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.
Objective To investigate the role of adenosine A2A receptor plays in retinal pathological neovascularization in mice. Methods A total of 202 mice were divided into room-air group (n=66) and oxygen induced retinopathy (OIR) group (n=136). Among room-air group, there were 18 A2A knock-out (KO) mice (KO subgroup) and 24 C57BL/6 mice as wide type (wide type subgroup). OIR group were divided into OIR control subgroup (n=48), A2A-OIR subgroup (n=24) and Caffeine-OIR subgroup (n=64). The retinal neovascularization of OIR group was induced by oxygen. The pathological neovascularization was determined by retinal sections. Fluorescent quantitative polymerase chain reaction (PCR) was used to measure the mRNA expression of A2A and vascular endothelial growth factor (VEGF). 0.1, 0.3, 1.0 g/L Caffeine was dissolve in drinking water of lactating females in Caffeine-OIR subgroup, non-perfusion areas of retina in mice at the age of 0 - 17, 0 - 7, 7- 17, 7-12, and 12- 17 days were analyzed in different dosage and when the dosage as 1.0 g/L. Results Compared with OIR control subgroup, the retinal non-perfusion areas and the numbers of endothelial cell nuclei breaking through the internal limiting membrane in A2A- OIR subgroup were reduced significantly (t=7.694, 7.747;P＜0.001). Compared with wide type subgroup, the level of A2A and VEGF mRNA in OIR control subgroup increased significantly (t=4.036, 2.230;P＜0.05). Compared with OIR control subgroup, the level of VEGF mRNA in A2A- OIR subgroup decreased significantly (t=3.122,P＜0.01). Compared with OIR control subgroup, the retinal non-perfusion areas in mice at the dosage of 0.1 and 1.0 g/L (t=2.397, 4.533) and at the age of 0 -17, 0 -7 days when the dosage as 1.0 g/L (t=4.070, 2.399) were reduced significantly (P＜0.05). Conclusions The expression of adenosine A2A receptor increases in oxygen-induced retinal pathological neovascularization. Adenosine A2A receptor may regulate the expression of VEGF. A2A receptor inactivation can inhibit oxygen-induced retinal pathological neovascularization.
Objective To investigate the effects of adenosine 2A receptor (A2AR) activation on oxidative stress in small-forsize liver transplantation. Methods A rat orthotopic liver transplantation model was performed using 40% graft, 18 recipients were given intravenously saline (control group), CGS21680 (A2AR agonist, CGS21680 group) or ZM241385 (A2AR antagonist, CGS21680+ZM241385 group) randomly. Aspartate aminotransferase (AST), enzymatic antioxidants 〔superoxide dismutase (SOD); catalase (CAT); glutathione peroxidase (GSH-Px)〕, non-enzymatic antioxidants 〔ascorbic acid (AA); glutathione (GSH); α-tocopherol (TOC)〕 and lipid oxidant metabolites malondialdehyde (MDA) were measured and analyzed at 6 h after reperfusion. Results Compared with the control group and CGS21680+ZM241385 group, A2AR activation increased the activities of SOD and GSHPx (Plt;0.05), reduced the productions of AST and MDA (Plt;0.05), increased the levels of AA, GSH and TOC (Plt;0.05) in CGS21680 group. But there was no significant change in CAT activity (Pgt;0.05) among 3 groups. Conclusions A2AR activation improves the antioxidant enzyme activities, promotes the production of antioxidants, and slowes down the increase in MDA level, depresses of the increase in AST activity. A2AR activation suppresses oxidative damage and increases the antioxidant capacity which in turn minimizes their harmful effects of ischemia-reperfusion in small-for-size liver transplantation.
