Dataset Information

SIRT6 protects vascular smooth muscle cells from osteogenic transdifferentiation via Runx2 in chronic kidney disease.

ABSTRACT: Vascular calcification (VC) is regarded as an important pathological change lacking effective treatment and associated with high mortality. Sirtuin 6 (SIRT6) is a member of the Sirtuin family, a class III histone deacetylase and a key epigenetic regulator. SIRT6 has a protective role in patients with chronic kidney disease (CKD). However, the exact role and molecular mechanism of SIRT6 in VC in patients with CKD remain unclear. Here, we demonstrated that SIRT6 was markedly downregulated in peripheral blood mononuclear cells (PBMCs) and in the radial artery tissue of patients with CKD with VC. SIRT6-transgenic (SIRT6-Tg) mice showed alleviated VC, while vascular smooth muscle cell-specific (VSMC-specific) SIRT6 knocked-down mice showed severe VC in CKD. SIRT6 suppressed the osteogenic transdifferentiation of VSMCs via regulation of runt-related transcription factor 2 (Runx2). Coimmunoprecipitation (co-IP) and immunoprecipitation (IP) assays confirmed that SIRT6 bound to Runx2. Moreover, Runx2 was deacetylated by SIRT6 and further promoted nuclear export via exportin 1 (XPO1), which in turn caused degradation of Runx2 through the ubiquitin-proteasome system. These results demonstrated that SIRT6 prevented VC by suppressing the osteogenic transdifferentiation of VSMCs, and as such targeting SIRT6 may be an appealing therapeutic target for VC in CKD.

SUBMITTER: Li W

PROVIDER: S-EPMC8718147 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

SIRT6 protects vascular smooth muscle cells from osteogenic transdifferentiation via Runx2 in chronic kidney disease.

Li Wenxin W Feng Weijing W Su Xiaoyan X Luo Dongling D Li Zhibing Z Zhou Yongqiao Y Zhu Yongjun Y Zhang Mengbi M Chen Jie J Liu Baohua B Huang Hui H

The Journal of clinical investigation 20220101 1

Vascular calcification (VC) is regarded as an important pathological change lacking effective treatment and associated with high mortality. Sirtuin 6 (SIRT6) is a member of the Sirtuin family, a class III histone deacetylase and a key epigenetic regulator. SIRT6 has a protective role in patients with chronic kidney disease (CKD). However, the exact role and molecular mechanism of SIRT6 in VC in patients with CKD remain unclear. Here, we demonstrated that SIRT6 was markedly downregulated in perip ...[more]

PMID: 34793336

Similar Datasets

Project description:Vascular calcification is prominent in patients with chronic kidney disease (CKD) and is a strong predictor of cardiovascular mortality in the CKD population. However, the mechanism underlying CKD-associated vascular calcification remains unclear. To identify potential therapeutic targets, a 5/6 nephrectomy rat model was established by feeding of a high-phosphorous diet as the CKD group and compared with sham group rats at 4 and 16 weeks. Sequencing analyses of the rat aorta revealed 643 upregulated and 1023 downregulated genes at 4 weeks, as well as 899 upregulated and 1185 downregulated genes at 16 weeks in the CKD group compared to the sham group. Bioinformatics analyses suggested that SOST (which encodes sclerostin) and Wnt signaling are involved in CKD-associated vascular calcification. Furthermore, protein-protein interactions analysis revealed interactions between SOST, WNT5A, and WNT5B, that involved runt-related transcription factor 2 (RUNX2) and transgelin (TAGLN). SOST was increased in CKD-associated vascular calcification following reduction of the Wnt signaling, including WNT5A and WNT5B, both in vivo and in vitro. TargetScan was used to predict the microRNAs (miRNAs) targeting WNT5A and WNT5B. The expression levels of miR-542-3p, miR-298-3p, miR-376b-5p, and miR-3568 were significantly reduced, whereas that of miR-742-3p was significantly increased in calcified rat aortic vascular smooth muscle cells (VSMCs). In CKD rat aortas, the expression of miR-542-3p, miR-298-3p, miR-376b-5p, miR-3568, miR-742-3p, and miR-22-5p were significantly reduced at both 4 and 16 weeks. Altogether, owing to several assessments, potentially diagnostic and prognostic biomarkers for improving common CKD diagnostic tools were identified in this study. Abbreviations: BUN: blood urea nitrogen; CKD: chronic kidney disease; CKD-MBD: chronic kidney disease-mineral bone disorder; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GO: the Gene Ontology; HE: hematoxylin-eosin; HRP: horseradish peroxidase; KEGG: Kyoto Encyclopedia of Genes and Genomes; MiRNAs: microRNAs; PAS: periodic acid-Schiff; RUNX2: runt-related transcription factor 2; SCr: serum creatinine; STRING: the Search Tool for the Retrieval of Interacting Genes/Proteins; TAGLN: transgelin; VSMC: vascular smooth muscle cell.

