Msx2 promotes cardiovascular calcification by activating paracrine Wnt signals

Cardiovascular Safety of Romosozumab Compared to Commonly Used Anti-osteoporosis Medications in Postmenopausal Osteoporosis: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

INTRODUCTION

The aim of this study was to investigate the cardiovascular safety of romosozumab in postmenopausal women with osteoporosis. Romosozumab, a monoclonal antibody targeting sclerostin, has been shown to increase bone mineral density and reduce the risk of osteoporotic fractures. However, in previous studies, romosozumab therapy was identified as a potential risk factor for cardiovascular events, particularly in patients with predisposing cardiovascular disease.

METHODS

A systematic literature search was performed in the Cochrane Library, Embase, PubMed, and Web of Science databases to identify randomized controlled trials (RCTs) comparing the safety and efficacy of romosozumab versus alendronate, teriparatide, denosumab, or placebo in postmenopausal women with osteoporosis. Contrast-based network meta-analysis was performed using a random-effects model. The pooled estimates are presented as risk ratios with 95% confidence intervals.

RESULTS

Of the 5282 articles retrieved, 25 RCTs were included in this review (n = 24,942), and 18 randomized controlled trials (n = 16,777) were included in the network meta-analysis. The results indicated no significant differences in cardiovascular mortality rate between romosozumab and placebo. Regarding the risk of major cardiovascular events, no significant differences were found in the direct evidence or the network meta-analysis with placebo as the reference.

CONCLUSION

Romosozumab might be a safe option for treating postmenopausal women with osteoporosis. The cardiovascular concerns associated with this treatment seem less significant than previously suggested, although additional real-world data are required to confirm this conclusion.

Placental Tissue Calcification and Its Molecular Pathways in Female Patients with Late-Onset Preeclampsia

Preeclampsia (PE) is a complex multisystem disease characterized by hypertension of sudden onset (>20 weeks' gestation) coupled with the presence of at least one additional complication, such as proteinuria, maternal organ dysfunction, or uteroplacental dysfunction. Hypertensive states during pregnancy carry life-threatening risks for both mother and baby. The pathogenesis of PE develops due to a dysfunctional placenta with aberrant architecture that releases factors contributing to endothelial dysfunction, an antiangiogenic state, increased oxidative stress, and maternal inflammatory responses. Previous studies have shown a correlation between grade 3 placental calcifications and an elevated risk of developing PE at term. However, little is known about the molecular pathways leading to placental calcification. In this work, we studied the gene and protein expression of c-Jun N-terminal kinase (JNK), Runt-related transcription factor 2 (RUNX2), osteocalcin (OSC), osteopontin (OSP), pigment epithelium-derived factor (PEDF), MSX-2/HOX8, SOX-9, WNT-1, and β-catenin in placental tissue from women with late-onset PE (LO-PE). In addition, we employed von Kossa staining to detect mineral deposits in placental tissues. Our results show a significant increase of all these components in placentas from women with LO-PE. Therefore, our study suggests that LO-PE may be associated with the activation of molecular pathways of placental calcification. These results could be the starting point for future research to describe the molecular mechanisms that promote placental calcification in PE and the development of therapeutic strategies directed against it.

In Vitro Models of Cardiovascular Calcification

Cardiovascular calcification, characterized by hydroxyapatite deposition in the arterial wall and heart valves, is associated with high cardiovascular morbidity and mortality. Cardiovascular calcification is a hallmark of aging but is frequently seen in association with chronic diseases, such as chronic kidney disease (CKD), diabetes, dyslipidemia, and hypertension in the younger population as well. Currently, there is no therapeutic approach to prevent or cure cardiovascular calcification. The pathophysiology of cardiovascular calcification is highly complex and involves osteogenic differentiation of various cell types of the cardiovascular system, such as vascular smooth muscle cells and valve interstitial cells. In vitro cellular and ex vivo tissue culture models are simple and useful tools in cardiovascular calcification research. These models contributed largely to the discoveries of the numerous calcification inducers, inhibitors, and molecular mechanisms. In this review, we provide an overview of the in vitro cell culture and the ex vivo tissue culture models applied in the research of cardiovascular calcification.

"Photo-Thermo-Electric" Dental Implant for Anti-Infection and Enhanced Osteoimmunomodulation

The dental implant market has experienced explosive growth, owing to the widespread acceptance of implants as the core of oral rehabilitation. Clinically, achieving simultaneous anti-infective effects and rapid osseointegration is a crucial but challenging task for implants. The demand for implants with long-term broad-spectrum antibacterial and immune-osteogenic properties is growing. Existing methods are limited by a lack of safety, efficiency, short-lasting anti-infective ability, and inadequate consideration of the immunomodulatory effects on osteogenesis. Herein, a ZnO/black TiO2-x heterojunction surface structure was designed as a near-infrared (NIR) light-responsive nanofilm immobilized on a titanium (Ti) implant surface. This nanofilm introduces abundant oxygen vacancies and heterojunctions, which enhance the photothermal and photoelectric abilities of Ti implants under NIR illumination by narrowing the band gap and improving interfacial charge transfer. The "photo-thermo-electric" implant exhibits excellent broad-spectrum antibacterial efficacy against three dental pathogenic bacteria (Porphyromonas gingivalis, Fusobacterium nucleatum, and Staphylococcus aureus, >99.4%) by destroying the bacterial membrane and increasing the production of intracellular reactive oxygen species. Additionally, the implant can effectively eliminate mature multispecies biofilms and kill bacteria inside the biofilms under NIR irradiation. Meanwhile, this implant can also induce the pro-regenerative transformation of macrophages and promote osteoblast proliferation and differentiation. Moreover, in vivo results confirmed the superior antibacterial and osteoimmunomodulatory properties of this dental implant. RNA sequencing revealed that the underlying osteogenic mechanisms involve activation of the Wnt/β-catenin signaling pathway and bone development. Overall, this versatile "photo-thermo-electric" platform endows implants with anti-infection and bone integration performance simultaneously, which holds great potential for dental implants.

Parathyroid hormone-PTH1R signaling in cardiovascular disease and homeostasis

Primary hyperparathyroidism (pHPT) afflicts our aging population with an incidence approaching 50 per 100 000 patient-years at a female:male ratio of ~3:1. Decisions surrounding surgical management are currently driven by age, hypercalcemia severity, presence of osteoporosis, renal insufficiency, or hypercalciuria with or without nephrolithiasis. Cardiovascular (CV) disease (CVD) is not systematically considered. This is notable since the parathyroid hormone (PTH) 1 receptor (PTH1R) is biologically active in the vasculature, and adjusted CV mortality risk is increased almost threefold in individuals with pHPT who do not meet contemporary recommendations for surgical cure. We provide an overview of epidemiology, pharmacology, and physiology that highlights the need to: (i) identify biomarkers that establish a healthy 'set point' for CV PTH1R signaling tone; (ii) better understand the pharmacokinetic-pharmacodynamic (PK-PD) relationships of PTH1R ligands in CV homeostasis; and (iii) incorporate CVD risk assessment into the management of hyperparathyroidism.

In chronic kidney disease altered cardiac metabolism precedes cardiac hypertrophy

Conduit arterial disease in chronic kidney disease (CKD) is an important cause of cardiac complications. Cardiac function in CKD has not been studied in the absence of arterial disease. In an Alport syndrome model bred not to have conduit arterial disease, mice at 225 days of life (dol) had CKD equivalent to humans with CKD stage 4-5. Parathyroid hormone (PTH) and FGF23 levels were one log order elevated, circulating sclerostin was elevated, and renal activin A was strongly induced. Aortic Ca levels were not increased, and vascular smooth muscle cell (VSMC) transdifferentiation was absent. The CKD mice were not hypertensive, and cardiac hypertrophy was absent. Freshly excised cardiac tissue respirometry (Oroboros) showed that ADP-stimulated O2 flux was diminished from 52 to 22 pmol/mg (P = 0.022). RNA-Seq of cardiac tissue from CKD mice revealed significantly decreased levels of cardiac mitochondrial oxidative phosphorylation genes. To examine the effect of activin A signaling, some Alport mice were treated with a monoclonal Ab to activin A or an isotype-matched IgG beginning at 75 days of life until euthanasia. Treatment with the activin A antibody (Ab) did not affect cardiac oxidative phosphorylation. However, the activin A antibody was active in the skeleton, disrupting the effect of CKD to stimulate osteoclast number, eroded surfaces, and the stimulation of osteoclast-driven remodeling. The data reported here show that cardiac mitochondrial respiration is impaired in CKD in the absence of conduit arterial disease. This is the first report of the direct effect of CKD on cardiac respiration.NEW & NOTEWORTHY Heart disease is an important morbidity of chronic kidney disease (CKD). Hypertension, vascular stiffness, and vascular calcification all contribute to cardiac pathophysiology. However, cardiac function in CKD devoid of vascular disease has not been studied. Here, in an animal model of human CKD without conduit arterial disease, we analyze cardiac respiration and discover that CKD directly impairs cardiac mitochondrial function by decreasing oxidative phosphorylation. Protection of cardiac oxidative phosphorylation may be a therapeutic target in CKD.