The Dacron grafts seeded with autologous venous fragments were implanted into IVC of 13 canines as seeded group and the control grafts (8 cases), which were only preclotted with fresh blood. The amounts of cAMP and cGMP in serum and within platelet were measured. All of the specimens explanted at exsaguination were observed morphologically. The results shown that the total patency rate were 61.5% in seeded group, but 25.0% in control one and new endothelial lining formed at two weeks after implantation of the seeded grafts. The amounts of cAMP in serum and within platelet were higher in seeded group, but the amounts of cGMP were lower in serum and within platelet. These were in accordance with the results that the endothelialization of the grafts were complete in seeded group but not complete in control one. The results indicate that seeding Dacron with autologous venous fragment makes new endothelium formed at two weeks after implantation, increases the amounts of cAMP in serum and within platelet, but reduces the amounts of cGMP and thus improves graft patency rate.
Abstract： Objective To investigate the protective effects of adenosine (ADO) on lung ischemia/reperfusion injury following heart-lung transplantation in canine. Methods Canine heart-lung transplantation was performed．Canines were divided into two groups: transplant control groupand ADO group. The changes of arterial partial pressure of oxygen(PaO2) after reperfusion in two groups at 30，60，90，120 min were observed．The tissue contents of nitric oxide (NO) were measured at 10 min before ischemia, 10 min and 120 min after ischemia; 10 min and 60 min after reperfusion．The lung tissue samples were obtained 1h after reperfusion．The tissue myeloperoxidase(MPO) activity,content of malondialdehyde(MDA), content of superoxide dismutase(SOD), wet/dry ratio of lung(W/D) were measured.Microscopic examination of lungs was also conducted. Results (1)In ADO group，PaO2 were significantly higher than that in control group at 30，60，90 and 120 min after reperfusion (Plt;0.05)．(2) The tissue contents of NO at 120 min after ischemia, 10 min and 60 min after reperfusion were significantly lower than that at 10 min before ischemia(Plt;0.05). In ADO group，the tissue contents of NO at 120 min after ischemia, 10 min and 60 min after reperfusion were higher than that in control group respectively(Plt;0.05). (3)The tissue MPO activity, content of MDA, W/D in ADO group were significantly lower than those in corresponding control group. The content of SOD in ADO group were higher than that in control group(Plt;0. 05)．(4)The microscopic examination showed that there were severe leukocyte infiltration and edema formation in the alveolar space in control group, but the changes were less severe in ADO group. Conclusion Administration of ADO in canine heart-lung transplantation can protect the donor lung against ischemia／reperfusion injury．
目的:评价国产腺苷临床应用安全性及腺苷负荷心肌灌注显像对冠心病的诊断价值。方法:对51例临床疑诊冠心病患者,分别静脉注射腺苷,注射3min末,静脉注射核素显像剂99TcmMIBI 925 MBq,1～1.5h行心肌灌注断层显像,分析患者在腺苷注入后的血流动力学改变、副作用发生情况。经半年以上随访排除或确诊冠心病,评价腺苷负荷心肌灌注显像对冠心病的诊断价值。结果:腺苷输注后,86.3%(44/51) 患者出现各种副作用,停药后均很快缓解。腺苷负荷试验心肌灌注显像诊断冠心病的敏感性90.9%,特异性71.4%,准确性88.2%,阳性预测值95.2%,阴性预测值55.6%。结论:国产腺苷可安全地应用于负荷心肌灌注显像。腺苷负荷心肌灌注显像诊断冠心病敏感性较高,具有重要的临床应用价值。
Objective To investigate the effect of mild hypothermia on neurological function in rats with spinal cord injury (SCI) based on the adenosine monophosphate activated protein kinase (AMPK)/Nod-like receptor protein 3 (NLRP3) pathway. MethodsFifty 7-8 weeks old SPF male Sprague Dawley rats were used to establish rat model of SCI by Allen’s method. Among them, 48 successfully modeled rats were randomly divided into SCI group, mild hypothermia group (SCI+mild hypothermia treatment), and Compound C group (SCI+mild hypothermia+20 mg/kg AMPK/NLRP3 pathway inhibitor Compound C), with 16 rats in each group; another 16 normal rats with laminectomy were selected as sham-operation group. Basso-Beattie-Bresnahan (BBB) score was used to evaluate the motor ability of rats at 1, 3, 7, 14 days after