Nerve growth factor (NGF) functions to modulate osteoarthritis (OA)-associated pain. Although recent studies suggest that tumour necrosis factor (TNF)-α and interleukin (IL)-1β mediate NGF activity in human synovial fibroblasts, the regulation of NGF expression in human synovial macrophages remains unclear. Here, we examined the role of macrophages in the production and regulation of synovial (SYN) NGF in osteoarthritic knee joints by examining the mRNA expression of TNF-α and IL-1β in freshly isolated CD14-positive (macrophage-rich fraction) and CD14-negative cells (fibroblast-rich fraction) in synovial tissue from OA patients by quantitative polymerase chain reaction. We also examined the effects of IL-1β and TNF-α on NGF mRNA expression in cultured CD14-positive (macrophage-rich fraction) and CD14-negative cells (fibroblast-rich fraction). In addition, to examine the contribution of macrophages to NGF, TNF-α and IL-1β expression, we injected clodronate liposomes systemically into STR/Ort mice, an osteoarthritis animal model, to deplete macrophages. TNF-α and IL-1β mRNA levels in CD14-positive cells from the SYN of OA patients was significantly higher than that in CD14-negative cells, while NGF expression did not differ markedly between the two cell fractions. In addition, treatment of human cultured CD14-positive and -negative cells with IL-1β and TNF-α enhanced NGF mRNA and protein levels. Expression of NGF, IL-1β and TNF-α was also reduced significantly in STR/Ort mice upon macrophage depletion. These findings suggest that IL-1β and TNF-α regulate NGF expression and production in synovial macrophages and fibroblasts in osteoarthritic joints.
To identify proteins involved in ovarian clear cell carcinoma (OCCCa), shotgun proteomics analysis was applied using formalin-fixed and paraffin-embedded samples of ovarian carcinoma. Analysis of 1521 proteins revealed that 52 were differentially expressed between four OCCCa and 12 non-OCCCa samples. Of the highly expressed proteins in OCCCa, we focused on left-right determination factor (LEFTY), a novel member of the transforming growth factor-β superfamily. In 143 cases of ovarian epithelial carcinoma including 99 OCCCas and 44 non-OCCCas, LEFTY expression at both mRNA and protein levels was significantly higher in OCCCas compared with non-OCCCas, with the mRNA expression of LEFTY1 being predominant compared to that of LEFTY2. OCCCa cells stably overexpressing LEFTY1 showed reduced cell proliferation, along with decreased pSmad2 expression, and also either displayed an activated p53/p21waf1 pathway or increased p27kip1 expression, directly or indirectly. Moreover, the treatment of stable cell lines with cisplatin led to increased apoptotic cells, together with the inhibition of protein expression of a pSmad2-mediated X-linked inhibitor of apoptosis and a decreased bcl2/bax ratio. Blocking LEFTY1 expression with a specific short hairpin RNA inhibited cisplatin-induced apoptosis, probably through the increased expression of both XIAP and bcl2, but not bax. In clinical samples, a significantly higher number of apoptotic cells and lower Ki-67 labeling indices were observed in OCCCas with a high LEFTY score relative to those with a low score. These findings suggest that LEFTY may be an excellent OCCCa-specific molecular marker, which has anti-tumor effects in altering cell proliferation and cellular susceptibility to apoptosis.
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