Superoxide Dismutase 2 (SOD2) in Vascular Calcification: A Focus on Vascular Smooth Muscle Cells, Calcification Pathogenesis, and Therapeutic Strategies

Advances in metal-organic framework-based nanozymes in ROS scavenging medicine

Reactive oxygen species (ROS) play important roles in regulating various physiological functions in the human body, however, excessive ROS can cause serious damage to the human body, considering the various limitations of natural enzymes as scavengers of ROS in the body, the development of better materials for the scavenging of ROS is of great significance to the biomedical field, and nanozymes, as a kind of nanomaterials which can show the activity of natural enzymes. Have a good potential for the development in the area of ROS scavenging. Metal-organic frameworks (MOFs), which are porous crystalline materials with a periodic network structure composed of metal nodes and organic ligands, have been developed with a variety of active nanozymes including catalase-like, superoxide dismutase-like, and glutathione peroxidase-like enzymes due to the adjustability of active sites, structural diversity, excellent biocompatibility, and they have shown a wide range of applications and prospects. In the present review, we first introduce three representative natural enzymes for ROS scavenging in the human body, methods for the detection of relevant enzyme-like activities and mechanisms of enzyme-like clearance are discussed, meanwhile, we systematically summarize the progress of the research on MOF-based nanozymes, including the design strategy, mechanism of action, and medical application, etc. Finally, the current challenges of MOF-based nanozymes are summarized, and the future development direction is anticipated. We hope that this review can contribute to the research of MOF-based nanozymes in the medical field related to the scavenging of ROS.

Mitochondria-Targeted Natural Antioxidant Nanosystem for Diabetic Vascular Calcification Therapy

The development of nanotherapy targeting mitochondria to alleviate oxidative stress is a critical therapeutic strategy for vascular calcification (VC) in diabetes. In this study, we engineered mitochondria-targeted nanodrugs (T4O@TPP/PEG-PLGA) utilizing terpinen-4-ol (T4O) as a natural antioxidant and mitochondrial protector, PEG-PLGA as the nanocarrier, and triphenylphosphine (TPP) as the mitochondrial targeting ligand. In vitro assessments demonstrated enhanced cellular uptake of T4O@TPP/PEG-PLGA, with effective mitochondrial targeting. This nanodrug successfully reduced oxidative stress induced by high glucose levels in vascular smooth muscle cells. In vivo studies showed prolonged retention of the nanomaterials in the thoracic aorta for up to 24 h. Importantly, experiments in diabetic VC models underscored the potent antioxidant properties of T4O@TPP/PEG-PLGA, as evidenced by its ability to mitigate VC and restore mitochondrial morphology. These results suggest that these nanodrugs could be a promising strategy for managing diabetic VC.

Current status of superoxide dismutase 2 on oral disease progression by supervision of ROS

The recent Global Burden of Disease results have demonstrated that oral diseases are some of the most significant public health challenges facing the world. Owing to its specific localization advantage, superoxide dismutase 2 (SOD2 or MnSOD) has the ability to process the reactive oxygen species (ROS) produced by mitochondrial respiration before anything else, thereby impacting the occurrence and development of diseases. In this review, we summarize the processes of common oral diseases in which SOD2 is involved. SOD2 is upregulated in periodontitis to protect the tissue from the distant damage caused by excessive ROS and further reduce inflammatory progression. SOD2 also participates in the specific pathogenesis of oral cancers and dental diseases. The clinical application prospects of SOD2 in oral diseases will be discussed further, referencing the differences and relationship between oral diseases and other clinical systemic diseases.

Vascular Calcification Heterogeneity from Bench to Bedside: Implications for Manifestations, Pathogenesis, and Treatment Considerations

Vascular calcification (VC) is the ectopic deposition of calcium-containing apatite within vascular walls, exhibiting a high prevalence in older adults, and those with diabetes or chronic kidney disease. VC is a subclinical cardiovascular risk trait that increases mortality and functional deterioration. However, effective treatments for VC remain largely unavailable despite multiple attempts. Part of this therapeutic nihilism results from the failure to appreciate the diversity of VC as a pathological complex, with unforeseeable variations in morphology, risk associates, and anatomical and molecular pathogenesis, affecting clinical management strategies. VC should not be considered a homogeneous pathology because accumulating evidence refutes its conceptual and content uniformity. Here, we summarize the pathophysiological sources of VC heterogeneity from the intersecting pathways and networks of cellular, subcellular, and molecular crosstalk. Part of these pathological connections are synergistic or mutually antagonistic. We then introduce clinical implications related to the VC heterogeneity concept. Even within the same individual, a specific artery may exhibit the strongest tendency for calcification compared with other arteries. The prognostic value of VC may only be detectable with a detailed characterization of calcification morphology and features. VC heterogeneity is also evident, as VC risk factors vary between different arterial segments and layers. Therefore, diagnostic and screening strategies for VC may be improved based on VC heterogeneity, including the use of radiomics. Finally, pursuing a homogeneous treatment strategy is discouraged and we suggest a more rational approach by diversifying the treatment spectrum. This may greatly benefit subsequent efforts to identify effective VC therapeutics.

