Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and funct...Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and functional capability in vivo.Monitoring of superparamagnetic iron oxide(SPIO) particles by magnetic resonance imaging(MRI) has been used in animal models and clinical settings to track labeled cells.A major limitation of MRI is that the signals do not show biological characteristics of transplanted cells in vivo.Bone marrow mesenchymal stem cells(MSCs) have been extensively investigated for their various therapeutic properties,and exhibit the potential to differentiate into cells of diverse lineages.In this study,cynomolgus monkey MSCs(cMSCs) were labeled with Molday ION Rhodamine-BTM(MIRB),a new SPIO agent,to investigate and characterize the biophysical and MRI properties of labeled cMSCs in vitro and in vivo.The results indicate that MIRB is biocompatible and useful for cMSCs labeling and cell tracking by multimodality imaging.Our method is helpful for detection of transplanted stem cells in vivo,which is required for understanding mechanisms of cell therapy.展开更多
Glial cell derived neurotrophic factor （GDNF） holds promises for treating neurodegenerative diseases such as Parkinson＇s dis- ease. Human neural stem cells （hNSCs） have proved to be a suitable cell delivery vehic...Glial cell derived neurotrophic factor （GDNF） holds promises for treating neurodegenerative diseases such as Parkinson＇s dis- ease. Human neural stem cells （hNSCs） have proved to be a suitable cell delivery vehicle for the safe and efficient introduction of GDNF into the brain. In this study, we used hNSCs-infected with a lentivirus encoding GDNF and the hygromycin re- sistance gene as such vehicles. A modified tetracycline operator 7 （tetO7） was inserted into a region upstream of the EFI-α promoter to drive GDNF expression. After hygromycin selection, hNSCs were infected with a lentivirus encoding a KRAB-tetracycline repressor fusion protein （TTS）. TTS bound to tetO7 and suppressed the expression of GDNF in hNSCs. Upon administration of doxycycline （Dox） the TTS-tetO7 complex separated and the expression of GDNF resumed. The hNSCs infected with GDNF expressed the neural stem cell specific markers, nestin and sox2, and exhibited no significant change in proliferation rate. However, the rate of apoptosis in hNSCs expressing GDNF was lower compared with normal NSCs in response to actinomycin treatment. Furthermore, a higher percentage of Tuj-I positive cells were obtained from GDNF-producing NSCs under conditions that induced differentiation compared to control NSCs. The inducible expression of GDNF in hNSCs may provide a system for the controllable delivery of GDNF in patients with neurodegenerative diseases.展开更多
Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin...Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin （STZ）, and find the optimal dose for inducing diabetes in these monkeys. Fifteen juvenile （2-3 years old） cynomolgus monkeys were separated into three groups and administered with different doses of STZ （100, 68 or 60 mg kg-l）. Basal and glucose-stimulated blood glucose, in- sulin, and C-peptide levels, as well as body weights were monitored. Hepatic and renal function tests and pancreatic immuno- histochemistry were performed before and after STZ treatment. Monkeys treated with both 100 and 68 mg kg-1 of STZ exhib- ited continuous hyperglycemia, which coincided with a nearly complete loss of islet 13-cells. Two monkeys received 60 mg kg-1 of STZ, but only one became completely diabetic. During the first week following STZ treatment, hepatic and renal func- tion slightly increased in these three groups. However. 24 hours post-STZ, serum total bile acid levels were significantly in- creased in monkeys treated with 100 mg kg-1 than those treated with 68 mg kg-I of STZ （P〈0.05）. These data suggest that 100 mg kg-1 and 68 mg kg-1 of STZ can safely induce diabetes in cynomolgus monkeys aged 2-3 years, but 68 mg kg-1 of STZ, rather than 100 mg kg-1 of STZ, may be more appropriate for inducing diabetes in these monkeys. Furthermore, body surface area, rather than body weight, was a more reliable determinant of dosage, where 700 mg m-2 of STZ should be the lower limit for inducing diabetes in juvenile monkeys.展开更多
基金supported by the National Basic Research Program of China (Grant No. 2007CB947704)Research Assistance Fund of Anhui Medical University (Grant No. XJ201008)
文摘Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and functional capability in vivo.Monitoring of superparamagnetic iron oxide(SPIO) particles by magnetic resonance imaging(MRI) has been used in animal models and clinical settings to track labeled cells.A major limitation of MRI is that the signals do not show biological characteristics of transplanted cells in vivo.Bone marrow mesenchymal stem cells(MSCs) have been extensively investigated for their various therapeutic properties,and exhibit the potential to differentiate into cells of diverse lineages.In this study,cynomolgus monkey MSCs(cMSCs) were labeled with Molday ION Rhodamine-BTM(MIRB),a new SPIO agent,to investigate and characterize the biophysical and MRI properties of labeled cMSCs in vitro and in vivo.The results indicate that MIRB is biocompatible and useful for cMSCs labeling and cell tracking by multimodality imaging.Our method is helpful for detection of transplanted stem cells in vivo,which is required for understanding mechanisms of cell therapy.
