A model of functional recovery after significant loss of neural tissue: biofeedback based healing of vestibular dysfunction

ISSN:1471-220

The Syk Kinase SmTK4 of Schistosoma mansoni Is Involved in the Regulation of Spermatogenesis and Oogenesis

The signal transduction protein SmTK4 from Schistosoma mansoni belongs to the family of Syk kinases. In vertebrates, Syk kinases are known to play specialized roles in signaling pathways in cells of the hematopoietic system. Although Syk kinases were identified in some invertebrates, their role in this group of animals has not yet been elucidated. Since SmTK4 is the first Syk kinase from a parasitic helminth, shown to be predominantly expressed in the testes and ovary of adult worms, we investigated its function. To unravel signaling cascades in which SmTK4 is involved, yeast two-/three-hybrid library screenings were performed with either the tandem SH2-domain, or with the linker region including the tyrosine kinase domain of SmTK4. Besides the Src kinase SmTK3 we identified a new Src kinase (SmTK6) acting upstream of SmTK4 and a MAPK-activating protein, as well as mapmodulin acting downstream. Their identities and colocalization studies pointed to a role of SmTK4 in a signaling cascade regulating the proliferation and/or differentiation of cells in the gonads of schistosomes. To confirm this decisive role we performed biochemical and molecular approaches to knock down SmTK4 combined with a novel protocol for confocal laser scanning microscopy for morphological analyses. Using the Syk kinase-specific inhibitor Piceatannol or by RNAi treatment of adult schistosomes in vitro, corresponding phenotypes were detected in the testes and ovary. In the Xenopus oocyte system it was finally confirmed that Piceatannol suppressed the activity of the catalytic kinase domain of SmTK4. Our findings demonstrate a pivotal role of SmTK4 in gametogenesis, a new function for Syk kinases in eukaryotes

Holistically convergent modular networks: a biological principle for recurrent network architecture

ISSN:1471-220

Colorectal cancer in Crohn’s colitis is associated with advanced tumor invasion and a poorer survival compared with ulcerative colitis: a retrospective dual-center study

Purpose!#!Colorectal cancer is a well-recognized complication of inflammatory bowel diseases (IBD), such as ulcerative colitis (UC) and Crohn's colitis (CC). In this study, we assess the clinico-pathological features and outcomes of patients with colorectal cancer from UC in comparison with CC.!##!Methods!#!Data of all patients with colitis-associated cancer (CAC) who underwent surgery at Erlangen or Würzburg University Clinic between 1995 and 2015 were selected. Clinical, histopathological, and survival data were analyzed retrospectively.!##!Results!#!Of all 88 patients with CAC, 20 patients had Crohn's colitis and 68 patients had ulcerative colitis. We observed a young median age at tumor diagnosis (49.5 years UC; 45.5 years CC, p = 0.208) in both diseases and a long median disease duration before CAC (19 years UC; 18 years CC; p = 0.840). Patients with CC suffered more often from rectal cancer (14 (70.0%) in CC; 23 (33.8%) in UC; p = 0.005) and advanced tumor stages (8 (47.0%) pT4 in CC; 14 (25.0%) pT4/ypT4 in UC; p = 0.008). Five-year overall survival rate was 39.3% for CC and 67.1% for UC (p = 0.009 for difference between the groups). Survival did not differ significantly between UC and CC in the multivariate analysis after correction for UICC tumor stage.!##!Conclusion!#!CAC in CC showed advanced tumor stages associated with reduced survival compared with CAC in UC. This may be explained by less intense surveillance in patients with CC leading to delayed cancer diagnosis