Histone deacetylase 9-mediated phenotypic transformation of vascular smooth muscle cells is a potential target for treating aortic aneurysm/dissection

Aortic aneurysm/dissection (AAD) is a serious cardiovascular condition characterized by rapid onset and high mortality rates. Currently, no effective drug treatment options are known for AAD. AAD pathogenesis is associated with the phenotypic transformation and abnormal proliferation of vascular smooth muscle cells (VSMCs). However, endogenous factors that contribute to AAD progression remain unclear. We aimed to investigate the role of histone deacetylase 9 (HDAC9) in AAD pathogenesis. HDAC9 expression was considerably increased in human thoracic aortic dissection specimens. Using RNA-sequencing (RNA-seq) and chromatin immunoprecipitation, we demonstrated that HDAC9 transcriptionally inhibited the expression of superoxide dismutase 2 and insulin-like growth factor-binding protein-3, which are critically involved in various signaling pathways. Furthermore, HDAC9 triggered the transformation of VSMCs from a systolic to synthetic phenotype, increasing their proliferation and migration abilities and suppressing their apoptosis. Consistent with these results, in vivo experiments revealed that TMP195, a pharmacological inhibitor of HDAC9, suppressed the formation of the β-aminopropionitrile-induced AAD phenotype in mice. Our findings indicate that HDAC9 may be a novel endogenous risk factor that promotes the onset of AAD by mediating the phenotypic transformation of VSMCs. Therefore, HDAC9 may serve as a potential therapeutic target for drug-based AAD treatment. Furthermore, TMP195 holds potential as a therapeutic agent for AAD treatment.

Epigenetically regulated inflammation in vascular senescence and renal progression of chronic kidney disease

Chronic kidney disease (CKD) and its complications, including vascular senescence and progressive renal fibrosis, are associated with inflammation. Vascular senescence, in particular, has emerged as an instrumental mediator of vascular inflammation that potentially worsens renal function. Epigenetically regulated inflammation involving histone modification, DNA methylation, actions of microRNAs and other non-coding RNAs, and their reciprocal reactions during vascular senescence and inflammaging are underappreciated. Their synergistic effects can contribute to CKD progression. Vascular senotherapeutics or pharmacological anti-senescent therapies based on epigenetic machineries can therefore be plausible options for ameliorating vascular aging and even halting the worsening of renal fibrosis. These include histone deacetylase modulators, histone methyltransferase modulators, other histone modification effectors, DNA methyltransferase inhibitors, telomerase reverse transcriptase enhancers, microRNA mimic delivery, and small molecules with microRNA-regulating potentials. Some of these molecules have already been tested and have shown anecdotal evidence for treating uremic vasculopathy and renal fibrosis, supporting the feasibility of this approach.

Diabetes Mellitus to Accelerated Atherosclerosis: Shared Cellular and Molecular Mechanisms in Glucose and Lipid Metabolism

Diabetes is one of the critical independent risk factors for the progression of cardiovascular disease, and the underlying mechanism regarding this association remains poorly understood. Hence, it is urgent to decipher the fundamental pathophysiology and consequently provide new insights into the identification of innovative therapeutic targets for diabetic atherosclerosis. It is now appreciated that different cell types are heavily involved in the progress of diabetic atherosclerosis, including endothelial cells, macrophages, vascular smooth muscle cells, dependence on altered metabolic pathways, intracellular lipids, and high glucose. Additionally, extensive studies have elucidated that diabetes accelerates the odds of atherosclerosis with the explanation that these two chronic disorders share some common mechanisms, such as endothelial dysfunction and inflammation. In this review, we initially summarize the current research and proposed mechanisms and then highlight the role of these three cell types in diabetes-accelerated atherosclerosis and finally establish the mechanism pinpointing the relationship between diabetes and atherosclerosis.

Aortic arch calcification increases major adverse cardiac event risk, modifiable by echocardiographic left ventricular hypertrophy, in end-stage kidney disease patients

Background

The factors affecting cardiovascular risk associated with vascular calcification in patients with chronic kidney disease are less well addressed. Distinct risk factors may contribute synergistically to this elevated cardiovascular risk in this population.

Objectives

We aimed to determine whether echocardiographic left ventricular hypertrophy (LVH) affects the risk of major adverse cardiac events (MACE) associated with vascular calcification in end-stage kidney disease (ESKD) patients.