Project description:RationaleVascular smooth muscle cell (VSMC) senescence promotes atherosclerosis and features of plaque instability, in part, through lipid-mediated oxidative DNA damage and telomere dysfunction. SIRT6 (Sirtuin 6) is a nuclear deacetylase involved in DNA damage response signaling, inflammation, and metabolism; however, its role in regulating VSMC senescence and atherosclerosis is unclear.ObjectiveWe examined SIRT6 expression in human VSMCs, the role, regulation, and downstream pathways activated by SIRT6, and how VSMC SIRT6 regulates atherogenesis.Methods and resultsSIRT6 protein, but not mRNA, expression was markedly reduced in VSMCs in human and mouse atherosclerotic plaques, and in human VSMCs derived from plaques or undergoing replicative or palmitate-induced senescence versus healthy aortic VSMCs. The ubiquitin ligase CHIP (C terminus of HSC70-interacting protein) promoted SIRT6 stability, but CHIP expression was reduced in human and mouse plaque VSMCs and by palmitate in a p38- and c-Jun N-terminal kinase-dependent manner. SIRT6 bound to telomeres, while SIRT6 inhibition using shRNA or a deacetylase-inactive mutant (SIRT6H133Y) shortened human VSMC lifespan and induced senescence, associated with telomeric H3K9 (histone H3 lysine 9) hyperacetylation and 53BP1 (p53 binding protein 1) binding, indicative of telomere damage. In contrast, SIRT6 overexpression preserved telomere integrity, delayed cellular senescence, and reduced inflammatory cytokine expression and changes in VSMC metabolism associated with senescence. SIRT6, but not SIRT6H133Y, promoted proliferation and lifespan of mouse VSMCs, and prevented senescence-associated metabolic changes. ApoE-/- (apolipoprotein E) mice were generated that overexpress SIRT6 or SIRT6H133Y in VSMCs only. SM22α-hSIRT6/ApoE-/- mice had reduced atherosclerosis, markers of senescence and inflammation compared with littermate controls, while plaques of SM22α-hSIRT6H133Y/ApoE-/- mice showed increased features of plaque instability.ConclusionsSIRT6 protein expression is reduced in human and mouse plaque VSMCs and is positively regulated by CHIP. SIRT6 regulates telomere maintenance and VSMC lifespan and inhibits atherogenesis, all dependent on its deacetylase activity. Our data show that endogenous SIRT6 deacetylase is an important and unrecognized inhibitor of VSMC senescence and atherosclerosis.

Project description:BACKGROUND:In vitro cell culture is a widely used technique for investigating a range of processes such as stem cell behavior, regenerative medicine, tissue engineering, and drug discovery. Conventional cell culture is performed in Petri dishes or flasks where cells typically attach to a flat glass or plastic surface as a cell monolayer. However, 2D cell monolayers do not provide a satisfactory representation of in vivo conditions. A 3D culture could be a much better system for representing the conditions that prevail in vivo. METHODS AND RESULTS:To simulate 3D conditions, vascular smooth muscle cells (VSMCs) were loaded with gold-polyvmer-iron oxide hydrogel, enabling levitation of the cells by using spatially varying magnetic fields. These magnetically levitated 3D cultures appeared as freely suspended, clustered cells which proliferated 3-4 times faster than cells in conventional 2D cultures. When the levitated cells were treated with 10nM lysophosphatidylcholine (LPC), for 3days, cell clusters exhibited translucent extensions/rods 60-80?m wide and 200-250?m long. When 0.5?g/?l Schnurri-3 was added to the culture containing LPC, these extensions were smaller or absent. When excited with 590-650nm light, these extensions emitted intrinsic fluorescence at >667nm. When the 3D cultures were treated with a fluorescent probe specific for calcium hydroxyapatite (FITC-HABP-19), the cell extensions/rods emitted intensely at 518nm, the ?max for FITC emission. Pellets of cells treated with LPC were more enriched in calcium, phosphate, and glycosaminoglycans than cells treated with LPC and Schnurri-3. CONCLUSIONS:In 3D cultures, VSMCs grow more rapidly and form larger calcification clusters than cells in 2D cultures. Transdifferentiation of VSMC into calcifying vascular cells is enhanced by LPC and attenuated by Schnurri-3. GENERAL SIGNIFICANCE:The formation of calcified structures in 3D VSMC cultures suggests that similar structures may be formed in vivo.

Dataset Information

SIRT6 protects vascular smooth muscle cells from osteogenic transdifferentiation via Runx2 in chronic kidney disease.

Publications

SIRT6 protects vascular smooth muscle cells from osteogenic transdifferentiation via Runx2 in chronic kidney disease.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets