ObjectiveTo study the influence of hemin on blood pressure of intermittent hypoxic rats and investigate the mechanism of hypertension caused by intermittent hypoxia.MethodsTwenty-four male SD rats were randomly divided into a hemin group, an intermittent hypoxia group (IH group) and a normal group. Thirty minutes after intraperitoneal injection of hemin, the rats in the hemin group were exposed to intermittent normobaric hypoxic environment (8 h/d). The rats in the IH group were intraperitoneal injected with normal sodium and then exposed to the same environment (8 h/d). The rats in the normal group were intraperitoneal injected with normal sodium and placed in the glass box. The three groups were bred in the same condition. Thirty-five days later, the mean carotid artery pressure (mCAP) of the rats was measured and their plasma carbon monoxide (CO) level was measured by Chalmer’s method. Reverse transcription polymerase chain reaction was performed to detect the levels of heme oxygenase-1 (HO-1) mRNA expression in lung, liver, spleen, kidney and other organs. The expression of HO-1 protein in the organs was detected by immunohistochemistry.ResultsThe mCAP in the IH group was significantly higher than the hemin group and the normal group (P<0.05), and was higher in the hemin group than the normal group (P<0.05). The concentration of plasma CO in the hemin group was higher than the IH group and the normal group (P<0.05). There was no significant difference in plasma CO between the IH group and the normal group (P>0.05). The expression of HO-1 mRNA of lung, liver, spleen and kidney in the hemin group and the IH group was higher than the normal group (P<0.05), and was higher in the hemin group than the IH group (P<0.05). The relationship between mCAP and HO-1 mRNA showed a curvilinear trend. The quadratic curve fitting equation was Y=39.715+446.640X-334.353X2.ConclusionsIntermittent hypoxia can cause hypertension in rats. The HO-1 expression is increased in hypoxic rats, but the plasma CO does not increase significantly. As an inducer of HO-1, hemin can increase the expression of HO-1 and CO in hypoxic rats, then lower their blood pressure to some extent.
Objective To observe the effect of melatonin (MT) on retinal apoptosis in rats with ischemia-reperfusion injury (RIRI). Methods A total of 54 male healthy Sprague-Dawley adult rats were randomly divided into the normal control (CON) group (6 rats), RIRI group (24 rats) and MT group (24 rats). The rats of RIRI and MT group were induced using suture-occluded methods to establish RIRI model. The rats of MT group were injected with MT in the left carotid artery 30 minutes after RIRI, and RIRI group was injected with the same amount of saline. On 6, 24 hours and 3, 7 days after RIRI, the morphological changes of retina were evaluated by hematoxylin and eosin (HE) staining; the effects of MT on retinal cell apoptosis and Nrf2, HO-1 proteins were examined by immunohistochemistry staining. The correlation between active Caspase-3 and Nrf2 protein, active Caspase-3 and HO-1 protein in MT group were analyzed by linear regression analysis. Results HE staining results showed that the morphology of retinal cells was regular and retinal cells were well arranged in the CON and MT group. In the RIRI group, both the thickness of inner retinal layer and the number of retinal ganglion cells (RGC) were decreased. On 6, 24 hours and 3, 7 days after RIRI, the thickness of inner retinal layer (F=16.710, 62.303, 68.389, 57.132; P＜0.01) and RGC number (F=24.250, 11.624, 14.155, 32.442; P＜0.05) in MT group were more than those in RIRI group. Immunohistochemistry staining results showed that less active Caspase-3+ cells were observed in MT group as compared with those in RIRI group at each time points (F=49.118, 134.173, 76.225, 18.385; P＜0.01). There were more Nrf2+ (F=11.041, 31.480, 59.246, 6.740; P＜0.05) and HO-1+ cells (F=128.993, 21.606, 51.349, 8.244; P＜0.05) in MT group as compared with those in RIRI group at each time points. Linear regression analysis results showed that the difference of active Caspase-3+ cells were all linearly correlated with the Nrf2+ cells and HO-1+cells in the MT group (r2=0.810, 0.730; P＜0.01). Conclusion MT could reduce retinal cell apoptosis in RIRI rats, and its mechanism may be associated with increased Nrf2 and HO-1 expression, reduced active Caspase-3 expression.
