BACKGROUND: Bone marrow mesenchymal stem cells (BMMSCs) can be induced differentiating into osteoblasts and chondroblasts, DNA methylate depressant 5-azacytidine can induce BMMSCs expressing myogenic regulating factors: Myf5 and myopoietin, which involving in the differentiation of BMMSCs into myoblasts.OBJECTIVE: Muscular traumatic fluid containing the highest protein content was screened out and co-cultured with BMMSCs,in order to explore the inductive effect on the proliferation and myogeneis of BMMSCs.DESIGN : Standardized comparative study.SETTING .:At State Key Laboratory of Trauma, Bums and Combined Injury,Institute of Combined Injury, Medical College of Preventive Medicine, Third Military Medical University of Chinese PLA.MATERIALS: Muscular traumatic model was established on 18 Balb/C pure rats for the extraction of muscular traumatic fluid, the inductive effect of the fluid on BMMSC was then compared with 5-azacytidine.METHODS:This study was carried out at State Key Laboratory of Trauma,Burns and Combined Injury, Institute of Combined Injury, College of Preventive Medicine, Third Military Medical University of Chinese PLA from April 2001 and September 2003. Bradford colorimetric was used to detect the protein content in the muscular traumatic fluid, and the fluid with the highest protein was used to co-culture with BMMSC, whose effect on the proliferation of BMMSC was measured with MTT methods at day 0, 3, 6, 9, 12, 15.RT-PCR technique was used to detect the expression of myopoietin at day 6,with its myogenic effect compared with that of 5-azacytidine.fluid on BMMSC.eration of BMMSC: the proloferative activity of BMMSC in traumatic fluid genic effect of traumatic fluid on BMMSC: myopoietin could not be found expressed in traumatic fluid group, but strongly expressed in 5-azacytidine group.CONCLUSION: Muscular traumatic fluid can promote the proliferation of BMMSC, but has no myogenic effect.

Objective Non-muscle myosin heavy chain 9 (MYH9) plays an important regulatory role in the development of tumor.This study aimed to explore the expression of MYH9 in osteosarcoma tissues and its effects on epithelial-mesenchymal transition and invasion of osteosarcoma cells.Methods We collected 52 cases of osteosarcoma tissues and para-carcinoma tissues at 5 cm form the edge of the tumor.RT-PCR and immunohistochemistry were used to analyze the expression level of MYH9 mRNA and protein in the osteosarcoma tissues and para-carcinoma tissues.MYH9 shRNA plasmid was transfected into U2-OS cells to silenced the expression of MYH9, after transfected, the cells were divided into three groups: the normal U2-OS cells were the control group, the U2-OS cells transfected with empty plasmid were the empty group and U2-OS cells transfected with MYH9 shRNA were interference group.RT-PCR was used to detect the changes of MYH9 mRNA levels in the U2-OS cells, the protein level of MYH9, EMT related protein E-cadherin and Vimentin were detected by Western blot, and the ability of cell invasion was evaluated by Transwell assay.Results The results of RT-PCR showed that the relative expression MYH9 mRNA in para-carcinoma tissues(1.526±0.148) was significantly lower than that in cancer tissues (3.547±0.195) (P<0.05).The results of immunohistochemistry showed that MYH9 protein was mainly expressed in cytoplasm, and the expression in cancer tissues was significantly higher than that in para-carcinoma tissues, the positive expression rate were 59.6%(31/52) and 26.9%(14/52) respectively, the difference was statistically significant(P<0.05).The results of Western blot showed that the relative expression of MYH9 mRNA in interference group was significantly lower than that in control group and empty group (P<0.05) after silenced MYH9 gene, and compared with the control group, the E-cadherin in U2-OS cells was significantly up-regulated but the Vimentin was down-regulated.After 48h, all of the groups had cells through the microfiltration membrane, the numbers of cells through the microfiltration membrane in interference group(41.2±15.1) was significantly lower than that in control group(117.3±12.4) and empty group(193.5±14.7) (P<0.05).Conclusion The expression of MYH9 protein in osteosarcoma tissues was significantly higher than that in para-carcinoma t tissues, silenced MYH9 gene can reduce the invasive ability of osteosarcoma by reducing the epithelial interstitial transition.

