Spatial multiomics atlas reveals smooth muscle phenotypic transformation and metabolic reprogramming in diabetic macroangiopathy.

BACKGROUND: Diabetic macroangiopathy has been the main cause of death and disability in diabetic patients. The mechanisms underlying smooth muscle cell transformation and metabolic reprogramming other than abnormal glucose and lipid metabolism remain to be further explored. METHOD: Single-cell transcriptome, spatial transcriptome and spatial metabolome sequencing were performed on anterior tibial artery from 11 diabetic patients with amputation. Multi-omics integration, cell communication analysis, time series analysis, network analysis, enrichment analysis, and gene expression analysis were performed to elucidate the potential molecular features. RESULT: We constructed a spatial multiomics map of diabetic blood vessels based on multiomics integration, indicating single-cell and spatial landscape of transcriptome and spatial landscape of metabolome. At the same time, the characteristics of cell composition and biological function of calcified regions were obtained by integrating spatial omics and single cell omics. On this basis, our study provides favorable evidence for the cellular fate of smooth muscle cells, which can be transformed into pro-inflammatory chemotactic smooth muscle cells, macrophage-like smooth muscle cells/foam-like smooth muscle cells, and fibroblast/chondroblast smooth muscle cells in the anterior tibial artery of diabetic patients. The smooth muscle cell phenotypic transformation is driven by transcription factors net including KDM5B, DDIT3, etc. In addition, in order to focus on metabolic reprogramming apart from abnormal glucose and lipid metabolism, we constructed a metabolic network of diabetic vascular activation, and found that HNMT and CYP27A1 participate in diabetic vascular metabolic reprogramming by combining public data. CONCLUSION: This study constructs the spatial gene-metabolism map of the whole anterior tibial artery for the first time and reveals the characteristics of vascular calcification, the phenotypic transformation trend of SMCs, and the transcriptional driving network of SMCs phenotypic transformation of diabetic macrovascular disease. In the perspective of combining the transcriptome and metabolome, the study demonstrates the activated metabolic pathways in diabetic blood vessels and the key genes involved in diabetic metabolic reprogramming.

Nesfatin-1 enhances vascular smooth muscle calcification through facilitating BMP-2 osteogenic signaling.

Vascular calcification (VC) arises from the accumulation of calcium salts in the intimal or tunica media layer of the aorta, contributing to higher risk of cardiovascular events and mortality. Despite this, the mechanisms driving VC remain incompletely understood. We previously described that nesfatin-1 functioned as a switch for vascular smooth muscle cells (VSMCs) plasticity in hypertension and neointimal hyperplasia. In this study, we sought to investigate the role and mechanism of nesfatin-1 in VC. The expression of nesfatin-1 was measured in calcified VSMCs and aortas, as well as in patients. Loss- and gain-of-function experiments were evaluated the roles of nesfatin-1 in VC pathogenesis. The transcription activation of nesfatin-1 was detected using a mass spectrometry. We found higher levels of nesfatin-1 in both calcified VSMCs and aortas, as well as in patients with coronary calcification. Loss-of-function and gain-of-function experiments revealed that nesfatin-1 was a key regulator of VC by facilitating the osteogenic transformation of VSMCs. Mechanistically, nesfatin-1 promoted the de-ubiquitination and stability of BMP-2 via inhibiting the E3 ligase SYTL4, and the interaction of nesfatin-1 with BMP-2 potentiated BMP-2 signaling and induced phosphorylation of Smad, followed by HDAC4 phosphorylation and nuclear exclusion. The dissociation of HDAC4 from RUNX2 elicited RUNX2 acetylation and subsequent nuclear translocation, leading to the transcription upregulation of OPN, a critical player in VC. From a small library of natural compounds, we identified that Curculigoside and Chebulagic acid reduced VC development via binding to and inhibiting nesfatin-1. Eventually, we designed a mass spectrometry-based DNA-protein interaction screening to identify that STAT3 mediated the transcription activation of nesfatin-1 in the context of VC. Overall, our study demonstrates that nesfatin-1 enhances BMP-2 signaling by inhibiting the E3 ligase SYTL4, thereby stabilizing BMP-2 and facilitating the downstream phosphorylation of SMAD1/5/9 and HDAC4. This signaling cascade leads to RUNX2 activation and the transcriptional upregulation of MSX2, driving VC. These insights position nesfatin-1 as a potential therapeutic target for preventing or treating VC, advancing our understanding of the molecular mechanisms underlying this critical cardiovascular condition.

Endothelial cells derived extracellular vesicles promote diabetic arterial calcification via circ_0008362/miR-1251-5p/Runx2 axial.

