Objective To investigate the impact of bone marrow mesenchymal stem cell transplantation on a rat model of experimental autoimmune uveitis (EAU) and analyze its immune regulatory mechanisms in vivo.Methods Eighteen Lewis rats were randomly divided into three groups: model control group, intervention group and normal control group, six animals in each group. Human retinal S-antigen peptide (HS-AgP35, 1 mg/ml) was mixed and emulsified with complete Freundprime;s adjuvant and injected into hind foot pad of rats on the first and eighth day to establish the animal model of EAU. For bone marrow mesenchymal stem cell transplantation, 1 ml of cell suspension (2times;106 cells/ml) was injected into tail vein of the intervention group rats on the first day when the emulsified S-antigen was injected. EAU manifestation, pathological change and IFN-gamma; level were evaluated and compared among those three groups after two weeks. Results No abnormal signs were found in the eyes of rats in normal control group. The manifestation grading of the intervention group (two rats at grade 0, three rats at grade 0.5, one rat at grade one) was significantly different from the model control group (one rat at grade one, one rat at grade two, three rats at grade three, one rat at grade four) (P=0.015). The retina of rats in normal control group was ordinary under light microscope. The histopathologrical grading of the intervention group (one rat at grade 0, four rats at grade 0.5,one rat at grade one) and the model control group (four rats at grade three, two rats at grade four) was also statistically different (P＜0.01). Furthermore, the IFN-gamma; level in peripheral blood of the intervention group rats declined significantly compared to the model control group (t=9.0574, P=0.01). Conclusions Bone marrow mesenchymal stem cells can inhibit EAU significantly, possibly by lowering the level of IFN－gamma;, thereby reduce the severity of uveitis and improve the condition of uveitis in rats.
Objective To introduce the research of mesenchymal stemcells(MSCs) transplantation for treating intervertebral disc degeneration. Methods The recent original articles about the MSCs transplantation for treating intervertebral disc degeneration were extensively reviewed. Results Transplanted MSCs in intervertebral disc can express chrondcyte-like phenotype in certain conditions, increase matrix synthesis and release intervertebral disc degeneration. Conclusion MSCs transplantation for treating intervertebral disc degeneration may be a future approach.
Objective?To review the recent progress of the researches in construction of tissue engineered osteochondral composites, and to discuss the challenges in construction of tissue engineered osteochondral composites.?Methods?The recent literature on the construction of tissue engineered osteochondral composites was extensively reviewed and analyzed.?Results?The studies on the construction of tissue engineered osteochondral composites are relatively more in vivo, the current focus is that different tissues derived mesenchymal stem cells are widely used to be seed cells; single-phase scaffold has been limited, studies on biphase scaffold and triphase scaffold are new trends; the design and performance of bioreactor need to be further optimized in the future.?Conclusion?The construction of tissue engineered osteochondral composites will be a promising method for the treatment of cartilage defects.
Objective To investigate the curative effects of homograft of the mesenchymal stem cells(MSCs) compbined with the medical collagen membrane of the guided tissue regeneration(MCMG) on the full thickness defects of the articular cartilage. Methods MSCs derived from New Zealand rabbits aged 3-4 months weighing 2.1-3.4 kg were cultured in vitro with a density of 5.5×108/ml and seeded onto MCMG. The MSC/MCMG complex was cultured for 48 h and transplanted into the fullthickness defects on the inboardcondyle and trochlea. Twenty-seven healthy New Zealand rabbits were randomly divided into 3 groups of 9rabbits in each. The cartilage defects in the inboard condyle and trochlea werefilled with the auto bone marrow MSCs and MCMG complex (MSCs/ MCMG) in Group A (Management A), with only MCMG in Group B (Management B)and with nothing in Group C (Management C). Three rabbits were killed at 4, 8 and 12 weeks after operation in each group, and the reparative tissue samples evaluated grossly,histologically and immunohistochemically were graded according tothe gross and histological scale. Results Four weeks after transplantation, the cartilage and subchondralbone were regenerated in Group A;for 12 weeks, the regenerated cartilage gradually thicked; 12 week after transplantation, the defect was repaired and the structures of the carticular surface and subchondral bone was in integrity.The defects in Group A were repaired by the hylinelike tissue and the defects in Groups B and C were repaired by the fibrous tissues. Glycosaminoglycan and type Ⅱcollagen in Groups A,B and C were reduced gradually.The statistical analysis on the gross at 12 weeks and the histologicalgradings at 4 weeks,8 weeks and 12 weeks showed that the inboardcondylar repairhad no significant difference compared with the rochlearepair(Pgt;0.05).Management A was significantly better than Managements B and C (Plt;0.05), and Management B was better than Management C(Plt;0.05). Conclusion Transplantation of the MSCs combined with MCMG on the full thickness defects of the articular cartilage is a promising approach to the the treatment of cartilage defects. MCMG can satisfy the demands of the scaffold for the tissue-engineered cartilage.