基金supported by the National Basic Research Program of China (2007CB947704)the High-level Technical Personnel Training of Health Plan of Beijing
文摘Glial cell derived neurotrophic factor （GDNF） holds promises for treating neurodegenerative diseases such as Parkinson＇s dis- ease. Human neural stem cells （hNSCs） have proved to be a suitable cell delivery vehicle for the safe and efficient introduction of GDNF into the brain. In this study, we used hNSCs-infected with a lentivirus encoding GDNF and the hygromycin re- sistance gene as such vehicles. A modified tetracycline operator 7 （tetO7） was inserted into a region upstream of the EFI-α promoter to drive GDNF expression. After hygromycin selection, hNSCs were infected with a lentivirus encoding a KRAB-tetracycline repressor fusion protein （TTS）. TTS bound to tetO7 and suppressed the expression of GDNF in hNSCs. Upon administration of doxycycline （Dox） the TTS-tetO7 complex separated and the expression of GDNF resumed. The hNSCs infected with GDNF expressed the neural stem cell specific markers, nestin and sox2, and exhibited no significant change in proliferation rate. However, the rate of apoptosis in hNSCs expressing GDNF was lower compared with normal NSCs in response to actinomycin treatment. Furthermore, a higher percentage of Tuj-I positive cells were obtained from GDNF-producing NSCs under conditions that induced differentiation compared to control NSCs. The inducible expression of GDNF in hNSCs may provide a system for the controllable delivery of GDNF in patients with neurodegenerative diseases.
基金supported by the National Basic Research Program of China(Grant No.2007CB947704)the National High Technology Research and Development Program of China(Grant Nos. 2006AA02A112 and 2006AA02A116)High Level Talent Fund of the Beijing Healthcare System(Grant No.2009-2-14)
文摘Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin （STZ）, and find the optimal dose for inducing diabetes in these monkeys. Fifteen juvenile （2-3 years old） cynomolgus monkeys were separated into three groups and administered with different doses of STZ （100, 68 or 60 mg kg-l）. Basal and glucose-stimulated blood glucose, in- sulin, and C-peptide levels, as well as body weights were monitored. Hepatic and renal function tests and pancreatic immuno- histochemistry were performed before and after STZ treatment. Monkeys treated with both 100 and 68 mg kg-1 of STZ exhib- ited continuous hyperglycemia, which coincided with a nearly complete loss of islet 13-cells. Two monkeys received 60 mg kg-1 of STZ, but only one became completely diabetic. During the first week following STZ treatment, hepatic and renal func- tion slightly increased in these three groups. However. 24 hours post-STZ, serum total bile acid levels were significantly in- creased in monkeys treated with 100 mg kg-1 than those treated with 68 mg kg-I of STZ （P〈0.05）. These data suggest that 100 mg kg-1 and 68 mg kg-1 of STZ can safely induce diabetes in cynomolgus monkeys aged 2-3 years, but 68 mg kg-1 of STZ, rather than 100 mg kg-1 of STZ, may be more appropriate for inducing diabetes in these monkeys. Furthermore, body surface area, rather than body weight, was a more reliable determinant of dosage, where 700 mg m-2 of STZ should be the lower limit for inducing diabetes in juvenile monkeys.
