Melatonin inhibits angiotensin II-induced atrial fibrillation through preventing degradation of Ang II Type I Receptor-Associated Protein (ATRAP)

Angiotensin II (Ang II) induced Atrial fibrillation (AF) often accompanied with reduced ATRAP which is a negative modulator of Ang II type 1 receptor (AT1R). Melatonin can protect against AF, but the underlying molecular mechanism remains poorly understood. In this study, Ang II was used to induce AF, and AF inducibility and duration were documented telemetrically. Ang II-infused mice had a higher AF incidence, which was associated with atrial fibrosis, inflammation, and oxidative stress. Melatonin partially inhibited these effects, and enforced expression of siRNA-ATRAP in atria counteracted the beneficial role of melatonin. Specifically, melatonin inhibited expression of Ang II-induced proteasome and immunoproteasome subunits β2, β2i, β5, and β5i as well as their corresponding trypsin-like and chymotrypsin-like activities and blocked ATRAP degradation. In turn, this inhibited AT1R-mediated NF-κB signaling, transforming growth factor (TGF)-β1/Smad signaling in the atria, and thereby affected atrial remodeling and AF. Melatonin receptor inhibition by the chemical inhibitor luzindole partially inhibited the inhibitory effects of melatonin on proteasome activity and also Ang II-induced pathological changes in the atria. Overall, our study demonstrates that melatonin protects against Ang II-induced AF by inhibiting proteasome activity and stabilizing ATRAP expression, and these effects are partially dependent on melatonin receptor activation.

Rutaecarpine Inhibits Doxorubicin-Induced Oxidative Stress and Apoptosis by Activating AKT Signaling Pathway

Patients with cancer who receive doxorubicin (DOX) treatment can experience cardiac dysfunction, which can finally develop into heart failure. Oxidative stress is considered the most important mechanism for DOX-mediated cardiotoxicity. Rutaecarpine (Rut), a quinazolinocarboline alkaloid extracted from Evodia rutaecarpa was shown to have a protective effect on cardiac disease. The purpose of this study is to investigate the role of Rut in DOX-induced cardiotoxicity and explore the underlying mechanism. Intravenous injection of DOX (5 mg/kg, once a week) in mice for 4 weeks was used to establish the cardiotoxic model. Echocardiography and pathological staining analysis were used to detect the changes in structure and function in the heart. Western blot and real-time PCR analysis were used to detect the molecular changes. In this study, we found that DOX time-dependently decreased cardiac function with few systemic side effects. Rut inhibited DOX-induced cardiac fibrosis, reduction in heart size, and decrease in heart function. DOX-induced reduction in superoxide dismutase (SOD) and glutathione (GSH), enhancement of malondialdehyde (MDA) was inhibited by Rut administration. Meanwhile, Rut inhibited DOX-induced apoptosis in the heart. Importantly, we further found that Rut activated AKT or nuclear factor erythroid 2-related factor 2 (Nrf-2) which further upregulated the antioxidant enzymes such as heme oxygenase-1 (HO-1) and GSH cysteine ligase modulatory subunit (GCLM) expression. AKT inhibitor (AKTi) partially inhibited Nrf-2, HO-1, and GCLM expression and abolished the protective role of Rut in DOX-induced cardiotoxicity. In conclusion, this study identified Rut as a potential therapeutic agent for treating DOX-induced cardiotoxicity by activating AKT.

[A clinical analysis of Graves' ophthalmopathy and ophthalmic Graves' disease]

Clinical analysis of 29 cases of Graves' ophthalmopathy and 71 cases of ophthalmic Graves' disease showed that both identities had common ocular features of lid retraction, upper lid lag and exophthalmos, while Graves' ophthalmopathy tended to occur in later life, with longer morbid course, marked systemic symptoms and binocular involvement in contrast to ophthalmic Graves' disease. The clinical and differential diagnoses and treatment of the maladies were discussed.

[Immunologic analysis of Graves' ophthalmopathy and ophthalmic Graves' disease]

The authors found in 10 cases of Graves' ophthalmopathy and 35 cases of ophthalmic Graves' disease that the IgA, IgM, IgE, Tr, and Tr/Ts were higher and Ts was lower than those of the normal controls, and IgG, IgA, Et-RFC, Tr, OKT3 and OKT4 in the two diseases differed insignificantly, while the IgM, IgE, Ts, Tr/Ts, and OKT8 differed significantly.

[Enzyme linked counter reference electrophoresis assay and reverse passive hemagglutination assay in general survey of liver cancer]

The AFP content in sera of 11735 persons was tested by the new method-enzyme linked counter reference electrophoresis assay and the conventional method-reverse passive hemagglutination assay (RPHA). AFP level in 15 out of 11735 persons, determined by the former technique, was over the normal range, quite similar to those by radiorocket electrophoresis. A good correlation was noted between the two techniques. But by RPHA, AFP was positive only in 7/15 and gave a false positive up to 4.53% (532/11735). It is indicated that the new method is more specific and sensitive than RPHA, and more suitable for general survey of liver cancer.