INTRODUCTION: Arterial calcification, an independent predictor of cardiovascular events, increases morbidity and mortality in patients with diabetes mellitus (DM), but its mechanisms remain unclear. Extracellular vesicles (EVs) play an important role in intercellular communication. The study investigates the role and potential mechanisms of EVs derived from endothelial cells (ECs) in regulating vascular smooth muscle cell (VSMC) calcification under high glucose (HG) condition, with a goal of developing effective prevention and treatment strategies for diabetic arterial calcification. RESULTS: The results showed that EVs derived from HG induced ECs (ECHG-EVs) exhibited a bilayer structure morphology with a mean diameter of 74.08 ± 31.78 nm, expressing EVs markers including CD9, CD63 and TSG101, but not express calnexin. ECHG-EVs was internalized by VSMCs and induced VSMC calcification by increasing Runx2 expression and mineralized nodule formation. The circ_0008362 was enriched in ECHG-EVs, and it can be transmitted to VSMCs to promote VSMC calcification both in vitro and in vivo. Mechanistically, miR-1251-5p might be one of the targets of circ_0008362 and they were co-localization in the cytoplasm of VSMCs. Runx2 was identified as the downstream target of miR-1251-5p, and circ_0008362 acted as a sponge, enhancing Runx2 expression and then promoted VSMC calcification. Besides, circ_0008362 could directly interact with Runx2 to aggravate VSMC calcification. Notably, DiR-labelled ECHG-EVs was detected in the vessels of mice. Meanwhile, the level of circ_0008362 and Runx2 were increased significantly, while the expression of miR-1251-5p was decreased significantly in calcified artery tissues of mice. However, inhibiting the release of EVs by GW4869 attenuated arterial calcification in diabetic mice. Finally, the level of circulation of plasma EVs circ_0008362 was significantly higher in patients with DM compared with normal controls. Elevated levels of plasma EVs circ_0008362 were associated with more severe coronary and aorta artery calcification in patients with DM. CONCLUSIONS: Our findings suggested that circ_0008362 was enriched in EVs derived from ECs and promoted VSMC calcification under HG conditions, both by sponging miR-1251-5p to upregulate Runx2 expression and through direct interaction with Runx2. Furthermore, elevated levels of plasma EVs circ_0008362 were associated with more severe coronary and aorta artery calcification in patients with DM. These results may serve as a potential prevention and therapeutic target for diabetic arterial calcification.

Construction of competitive endogenous RNA network and identification of potential regulatory axis in vascular calcification.

Competitive endogenous RNAs (ceRNA) theory has been proved in numerous biological processes. Nevertheless, there is a lack of research applying the ceRNA theory to the study of vascular calcification (VC) in chronic kidney diseases (CKD). In the present study, a ceRNA network was constructed after conducting transcriptome sequencing of differentially expressed genes, followed by experimental validation to identify a new target for the diagnosis and treatment of vascular calcification. Total RNA was extracted from ß-glycerophosphate (ß-GP) cultured vascular smooth muscle cells (VSMCs) on Day 7. Illumina HiSeq platform was utilized to build sequencing libraries. GO and KEGG analysis was conducted to identify the function of the differentially expressed genes. Protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database. A ceRNA network was established based on TargetScan, miRDB, miRWALK, and miRanda database. Western blot and qRT-PCR were used to explore the expression level of protein and RNA, respectively. The direct binding sites were confirmed by dual-luciferase reporter assay. In total, 647 differentially expressed lncRNAs and 289 differentially expressed mRNAs were identified (|log2FC| ≥ 1, p < .05). The function of differentially expressed mRNAs was mainly enriched in negative regulation of osteoblast differentiation, regulation of RNA metabolic process, and other typical pathways. The ceRNA network was generated with a total of 107 interaction pairs. The lncRNA Prrc2c/miR-145-5p/Smad3 axis was considered a potential regulatory pathway within the ceRNA network. The regulatory relationship and targets of this ceRNA axis were validated via in vitro experiments. For the first time, we found that lncRNA Prrc2c was highly expressed and promoted calcification of VSMCs. Luciferase reporter assay showed that lncRNA Prrc2c could bind miR-145-5p at site 1755-1761. Similarly, luciferase reporter assay showed that miR-145-5p inhibited Smad3 expression by binding to its 3'UTR. Our findings provide a comprehensive examination of the ceRNA networks in vascular smooth muscle cells (VSMCs) treated with high phosphorate. Specifically, we have identified the role of lncRNA Prrc2c in promoting VSMC calcification through the miR-145-5p/Smad3 axis.

Generalized Arterial Calcification of Infancy (GACI).

