Background and purpose:miR-196a2 functions as an oncogene during tumor initiation and pro-gression. The up-regulation promotes tumor cell proliferation, invasion and metastasis. Therefore, it is promising to be an important tumor biomarker. The aim of this study was to investigate whether rs11614913, a gene polymorphic site ofmiR-196a2, is associated with the risk of leukemia.Methods:A case-control analysis was employed. Bone marrow or periph-eral blood was collected from 210 leukemia patients diagnosed from Jan. 2009 to Jul. 2015 in Yantaishan Hospital (case group) as well as 250 healthy people who were physically examined during the same period (control group). Polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP) was used to detect the genotype of rs11614913. Application test was used to compare the difference in the frequency of each genotype between case group and control group. The odds ratio (OR) of SNP allelic genes was calculated using logistic regression analysis and 95%CI represented the risk of leukemia for each genotype.Results:The distribution differences in the frequency of T/T, C/C, C/T genotype of miR-196a2 rs11614913 between case group and control group were statistically significant (P<0.05). The risk of leukemia for individuals who carried mutant homozygous C/C was 2.661-fold higher than those carried wild-type homozygous T/T, and the difference was statistically significant (P<0.05).Conclusion:ThemiR-196a2 gene polymorphic site rs11614913 was associated with the risk of leukemia. Mutant homozygous C/C or C allelic gene carrying was probably a risk factor for leukemia.

BACKGROUNDTissue-engineered heart valves have the potential to overcome the limitations of present heart valve replacements. This study was designed to develop a tissue engineering heart valve by using human umbilical cord blood-derived endothelial progenitor cells (EPCs) and decellularized valve scaffolds.

METHODSDecellularized valve scaffolds were prepared from fresh porcine heart valves. EPCs were isolated from fresh human umbilical cord blood by density gradient centrifugation, cultured for 3 weeks in EGM-2-MV medium, by which time the resultant cell population became endothelial in nature, as assessed by immunofluorescent staining. EPC-derived endothelial cells were seeded onto the decellularized scaffold at 3 x 10(6) cells/cm(2) and cultured under static conditions for 7 days. Proliferation of the seeded cells on the scaffolds was detected using the MTT assay. Tissue-engineered heart valves were analyzed by HE staining, immunofluorescent staining and scanning electron microscopy. The anti-thrombogenic function of the endothelium on the engineered heart valves was evaluated by platelet adhesion experiments and reverse transcription-polymerase chain reaction (RT-PCR) analysis for the expression of endothelial nitric oxide synthase (eNOS) and tissue-type plasminogen activator (t-PA).

RESULTSEPC-derived endothelial cells showed a histolytic cobblestone morphology, expressed specific markers of the endothelial cell lineage including von Willebrand factor (vWF) and CD31, bound a human endothelial cell-specific lectin, Ulex Europaeus agglutinin-1 (UEA-1), and took up Dil-labeled low density lipoprotein (Dil-Ac-LDL). After seeding on the decellularized scaffold, the cells showed excellent metabolic activity and proliferation. The cells formed confluent endothelial monolayers atop the decellularized matrix, as assessed by HE staining and immunostaining for vWF and CD31. Scanning electron microscopy demonstrated the occurrence of tight junctions between cells forming the confluent monolayer. Platelets adhesion experiments suggested that the neo-endothelium was non-thrombogenic. The expression levels of eNOS and t-PA genes in the neo-endothelium were quite similar to those in human umbilical vein endothelial cells.

CONCLUSIONSEPCs isolated from the human umbilical cord blood can differentiate into endothelial cells in vitro and form a functional endothelium atop decellularized heart valve scaffolds. Thus, EPCs may be a promising cell source for constructing tissue-engineered heart valves.

Animals ; Cell Proliferation ; Endothelial Cells ; cytology ; metabolism ; Heart Valve Prosthesis ; Heart Valves ; cytology ; metabolism ; ultrastructure ; Humans ; Immunohistochemistry ; Microscopy, Electron, Scanning ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Platelet Aggregation ; Reverse Transcriptase Polymerase Chain Reaction ; Stem Cells ; cytology ; metabolism ; Swine ; Tissue Engineering ; methods ; Tissue Plasminogen Activator ; genetics ; metabolism ; Umbilical Cord ; cytology

BACKGROUNDA major shortcoming in tissue engineered blood vessels (TEBVs) is the lack of healthy and easily attainable smooth muscle cells (SMCs). Smooth muscle progenitor cells (SPCs), especially from peripheral blood, may offer an alternative cell source for tissue engineering involving a less invasive harvesting technique.

METHODSSPCs were isolated from 5-ml fresh rat peripheral blood by density-gradient centrifugation and cultured for 3 weeks in endothelial growth medium-2-MV (EGM-2-MV) medium containing platelet-derived growth factor-BB (PDGF BB). Before seeded on the synthesized scaffold, SPC-derived smooth muscle outgrowth cell (SOC) phenotypes were assessed by immuno-fluorescent staining, Western blot analysis, and reverse transcription polymerase chain reaction (RT-PCR). The cells were seeded onto the silk fibroin-modified poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (SF-PHBHHx) scaffolds by 6x10(4) cells/cm2 and cultured under the static condition for 3 weeks. The growth and proliferation of the seeded cells on the scaffold were analyzed by 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide (MTT) assay, scanning electron microscope (SEM), and 4,6-diamidino-2-phenylindole (DAPI) staining.

RESULTSSOCs displayed specific "hill and valley" morphology, expressed the specific markers of the SMC lineage: smooth muscle (SM) alpha-actin, calponin and smooth muscle myosin heavy chain (SM MHC) at protein and messenger ribonucleic acid (mRNA) levels. RT-PCR results demonstrate that SOCs also expressed smooth muscle protein 22alpha (SM22alpha), a contractile protein, and extracellular matrix components elastin and matrix Gla protein (MGP), as well as vascular endothelial growth factor (VEGF). After seeded on the SF-PHBHHx scaffold, the cells showed excellent metabolic activity and proliferation.

CONCLUSIONSPCs isolated from peripheral blood can be differentiated into the SMCs in vitro and have an impressive growth potential in the biodegradable synthesized scaffold. Thus, SPCs may be a promising cell source for constructing TEBVs.

3-Hydroxybutyric Acid ; chemistry ; Animals ; Blood Vessels ; cytology ; Caproates ; chemistry ; Cell Adhesion ; Cell Differentiation ; Cell Proliferation ; Immunophenotyping ; Microscopy, Electron, Scanning ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; RNA, Messenger ; analysis ; Rats ; Tissue Engineering ; Vascular Endothelial Growth Factor A ; genetics