Aortic Cellular Heterogeneity in Health and Disease: Novel Insights Into Aortic Diseases From Single-Cell RNA Transcriptomic Data Sets

Aortic diseases such as atherosclerosis, aortic aneurysms, and aortic stiffening are significant complications that can have significant impact on end-stage cardiovascular disease. With limited pharmacological therapeutic strategies that target the structural changes in the aorta, surgical intervention remains the only option for some patients with these diseases. Although there have been significant contributions to our understanding of the cellular architecture of the diseased aorta, particularly in the context of atherosclerosis, furthering our insight into the cellular drivers of disease is required. The major cell types of the aorta are well defined; however, the advent of single-cell RNA sequencing provides unrivaled insights into the cellular heterogeneity of each aortic cell type and the inferred biological processes associated with each cell in health and disease. This review discusses previous concepts that have now been enhanced with recent advances made by single-cell RNA sequencing with a focus on aortic cellular heterogeneity.

Machine learning based biomarker discovery for chronic kidney disease-mineral and bone disorder (CKD-MBD)

INTRODUCTION

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is characterized by bone abnormalities, vascular calcification, and some other complications. Although there are diagnostic criteria for CKD-MBD, in situations when conducting target feature examining are unavailable, there is a need to investigate and discover alternative biochemical criteria that are easy to obtain. Moreover, studying the correlations between the newly discovered biomarkers and the existing ones may provide insights into the underlying molecular mechanisms of CKD-MBD.

METHODS

We collected a cohort of 116 individuals, consisting of three subtypes of CKD-MBD: calcium abnormality, phosphorus abnormality, and PTH abnormality. To identify the best biomarker panel for discrimination, we conducted six machine learning prediction methods and employed a sequential forward feature selection approach for each subtype. Additionally, we collected a separate prospective cohort of 114 samples to validate the discriminative power of the trained prediction models.

RESULTS

Using machine learning under cross validation setting, the feature selection method selected a concise biomarker panel for each CKD-MBD subtype as well as for the general one. Using the consensus of these features, best area under ROC curve reached up to 0.95 for the training dataset and 0.74 for the perspective dataset, respectively.

DISCUSSION/CONCLUSION

For the first time, we utilized machine learning methods to analyze biochemical criteria associated with CKD-MBD. Our aim was to identify alternative biomarkers that could serve not only as early detection indicators for CKD-MBD, but also as potential candidates for studying the underlying molecular mechanisms of the condition.

Similarities and Differences of Vascular Calcification in Diabetes and Chronic Kidney Disease

Presently, the mechanism of occurrence and development of vascular calcification (VC) is not fully understood; a range of evidence suggests a positive association between diabetes mellitus (DM) and VC. Furthermore, the increasing burden of central vascular disease in patients with chronic kidney disease (CKD) may be due, at least in part, to VC. In this review, we will review recent advances in the mechanisms of VC in the context of CKD and diabetes. The study further unveiled that VC is induced through the stimulation of pro-inflammatory factors, which in turn impairs endothelial function and triggers similar mechanisms in both disease contexts. Notably, hyperglycemia was identified as the distinctive mechanism driving calcification in DM. Conversely, in CKD, calcification is facilitated by mechanisms including mineral metabolism imbalance and the presence of uremic toxins. Additionally, we underscore the significance of investigating vascular alterations and newly identified molecular pathways as potential avenues for therapeutic intervention.

Vascular calcification and cellular signaling pathways as potential therapeutic targets

Increased vascular calcification (VC) is observed in patients with cardiovascular diseases such as atherosclerosis, diabetes, and chronic kidney disease. VC is divided into three types according to its location: intimal, medial, and valvular. Various cellular signaling pathways are associated with VC, including the Wnt, mitogen-activated protein kinase, phosphatidylinositol-3 kinase/Akt, cyclic nucleotide-dependent protein kinase, protein kinase C, calcium/calmodulin-dependent kinase II, adenosine monophosphate-activated protein kinase/mammalian target of rapamycin, Ras homologous GTPase, apoptosis, Notch, and cytokine signaling pathways. In this review, we discuss the literature concerning the key cellular signaling pathways associated with VC and their role as potential therapeutic targets. Inhibitors to these pathways represent good candidates for use as potential therapeutic agents for the prevention and treatment of VC.

Dietary antioxidants and vascular calcification: From pharmacological mechanisms to challenges

Vascular calcification (VC), an actively regulated process, has been recognized as an independent and strong predictor of cardiovascular disease (CVD) and mortality worldwide. Diet has been shown to have a major role in the progression of VC. Oxidative stress (OS), a common pro-calcification factor, is closely related to VC, and evidence strongly suggests that dietary antioxidants directly prevent VC. Herein, we provided an overview of OS and its key role in VC and underlined the mechanisms of harmful effects of OS on VC. Furthermore, we introduced dietary antioxidants, and discussed about surrounding the challenges of dietary antioxidants in VC management. This review will benefit future research about the effects of dietary antioxidants on cardiovascular health.

Lower limb arterial calcification and its clinical relevance with peripheral arterial disease

Lower limb arterial calcification (LLAC) is associated with an increased risk of mortality and it predicts poor outcomes after endovascular interventions in patients with peripheral artery disease (PAD). Detailed histological analysis of human lower artery specimens pinpointed the presence of LLAC in two distinct layers: the intima and the media. Intimal calcification has been assumed to be an atherosclerotic pathology and it is associated with smoking and obesity. It becomes instrumental in lumen stenosis, thereby playing a crucial role in disease progression. On the contrary, medial calcification is a separate process, systematically regulated and linked with age advancement, diabetes, and chronic kidney disease. It prominently interacts with vasodilation and arterial stiffness. Given that both types of calcifications frequently co-exist in PAD patients, it is vital to understand their respective mechanisms within the context of PAD. Calcification can be easily identifiable entity on imaging scans. Considering the highly improved abilities of novel imaging technologies in differentiating intimal and medial calcification within the lower limb arteries, this review aimed to describe the distinct histological and imaging features of the two types of LLAC. Additionally, it aims to provide in-depth insight into the risk factors, the effects on hemodynamics, and the clinical implications of LLAC, either occurring in the intimal or medial layers.

The association of moderate-to-vigorous physical activity and sedentary behaviour with abdominal aortic calcification

BACKGROUND AND AIMS

The increasing prevalence of metabolic and cardiovascular diseases poses a significant challenge to global healthcare systems. Regular physical activity (PA) is recognized for its positive impact on cardiovascular risk factors. This study aimed to investigate the relationship between moderate-to-vigorous physical activity (MVPA), sedentary behavior (SB), and abdominal aortic calcification (AAC) using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

The study used data from NHANES participants aged 40 and above during the 2013-2014 cycle. AAC scores were assessed using the Kauppila scoring system, and MVPA and SB were self-reported. Sociodemographic variables were considered, and multivariable linear regression models were used to analyze associations between MVPA, SB, and AAC scores. Subgroup analyses were conducted based on age, sex, BMI, hypertension, and diabetes.

RESULTS

The study included 2843 participants. AAC prevalence was higher in older age groups, smokers, and those with diabetes or hypertension. Lower socioeconomic status was associated with higher AAC prevalence. Individuals engaged in any level of MVPA exhibited lower AAC rates compared to inactive individuals. Not engaging in occupational MVPA (β = 0.46, 95% confidence interval = 0.24‒0.67, p < .001) and prolonged SB (β = 0.28, 95% confidence interval = 0.04‒0.52, p = .023) were associated with higher AAC scores. However, no significant associations were found for transportation and leisure time MVPA. Subgroup analysis revealed age and hypertension as effect modifiers in the MVPA-AAC relationship.

CONCLUSIONS

This study highlights the potential benefits of engaging in occupational MVPA and reducing SB in mitigating AAC scores, particularly among older individuals and those with hypertension.