Methods

In this retrospective cohort study, ESKD patients underwent chest radiography and echocardiography to assess aortic arch calcification (AoAC) and LVH, respectively, and were classified into three groups accordingly: non-to-mild AoAC without LVH, non-to-mild AoAC with LVH, and moderate-to-severe AoAC. The risks of MACE, cardiovascular mortality, and overall mortality were assessed using Cox proportional hazard analysis.

Results

Of the 283 enrolled ESKD patients, 44 (15.5%) had non-to-mild AoAC without LVH, 117 (41.3%) had non-to-mild AoAC with LVH, and 122 (43.1%) had moderate-to-severe AoAC. After 34.1 months, 107 (37.8%) participants developed MACE, including 6 (13.6%), 40 (34.2%), and 61 (50%) from each respective group. Those with moderate-to-severe AoAC (Hazard ratio, 3.72; 95% confidence interval, 1.58-8.73) had a significantly higher risk of MACE than did those with non-to-mild AoAC without LVH or with non-to-mild AoAC and LVH (Hazard ratio, 2.73; 95% confidence interval, 1.16-6.46). A similar trend was observed for cardiovascular and overall mortality.

Conclusion

Echocardiographic LVH could modify the risk of adverse cardiovascular events associated with vascular calcification in ESKD patients. Interventions aiming to ameliorate both morbidities might be translated into a lower MACE risk in this population.

Left Ventricular Hypertrophy Geometry and Vascular Calcification Co-Modify the Risk of Cardiovascular Mortality in Patients with End-Stage Kidney Disease: A Retrospective Cohort Study

AIM

Patients with end-stage kidney disease (ESKD) have an unparalleled risk of left ventricular hypertrophy (LVH) and vascular calcification (VC), both of which introduce excessive cardiovascular risk. However, it remains unclear whether LVH geometry co-modulates cardiovascular outcomes with VC in this population.

METHODS

A retrospective cohort study was conducted. Patients with ESKD requiring chronic hemodialysis were identified from Shin Kong Wu Ho-Su Memorial Hospital between October and December 2018, with echocardiographic LVH geometry and aortic arch calcification (AoAC) determined. They were divided into four groups according to AoAC severity and eccentric or concentric LVH. We used Kaplan-Meier analysis and Cox proportional hazard regression to analyze their cardiovascular and all-cause mortality after multivariate adjustment.

RESULTS

Overall, 223 patients with ESKD with LVH were analyzed, among whom 29.1%, 23.3%, 25.1%, and 22.4% had non-to-mild AoAC with eccentric and concentric LVH and moderate-to-severe AoAC with eccentric and concentric LVH, respectively. After 3.5 years of follow-up, patients with ESKD with moderate-to-severe AoAC and concentric LVH had a significantly higher risk of cardiovascular mortality than those with non-to-mild AoAC and eccentric LVH (hazard ratio 3.35, p=0.002). However, those with moderate-to-severe AoAC but eccentric LVH did not have higher cardiovascular mortality. Similarly, patients with ESKD with moderate-to-severe AoAC and concentric LVH had a significantly higher all-cause mortality than those with non-to-mild AoAC and eccentric LVH, whereas the other two groups did not have higher risk.

CONCLUSION

LVH geometry could help stratify the risk of patients with ESKD when they had severe VC, and co-existing severe VC and concentric LVH aggravated cardiovascular risk.

Targeting oxidative stress as a preventive and therapeutic approach for cardiovascular disease

Cardiovascular diseases (CVDs) continue to exert a significant impact on global mortality rates, encompassing conditions like pulmonary arterial hypertension (PAH), atherosclerosis (AS), and myocardial infarction (MI). Oxidative stress (OS) plays a crucial role in the pathogenesis and advancement of CVDs, highlighting its significance as a contributing factor. Maintaining an equilibrium between reactive oxygen species (ROS) and antioxidant systems not only aids in mitigating oxidative stress but also confers protective benefits on cardiac health. Herbal monomers can inhibit OS in CVDs by activating multiple signaling pathways, such as increasing the activity of endogenous antioxidant systems and decreasing the level of ROS expression. Given the actions of herbal monomers to significantly protect the normal function of the heart and reduce the damage caused by OS to the organism. Hence, it is imperative to recognize the significance of herbal monomers as prospective therapeutic interventions for mitigating oxidative damage in CVDs. This paper aims to comprehensively review the origins and mechanisms underlying OS, elucidate the intricate association between CVDs and OS, and explore the therapeutic potential of antioxidant treatment utilizing herbal monomers. Furthermore, particular emphasis will be placed on examining the cardioprotective effects of herbal monomers by evaluating their impact on cardiac signaling pathways subsequent to treatment.

