The osteogenc potential of bone marrow has been proved by experiment. To investigate more in details, bone marrow was obtained from the trochanteric region of femur of NewZealand rabbit in 4 to 8 weeks old. After being cultured in vitro for one week, the hematopoietic component of the bone marrow had disappeared, thus the stromal cells were obtained. Then the stromal cells were subcultured in cultural fluid containing dexamethasone (10-8 mol/L) and natrium glycerophosphate (10mmol/L). Under the phasecontrast microscope, it was found that being cultured for 15 days. The stromal cells were lined up in one layer and late the secretion activity was increased and gradually transformed into multilayer structure and was congregated into diffused opaque clusters in twenty days. During culture, the cells were examined by tetracycline fluorescence label, histochemistry stains, transmission electron microscopy, scanning electron microscopy and energy dispersive X-ray microanalysis. The results showed that the morphological and biological characteristics of the cultured stromal cells derived from the bone marrow were similiar to those of osteoblasts and could synthesized mineralized new bone tissue in vitro.
Objective To investigate the influence on matrix metalloproteinases (MMP) 3, 9, and 13 levels of human articular cartilage cells after blocking stromal cell derived factor 1 (SDF-1)/ chemokine receptor 4 (CXCR4) signaling pathway withAMD3100 and to define the function mechanism of AMD3100. Methods A total of 144 cartilage blocks from 12 osteoarthritis (OA) patients undergoing total knee arthroplasty (OA cartilage group) and 144 normal cartilage blocks (Mankin score of 0 or 1) from 12 patients undergoing traumatic amputation (normal cartilage group). OA cartilage group was further divided into subgroups A1, B1, and C1, and normal cartilage group into subgroups A2, B2, and C2. The cartilage tissues were cultured in DMEM solution containing 100 ng/mL SDF-1 and 1 000 nmol/L AMD3100 in subgroup A, 100 ng/mL SDF-1 and 1 000 nmol/L MAB310 in subgroup B, and 100 ng/mL SDF-1 in subgroup C, respectively. The levels of MMP-3, 9, and 13 were measured by ELISA; the expressions of MMP-3, 9, and 13mRNA were tested by RT-PCR. Results ELISA and RT-PCR results showed that the levels of MMP-3, 9, and 13 and the expressions of MMP-3, 9, and 13 mRNA were significantly lower in subgroup A than in subgroups B and C at the same time points (P lt; 0.05); the levels of MMP-3, 9, and 13 and the expressions of MMP-3, 9, and 13 mRNA were significantly higher in OA cartilage group than in normal cartilage group at the same time points (P lt; 0.05). Conclusion SDF-1 could induce overexpression and release of MMP-3, 9, and 13 in the articular cartilage through the SDF-1/CXCR4 signaling pathway; AMD3100 could reduce the mRNA expressions and secretion of MMP-3, 9, and 13 in OA cartilage by blocking the SDF-1/CXCR4 signaling pathway; but AMD3100 could not make the secretion of MMP-3, 9, and 13 return to normal levels in OA cartilage.
Objective To find a kind of simple and effective method for purifying and label ing stromal vascular fraction cells (SVFs) so as to provide a theoretical basis for cl inical application of SVFs. Methods The subcutaneous adi pose tissue were harvested form volunteers. The adi pose tissue was digested with 0.065%, 0.125%, and 0.185% type I collagenase,respectively. SVFs were harvested after digestion and counted. After trypan blue staining, the rate of viable cells was observed. SVFs was labeled by 1, 1’-dioctadecyl-3, 3, 3’, 3’-2-tetramethy-lindocyanine perchlorate (DiI). The fluorescent label ing and growth was observed under an inverted fluorescence microscope. MTT assay was used to detect cell proliferation. Results The number of SVFs was (138.68 ± 11.64) × 104, (183.80 ± 10.16) × 104, and (293.07 ± 8.31) × 104 in 0.065% group, 0.125% group, and 0.185% group, respectively, showing significant differences among 3 groups (P lt; 0.01). The rates of viable cells were 91% ± 2%, 90% ± 2%, and 81% ± 2% in 0.065% group, 0.125% group, and 0.185% group, respectively, and it was significantly higher in 0.065% group and 0.125% group than in 0.185% group (P lt; 0.01), but no significant difference was found between 0.065% group and 0.125% group (P=0.881). Inverted fluorescence microscope showed that the cell membranes could be labeled by DiI with intact cell membrane, abundant cytoplasm, and good shape, but nucleus could not labeled. SVFs labeled by DiI could be cultured successfully and maintained a normal form. MTT assay showed that similar curves of the cell growth were observed before and after DiI labeled to SVFs. Conclusion The optimal collagenase concentration for purifying SVFs is 0.125%. DiI is a kind of ideal fluorescent dye for SVFs.