Generalized arterial calcification of infancy (GACI) is an ultra-rare autosomal recessive disorder associated with pathogenic variants in ENPP1, the major gene involved in this condition, and in ABCC6, which is involved in a small fraction of affected individuals. Loss-of-function pathogenic variants of ENPP1 and ABCC6 lead to perturbations in the PPi/Pi ratio, thereby promoting hydroxyapatite mineralization in peripheral tissues. GACI is initially characterized by an abnormal ectopic mineralization process in arteries and soft tissue. Nearly half of the patients die within the first 6 months of life from cardiovascular complications, hence the poor prognosis associated with an early diagnosis. In recent years, progress has been made in our understanding of the long-term natural history of GACI, the intricate symptoms due to vascular calcifications, the overmineralization of soft tissues, of hypophosphatemia designated as ARHR2, and of the consequences such as undermineralization of the skeleton, but also of the features possibly seen in pseudoxanthoma elasticum (PXE). Indeed, GACI, PXE, and ARHR2 share common pathophysiological pathways and clinical features beyond the vascular calcifications. Treatment options for severe forms of GACI are mostly based on symptomatic management, including the option of starting bisphosphonates early after birth, such as etidronate and pamidronate, analogues of PPi. Follow-up within an expert and coordinated multidisciplinary team includes treatment of arterial hypertension, calcitriol and phosphorus adjustments, hearing aids, and early detection of possible angioid streaks. It is hoped that ongoing basic and clinical research will lead to the development of effective therapies that specifically target the abnormal PPi regulation and the other mechanisms involved in this disorder.

Clinical presentation and burden of ENPP1 deficiency in adults.

While the clinical consequences of severe ENPP1 deficiency leading to the rare disorders generalized arterial calcification of infancy (GACI) and autosomal recessive hypophosphatemic rickets type 2 (ARHR2) are well defined and understood, much less is known about how this evolves into adulthood and how moderate ENPP1 deficiency can first manifest in adulthood. Moreover, growing evidence substantiates an association of genetic variants in the ENPP1 gene with a wide range of further clinical manifestations including early-onset osteoporosis, osteoarthritis, and different forms of spinal ligament calcifications, i.e., diffuse idiopathic skeletal hyperostosis (DISH) and ossification of the posterior/anterior longitudinal ligament (OPLL/OALL). Furthermore, conditions with primarily extraskeletal signs and symptoms such as Cole disease, coagulopathies, and metabolic syndrome can seemingly result from ENPP1 variants. The causality and the pathophysiology behind these different clinical presentations appear complex and require further research, especially since the coincidence of these different phenotypes is rarely described and available evidence suggests that part of the aforementioned manifestations may result from ENPP1 effects beyond the catalytic activity of processing ATP to AMP and inorganic pyrophosphate (PPi). Growing awareness of the additional ENPP1-related manifestations across the lifespan will advance our understanding of this complex condition and help to standardize diagnostic approaches and develop individually tailored treatment concepts.

Gene inactivation of lysyl oxidase in smooth muscle cells reduces atherosclerosis burden and plaque calcification in hyperlipidemic mice.

BACKGROUND AND AIMS: Lysyl oxidase (LOX) catalyzes the crosslinking of collagen and elastin to maintain tensile strength and structural integrity of the vasculature. Excessive LOX activity increases vascular stiffness and the severity of occlusive diseases. Herein, we investigated the mechanisms by which LOX controls atherogenesis and osteogenic differentiation of vascular smooth muscle cells (SMC) in hyperlipidemic mice. METHODS: Gene inactivation of Lox in SMC was achieved in conditional knockout mice after tamoxifen injections. Atherosclerosis burden and vascular calcification were assessed in hyperlipidemic conditional [Loxf/fMyh11-CreERT2ApoE-/-] and sibling control mice [Loxwt/wtMyh11-CreERT2ApoE-/-]. Mechanistic studies were performed with primary aortic SMC from Lox mutant and wild type mice. RESULTS: Inactivation of Lox in SMCs decreased > 70 % its RNA expression and protein level in the aortic wall and significantly reduced LOX activity without compromising vascular structure and function. Moreover, LOX deficiency protected mice against atherosclerotic burden (13 ± 2 versus 23 ± 1 %, p < 0.01) and plaque calcification (5 ± 0.4 versus 11.8 ± 3 %, p < 0.05) compared to sibling controls. Interestingly, gene inactivation of Lox in SMCs preserved the contractile phenotype of vascular SMC under hyperlipidemic conditions as demonstrated by single-cell RNA sequencing and immunofluorescence. Mechanistically, the absence of LOX in SMC prevented excessive collagen crosslinking and the subsequent activation of the pro-osteogenic FAK/ß-catenin signaling axis. CONCLUSIONS: Lox inactivation in SMC protects mice against atherosclerosis and plaque calcification by reducing SMC modulation and FAK/ß-catenin signaling.

