Osteoclasts are giant bone-digesting cells that harbor specialized lysosome-related organelles termed secretory lysosomes (SLs). SLs store cathepsin K and serve as a membrane precursor to the ruffled border, the osteoclast's 'resorptive apparatus'. Yet, the molecular composition and spatiotemporal organization of SLs remains incompletely understood.
View Article and Find Full Text PDFCalcium/calmodulin-dependent protein kinase (CaMK) is a major down stream mediator of Ca(2+) signaling in a wide range of cellular functions, including ion channel and cell cycle regulation and neurotransmitter synthesis and release. Here we have investigated the role of the CaMK signaling pathway in osteoclast differentiation and bone resorption. We observed that the CaMKI, CaMKII gamma isoforms were present in both bone-marrow derived macrophages and RAW264.
View Article and Find Full Text PDFThe mechanisms by which erythemal UVB irradiation modulates systemic immune responses to antigens applied to non-irradiated sites are poorly understood. In this study, regulatory CD4+ T cells were identified in the skin-draining lymph nodes (SDLNs) of UVB-irradiated, but otherwise naive mice. A transgenic mouse strain (DO11.
View Article and Find Full Text PDFUVB irradiation of the shaved dorsal skin of mice can cause both local and systemic suppression of contact hypersensitivity responses; the former demonstrated by administration of the sensitizing Ag/hapten to the irradiated site and the latter by its administration at least 72 h later to distal unirradiated sites. The immunological basis of systemic immunomodulation is not clear. When haptens (trinitrochlorobenzene, FITC) were administered to the shaved ventral skin 4 days after irradiation (8 kJ/m(2)) to the shaved dorsum of BALB/c mice, CD11c(+)/FITC(+) cells in the skin-draining lymph nodes from control and irradiated mice produced on a per cell basis similar levels of IL-12 and PGE(2) were phenotypically mature and efficient at presenting FITC to lymphocytes from FITC-sensitized mice.
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