The WNT/β-catenin system in chronic kidney disease-mineral bone disorder syndrome

BACKGROUND

The WNT/β-catenin system is an evolutionarily conserved signaling pathway that plays a crucial role in morphogenesis and cell tissue formation during embryogenesis. Although usually suppressed in adulthood, it can be reactivated during organ damage and regeneration. Transient activation of the WNT/β-catenin pathway stimulates tissue regeneration after acute kidney injury, while persistent (uncontrolled) activation can promote the development of chronic kidney disease (CKD). CKD-MBD is a clinical syndrome that develops with systemic mineral and bone metabolism disorders caused by CKD, characterized by abnormal bone mineral metabolism and/or extraosseous calcification, as well as cardiovascular disease associated with CKD, including vascular stiffness and calcification.

OBJECTIVE

This paper aims to comprehensively review the WNT/β-catenin signaling pathway in relation to CKD-MBD, focusing on its components, regulatory molecules, and regulatory mechanisms. Additionally, this review highlights the challenges and opportunities for using small molecular compounds to target the WNT/β-catenin signaling pathway in CKD-MBD therapy.

METHODS

We conducted a comprehensive literature review using various scientific databases, including PubMed, Scopus, and Web of Science, to identify relevant articles. We searched for articles that discussed the WNT/β-catenin signaling pathway, CKD-MBD, and their relationship. We also reviewed articles that discussed the components of the WNT/β-catenin signaling pathway, its regulatory molecules, and regulatory mechanisms.

RESULTS

The WNT/β-catenin signaling pathway plays a crucial role in CKD-MBD by promoting vascular calcification and bone mineral metabolism disorders. The pathway's components include WNT ligands, Frizzled receptors, and LRP5/6 co-receptors, which initiate downstream signaling cascades leading to the activation of β-catenin. Several regulatory molecules, including GSK-3β, APC, and Axin, modulate β-catenin activation. The WNT/β-catenin signaling pathway also interacts with other signaling pathways, such as the BMP pathway, to regulate CKD-MBD.

CONCLUSIONS

The WNT/β-catenin signaling pathway is a potential therapeutic target for CKD-MBD. Small molecular compounds that target the components or regulatory molecules of the pathway may provide a promising approach to treat CKD-MBD. However, more research is needed to identify safe and effective compounds and to determine the optimal dosages and treatment regimens.

Molecular Mechanisms of Vascular Health: Insights From Vascular Aging and Calcification

Cardiovascular disease is the most common cause of death worldwide, especially beyond the age of 65 years, with the vast majority of morbidity and mortality due to myocardial infarction and stroke. Vascular pathology stems from a combination of genetic risk, environmental factors, and the biologic changes associated with aging. The pathogenesis underlying the development of vascular aging, and vascular calcification with aging, in particular, is still not fully understood. Accumulating data suggests that genetic risk, likely compounded by epigenetic modifications, environmental factors, including diabetes and chronic kidney disease, and the plasticity of vascular smooth muscle cells to acquire an osteogenic phenotype are major determinants of age-associated vascular calcification. Understanding the molecular mechanisms underlying genetic and modifiable risk factors in regulating age-associated vascular pathology may inspire strategies to promote healthy vascular aging. This article summarizes current knowledge of concepts and mechanisms of age-associated vascular disease, with an emphasis on vascular calcification.

Signaling pathways of adipose stem cell-derived exosomes promoting muscle regeneration

ABSTRACT

Severe muscle injury is still a challenging clinical problem. Exosomes derived from adipose stem cells (ASC-exos) may be a potential therapeutic tool, but their mechanism is not completely clear. This review aims to elaborate the possible mechanism of ASC-exos in muscle regeneration from the perspective of signal pathways and provide guidance for further study. Literature cited in this review was acquired through PubMed using keywords or medical subject headings, including adipose stem cells, exosomes, muscle regeneration, myogenic differentiation, myogenesis, wingless/integrated (Wnt), mitogen-activated protein kinases, phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B (PI3K/Akt), Janus kinase/signal transducers and activators of transcription, and their combinations. We obtained the related signal pathways from proteomics analysis of ASC-exos in the literature, and identified that ASC-exos make different contributions to multiple stages of skeletal muscle regeneration by those signal pathways.

The two facets of receptor tyrosine kinase in cardiovascular calcification-can tyrosine kinase inhibitors benefit cardiovascular system?

Tyrosine kinase inhibitors (TKIs) are widely used in cancer treatment due to their effectiveness in cancer cell killing. However, an off-target of this agent limits its success. Cardiotoxicity-associated TKIs have been widely reported. Tyrosine kinase is involved in many regulatory processes in a cell, and it is involved in cancer formation. Recent evidence suggests the role of tyrosine kinase in cardiovascular calcification, specifically, the calcification of heart vessels and valves. Herein, we summarized the accumulating evidence of the crucial role of receptor tyrosine kinase (RTK) in cardiovascular calcification and provided the potential clinical implication of TKIs-related ectopic calcification. We found that RTKs, depending on the ligand and tissue, can induce or suppress cardiovascular calcification. Therefore, RTKs may have varying effects on ectopic calcification. Additionally, in the context of cardiovascular calcification, TKIs do not always relate to an unfavored outcome-they might offer benefits in some cases.

The short-chain fatty acid butyrate accelerates vascular calcification via regulation of histone deacetylases and NF-κB signaling

Recent studies have shown that short-chain fatty acids (SCFAs), primarily acetate, propionate and butyrate, play a crucial role in the pathogenesis of cardiovascular disease. Whether SCFAs regulate vascular calcification, a common pathological change in cardiovascular tissues, remains unclear. This study aimed to investigate the potential role of SCFAs in vascular calcification. Using cellular and animal models of vascular calcification, we showed that butyrate significantly enhanced high phosphate (Pi)-induced calcification and osteogenic transition of vascular smooth muscle cells (VSMC) in vitro, whereas acetate and propionate had no effects. Subsequent studies confirmed that butyrate significantly promoted high Pi-induced aortic ring calcification ex vivo and high dose vitamin D₃ (vD₃)-induced mouse vascular calcification in vivo. Mechanistically, butyrate significantly inhibited histone deacetylase (HDAC) expression in VSMCs, and a pan HDAC inhibitor Trichostatin A showed similar inductive effects on calcification and osteogenic transition of VSMCs to butyrate. In addition, the SCFA sensing receptors Gpr41 and Gpr109a were primarily expressed by VSMCs, and butyrate induced the rapid activation of NF-κB, Wnt and Akt signaling in VSMCs. Intriguingly, the NF-κB inhibitor SC75741 significantly attenuated butyrate-induced calcification and the osteogenic gene Msx2 expression in VSMCs. We showed that knockdown of Gpr41 but not Gpr109a attenuated butyrate-induced VSMC calcification. This study reveals that butyrate accelerates vascular calcification via its dual effects on HDAC inhibition and NF-κB activation. Our data provide novel insights into the role of microbe-host interaction in vascular calcification, and may have implications for the development of potential therapy for vascular calcification.

Skeletal and extraskeletal disorders of biomineralization

The physiological process of biomineralization is complex and deviation from it leads to a variety of diseases. Progress in the past 10 years has enhanced understanding of the genetic, molecular and cellular pathophysiology underlying these disorders; sometimes, this knowledge has both facilitated restoration of health and clarified the very nature of biomineralization as it occurs in humans. In this Review, we consider the principal regulators of mineralization and crystallization, and how dysregulation of these processes can lead to human disease. The knowledge acquired to date and gaps still to be filled are highlighted. The disorders of mineralization discussed comprise a broad spectrum of conditions that encompass bone disorders associated with alterations of mineral quantity and quality, as well as disorders of extraskeletal mineralization (hyperphosphataemic familial tumoural calcinosis). Included are disorders of alkaline phosphatase (hypophosphatasia) and phosphate homeostasis (X-linked hypophosphataemic rickets, fluorosis, rickets and osteomalacia). Furthermore, crystallopathies are covered as well as arterial and renal calcification. This Review discusses the current knowledge of biomineralization derived from basic and clinical research and points to future studies that will lead to new therapeutic approaches for biomineralization disorders.