NIPSNAP1 directs dual mechanisms to restrain senescence in cancer cells

BACKGROUND

Although the executive pathways of senescence are known, the underlying control mechanisms are diverse and not fully understood, particularly how cancer cells avoid triggering senescence despite experiencing exacerbated stress conditions within the tumor microenvironment.

METHODS

Mass spectrometry (MS)-based proteomic screening was used to identify differentially regulated genes in serum-starved hepatocellular carcinoma cells and RNAi employed to determine knockdown phenotypes of prioritized genes. Thereafter, gene function was investigated using cell proliferation assays (colony-formation, CCK-8, Edu incorporation and cell cycle) together with cellular senescence assays (SA-β-gal, SAHF and SASP). Gene overexpression and knockdown techniques were applied to examine mRNA and protein regulation in combination with luciferase reporter and proteasome degradation assays, respectively. Flow cytometry was applied to detect changes in cellular reactive oxygen species (ROS) and in vivo gene function examined using a xenograft model.

RESULTS

Among the genes induced by serum deprivation, NIPSNAP1 was selected for investigation. Subsequent experiments revealed that NIPSNAP1 promotes cancer cell proliferation and inhibits P27-dependent induction of senescence via dual mechanisms. Firstly, NIPSNAP1 maintains the levels of c-Myc by sequestering the E3 ubiquitin ligase FBXL14 to prevent the proteasome-mediated turnover of c-Myc. Intriguingly, NIPSNAP1 levels are restrained by transcriptional repression mediated by c-Myc-Miz1, with repression lifted in response to serum withdrawal, thus identifying feedback regulation between NIPSNAP1 and c-Myc. Secondly, NIPSNAP1 was shown to modulate ROS levels by promoting interactions between the deacetylase SIRT3 and superoxide dismutase 2 (SOD2). Consequent activation of SOD2 serves to maintain cellular ROS levels below the critical levels required to induce cell cycle arrest and senescence. Importantly, the actions of NIPSNAP1 in promoting cancer cell proliferation and preventing senescence were recapitulated in vivo using xenograft models.

CONCLUSIONS

Together, these findings reveal NIPSNAP1 as an important mediator of c-Myc function and a negative regulator of cellular senescence. These findings also provide a theoretical basis for cancer therapy where targeting NIPSNAP1 invokes cellular senescence.

Urinary Exosomal Metabolites: Overlooked Clue for Predicting Cardiovascular Risk

Over the last decade, increasing research has focused on urinary exosomes (UEs) in biological fluids and their relationship with physiological and pathological processes. UEs are membranous vesicles with a size of 40-100 nm, containing a number of bioactive molecules such as proteins, lipids, mRNAs, and miRNAs. These vesicles are an inexpensive non-invasive source that can be used in clinical settings to differentiate healthy patients from diseased patients, thereby serving as potential biomarkers for the early identification of disease. Recent studies have reported the isolation of small molecules called exosomal metabolites from individuals' urine with different diseases. These metabolites could utilize for a variety of purposes, such as the discovery of biomarkers, investigation of mechanisms related to disease development, and importantly prediction of cardiovascular diseases (CVDs) risk factors, including thrombosis, inflammation, oxidative stress, hyperlipidemia as well as homocysteine. It has been indicated that alteration in urinary metabolites of N1-methylnicotinamide, 4-aminohippuric acid, and citric acid can be valuable in predicting cardiovascular risk factors, providing a novel approach to evaluating the pathological status of CVDs. Since the UEs metabolome has been clearly and precisely so far unexplored in CVDs, the present study has specifically addressed the role of the mentioned metabolites in the prediction of CVDs risk factors.

Calciphylaxis and its co-occurrence with connective tissue diseases

Calciphylaxis, also known as calcific uremic arteriopathy, is a rare calcification syndrome that presents as ischemic skin necrosis and severe pain. It has a high mortality rate and is characterised by calcification of the small and medium arteries and micro-thrombosis. Calciphylaxis mainly occurs in patients with end-stage renal disease. In recent years, there have been an increasing number of cases of calciphylaxis associated with connective tissue diseases. Given the absence of clear diagnostic criteria for calciphylaxis thus far, an early diagnosis is crucial for designing an effective multidisciplinary treatment plan. In this article, we review the research progress on calciphylaxis and describe its characteristics in the context of connective tissue diseases.

