Transplantation of EPCs overexpressing PDGFR-ß promotes vascular repair in the early phase after vascular injury.

BACKGROUND: Endothelial progenitor cells (EPCs) play important roles in the regeneration of the vascular endothelial cells (ECs). Platelet-derived growth factor receptor (PDGFR)-ß is known to contribute to proliferation, migration, and angiogenesis of EPCs, this study aims to investigate effects of transplantation of EPCs overexpressing PDGFR-ß on vascular regeneration. METHODS: We transplanted genetically modified EPCs overexpressing PDGFR-ß into a mouse model with carotid artery injury. After 3 days of EPCs transplantation, the enhanced green fluorescent protein (EGFP)-expressing cells were found at the injury site and the lining of the lumen by laser scanning confocal microscope (LSCM). At 4, 7, and 14 days of the carotid artery injury, reendothelialization was evaluated by Evans Blue staining. Neointima formation was evaluated at day 14 with hematoxylin and eosin (HE) staining by calculating the neointimal area, medial area, and neointimal/media (NI/M) ratio. Intimal cell apoptosis was evaluated using TUNEL assay. Then we tested whether PDGF-BB-induced VSMC migration and PDGF-BB's function in reducing VSMC apoptosis can be attenuated by EPCs overexpressing PDGFR-ß in a transwell co-culture system. RESULTS: Our results showed that EPCs overexpressing PDGFR-ß accelerates reendothelialization and mitigates neointimal formation at 14 days after injury. Moreover, we found that there is great possibility that EPCs overexpressing PDGFR-ß enhanc VSMC apoptosis and suppress VSMC migration by competitive consumption of PDGF-BB in the early phase after carotid artery injury in mice. CONCLUSIONS: We report the first in vivo and in vitro evidence that transplantation of genetically modified EPC can have a combined effect of both amplifying the reendothelialization capacity of EPCs and inhibiting neointima formation so as to facilitate better inhibition of adverse remodeling after vascular injury.

Sphingosine-1-Phosphate Induces the Migration and Angiogenesis of Epcs Through the Akt Signaling Pathway via Sphingosine-1-Phosphate Receptor 3/Platelet-Derived Growth Factor Receptor-ß.

Endothelial progenitor cells (EPCs) play a fundamental role in neoangiogenesis and tumor angiogenesis. Through the sphingosine-1-phosphate receptor 3 (S1PR3), sphingosine-1-phosphate (S1P) can stimulate the functional capacity of EPCs. Platelet-derived growth factor receptor-beta (PDGFR-ß) contributes to the migration and angiogenesis of EPCs. This study aimed to investigate whether S1P induces the migration and angiogenesis of EPCs through the S1PR3/PDGFR-ß/Akt signaling pathway. We used the Transwell system and the Chemicon In Vitro Angiogenesis Assay Kit with CAY10444 (an S1PR3 antagonist), AG1295 (a PDGFR kinase inhibitor) and sc-221226 (an Akt inhibitor) to examine the role of the S1PR3/PDGFR-ß/Akt pathway in the S1Pinduced migration and angiogenesis of EPCs.

[The effect of oxidized low-density lipoprotein on the maturation and its immune function of monocyte-derived dendritic cells].

OBJECTIVE: To observe the effects of ox-LDL on monocyte-derived dendritic cells. METHODS: DCs were derived from healthy donors and divided into four groups according to the method of stimulation. The cells of blank group, negative group, experimental group and positive group which were treated with PBS, LDL, ox-LDL, TNF-alpha, individually. ox-LDL was added during the late stage of monocyte differentiation. Flow cytometry was used to analyze the cell surface markers and the endocytoses of DCs. (3)H-TdR incorporation was used to measure the proliferation of syngeneic and allogeneic T cells. ELISA assay was used to measure IL-12, MCP-1and MIP1 in cultured medium. Western blot analysis was used to evaluate the content of IkappaBalpha and NF-kappaB of DCs. RESULTS: Addition of ox-LDL during the late stage of monocytes differentiation can upregulate the cell surface markers including CD40 (22.3% vs. 45.6%) and CD86 (25.9% vs. 82.4%), increase the secretion of IL-12 (31.43 pg/ml vs. 126.73 pg/ml) and MCP-1 (59.6 ng/ml vs. 116.3 ng/ml), reduce DCs uptake capacity (46.8% vs. 10.7%), enhance allogeneic T cells proliferation (SI: 4.5 vs. 5.7), promote IkappaBalpha degradation and upregulate the expression of NF-kappaB in DCs. CONCLUSION: ox-LDL can promote the maturation of PBMCs-derived DCs by promoting IkappaBalpha degradation.

Effect of ginkgo biloba extract on livers in aged rats.

AIM: To investigate the protective effect of ginkgo biloba extract (GBE) on livers of aged rats and the associated mechanisms. METHODS: Two-mo- and 20-mo-old rats were treated with GBE/saline for 3 mo. Liver tissue samples from 5-mo-old rats treated with saline (group Y) and 23-mo-old rats treated with GBE (group E) or saline (group N) were used for histopathological examinations (hematoxylin-eosin and Masson staining, Lipofuscin staining-Schmorl staining) and determination of expression of tissue inhibitor-1 of metalloproteinase (TIMP-1) and the level of malondialdehyde (MDA), glutathione peroxidase (GPx) and superoxide dismutase (SOD). Blood samples were collected for determination of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL) and albumin. RESULTS: Microscopic studies with Masson staining revealed mild liver fibrosis in aged rats (group N), while the livers of aged rats receiving GBE (group E) showed amelioration in fibrosis (2.2+/-0.1 vs 2.8+/-0.1, P<0.01) and deposition of lipofuscin (33.7+/-5.3 vs 62.8+/-5.7, P<0.01). The expression of TIMP-1 and the level of liver MDA (1.0+/-0.1 vs 1.2+/-0.2, P<0.05) also decreased but the activity of GPx (97.1+/-15.3 vs 61.8+/-14.5, P<0.01) increased in group E. Compared with group Y, the level of liver MDA (0.8+/-0.1 vs 1.2+/-0.2, P<0.01), lipofuscin (32.4+/-6.0 vs 62.8+/-5.7, P<0.01) and TIMP-1 expression were increased, while the activity of GPx (103.2+/-17.6 vs 61.8+/-14.5, P<0.01) and SOD (16.7+/-4.4 vs 11.8+/-3.9, P<0.05) was decreased in group N. There was no difference in liver function among these three groups. CONCLUSION: GBE has protective effects on aging liver. The possible mechanisms might be its antioxidant activity and inhibition of TIMP-1 expression.