Effects of Gingko biloba extract (EGb 761) on vascular smooth muscle cell calcification induced by ß-glycerophosphate.

OBJECTIVE: To investigate the effects of Gingko biloba extract (EGb 761) on calcification induced by ß-glycerophosphate in rat aortic vascular smooth muscle cells. METHODS: Rat aortic vascular smooth muscle cells were cultured with various concentrations of EGb 761 and ß-glycerophosphate for 7 days. Calcium content in the cells, alkaline phosphatase activity, cell protein content, NF-κB activation, and reactive oxygen species production were assayed, respectively. RESULTS: The calcium depositions of vascular smooth muscle cells of the ß-glycerophosphate group were significantly higher than those of the control group (p < 0.01), and were inhibited by EGb 761 in a concentration-dependent manner (p < 0.05). Data showed ß-glycerophosphate induced the enhanced expression of alkaline phosphatase, up-regulated the NF-κB activity and increased reactive oxygen species production of vascular smooth muscle cells while these decreased when administrated with EGb 761(p < 0.05). CONCLUSIONS: EGb 761 significantly reduced deposition of calcium induced by ß-glycerophosphate in rat aortic vascular smooth muscle cells. It not only reduced the deposition of calcium, but also inhibited osteogenic transdifferentiation, which may be associated with decreasing expression of alkaline phosphatase, down-regulating the NF-κB activity, and reducing reactive oxygen species production of vascular smooth muscle cells, and may have the potential to serve as a role for vascular calcification in clinical situations.

HLA class I (ABC) upregulation on peripheral blood CD3+/CD8+ T lymphocyte surface is a potential predictor of acute rejection in renal transplantation.

BACKGROUND: Renal transplantation is currently the prevalent therapy for most patients with end-stage renal disease. No clinical markers for such rejection have been universally accepted. We aimed to investigate the possibility of use of human leukocyte antigen (HLA) class I (ABC) on peripheral blood CD3+/CD8+ T lymphocytes as a marker of acute rejection. METHODS: For recipients undergoing renal transplantation from September 2007 to November 2008, peripheral blood samples were obtained pretransplantation and at days 3 and 7 posttransplantation when the patients were still hospitalized and at weeks 2 and 3 and months 1, 2, 3, and 6 posttransplantation. For patients with fever, lumbodynia, gross hematuria, or oliguria after transplantation, blood samples were collected immediately before and at days 3 and 7 after the administration of anti-inflammatory regents. The level of HLA class I (ABC) on peripheral-blood CD3+/CD8+ T lymphocytes was measured on flow cytometry. RESULTS: For the 79 transplant recipients, the level of HLA class I (ABC) on peripheral-blood CD3+/CD8+ T lymphocytes was consistently elevated during the first 3 weeks after transplantation, declined gradually to pretransplantation levels, then tapered off and remained stable. Patients experiencing acute rejection (AR) or not after transplantation did not differ in level of HLA class I (ABC) up to 6-month follow-up, except at days 14 and 21 after transplantation, when the level was higher for patients experiencing AR (P<0.01). CONCLUSIONS: Upregulation of HLA class I (ABC) on peripheral-blood CD3+/CD8+ T lymphocytes could be used as an accurate and reliable predictor of AR after renal transplantation.