Objective To explore the expression and effect of heme oxygenase-1 ( HO-1) in ventilator-induced lung injury. Methods Twenty-four New Zealand rabbits were randomly assigned to three groups, ie. a conventional ventilation + PEEP group( C group) , a ventilator-induced lung injury group( VILI group) , and a VILI + HO-1 inducer hemin group( Hm group) .Western blot and immunohistochemistry assay were used to investigate the expression of HO-1 protein. Blood gas analysis, lung wet /dry ratio, lunghistopathology and lung injury score were used to evaluate lung injury. Results HO-1 protein expression significantly increased in the VILI group compared with the C group. HO-1 was found mainly in alveolar epithelial cells and vascular endothelial cells, as well as in alveolar macrophages and neutrophils. Compared with the VILI group, HO-1 protein and PaO2 /FiO2 increased, while lung wet/dry ratio and lung injury score decreased in the Hmgroup significantly( P lt;0. 05) . Conclusion High HO-1 expression can alleviate lung injury from large tidal volume ventilation, implying its protective role in lung pathogenesis.
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.
Objective To determine the anti-apoptosis effects of heme oxygenase-1 (HO-1) on lung injury after cardiopulmonary bypass (CPB), and to investigate its probable mechanisms. Methods A total of 144 male Wistar rats with wight of 250-350 g were divided into 3 groups: group A (control group), group B (cobalt protoporphyrin, CoPP), and group C [CoPP and zinc protoporphyrin (ZnPP)] randomly. A modified rat model of CPB-induced lung injury was established. And then the lung tissues were taken at different times for the relevant indicators test: before CPB (T0), immediately after CPB (T1), 2 h after CPB (T2), 6 h after CPB (T3), 12 h after CPB (T4), and 24 h after CPB (T5). The expression of HO-1 and Bcl-2 protein in each group was tested by immunohistochemistry, and cell apoptosis by TUNEL. Results The HO-1 protein expression in group B was significantly higher than that in groups A and C at any given time point, so was the HO-1 activity (P<0.05). There was no significant difference in Bcl-2 expression of lung tissue before CPB among each group (P>0.05). The Bcl-2 protein reduced gradually after CPB. The expressions of Bcl-2 protein in group B at all time points after bypass were significantly higher than that in groups A and C (P<0.05). The apoptosis index (AI) showed no significant difference before CPB in each group (P>0.05), and increased gradually after CPB. AI in group B at any time point after bypass was lower than that in groups A and C (P<0.05). The HE staining results showed that the damage of lung tissue in group B obviously reduced compared with groups A and C. Conclusion CoPP can induce a large amount of HO-1 expression in the lung tissue, and it is still highly expressed after CPB. So it plays an important role in anti-apoptosis through the up-regulation of Bcl-2 protein expression.
Objective To observe the effect of high expression of polypyrimidine tract-binding protein-associated splicing factor (PSF) on low concentration of 4-hydroxynonenal (4-HNE) induced human retinal microvascular endothelial cells (HRMECs), and explore the possible mechanism. MethodsThe HRMECs cultured in vitro were divided into 4-HNE treated group, PSF overexpression group combined with 4-HNE group (PSF+4-HNE group), PSF overexpression+ML385 treatment combined with 4-HNE group (PSF+ML385+4-HNE group), and 4-HNE induced PSF overexpression group with LY294002 pretreatment (LY294002+4-HNE+PSF group). Cell culture medium containing 10 μmmol/L 4-HNE was added into 4-HNE treatment group, PSF+4-HNE group, PSF+ML385+4-HNE group for 12 hours to stimulate oxidative stress. 