[Effects of ursolic acid on oxidative stress and inflammatory factors in a rat model of AR after PM2.5 exposure]

Objective: To investigate the effects of ursolic acid (UA) on oxidative stress and inflammatory factors in a rat model of AR after PM2.5 exposure. Methods: Sixty healthy female SD rats were randomly divided into five groups: normal control group (NC group), PM2.5 unexposed AR group (AR group), PM2.5 exposed AR group (ARE group), UA intervention AR group (AR+UA group), and UA intervention PM2.5 exposed AR group (ARE+UA group), with 12 rats in each group. AR model was performed by a basal sensitization with intraperitoneal injection of ovalbumin (OVA) and followed by nasal instillation. PM2.5 exposure was carried out by inhalation exposure system at a concentration of 200 μg/m³ for 3 h/d for 30 days. UA intervention group was given UA intragastric administration at 20 mg/(kg·d). AR symptoms including sneezing, nasal scratching and nasal secretion of rats in each group were observed. The activities of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in nasal mucosa were tested. The pathological changes of nasal mucosa were observed by HE staining. The levels of OVA-sIgE, IL-6 and IL-17 in serum were measured by enzyme-linked immunosorbent assay (ELISA). Protein microarray was used to measure the expression of multiple inflammation cell factors in nasal mucosa. Statistical analysis was performed with SPSS 20.0. Results: After UA intervention, the frequency of nasal sneezing, scratching and nasal secretion in ARE+UA group were lower than those of ARE group (P<0.05). Pathological examination of nasal mucosa showed that ARE+UA group had less inflammatory granulocyte infiltration and less pathological damage to the epithelial layer than ARE group. The activities of SOD in nasal mucosa of ARE+UA group were higher than those of ARE group ((50.10±3.09) U/mg vs (20.13±1.30) U/mg, F value was 597.54, P<0.01). The contents of MDA in nasal mucosa of ARE+UA group were lower than those of ARE group ((57.78±12.36) nmol/g vs (124.12±9.40) nmol/g, F value was 115.51, P<0.01). The expression levels of OVA-sIgE, IL-6 and IL-17 proteins were lower in the ARE+UA group than those in ARE group ((11.61±0.27) ng/ml vs (20.30±0.67) ng/ml, (47.59±15.49) pg/ml vs (98.83±10.98) pg/ml, (623.30±8.75) pg/ml vs (913.32±9.06) pg/ml, F value was 283.42, 80.45, 683.73, respectively, all P<0.01). After UA intervention, protein microarray analysis showed that the expression of IL-4, IL-6, IL-13, chemokine CXCL7, IL-1α, IL-1β, MMP-8 and MCP-1 in ARE+UA group was decreased compared with ARE group while IFN-γ and IL-10 increased (all P<0.01). Conclusion: UA can reduce the aggravated AR symptoms and pathological damage of nasal mucosa, inhibit oxidative stress and release of inflammatory factors after PM2.5 exposure, and thus plays a protective role in the pathological damage of AR induced by PM2.5 exposure.

5-hydroxymethylcytosine profiles in circulating cell-free DNA as candidate diagnostic and predictive biomarkers for coronary artery disease

Background

DNA 5-hydroxymethylcytosine (5hmC) modification is an epigenetic marker involved in a range of biological processes. However, little information is available about its role in coronary artery disease (CAD), particularly in the acute phase of acute coronary syndrome (ACS).

Aims

To investigate whether 5hmC modification correlates with the pathogenesis and progression of CAD and whether 5hmC in cfDNA can be used as biomarkers.

Methods

We utilized 5hmC-Seal to generate genome-wide 5hmC profiles in plasma cell-free DNA (cfDNA) of normal coronary artery (NCA, n=200) controls and CAD patients, including stable coronary artery disease (sCAD, n=200) patients and ACS patients (n=371). To investigate the correlation between 5hmC modifications and CAD subtypes, we separated samples into training and validation cohorts and developed a 5hmC-based logistic regression model from the training cohort to predict the progression of CAD in the validation cohort.

Results

We detected a significant difference of 5hmC enrichment in gene bodies from CAD patients compared with NCA individuals. Particularly, our results showed that patients of CAD subgroups can be well separated from NCA individuals by 5hmC markers. The prediction performance of the model established by differentially regulated 5hmC modified genes achieved an AUC of 0.81 (sCAD vs. NCA) and 0.74 (ACS vs. NCA) in validation cohorts.

Conclusions

Our results demonstrated that patients of CAD subtypes and NCA individuals had distinct differences in 5hmC enrichment. 5hmC markers derived from plasma cfDNA may potentially serve as a clinical-applicable, minimally invasive, and liquid biopsy-based approach to diagnose CAD, particularly used to predict the occurrence of fetal ACS.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Chinese Academy of Medical Science (CAMS) Innovation Fund for Medical Sciences Figure 1Figure 2

The effects of normovolemic hemodilution with dextran-40 on acute myocardial ischemia/reperfusion injury in rabbits

The effects of decreasing blood viscosity by normovolemic hemodilution with dextran-40 or normal saline (NS) on myocardial lipid peroxides, superoxide dismutase, infarct size and left ventricular function during acute myocardial ischemia/reperfusion were studied in rabbits. It was found that normovolemic hemodilution with dextran-40 could decrease the content of ischemic myocardial malondialdehyde and preserve ischemic myocardial superoxide dismutase activity after 1 h of coronary occlusion followed by 1 h of reperfusion. However, after administration of NS only a tendency in this aspect exhibited without statistical significance. Besides, hemodilution with dextran-40 reduced infarct size and improved left ventricular systolic function after 1 h of ischemia followed by 23 h of reperfusion. These results suggest that normovolemic hemodilution with dextran-40 may have anti-injury effect on acute myocardial ischemia/reperfusion to a certain degree.