ObjectiveTo investigate the protective effect and the regulation mechanism of oxaloacetate (OAA) on myocardial ischemia reperfusion injury in rats. MethodsSixty rats, weight ranged from 200 to 250 grams, were randomly divided into 6 groups:a negative control group, a sham operation control group, a model control group, an OAA pretreatment myocardial ischemia-reperfusion model group (three subgroups:15 mg/kg, 60 mg/kg, 240 mg/kg). We established the model of myocardial ischemia reperfusion of rats and recorded the internal pressure of left ventricle (LVSP), the maximal rate of left ventricular pressure change (±dp/dtmax) and left ventricular end diastolic pressure (LVEDP). We restored reperfusion 180 minutes after ligating the left anterior descending coronary artery 30 minutes and determinated cardiac troponin Ⅰ (cTn-I), lactate dehydrogenase (LDH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px). We took out heart tissues, stained it and calculated the infarcted size. We used the Western blot to detect the expression of NF-E2 related factor 2 (Nrf2), Kelch-like ECH-associated protein-1 (Keap1) and heme oxygenase-1 (HO-1). ResultsCompared with the sham operation group, heart function indexes in the negative control group had no significant difference (P>0.05). But in the model control group there was a decrease (P<0.05) And the serum levels of LDH, cTn-I, and myocardial infarcted size were significantly increased (P<0.01). Compared with the model control group, heart function indexes in the OAA pretreatment groups improved, the serum LDH, cTn-I activity, and infarct size decreased (P<0.05), SOD and GSH-Px activity increased (P<0.05). And these results were statistically different (P<0.01) in the high dose OAA pretreatment groups. Compared with the model control group, the expression of Keap1 in the OAA pretreatment group was down-regulated (P<0.001) while total Nrf2, nucleus Nrf2 and its downstream HO-1 was up-regulated (P<0.001), which suggested that OAA enhanced antioxidant capacity by (at least in part) Keap1-Nrf2 pathway, resulting in reducing myocardial damage and protecting myocardium after acute myocardial ischemia reperfusion injury. ConclusionOxaloacetate can provide protective effects on myocardial ischemia reperfusion injury through down-regulating the expression of Keap1 and up-regulating the expression of Nrf2 and its downstream peroxiredoxins to improve antioxidant capacity.
The bone marrow mononuclear cell（BMMNC） subset comprises mesenchymal stem cells, hematopoietic stem cells, endothelial progenitor cells. These cells can differentiate into cardiomyocytes, vascular endothelial cells and smooth muscle cells, and they can also release a wide array of cytokines that exert their effects on surrounding cells, including inducing neovascularization, preventing apoptosis of home cells and homing of endogenous systemic repairing cells. Many trials have been developed to evaluate the effect of bone marrow mononuclear cell transplantation in treating ischemia heart diseases in this country and others. Several routes have been used to deliver these cells to human myocardium or to the coronary circulation in these trials, such as intracoronary injection, intravenous infusion, direct injection into the ventricular wall, or transepicardial/transendocardial infusions，and the cells are constructed into fragmented cell sheets to improve cell retention, or some cytokines are used to enhance therapeutic effect. Although the results of the recent clinical trials in this area are rather conflicting, these therapeutic approaches seem to be promising forthe treatment of ischemic heart disease. In this review, many aspects of bone marrow mononuclear cell transplantation in myocardial infarction are summarized such as the mechanism, delivery routes, retaining of cells, homing, survival and future development, etc.
Objective To investigate the dose-dependent relationship of bone marrow mesenchymal stem cells(MSCs) transplantation in improving ischemic myocardial dysfunction? in a rat ischemic heart model. Methods Myocardial infarction was induced in 32 inbred F344 rats by acute ligation of the left anterior descending(LAD) coronary artery. One week after ligation, the ratswere randomized? into four equal groups, with eight rats in each group. Equal volume Iscove’s modified Dulbecco’s medium was injected in the control group, 1×103(group 1), 1×105(group 2), and 1×107(group 3) 5-bromodeoxyuridine (BrdU) labeled bone marrow MSCs were injected into the infarcted myocardium. Cardiac function was evaluated by ultrasound before the ligation of the LAD, before the transplantation and the 4th week after transplantation. The expressions of BrdU,Connexin43,Myosin heavy chain β(MHC), and smooth muscle actin α(α-SMA) were detected by immunofluorescence and immunohistochemistry at the 4th week after transplantation. The amount of functional vessels stained by α-SMA was counted simultaneously. Results At the 4th week? after transplantation, the ejection fraction(EF) in goup 2 was more significantly improved than that in group1(0.54±0.20 vs. 0.34±0.16, P＝0.004) and EF in group 3 was more significantly improved than that in group 2(0.71±0.24 vs. 0.54±0.20,P＝0.018), whereas no significant difference between group 1 and control group was detected (0.34±0.16 vs. 0.36±0.15,Pgt;0.05). The BrdU labeled MSCs could be found in host myocardium. The number of cells in group 2 by double staining both for BrdU and for MHC observed in ischemic myocardium were significantly more than that in group 1? (323.20±91.62 n/HP vs. 51.75±27.58 n/HP,P＝0.049) and the same was true between group 3 and group 2(409.75±106.65 n/HP vs. 323.20±91.62 n/HP,Plt;0.001), whereas the result of control group was negative.The majority of transplanted cells were found positive staining both for MHC and for Connexin43 in all groups. There were lots of positive staining of α-SMA whose form were partly irregular in ischemic myocardium indicating that there was neovascularization in group1 and control group. More neovascularization in group2 was found than that in group 1 (28.38±12.79 n/HP vs. 22.75±9.07 n/HP, P＝0015) and more neovascularization in group 3 was found? than that in group 2 (35.63±13.27 n/HP vs. 28.38±12.79 n/HP, P＝0.002) . Conclusion Transplanted into infarcted myocardium, bone marrow MSCs may have significant and dose-dependent potential for cardiomyogenesis with functional recovery from myocardial ischemia.