Genetically predicted HLA-DR+ natural killer cells as potential mediators in the lipid-coronary artery disease/ calcification (CAD/CAC) causal pathway.

Background: Coronary artery disease (CAD) imposes a significant global health burden, necessitating a deeper comprehension of its genetic foundations to uncover innovative therapeutic targets. Employing a comprehensive Mendelian randomization (MR) approach, we aimed to explore the genetic associations between lipid profiles, immune cell phenotypes, and CAD risk. Methods: Utilizing data from recent large-scale genome-wide association studies (GWAS), we scrutinized 179 lipid and 731 immune cell phenotypes to delineate their genetic contributions to CAD pathogenesis, including coronary artery calcification (CAC). Moreover, specific immune cell phenotypes were examined as potential mediators of the lipid-CAD/CAC causal pathway. Results: Among the 162 lipid species with qualified instrumental variables (IVs) included in the analysis, we identified 36 lipids that exhibit a genetic causal relationship with CAD, with 29 being risk factors and 7 serving as protective factors. Phosphatidylethanolamine (18:0_20:4) with 8 IVs (OR, 95% CI, P-value: 1.04, 1.02-1.06, 1.50E-04) met the Bonferroni-corrected significance threshold (0.05/162 = 3.09E-04). Notably, all 18 shared lipids were determined to be risk factors for both CAD and CAC, including 16 triacylglycerol traits (15 of which had ≥ 3 IVs), with (50:1) exhibiting the highest risk [OR (95% CI) in CAC: 1.428 (1.129-1.807); OR (95% CI) in CAD: 1.119 (1.046-1.198)], and 2 diacylglycerol traits. Furthermore, we identified HLA DR+ natural killer cells (IVs = 3) as nominally significant with lipids and as potential mediators in the causal pathway between diacylglycerol (16:1_18:1) or various triacylglycerols and CAD (mediated effect: 0.007 to 0.013). Conclusions: This study provides preliminary insights into the genetic correlations between lipid metabolism, immune cell dynamics, and CAD susceptibility, highlighting the potential involvement of natural killer cells in the lipid-CAD/CAC causal pathway and suggesting new targets for therapy. Further evidence is necessary to substantiate our findings.

Causal association between blood metabolites and abdominal aortic calcification: A bidirectional Mendelian randomization study.

Previous studies have reported correlations between metabolic factors and abdominal aortic calcification (AAC). However, the causal relationship between blood metabolites and AAC remains to be fully explored. We employed bidirectional two-sample Mendelian randomization (MR) to investigate the potential causal relationships between 486 blood metabolites and AAC. The inverse variance weighted method was primarily utilized for MR analysis, and the MR-Egger, weighted median, and Robust Adjusted Profile Score methods were used for supplementary analysis. Sensitivity analyses were conducted using Radial MR, MR-PRESSO, Cochran Q test, MR-Egger intercept, and leave-one-out analysis to evaluate the heterogeneity and pleiotropy. Furthermore, the Steiger test and linkage disequilibrium score regression were used to assess genetic correlation and directionality. Multivariable MR analysis was performed to evaluate the direct effect of metabolites on AAC. Through rigorous screening, we identified 6 metabolites with presumed causal effects on AAC: 4-methyl-2-oxopentanoate (effect size [ES] 0.46, 95% confidence interval [CI]: 0.10-0.82), erythrose (ES -0.35, 95% CI: -0.59 to -0.11), 10-undecenoate (11:1n1) (ES 0.14, 95% CI: 0.03-0.25), 1-myristoylglycerophosphocholine (ES 0.31, 95% CI: 0.11-0.50), glycerol 2-phosphate (ES 0.20, 95% CI: 0.04-0.37), and the unidentified metabolite X-11469 (ES 0.19, 95% CI: 0.08-0.30). Multivariable MR analysis revealed that genetically predicted erythrose, 10-undecenoate, 1-myristoylglycerophosphocholine, and X-11469 could directly affect AAC independent of other metabolites. Reverse MR analysis revealed an alteration in 12 blood metabolites due to AAC, including caffeine, 1,7-dimethylurate, arachidonic acid, and 1-arachidonoylglycerophosphocholine. This study provides evidence supporting a causal relationship between metabolites and AAC. These findings help elucidate the underlying biological mechanisms of AAC and may offer insights into screening, prevention, and treatment approaches.

