Objective To observe the effects of cryopreservation and resuscitation on the biological characteristics of mesenchymal stem cells (MSCs) derived f rom human umbilical cord blood. Methods MSCs were isolated and cultured f rom human umbilical cord blood in vitro. The cells were passaged , and the third generation of MSCs were cryopreserved in－196 ℃ liquid nitrogen for 4 weeks with cryopreservation medium , which contained 10 % dimethyl sulfoxide (DMSO) and 90 % fetal calf serum ( FCS) . The morphology , proliferation and differentiation of MSCs were investigated and compared with those of MSCs before cryopreservation. Results There was no significant difference of morphology between pre-cryopreserved MSCs and the ones af ter resuscitation. It was observed that all MSCs were spindle-shaped and showed adherence growth characteristic before and af ter cryopreservation. The cell growth curves of MSCs were also similar before and af ter cryopreservation. Even though the curve of resuscitated MSCs descended a little as compared with that of pre-cryopreserved MSCs , there was no significant difference ( Pgt; 0. 05) . After 2-week adipocytic differentiation induction , fat drops could be found in the kytoplasm of MSCs and they were red when stained with oil-red O staining , which suggested that MSCs could be induced and differentiated into adipocytes. Af ter 4-week osteoblastic differentiation induction , MSCs could be induced and differentiated into osteoblasts , and calcium node showed black when stained with Von Kossa staining. There were no significant changes of the differentiating ability of MSCs into adipocyte and osteoblast before and after cryopreservation. Conclusion MSCs derived from human umbilical cord blood maintains their biological characteristics af ter cryopreservation and resuscitation.
Objective To study biological rule of recombinant human bone morphogenetic protein 2 (rhBMP-2) in regulating the expression of vascular endothelial growth factor (VEGF) of adipose-derived stem cells (ADSCs) at different induced concentrations and time points at gene level and protein level. Methods ADSCs were separated from adult human adipose tissues and cultured until passage 3. After ADSCs were induced by rhBMP-2 in concentrations of 0, 50, 100, and 200 ng/ mL respectively for 24 hours, and by 100 ng/mL rhBMP-2 for 3, 6, 12, 18, 24, 36, and 48 hours (ADSCs were not induced at corresponding time point as controls) respectively, the VEGF mRNA and protein expressions were detected by RT-PCR and ELISA. Results The VEGF mRNA and protein expressions induced by rhBMP-2 were concentration-dependent; the expressions were highest in a concentration of 100 ng/mL. The VEGF mRNA expression in concentrations of 50, 100, and 200 ng/mL were significantly higher than that in a concentration of 0 ng/mL (P lt; 0.05); and the expression in concentration of 100 ng/ mL was significantly higher than that in concentrations of 50 and 200 ng/mL (P lt; 0.05). The VEGF protein expression in a concentration of 100 ng/mL was significantly higher than that in the other concentrations (P lt; 0.05). The VEGF mRNA and protein expressions induced by rhBMP-2 were time-dependent. The VEGF mRNA and protein expressions at 3 and 6 hours after induction were significantly lower than those of non-induced ADSCs (P lt; 0.05); the expressions were lower at 12 hours after induction, showing no significant difference when compared with those of non-induced ADSCs (P gt; 0.05); the expressions reached peak at 18 and 24 hours after induction, and were significantly higher than those of non-induced ADSCs (P lt; 0.05); the expressions decreased in induced and non-induced ADSCs at 36 and 48 hours, showing no significant difference between induced and non-induced ADSCs (P gt; 0.05). Conclusion rhBMP-2 adjusts VEGF expression of ADSCs in a concentration- and time-dependent manner. The optimum inductive concentration of rhBMP-2 is 100 ng/mL, induced to 18-24 hours is a key period when rhBMP-2 is used to promote tissue engineering bone vascularization.
Objective To summarize the research progress of biological characteristics and advantages of Wharton’s jelly-mesenchymal stem cells (WJ-MSCs). Methods The related l iterature on the biological characteristics of WJ-MSCs,umbil ical cord blood MSCs (UBMSCs) and bone marrow MSCs (BMSCs) was extensively reviewed and analyzed. Results A large number of MSCs which are able to self-repl icate, self-renew and have high prol iferation and multipotent differentiation can be isolated from the Wharton’s jelly of umbil ical cord. WJ-MSCs have many advantages in isolation time, isolation efficience, expansion time, passage capacity, expansion capacity when compared with UBMSCs and BMSCs. Conclusion WJ- MSCs have numerous advantages of convenient and abundant sources, relatively pure, non-ethical issues, and so on, which can be used for cell transplant therapy, gene therapy, and the ideal seed cells of building tissue engineered organ, so they provide new ideas for tissue regeneration repair and reconstruction.
