Sirtuin 2 deficiency aggravates ageing-induced vascular remodelling in humans and mice.

AIMS: The mechanisms underlying ageing-induced vascular remodelling remain unclear. This study investigates the role and underlying mechanisms of the cytoplasmic deacetylase sirtuin 2 (SIRT2) in ageing-induced vascular remodelling. METHODS AND RESULTS: Transcriptome and quantitative real-time PCR data were used to analyse sirtuin expression. Young and old wild-type and Sirt2 knockout mice were used to explore vascular function and pathological remodelling. RNA-seq, histochemical staining, and biochemical assays were used to evaluate the effects of Sirt2 knockout on the vascular transcriptome and pathological remodelling and explore the underlying biochemical mechanisms. Among the sirtuins, SIRT2 had the highest levels in human and mouse aortas. Sirtuin 2 activity was reduced in aged aortas, and loss of SIRT2 accelerated vascular ageing. In old mice, SIRT2 deficiency aggravated ageing-induced arterial stiffness and constriction-relaxation dysfunction, accompanied by aortic remodelling (thickened vascular medial layers, breakage of elastin fibres, collagen deposition, and inflammation). Transcriptome and biochemical analyses revealed that the ageing-controlling protein p66Shc and metabolism of mitochondrial reactive oxygen species (mROS) contributed to SIRT2 function in vascular ageing. Sirtuin 2 repressed p66Shc activation and mROS production by deacetylating p66Shc at lysine 81. Elimination of reactive oxygen species by MnTBAP repressed the SIRT2 deficiency-mediated aggravation of vascular remodelling and dysfunction in angiotensin II-challenged and aged mice. The SIRT2 coexpression module in aortas was reduced with ageing across species and was a significant predictor of age-related aortic diseases in humans. CONCLUSION: The deacetylase SIRT2 is a response to ageing that delays vascular ageing, and the cytoplasm-mitochondria axis (SIRT2-p66Shc-mROS) is important for vascular ageing. Therefore, SIRT2 may serve as a potential therapeutic target for vascular rejuvenation.

SIRT6 in Vascular Diseases, from Bench to Bedside.

Aging is a key risk factor for angiogenic dysfunction and cardiovascular diseases, including heart failure, hypertension, atherosclerosis, diabetes, and stroke. Members of the NAD+-dependent class III histone deacetylase family, sirtuins, are conserved regulators of aging and cardiovascular and cerebrovascular diseases. The sirtuin SIRT6 is predominantly located in the nucleus and shows deacetylase activity for acetylated histone 3 lysine 56 and lysine 9 as well as for some non-histone proteins. Over the past decade, experimental analyses in rodents and non-human primates have demonstrated the critical role of SIRT6 in extending lifespan. Recent studies highlighted the pleiotropic protective actions of SIRT6 in angiogenesis and cardiovascular diseases, including atherosclerosis, hypertension, heart failure, and stroke. Mechanistically, SIRT6 participates in vascular diseases via epigenetic regulation of endothelial cells, vascular smooth muscle cells, and immune cells. Importantly, SIRT6 activators (e.g., MDL-800/MDL-811) have provided therapeutic value for treating age-related vascular disorders. Here, we summarized the roles of sirtuins in cardiovascular diseases; reviewed recent advances in the understanding of SIRT6 in vascular biology, cardiovascular aging, and diseases; highlighted its therapeutic potential; and discussed future perspectives.

Vascular Calcification in Chronic Kidney Disease: An Update and Perspective.

Chronic kidney disease is a devastating condition resulting from irreversible loss of nephron numbers and function and leading to end-stage renal disease and mineral disorders. Vascular calcification, an ectopic deposition of calcium-phosphate salts in blood vessel walls and heart valves, is an independent risk factor of cardiovascular morbidity and mortality in chronic kidney disease. Moreover, aging and related metabolic disorders are essential risk factors for chronic kidney disease and vascular calcification. Marked progress has been recently made in understanding and treating vascular calcification in chronic kidney disease. However, there is a paucity of systematic reviews summarizing this progress, and investigating unresolved issues is warranted. In this systematic review, we aimed to overview the underlying mechanisms of vascular calcification in chronic kidney diseases and discuss the impact of chronic kidney disease on the pathophysiology of vascular calcification. Additionally, we summarized potential clinical diagnostic biomarkers and therapeutic applications for vascular calcification with chronic kidney disease. This review may offer new insights into the pathogenesis, diagnosis, and therapeutic intervention of vascular calcification.

Long-segment restrictive tear of radial artery under ultrasound guide for arteriovenous fistula by PTA: A case report.

Considerable calcification and stenosis frequently occur in the radial artery (RA) in diabetic nephropathy. PTA was performed successfully using a balloon to expand and restrictively tear the longitudinal axis of the RA. This approach seems to be a useful measure of promoting the maturation of AVF in diabetic nephropathy.

[Generalized science of Chinese material medica-from preventive treatment of disease to Chinese medicine health industry].

Based on the systematic summary of the results of the fourth general survey of traditional Chinese medicine resources, the cultivation of large varieties of Chinese material medica and the latest research on health industrial development, the novel concepts and scientific connotations of generalized science of Chinese material medica are put forward, and the basic ideas and methods of a new Chinese medicine academic system, the cultivation system of large varieties of Chinese medicinal materials and the application system of the large health industry are constructed. This kind of generalized science of Chinese material medica, rooted in the traditional Chinese culture and the theory of "preventive treatment of disease", can avoid the narrow prospect induced by the increasing specialization and refinement of knowledge of science of Chinese material medica. It will play an important role in the modernization, industrialization, internationalization of traditional Chinese medicine.