Vascular frailty, a proposal for new frailty type: A narrative review

Frailty is the incremental accumulation of minute defects that progressively impair health and performance. Frailty is commonly observed in older adults; however, secondary frailty may also occur in patients with metabolic disorders or major organ failure. In addition to physical frailty, several distinct types of frailty have been identified, including oral, cognitive, and social frailty, each of which is of practical importance. This nomenclature suggests that detailed descriptions of frailty can potentially advance relevant researches. In this narrative review, we first summarize the clinical value and plausible biological origin of frailty, as well as how to appropriately assess it using physical frailty phenotypes and frailty indexes. In the second part, we discuss the issue of vascular tissue as a relatively underappreciated organ whose pathologies contribute to the development of physical frailty. Moreover, when vascular tissue undergoes degeneration, it exhibits vulnerability to subtle injuries and manifests a unique phenotype amenable to clinical assessment prior to or accompanying physical frailty development. Finally, we propose that vascular frailty, based on an extensive set of experimental and clinical evidence, can be considered a new frailty type that requires our attention. We also outline potential methods for the operationalization of vascular frailty. Further studies are required to validate our claim and sharpen the spectrum of this degenerative phenotype.

The context-dependent role of transforming growth factor-β/miR-378a-3p/connective tissue growth factor in vascular calcification: a translational study

BACKGROUND

Vascular calcification (VC) constitutes an important vascular pathology with prognostic importance. The pathogenic role of transforming growth factor-β (TGF-β) in VC remains unclear, with heterogeneous findings that we aimed to evaluate using experimental models and clinical specimens.

METHODS

Two approaches, exogenous administration and endogenous expression upon osteogenic media (OM) exposure, were adopted. Aortic smooth muscle cells (ASMCs) were subjected to TGF-β1 alone, OM alone, or both, with calcification severity determined. We evaluated miR-378a-3p and TGF-β1 effectors (connective tissue growth factor; CTGF) at different periods of calcification. Results were validated in an ex vivo model and further in sera from older adults without or with severe aortic arch calcification.

RESULTS

TGF-β1 treatment induced a significant dose-responsive increase in ASMC calcification without or with OM at the mature but not early or mid-term VC period. On the other hand, OM alone induced VC accompanied by suppressed TGF-β1 expressions over time; this phenomenon paralleled the declining miR-378a-3p and CTGF expressions since early VC. TGF-β1 treatment led to an upregulation of CTGF since early VC but not miR-378a-3p until mid-term VC, while miR-378a-3p overexpression suppressed CTGF expressions without altering TGF-β1 levels. The OM-induced down-regulation of TGF-β1 and CTGF was also observed in the ex vivo models, with compatible results identified from human sera.

CONCLUSIONS

We showed that TGF-β1 played a context-dependent role in VC, involving a time-dependent self-regulatory loop of TGF-β1/miR-378a-3p/CTGF signaling. Our findings may assist subsequent studies in devising potential therapeutics against VC.

Mitochondrial Homeostasis in VSMCs as a Central Hub in Vascular Remodeling

Vascular remodeling is a common pathological hallmark of many cardiovascular diseases. Vascular smooth muscle cells (VSMCs) are the predominant cell type lining the tunica media and play a crucial role in maintaining aortic morphology, integrity, contraction and elasticity. Their abnormal proliferation, migration, apoptosis and other activities are tightly associated with a spectrum of structural and functional alterations in blood vessels. Emerging evidence suggests that mitochondria, the energy center of VSMCs, participate in vascular remodeling through multiple mechanisms. For example, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α)-mediated mitochondrial biogenesis prevents VSMCs from proliferation and senescence. The imbalance between mitochondrial fusion and fission controls the abnormal proliferation, migration and phenotypic transformation of VSMCs. Guanosine triphosphate-hydrolyzing enzymes, including mitofusin 1 (MFN1), mitofusin 2 (MFN2), optic atrophy protein 1 (OPA1) and dynamin-related protein 1 (DRP1), are crucial for mitochondrial fusion and fission. In addition, abnormal mitophagy accelerates the senescence and apoptosis of VSMCs. PINK/Parkin and NIX/BINP3 pathways alleviate vascular remodeling by awakening mitophagy in VSMCs. Mitochondrial DNA (mtDNA) damage destroys the respiratory chain of VSMCs, resulting in excessive ROS production and decreased ATP levels, which are related to the proliferation, migration and apoptosis of VSMCs. Thus, maintaining mitochondrial homeostasis in VSMCs is a possible way to relieve pathologic vascular remodeling. This review aims to provide an overview of the role of mitochondria homeostasis in VSMCs during vascular remodeling and potential mitochondria-targeted therapies.

Modified Linggui Zhugan Decoction protects against ventricular remodeling through ameliorating mitochondrial damage in post-myocardial infarction rats

Introduction

Modified Linggui Zhugan Decoction (MLZD) is a Traditional Chinese Medicine prescription developed from Linggui Zhugan Decoction (LZD) that has been used for the clinical treatment of ischemic cardiovascular diseases. However, the cardioprotective mechanism of MLZD against post-myocardial infarction (MI) ventricular remodeling remains unclear.

