Microglia, macrophage-like cells in the CNS, are multifunctional cells; they play an important role in removal of dead cells or their remnants by phagocytosis in the CNS degeneration and are one of important cells in the CNS cytokine network to produce and respond to a variety of cytokines. The functions of microglia are regulated by inhibitory cytokines. We have reported the expression of interleukin (IL)-10, one of the inhibitory cytokines, and its receptor in mouse microglia; therefore, IL-10 may affect microglial functions. In this study, we investigated the effects of IL-10 on purified microglia in culture. IL-10 inhibited lipopolysaccharide-induced IL-1␤ and tumor necrosis factor-␣ production, lysosomal enzyme activity, and superoxide anion production in a dose-dependent manner, but did not affect granulocyte/ macrophage colony-stimulating factor-dependent proliferation of microglia. IL-10 also decreased the expression of both IL-6 receptor and lipopolysaccharide-induced IL-2 receptor but not IL-4 receptor on microglia as measured by flow cytometric analysis with an indirect immunofluorescence technique. IL-10 also decreased mRNA expression of IL-2 and IL-6 cytokine receptors. These results suggest that IL-10 is a unique and potent inhibitory factor in the CNS cytokine network involved in decreasing the expression of cytokine receptors as well as cytokine production by microglia.

ABSTRACT. The pr22 gene was isolated as a gene which is expressed in proliferating cells but not in cells which are differentiated or growth-arrested. Whencells of the human monocytic cell line, U937, were differentiated into macrophages, transcription of pr22 was almost completely suppressed. Serum starvation resulted in the inhibition of transcription, although U937failed to differentiate. In a culture synchronized with excess thymidine, mRNAofpr22 was detected at the Gl/S boundary, with the level increasing in the S phase and decreasing in the G2 phase. The gene product,pr22 protein (Pr22) was found to be identical to Opl8 as well as to a catastrophe factor. Genes homologous to pr22 were detected in the genome of mouse but not in that of yeast, or Drosophila. The 5' up-stream region of the genomicpr22 contained CpGislands but no TATAbox at its appropriate position. About 20%of cell nuclei of normal human fibroblasts were stained in a speckled manner with a monoclonal antibody for C-terminal peptide of Pr22, and these cells were found to be in phases S and G2. The mitotic apparatus was also strongly stained. By Western blot analysis, Pr22 was detected in the nuclear fraction but not in the cytoplasm. The level increased from middle S to G2 phase and remained high until the early Gl phase. N-terminal truncated Pr22 was also detected in these phases. These results suggest that Pr22 mayhave an additional role other than just functioning in association with microtubules.

ABSTRACT. U937 cells were differentiated into macrophages after being treated with 12-o-tetradecanoylphorbol-13-acetate (TPA) for the first two days and dedifferentiated with daily medium renewal for 10 days. Cell proliferation slowed down and the number of cells reached the maximumlevel on day 2. By day 4, all of the cells had spread and attached firmly to the culture dish, and more than 90% of the cells expressed the Fc-receptor and produced superoxide anion. From there on, the number of adherent, living cells decreased gradually to about half the initial count. Most of the cells eliminated from the culture by cell death were in the S phase at the time of TPA treatment. After day 8, the number of cells expressing macrophage-specific phenotypes gradually decreased, cell adhesion was weakened, and at the same time, DNAsynthesis was initiated anew. The cells became round and began to proliferate as floating cells on days 9 to 10, and thereafter they became sensitive to the second round of TPAtreatment. On the basis of all the results taken together, it is suggested that fully differentiated U937 cells were dedifferentiated after being cultured with frequent mediumrenewal.

Background Online hemodiafiltration (OL-HDF), whether in pre-dilution OL-HDF (pre-HDF) or post-dilution OL-HDF (post-HDF), is conducted to efficiently remove low molecular weight proteins from the blood of patients requiring dialysis. β2-microglobulin (β2-MG) and α1-microglobulin (α1-MG) are used as biomarkers to evaluate removal efficiency of OL-HDF. We aimed to evaluate the relationship between β2-MG and α1-MG reduction rates and the amount of albumin leakage. Furthermore, we statistically analyzed the relationship between the α1-MG reduction rate and α1-MG removal amount, and its suitability as a biomarker for evaluating the removal efficiency of OL-HDF. Methods We collected the results of regularly conducted routine evaluations to assess the efficiency of OL-HDF from cases of patients undergoing maintenance dialysis at our clinic from 2018 to 2019. Data on was collected on both pre-HDF and post-HDF sessions. β2-MG and α1-MG reduction rates were analyzed. Regression analysis on reduction rates showed a significant correlation between the α1-MG reduction rate and the α1-MG removal amount. Results We conducted 435 tests on OL-HDF efficiency in 87 cases undergoing maintenance dialysis at our clinic in 2018 and 2019. There were 80.7 ± 4.5% for the β2-MG reduction rate, 33.8 ± 9.4% for the α1-MG reduction rate, and 3.9 ± 1.8 g/s for the amount of albumin leakage. There was no correlation between the β2-MG reduction rate and the α1-MG reduction rate, or between the amount of albumin leakage and β2-MG reduction rate. Conclusion α1-MG reduction rate was found to correlate with its removal amount, demonstrating its suitability as a biomarker for evaluating the removal efficiency of OL-HDF. Trial registration Retrospectively registered.

Numerous studies have been carried out to investigate the solute removal efficiency of hemodiafiltration (HDF). However, the effect of the dilution mode on blood cell damage during HDF has not yet been examined in detail. Here, we compared predilution and postdilution HDF with respect to their effects on blood cells. Five patients were allocated to one session each of predilution HDF and postdilution HDF. Concentrations of interleukin (IL)-6, intercellular adhesion molecule (ICAM)-1, and platelet-derived microparticles (PDMP), and the phagocytotic and sterilizing functions of neutrophils before and after the HDF sessions were evaluated. Lymphocyte blastoid transformation induced by mitogens was also evaluated by measurement of the [(3)H]-thymidine uptake. The IL-6 and ICAM-1 concentrations decreased after predilution HDF, and increased after postdilution HDF. Lymphocyte blastoid transformation was more pronounced after predilution HDF than after postdilution HDF. There was no significant difference in PDMP between the dilution modes. We conclude that predilution HDF could be more favorable for dialysis patients than postdilution HDF from the point of view of the effects on the blood cells, especially neutrophils and lymphocytes.