gene-induced phenotypes in melanoma cells. An ET-3 gene sequence-specific shRNA vector pLVTHM-ET3-RNAi was constructed and transfected into human malignant melanoma cells A375 and MMRU, and the resultant molecular events and cellular changes were examined. As compared with the empty-vector group, cell proliferation was slowed down, and the growth inhibition rates were 38.9% in A375 cells and 38.4% in MMRU cells after transfection. In addition, cell invasion capability was also inhibited, with a reduction of 62.2% in A375 cells and 54.3% in MMRU cells. The percentage of apoptotic cells was found to increase. Meanwhile, in both cell lines, secreted protein acidic and rich in cysteine (SPARC) levels were down-regulated together with inhibition of its upstream signaling molecule, NF-κB. Thus, the current results suggested that down-regulated expression of ET3 attenuates the malignant behaviors of human melanoma cells partially by decreasing the expression of SPARC and NF-κB.

RasGRP3 in peripheral blood mononuclear cells is associated with disease activity and implicated in the development of systemic lupus erythematosus.

This study examined the relationship between the expression of Ras guanyl nucleotide-releasing protein 3 (RasGRP3) and disease activity in systemic lupus erythematosus (SLE) and explored the possible mechanisms in MRL/lpr mice. We detected the expression of RasGRP3 in peripheral blood mononuclear cells (PBMCs) of SLE patients (n=26) and healthy controls (n=20) by employing RT-PCR and studied the association between the mRNA expression of RasGRP3 in PBMCs and the clinical findings. We also measured the protein level of RasGRP3 in PBMCs by Western blotting (n=10). In addition, we isolated the B cells from PBMCs with magnetic bead separation and determined the RasGRP3 expression by RT-PCR (n=10). Furthermore, we extracted spleen B cells from MRL/lpr mice and knocked down RasGRP3 by siRNA transfection to study the role of RasGRP3 in the pathway of B cell receptor (BCR) activation and the production of pro-inflammatory cytokines. Compared with healthy volunteers, the expression of RasGRP3 was significantly elevated in PBMCs and purified B cells from SLE patients. The mRNA expression of RasGRP3 in PBMCs was positively correlated with SLE disease activity index (SLEDAI). Moreover, silencing RasGRP3 could inhibit Akt and Erk1/2 activation in marginal zone (MZ) and follicular (FO) B cells of MRL/lpr mice. Additionally, the production of pro-inflammatory cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), was decreased whereas activation of caspase-3 cleavage was induced in vitro. In conclusion, over-expression of RasGRP3 is associated with disease activity and might be involved in the pathogenesis of SLE.