Sox9 Accelerates Vascular Aging by Regulating Extracellular Matrix Composition and Stiffness

NAT10 promotes vascular remodelling via mRNA ac4C acetylation

BACKGROUND AND AIMS

Vascular smooth muscle cell (VSMC) phenotype switching is a pathological hallmark in various cardiovascular diseases. N4-acetylcytidine (ac4C) catalyzed by N-acetyltransferase 10 (NAT10) is well conserved in the enzymatic modification of ribonucleic acid (RNA). NAT10-mediated ac4C acetylation is involved in various physiological and pathological processes, including cardiac remodelling. However, the biological functions and underlying regulatory mechanisms of mRNA ac4C modifications in vascular diseases remain elusive.

METHODS

By combining in-vitro and in-vivo vascular injury models, NAT10 was identified as a crucial protein involved in the promotion of post-injury neointima formation, as well as VSMC phenotype switching. The potential mechanisms of NAT10 in the vascular neointima formation were clarified by RNA sequence (RNA-seq), acetylated mRNA immunoprecipitation sequence (acRIP-seq), and RNA binding protein immunoprecipitation sequence (RIP-seq).

RESULTS

NAT10 and ac4C modifications were upregulated in injured human and rodent arteries. Deletion of NAT10 in VSMCs effectively reduced post-injury neointima formation and VSMC phenotype switching. Further RNA-seq, RIP-seq, and acRIP-seq revealed that NAT10, by its ac4C modification, directly interacts with genes, including integrin-β1 (ITGB1) and collagen type I alpha 2 chain (Col1a2) mRNAs. Taking ITGB1 as one example, it showed that NAT10-mediated ac4C consequently increased ITGB1 mRNA stability and its downstream focal adhesion kinase (FAK) signaling, directly influencing the proliferation of VSMCs and vascular remodelling. The regulation of NAT10 on the VSMC phenotype is of translational significance because the administration of Remodelin, a NAT10 inhibitor, effectively prevents neointima formation by suppressing VSMC proliferation and downregulating ITGB1 expression and deactivating its FAK signaling.

CONCLUSIONS

This study reveals that NAT10 promotes vascular remodelling via mRNA ac4C acetylation, which may be a promising therapeutic target against vascular remodelling.

Cellular senescence contributes to spontaneous repair of the rat meniscus

Cellular senescence, traditionally associated with aging and chronic diseases, has recently been identified as a potential facilitator of tissue regeneration via a senescence-associated secretory phenotype (SASP). In rodents, the meniscus is known to regenerate spontaneously from the surrounding synovium, but the mechanism, and especially its relationship to cellular senescence, remains unclear. This study investigated the contribution of cellular senescence to spontaneous repair of the rat meniscus. We created a rat partial medial meniscectomy (pMx) model to evaluate time-course changes in regenerative tissue. Immunohistochemistry revealed marked increases in p16 expression and senescence-associated beta-galactosidase (SA-β-gal) activity in the regenerating tissue at the early phase after pMx surgery. RNA sequencing of regenerating tissues identified the upregulation of genes related to aging, extracellular matrix organization, and cell proliferation. Fluorescence staining identified high expression of SOX9, a master regulator of cartilage/meniscus development, adjacent to p16-positive cells. In vitro investigations of the effect of SASP factors on synovial fibroblasts (SFs) demonstrated that conditioned medium from senescent SFs stimulated the proliferation and chondrogenic differentiation of normal SFs. In vivo histological evaluation to determine whether selective elimination of senescent cells with a senolytic drug (ABT-263) retarded spontaneous repair of meniscus in vivo confirmed that ABT-263 decreased the meniscus score and expression of SOX9, aggrecan, and type 1 collagen. Our findings indicate that transient senescent cell accumulation and SASP in regenerating tissues beneficially contribute to spontaneous repair of the rat meniscus. Further research into the molecular mechanism will provide a novel strategy for meniscus regeneration based on cellular senescence.

Advances in the mechanisms of vascular calcification in chronic kidney disease

Vascular calcification (VC) is common in patients with advanced chronic kidney disease (CKD).A series of factors, such as calcium and phosphorus metabolism disorders, uremic toxin accumulation, inflammation and oxidative stress and cellular senescence, cause osteoblast-like differentiation of vascular smooth muscle cells, secretion of extracellular vesicles, and imbalance of calcium regulatory factors, which together promote the development of VC in CKD. Recent advances in epigenetics have provided better tools for the investigation of VC etiology and new approaches for finding more accurate biomarkers. These advances have not only deepened our understanding of the pathophysiological mechanisms of VC in CKD, but also provided valuable clues for the optimization of clinical predictors and the exploration of potential therapeutic targets. The aim of this article is to provide a comprehensive overview of the pathogenesis of CKD VC, especially the new advances made in recent years, including the various key factors mentioned above. Through the comprehensive analysis, we expect to provide a solid theoretical foundation and research direction for future studies targeting the specific mechanisms of CKD VC, the establishment of clinical predictive indicators and the development of potential therapeutic strategies.