Role of Sclerostin in Cardiovascular Disease

Sclerostin is most recognized for its role in controlling bone formation but is also expressed in the heart, aorta, coronary, and peripheral arteries. This review summarizes research on sclerostin's role in cardiovascular disease. Rodent studies have found sclerostin to be expressed at sites of arterial calcification. In contrast, aortic sclerostin was reported to be downregulated in a mouse model of abdominal aortic aneurysm, and transgenic upregulation or administration of sclerostin was found to prevent abdominal aortic aneurysm and atherosclerosis formation. Sclerostin deficiency was reported to stimulate cardiac rupture in one rodent model. In humans, 7 of 11 studies reported a significant association between high serum sclerostin and high carotid intima media thickness. Ten of 15 studies reported a significant association between high serum sclerostin and severe arterial calcification. Twelve of 14 studies reported a significant association between high serum sclerostin and high arterial stiffness or atherosclerosis severity. Four of 9 studies reported a significant association between high serum sclerostin and high risk of cardiovascular events. A meta-analysis of randomized controlled trials suggested that administration of the sclerostin blocking antibody romosozumab did not significantly increase the risk of major adverse cardiovascular events (risk ratio, 1.14 [95% CI, 0.83-1.57]; P=0.54) or cardiovascular death (risk ratio, 0.92 [95% CI, 0.53-1.59]; P=0.71). Human genetic studies reported variants predisposing to low arterial sclerostin expression were associated with a high risk of cardiovascular events. Overall, past research suggests a cardiovascular protective role of sclerostin but findings have been inconsistent, possibly due to variations in study design, the unique populations and models studied, and the heterogeneous methods used.

Cardiac Calcifications: Phenotypes, Mechanisms, Clinical and Prognostic Implications

There is a growing interest in arterial and heart valve calcifications, as these contribute to cardiovascular outcome, and are leading predictors of cardiovascular and kidney diseases. Cardiovascular calcifications are often considered as one disease, but, in effect, they represent multifaced disorders, occurring in different milieus and biological phenotypes, following different pathways. Herein, we explore each different molecular process, its relative link with the specific clinical condition, and the current therapeutic approaches to counteract calcifications. Thus, first, we explore the peculiarities between vascular and valvular calcium deposition, as this occurs in different tissues, responds differently to shear stress, has specific etiology and time courses to calcification. Then, we differentiate the mechanisms and pathways leading to hyperphosphatemic calcification, typical of the media layer of the vessel and mainly related to chronic kidney diseases, to those of inflammation, typical of the intima vascular calcification, which predominantly occur in atherosclerotic vascular diseases. Finally, we examine calcifications secondary to rheumatic valve disease or other bacterial lesions and those occurring in autoimmune diseases. The underlying clinical conditions of each of the biological calcification phenotypes and the specific opportunities of therapeutic intervention are also considered and discussed.

Bone Health in Patients with Dyslipidemias: An Underestimated Aspect

Beyond being aging-related diseases, atherosclerosis and osteoporosis share common pathogenetic pathways implicated in bone and vascular mineralization. However, the contributory role of dyslipidemia in this interplay is less documented. The purpose of this narrative review is to provide epidemiological evidence regarding the prevalence of bone disease (osteoporosis, fracture risk) in patients with dyslipidemias and to discuss potential common pathophysiological mechanisms linking osteoporosis and atherosclerosis. The effect of hypolipidemic therapy on bone metabolism is also discussed. Despite the high data heterogeneity and the variable quality of studies, dyslipidemia, mainly elevated total and low-density lipoprotein cholesterol concentrations, is associated with low bone mass and increased fracture risk. This effect may be mediated directly by the increased oxidative stress and systemic inflammation associated with dyslipidemia, leading to increased osteoclastic activity and reduced bone formation. Moreover, factors such as estrogen, vitamin D and K deficiency, and increased concentrations of parathyroid hormone, homocysteine and lipid oxidation products, can also contribute. Regarding the effect of hypolipidemic medications on bone metabolism, statins may slightly increase BMD and reduce fracture risk, although the evidence is not robust, as it is for omega-3 fatty acids. No evidence exists for the effects of ezetimibe, fibrates, and niacin. In any case, more prospective studies are needed further to elucidate the association between lipids and bone strength.

Iron overload impairs renal function and is associated with vascular calcification in rat aorta

Vascular calcification (VC) has been associated with a risk of cardiovascular diseases. Iron may play a critical role in progressive VC. Therefore, we investigated the effects of iron overload on the aorta of rats. A rat model of iron overload was established by intraperitoneal injection of Iron-Dextran. The levels of iron, calcium, and ALP activity were detected. Von Kossa staining and Perl's staining were conducted. The expression of iron metabolism-related and calcification related factors were examined in the aortic tissue of rats. The results showed serum and aortic tissue iron were increased induced by iron overload and excessive iron induced hepatic and renal damage. In iron overload rats, the expression of divalent metal transporter 1 (DMT1) and hepcidin were higher, but ferroportin1 (FPN1) was lower. Von Kossa staining demonstrated calcium deposition in the aorta of iron overload rats. The calcium content and ALP activity in serum and aortic tissue were increased and iron level in aortic tissue highly correlated with calcium content and ALP activity. The expressions of the osteogenic markers were increased while a decrease of Alpha-smooth muscle actin (α-SMA) in the aortic tissue of iron overload rats. IL-24 was increased during the calcification process induced by iron. Overall, we demonstrated excessive iron accumulation in the aortic tissue and induced organs damage. The iron metabolism-related factors were significantly changed during iron overload. Moreover, we found that iron overload leads to calcium deposition in aorta, playing a key role in the pathological process of VC by mediating osteoblast differentiation factors.

Unspliced XBP1 Counteracts β-catenin to Inhibit Vascular Calcification

Background: Vascular calcification is a prevalent complication in chronic kidney disease and contributes to increased cardiovascular morbidity and mortality. XBP1 (X-box binding protein 1), existing as the unspliced (XBP1u) and spliced (XBP1s) forms, is a key component of the endoplasmic reticulum stress involved in vascular diseases. However, whether XBP1u participates in the development of vascular calcification remains unclear. Methods: We aim to investigate the role of XBP1u in vascular calcification.XBP1u protein levels were reduced in high phosphate (Pi)-induced calcified vascular smooth muscle cells (VSMCs), calcified aortas from mice with adenine diet-induced chronic renal failure (CRF) and calcified radial arteries from CRF patients. Results: Inhibition of XBP1u rather than XBP1s upregulated in the expression of the osteogenic markers runt-related transcription factor 2 (Runx2) and msh homeobox2 (Msx2), and exacerbated high Pi-induced VSMC calcification, as verified by calcium deposition and Alizarin red S staining. In contrast, XBP1u overexpression in high Pi-induced VSMCs significantly inhibited osteogenic differentiation and calcification. Consistently, SMC-specific XBP1 deficiency in mice markedly aggravated the adenine diet- and 5/6 nephrectomy-induced vascular calcification compared with that in the control littermates. Further interactome analysis revealed that XBP1u bound directly to β-catenin, a key regulator of vascular calcification, via aa 205-230 in its C-terminal degradation domain. XBP1u interacted with β-catenin to promote its ubiquitin-proteasomal degradation and thus inhibited β-catenin/T-cell factor (TCF)-mediated Runx2 and Msx2 transcription. Knockdown of β-catenin abolished the effect of XBP1u deficiency on VSMC calcification, suggesting a β-catenin-mediated mechanism. Moreover, the degradation of β-catenin promoted by XBP1u was independent of glycogen synthase kinase 3β (GSK-3β)-involved destruction complex. Conclusions: Our study identified XBP1u as a novel endogenous inhibitor of vascular calcification by counteracting β-catenin and promoting its ubiquitin-proteasomal degradation, which represents a new regulatory pathway of β-catenin and a promising target for vascular calcification treatment.

Regulation of MDM2 E3 ligase-dependent vascular calcification by MSX1/2

Vascular calcification increases morbidity and mortality in patients with cardiovascular and renal diseases. Previously, we reported that histone deacetylase 1 prevents vascular calcification, whereas its E3 ligase, mouse double minute 2 homolog (MDM2), induces vascular calcification. In the present study, we identified the upstream regulator of MDM2. By utilizing cellular models and transgenic mice, we confirmed that E3 ligase activity is required for vascular calcification. By promoter analysis, we found that both msh homeobox 1 (Msx1) and msh homeobox 2 (Msx2) bound to the MDM2 promoter region, which resulted in transcriptional activation of MDM2. The expression levels of both Msx1 and Msx2 were increased in mouse models of vascular calcification and in calcified human coronary arteries. Msx1 and Msx2 potentiated vascular calcification in cellular and mouse models in an MDM2-dependent manner. Our results establish a novel role for MSX1/MSX2 in the transcriptional activation of MDM2 and the resultant increase in MDM2 E3 ligase activity during vascular calcification.

The identification of a signaling pathway involved in triggering vascular calcification, the deposition of calcium phosphate crystals in blood vessels, could inform new therapeutic interventions for related cardiovascular complications. Vascular calcification causes significant complications in patients with metabolic syndrome, renal failure, or cardiovascular disease. In their previous work, Hyun Kook and Duk-Hwa Kwon at Chonnam National University Medical School, Jeollanamdo, Republic of Korea, and coworkers demonstrated that the E3 ligase activity of a protein called MDM2 induces calcification. Now, following further mouse trials, the team have identified an upstream signaling pathway involving several development proteins such as MSX1 and MSX2 which activate MDM2. The activation of this signaling axis leads to the degradation of a key protein that would otherwise prevent calcification. The results may provide a platform for novel therapies targeting the condition.

Screening of key biomarkers of tendinopathy based on bioinformatics and machine learning algorithms

Tendinopathy is a complex multifaceted tendinopathy often associated with overuse and with its high prevalence resulting in significant health care costs. At present, the pathogenesis and effective treatment of tendinopathy are still not sufficiently elucidated. The purpose of this research is to intensely explore the genes, functional pathways, and immune infiltration characteristics of the occurrence and development of tendinopathy. The gene expression profile of GSE106292, GSE26051 and GSE167226 are downloaded from GEO (NCBI comprehensive gene expression database) and analyzed by WGCNA software bag using R software, GSE26051, GSE167226 data set is combined to screen the differential gene analysis. We subsequently performed gene enrichment analysis of Gene Ontology (GO) and "Kyoto Encyclopedia of Genes and Genomes" (KEGG), and immune cell infiltration analysis. By constructing the LASSO regression model, Support vector machine (SVM-REF) and Gaussian mixture model (GMMs) algorithms are used to screen, to identify early diagnostic genes. We have obtained a total of 171 DEGs through WGCNA analysis and differentially expressed genes (DEGs) screening. By GO and KEGG enrichment analysis, it is found that these dysregulated genes were related to mTOR, HIF-1, MAPK, NF-κB and VEGF signaling pathways. Immune infiltration analysis showed that M1 macrophages, activated mast cells and activated NK cells had infiltration significance. After analysis of THE LASSO SVM-REF and GMMs algorithms, we found that the gene MACROD1 may be a gene for early diagnosis. We identified the potential of tendon disease early diagnosis way and immune gene regulation MACROD1 key infiltration characteristics based on comprehensive bioinformatics analysis. These hub genes and functional pathways may as early biomarkers of tendon injuries and molecular therapy level target is used to guide drug and basic research.

Immunohistochemical Detection of Bacteria in the Resected Valves was Associated with Stromal Immune Checkpoint Protein Expression that may Contribute to Calcific Aortic Stenosis

Aortic stenosis (AS) is a disease characterized by narrowing of the aortic valve (AV) orifice. The purpose of this study was to clarify the significance of bacterial detection and clinicopathological factors, including valve-infiltrating immune cells and disease severity, in relation to AS. After obtaining the written informed consent form from 50 patients with AS, we performed immunohistochemical analysis of lipopolysaccharide (LPS) for gram-negative bacteria and lipoteichoic acid (LTA) for gram-positive bacteria on surgically resected-AVs. Moreover, we evaluated the relationships among the presence of bacteria, immune checkpoint protein PD-L1 expression, and immune cell infiltrations such as CD8-positive T lymphocytes, CD163-positive macrophages, and FOXP3-positive regulatory T cell (Treg) in resected-aortic valves. LPS detection in the resected-aortic valve tissues was significantly associated with stromal PD-L1 expression, valve calcification, and LTA existence in resected samples. We showed that the presence of LPS was significantly related to high PD-L1 expression only in calcified-AVs, not in non-calcified-AVs. Moreover, the high expression of PD-L1 in AS samples without LPS was significantly associated with positive infiltration of CD163-positive macrophages and FOXP3-positive Tregs. Immunohistochemical bacterial detection in resected-aortic valves was associated with PD-L1 accumulation and valve calcification. PD-L1 significantly accumulated only in calcified valves with LPS existence.

Sitagliptin attenuates arterial calcification by downregulating oxidative stress-induced receptor for advanced glycation end products in LDLR knockout mice

Diabetes is a complex disease characterized by hyperglycemia, dyslipidemia, and insulin resistance. Plasma advanced glycation end products (AGEs) activated the receptor for advanced glycation end products (RAGE) and the activation of RAGE is implicated to be the pathogenesis of type 2 diabetic mellitus (T2DM) patient vascular complications. Sitagliptin, a dipeptidyl peptidase-4 (DPP4) inhibitor, is a new oral hypoglycemic agent for the treatment of T2DM. However, the beneficial effects on vascular calcification remain unclear. In this study, we used a high-fat diet (HFD)-fed low-density lipoprotein receptor deficiency (LDLR^−/−) mice model to investigate the potential effects of sitagliptin on HFD-induced arterial calcification. Mice were randomly divided into 3 groups: (1) normal diet group, (2) HFD group and (3) HFD + sitagliptin group. After 24 weeks treatment, we collected the blood for chemistry parameters and DPP4 activity measurement, and harvested the aorta to evaluate calcification using immunohistochemistry and calcium content. To determine the effects of sitagliptin, tumor necrosis factor (TNF)-α combined with S100A12 was used to induce oxidative stress, activation of nicotinamide adenine dinucleotide phosphate (NADPH), up-regulation of bone markers and RAGE expression, and cell calcium deposition on human aortic smooth muscle cells (HASMCs). We found that sitagliptin effectively blunted the HFD-induced artery calcification and significantly lowered the levels of fasting serum glucose, triglyceride (TG), nitrotyrosine and TNF-α, decreased the calcium deposits, and reduced arterial calcification. In an in-vitro study, both S100A12 and TNF-α stimulated RAGE expression and cellular calcium deposits in HASMCs. The potency of S100A12 on HASMCs was amplified by the presence of TNF-α. Sitagliptin and Apocynin (APO), an NADPH oxidase inhibitor, inhibited the TNF-α + S100A12-induced NADPH oxidase and nuclear factor (NF)-κB activation, cellular oxidative stress, RAGE expression, osteo transcription factors expression and calcium deposition. In addition, treatment with sitagliptin, knockdown of RAGE or TNF-α receptor blunted the TNF-α + S100A12-induced RAGE expression. Our findings suggest that sitagliptin may suppress the initiation and progression of arterial calcification by inhibiting the activation of NADPH oxidase and NF-κB, followed by decreasing the expression of RAGE.

BGP-15 Inhibits Hyperglycemia-Aggravated VSMC Calcification Induced by High Phosphate

Vascular calcification associated with high plasma phosphate (Pi) level is a frequent complication of hyperglycemia, diabetes mellitus, and chronic kidney disease. BGP-15 is an emerging anti-diabetic drug candidate. This study was aimed to explore whether BGP-15 inhibits high Pi-induced calcification of human vascular smooth muscle cells (VSMCs) under normal glucose (NG) and high glucose (HG) conditions. Exposure of VSMCs to Pi resulted in accumulation of extracellular calcium, elevated cellular Pi uptake and intracellular pyruvate dehydrogenase kinase-4 (PDK-4) level, loss of smooth muscle cell markers (ACTA, TAGLN), and enhanced osteochondrogenic gene expression (KLF-5, Msx-2, Sp7, BMP-2). Increased Annexin A2 and decreased matrix Gla protein (MGP) content were found in extracellular vesicles (EVs). The HG condition markedly aggravated Pi-induced VSMC calcification. BGP-15 inhibited Pi uptake and PDK-4 expression that was accompanied by the decreased nuclear translocation of KLF-5, Msx-2, Sp7, retained VSMC markers (ACTA, TAGLN), and decreased BMP-2 in both NG and HG conditions. EVs exhibited increased MGP content and decreased Annexin A2. Importantly, BGP-15 prevented the deposition of calcium in the extracellular matrix. In conclusion, BGP-15 inhibits Pi-induced osteochondrogenic phenotypic switch and mineralization of VSMCs in vitro that make BGP-15 an ideal candidate to attenuate both diabetic and non-diabetic vascular calcification.

