The Function And Mechanism Of PEDF On Proliferation Of Different Cells Of Velvet Antler

Deer antler is the only mammalian appendage organ found so far that can regenerate completely.Basic research on antler not only provides a scientific reference for organ regeneration,but also provides a scientific theoretical basis for practical production.PEDF is expressed in most organs,can inhibit angiogenesis and play an important role in bone formation and ossification.PEDF is widely distributed in various tissue layers of velvet antler and involves high-speed proliferation and differentiation of epidermis,dermis,cartilage,bone,blood vessels and nerves in antler.However,the specific mechanism of PEDF promoting the proliferation or differentiation of antler cells remains unclear.Therefore,in this study,the antler cells(mesenchymal cells,pre-cartilage,chondrocytes)were taken as the research object.The function and mechanism of PEDF in antler cell growth and development were explored by RNA interference and other technical methods.The main results are as follows:(1)Detection of LR siRNA interference efficiency: After interference with LR,the expression of LR was significantly down-regulated(p<0.05),in which MSCs was down-regulated by 68.02%,QCs was down-regulated by 93.3%,RCs was down-regulated by 60.25%,indicating that the siRNA interference was efficiency(p< 0.05).(2)PEDF regulates cell cycle of velvet antler: In the interference LR group(siLR),the S phase of all three cells was significantly down-regulated(p<0.05).The S phase of the PEDF treatment group was significantly up-regulated except for MSCs.qRT-PCR and western blot results indicated that PEDF significantly promoted the expression of CyclinD1 in antler cells except MSCs(p<0.05).(3)PEDF promoted the proliferation of velvet antler cells: In the CCK-8 experiment,cell viability was significantly down-regulated in the interference LR group(siLR)(p<0.05),and the PEDF treatment group was significantly up-regulated(p<0.05).Detected the expression of PCNA by qRT-PCR and western blot,results indicated that PEDF significantly promoted the expression of PCNA in antler cells.(4)PEDF may regulates the expression of VEGF: The expression of VEGF mRNA was significantly down-regulated in the interference LR group(siLR)(p<0.05),and the expression of VEGF was significantly up-regulated in PEDF treatment group(p<0.05).(5)PEDF regulated the growth of velvet antler cells through ERK1/2 signaling pathway: WB results showed that the expression of p-ERK1/2 in RCs was down-regulated in the interference LR group(siLR)(p<0.05),but there is no significant effect by treat with PEDF alone(p< 0.05).In MSCs,p-ERK1/2 expression was up-regulated in the interference LR group(siLR)(p<0.05),but down-regulated after PEDF treatment alone(p< 0.05).In QCs,p-ERK1/2 expression was down-regulated in the interference LR group(siLR)(p<0.05)and was up-regulated after PEDF treatment alone(p<0.05).The results of these experiment indicated that: PEDF can promote the proliferation and cell cycle of velvet antler cells.After interfering with the receptor LR which plays a major role of PEDF in antler,the cell viability was significantly down-regulated and the cell cycle was hindered as well as the inhibition of VEGF expression.