Objective To evaluate the biocompatibility and safety of a novel orthopedics materials-graded zirconia(ZrO2)hydroxyapatite(HA) composite biomaterials. Methods First, ultrafine powers of ZrO2 and HA powder were prepared by chemical precipitation method, then graded ZrO2-HA composite was synthesized by dry-laying and sintering method. After the physiological saline and culture medium extracts of the composite were prepared, four experiments were conducted as follows:① The mouse acute toxic test consists of 2 groups(n=10). The extracts were intravenously injected to mice in the first group, and physiological saline to mice in the second group. The dose was 50 g/kg. Their toxicity manifestation, morality and the change of weight were recorded.② The standard curve of proliferation and metabolism of L929 cells was established. ③ The cytotoxinic test consists of 3 groups: materials group (extracts of the materials), positive control group (culture fluid with 0.64% phenol), and negative control group (RPMI-1640 culture fluid). Each of three was cultured with cell suspension, and then the morphology of the cells was observed, the relative proliferation rate (RGR) was calculated, and the toxicity was classified. ④ In vitrohemolytic test was divided into 3 groups: extracts, sterile distilled water (positive control) and 0.9% physiological saline. In each of three, 0.2 ml anticoagulant diluted fresh rabbit blood was added. The percentage of hemolysis was tested. ⑤ The muscle and implantation test were divided into 4 groups(n=3). The composite biomaterials were implanted into pygal muscleson either side and lateral condyles of femurs. After surgery, the rats of four groups were sacrificed at 12 and 24 weeks respectively.Tissue slice and scanning electronic microscopy were performed. Results General acute toxic test: no mouse died within 3 weeks; no toxicity symptom or adverse effects were shown within 3 days. The weight of materials group increased by 3.57±0.49 g, and the control group by 3.62±0.61 g, showing no statistically significant difference（Ρgt;0.05）.The standard curve of L929 cell perliferation and metabolism showed that their existed a positive correlation between the number of L929 cells and the perliferation. ③ Cytotoxinic test: cytosomes in the positive control group diminished and appeared round, there were pyknotic nucleus, the attached cells agglomerated; the toxicity was level Ⅳ. The morphology of cells in materials groupand negative control group was normal, and the number of them increased; the toxicity was level Ⅰand level 0, respectively. The MTT color experiments showed that positive control group was significantly lower than materials group and negative control group, showing statistically significant difference (Plt;0.01); there was no statistically significant difference between materials group and negative group.④ Hemolytic test: in vitrohemolytic rate of negative control group was0, of positive control group was 100%, and of materials group was 1.66%, which accords with the standard that hemolytic rate should be lower than 5% specified in ISO. ⑤ Implant test:No apparent rejection reaction took place after the composite was implanted; the composite bonded with the bones of the receptors firmly, which had good bonedinduced effect. Conclusion Graded ZrO2-HA composite bioceramic has good biocompatibility and is suitable for orthopedic biomaterials.
ObjectiveTo investigate the effect of nicotinamide mononucleotide adenosyl transferase 3 (NMNAT3) on the mitochondrial function and anti-oxidative stress of rabbit bone marrow mesenchymal stem cells (BMSCs) under oxidative stress in vitro by regulating nicotinamide adenine dinucleotide (NAD+) levels.MethodsThe bone marrow of femur and tibia of New Zealand white rabbits were extracted. BMSCs were isolated and cultured in vitro by density gradient centrifugation combined with adherent culture. The third generation cells were identified by flow cytometry and multi-directional induction. Overexpression of NMNAT3 gene was transfected into rabbit BMSCs by enhanced green fluorescent protein (EGFP) labeled lentivirus (BMSCs/Lv-NMNAT3-EGFP), and then the expression of NMNAT3 was detected by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot and cell proliferation by cell counting kit 8 (CCK-8) method. BMSCs transfected with negative lentivirus (BMSCs/Lv-EGFP) and untransfected BMSCs were used as controls. The oxidative stress injury cell model was established by using H2O2 to treat rabbit BMSCs. According to the experimental treatment conditions, they were divided into 4 groups: Group A was normal BMSCs without H2O2 treatment; untransfected BMSCs, BMSCs/Lv-EGFP, and BMSCs/Lv-NMNAT3-EGFP in groups B, C, and D were treated with H2O2 simulated oxidative stress, respectively. The effects of NMNAT3 on the mitochondrial function of BMSCs under oxidative stress [changes of mitochondrial membrane potential, NAD+ and adenosine triphosphate (ATP) levels], the changes of anti-oxidative stress ability of BMSCs [reactive oxygen species (ROS) and malondialdehyde (MDA) levels, manganese superoxide dismutase (Mn-SOD) and catalase (CAT) activities], and the effects of BMSCs on senescence and apoptosis [senescence associated-β-galactosidase (SA-β-gal) staining and TUNEL staining] were detected after 24 hours of treatment.ResultsThe rabbit BMSCs were successfully isolated and cultured in vitro. The stable strain of rabbit BMSCs with high expression of NMNAT3 gene was successfully obtained by lentiviral transfection, and the expressions of NMNAT3 gene and protein significantly increased (P<0.05). There was no significant difference in the trend of cell proliferation compared with normal BMSCs. After treatment with H2O2, the function of mitochondria was damaged and apoptosis increased in all groups. However, compared with groups B and C, the group D showed that the mitochondrial function of BMSCs improved, the membrane potential increased, the level of NAD+ and ATP synthesis of mitochondria increased; the anti-oxidative stress ability of BMSCs enhanced, the levels of ROS and MDA decreased, and the activities of antioxidant enzymes (Mn-SOD, CAT) increased; and the proportion of SA-β-gal positive cells and the rate of apoptosis decreased. The differences in all indicators between group D and groups B and C were significant (P<0.05).ConclusionNMNAT3 can effectively improve the mitochondrial function of rabbit BMSCs via increasing the NAD+ levels, and enhance its anti-oxidative stress and improve the survival of BMSCs under oxidative stress conditions.