Objective To clone platelet-derived growth factor A chain (PDGF-A) gene and insert PDGF-A gene into. Enhanced green fluorescent protein (EGFP) vector and then transformed into dermis-drived mesenchymal stem cells (DMSCs). Methods cDNA clones encoding human PDGF-A gene were isolated from a human hepatoma cell line mRNA by reverse transcription-polymerase chain reaction (RT-PCR). The PCR amplified fragment of PDGF-A gene was cloned into pMD18-T vector. The eukaryotic expression vector pEGFP-N1/PDGF-A was constructed by subcolone PDGF-A gene into pEGFP-N1 vector. PDGF-A gene was transfected into DMSCs with the help of Fugene 6 transfection reagent. Results Full cDNA sequence encoding human PDGF-A gene had been cloned, which sequence was consistent with the reported sequence in GenBank by sequence assaying. Conclusion cDNA sequence encoding human PDGF-A gene was successfully cloned into pEGFP-N1. The transient expression of PDGF-A gene in DMSCs has been realized.

Objective To explore the protective effect of atorvastatin on irradiated endothelium and the thrombomodulin(TM)expression.Methods Cultured human coronary artery endothelial cells(HCAEC)and human umbilical vein endothelial cells(HUVEC)were treated by atorvastatin at the final concentration of 10 μmol/ml for 10 min,and then irradiated with 2 and 25 Gy.Cell cycles status and TM expression were quantitatively measured by flow cytometry 24 hours after irradiation.Protein C activation in endothelial cells was also assessod.Results After administration with atorvastatin for 24 h,the TM expression increased by 77%,59% and 61% in normal control group,2 Gy group and 25 Gy group,respectively(t=27.395,26.420,58.065;P=0.000).The protein C levels decreased by 23% and 34% compared with the normal group post-irradiation to 2 and 25 Gy,but increased by 79% and 76% compared with the irradiated control group after administration with atorvastatin.The rates of cell apoptosis decreased by 6% and 16% in 2 Gy and 25 Gy groups,respectively after administration with atorvastatin for 24 h(t=4.178,17.863;P=0.000).Conclusions Atorva statin can protect endothelia cell from irradiation-induced apeptosis by increasing TM expression and protein C activation.

BACKGROUND:Studies have shown that craniocerebral injury can promote the repair of sciatic nerve injury in rats, but its precise mechanism remains unclear.
OBJECTIVE:To further explore the action mechanism of craniocerebral injury on the repair of sciatic nerve injury using morphology and histology.
METHODS:Sixty specific-pathogen-free healthy male Sprague-Dawley rats were randomly divided into two groups. Rats with craniocerebral injury and sciatic nerve injury were considered as the experimental group. Rats with simple sciatic nerve injury were considered as the control group. Classical Feeney method was used in models of craniocerebral injury and SunderlandV sciatic nerve injury. At 8 and 12 weeks after modeling, sciatic nerve index was detected. Masson staining and NF200 immunofluorescence staining were used to observethe nerve regeneration atthe anstomotic site. Transmission electron microscope was used to observe the number of regenerative axons.
RESULTS AND CONCLUSION:At 8 and 12 weeks after modeling, compared with the control group, gait and sciatic nerve index recovered better in the experimental group. In the experimental group, Masson staining showed fewer nerve membrane colagen fibers, and the axon arranged neatly.NF200 immunohistochemistry showed that in the experimental group, the density of regenerated nerves was high, and nerveswere regularly distributed. Transmission electron microscopy showed that in the experimental group, regenerative axons were regularly arranged, colagen scar was less, and myelin layer arranged regularly. Results suggested that the craniocerebral injury in rats may promote the repair of peripheral nerve injury by reducing scar colagen in nerve endings.

