Search

BACKGROUND: At present, human placental mesenchymal stem cells are rarely used in bone tissue engineering research, and the use of human placental mesenchymal stem cells in the treatment of osteoporotic fractures is likely to open new horizons for their therapeutic methods. OBJECTIVE: To investigate the mechanism of human placenta-derived mesenchymal stem cells in the treatment of tree shrews with osteoporotic fracture, and the effect of different drug delivery methods on the efficacy of tree shrews with osteoporotic fracture. METHODS: Bilateral ovaries and uterus were removed from female tree shrews to simulate postmenopausal osteoporosis, and they were naturally fed for 180 days. The osteoporotic fracture tree shrew model was established by performing a right femoral fracture. The 24 tree shrews with osteoporotic fracture were randomly divided into four groups. We adjusted the concentration of the human placenta-derived mesenchymal stem cells to 1×109 L-1. In the tail vein injection group, human placenta-derived mesenchymal stem cells were injected with 1 mL in the tail vein. In the tail vein combined with fracture injection group, human placenta-derived mesenchymal stem cells were injected with 0.5 mL in the tail vein and 0.5 mL at the fracture site. In the tail vein combined with intraperitoneal injection group, human placenta-derived mesenchymal stem cells were injected with 0.5 mL in the enterocoelia and 0.5 mL in the tail vein. In the model group, 1 mL physiological saline was injected through tail vein. From the 3rd day after the fracture, tree shrews were injected once a week and three times in a row. Eight weeks after the last treatment, bone mineral density was tested in tree shrews of each group. Three-point bone biomechanics and hematoxylin-eosin staining experiments were performed on the femurs of tree shrews in each group. The expression levels of osteocalcin, estrogen, bone alkaline phosphatase and tartrate resistant acid phosphatase were measured by ELISA in all groups. The mRNA expression levels of bone morphogenetic protein-2, osteoprotegerin and receptor activator of nuclear factor-κB ligand were measured by quantitative real time polymerase chain reaction. RESULTS AND CONCLUSION: (1) Eight weeks after the last treatment, compared with the model group, the other three groups showed increased bone mineral density, maximum load, structural stiffness and energy absorption, with tail vein injection group showed the most significant increase. (2) Serum estrogen, bone alkaline phosphatase and osteocalcin expression levels in tail vein injection group, tail vein combined with fracture injection group, and tail vein combined with intraperitoneal injection group increased significantly compared with the model group. Serum tartrate resistant acid phosphatase levels decreased significantly in the tail vein injection group, tail vein combined with fracture injection group, and tail vein combined with intraperitoneal injection group compared with the model group. These serum detection results showed the most obvious improvement in tail vein injection group. (3) Hematoxylineosin staining showed significant improvement of pathological changes in tail vein injection group and tail vein combined with fracture injection group. (4) The expression level of osteoprotegerin and bone morphogenetic protein-2 mRNA in tail vein injection group, tail vein combined with fracture injection group, and tail vein combined with intraperitoneal injection group increased to varying degrees compared with model group; the tail vein combined with fracture injection group had the highest level. (5) The expression level of receptor activator of nuclear factor-κB ligand mRNA in tail vein injection group, tail vein combined with fracture injection group, and tail vein combined with intraperitoneal injection group decreased to different degrees compared with model group, with tail vein combined with fracture injection group having the lowest level. (6) It is concluded that human placenta-derived mesenchymal stem cell transplantation can effectively improve the symptom of tree shrews with osteoporotic fracture, increase bone formation indexes such as bone alkaline phosphatase, osteocalcin and osteoprotegerin, decrease bone resorption indexes such as tartrate resistant acid phosphatase and receptor activator of nuclear factor-κB ligand, and improve bone mineral density and bone biomechanics of tree shrews. Tail vein injection group had the best results for systemic treatment and tail vein combined with fracture injection group showed better results for treatment at the fracture site. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fibroblast-like synoviocytes play an important role in the pathological process of rheumatoid arthritis. When inflammatory arthritis occurs, fibroblast-like synoviocytes in the synovial lining layer will proliferate in large quantities, and the release of inflammatory factors during this period can cause joint inflammation and cartilage damage. OBJECTIVE: To establish methods for isolation, culture, purification, and identification of tree shrew knee joint fibroblast-like synoviocytes in vitro, and explore their biological characteristics; to establish methods for detection of TLR8 pathway related molecules in fibroblast-like synoviocytes from tree shrews, and preliminarily explore the activation of TLR8 pathway in the cells. METHODS: Fibroblast-like synoviocytes from tree shrews were isolated and purified using tissue block method and continuous passage method. Cell proliferation was detected using cell counting kit-8. Cell morphology was observed using hematoxylin-eosin staining. Immunocytochemical staining was used to detect the expression of vimentin in synoviocytes. Before and after stimulation with human TLR8 ligand R848, the expression of TLR8 and its signaling pathway proteins in tree shrew fibroblast-like synoviocytes and human fibroblast-like synoviocytes was detected using western blot assay, while the expression of TLR8 pathway and its downstream mRNAs in tree shrew fibroblast-like synoviocytes were detected using RT-PCR. RESULTS AND CONCLUSION: Under an inverted microscope, tree shrew fibroblast-like synoviocytes after 3 generations of subculture were mostly spindleshaped cells with similar size, high purity, good growth and proliferation in vitro. Hematoxylin-eosin staining revealed that the cells were mostly spindle-shaped, similar in size. Immunocytochemical staining results showed that Vimentin positively expressed in fibroblast-like synoviocytes. Cell counting kit-8 testing results showed an “S”-shaped growth curve of tree shrew fibroblast-like synoviocytes. Western blot results revealed that at 48 hours after R848 stimulation, the expression level of nuclear factor-κB protein significantly increased (P < 0.05), the expression level of p-P38 protein decreased (P < 0.05), and there was no change in the expression of TLR8, MyD88, P38, p-Erk1/2, and RANKL proteins (in tree shrew fibroblast-like synoviocytes (P > 0.05). After R848 stimulation, the expression of p-P38 in human fibroblast-like synoviocytes also significantly decreased, and no changes were found in the expression of TLR8, MyD88, P38, p-Erk1/2, and RANKL proteins (P > 0.05). Findings from RT-PCR and agarose gel electrophoresis detection showed that the mRNA expression of tumor necrosis factor ɑ, interleukin 6, interferon β, TLR9-2, TLR9-1, TLR8-2, TLR8-1, TLR7-2, and TLR7-1 mRNA expression had no significant change after 48 hours of stimulation with R848 (P > 0.05). To conclude, the tissue block adherence method can be used to isolate tree shrew fibroblast-like synoviocytes, and TLR8 pathway-related molecular detection method for tree shrew fibroblast-like synoviocytes is successfully established. [ABSTRACT FROM AUTHOR]

