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Xu Y.,Peking Union Medical College | Meng H.,National Research Center for Stem Cell Engineering and Technology | Li C.,Peking Union Medical College | Hao M.,Peking Union Medical College | And 9 more authors.
Stem Cells and Development | Year: 2010

Stem cells transplantation holds great promise for the treatment of ischemic diseases through functional revascularization. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) are also an ideal candidate for cell-based bioengineering. Herein, we report on the development of a simple and effective protocol to isolate UC-MSCs, and confirm their endothelial potential both in vitro and in vivo. UC-MSCs were isolated by a novel explantation technique and induced to differentiate into endothelial-like cells. Then UC-MSCs were transplanted into ischemic mouse model and cultured on 3D gel/MMT-CS composite scaffolds. Morphological and proliferation assessments show that sufficient UC-MSCs can be generated during a relatively short culture period with explantation technique. Increased expression of endothelial-specific markers (KDR and vWF), and functional markers (ac-LDL uptake and UEA-1 binding), indicate that functional endothelial progenitor cells are induced after 9 days of in vitro culture. In an ischemic hindlimb mouse model, the ratio of ischemic/nonischemic limb perfusion 4 weeks after MSCs transplantation reached 0.84 ± 0.09. The capillary density of this group was 2.57-fold greater than that of sham-injected mice (P < 0.05). Immunofluorescence and immunohistological analyses indicate that MSCs may act to salvage the ischemic tissue by incorporating into the local vasculature. In vitro, UC-MSCs were observed to incorporate into 3D gel/MMT-CS composite scaffolds, to secrete extracellular matrix, to remain viable, and to retain their proliferation capacity. In conclusion, UC-MSCs isolated by novel yet simple explantation technique are well suited for application in the development of novel stem cell-based revascularization therapies. © 2010, Mary Ann Liebert, Inc.

Wang L.-F.,Zhejiang Medical College | Han Z.-B.,Peking Union Medical College | Li M.,CAS Institute of Biophysics | Yang P.,Peking Union Medical College | And 4 more authors.
Molecular Medicine Reports | Year: 2013

Hemangiopoietin (HAPO) is a novel growth factor stimulating the proliferation of hematopoietic and endothelial progenitor cells in vitro and in vivo. The native protein is a 294-amino acid multimodular protein. The N-terminus constitutes of two somatomedin B (SMB) homology domains that contain 14 cysteines. The central region is a putative heparin-binding domain (pHBD) and the C-terminus contains mucin-like repeats. In the present study, we demonstrated that prokaryotic recombinant human HAPO (rhHAPO) self-associates into a multimeric form with a mass weight of ∼129 kDa, suggesting a homologous tetramer. rhHAPO in its multimeric form was found to be more stable and more potent in promoting HESS-5 cell adhesion. Multimeric rhHAPO had a higher affinity to heparin compared with its dimeric form, although there was no significant conformational change. C-terminal repeats-truncated rhHAPO (rhHAPOΔmucin) was also found to be assembled into a multimer, while deletion of pHBD (rhHAPOΔmucin-pHBD) caused the protein to remain in a dimeric form, demonstrating that SMB domains participate in self-aggregation of the molecule and that the pHBD region promotes the tetramerization.

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