BACKGROUND:Recovery of motor and sensory function from peripheral nerve injury is relatively slow and incomplete. It is a difficult problem for orthopedic surgeons that mainly leads to the decline in the quality of life in patients.
OBJECTIVE: To conclude the methods and corresponding outcomes in peripheral nerve regeneration by analyzing the new treatment means for peripheral nerve injury.
METHODS:PubMed, Wanfang, CNKI databases were retrieved for relevant articles using key words of “nerve injury, regeneration”, and then retrieval data were sorted and analyzed.
RESULTS AND CONCLUSION:In recent years, in-depth studies on peripheral nerve repair have been made in the folowing aspects: surgical mode, drug, cytokine, gene transfer and biomaterials as wel as traditional Chinese medicine. If the detect size is four times longer than the diameter of nerves, the nerve regeneration chamber can achieve good outcomes. The methods of restoring nerve continuity folowing nerve injury are developed from surgical anastomosis to photochemohistological method, thermal laser welding, plastic repair and other emerging technologies. Studies have found that plasminogen activator, nerve growth factor, neurotrophic factor, recombinant erythropoietin, human tissue kalikrein, B vitamins and their derivatives, herbal preparations, immunosuppressive agents al can promote nerve regeneration.

Objective To explore the activation of PI3k/Akt pathway of serum deprived IEC-6 cells by the serum of rats exposed to single radiation,burn or combined injury.Methods The IEC-6 cells were cultured in serum deprived media for 24 h,and stimulated by the serum of rats exposed to single radiation(~(60)Co ? ray at dose of 9 Gy),single burn(exposure to 5 kW tungsten-halogen light till whole body Ⅲ degree burn) or combined injury(burn first and radiation),and the cells stimulated by the serum from the normal rats and serum starved cells served as the control group.The total proteins of different group cells were extracted and the levels of phosphorylation of Akt were tested by Western blotting.The differentially expressed low mass proteins in the serums were detected by SELDI proteinchip technology,and primarily analyzed by related software as well as bioinformatic methods.Results The level of phosphorylation of Akt in the IEC-6 cells stimulated by serum from rats exposed to single radiation,single burn or combined injury was higher than in the cells stimulated by the serum from normal rats,in which the burn serum caused the highest level.As compared to burn rat serum,the serum of radiation and combined injury had 13 and 6 differentially expressed protein peaks respectively.Conclusion All the serums from rats exposed to different kinds of damage agents could activate the PI3K/Akt pathway of IEC-6 cells efficiently.The special components of burnt rat serum may contribute to the highest effect on the phosphorylation of Akt.

Objective To detect whether mice bone marrow mesenchymal stem cells(BMSCs)can contribute to the regeneration of hepatocytes in bone marrow chimeric mice.Methods Female recipient mice(C57BL/6J)underwent whole body gamma-ray irradiation with a dose of 10 Gy to ablate their bone marrow,followed by immediate tail vein injection of BMSCs isolated from male GFP transgenic mice.Animals were killed at different phase points:1 week,1 month,and 3 months.Using fluorescence microscope we directly observed GFP-positive cells in the liver frozen sections,and we also prepared the parafilm sections to detect the GFP-positive cells and the coexpression of GFP and Alb,CK18 by immunohistochemistry and immunofluorescence respectively.Results We found numerous GFP-positive cells in recipient mice liver at 1 week after BMSCs transplantation,some at 1 month and seldom at 3 months.There were some cells coexpressing GFP and Alb,CK18 at all the phase points.Conclusion Allotype BMSCs can differentiate into Alb and CK18 positive hepatocytes in bone marrow chimeric mice,which will become an ideal cell resource for liver tissue project.

