ObjectiveTo determine the expression level of Sonic hedgehog (Shh) in the passage of hair follicle stem cells (HFSCs), analyze the effect of Shh overexpression on the proliferation activity of HFSCs, and explore the survival of HFSCs after Shh overexpression and its effect on hair follicle regeneration. MethodsHair follicles from the normal area (H1 group) and alopecia area (H2 group) of the scalp donated by 20 female alopecia patients aged 40-50 years old were taken, and the middle part of the hair follicle was cut under the microscope to culture, and the primary HFSCs were obtained and passaged; the positive markers (CD29, CD71) and negative marker (CD34) on the surface of the fourth generation HFSCs were identified by flow cytometry. The two groups of HFSCs were transfected with Shh-overexpressed lentivirus. Flow cytometry and cell counting kit 8 assay were used to detect the cell cycle changes and cell proliferation of HFSCs before and after transfection, respectively. Then the HFSCs transfected with Shh lentivirus were transplanted subcutaneously into the back of nude mice as the experimental group, and the same amount of saline was injected as the control group. At 5 weeks after cell transplantation, the expression of Shh protein in the back skin tissue of nude mice was detected by Western blot. HE staining and immunofluorescence staining were used to compare the number of hair follicles and the survival of HFSCs between groups. ResultsThe isolated and cultured cells were fusiform and firmly attached to the wall; flow cytometry showed that CD29 and CD71 were highly expressed on the surface of the cells, while CD34 was lowly expressed, suggesting that the cultured cells were HFSCs. The results of real-time fluorescence quantitative PCR and Western blot showed that the expression levels of Shh protein and gene in the 4th, 7th, and 10th passages of cells in H1 and H2 groups decreased gradually with the prolongation of culture time in vitro. After overexpression of Shh, the proliferation activity of HFSCs in the two groups was significantly higher than that in the blank group (not transfected with lentivirus) and the negative control group (transfected with negative control lentivirus), and the proliferation activity of HFSCs in H1 group was significantly higher than that in H2 group before and after transfection, showing significant differences (P<0.05). At 5 weeks after cell transplantation, Shh protein was stably expressed in the dorsal skin of each experimental group; the number of hair follicles and the expression levels of HFSCs markers (CD71, cytokeratin 15) in each experimental group were significantly higher than those in the control group, and the number of hair follicles and the expression levels of HFSCs markers in H1 group were significantly higher than those in H2 group, and the differences were significant (P<0.05). ConclusionLentivirus-mediated Shh can be successfully transfected into HFSCs, the proliferation activity of HFSCs significantly increase after overexpression of Shh, which can secrete and express Shh continuously and stably, and promote hair follicle regeneration by combining the advantages of stem cells and Shh.
Stargardt disease (STGD) is one of the most prevalent inherited macular dystrophy, and most often occurs in child or adolescence. Irreversible vision loss is observed in almost all cases. Type 1 (STGD1) is one of the most common type. It is an autosomal recessive condition, caused by mutations in the Abca4 gene. In recent years, encouraging progress has been made in the treatment of STGD1. C20-D3-retinyl acetate (ALK-001), fenretinide and ICR-14967 (A1120) as visual cycle modulators, StarGen as gene supplementation therapies, and the stem cell transplantation of human embryonic stem cell-derived retinal pigment epithelium cells are the most promising therapies. With the development of studies and clinical trials, the clinical application of various treatments of STGD1 are expected in the near feature, which are expected to save the vision of most patients.