PALMD haploinsufficiency aggravates extracellular matrix remodeling in vascular smooth muscle cells and promotes calcification.

Reduced PALMD expression is strongly associated with the development of calcified aortic valve stenosis; however, the role of PALMD in vascular calcification remains unknown. Calcified arteries were collected from mice to detect PALMD expression. Heterozygous Palmd knockout (Palmd+/-) mice were established to explore the role of PALMD in subtotal nephrectomy-induced vascular calcification. RNA sequencing was applied to detect molecular changes in aortas from Palmd+/- mice. Primary Palmd+/- vascular smooth muscle cells (VSMCs) or PALMD-silenced VSMCs by short interfering RNA were used to analyze PALMD function in phenotypic changes and calcification. PALMD haploinsufficiency aggravated subtotal nephrectomy-induced vascular calcification. RNA sequencing analysis showed that loss of PALMD disturbed the synthesis and degradation of the extracellular matrix (ECM) in aortas, including collagens and matrix metalloproteinases (Col6a6, Mmp2, Mmp9, etc.). In vitro experiments revealed that PALMD-deficient VSMCs were more susceptible to high phosphate-induced calcification. Downregulation of SMAD6 expression and increased levels of p-SMAD2 were detected in Palmd+/- VSMCs, suggesting that transforming growth factor-ß signaling may be involved in PALMD haploinsufficiency-induced vascular calcification. Our data revealed that PALMD haploinsufficiency causes ECM dysregulation in VSMCs and aggravates vascular calcification. Our findings suggest that reduced PALMD expression is also linked to vascular calcification, and PALMD may be a potential therapeutic target for this disease. NEW & NOTEWORTHY We found that PALMD haploinsufficiency causes extracellular matrix dysregulation, reduced PALMD expression links to vascular calcification, and PALMD mutations may lead to the risk of both calcific aortic valve stenosis and vascular calcification.

Genetic Risk and Coronary Artery Calcium in Personalizing Antihypertensive Treatment: A Pooled Cohort Analysis.

OBJECTIVE: To assess the role of the systolic blood pressure polygenic risk score (SBP-PRS) in antihypertensive treatment initiation and its comparative efficacy with coronary artery calcium (CAC) scores. PATIENTS AND METHODS: This retrospective cohort study included participants with whole genome sequencing data who underwent CAC scanning between 1971 and 2008, were free of prevalent cardiovascular disease (CVD), and were not taking antihypertensive medications. The cohort was stratified by blood pressure (BP) treatment group and SBP-PRS (low/intermediate, first and second tertiles; high, third tertile) and CAC score (0 vs >0) subgroups. The primary outcome was the first occurence of adjudicated coronary heart disease, heart failure, or stroke during 10-year follow-up. The 10-year number needed to treat (NNT) to prevent 1 event of the primary outcome was estimated. A relative risk reduction of 25% for the primary outcome based on the treatment effect of intensive control (SBP <120 mm Hg) of hypertension in SPRINT (Systolic Blood Pressure Intervention Trial) was used for estimating the NNT. RESULTS: Among the 5267 study participants, the median age was 59 years (interquartile range, 51-68 years); 2817 (53.5%) were women and 2880 (54.7%) were non-White individuals. Among 1317 individuals with elevated BP/low-risk stage 1 hypertension not recommended treatment, the 10-year incidence rate of the primary outcome was 5.6% for low/intermediate SBP-PRS and 6.3% for high SBP-PRS with NNTs of 63 and 59, respectively. Similarly, the 10-year incidence rate of the primary outcome was 2.9% for CAC score 0 and 9.7% for CAC score greater than 0, with NNTs of 117 and 37, respectively. CONCLUSION: Including genetic information in risk estimation of individuals with elevated BP/low-risk stage 1 hypertension has modest value in the initiation of antihypertensive therapy. Genetic risk and CAC both have efficacy in personalizing antihypertensive therapy.

Augmentative effects of leukemia inhibitory factor reveal a critical role for TYK2 signaling in vascular calcification.