ObjectiveTo investigate the regulatory mechanism of thioredoxin binding protein (TXNIP)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) pathway in the occurrence and development of breast cancer.MethodsThe resected 15 cases of breast cancer tissues and their adjacent tissues in our hospital from September 2019 to June 2020 were selected, and the immunohistochemistry was used to detect the expression levels of TXNIP and NLRP3 in breast cancer and its adjacent tissues. Three kinds of breast cancer cell lines (MDA-MB231, MCF-7 and SKBR3) and normal breast epithelial cell line (HMEC) were collected. Western blot was used to detect the relative expression levels of TXNIP and NLRP3 in three kinds of breast cancer cell lines and HMEC cell line. MDA-MB231 cancer cells were divided into blank control group (normal culture without any treatment), TXNIP overexpression group (Ad-TXNIP group, transfected with adenovirus vector carrying TXNIP overexpression sequence), Ad-TXNIP negative control group (Ad-eGFP1 group, transfected of empty adenovirus vector without TXNIP overexpression sequence), NLRP3 overexpression group (Ad-NLRP3 group, transfected with adenovirus vector containing NLRP3 overexpression sequence), TXNIP and NLRP3 overexpression co-transfection group (Ad-TXNIP+Ad-NLRP3 group, co-transfection of adenovirus vector carrying TXNIP and NLRP3 overexpression sequence), TXNIP overexpression and Ad-NLRP3 negative control (Ad-eGFP2) co-transfection group (Ad-TXNIP+Ad-eGFP2 group,co-transfection of adenovirus vector carrying TXNIP overexpression sequence and empty adenovirus without NLRP3 overexpression sequence). After 24 hours of transfection and culture, CCK-8 method was used to detect the MDA-MB231 cells proliferation. Transwell chamber method was used to detect MDA-MB231 cells migration and invasion. Nude mice tumorigenicity test was used to detect the tumorigenicity of the MDA-MB231 cells in vivo. Western blot was used to detect the expressions of TXNIP, NLRP3, proliferation marker protein (Ki-67), caspase-1, vascular endothelial growth factor (VEGF), interleukin (IL)-1β, IL-18 and caspase-1 precursor protein (pro-caspase-1) in the MDA-MB231 cells.ResultsCompared with the adjacent tissues, the relative expression level of TXNIP decreased (P<0.05) and the relative expression level of NLRP3 increased (P<0.05) in breast cancer tissues. Compared with normal breast epithelial cell line (HMEC cell line), the relative expression levels of TXNIP in MDA-MB231, MCF-7 and SKBR3 breast cancer cell lines were decreased (P<0.05), and the relative expression levels of NLRP3 were increased (P<0.05). Compared with the blank control group, the relative expression levels of TXNIP, NLRP3, IL-1β, IL-18, pro-caspase-1 and caspase-1 were increased (P<0.05), the relative expression levels of Ki-67 and VEGF, the proliferation activity, invasion and migration ability of MDA-MB231 cells and tumor weight were decreased (P<0.05) in the Ad-TXNIP group and the Ad-NLRP3 group. Compared with the Ad-TXNIP group and the Ad-NLRP3 group, the relative expression levels of TXNIP, NLRP3, IL-1β, IL-18, pro-caspase-1 and caspase-1 were further increased (P<0.05), the relative expression levels of Ki-67 and VEGF, the proliferation activity, invasion and migration ability of MDA-MB231 cells and tumor weight were further decreased (P<0.05) in the Ad-TXNIP+Ad-NLRP3 group.ConclusionsIn breast cancer tissues and breast cancer cell lines, TXNIP is low expression and NLRP3 is high expression. They can interact with each other to promote pyroptosis and inhibit the proliferation, invasion and migration of breast cancer cells.