【Abstract】 Objective To explore an effective method to cultivate esophageal mucosa epithel ial cells (EMECs)of canine in vitro, and to observe the biological characteristics of EMECs growing on SIS in order to provide an experimental basis for esophagus tissue engineering. Methods Esophageal tissues were obtained from five healthy dogs aged 2 to 5 weeks under sterile conditions. The primary EMECs were cultivated with defined keratinocyte serum free medium (DKSFM) containing 6% FBS. The morphological characteristics and the growth curve of EMECs of the 2nd generation were observed for 1 to 5 days. The expressions of the EMECs marker (cytokeratin 19, CK-19) were examined by immunocytochemistry. The 2nd generation of EMECs was seeded on SIS and observed by HE staining, immunohistochemical staining, and SEM for 4 and 8 days. Results The primary culture of canine EMECs arranged l ike slabstone. Immunohistochemical staining of CK-19 of the2nd generation EMECs showed positive broadly. The cells growth reached the peak level at 2 days by MTT method. E MECs werepolygon in shape and arranged l ike slabstone, and formed a single layer on the surface of SIS. The cells were contact ed closely with each other for 4 days. Eight days later, 2 to 3 layers stratified structure was formed. Lots of EMECs were grown on SIS, andshowed laminate arrangement. Conclusion With mixed enzymatic digestion, the culture of EMECs in DKSFM containing 6 %FBS is a simple and feasible method. SIS shows good biocompatibil ity and can be used as a good scaffold material in th e tissue engineered esophagus.
Objective To explore an effective method to culture and purify canine bladder transitional epithelial cells.Methods Bladder tissue was obtained from healthy puppy under sterile conditions. Bladder mucosa was removed from the remaining tissue with fine scissor and minced into small pieces, and then were dissociated into single cell suspensions with 0.125% trypsin. The bladder epithelial cells were cultured in defined keratinocyte serum free medium. The cells were passaged and purified by 0.05% trypsin and 0.02% EDTA. Morphological characterization were studied under inverted phase contrast microscope and transmission electron microscope. Expression of cell specific marker protein was assessed by immunohistochemistry. Results Canine bladder transitional epithelial cells could be efficiently cultivated and expanded in serum-free medium without fibroblast contamination. The cells could be passaged 4-6 times without a distinguished decrease in cell proliferation. The cells were characterized by well-developed micro filament and desmosome junction under transmission electron microscope. Immunohistochemical staining with broadly reacting anticytokeratin antibodies (AE1/AE3) confirmed the epithelial phenotype of the cells.Different generations of cells showed diploid cells. Conclusion A large number of bladder transitional epithelial cells can be obtained from small bladder tissue with our digestion method. The cultured bladder epithelial cells can be proliferated to sufficient quantities for further reconstructive purposes.
Objective To explore a method to isolate, culture and multiplicate the placentaderived mesenchymal stem cells (PMSCs) and the bone marrow-derived mesenchymal stem cells (BMSCs) of rabbit，and to compare their biological characteristics. Methods PMSCs were isolated from placenta of 1fetation rabbitby Percoll density gradient centrifuge and cultured in vitro. BMSCs were isolated from hindlimb bone marrow blood of 1 new born rabbit by direct plates culturemethod. The 3rd passage PMSCs and BMSCs were observed by inverted phase contrast microscope. The stem cell marker (CD44, CD105, CD34 and CD40L) were examined by immunohistochemistry. The 2nd passage PMSCs and BMSCs were co-cultured with biomaterials，(1.0-1.5)×106 cells in one biomaterial， and then observed by aematoxylinstaining after 5 days,and by SEM after 3 days and 8 days. Results PMSCs and BMSCs were both uniformly spondle-shaped in appearance and showed active proliferative capacity. The proliferative ability of PMSCs were quite b and declined with passages. After cultured 10 passages in vitro, its growthslowed. Both PMSCs and BMSCs expressed CD44 and CD105,but did not express CD34 and CD40L immunoreactivity. PMSCs and BMSCs poliferated and adhered to the surface of biomaterials, and cell formed clumps and network; the cells proliferation and the matrix were seen in the pore after 5 days of culture. The observation ofSEM showed that many cells adhered to the biomaterials with spindle-shape and polygon after 3 days; and that PMSCs and BMSCs grew,arranged in layers andsecreted many matrices; the reticular collagen formed arround cells after 8 days. Conclusion PMSCs and BMSCs have similar biological characteristics and PMSCs can be served as excellent seedingcells for tissue engineering.