Objective To observe the retinal apoptosis of laser-induced retinal injury in mice after bone marrow mesenchymal stem cells transplantation. Methods Green fluorescent protein (GFP) labeled MSCs from C57BL/6 mice were cultured in vitro. A total of 135 C57BL/6 mice were divided into three groups including normal control group (15 mice), injured control group (60 mice) and MSCs treatment group (60 mice). Laser retinal injuries were induced by laser photocoagulation. One day after photocoagulation, 02 ml cell suspension, which contained 1times;106 GFP-MSCs, were injected into the mice in treatment group via tail vein, and the mice in injured control group were given equal volume of phosphate buffer solution. Animal were execute on three, seven, 14 and 21 days following laser damage. Hematoxylin and eosin (HE) staining was performed to assess the changes of injured retinas. The diameters of laser spots and areas with total loss of cells in outer nuclear layer (ONL) were analyzed by image processing software. The apoptosis of retinal cells was examined by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) staining. The migration of GFP-MSCs into the retina was observed by fluorescence microscope. Results HE staining showed that the retinal structures were integrated in normal control group. Retinal damages were observed both in injured control group and MSCs treatment group, but milder in the latter. Though the average diameter of area with total loss of cells in ONL of MSCs treatment group was less than the injured control group (t=5.769, P＜0.05), the diameters of laser spots show no difference (t=0.964,P＞0.05) on day three. Both the average diameter of laser spots (t=5.180, 5.417, 2.381) and area with total loss of cells in ONL (t=3.530, 3.224, 3.162) were less in the MSCs treatment group on day seven, 14 and 21 (P＜0.05). TUNEL staining shows that the apoptosis were decreased after MSCs transplantation on day three, seven, 14 and 21 (t=11.142, 7.479, 6.678, 3.953,P＜0.05). No apoptosis was observed in normal control group. Very few GFP-MSCs were observed in the retina at all time-points. They were only seen in the subretinal and choroidal neovascularization occasionally on day seven and 14. Conclusion MSCs transplantation can effectively limit the range of retinal laser damage and inhibit cell apoptosis.
Objective To observe the effects of the bone marrow mesenchymal stem cells (BMSCs) on the expression of neurotrophic factor protein gene in the retinal detachment (RD) rabbits. Methods 60 healthy rabbits were randomly divided into control group (group A), retinal detachment with PBS group (group B), retinal detachment with BMSCs group (group C), 20 rabbits in each group. RD model were established for rabbits in group B and C. 10 μl PBS was injected into the subretinal space of rabbits in group B, while 10 μl CM-Dil labeled BMSC PBS was injected into subretinal space of rabbits in group C. The rabbits in the group A received no treatment. At 1, 2 and 4 weeks after modeling, the mRNA expression of basic fibroblast growth factor (bFGF), brain derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) were measured by real-time quantitative PCR. Results At 1, 2 and 4 weeks after modeling, the mRNA expression of bFGF, BDNF, CNTF on retinal tissue were increased significantly in group C as compared with group A and B (P < 0.01). At 1 week after modeling, the mRNA expression of bFGF and CNTF on retinal tissue were increased significantly in group B as compared with group A, the mRNA expression of BDNF on retinal tissue in group B was similar with group C. At 2 and 4 weeks after modeling, the mRNA expression of bFGF, BDNF, CNTF were decreased in group B as compared with group A. Conclusion Subretinal transplantation of BMSC can increase the mRNA expression of bFGF, BDNF and CNTF on retinal tissue in RD rabbits.