[New method for evaluating pharmacodynamics of traditional Chinese medicine compounds based on its moderate regulation and principle of balanced adjustment of immunity under pan-immunomic].

For the basic research on the traditional Chinese medicine(TCM), objective syndrome of traditional Chinese medicine and evaluation criteria of traditional Chinese medicine compounds are hardly to break though. While, the modern immunology points out that the body is a counterbalance state and immune imbalance is the root of sickness. The thinking mode of treating diseases in traditional Chinese medicine is also "balance", considering disease is the result of bias which present the imbalance of "Yin counters Yang", "exterior counters interior", "cold counters heat" and "weak counters strong". The Chinese herbal compound formula preparation was applied on disease therapy based on theory of Chinese medicine, which was confirmed by long period clinical application. It is composed of multi-compounds and has the characteristic of multi-targeting. Integrative medicine has spawned pan-immunomics, and the evaluation of immune function (immune balance) has become an important basis for diagnosis and treatment models of integrative medicine. In addition, balance is the core idea of whole-systemic conception of traditional Chinese medicine. Therefore, we speculate that immune balance under pan-immunomic can bridge the traditional Chinese medicine and modern integrative medicine and is the important basis for objective syndrome of traditional Chinese medicine and evaluation criteria of traditional Chinese medicine compounds. According to the bridging theory, we attempt to utilize informatics and statistical methods to construct an evaluation system for pharmacodynamics of traditional Chinese medicine based on its moderate regulation and the balanced adjustment of immunity under pan-immunomic, which further reveal the scientific essence of the whole-systemic view of traditional Chinese medicine. This research brings out a new valuable strategy and provides a theoretical basis for accelerating the transformation of traditional Chinese medicine, especially the exploitation of Chinese herbal compound formula, and constructing the new drug innovation and review system for traditional Chinese medicine. Besides as a reference for traditional Chinese medicine objective syndrome and pharmacodynamics of traditional Chinese medicine compounds, the evaluation system can screen the immunity of sub-health population also. With the continuous accumulation of clinical sample and data, the evaluation system will be more accurate and intelligent.

Epigenetic regulation of NKG2D ligands is involved in exacerbated atherosclerosis development in Sirt6 heterozygous mice.

Sirt6 is a member of the class III histone deacetylase family which is associated with aging and longevity. Sirt6 deficient mice show an aging-like phenotype, while male transgenic mice of Sirt6 show increased longevity. Sirt6 acts as a tumor suppressor and deficiency of Sirt6 leads to cardiac hypertrophy and heart failure. Whether Sirt6 is involved in atherosclerosis development, the major cause of cardiovascular diseases, is unknown. We found that the expression of Sirt6 is lower in human atherosclerotic plaques than that in controls. When Sirt6(+/-)ApoE(-/-) and ApoE(-/-) mice are fed with high fat diet for 16 weeks, Sirt6(+/-)ApoE(-/-) mice show increased plaque fromation and exhibit feature of plaque instability. Furthermore, Sirt6 downregulation increases expression of NKG2D ligands, which leads to increased cytokine expression. Blocking NKG2D ligand almost completely blocks this effect. Mechanistically, Sirt6 binds to promoters of NKG2D ligand genes and regulates the H3K9 and H3K56 acetylation levels.

[Quercetin permeability across blood-brain barrier and its effect on the viability of U251 cells].

OBJECTIVE: To investigate the permeability of quercetin across blood-brain barrier (BBB) and its impact on the proliferation and apoptosis of U251 cells. METHODS: The BBB model was established through culture of primary brain microvessel endothelial cells (BMVEC) and primary astroglia cells (AC), which was confirmed by transmission electron microscopy (TEM) and trans epithelial electric resistance (TEER). High pressure liquid chromatography (HPLC) was performed to determine quercetin permeability across BBB. U251 cells were exposed to quercetin. MTT assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), single-cell gel electrophoresis (SCGE) and flow cytometry (FCM) were performed to analyze cell proliferation, apoptosis, DNA damage and cell cycle distribution. RESULTS: The BBB was constructed successfully. Up to 65.54% of quercetin permeated across the BBB. Quercetin attenuated the proliferation of U251 and induced apoptosis. The FCM revealed that the U251 cells were inhibited at the G2/M point. CONCLUSION: Quercetin can permeate across the BBB effectively, restraining the proliferation of U251 cells and inducing apoptosis.

[The effects of human 21.5 kDa MBP gene on HepG-2 proliferation and apoptosis].

OBJECTIVE: To test the effects of the 21.5 kDa human brain myelin basic protein (MBP) on the proliferation and apoptosis of HepG-2. METHODS: pSVCEP-MBP-CAT plasmid containing the full-length 21.5 kDa MBP cDNA was transfected into human hepatoma carcinoma cells (HepG-2). The pSVCEP-CAT vector transfected HepG-2 cells served as negative control. RT-PCR and Western blot were performed to confirm the effectiveness of the transfection. MTT measures were used to determine the proliferative curve of cells. H2O2 was then added to induce cell apoptosis. DNA ladder, immunohistochemistry assay, comet electrophoresis and TUNEL (Terminal Deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling) were used to detect the apoptosis and relevant protein expressions. RESULTS: The 21.5 KDa MBP cDNA was transfected into HepG-2 cells successfully. MTT measures of pSVCEP-MBP-CAT transfected group showed increased proliferation and anti-apoptosis. The control group displayed with more typical DNA ladders and much higher level of Caspase-3 than the MBP group. Comet and TUNEL assays revealed that the control group cells had significant DNA damages and serious apoptosis, whereas the MBP group showed slight changes. CONCLUSION: The 21.5 kDa MBP promotes the proliferation of HepG-2 and blocks apoptosis.