No abstract

The aorta, with ascending, arch, thoracic and abdominal segments, responds to the heartbeat, senses metabolites and distributes blood to all parts of the body. However, the heterogeneity across aortic segments and how metabolic pathologies change it are not known. Here, a total of 216 612 individual cells from the ascending aorta, aortic arch, and thoracic and abdominal segments of mouse aortas under normal conditions or with high blood glucose levels, high dietary salt, or high fat intake were profiled using single-cell RNA sequencing. We generated a compendium of 10 distinct cell types, mainly endothelial (EC), smooth muscle (SMC), stromal and immune cells. The distributions of the different cells and their intercommunication were influenced by the hemodynamic microenvironment across anatomical segments, and the spatial heterogeneity of ECs and SMCs may contribute to differential vascular dilation and constriction that were measured by wire myography. Importantly, the composition of aortic cells, their gene expression profiles and their regulatory intercellular networks broadly changed in response to high fat/salt/glucose conditions. Notably, the abdominal aorta showed the most dramatic changes in cellular composition, particularly involving ECs, fibroblasts and myeloid cells with cardiovascular risk factor-related regulons and gene expression networks. Our study elucidates the nature and range of aortic cell diversity, with implications for the treatment of metabolic pathologies.

Vascular dementia (VaD) is the second most common type of dementia and has become a major public health challenge as the global population ages. VaD is caused by cerebrovascular disease, and most patients with VaD have been reported to also have Alzheimer's pathologies, which is the formation of neurofibrillary tangles and amyloid plaques that are mainly composed of hyperphosphorylated Tau and amyloid β (Aβ) respectively. However, the mechanisms of VaD are not completely understood, and very few drugs are available to treat this condition. Gastrodin (Gas) is the main bioactive component of the traditional Chinese herbal plant named Tian Ma (Gastrodia elata), and it has been used to treat neurasthenia in the clinical practice of Chinese Medicine for many years. Here, we hypothesize that Gas alleviates VaD in a rat model of permanent bilateral common carotid artery occlusion (2-VO)-induced VaD. Based on the results of the Morris water maze test and attention set shift test, either 22.5 or 90 mg/kg/day Gas improved the executive dysfunc-tion and memory impairment of 2-VO rats following an intragastric administration for 4 weeks. Both 22.5 and 90 mg/kg/ day Gas reduced Aβ 1-40 and Aβ 1-42 plaques in plasma and hippocampus of 2-VO rats. Mechanistically, in 2-VO rats, treatment with Gas (90 mg/kg/day) suppressed Aβ plaque deposition by decreasing the hippocampus levels of phosphorylated Tau. Thus, Gas ameliorated the cognitive deficits of 2-VO rats by inhibiting the abnormal phosphorylation of Aβ and Tau.

Cardiac hypertrophy is a major risk factor for heart failure, which are among the leading causes of human death. Gastrodin is a small molecule that has been used clinically to treat neurological and vascular diseases for many years without safety issues. In the present study, we examined protective effect of gastrodin against cardiac hypertrophy and explored the underlying mechanism. Phenylephrine and angiotensin II were used to induce cardiac hypertrophy in a mouse model and a cultured cardiomyocyte model. Gastrodin was found to alleviate the cardiac hypertrophy in both models. Mechanistically, gastrodin attenuated the store-operated Ca2+ entry (SOCE) by reducing the expression of STIM1 and Orai1, two key proteins in SOCE, in animal models as well as in cultured cardiomyocyte model. Furthermore, suppressing SOCE by RO2959, Orai1-siRNAs or STIM1-siRNAs markedly attenuated the phenylephrine-induced hypertrophy in cultured cardiomyocyte model. Together, these results showed that gastrodin inhibited cardiac hypertrophy and it also reduced the SOCE via its action on the expression of STIM1 and Orai1. Furthermore, suppression of SOCE could reduce the phenylephrine-induced cardiomyocyte hypertrophy, suggesting that SOCE-STIM1-Orai1 is located upstream of hypertrophy.

The pathophysiology of cardiac hypertrophy is complex and multifactorial. Both the store-operated Ca2+ entry (SOCE) and excessive autophagy are the major causative factors for pathological cardiac hypertrophy. However, it is unclear whether these two causative factors are interdependent. In this study, we examined the functional role of SOCE and Orai1 in angiotensin II (Ang II)-induced autophagy and hypertrophy using in vitro neonatal rat cardiomyocytes (NRCMs) and in vivo mouse model, respectively. We show that YM-58483 or SKF-96365 mediated pharmacological inhibition of SOCE, or silencing of Orai1 with Orail-siRNA inhibited Ang II-induced cardiomyocyte autophagy both in vitro and in vivo. Also, the knockdown of Orai1 attenuated Ang II-induced pathological cardiac hypertrophy. Together, these data suggest that Ang II promotes excessive cardiomyocyte autophagy through SOCE/Orai1 which can be the prime contributing factors in cardiac hypertrophy.