ObjectiveTo study the possbility of using intranasal instillation of fine particulate matter (PM2.5) combined with inhalation of ozone (O3) to establish mouse model of combined pulmonary fibrosis and emphysema (CPFE), and to provide a reference for the establishment of CPFE model.MethodsMale C57/BL6 mice were divided randomly into phosphate buffer saline (PBS) intranasal instillation+air inhalation group, PBS intranasal instillation+O3 inhalation group and PM2.5 intranasal instillation+O3 inhalation group, with 8 mice in each group. The mice were intranasally instilled with PBS or PM2.5 suspension (7.8 mg/kg) followed by air or ozone inhalation 24 hours later, twice a week over 8 weeks. Lung function, bronchoalveolar lavage fluid (BALF) cell counts and classification were detected, the pathological changes of lung tissues in hematoxylin-eosin staining were observed, including inflammation scores and mean linear intercept (Lm). The thickness of collagen deposition in subepithelium was measured in lung tissues in Masson staining, and simultaneously hydroxyproline contents in lung tissues were determined.ResultsCompared to PBS instillation+air inhalation group, inspiratory capacity (IC), total lung capacity (TLC) and chord compliance (Cchord) were increased, FEV25 (the forced expiratory volume at 25 ms)/FVC (forced vital capacity) was decreased, total cell counts in BALF, Lm and lung inflammatory scores were increased, the thickness of the subepithelial collagen layer (SEc/Pbm) or hydroxyproline contents was not changed in PBS instillation +O3 inhalation group; IC was decreased, functional residual capacity (FRC) was increased, TLC was increased, Cchord was decreased, FEV25/FVC and FEV50 (the forced expiratory volume at 50 ms)/FVC were decreased, total cell counts in BALF, Lm, lung inflammatory scores, SEc/Pbm and hydroxyproline contents were increased in PM2.5 instillation+O3 inhalation group. Compared to PBS instillation+O3 inhalation group, IC was decreased, FRC was increased, Cchord was decreased, FEV25/FVC and FEV50/FVC were decreased, total cell counts in BALF, Lm, lung inflammatory scores, SEc/Pbm and hydroxyproline contents were increased in PM2.5 instillation +O3 inhalation group.ConclusionCPFE mouse model can be successfully established by PM2.5 intranasal instillation combined with ozone inhalation for consecutive 8 weeks.
Objective To investigate the effect of monocyte chemoattractant protein 1 (MCP-1) on the migration of the induced and differentiated mouse bone marrow mesenchymal stem cells (BMSCs) for raising the efficacy of intravenous transplantation of BMSCs. Methods The BMSCs were cultured with the method of differential adhesion and density gradient centrifugation of C57/BL10 mice, and were identified by alkal ine phosphatase Gomori modified staining after osteogenic inducing. At the 3rd passage, the BMSCs were induced to the myoblasts with 5-azacytidine (5-Aza). The chemotaxis of MCP-1 in the induced and differentiated BMSCs in vitro at concentrations of 25, 50, 100, 200, and 400 ng/mL was observed through the migration test, by counting the number of the migrated cells. The expression of the chemokine receptor 2 (CKR-2) in the induced and differentiated BMSCs was detected with the flow cytometry. Results The cells could be cultured with the methods of differential adhesion and density gradient centrifugation and still had higher prol iferative and differentiative potency; the induced cells at the 3rd passage could differenciate to the osteoblasts, confirming that the cells were BMSCs; the myogenic induced BMSCs possesed the sarcotubule structure. The number of the migrating BMSCs at MCP-1 concentrations of 25-400 ng/ mL were respectively 35.066 7 ± 6.584 2, 43.200 0 ± 6.460 8, 44.466 7 ± 4.823 5, 45.600 0 ± 8.650 3, and 50.733 3 ± 7.582 5; showing significant difference when compared with control group (28.333 3 ± 8.917 6, P lt; 0.05), and presenting significant difference among 25, 50, 400 ng/mL groups compared with each other (P lt; 0.05). The expression of CKR-2 in the mouse BMSCs (48.0%) was significantly higher (P lt; 0.001) than those of blank control (0.6%) and negative control (17.0%). Conclusion The results indicate that the MCP-1 can induce the migration of mouse BMSCs by MCP-1/CKR-2 pathway.
