Arterial Calcification in Diabetes Mellitus: Preclinical Models and Translational Implications

12,13-diHOME attenuates high glucose-induced calcification of vascular smooth muscle cells through repressing CPT1A-mediated HMGB1 succinylation

Diabetes is closely associated with vascular calcification (VC). Exorbitant glucose concentration activates pro-calcific effects in vascular smooth muscle cells (VSMCs). This study enrolled 159 elderly patients with type 2 diabetes and divided them into three groups, T1, T2 and T3, according to brachial-ankle pulse wave velocity(BaPWV). There were statistically significant differences in the waist circumference, waist hip ratio, systolic blood pressure, 12,13-diHOME (a lipokin) concentration among T1, T2 and T3. 12,13-diHOME levels were positively correlated to high density lipoprotein cholesterol and total cholesterol, but negatively correlated to with waist circumference, waist hip ratio, systolic blood pressure and baPWV. Studies in vitro showed that 12,13-diHOME effectively inhibits calcification in VSMCs under high glucose conditions. Notably, 12,13-diHOME suppressed the up-regulation of carnitine O-palmitoyltransferase 1 (CPT1A) and CPT1A-induced succinylation of HMGB1. The succinylation of HMGB1 at the K90 promoted the protein stability and induced the enrichment of HMGB1 in cytoplasm, which induced the calcification in VSMCs. Together, 12,13-diHOME attenuates high glucose-induced calcification in VSMCs through repressing CPT1A-mediated HMGB1 succinylation.

A machine learning approach to predicting vascular calcification risk of type 2 diabetes: A retrospective study

BACKGROUND

Recently, patients with type 2 diabetes mellitus (T2DM) have experienced a higher incidence and severer degree of vascular calcification (VC), which leads to an increase in the incidence and mortality of vascular complications in patients with T2DM.

HYPOTHESIS

To construct and validate prediction models for the risk of VC in patients with T2DM.

METHODS

Twenty-three baseline demographic and clinical characteristics were extracted from the electronic medical record system. Ten clinical features were screened with least absolute shrinkage and selection operator method and were used to develop prediction models based on eight machine learning (ML) algorithms (k-nearest neighbor [k-NN], light gradient boosting machine, logistic regression [LR], multilayer perception [(MLP], Naive Bayes [NB], random forest [RF], support vector machine [SVM], XGBoost [XGB]). Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy, and precision.

RESULTS

A total of 1407 and 352 patients were retrospectively collected in the training and test sets, respectively. Among the eight models, the AUC value in the NB model was higher than the other models (NB: 0.753, LGB: 0.719, LR: 0.749, MLP: 0.715, RF: 0.722, SVM: 0.689, XGB:0.707, p < .05 for all). The k-NN model achieved the highest sensitivity of 0.75 (95% confidence interval [CI]: 0.633-0.857), the MLP model achieved the highest accuracy of 0.81 (95% CI: 0.767-0.852) and specificity of 0.875 (95% CI: 0.836-0.912).

CONCLUSIONS

This study developed a predictive model of VC based on ML and clinical features in type 2 diabetic patients. The NB model is a tool with potential to facilitate clinicians in identifying VC in high-risk patients.

Toe brachial index and not ankle brachial index is appropriate in initial evaluation of peripheral arterial disease in type 2 diabetes

BACKGROUND

Non-invasive clinic-based tools for assessing PAD are not without limitations. Therefore, costly tests like Doppler study, CT angiography and MR angiography are often required to make a diagnosis. Ankle brachial index (ABI), commonly used for assessment of PAD, has high false positivity rates in sclerosed, calcified arteries which render them non-compressible. Toe brachial index (TBI) can be an alternative, as digital arteries are relatively unaffected by these changes.

AIM

To compare the reliability of ABI and TBI in diagnosing PAD in type 2 diabetes using CT angiography (CTA) as the reference.

METHODS

175 adults with T2D were selected. ABI &TBI were measured with an automated vascular Doppler XT 6 ports bilaterally for all subjects. For any subject, the limb with lower ABI and TBI was included for analysis. ABI < 0.9 & TBI < 0.6 were taken as evidence of PAD. CTA showing > 50% narrowing was taken as evidence of PAD.

RESULTS

24% of our study subjects had CTA confirmed PAD. ABI has low sensitivity of 35.29% (95% CI 0.21-0.52) compared to TBI being 82.35% (95% CI 0.66-0.92). The specificity however was similar. ABI < 0.9 was able to detect CTA confirmed PAD, but ABI > 0.9, including the so-called normal ABI (0.9-1.3) was unable to detect PAD. ROC showed ABI at 1.005 has sensitivity 64.71% (95% CI 0.48- 0.79) and specificity 61.7% (95% CI 0.53-0.69) and TBI at 0.6 has sensitivity 82.35% (95% CI 0.66-0.92) & specificity 92% (95% CI 0.87-0.96). Utilizing Cohen's Kappa, the reliability of ABI with respect to CTA showed fair agreement (K = 0.225, p = 0.001), whereas the reliability of TBI with respect to CTA showed substantial agreement (K = 0.759, p < 0.0001).

CONCLUSION

ABI < 0.9 detects PAD reliably, but presence of PAD in patients with ABI > 9.0 including the normal of ABI (0.9-1.3) can be confirmed with TBI, which correlated strongly with CTA. TBI is also non-inferior for PAD detection, when ABI < 0.9. TBI and not ABI can be utilized for initial assessment of PAD in subjects with T2D.

Novel Glycomimetics Protect against Glycated Low-Density Lipoprotein-Induced Vascular Calcification In Vitro via Attenuation of the RAGE/ERK/CREB Pathway

Heparan sulphate (HS) can act as a co-receptor on the cell surface and alterations in this process underpin many pathological conditions. We have previously described the usefulness of mimics of HS (glycomimetics) in protection against β-glycerophosphate-induced vascular calcification and in the restoration of the functional capacity of diabetic endothelial colony-forming cells in vitro. This study aims to investigate whether our novel glycomimetic compounds can attenuate glycated low-density lipoprotein (g-LDL)-induced calcification by inhibiting RAGE signalling within the context of critical limb ischemia (CLI). We used an established osteogenic in vitro vascular smooth muscle cell (VSMC) model. Osteoprotegerin (OPG), sclerostin and glycation levels were all significantly increased in CLI serum compared to healthy controls, while the vascular calcification marker osteocalcin (OCN) was down-regulated in CLI patients vs. controls. Incubation with both CLI serum and g-LDL (10 µg/mL) significantly increased VSMC calcification vs. controls after 21 days, with CLI serum-induced calcification apparent after only 10 days. Glycomimetics (C2 and C3) significantly inhibited g-LDL and CLI serum-induced mineralisation, as shown by a reduction in alizarin red (AR) staining and alkaline phosphatase (ALP) activity. Furthermore, secretion of the osteogenic marker OCN was significantly reduced in VSMCs incubated with CLI serum in the presence of glycomimetics. Phosphorylation of cyclic AMP response element-binding protein (CREB) was significantly increased in g-LDL-treated cells vs. untreated controls, which was attenuated with glycomimetics. Blocking CREB activation with a pharmacological inhibitor 666-15 replicated the protective effects of glycomimetics, evidenced by elevated AR staining. In silico molecular docking simulations revealed the binding affinity of the glycomimetics C2 and C3 with the V domain of RAGE. In conclusion, these findings demonstrate that novel glycomimetics, C2 and C3 have potent anti-calcification properties in vitro, inhibiting both g-LDL and CLI serum-induced VSMC mineralisation via the inhibition of LDLR, RAGE, CREB and subsequent expression of the downstream osteogenic markers, ALP and OCN.

Substrate stiffness promotes vascular smooth muscle cell calcification by reducing the levels of nuclear actin monomers

BACKGROUND

Vascular calcification (VC) is a prevalent independent risk factor for adverse cardiovascular events and is associated with diabetes, hypertension, chronic kidney disease, and atherosclerosis. However, the mechanisms regulating the osteogenic differentiation of vascular smooth muscle cells (VSMC) are not fully understood.

METHODS

Using hydrogels of tuneable stiffness and lysyl oxidase-mediated stiffening of human saphenous vein ex vivo, we investigated the role of substrate stiffness in the regulation of VSMC calcification.

RESULTS

We demonstrate that increased substrate stiffness enhances VSMC osteogenic differentiation and VSMC calcification. We show that the effects of substrate stiffness are mediated via a reduction in the level of actin monomer within the nucleus. We show that in cells interacting with soft substrate, elevated levels of nuclear actin monomer repress osteogenic differentiation and calcification by repressing YAP-mediated activation of both TEA Domain transcription factor (TEAD) and RUNX Family Transcription factor 2 (RUNX2).

CONCLUSION

This work highlights for the first time the role of nuclear actin in mediating substrate stiffness-dependent VSMC calcification and the dual role of YAP-TEAD and YAP-RUNX2 transcriptional complexes.