Objective To observe the main biological characteristics and chondrogenesis potency of bone marrow -derived stromal cells(MSCs) after cytokinesinduction or gene modification in vitro. Methods MSCs from an adult New Zealand white rabbit were isolated and cultivated, and then MSCs were divided into the common medium group(Group A, 15%FBS in DMEM), the induced group by cytokines (Group B), the transfected group(Group C)with adenovirus-hepatocyte growth factor transgene (adHGF). The medium of group B consisted of transforming growth factor-β1(TGF-β1,10 ng/ml), basic fibroblast growth factor(bFGF,25 ng/ml) addexamethasone (DEX,10-7mol/L) with 15%FBS in DMEM. Cartilage slices wereobtained from femoral condyles and patellar grove in the same rabbit. The minced cartilage was digested in Ⅱ collagenase (3 mg/ml) to obtain chondrocytes(Group D). The change of cell appearance, proliferation capacity, glycosaminoglycans(GAG), immunohistochemical staining for type Ⅰ, Ⅱ collagen were observed during the 5th passage MSCs and MSCs after induction or gene modification. Expression of mRNA for type Ⅰ and Ⅱ collagen was detected by RT-PCR. Results Primary MSCs proliferated as shortspindle shape, while the 5th MSCs showed longspindle shape. Positive stain of type Ⅰ collagen could be found in groups A, B and C, while positivestain of type Ⅱ collagen was shown in groups B and D. The content of GAG in group B was higher than that in group A, but there was no significant difference between them（Pgt;0.05）, and there was significant difference between groups A and D（Plt;0.05）. No significant difference was noted in groups A,B and C on proliferation by MTT（Pgt;0.05）,except that of at the fourth day after transfection between groups A and C（Plt;0.05）. RT-PCR demonstrated that MSCs always had higher levelsof mRNA type Ⅰ collagen in groups A, B and C. The expression of mRNA type Ⅱ collagen was identified in groups B and D, and only low levels of mRNA type Ⅱ collagen in group C. Conclusion The above results indicate MSCs have a natural tendency of osteogenic differentiation in vitro culture, and also demonstrate the chondrogenic potency with the technique of cytokines induction or gene modification after passage. MSCs can be transfected efficiently being seed cells in tissue engineered bone or cartilage to accept target genes such as adHGF, and have a higher levels of expression in vitro, which lasted 4 weeks at least.
OBJECTIVE This paper was to study the biological characteristics of the transformed human embryonic tendon cells, the relation between cell growth and culture conditions, and to compare these features with that of human embryonic tendon cells. METHODS The pts A58H plasmid had successfully used to transform a tendon cell line from human embryo in our past work. The human embryonic tendon cells and the transformed human embryonic tendon cells were cultured in vitro. In different culture conditions, the growth curve were drawn respectively. Population dependence and proliferation capability of the cells were investigated through plate cloning test and soft agar culture. The collagen secreted by cells was identified by immunohistochemical method. RESULTS In routine culture condition, the growth properties of the human embryonic tendon cell and transformed cells were almost identical. The growth properties of the transformed cells were not changed when the cells were frozen storage. There were changes of growth characteristics of the transformed cells when the culture temperature was changed. The transformed cells could subcultured continually and permanently. The proliferation capability of the transformed cells were ber than that of the human embryonic tendon cells. Moreover, the growth of the transformed cells was serum-dependent, and the phenomenon of contact inhibition was observed. The transformed cells were not able to grow on soft agar culture. They had the capacity of secreting collagen type I. CONCLUSION The transformed human embryonic tendon cells could be subcultured continually and permanently, and their growth could be controlled by changing their culture conditions and they had no malignant tendency in biological characteristics. They could be taken as an ideal experimental material for tendon engineering.
Following the peritendon was removed by means of microsurgical technique, the tenocyte was isolated from the human embryonic tendons by digesting it with trypsin and collagenase. These cells were all stored in frozen condition until they were cultured by F12 culture fluid added with 20% FBS to the 15th generation.These cells were able to grow adhering to the wall and stop growing with contact inhibition. The time of cellsgroup duplication was 4 days, which was similar to the peak time of its mitosis. The number of its chromosome group 2n=46 was 87.5-91.0%. The optimal conditions for tendon cell culture in vitro were investigated, and it was found that after they were reaminated and subcultured the frozen storage didn’t influence their growth, morphology, genetic characteristics. In our research we detected the content generation cells and found the cultured human embryonic tenocyte had same ability never changed with the cells subcultured. We also disscussed the future of tenocyte-a biomaterial in the field of artificial implant.
ObjectiveTo summarize the research status and biological characteristics of stromal fibroblast in breast cancer. MethodsRelevant literatures about the breast cancer stromal fibroblasts published recently were collected and reviewed. ResultsIn addition to cancer cells, breast cancer included stromal cells. The fibroblasts were the major components of breast cancer stromal, which had significantly different biological characteristics from normal fibroblasts. The fibroblasts were characterized by α-SMA positive, p53 gene mutation, secretion of various cytokines or chemokines in addition to the production of collagen substances, involving in breast cancer growth, migration, invasion and metastasis through a variety of signaling pathways. ConclusionThe biological characteristics of stromal fibroblasts in breast cancer may reflect lesion properties, be of great importance to diagnosis and differential diagnosis and prognosis prediction of breast cancer. More attentions will be paid to the target therapy for stromal fibroblasts in breast cancer.