Objective To investigate the effect of M2 microglia (M2-MG) transplantation on spinal cord injury (SCI) repair in mice. Methods Primary MG were obtained from the cerebral cortex of 15 C57BL/6 mice born 2-3 days old by pancreatic enzyme digestion and identified by immunofluorescence staining of Iba1. Then the primary MG were co-cultured with interleukin 4 for 48 hours (experimental group) to induce into M2 phenotype and identified by immunofluorescence staining of Arginase 1 (Arg-1) and Iba1. The normal MG were harvested as control (control group). The dorsal root ganglion (DRG) of 5 C57BL/6 mice born 1 week old were co-cultured with M2-MG for 5 days to observe the axon length, the DRG alone was used as control. Forty-two 6-week-old female C57BL/6 mice were randomly divided into sham group (n=6), SCI group (n=18), and SCI+M2-MG group (n=18). In sham group, only the laminae of T10 level were removed; SCI group and SCI+M2-MG group underwent SCI modeling, and SCI+M2-MG group was simultaneously injected with M2-MG. The survival of mice in each group was observed after operation. At immediate (0), 3, 7, 14, 21, and 28 days after operation, the motor function of mice was evaluated by Basso Mouse Scale (BMS) score, and the gait was evaluated by footprint experiment at 28 days. The spinal cord tissue was taken after operation for immunofluorescence staining, in which glial fibrillary acidic protein (GFAP) staining at 7, 14, and 28 days was used to observe the injured area of the spinal cord, neuronal nuclei antigen staining at 28 days was used to observe the survival of neurons, and GFAP/C3 double staining at 7 and 14 days was used to observe the changes in the number of A1 astrocytes. Results The purity of MG in vitro reached 90%, and the most of the cells were polarized into M2 phenotype identified by Arg-1 immunofluorescence staining. M2-MG promoted the axon growth when co-cultured with DRGs in vitro (P<0.05). All groups of mice survived until the experiment was completed. The hind limb motor function of SCI group and SCI+M2-MG group gradually recovered over time. Among them, the SCI+M2-MG group had significantly higher BMS scores than the SCI group at 21 and 28 days (P<0.05), and the dragging gait significantly improved at 28 days, but it did not reach the level of the sham group. Immunofluorescence staining showed that compared with the SCI group, the SCI+M2-MG group had a smaller injury area at 7, 14, and 28 days, an increase in neuronal survival at 28 days, and a decrease in the number of A1 astrocytes at 7 and 14 days, with significant differences (P<0.05). ConclusionM2-MG transplantation improves the motor function of the hind limbs of SCI mice by promoting neuron survival and axon regeneration. This neuroprotective effect is related to the inhibition of A1 astrocytes polarization.
Objective To summarize the research progress of stem cell transplantation in treating spinal cord injury (SCI) at different stages based on the pathophysiological mechanism of SCI. Methods The relevant research literature at home and abroad was extensively reviewed to explore the impact of transplantation timing on the effectiveness of stem cell transplantation in treating SCI. Results Researchers performed different types of stem cell transplantation for subjects at different stages of SCI through different transplantation approaches. Clinical trials have proved the safety and feasibility of stem cell transplantation at acute, subacute, and chronic stages, which can alleviate inflammation at the injured site and restore the function of the damaged nerve cells. But the reliable clinical trials comparing the effectiveness of stem cell transplantation at different stages of SCI are still lacking. Conclusion Stem cell transplantation has a good prospect in treating SCI. In the future, the multi-center, large sample randomized controlled clinical trials are needed, with a focus on the long-term effectiveness of stem cell transplantation.
ObjectiveTo observe the effects of human umbilical cord mesenchymal stem cells (hUCMSCs) on blood glucose levels and diabetic retinopathy in diabetes mellitus (DM) rats. MethodA total of 45 healthy male Sprague-Dawley rats were randomly divided into normal control group (group A, 10 rats) and DM group (33 rats). Diabetic model was established in DM group by tail vein injection of streptozotocin.The DM group was further randomly divided into 3 groups (11 rats in each group), including group B (no transplantation), group C (hUCMSC was injected through tail vein) and group D (hUCMSC was injected into the vitreous). Blood glucose, retina wholemont staining and expression of brain derived neurotrophic factor (BDNF) in the retina were measured at 2, 4, 6, 8 weeks after hUCMSC injection. The blood glucose was significantly different between A-D groups before injection (t=-64.400, -60.601, -44.065, -43.872; P=0.000) BDNF expression was studied by real time fluorescence quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry staining. ResultsThe blood glucose was significantly different between A-D groups after hUCMSC injection (F=400.017, 404.410, 422.043, 344.109; P=0.000), and between group C and group B/D (t=4.447, 4.990; P < 0.01). Immuno-staining shown that BDNF was positive in ganglion cell layer (RGC) of group A, weak in group B while BDNF expression increased in group C/D. BDNF mRNA expression was significantly different between group B, C and D at 4, 6 and 8 weeks after hUCMSC injection (F=29.372, 188.492, 421.537; P=0.000), and between group B and C/D (t=66.781, 72.401, 63.880, 88.423, 75.120, 83.002; P < 0.01) by RT-PCR analysis. The BDNF mRNA expression was significantly different between C and D groups only at 8 weeks after hUCMSC injection (t=127.321, P=0.005). ConclusionsTail vein injection of hUCMSCs can significantly reduce the blood glucose levels of rats. Intravenous and intravitreal injection of hUCMSCs can increase the expression of BDNF.