Objective To investigate the targeted combination and anti-inflammatory effects of anti-intercellular adhesion molecule 1 (ICAM-1) targeted perfluorooctylbromide (PFOB) particles on myocardial ischemia-reperfusion injury in rat model. Methods Seventy-six adult Sprague Dawley rats (male or female, weighing 250-300 g) were selected for experiment. The models of myocardial ischemia-reperfusion injury were established by ligating the left anterior descending coronary artery for 30 minutes in 30 rats. The expression of ICAM-1 protein was detected by immunohistochemistry staining at 6 hours after reperfusion, and the normal myocardium of 10 rats were harvested as control; then the content of interleukin 8 (IL-8) in serum was tested every 6 hours from 6 hours to 48 hours after reperfusion. The other 36 rats were randomly divided into 6 groups (n=6): ischemia-reperfusion injury model/targeted PFOB particles group (group A), ischemia-reperfusion injury model/untargeted PFOB group (group B), normal control/targeted PFOB particles group (group C), normal control/untargeted PFOB particles group (group D), ischemia-reperfusion injury model/normal saline group (group E), and sham operation group (group F). The ischemia-reperfusion injury models were established in groups A, B, and E; while a thread crossed under the coronary artery, which was not ligated after open-chest in group F. After 6 hours of reperfusion, 1 mL of corresponding PFOB particles was injected through juglar vein in groups A, B, C, and D, while 1 mL of nomal saline was injected in group E. Ultrasonography was performed in groups A, B, C, and D before and after injection. The targeted combination was tested by fluorescence microscope. The content of IL-8 was tested after 6 and 24 hours of reperfusion by liquid chip technology in groups A, B, E, and F. Results After 6 hours of reperfusion, the expression of ICAM-1 protein significantly increased in the anterior septum and left ventricular anterior wall of the rat model. The content of IL-8 rised markedly from 6 hours after reperfusion, and reached the peak at 24 hours. Ultrasonography observation showed no specific acoustic enhancement after injection of PFOB particles in groups A, B, C, and D. Targeted combination was observed in the anterior septum and left ventricular anterior wall in group A, but no targeted combination in groups B, C, and D. There was no significant difference in the content of IL-8 among groups A, B, and E after 6 hours of reperfusion (P gt; 0.05), but the content in groups A, B, and E was significantly higher than that in group F (P lt; 0.05). After 24 hours of reperfusion, no sigificant difference was found in the content of IL-8 between groups A and B (P gt; 0.05), but the content of IL-8 in groups A and B were significantly lower than that in group E (P lt; 0.05). Conclusion Anti-ICAM-1 targeted PFOB particles can target to bind and pretect injured myocardium of rat by its anti-inflammation effects.
ObjectiveTo compare the myocardial protective effect of HTK solution and St.ThomasⅡ(STH) solution in immature rabbit myocardium at different cardiac arrest time. MethodsAccording to cardioplegia and cardiac arrest time, 32 immature New Zealand white rabbits (aged 2-3 weeks) were randomly divided into four groups. A group SO (8 rabbits) underwent 1 hour cardiac arrest with STH solution, a group ST (8 rabbits) underwent 2 hours cardiac arrest with STH solution, a group HO (8 rabbits) underwent 1 hour cardiac arrest with HTK solution, a group Ht (8 rabbits) underwent 2 hours cardiac arrest with HTK solution. Compare the myocardial protective effect of HTK and STH solution in immature myocardium at different cardiac arrest time. ResultsThe Langendorff models were successfully established in 30 cases (8 cases in the group SO and HO, 7 cases in the group ST and HT). There were no statistical differences in hemodynamics and myocardial enzyme (CK-MB, LDH) (P > 0.05), but HTK solution reduced the activity of nitric oxide synthase (NOS) and content of malonaldehyde (MDA) and NO, maintained high activity of superoxide dismutase (SOD) and Ca2+-ATPase (P < 0.05), performed more effective myocardial protection for immature myocardium. ConclusionHTK solution has more effective myocardial protection for immature myocardium than STH solution does, but STH solution still has good outcomes within short cardiac arrest time (1h).
