Regulating promoter element of iron-dependent gene FRP1 in Candida albicans by site-directed mutation / 生物工程学报

Microarray analysis revealed that the expression of ferric reductase (FRP1) can be regulated by the Riml01 protein. In order to find new transcriptional regulatory element in the promoter of FRP1, we analyzed the 1000 bp sequence upstream of ATG to find 2 potential Riml01p binding sites. We generated site-specific mutations in each of the two sites and fused these mutated promoters to LacZ. Then the promoter-LacZ fusion construct was recombinant into wild type and riml01-/- strains for beta-galactosidase assay. The results revealed that the FRP1 was up-regulated in alkaline pH and this was caused by iron starvation. The -650 site, not the -160 site, had an important role in FRP1 Riml01p-dependent expression. We conclude that Riml01p may interact with the -650 binding site of the promoter to regulate the FRP1 expression.

Application of adipose-derived cells in reconstruction of tissue engineered cartilage in vitro / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the feasibility of application of adipose-derived cells (ADCs) in reconstruction of tissue engineered cartilage in vitro.</p><p><b>METHODS</b>Adipose tissue were obtained from human liposuction aspirate (19 cases, 31.5 +/- 5.8 years old). ADCs were isolated by collagenase digestion from liposuction aspirates. 3rd passage cells were seeded into PLGA scaffolds. The copolymer constructs were cultured in conditioned or non-conditioned medium in vitro for 4 weeks. The constructs were evaluated though gross morphology, histology, and immunohistochemistry.</p><p><b>RESULTS</b>The cell-polymer constructs kept its original shape in the induced group, but lost its original shape in the non-induced group. The scaffold group were collapsed. Histologically, the induced groups showed dense cellularity and lacunae-containing cells embedded in a basophilic matrix, while non-induced groups showed connective tissue-like morphology. Collagen and proteoglycan deposition was revealed by Massons's trichome and Safranin' O staining, and minor collagen II expression in the matrix was detected by immunohistochemistry staining in the induced group. They were all negative in the non-induced groups.</p><p><b>CONCLUSIONS</b>Although ADCs included many kinds of cells, it is feasible to use ADCs as seeds cells for reconstruction of tissue engineered cartilage.</p>