Suppressor Of Cytokine Signaling3Inhibits The Osteogenic Differentiation Of Aortic Valve Interstitial Cells Via The Modulation Of The IL-6/JAK2/STAT3Pathway

Part ⅠSuppressor of cytokine signaling3inhibits the osteogenic differentiation of aortic valve interstitial cells via the modulation of the IL-6/JAK2/STAT3pathwayAbstractAim:Calcific aortic valve disease (CAVD) has become the most common heart valve disease worldwide; however, the cellular and molecular mechanisms underlying CAVD remain unclear. We investigated the effects of SOCS3modulation on the osteogenic differentiation and the activity of the JAK2/STAT3pathway in aortic valve interstitial cells (AVICs) following LPS stimulation.Methods and results:The AVICs of stenotic valves express higher levels of SOCS3. The augmented expression of osteogenic markers was detected following LPS stimulation. The pro-osteogenic response was suppressed via SOCS3overexpression, whereas the silencing of SOCS3amplified this response. IL-6secretion was increased in the AVICs following LPS stimulation and was inhibited by SOCS3overexpression. LPS induced the phosphorylation of STAT3, a process that was reversed by an anti-IL-6antibody. IL-6blockage and the JAK2/STAT3pathway inhibitor, AG490, abolished the suppressive effects of SOCS3on both osteogenic differentiation and STAT3activity in the AVICs.Conclusion:SOCS3mediates the pro-osteogenic response to LPS stimulation in AVICs via the suppression of both IL-6secretion and the JAK2/STAT3pathway. IL-6plays an important role in osteogenic differentiation of AVICs. These pathways may be potential therapeutic targets for the prevention of calcific aortic valve disease. Part ⅡInterleukin-6promotes osteoblastic differentiation and mineralization in Human aortic valve interstitial cellsAbstractObjective:To explore the potential effects of IL-6on osteoblastic differentiation and mineralization in normal aortic valve interstitial cells.Methods:Normal aortic valves were collected form three aortic dissection(Debakey I) patients under Bentall procedures. Cells were isolated with Collagenase Ⅱ(2.5mg/ml) and cultured in DMEM medium. Immunoflurescence was used to detect α-SMA and vimentin for phenotype identification. Immunblotting was applied to demonstrate the protein levels of ALP and BMP-2in aortic valve interstitial cells after IL-6stimulation in presence or absence of anti-IL-6antibody. The calcified nodes were detected by Alizarin Red S staining and analyzed for content quantity.Results:Over90percents of cells were stained by both α-SMA and vimentin antibodies. We found remarkable elevated ALP and BMP-2expression in aortic valve interstitial cells after IL-6stimulation(P<0.05versus control group), however, after addition of anti-IL-6antibody, we found the augmented ALP and BMP-2expression was reduced significantly(P<0.05versus IL-6only group). The results of Alizarin Red S staining were accordant with Western blots. The calcified nodes was increased dramatically in cells after IL-6stimulation(P<0.05versus control group), however, IL-6neutralization with anti-IL-6antibody manifestly reversed this increased calcium deposition(P<0.05versus IL-6group).Conclusion:Interleukin-6promotes the osteoblastic differentiation and mineralization in human aortic valve cells.