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.

Cystathionine γ-Lyase Attenuates Vascular Smooth Muscle Cell Senescence via Foxm1-Gas1 Pathway to Mediate Arterial Stiffness

Aims: Arterial stiffness, a hallmark of vascular aging, significantly contributes to hypertension and impaired organ perfusion. Vascular smooth muscle cell (VSMC) dysfunction, particularly VSMC senescence and its interaction with stiffness, is crucial in the pathogenesis of arterial stiffness. Although hydrogen sulfide (H2S) and its key enzyme cystathionine γ-lyase (CSE) are known to play roles in cardiovascular diseases, their effects on arterial stiffness are not well understood. Methods & Results: First, we observed a downregulation of CSE/H2S in the aortic media during biological aging and angiotensin II (AngII)-induced aging. The VSMC-specific CSE knockout mice were created by loxp-cre (Tagln-cre) system and which exacerbated AngII-induced aortic aging and stiffness in vivo and VSMC senescence and stiffness in vitro. Conversely, the CSE agonist norswertianolin mitigated these effects. Next, we identified growth arrest-specific 1 (Gas1) as a crucial target of CSE/H2S and found it to be a downstream target gene of forkhead box protein M1 (Foxm1). siRNA knockdown Foxm1 increased Gas1 transcription and reduced the protective effects of H2S on VSMC senescence and stiffness. Finally, we demonstrated that CSE/H2S sulfhydrates Foxm1 at the C210 site, regulating its nuclear translocation and activity, thus reducing VSMC senescence and stiffness. Innovation: Our findings highlight the protective role of CSE/H2S in arterial stiffness, emphasizing the novel contributions of CSE, Gas1, and Foxm1 to VSMC senescence and stiffness. Conclusion: Endogenous CSE/H2S in VSMCs reduces VSMC senescence and stiffness, thereby attenuating arterial stiffness and aging, partly through sulfhydration-mediated activation of Foxm1 and subsequent inhibition of Gas1 signaling pathways.

Current Understanding of Cardiovascular Calcification in Patients with Chronic Kidney Disease

The burden of chronic kidney disease (CKD) is increasing, posing a serious threat to human health. Cardiovascular calcification (CVC) is one of the most common manifestations of CKD, which significantly influences the morbidity and mortality of patients. The manifestation of CVC is an unusual accumulation of mineral substances containing calcium and phosphate. The main component is hydroxyapatite. Many cells are involved in this process, such as smooth muscle cells (SMCs) and endothelial cells. CVC is an osteogenic process initiated by complex mechanisms such as metabolic disorders of calcium and phosphorus minerals, inflammation, extracellular vesicles, autophagy, and micro-RNAs with a variety of signaling pathways like Notch, STAT, and JAK. Although drug therapy and dialysis technology continue to advance, the survival time and quality of life of CVC patients still face challenges. Therefore, early diagnosis and prevention of CKD-related CVC, reducing its mortality rate, and improving patients' quality of life have become urgent issues in the field of public health. In this review, we try to summarize the state-of-the-art understanding of the progression of CVC and hope that it will help in the prevention and treatment of CVC in CKD.

Effect of Vascular Senescence on the Efficacy and Safety of Warfarin: Insights from Rat Models and a Prospective Cohort Study

Warfarin, with its narrow therapeutic range, requires the understanding of various influencing factors for personalized medication. Vascular senescence, marked by vascular stiffening and endothelial dysfunction, has an unclear effect on the efficacy and safety of warfarin. Based on previous studies, we hypothesized that vascular senescence increases the risk of bleeding during warfarin therapy. This study aimed to explore these effects using animal models and clinical cohorts. We established rat models of vascular senescence and calcification using d-galactose, vitamin D, and nicotine. After validating the models, we examined changes in the international normalized ratio (INR) at fixed warfarin doses (0.20 and 0.35 mg/kg). We found that vascular senescence caused significantly elevated INR values and increased bleeding risk. In the prospective clinical cohort study (NCT06428110), hospitalized warfarin patients with standard dose adjustments were divided into vascular senescence and control groups based on ultrasound and computed tomography diagnosis. Using propensity score matching to exclude the influence of confounding factors, we found that the vascular senescence group had lower steady-state warfarin doses and larger dose adjustments, with a higher probability of INR exceeding the therapeutic range. The vascular senescence group tended to experience more bleeding or thromboembolic/ischemic events during 1 year of follow-up, while there was no statistical difference. In conclusion, vascular senescence leads to unstable INR values and increases higher bleeding risk during warfarin therapy, highlighting the importance of considering vascular senescence in future precision warfarin therapies. SIGNIFICANCE STATEMENT: Many factors influence warfarin efficacy; however, the effect of vascular senescence remains unclear. This study aimed to investigate the effects of vascular senescence on the efficacy and safety of warfarin. Through both rat models and clinical cohort studies, our findings indicated that vascular senescence may compromise the stability of warfarin, presenting challenges in maintaining its efficacy and safety.

