Sleep deprivation reduces the baroreflex sensitivity through elevated angiotensin (Ang) II subtype 1 receptor expression in the nucleus tractus solitarii.

Introduction: Sleep insufficiency has been linked to an increased risk of high blood pressure and cardiovascular diseases. Emerging studies have demonstrated that impaired baroreflex sensitivity (BRS) is involved in the adverse cardiovascular effects caused by sleep deprivation, however, the underlying mechanisms remain unknown. Therefore, the present study aims to clarify the role of abnormal renin-angiotensin system in the nucleus tractus solitarii (NTS) in impaired BRS induced by sleep deprivation. Methods: Rats were randomly divided into two groups: normal sleep (Ctrl) and chronic sleep deprivation (CSD) group. Rats were sleep deprived by an automated sleep deprivation system. The blood pressure, heart rate, BRS, the number of c-Fos positive cells and the expression of angiotensin (Ang) II subtype 1 receptors (AT1R) in the NTS of rats were assessed. Results: Compared to Ctrl group, CSD group exhibited a higher blood pressure, heart rate, and reduced BRS. Moreover, the number of c-Fos positive cells and local field potential in the NTS in CSD group were increased compared with the Ctrl group. It was shown that the expression of the AT1R and the content of Ang II and the ratio of Ang II to Ang-(1-7) were increased in the NTS of rats in CSD group compared to Ctrl group. In addition, microinjection of losartan into the NTS significantly improved the impaired BRS caused by sleep deprivation. Discussion: In conclusion, these data suggest that the elevated AT1R expression in the NTS mediates the reduced BRS induced by chronic sleep deprivation.

Inflammatory Response: A Crucial Way for Gut Microbes to Regulate Cardiovascular Diseases.

Gut microbiota is the largest and most complex microflora in the human body, which plays a crucial role in human health and disease. Over the past 20 years, the bidirectional communication between gut microbiota and extra-intestinal organs has been extensively studied. A better comprehension of the alternative mechanisms for physiological and pathophysiological processes could pave the way for health. Cardiovascular disease (CVD) is one of the most common diseases that seriously threatens human health. Although previous studies have shown that cardiovascular diseases, such as heart failure, hypertension, and coronary atherosclerosis, are closely related to gut microbiota, limited understanding of the complex pathogenesis leads to poor effectiveness of clinical treatment. Dysregulation of inflammation always accounts for the damaged gastrointestinal function and deranged interaction with the cardiovascular system. This review focuses on the characteristics of gut microbiota in CVD and the significance of inflammation regulation during the whole process. In addition, strategies to prevent and treat CVD through proper regulation of gut microbiota and its metabolites are also discussed.

[Effect of Simulated Warming on Microbial Community in Glacier Forefield].

Glaciers are constantly retreating because of global warming. In this study, three soil samples along the forefield of Urumqi Glacier No. 1 were collected. The effects of warming on the microbial community in the glacier forefield were investigated through a 150-day laboratory experiment. In this experiment, two temperature treatments were performed at 5℃and 15℃. The results showed that with increasing deglaciation age, the concentrations of carbon and nitrogen increased and the abundance and alpha diversity of microbial communities increased in the original samples. The 150-day laboratory experiment indicated that warming insignificantly changed the copy number of archaea and bacteria. Furthermore, it changed the microbial community composition, and the changes varied in different sampling sites. Based on the analysis of abundant OTUs changing significantly with warming, the sampling sites with shorter deglaciation age had stronger response with warming, representing an increase in the abundance of genus Thiobacillus. Furthermore, these results revealed that warming caused different effects on microbes along glacier forefield and thus, it could provide important characteristics of the microbial community with warming in alpine glacier regions.