Objective To introduce types and differentiation potentials of stem cells from adipose tissue, and its applications on regenerative medicine and advantages. Methods The literature of original experimental study and clinical research about bone marrow mesenchymal stem cells (BMSCs), adipose-derived stem cells (ADSCs), and dedifferentiated fat (DFAT) cells was extensively reviewed and analyzed. Results ADSCs can be isolated from stromal vascular fraction. As ADSCs have multi-lineage potentials, such as adipogenesis, osteogenesis, chondrogenesis, angiogenesis, myogenesis, and neurogenesis, they have already been successfully used in regenerative medicine areas. Dramatically, mature fat cells can be dedifferentiated and changed into fibroblast-like cells, named DFAT cells, via ceiling culture method. DFAT cells also had the same multi-lineage potentials as ADSCs, differentiating into adipocytes, osteocytes, chondrocytes, endothelial cells, muscle cells, and nerve cells. Compared with BMSCs which are commonly used as adult stem cells, ADSCs and DFAT cells have extensive sources and can be easily acquired. While compared with ADSCs, DFAT cells have good homogeneity and b proliferation capacity. Conclusion As a potential source of stem cells, adipose tissue will provide a new promising for regenerative medicine.
ObjectiveTo observe the effect of stromal vascular fraction cells (SVFs) from rat fat tissue combined with sustained release of recombinant human bone morphogenetic protein-2 (rhBMP-2) in promoting the lumbar fusion in rat model.MethodsSVFs were harvested from subcutaneous fat of bilateral inguinal region of 4-month-old rat through the collagenase I digestion. The sustained release carrier was prepared via covalent bond of the rhBMP-2 and β-tricalcium phosphate (β-TCP) by the biominetic apatite coating process. The sustained release effect was measured by BCA method. Thirty-two rats were selected to establish the posterolateral lumbar fusion model and were divided into 4 groups, 8 rats each group. The decalcified bone matrix (DBX) scaffold+PBS, DBX scaffold+rhBMP-2/β-TCP sustained release carrier, DBX scaffold+SVFs, and DBX scaffold+rhBMP-2/β-TCP sustained release carrier+SVFs were implanted in groups A, B, C, and D respectively. X-ray films, manual spine palpation, and high-resolution micro-CT were used to evaluate spinal fusion at 8 weeks after operation; bone mineral density (BMD) and bone volume fraction were analyzed; the new bone formation was evaluated by HE staining and Masson’s trichrome staining, osteocalcin (OCN) was detected by immunohistochemical staining.ResultsThe cumulative release amount of rhBMP-2 was about 40% at 2 weeks, indicating sustained release effect of rhBMP-2; while the control group was almost released within 2 weeks. At 8 weeks, the combination of manual spine palpation, X-ray, and micro-CT evaluation showed that group D had the strongest bone formation (100%, 8/8), followed by group B (75%, 6/8), group C (37.5%, 3/8), and group A (12.5%, 1/8). Micro-CT analysis showed BMD and bone volume fraction were significantly higher in group D than groups A, B, and C (P<0.05), and in group B than groups A and C (P<0.05). HE staining, Masson’s trichrome staining, and immunohistochemistry staining for OCN staining exhibited a large number of cartilage cells with bone matrix deposition, and an active osteogenic process similar to the mineralization of long bones in group D. The bone formation of group B was weaker than that of group D, and there was no effective new bone formation in groups A and C.ConclusionThe combination of sustained release of rhBMP-2 and freshly SVFs can significantly promote spinal fusion in rat model, providing a theoretical basis for further clinical applications.
Objective To investigate the feature of c-kit gene mutation in gastrointestinal stromal tumor （GIST） and its correlation with clinicolpathology， molecular targeted therapy，and prognosis. Methods The related literatures about the molecular genetic mechanism of GIST were reviewed. Results The c-kit gene mutation， which is prevalent in GIST， may be the early genomic events， and they are not the independent prognostic factor. However， different molecular subtype as a new indicator to regulate biological behaviors and assess prognosis of GIST is still controversial. Conclusions The study of genotype in GIST has advanced our understanding of pathogenesis， evaluating the prognosis and conducting treatment optimization. However， subsequent work remains to be done.
