ABSTRACT
ObjectiveTo observe the effect of earthworm protein on the expression of phosphatidylinositol 3-kinase/protein kinase B/nuclear factor E2-related factor 2 （PI3K/Akt/Nrf2） pathway in the aorta of spontaneously hypertensive rats （SHR） and explore mechanism of earthworm protein in treating hypertensive vascular endothelial dysfunction （VED）. MethodTen 10-week-old Wistar Kyoto （WKY） rats and fifty SHR rats were selected for a week of adaptive feeding. WKY rats were selected as the normal group， and fifty SHR rats were randomized according to body weight into model， valsartan （8×10-3 g·kg-1·d-1）， and high-， medium-， and low-dose （0.2， 0.1， 0.05 g·kg-1·d-1， respectively） earthworm protein groups. The normal and model groups were administrated with equal volume of double distilled water by gavage. During the drug intervention period， the general situations of rats in each group were observed and their blood pressure was monitored at specific time points every other week before and after administration. After 8 weeks of drug intervention， enzyme-linked immunosorbent assay was employed to measure the levels of angiotensin-Ⅱ （Ang-Ⅱ） and endothelin-1 （ET-1） in the serum of rats in each group. The corresponding kits were used to determine the levels of nitric oxide （NO）， malondialdehyde （MDA）， glutathione peroxidase （GPX）， superoxide dismutase （SOD）， and ferrous ion （Fe2+）. Hematoxylin-eosin （HE） staining was employed to observe the changes in the intima of the aorta. Fluorescence quantitative polymerase chain reaction （Real-time PCR） was employed to measure the mRNA levels of PI3K， Akt， Nrf2， heme oxygenase-1 （HO-1）， and glutathione peroxidase 4 （GPX4） in the aortic tissue. Western blotting was used to determine the protein levels of p-PI3K （Tyr467/199）， PI3K， p-Akt （Ser473）， Akt， Nrf2， HO-1， and GPX4 in the thoracic aorta. ResultCompared with the normal group， the model group had decreased body mass， increased irritability， severe endothelial damage， elevated blood pressure and serum levels of Ang-Ⅱ， ET1， MDA， and Fe2+ （P<0.01）， lowered NO level （P<0.01）， and down-regulated mRNA and protein levels of p-PI3K （Tyr467/199）， PI3K， p-Akt （Ser473）， Akt， Nrf2， HO-1， and GPX4 in the aortic tissue （P<0.01）. Compared with the model group， drug intervention caused no significant change in the body mass， calmed the rats， alleviated the endothelial damage， lowered blood pressure and serum levels of Ang-Ⅱ， ET1， MDA， and Fe2+ （P<0.01）， elevated the NO level （P<0.05）， and up-regulated the mRNA and protein levels of p-PI3K （Tyr467/199）， PI3K， p-Akt （Ser473）， Akt， Nrf2， HO-1， and GPX4 （P<0.05）. ConclusionThe earthworm protein can exert antihypertensive effects by ameliorating VED in SHR. Specifically， it may regulate the PI3K/Akt/Nrf2 signaling pathway to inhibit oxidative stress and ferroptosis.
