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We recently found that erythroblast-like cells derived from human leukaemia K562 cells express C5a receptor (C5aR) and produce its antagonistic and agonistic ligand ribosomal protein S19 (RP S19) polymer, which is cross-linked between K122 and Q137 by tissue transglutaminases. RP S19 polymer binds to the reciprocal C5aRs on erythroblast-like cells and macrophage-like cells derived from human monocytic THP-1 cells and promotes differentiation into reticulocyte-like cells through enucleation in vitro . To examine the roles of RP S19 polymer in mouse erythropoiesis, we prepared Q137E mutant RP S19 gene knock-in C57BL/6J mice. In contrast to wild-type mice, erythroblast numbers at the preliminary stage (CD71 high /TER119 low ) in spleen based on transferrin receptor (CD71) and glycophorin A (TER119) values and erythrocyte numbers in orbital artery bloods were not largely changed in knock-in mice. Conversely, erythroblast numbers at the early stage (CD71 high /TER119 high ) were significantly decreased in spleen by knock-in mice. The reduction of early erythroblast numbers in spleen was enhanced by the phenylhydrazine-induced pernicious anemia model knock-in mice and was rescued by a functional analogue of RP S19 dimer S-tagged C5a/RP S19. These data indicated that RP S19 polymer plays the roles in the early erythroblast differentiation of C57BL/6J mouse spleen. [ABSTRACT FROM AUTHOR]

Abstract: The oral administration of thioacetamide to rats induces cholangiofibrosis characterized by hyperplasia of ductules surrounded by fibrous tissue. In the present study, we examined the expression of markers of cholangiocyte and hepatocyte phenotypes in these hyperplastic ductule cells and their proliferative activity immunohistochemically. The oral administration of thioacetamide to 21-day-old male Fisher 344 rats for 12 weeks induced multiple areas of various sizes with hyperplastic ductules. The ductules consisted of two types of ductules; ductules composed of cholangiocyte-like cuboidal cells with transparent nuclei and cytoplasm, and of intestinal epithelium-like (IE-like) cells of basophilic nuclei and cytoplasm, and the transition of these two types of cells in the same ductule was sometimes observed. The cholangiocyte-like cells expressed cytokeratin (CK)-7, CK-19 and OV-6 (cholangiocyte phenotype markers) but not Hep Par-1 antigen or HNF4α (hepatocyte phenotype markers). In contrast, the IE-like cells expressed Hep Par-1 antigen and HNF4α but not CK-7, CK-19 or OV-6. The examination of Ki-67 expression showed a much higher proliferative activity for the IE-like cells compared to the cholangiocyte-like cells. The present results show that the hyperplastic ductules induced by thioacetamide are composed of IE-like cells with a high proliferative activity expressing the hepatocyte phenotype markers and of cholangiocyte-like cells with a low proliferative activity expressing the cholangiocyte phenotype markers. [Copyright &y& Elsevier]

C5-deficient mice usually present moderate neutrophil activation during the initiation phase of acute inflammation. Conversely, C5a receptor (C5aR)-deficient mice show unusually excessive activation of neutrophils. We identified the ribosomal protein S19 (RP S19) polymer, which is cross-linked at Lys122 and Gln137 by transglutaminases in apoptotic neutrophils, as a second C5aR ligand during the resolution phase of acute inflammation. The RP S19 polymer promotes apoptosis via the neutrophil C5aR and phagocytosis via the macrophage C5aR. To confirm the roles of the RP S19 polymer, we employed a carrageenan-induced acute pleurisy mouse model using C57BL/6J mice with a knock-in of the Gln137Glu mutant RP S19 gene and replaced the RP S19 polymer with either an S-tagged C5a/RP S19 recombinant protein or the RP S19 122–145 peptide monomer and dimer (as functional C5aR agonists/antagonists) and the RP S19 122–145 peptide trimer (as a functional C5aR antagonist). Neutrophils and macrophages were still present in the thoracic cavities of the knock-in mice at 24 h and 7 days after carrageenan injection, respectively. Knock-in mice showed structural organization and severe hemorrhaging from the surrounding small vessels of the alveolar walls in the lung parenchyma. In contrast to the RP S19 122–145 peptide monomer and trimer, the simultaneous presence of S-tagged C5a/RP S19 and the RP S19 122–145 peptide dimer completely improved the physiological and pathological acute inflammatory cues. The RP S19 polymer, especially the dimer, appears to play a role at the resolution phase of carrageenan-induced acute pleurisy in C57BL/6J model mice. [ABSTRACT FROM AUTHOR]

Abstract: This study documents a case of an epithelial–myoepithelial carcinoma (EMC) in the left nasal cavity. A 70-year-old woman who presented with recurrent epistaxis of the left nasal nostril of 3 months duration was found to have a polypoid tumor in the left nasal cavity. A computed tomography (CT) scan revealed a tumor to occupy the left inferior and middle nasal cavity which had destroyed the inferior nasal turbinate, and a horizontal scan showed the tumor to occupy the middle and posterior nasal cavity. Since the tumor was connected to the lateral wall of the left nasal cavity with a narrow stalk, the tumor was excised by peeling the mucosa from the wall of the left nasal cavity. Based on the histological and immunohistochemical findings, the tumor was diagnosed to be an EMC. The follow-up at 12 months after the operation showed no evidence of recurrence. [Copyright &y& Elsevier]