treatment. After 14 days, the rats were sacrificed, and the spinal cord histopathological morphology was observed by HE staining, the neuronal apoptosis in spinal cord tissue was detected by TUNEL assay, and the serum levels of interleukin 2 (IL-2), IL-6, transforming growth factor β1 (TGF-β1), malondialdehyde (MDA), and superoxide dismutase (SOD) were detected by ELISA. The expression of AMPK/NLRP3 pathway protein, including B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and cleaved-Caspase-9 were detected by Western blot. Results At 1 day after treatment, the rats in SCI group, mild hypothermia group, and Compound C group did not recover their motor ability; at 3, 7, and 14 days, the BBB score of SCI group was significantly lower than that of SCI group (P<0.05), the BBB score of mild hypothermia group was significantly higher than that of SCI group (P<0.05), and the BBB score of Compound C group was significantly lower than that of mild hypothermia group (P<0.05). Compared with the sham-operation group, the SCI group displayed obvious pathological changes in the spinal cord tissue, with disordered tissue architecture, inflammatory infiltration, and blurred interstitial boundaries. The neuronal apoptosis rate, Bax/Bcl-2 ratio, cleaved Caspase-9 expression, NLRP3 protein expression, serum IL-2, IL-6, and MDA levels were elevated, whereas serum TGF-β1, SOD levels, and spinal cord phosphorylation AMPK/AMPK protein expression significantly decreased (P<0.05). Compared with the SCI group, the above phenomena significantly improved in the mild hypothermia group (P<0.05), while the Compound C group showed the opposite trend of change compared to the mild hypothermia group (P<0.05). Conclusion Mild hypothermia can attenuate neurological dysfunction after SCI in rats, potentially by activating the AMPK/NLRP3 pathway.
Objective To investigate the changes and roles of myocardial adenosine triphosphate enzyme(ATPase) in the mechanism of cardiac dysfunction after blunt chest trauma（BCT）. Methods Thirtysix rabbits were divided into 6 groups with random number table, control group, 2 h group, 4 h group, 8 h group, 12 h group and 24 h group, 6 in each group. The models of BCT were established with BIMⅡ biological impact machine, catheterization technique was used through the right jugular artery into the left ventricle measure its pressure. The hemodynamics and the activities of ATPase in myocardial cell plasm, homogenate and mitochondria were measured at preinjury(control group), 2 h, 4 h, 8 h, 12 h and 24 h postinjury. Results Left ventricular endsystolic pressure(LVESP), the maximal ascending rate of left intraventricular pressure(+dp/dtmax), isovolemec pressure(IP) and the maximal physiological velocity(Vpm) decreased significantly at 2 h group after BCT(Plt;0.05）, and recovered to preinjury level in 4 h, 8 h and 12 h group during 4-12 h after BCT; isovolumic relaxation phase left ventricular pressure descending time constant (T). Left ventricular enddiastolic pressure(LVEDP) and the maximal descending rate of left intraventricular pressure(-dp/dtmax) were significantly higher （Plt;0.05, 0.01）. The activity of ATPase in homogenate, mitochondria and cell plasm decreased significantly at 2 h group and 4 h group after BCT（Plt;0.05, 001, respectively）, and 8 h group and 12 h group recovered after BCT. There was negative correlations between [CM(159mm]LVEDP and -dp/dtmax and the decrease of the activity of Na+-K+-ATPase in homogenate（r=-0.674, -0.691, Plt;0.05）, the Ca2+-ATPase in homogenate（r=-0.613,-0.642, Plt;0.05）, the Na+-K+-ATPase in mitochondria（r=-0.622,-0.616, Plt;0.05）,the Ca2+-ATPase in myocardial cell plasm（r=-0.672,-0.658, Plt;0.05）, the Na+-K+-ATPase in myocardial cell plasm（r=-0.627,-0.632,Plt;0.05）,and the Mg2+-ATPase in myocardial cell plasm（r=-0.677,-0.661, Plt;0.05）. Conclusion The left ventricular function is impaired obviously after BCT, especially in diastolic phase. The decrease of the activity of ATPase in myocardial cells may be one of the reasons of cardiac dysfunction after BCT.