The Sprouty-related protein, Spred, inhibits cell motility, metastasis, and Rho-mediated actin reorganization.

Sprouty and the Sprouty-related protein, Spred (Sprouty-related Ena/vasodilator-stimulated phosphoprotein homology-1 (EVH1) domain-containing protein), inhibit Ras-dependent extracellular signal-regulated kinase (ERK) signaling induced by a variety of growth factors. Since Sprouty proteins have been shown to inhibit not only ERK activation but also cell migration, we postulated that Spreds also inhibit cellular migration. Using stably highly metastatic LM8 cells infected with the Spred1-Sendai virus vector, we demonstrated that Spred1 inhibits the metastasis of LM8 cells in nude mice. Spred1 overexpression also inhibited migration of cells in vitro in response to chemokines, CCL19 and CCL21. We also found that Spred1 overexpression dissolved actin-stress fibers. Both EVH1 domain and C-terminal Sprouty-related domain were required for actin reassembly. Spred1 and Spred2 suppressed constitutively activated RhoA (V14RhoA)-induced stress fiber formation and serum response factor activation. Spred1 bound to activated RhoA, but not cdc42 and Rac. Spred1 also inhibited chemokine-induced RhoA activation and active RhoA-induced Rho-kinase activation. These data suggest that Spreds are key regulators of RhoA-mediated cell motility and signal transduction. Furthermore, our study suggests that the induction of Spreds could be a novel strategy for preventing cancer cell metastasis.

Surgical results of percutaneous suction aspiration and drainage for pyogenic spondylitis.

Forty patients (24 male and 16 female; age 13-87 years, mean 66 years) with pyogenic spondylitis were treated by percutaneous suction aspiration and drainage between January 1997 and September 2007 at Kurume University Hospital. The surgical procedure and transpedicular approach were similar to those used for percutaneous discectomy in the treatment of intervertebral disc herniation. The average postoperative follow-up period was 22.6 months. Two patients had died by the time of the survey, and two had undergone multiple operations. The clinical outcomes were excellent in 12 patients, good in 17 patients, fair in 5 patients, and poor in 6 patients. The response rate (cases with "excellent" or "good" outcomes) was 72.5% (29 patients). Identification of the organism was possible in 26 patients (65%). The most frequently identified organism was methicillin-resistant Staphylococcus aureus (MRSA; 11 cases), followed by methicillin-sensitive Staphylococcus aureus (MSSA; 5 cases) and Escherichia coli (3 cases). Percutaneous suction aspiration and drainage has been demonstrated as an effective means of treating early spondylitis. This procedure is minimally invasive and enables pathogen identification, histopathological diagnosis and even simultaneous treatment. This is the only means of treatment available for patients who cannot tolerate open surgery. This therapy also promises medico-economic advantages by shortening treatment periods and eliminating open surgery.

Molecular cloning of mammalian Spred-3 which suppresses tyrosine kinase-mediated Erk activation.

We have reported on Spred-1 and Spred-2, which inhibit MAP kinase activation by interacting with c-kit and ras/raf. Here, we report the cloning of a third member in this family, Spred-3. Spred-3 is expressed exclusively in the brain and its gene locates in chromosome 19q13.13 in human. Like Spred-1 and -2, Spred-3 contains an EVH1 domain in the N-terminus and a Sprouty-related cysteine-rich region (SPR domain) in the C-terminus that is necessary for membrane localization. However, Spred-3 does not possess a functional c-kit binding domain (KBD), since the critical amino acid Arg residue in this region was replaced with Gly in Spred-3. Although Spred-3 suppressed growth factor-induced MAP kinase (Erk) activation, inhibitory activity of Spred-3 was lower than that of Spred-1 or Spred-2. By the analysis of chimeric molecules between Spred-3 and Spred-1, we found that the SPR domain, rather than KBD, is responsible for efficient Erk suppression. The finding of Spred-3 revealed the presence of a novel family of regulators for the Ras/MAP kinase pathway, each member of which may have different specificities for extracellular signals.