Decreased expression of Src homology 2-containing inositol phosphatase-1 (SHIP-1) in gouty arthritis. (A) Expression of mRNA for SHIP-1 in peripheral blood mononuclear cells (PBMCs) from healthy controls (HCs), PBMCs and synovial fluid mononuclear cells (SFMCs) of gouty arthritis patients. (B) PBMCs from HCs were cultured for the indicated times in the presence of the monosodium urate (MSU) crystals. Real-time PCR was performed to determine the mRNA expression of SHIP-1. Results are representative of three independent experiments. Values are shown as the mean ± standard error of the mean. (C) Synovial specimens from acute gouty arthritis and osteoarthritis patients were processed for immunohistochemical staining using anti-human SHIP-1 antibody. Scale bars in d = 50 μm. (D) THP-1 cells were stimulated or not, with MSU crystal and/or miR-155 tranfection. The scrambled controls were transfected in all of miR-155 negative cells to rule out the possibility of a non-specific anti-RNA response. It was analyzed by western blot for SHIP-1, phophrylated Akt, total Akt, IkB proteins. *P <0.05, Mann–Whitney U-test. OA, osteoarthritis.