Intermedin1‑47 inhibits high phosphate‑induced vascular smooth muscle cell calcification by regulating Wnt/β‑catenin signaling

Vascular calcification is a major risk factor for cardiovascular disease and accounts for a large proportion of deaths from cardiovascular disease in patients with chronic kidney disease. The high incidence, rapid progression and irreversibility of vascular smooth muscle cell (VSMC) calcification in patients has attracted attention. In the present study, the effect of intermedin1‑47 (IMD1‑47), an important isoform of intermedin, was investigated on the calcification of rat cardiovascular VSMCs induced by high phosphate (HP). To stimulate osteoblast‑like differentiation and calcification in rat VSMCs, 10 mM β‑sodium glycerophosphate was used. The VSMCs were then treated with three doses of IMD1‑47 and the effects of IMD1‑47 on VSMC calcification, on the expression of osteogenic markers [osteoprotegerin, Runt‑related transcription factor 2 (Runx2) and osteopontin (OPN)] and on alkaline phosphatase (ALP) activity were assessed. HP treatment significantly enhanced the cellular calcium content of VSMCs, the expression of osteogenic markers, and ALP activity, while IMD1‑47 significantly reversed these effects in a dose‑dependent manner. The protein expression levels of Wnt1, Wnt3a and active β‑catenin were determined and it was found that IMD1‑47 significantly inhibited their expression. Following β‑catenin silencing, the protein expression levels Runx2 and OPN were increased compared with the IMD1‑47 treatment alone, indicating a role for the Wnt/β‑catenin pathway in the effects of IMD1‑47 on osteogenic markers. The present study suggested that IMD1‑47 inhibited HP‑induced VSMC calcification by regulating the Wnt/β‑catenin signaling pathway.

Mitochondria Homeostasis and Vascular Medial Calcification

Vascular calcification occurs highly prevalent, which commonly predicts adverse cardiovascular events. The pathogenesis of calcification, a complicated and multifactorial process, is incompletely characterized. Accumulating evidence shows that mitochondrial dysfunction may ultimately be more detrimental in the vascular smooth muscle cells (VSMCs) calcification. This review summarizes the role of mitochondrial dysfunction and metabolic reprogramming in vascular calcification, and indicates that metabolic regulation may be a therapeutic target in vascular calcification.

RAGE Differentially Altered in vitro Responses in Vascular Smooth Muscle Cells and Adventitial Fibroblasts in Diabetes-Induced Vascular Calcification

The Advanced Glycation End-Products (AGE)/Receptor for AGEs (RAGE) signaling pathway exacerbates diabetes-mediated vascular calcification (VC) in vascular smooth muscle cells (VSMCs). Other cell types are involved in VC, such as adventitial fibroblasts (AFBs). We hope to elucidate some of the mechanisms responsible for differential signaling in diabetes-mediated VC with this work. This work utilizes RAGE knockout animals and in vitro calcification to measure calcification and protein responses. Our calcification data revealed that VSMCs calcification was AGE/RAGE dependent, yet AFBs calcification was not an AGE-mediated RAGE response. Protein expression data showed VSMCs lost their phenotype marker, α-smooth muscle actin, and had a higher RAGE expression over non-diabetics. RAGE knockout (RKO) VSMCs did not show changes in phenotype markers. P38 MAPK, a downstream RAGE-associated signaling molecule, had significantly increased activation with calcification in both diabetic and diabetic RKO VSMCs. AFBs showed a loss in myofibroblast marker, α-SMA, due to calcification treatment. RAGE expression decreased in calcified diabetic AFBs, and P38 MAPK activation significantly increased in diabetic and diabetic RKO AFBs. These findings point to potentially an alternate receptor mediating the calcification response in the absence of RAGE. Overall, VSMCs and AFBs respond differently to calcification and the application of AGEs.

The complex role of Wnt ligands in type 2 diabetes mellitus and related complications

Type 2 diabetes mellitus (T2DM) is one of the major chronic diseases, whose prevalence is increasing dramatically worldwide and can lead to a range of serious complications. Wnt ligands (Wnts) and their activating Wnt signalling pathways are closely involved in the regulation of various processes that are important for the occurrence and progression of T2DM and related complications. However, our understanding of their roles in these diseases is quite rudimentary due to the numerous family members of Wnts and conflicting effects via activating the canonical and/or non-canonical Wnt signalling pathways. In this review, we summarize the current findings on the expression pattern and exact role of each human Wnt in T2DM and related complications, including Wnt1, Wnt2, Wnt2b, Wnt3, Wnt3a, Wnt4, Wnt5a, Wnt5b, Wnt6, Wnt7a, Wnt7b, Wnt8a, Wnt8b, Wnt9a, Wnt9b, Wnt10a, Wnt10b, Wnt11 and Wnt16. Moreover, the role of main antagonists (sFRPs and WIF-1) and coreceptor (LRP6) of Wnts in T2DM and related complications and main challenges in designing Wnt-based therapeutic approaches for these diseases are discussed. We hope a deep understanding of the mechanistic links between Wnt signalling pathways and diabetic-related diseases will ultimately result in a better management of these diseases.

Vascular Calcification in Rodent Models-Keeping Track with an Extented Method Assortment

Simple Summary

Arterial vessel diseases are the leading cause of death in the elderly and their accelerated pathogenesis is responsible for premature death in patients with chronic renal failure. Since no functioning therapy concepts exist so far, the identification of the main signaling pathways is of current research interest. To develop therapeutic concepts, different experimental rodent models are needed, which should be subject to the 3R principle of Russel and Burch: “Replace, Reduce and Refine”. This review aims to summarize the current available experimental rodent models for studying vascular calcification and their quantification methods.

Abstract

Vascular calcification is a multifaceted disease and a significant contributor to cardiovascular morbidity and mortality. The calcification deposits in the vessel wall can vary in size and localization. Various pathophysiological pathways may be involved in disease progression. With respect to the calcification diversity, a great number of research models and detection methods have been established in basic research, relying mostly on rodent models. The aim of this review is to provide an overview of the currently available rodent models and quantification methods for vascular calcification, emphasizing animal burden and assessing prospects to use available methods in a way to address the 3R principles of Russel and Burch: “Replace, Reduce and Refine”.

The Cell Origin and Role of Osteoclastogenesis and Osteoblastogenesis in Vascular Calcification

Arterial calcification refers to the abnormal deposition of calcium salts in the arterial wall, which results in vessel lumen stenosis and vascular remodeling. Studies increasingly show that arterial calcification is a cell mediated, reversible and active regulated process similar to physiological bone mineralization. The osteoblasts and chondrocytes-like cells are present in large numbers in the calcified lesions, and express osteogenic transcription factor and bone matrix proteins that are known to initiate and promote arterial calcification. In addition, osteoclast-like cells have also been detected in calcified arterial walls wherein they possibly inhibit vascular calcification, similar to the catabolic process of bone mineral resorption. Therefore, tilting the balance between osteoblast-like and osteoclast-like cells to the latter maybe a promising therapeutic strategy against vascular calcification. In this review, we have summarized the current findings on the origin and functions of osteoblast-like and osteoclast-like cells in the development and progression of vascular progression, and explored novel therapeutic possibilities.

Prevalence and risk factors for the development of abdominal aortic calcification among the US population: NHANES study

Introduction

Abdominal aortic calcification (AAC) is an important marker of subclinical cardiovascular disease and its prognosis. Advanced age, hypertension, smoking, dyslipidemia, diabetes mellitus, and higher truncal fat are known markers of AAC in studies conducted around the world. However, literature for these risk factors and their co-occurrence is limited in the US.

Material and methods

We used data from dual energy X-ray absorptiometry (Hologic, v4.0) to detect the occurrence of AAC in a sample population (n = 3140) of the NHANES survey using a computer-assisted interviewing system to assess the risk factors for AAC.

Results

We found the national prevalence of AAC in the US to be 28.8%. After adjusting for confounders, persons with hypertension: OR = 1.66 (95% CI: 1.30–2.13) and smokers: OR = 1.63 (95% CI: 1.24–2.14) were more likely to have AAC compared to their respective counterparts. Increasing age was positively associated with AAC: OR = 1.06 (95% CI: 1.04–1.08). There was a statistically significant negative association between body mass index (BMI) and AAC, more so in smokers than in non-smokers: OR = 0.97 (95% CI: 0.94–0.97). We did not observe any statistically significant association between diabetes and AAC.

Conclusions

Advanced age, smoking, and hypertension was associated with increased occurrence of AAC. Paradoxically, increasing BMI was inversely associated with AAC and there was no statistically significant association between total body and trunk fat percentages and AAC. To the best of our knowledge, this is the first study to establish the nationwide prevalence and associated factors in the US.