ObjectiveTo explore the methods of separation， culture， and identification of breast cancer stromal fibroblasts (BCSFs), which could build up a good basis for the further research of function. MethodsBreast cancer tissues were obtained during breast cancer operation， and were cut into pieces with size of 1 mm×1 mm×1 mm under aseptic conditions， then the pieces of the tissues were digested by collagenase Ⅰ and hyaluronidase. Finally the cells separated from the tissues incubated at 37 ℃ with 5% CO2 and 95% air humidified incubator. Morphological characteristics of the fibroblasts were observed under light microscope. The certain proteins were examined by immunohistochemistry （using CK， Vimentin， α-SMA, and TE-7 antibody） and flow cytometric analysis (CD34 and CD45). ResultsThe separated cells begin to attach to the wall of flask within 24 h and reached almost confluency in about 7 d to 10 d . According to identification, the successful rate of separation and culture of BCSFs was 90%（18/20）, and the characteristics of cells showed that morphological characteristics of the fibroblasts was flat spindle， rich cytoplasm, and a flat ovoid cystic nuclear. The fibroblasts in breast cancer tissues showed negative staining for cytokeratin， positive staining for vimentin， alpha-smooth muscle actin, and TE-7， and negative for CD34 and CD45 by flow cytometric analysis. ConclusionsThe fibroblasts in breast cancer tissues could be easily obtained by tissues cuting combined enzyme digestion and rocking technology in vitro. The present study provide an experimental foundation for further studies on fibroblasts in breast cancer.
Objective To investigate the expression of stromal cell-derived factor-1 (SDF-1) and its clinical significance in blood plasma of patients with breast tumor. Methods The level of SDF-1 protein was examined by enzyme linked immunosorbent assay (ELISA) in blood plasma of 26 patients with breast benign tumor and 52 patients with breast cancer. Results The SDF-1 protein in blood plasma was detected in both breast benign tumor patients and breast cancer ones. The level of SDF-1 protein in patients with breast cancer was higher than that in ones with breast benign tumor, and there was a statistical difference between them （P=0.000）. In patients with breast cancer, the level of SDF-1 protein in axillary lymph node (ALN) metastasis positive patients was significantly higher than that in ALN metastasis negative ones （P=0.036）. Conclusion The level of SDF-1 protein in blood plasma may be a specific tumor marker. Its level is correlated with lymph node involvement in breast cancer.
Objective To investigate the role and relative mechanism of stromal cell derived factorl (SDF-1) secreted by nucleus pulposus cells (NPCs) on the proliferation of vascular endothelial cells (VECs). Methods The NPCs were isolated from the degenerated disc specimens after discectomy. NPCs at passage 1 were transfected with lentivirus-mediated SDF-1 over-expression; transfected and untransfected NPCs at passage 2 were cultured in the three-dimensional alvetex® scaffold, then they were co-cultured with HMEC-1 cells. The morphology of NPCs was observed by scanning electron microscope (SEM), and the apoptosis of HMEC-1 cells was detected by Annexin V/propidiumiodide staining after 72 hours co-culutre. The proliferation of HMEC-1 cells was detected by cell counting kit 8 at 12, 24, 48, and 72 hours in transfected group and untransfected group, respectively. ELISA was used to measure the vascular endothelial growth factor (VEGF) expression level. The virus transfection efficiency and relative Akt pathway were determined by Western blot. Results The NPCs maintained cell phenotype and secreted much extracellular matrix in three-dimensional-culture by SEM observation. In the co-culutre system, after NPCs were transfected with SDF-1 over-expression lentivirus, the proliferation of HMEC-1 cells was significantly increased, while the apoptosis was decreased obviously. The ELISA results demonstrated that the amount of VEGF was remarkably increased in the culture medium. Furthermore, SDF-1 promoted the up-regulation of phosphorylate Akt expression; after inhibition of Akt expression by GSK690693, the proliferation rate of VECs decreased significantly. Conclusion Over-expression of SDF-1 by NPCs is beneficial for VECs proliferation, which is involved in SDF-1-Akt signalling pathway.
Objective To introduce the related issues in the clinical translational application of adipose-derived stem cells (ASCs). Methods The latest papers were extensively reviewed, concerning the issues of ASCs production, management, transportation, use, and safety during clinical application. Results ASCs, as a new member of adult stem cells family, bring to wide application prospect in the field of regenerative medicine. Over 40 clinical trials using ASCs conducted in 15 countries have been registered on the website (http://www.clinicaltrials.gov) of the National Institutes of Health (NIH), suggesting that ASCs represents a promising approach to future cell-based therapies. In the clinical translational application, the related issues included the quality control standard that management and production should follow, the prevention measures of pathogenic microorganism pollution, the requirements of enzymes and related reagent in separation process, possible effect of donor site, age, and sex in sampling, low temperature storage, product transportation, and safety. Conclusion ASCs have the advantage of clinical translational application, much attention should be paid to these issues in clinical application to accelerate the clinical translation process.