Methods

We explored the effects of MLZD on ventricular remodeling and their underlying mechanisms, respectively, in SD rats with MI models and in H9c2 cardiomyocytes with oxygen-glucose deprivation (OGD) models. The cardiac structure and function of rats were measured by echocardiography, HE staining, and Masson staining. Apoptosis, inflammation, mitochondrial structure and function, and sirtuin 3 (SIRT3) expression were additionally examined.

Results

MLZD treatment significantly ameliorated cardiac structure and function, and thus reversed ventricular remodeling, compared with the control. Further research showed that MLZD ameliorated mitochondrial structural disruption, protected against mitochondrial dynamics disorder, restored impaired mitochondrial function, inhibited inflammation, and thus inhibited apoptosis. Moreover, the decreased expression level of SIRT3 was enhanced after MLZD treatment. The protective effects of MLZD on SIRT3 and mitochondria, nevertheless, were blocked by 3-TYP, a selective inhibitor of SIRT3.

Discussion

These findings together revealed that MLZD could improve the ventricular remodeling of MI rats by ameliorating mitochondrial damage and its associated apoptosis, which might exert protective effects by targeting SIRT3.

Phenotypic plasticity of vascular smooth muscle cells in vascular calcification: Role of mitochondria

Vascular calcification (VC) is an important hallmark of cardiovascular disease, the osteo-/chondrocyte phenotype differentiation of vascular smooth muscle cells (VSMCs) is the main cause of vascular calcification. Accumulating evidence shows that mitochondrial dysfunction may ultimately be more detrimental in the VSMCs calcification. Mitochondrial participate in essential cellular functions, including energy production, metabolism, redox homeostasis regulation, intracellular calcium homeostasis, apoptosis, and signal transduction. Mitochondrial dysfunction under pathological conditions results in mitochondrial reactive oxygen species (ROS) generation and metabolic disorders, which further lead to abnormal phenotypic differentiation of VSMCs. In this review, we summarize existing studies targeting mitochondria as a treatment for VC, and focus on VSMCs, highlighting recent progress in determining the roles of mitochondrial processes in regulating the phenotype transition of VSMCs, including mitochondrial biogenesis, mitochondrial dynamics, mitophagy, mitochondrial energy metabolism, and mitochondria/ER interactions. Along these lines, the impact of mitochondrial homeostasis on VC is discussed.

Intermedin Alleviates Vascular Calcification in CKD through Sirtuin 3-Mediated Inhibition of Mitochondrial Oxidative Stress

Vascular calcification (VC) is a common pathophysiological process of chronic kidney disease (CKD). Sirtuin 3 (Sirt3), a major NAD⁺-dependent protein deacetylase predominantly in mitochondria, is involved in the pathogenesis of VC. We previously reported that intermedin (IMD) could protect against VC. In this study, we investigated whether IMD attenuates VC by Sirt3-mediated inhibition of mitochondrial oxidative stress. A rat VC with CKD model was induced by the 5/6 nephrectomy plus vitamin D₃. Vascular smooth muscle cell (VSMC) calcification was induced by CaCl₂ and β-glycerophosphate. IMD_1-53 treatment attenuated VC in vitro and in vivo, rescued the depressed mitochondrial membrane potential (MMP) level and decreased mitochondrial ROS levels in calcified VSMCs. IMD_1-53 treatment recovered the reduced protein level of Sirt3 in calcified rat aortas and VSMCs. Inhibition of VSMC calcification by IMD_1-53 disappeared when the cells were Sirt3 absent or pretreated with the Sirt3 inhibitor 3-TYP. Furthermore, 3-TYP pretreatment blocked IMD_1-53-mediated restoration of the MMP level and inhibition of mitochondrial oxidative stress in calcified VSMCs. The attenuation of VSMC calcification by IMD_1-53 through upregulation of Sirt3 might be achieved through activation of the IMD receptor and post-receptor signaling pathway AMPK, as indicated by pretreatment with an IMD receptor antagonist or AMPK inhibitor blocking the inhibition of VSMC calcification and upregulation of Sirt3 by IMD_1-53. AMPK inhibitor treatment reversed the effects of IMD_1-53 on restoring the MMP level and inhibiting mitochondrial oxidative stress in calcified VSMCs. In conclusion, IMD attenuates VC by improving mitochondrial function and inhibiting mitochondrial oxidative stress through upregulating Sirt3.

Deep Learning-Assisted Repurposing of Plant Compounds for Treating Vascular Calcification: An In Silico Study with Experimental Validation

Background

Vascular calcification (VC) constitutes subclinical vascular burden and increases cardiovascular mortality. Effective therapeutics for VC remains to be procured. We aimed to use a deep learning-based strategy to screen and uncover plant compounds that potentially can be repurposed for managing VC.

