Multiple variants of receptor-type protein tyrosine phosphatase beta are expressed in the central nervous system of Xenopus

Significance of PTPRZ1 and CIN85 expression in cervical carcinoma

PURPOSE

To investigate PTPRZ1 and CIN85 expression and their significance in cervical carcinoma.

METHODS

The expression of PTPRZ1 and CIN85 was detected by immunohistochemistry and the association between PTPRZ1 and CIN85 expression and clinical pathological variables were analyzed.

RESULTS

The expression of PTPRZ1 and CIN85 were significantly higher in cervical carcinoma than those in normal cervical epithelium. CIN85 expression was significantly higher in patients with deeper cervical invasion when compared with that with superficial invasion, while PTPRZ1 expression was significantly higher in patients with smaller tumor size (≤2 cm) than that with larger size (>2 cm). The expression of PTPRZ1 and CIN85 were higher in squamous cell carcinoma than those in adenocarcinoma.

CONCLUSIONS

There exist increased PTPRZ1 and CIN85 expression in cervical carcinoma and they are probably associated with tumor growth or invasion. PTPRZ1 and CIN85 expression were higher in squamous cell carcinoma than those in adenocarcinoma.

DSD-1-Proteoglycan/Phosphacan and Receptor Protein Tyrosine Phosphatase-Beta Isoforms during Development and Regeneration of Neural Tissues

Interactions between neurons and glial cells play important roles in regulating key events of development and regeneration of the CNS. Thus, migrating neurons are partly guided by radial glia to their target, and glial scaffolds direct the growth and directional choice of advancing axons, e.g., at the midline. In the adult, reactive astrocytes and myelin components play a pivotal role in the inhibition of regeneration. The past years have shown that astrocytic functions are mediated on the molecular level by extracellular matrix components, which include various glycoproteins and proteoglycans. One important, developmentally regulated chondroitin sulfate proteoglycan is DSD-1-PG/phosphacan, a glial derived proteoglycan which represents a splice variant of the receptor protein tyrosine phosphatase (RPTP)-beta (also known as PTP-zeta). Current evidence suggests that this proteoglycan influences axon growth in development and regeneration, displaying inhibitory or stimulatory effects dependent on the mode of presentation, and the neuronal lineage. These effects seem to be mediated by neuronal receptors of the Ig-CAM superfamily.

Functional divergence of two zebrafish midkine growth factors following fish-specific gene duplication

In mammals, the unique midkine (mdk) gene encodes a secreted heparin-binding growth factor with neurotrophic activity. Here, we show the presence of two functional mdk genes named mdka and mdkb in zebrafish and rainbow trout. Both midkine proteins are clearly different from the related pleiotrophin, which was also identified in zebrafish and other fishes. Zebrafish mdka and mdkb genes map to linkage groups LG7 and LG25, respectively, both presenting synteny to human chromosome 11, in which the unique human ortholog mdk is located. At least four other genes unique in mammals are also present as duplicates on LG7 and LG25. Phylogenetic and divergence analyses suggested that LG7/LG25 paralogs including mdka and mdkb have been formed at approximately the same time, early during the evolution of the fish lineage. Hence, zebrafish and rainbow trout mdka and mdkb might have been generated by an ancient block duplication, and might be remnants of the proposed fish-specific whole-genome duplication. In contrast to the ubiquitous expression of their mammalian counterpart, zebrafish mdka and mdkb are expressed in spatially restricted, mostly nonoverlapping patterns during embryonic development and strongly in distinct domains in the adult brain. Ectopic ubiquitous expression of both mdk genes in early zebrafish embryos caused completely distinct effects on neural crest and floorplate development. These data indicate that mdka and mdkb underwent functional divergence after duplication. This provides an outstanding model to analyze the molecular mechanisms that lead to differences in pathways regulating the formation of homologous embryonic structures in different vertebrates.