Association Between Serum Uric Acid and Abdominal Aortic Calcification in Adults Aged 40 to 80 years: A Retrospective Cross-Sectional Study

There are numerous causes of abdominal aortic calcification (AAC), among which the relationship between serum uric acid and AAC still needs to be investigated further. The aim of this research was to ascertain whether serum uric acid is correlated with AAC. Our study included 3007 participants. We described the study population characteristics and utilized univariate analysis, stratified analysis, multiple equation regression analysis, smoothed curve fitting, and threshold effects analysis. AAC Total 24 score is used to reflect the range of aortic calcification at each vertebral level. As serum uric acid increased, the AAC Total 24 score first decreased and then increased. The fold point is located when serum uric is at 3.5 mg/dL. After adjusting for 16 covariates, the beta values for the groups with moderate and high serum uric acid levels were 0.34 and 0.53, respectively, compared with the low serum uric acid tertile group (P < .05). Our research indicates a negative correlation between serum acid level and AAC when serum uric acid <3.5 mg/dl, but it is positively correlated with the formation of AAC when serum uric acid >3.5 mg/dl.

Wnt16 Promotes Vascular Smooth Muscle Contractile Phenotype and Function via Taz (Wwtr1) Activation in Male LDLR-/- Mice

Wnt16 is expressed in bone and arteries, and maintains bone mass in mice and humans, but its role in cardiovascular physiology is unknown. We show that Wnt16 protein accumulates in murine and human vascular smooth muscle (VSM). WNT16 genotypes that convey risk for bone frailty also convey risk for cardiovascular events in the Dallas Heart Study. Murine Wnt16 deficiency, which causes postnatal bone loss, also reduced systolic blood pressure. Electron microscopy demonstrated abnormal VSM mitochondrial morphology in Wnt16-null mice, with reductions in mitochondrial respiration. Following angiotensin-II (AngII) infusion, thoracic ascending aorta (TAA) dilatation was greater in Wnt16-/- vs Wnt16+/+ mice (LDLR-/- background). Acta2 (vascular smooth muscle alpha actin) deficiency has been shown to impair contractile phenotype and worsen TAA aneurysm with concomitant reductions in blood pressure. Wnt16 deficiency reduced expression of Acta2, SM22 (transgelin), and other contractile genes, and reduced VSM contraction induced by TGFβ. Acta2 and SM22 proteins were reduced in Wnt16-/- VSM as was Ankrd1, a prototypic contractile target of Yap1 and Taz activation via TEA domain (TEAD)-directed transcription. Wnt16-/- VSM exhibited reduced nuclear Taz and Yap1 protein accumulation. SiRNA targeting Wnt16 or Taz, but not Yap1, phenocopied Wnt16 deficiency, and Taz siRNA inhibited contractile gene upregulation by Wnt16. Wnt16 incubation stimulated mitochondrial respiration and contraction (reversed by verteporfin, a Yap/Taz inhibitor). SiRNA targeting Taz inhibitors Ccm2 and Lats1/2 mimicked Wnt16 treatment. Wnt16 stimulated Taz binding to Acta2 chromatin and H3K4me3 methylation. TEAD cognates in the Acta2 promoter conveyed transcriptional responses to Wnt16 and Taz. Wnt16 regulates cardiovascular physiology and VSM contractile phenotype, mediated via Taz signaling.

Effects of advanced glycation end-products, diabetes and metformin on the osteoblastic transdifferentiation capacity of vascular smooth muscle cells: In vivo and in vitro studies

AIMS

Our objective was to study the vascular smooth muscle cells (VSMC) osteoblastic transdifferentiation in AGE exposed cells or those from diabetic animals, and its response to metformin treatment.

METHODS

VSMC were obtained from non-diabetic rats, grown with or without AGE; while VSMC of in vivo-ex vivo studies were obtained from non-diabetic control animals (C), diabetic (D), C treated with metformin (M) and D treated with metformin (D-M). We studied the osteoblastic differentiation by evaluating alkaline phosphatase (ALP), type I collagen (Col) and mineral deposit.

RESULTS

In vitro, AGE increased proliferation, migration, and osteoblastic differentiation of VSMC. Metformin cotreatment prevented the AGE induced proliferation and migration. Both AGE and metformin stimulated the expression of ALP and Col. AGE induced mineralization was prevented by metformin. VSMC from D expressed a higher production of Col and ALP. Those from D-M showed an ALP increase vs C and M, and a partial decrease vs D. Cultured in osteogenic medium, ALP, Col and mineralization increased in D vs C, remained unchanged in M, and were prevented in D-M animals.

CONCLUSION

Both AGE and DM favor VSMC differentiation towards the osteogenic phenotype and this effect can be prevented by metformin.

Intermedin alleviates diabetic vascular calcification by inhibiting GLUT1 through activation of the cAMP/PKA signaling pathway

BACKGROUND AND AIMS

Vascular calcification (VC) is regarded as an independent risk factor for cardiovascular events in type 2 diabetic patients. Glucose transporter 1 (GLUT1) involves VC. Intermedin/Adrenomedullin-2 (IMD/ADM2) is a cardiovascular protective peptide that can inhibit multiple disease-associated VC. However, the role and mechanism of IMD in diabetic VC remain unclear. Here, we investigated whether IMD inhibits diabetic VC by inhibiting GLUT1.

METHODS AND RESULTS

It was found that plasma IMD concentration was significantly decreased in type 2 diabetic patients and in fructose-induced diabetic rats compared with that in controls. Plasma IMD content was inversely correlated with fasting blood glucose level and VC severity. IMD alleviated VC in fructose-induced diabetic rats. Deficiency of Adm2 aggravated and Adm2 overexpression attenuated VC in high-fat diet-induced diabetic mice. In vitro, IMD mitigated high glucose-induced calcification of vascular smooth muscle cells (VSMCs). Mechanistically, IMD reduced advanced glycation end products (AGEs) content and the level of receptor for AGEs (RAGE). IMD decreased glucose transporter 1 (GLUT1) levels. The inhibitory effect of IMD on RAGE protein level was blocked by GLUT1 knockdown. GLUT1 knockdown abolished the effect of IMD on alleviating VSMC calcification. IMD receptor antagonist IMD17-47 and cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) inhibitor H89 abolished the inhibitory effects of IMD on GLUT1 and VSMC calcification.

CONCLUSIONS

These findings revealed that IMD exerted its anti-calcification effect by inhibiting GLUT1, providing a novel therapeutic target for diabetic VC.

Impaired intracellular calcium homeostasis enhances protein O-GlcNAcylation and promotes vascular calcification and stiffness in diabetes

Vascular calcification is accelerated in patients with diabetes mellitus and increases risk of cardiovascular events and mortality. Vascular smooth muscle cells (VSMC) play a key role in regulating vascular tone and contribute significantly to the development of diabetic vasculopathy. In this study, the function of stromal interaction molecule 1 (STIM1), an important regulator for intracellular calcium homeostasis, in diabetic vascular calcification was investigated, and the underlying molecular mechanisms were uncovered. A SMC-specific STIM1 deletion mouse model (STIM1Δ/Δ) was generated by breeding the STIM1 floxed mice (STIM1f/f) with SM22α-Cre transgenic mice. Using aortic arteries from the STIM1Δ/Δ mice and their STIM1f/f littermates, we found that SMC-specific STIM1 deletion induced calcification of aortic arteries cultured in osteogenic media ex vivo. Furthermore, STIM1 deficiency promoted osteogenic differentiation and calcification of VSMC from the STIM1Δ/Δ mice. In the low-dose streptozotocin (STZ)-induced mouse model of diabetes, SMC-specific STIM1 deletion markedly enhanced STZ-induced vascular calcification and stiffness in the STIM1Δ/Δ mice. The diabetic mice with SMC-specific STIM1 ablation also exhibited increased aortic expression of the key osteogenic transcription factor, Runx2, and protein O-GlcNAcylation, an important post-translational modulation that we have reported to promote vascular calcification and stiffness in diabetes. Consistently, elevation of O-GlcNAcylation was demonstrated in aortic arteries and VSMC from the STIM1Δ/Δ mice. Inhibition of O-GlcNAcylation with a pharmacological inhibitor abolished STIM1 deficiency-induced VSMC calcification, supporting a critical role of O-GlcNAcylation in mediating STIM1 deficiency-induced VSMC calcification. Mechanistically, we identified that STIM1 deficiency resulted in impaired calcium homeostasis, which activated calcium signaling and increased endoplasmic reticulum (ER) stress in VSMC, while inhibition of ER stress attenuated STIM1-induced elevation of protein O-GlcNAcylation. In conclusion, the study has demonstrated a causative role of SMC-expressed STIM1 in regulating vascular calcification and stiffness in diabetes. We have further identified a novel mechanisms underlying STIM1 deficiency-induced impairment of calcium homeostasis and ER stress in upregulation of protein O-GlcNAcylation in VSMC, which promotes VSMC osteogenic differentiation and calcification in diabetes.

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.