Downregulation of stromal interaction molecule-1 is implicated in the age-associated vasoconstriction dysfunction of aorta, intrarenal, and coronary arteries

The contractile function of vascular smooth muscle cells (VSMCs) typically undergoes significant changes with advancing age, leading to severe vascular aging-related diseases. The precise role and mechanism of stromal interaction molecule-1 (STIM1) in age-mediated Ca2+ signaling and vasocontraction remain unclear. The connection between STIM1 and age-related vascular dysfunction was investigated using a multi-myograph system, immunohistochemical analysis, protein blotting, and SA-β-gal staining. Results showed that vasoconstrictor responses in the thoracic aorta, intrarenal artery, and coronary artery decreased with age. STIM1 knockdown in the intrarenal and coronary arteries reduced vascular tone in young mice, while no change was observed in the thoracic aorta. A significant reduction in vascular tone occurred in the STIM1 knockout group with nifedipine. In the thoracic aorta, vasoconstriction significantly decreased with age following the use of nifedipine and thapsigargin and almost disappeared after STIM1 knockdown. The proportion of senescent VSMCs increased significantly in aged mice and further increased in sm-STIM1 KO aged mice. Moreover, the expression of senescence markers p21, p16, and IL-6 significantly increased with age, with p21 expression further increased in the STIM1 knockdown aged group, but not p16 or IL-6. These findings indicate that different arteries exhibit distinct organ-specific features and that STIM1 downregulation may contribute to age-related vasoconstrictive dysfunction through activation of the p21 pathway.

Isopropyl 3-(3,4-Dihydroxyphenyl)-2-hydroxypropanoate Alleviates Palmitic Acid-Induced Vascular Aging in HUVEC Cells through ROS/Ferroptosis Pathway

Vascular aging is an important factor leading to cardiovascular diseases such as hypertension and atherosclerosis. Hyperlipidemia or fat accumulation may play an important role in vascular aging and cardiovascular disease. Isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoate (IDHP) has biological activity and can exert cardiovascular protection, which may be related to ferroptosis. However, the exact mechanism remains undefined. We hypothesized that IDHP may have a protective effect on blood vessels by regulating vascular aging caused by hyperlipidemia or vascular wall fat accumulation. The aim of this study is to investigate the protective effect and mechanism of IDHP on palmitic acid-induced human umbilical vein endothelial cells (HUVEC) based on senescence and ferroptosis. We found that IDHP could delay vascular aging, reduce the degree of ferrous ion accumulation and lipid peroxidation, and protect vascular cells from injury. These effects may be achieved by attenuating excessive reactive oxygen species (ROS) and ferroptosis signaling pathways generated in vascular endothelial cells. In short, our study identified IDHP as one of the antioxidant agents to slow down lipotoxicity-induced vascular senescence through the ROS/ferroptosis pathway. IDHP has new medicinal value and provides a new therapeutic idea for delaying vascular aging in patients with dyslipidemia.

The 9p21.3 coronary artery disease risk locus drives vascular smooth muscle cells to an osteochondrogenic state

Genome-wide association studies have identified common genetic variants at ~400 human genomic loci linked to coronary artery disease (CAD) susceptibility. Among these genomic regions, the most impactful is the 9p21.3 CAD risk locus, which spans a 60 kb gene desert and encompasses ~80 SNPs in high linkage disequilibrium. Despite nearly two decades since its discovery, the functional mechanism of this genomic region remains incompletely resolved. To investigate the transcriptional gene programs mediated by 9p21.3 risk locus, we applied a model of induced pluripotent stem cells (iPSCs) from risk and non-risk donors at 9p21.3, as well as isogenic lines with a full haplotype deletion. Upon differentiation to vascular smooth muscle cells (VSMC), single-cell transcriptomic profiling demonstrated iPSC-VSMC phenotypes resembling those from native human coronary arteries, confirming the robustness of this model. Remarkably, our analyses revealed that VSMCs harboring the 9p21.3 risk haplotype preferentially adopt an osteochondrogenic state. Importantly, we identified LIMCH1 and CRABP1 as signature genes critical for defining this transcriptional program. Our study provides new insights into the mechanism at the 9p21.3 risk locus and defines its role in driving a disease-prone transcriptional state in VSMCs.

Advances in Molecular Research on Hip Joint Impingement-A Vascular Perspective

With the rise in longevity within the population, medicine continues to encounter fresh hurdles necessitating prompt actions, among which are those associated with hip joint aging. Age-related arthropathies encompass damage to bones' articulating extremities and their supporting structures, such as articular cartilage, and alterations in the quantity and quality of synovial fluid. This study aims to summarize the biomolecular methods of hip joint evaluation focused on its vascularization, using data correlated with biomolecular research on other joints and tissues, in order to reach an objective opinion of the study prospects in this field. Following a retrospective study on most modern biomolecular research methods on the synovium, the capsule, and the articular cartilage of the hip joint, we have hereby concretized certain future research directions in this field that will improve the qualitative and morphofunctional management of the hip joint at an advanced age, even within population categories at risk of developing various degenerative joint pathologies.