Purpose: To find the effect of lumbrokinase (LK) on P-selectin and E-selectin in ischemic rats. Methods: Male healthy Spragur-Dawley rats weighing 180-220 g (n=90) were divided into 4 groups: (1) normal control group ...Purpose: To find the effect of lumbrokinase (LK) on P-selectin and E-selectin in ischemic rats. Methods: Male healthy Spragur-Dawley rats weighing 180-220 g (n=90) were divided into 4 groups: (1) normal control group (n=5), (2) sham-operated group (n=35), (3) ischemic group (n=35), (4) LK group (n=15). LK 10mg/kg (2000UK activity of LK) was given by intraperitoneal injection in the LK group 30 minutes before experiment. Same volume of normal saline was given in the sham-operated group and ischemic group. The ischemic model was made by modified Haruo Nagasawa's method. Immunohistochemistry was used to observe the P-selectin and E-selectin positive cells in the ischemic region. Results: P-selectin and E-selectin positive cells in ischemic regions were observed in the ischemic group, and the peak of expression was at 6 hours and 12 hours, respectively. The similar changes were not observed in normal control group. There were only a few positive cells in the sham-operated group. In LK group, the P-selectin and E-selectin positive cells were significantly less than those in the ischemic group (P<0.05 at 3 hours after the onset, P<0.01 at 6 hours and P<0.01 at 12 hours, respectively). Conclusions: LK might significantly decrease the immunoreactions of P-selectin and E-selectin in ischemic lesion.展开更多
Circulating leukocytes in trafficking to the inflammatory sites, will be first tether to, and then roll on the vascular surface. This event is mediated through specific interaction of P-selectin and P-selectin glycopr...Circulating leukocytes in trafficking to the inflammatory sites, will be first tether to, and then roll on the vascular surface. This event is mediated through specific interaction of P-selectin and P-selectin glycoprotein ligand-1 （PSGL-1）, and regulated by hemodynamics. Poor data were reported in understanding P-selectin-mediated rolling. With the flow chamber technique, we herein observed HL-60 cell rolling on P-selectin with or without 3% Ficoll at various wall shear stresses from 0.05 to 0.4 dyn/cm：. The results demonstrated that force rather than transport regulated the rolling, similar to rolling on L- and E-selectin. The rolling was accelerated quickly by an increasing force below the optimal shear threshold of 0.15 dyn/cm2 first and then followed by a slowly decelerating phase starting at the optimum, showing a catch-slip transition and serving as a mechanism for the rolling. The catch-slip transition was completely reflected to the tether lifetime and other rolling parameters, such as the mean and fractional stop time. The narrow catch bond regime stabilized the rolling quickly, through steeply increasing frac- tional stop time to a plateau of about 0.85. Data presented here suggest that the low shear stress threshold serves as a mecha- nism for most cell rolling events through P-selectin.展开更多
Gene therapies have been applied to the treatment of cardiovascular disease, but their use is limited by the need to deliver them to the right target. We have employed targeted contrast ultrasound-mediated gene transf...Gene therapies have been applied to the treatment of cardiovascular disease, but their use is limited by the need to deliver them to the right target. We have employed targeted contrast ultrasound-mediated gene transfection （TCUMGT） via ultrasound-targeted microbubble destruction （UTMD） to transfer therapeutic genes to specific anatomic and pathological targets. Phospholipid microbubbles （MBs） with pcDNA3.l-human vascular endothelial growth factor 165 （pcDNA3.I-hVEGFls5） plasmids targeted to P-selectin （MB＋P＋VEGFp） were created by conjugating monoclonal antibodies against P-selectin to the lipid shell. These microbubbles were divided into four groups： microbubble only （MB）, microbubble＋P-selectin （MB＋P）, microbubble＋pcDNA3.l-hVEGF185 plasmid （MB＋VEGFp）, and microbubbie＋ P-selectin＋pcDNA3.1-hVEGF185 piasmid （MB＋P＋VEGFp）. The reverse transcription polymerase chain reaction （RT-PCR） and enzyme-linked immunosorbent assay （ELISA） results showed that the VEGF gene was successfully transfected by TCUMGT and the efficiency is increased with P-selectin targeting moiety. UTMD-mediated delivery of VEGF increased myocardial vascular density and improved cardiac function, and MB＋P＋VEGFp delivery showed greater improvement than MB＋VEGFp. This study drew support from TCUGMT technology and took advantage of targeted ultrasound contrast agent to identify ischemic myocardium, release pcDNA3.1-hVEGF165 recombinant plasmid, and improve the myocardial microenvironment, so promoting the restoration of myocardial function.展开更多
文摘Purpose: To find the effect of lumbrokinase (LK) on P-selectin and E-selectin in ischemic rats. Methods: Male healthy Spragur-Dawley rats weighing 180-220 g (n=90) were divided into 4 groups: (1) normal control group (n=5), (2) sham-operated group (n=35), (3) ischemic group (n=35), (4) LK group (n=15). LK 10mg/kg (2000UK activity of LK) was given by intraperitoneal injection in the LK group 30 minutes before experiment. Same volume of normal saline was given in the sham-operated group and ischemic group. The ischemic model was made by modified Haruo Nagasawa's method. Immunohistochemistry was used to observe the P-selectin and E-selectin positive cells in the ischemic region. Results: P-selectin and E-selectin positive cells in ischemic regions were observed in the ischemic group, and the peak of expression was at 6 hours and 12 hours, respectively. The similar changes were not observed in normal control group. There were only a few positive cells in the sham-operated group. In LK group, the P-selectin and E-selectin positive cells were significantly less than those in the ischemic group (P<0.05 at 3 hours after the onset, P<0.01 at 6 hours and P<0.01 at 12 hours, respectively). Conclusions: LK might significantly decrease the immunoreactions of P-selectin and E-selectin in ischemic lesion.