Medial vascular calcification in chronic kidney disease (CKD) involves pro-inflammatory pathways induced by hyperphosphatemia. Several interleukin 6 family members have been associated with pro-calcific effects in vascular smooth muscle cells (VSMCs) and are considered as therapeutic targets. Therefore, we investigated the role of leukemia inhibitory factor (LIF) during VSMC calcification. LIF expression was found to be increased following phosphate exposure of VSMCs. LIF supplementation aggravated, while silencing of endogenous LIF or LIF receptor (LIFR) ameliorated the pro-calcific effects of phosphate in VSMCs. The soluble LIFR mediated antagonistic effects towards LIF and reduced VSMC calcification. Mechanistically, LIF induced phosphorylation of the non-receptor tyrosine-protein kinase 2 (TYK2) and signal transducer and activator of transcription-3 (STAT3) in VSMCs. TYK2 inhibition by deucravacitinib, a selective, allosteric oral immunosuppressant used in psoriasis treatment, not only blunted the effects of LIF, but also interfered with the pro-calcific effects induced by phosphate. Conversely, TYK2 overexpression aggravated VSMC calcification. Ex vivo calcification of mouse aortic rings was ameliorated by Tyk2 pharmacological inhibition and genetic deficiency. Cholecalciferol-induced vascular calcification in mice was improved by Tyk2 inhibition and in the Tyk2-deficient mice. Similarly, calcification was ameliorated in Abcc6/Tyk2-deficient mice after adenine/high phosphorus-induced CKD. Thus, our observations indicate a role for LIF in CKD-associated vascular calcification. Hence, the effects of LIF identify a central pro-calcific role of TYK2 signaling, which may be a future target to reduce the burden of vascular calcification in CKD.

Sirt7 protects against vascular calcification via modulation of reactive oxygen species and senescence of vascular smooth muscle cells.

Vascular calcification is frequently seen in patients with chronic kidney disease (CKD), and significantly increases cardiovascular mortality and morbidity. Sirt7, a NAD+-dependent histone deacetylases, plays a crucial role in cardiovascular disease. However, the role of Sirt7 in vascular calcification remains largely unknown. Using in vitro and in vivo models of vascular calcification, this study showed that Sirt7 expression was significantly reduced in calcified arteries from mice administered with high dose of vitamin D3 (vD3). We found that knockdown or inhibition of Sirt7 promoted vascular smooth muscle cell (VSMC), aortic ring and vascular calcification in mice, whereas overexpression of Sirt7 had opposite effects. Intriguingly, this protective effect of Sirt7 on vascular calcification is dependent on its deacetylase activity. Unexpectedly, Sirt7 did not alter the osteogenic transition of VSMCs. However, our RNA-seq and subsequent studies demonstrated that knockdown of Sirt7 in VSMCs resulted in increased intracellular reactive oxygen species (ROS) accumulation, and induced an Nrf-2 mediated oxidative stress response. Treatment with the ROS inhibitor N-acetylcysteine (NAC) significantly attenuated the inhibitory effect of Sirt7 on VSMC calcification. Furthermore, we found that knockdown of Sirt7 delayed cell cycle progression and accelerated cellular senescence of VSMCs. Taken together, our results indicate that Sirt7 regulates vascular calcification at least in part through modulation of ROS and cellular senescence of VSMCs. Sirt7 may be a potential therapeutic target for vascular calcification.

Inhibition of Vascular Smooth Muscle Cell Proliferation by ENPP1: The Role of CD73 and the Adenosine Signaling Axis.

The Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 (ENPP1) ectoenzyme regulates vascular intimal proliferation and mineralization of bone and soft tissues. ENPP1 variants cause Generalized Arterial Calcification of Infancy (GACI), a rare genetic disorder characterized by ectopic calcification, intimal proliferation, and stenosis of large- and medium-sized arteries. ENPP1 hydrolyzes extracellular ATP to pyrophosphate (PPi) and AMP. AMP is the precursor of adenosine, which has been implicated in the control of neointimal formation. Herein, we demonstrate that an ENPP1-Fc recombinant therapeutic inhibits proliferation of vascular smooth muscle cells (VSMCs) in vitro and in vivo. Addition of ENPP1 and ATP to cultured VSMCs generated AMP, which was metabolized to adenosine. It also significantly decreased cell proliferation. AMP or adenosine alone inhibited VSMC growth. Inhibition of ecto-5'-nucleotidase CD73 decreased adenosine accumulation and suppressed the anti-proliferative effects of ENPP1/ATP. Addition of AMP increased cAMP synthesis and phosphorylation of VASP at Ser157. This AMP-mediated cAMP increase was abrogated by CD73 inhibitors or by A2aR and A2bR antagonists. Ligation of the carotid artery promoted neointimal hyperplasia in wild-type mice, which was exacerbated in ENPP1-deficient ttw/ttw mice. Prophylactic or therapeutic treatments with ENPP1 significantly reduced intimal hyperplasia not only in ttw/ttw but also in wild-type mice. These findings provide the first insight into the mechanism of the anti-proliferative effect of ENPP1 and broaden its potential therapeutic applications beyond enzyme replacement therapy.

EVs-miR-17-5p attenuates the osteogenic differentiation of vascular smooth muscle cells potentially via inhibition of TGF-ß signaling under high glucose conditions.

