Association of vascular calcification and gremlin expression in radial arteries of patients with stage 5 of chronic kidney disease / 中华肾脏病杂志

Objective To study the association of the expression of bone morphogenetic protein (BMP) antagonist gremlin and vascular calcification in radial arteries of patients with stage 5 of chronic kidney disease (CKD).Methods Radial arteries of 40 patients with stage 5 of CKD were collected as specimens of the study group,which were trimmed off during arterial venous fistula operations.Splenic trabecular arteries were collected as specimens of the control group,which were removed from 38 patients with simple traumatic splenic rupture.All the arteries were examined histologically for calcification with yon Kossa stain.Expressions of gremlin and BMP-2,-7were detected by immunohistochemistry and their serum concentrations were detected by ELISA.Images of histological sections were semi-quantitatively analyzed by Image-Pro Plus 6.0.SPSS 19.0software was used to perform statistical analysis.Results Significantly positive von Kossa stain was found in radial arteries from 12 of 40 patients (30％) in study group,which located in the layer of medial smooth muscle cells.However,there was no obvious positive stain in control group.Additionally,in study group,significant expressions of gremlin and BMP-2 were detected in those radial arteries of positive yon Kossa stain,which also located in the layer of medial smooth muscle cells.Positive correlations were found among gremlin expression level,BMP-2 expression level and yon Kossa stain intensity.However,the BMP-7 expression intensity in arteries of study group was much weaker as compared to control group.Conclusions Both gremlin and BMP-2 may be involved in the process that the smooth muscle cells of radial arteries in patients with stage 5 of CKD phenotypically transform into osteoblast-like cells.However,BMP-7 possibly prevents this process.

The study of hBMP-4 gene modified tissue-engineered bone / 中华口腔医学杂志

<p><b>OBJECTIVE</b>Bone marrow stromal cells (bMSCs) of rabbits transferred with mammalian hBMP-4 expression plasmid were used to construct tissue-engineered bone. Gene therapy combined with tissue-engineering technique was explored to further improve osteogenesis.</p><p><b>METHODS</b>pEGFP-hBMP-4 plasmid was constructed by subcloning technique. bMSCs were then transferred with either pEGFP-hBMP-4, pEGFP plasmid by lipofectamine or left uninfected in vitro. The cells from the 3 groups were combined with natural non-organic bone (NNB) to construct tissue-engineered bones, which were subcutaneously implanted into nude mice (6 implants per group) for 4 weeks. Specimens were evaluated through histological and computerized new bone formation analysis.</p><p><b>RESULTS</b>pEGFP-hBMP-4 plasmid was successfully constructed. bMSCs could attach and proliferate on the surface on NNB. In vivo experiment showed that new bone formation in pEGFP-hBMP-4 group was higher than those of the control groups.</p><p><b>CONCLUSIONS</b>Tissue-engineered bone using hBMP-4 gene modified bMSCs might be an ideal alternative for the repair of bone.</p>