Zebrafish Models to Study Ectopic Calcification and Calcium-Associated Pathologies

Ectopic calcification refers to the pathological accumulation of calcium ions in soft tissues and is often the result of a dysregulated action or disrupted function of proteins involved in extracellular matrix mineralization. While the mouse has traditionally been the go-to model organism for the study of pathologies associated with abnormal calcium deposition, many mouse mutants often have exacerbated phenotypes and die prematurely, limiting the understanding of the disease and the development of effective therapies. Since the mechanisms underlying ectopic calcification share some analogy with those of bone formation, the zebrafish (Danio rerio)-a well-established model for studying osteogenesis and mineralogenesis-has recently gained momentum as a model to study ectopic calcification disorders. In this review, we outline the mechanisms of ectopic mineralization in zebrafish, provide insights into zebrafish mutants that share phenotypic similarities with human pathological mineralization disorders, list the compounds capable of rescuing mutant phenotypes, and describe current methods to induce and characterize ectopic calcification in zebrafish.

Medial artery calcification in peripheral artery disease

Medial artery calcification (MAC) is a distinct, highly regulated process that is often identified in small and mid-sized arteries of the lower extremities. It is associated with advanced age, diabetes, and chronic kidney disease. MAC often occurs in conjunction with atherosclerotic occlusive disease in lower extremity arteries, and when seen together or in isolation, long-term limb outcomes are negatively affected. In patients with peripheral artery disease (PAD), the extent of MAC independently correlates with major amputation and mortality rates, and it predicts poor outcomes after endovascular interventions. It is associated with increased arterial stiffness and decreased pedal perfusion. New endovascular methods aimed at treating calcified lower-extremity lesions may improve our ability to treat patients with limb-threatening ischemia. Although recent developments have increased our understanding of the mechanisms contributing to MAC, further investigations are needed to understand the role of medial calcification in PAD, and to develop strategies aimed at improving patient outcomes.

Growth hormone-releasing hormone agonist attenuates vascular calcification in diabetic db/db mice

Introduction

Vascular calcification (VC) is an independent risk factor for cardiovascular diseases. VC increases mortality of all-causes. VC is one of most common cardiovascular complications in type II diabetes. So far, no therapy has been proven to be effective in treatment of clinical VC. The present study investigated the therapeutic effects of MR409, an agonistic analog of growth hormone-releasing hormone (GHRH-A), on VC in diabetic db/db mice.

Method and result

Diabetic mice were injected with MR409 subcutaneously every day for 8 weeks. Long-term treatment with MR409 improved serum lipid profile and endothelium-dependent relaxation to acetylcholine, and reduced vascular structural injury in diabetic mice without affecting serum growth hormone level. Echocardiography showed that calcium plaques present in heart valve of diabetic mice disappeared in diabetic mice after treatment with MR409. MR409 inhibited vascular calcium deposition associated with a marked reduction in the expressions of osteogenic-regulated alkaline phosphatase (ALP) and transcription osteogenic marker gene Runx2 in diabetic mice. MR409 also inhibited vascular reactive oxygen species (ROS) generation and upregulated the expressions of anti-calcifying protein Klotho in diabetic mice.

Discussion

Our results demonstrate that GHRH-A MR409 can effectively attenuate VC and heart valve calcification, and protect against endothelial dysfunction and vascular injury in diabetic mice without significantly affecting pituitary-growth hormone axis. The mechanisms may involve upregulation of anti-calcifying protein Klotho and reduction in vascular ROS and the expression of redox sensitive osteogenic genes Runx2 and ALP. GHRH-A may represent a new pharmacological strategy for treatment of VC and diabetics associated cardiovascular complications.

Emerging structural and pathological analyses on the erectile organ, corpus cavernous containing sinusoids

Background

The corpus cavernosum (CC) containing sinusoids plays fundamental roles for erection. Analysis of pathological changes in the erectile system is studied by recent experimental systems. Various in vitro models utilizing genital mesenchymal-derived cells and explant culture systems are summarized.

Methods

3D reconstruction of section images of murine CC was created. Ectopic chondrogenesis in aged mouse CC was shown by a gene expression study revealing the prominent expression of Sox9. Various experimental strategies utilizing mesenchyme-derived primary cells and tissue explants are introduced.

Main Findings

Possible roles of Sox9 in chondrogenesis and its regulation by several signals are suggested. The unique character of genital mesenchyme is shown by various analyses of external genitalia (ExG) derived cells and explant cultures. Such strategies are also applied to the analysis of erectile contraction/relaxation responses to many signals and aging process.

Conclusion

Erectile dysfunction (ED) is one of the essential topics for the modern aged society. More comprehensive studies are necessary to reveal the nature of the erectile system by combining multiple cell culture strategies.

Peripheral artery disease and the risk of venous thromboembolism

Summary: Background: Peripheral artery disease (PAD) impacts 3–12% of patients worldwide and is characterized by endothelial dysfunction and inflammatory pathways which are also common to venous thromboembolism (VTE), but there is a paucity of evidence regarding VTE risk in PAD patients. We investigated whether PAD is an independent risk factor for VTE. Patients and methods: We reviewed medical records of patients undergoing ABI studies at Mayo Clinic from 01/1996-02/2020. We classified patients by ABI (low [<1.0], normal [1.0–1.4], or elevated [>1.4]), as well as by specific low ABI subgroup: severely reduced (ABI: 0.00–0.39), moderately reduced (0.40–0.69), mildly reduced (0.70–0.90), and borderline reduced (0.91–0.99). The primary outcome was incident VTE event (acute lower extremity deep vein thrombosis or pulmonary embolism) after ABI measurement. Multivariable Cox proportional regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for age, sex, active smoking, cancer, previous VTE, thrombophilia, anticoagulation, and revascularization. Results: 39,834 unique patients (mean age 66.3±14.3 years, median follow-up 34 months) were identified. 2,305 VTE events occurred in patients without PAD (13.0%), 2,218 in low ABI patients (13.0%), and 751 in elevated ABI patients (14.8%). After risk factor adjustment, VTE risk was modestly increased for PAD overall (HR: 1.12, 95% CI [1.06, 1.18]), including low ABI (HR: 1.11, 95% CI [1.04, 1.18]) and elevated ABI groups (HR: 1.15, 95% CI [1.04, 1.26]), compared to patients without PAD. The greatest VTE risk was in severely low ABI patients (HR: 1.46, 95% CI [1.31, 1.64]). Conclusions: In a large longitudinal cohort, we present strong clinical evidence of PAD, with low and elevated ABI, as an independent VTE risk factor, with the highest risk seen in patients with severely low ABI. Continued research is required to further investigate this relationship and its intersection with functional performance status to optimize VTE risk reduction or anticoagulation strategies in the PAD population.

Maternal high-fat diet promotes calcified atherosclerotic plaque formation in adult offspring by enhancing transformation of VSMCs to osteochondrocytic-like phenotype

Aim

Maternal high-fat diet (HFD) is associated with the development of cardiovascular disease (CVD) in adult offspring. Atherosclerotic vascular calcification is well documented in patients with CVD. We examined the effect of maternal HFD on calcified plaque formation.

Methods and results

Seven-week-old female apo-E^−/− mice (C57BL6/J) were nourished either an HFD or a normal diet (ND) a week before mating, and during gestation and lactation. Offspring of both the groups were fed a high-cholesterol diet (HCD) from 8 weeks of age. Osteogenic activity of the thoracic aorta, assessed using an ex vivo imaging system, was significantly increased after 3 months of HCD in male offspring of HFD-fed dams (O-HFD) as compared with those of ND-fed dams (O-ND). Alizarin-red-positive area in the aortic root was significantly increased after 6 months of HCD in male O-HFD as compared to that of O-ND. Plaque size and Oil Red O-positive staining were comparable between the two groups. Primary cultured vascular smooth muscle cells (VSMCs) of the thoracic aorta were treated with phosphate and interleukinL-1β (IL-1β) to transform them into an osteochondrocytic-like phenotype. Intracellular calcium content and alkaline phosphatase activity were markedly higher in the VSMCs of O-HFD than in O-ND. IL-1β concentration in the supernatant of bone marrow-derived macrophages was markedly higher in O-HFD than in O-ND.

Conclusion

Our findings indicate that maternal HFD accelerates the expansion of atherogenic calcification independent of plaque progression. In vitro phosphate- and IL-1β-induced osteochondrocytic transformation of VSMCs was augmented in O-HFD. Inhibition of VSMCs, skewing toward osteochondrocytic-like cells, might be a potential therapeutic strategy for preventing maternal HFD-associated CVD development.

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.

Different Metabolic Phenotypes of Obesity and Risk of Coronary Artery Calcium Progression and Incident Cardiovascular Disease Events: The CARDIA Study

BACKGROUND

To investigate whether obesity with or without metabolic syndrome is prospectively associated with coronary artery calcium (CAC) progression and incident cardiovascular disease events.

