Selenium Deficiency Promotes Dilatation of the Aorta by Increasing Expression and Activity of Vascular Smooth Muscle Cell Derived Matrix Metalloproteinase-2.

OBJECTIVE: Selenium (Se) is a key part of the body's oxidation defence system. However, it is unclear whether Se affects the development of aortic aneurysm (AA). An animal experiment was conducted to clarify the role of Se in AA development. METHODS: C57BL/6N male mice were fed with a Se deficient (Se-D, < 0.05 mg/kg), Se adequate (Se-A, 0.2 mg/kg), or Se supplemented (Se-S, 1 mg/kg) diet for 8 weeks. Subsequently, an AA murine model (Se-D, n = 11; Se-A, n = 12; Se-S, n = 15) was established using angiotensin II (Ang II, 1 mg/kg/min) for four weeks plus ß-aminopropionitrile (BAPN, 1 mg/mL) for the first two weeks. Saline replaced Ang II, and BAPN was removed during the modelling process for sham mice (Se-A, n = 9). To determine whether Se deficiency promoted aortic dilation via matrix metalloproteinase-2 (MMP-2), the non-specific MMP inhibitor doxycycline (Dox, 100 mg/kg/day) was given to Se-D AA mice (n = 7) for two weeks. RESULTS: The maximum aortic diameter in Se-D AA model mice was significantly increased compared with Se-A AA model mice. MMP-2 expression and activity in the aortic media of Se-D AA model mice was significantly increased compared with Se-A AA model mice. A large number of vascular smooth muscle cells (VSMCs) were found aggregating in the media of the non-dilated aorta of Se-D AA model mice, which was completely inhibited by Dox. The percentage of VSMCs in aortic media of Se-D AA model mice was significantly higher than in Se-A AA model mice. The maximum aortic diameter and occurrence rate of AA in Se-D AA model mice with Dox were significantly reduced compared with Se-D AA model mice. CONCLUSION: Se deficiency promoted dilatation of the aorta in AA model mice by increasing expression and activity of VSMC derived MMP-2, causing abnormal aggregation and proliferation of VSMCs in aortic media.

Clinical Outcomes of Cardiac Shockwave Therapy in Severe Coronary Artery Disease Patients after Coronary Artery Bypass Grafting.

Cardiac shockwave therapy (CSWT) is a noninvasive treatment for patients with refractory angina or myocardial ischemia. This study aims to evaluate the potential beneficial effect and safety of CSWT in patients with severe coronary artery disease (CAD) who have undergone coronary artery bypass grafting (CABG).This was a single-arm prospective cohort study. A total of 30 patients with severe CAD who were not suitable for coronary revascularization and who had undergone CABG were enrolled. All patients received CSWT for nine sessions. Evaluation was performed before and after CSWT, including the Canadian Cardiovascular Society (CCS) classification, New York Heart Association (NYHA) classification, 6-minute walk test (6MWT), Seattle Angina Questionnaire (SAQ) score, nitroglycerin dosage, echocardiography, myocardial perfusion imaging (MPI), and safety parameters. All patients were followed up at both 1 month and 9 months after CSWT.After treatment, CSWT significantly improved CCS classification (P < 0.05), NYHA classification (P < 0.05), nitroglycerin dosage (P < 0.001), and 6MWT (P < 0.05) at 1 month and 9 months after CSWT. SAQ score (P < 0.05) and left ventricular ejection fraction (LVEF; P = 0.037) by echocardiography significantly improved at 1 month after CSWT. Significant decreases in summed stress score (SSS), summed difference score (SDS), ischemic area stress, and ischemic area difference by MPI were observed at 1 month and 9 months after CSWT (P < 0.01). There were no changes in safety parameters before and after CSWT.CSWT may have a beneficial effect on improving myocardial perfusion, clinical symptoms, exertional capacity, and quality of life and is a safe alternative treatment for patients with severe CAD who have undergone CABG.

Magnetic Resonance/Infrared Dual-Modal Imaging-Guided Synergistic Photothermal/Photodynamic Therapy Nanoplatform Based on Cu1.96S-Gd@FA for Precision Cancer Theranostics.

Developing new nanoplatforms for dynamically and quantitatively visualizing drug accumulation and targeting within tumors is crucial for precision cancer theranostic. However, achieving efficient tumor therapy via synergistic photothermal/photodynamic therapy (PTT/PDT) using a single excitation light source, remains a challenge. In this work, we designed Gd-surface functionalized copper sulfide nanoparticles that were modified with folic acid (FA) (Cu1.96S-Gd@FA) to overcome the above limitations and promote PTT/PDT therapeutics. Here, Cu1.96S-Gd nanoparticles were synthesized via a coprecipitation method. All samples exhibited high longitudinal relaxivity (up to 12.9 mM-1 s-1) and strong photothermal conversion efficiency (50.6%). Furthermore, the Gd ions promoted electron-hole segregation, inducing the Cu1.96S-Gd nanoparticles to generate more reactive oxygen species (ROS) than pure Cu1.96S nanoparticles. The Cu1.96S-Gd@FA enabled the targeting of folate receptor (FR) and promoted cellular uptake, consequently enhancing oncotherapy efficacy. Compared to non-targeted Cu1.96S-Gd, a higher signal enhancement for magnetic resonance (MR) imaging in vivo by Cu1.96S-Gd@FA was recorded. Given photothermal ability, the nanoparticles also could be visualized in infrared (IR) imaging. Furthermore, the nanoparticles exhibited biodegradation behavior and achieved good drug elimination performance via renal clearance. Our strategy, integrating Cu1.96S-Gd@FA nanoparticles, MR/IR dual-modal imaging, and PTT/PDT into one nanoplatform, demonstrated great potential for anti-breast cancer therapy by effectively targeting FR overexpressed breast cancer cells.

Identification of CD4+ T-cell epitopes on iron-regulated surface determinant B of Staphylococcus aureus.

Iron-regulated surface determinant B (IsdB) of Staphylococcus aureus (S. aureus) is a highly conserved surface protein that can induce protective CD4(+) T-cell immune response. A pivotal role of CD4(+) T-cells in effective immunity against S. aureus infection has been proved, but CD4(+) T-cell epitopes on the S. aureus IsdB have not been well identified. In this study, MHC binding assay was firstly used to predict CD4(+) T-cell epitopes on S. aureus IsdB protein, and six peptides were synthesized to validate the probable epitopes. Two novel IsdB CD4(+) T-cell epitopes, P1 (residues 159-178) and P4 (residues 287-306), were for the first time identified using CD4(+) T-cells obtained from IsdB-immunized C57BL/6 (H-2(b)) and BALB/c (H-2(d)) mice spleen based on cell proliferation and cytokines response. The results showed that P1 and P4 emulsified in Freund's adjuvant (FA) induced much higher cell proliferation compared with PBS emulsified in FA. CD4(+) T-cells stimulated with peptides P1 and P4 secreted significantly higher levels of IFN-γ and IL-17A. However, the level of the cytokine IL-4 almost remained unchanged, suggesting that P1 and P4 preferentially elicited polarized Th1-type responses. In addition, BALB/c mice just respond to P4 not P1, while C57BL/6 mice respond to P1 not P4, implying that epitope P1 and P4 were determined as H-2(b) and H-2(d) restricted epitope, respectively. Taken together, our data may provide an explanation of the IsdB-induced protection against S. aureus and highlight the possibility of developing the epitope-based vaccine against the S. aureus.