Predictors for Rapid Progression of Coronary Calcification: An Optical Coherence Tomography Study

Background The role of coronary calcification in cardiovascular events and plaque stabilization is still being debated, and factors involved in the progression of coronary calcification are not fully understood. This study aimed to identify the predictors for rapid progression of coronary calcification. Methods and Results Patients with serial optical coherence tomography imaging at baseline and at 6 months were selected. Changes in the calcification index and predictors for progression of calcification were studied. Calcification index was defined as the product of the mean calcification arc and calcification length. Rapid progression of calcification was defined as an increase in the calcification index above the median value. Among 187 patients who had serial optical coherence tomography imaging, 235 calcified plaques were identified in 105 patients (56.1%) at baseline. After 6 months, the calcification index increased in 95.3% of calcified plaques from 132.0 to 178.2 (P<0.001). In multivariable analysis, diabetes mellitus (odds ratio [OR], 3.911; P<0.001), chronic kidney disease (OR, 2.432; P=0.037), lipid-rich plaque (OR, 2.698; P=0.034), and macrophages (OR, 6.782; P<0.001) were found to be independent predictors for rapid progression of coronary calcification. Interestingly, rapid progression of calcification was associated with a significant reduction of inflammatory features (thin-cap fibroatheroma; from 21.2% to 11.9%, P=0.003; macrophages; from 74.6% to 61.0%, P=0.001). Conclusions Diabetes mellitus, chronic kidney disease, lipid-rich plaque, and macrophages were independent predictors for rapid progression of coronary calcification. Baseline vascular inflammation and subsequent stabilization may be related to rapid progression of calcification. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01110538.

Adipokines in vascular calcification

Adipose tissue (AT), a critical endocrine gland, is capable of producing and secreting abundant adipokines. Adipokines act on distant or adjacent organ tissues via paracrine, autocrine, and endocrine mechanism, which play attractive roles in the regulation of glycolipid metabolism and inflammatory response. Increasing evidence shows that adipokines can connect obesity with cardiovascular diseases by serving as promoters or inhibitors in vascular calcification. The chronic hypoxia in AT, caused by the adipocyte hypertrophy, is able to trigger imbalanced adipokine generation, which leads to apoptosis, osteogenic differentiation of vascular smooth muscle cells (VSMCs), vascular inflammation, and abnormal deposition of calcium and phosphorus in the vessel wall. The objectives of this review aim at providing a brief summary of the crucial influence of major adipokines on the formation and development of vascular calcification, which may contribute to better understanding these adipokines for establishing the appropriate therapeutic strategies to counteract obesity-associated vascular calcification.

Transcriptional Programming in Arteriosclerotic Disease: A Multifaceted Function of the Runx2 (Runt-Related Transcription Factor 2)

Despite successful therapeutic strategies in the prevention and treatment of arteriosclerosis, the cardiovascular complications remain a major clinical and societal issue worldwide. Increased vascular calcification promotes arterial stiffness and accelerates cardiovascular morbidity and mortality. Upregulation of the Runx2 (Runt-related transcription factor 2), an essential osteogenic transcription factor for bone formation, in the cardiovascular system has emerged as an important regulator for adverse cellular events that drive cardiovascular pathology. This review discusses the regulatory mechanisms that are critical for Runx2 expression and function and highlights the dynamic and complex cross talks of a wide variety of posttranslational modifications, including phosphorylation, acetylation, ubiquitination, and O-linked β-N-acetylglucosamine modification, in regulating Runx2 stability, cellular localization, and osteogenic transcriptional activity. How the activation of an array of signaling cascades by circulating and local microenvironmental factors upregulates Runx2 in vascular cells and promotes Runx2-mediated osteogenic transdifferentiation of vascular smooth muscle cells and expression of inflammatory cytokines that accelerate macrophage infiltration and vascular osteoclast formation is summarized. Furthermore, the increasing appreciation of a new role of Runx2 upregulation in promoting vascular smooth muscle cell phenotypic switch, and Runx2 modulated by O-linked β-N-acetylglucosamine modification and Runx2-dependent repression of smooth muscle cell-specific gene expression are discussed. Further exploring the regulation of this key osteogenic transcription factor and its new perspectives in the vasculature will provide novel insights into the transcriptional regulation of vascular smooth muscle cell phenotype switch, reprograming, and vascular inflammation that promote the pathogenesis of arteriosclerosis.

2020 Jeffrey M. Hoeg Award Lecture: Calcifying Extracellular Vesicles as Building Blocks of Microcalcifications in Cardiovascular Disorders

Cardiovascular calcification is an insidious form of ectopic tissue mineralization that presents as a frequent comorbidity of atherosclerosis, aortic valve stenosis, diabetes, renal failure, and chronic inflammation. Calcification of the vasculature and heart valves contributes to mortality in these diseases. An inability to clinically image or detect early microcalcification coupled with an utter lack of pharmaceutical therapies capable of inhibiting or regressing entrenched and detectable macrocalcification has led to a prominent and deadly gap in care for a growing portion of our rapidly aging population. Recognition of this mounting concern has arisen over the past decade and led to a series of revolutionary works that has begun to pull back the curtain on the pathogenesis, mechanistic basis, and causative drivers of cardiovascular calcification. Central to this progress is the discovery that calcifying extracellular vesicles act as active precursors of cardiovascular microcalcification in diverse vascular beds. More recently, the omics revolution has resulted in the collection and quantification of vast amounts of molecular-level data. As the field has become poised to leverage these resources for drug discovery, new means of deriving relevant biological insights from these rich and complex datasets have come into focus through the careful application of systems biology and network medicine approaches. As we look onward toward the next decade, we envision a growing need to standardize approaches to study this complex and multifaceted clinical problem and expect that a push to translate mechanistic findings into therapeutics will begin to finally provide relief for those impacted by this disease.

YAP/TAZ Are Required to Suppress Osteogenic Differentiation of Vascular Smooth Muscle Cells

Vascular smooth muscle cells (VSMCs) represent the prevailing cell type of arterial vessels and are essential for blood vessel structure and homeostasis. They have substantial potential for phenotypic plasticity when exposed to various stimuli in their local microenvironment. How VSMCs maintain their differentiated contractile phenotype is still poorly understood. Here we demonstrate that the Hippo pathway effectors YAP and TAZ play a critical role in maintaining the differentiated contractile phenotype of VSMCs. In the absence of YAP/TAZ, VSMCs lose their differentiated phenotype and undergo osteogenic differentiation, which results in vascular calcification. Osteogenic transdifferentiation was accompanied by the upregulation of Wnt target genes. The absence of YAP/TAZ in VSMCs led to Disheveled 3 (DVL3) nuclear translocation and upregulation of osteogenesis-associated genes independent of canonical Wnt/β-catenin signaling activation. Our data indicate that cytoplasmic YAP/TAZ interact with DVL3 to avoid its nuclear translocation and osteogenic differentiation, thereby maintaining the differentiated phenotype of VSMCs.

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YAP/TAZ play an important role in maintaining vascular SMCs contractile phenotype

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Loss of YAP/TAZ in vSMCs leads to reduced expression of smooth muscle marker genes

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Loss of YAP/TAZ in vSMCs results in reduced artery contractility

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Deficiency of YAP/TAZ in vSMCs leads to osteogenic transdifferentiation

Calcified Aortic Valve Disease in Patients With Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a rare autosomal gene deficiency disease with increased low-density lipoprotein cholesterol, xanthoma, and premature coronary heart disease. Calcified aortic valve disease (CAVD) is prevalent in FH patients, resulting in adverse events and heavy health care burden. Aortic valve calcification is currently considered an active biological process, which shares several common risk factors with atherosclerosis, including aging, hypertension, dyslipidemia, and so on. Unfortunately, the pathogenesis and therapy of CAVD in FH are still controversial. There is no pharmacological intervention recommended to delay the development of CAVD in FH, and the only effective treatment for severe CAVD is aortic valve replacement. In this review, we summarize the detailed description of the pathophysiology, molecular mechanism, risk factors, and treatment of CAVD in FH patients.