METHODS

A total of 1730 participants from the CARDIA study (Coronary Artery Risk Development in Young Adults) were included (age, 40.1±3.6 years; 38.3% men), who completed computed tomography of CAC at baseline (year 15: 2000-2001) and follow-up (year 20 or 25). Metabolically healthy obesity (MHO) was defined as body mass index≥30 kg/m² without any metabolic syndrome components in our main analysis. Sensitivity analyses were conducted for several conditions characterizing 4 metabolic phenotypes.

RESULTS

During a mean follow-up of 9.1 years, 439 participants had CAC progression. MHO subjects had a significantly higher risk of CAC progression than their metabolically healthy normal weight counterparts (adjusted hazard ratios [95% CIs] from 1.761 [1.369-2.264] to 2.047 [1.380-3.036]) depending on the definition of MHO adopted. Obesity with unhealthy metabolic profile remained the highest significant risk of CAC progression and cardiovascular disease events whatever the definitions adopted for metabolically unhealthy status. Up to 60% of participants with MHO converted to metabolically unhealthy obesity from year 15 to year 20 or year 25. Further sensitivity analysis showed that MHO throughout carried a similar risk of incident cardiovascular disease events compared with metabolically healthy normal weight throughout.

CONCLUSIONS

Different metabolic phenotypes of obesity beginning at a young age exhibit distinct risks of CAC progression and subsequent cardiovascular disease events in later midlife. MHO represents an intermediate phenotype between metabolically low- to high-risk obese individuals.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT00005130.

Type 2 diabetes and the clinically normal pulp - An in-vitro study

Aim

The aim of this study was to investigate the effect of type 2 diabetes (T2D) on clinically normal dental pulp tissue by using special stains and immunohistochemistry (IHC) to determine the morphology of the coronal pulp and distribution of immune markers in non‐T2D and T2D groups.

Methodology

Ethics approval for this in vitro pilot study was obtained from the University of Otago Human Ethics Committee (16/069). Twenty extracted permanent molar teeth diagnosed as having clinically normal pulp status were collected. Ten teeth were from participants with well‐controlled T2D and ten from participants without diabetes (non‐T2D). Each tooth was sectioned transversely at the cemento‐enamel junction before the crowns were decalcified and embedded in paraffin. Sections were stained with haematoxylin and eosin, Massons trichrome, and van Gieson stains for histological and morphological evaluation. IHC using anti‐CD4, anti‐CD68 and anti‐CD83 and anti‐IL1β, anti‐IL6, anti‐IL17, anti‐TNF‐α, anti‐TLR2, anti‐TLR4 and anti‐FOXP3 identified proteins of interest. Qualitative and semi‐quantitative analyses evaluated the morphology of the dental pulp and protein expression. Data analyses were performed with GraphPad Prism, using Student's t‐test and multiple regression using SPSS at p < .05.

Results

Special stains demonstrated morphological differences in the T2D dental pulp compared with non‐T2D. Qualitative analysis indicated that the pulp in the T2D samples was consistently less cellular, less vascular, showed evidence of thickened blood vessel walls, increased pulp calcification and collagen deposition. Semi‐quantitative analysis of IHC samples showed the T2D pulp had significantly increased expression of macrophage and dendritic cell markers CD68 (p < .001) and CD83 (p = .04), and there was significantly greater expression of inflammatory cytokines IL1β (p = .01), IL6 (p < .0001), IL17 (p < .0001) and TNF‐α (p = .01). T2D samples showed a significant increase in markers of innate inflammation, TLR2 (p < .001) and TLR4 (p < .001) and decreased expression of regulatory T‐cell marker, FOXP3 (p = .01). Multiple regression showed that age‐corrected differences were statistically significant.

Conclusion

Preliminary findings suggest that T2D may exert a similar response in the pulp to complications in other body sites. Hyperglycaemia is associated with changes in the morphology of the clinically normal dental pulp with altered immune cell and cytokine expression.

Automatic measurement of vascular calcifications in patients with aorto-iliac occlusive disease to predict the risk of re-intervention after endovascular repair

OBJECTIVE

There is currently a lack of consensus and tools to easily measure vascular calcification using computed tomography angiography (CTA). The aim of this study was to develop a fully automatic software to measure calcifications and to evaluate the interest as predictive factor in patients with aorto-iliac occlusive disease.

METHODS

This study retrospectively included 171 patients who had endovascular repair of an aorto-iliac occlusive lesion at the University Hospital of Nice between January 2011 and December 2019. Calcifications volumes were measured from CT-angiography (CTA) using an automatic method consisting in 3 sequential steps: image pre-processing, lumen segmentation using expert system and deep learning algorithms and segmentation of calcifications. Calcification volumes were measured in the infrarenal abdominal aorta and the iliac arterial segments, corresponding to the common and the external iliac arteries.

RESULTS

Among 171 patients included with a mean age of 65 years, the revascularization was performed on the native external and internal iliac arteries in respectively: 83 patients (48.5%); 107 (62.3%) and 7 (4.1%). The mean volumes of calcifications were 2759 mm³ in the infrarenal abdominal aorta, 1821 mm³ and 1795 mm³ in the right and left iliac arteries. For a mean follow up of 39 months, TLR was performed in 55 patients (32.2%). These patients had higher volume of calcifications in the right and left iliac arteries, compared with patients who did not have a re-intervention (2274 mm³ vs 1606 mm³, p=0.0319 and 2278 vs 1567 mm³, p=0.0213).

CONCLUSION

The development of a fully automatic software would be useful to facilitate the measurement of vascular calcifications and possibly better inform the prognosis of patients.

Impact of Different Measures of Body Size on the Radiation Dose During Coronary Angiography and Percutaneous Coronary Intervention: Results from a Large Single Center Cohort

Efforts to reduce and optimize the radiation exposure during coronary angiography and intervention have pointed at patients' body size as a major determinant of irradiation for the patients and operators. We aimed at comparing body weight and body mass index (BMI) among consecutive patients undergoing angiographic procedures (coronary angiography and/or interventions) in a single center. Patients were divided in normal weight (NW, BMI <25 Kg/m²) and overweight (OW, BMI ≥25 Kg/m²). Patients' dose exposure was evaluated as dose area product (DAP), time of exposure (fluoroscopy duration), and relative DAP (DAP/minutes of exposure). We included 748 patients, 61.6% undergoing percutaneous coronary interventions and 56.8% classified as OW. OW patients were more often men (P < .001), with history of hypertension (P < .001) and diabetes (P = .001). Mean DAP and relative DAP were significantly higher among OW compared with NW patients (P < .001). DAP and relative DAP were directly related with body weight (both r = .22, P < .001); a similar linear association was also described for BMI (r = .18, P < .001 and r = .19, P < .001, respectively). At multivariate analysis, however, body weight, but not BMI, independently predicted the DAP. Therefore, body weight should be considered as the preferred indicator of body size in the setting and optimization of radiation exposure during coronary diagnostic and intervention procedures.

Fat reducing effects of Nelumbo nucifera leaf extract in overweight patients

The leaf of Nelumbo nucifera (Family Nelumbonaceae) has been widely included in the diet of Chinese people from the time of the Min Dynasty. In this study, a randomized double-blind trial (n = 60) was performed to determine the effects of extract from sun dried Nelumbo nucifera leaves (NnEx), which included quercetin-3-glucuronide (Q3GA) as the main components, in overweight patients (24 kg/m²<body mass index < 28 kg/m²) during 12 weeks. For both men and women, compared with those in the non-intervention control groups, the whole body fat was significantly decreased after NnEx ingestion, and men also significantly reduced visceral fat and waist circumference after NnEx ingestion compared with those in the control group.

IL-1β in atherosclerotic vascular calcification: From bench to bedside

Atherosclerotic vascular calcification contributes to increased risk of death in patients with cardiovascular diseases. Assessing the type and severity of inflammation is crucial in the treatment of numerous cardiovascular conditions. IL-1β, a potent proinflammatory cytokine, plays diverse roles in the pathogenesis of atherosclerotic vascular calcification. Several large-scale, population cohort trials have shown that the incidence of cardiovascular events is clinically reduced by the administration of anti-IL-1β therapy. Anti-IL-1β therapy might reduce the incidence of cardiovascular events by affecting atherosclerotic vascular calcification, but the mechanism underlying this effect remains unclear. In this review, we summarize current knowledge on the role of IL-1β in atherosclerotic vascular calcification, and describe the latest results reported in clinical trials evaluating anti-IL-1β therapies for the treatment of cardiovascular diseases. This review will aid in improving current understanding of the pathophysiological roles of IL-1β and mechanisms underlying its activity.