ABSTRACT
Objectives To establish a model of carotid atherosclerotic (AS)stenosis in rabbits and to preliminarily investigate the expression of asparaginyl endopeptidase. Methods Fourteen New Zealand white rabbits were divided into either an model group (n = 8)or a sham operation group (n = 6)according to the random number table. The carotid intima was injured by operation in the model group. The rabbits in both groups were fed with high fat diets containing magnesium for 10 weeks. The rabbits were weighted and their blood lipids were tested every 2 weeks. At the end of the fifth and tenth weeks after procedure,the plaque and vessel stenosis of the rabbits were observed by MRI. At the end of the tenth week after proce-dure,the specimens were collected and sliced. Hematoxylin and eosin (HE)staining was used to observe the pathological changes. Immunohistochemical staining was used to analyze the expression of asparaginyl endopeptidase (AEP). Results One rabbit in the model group died of carotid artery injury. After being fed with high-fat diets,the body quality and the level of blood lipid were increased in the rabbits of both groups compared with those before procedure (all P < 0. 01). At the end of the fifth and tenth weeks after procedure,MRI revealed that the luminal stenosis rates in the operation group were 16 ± 11% and 53 ± 20% respectively. There was significant difference within the group (t = - 4. 83,P < 0. 01). MRI revealed no luminal stenosis twice in the sham operation group. HE staining showed intimal hyperplasia,AS plaque formation,lipid deposition in plaques,macrophage and smooth muscle cells migration and infiltration forming foam cells in the model group. No AS formation was observed in the sham operation group. The expression of AEP was higher in the rabbit carotid artery tissue in the model group,and it expressed rarely in the sham surgery group. The absorbance values were 0. 072 0 ± 0. 028 0 and 0. 002 0 ± 0. 000 9 respectively. There was significant difference (t = 6. 61,P < 0. 01). Conclusions The methods of injuring carotid intima combined with magnesium containing high-fat diet may exactly,reliably,and quickly establish an AS carotid artery stenosis model. AEP may associat with the occurrence of AS plaques.
ABSTRACT
ObjectiveTo evaluate the ability of high resolution magnetic resonance (MR) imaging at 3.0 tesla to depict the characterization of human carotid arterial vessel wall and detect atherosclerotic lesions ex vivo in comparison to histopathologic results. MethodsEighteen carotid arteries obtained from 9 elderly donors underwent fat-suppressed T1 - and T2-weighted MR imaging at 3.0 tesla MR system with a mouse coil. Corresponding histological sections were obtained for the comparison. Correlation between MR images and histopathologic slices was obtained by Pearson or Spearman correlation coefficient.Cohen K was computed to quantify the agreement between MRI and histopathologic findings.Results Lumen area,intima and media area measured on fat-suppressed T2-weighted images showed stronger correlation with the corresponding histopathologic slices [ MRI vs.histopathology:( 27. 53 ± 6. 77 ) mm2 vs.( 25.83 ±6. 69 ) mm2, r2 ＝ 0. 91,P2 ＝ 0. 024, ( 12.31 ± 3. 31 ) mm2 vs.( 12. 28 ± 3.71 ) mm2, r2 ＝ 0. 70, P2 ＝ 0. 020,Median 12. 29 mm2(Min 1.12 mm2, Max 33.18 mm2) vs.Median 11.62 mm2(Min 0.89 mm2, Max 32. 84 mm2 ), r2 ＝ 0. 74, P2 ＝ 0. 016, respectively]. The Cohen K score between the MR imaging and American Heart Association classifications was 0. 74, which corresponds to a good agreement. Conclusions 3.0 T high-resolution multi-sequence MRI can clearly show the structure of ex vivo carotid artery wall and allow quantitative assessment.Fat-suppressed T2Wimaging has a greater advantagein presenting atherosclerotic lesions.
ABSTRACT
Objective To analyze and explore the value of 3 T high resolution magnetic resonance vessel wall imaging for identifying the activity of Takayasu arteritis. Methods Twenty-six consecutive patients with Takayasu arteritis underwent 3.0 T high resolution MR vessel wall imaging on supraortic vessels (according to the classification of Lupi-Herrea , type Ⅰ and Ⅲ were included). Sixteen patients were in active phase and 10 in inactive phase based on the Kerr criteria. The MR vessel wall imaging appearances of Takayasu arteritis were compared between the active phase and inactive phase cases. Results Wall thickening was demonstrated in all involved arteries. There were statistically significant differences between active phase and inactive phase cases in MR appearances including multi-ring thickening of vessel wall (75/80 and 18/50), arterial inner wail enhancement (50/80 and 19/50), obscurity of perivascular fat (55/80 and 18/50,X<'2>=50.39,7.41,13.40,P<0.01). There was also a statistically significant difference in the thickness of carotid artery wall between the two groups [ (3.8±0.2) mm vs (2.5±0.8) mm]. Conclusion 3 T high resolution MR vessel wall imaging is valuable for identifying the activity of Takayasu arteritis.