基金supported by the National Natural Science Foundation of China(Grant Nos.11272125,11072080,31170887 and 31200705)Guangdong Natural Science Foundation(Grant No.S2011010005451)Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20110172110030)
文摘Circulating leukocytes in trafficking to the inflammatory sites, will be first tether to, and then roll on the vascular surface. This event is mediated through specific interaction of P-selectin and P-selectin glycoprotein ligand-1 （PSGL-1）, and regulated by hemodynamics. Poor data were reported in understanding P-selectin-mediated rolling. With the flow chamber technique, we herein observed HL-60 cell rolling on P-selectin with or without 3% Ficoll at various wall shear stresses from 0.05 to 0.4 dyn/cm：. The results demonstrated that force rather than transport regulated the rolling, similar to rolling on L- and E-selectin. The rolling was accelerated quickly by an increasing force below the optimal shear threshold of 0.15 dyn/cm2 first and then followed by a slowly decelerating phase starting at the optimum, showing a catch-slip transition and serving as a mechanism for the rolling. The catch-slip transition was completely reflected to the tether lifetime and other rolling parameters, such as the mean and fractional stop time. The narrow catch bond regime stabilized the rolling quickly, through steeply increasing frac- tional stop time to a plateau of about 0.85. Data presented here suggest that the low shear stress threshold serves as a mecha- nism for most cell rolling events through P-selectin.
基金Project supported by the Natural Science Foundation of Zhejiang Province(No.LY14H180003)the National Natural Science Foundation of China(No.81301231)the General Research Project of Zhejiang Provincial Department of Education(No.Y201636244),China
文摘Gene therapies have been applied to the treatment of cardiovascular disease, but their use is limited by the need to deliver them to the right target. We have employed targeted contrast ultrasound-mediated gene transfection （TCUMGT） via ultrasound-targeted microbubble destruction （UTMD） to transfer therapeutic genes to specific anatomic and pathological targets. Phospholipid microbubbles （MBs） with pcDNA3.l-human vascular endothelial growth factor 165 （pcDNA3.I-hVEGFls5） plasmids targeted to P-selectin （MB＋P＋VEGFp） were created by conjugating monoclonal antibodies against P-selectin to the lipid shell. These microbubbles were divided into four groups： microbubble only （MB）, microbubble＋P-selectin （MB＋P）, microbubble＋pcDNA3.l-hVEGF185 plasmid （MB＋VEGFp）, and microbubbie＋ P-selectin＋pcDNA3.1-hVEGF185 piasmid （MB＋P＋VEGFp）. The reverse transcription polymerase chain reaction （RT-PCR） and enzyme-linked immunosorbent assay （ELISA） results showed that the VEGF gene was successfully transfected by TCUMGT and the efficiency is increased with P-selectin targeting moiety. UTMD-mediated delivery of VEGF increased myocardial vascular density and improved cardiac function, and MB＋P＋VEGFp delivery showed greater improvement than MB＋VEGFp. This study drew support from TCUGMT technology and took advantage of targeted ultrasound contrast agent to identify ischemic myocardium, release pcDNA3.1-hVEGF165 recombinant plasmid, and improve the myocardial microenvironment, so promoting the restoration of myocardial function.
