ABSTRACT
The present study was purposed to evaluate the safety of mesenchymal stem cell (MSC)-based therapy impacting on atherosclerosis. Allogeneic MSCs were obtained from rabbit bone marrow aspirates and expanded in vitro. New Zealand white rabbits were divided into three groups: 24 rabbits with hypercholesterolemia receiving intravenous injection of either 5 x 10(7) MSCs (n = 12) or saline (n = 12) after 5 weeks on a high lipid diet and additional rabbits (n = 6) fed with standard rabbit diet were served as controls. Body weight and blood lipids were measured at weeks 0, 5, 9 and 13 during the study. All rabbits were sacrificed at week 13. Atherosclerotic lesion size and vasa vasorum were evaluated by using pathological analysis and immunocytochemical technique. The results showed that the aortic sinus lesion size significantly increased in rabbits infused with MSCs as compared with controls receiving saline (23.35 +/- 3.51% and 11.39 +/- 3.08% respectively). The lesion size in whole aortas of MSC-treated rabbits was 76.64 +/- 12.70% versus 57.61 +/- 9.00% in saline-treated animals (p < 0.05). Moreover, vasa vasorum networks in MSC-treated aortas were more numerous and had increased capillary density. It is concluded that the allogeneic MSC transfusion may result in an increase in atherosclerotic lesion size. In cell therapy with MSCs or cell populations containing MSCs a strategy to attenuate the high potential of MSCs involved in atherogenesis of atherosclerosis should be taken in account.
Subject(s)
Animals , Male , Rabbits , Cell Differentiation , Disease Models, Animal , Mesenchymal Stem Cell Transplantation , Methods , Plaque, AtheroscleroticABSTRACT
Seventy-two strains of endophytic fungi were isolated from the healthy bark, branches and leaves of Cephalotaxus hainanensis L.. Sixty-eight of them were morphologically classified into Fungi Imperfecti, thirty-three sporulated were identified to five genera. For those did not sporulate, one was identified to Rhizoctonia sp., the rest were tentatively classified into Mycelia Sterilia. Four were identified to Basidiomycetes. The result indicated the endophytic fungi of C. hainanensis show a degree of tissue specificity. There were significant differences about the quantity, genera and composition between the fungi isolated from bark and those from branches and leaves.
ABSTRACT
Nitrite reductases (NiRs) are the key enzymes in the denitrification pathway of the nitrogen cycle. By the catalysis of NiRs, the nitrites are turned into nitric oxides and the nitrogen pollution is decreased in water body. NiRs are divided into two different types based on their prosthetic groups, namely heme-containing nitrite reductases (cd1-NiRs) and Copper-containing nitrite reductases (Cu-NiRs). As all know, Cu-NiRs have trimeric structures, in their each monomer, there exist two types of Cu centers that play pivotal roles as the components of electron transfer pathway in the process of catalysis. Furthermore, some residues alteration of Cu-NiRs would contribute to the catalytic reaction. In this review, the latest progresses about the construction features, the process of electron transfer and catalytic mechanism of Cu-NiRs were discussed.
ABSTRACT
Objective :To construct and identify a ScFv phage display library against human umbilical cord mesenchymal stem cells.Methods: BALB/c mice were immunized with cultured UC-MSCs.After the third immunization,the total RNA was extracted from the spleen cells of the immunized BALB/c mice and purified by affinity chromatography with mRNA Purification Kit.The heavy-chain and light-chain variable region genes(VH and VL) were amplified by PCR using relevant primers.PCR products of VH and VL genes were cloned into the phagemid vector pSEX81 and electroporated into the XL1-Blue strain of E.coli.The ScFv phage display library against human umbilical cord mesenchymal stem cells was constructed and the capacity of library was measured.The library was panned by three cycles and screened with purified UC-MSCs.The percentage of clones containing a full-length scFv-encoding insert and their diversity was determined for unselected and selected libraries.Results: The amplified fragments of VH and VL genes by RT-PCR were about 399bp and 357bp,respectively.VH and VL genes were all successfully cloned into the phagemid vector pSEX81,which were confirmed by the amplication of 786bp full-length scFv fragments by PCR.The ScFv phage display library had a capacity of approximately 2?107 cfu.After three cycles of panning,PCR of plasmid DNA prepared from 15 individual phage clones showed that the recombination rate increased from 93% to 100%.BstN1 fingerprinting of insert DNA showed that the diversity of clones decreased with increasing rounds of selection.After three rounds of selection,3 clones showed an identical restriction enzyme pattern.There was a 330-fold enrichment of library phage after 2 rounds of selection and after 3 rounds,a further 8-fold enrichment of library phage was obtained.Conclusion: The ScFv phage display library against human umbilical cord mesenchymal stem cells was successfully constructed.It can be used for succeeding screening of specific antibody against human umbilical cord mesenchymal stem cells and further studying of the cell surface molecules of mesenchymal stem cells.