Oxidative Stress in ESRD Patients on Dialysis and the Risk of Cardiovascular Diseases

Chronic kidney disease is highly prevalent worldwide. The decline of renal function is associated with inadequate removal of a variety of uremic toxins that exert detrimental effects on cells functioning, thus affecting the cardiovascular system. The occurrence of cardiovascular aberrations in CKD is related to the impact of traditional risk factors and non-traditional CKD-associated risk factors, including anemia; inflammation; oxidative stress; the presence of some uremic toxins; and factors related to the type, frequency of dialysis and the composition of dialysis fluid. Cardiovascular diseases are the most frequent cause for the deaths of patients with all stages of renal failure. The kidney is one of the vital sources of antioxidant enzymes, therefore, the impairment of this organ is associated with decreased levels of these enzymes as well as increased levels of pro-oxidants. Uremic toxins have been shown to play a vital role in the onset of oxidative stress. Hemodialysis itself also enhances oxidative stress. Elevated oxidative stress has been demonstrated to be strictly related to kidney and cardiac damage as it aggravates kidney dysfunction and induces cardiac hypertrophy. Antioxidant therapies may prove to be beneficial since they can decrease oxidative stress, reduce uremic cardiovascular toxicity and improve survival.

The Phosphodiesterase-5 Inhibitor Vardenafil Improves the Activation of BMP Signaling in Response to Hydrogen Peroxide

PURPOSE

The pleiotropic roles of phosphodiesterase-5 inhibitors (PDE5is) in cardiovascular diseases have attracted attention. The effect of vardenafil (a PDE5i) is partly mediated through reduced oxidative stress, but it is unclear whether vardenafil protects against hydrogen peroxide (H₂O₂)-induced endothelial cell injury, and the molecular mechanisms that are involved remain unknown. We determined the protective role of vardenafil on H₂O₂-induced endothelial cell injury in cultured human umbilical vein endothelial cells (HUVECs).

METHODS AND RESULTS

Vardenafil decreased the number of TUNEL-positive cells, increased the Bcl2/Bax ratio, and ameliorated the numbers of BrdU-positive cells in H₂O₂-treated HUVECs. The bone morphogenetic protein receptor (BMPR)/p-Smad/MSX2 pathway was enhanced in response to H₂O₂, and vardenafil treatment could normalize this pathway. To determine whether the BMP pathway is involved, we blocked the BMP pathway using dorsomorphin, which abolished the protective effects of vardenafil. We found that vardenafil improved the H₂O₂-induced downregulation of BMP-binding endothelial regulator protein (BMPER), which possibly intersects with the BMP pathway in the regulation of endothelial cell injury in response to oxidative stress.

CONCLUSIONS

We demonstrated for the first time that exogenous H₂O₂ activates BMPR expression and promotes Smad1/5/8 phosphorylation. Additionally, vardenafil can attenuate H₂O₂-induced endothelial cell injury in HUVECs. Vardenafil decreases apoptosis through an improved Bcl-2/Bax ratio and increases cell proliferation. Vardenafil protects against endothelial cell injury through ameliorating the intracellular oxidative stress level and BMPER expression. The protective role of vardenafil on H₂O₂-induced endothelial cell injury is mediated through BMPR/p-Smad/MSX2 in HUVECs.

Current Treatment Modalities for Calcified Coronary Artery Disease: A Review Article Comparing Novel Intravascular Lithotripsy and Traditional Rotational Atherectomy

The coronary artery calcium score is considered the most useful marker for predicting coronary events. The high score reflects heavy calcification in the vessel, which is more challenging to treat with the percutaneous intervention (PCI). To prepare this type of heavily calcified lesion intravascular lithotripsy (IVL) technology can be used prior to PCI, which is based on the concept of converting electrical energy into mechanical energy. It harmlessly and selectively disrupts both the shallow and deep deposits of calcium. The balloon-based catheters of this system emit sonic waves that transfer to the adjacent tissue resulting in improvement in vessel compliance with the slightest soft tissue loss. Therefore, making the treatment of calcified lesions more feasible, effective, and also simplify complex lesions. The lesions considered for lithotripsy-enhanced balloon dilation include calcified coronary lesions and peripheral vasculature lesions. This article reviews the use of IVL in calcified coronary artery disease, its advantages, and disadvantages while comparing it with other techniques like high-pressure balloons and rotational atherectomy devices. A thorough search of databases like PubMed and Google Scholar was performed, which uncovered 35 peer review articles. Keywords utilized in the data search were calcified coronary artery disease, coronary lithotripsy, calcification, and calcified atherosclerotic plaque. According to rotational atherectomy and intravascular lithotripsy trials, the latter was safer, mainly by decreasing atheromatous embolization risk. Deciphering these studies, it seems like IVL is better at parameters like procedural and clinical success rate, acute lumen gain, and less residual stenosis except in-hospital major adverse cardiovascular events (MACE), which was better in rotational atherectomy (RA). However, when lesion crossings are present, the atherectomy technique is still considered as first-line therapy. In clinical practice, despite these encouraging data for treating calcified lesions, IVL is grossly underutilized because of substantial costs and perceived significant procedural risk effects on the cardiac rhythm like causing 'shock topics' and asynchronous cardiac pacing. More longer-term clinical data and extensive researches are required to validate its safety and efficiency.

Regulation of Vascular Calcification by Reactive Oxygen Species

Vascular calcification is the deposition of hydroxyapatite crystals in the medial or intimal layers of arteries that is usually associated with other pathological conditions including but not limited to chronic kidney disease, atherosclerosis and diabetes. Calcification is an active, cell-regulated process involving the phenotype transition of vascular smooth muscle cells (VSMCs) from contractile to osteoblast/chondrocyte-like cells. Diverse triggers and signal transduction pathways have been identified behind vascular calcification. In this review, we focus on the role of reactive oxygen species (ROS) in the osteochondrogenic phenotype switch of VSMCs and subsequent calcification. Vascular calcification is associated with elevated ROS production. Excessive ROS contribute to the activation of certain osteochondrogenic signal transduction pathways, thereby accelerating osteochondrogenic transdifferentiation of VSMCs. Inhibition of ROS production and ROS scavengers and activation of endogenous protective mechanisms are promising therapeutic approaches in the prevention of osteochondrogenic transdifferentiation of VSMCs and subsequent vascular calcification. The present review discusses the formation and actions of excess ROS in different experimental models of calcification, and the potential of ROS-lowering strategies in the prevention of this deleterious condition.

The role of Wnt signalling in development of coronary artery disease and its risk factors

The Wnt signalling pathways are composed of a highly conserved cascade of events that govern cell differentiation, apoptosis and cell orientation. Three major and distinct Wnt signalling pathways have been characterized: the canonical Wnt pathway (or Wnt/β-catenin pathway), the non-canonical planar cell polarity pathway and the non-canonical Wnt/Ca2+ pathway. Altered Wnt signalling pathway has been associated with diverse diseases such as disorders of bone density, different malignancies, cardiac malformations and heart failure. Coronary artery disease is the most common type of heart disease in the United States. Atherosclerosis is a multi-step pathological process, which starts with lipid deposition and endothelial cell dysfunction, triggering inflammatory reactions, followed by recruitment and aggregation of monocytes. Subsequently, monocytes differentiate into tissue-resident macrophages and transform into foam cells by the uptake of modified low-density lipoprotein. Meanwhile, further accumulations of lipids, infiltration and proliferation of vascular smooth muscle cells, and deposition of the extracellular matrix occur under the intima. An atheromatous plaque or hyperplasia of the intima and media is eventually formed, resulting in luminal narrowing and reduced blood flow to the myocardium, leading to chest pain, angina and even myocardial infarction. The Wnt pathway participates in all different stages of this process, from endothelial dysfunction to lipid deposit, and from initial inflammation to plaque formation. Here, we focus on the role of Wnt cascade in pathophysiological mechanisms that take part in coronary artery disease from both clinical and experimental perspectives.

WNT-β-catenin signalling - a versatile player in kidney injury and repair

The WNT-β-catenin system is an evolutionary conserved signalling pathway that is of particular importance for morphogenesis and cell organization during embryogenesis. The system is usually suppressed in adulthood; however, it can be re-activated in organ injury and regeneration. WNT-deficient mice display severe kidney defects at birth. Transient WNT-β-catenin activation stimulates tissue regeneration after acute kidney injury, whereas sustained (uncontrolled) WNT-β-catenin signalling promotes kidney fibrosis in chronic kidney disease (CKD), podocyte injury and proteinuria, persistent tissue damage during acute kidney injury and cystic kidney diseases. Additionally, WNT-β-catenin signalling is involved in CKD-associated vascular calcification and mineral bone disease. The WNT-β-catenin pathway is tightly regulated, for example, by proteins of the Dickkopf (DKK) family. In particular, DKK3 is released by 'stressed' tubular epithelial cells; DKK3 drives kidney fibrosis and is associated with short-term risk of CKD progression and acute kidney injury. Thus, targeting the WNT-β-catenin pathway might represent a promising therapeutic strategy in kidney injury and associated complications.