Methods

We integrated drugome, interactome, and diseasome information from Comparative Toxicogenomic Database (CTD), DrugBank, PubChem, Gene Ontology (GO), and BioGrid to analyze drug-disease associations. A deep representation learning was done using a high-level description of the local network architecture and features of the entities, followed by learning the global embeddings of nodes derived from a heterogeneous network using the graph neural network architecture and a random forest classifier established for prediction. Predicted results were tested in an in vitro VC model for validity based on the probability scores.

Results

We collected 6,790 compounds with available Simplified Molecular-Input Line-Entry System (SMILES) data, 11,958 GO terms, 7,238 diseases, and 25,482 proteins, followed by local embedding vectors using an end-to-end transformer network and a node2vec algorithm and global embedding vectors learned from heterogeneous network via the graph neural network. Our algorithm conferred a good distinction between potential compounds, presenting as higher prediction scores for the compound categories with a higher potential but lower scores for other categories. Probability score-dependent selection revealed that antioxidants such as sulforaphane and daidzein were potentially effective compounds against VC, while catechin had low probability. All three compounds were validated in vitro.

Conclusions

Our findings exemplify the utility of deep learning in identifying promising VC-treating plant compounds. Our model can be a quick and comprehensive computational screening tool to assist in the early drug discovery process.

Antioxidant enzymes and vascular diseases

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a fundamental role in regulating endothelial function and vascular tone in the physiological conditions of a vascular system. However, oxidative stress has detrimental effects on human health, and numerous studies confirmed that high ROS/RNS production contributes to the initiation and progression of cardiovascular diseases. The antioxidant defense has an essential role in the homeostatic functioning of the vascular endothelial system. Endogenous antioxidative defense includes various molecules and enzymes such as superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase. Together all these antioxidative enzymes are essential for defense against harmful ROS features. ROS are mainly generated from redox-active compounds involved in the mitochondrial respiratory chain. Thus, targeting antioxidative enzymes and mitochondria oxidative balance may be a promising approach for vascular diseases occurrence and treatment. This review summarized the most recent research on the regulation of antioxidative enzymes in vascular diseases.

Accelerated discovery of superoxide-dismutase nanozymes via high-throughput computational screening

The activity of nanomaterials (NMs) in catalytically scavenging superoxide anions mimics that of superoxide dismutase (SOD). Although dozens of NMs have been demonstrated to possess such activity, the underlying principles are unclear, hindering the discovery of NMs as the novel SOD mimics. In this work, we use density functional theory calculations to study the thermodynamics and kinetics of the catalytic processes, and we develop two principles, namely, an energy level principle and an adsorption energy principle, for the activity. The first principle quantitatively describes the role of the intermediate frontier molecular orbital in transferring electrons for catalysis. The second one quantitatively describes the competition between the desired catalytic reaction and undesired side reactions. The ability of the principles to predict the SOD-like activities of metal-organic frameworks were verified by experiments. Both principles can be easily implemented in computer programs to computationally screen NMs with the intrinsic SOD-like activity.

Construction of the circRNA-miRNA-mRNA Regulatory Network of an Abdominal Aortic Aneurysm to Explore Its Potential Pathogenesis

Background

Abdominal aortic aneurysm (AAA) is a progressive cardiovascular disease, which is a permanent and localized dilatation of the abdominal aorta with potentially fatal consequence of aortic rupture. Dysregulation of circRNAs is correlated with the development of various pathological events in cardiovascular diseases. However, the function of circRNAs in abdominal aortic aneurysm (AAA) is unknown and remains to be explored. This study is aimed at determining the regulatory mechanisms of circRNAs in AAAs. This study was aimed at exploring the underlying molecular mechanisms of abdominal aortic aneurysms based on the competing endogenous RNA (ceRNA) regulatory hypothesis of circRNA, miRNA, and mRNA.

Methods

The expression profiles of circRNAs (GSE144431), miRNAs (GSE62179), and mRNAs (GSE7084, GSE57691, and GSE47472) in human tissue sample from the aneurysm group and normal group were obtained from the Gene Expression Omnibus database, respectively. The circRNA-miRNA-mRNA network was constructed by using Cytoscape 3.7.2 software; then, the protein-protein interaction (PPI) network was constructed by using the STRING database, and the hub genes were identified by using the cytoHubba plug-in. The circRNA-miRNA-hub gene regulatory subnetwork was formed to understand the regulatory axis of hub genes in AAAs.

