Expression of bone-related genes in bone marrow MSCs after cyclic mechanical strain: implications for distraction osteogenesis / 国际口腔科学杂志·英文版

<p><b>AIM</b>Understanding the response of mesenchymal stem cells (MSCs) to mechanical strain and their consequent gene expression patterns will broaden our knowledge of the mechanobiology of distraction osteogenesis.</p><p><b>METHODOLOGY</b>In this study, a single period of cyclic mechanical stretch (0.5 Hz, 2,000 microepsilon) was performed on rat bone marrow MSCs. Cellular proliferation and alkaline phosphatase (ALP) activity was examined. The mRNA expression of six bone-related genes (Ets-1, bFGF, IGF-II, TGF-beta, Cbfa1 and ALP) was detected using real-time quantitative RT-PCR.</p><p><b>RESULTS</b>The results showed that mechanical strain can promote MSCs proliferation, increase ALP activity, and up-regulate the expression of these genes. A significant increase in Ets-1 expression was detected immediately after mechanical stimulation, but Cbfa1 expression became elevated later. The temporal expression pattern of ALP coincided perfectly with Cbfa1.</p><p><b>CONCLUSION</b>The results of this study suggest that mechanical strain may act as a stimulator to induce differentiation of MSCs into osteoblasts, and that these bone-related genes may play different roles in the response of MSCs to mechanical stimulation.</p>

Correction of the epicanthal fold and angulus oculi using the Z-epicanthoplasty / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore a new procedure for aesthetic correction of the medial epicanthal fold aim at the etiopathogenesis.</p><p><b>METHODS</b>The new Z-epicanthoplasty devise the upper and inferior margin of angle of eye medial as one angle of the Z.</p><p><b>RESULTS</b>From 2004 to 2006, 129 patients were treated by using the method. Follow-up 6 to 24 months, all patients were satisfied by eliminating the medial epicanthal fold without obvious scar.</p><p><b>CONCLUSIONS</b>The method is more effect than traditionally Z-plasty. Our technique is a simple, advanced procedure that can be performed widely.</p>

Effects of mesenchymal stem cells transplantation on cranial suture distraction osteogenesis in growing goats / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe the effects of mesenchymal stem cells (MSCs)on cranial suture under mechanical strain in growing goats.</p><p><b>METHODS</b>10 growing goats were used in this study. A customized distractor was used for distraction of the coronal suture at a rate of 0.4 mm/day for 8 days. The experimental group(5 goats) was injected with autologous MSCs into the distracted region, whereas the control group (5 goats) with injection of physiological saline. All animals were killed at 4 weeks after the end of distraction. Scanning electron microscopy and histological analysis were taken to observe the samples.</p><p><b>RESULTS</b>4 weeks after the end of distraction, the cranial sutures in all animals were separated successfully. The new bone formation at the edge of suture in the experimental group was superior to that in the control group.</p><p><b>CONCLUSION</b>Autologous MSCs transplantation may promote the cranial suture distraction osteogenesis in the growing goats.</p>

Construction of recombinant plasmid pEGFP-BMP7 and its expression in rat bone marrow mesenchymal stem cells in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To construct recombinant plasmid pEGFP-BMP7 and determine its expression in rat bone marrow mesenchymal stem cells (MSCs) in vitro.</p><p><b>METHODS</b>cDNA of target gene was obtained from neonatal rat kidney by RT-PCR. After sequencing the target gene, the cDNA was subcloned into a eukaryote plasmid pEGFP-N1 by directed cloning and then digested with two restrictive endonucleases to verify the correctiveness of the recombinant plasmid pEGFP-BMP7. Rat bone marrow MSCs were transiently transfected with the pEGFP-BMP7 and transfection efficiency of the Green Fluorescent Protein (GFP) was determined. RT-PCR and immunocytochemical analysis were also performed to detect the expression of BMP7 in rat MSCs.</p><p><b>RESULTS</b>1 311 bp cDNA fragment was obtained by RT-PCR and sequence analysis showed it matched perfectly with that of rat BMP7 gene except a single nucleotide change at 756 bp from T to A. Digestion of the recombinant plasmid showed two 1.3 kb and 4.7 kb fragments and their size were same as those of BMP7 and pEGFP. This indicated that BMP7 cDNA was successfully subcloned into pEGFP. Transient transfection showed an efficiency of 33% at day 2 in rat MSCs. After transfection, transcription of BMP7 was detected in MSCs and expression of BMP7 protein was also verified.</p><p><b>CONCLUSION</b>Recombinant eukaryote plasmid pEGFP-BMP7 was successfully constructed and expressed in rat bone marrow MSCs. This procedure may provide a unique method for stimulation of callus formation in distraction osteogenesis and reconstruction of craniofacial bone defects.</p>