Objective To fabricate a novel gelatinchondroitin sulfate-sodium hyaluronate tri-copolymer scaffold and to confirm the feasibility of serving as ascaffold for cartilage tissue engineering. Methods Different scaffolds was prepared with gelatin-chondroitin sulfatesodium hyaluronate tri-copolymer by varying the freezing temperatures (-20℃,-80℃ and liquid nitrogen). Pore size, porosity, inter pores and density were observed with light microscopy and scanning electron microscopy (SEM). The load-stiffness curves were compared between different scaffolds and normal cartilage. The number of MSCs attaching to different scaffolds and the function of cells were also detected with MTT colorimetric microassay. Results The pore size was 300±45, 230±30 and 45±10 μm; the porosity was 81%, 79% and 56%; the density was 9.41±0.25, 11.50±0.36 and 29.50±0.61 μg/mm3 respectively in different scaffolds fabricated at -20℃,-80℃ and liquid nitrogen; the latter two scaffolds had nearly the same mechanical property with normal cartilage; the cell adhesion rates were 85.0%, 87.5% and 56.3% respectively in different scaffolds and the scaffolds can mildly promote the proliferation of MSCs. Conclusion Gelatin-chondroitin sulfatesodium hyaluronate tricopolymer scaffold fabricated at -80℃ had proper pore size, porosity and mechanical property. It is a novel potential scaffold for cartilage tissue engineering.
Objective To explore the method that can inducethe mesenchymal stem cells (MSCs) to differentiate into the neuronlike cells in vitro．Methods The neuron-like cells were isolated froman SD rat (age, 3 months; weight, 200 g). They underwent a primary culture; theinduced liquid supernatant was collected, and was identified by the cell immunohistochemistry. The C3H1OT1/2 cells were cultured, as an MSCs model, and they were induced into differentiation by β-mercaptoethanol (Group A) and by the liquid supernatant of the neuron-like primary cells (Group B), respectively. The cells were cultured without any induction were used as a control (Group C). Immunohistochemistrywas used to identify the type of the cells． Results The result of the immunochemistry showed that the cells undergoing the primary culture expressed the neurofilament protein (NF) and the neuronspecific enolase (NSE), and they were neuron-like cells. β-mercaptoethanol could induce the C3H1OT1/2 cells toexpress NF and NSE at 2 h, and the expression intensity increased at 5 h. The liquid supernatant of the primarily-cultured neuron-like cells could induce theC3H1OT1/2 cells to express NF and NSE at 1 d, but the expression intensity induced by the liquid supernatant was weaker than that induced by β-mercaptoethanol. The positivity rate and the intensity expression of NSE were higher than those of NF. Conclusion MSCs can differentiate into the neuron-like cells by β-mercaptoethanol and the microenvironment humoral factor, which can pave the way for a further study of the differentiation of MSCs and the effectof the differentiation on the brain trauma repair.