1.0 μg of pcDNA-PSF eukaryotic expression plasmid were transfected into PSF+4-HNE group and PSF+ML385+4-HNE group to achieve the overexpression of PSF. Also cells were pretreated with ML385 (5 μmol/L) for 48 hours in the PSF+ML385+4-HNE group, meanwhile within the LY294002+4-HNE+PSF group, after pretreatment with LY294002, cells were treated with plasmid transfection and 4-HNE induction. Transwell detects the migration ability of PSF to HRMECs. The effect of PSF on the lumen formation of HRMECs was detected by using Matrigel in vitro three-dimensional molding method. Flow cytometer was used to detect the effect of PSF overexpression on reactive oxygen (ROS) level in HRMECs. Protein immunoblotting was used to detect the relative expression of PSF, nuclear factor E2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1) protein, and phosphoserine threonine protein kinase (pAkt) protein. The comparison between the two groups was performed using a t-test. ResultsThe number of live cells, migrating cells, and intact lumen formation in the 4-HNE treatment group and the PSF+4-HNE group were 1.70±0.06, 0.80±0.13, 24.00±0.58, 10.00±0.67, and 725.00±5.77, 318.7±12.13, respectively. There were significant differences in the number of live cells, migrating cells, and intact lumen formation between the two groups (t=12.311, 15.643, 17.346; P＜0.001). The results of flow cytometry showed that the ROS levels in the 4-HNE treatment group, PSF+4-HNE group, and PSF+ML385+4-HNE group were 816.70±16.67, 416.70±15.44, and 783.30±17.41, respectively. There were statistically significant differences between the two groups (t=16.311, 14.833, 18.442; P＜0.001). Western blot analysis showed that the relative expression levels of pAkt, Nrf2, and HO-1 proteins in HRMECs in the 4-HNE treatment group, PSF+4-HNE group and LY294002+4-HNE+PSF group were 0.08±0.01, 0.57±0.04, 0.35±0.09, 0.17±0.03, 1.10±0.06, 0.08±0.11 and 0.80±0.14, 2.50±0.07, 0.50±0.05, respectively. Compared with the PSF+4-HNE group, the relative expression of pAkt, Nrf2, and HO-1proteins in the LY294002+4-HNE+PSF group decreased significantly, with significant differences (t=17.342, 16.813, 18.794; P＜0.001). ConclusionPSF upregulates the expression of HO-1 by activating the phosphatidylinositol 3 kinase/Akt pathway and inhibits cell proliferation, migration, and lumen formation induced by low concentrations of 4-HNE.
ObjectiveTo observe the serum vascular endothelial growth factor (VEGF), apelin and heme oxygenase-1 (HO-1) levels in patients with type 2 diabetes mellitus (T2DM) and to explore their their relationship with diabetic retinopathy (DR).MethodsA total of 208 patients with T2DM and 50 healthy subjects (control group) from the Central Hospital of Western Hainan during January 2014 and December 2017 were selected in this study. Vision, slit lamp microscope, indirect ophthalmoscope and FFA examinations were performed on all the subjects. According to the results of the examinations combined with the DR clinical staging criteria, the patients were divided into non-DR (NDR) group, non-proliferative DR (NPDR) group, and proliferative DR (PDR) group, with 72, 76 and 60 patients in each, respectively. The clinical data of each group were recorded, and the levels of fasting blood glucose (FPG), HbA1c, total cholesterol (TC), three acylglycerol (TG), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), VEGF, apelin and HO-1 were detected in each group. The receiver operating characteristic curve (ROC) were used to analyze the value of VEGF, apelin and HO-1 in predicting the occurrence of PDR. Correlation analysis of serum VEGF, Apelin and HO-1 with clinical parameters in PDR patients by Pearson correlation analysis.ResultsThe level of VEGF (56.82±10.16 vs 91.74±22.83, 140.15±36.40, 195.28±42.26 pg/ml) and apelin (2.95±0.53 vs 4.68±0.74, 7.25±1.13, 10.16±1.35 ng/ml) in PDR group were significantly higher than those in NPDR, NDR and control groups (F=17.306, 21.814; P＜0.05). The level of HO-1 (50.37±10.14 vs 43.58±8.16, 30.25±6.28, 22.60±4.72 mmol/L) in PDR group was significantly lower than those in NPDR, NDR and control groups (F=15.827, P＜0.05). The ROC curve analysis showed that the best cut-off values of serum VEGF, apelin and HO-1 were 162.50 pg/ml, 8.30 ng/ml, 27.13 mmol/L, and the three combined to predict PDR of AUC (95%CI) was 0.906 (0.849−0.962), and their sensitivity (90.3%) and specificity (83%) were better. The correlation analysis showed that the VEGF, apelin and HO-1 of PDR patients were correlated with the course of diabetes (r=0.382, 0.416, −0.36; P＜0.05), FPG (r=0.438, 0.460, −0.397; P＜0.05) and HbAlc (r=0.375, 0.478, −0.405; P＜0.05), and the serum VEGF were correlated with apelin and HO-1 (r=0.793, −0.594; P＜0.01).ConclusionElevated serum VEGF and apelin levels and reduced HO-1 levels are associated with the progression of DR, and the three combination helps predict the occurrence of PDR.