Results

The present study identified 40 differentially expressed circRNAs (DECs) in the GSE144431, 90 differentially expressed miRNAs (DEmiRs) in the GSE62179, and 168 differentially expressed mRNAs (DEGs) with the same direction regulation (130 downregulated and 38 upregulated) in the GSE7084, GSE57691, and GSE47472 datasets identified regarding AAAs. The miRNA response elements (MREs) of three DECs were then predicted. Four overlapping miRNAs were obtained by intersecting the predicted miRNA and DEmiRs. Then, 17 overlapping mRNAs were obtained by intersecting the predicted target mRNAs of 4 miRNAs with 168 DEGs. Furthermore, the circRNA-miRNA-mRNA network was constructed through 3 circRNAs, 4 miRNAs, and 17 mRNAs, and three hub genes (SOD2, CCR7, and PGRMC1) were identified. Simultaneously, functional enrichment and pathway analysis were performed within genes in the circRNA-miRNA-mRNA network. Three of them (SOD2, CCR7, and PGRMC1) were suggested to be crucial based on functional enrichment, protein-protein interaction, and ceRNA network analysis. Furthermore, the expression of SOD2 and CCR7 may be regulated by hsa_circ_0011449/hsa_circ_0081968/hsa-let-7f-5p; the expression of PGRMC1 may be regulated by hsa_circ_0011449/hsa_circ_0081968-hsa-let-7f-5p/hsa-let-7e-5p.

Conclusion

In conclusion, the ceRNA interaction axis we identified may be an important target for the treatment of abdominal aortic aneurysms. This study provided further understanding of the potential pathogenesis from the perspective of the circRNA-related competitive endogenous RNA network in AAAs.

Gender-Related Differences in Chronic Kidney Disease-Associated Vascular Calcification Risk and Potential Risk Mediators: A Scoping Review

Vascular calcification (VC) involves the deposition of calcium apatite in vascular intima or media. Individuals of advanced age, having diabetes mellitus or chronic kidney disease (CKD) are particularly at risk. The pathogenesis of CKD-associated VC evolves considerably. The core driver is the phenotypic change involving vascular wall constituent cells toward manifestations similar to that undergone by osteoblasts. Gender-related differences are observed regarding the expressions of osteogenesis-regulating effectors, and presumably the prevalence/risk of CKD-associated VC exhibits gender-related differences as well. Despite the wealth of data focusing on gender-related differences in the risk of atherosclerosis, few report whether gender modifies the risk of VC, especially CKD-associated cases. We systematically identified studies of CKD-associated VC or its regulators/modifiers reporting data about gender distributions, and extracted results from 167 articles. A significantly higher risk of CKD-associated VC was observed in males among the majority of original investigations. However, substantial heterogeneity exists, since multiple large-scale studies yielded neutral findings. Differences in gender-related VC risk may result from variations in VC assessment methods, the anatomical segments of interest, study sample size, and even the ethnic origins of participants. From a biological perspective, plausible mediators of gender-related VC differences include body composition discrepancies, alterations involving lipid profiles, inflammatory severity, diversities in matrix Gla protein (MGP), soluble Klotho, vitamin D, sclerostin, parathyroid hormone (PTH), fibroblast growth factor-23 (FGF-23), and osteoprotegerin levels. Based on our findings, it may be inappropriate to monotonously assume that male patients with CKD are at risk of VC compared to females, and we should consider more background in context before result interpretation.

Uremic Toxins and Frailty in Patients with Chronic Kidney Disease: A Molecular Insight

The accumulation of uremic toxins (UTs) is a prototypical manifestation of uremic milieu that follows renal function decline (chronic kidney disease, CKD). Frailty as a potential outcome-relevant indicator is also prevalent in CKD. The intertwined relationship between uremic toxins, including small/large solutes (phosphate, asymmetric dimethylarginine) and protein-bound ones like indoxyl sulfate (IS) and p-cresyl sulfate (pCS), and frailty pathogenesis has been documented recently. Uremic toxins were shown in vitro and in vivo to induce noxious effects on many organ systems and likely influenced frailty development through their effects on multiple preceding events and companions of frailty, such as sarcopenia/muscle wasting, cognitive impairment/cognitive frailty, osteoporosis/osteodystrophy, vascular calcification, and cardiopulmonary deconditioning. These organ-specific effects may be mediated through different molecular mechanisms or signal pathways such as peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), mitogen-activated protein kinase (MAPK) signaling, aryl hydrocarbon receptor (AhR)/nuclear factor-κB (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Runt-related transcription factor 2 (RUNX2), bone morphogenic protein 2 (BMP2), osterix, Notch signaling, autophagy effectors, microRNAs, and reactive oxygen species induction. Anecdotal clinical studies also suggest that frailty may further accelerate renal function decline, thereby augmenting the accumulation of UTs in affected individuals. Judging from these threads of evidence, management strategies aiming for uremic toxin reduction may be a promising approach for frailty amelioration in patients with CKD. Uremic toxin lowering strategies may bear the potential of improving patients’ outcomes and restoring their quality of life, through frailty attenuation. Pathogenic molecule-targeted therapeutics potentially disconnect the association between uremic toxins and frailty, additionally serving as an outcome-modifying approach in the future.