Carotid Artery Plaque Calcifications: Lessons From Histopathology to Diagnostic Imaging

The role of calcium in atherosclerosis is controversial and the relationship between vascular calcification and plaque vulnerability is not fully understood. Although calcifications are present in ≈50% to 60% of carotid plaques, their association with cerebrovascular ischemic events remains unclear. In this review, we summarize current understanding of carotid plaque calcification. We outline the role of calcium in atherosclerotic carotid disease by analyzing laboratory studies and histopathologic studies, as well as imaging findings to understand clinical implications of carotid artery calcifications. Differences in mechanism of calcium deposition express themselves into a wide range of calcification phenotypes in carotid plaques. Some patterns, such as rim calcification, are suggestive of plaques with inflammatory activity with leakage of the vasa vasourm and intraplaque hemorrhage. Other patterns such as dense, nodular calcifications may confer greater mechanical stability to the plaque and reduce the risk of embolization for a given degree of plaque size and luminal stenosis. Various distributions and patterns of carotid plaque calcification, often influenced by the underlying systemic pathological condition, have a different role in affecting plaque stability. Modern imaging techniques afford multiple approaches to assess geometry, pattern of distribution, size, and composition of carotid artery calcifications. Future investigations with these novel technologies will further improve our understanding of carotid artery calcification and will play an important role in understanding and minimizing stroke risk in patients with carotid plaques.

Zinc Ameliorates the Osteogenic Effects of High Glucose in Vascular Smooth Muscle Cells

In diabetic patients, medial vascular calcification is common and associated with increased cardiovascular mortality. Excessive glucose concentrations can activate the nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-kB) and trigger pro-calcific effects in vascular smooth muscle cells (VSMCs), which may actively augment vascular calcification. Zinc is able to mitigate phosphate-induced VSMC calcification. Reduced serum zinc levels have been reported in diabetes mellitus. Therefore, in this study the effects of zinc supplementation were investigated in primary human aortic VSMCs exposed to excessive glucose concentrations. Zinc treatment was found to abrogate the stimulating effects of high glucose on VSMC calcification. Furthermore, zinc was found to blunt the increased expression of osteogenic and chondrogenic markers in high glucose-treated VSMCs. High glucose exposure was shown to activate NF-kB in VSMCs, an effect that was blunted by additional zinc treatment. Zinc was further found to increase the expression of TNFα-induced protein 3 (TNFAIP3) in high glucose-treated VSMCs. The silencing of TNFAIP3 was shown to abolish the protective effects of zinc on high glucose-induced NF-kB-dependent transcriptional activation, osteogenic marker expression, and the calcification of VSMCs. Silencing of the zinc-sensing receptor G protein-coupled receptor 39 (GPR39) was shown to abolish zinc-induced TNFAIP3 expression and the effects of zinc on high glucose-induced osteogenic marker expression. These observations indicate that zinc may be a protective factor during vascular calcification in hyperglycemic conditions.

Biomolecules Orchestrating Cardiovascular Calcification

Vascular calcification, once considered a degenerative, end-stage, and inevitable condition, is now recognized as a complex process regulated in a manner similar to skeletal bone at the molecular and cellular levels. Since the initial discovery of bone morphogenetic protein in calcified human atherosclerotic lesions, decades of research have now led to the recognition that the regulatory mechanisms and the biomolecules that control cardiovascular calcification overlap with those controlling skeletal mineralization. In this review, we focus on key biomolecules driving the ectopic calcification in the circulation and their regulation by metabolic, hormonal, and inflammatory stimuli. Although calcium deposits in the vessel wall introduce rupture stress at their edges facing applied tensile stress, they simultaneously reduce rupture stress at the orthogonal edges, leaving the net risk of plaque rupture and consequent cardiac events depending on local material strength. A clinically important consequence of the shared mechanisms between the vascular and bone tissues is that therapeutic agents designed to inhibit vascular calcification may adversely affect skeletal mineralization and vice versa. Thus, it is essential to consider both systems when developing therapeutic strategies.

Gycyrrhizic acid alleviates atherosclerotic lesions in rats with diabetes mellitus

Gycyrrhizic acid (GA), an inhibitor of high mobility group box 1 (HMGB1), inhibits inflammatory responses and is involved in the occurrence and development of several inflammation-related diseases. However, the role of GA in the atherosclerotic lesions caused by diabetes mellitus (DM) remains unknown. In the present study, Sprague Dawley rats were selected to desi=gn a diabetic atherosclerosis (AS) model. Rats from the DM-AS group were subsequently divided into DM-AS, DM-AS + GA (50 mg/kg) and DM-AS + GA (150 mg/kg) groups. Biochemical analyzers were used to measure levels of blood glucose, fasting insulin, total cholesterol, total triglyceride, low-density lipoprotein and high-density lipoprotein. The number of plaques was recorded after collection of thoracic aortas from the rats. The intimal thickness of arterial tissue was detected by hematoxylin and eosin staining. The expression levels of CD68 and α-smooth muscle actin (α-SMA) were detected by immunohistochemistry. The expression of tumor necrosis factor-α, interleukin (IL)-6 and IL-1β in the serum of the rats was detected by ELISA. The expression of fatty acid synthetase, sterol regulatory element binding protein 1C, HMGB1 and receptor for advanced glycation end products (RAGE) was detected by western blotting. Reverse transcription quantitative PCR was used to detect the mRNA expression of HMGB1 and RAGE. The results demonstrated that GA treatment could decrease the body weight, blood glucose level and biochemical parameters of AS DM rats in a dose-dependent manner. In addition, GA decreased the intimal thickness of carotid artery and the formation of plaque in rats with diabetic AS. Furthermore, GA inhibited macrophage activation and decreased α-SMA expression in vascular smooth muscle cells, and decreased the expression of proteins (FAS and SREBP-1c) and inflammatory factors. Taken together, the findings from the present study demonstrated that GA may have a therapeutic effect on DM-associated AS. This study provides a theoretical basis for the treatment of diabetic AS.

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.

Flavocoxid Ameliorates Aortic Calcification Induced by Hypervitaminosis D3 and Nicotine in Rats Via Targeting TNF-α, IL-1β, iNOS, and Osteogenic Runx2

PURPOSE

This research was designed to investigate the effects and mechanisms of flavocoxid (FCX) on vascular calcification (VC) in rats.

METHODS

Vitamin D₃ and nicotine were administered to Wistar rats, which then received FCX (VC-FCX group) or its vehicle (VC group) for 4 weeks. Control and FCX groups served as controls. Systolic (SBP) and diastolic (DBP) blood pressures, heart rate (HR), and left ventricular weight (LVW)/BW were measured. Serum concentrations of calcium, phosphate, creatinine, uric acid, and alkaline phosphatase were determined. Moreover, aortic calcium content and aortic expression of runt-related transcription factor (Runx2), osteopontin (OPN), Il-1β, α-smooth muscle actin (α-SMA), matrix metalloproteinase-9 (MMP-9), inducible nitric oxide synthase (iNOS), and tumor necrosis factor-α (TNF-α) were assessed. Oxidative status in aortic homogenates was investigated.

RESULTS

Compared to untreated VC rats, FCX treatment prevented body weight loss, reduced aortic calcium deposition, restored normal values of SBP, DBP, and HR, and attenuated LV hypertrophy. FCX also improved renal function and ameliorated serum levels of phosphorus, calcium, and ALP in rats with VC. FCX abolished aortic lipid peroxidation in VC rats. Moreover, VC-FCX rats showed marked reductions in aortic levels of Il-1β and osteogenic marker (Runx2) and attenuated aortic expression of TNF-α, iNOS, and MMP-9 proteins compared to untreated VC rats. The expression of the smooth muscle lineage marker α-SMA was greatly enhanced in aortas from VC rats upon FCX treatment.

CONCLUSION

These findings demonstrate FCX ability to attenuate VDN-induced aortic calcinosis in rats, suggesting its potential for preventing arteiocalcinosis in diabetic patients and those with chronic kidney disease.

Bibliometric and Visual Analysis of Vascular Calcification Research

Background: Extensive studies related to vascular calcification (VC) were conducted in recent years. However, no bibliometric analysis has systematically investigated this topic. Our study aimed to determine the hotspots and frontiers of VC research in the past decade and provide a reference for future scientific research directions and decision-making in the VC field.

Methods: VC studies were acquired from the Web of Science Core Collection. Bibliometric and visual analyses were performed using CiteSpace, VOSviewer, and Microsoft Excel software.

Results: A total of 8,238 English articles on VC research published in 2011–2020 were obtained. In the past decade, annual publications and citations showed a significant growth trend, especially in 2018–2020. The most productive country, institution, journal and author are the United States, the University of California System, PLOS ONE, and Budoff MJ, respectively. The most frequently cited country, journal, and author are the United States, Journal of the American College of Cardiology, and Floege J, respectively. “Vascular calcification,” “atherosclerosis,” “chronic kidney disease,” and “cardiovascular disease” are the primary keywords. The burst keywords “revascularization,” “calciprotein particle,” “microRNA,” and “microcalcification” are speculated to be the research frontiers.

Conclusion: The main research hotspots in the VC field are the molecular mechanisms and prognosis of VC in patients with chronic kidney disease or cardiovascular disease. In addition, endovascular therapy and the development of new drugs targeting signal pathways for VC will become the focus of future research. Moreover, non-coding RNAs related to the diagnosis and treatment of VC are great research prospects.