ObjectiveTo evaluate the effect of ZnPP Ⅸ on the expressions of heme oxygenase-1 (HO-1) and glutathione-Stransferase-π （GST-π） and the chemosensitivity of drug-resistant hepatic carcinoma cell line Bel/Fu, and explore it’s possibility to reverse drug-resistance and the relevant regulating mechanism. Methods①MTT assay was adopted to detect the drug sensitivity for adriamycin, mitomycin, and 5-fluorouracil of Bel/Fu cell after ZnPP Ⅸ being induced for 24 h. ②RTPCR was carried out to detect the expressions of HO-1 and GST-π mRNA after Bel/FU cells being treated with different concentrations ZnPP Ⅸ for 24 h. ResultsAfter Bel/Fu cells being treated with ZnPP Ⅸ for 24 h, the 50% inhibiting concentration (IC50) for drugs was decreased dramatically （Plt;0.05）. Meanwhile, the expressions of HO-1 and GST-π mRNA in the treated cells also decreased dose-dependently (Plt;0.01). ConclusionsZnPP Ⅸ can increase the chemosensitivity of Bel/FU cells by down-regulation of HO-1 and GST-π expression. ZnPP Ⅸ is a potential agent to reverse multidrug resistance of hepatic carcinoma cells.
【Abstract】ObjectiveTo investigate whether heme oxygenase-1 can alleviate the ischemiareperfusion injury of the aged donor liver. MethodsThe activity of superoxide dismutase (SOD) and catalase (CAT), and the contents of tocopherol (Vit E), ascorbic acid (Vit C) and malondialdehyde (MDA) were measured in the livers of adult SD rats (n=5) and aged SD rats (n=5). The experimental aged donor group (n=30) received intraperitoneal injection of Hemin 24 hours before operation, the control aged donor group(n=30) received saline. The histologic changes and apoptosis in the donor liver were observed. ResultsThe activity of SOD and the contents of Vit E and Vit C decreased significantly in 5 aged rats（P＜0.05）, but the content of MDA increased（P＜0.05）. Before the harvesting of the grafts, the activity of SOD and the contents of Vit E and Vit C increased significantly in rats pretreated with Hemin （P＜0.05） and the content of MDA decreased（P＜0.05）. The apoptotic cells in the livers pretreated with Hemin also decreased significantly after reperfusion（P＜0.05）. ConclusionThe liver of aged rat presents oxidative stress and peroxidative state. Ischemia-reperfusion injury can be alleviated by the induction of HO-1.
Objective To investigate the effect of heme oxygenase-1 (HO-1) activity on rat liver transplantation model. Methods One hundred and thirty-seven rats were divided into 4 groups. Study control group (n＝44)： 24 h before operation, saline 5 ml/kg was infused into peritoneal cavity of donor rats; Hemin group (n＝44)： hemin 100 mg/kg was infused into peritoneal cavity of donor rats 24 h before operation, and hemin 100 mg/kg was infused into portal vein during the preserve time in 4 ℃ saline； ZnPP group (n＝44)： ZnPP 5 mg/kg was infused into peritoneal cavity of donor rats 24 h before operation, and ZnPP 5 mg/kg was infused into portal vein during the preserve time in 4 ℃ saline； Normal control group (n＝5)： normal rats as normal control group. Expressions of HO-1 protein and mRNA were detected with immunohistochemistry and RT-PCR technique respectively. The apoptosis rate of hepatocytes was analyzed by flow cytometry. Results Expression of HO-1 mRNA in the liver of hemin group after transplantation was higher than that in study control group obviously, serum ALT and AST levels were lower than those in study control group (P＜0.05); HO-1 mRNA expression in ZnPP group liver was lower than that in study control group, serum ALT and AST levels were higher than those in study control group (P＜0.05). About liver cell apoptosis rate 48 h after liver transplantation, ZnPP group was the highest, hemin group was the minimum, and there had a significant difference between two groups (P＜0.05). Seven days after transplantation, the survival ratios of control study group, hemin group and ZnPP group were 7/12, 9/12 and 4/12 in turn, the inter-group differences had statistical significance (P＜0.05). Conclusion Activity of HO-1 could be induced by the transplant operation. HO-1 increases the survival rate after liver transplantation which was related with reducing apoptotic ratio of hepatocyte and improve hepatic function.