BACKGROUND: Human amniotic membrane (HAM) contains various ingredents such as collagen, glycoprotein,proteoglycan, integrin and laminated body, and so on, and expresses many kinds of growth factors and mRNA-associated proteins. And these ingredents can supply abundant nutriments for cellular proliferation and differentiation, and benefit cells to grow and propagate. Whether or not HAM can load porcine bone marrow-derived mesenchymal stem cells (BMSCs) to well grow on it deserves to be further investigated.OBJECTIVE: To set up a method of tissue engineering of human amniotic membrane loading porcine BMSCs and observe the morphological characteristics of growth and proliferation of BMSCs seeded on HAM.DESIGN: Randomized controlled observation.SETTING: State Key Laboratory of Trauma, Burn and Combined Injury, General Institute of Combined Injuries, Academy of Preventive Medicine, Third Military Medical University of Chinese PLA.MATERIALS: This experiment was carried out in the State Key Laboratory of Trauma, Burn and Combined Injury,General Institute of Combined Injuries, Academy of Preventive Medicine, Third Military Medical University of Chinese PLA between January and November 2003. Three Guizhou minipigs of either gender, aged 2 to 3 months, weighing from 6 to 8 kg, were provided by the Experimental Animal Center, Third Military Medical University of Chinese PLA. Main reagent:ISCOVE'S modified DULBECCO'S medium (IMDM) culture medium (Hyclone, USA); high-quality fetal bovine serum PAA (Germany); haematoxylin (China); Eosin B (Sigma, USA) and OCT embedding medium (USA). Main instruments: BX51 stereoscopic fluorescence microscope (Olympus, JaPan); IX70 inverted fluorescence microscope (Olympus, Japan);cryostat (2700-Frigcut, Germany); myeloid puncture needle (Jiangsu); superclean bench (Sujing Bloc Antai Company);CO2 constant-temperature incubator (QUEUE, USA).METHODS: HAM was prepared as previously described. The BMSCs of Guizhou minipigs isolated and cultured according to method described previously were primarily cultured and passaged, then they were inoculated to the stromal surface of HAM at different densities (0.84×105 cells/cm2,1.54×105 cells/cm2,2.75×105 cells/cm2); The growth and proliferation of BMSCs of different densities were observed under an inverted microscope and scanning electron microscope; BMSCs of the second or the third passages were inoculated on HAM held with tissue-holding device at a density of 1.54×105 cells/cm2, and they were cultured for 18 days at most. The HAM was daily rolled, sliced and stained by HE for observing the growth of BMSCs loaded on HAM under the light, scanning and transmission electron microscopes.MAIN OUTCOME MEASURES: The growth of BMSCs on HAM was examined at different densities and different time points.RESULTS: ① Comparison of growths of BMSCs promoted by different densities of HAM: BMSCs,which were planted on HAM at the density of 0.84×105 cells/cm2 were irregular and scattered under an invert microscope. Distances between BMSCs were biggish. BMSCs seeded on HAM at the density of 1.54×105 cells/cm2 were regular in arrangement and moderate in density, with clear cell outline and good cell activity before 24 hours, and seeded at the density of 2.75×105 cells/cm2 were congested with many nonattached cells and the longer the growing time of the cells was, the more the cellular debris were observed. BMSCs,which were planted on HAM at the density of 0.84×105 cells/cm2 under the scanning electron microscope, scatted on HAM presented in shapes of irregular, long, thin and flat polygon. Their membrane protuberances presented in shapes of thick and thin, and the distances between cells were biggish. BMSCs,which were planted on HAM at the density of 1.54×105 cells/cm2 have similar appearance of their bodies and membrane protuberances, and the membrane protuberances were more compared with the BMSCs planted at the density of 0.84×105 cells/cm2. Their membrane protuberances intercrossed each other, and the margin of some BMSCs overlapped each other. BMSCs planted at the density of 2.75×105 cells/cm2, arraved on HAM crowdedly and overlappedly with many debris. Their membrane protuberances were not obviously. The margin of some BMSCs was overlapped.② Comparisonof growths of BMSCs promoted by HAM at different time points: Under the inverted microscope, the BMSCs adhered quickly to HAM after being incubated for about 30 minutes. All of BMSCs adhered to HAM within 24 hours, and formed monolayer on it within 48 hours, and grew densely on HAM after being cultured for 4 to18 days. Under the light and electron microscopes, HE results revealed that BMSCs adhered tightly and grew on HAM in different arrays, such as emitting, whirlpool or parallel,and their nuclei located in middle, dense in staining, were big and clear. The shapes of BMSCs were comparatively consistent on HAM. HAM loaded with BMSCs grew 4 days, and BMSCs covered HAM completely. The densities of BMSCs on HAM were suitable, and their bodies were large, and presented irregular, long,thin and flat polygon under the scanning electron microscope. The margin of some BMSCs overlapped each other. The protuberances of cellular membrane of BMSCs were abundant in the shapes of thick and thin. Some protuberances intercrossed each other in the shape of net. BMSCs adhered tightly to HAM through these protuberances. HAM loading BMSCs grow 4 days; most of BMSCs grew on HAM in double layers with the shapes of cambiform under the transmission electron microscope, Their nucleoli were clear. The protuberances of cellular membrane of BMSCs, which situated at two sides of nuclei and overlapped each other, were long. Most of chromatins of BMSCs were autosome.Abundant organell such as rough endoplasmic reticulum (RER),mitochondria could be observed in BMSCs.CONCLUSION:HAM is able to promote the proliferation of BMSCs significantly. BMSCs may be cultured on HAM ex vivo.HAM is a good carrier of BMSCs.