Transthyretin: From Structural Stability to Osteoarticular and Cardiovascular Diseases

Transthyretin (TTR) is a tetrameric protein transporting hormones in the plasma and brain, which has many other activities that have not been fully acknowledged. TTR is a positive indicator of nutrition status and is negatively correlated with inflammation. TTR is a neuroprotective and oxidative-stress-suppressing factor. The TTR structure is destabilized by mutations, oxidative modifications, aging, proteolysis, and metal cations, including Ca2+. Destabilized TTR molecules form amyloid deposits, resulting in senile and familial amyloidopathies. This review links structural stability of TTR with the environmental factors, particularly oxidative stress and Ca2+, and the processes involved in the pathogenesis of TTR-related diseases. The roles of TTR in biomineralization, calcification, and osteoarticular and cardiovascular diseases are broadly discussed. The association of TTR-related diseases and vascular and ligament tissue calcification with TTR levels and TTR structure is presented. It is indicated that unaggregated TTR and TTR amyloid are bound by vicious cycles, and that TTR may have an as yet undetermined role(s) at the crossroads of calcification, blood coagulation, and immune response.

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 ameliorative effect of terpinen-4-ol on ER stress-induced vascular calcification depends on SIRT1-mediated regulation of PERK acetylation

Endoplasmic reticulum (ER) stress-mediated phenotypic switching of vascular smooth muscle cells (VSMCs) is key to vascular calcification (VC) in patients with chronic kidney disease (CKD). Studies have shown that activation/upregulation of SIRT1 has a protective effect on CKD-VC. Meanwhile, although terpinen-4-ol has been shown to exert a protective effect against cardiovascular disease, its role and underlying mechanism in VC remain unclear. Herein, we explored whether terpinen-4-ol alleviates ER stress-mediated VC through sirtuin 1 (SIRT1) and elucidated its mechanism to provide evidence for its application in the clinical prevention and treatment of VC. To this end, a CKD-related VC animal model and β-glycerophosphate (β-GP)-induced VSMC calcification model were established to investigate the role of terpinen-4-ol in ER stress-induced VC, in vitro and in vivo. Additionally, to evaluate the involvement of SIRT1, mouse and VSMC Sirt1-knockdown models were established. Results show that terpinen-4-ol inhibits calcium deposition, phenotypic switching, and ER stress in VSMCs in vitro and in vivo. Furthermore, pre-incubation of VSMCs with terpinen-4-ol or a SIRT1 agonist, decreased β-GP-induced calcium salt deposition, increased SIRT1 protein level, and inhibited PERK-eIF2α-ATF4 pathway activation, thus, alleviating VC. Similar results were observed in VSMCs induced to overexpress SIRT1 via lentivirus transcription. Meanwhile, the opposite results were obtained in SIRT1-knockdown models. Further, results suggest that SIRT1 physically interacts with, and deacetylates PERK. Specifically, mass spectrometry analysis identified lysine K889 as the acetylation site of SIRT1, which regulates PERK. Finally, inhibition of SIRT1 reduced the effect of terpinen-4-ol on the deacetylation of PERK in vitro and in vivo and weakened the inhibitory effect of terpinen-4-ol against ER stress-mediated VC. Cumulatively, terpinen-4-ol was found to inhibit post-translational modification of PERK at the K889 acetylation site by upregulating SIRT1 expression, thereby ameliorating VC by regulating ER stress. This study provides insights into the underlying molecular mechanism of terpinen-4-ol, supporting its development as a promising therapeutic agent for CKD-VC.

Ascending Aortic Calcification as a Potential Predictor for Low Bone Mineral Density: A Pilot Study

BACKGROUND

Identifying the factors related to low bone mineral density (BMD) can have significant implications for preventing hip fractures. The correlation between ascending aortic calcification and BMD has never been reported. Therefore, the purpose of the current study is to confirm the hypothesis that ascending aortic calcification can be used as a predictive factor for low BMD and to find a radiographic sign to show it.

METHOD

Plain film and computed tomography (CT) images of the thorax were obtained from 91 patients with hip fractures. Using the images, the calcification line of the ascending aorta adjacent to the aortic arch was evaluated. A prominent calcification line confirmed by both plain film and CT was classified as +2. A line which was ambiguous on plain film but confirmed by CT was classified as +1. Cases with no calcification were categorized as 0 (control). We compared the classified score with the BMD and calculated the kappa coefficient to measure intraobserver reliabilities for this radiographic finding.

RESULTS

Twenty-eight patients showed a +2 line, twenty-four patients showed a +1 line, and thirty-nine patients showed 0 lines. The median BMD of each group was 0.37 for the +2 line, 0.45 for the +1 line, and 0.51 for the 0 line. The BMD for the +2 group was significantly lower than the others. The kappa coefficient was approximately 0.6 (p < 0.01).

CONCLUSION

The imaging finding of calcification of the ascending aorta might be considered as a potential surrogate marker of low BMD. In such subjects, BMD might be ordered for the confirmation of diagnosis of osteoporosis. Mini-Abstract. The Aortic Arch Tail Sign, a calcification line on the ascending aorta, was relevant to low BMD in the current study. BMD can be ordered for the confirmation of diagnosis of osteoporosis in a subject incidentally found to have ascending aorta calcification on X-ray or CT.

Oxidative stress in vascular calcification

Vascular calcification (VC), which is closely associated with significant mortality in cardiovascular disease, chronic kidney disease (CKD), and/or diabetes mellitus, is characterized by abnormal deposits of hydroxyapatite minerals in the arterial wall. The impact of oxidative stress (OS) on the onset and progression of VC has not been well described. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, xanthine oxidases, myeloperoxidase (MPO), nitric oxide synthases (NOSs), superoxide dismutase (SOD) and paraoxonases (PONs) are relevant factors that influence the production of reactive oxygen species (ROS). Furthermore, excess ROS-induced OS has emerged as a critical mediator promoting VC through several mechanisms, including phosphate balance, differentiation of vascular smooth muscle cells (VSMCs), inflammation, DNA damage, and extracellular matrix remodeling. Because OS is a significant regulator of VC, antioxidants may be considered as novel treatment options.

The Thermodynamics of Medial Vascular Calcification

Medial vascular calcification (MVC) is a degenerative process that involves the deposition of calcium in the arteries, with a high prevalence in chronic kidney disease (CKD), diabetes, and aging. Calcification is the process of precipitation largely of calcium phosphate, governed by the laws of thermodynamics that should be acknowledged in studies of this disease. Amorphous calcium phosphate (ACP) is the key constituent of early calcifications, mainly composed of Ca2+ and PO4 3- ions, which over time transform into hydroxyapatite (HAP) crystals. The supersaturation of ACP related to Ca2+ and PO4 3- activities establishes the risk of MVC, which can be modulated by the presence of promoter and inhibitor biomolecules. According to the thermodynamic parameters, the process of MVC implies: (i) an increase in Ca2+ and PO4 3- activities (rather than concentrations) exceeding the solubility product at the precipitating sites in the media; (ii) focally impaired equilibrium between promoter and inhibitor biomolecules; and (iii) the progression of HAP crystallization associated with nominal irreversibility of the process, even when the levels of Ca2+ and PO4 3- ions return to normal. Thus, physical-chemical processes in the media are fundamental to understanding MVC and represent the most critical factor for treatments' considerations. Any pathogenetical proposal must therefore comply with the laws of thermodynamics and their expression within the medial layer.

POSTN promotes diabetic vascular calcification by interfering with autophagic flux

Autophagy is a lysosomal degradative process that is closely related to the pathogenesis of vascular calcification. Recent evidence suggests that periostin (POSTN) is a unique extracellular matrix protein that is associated with diabetic vascular complications. The aim of current study is to investigate the role of POSTN in diabetic vascular calcification and the underlying mechanisms. Results showed that POSTN was highly upregulated in both calcified arteries of diabetic rats and AGEs-BSA mediated vascular smooth muscle cell (VSMC) calcification. POSTN blocked autophagic flux during the diabetic calcification process, as evidenced by increased protein expression of Beclin1, LC3-II, and P62, as well as the co-localization of LC3-II and LAMP1. Inhibition of POSTN alleviated AGEs-BSA-induced autophagic flux blockade, thereby attenuating AGEs-BSA-induced VSMC calcification. Mechanistically, the upregulation of POSTN impaired the fusion of autophagosomes and lysosome and resulted in the autophagic flux blockade in AGEs-BSA-treated VSMC. Furthermore, this autophagic blockade was intracellular ROS-dependent. In summary, this study uncovered a novel mechanism of POSTN in autophagy regulation of diabetic vascular calcification.