ObjectiveTo investigate the effectiveness of human placental decidua basalis derived mesenchymal stem cells (PDB-MSCs) in repairing full-thickness skin defect of nude mice. MethodsHuman placenta samples were obtained from healthy donor mothers with written informed consent. PDB-MSCs were isolated through enzymic digestion and density gradient centrifugation; the 4th passage cells were identified by cellular morphology, cell adipogenic and osteogenic differentiation, and phenotype evaluation. Forty-two 4-5-week-old BALB/c female nude mice were randomly divided into experimental group (n=21) and control group (n=21). The 4th passage PDB-MSCs solution (200 μL, 5×106/mL) was injected into the mice of experimental group via caudal vein; the mice of control group were given equal volume of PBS. The full-thickness skin defect model of 1.5 cm×1.5 cm in size was made after 3 days. The wound healing was observed generally at 1, 2, 4, 7, 14, 18, 21, 25, and 30 days after operation, and the wound healing rate was calculated after wound decrustation. HE staining was used to observe the wound repair at 1, 7, 14, 21, and 31 days; immunofluorescent staining was used for cellular localization at 7, 14, and 31 days after operation. ResultsCells isolated from human placenta were MSCs which had multipotential differentiation ability and expressed MSCs phenotype. Animals survived to the end of the experiment. The general observation showed that the experimental group had a faster skin repairing speed than the control group; the time for decrustation was 12-14 days in experimental group and was 14-17 days after operation in the control group. The wound healing rate of experimental group was significantly higher than that of control group at 14, 18, and 21 days (t=4.001, P=0.016; t=3.380, P=0.028; t=3.888, P=0.018), but no significance was found at 25 and 30 days (t=1.565, P=0.193; t=1.000, P=0.423). HE staining showed lower inflammatory reaction, and better regeneration of the whole skin and glands with time in the experimental group. The immunofluorescent staining was positive in skin defect area of experimental group at different time points which displayed that human PDB-MSCs existed. ConclusionThrough enzymic digestion and density gradient centrifugation, PDB-MSCs can be obtained. Pre-stored PDB-MSCs can mobilize to the defect area and participate in repair of nude mice skin.
ObjectiveTo summarize the research situation of mesenchymal stem cells (MSCs) senescence, including the characteristics and mechanisms of senescence. MethodsThe original articles in recent years about MSCs senescence were extensively reviewed, and comprehensively analyzed. ResultsThe senescence of MSCs which manifests as morphological senescence, reduced proliferation and differentiation potential, altered immunoregulation are found during the cultivation in experiment, which profoundly affects clinical application of MSCs. The research about the mechanisms of MSCs senescence includes telomere and telomerase, and stress-mediated injury etc, involving regulation of telomerase, and regulation of signal pathways of p53/p21, P13K/Akt, and Wnt/β-catenin etc. ConclusionThe further study of senescence mechanisms will help to accelerate the clinical application of MSCs in the future.
ObjectiveTo review the mechanisms of bioactive substances of mesenchymal stem cells-derived exosomes (MEX) in tissue repair and analyze the therapeutic values of MEX. MethodRecent relevant literature about MEX for tissue repair was extensively reviewed and analyzed. ResultsThe diameter of exosomes ranges from 30 to 100 nm which contain an abundance of bioactive substances, such as mRNA, microRNA, and protein. The majority of the exact bioactive substances in MEX, which are therapeutically beneficial to a wide range of diseases, are still unclear. ConclusionsBioactive substances contained in the MEX have repairing effect in tissue injury, which could provide a new insight for the clinical treatment of tissue damage. However, further studies are required to investigate the individual differences of MEX and the possible risk of accelerating cancer progression of MEX.
Objective To explore the migration and differentiation of bone marrow mesenchymal stem cells（MSCs） in lung . Methods MSCs were harvested from a male Wister rat. Sixty female Wister rats were randomly divided into four groups. The pulmonary fibrosis model was established by intratracheal instillation of bleomycin in group A-D. Immediately and 7 days after bleomycin administration respectively，the rats in group B and C received infusion with 5-bromodeoxynridine （BrdU） labeled MSCs via tail vein. And the rats in group D were infused MSCs without BrdU labeling serving as a negative control. The sry gene of Y chromosome was detected by polymerase chain reaction （PCR）. Double immunofluorescence staining was used to detected BrdU and surfactant associated protein-C （SP-C） expression in lung tissue，fresh bone marrow，and the 5th generation MSCs. Reverse transcriptipon-PCR was used to detect the expressions of SP-C mRNA and AQP-5 mRNA. Results The sry gene was detected in bleomycin induced lung injury tissues of the rats after MSCs infusion immediately and on the 7th day The MSCs in lung tissue could transformed into cells with ACEⅡ morphological features and molecular phenotype. The transformation rate was higher in the rats received MSCs infusion immediately than the rats received on 7th day. The 5th generation MSCs and fresh bone marrow expressed SP-C mRNA，without AQP-5 mRNA and SP-C expression. Conclusions Exogenous MSCs can be transplanted into injured lung tissues and transform into AECⅡ，especially in early stage of lung injury. The differentiation potential of MSCs can be activated in injury micro-environment.