BACKGROUND: As a kind of semitransparent membrane, human amniotic membrance contains many kinds of nutrients, which is a good biological material loaded with keratinocytes.OBJECTIVE: To construct epidermal substitute of the skin from human amniotic membrane loaded with porcine keratinocytes and examine the morphological characteristics of the growth and proliferation of keratinocytes seeded on human amniotic membrane.DESIGN: Single sample study and repetitive measured observation based on the cells.SETTING: Institute of Combined Injuries of Chinese PLA, Academy of Preventive Medicine, Third Military Medical University of Chinese PLA.MATERIALS: The experiment was completed in the State Key Laboratory of Trauma, Burn and Combined Injury and Institute of Combined Injuries of Chinese PLA, Academy of Preventive Medicine, Third Military Medical University of Chinese PLA from January to November 2001. Porcine keratinocytes was collected from Guizhou minipigs aged 3 weeks.METHODS: The primarily cultured keratinocytes of Guizhou minipigs were subcuhured, expanded and bred on the stroma surface of human amniotic membrance at the density of 1.63 × 105/cm2. The growth and proliferation of keratinocytes were observed under inverted microscope every day. From the 3rd day and the 15th day after being cultured, the growth of keratinocytes on human amniotic membrane was examined under light microscope and electron microscope.MAIN OUTCOME MEASURES: The growth of keratinocytes on human amniotic membrane was examined RESULTS: Keratinocytes evidently adhered to the stroma surface of human amniotic membrane about 30 minutes after being cultured, which was observed under inverted microscope. Most keratinocytes grew and adhered to the stroma surface of human amniotic membrane within 24 hours. Monolayer of keratinocytes formed and completely covered human amniotic membrane within 3 days. It was observed under the light microscope that the monolayer of keratinocytes adhered to human amniotic membrane and arrayed tightly. The keratinocytes presented in the shape of polygon, and plasmalemmas of keratinocytes formed many pseudopods under the observation with scanning electron microscope. Keratinocytes adhered to human amniotic membrane well and with many keratinofilaments in them under the observation with transmission electron microscope. Keratinocytes arrayed on human amniotic membrane densely with many cellular debris and some keratinocytes formed cavitations in them due to aging after growth for 15 days under the observation with inverted microscope.CONCLUSION: Human amitotic membrane is a good carrier of keratinocytes cultured on it in vitro, and is able to promote the proliferation of keratinocytes significantly. However, when keratinocytes were loaded on the human amniotic membrane for 15 days, some keratinocytes formed cavitations in them due to aging.