Vascular calcification, which is a major complication of diabetes mellitus, is an independent risk factor for cardiovascular disease. Osteogenic differentiation of vascular smooth muscle cells (VSMCs) is one of the key mechanisms underlying vascular calcification. Emerging evidence suggests that macrophage-derived extracellular vesicles (EVs) may be involved in calcification within atherosclerotic plaques in patients with diabetes mellitus. However, the role of macrophage-derived EVs in the progression of vascular calcification is largely unknown. In this study, we investigated whether macrophage-derived EVs contribute to the osteogenic differentiation of VSMCs under high glucose conditions. We isolated EVs that were secreted by murine peritoneal macrophages under normal glucose (EVs-NG) or high glucose (EVs-HG) conditions. miRNA array analysis in EVs from murine macrophages showed that miR-17-5p was significantly increased in EVs-HG compared with EVs-NG. Prediction analysis with miRbase identified transforming growth factor ß receptor type II (TGF-ß RII) as a potential target of miR-17-5p. EVs-HG as well as miR-17-5p overexpression with lipid nanoparticles inhibited the gene expression of Runx2, and TGF-ß RII. Furthermore, we demonstrated that VSMCs transfected with miR-17-5p mimic inhibited calcium deposition. Our findings reveal a novel role of macrophage-derived EVs in the negative regulation of osteogenic differentiation in VSMCs under high glucose conditions.

Smooth muscle NF90 deficiency ameliorates diabetic atherosclerotic calcification in male mice via FBXW7-AGER1-AGEs axis.

Hyperglycemia accelerates calcification of atherosclerotic plaques in diabetic patients, and the accumulation of advanced glycation end products (AGEs) is closely related to the atherosclerotic calcification. Here, we show that hyperglycemia-mediated AGEs markedly increase vascular smooth muscle cells (VSMCs) NF90/110 activation in male diabetic patients with atherosclerotic calcified samples. VSMC-specific NF90/110 knockout in male mice decreases obviously AGEs-induced atherosclerotic calcification, along with the inhibitions of VSMC phenotypic changes to osteoblast-like cells, apoptosis, and matrix vesicle release. Mechanistically, AGEs increase the activity of NF90, which then enhances ubiquitination and degradation of AGE receptor 1 (AGER1) by stabilizing the mRNA of E3 ubiquitin ligase FBXW7, thus causing the accumulation of more AGEs and atherosclerotic calcification. Collectively, our study demonstrates the effects of VSMC NF90 in mediating the metabolic imbalance of AGEs to accelerate diabetic atherosclerotic calcification. Therefore, inhibition of VSMC NF90 may be a potential therapeutic target for diabetic atherosclerotic calcification.

STING1-accelerated vascular smooth muscle cell senescence-associated vascular calcification in diabetes is ameliorated by oleoylethanolamide via improved mitochondrial DNA oxidative damage.

Vascular calcification is a prevalent hallmark of cardiovascular risk in elderly and diabetic individuals. Senescent vascular smooth muscle cells (VSMCs) participate in calcification; however, the associated underlying mechanisms remain unknown. Aberrant activation of the cytosolic DNA sensing adaptor stimulator of interferon gene 1 (STING1) caused by cytosolic DNA, particularly that leaked from damaged mitochondria, is a catalyst for aging-related diseases. Although oleoylethanolamide (OEA) is an endogenous bioactive lipid mediator with lipid overload-associated vasoprotective effects, its benefit in diabetic vascular calcification remains uncharacterized. This study focused on the role of STING1 in mitochondrial dysfunction-mediated calcification and premature VMSC senescence in diabetes and the effects of OEA on these pathological processes. In diabetic in vivo rat/mouse aorta calcification models and an in vitro VSMC calcification model induced by Nε-carboxymethyl-lysine (CML), senescence levels, STING1 signaling activation, and mitochondrial damage markers were significantly augmented; however, these alterations were markedly alleviated by OEA, partially in a nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent manner, and similar anti-calcification and senescence effects were observed in STING1-knockout mice and STING1-knockdown VSMCs. Mechanistically, mitochondrial DNA (mtDNA) damage was aggravated by CML in a reactive oxygen species-dependent manner, followed by mtDNA leakage into the cytosol, contributing to VSMC senescence-associated calcification via STING1 pathway activation. OEA treatment significantly attenuated the aforementioned cytotoxic effects of CML by enhancing cellular antioxidant capacity through the maintenance of Nrf2 translocation to the nucleus. Collectively, targeting STING1, a newly defined VSMC senescence regulator, contributes to anti-vascular calcification effects.

Vascular calcification in chronic kidney disease associated with pathogenic variants in ABCC6.