【摘要】 目的 观察长期大量酒精摄入对大鼠心肌结构及心肌组织中丙二醛(MDA)、超氧化物歧化酶(SOD)和金属硫蛋白(MT)含量的影响,探讨氧化应激在酒精性心肌病大鼠中的作用。 方法 雄性健康SD大鼠45只,随机分为2组,即对照组20只和模型组25只。模型组酒精浓度从5%、10%、20%和30%依次各自由饮1周,然后递增至36%后以该浓度维持饲喂。对照组每日饮用与模型组酒精同等热量的葡萄糖水。6个月后,观察大鼠心肌组织的形态学改变及超微结构的变化,测定心肌组织中MDA、SOD及MT的含量。结果 模型组大鼠心肌细胞排列紊乱、间质充血、炎细胞浸润、线粒体肿胀、空泡形成、肌丝溶解、核膜不规则和核仁裂解。心肌组织中MDA含量明显升高(Plt;0.01),SOD活力含量明显降低(Plt;0.01),MT含量明显降低(Plt;0.01)。 结论 长期摄入大量酒精可使氧自由基代谢失衡,导致心肌损伤。氧化应激在酒精性心肌病发病机制中发挥着重要的作用。【Abstract】 Objective To observe the effect of longterm and large quantities of alcohol intake on myocardial structure of rats and the content of malondialdehyde (MDA), superoxide dismutase (SOD) and metallothionein (MT) in myocardium tissue. To study the effect of oxidative stress on the rats with alcoholic cardiomyopathy. Methods Fortyfive male and healthy SD rats were randomly divided into the control group (20 rats) and model group (25 rats).The alcoholic concentrate in model group was increased from 5%,10%,20% to 30% every week, and maintain free drinking mass concentration of 36% alcohol. The control group drink the same calories of glucose water. Six months later, the myocardial tissues were observed both in light microscope and electron microscope .The level of MDA、SOD and MT were tested in myocardium tissue. Results In the model rats, the cells of myocardial disarray, interstitial congestion, inflammatory cell infiltration, mitochondrial swelling, vacuole formation, melt filaments, irregular nuclear membrane and nucleolus cracking. The content of MDA incresed(Plt;0.01)and the activities of SOD decreased(Plt;001),levels of MT decreased (Plt;0.01) in the cardiac muscular tissues in the model group compared with the control group. Conclusion Longterm intake of large amounts of alcohol can break the balance of oxygen free radicals, which leading to the damage of myocardial. Oxidative stress plays an important role in the etiopathogenesis of alcoholic cardiomyopathy.
Objective To investigate the feasibility of imaging of bone marrow mesenchymal stem cells (BMMSCs) labeled with superparamagnetic iron oxide(SPIO) transplanted into coronary artery in vivo using magnetic resonance imaging (MRI), and the redistribution of the cells into other organs. Methods BMMSCs were isolated, cultured from bone marrow of Chinese mini swine, and double labeled with SPIO and CMDiI(Cell TrackerTM C-7001). The labeled cells were injected into left anterior descending coronary artery through a catheter. The injected cells were detected by using MRI at 1 week,3weeks after transplantation. And different organs were harvested and evaluated the redistribution of transplanted cells through pathology. Results The SPIO labeled BMMSCs injected into coronary artery could be detected through MRI and confirmed by pathology and maintained more than 3 weeks. The SPIO labeled cells could be clearly imaged as signal void lesions in the related artery. The pathology showed that the injected cells could be distributed into the area of related artery, and the cells injected into coronary artery could be found in the lung, spleen, kidney, but scarcely in the liver, the structures of these organs remained normal. Conclusion The SPIO labeled BMMSCs injected into coronary artery can be detected by using MRI, the transplanted cells can be redistributed into the non-targeted organs.
OBJECTIVE To determine the role of endogenous carbon monoxide(CO) in oxidant-mediated organ injury following limb ischemia-reperfusion (I/R) in rats. METHODS: Sixty-four SD rats were divided into 4 groups: Sham group, Sham + zinc protoporphyrin (ZnPP, an inhibitor of heme oxygenase activity), 2-hour ischemia followed by 4-hour reperfusion (I/R) group and I/R + ZnPP group. Carboxyhemoglobin (COHb) level in the artery blood, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung, heart, liver and kidney were detected. The 24-hour survival rate of rats was studied. RESULTS: Compared with the sham group, the COHb level and MDA content significantly increased, while the SOD activity and the survival rate significantly decreased in I/R group (P lt; 0.05). Compared with the I/R group, MDA content significantly increased, while the SOD activity, the 24-hour survival rate and COHb level significantly decreased in I/R + ZnPP group (P lt; 0.05, respectively). CONCLUSION: Limb I/R could lead to the oxidant-mediated multiple organ injury accompanied by the increase of CO level which play an important role in the defense against I/R-induced remote multiple organ injury in rats.