Objective To investigate the effect of NGF on fracture heal ing, and to study the role of BMP-2 induced osteoblast. Methods Sixty cleaned male Kunming mice (aging 6-8 weeks and weighing 23-25 g) were made fracture models in the middle of femoral shaft and randomly divided into four groups (groups A, B, C and D, n=15). Fracture was treated with NGF/ normal sal ine, BMP-2, BMP-2 /NGF/normal sal ine, and normal sal ine in groups A, B, C and D, respectively. After 14, 21 and 28 days, the specimens were selected from 5 mice each group to do the biochemical and histological analysis. Beforethe mice were killed, the arteriovenous blood was taken from their eye-ball to test the ALP activity. Results After 14 days,21 days and 28 days, the gross observation showed that the size and hardness of bone tissue, and callus tissue growth increased in groups A, B and C order and were higher than those in group D; the X-ray films showed that the calcified area increased in groups A, B and C order and were higher than those in group D; the histological observation showed that the trabecular maturity increased in groups A, B and C order and were higher than those in group D. The osteoblast area, the gray degree value of the radiographs in callus tissue, the ALP contents of serum and callus tissue, calcium content of callus tissue and net weight of callus were higher in groups A, B and C than in group D. There were significant differences (P lt; 0.05) in osteoblast area and gray degree values of the radiographs at 14, 21 and 28 days; in ALP contents of serum at 14 days; in ALP contents of callus tissue at 14 days and 21 days; in calcium content of callus tissue at 21 days and 28 days among 4 groups. There were significant differences in net weight of callus between groups B, C and groups A, D at 14 days (P lt; 0.05). At 21 days and 28 days, the trabecular surface index of osteoblast, the average trabecular volume and the mean trabecular width decreased as time went on, having an increase order of groups A, B, C and was higher in groups A, B, C than in group D, showing significant differences among 4 groups (P lt; 0.05). Conclusion NGF promotes the heal ing of fractures. NGF possesses synergistic effect on ectopic bone formation induced by BMP-2.
Objective To investigate the gene expression of beta-defensin-4 (mBD-4) and mBD-6 in acute lung injury (ALI) mouse.Methods Sixty adult mice were randomly divided into a control group and a ALI group.ALI was induced by intraperitoneal injection of lipopolysaccharide (LPS) in the ALI group.The control group was treated with same dose of normal saline.The lung tissues were harvested at different time point after stimulation.The expression of mBD-4 and mBD-6 mRNA was measured by real-time quantitative reverse transcription polymerase chain reaction.DNA sequencing was used to confirm the specificity of mBD-4 and mBD-6 cDNA fragment.Results There were no obvious mBD-4 and mBD-6 mRNA expression in mouse lung in the control group at all time points and ALI 6 h group.In the ALI group a marked increasing expression was found on 12 h，1 d and 3 d after LPS stimulation.The mBD-4 mRNA expression was significant higher in the ALI groups of 1 d and 3 d points than that of ALI 12 h group with no obvious difference between each other.There were no significant differences of mBD-6 mRNA expression between ALI groups of 12 h，1 d and 3 d points Conclusion mBD-4 and mBD-6 mRNA is not constitutive expressed in mouse lung and show a up-regulative expression pattern after ALI.
Objective Aseptic loosening of prosthesis is associated with peri prosthetical osteolysis caused by osteoclast activation. Receptor activator of nuclear factor kappa B (NF-κB) l igand (RANKL)/receptor activator of NF-κB (RANK) signalpathway is fundamental in osteoclast activation. To determine whether RANKL antibody can inhibit inflammatory osteolysis in a osteolysis model of mouse. Methods Sixty female BALB/c mice (aged 8-10 weeks, weighing 18-20 g) were selected. The skull bone piece was harvested from 20 mice as the donor of bone graft; the subcutaneous air pouches (2 cm × 2 cm) models were established on the back of the other 40 mice and the skull bone piece was inserted into the air pouches. The 40 mice were equally divided into groups A (negative control group), B (positive control group), C (low-dose RANKL antibody group), and D (high-dose RANKL antibody group). At 1 day after bone graft, 0.5 mL PBS was injected into the pouch of group A, 0.5 mL PBS containing titanium particle into groups B, C, and D. At 2 days before the titanium particle was injected, RANKL antibody (0.1 mL) were injected into the pouch of group C (50 μg/mL) and group D (500 μg/mL), respectively every day for 2 days, and 0.1 mL PBS into groups A and B. At 14 days after bone implantation, the pouchmembranes containing implanted bone were harvested for gross observation and histological analyse. Results All mice survived to the end of experiment, and incisions healed well. The gross observation showed that inflammatory responses, exudation, and vascular proliferation were obvious in group B, and were inconspicuous in groups A, C, and D. The histological analysis showed that significantly more infiltration of inflammatory cells, more obvious bone resorption, more bone collagen loss, and more positive staining area were observed in group B than in groups A, C, and D. There were significant differences in inflammatory cell number, pouch membrane thickness, bone collagen loss, and osteoclast content between group B and groups A, C, and D (P lt; 0.05). Conclusion RANKL antibody can directly blockRANKL/RANK signal pathway, which is an efficient therapy to inhibit bone absorption associated with implant wearing particles.