Cardiovascular calcifications in kidney transplant recipients

Vascular and valvular calcifications are highly prevalent in kidney transplant recipients and are associated with an increased risk of cardiovascular events, which represent the leading cause of long-term mortality in these patients. However, cardiovascular calcification has been traditionally considered as a condition mostly associated with advanced chronic kidney disease stages and dialysis, and comparatively fewer studies have assessed its impact after kidney transplantation. Despite partial or complete resolution of uremia-associated metabolic derangements, kidney transplant recipients are still exposed to several pro-calcifying stimuli that favour the progression of pre-existing vascular calcifications or their de novo development. Traditional risk factors, bone mineral disorders, inflammation, immunosuppressive drugs and deficiency of calcification inhibitors may all play a role, and strategies to correct or minimize their effects are urgently needed. The aim of this work is to provide an overview of established and putative mediators involved in the pathogenesis of cardiovascular calcification in kidney transplantation, and to describe the clinical and radiological features of these forms. We also discuss current evidence on preventive strategies to delay the progression of cardiovascular calcifications in kidney transplant recipients, as well as novel therapeutic candidates to potentially prevent their long-term deleterious effects.

Endothelial to Mesenchymal Transition in the Cardiogenesis and Cardiovascular Diseases

Today, cardiovascular diseases remain a leading cause of morbidity and mortality worldwide. Endothelial to mesenchymal transition (EndMT) does not only play a major role in the course of development but also contributes to several cardiovascular diseases in adulthood. EndMT is characterized by down-regulation of the endothelial proteins and highly up-regulated fibrotic specific genes and extracellular matrix-forming proteins. EndMT is also a transforming growth factor-β-driven (TGF-β) process in which endothelial cells lose their endothelial characteristics and acquire a mesenchymal phenotype with expression of α-smooth muscle actin (α-SMA), fibroblast-specific protein 1, etc. EndMT is a vital process during cardiac development, thus disrupted EndMT gives rise to the congenital heart diseases, namely septal defects and valve abnormalities. In this review, we have discussed the main signaling pathways and mechanisms participating in the process of EndMT such as TGF-β and Bone morphogenetic protein (BMP), Wnt^#, and Notch signaling pathway and also studied the role of EndMT in physiological cardiovascular development and pathological conditions including myocardial infarction, pulmonary arterial hypertension, congenital heart defects, cardiac fibrosis, and atherosclerosis. As a perspective view, having a clear understanding of involving cellular and molecular mechanisms in EndMT and conducting Randomized controlled trials (RCTs) with a large number of samples for involving pharmacological agents may guide us into novel therapeutic approaches of congenital disorders and heart diseases.

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.

The Role of Fibroblast Growth Factor 21 in Diabetic Cardiovascular Complications and Related Epigenetic Mechanisms

Fibroblast growth factor 21 (FGF21), is an emerging metabolic regulator mediates multiple beneficial effects in the treatment of metabolic disorders and related complications. Recent studies showed that FGF21 acts as an important inhibitor in the onset and progression of cardiovascular complications of diabetes mellitus (DM). Furthermore, evidences discussed so far demonstrate that epigenetic modifications exert a crucial role in the initiation and development of DM-related cardiovascular complications. Thus, epigenetic modifications may involve in the function of FGF21 on DM-induced cardiovascular complications. Therefore, this review mainly interprets and delineates the recent advances of role of FGF21 in DM cardiovascular complications. Then, the possible changes of epigenetics related to the role of FGF21 on DM-induced cardiovascular complications are discussed. Thus, this article not only implies deeper understanding of the pathological mechanism of DM-related cardiovascular complications, but also provides the possible novel therapeutic strategy for DM-induced cardiovascular complications by targeting FGF21 and related epigenetic mechanism.

Positive Association of Leptin and Artery Calcification of Lower Extremity in Patients With Type 2 Diabetes Mellitus: A Pilot Study

OBJECTIVE

We aimed to explore the role and possible mechanism of leptin in lower-extremity artery calcification in patients with type 2 diabetes mellitus (T2DM).

METHODS

We recruited 59 male patients with T2DM and 39 non-diabetic male participants. All participants underwent computed tomography scan of lower-extremity arteries. The calcification scores (CSs) were analyzed by standardized software. Plasma leptin level was determined by radioimmunoassay kits. Human vascular smooth muscle cells (VSMCs) calcification model was established by beta-glycerophosphate and calcium chlorideinduction. Calcium deposition and mineralization were measured by the o-cresolphthalein complexone method and Alizarin Red staining. The mRNA expression of bone morphogenic protein 2 (BMP2), runt-related transcription factor 2 (Runx2), osteocalcin (OCN) and osteopontin (OPN) was determined by quantitative RT-PCR. The protein levels of BMP2, Runx2, α-smooth muscle actin (α-SMA) and (p)-Akt was determined by Western-blot analysis, and α-SMA was also measured by immunofluorescence analysis.

RESULTS

Compared with controls, patients with T2DM showed higher median calcification score in lower-extremity artery [286.50 (IQR 83.41, 1082.00) vs 68.66 (3.41, 141.30), p<0.01]. Plasma leptin level was higher in patients with calcification score ≥300 than ≥100 (252.67 ± 98.57 vs 189.38 ± 44.19 pg/ml, p<0.05). Compared with calcification medium, intracellular calcium content was significantly increased in VSMCs treated by leptin (200, 400 and 800 ng/ml) combined with calcification medium [11.99 ± 3.63, 15.18 ± 4.55, and 24.14 ± 5.85 mg/ml, respectively, vs 7.27 ± 1.54 mg/ml, all p<0.01]. Compared with calcification medium, Alizarin Red staining showed calcium disposition was more obvious, and the mRNA level of BMP2, Runx2 and OCN was significantly increased, and immunofluorescence and Western blot analysis showed that the expression of α-SMA was downregulated in VSMCs treated by leptin (400 ng/ml) combined with calcification medium, respectively. Compared with calcification medium, the protein level of BMP2 and Runx2 was upregulated in VSMCs treated by leptin (400 ng/ml) combined with calcification medium. Moreover, blocking PI3K/Akt signaling pathway can decrease the protein expression of BMP2 and Runx2 in VSMCs treated by leptin (400 ng/ml) combined with calcification medium.

CONCLUSIONS

Leptin promoted lower-extremity artery calcification of T2DM by upregulating the expression of BMP2 and Runx2, and regulating phenotypic switch of VSMCs via PI3K/Akt signaling pathway.

Atherosclerosis Imaging with 18F-Sodium Fluoride PET

The evidence on atherosclerosis imaging with ¹⁸F-sodium-fluoride (NaF) positron emission tomography (PET) is hotly debated because of the different patient characteristics, methodology, vascular beds, etc. in reported studies. This review is a continuation of a previous review on this topic, which covered the period 2010-2018. The purpose was to examine whether some of the most important questions that the previous review had left open had been elucidated by the most recent literature. Using principles of a systematic review, we ended analyzing 25 articles dealing with the carotids, coronary arteries, aorta, femoral, intracranial, renal, and penile arteries. The knowledge thus far can be summarized as follows: by targeting active arterial microcalcification, NaF uptake is considered a marker of early stage atherosclerosis, is age-dependent, and consistently associated with cardiovascular risk. Longitudinal studies on NaF uptake, conducted in the abdominal aorta only, showed unchanged uptake in postmenopausal women for nearly four years and varying uptake in prostate cancer patients over 1.5 years, despite constant or increasing calcium volume detected by computed tomography (CT). Thus, uncertainty remains about the transition from active arterial wall calcification marked by increased NaF uptake to less active or consolidated calcification detected by CT. The question of whether early-phase atherosclerosis and calcification can be modified remains also unanswered due to lack of intervention studies.

Prevalence of Vas Deferens Calcifications on Abdominal CT Examinations and Association With Systemic Conditions

OBJECTIVE. The purpose of this study was to describe the prevalence of vas deferens (VD) calcifications on abdominal CT examinations and the associations between VD calcifications and several systemic conditions. MATERIALS AND METHODS. The CT examinations of male patients from January 2010 to December 2011 were retrospectively reviewed. After exclusions, the records of 1915 consecutively identified patients were analyzed. Five readers, 3rd- and 4th-year radiology residents, recorded the presence and laterality of VD calcifications and of vascular calcifications presumed due to atherosclerosis. A sixth reader parsed the patient records for diagnoses of type 2 diabetes mellitus (DM) and chronic kidney disease (CKD). RESULTS. The mean age of the entire sample population was 52.9 ± 18.9 years (range, 1-93 years). The mean age of patients with VD calcifications was 59.3 ± 12.0 (SD) years and of the group without VD calcifications was 52.9 ± 19.1 years (p = 0.17). The prevalence of VD calcification was 1.61% (31 patients): 21 (67.7%) of the patients had bilateral calcification; seven (22.6%), right-sided only; and three, (9.7%) left-sided. The frequency of DM was 28.8% (551/1915), of CKD was 7.58% (150/1915), and of atherosclerosis, 60.4% (1156/1915). The mean caliber of calcified VDs was 5.31 ± 1.29 mm versus 3.63 ± 0.63 mm for patients without calcification or any chronic condition (p < 0.0001). Among age, atherosclerosis, DM, and CKD in univariate regression analysis, only DM was associated with VD calcification (p = 0.006). However, because age (p = 0.063) and atherosclerosis (p = 0.057) were close to significant, they were included in the multivariate analysis, which also showed only DM associated with VD calcification (odds ratio, 2.14 ± 0.85). CONCLUSION. In the large cohort in this study, the prevalence of VD calcification was 1.61%. VD calcification was strongly associated with DM. The pathologic implications of VD calcification remain unclear and warrant further investigation in prospective longitudinal studies.