ObjectiveTo investigate the effect of microencapsulated transgenic bone marrow mesenchymal stem cells (BMSCs) transplantation on early steroid induced osteonecrosis of femoral head (SONFH) in rabbits.MethodsAlginate poly-L-lysine-sodium alginate (APA) microencapsulated transgenic BMSCs with high expression of Foxc2 were prepared by high-voltage electrostatic method. Part of the cells were cultured in osteoblasts and observed by alizarin red staining at 2 and 3 weeks. Forty New Zealand white rabbits were used to prepare SONFH models by using hormone and endotoxin. Thirty two rabbits who were successful modeling were screened out by MRI and randomly divided into 4 groups (groups A, B, C and D, n=8); another 6 normal rabbits were taken as normal control (group E). The rabbits in group A did not receive any treatment; and in groups B, C, and D were injected with normal saline, allogeneic BMSCs, and APA microencapsulated transgenic BMSCs respectively after core decompression. At 6 and 12 weeks after operation, specimens of femoral head were taken for HE staining to observe bone ingrowth; the expressions of osteocalcin (OCN), peroxisome proliferative activated receptor γ 2 (PPARγ-2), and vascular endothelial growth factor (VEGF) proteins were observed by immunohistochemistry staining. At 12 weeks after operation, the bone microstructure was observed by transmission electron microscope, and the maximum compressive strength and average elastic modulus of cancellous bone and subchondral bone were measured by biomechanics.ResultsAfter 2 and 3 weeks of induction culture, alizarin red staining showed the formation of calcium nodules, and the number of calcium nodules increased at 3 weeks when compared with 2 weeks. The rabbits in each group survived until the experiment was completed. Compared with groups A, B, and C, the trabeculae of group D were more orderly, the empty bone lacunae were less, there were abundant functional organelles, and obvious osteogenesis was observed, and the necrotic area was completely repaired at 12 weeks. Immunohistochemical staining showed that, at 6 and 12 weeks after operation, the expressions of OCN and VEGF in groups A, B, and C were significantly lower than those in groups D and E, while those in groups B and C were significantly higher than those in group A, and in group E than in group D (P<0.05). The expression of PPARγ-2 was significantly higher in groups A, B, and C than in groups D and E, and in group A than in groups B and C, and in group D than in group E (P<0.05). At 12 weeks after operation, biomechanical test showed that the average elastic modulus and maximum compressive strength of cancellous bone and subchondral bone in groups D and E were significantly higher than those in groups A, B, and C (P<0.05); there was no significant difference between groups A, B, and C and between groups D and E (P>0.05).ConclusionIn vivo transplantation of microencapsulated transgenic BMSCs can repair early SONFH in rabbits.
Replacement therapy of stem cells transplantation represents a potential treatment for neural retinal diseases. Despite the encouraging results in laboratory, the clinical application of cells replacement therapy is still difficult because the limitation of seed cells, immunologic rejection, oncogenicity and ethical problems, etc. Recent breakthrough in somatic reprogramming provides a promising solution overcoming these obstacles. Further researches on virus free reprogramming will make the clinical application of stem cell replacement therapy possible.