Objective To observe the expressions of CXC chemokine receptor 4 (CXCR4) in muscle satell ite cells in situ of normal and cardiotoxin-intoxicated muscle tissues so as to further investigate the molecular mechanism involving inmuscle regeneration such as progressing muscular dystrophy (PMD) for seeking the way to cure muscle retrogression. Methods The muscle injured model of 12 C57 male mice was made by injecting cardiotoxin (5 μg per mouse) in left quadriceps femoris, their right quadriceps femoris was used as control without any injection. The histological, immunohistochemical analysis and RT-PCR were done to investigate the expression of CXCR4 in the quadriceps femoris in situ after 1 day, 4 days, 1 week, 2 weeks, 4 weeks and 6 weeks. Results HE staining results demonstrated that the muscle tissues experienced the process from muscle injury, repair to regeneration. The result of immunohistochemistry showed that the expressions of CXCR4 in injured muscle tissue were 1 955.6 ± 150.3, 2 223.2 ± 264.3, 2 317.6 ± 178.7, 3 066.5 ± 269.6, 1 770.9 ± 98.7 and 1 505.7 ± 107.1 at 1 day, 4 days, 1 week, 2 weeks, 4 weeks and 6 weeks after injection of cardiotoxin, there was significant difference when compared with normal muscle (640.3 ± 124.0, P lt; 0.001). The RT-PCR showed that the expressions of CXCR4 mRNA in injured muscle tissue were0.822 ± 0.013, 0.882 ± 0.025, 1.025 ± 0.028, 1.065 ± 0.041, 0.837 ± 0.011 and 0.777 ± 0.015 at 1 day, 4 days, 1 week, 2 weeks, 4 weeks and 6 weeks after injection of cardiotoxin, there was significant difference when compared with normal muscle (0.349 ± 0.006, P lt; 0.001). Conclusion CXCR4 may be the critical protein in the process of muscle impairment and reparation.
Objective To investigate the expression of micro-dystrophin gene in myoblast cultured in vitro, to explore the possibil ity of combining myoblast transplantation with gene transfer for Duchenne muscular dystrophy therapy. Methods Competent Escherichia coli JM109 was prepared, which transformed with plasmid pSL139, and positive clones were picked to cultivate. Plasmid was extracted with Alkal ine lysis method and cutted with both Pvu I and Cla I enzyme. Agarose gel electrophoresis was employed to take pictures. Ten healthy 5-7 days old male C57/BL10 mice were selected, weighing4-5 g, the primary and subcultured myoblasts were cultured with multi-step enzymatic digestion and differential adhesionmethod, and Desmin immunofluorescent method was used to identfy. The 3rd generation myoblasts that were transfected with plasmid pSL139 mediated by l iposome served as the experimental group, untransfected cells served as the control group. After 48 hours of transfection, the expressions of micro-dystrophin mRNA and protein in myoblasts were detected with RTPCR and cell immunofluorescent methods, and the transfection efficiency was caculated. Results After pSL139 plasmids being digested and for 40 minutes agarose gel of electrophoresis, 3.75 kb fragment of target gene and vector were observed. The cells were almost uniform, and triangular or diamond shape after 24-48 hours of culture; the cells turned to fusion manner and could be passaged after 4-6 days. Desmin immunofluorescent result showed that green fluorescence was seen in cytoplasm of most 2nd myoblasts, and the purity of the myoblasts was above 90%. At 48 hours after transfection of myoblasts with plasmid pSL139, RT- PCR results showed that about 300 bp fragment was seen in the experimental group and the control group, and the brightness was higher in experimental group. Immunofluorescent staining displayed that green fluorescence was seen in the cytoplasm of the myoblasts in the experimental group and no green fluorescence in the control group; the expression efficiency of positive cells for micro-dystrophin was 45%-55% in experimental group. Conclusion Micro-dystrophin gene can highly express at the levels of mRNA and protein respectively in myoblasts transfected with plasmid pSL139 mediated by l iposome.