Vascular calcification is prevalent in chronic kidney disease (CKD). Genetic causes of CKD account for 10-20% of adult-onset disease. Vascular calcification is thought to be one of the most important risk factors for increased cardiovascular morbidity and mortality in CKD patients and is detectable in 80% of patients with end stage kidney disease (ESKD). Despite the high prevalence of vascular calcification in CKD, no single gene cause has been described. We hypothesized that variants in vascular calcification genes may contribute to disease pathogenesis in CKD, particularly in families who exhibit a predominant vascular calcification phenotype. We developed a list of eight genes that are hypothesized to play a role in vascular calcification due to their involvement in the ectopic calcification pathway: ABCC6, ALPL, ANK1, ENPP1, NT5E, SLC29A1, SLC20A2, and S100A12. With this, we assessed exome data from 77 CKD patients, who remained unsolved following evaluation for all known monogenic causes of CKD. We also analyzed an independent cohort (Ontario Neurodegenerative Disease Research Initiative (ONDRI), n = 520) who were screened for variants in ABCC6 and compared this to a control cohort of healthy adults (n = 52). We identified two CKD families with heterozygous pathogenic variants (R1141X and A667fs) in ABCC6. We identified 10 participants from the ONDRI cohort with heterozygous pathogenic or likely pathogenic variant in ABCC6. Replication in a healthy control cohort did not reveal any variants. Our study provides preliminary data supporting the hypothesis that ABCC6 may play a role in vascular calcification in CKD. By screening CKD patients for genetic causes early in the diagnostic pathway, patients with genetic causes associated with vascular calcification can potentially be preventatively treated with new therapeutics with aims to decrease mortality.

CircTOP1 targeted regulation of PTBP1 expression promotes the progression of coronary artery calcification.

Coronary artery calcification (CAC) is a hallmark event in the pathogenesis of cardiovascular disease, involving the phenotypic transformation of vascular smooth muscle cells (VSMC) towards an osteogenic state. Despite this understanding, the molecular mechanisms governing the VSMC osteogenic switch remain incompletely elucidated. Here, we sought to examine the potential role of circular RNA (circRNA) in the context of CAC. Through transcriptome analysis of circRNA-seq, we identified circTOP1 as a potential candidate circRNA in individuals with CAC. Furthermore, we observed that overexpression of circTOP1 exacerbated vascular calcification in a CAC model. Subsequent pull-down assays revealed an interaction between circTOP1 and PTBP1, a putative target gene of circTOP1 in the context of CAC. In both in vivo and in vitro experiments, we observed heightened expression of circTOP1 and PTBP1 in the CAC model, and noted that reducing circTOP1 expression effectively reduced calcium salt deposits and mineralized nodules in model mice. Additionally, in vitro experiments demonstrated that overexpression of PTBP1 reversed the weakening of signaling caused by silencing circTOP1, thereby exacerbating the osteogenic transition and calcification of VSMC. Collectively, our findings suggested that circTOP1 promotes CAC by modulating PTBP1 expression to mediate VSMC transdifferentiation.

A CEBPB/miR-32-5p/GATA6 axis promotes vascular calcification in type 2 diabetes.

Vascular calcification in diabetes patients is a major independent risk factor for developing diabetic cardiovascular complications. However, the mechanisms by which diabetes leads to vascular calcification are complex and not yet fully understood. Our previous study revealed that miR-32-5p is a potential new diagnostic marker for coronary artery calcification. In this study, we found that miR-32-5p levels were significantly greater in the plasma of type 2 diabetes patients with coronary artery calcification and were positively correlated with the coronary artery calcification score. In type 2 diabetic mice, miR-32-5p levels were also elevated in the aorta, and knockout of miR-32-5p inhibited the osteogenic differentiation of vascular smooth muscle cells in vivo. Furthermore, overexpression of miR-32-5p promoted vascular smooth muscle cell calcification, while antagonism of miR-32-5p inhibited vascular smooth muscle cell calcification under high-glucose conditions. GATA binding protein 6 (GATA6) was identified as the key target gene through which miR-32-5p promotes vascular smooth muscle cell calcification. Overexpression of GATA6 antagonized the effects of miR-32-5p on vascular calcification. Additionally, high glucose levels were shown to induce the upregulation of miR-32-5p by activating CCAAT/enhancer binding protein beta (CEBPB). These results suggest that miR-32-5p is an important procalcification factor in vascular calcification associated with type 2 diabetes and identify the CEBPB/miR-32-5p/GATA6 axis as a potential biomarker and therapeutic target for preventing and treating vascular calcification in type 2 diabetes.