ABSTRACT
AIM:To explore the effects of confluent endothelial progenitor cells (EPCs) derived from young and aged rats on the phenotype conversion, proliferation and migration of vascular smooth muscle cells ( SMCs) .METH-ODS:Mononuclear cells were obtained from the bone marrow of young (1~2 month old) and aged (19 to 26 month old) Sprague-Dawley rats and cultured with medium DMEM/F12 ( containing 15% fetal bovine serum, endothelial cell growth supplements (ECGs) 100 g/L, 1 ×105 units/L of penicillin and streptomycin, respectively).EPCs were characterized as double positive for DiI-Ac-LDL uptake and lectin binding.Abdominal aorta was obtained from 1 to 2 month old Sprague-Dawley rats.Vascular SMCs were cultured by tissue explant method and identified byα-SM-actin immunofluorescence.In transwell co-culture system, the confluent EPCs located in the upper chamber and SMCs were seeded on the lower cham-ber.The experiments were divided into passage 3 SMCs group (P3), passage 4 SMCs group (P4), passage 4 SMCs co-culture with EPCs derived from young rats group (P4YE) and passage 4 SMCs co-culture with EPCs derived from aged rats group (P4AE).The protein expression ofα-SM-actin and osteopontin was detected by Western blotting.[3H]-TdR incor-poration assay was used to determine the proliferation.SMC migration was analyzed by scratch wound healing assay.RE-SULTS:Compared with P3 group,α-SM-actin expression in P4 group significantly decreased and osteopontin protein ex-pression obviously increased, whereas no significant change was found in P4YE group.Compared with P4 group, confluent EPCs derived from young and aged rats both markedly increased α-SM-actin and decreased osteopontin expression in P4 SMCs.Compared with aged rat-derived EPCs, young rat-derived EPCs were more effectively to induce a delayed SMC phe-notype transition (from contractile phenotype to a synthetic phenotype), and to inhibit SMC proliferation and migration. CONCLUSION:Co-culture of confluent EPC induces a delayed vascular SMC phenotype transition and inhibits SMCs pro-liferation and migration.Young rat derived EPCs are more effective to induce a delayed vascular SMC phenotype transition and has stronger inhibitory effects on SMCs proliferation and migration compared with that derived from aged rats.
ABSTRACT
AIM:To study the expression of Jagged 2/Notch3 signaling molecules in pulmonary vascular wall of pulmonary hypertensive rats induced by monocrotaline .METHODS: SD rats were randomly divided into normal control group (C group,n=15), solvent control group (S group,n=15) and monocrotaline model groups (M group,n=15).The model of pulmonary hypertension was established by a single subcutaneous injection of monocrotaline (50 mg/kg).The rats in S group were given a single subcutaneous injection of the same dose of solvent .After 4 weeks, the pulmonary vascular remodeling was assessed by HE staining , and the mean pulmonary artery pressure ( mPAP) and right ventricular systolic pressure (RVSP) were determined by right heart catheterization .The expression of Jagged2/Notch3 /Hes5 molecules in the pulmonary vascular wall was detected by immunohistochemical method and real -time PCR.RESULTS:Compared with S group and C group , the percentage of medial wall thickness of smaller arteries in model group increased significantly (P<0.01).The levels of mPAP and RVSP in M group were significantly higher than those in S group and C groups (P<0.01).The results of real-time PCR showed that the expression of Jagged 2, Notch3 and Hes5 was significantly increased in M group compared with S group and C group .The data from immunohistochemical detection indicated that Jagged 2 mainly expressed in the intima of small lung artery , Notch3 and Hes5 mainly expressed in the medial smooth muscle cells .Com-pared with S group and C group , the expression of Jagged 2 and Notch3 was significantly increased in the lung small arteries of M group.CONCLUSION:The activation of Jagged2/Notch3 signaling pathway might play an important role in the for-mation of pulmonary hypertension .
ABSTRACT
<p><b>OBJECTIVE</b>To observe the effect of platelet derived growth factor receptor β (PDGFR-β) transfected endothelial progenitor cells (EPCs) on vascular regeneration.</p><p><b>METHODS</b>Spleen-derived mononuclear cells (MNCs) were isolated using density gradient centrifugation and induced with special culture medium. EPCs transfection was performed with Lipofectamine(TM) 2000 reagent according to the instruction manual. Carotid artery injury was induced in splenectomized mice. EPCs were injected by tail vein immediately and at 24 h after endothelial injury of the carotid artery. Evans blue staining was performed to evaluate reendothelialization at 7 days after endothelial injury of the carotid artery.</p><p><b>RESULTS</b>Most adherent cells were LDL and UEA-I double positive. Laser scanning confocal microscopy showed that transfection efficiency was about 50%-60%. The reendothelialized area in the PDGFR-β-EPCs group was significantly larger than that in EGFP-EPCs group.</p><p><b>CONCLUSION</b>Transplantation of PDGFR-β over-expressed EPCs can promote reendothelialization in the early phase after carotid artery injury.</p>