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Abstract: Objectives: To investigate the effects of benzo[a]pyrene (B[a]P), a major toxic component of cigarette smoke, on the expression of Slug and to determine the effect of B[a]P/Slug on the invasive properties of rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS). Method: The expression of Slug was measured by real-time PCR following the stimulation of FLS with different concentrations of B[a]P or EGF. The phosphorylation of the key enzymes in the signaling pathway was analyzed by western blots. Inhibitors of PI3K/Akt/mTOR pathway were used to confirm the critical pathway for Slug expression. An in vitro cell invasion assay was performed using RA FLS treated with Slug cDNA, Slug small interference RNA, or control. Results: Slug expression increased significantly following treatment with B[a]P or EGF in a dose-dependent manner. The stimulation of FLS with B[a]P or EGF induced the phosphorylation of Akt kinase, but not in ERK, JNK and p38. The Slug mRNA expression induced by B[a]P and EGF decreased significantly following the treatment with PI3K/Akt/mTOR inhibitors. Slug overexpression using Slug cDNA upregulated the invasive function of FLS, and Slug depletion using siRNA showed the opposite effect compared with the control. In addition, the stimulation with B[a]P increased the invasive function of the control siRNA-treated FLS but not in the Slug siRNA-treated FLS. Conclusion: Our data showed that B[a]P regulates the invasive properties of RA FLS through Slug expression. This mechanism may provide a novel molecular link underlying the association between smoking and increased radiographic progression in RA. [Copyright &y& Elsevier]

The aim of this study is to investigate the effects of CIP2A (Cancerous inhibitor of protein phosphatase 2A) on the apoptosis of RA FLS. Proliferation and apoptotic activity of RA FLS following treatment with CIP2A siRNA or control siRNA were analyzed using MTT assays and Cell Death Detection kit. RA FLS was treated with CIP2A siRNA or control siRNA in 3-, 6-, and 9-day intervals for a Western blot analysis to determine C-Myc expression. To evaluate the signal transduction pathways engaged in apoptosis, caspase-3 activity, caspase-9 activity, PARP, and phosphorylation of the Akt kinase were analyzed by Western blot. Cell viability of RA FLS was significantly lower in the CIP2A siRNA-treated group compared with the control after 7 days ( p = 0.022). Apoptosis of RA FLS was significantly higher in the CIP2A siRNA-treated group compared with the control when incubated for 3, 6, and 9 days ( p = 0.029, p = 0.021, p = 0.043, respectively). C-Myc expression did not change with the different incubation periods. CIP2A siRNA-treated FLS expressed higher level of activated caspase-3, caspase-9, and PARP ( p = 0.014, p = 0.020, p = 0.021, respectively) and lower level of phosphorylated Akt ( p = 0.001) compared with those treated with the control siRNA. Our data show that CIP2A expression in RA FLS is an important mediator of dysfunctional apoptosis independent of c-Myc stabilization. Expression of CIP2A may contribute to apoptotic resistance of RA FLS through the activation of Akt and deactivation of caspase-3, caspase-9, and PARP. Inhibition of CIP2A may therefore constitute a novel, promising therapeutic target in RA. [ABSTRACT FROM AUTHOR]

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified oncoprotein that leads to cellular proliferation in cancer cells. We aim to investigate CIP2A expression in fibroblast-like synoviocytes (FLS) and its association with the histopathological grade of synovitis and the invasive function of FLS in rheumatoid arthritis (RA). CIP2A protein expression was measured in 8 RA FLS and 8 OA FLS using Western blot analysis. CIP2A mRNA expression from 19 RA FLS and 7 OA FLS was measured using real-time PCR. Synovitis score of RA FLS-matched synovial tissues was semiquantitatively measured by two independent pathologists. An in vitro cell invasion assay was performed using RA FLS treated with CIP2A small interfering RNA (siRNA) or with control vector. Western blot analysis showed that CIP2A is more frequently overexpressed in RA FLS compared with OA FLS. CIP2A mRNA expression was higher in RA FLS compared with those in OA FLS, but did not reach statistical significance ( P = 0.076). In RA, total synovitis score was strongly correlated with FLS CIP2A mRNA expression ( rs = 0.849, P = 0.043). TNF-α treatment induced a robust increase in the invasive function of control FLS ( P = 0.0021), but no significant effect was observed in CIP2A siRNA-treated FLS. Our data demonstrate that CIP2A expression is closely associated with the histopathological score of synovitis and invasive function of FLS in RA. These results suggest that CIP2A may play a critical role in the destructive process in RA and warrant further investigation of CIP2A as a therapeutic target. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The aim of this study is to measure α-defensin-1 expression in the peripheral blood of patients with Behçet''s disease (BD) and healthy control (HC) and to assess the association between α-defensin-1 expression and clinical features of BD. Methods: Our patients fulfilled the diagnostic criteria of the international BD study group. ELISA and real-time PCR were performed to measure α-defensin-1 protein level in the sera and α-defensin-1 mRNA level in peripheral blood mononuclear cells (PBMC), respectively. Results: The α-defensin-1 mRNA expression was significantly higher in BD patients (n =59) than HC (n =34) (0.49±0.10 vs. 0.19±0.45, P =0.03). The level of α-defensin-1 mRNA and protein was significantly higher in active patients than inactive patients (n =15, 0.91±0.28 vs. n =44, 0.35±0.09, P <0.001 and n =21, 7.50±2.14ng/ml vs. n =50, 3.32±0.96ng/ml, P =0.001, respectively). The level of α-defensin-1 mRNA was significant higher in patients with arthritis (n =20) than those without arthritis (n =39). Conclusion: α-defensin-1 mRNA and protein levels are significantly increased in BD patients, especially in active BD patients. Furthermore, α-defensin-1 mRNA is over-expressed in the PBMC of BD patients with arthritis. The present study suggests that α-defensin-1 may be involved in the pathogenesis of BD and can be used as valuable biologic marker for estimation of disease activity in BD. [Copyright &y& Elsevier]