ObjectiveTo investigate the effect and significance of early coronary artery bypass graft (CABG) on the expression level of ionophorous protein at infracted border zone (IBZ) in dog with acute myocardial infarction. MethodsThe anterior descending coronary artery of all thirty healthy mongrel dogs were ligated into myocardial infarction model, whose successful criteria was that the regional myocardium supplied by ligated coronary artery became darker. Coronary artery bypass surgery performed at different time points after myocardial infarction (in the 1st week, the 2nd week, the 4th week, the 6th week respectively) was as an experimental group. While myocardial infarction without coronary artery bypass surgery was set up as a control group. Myocardial tissue without ligation of coronary artery was as a normal group. After 8 weeks, myocardial specimens were cut out in the experimental group and the control group. The local expression levels of ionophorous proteins such as Cav1.2, Kv4.3 and KchIP2 mRNA were detected by means of reverse transcription- polymerase chain reaction (RT-PCR) at normal myocardium and IBZ of the experimental group and the control group. ResultsFour dogs in every experimental group and all dogs in the control group survived to the end of the study. Three myocardial ion channel proteins expression in the control group were lower than those of the normal group or the experimental group significantly (P<0.01). Cav1.2 mRNA expression in the experimental group in the 4th week or the 6th week was lower than that in the normal group significantly (P<0.05). Kv4.3 and KchIP2 mRNA expression in the experimental group in the 4th week or the 6th week were lower than those in the normal group and the experimental group significantly in the 1st week or the 2nd week (P<0.05). ConclusionEarly CABG surgery for acute myocardial infarction could lessen the changes of expression level of ionophorous protein at infracted border zone (IBZ) of dog with acute myocardial infarction. Especially, CABG surgery among two weeks could improve expression level of ionophorous protein, and reduce the effect of ischemia for ionophorous protein and myocardial electrophysiology at IBZ.
Objective To study the effect and mechanism of recombinant human brain natriuretic peptide (rh-BNP) in alleviating myocardial ischemia-reperfusion (I/R) injury by regulating mitogen activated protein kinase (MAPK) pathway. Methods A total of 128 adult male Sprague-Dawley (SD) rats with specific pathogen free were selected. The SD rats were divided into groups according to random number table, including, sham operation (Sham) group, I/R group, I/R+rh-BNP group, negative control adenovirus (Ad-NC)+Sham group, Ad-NC+I/R group, Ad-NC+I/R+rh-BNP group, p38 mitogen-activated protein kinase adenovirus (Ad-p38MAPK)+I/R group and Ad-p38MAPK+I/R+rh-BNP group, with 16 SD rats in each group. Myocardial I/R injury model was established by ligation of left anterior descending coronary artery. Before modeling, rh-BNP was injected intraperitoneally or adenovirus was injected into myocardium; 180 minutes after reperfusion, the contents of lactate dehydrogenase (LDH), creatine kinase isoenzyme (CK-MB) in serum, myocardial infarction size, the contents of reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α) and the expression of phosphorylated p38MAPK (p-p38MAPK), phosphorylated JNK (p-JNK) and phosphorylated extracellular regulated protein kinases 1/2 (p-ERK1/2) were detected. Results The contents of LDH, CK-MB, myocardial infarction size, the contents of TNF-α, ROS and the expression of p-p38MAPK and p-JNK in I/R group were higher than those in Sham group, p-ERK1/2 expression level was lower than that in Sham group (P<0.05). The contents of LDH, CK-MB, myocardial infarction size, the contents of TNF-α, ROS and the expression of p-p38MAPK in I/R+rh-BNP group were lower than those in I/R group (P<0.05), the expression of p-JNK and p-ERK1/2 had no significant difference compared with I/R group (P>0.05). The contents of LDH, CK-MB, myocardial infarction size, the contents of TNF-α, ROS and the expression of p-p38MAPK in Ad-p38mapk+I/R+rh-BNP group were higher than those in Ad-NC+I/R-rh-BNP group (P<0.05). Conclusion rh-BNP can alleviate myocardial I/R injury, which is related to inhibiting p38MAPK pathway, reducing inflammation response and oxidative stress response.