ObjectiveTo compare the effects on the osteogenesis of bone marrow mesenchymal stem cells (BMSCs) between hypoxia and hypoxia mimetic agents dimethyloxalylglycine (DMOG) under normal oxygen condition. MethodsBMSCs were isolated and cultured from healthy 3-4 weeks old Kunming mouse. Cell phenotype of CD29, CD44, CD90, and CD34 was assayed with flow cytometry; after osteogenic, adipogenic, and chondrogenic induction, alizarin red staining, oil red O staining, and toluidine blue staining were performed. The passage 3 BMSCs were cultured under normal oxygen in control group (group A), under 1%O2 in hypoxia group (group B), and under normal oxygen and 0.5 mmol/L DMOG in DMOG intervention group (group C). BMSCs proliferation was estimated by methyl thiazolyl tetrazolium assay at 1, 2, 3, and 4 days. Alkaline phophatase (ALP) expression was determined at 7 and 14 days after osteogenic induction. Western blot was employed for detecting hypoxia inducible factor-1α(HIF-1α) at 24 hours. Real time fluorescence quantitative PCR was employed for detecting the mRNA expression of runt-related transcription factor 2 (RUNX2) and Osterix at 3 and 7 days. Alizarin red staining was applied to assess the deposition of calcium tubercle at 21 days. ResultsThe BMSCs presented CD29(+), CD44(+), CD90(+), and CD34(-); and results of the alizarin red staining, oil red O staining, and toluidine blue staining were positive after osteogenic, adipogenic, and chondrogenic induction. No significant difference in BMSCs proliferation was observed among 3 groups at 1 day (P>0.05); compared with group A, BMSCs proliferation was inhibited in group C at 2, 3, and 4 days, but no significant difference was observed (P>0.05); compared with group A, BMSCs proliferation was significantly promoted in group B (P < 0.05). At each time point, compared with group A, the ALP expression, HIF-1αprotein relative expression, and mRNA relative expressions of RUNX2 and Osterix were significantly up-regulated in groups B and C (P < 0.05); compared with group B, the ALP expression, the RUNX2 and Osterix mRNA relative expression were significantly up-regulated in group C (P < 0.05); compared with group C, the HIF-1αprotein relative expression was significantly up-regulated in group B (P < 0.05). The alizarin red staining showed little red staining materials in group A, some red staining materials in group B, and a large number of red staining materials in group C. ConclusionHypoxia can promote BMSCs proliferation, DMOG can not influence the BMSCs proliferation; both hypoxia and DMOG can improve osteogenic differentiation of BMSCs, and DMOG is better than hypoxia in improving the BMSCs osteogenesis.