BACKGROUND: The research on the prevention and treatment of war trauma has always been the core content in the field of military medicine. It is of great military and scientific significance to establish repeatable animal models of war traumatic infection, systemic inflammatory response syndrome, shock, multiple organ failure and new treatment methods based on the animal model. OBJECTIVE: To investigate the efficacy of umbilical cord mesenchymal stem cells in the treatment of traumatic systemic inflammatory response syndrome. METHODS: Totally 40 out of 50 tree shrews were used to establish the model of traumatic systemic inflammatory response syndrome by intravenous injection of lipopolysaccharide after unilateral femoral comminuted fracture using the impact method. The other 10 tree shrews were used as normal controls. After the model was established for 10 days, umbilical cord mesenchymal stem cells labeled with GFP were transfused through tail vein of 20 tree shrews, and 18 were not reinfused as model control group. The distribution of GFP-labeled cells in vivo was measured in each group at 2 and 10 days after GFP-labeled UCMSCs injection. At 20 days after cell transplantation, samples were taken to observe the pathological changes of each tissue, and peripheral venous blood samples were taken to examine the changes in liver function, renal function and heart function. RESULTS AND CONCLUSION: (1) GFP-positive cell distribution was observed in all tissues at 2 and 10 days after cell transplantation. The distribution of GFPpositive cells in pancreatic tissue was more obvious at 2 days after transplantation, and more GFP-positive cells were found in liver tissue 10 days after transplantation. (2) At 20 days after transplantation, hematoxylin eosin staining results showed that cell necrosis and inflammatory cell infiltration were observed in each organ of the model control group, and the treatment group was close to the normal control group. The results of liver function, renal function and heart function in the treatment group returned to normal. (3) These results indicate that umbilical cord mesenchymal stem cells have a certain effect on the treatment of traumatic systemic inflammatory response syndrome, and this method provides a new technical solution for treatment of modern weapon trauma. [ABSTRACT FROM AUTHOR]

BACKGROUND: Current treatments for metabolic syndrome are comprehensive treatments with drugs, aiming to improve patient’s life. Patients are required to have a high compliance to follow-up and have developed various adverse reactions. Therefore, there is no treatment to fundamentally delay the development of metabolic syndrome. OBJECTIVE: To establish a tree shrew model of metabolic syndrome and evaluation techniques, and to explore the therapeutic effect of umbilical cord mesenchymal stem cells in the tree shrew model, providing theoretical basis and reference method for clinical application of stem cell transplantation in metabolic syndromes. METHODS: Umbilical cord mesenchymal stem cells of tree shrews were obtained by adherent culture method, and met the biological characteristics of umbilical cord mesenchymal stem cells. The dark red fluorescent iodide DIR was used to label tree umbilical cord mesenchymal stem cells. Thirty-two tree shrews were fed high-sugar, high-cholesterol, high-salt diet and syrup diet, and injected streptozotocin to make metabolic syndrome models. Animal models were randomly divided into model control group (n=10) and cell treatment group (n=22). In the cell treatment group, the umbilical cord mesenchymal stem cells labeled in vitro were injected into the tail vein, and the model group was injected an equal volume of physiological saline in the meanwhile. Blood biochemical indicators, glucose tolerance, insulin resistance index and arterial blood pressure were measured after transplantation. RESULTS AND CONCLUSION: The tree shrew model of metabolic syndrome was successfully constructed, showing obvious insulin resistance, hyperglycemia, lipid metabolism disorder, and hypertension, which met the diagnostic criteria of metabolic syndrome. Umbilical cord mesenchymal stem cells transplantation could significantly reduce the blood glucose and blood lipid levels, improve insulin resistance and regulate insulin secretion in the tree shrew model of metabolic syndrome. Transplanted umbilical cord mesenchymal stem cells could be homing to the liver, kidney and pancreas of the tree shrew model of metabolic syndrome, and produce certain repairing effects. [ABSTRACT FROM AUTHOR]