D-arginine oligomers have been widely used as intracellular delivery vectors both in in vitro andin vivo application.Nevertheless,their intemalization pathway is obscure and conficting resultshave been obtained concer...D-arginine oligomers have been widely used as intracellular delivery vectors both in in vitro andin vivo application.Nevertheless,their intemalization pathway is obscure and conficting resultshave been obtained concerning their intracellular distribution.In this study,we demonstrate that octa-D-arginine(r:)undergoes diffuse localization throughout the cytoplasm and nucleus even atlow concentrations and that rs(r:D-arginine)enters the cells via direct membrane translocation,unlike R:(R:L-arginine),of which endocytosis is the major internalization pathway.The observation that Rs and rg enter the cells through two clearly distinct internalization pathways suggests that the backbone stereochemistry affects the uptake mechanism of oligoarginines.展开更多
Cell migration is an important biological process regulated by mechanical stimulation,which leads to intracellular calcium response.Cell migration are dependent on the distribution and dynamic changes of intracellular...Cell migration is an important biological process regulated by mechanical stimulation,which leads to intracellular calcium response.Cell migration are dependent on the distribution and dynamic changes of intracellular calcium concentration.However,the temporal relation among mechanical stimulation,cell migration,and intracellular calcium distribution remains unclear.In this study,unidirectional flow and oscillatory flow were applied on osteoclast precursor RAW264.7 cells.The parameters of cell migration under fluid flow and intracellular calcium distribution along the migration or flow direction were calculated.Experimental results suggest the cells to adjust the[Ca^(2+)]_(i) distribution in the migration direction is independent of flow application or the reverse of flow direction,but the[Ca^(2+)]_(i) distribution in the flow direction is determined by the[Ca^(2+)]_(i) distribution-adjusting ability of cells and flow stimulation.Blocking calcium signaling pathways,namely,mechanosensitive cationselective channels,phospholipase C,and endoplasmic reticulum,and removing extracellular calcium inhibited cell migration along the flow direction and the gradient distribution of intracellular calcium.This study provided insights into the mechanism of flow-induced cell migration and quantitative data for the recruitment of osteoclast precursors targeting the location of bone resorption.展开更多
基金supported by the National High-Tech Research and Development Program of China(863 Program:2008AA02Z107)the National Natural Science Foundation of China(grant no.30800183)the Scientific Research Foundation for the Returned Overseas,Chinese Scholars,State Education Ministry(Y.-H.Zhang).
文摘D-arginine oligomers have been widely used as intracellular delivery vectors both in in vitro andin vivo application.Nevertheless,their intemalization pathway is obscure and conficting resultshave been obtained concerning their intracellular distribution.In this study,we demonstrate that octa-D-arginine(r:)undergoes diffuse localization throughout the cytoplasm and nucleus even atlow concentrations and that rs(r:D-arginine)enters the cells via direct membrane translocation,unlike R:(R:L-arginine),of which endocytosis is the major internalization pathway.The observation that Rs and rg enter the cells through two clearly distinct internalization pathways suggests that the backbone stereochemistry affects the uptake mechanism of oligoarginines.
基金supported by the National Natural Science Foundation of China[12072034(BH),11572043(BH)].
文摘Cell migration is an important biological process regulated by mechanical stimulation,which leads to intracellular calcium response.Cell migration are dependent on the distribution and dynamic changes of intracellular calcium concentration.However,the temporal relation among mechanical stimulation,cell migration,and intracellular calcium distribution remains unclear.In this study,unidirectional flow and oscillatory flow were applied on osteoclast precursor RAW264.7 cells.The parameters of cell migration under fluid flow and intracellular calcium distribution along the migration or flow direction were calculated.Experimental results suggest the cells to adjust the[Ca^(2+)]_(i) distribution in the migration direction is independent of flow application or the reverse of flow direction,but the[Ca^(2+)]_(i) distribution in the flow direction is determined by the[Ca^(2+)]_(i) distribution-adjusting ability of cells and flow stimulation.Blocking calcium signaling pathways,namely,mechanosensitive cationselective channels,phospholipase C,and endoplasmic reticulum,and removing extracellular calcium inhibited cell migration along the flow direction and the gradient distribution of intracellular calcium.This study provided insights into the mechanism of flow-induced cell migration and quantitative data for the recruitment of osteoclast precursors targeting the location of bone resorption.