ObjectiveTo establish the system of isolation, cultivation, and identification of the neural stem cells (NSCs) from subventricular zone (SVZ) of neonatal mice so as to seek for the appropriate seed cells for potential therapeutic interventions of neurological disorders. MethodsNSCs were isolated enzymatically and mechanically from SVZ of neonatal mice and cultured. The cellular morphology was observed by inverted microscopy. Immunocytochemical stainings of anti-Nestin and anti-SOX-2 were used to identify NSCs of passage 3. To study the differentiation of NSCs, NSCs were plated into 24-wells in the medium supplemented without epidermal growth factor (EGF) and basic fibroblastic growth factor (bFGF) for 3 or 7 days. To compare the differentiation and proliferation potential of NSCs with different cultivation time, the BrdU pulse-labeling method and MTT test were used. To identify neurons and astrocytes, the anti-β-tubulin Ⅲ (Tuj-1) and anti-glial fibrillary acidic protein (GFAP) staining were used. ResultsThe cells of the SVZ can be isolated and cultured in vitro, and these cells began to form neurospheres after cultured for 3 days at primary passage. While cultured for 7 days, these cells formed more neurospheres, and the volume of the neurospheres became bigger than neurospheres cultured for 3 days. In addition, after cultured for 7 days, the phenomena of fusion of neurospheres and adherent differentiation of neurospheres were observed under inverted microscope. These cells were provided with the typical phenotype of NSCs. The immunofluorescence staining results revealed that these cells showed positive immunoreactivity to Nestin and SOX-2. During the 4 hours BrdU pulse, the number of proliferated NSCs cultured for 3 days (75.817±2.961) was significantly higher than that of NSCs cultured for 7 days (56.600±4.881) (t=3.366, P=0.028). The results of MTT assay revealed that the absorbance (A) value of NSCs cultured for 3 days (0.478±0.025) was significantly higher than that of NSCs which were cultured for 7 days (0.366±0.032)(t=2.752, P=0.011). After cultivated without EGF and bFGF, the percentage of Tuj-1 and GFAP positive cells in NSCs was 23.1%±3.7% and 23.7%±3.8% for 3 days and was 40.1%±3.6% and 37.1%±4.5% for 7 days, respectively, all showing significant differences (t=3.285, P=0.030; t=3.930, P=0.017). ConclusionThe NSCs from SVZ of neonatal mice have potentials of self-renewal and multipotential differentiation in vitro. With different cultivation time, the potentials of proliferation and differentiation of NSCs are different.
Objective To make a mouse model of traumatic spinal cord injury (SCI) by Allen’s weight dropping (WD),which might be helpful for further research on the mechanism of SCI. Methods A total of 180 healthy female mice, weighing 17 - 23 g (20 g on average), were randomized into 4 groups (n=45 per group): the experimental groups of A, B and C and the control group of D. Experimental groups were distinguished by the amount of weight or the height from which the weight was dropped onto an impounder resting on the dura (2.0 × 2.5 g·cm, 2.5 × 3.0 g·cm, 3.0 × 5.0 g·cm). In group D, neural scute was opened only and spinal cord was exposed without SCI. The recovery of the lower extremity was observed at various time points (0,6 and 12 hours, 1 and 3 days, 1, 2, 4 and 8 weeks) by using the Basso mouse scale (BMS) scoring system, motor evoked potentials (MEP) and histological observation. Results MEP displayed that the incubation period of N1 wave was extended in group B after 6 hours and in group C after 12 hours. As time passed by, the incubation periods of N1 wave in group A, group B and group C began to shorten. The incubation period in group A was close to normal at 4 weeks (2.40 ± 0.12) ms, and there was no significant difference compared with group D (P gt; 0.05). The incubation period in group B was close to normal at 8 weeks (2.96 ± 0.15) ms, and there was no significant difference compared with group D (P gt; 0.05). The incubation period in group C was still relatively high at 8 weeks (3.76 ± 0.13) ms, and there was a significant difference compared with group D (P﹤0.05). Both hind l imbs of all mice were paralytic instantly after SCI, the score of main BMS was 0 point; the score of main BMS was close to 0 at the first 3 days after SCI, the score of main BMS of group A was 8.00 ± 0.13 and group B was 7.50 ± 0.31 at 8 weeks;the score of main BMS of group A was 5.45 ± 0.12 at 1 week and group B was 5.45 ± 0.15 at 2 weeks which were significant difference compared with group D (P﹤0.05).There were significant differences among groups A, B and C after 1 week of SCI (P lt; 0.05), and group C was lower than the others(P﹤0.01). The score of adjuvant BMS of group A was 10.12 ± 0.76 at 2 weeks and group B was 9.85 ± 0.55 at 8 weeks which was no significant difference compared with the group D at the same time (P gt; 0.05). Histological observation showed hemorrhage, cellular edema, inflammatory cell infiltration, nerve cell swell and solution of Nissl body 12 hours after SCI in group C. As time passed by, the number of nerve cells decreased, the gl ial cell prol iferated and Nissl body vanished. There was much gl ial cell prol iferation and cavitation 2 weeks after SCI in group C. The nerve cell decrease and cavitation in group B was sl ighter than that in group C, and group A was the sl ightest. In group D, there was no obvious change of the number of cells during the observation apart from sl ight edema in early period. Conclusion The mouse model precisely reflects the pathological and physiological features and law of change after different degrees of SCI, and can be used as a standard of mouse model of traumatic SCI by Allen’s WD.