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SummaryThe Himalayan marmot (Marmota himalayana) is a hibernating mammal that inhabits the high-elevation regions of the Himalayan mountains. Here we present a draft genome of the Himalayan marmot, with a total assembly length of 2.47 Gb. Phylogenetic analyses showed that the Himalayan marmot diverged from the Mongolian marmot approximately 1.98 million years ago. Transcriptional changes during hibernation included genes responsible for fatty acid metabolism in liver and genes involved in complement and coagulation cascades and stem cell pluripotency pathways in brain. Two selective sweep genes, Slc25a14 and ψAamp, showed apparent genotyping differences between low- and high-altitude populations. As a processed pseudogene, ψAamp may be biologically active to influence the stability of Aamp through competitive microRNA binding. These findings shed light on the molecular and genetic basis underlying adaptation to extreme environments in the Himalayan marmot.

Hyperhomocysteinemia (HHcy) is a risk factor for cardiovascular disease. The S-nitrosylation of proteins is involved in the regulation of cardiovascular functions. However, whether homocysteine (Hcy) impairs vascular functions through the inhibition of protein S-nitrosylation in the endothelium remains to be determined. The experiments were performed in human umbilical vein endothelial cells (HUVECs). Male Sprague‑Dawley rats, with or without administration of L-methionine, were used for the in vivo validation of findings. S-nitrosylation was analyzed using immunofluorescence for nitrosocysteine, and further confirmed by the biotin switch method. The levels of reactive oxygen species (ROS) were detected by 2',7'-dichlorofluorescein diacetate (DCFH-DA) staining. The levels of nitric oxide (ΝΟ) were determined by the nitrate reduction method. Protein expression was analysed by western blot analysis. The activity of nuclear factor κB (NF-κB) was evaluated by an electrophoretic mobility shift assay (EMSA). The levels of plasma Hcy were measured by ELISA. The results showed that Hcy significantly reduced the levels of protein S-nitrosylation in HUVECs and endothelial S-nitrosylation of aorta. This reduction of protein S-nitrosylation was accompanied by increasing ROS, decreasing phosphorylation levels of Akt and endothelial nitric oxide synthase (eNOS), and reduced levels of nitric oxide in HUVECs. In addition, it was found that Hcy increased the protein expression of vascular cell adhesion molecule-1 by attenuating the cytoplasm S-nitrosylation of NF-κB (p65). These data suggested that Hcy impairs endothelial functions by inhibiting endothelial protein S-nitrosylation.

Objective: Apo (apolipoprotein) CIII mediates the metabolism of triglyceride (TG)-rich lipoproteins. High levels of plasma apoCIII are positively correlated with the plasma TG levels and increase the cardiovascular risk. However, whether apoCIII is directly involved in the development of atherosclerosis has not been fully elucidated. Approach and Results: To examine the possible roles of apoCIII in lipoprotein metabolism and atherosclerosis, we generated apoCIII KO (knockout) rabbits using ZFN (zinc finger nuclease) technique. On a normal standard diet, apoCIII KO rabbits exhibited significantly lower plasma levels of TG than those of WT (wild type) rabbits while total cholesterol and HDL (high-density lipoprotein) cholesterol levels were unchanged. Analysis of lipoproteins isolated by sequential ultracentrifugation revealed that reduced plasma TG levels in KO rabbits were accompanied by prominent reduction of VLDLs (very-low-density lipoproteins) and IDLs (intermediate-density lipoproteins). In addition, KO rabbits showed faster TG clearance rate after intravenous fat load than WT rabbits. On a cholesterol-rich diet, KO rabbits exhibited constantly and significantly lower levels of plasma total cholesterol and TG than WT rabbits, which was caused by a remarkable reduction of β-VLDLs—the major atherogenic lipoproteins. β-VLDLs of KO rabbits showed higher uptake by cultured hepatocytes and were cleared faster from the circulation than β-VLDLs isolated from WT rabbits. Both aortic and coronary atherosclerosis was significantly reduced in KO rabbits compared with WT rabbits. Conclusions: These results indicate that apoCIII deficiency facilitates TG-rich lipoprotein catabolism, and therapeutic inhibition of apoCIII expression may become a novel means not only for the treatment of hyperlipidemia but also for atherosclerosis.

Increased plasma levels of C-reactive protein (CRP) are closely associated with cardiovascular diseases, but whether CRP is directly involved in the pathogenesis of atherosclerosis is still under debate. Many controversial and contradictory results using transgenic mice and rabbits have been published but it is also unclear whether CRP lowering can be used for the treatment of atherosclerosis. In the current study, we examined the effects of the rabbit CRP antisense oligonucleotides (ASO) on the development of atherosclerosis in WHHL rabbits. CRP ASO treatment led to a significant reduction of plasma CRP levels; however, both aortic and coronary atherosclerotic lesions were not significantly changed compared to those of control WHHL rabbits. These results suggest that inhibition of plasma CRP does not affect the development of atherosclerosis in WHHL rabbits.