Febuxostat attenuates vascular calcification induced by vitamin D3 plus nicotine in rats

This study was undertaken to investigate the possible ameliorative influences of febuxostat (FEB) on vitamin D3 plus nicotine (VDN)-induced vascular calcification (VC) in Wistar rats. VDN rats received a single dose of vitamin D3 (300.000 IU/kg, I.M) and two oral doses of nicotine (25 mg/kg) on day 1. They were then administrated FEB, in two doses (10 and 15 mg/kg/day, orally), or the drug vehicle, for 4 weeks. Age-matched normal rats served as control. At the end of the experiment, body weight, kidney function parameters, serum ionic composition, cardiovascular measures, aortic calcium deposition and aortic levels of oxidative stress markers, interleukin 1β (IL-1β), runt-related transcription factor 2 (Runx2) and osteopontin (OPN) were determined. Aortic immunoexpressions of tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), matrix metalloproteinase-9 (MMP-9) and α-smooth muscle actin (α-SMA) were evaluated. FEB significantly restored body weight loss, ameliorated kidney function and diminished serum disturbances of calcium and phosphorus in VDN rats. Moreover, FEB reduced VDN-induced elevations in aortic calcium deposition, SBP and DBP. FEB (15 mg/kg) markedly decreased left ventricular hypertrophy and bradycardia in VDN group. Mechanistically, FEB dose-dependently improved oxidative damage, decreased levels of IL-1β and Runx2, lessened expression of TNF-α, iNOS and MMP-9 and enhanced expression of OPN and α-SMA in VDN aortas relative to controls. These findings indicate that FEB, mainly at the higher administered dose (15 mg/kg), successfully attenuated VDN-induced VC. FEB may be useful in reducing VC in patients at high risk, including those with chronic kidney disease and diabetes mellitus.

Role of SGK1 in the Osteogenic Transdifferentiation and Calcification of Vascular Smooth Muscle Cells Promoted by Hyperglycemic Conditions

In diabetes mellitus, hyperglycemia promotes the osteogenic transdifferentiation of vascular smooth muscle cells (VSMCs) to enhance medial vascular calcification, a common complication strongly associated with cardiovascular disease and mortality. The mechanisms involved are, however, still poorly understood. Therefore, the present study explored the potential role of serum- and glucocorticoid-inducible kinase 1 (SGK1) during vascular calcification promoted by hyperglycemic conditions. Exposure to high-glucose conditions up-regulated the SGK1 expression in primary human aortic VSMCs. High glucose increased osteogenic marker expression and activity and, thus, promoted the osteogenic transdifferentiation of VSMCs, effects significantly suppressed by additional treatment with the SGK1 inhibitor EMD638683. Moreover, high glucose augmented the mineralization of VSMCs in the presence of calcification medium, effects again significantly reduced by SGK1 inhibition. Similarly, SGK1 knockdown blunted the high glucose-induced osteogenic transdifferentiation of VSMCs. The osteoinductive signaling promoted by high glucose required SGK1-dependent NF-kB activation. In addition, advanced glycation end products (AGEs) increased the SGK1 expression in VSMCs, and SGK1 inhibition was able to interfere with AGEs-induced osteogenic signaling. In conclusion, SGK1 is up-regulated and mediates, at least partly, the osteogenic transdifferentiation and calcification of VSMCs during hyperglycemic conditions. Thus, SGK1 inhibition may reduce the development of vascular calcification promoted by hyperglycemia in diabetes.

Circulating Receptor Activator of Nuclear Factor kB Ligand and triglycerides are associated with progression of lower limb arterial calcification in type 2 diabetes: a prospective, observational cohort study

Background

Lower limb arterial calcification is a frequent, underestimated but serious complication of diabetes. The DIACART study is a prospective cohort study designed to evaluate the determinants of the progression of lower limb arterial calcification in 198 patients with type 2 diabetes.

Methods

Lower limb arterial calcification scores were determined by computed tomography at baseline and after a mean follow up of 31.20 ± 3.86 months. Serum RANKL (Receptor Activator of Nuclear factor kB Ligand) and bone remodeling, inflammatory and metabolic parameters were measured at baseline. The predictive effect of these markers on calcification progression was analyzed by a multivariate linear regression model.

Results

At baseline, mean ± SD and median lower limb arterial calcification scores were, 2364 ± 5613 and 527 respectively and at the end of the study, 3739 ± 6886 and 1355 respectively. Using multivariate analysis, the progression of lower limb arterial log calcification score was found to be associated with (β coefficient [slope], 95% CI, p-value) baseline log(calcification score) (1.02, 1.00–1.04, p < 0.001), triglycerides (0.11, 0.03–0.20, p = 0.007), log(RANKL) (0.07, 0.02–0.11, p = 0.016), previous ischemic cardiomyopathy (0.36, 0.15–0.57, p = 0.001), statin use (0.39, 0.06–0.72, p = 0.023) and duration of follow up (0.04, 0.01–0.06, p = 0.004).

Conclusion

In patients with type 2 diabetes, lower limb arterial calcification is frequent and can progress rapidly. Circulating RANKL and triglycerides are independently associated with this progression. These results open new therapeutic perspectives in peripheral diabetic calcifying arteriopathy.

Trial registration NCT02431234

Patients with type 2 diabetes present with multiple anomalies of the pancreatic arterial tree on abdominal computed tomography: comparison between patients with type 2 diabetes and a matched control group

Background

Studies suggest that cardio-vascular risk factors could foster the development of type 2 diabetes (T2D). This could partly be mediated by pancreatic atherosclerosis resulting in pancreatic ischemia. We hypothesized that patients with T2D present with more severe atherosclerosis of pancreas-bound arteries than control patients without T2D.

Methods

We performed a retrospective study comparing the abdominal computed tomography of patients with T2D and of control subjects matched for gender and for age. We performed a multivariate logistic regression with adjustment for age, gender, BMI and the presence or absence of hypertension.

Results

Forty-eight patients with T2D and 48 control subjects were included. A calcification score of the splenic artery was defined (from 0: no calcification to 3: continuous linear calcifications). Seventeen percent of the patients with T2D presented with a high calcification score (i.e. 2 or 3), versus only 2% of the control subjects (p = 0.04). The mean number of pancreas-bound branches among the greater pancreatic artery, dorsal pancreatic artery and inferior pancreatic artery (from 0 to 3) was lower in patients with T2D than in control subjects (1.1 vs 1.7, p = 0.003). The mean number of visible intrapancreatic arterial subdivisions (from 0 to 2) was lower in patients with T2D than in control subjects (0.7 vs 1.3, p = 0.0017). All these differences hold true using multivariate logistic regression. None of these differences correlated with the duration of diabetes. The relationship between pancreas volume and BMI seen in control subjects was not confirmed in patients with T2D. Conversely, in patients with T2D but not in control subjects, the splenic artery diameter correlated with the pancreas volume.

Conclusions

Patients with T2D present with more calcifications of the splenic artery and with a less dense pancreatic arterial tree than control subjects.

Biologically-engineered mechanical model of a calcified artery

Vascular calcification is a commonly occurring pathological process and is recognized as an independent prognostic marker for cardiovascular morbidity and mortality. Recent progress in developing novel therapies to modify vascular calcification is critically hampered due to the lack of reliable in vitro experimental models that recapitulate the structural and mechanical attributes of calcified arteries. In this study, we show the ability to model the behavior of diffuse vascular calcification in vitro using biologically-engineered grafts approximating the composition, structure, and mechanical properties of arteries. Transmural calcification was achieved by exposing the acellular grafts of collagenous ECM to complete medium containing elevated Calcium (Ca) and Phosphate (P) concentrations. It was found that increasing the serum concentration from 2% to 10% increased the extent and degree of calcification based on histochemical, ultrastructural, chemical and thermal analyses. The presence of variably-sized spherical calcific deposits within the matrix further confirmed its morphological similarity to pathologic calcification. Mechanical testing demonstrated up to a 16-fold decrease in compliance due to the calcification, consistent with prior reports for calcified arteries. The model developed thus has potential to improve the design and development of interventional devices and therapies for the diagnosis and treatment of arterial calcification. STATEMENT OF SIGNIFICANCE: The presence of extensive vascular calcification makes angiographic/interventional procedures difficult due to reduced arterial compliance. Current attempts to develop safe and effective non-surgical adjunctive techniques to treat calcified arteries are largely limited by the lack of a physiologically relevant testing platform that mimics the structural and mechanical features of vascular calcification. Herein, we developed an off-the-shelf calcified artery model, with the goal to accelerate the pre-clinical development of novel therapies for the management of arterial calcification. To the extent of our knowledge, this is the first report of an in vitro tissue-engineered model of diffuse arterial calcification.